Resguardo inicial

linux-7.2.3/drivers/firmware/arm_scmi/Kconfig

@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "ARM System Control and Management Interface Protocol"
+
+config ARM_SCMI_PROTOCOL
+	tristate "ARM System Control and Management Interface (SCMI) Message Protocol"
+	depends on ARM || ARM64 || COMPILE_TEST
+	help
+	  ARM System Control and Management Interface (SCMI) protocol is a
+	  set of operating system-independent software interfaces that are
+	  used in system management. SCMI is extensible and currently provides
+	  interfaces for: Discovery and self-description of the interfaces
+	  it supports, Power domain management which is the ability to place
+	  a given device or domain into the various power-saving states that
+	  it supports, Performance management which is the ability to control
+	  the performance of a domain that is composed of compute engines
+	  such as application processors and other accelerators, Clock
+	  management which is the ability to set and inquire rates on platform
+	  managed clocks and Sensor management which is the ability to read
+	  sensor data, and be notified of sensor value.
+
+	  This protocol library provides interface for all the client drivers
+	  making use of the features offered by the SCMI.
+
+if ARM_SCMI_PROTOCOL
+
+config ARM_SCMI_NEED_DEBUGFS
+	bool
+	help
+	  This declares whether at least one SCMI facility is configured
+	  which needs debugfs support. When selected causess the creation
+	  of a common SCMI debugfs root directory.
+
+config ARM_SCMI_RAW_MODE_SUPPORT
+	bool "Enable support for SCMI Raw transmission mode"
+	depends on DEBUG_FS
+	select ARM_SCMI_NEED_DEBUGFS
+	help
+	  Enable support for SCMI Raw transmission mode.
+
+	  If enabled allows the direct injection and snooping of SCMI bare
+	  messages through a dedicated debugfs interface.
+	  It is meant to be used by SCMI compliance/testing suites.
+
+	  When enabled regular SCMI drivers interactions are inhibited in
+	  order to avoid unexpected interactions with the SCMI Raw message
+	  flow. If unsure say N.
+
+config ARM_SCMI_RAW_MODE_SUPPORT_COEX
+	bool "Allow SCMI Raw mode coexistence with normal SCMI stack"
+	depends on ARM_SCMI_RAW_MODE_SUPPORT
+	help
+	  Allow SCMI Raw transmission mode to coexist with normal SCMI stack.
+
+	  This will allow regular SCMI drivers to register with the core and
+	  operate normally, thing which could make an SCMI test suite using the
+	  SCMI Raw mode support unreliable. If unsure, say N.
+
+config ARM_SCMI_DEBUG_COUNTERS
+	bool "Enable SCMI communication debug metrics tracking"
+	select ARM_SCMI_NEED_DEBUGFS
+	depends on DEBUG_FS
+	default n
+	help
+	  Enables tracking of some key communication metrics for debug
+	  purposes. It may track metrics like how many messages were sent
+	  or received, were there any failures, what kind of failures, ..etc.
+
+	  Enable this option to create a new debugfs directory which contains
+	  such useful debug counters. This can be helpful for debugging and
+	  SCMI monitoring.
+
+config ARM_SCMI_QUIRKS
+	bool "Enable SCMI Quirks framework"
+	depends on JUMP_LABEL || COMPILE_TEST
+	default y
+	help
+	  Enables support for SCMI Quirks framework to workaround SCMI platform
+	  firmware bugs on system already deployed in the wild.
+
+	  The framework allows the definition of platform-specific code quirks
+	  that will be associated and enabled only on the desired platforms
+	  depending on the SCMI firmware advertised versions and/or machine
+	  compatibles.
+
+source "drivers/firmware/arm_scmi/transports/Kconfig"
+source "drivers/firmware/arm_scmi/vendors/imx/Kconfig"
+
+endif #ARM_SCMI_PROTOCOL
+
+config ARM_SCMI_POWER_CONTROL
+	tristate "SCMI system power control driver"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	help
+	  This enables System Power control logic which binds system shutdown or
+	  reboot actions to SCMI System Power notifications generated by SCP
+	  firmware.
+
+	  This driver can also be built as a module.  If so, the module will be
+	  called scmi_power_control. Note this may be needed early in boot to
+	  catch early shutdown/reboot SCMI requests.
+
+endmenu

linux-7.2.3/drivers/firmware/arm_scmi/Makefile

@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-only
+scmi-bus-y = bus.o
+scmi-core-objs := $(scmi-bus-y)
+
+scmi-driver-y = driver.o notify.o
+scmi-driver-$(CONFIG_ARM_SCMI_QUIRKS) += quirks.o
+scmi-driver-$(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) += raw_mode.o
+scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
+scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o
+scmi-protocols-y := base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o powercap.o
+scmi-protocols-y += pinctrl.o
+scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
+
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += transports/
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += vendors/imx/
+
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
+
+obj-$(CONFIG_ARM_SCMI_POWER_CONTROL) += scmi_power_control.o

linux-7.2.3/drivers/firmware/arm_scmi/base.c

@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Base Protocol
+ *
+ * Copyright (C) 2018-2021 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
+
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+
+#include "common.h"
+#include "notify.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x20001
+
+#define SCMI_BASE_NUM_SOURCES		1
+#define SCMI_BASE_MAX_CMD_ERR_COUNT	1024
+
+enum scmi_base_protocol_cmd {
+	BASE_DISCOVER_VENDOR = 0x3,
+	BASE_DISCOVER_SUB_VENDOR = 0x4,
+	BASE_DISCOVER_IMPLEMENT_VERSION = 0x5,
+	BASE_DISCOVER_LIST_PROTOCOLS = 0x6,
+	BASE_DISCOVER_AGENT = 0x7,
+	BASE_NOTIFY_ERRORS = 0x8,
+	BASE_SET_DEVICE_PERMISSIONS = 0x9,
+	BASE_SET_PROTOCOL_PERMISSIONS = 0xa,
+	BASE_RESET_AGENT_CONFIGURATION = 0xb,
+};
+
+struct scmi_msg_resp_base_attributes {
+	u8 num_protocols;
+	u8 num_agents;
+	__le16 reserved;
+};
+
+struct scmi_msg_resp_base_discover_agent {
+	__le32 agent_id;
+	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+};
+
+struct scmi_msg_base_error_notify {
+	__le32 event_control;
+#define BASE_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_base_error_notify_payld {
+	__le32 agent_id;
+	__le32 error_status;
+#define IS_FATAL_ERROR(x)	((x) & BIT(31))
+#define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
+	__le64 msg_reports[SCMI_BASE_MAX_CMD_ERR_COUNT];
+};
+
+/**
+ * scmi_base_attributes_get() - gets the implementation details
+ *	that are associated with the base protocol.
+ *
+ * @ph: SCMI protocol handle
+ *
+ * Return: 0 on success, else appropriate SCMI error.
+ */
+static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_base_attributes *attr_info;
+	struct scmi_base_info *rev = ph->get_priv(ph);
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr_info), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		attr_info = t->rx.buf;
+		rev->num_protocols = attr_info->num_protocols;
+		rev->num_agents = attr_info->num_agents;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+/**
+ * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
+ *
+ * @ph: SCMI protocol handle
+ * @sub_vendor: specify true if sub-vendor ID is needed
+ *
+ * Return: 0 on success, else appropriate SCMI error.
+ */
+static int
+scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
+{
+	u8 cmd;
+	int ret, size;
+	char *vendor_id;
+	struct scmi_xfer *t;
+	struct scmi_base_info *rev = ph->get_priv(ph);
+
+	if (sub_vendor) {
+		cmd = BASE_DISCOVER_SUB_VENDOR;
+		vendor_id = rev->sub_vendor_id;
+		size = ARRAY_SIZE(rev->sub_vendor_id);
+	} else {
+		cmd = BASE_DISCOVER_VENDOR;
+		vendor_id = rev->vendor_id;
+		size = ARRAY_SIZE(rev->vendor_id);
+	}
+
+	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		strscpy(vendor_id, t->rx.buf, size);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+/**
+ * scmi_base_implementation_version_get() - gets a vendor-specific
+ *	implementation 32-bit version. The format of the version number is
+ *	vendor-specific
+ *
+ * @ph: SCMI protocol handle
+ *
+ * Return: 0 on success, else appropriate SCMI error.
+ */
+static int
+scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
+{
+	int ret;
+	__le32 *impl_ver;
+	struct scmi_xfer *t;
+	struct scmi_base_info *rev = ph->get_priv(ph);
+
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
+				      0, sizeof(*impl_ver), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		impl_ver = t->rx.buf;
+		rev->impl_ver = le32_to_cpu(*impl_ver);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+/**
+ * scmi_base_implementation_list_get() - gets the list of protocols it is
+ *	OSPM is allowed to access
+ *
+ * @ph: SCMI protocol handle
+ * @protocols_imp: pointer to hold the list of protocol identifiers
+ *
+ * Return: 0 on success, else appropriate SCMI error.
+ */
+static int
+scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
+				  u8 *protocols_imp)
+{
+	u8 *list;
+	int ret, loop;
+	struct scmi_xfer *t;
+	__le32 *num_skip, *num_ret;
+	u32 tot_num_ret = 0, loop_num_ret;
+	struct device *dev = ph->dev;
+	struct scmi_base_info *rev = ph->get_priv(ph);
+
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
+				      sizeof(*num_skip), 0, &t);
+	if (ret)
+		return ret;
+
+	num_skip = t->tx.buf;
+	num_ret = t->rx.buf;
+	list = t->rx.buf + sizeof(*num_ret);
+
+	do {
+		size_t real_list_sz;
+		u32 calc_list_sz;
+
+		/* Set the number of protocols to be skipped/already read */
+		*num_skip = cpu_to_le32(tot_num_ret);
+
+		ret = ph->xops->do_xfer(ph, t);
+		if (ret)
+			break;
+
+		loop_num_ret = le32_to_cpu(*num_ret);
+		if (!loop_num_ret)
+			break;
+
+		if (loop_num_ret > rev->num_protocols - tot_num_ret) {
+			dev_err(dev,
+				"No. Returned protocols > Total protocols.\n");
+			break;
+		}
+
+		if (t->rx.len < (sizeof(u32) * 2)) {
+			dev_err(dev, "Truncated reply - rx.len:%zd\n",
+				t->rx.len);
+			ret = -EPROTO;
+			break;
+		}
+
+		real_list_sz = t->rx.len - sizeof(u32);
+		calc_list_sz = round_up(loop_num_ret, sizeof(u32));
+		if (calc_list_sz != real_list_sz) {
+			dev_warn(dev,
+				 "Malformed reply - real_sz:%zd  calc_sz:%u  (loop_num_ret:%d)\n",
+				 real_list_sz, calc_list_sz, loop_num_ret);
+			/*
+			 * Bail out if the expected list size is bigger than the
+			 * total payload size of the received reply.
+			 */
+			if (calc_list_sz > real_list_sz) {
+				ret = -EPROTO;
+				break;
+			}
+		}
+
+		for (loop = 0; loop < loop_num_ret; loop++)
+			protocols_imp[tot_num_ret + loop] = *(list + loop);
+
+		tot_num_ret += loop_num_ret;
+
+		ph->xops->reset_rx_to_maxsz(ph, t);
+	} while (tot_num_ret < rev->num_protocols);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+/**
+ * scmi_base_discover_agent_get() - discover the name of an agent
+ *
+ * @ph: SCMI protocol handle
+ * @id: Agent identifier
+ * @name: Agent identifier ASCII string
+ *
+ * An agent id of 0 is reserved to identify the platform itself.
+ * Generally operating system is represented as "OSPM"
+ *
+ * Return: 0 on success, else appropriate SCMI error.
+ */
+static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
+					int id, char *name)
+{
+	int ret;
+	struct scmi_msg_resp_base_discover_agent *agent_info;
+	struct scmi_xfer *t;
+
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
+				      sizeof(__le32), sizeof(*agent_info), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(id, t->tx.buf);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		agent_info = t->rx.buf;
+		strscpy(name, agent_info->name, SCMI_SHORT_NAME_MAX_SIZE);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
+				  bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_base_error_notify *cfg;
+
+	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
+				      sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_base_error_notify(ph, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
+
+	return ret;
+}
+
+static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
+					  u8 evt_id, ktime_t timestamp,
+					  const void *payld, size_t payld_sz,
+					  void *report, u32 *src_id)
+{
+	int i;
+	u32 error_status;
+	size_t expected_sz;
+	const struct scmi_base_error_notify_payld *p = payld;
+	struct scmi_base_error_report *r = report;
+
+	/*
+	 * BaseError notification payload is variable in size but
+	 * up to a maximum length determined by the struct ponted by p.
+	 * Instead payld_sz is the effective length of this notification
+	 * payload so cannot be greater of the maximum allowed size as
+	 * pointed by p.
+	 */
+	if (evt_id != SCMI_EVENT_BASE_ERROR_EVENT || sizeof(*p) < payld_sz)
+		return NULL;
+
+	expected_sz = offsetof(typeof(*p), msg_reports);
+	if (payld_sz < expected_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	error_status = le32_to_cpu(p->error_status);
+	r->fatal = IS_FATAL_ERROR(error_status);
+	r->cmd_count = ERROR_CMD_COUNT(error_status);
+	expected_sz += r->cmd_count * sizeof(p->msg_reports[0]);
+	if (payld_sz < expected_sz)
+		return NULL;
+
+	for (i = 0; i < r->cmd_count; i++)
+		r->reports[i] = le64_to_cpu(p->msg_reports[i]);
+	*src_id = 0;
+
+	return r;
+}
+
+static const struct scmi_event base_events[] = {
+	{
+		.id = SCMI_EVENT_BASE_ERROR_EVENT,
+		.max_payld_sz = sizeof(struct scmi_base_error_notify_payld),
+		.max_report_sz = sizeof(struct scmi_base_error_report) +
+				  SCMI_BASE_MAX_CMD_ERR_COUNT * sizeof(u64),
+	},
+};
+
+static const struct scmi_event_ops base_event_ops = {
+	.set_notify_enabled = scmi_base_set_notify_enabled,
+	.fill_custom_report = scmi_base_fill_custom_report,
+};
+
+static const struct scmi_protocol_events base_protocol_events = {
+	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
+	.ops = &base_event_ops,
+	.evts = base_events,
+	.num_events = ARRAY_SIZE(base_events),
+	.num_sources = SCMI_BASE_NUM_SOURCES,
+};
+
+static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int id, ret;
+	u8 *prot_imp;
+	char name[SCMI_SHORT_NAME_MAX_SIZE];
+	struct device *dev = ph->dev;
+	struct scmi_base_info *rev = scmi_revision_area_get(ph);
+
+	rev->major_ver = PROTOCOL_REV_MAJOR(ph->version);
+	rev->minor_ver = PROTOCOL_REV_MINOR(ph->version);
+	ph->set_priv(ph, rev);
+
+	ret = scmi_base_attributes_get(ph);
+	if (ret)
+		return ret;
+
+	prot_imp = devm_kcalloc(dev, rev->num_protocols, sizeof(u8),
+				GFP_KERNEL);
+	if (!prot_imp)
+		return -ENOMEM;
+
+	scmi_base_vendor_id_get(ph, false);
+	scmi_base_vendor_id_get(ph, true);
+	scmi_base_implementation_version_get(ph);
+	scmi_base_implementation_list_get(ph, prot_imp);
+
+	scmi_setup_protocol_implemented(ph, prot_imp);
+
+	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
+		 rev->major_ver, rev->minor_ver, rev->vendor_id,
+		 rev->sub_vendor_id, rev->impl_ver);
+	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
+		rev->num_agents);
+
+	for (id = 0; id < rev->num_agents; id++) {
+		scmi_base_discover_agent_get(ph, id, name);
+		dev_dbg(dev, "Agent %d: %s\n", id, name);
+	}
+
+	return 0;
+}
+
+static const struct scmi_protocol scmi_base = {
+	.id = SCMI_PROTOCOL_BASE,
+	.owner = NULL,
+	.instance_init = &scmi_base_protocol_init,
+	.ops = NULL,
+	.events = &base_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)

linux-7.2.3/drivers/firmware/arm_scmi/bus.c

@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Protocol bus layer
+ *
+ * Copyright (C) 2018-2021 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+
+#include "common.h"
+
+#define SCMI_UEVENT_MODALIAS_FMT	"%s:%02x:%s"
+
+BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh);
+EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
+
+static DEFINE_IDA(scmi_bus_id);
+
+static DEFINE_IDR(scmi_requested_devices);
+/* Protect access to scmi_requested_devices */
+static DEFINE_MUTEX(scmi_requested_devices_mtx);
+
+struct scmi_requested_dev {
+	const struct scmi_device_id *id_table;
+	struct list_head node;
+};
+
+/* Track globally the creation of SCMI SystemPower related devices */
+static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
+
+/**
+ * scmi_protocol_device_request  - Helper to request a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be created.
+ *
+ * This helper let an SCMI driver request specific devices identified by the
+ * @id_table to be created for each active SCMI instance.
+ *
+ * The requested device name MUST NOT be already existent for this protocol;
+ * at first the freshly requested @id_table is annotated in the IDR table
+ * @scmi_requested_devices and then the requested device is advertised to any
+ * registered party via the @scmi_requested_devices_nh notification chain.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
+{
+	int ret = 0;
+	struct list_head *head, *phead = NULL;
+	struct scmi_requested_dev *rdev;
+
+	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) &&
+	    !IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX)) {
+		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+			id_table->name, id_table->protocol_id);
+		return -EINVAL;
+	}
+
+	/*
+	 * Find the matching protocol rdev list and then search of any
+	 * existent equally named device...fails if any duplicate found.
+	 */
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		head = phead;
+		list_for_each_entry(rdev, head, node) {
+			if (!strcmp(rdev->id_table->name, id_table->name)) {
+				pr_err("Ignoring duplicate request [%d] %s\n",
+				       rdev->id_table->protocol_id,
+				       rdev->id_table->name);
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	/*
+	 * No duplicate found for requested id_table, so let's create a new
+	 * requested device entry for this new valid request.
+	 */
+	rdev = kzalloc_obj(*rdev);
+	if (!rdev) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	rdev->id_table = id_table;
+
+	/*
+	 * Append the new requested device table descriptor to the head of the
+	 * related protocol list, eventually creating such head if not already
+	 * there.
+	 */
+	if (!phead) {
+		phead = kzalloc_obj(*phead);
+		if (!phead) {
+			kfree(rdev);
+			ret = -ENOMEM;
+			goto out;
+		}
+		INIT_LIST_HEAD(phead);
+
+		ret = idr_alloc(&scmi_requested_devices, (void *)phead,
+				id_table->protocol_id,
+				id_table->protocol_id + 1, GFP_KERNEL);
+		if (ret != id_table->protocol_id) {
+			pr_err("Failed to save SCMI device - ret:%d\n", ret);
+			kfree(rdev);
+			kfree(phead);
+			ret = -EINVAL;
+			goto out;
+		}
+		ret = 0;
+	}
+	list_add(&rdev->node, phead);
+
+out:
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	if (!ret)
+		blocking_notifier_call_chain(&scmi_requested_devices_nh,
+					     SCMI_BUS_NOTIFY_DEVICE_REQUEST,
+					     (void *)rdev->id_table);
+
+	return ret;
+}
+
+static int scmi_protocol_table_register(const struct scmi_device_id *id_table)
+{
+	int ret = 0;
+	const struct scmi_device_id *entry;
+
+	for (entry = id_table; entry->name && ret == 0; entry++)
+		ret = scmi_protocol_device_request(entry);
+
+	return ret;
+}
+
+/**
+ * scmi_protocol_device_unrequest  - Helper to unrequest a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be unrequested.
+ *
+ * The unrequested device, described by the provided id_table, is at first
+ * removed from the IDR @scmi_requested_devices and then the removal is
+ * advertised to any registered party via the @scmi_requested_devices_nh
+ * notification chain.
+ */
+static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
+{
+	struct list_head *phead;
+
+	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		struct scmi_requested_dev *victim, *tmp;
+
+		list_for_each_entry_safe(victim, tmp, phead, node) {
+			if (!strcmp(victim->id_table->name, id_table->name)) {
+				list_del(&victim->node);
+
+				mutex_unlock(&scmi_requested_devices_mtx);
+				blocking_notifier_call_chain(&scmi_requested_devices_nh,
+							     SCMI_BUS_NOTIFY_DEVICE_UNREQUEST,
+							     (void *)victim->id_table);
+				kfree(victim);
+				mutex_lock(&scmi_requested_devices_mtx);
+				break;
+			}
+		}
+
+		if (list_empty(phead)) {
+			idr_remove(&scmi_requested_devices,
+				   id_table->protocol_id);
+			kfree(phead);
+		}
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
+}
+
+static void
+scmi_protocol_table_unregister(const struct scmi_device_id *id_table)
+{
+	const struct scmi_device_id *entry;
+
+	for (entry = id_table; entry->name; entry++)
+		scmi_protocol_device_unrequest(entry);
+}
+
+static int scmi_dev_match_by_id_table(struct scmi_device *scmi_dev,
+				      const struct scmi_device_id *id_table)
+{
+	if (!id_table || !id_table->name)
+		return 0;
+
+	/* Always skip transport devices from matching */
+	for (; id_table->protocol_id && id_table->name; id_table++)
+		if (id_table->protocol_id == scmi_dev->protocol_id &&
+		    strncmp(scmi_dev->name, "__scmi_transport_device", 23) &&
+		    !strcmp(id_table->name, scmi_dev->name))
+			return 1;
+	return 0;
+}
+
+static int scmi_dev_match_id(struct scmi_device *scmi_dev,
+			     const struct scmi_driver *scmi_drv)
+{
+	return scmi_dev_match_by_id_table(scmi_dev, scmi_drv->id_table);
+}
+
+static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
+{
+	const struct scmi_driver *scmi_drv = to_scmi_driver(drv);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return scmi_dev_match_id(scmi_dev, scmi_drv);
+}
+
+static int scmi_match_by_id_table(struct device *dev, const void *data)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+	const struct scmi_device_id *id_table = data;
+
+	return scmi_dev_match_by_id_table(scmi_dev, id_table);
+}
+
+static struct scmi_device *scmi_child_dev_find(struct device *parent,
+					       int prot_id, const char *name)
+{
+	struct scmi_device_id id_table[2] = { 0 };
+	struct device *dev;
+
+	id_table[0].protocol_id = prot_id;
+	id_table[0].name = name;
+
+	dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
+	if (!dev)
+		return NULL;
+
+	/* Drop the refcnt bumped implicitly by device_find_child */
+	put_device(dev);
+
+	return to_scmi_dev(dev);
+}
+
+static int scmi_dev_probe(struct device *dev)
+{
+	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	if (!scmi_dev->handle)
+		return -EPROBE_DEFER;
+
+	return scmi_drv->probe(scmi_dev);
+}
+
+static void scmi_dev_remove(struct device *dev)
+{
+	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	if (scmi_drv->remove)
+		scmi_drv->remove(scmi_dev);
+}
+
+static int scmi_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return add_uevent_var(env, "MODALIAS=" SCMI_UEVENT_MODALIAS_FMT,
+			      dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			      scmi_dev->name);
+}
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sysfs_emit(buf, SCMI_UEVENT_MODALIAS_FMT,
+			  dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			  scmi_dev->name);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t protocol_id_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "0x%02x\n", scmi_dev->protocol_id);
+}
+static DEVICE_ATTR_RO(protocol_id);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "%s\n", scmi_dev->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *scmi_device_attributes_attrs[] = {
+	&dev_attr_protocol_id.attr,
+	&dev_attr_name.attr,
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(scmi_device_attributes);
+
+static int scmi_pm_suspend(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+
+	if (drv && drv->pm && drv->pm->suspend)
+		return drv->pm->suspend(dev);
+
+	return 0;
+}
+
+static int scmi_pm_resume(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+
+	if (drv && drv->pm && drv->pm->resume)
+		return drv->pm->resume(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops scmi_dev_pm_ops = {
+	.suspend = pm_sleep_ptr(scmi_pm_suspend),
+	.resume = pm_sleep_ptr(scmi_pm_resume),
+};
+
+const struct bus_type scmi_bus_type = {
+	.name =	"scmi_protocol",
+	.match = scmi_dev_match,
+	.probe = scmi_dev_probe,
+	.remove = scmi_dev_remove,
+	.uevent	= scmi_device_uevent,
+	.dev_groups = scmi_device_attributes_groups,
+	.pm = &scmi_dev_pm_ops,
+};
+EXPORT_SYMBOL_GPL(scmi_bus_type);
+
+int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
+			 const char *mod_name)
+{
+	int retval;
+
+	if (!driver->probe)
+		return -EINVAL;
+
+	retval = scmi_protocol_table_register(driver->id_table);
+	if (retval)
+		return retval;
+
+	driver->driver.bus = &scmi_bus_type;
+	driver->driver.name = driver->name;
+	driver->driver.owner = owner;
+	driver->driver.mod_name = mod_name;
+
+	retval = driver_register(&driver->driver);
+	if (!retval)
+		pr_debug("Registered new scmi driver %s\n", driver->name);
+
+	return retval;
+}
+EXPORT_SYMBOL_GPL(scmi_driver_register);
+
+void scmi_driver_unregister(struct scmi_driver *driver)
+{
+	driver_unregister(&driver->driver);
+	scmi_protocol_table_unregister(driver->id_table);
+}
+EXPORT_SYMBOL_GPL(scmi_driver_unregister);
+
+static void scmi_device_release(struct device *dev)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	kfree_const(scmi_dev->name);
+	kfree(scmi_dev);
+}
+
+static void __scmi_device_destroy(struct scmi_device *scmi_dev)
+{
+	pr_debug("(%pOF) Destroying SCMI device '%s' for protocol 0x%x (%s)\n",
+		 scmi_dev->dev.parent->of_node,
+		 dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+		 scmi_dev->name);
+
+	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
+		atomic_set(&scmi_syspower_registered, 0);
+
+	ida_free(&scmi_bus_id, scmi_dev->id);
+	device_unregister(&scmi_dev->dev);
+}
+
+static struct scmi_device *
+__scmi_device_create(struct device_node *np, struct device *parent,
+		     int protocol, const char *name)
+{
+	int id, retval;
+	struct scmi_device *scmi_dev;
+
+	/*
+	 * If the same protocol/name device already exist under the same parent
+	 * (i.e. SCMI instance) just return the existent device.
+	 * This avoids any race between the SCMI driver, creating devices for
+	 * each DT defined protocol at probe time, and the concurrent
+	 * registration of SCMI drivers.
+	 */
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		return scmi_dev;
+
+	/*
+	 * Ignore any possible subsequent failures while creating the device
+	 * since we are doomed anyway at that point; not using a mutex which
+	 * spans across this whole function to keep things simple and to avoid
+	 * to serialize all the __scmi_device_create calls across possibly
+	 * different SCMI server instances (parent)
+	 */
+	if (protocol == SCMI_PROTOCOL_SYSTEM &&
+	    atomic_cmpxchg(&scmi_syspower_registered, 0, 1)) {
+		dev_warn(parent,
+			 "SCMI SystemPower protocol device must be unique !\n");
+		return NULL;
+	}
+
+	scmi_dev = kzalloc_obj(*scmi_dev);
+	if (!scmi_dev)
+		return NULL;
+
+	scmi_dev->name = kstrdup_const(name ?: "unknown", GFP_KERNEL);
+	if (!scmi_dev->name) {
+		kfree(scmi_dev);
+		return NULL;
+	}
+
+	id = ida_alloc_min(&scmi_bus_id, 1, GFP_KERNEL);
+	if (id < 0) {
+		kfree_const(scmi_dev->name);
+		kfree(scmi_dev);
+		return NULL;
+	}
+
+	scmi_dev->id = id;
+	scmi_dev->protocol_id = protocol;
+	scmi_dev->dev.parent = parent;
+	device_set_node(&scmi_dev->dev, of_fwnode_handle(np));
+	scmi_dev->dev.bus = &scmi_bus_type;
+	scmi_dev->dev.release = scmi_device_release;
+	dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);
+
+	retval = device_register(&scmi_dev->dev);
+	if (retval)
+		goto put_dev;
+
+	pr_debug("(%pOF) Created SCMI device '%s' for protocol 0x%x (%s)\n",
+		 parent->of_node, dev_name(&scmi_dev->dev), protocol, name);
+
+	return scmi_dev;
+put_dev:
+	put_device(&scmi_dev->dev);
+	ida_free(&scmi_bus_id, id);
+	return NULL;
+}
+
+static struct scmi_device *
+_scmi_device_create(struct device_node *np, struct device *parent,
+		    int protocol, const char *name)
+{
+	struct scmi_device *sdev;
+
+	sdev = __scmi_device_create(np, parent, protocol, name);
+	if (!sdev)
+		pr_err("(%pOF) Failed to create device for protocol 0x%x (%s)\n",
+		       parent->of_node, protocol, name);
+
+	return sdev;
+}
+
+/**
+ * scmi_device_create  - A method to create one or more SCMI devices
+ *
+ * @np: A reference to the device node to use for the new device(s)
+ * @parent: The parent device to use identifying a specific SCMI instance
+ * @protocol: The SCMI protocol to be associated with this device
+ * @name: The requested-name of the device to be created; this is optional
+ *	  and if no @name is provided, all the devices currently known to
+ *	  be requested on the SCMI bus for @protocol will be created.
+ *
+ * This method can be invoked to create a single well-defined device (like
+ * a transport device or a device requested by an SCMI driver loaded after
+ * the core SCMI stack has been probed), or to create all the devices currently
+ * known to have been requested by the loaded SCMI drivers for a specific
+ * protocol (typically during SCMI core protocol enumeration at probe time).
+ *
+ * Return: The created device (or one of them if @name was NOT provided and
+ *	   multiple devices were created) or NULL if no device was created;
+ *	   note that NULL indicates an error ONLY in case a specific @name
+ *	   was provided: when @name param was not provided, a number of devices
+ *	   could have been potentially created for a whole protocol, unless no
+ *	   device was found to have been requested for that specific protocol.
+ */
+struct scmi_device *scmi_device_create(struct device_node *np,
+				       struct device *parent, int protocol,
+				       const char *name)
+{
+	struct list_head *phead;
+	struct scmi_requested_dev *rdev;
+	struct scmi_device *scmi_dev = NULL;
+
+	if (name)
+		return _scmi_device_create(np, parent, protocol, name);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, protocol);
+	/* Nothing to do. */
+	if (!phead) {
+		mutex_unlock(&scmi_requested_devices_mtx);
+		return NULL;
+	}
+
+	/* Walk the list of requested devices for protocol and create them */
+	list_for_each_entry(rdev, phead, node) {
+		struct scmi_device *sdev;
+
+		sdev = _scmi_device_create(np, parent,
+					   rdev->id_table->protocol_id,
+					   rdev->id_table->name);
+		if (sdev)
+			scmi_dev = sdev;
+	}
+
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	return scmi_dev;
+}
+EXPORT_SYMBOL_GPL(scmi_device_create);
+
+void scmi_device_destroy(struct device *parent, int protocol, const char *name)
+{
+	struct scmi_device *scmi_dev;
+
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		__scmi_device_destroy(scmi_dev);
+}
+EXPORT_SYMBOL_GPL(scmi_device_destroy);
+
+static int __scmi_devices_unregister(struct device *dev, void *data)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	__scmi_device_destroy(scmi_dev);
+	return 0;
+}
+
+static void scmi_devices_unregister(void)
+{
+	bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister);
+}
+
+static int __init scmi_bus_init(void)
+{
+	int retval;
+
+	retval = bus_register(&scmi_bus_type);
+	if (retval)
+		pr_err("SCMI protocol bus register failed (%d)\n", retval);
+
+	pr_info("SCMI protocol bus registered\n");
+
+	return retval;
+}
+subsys_initcall(scmi_bus_init);
+
+static void __exit scmi_bus_exit(void)
+{
+	/*
+	 * Destroy all remaining devices: just in case the drivers were
+	 * manually unbound and at first and then the modules unloaded.
+	 */
+	scmi_devices_unregister();
+	bus_unregister(&scmi_bus_type);
+	ida_destroy(&scmi_bus_id);
+}
+module_exit(scmi_bus_exit);
+
+MODULE_ALIAS("scmi-core");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI protocol bus");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/common.h

@@ -0,0 +1,688 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * driver common header file containing some definitions, structures
+ * and function prototypes used in all the different SCMI protocols.
+ *
+ * Copyright (C) 2018-2024 ARM Ltd.
+ */
+#ifndef _SCMI_COMMON_H
+#define _SCMI_COMMON_H
+
+#include <linux/bitfield.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/hashtable.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/refcount.h>
+#include <linux/scmi_protocol.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <linux/unaligned.h>
+
+#include "protocols.h"
+#include "notify.h"
+
+#define SCMI_MAX_CHANNELS		256
+
+#define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
+
+#define SCMI_SHMEM_MAX_PAYLOAD_SIZE	104
+
+enum scmi_error_codes {
+	SCMI_SUCCESS = 0,	/* Success */
+	SCMI_ERR_SUPPORT = -1,	/* Not supported */
+	SCMI_ERR_PARAMS = -2,	/* Invalid Parameters */
+	SCMI_ERR_ACCESS = -3,	/* Invalid access/permission denied */
+	SCMI_ERR_ENTRY = -4,	/* Not found */
+	SCMI_ERR_RANGE = -5,	/* Value out of range */
+	SCMI_ERR_BUSY = -6,	/* Device busy */
+	SCMI_ERR_COMMS = -7,	/* Communication Error */
+	SCMI_ERR_GENERIC = -8,	/* Generic Error */
+	SCMI_ERR_HARDWARE = -9,	/* Hardware Error */
+	SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
+};
+
+static const int scmi_linux_errmap[] = {
+	/* better than switch case as long as return value is continuous */
+	0,			/* SCMI_SUCCESS */
+	-EOPNOTSUPP,		/* SCMI_ERR_SUPPORT */
+	-EINVAL,		/* SCMI_ERR_PARAM */
+	-EACCES,		/* SCMI_ERR_ACCESS */
+	-ENOENT,		/* SCMI_ERR_ENTRY */
+	-ERANGE,		/* SCMI_ERR_RANGE */
+	-EBUSY,			/* SCMI_ERR_BUSY */
+	-ECOMM,			/* SCMI_ERR_COMMS */
+	-EIO,			/* SCMI_ERR_GENERIC */
+	-EREMOTEIO,		/* SCMI_ERR_HARDWARE */
+	-EPROTO,		/* SCMI_ERR_PROTOCOL */
+};
+
+static inline int scmi_to_linux_errno(int errno)
+{
+	int err_idx = -errno;
+
+	if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
+		return scmi_linux_errmap[err_idx];
+	return -EIO;
+}
+
+#define MSG_ID_MASK		GENMASK(7, 0)
+#define MSG_XTRACT_ID(hdr)	FIELD_GET(MSG_ID_MASK, (hdr))
+#define MSG_TYPE_MASK		GENMASK(9, 8)
+#define MSG_XTRACT_TYPE(hdr)	FIELD_GET(MSG_TYPE_MASK, (hdr))
+#define MSG_TYPE_COMMAND	0
+#define MSG_TYPE_DELAYED_RESP	2
+#define MSG_TYPE_NOTIFICATION	3
+#define MSG_PROTOCOL_ID_MASK	GENMASK(17, 10)
+#define MSG_XTRACT_PROT_ID(hdr)	FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
+#define MSG_TOKEN_ID_MASK	GENMASK(27, 18)
+#define MSG_XTRACT_TOKEN(hdr)	FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
+#define MSG_TOKEN_MAX		(MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
+
+/*
+ * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in
+ * order to minimize space and collisions, this should equal max_msg, i.e. the
+ * maximum number of in-flight messages on a specific platform, but such value
+ * is only available at runtime while kernel hashtables are statically sized:
+ * pick instead as a fixed static size the maximum number of entries that can
+ * fit the whole table into one 4k page.
+ */
+#define SCMI_PENDING_XFERS_HT_ORDER_SZ		9
+
+/**
+ * pack_scmi_header() - packs and returns 32-bit header
+ *
+ * @hdr: pointer to header containing all the information on message id,
+ *	protocol id, sequence id and type.
+ *
+ * Return: 32-bit packed message header to be sent to the platform.
+ */
+static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
+{
+	return FIELD_PREP(MSG_ID_MASK, hdr->id) |
+		FIELD_PREP(MSG_TYPE_MASK, hdr->type) |
+		FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
+		FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
+}
+
+/**
+ * unpack_scmi_header() - unpacks and records message and protocol id
+ *
+ * @msg_hdr: 32-bit packed message header sent from the platform
+ * @hdr: pointer to header to fetch message and protocol id.
+ */
+static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
+{
+	hdr->id = MSG_XTRACT_ID(msg_hdr);
+	hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
+	hdr->type = MSG_XTRACT_TYPE(msg_hdr);
+}
+
+/*
+ * An helper macro to lookup an xfer from the @pending_xfers hashtable
+ * using the message sequence number token as a key.
+ */
+#define XFER_FIND(__ht, __k)					\
+({								\
+	typeof(__k) k_ = __k;					\
+	struct scmi_xfer *xfer_ = NULL;				\
+								\
+	hash_for_each_possible((__ht), xfer_, node, k_)		\
+		if (xfer_->hdr.seq == k_)			\
+			break;					\
+	xfer_;							\
+})
+
+struct scmi_base_info *
+scmi_revision_area_get(const struct scmi_protocol_handle *ph);
+void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
+				     u8 *prot_imp);
+
+extern const struct bus_type scmi_bus_type;
+
+#define SCMI_BUS_NOTIFY_DEVICE_REQUEST		0
+#define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST	1
+extern struct blocking_notifier_head scmi_requested_devices_nh;
+
+struct scmi_device *scmi_device_create(struct device_node *np,
+				       struct device *parent, int protocol,
+				       const char *name);
+void scmi_device_destroy(struct device *parent, int protocol, const char *name);
+
+int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
+void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
+
+/* SCMI Transport */
+/**
+ * struct scmi_chan_info - Structure representing a SCMI channel information
+ *
+ * @id: An identifier for this channel: this matches the protocol number
+ *      used to initialize this channel
+ * @dev: Reference to device in the SCMI hierarchy corresponding to this
+ *	 channel
+ * @is_p2a: A flag to identify a channel as P2A (RX)
+ * @rx_timeout_ms: The configured RX timeout in milliseconds.
+ * @max_msg_size: Maximum size of message payload.
+ * @handle: Pointer to SCMI entity handle
+ * @no_completion_irq: Flag to indicate that this channel has no completion
+ *		       interrupt mechanism for synchronous commands.
+ *		       This can be dynamically set by transports at run-time
+ *		       inside their provided .chan_setup().
+ * @transport_info: Transport layer related information
+ */
+struct scmi_chan_info {
+	int id;
+	struct device *dev;
+	bool is_p2a;
+	unsigned int rx_timeout_ms;
+	unsigned int max_msg_size;
+	struct scmi_handle *handle;
+	bool no_completion_irq;
+	void *transport_info;
+};
+
+/**
+ * struct scmi_transport_ops - Structure representing a SCMI transport ops
+ *
+ * @chan_available: Callback to check if channel is available or not
+ * @chan_setup: Callback to allocate and setup a channel
+ * @chan_free: Callback to free a channel
+ * @get_max_msg: Optional callback to provide max_msg dynamically
+ *		 Returns the maximum number of messages for the channel type
+ *		 (tx or rx) that can be pending simultaneously in the system
+ * @send_message: Callback to send a message
+ * @mark_txdone: Callback to mark tx as done
+ * @fetch_response: Callback to fetch response
+ * @fetch_notification: Callback to fetch notification
+ * @clear_channel: Callback to clear a channel
+ * @poll_done: Callback to poll transfer status
+ */
+struct scmi_transport_ops {
+	bool (*chan_available)(struct device_node *of_node, int idx);
+	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
+			  bool tx);
+	int (*chan_free)(int id, void *p, void *data);
+	unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);
+	int (*send_message)(struct scmi_chan_info *cinfo,
+			    struct scmi_xfer *xfer);
+	void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,
+			    struct scmi_xfer *xfer);
+	void (*fetch_response)(struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer);
+	void (*fetch_notification)(struct scmi_chan_info *cinfo,
+				   size_t max_len, struct scmi_xfer *xfer);
+	void (*clear_channel)(struct scmi_chan_info *cinfo);
+	bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
+};
+
+/**
+ * struct scmi_desc - Description of SoC integration
+ *
+ * @ops: Pointer to the transport specific ops structure
+ * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
+ * @max_msg: Maximum number of messages for a channel type (tx or rx) that can
+ *	be pending simultaneously in the system. May be overridden by the
+ *	get_max_msg op.
+ * @max_msg_size: Maximum size of data payload per message that can be handled.
+ * @atomic_threshold: Optional system wide DT-configured threshold, expressed
+ *		      in microseconds, for atomic operations.
+ *		      Only SCMI synchronous commands reported by the platform
+ *		      to have an execution latency lesser-equal to the threshold
+ *		      should be considered for atomic mode operation: such
+ *		      decision is finally left up to the SCMI drivers.
+ * @no_completion_irq: Flag to indicate that this transport has no completion
+ *		       interrupt and has to be polled. This is similar to the
+ *		       force_polling below, except this is set via DT property.
+ * @force_polling: Flag to force this whole transport to use SCMI core polling
+ *		   mechanism instead of completion interrupts even if available.
+ * @sync_cmds_completed_on_ret: Flag to indicate that the transport assures
+ *				synchronous-command messages are atomically
+ *				completed on .send_message: no need to poll
+ *				actively waiting for a response.
+ *				Used by core internally only when polling is
+ *				selected as a waiting for reply method: i.e.
+ *				if a completion irq was found use that anyway.
+ * @atomic_enabled: Flag to indicate that this transport, which is assured not
+ *		    to sleep anywhere on the TX path, can be used in atomic mode
+ *		    when requested.
+ */
+struct scmi_desc {
+	const struct scmi_transport_ops *ops;
+	int max_rx_timeout_ms;
+	int max_msg;
+	int max_msg_size;
+	unsigned int atomic_threshold;
+	bool no_completion_irq;
+	const bool force_polling;
+	const bool sync_cmds_completed_on_ret;
+	const bool atomic_enabled;
+};
+
+static inline bool is_polling_required(struct scmi_chan_info *cinfo,
+				       const struct scmi_desc *desc)
+{
+	return cinfo->no_completion_irq || desc->force_polling;
+}
+
+static inline bool is_transport_polling_capable(const struct scmi_desc *desc)
+{
+	return desc->ops->poll_done || desc->sync_cmds_completed_on_ret;
+}
+
+static inline bool is_polling_enabled(struct scmi_chan_info *cinfo,
+				      const struct scmi_desc *desc)
+{
+	return is_polling_required(cinfo, desc) &&
+		is_transport_polling_capable(desc);
+}
+
+void scmi_xfer_raw_put(const struct scmi_handle *handle,
+		       struct scmi_xfer *xfer);
+struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle);
+struct scmi_chan_info *
+scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id);
+
+int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
+				    struct scmi_xfer *xfer);
+
+int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
+					    struct scmi_xfer *xfer,
+					    unsigned int timeout_ms);
+
+enum debug_counters {
+	SENT_OK,
+	SENT_FAIL,
+	SENT_FAIL_POLLING_UNSUPPORTED,
+	SENT_FAIL_CHANNEL_NOT_FOUND,
+	RESPONSE_OK,
+	NOTIFICATION_OK,
+	DELAYED_RESPONSE_OK,
+	XFERS_RESPONSE_TIMEOUT,
+	XFERS_RESPONSE_POLLED_TIMEOUT,
+	RESPONSE_POLLED_OK,
+	ERR_MSG_UNEXPECTED,
+	ERR_MSG_INVALID,
+	ERR_MSG_NOMEM,
+	ERR_PROTOCOL,
+	XFERS_INFLIGHT,
+	SCMI_DEBUG_COUNTERS_LAST
+};
+
+/**
+ * struct scmi_debug_info  - Debug common info
+ * @top_dentry: A reference to the top debugfs dentry
+ * @name: Name of this SCMI instance
+ * @type: Type of this SCMI instance
+ * @is_atomic: Flag to state if the transport of this instance is atomic
+ * @counters: An array of atomic_c's used for tracking statistics (if enabled)
+ */
+struct scmi_debug_info {
+	struct dentry *top_dentry;
+	const char *name;
+	const char *type;
+	bool is_atomic;
+	atomic_t counters[SCMI_DEBUG_COUNTERS_LAST];
+};
+
+static inline void scmi_inc_count(struct scmi_debug_info *dbg, int stat)
+{
+	if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) {
+		if (dbg)
+			atomic_inc(&dbg->counters[stat]);
+	}
+}
+
+static inline void scmi_dec_count(struct scmi_debug_info *dbg, int stat)
+{
+	if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) {
+		if (dbg)
+			atomic_dec(&dbg->counters[stat]);
+	}
+}
+
+enum scmi_bad_msg {
+	MSG_UNEXPECTED = -1,
+	MSG_INVALID = -2,
+	MSG_UNKNOWN = -3,
+	MSG_NOMEM = -4,
+	MSG_MBOX_SPURIOUS = -5,
+};
+
+/* Used for compactness and signature validation of the function pointers being
+ * passed.
+ */
+typedef void (*shmem_copy_toio_t)(void __iomem *to, const void *from,
+				  size_t count);
+typedef void (*shmem_copy_fromio_t)(void *to, const void __iomem *from,
+				    size_t count);
+
+/**
+ * struct scmi_shmem_io_ops  - I/O operations to read from/write to
+ * Shared Memory
+ *
+ * @toio: Copy data to the shared memory area
+ * @fromio: Copy data from the shared memory area
+ */
+struct scmi_shmem_io_ops {
+	shmem_copy_fromio_t fromio;
+	shmem_copy_toio_t toio;
+};
+
+/* shmem related declarations */
+struct scmi_shared_mem;
+
+/**
+ * struct scmi_shared_mem_operations  - Transport core operations for
+ * Shared Memory
+ *
+ * @tx_prepare: Prepare the @xfer message for transmission on the chosen @shmem
+ * @read_header: Read header of the message currently hold in @shmem
+ * @fetch_response: Copy the message response from @shmem into @xfer
+ * @fetch_notification: Copy the message notification from @shmem into @xfer
+ * @clear_channel: Clear the @shmem channel busy flag
+ * @poll_done: Check if poll has completed for @xfer on @shmem
+ * @channel_free: Check if @shmem channel is marked as free
+ * @channel_intr_enabled: Check is @shmem channel has requested a completion irq
+ * @setup_iomap: Setup IO shared memory for channel @cinfo
+ */
+struct scmi_shared_mem_operations {
+	void (*tx_prepare)(struct scmi_shared_mem __iomem *shmem,
+			   struct scmi_xfer *xfer,
+			   struct scmi_chan_info *cinfo,
+			   shmem_copy_toio_t toio);
+	u32 (*read_header)(struct scmi_shared_mem __iomem *shmem);
+
+	void (*fetch_response)(struct scmi_shared_mem __iomem *shmem,
+			       struct scmi_xfer *xfer,
+			       shmem_copy_fromio_t fromio);
+	void (*fetch_notification)(struct scmi_shared_mem __iomem *shmem,
+				   size_t max_len, struct scmi_xfer *xfer,
+				   shmem_copy_fromio_t fromio);
+	void (*clear_channel)(struct scmi_shared_mem __iomem *shmem);
+	bool (*poll_done)(struct scmi_shared_mem __iomem *shmem,
+			  struct scmi_xfer *xfer);
+	bool (*channel_free)(struct scmi_shared_mem __iomem *shmem);
+	bool (*channel_intr_enabled)(struct scmi_shared_mem __iomem *shmem);
+	void __iomem *(*setup_iomap)(struct scmi_chan_info *cinfo,
+				     struct device *dev,
+				     bool tx, struct resource *res,
+				     struct scmi_shmem_io_ops **ops);
+};
+
+const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void);
+
+/* declarations for message passing transports */
+struct scmi_msg_payld;
+
+/* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
+#define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
+
+/**
+ * struct scmi_message_operations  - Transport core operations for Message
+ *
+ * @response_size: Get calculated response size for @xfer
+ * @command_size: Get calculated command size for @xfer
+ * @tx_prepare: Prepare the @xfer message for transmission on the provided @msg
+ * @read_header: Read header of the message currently hold in @msg
+ * @fetch_response: Copy the message response from @msg into @xfer
+ * @fetch_notification: Copy the message notification from @msg into @xfer
+ */
+struct scmi_message_operations {
+	size_t (*response_size)(struct scmi_xfer *xfer);
+	size_t (*command_size)(struct scmi_xfer *xfer);
+	void (*tx_prepare)(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
+	u32 (*read_header)(struct scmi_msg_payld *msg);
+	void (*fetch_response)(struct scmi_msg_payld *msg, size_t len,
+			       struct scmi_xfer *xfer);
+	void (*fetch_notification)(struct scmi_msg_payld *msg, size_t len,
+				   size_t max_len, struct scmi_xfer *xfer);
+};
+
+const struct scmi_message_operations *scmi_message_operations_get(void);
+
+/**
+ * struct scmi_transport_core_operations  - Transpoert core operations
+ *
+ * @bad_message_trace: An helper to report a malformed/unexpected message
+ * @rx_callback: Callback to report received messages
+ * @shmem: Datagram operations for shared memory based transports
+ * @msg: Datagram operations for message based transports
+ */
+struct scmi_transport_core_operations {
+	void (*bad_message_trace)(struct scmi_chan_info *cinfo,
+				  u32 msg_hdr, enum scmi_bad_msg err);
+	void (*rx_callback)(struct scmi_chan_info *cinfo, u32 msg_hdr,
+			    void *priv);
+	const struct scmi_shared_mem_operations *shmem;
+	const struct scmi_message_operations *msg;
+};
+
+/**
+ * struct scmi_transport_handle  - Transport instance handle
+ * @supplier_get: A helper to retrieve the device descriptor, identifying the
+ *		  transport driver serving this SCMI instance, which will be
+ *		  used as a supplier for the core SCMI driver: returning an
+ *		  error here causes the probe sequence to be interrupted and
+ *		  return that same error code, so that each transport can decide
+ *		  which policy to implement by choosing an appropriate error.
+ * @supplier_put: A helper to signal that the specified transport supplier is
+ *		  no more being used and it is made available again.
+ *
+ * Note that these helpers are needed and provided only by those transports
+ * whose initialization relies on some other subsystem and whose relations to
+ * the core SCMI driver is not tracked by firmware descriptions.
+ */
+struct scmi_transport_handle {
+	struct device __must_check *(*supplier_get)
+		(const struct scmi_transport_handle *th);
+	int (*supplier_put)(const struct scmi_transport_handle *th,
+			    struct device *dev);
+};
+
+/**
+ * struct scmi_transport  - A structure representing a configured transport
+ *
+ * @supplier: Device representing the transport and acting as a supplier for
+ *	      the core SCMI stack
+ * @desc: Transport descriptor
+ * @core_ops: A pointer to a pointer used by the core SCMI stack to make the
+ *	      core transport operations accessible to the transports.
+ * @th: An optional pointer to the transport handle
+ */
+struct scmi_transport {
+	struct device *supplier;
+	struct scmi_desc desc;
+	struct scmi_transport_core_operations **core_ops;
+	const struct scmi_transport_handle *th;
+};
+
+/**
+ * struct scmi_transport_supplier  - Transport descriptor
+ * @mtx: A mutex to protect @available
+ * @available: A reference to an initialized transport device, when available.
+ *	       This reference is implicitly used to track the status of the
+ *	       supplier and it can cycle through the following 3 states:
+ *	       1. NOT_READY - PTR_ERR(-EPROBE_DEFER): no supplier available;
+ *		  this is the transport initial state.
+ *	       2. AVAILABLE - <supplier_dev>: a transport supplier has been
+ *		  initialized and it is available, ready to use.
+ *	       3. BUSY _ PTR_ERR(-EBUSY): transport supplier is currently in use.
+ * @th: An embedded transport handle object that embeds the helpers
+ *	implementing the above mentioned logic
+ *
+ * Note that this transport driver enforces single instance probing.
+ */
+struct scmi_transport_supplier {
+	/* Protect @available */
+	struct mutex mtx;
+	struct device *available;
+	const struct scmi_transport_handle th;
+};
+
+#define to_sup(t)	container_of(t, struct scmi_transport_supplier, th)
+
+/**
+ * scmi_transport_supplier_put  - A helper to dispose of a supplier
+ * @th: A reference to the transport handle to use
+ * @supplier: A reference to the device supplier to manage, cannot be NULL
+ *	      or ERR_PTR.
+ *
+ * Note that putting a supplier will have different effect based on the
+ * current state of scmi_transport_supplier.available:
+ *  - NOT_READY/BUSY: @supplier will be set as the new available device: this
+ *		      can be used to made available a supplier OR stop using one.
+ *  - AVAILABLE: if the @supplier we are disposing of matches the currently
+ *		 available one, roll back to NOT_READY state.
+ *		 Any other attempt to override an available supplier with a
+ *		 new one is rejected, effectively enforcing one single supplier.
+ *
+ * Return: 0 on Success, errno otherwise.
+ */
+static inline int
+scmi_transport_supplier_put(const struct scmi_transport_handle *th,
+			    struct device *supplier)
+{
+	struct scmi_transport_supplier *sup = to_sup(th);
+
+	/* Nothing to do when the provided supplier was never real */
+	if (IS_ERR_OR_NULL(supplier))
+		return 0;
+
+	guard(mutex)(&sup->mtx);
+	switch (PTR_ERR_OR_ZERO(sup->available)) {
+	case -EPROBE_DEFER:
+	case -EBUSY:
+		sup->available = supplier;
+		break;
+	case 0:
+		/* Putting a supplier when in the AVAILABLE state causes a
+		 * transition back to the NOT_READY state, BUT only if the
+		 * supplier we are disposing of was exactly the device that was
+		 * previously made readily available.
+		 */
+		if (supplier != sup->available)
+			return -EINVAL;
+		sup->available = ERR_PTR(-EPROBE_DEFER);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * scmi_transport_supplier_get  - A helper to get hold of a supplier
+ * @th: A reference to the transport handle to use
+ *
+ * Note that, trying to get a supplier device can return:
+ *  - a ready to use supplier device, (subsequently made unavailable)
+ *  - PTR_ERR(-EPROBE_DEFER): no supplier is available
+ *  - PTR_ERR(-BUSY): supplier was already taken by a previous get
+ *
+ *  This allows the probe to defer and wait when a possible device can
+ *  be reasonably expected to appear.
+ *
+ * Return: a usable supplier device on Success or PTR_ERR on Failure.
+ */
+static inline struct device *
+scmi_transport_supplier_get(const struct scmi_transport_handle *th)
+{
+	struct scmi_transport_supplier *sup = to_sup(th);
+	struct device *supplier;
+
+	guard(mutex)(&sup->mtx);
+	supplier = sup->available;
+	if (!IS_ERR(sup->available))
+		sup->available = ERR_PTR(-EBUSY);
+
+	return supplier;
+}
+
+#define DEFINE_SCMI_TRANSPORT_SUPPLIER(__supplier)		\
+struct scmi_transport_supplier __supplier = {			\
+	.mtx = __MUTEX_INITIALIZER(__supplier.mtx),		\
+	.available = INIT_ERR_PTR(-EPROBE_DEFER),		\
+	.th.supplier_get = scmi_transport_supplier_get,		\
+	.th.supplier_put = scmi_transport_supplier_put,		\
+}
+
+#define DEFINE_SCMI_TRANSPORT_DRIVER(__tag, __drv, __desc, __match, __core_ops)\
+static void __tag##_dev_free(void *data)				       \
+{									       \
+	struct platform_device *spdev = data;				       \
+	struct scmi_transport *strans;					       \
+									       \
+	strans = dev_get_platdata(&spdev->dev);				       \
+	if (strans && strans->th)					       \
+		strans->th->supplier_put(strans->th, strans->supplier);	       \
+									       \
+	platform_device_unregister(spdev);				       \
+}									       \
+									       \
+static int __tag##_probe(struct platform_device *pdev)			       \
+{									       \
+	struct device *dev = &pdev->dev, *supplier;			       \
+	struct platform_device *spdev;					       \
+	struct scmi_transport strans;					       \
+	int ret;							       \
+									       \
+	supplier = dev;							       \
+	strans.th = device_get_match_data(dev);				       \
+	if (strans.th) {						       \
+		supplier = strans.th->supplier_get(strans.th);		       \
+		if (IS_ERR(supplier))					       \
+			return PTR_ERR(supplier);			       \
+	}								       \
+									       \
+	spdev = platform_device_alloc("arm-scmi", PLATFORM_DEVID_AUTO);	       \
+	if (!spdev) {							       \
+		ret = -ENOMEM;						       \
+		goto err_mem;						       \
+	}								       \
+									       \
+	device_set_of_node_from_dev(&spdev->dev, dev);			       \
+									       \
+	strans.supplier = supplier;					       \
+	memcpy(&strans.desc, &(__desc), sizeof(strans.desc));		       \
+	strans.core_ops = &(__core_ops);				       \
+									       \
+	ret = platform_device_add_data(spdev, &strans, sizeof(strans));	       \
+	if (ret)							       \
+		goto err;						       \
+									       \
+	spdev->dev.parent = dev;					       \
+	ret = platform_device_add(spdev);				       \
+	if (ret)							       \
+		goto err;						       \
+									       \
+	return devm_add_action_or_reset(dev, __tag##_dev_free, spdev);	       \
+									       \
+err:									       \
+	platform_device_put(spdev);					       \
+err_mem:								       \
+	if (strans.th)							       \
+		strans.th->supplier_put(strans.th, supplier);			       \
+									       \
+	return ret;							       \
+}									       \
+									       \
+static struct platform_driver __drv = {					       \
+	.driver = {							       \
+		   .name = #__tag "_transport",				       \
+		   .of_match_table = __match,				       \
+		   },							       \
+	.probe = __tag##_probe,						       \
+}
+
+void scmi_notification_instance_data_set(const struct scmi_handle *handle,
+					 void *priv);
+void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
+int scmi_inflight_count(const struct scmi_handle *handle);
+#endif /* _SCMI_COMMON_H */

linux-7.2.3/drivers/firmware/arm_scmi/msg.c

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * For transports using message passing.
+ *
+ * Derived from shm.c.
+ *
+ * Copyright (C) 2019-2024 ARM Ltd.
+ * Copyright (C) 2020-2021 OpenSynergy GmbH
+ */
+
+#include <linux/types.h>
+
+#include "common.h"
+
+/*
+ * struct scmi_msg_payld - Transport SDU layout
+ *
+ * The SCMI specification requires all parameters, message headers, return
+ * arguments or any protocol data to be expressed in little endian format only.
+ */
+struct scmi_msg_payld {
+	__le32 msg_header;
+	__le32 msg_payload[];
+};
+
+/**
+ * msg_command_size() - Actual size of transport SDU for command.
+ *
+ * @xfer: message which core has prepared for sending
+ *
+ * Return: transport SDU size.
+ */
+static size_t msg_command_size(struct scmi_xfer *xfer)
+{
+	return sizeof(struct scmi_msg_payld) + xfer->tx.len;
+}
+
+/**
+ * msg_response_size() - Maximum size of transport SDU for response.
+ *
+ * @xfer: message which core has prepared for sending
+ *
+ * Return: transport SDU size.
+ */
+static size_t msg_response_size(struct scmi_xfer *xfer)
+{
+	return sizeof(struct scmi_msg_payld) + sizeof(__le32) + xfer->rx.len;
+}
+
+/**
+ * msg_tx_prepare() - Set up transport SDU for command.
+ *
+ * @msg: transport SDU for command
+ * @xfer: message which is being sent
+ */
+static void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer)
+{
+	msg->msg_header = cpu_to_le32(pack_scmi_header(&xfer->hdr));
+	if (xfer->tx.buf)
+		memcpy(msg->msg_payload, xfer->tx.buf, xfer->tx.len);
+}
+
+/**
+ * msg_read_header() - Read SCMI header from transport SDU.
+ *
+ * @msg: transport SDU
+ *
+ * Return: SCMI header
+ */
+static u32 msg_read_header(struct scmi_msg_payld *msg)
+{
+	return le32_to_cpu(msg->msg_header);
+}
+
+/**
+ * msg_fetch_response() - Fetch response SCMI payload from transport SDU.
+ *
+ * @msg: transport SDU with response
+ * @len: transport SDU size
+ * @xfer: message being responded to
+ */
+static void msg_fetch_response(struct scmi_msg_payld *msg,
+			       size_t len, struct scmi_xfer *xfer)
+{
+	size_t prefix_len = sizeof(*msg) + sizeof(msg->msg_payload[0]);
+
+	xfer->hdr.status = le32_to_cpu(msg->msg_payload[0]);
+	xfer->rx.len = min_t(size_t, xfer->rx.len,
+			     len >= prefix_len ? len - prefix_len : 0);
+
+	/* Take a copy to the rx buffer.. */
+	memcpy(xfer->rx.buf, &msg->msg_payload[1], xfer->rx.len);
+}
+
+/**
+ * msg_fetch_notification() - Fetch notification payload from transport SDU.
+ *
+ * @msg: transport SDU with notification
+ * @len: transport SDU size
+ * @max_len: maximum SCMI payload size to fetch
+ * @xfer: notification message
+ */
+static void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
+				   size_t max_len, struct scmi_xfer *xfer)
+{
+	xfer->rx.len = min_t(size_t, max_len,
+			     len >= sizeof(*msg) ? len - sizeof(*msg) : 0);
+
+	/* Take a copy to the rx buffer.. */
+	memcpy(xfer->rx.buf, msg->msg_payload, xfer->rx.len);
+}
+
+static const struct scmi_message_operations scmi_msg_ops = {
+	.tx_prepare = msg_tx_prepare,
+	.command_size = msg_command_size,
+	.response_size = msg_response_size,
+	.read_header = msg_read_header,
+	.fetch_response = msg_fetch_response,
+	.fetch_notification = msg_fetch_notification,
+};
+
+const struct scmi_message_operations *scmi_message_operations_get(void)
+{
+	return &scmi_msg_ops;
+}

linux-7.2.3/drivers/firmware/arm_scmi/notify.h

@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * notification header file containing some definitions, structures
+ * and function prototypes related to SCMI Notification handling.
+ *
+ * Copyright (C) 2020-2021 ARM Ltd.
+ */
+#ifndef _SCMI_NOTIFY_H
+#define _SCMI_NOTIFY_H
+
+#include <linux/device.h>
+#include <linux/ktime.h>
+#include <linux/types.h>
+
+#define SCMI_PROTO_QUEUE_SZ	4096
+
+/**
+ * struct scmi_event  - Describes an event to be supported
+ * @id: Event ID
+ * @max_payld_sz: Max possible size for the payload of a notification message
+ * @max_report_sz: Max possible size for the report of a notification message
+ *
+ * Each SCMI protocol, during its initialization phase, can describe the events
+ * it wishes to support in a few struct scmi_event and pass them to the core
+ * using scmi_register_protocol_events().
+ */
+struct scmi_event {
+	u8	id;
+	size_t	max_payld_sz;
+	size_t	max_report_sz;
+};
+
+struct scmi_protocol_handle;
+
+/**
+ * struct scmi_event_ops  - Protocol helpers called by the notification core.
+ * @is_notify_supported: Return 0 if the specified notification for the
+ *			 specified resource (src_id) is supported.
+ * @get_num_sources: Returns the number of possible events' sources for this
+ *		     protocol
+ * @set_notify_enabled: Enable/disable the required evt_id/src_id notifications
+ *			using the proper custom protocol commands.
+ *			Return 0 on Success
+ * @fill_custom_report: fills a custom event report from the provided
+ *			event message payld identifying the event
+ *			specific src_id.
+ *			Return NULL on failure otherwise @report now fully
+ *			populated
+ *
+ * Context: Helpers described in &struct scmi_event_ops are called only in
+ *	    process context.
+ */
+struct scmi_event_ops {
+	bool (*is_notify_supported)(const struct scmi_protocol_handle *ph,
+				    u8 evt_id, u32 src_id);
+	int (*get_num_sources)(const struct scmi_protocol_handle *ph);
+	int (*set_notify_enabled)(const struct scmi_protocol_handle *ph,
+				  u8 evt_id, u32 src_id, bool enabled);
+	void *(*fill_custom_report)(const struct scmi_protocol_handle *ph,
+				    u8 evt_id, ktime_t timestamp,
+				    const void *payld, size_t payld_sz,
+				    void *report, u32 *src_id);
+};
+
+/**
+ * struct scmi_protocol_events  - Per-protocol description of available events
+ * @queue_sz: Size in bytes of the per-protocol queue to use.
+ * @ops: Array of protocol-specific events operations.
+ * @evts: Array of supported protocol's events.
+ * @num_events: Number of supported protocol's events described in @evts.
+ * @num_sources: Number of protocol's sources, should be greater than 0; if not
+ *		 available at compile time, it will be provided at run-time via
+ *		 @get_num_sources.
+ */
+struct scmi_protocol_events {
+	size_t				queue_sz;
+	const struct scmi_event_ops	*ops;
+	const struct scmi_event		*evts;
+	unsigned int			num_events;
+	unsigned int			num_sources;
+};
+
+int scmi_notification_init(struct scmi_handle *handle);
+void scmi_notification_exit(struct scmi_handle *handle);
+int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id,
+				  const struct scmi_protocol_handle *ph,
+				  const struct scmi_protocol_events *ee);
+void scmi_deregister_protocol_events(const struct scmi_handle *handle,
+				     u8 proto_id);
+int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
+		const void *buf, size_t len, ktime_t ts);
+
+#endif /* _SCMI_NOTIFY_H */

linux-7.2.3/drivers/firmware/arm_scmi/pinctrl.c

@@ -0,0 +1,899 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Pinctrl Protocol
+ *
+ * Copyright (C) 2024 EPAM
+ * Copyright 2024 NXP
+ */
+
+#include <asm/byteorder.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "common.h"
+#include "protocols.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+#define GET_GROUPS_NR(x)	le32_get_bits((x), GENMASK(31, 16))
+#define GET_PINS_NR(x)		le32_get_bits((x), GENMASK(15, 0))
+#define GET_FUNCTIONS_NR(x)	le32_get_bits((x), GENMASK(15, 0))
+
+#define EXT_NAME_FLAG(x)	le32_get_bits((x), BIT(31))
+#define NUM_ELEMS(x)		le32_get_bits((x), GENMASK(15, 0))
+
+#define REMAINING(x)		le32_get_bits((x), GENMASK(31, 16))
+#define RETURNED(x)		le32_get_bits((x), GENMASK(11, 0))
+
+#define CONFIG_FLAG_MASK	GENMASK(19, 18)
+#define SELECTOR_MASK		GENMASK(17, 16)
+#define SKIP_CONFIGS_MASK	GENMASK(15, 8)
+#define CONFIG_TYPE_MASK	GENMASK(7, 0)
+
+enum scmi_pinctrl_protocol_cmd {
+	PINCTRL_ATTRIBUTES = 0x3,
+	PINCTRL_LIST_ASSOCIATIONS = 0x4,
+	PINCTRL_SETTINGS_GET = 0x5,
+	PINCTRL_SETTINGS_CONFIGURE = 0x6,
+	PINCTRL_REQUEST = 0x7,
+	PINCTRL_RELEASE = 0x8,
+	PINCTRL_NAME_GET = 0x9,
+	PINCTRL_SET_PERMISSIONS = 0xa,
+};
+
+struct scmi_msg_settings_conf {
+	__le32 identifier;
+	__le32 function_id;
+	__le32 attributes;
+	__le32 configs[];
+};
+
+struct scmi_msg_settings_get {
+	__le32 identifier;
+	__le32 attributes;
+};
+
+struct scmi_resp_settings_get {
+	__le32 function_selected;
+	__le32 num_configs;
+	__le32 configs[];
+};
+
+struct scmi_msg_pinctrl_protocol_attributes {
+	__le32 attributes_low;
+	__le32 attributes_high;
+};
+
+struct scmi_msg_pinctrl_attributes {
+	__le32 identifier;
+	__le32 flags;
+};
+
+struct scmi_resp_pinctrl_attributes {
+	__le32 attributes;
+	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+};
+
+struct scmi_msg_pinctrl_list_assoc {
+	__le32 identifier;
+	__le32 flags;
+	__le32 index;
+};
+
+struct scmi_resp_pinctrl_list_assoc {
+	__le32 flags;
+	__le16 array[];
+};
+
+struct scmi_msg_request {
+	__le32 identifier;
+	__le32 flags;
+};
+
+struct scmi_group_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool present;
+	u32 *group_pins;
+	u32 nr_pins;
+};
+
+struct scmi_function_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool present;
+	u32 *groups;
+	u32 nr_groups;
+};
+
+struct scmi_pin_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool present;
+};
+
+struct scmi_pinctrl_info {
+	int nr_groups;
+	int nr_functions;
+	int nr_pins;
+	struct scmi_group_info *groups;
+	struct scmi_function_info *functions;
+	struct scmi_pin_info *pins;
+};
+
+static int scmi_pinctrl_attributes_get(const struct scmi_protocol_handle *ph,
+				       struct scmi_pinctrl_info *pi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_pinctrl_protocol_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		pi->nr_functions = GET_FUNCTIONS_NR(attr->attributes_high);
+		pi->nr_groups = GET_GROUPS_NR(attr->attributes_low);
+		pi->nr_pins = GET_PINS_NR(attr->attributes_low);
+		if (pi->nr_pins == 0) {
+			dev_warn(ph->dev, "returned zero pins\n");
+			ret = -EINVAL;
+		}
+	}
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_pinctrl_count_get(const struct scmi_protocol_handle *ph,
+				  enum scmi_pinctrl_selector_type type)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+
+	switch (type) {
+	case PIN_TYPE:
+		return pi->nr_pins;
+	case GROUP_TYPE:
+		return pi->nr_groups;
+	case FUNCTION_TYPE:
+		return pi->nr_functions;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int scmi_pinctrl_validate_id(const struct scmi_protocol_handle *ph,
+				    u32 selector,
+				    enum scmi_pinctrl_selector_type type)
+{
+	int value;
+
+	value = scmi_pinctrl_count_get(ph, type);
+	if (value < 0)
+		return value;
+
+	if (selector >= value || value == 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_pinctrl_attributes(const struct scmi_protocol_handle *ph,
+				   enum scmi_pinctrl_selector_type type,
+				   u32 selector, char *name,
+				   u32 *n_elems)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_pinctrl_attributes *tx;
+	struct scmi_resp_pinctrl_attributes *rx;
+	bool ext_name_flag;
+
+	if (!name)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_validate_id(ph, selector, type);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, PINCTRL_ATTRIBUTES, sizeof(*tx),
+				      sizeof(*rx), &t);
+	if (ret)
+		return ret;
+
+	tx = t->tx.buf;
+	rx = t->rx.buf;
+	tx->identifier = cpu_to_le32(selector);
+	tx->flags = cpu_to_le32(type);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		if (n_elems)
+			*n_elems = NUM_ELEMS(rx->attributes);
+
+		strscpy(name, rx->name, SCMI_SHORT_NAME_MAX_SIZE);
+
+		ext_name_flag = !!EXT_NAME_FLAG(rx->attributes);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	if (ret)
+		return ret;
+	/*
+	 * If supported overwrite short name with the extended one;
+	 * on error just carry on and use already provided short name.
+	 */
+	if (ext_name_flag)
+		ret = ph->hops->extended_name_get(ph, PINCTRL_NAME_GET,
+						  selector, (u32 *)&type, name,
+						  SCMI_MAX_STR_SIZE);
+	return ret;
+}
+
+struct scmi_pinctrl_ipriv {
+	u32 selector;
+	enum scmi_pinctrl_selector_type type;
+	u32 *array;
+};
+
+static void iter_pinctrl_assoc_prepare_message(void *message,
+					       u32 desc_index,
+					       const void *priv)
+{
+	struct scmi_msg_pinctrl_list_assoc *msg = message;
+	const struct scmi_pinctrl_ipriv *p = priv;
+
+	msg->identifier = cpu_to_le32(p->selector);
+	msg->flags = cpu_to_le32(p->type);
+	msg->index = cpu_to_le32(desc_index);
+}
+
+static int iter_pinctrl_assoc_update_state(struct scmi_iterator_state *st,
+					   const void *response, void *priv)
+{
+	const struct scmi_resp_pinctrl_list_assoc *r = response;
+
+	st->num_returned = RETURNED(r->flags);
+	st->num_remaining = REMAINING(r->flags);
+
+	return 0;
+}
+
+static int
+iter_pinctrl_assoc_process_response(const struct scmi_protocol_handle *ph,
+				    const void *response,
+				    struct scmi_iterator_state *st, void *priv)
+{
+	const struct scmi_resp_pinctrl_list_assoc *r = response;
+	struct scmi_pinctrl_ipriv *p = priv;
+
+	p->array[st->desc_index + st->loop_idx] =
+		le16_to_cpu(r->array[st->loop_idx]);
+
+	return 0;
+}
+
+static int scmi_pinctrl_list_associations(const struct scmi_protocol_handle *ph,
+					  u32 selector,
+					  enum scmi_pinctrl_selector_type type,
+					  u16 size, u32 *array)
+{
+	int ret;
+	void *iter;
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_pinctrl_assoc_prepare_message,
+		.update_state = iter_pinctrl_assoc_update_state,
+		.process_response = iter_pinctrl_assoc_process_response,
+	};
+	struct scmi_pinctrl_ipriv ipriv = {
+		.selector = selector,
+		.type = type,
+		.array = array,
+	};
+
+	if (!array || !size || type == PIN_TYPE)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_validate_id(ph, selector, type);
+	if (ret)
+		return ret;
+
+	iter = ph->hops->iter_response_init(ph, &ops, size,
+					    PINCTRL_LIST_ASSOCIATIONS,
+					    sizeof(struct scmi_msg_pinctrl_list_assoc),
+					    &ipriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	return ph->hops->iter_response_run(iter);
+}
+
+struct scmi_settings_get_ipriv {
+	u32 selector;
+	enum scmi_pinctrl_selector_type type;
+	bool get_all;
+	unsigned int *nr_configs;
+	enum scmi_pinctrl_conf_type *config_types;
+	u32 *config_values;
+};
+
+static void
+iter_pinctrl_settings_get_prepare_message(void *message, u32 desc_index,
+					  const void *priv)
+{
+	struct scmi_msg_settings_get *msg = message;
+	const struct scmi_settings_get_ipriv *p = priv;
+	u32 attributes;
+
+	attributes = FIELD_PREP(SELECTOR_MASK, p->type);
+
+	if (p->get_all) {
+		attributes |= FIELD_PREP(CONFIG_FLAG_MASK, 1) |
+			FIELD_PREP(SKIP_CONFIGS_MASK, desc_index);
+	} else {
+		attributes |= FIELD_PREP(CONFIG_TYPE_MASK, p->config_types[0]);
+	}
+
+	msg->attributes = cpu_to_le32(attributes);
+	msg->identifier = cpu_to_le32(p->selector);
+}
+
+static int
+iter_pinctrl_settings_get_update_state(struct scmi_iterator_state *st,
+				       const void *response, void *priv)
+{
+	const struct scmi_resp_settings_get *r = response;
+	struct scmi_settings_get_ipriv *p = priv;
+
+	if (p->get_all) {
+		st->num_returned = le32_get_bits(r->num_configs, GENMASK(7, 0));
+		st->num_remaining = le32_get_bits(r->num_configs, GENMASK(31, 24));
+	} else {
+		st->num_returned = 1;
+		st->num_remaining = 0;
+	}
+
+	return 0;
+}
+
+static int
+iter_pinctrl_settings_get_process_response(const struct scmi_protocol_handle *ph,
+					   const void *response,
+					   struct scmi_iterator_state *st,
+					   void *priv)
+{
+	const struct scmi_resp_settings_get *r = response;
+	struct scmi_settings_get_ipriv *p = priv;
+	u32 type = le32_get_bits(r->configs[st->loop_idx * 2], GENMASK(7, 0));
+	u32 val = le32_to_cpu(r->configs[st->loop_idx * 2 + 1]);
+
+	if (p->get_all) {
+		p->config_types[st->desc_index + st->loop_idx] = type;
+	} else {
+		if (p->config_types[0] != type)
+			return -EINVAL;
+	}
+
+	p->config_values[st->desc_index + st->loop_idx] = val;
+	++*p->nr_configs;
+
+	return 0;
+}
+
+static int
+scmi_pinctrl_settings_get(const struct scmi_protocol_handle *ph, u32 selector,
+			  enum scmi_pinctrl_selector_type type,
+			  unsigned int *nr_configs,
+			  enum scmi_pinctrl_conf_type *config_types,
+			  u32 *config_values)
+{
+	int ret;
+	void *iter;
+	unsigned int max_configs = *nr_configs;
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_pinctrl_settings_get_prepare_message,
+		.update_state = iter_pinctrl_settings_get_update_state,
+		.process_response = iter_pinctrl_settings_get_process_response,
+	};
+	struct scmi_settings_get_ipriv ipriv = {
+		.selector = selector,
+		.type = type,
+		.get_all = (max_configs > 1),
+		.nr_configs = nr_configs,
+		.config_types = config_types,
+		.config_values = config_values,
+	};
+
+	if (!config_types || !config_values || type == FUNCTION_TYPE)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_validate_id(ph, selector, type);
+	if (ret)
+		return ret;
+
+	/* Prepare to count returned configs */
+	*nr_configs = 0;
+	iter = ph->hops->iter_response_init(ph, &ops, max_configs,
+					    PINCTRL_SETTINGS_GET,
+					    sizeof(struct scmi_msg_settings_get),
+					    &ipriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	return ph->hops->iter_response_run(iter);
+}
+
+static int scmi_pinctrl_settings_get_one(const struct scmi_protocol_handle *ph,
+					 u32 selector,
+					 enum scmi_pinctrl_selector_type type,
+					 enum scmi_pinctrl_conf_type config_type,
+					 u32 *config_value)
+{
+	unsigned int nr_configs = 1;
+
+	return scmi_pinctrl_settings_get(ph, selector, type, &nr_configs,
+					 &config_type, config_value);
+}
+
+static int scmi_pinctrl_settings_get_all(const struct scmi_protocol_handle *ph,
+					 u32 selector,
+					 enum scmi_pinctrl_selector_type type,
+					 unsigned int *nr_configs,
+					 enum scmi_pinctrl_conf_type *config_types,
+					 u32 *config_values)
+{
+	if (!nr_configs || *nr_configs == 0)
+		return -EINVAL;
+
+	return scmi_pinctrl_settings_get(ph, selector, type, nr_configs,
+					 config_types, config_values);
+}
+
+static int
+scmi_pinctrl_settings_conf(const struct scmi_protocol_handle *ph,
+			   u32 selector,
+			   enum scmi_pinctrl_selector_type type,
+			   u32 nr_configs,
+			   enum scmi_pinctrl_conf_type *config_type,
+			   u32 *config_value)
+{
+	struct scmi_xfer *t;
+	struct scmi_msg_settings_conf *tx;
+	u32 attributes;
+	int ret, i;
+	u32 configs_in_chunk, conf_num = 0;
+	u32 chunk;
+	int max_msg_size = ph->hops->get_max_msg_size(ph);
+
+	if (!config_type || !config_value || type == FUNCTION_TYPE)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_validate_id(ph, selector, type);
+	if (ret)
+		return ret;
+
+	configs_in_chunk = (max_msg_size - sizeof(*tx)) / (sizeof(__le32) * 2);
+	while (conf_num < nr_configs) {
+		chunk = (nr_configs - conf_num > configs_in_chunk) ?
+			configs_in_chunk : nr_configs - conf_num;
+
+		ret = ph->xops->xfer_get_init(ph, PINCTRL_SETTINGS_CONFIGURE,
+					      sizeof(*tx) +
+					      chunk * 2 * sizeof(__le32), 0, &t);
+		if (ret)
+			break;
+
+		tx = t->tx.buf;
+		tx->identifier = cpu_to_le32(selector);
+		tx->function_id = cpu_to_le32(0xFFFFFFFF);
+		attributes = FIELD_PREP(GENMASK(1, 0), type) |
+			FIELD_PREP(GENMASK(9, 2), chunk);
+		tx->attributes = cpu_to_le32(attributes);
+
+		for (i = 0; i < chunk; i++) {
+			tx->configs[i * 2] =
+				cpu_to_le32(config_type[conf_num + i]);
+			tx->configs[i * 2 + 1] =
+				cpu_to_le32(config_value[conf_num + i]);
+		}
+
+		ret = ph->xops->do_xfer(ph, t);
+
+		ph->xops->xfer_put(ph, t);
+
+		if (ret)
+			break;
+
+		conf_num += chunk;
+	}
+
+	return ret;
+}
+
+static int scmi_pinctrl_function_select(const struct scmi_protocol_handle *ph,
+					u32 group,
+					enum scmi_pinctrl_selector_type type,
+					u32 function_id)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_settings_conf *tx;
+	u32 attributes;
+
+	ret = scmi_pinctrl_validate_id(ph, group, type);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, PINCTRL_SETTINGS_CONFIGURE,
+				      sizeof(*tx), 0, &t);
+	if (ret)
+		return ret;
+
+	tx = t->tx.buf;
+	tx->identifier = cpu_to_le32(group);
+	tx->function_id = cpu_to_le32(function_id);
+	attributes = FIELD_PREP(GENMASK(1, 0), type) | BIT(10);
+	tx->attributes = cpu_to_le32(attributes);
+
+	ret = ph->xops->do_xfer(ph, t);
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_pinctrl_request_free(const struct scmi_protocol_handle *ph,
+				     u32 identifier,
+				     enum scmi_pinctrl_selector_type type,
+				     enum scmi_pinctrl_protocol_cmd cmd)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_request *tx;
+
+	if (type == FUNCTION_TYPE)
+		return -EINVAL;
+
+	if (cmd != PINCTRL_REQUEST && cmd != PINCTRL_RELEASE)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_validate_id(ph, identifier, type);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, cmd, sizeof(*tx), 0, &t);
+	if (ret)
+		return ret;
+
+	tx = t->tx.buf;
+	tx->identifier = cpu_to_le32(identifier);
+	tx->flags = cpu_to_le32(type);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (ret == -EOPNOTSUPP)
+		ret = 0;
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_pinctrl_pin_request(const struct scmi_protocol_handle *ph,
+				    u32 pin)
+{
+	return scmi_pinctrl_request_free(ph, pin, PIN_TYPE, PINCTRL_REQUEST);
+}
+
+static int scmi_pinctrl_pin_free(const struct scmi_protocol_handle *ph, u32 pin)
+{
+	return scmi_pinctrl_request_free(ph, pin, PIN_TYPE, PINCTRL_RELEASE);
+}
+
+static int scmi_pinctrl_get_group_info(const struct scmi_protocol_handle *ph,
+				       u32 selector)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	struct scmi_group_info *group;
+	int ret;
+
+	if (selector >= pi->nr_groups)
+		return -EINVAL;
+
+	group = &pi->groups[selector];
+	if (group->present)
+		return 0;
+
+	ret = scmi_pinctrl_attributes(ph, GROUP_TYPE, selector, group->name,
+				      &group->nr_pins);
+	if (ret)
+		return ret;
+
+	if (!group->nr_pins) {
+		dev_err(ph->dev, "Group %d has 0 elements", selector);
+		return -ENODATA;
+	}
+
+	group->group_pins = kmalloc_array(group->nr_pins,
+					  sizeof(*group->group_pins),
+					  GFP_KERNEL);
+	if (!group->group_pins)
+		return -ENOMEM;
+
+	ret = scmi_pinctrl_list_associations(ph, selector, GROUP_TYPE,
+					     group->nr_pins, group->group_pins);
+	if (ret) {
+		kfree(group->group_pins);
+		return ret;
+	}
+
+	group->present = true;
+	return 0;
+}
+
+static int scmi_pinctrl_get_group_name(const struct scmi_protocol_handle *ph,
+				       u32 selector, const char **name)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	int ret;
+
+	if (!name)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_get_group_info(ph, selector);
+	if (ret)
+		return ret;
+
+	*name = pi->groups[selector].name;
+
+	return 0;
+}
+
+static int scmi_pinctrl_group_pins_get(const struct scmi_protocol_handle *ph,
+				       u32 selector, const u32 **pins,
+				       u32 *nr_pins)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	int ret;
+
+	if (!pins || !nr_pins)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_get_group_info(ph, selector);
+	if (ret)
+		return ret;
+
+	*pins = pi->groups[selector].group_pins;
+	*nr_pins = pi->groups[selector].nr_pins;
+
+	return 0;
+}
+
+static int scmi_pinctrl_get_function_info(const struct scmi_protocol_handle *ph,
+					  u32 selector)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	struct scmi_function_info *func;
+	int ret;
+
+	if (selector >= pi->nr_functions)
+		return -EINVAL;
+
+	func = &pi->functions[selector];
+	if (func->present)
+		return 0;
+
+	ret = scmi_pinctrl_attributes(ph, FUNCTION_TYPE, selector, func->name,
+				      &func->nr_groups);
+	if (ret)
+		return ret;
+
+	if (!func->nr_groups) {
+		dev_err(ph->dev, "Function %d has 0 elements", selector);
+		return -ENODATA;
+	}
+
+	func->groups = kmalloc_array(func->nr_groups, sizeof(*func->groups),
+				     GFP_KERNEL);
+	if (!func->groups)
+		return -ENOMEM;
+
+	ret = scmi_pinctrl_list_associations(ph, selector, FUNCTION_TYPE,
+					     func->nr_groups, func->groups);
+	if (ret) {
+		kfree(func->groups);
+		return ret;
+	}
+
+	func->present = true;
+	return 0;
+}
+
+static int scmi_pinctrl_get_function_name(const struct scmi_protocol_handle *ph,
+					  u32 selector, const char **name)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	int ret;
+
+	if (!name)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_get_function_info(ph, selector);
+	if (ret)
+		return ret;
+
+	*name = pi->functions[selector].name;
+	return 0;
+}
+
+static int
+scmi_pinctrl_function_groups_get(const struct scmi_protocol_handle *ph,
+				 u32 selector, u32 *nr_groups,
+				 const u32 **groups)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	int ret;
+
+	if (!groups || !nr_groups)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_get_function_info(ph, selector);
+	if (ret)
+		return ret;
+
+	*groups = pi->functions[selector].groups;
+	*nr_groups = pi->functions[selector].nr_groups;
+
+	return 0;
+}
+
+static int scmi_pinctrl_mux_set(const struct scmi_protocol_handle *ph,
+				u32 selector, u32 group)
+{
+	return scmi_pinctrl_function_select(ph, group, GROUP_TYPE, selector);
+}
+
+static int scmi_pinctrl_get_pin_info(const struct scmi_protocol_handle *ph,
+				     u32 selector)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	struct scmi_pin_info *pin;
+	int ret;
+
+	if (selector >= pi->nr_pins)
+		return -EINVAL;
+
+	pin = &pi->pins[selector];
+	if (pin->present)
+		return 0;
+
+	ret = scmi_pinctrl_attributes(ph, PIN_TYPE, selector, pin->name, NULL);
+	if (ret)
+		return ret;
+
+	pin->present = true;
+	return 0;
+}
+
+static int scmi_pinctrl_get_pin_name(const struct scmi_protocol_handle *ph,
+				     u32 selector, const char **name)
+{
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+	int ret;
+
+	if (!name)
+		return -EINVAL;
+
+	ret = scmi_pinctrl_get_pin_info(ph, selector);
+	if (ret)
+		return ret;
+
+	*name = pi->pins[selector].name;
+
+	return 0;
+}
+
+static int scmi_pinctrl_name_get(const struct scmi_protocol_handle *ph,
+				 u32 selector,
+				 enum scmi_pinctrl_selector_type type,
+				 const char **name)
+{
+	switch (type) {
+	case PIN_TYPE:
+		return scmi_pinctrl_get_pin_name(ph, selector, name);
+	case GROUP_TYPE:
+		return scmi_pinctrl_get_group_name(ph, selector, name);
+	case FUNCTION_TYPE:
+		return scmi_pinctrl_get_function_name(ph, selector, name);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct scmi_pinctrl_proto_ops pinctrl_proto_ops = {
+	.count_get = scmi_pinctrl_count_get,
+	.name_get = scmi_pinctrl_name_get,
+	.group_pins_get = scmi_pinctrl_group_pins_get,
+	.function_groups_get = scmi_pinctrl_function_groups_get,
+	.mux_set = scmi_pinctrl_mux_set,
+	.settings_get_one = scmi_pinctrl_settings_get_one,
+	.settings_get_all = scmi_pinctrl_settings_get_all,
+	.settings_conf = scmi_pinctrl_settings_conf,
+	.pin_request = scmi_pinctrl_pin_request,
+	.pin_free = scmi_pinctrl_pin_free,
+};
+
+static int scmi_pinctrl_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int ret;
+	struct scmi_pinctrl_info *pinfo;
+
+	dev_dbg(ph->dev, "Pinctrl Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	ret = scmi_pinctrl_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
+
+	pinfo->pins = devm_kcalloc(ph->dev, pinfo->nr_pins,
+				   sizeof(*pinfo->pins), GFP_KERNEL);
+	if (!pinfo->pins)
+		return -ENOMEM;
+
+	pinfo->groups = devm_kcalloc(ph->dev, pinfo->nr_groups,
+				     sizeof(*pinfo->groups), GFP_KERNEL);
+	if (!pinfo->groups)
+		return -ENOMEM;
+
+	pinfo->functions = devm_kcalloc(ph->dev, pinfo->nr_functions,
+					sizeof(*pinfo->functions), GFP_KERNEL);
+	if (!pinfo->functions)
+		return -ENOMEM;
+
+	return ph->set_priv(ph, pinfo);
+}
+
+static int scmi_pinctrl_protocol_deinit(const struct scmi_protocol_handle *ph)
+{
+	int i;
+	struct scmi_pinctrl_info *pi = ph->get_priv(ph);
+
+	/* Free groups_pins allocated in scmi_pinctrl_get_group_info */
+	for (i = 0; i < pi->nr_groups; i++) {
+		if (pi->groups[i].present) {
+			kfree(pi->groups[i].group_pins);
+			pi->groups[i].present = false;
+		}
+	}
+
+	/* Free groups allocated in scmi_pinctrl_get_function_info */
+	for (i = 0; i < pi->nr_functions; i++) {
+		if (pi->functions[i].present) {
+			kfree(pi->functions[i].groups);
+			pi->functions[i].present = false;
+		}
+	}
+
+	return 0;
+}
+
+static const struct scmi_protocol scmi_pinctrl = {
+	.id = SCMI_PROTOCOL_PINCTRL,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_pinctrl_protocol_init,
+	.instance_deinit = &scmi_pinctrl_protocol_deinit,
+	.ops = &pinctrl_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(pinctrl, scmi_pinctrl)

linux-7.2.3/drivers/firmware/arm_scmi/power.c

@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Power Protocol
+ *
+ * Copyright (C) 2018-2022 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications POWER - " fmt
+
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+
+#include "protocols.h"
+#include "notify.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x30001
+
+enum scmi_power_protocol_cmd {
+	POWER_DOMAIN_ATTRIBUTES = 0x3,
+	POWER_STATE_SET = 0x4,
+	POWER_STATE_GET = 0x5,
+	POWER_STATE_NOTIFY = 0x6,
+	POWER_DOMAIN_NAME_GET = 0x8,
+};
+
+struct scmi_msg_resp_power_attributes {
+	__le16 num_domains;
+	__le16 reserved;
+	__le32 stats_addr_low;
+	__le32 stats_addr_high;
+	__le32 stats_size;
+};
+
+struct scmi_msg_resp_power_domain_attributes {
+	__le32 flags;
+#define SUPPORTS_STATE_SET_NOTIFY(x)	((x) & BIT(31))
+#define SUPPORTS_STATE_SET_ASYNC(x)	((x) & BIT(30))
+#define SUPPORTS_STATE_SET_SYNC(x)	((x) & BIT(29))
+#define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(27))
+	    u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+};
+
+struct scmi_power_set_state {
+	__le32 flags;
+#define STATE_SET_ASYNC		BIT(0)
+	__le32 domain;
+	__le32 state;
+};
+
+struct scmi_power_state_notify {
+	__le32 domain;
+	__le32 notify_enable;
+};
+
+struct scmi_power_state_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 power_state;
+};
+
+struct power_dom_info {
+	bool state_set_sync;
+	bool state_set_async;
+	bool state_set_notify;
+	char name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_power_info {
+	bool notify_state_change_cmd;
+	int num_domains;
+	u64 stats_addr;
+	u32 stats_size;
+	struct power_dom_info *dom_info;
+};
+
+static int scmi_power_attributes_get(const struct scmi_protocol_handle *ph,
+				     struct scmi_power_info *pi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_power_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		pi->num_domains = le16_to_cpu(attr->num_domains);
+		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
+				(u64)le32_to_cpu(attr->stats_addr_high) << 32;
+		pi->stats_size = le32_to_cpu(attr->stats_size);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	if (!ret)
+		if (!ph->hops->protocol_msg_check(ph, POWER_STATE_NOTIFY, NULL))
+			pi->notify_state_change_cmd = true;
+
+	return ret;
+}
+
+static int
+scmi_power_domain_attributes_get(const struct scmi_protocol_handle *ph,
+				 u32 domain, struct power_dom_info *dom_info,
+				 bool notify_state_change_cmd)
+{
+	int ret;
+	u32 flags;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_power_domain_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, POWER_DOMAIN_ATTRIBUTES,
+				      sizeof(domain), sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(domain, t->tx.buf);
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		flags = le32_to_cpu(attr->flags);
+
+		if (notify_state_change_cmd)
+			dom_info->state_set_notify =
+				SUPPORTS_STATE_SET_NOTIFY(flags);
+		dom_info->state_set_async = SUPPORTS_STATE_SET_ASYNC(flags);
+		dom_info->state_set_sync = SUPPORTS_STATE_SET_SYNC(flags);
+		strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
+	}
+	ph->xops->xfer_put(ph, t);
+
+	/*
+	 * If supported overwrite short name with the extended one;
+	 * on error just carry on and use already provided short name.
+	 */
+	if (!ret && PROTOCOL_REV_MAJOR(ph->version) >= 0x3 &&
+	    SUPPORTS_EXTENDED_NAMES(flags)) {
+		ph->hops->extended_name_get(ph, POWER_DOMAIN_NAME_GET,
+					    domain, NULL, dom_info->name,
+					    SCMI_MAX_STR_SIZE);
+	}
+
+	return ret;
+}
+
+static int scmi_power_state_set(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 state)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_power_set_state *st;
+
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_SET, sizeof(*st), 0, &t);
+	if (ret)
+		return ret;
+
+	st = t->tx.buf;
+	st->flags = cpu_to_le32(0);
+	st->domain = cpu_to_le32(domain);
+	st->state = cpu_to_le32(state);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_power_state_get(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 *state)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_GET, sizeof(u32), sizeof(u32), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(domain, t->tx.buf);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		*state = get_unaligned_le32(t->rx.buf);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_power_num_domains_get(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_power_info *pi = ph->get_priv(ph);
+
+	return pi->num_domains;
+}
+
+static const char *
+scmi_power_name_get(const struct scmi_protocol_handle *ph,
+		    u32 domain)
+{
+	struct scmi_power_info *pi = ph->get_priv(ph);
+	struct power_dom_info *dom;
+
+	if (domain >= pi->num_domains)
+		return "unknown";
+
+	dom = pi->dom_info + domain;
+	return dom->name;
+}
+
+static const struct scmi_power_proto_ops power_proto_ops = {
+	.num_domains_get = scmi_power_num_domains_get,
+	.name_get = scmi_power_name_get,
+	.state_set = scmi_power_state_set,
+	.state_get = scmi_power_state_get,
+};
+
+static int scmi_power_request_notify(const struct scmi_protocol_handle *ph,
+				     u32 domain, bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_power_state_notify *notify;
+
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_NOTIFY,
+				      sizeof(*notify), 0, &t);
+	if (ret)
+		return ret;
+
+	notify = t->tx.buf;
+	notify->domain = cpu_to_le32(domain);
+	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static bool scmi_power_notify_supported(const struct scmi_protocol_handle *ph,
+					u8 evt_id, u32 src_id)
+{
+	struct power_dom_info *dom;
+	struct scmi_power_info *pinfo = ph->get_priv(ph);
+
+	if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED ||
+	    src_id >= pinfo->num_domains)
+		return false;
+
+	dom = pinfo->dom_info + src_id;
+	return dom->state_set_notify;
+}
+
+static int scmi_power_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					 u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_power_request_notify(ph, src_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *
+scmi_power_fill_custom_report(const struct scmi_protocol_handle *ph,
+			      u8 evt_id, ktime_t timestamp,
+			      const void *payld, size_t payld_sz,
+			      void *report, u32 *src_id)
+{
+	const struct scmi_power_state_notify_payld *p = payld;
+	struct scmi_power_state_changed_report *r = report;
+
+	if (evt_id != SCMI_EVENT_POWER_STATE_CHANGED || sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->domain_id = le32_to_cpu(p->domain_id);
+	r->power_state = le32_to_cpu(p->power_state);
+	*src_id = r->domain_id;
+
+	return r;
+}
+
+static int scmi_power_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_power_info *pinfo = ph->get_priv(ph);
+
+	if (!pinfo)
+		return -EINVAL;
+
+	return pinfo->num_domains;
+}
+
+static const struct scmi_event power_events[] = {
+	{
+		.id = SCMI_EVENT_POWER_STATE_CHANGED,
+		.max_payld_sz = sizeof(struct scmi_power_state_notify_payld),
+		.max_report_sz =
+			sizeof(struct scmi_power_state_changed_report),
+	},
+};
+
+static const struct scmi_event_ops power_event_ops = {
+	.is_notify_supported = scmi_power_notify_supported,
+	.get_num_sources = scmi_power_get_num_sources,
+	.set_notify_enabled = scmi_power_set_notify_enabled,
+	.fill_custom_report = scmi_power_fill_custom_report,
+};
+
+static const struct scmi_protocol_events power_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &power_event_ops,
+	.evts = power_events,
+	.num_events = ARRAY_SIZE(power_events),
+};
+
+static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int domain, ret;
+	struct scmi_power_info *pinfo;
+
+	dev_dbg(ph->dev, "Power Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	ret = scmi_power_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
+
+	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
+				       sizeof(*pinfo->dom_info), GFP_KERNEL);
+	if (!pinfo->dom_info)
+		return -ENOMEM;
+
+	for (domain = 0; domain < pinfo->num_domains; domain++) {
+		struct power_dom_info *dom = pinfo->dom_info + domain;
+
+		scmi_power_domain_attributes_get(ph, domain, dom,
+						 pinfo->notify_state_change_cmd);
+	}
+
+	return ph->set_priv(ph, pinfo);
+}
+
+static const struct scmi_protocol scmi_power = {
+	.id = SCMI_PROTOCOL_POWER,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_power_protocol_init,
+	.ops = &power_proto_ops,
+	.events = &power_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(power, scmi_power)

linux-7.2.3/drivers/firmware/arm_scmi/protocols.h

@@ -0,0 +1,395 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * protocols common header file containing some definitions, structures
+ * and function prototypes used in all the different SCMI protocols.
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+#ifndef _SCMI_PROTOCOLS_H
+#define _SCMI_PROTOCOLS_H
+
+#include <linux/bitfield.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/hashtable.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/refcount.h>
+#include <linux/scmi_protocol.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <linux/unaligned.h>
+
+#define PROTOCOL_REV_MINOR_MASK	GENMASK(15, 0)
+#define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
+#define PROTOCOL_REV_MAJOR(x)	((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x))))
+#define PROTOCOL_REV_MINOR(x)	((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x))))
+
+#define SCMI_PROTOCOL_VENDOR_BASE	0x80
+
+#define MSG_SUPPORTS_FASTCHANNEL(x)	((x) & BIT(0))
+
+enum scmi_common_cmd {
+	PROTOCOL_VERSION = 0x0,
+	PROTOCOL_ATTRIBUTES = 0x1,
+	PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
+	NEGOTIATE_PROTOCOL_VERSION = 0x10,
+};
+
+/**
+ * struct scmi_msg_resp_prot_version - Response for a message
+ *
+ * @minor_version: Minor version of the ABI that firmware supports
+ * @major_version: Major version of the ABI that firmware supports
+ *
+ * In general, ABI version changes follow the rule that minor version increments
+ * are backward compatible. Major revision changes in ABI may not be
+ * backward compatible.
+ *
+ * Response to a generic message with message type SCMI_MSG_VERSION
+ */
+struct scmi_msg_resp_prot_version {
+	__le16 minor_version;
+	__le16 major_version;
+};
+
+/**
+ * struct scmi_msg - Message(Tx/Rx) structure
+ *
+ * @buf: Buffer pointer
+ * @len: Length of data in the Buffer
+ */
+struct scmi_msg {
+	void *buf;
+	size_t len;
+};
+
+/**
+ * struct scmi_msg_hdr - Message(Tx/Rx) header
+ *
+ * @id: The identifier of the message being sent
+ * @protocol_id: The identifier of the protocol used to send @id message
+ * @type: The SCMI type for this message
+ * @seq: The token to identify the message. When a message returns, the
+ *	platform returns the whole message header unmodified including the
+ *	token
+ * @status: Status of the transfer once it's complete
+ * @poll_completion: Indicate if the transfer needs to be polled for
+ *	completion or interrupt mode is used
+ */
+struct scmi_msg_hdr {
+	u8 id;
+	u8 protocol_id;
+	u8 type;
+	u16 seq;
+	u32 status;
+	bool poll_completion;
+};
+
+/**
+ * struct scmi_xfer - Structure representing a message flow
+ *
+ * @transfer_id: Unique ID for debug & profiling purpose
+ * @hdr: Transmit message header
+ * @tx: Transmit message
+ * @rx: Receive message, the buffer should be pre-allocated to store
+ *	message. If request-ACK protocol is used, we can reuse the same
+ *	buffer for the rx path as we use for the tx path.
+ * @done: command message transmit completion event
+ * @async_done: pointer to delayed response message received event completion
+ * @pending: True for xfers added to @pending_xfers hashtable
+ * @node: An hlist_node reference used to store this xfer, alternatively, on
+ *	  the free list @free_xfers or in the @pending_xfers hashtable
+ * @users: A refcount to track the active users for this xfer.
+ *	   This is meant to protect against the possibility that, when a command
+ *	   transaction times out concurrently with the reception of a valid
+ *	   response message, the xfer could be finally put on the TX path, and
+ *	   so vanish, while on the RX path scmi_rx_callback() is still
+ *	   processing it: in such a case this refcounting will ensure that, even
+ *	   though the timed-out transaction will anyway cause the command
+ *	   request to be reported as failed by time-out, the underlying xfer
+ *	   cannot be discarded and possibly reused until the last one user on
+ *	   the RX path has released it.
+ * @busy: An atomic flag to ensure exclusive write access to this xfer
+ * @state: The current state of this transfer, with states transitions deemed
+ *	   valid being:
+ *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ]
+ *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK
+ *	      (Missing synchronous response is assumed OK and ignored)
+ * @flags: Optional flags associated to this xfer.
+ * @lock: A spinlock to protect state and busy fields.
+ * @priv: A pointer for transport private usage.
+ */
+struct scmi_xfer {
+	int transfer_id;
+	struct scmi_msg_hdr hdr;
+	struct scmi_msg tx;
+	struct scmi_msg rx;
+	struct completion done;
+	struct completion *async_done;
+	bool pending;
+	struct hlist_node node;
+	refcount_t users;
+#define SCMI_XFER_FREE		0
+#define SCMI_XFER_BUSY		1
+	atomic_t busy;
+#define SCMI_XFER_SENT_OK	0
+#define SCMI_XFER_RESP_OK	1
+#define SCMI_XFER_DRESP_OK	2
+	int state;
+#define SCMI_XFER_FLAG_IS_RAW	BIT(0)
+#define SCMI_XFER_IS_RAW(x)	((x)->flags & SCMI_XFER_FLAG_IS_RAW)
+#define SCMI_XFER_FLAG_CHAN_SET	BIT(1)
+#define SCMI_XFER_IS_CHAN_SET(x)	\
+	((x)->flags & SCMI_XFER_FLAG_CHAN_SET)
+	int flags;
+	/* A lock to protect state and busy fields */
+	spinlock_t lock;
+	void *priv;
+};
+
+struct scmi_xfer_ops;
+struct scmi_proto_helpers_ops;
+
+/**
+ * struct scmi_protocol_handle  - Reference to an initialized protocol instance
+ *
+ * @dev: A reference to the associated SCMI instance device (handle->dev).
+ * @version: The protocol version currently effectively in use by this
+ *	     initialized instance of the protocol as determined at the end of
+ *	     any possibly needed negotiations performed by the core.
+ * @xops: A reference to a struct holding refs to the core xfer operations that
+ *	  can be used by the protocol implementation to generate SCMI messages.
+ * @set_priv: A method to set protocol private data for this instance.
+ * @get_priv: A method to get protocol private data previously set.
+ *
+ * This structure represents a protocol initialized against specific SCMI
+ * instance and it will be used as follows:
+ * - as a parameter fed from the core to the protocol initialization code so
+ *   that it can access the core xfer operations to build and generate SCMI
+ *   messages exclusively for the specific underlying protocol instance.
+ * - as an opaque handle fed by an SCMI driver user when it tries to access
+ *   this protocol through its own protocol operations.
+ *   In this case this handle will be returned as an opaque object together
+ *   with the related protocol operations when the SCMI driver tries to access
+ *   the protocol.
+ */
+struct scmi_protocol_handle {
+	struct device *dev;
+	unsigned int version;
+	const struct scmi_xfer_ops *xops;
+	const struct scmi_proto_helpers_ops *hops;
+	int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv);
+	void *(*get_priv)(const struct scmi_protocol_handle *ph);
+};
+
+/**
+ * struct scmi_iterator_state  - Iterator current state descriptor
+ * @desc_index: Starting index for the current multi-part request.
+ * @num_returned: Number of returned items in the last multi-part reply.
+ * @num_remaining: Number of remaining items in the multi-part message.
+ * @max_resources: Maximum acceptable number of items, configured by the caller
+ *		   depending on the underlying resources that it is querying.
+ * @loop_idx: The iterator loop index in the current multi-part reply.
+ * @rx_len: Size in bytes of the currently processed message; it can be used by
+ *	    the user of the iterator to verify a reply size.
+ * @priv: Optional pointer to some additional state-related private data setup
+ *	  by the caller during the iterations.
+ */
+struct scmi_iterator_state {
+	unsigned int desc_index;
+	unsigned int num_returned;
+	unsigned int num_remaining;
+	unsigned int max_resources;
+	unsigned int loop_idx;
+	size_t rx_len;
+	void *priv;
+};
+
+/**
+ * struct scmi_iterator_ops  - Custom iterator operations
+ * @prepare_message: An operation to provide the custom logic to fill in the
+ *		     SCMI command request pointed by @message. @desc_index is
+ *		     a reference to the next index to use in the multi-part
+ *		     request.
+ * @update_state: An operation to provide the custom logic to update the
+ *		  iterator state from the actual message response.
+ * @process_response: An operation to provide the custom logic needed to process
+ *		      each chunk of the multi-part message.
+ */
+struct scmi_iterator_ops {
+	void (*prepare_message)(void *message, unsigned int desc_index,
+				const void *priv);
+	int (*update_state)(struct scmi_iterator_state *st,
+			    const void *response, void *priv);
+	int (*process_response)(const struct scmi_protocol_handle *ph,
+				const void *response,
+				struct scmi_iterator_state *st, void *priv);
+};
+
+struct scmi_fc_db_info {
+	int width;
+	u64 set;
+	u64 mask;
+	void __iomem *addr;
+};
+
+struct scmi_fc_info {
+	void __iomem *set_addr;
+	void __iomem *get_addr;
+	struct scmi_fc_db_info *set_db;
+	u32 rate_limit;
+};
+
+/**
+ * struct scmi_proto_helpers_ops  - References to common protocol helpers
+ * @extended_name_get: A common helper function to retrieve extended naming
+ *		       for the specified resource using the specified command.
+ *		       Result is returned as a NULL terminated string in the
+ *		       pre-allocated area pointed to by @name with maximum
+ *		       capacity of @len bytes.
+ * @iter_response_init: A common helper to initialize a generic iterator to
+ *			parse multi-message responses: when run the iterator
+ *			will take care to send the initial command request as
+ *			specified by @msg_id and @tx_size and then to parse the
+ *			multi-part responses using the custom operations
+ *			provided in @ops.
+ * @iter_response_run: A common helper to trigger the run of a previously
+ *		       initialized iterator. Note that unbound iterators are
+ *		       automatically cleaned up.
+ * @iter_response_run_bound: A common helper to trigger the run of a previously
+ *			     initialized iterator, but only within the
+ *			     specified, optional, @start and @end resource
+ *			     indexes. Note that these bound-iterators need
+ *			     explicit cleanup via @iter_response_bound_cleanup.
+ * @iter_response_bound_cleanup: A common helper to finally release the iterator
+ *				 for bound iterators.
+ * @protocol_msg_check: A common helper to check is a specific protocol message
+ *			is supported.
+ * @fastchannel_init: A common helper used to initialize FC descriptors by
+ *		      gathering FC descriptions from the SCMI platform server.
+ * @fastchannel_db_ring: A common helper to ring a FC doorbell.
+ * @get_max_msg_size: A common helper to get the maximum message size.
+ */
+struct scmi_proto_helpers_ops {
+	int (*extended_name_get)(const struct scmi_protocol_handle *ph,
+				 u8 cmd_id, u32 res_id, u32 *flags, char *name,
+				 size_t len);
+	void *(*iter_response_init)(const struct scmi_protocol_handle *ph,
+				    struct scmi_iterator_ops *ops,
+				    unsigned int max_resources, u8 msg_id,
+				    size_t tx_size, void *priv);
+	int (*iter_response_run)(void *iter);
+	int (*iter_response_run_bound)(void *iter,
+				       unsigned int *start, unsigned int *end);
+	void (*iter_response_bound_cleanup)(void *iter);
+	int (*protocol_msg_check)(const struct scmi_protocol_handle *ph,
+				  u32 message_id, u32 *attributes);
+	void (*fastchannel_init)(const struct scmi_protocol_handle *ph,
+				 u8 describe_id, u32 message_id,
+				 u32 valid_size, u32 domain,
+				 void __iomem **p_addr,
+				 struct scmi_fc_db_info **p_db,
+				 u32 *rate_limit);
+	void (*fastchannel_db_ring)(struct scmi_fc_db_info *db);
+	int (*get_max_msg_size)(const struct scmi_protocol_handle *ph);
+};
+
+/**
+ * struct scmi_xfer_ops  - References to the core SCMI xfer operations.
+ * @xfer_get_init: Initialize one struct xfer if any xfer slot is free.
+ * @reset_rx_to_maxsz: Reset rx size to max transport size.
+ * @do_xfer: Do the SCMI transfer.
+ * @do_xfer_with_response: Do the SCMI transfer waiting for a response.
+ * @xfer_put: Free the xfer slot.
+ *
+ * Note that all this operations expect a protocol handle as first parameter;
+ * they then internally use it to infer the underlying protocol number: this
+ * way is not possible for a protocol implementation to forge messages for
+ * another protocol.
+ */
+struct scmi_xfer_ops {
+	int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id,
+			     size_t tx_size, size_t rx_size,
+			     struct scmi_xfer **p);
+	void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph,
+				  struct scmi_xfer *xfer);
+	int (*do_xfer)(const struct scmi_protocol_handle *ph,
+		       struct scmi_xfer *xfer);
+	int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,
+				     struct scmi_xfer *xfer);
+	void (*xfer_put)(const struct scmi_protocol_handle *ph,
+			 struct scmi_xfer *xfer);
+};
+
+typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *);
+
+/**
+ * struct scmi_protocol  - Protocol descriptor
+ * @id: Protocol ID.
+ * @owner: Module reference if any.
+ * @instance_init: Mandatory protocol initialization function.
+ * @instance_deinit: Optional protocol de-initialization function.
+ * @ops: Optional reference to the operations provided by the protocol and
+ *	 exposed in scmi_protocol.h.
+ * @events: An optional reference to the events supported by this protocol.
+ * @supported_version: The highest version currently supported for this
+ *		       protocol by the agent. Each protocol implementation
+ *		       in the agent is supposed to downgrade to match the
+ *		       protocol version supported by the platform.
+ * @vendor_id: A firmware vendor string for vendor protocols matching.
+ *	       Ignored when @id identifies a standard protocol, cannot be NULL
+ *	       otherwise.
+ * @sub_vendor_id: A firmware sub_vendor string for vendor protocols matching.
+ *		   Ignored if NULL or when @id identifies a standard protocol.
+ * @impl_ver: A firmware implementation version for vendor protocols matching.
+ *	      Ignored if zero or if @id identifies a standard protocol.
+ *
+ * Note that vendor protocols matching at load time is performed by attempting
+ * the closest match first against the tuple (vendor, sub_vendor, impl_ver)
+ */
+struct scmi_protocol {
+	const u8				id;
+	struct module				*owner;
+	const scmi_prot_init_ph_fn_t		instance_init;
+	const scmi_prot_init_ph_fn_t		instance_deinit;
+	const void				*ops;
+	const struct scmi_protocol_events	*events;
+	unsigned int				supported_version;
+	char					*vendor_id;
+	char					*sub_vendor_id;
+	u32					impl_ver;
+};
+
+#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto)	\
+static const struct scmi_protocol *__this_proto = &(proto);	\
+								\
+int __init scmi_##name##_register(void)				\
+{								\
+	return scmi_protocol_register(__this_proto);		\
+}								\
+								\
+void __exit scmi_##name##_unregister(void)			\
+{								\
+	scmi_protocol_unregister(__this_proto);			\
+}
+
+#define DECLARE_SCMI_REGISTER_UNREGISTER(func)		\
+	int __init scmi_##func##_register(void);	\
+	void __exit scmi_##func##_unregister(void)
+DECLARE_SCMI_REGISTER_UNREGISTER(base);
+DECLARE_SCMI_REGISTER_UNREGISTER(clock);
+DECLARE_SCMI_REGISTER_UNREGISTER(perf);
+DECLARE_SCMI_REGISTER_UNREGISTER(pinctrl);
+DECLARE_SCMI_REGISTER_UNREGISTER(power);
+DECLARE_SCMI_REGISTER_UNREGISTER(reset);
+DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
+DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
+DECLARE_SCMI_REGISTER_UNREGISTER(system);
+DECLARE_SCMI_REGISTER_UNREGISTER(powercap);
+
+#endif /* _SCMI_PROTOCOLS_H */

linux-7.2.3/drivers/firmware/arm_scmi/quirks.c

@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Protocol Quirks
+ *
+ * Copyright (C) 2025 ARM Ltd.
+ */
+
+/**
+ * DOC: Theory of operation
+ *
+ * A framework to define SCMI quirks and their activation conditions based on
+ * existing static_keys kernel facilities.
+ *
+ * Quirks are named and their activation conditions defined using the macro
+ * DEFINE_SCMI_QUIRK() in this file.
+ *
+ * After a quirk is defined, a corresponding entry must also be added to the
+ * global @scmi_quirks_table in this file using __DECLARE_SCMI_QUIRK_ENTRY().
+ *
+ * Additionally a corresponding quirk declaration must be added also to the
+ * quirk.h file using DECLARE_SCMI_QUIRK().
+ *
+ * The needed quirk code-snippet itself will be defined local to the SCMI code
+ * that is meant to fix and will be associated to the previously defined quirk
+ * and related activation conditions using the macro SCMI_QUIRK().
+ *
+ * At runtime, during the SCMI stack probe sequence, once the SCMI Server had
+ * advertised the running platform Vendor, SubVendor and Implementation Version
+ * data, all the defined quirks matching the activation conditions will be
+ * enabled.
+ *
+ * Example
+ *
+ * quirk.c
+ * -------
+ *  DEFINE_SCMI_QUIRK(fix_me, "vendor", "subvend", "0x12000-0x30000",
+ *		      "someone,plat_A", "another,plat_b", "vend,sku");
+ *
+ *  static struct scmi_quirk *scmi_quirks_table[] = {
+ *	...
+ *	__DECLARE_SCMI_QUIRK_ENTRY(fix_me),
+ *	NULL
+ *  };
+ *
+ * quirk.h
+ * -------
+ *  DECLARE_SCMI_QUIRK(fix_me);
+ *
+ * <somewhere_in_the_scmi_stack.c>
+ * ------------------------------
+ *
+ *  #define QUIRK_CODE_SNIPPET_FIX_ME()		\
+ *  ({						\
+ *	if (p->condition)			\
+ *		a_ptr->calculated_val = 123;	\
+ *  })
+ *
+ *
+ *  int some_function_to_fix(int param, struct something *p)
+ *  {
+ *	struct some_strut *a_ptr;
+ *
+ *	a_ptr = some_load_func(p);
+ *	SCMI_QUIRK(fix_me, QUIRK_CODE_SNIPPET_FIX_ME);
+ *	some_more_func(a_ptr);
+ *	...
+ *
+ *	return 0;
+ *  }
+ *
+ */
+
+#include <linux/ctype.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/hashtable.h>
+#include <linux/kstrtox.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/static_key.h>
+#include <linux/string.h>
+#include <linux/stringhash.h>
+#include <linux/types.h>
+
+#include "quirks.h"
+
+#define SCMI_QUIRKS_HT_SZ	4
+
+struct scmi_quirk {
+	bool enabled;
+	const char *name;
+	const char *vendor;
+	const char *sub_vendor_id;
+	const char *impl_ver_range;
+	u32 start_range;
+	u32 end_range;
+	struct static_key_false *key;
+	struct hlist_node hash;
+	unsigned int hkey;
+	const char *const compats[];
+};
+
+#define __DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ...)	\
+	static struct scmi_quirk scmi_quirk_entry_ ## _qn = {		\
+		.name = __stringify(quirk_ ## _qn),			\
+		.vendor = _ven,						\
+		.sub_vendor_id = _sub,					\
+		.impl_ver_range = _impl,				\
+		.key = &(scmi_quirk_ ## _qn),				\
+		.compats = { __VA_ARGS__ __VA_OPT__(,) NULL },		\
+	}
+
+#define __DECLARE_SCMI_QUIRK_ENTRY(_qn)		(&(scmi_quirk_entry_ ## _qn))
+
+/*
+ * Define a quirk by name and provide the matching tokens where:
+ *
+ *  _qn: A string which will be used to build the quirk and the global
+ *	 static_key names.
+ *  _ven : SCMI Vendor ID string match, NULL means any.
+ *  _sub : SCMI SubVendor ID string match, NULL means any.
+ *  _impl : SCMI Implementation Version string match, NULL means any.
+ *          This string can be used to express version ranges which will be
+ *          interpreted as follows:
+ *
+ *			NULL		[0, 0xFFFFFFFF]
+ *			"X"		[X, X]
+ *			"X-"		[X, 0xFFFFFFFF]
+ *			"-X"		[0, X]
+ *			"X-Y"		[X, Y]
+ *
+ *          with X <= Y and <v> in [X, Y] meaning X <= <v> <= Y
+ *
+ *  ... : An optional variadic macros argument used to provide a comma-separated
+ *	  list of compatible strings matches; when no variadic argument is
+ *	  provided, ANY compatible will match this quirk.
+ *
+ *  This implicitly define also a properly named global static-key that
+ *  will be used to dynamically enable the quirk at initialization time.
+ *
+ *  Note that it is possible to associate multiple quirks to the same
+ *  matching pattern, if your firmware quality is really astounding :P
+ *
+ * Example:
+ *
+ * Compatibles list NOT provided, so ANY compatible will match:
+ *
+ *  DEFINE_SCMI_QUIRK(my_new_issue, "Vend", "SVend", "0x12000-0x30000");
+ *
+ *
+ * A few compatibles provided to match against:
+ *
+ *  DEFINE_SCMI_QUIRK(my_new_issue, "Vend", "SVend", "0x12000-0x30000",
+ *		      "xvend,plat_a", "xvend,plat_b", "xvend,sku_name");
+ */
+#define DEFINE_SCMI_QUIRK(_qn, _ven, _sub, _impl, ...)			\
+	DEFINE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn);			\
+	__DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ##__VA_ARGS__)
+
+/*
+ * Same as DEFINE_SCMI_QUIRK but EXPORTED: this is meant to address quirks
+ * that possibly reside in code that is included in loadable kernel modules
+ * that needs to be able to access the global static keys at runtime to
+ * determine if enabled or not. (see SCMI_QUIRK to understand usage)
+ */
+#define DEFINE_SCMI_QUIRK_EXPORTED(_qn, _ven, _sub, _impl, ...)		\
+	DEFINE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn);			\
+	EXPORT_SYMBOL_GPL(scmi_quirk_ ## _qn);				\
+	__DEFINE_SCMI_QUIRK_ENTRY(_qn, _ven, _sub, _impl, ##__VA_ARGS__)
+
+/* Global Quirks Definitions */
+DEFINE_SCMI_QUIRK(clock_rates_triplet_out_of_spec, NULL, NULL, NULL);
+DEFINE_SCMI_QUIRK(perf_level_get_fc_force, "Qualcomm", NULL, "0x20000-");
+
+/*
+ * Quirks Pointers Array
+ *
+ * This is filled at compile-time with the list of pointers to all the currently
+ * defined quirks descriptors.
+ */
+static struct scmi_quirk *scmi_quirks_table[] = {
+	__DECLARE_SCMI_QUIRK_ENTRY(clock_rates_triplet_out_of_spec),
+	__DECLARE_SCMI_QUIRK_ENTRY(perf_level_get_fc_force),
+	NULL
+};
+
+/*
+ * Quirks HashTable
+ *
+ * A run-time populated hashtable containing all the defined quirks descriptors
+ * hashed by matching pattern.
+ */
+static DEFINE_READ_MOSTLY_HASHTABLE(scmi_quirks_ht, SCMI_QUIRKS_HT_SZ);
+
+static unsigned int scmi_quirk_signature(const char *vend, const char *sub_vend)
+{
+	char *signature, *p;
+	unsigned int hash32;
+	unsigned long hash = 0;
+
+	/* vendor_id/sub_vendor_id guaranteed <= SCMI_SHORT_NAME_MAX_SIZE */
+	signature = kasprintf(GFP_KERNEL, "|%s|%s|", vend ?: "", sub_vend ?: "");
+	if (!signature)
+		return 0;
+
+	pr_debug("SCMI Quirk Signature >>>%s<<<\n", signature);
+
+	p = signature;
+	while (*p)
+		hash = partial_name_hash(tolower(*p++), hash);
+	hash32 = end_name_hash(hash);
+
+	kfree(signature);
+
+	return hash32;
+}
+
+static int scmi_quirk_range_parse(struct scmi_quirk *quirk)
+{
+	const char *last, *first __free(kfree) = NULL;
+	int ret = 0;
+	size_t len;
+	char *sep;
+
+	quirk->start_range = 0;
+	quirk->end_range = 0xFFFFFFFF;
+	len = quirk->impl_ver_range ? strlen(quirk->impl_ver_range) : 0;
+	if (!len)
+		return 0;
+
+	first = kmemdup(quirk->impl_ver_range, len + 1, GFP_KERNEL);
+	if (!first)
+		return -ENOMEM;
+
+	last = first + len - 1;
+	sep = strchr(first, '-');
+	if (sep)
+		*sep = '\0';
+
+	if (sep != first) /* X OR X- OR X-y */ {
+		ret = kstrtouint(first, 0, &quirk->start_range);
+		if (ret)
+			return ret;
+	}
+
+	if (!sep)
+		quirk->end_range = quirk->start_range;
+	else if (sep != last) /* -X OR x-Y */
+		ret = kstrtouint(sep + 1, 0, &quirk->end_range);
+
+	if (quirk->start_range > quirk->end_range)
+		return -EINVAL;
+
+	return ret;
+}
+
+void scmi_quirks_initialize(void)
+{
+	struct scmi_quirk *quirk;
+
+	for (unsigned int i = 0; (quirk = scmi_quirks_table[i]); i++) {
+		int ret;
+
+		ret = scmi_quirk_range_parse(quirk);
+		if (ret) {
+			pr_err("SCMI skip QUIRK [%s] - BAD RANGE - |%s|\n",
+			       quirk->name, quirk->impl_ver_range);
+			continue;
+		}
+		quirk->hkey = scmi_quirk_signature(quirk->vendor,
+						   quirk->sub_vendor_id);
+
+		hash_add(scmi_quirks_ht, &quirk->hash, quirk->hkey);
+
+		pr_debug("Registered SCMI QUIRK [%s] -- %p - Key [0x%08X] - %s/%s/[0x%08X-0x%08X]\n",
+			 quirk->name, quirk, quirk->hkey,
+			 quirk->vendor, quirk->sub_vendor_id,
+			 quirk->start_range, quirk->end_range);
+	}
+
+	pr_debug("SCMI Quirks initialized\n");
+}
+
+void scmi_quirks_enable(struct device *dev, const char *vend,
+			const char *subv, const u32 impl)
+{
+	for (int i = 3; i >= 0; i--) {
+		struct scmi_quirk *quirk;
+		unsigned int hkey;
+
+		hkey = scmi_quirk_signature(i > 1 ? vend : NULL,
+					    i > 2 ? subv : NULL);
+
+		/*
+		 * Note that there could be multiple matches so we
+		 * will enable multiple quirk part of a hash collision
+		 * domain...BUT we cannot assume that ALL quirks on the
+		 * same collision domain are a full match.
+		 */
+		hash_for_each_possible(scmi_quirks_ht, quirk, hash, hkey) {
+			if (quirk->enabled || quirk->hkey != hkey ||
+			    impl < quirk->start_range ||
+			    impl > quirk->end_range)
+				continue;
+
+			if (quirk->compats[0] &&
+			    !of_machine_compatible_match(quirk->compats))
+				continue;
+
+			dev_info(dev, "Enabling SCMI Quirk [%s]\n",
+				 quirk->name);
+
+			dev_dbg(dev,
+				"Quirk matched on: %s/%s/%s/[0x%08X-0x%08X]\n",
+				quirk->compats[0], quirk->vendor,
+				quirk->sub_vendor_id,
+				quirk->start_range, quirk->end_range);
+
+			static_branch_enable(quirk->key);
+			quirk->enabled = true;
+		}
+	}
+}

linux-7.2.3/drivers/firmware/arm_scmi/quirks.h

@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol Quirks
+ *
+ * Copyright (C) 2025 ARM Ltd.
+ */
+#ifndef _SCMI_QUIRKS_H
+#define _SCMI_QUIRKS_H
+
+#include <linux/static_key.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_ARM_SCMI_QUIRKS
+
+#define DECLARE_SCMI_QUIRK(_qn)						\
+	DECLARE_STATIC_KEY_FALSE(scmi_quirk_ ## _qn)
+
+/*
+ * A helper to associate the actual code snippet to use as a quirk
+ * named as _qn.
+ */
+#define SCMI_QUIRK(_qn, _blk)						\
+	({								\
+		if (static_branch_unlikely(&(scmi_quirk_ ## _qn)))	\
+			(_blk);						\
+	})
+
+void scmi_quirks_initialize(void);
+void scmi_quirks_enable(struct device *dev, const char *vend,
+			const char *subv, const u32 impl);
+
+#else
+
+#define DECLARE_SCMI_QUIRK(_qn)
+/* Force quirks compilation even when SCMI Quirks are disabled */
+#define SCMI_QUIRK(_qn, _blk)						\
+	({								\
+		if (0)							\
+			(_blk);						\
+	})
+
+static inline void scmi_quirks_initialize(void) { }
+static inline void scmi_quirks_enable(struct device *dev, const char *vend,
+				      const char *sub_vend, const u32 impl) { }
+
+#endif /* CONFIG_ARM_SCMI_QUIRKS */
+
+/* Quirk delarations */
+DECLARE_SCMI_QUIRK(clock_rates_triplet_out_of_spec);
+DECLARE_SCMI_QUIRK(perf_level_get_fc_force);
+
+#endif /* _SCMI_QUIRKS_H */

linux-7.2.3/drivers/firmware/arm_scmi/raw_mode.h

@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * System Control and Management Interface (SCMI) Message Protocol
+ * Raw mode support header.
+ *
+ * Copyright (C) 2022 ARM Ltd.
+ */
+#ifndef _SCMI_RAW_MODE_H
+#define _SCMI_RAW_MODE_H
+
+#include "common.h"
+
+enum {
+	SCMI_RAW_REPLY_QUEUE,
+	SCMI_RAW_NOTIF_QUEUE,
+	SCMI_RAW_ERRS_QUEUE,
+	SCMI_RAW_MAX_QUEUE
+};
+
+void *scmi_raw_mode_init(const struct scmi_handle *handle,
+			 struct dentry *top_dentry, int instance_id,
+			 u8 *channels, int num_chans,
+			 const struct scmi_desc *desc, int tx_max_msg);
+void scmi_raw_mode_cleanup(void *raw);
+
+void scmi_raw_message_report(void *raw, struct scmi_xfer *xfer,
+			     unsigned int idx, unsigned int chan_id);
+void scmi_raw_error_report(void *raw, struct scmi_chan_info *cinfo,
+			   u32 msg_hdr, void *priv);
+
+#endif /* _SCMI_RAW_MODE_H */

linux-7.2.3/drivers/firmware/arm_scmi/reset.c

@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Reset Protocol
+ *
+ * Copyright (C) 2019-2022 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
+
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+
+#include "protocols.h"
+#include "notify.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x30001
+
+enum scmi_reset_protocol_cmd {
+	RESET_DOMAIN_ATTRIBUTES = 0x3,
+	RESET = 0x4,
+	RESET_NOTIFY = 0x5,
+	RESET_DOMAIN_NAME_GET = 0x6,
+};
+
+#define NUM_RESET_DOMAIN_MASK	0xffff
+#define RESET_NOTIFY_ENABLE	BIT(0)
+
+struct scmi_msg_resp_reset_domain_attributes {
+	__le32 attributes;
+#define SUPPORTS_ASYNC_RESET(x)		((x) & BIT(31))
+#define SUPPORTS_NOTIFY_RESET(x)	((x) & BIT(30))
+#define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(29))
+	__le32 latency;
+	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+};
+
+struct scmi_msg_reset_domain_reset {
+	__le32 domain_id;
+	__le32 flags;
+#define AUTONOMOUS_RESET	BIT(0)
+#define EXPLICIT_RESET_ASSERT	BIT(1)
+#define ASYNCHRONOUS_RESET	BIT(2)
+	__le32 reset_state;
+#define ARCH_COLD_RESET		0
+};
+
+struct scmi_msg_reset_notify {
+	__le32 id;
+	__le32 event_control;
+#define RESET_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_reset_issued_notify_payld {
+	__le32 agent_id;
+	__le32 domain_id;
+	__le32 reset_state;
+};
+
+struct reset_dom_info {
+	bool async_reset;
+	bool reset_notify;
+	u32 latency_us;
+	char name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_reset_info {
+	int num_domains;
+	bool notify_reset_cmd;
+	struct reset_dom_info *dom_info;
+};
+
+static int scmi_reset_attributes_get(const struct scmi_protocol_handle *ph,
+				     struct scmi_reset_info *pi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	u32 attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(attr), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		attr = get_unaligned_le32(t->rx.buf);
+		pi->num_domains = attr & NUM_RESET_DOMAIN_MASK;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	if (!ret)
+		if (!ph->hops->protocol_msg_check(ph, RESET_NOTIFY, NULL))
+			pi->notify_reset_cmd = true;
+
+	return ret;
+}
+
+static struct reset_dom_info *
+scmi_reset_domain_lookup(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	struct scmi_reset_info *pi = ph->get_priv(ph);
+
+	if (domain >= pi->num_domains)
+		return ERR_PTR(-EINVAL);
+
+	return pi->dom_info + domain;
+}
+
+static int
+scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph,
+				 struct scmi_reset_info *pinfo, u32 domain)
+{
+	int ret;
+	u32 attributes;
+	struct scmi_xfer *t;
+	struct scmi_msg_resp_reset_domain_attributes *attr;
+	struct reset_dom_info *dom_info = pinfo->dom_info + domain;
+
+	ret = ph->xops->xfer_get_init(ph, RESET_DOMAIN_ATTRIBUTES,
+				      sizeof(domain), sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(domain, t->tx.buf);
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		attributes = le32_to_cpu(attr->attributes);
+
+		dom_info->async_reset = SUPPORTS_ASYNC_RESET(attributes);
+		if (pinfo->notify_reset_cmd)
+			dom_info->reset_notify =
+				SUPPORTS_NOTIFY_RESET(attributes);
+		dom_info->latency_us = le32_to_cpu(attr->latency);
+		if (dom_info->latency_us == U32_MAX)
+			dom_info->latency_us = 0;
+		strscpy(dom_info->name, attr->name, SCMI_SHORT_NAME_MAX_SIZE);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	/*
+	 * If supported overwrite short name with the extended one;
+	 * on error just carry on and use already provided short name.
+	 */
+	if (!ret && PROTOCOL_REV_MAJOR(ph->version) >= 0x3 &&
+	    SUPPORTS_EXTENDED_NAMES(attributes))
+		ph->hops->extended_name_get(ph, RESET_DOMAIN_NAME_GET, domain,
+					    NULL, dom_info->name,
+					    SCMI_MAX_STR_SIZE);
+
+	return ret;
+}
+
+static int scmi_reset_num_domains_get(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_reset_info *pi = ph->get_priv(ph);
+
+	return pi->num_domains;
+}
+
+static const char *
+scmi_reset_name_get(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	struct reset_dom_info *dom_info;
+
+	dom_info = scmi_reset_domain_lookup(ph, domain);
+	if (IS_ERR(dom_info))
+		return "unknown";
+
+	return dom_info->name;
+}
+
+static int scmi_reset_latency_get(const struct scmi_protocol_handle *ph,
+				  u32 domain)
+{
+	struct reset_dom_info *dom_info;
+
+	dom_info = scmi_reset_domain_lookup(ph, domain);
+	if (IS_ERR(dom_info))
+		return PTR_ERR(dom_info);
+
+	return dom_info->latency_us;
+}
+
+static int scmi_domain_reset(const struct scmi_protocol_handle *ph, u32 domain,
+			     u32 flags, u32 state)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_reset_domain_reset *dom;
+	struct reset_dom_info *dom_info;
+
+	dom_info = scmi_reset_domain_lookup(ph, domain);
+	if (IS_ERR(dom_info))
+		return PTR_ERR(dom_info);
+
+	if (dom_info->async_reset && flags & AUTONOMOUS_RESET)
+		flags |= ASYNCHRONOUS_RESET;
+
+	ret = ph->xops->xfer_get_init(ph, RESET, sizeof(*dom), 0, &t);
+	if (ret)
+		return ret;
+
+	dom = t->tx.buf;
+	dom->domain_id = cpu_to_le32(domain);
+	dom->flags = cpu_to_le32(flags);
+	dom->reset_state = cpu_to_le32(state);
+
+	if (flags & ASYNCHRONOUS_RESET)
+		ret = ph->xops->do_xfer_with_response(ph, t);
+	else
+		ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_reset_domain_reset(const struct scmi_protocol_handle *ph,
+				   u32 domain)
+{
+	return scmi_domain_reset(ph, domain, AUTONOMOUS_RESET,
+				 ARCH_COLD_RESET);
+}
+
+static int
+scmi_reset_domain_assert(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	return scmi_domain_reset(ph, domain, EXPLICIT_RESET_ASSERT,
+				 ARCH_COLD_RESET);
+}
+
+static int
+scmi_reset_domain_deassert(const struct scmi_protocol_handle *ph, u32 domain)
+{
+	return scmi_domain_reset(ph, domain, 0, ARCH_COLD_RESET);
+}
+
+static const struct scmi_reset_proto_ops reset_proto_ops = {
+	.num_domains_get = scmi_reset_num_domains_get,
+	.name_get = scmi_reset_name_get,
+	.latency_get = scmi_reset_latency_get,
+	.reset = scmi_reset_domain_reset,
+	.assert = scmi_reset_domain_assert,
+	.deassert = scmi_reset_domain_deassert,
+};
+
+static bool scmi_reset_notify_supported(const struct scmi_protocol_handle *ph,
+					u8 evt_id, u32 src_id)
+{
+	struct reset_dom_info *dom_info;
+
+	if (evt_id != SCMI_EVENT_RESET_ISSUED)
+		return false;
+
+	dom_info = scmi_reset_domain_lookup(ph, src_id);
+	if (IS_ERR(dom_info))
+		return false;
+
+	return dom_info->reset_notify;
+}
+
+static int scmi_reset_notify(const struct scmi_protocol_handle *ph,
+			     u32 domain_id, bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? RESET_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_reset_notify *cfg;
+
+	ret = ph->xops->xfer_get_init(ph, RESET_NOTIFY, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(domain_id);
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_reset_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					 u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_reset_notify(ph, src_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *
+scmi_reset_fill_custom_report(const struct scmi_protocol_handle *ph,
+			      u8 evt_id, ktime_t timestamp,
+			      const void *payld, size_t payld_sz,
+			      void *report, u32 *src_id)
+{
+	const struct scmi_reset_issued_notify_payld *p = payld;
+	struct scmi_reset_issued_report *r = report;
+
+	if (evt_id != SCMI_EVENT_RESET_ISSUED || sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->domain_id = le32_to_cpu(p->domain_id);
+	r->reset_state = le32_to_cpu(p->reset_state);
+	*src_id = r->domain_id;
+
+	return r;
+}
+
+static int scmi_reset_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_reset_info *pinfo = ph->get_priv(ph);
+
+	if (!pinfo)
+		return -EINVAL;
+
+	return pinfo->num_domains;
+}
+
+static const struct scmi_event reset_events[] = {
+	{
+		.id = SCMI_EVENT_RESET_ISSUED,
+		.max_payld_sz = sizeof(struct scmi_reset_issued_notify_payld),
+		.max_report_sz = sizeof(struct scmi_reset_issued_report),
+	},
+};
+
+static const struct scmi_event_ops reset_event_ops = {
+	.is_notify_supported = scmi_reset_notify_supported,
+	.get_num_sources = scmi_reset_get_num_sources,
+	.set_notify_enabled = scmi_reset_set_notify_enabled,
+	.fill_custom_report = scmi_reset_fill_custom_report,
+};
+
+static const struct scmi_protocol_events reset_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &reset_event_ops,
+	.evts = reset_events,
+	.num_events = ARRAY_SIZE(reset_events),
+};
+
+static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int domain, ret;
+	struct scmi_reset_info *pinfo;
+
+	dev_dbg(ph->dev, "Reset Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	ret = scmi_reset_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
+
+	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
+				       sizeof(*pinfo->dom_info), GFP_KERNEL);
+	if (!pinfo->dom_info)
+		return -ENOMEM;
+
+	for (domain = 0; domain < pinfo->num_domains; domain++)
+		scmi_reset_domain_attributes_get(ph, pinfo, domain);
+
+	return ph->set_priv(ph, pinfo);
+}
+
+static const struct scmi_protocol scmi_reset = {
+	.id = SCMI_PROTOCOL_RESET,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_reset_protocol_init,
+	.ops = &reset_proto_ops,
+	.events = &reset_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(reset, scmi_reset)

linux-7.2.3/drivers/firmware/arm_scmi/scmi_power_control.c

@@ -0,0 +1,393 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SCMI Generic SystemPower Control driver.
+ *
+ * Copyright (C) 2020-2022 ARM Ltd.
+ */
+/*
+ * In order to handle platform originated SCMI SystemPower requests (like
+ * shutdowns or cold/warm resets) we register an SCMI Notification notifier
+ * block to react when such SCMI SystemPower events are emitted by platform.
+ *
+ * Once such a notification is received we act accordingly to perform the
+ * required system transition depending on the kind of request.
+ *
+ * Graceful requests are routed to userspace through the same API methods
+ * (orderly_poweroff/reboot()) used by ACPI when handling ACPI Shutdown bus
+ * events.
+ *
+ * Direct forceful requests are not supported since are not meant to be sent
+ * by the SCMI platform to an OSPM like Linux.
+ *
+ * Additionally, graceful request notifications can carry an optional timeout
+ * field stating the maximum amount of time allowed by the platform for
+ * completion after which they are converted to forceful ones: the assumption
+ * here is that even graceful requests can be upper-bound by a maximum final
+ * timeout strictly enforced by the platform itself which can ultimately cut
+ * the power off at will anytime; in order to avoid such extreme scenario, we
+ * track progress of graceful requests through the means of a reboot notifier
+ * converting timed-out graceful requests to forceful ones, so at least we
+ * try to perform a clean sync and shutdown/restart before the power is cut.
+ *
+ * Given the peculiar nature of SCMI SystemPower protocol, that is being in
+ * charge of triggering system wide shutdown/reboot events, there should be
+ * only one SCMI platform actively emitting SystemPower events.
+ * For this reason the SCMI core takes care to enforce the creation of one
+ * single unique device associated to the SCMI System Power protocol; no matter
+ * how many SCMI platforms are defined on the system, only one can be designated
+ * to support System Power: as a consequence this driver will never be probed
+ * more than once.
+ *
+ * For similar reasons as soon as the first valid SystemPower is received by
+ * this driver and the shutdown/reboot is started, any further notification
+ * possibly emitted by the platform will be ignored.
+ */
+
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/printk.h>
+#include <linux/reboot.h>
+#include <linux/scmi_protocol.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/time64.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#ifndef MODULE
+#include <linux/fs.h>
+#endif
+
+enum scmi_syspower_state {
+	SCMI_SYSPOWER_IDLE,
+	SCMI_SYSPOWER_IN_PROGRESS,
+	SCMI_SYSPOWER_REBOOTING
+};
+
+/**
+ * struct scmi_syspower_conf  -  Common configuration
+ *
+ * @dev: A reference device
+ * @state: Current SystemPower state
+ * @state_mtx: @state related mutex
+ * @required_transition: The requested transition as decribed in the received
+ *			 SCMI SystemPower notification
+ * @userspace_nb: The notifier_block registered against the SCMI SystemPower
+ *		  notification to start the needed userspace interactions.
+ * @reboot_nb: A notifier_block optionally used to track reboot progress
+ * @forceful_work: A worker used to trigger a forceful transition once a
+ *		   graceful has timed out.
+ * @suspend_work: A worker used to trigger system suspend
+ */
+struct scmi_syspower_conf {
+	struct device *dev;
+	enum scmi_syspower_state state;
+	/* Protect access to state */
+	struct mutex state_mtx;
+	enum scmi_system_events required_transition;
+
+	struct notifier_block userspace_nb;
+	struct notifier_block reboot_nb;
+
+	struct delayed_work forceful_work;
+	struct work_struct suspend_work;
+};
+
+#define userspace_nb_to_sconf(x)	\
+	container_of(x, struct scmi_syspower_conf, userspace_nb)
+
+#define reboot_nb_to_sconf(x)		\
+	container_of(x, struct scmi_syspower_conf, reboot_nb)
+
+#define dwork_to_sconf(x)		\
+	container_of(x, struct scmi_syspower_conf, forceful_work)
+
+/**
+ * scmi_reboot_notifier  - A reboot notifier to catch an ongoing successful
+ * system transition
+ * @nb: Reference to the related notifier block
+ * @reason: The reason for the ongoing reboot
+ * @__unused: The cmd being executed on a restart request (unused)
+ *
+ * When an ongoing system transition is detected, compatible with the one
+ * requested by SCMI, cancel the delayed work.
+ *
+ * Return: NOTIFY_OK in any case
+ */
+static int scmi_reboot_notifier(struct notifier_block *nb,
+				unsigned long reason, void *__unused)
+{
+	struct scmi_syspower_conf *sc = reboot_nb_to_sconf(nb);
+
+	mutex_lock(&sc->state_mtx);
+	switch (reason) {
+	case SYS_HALT:
+	case SYS_POWER_OFF:
+		if (sc->required_transition == SCMI_SYSTEM_SHUTDOWN)
+			sc->state = SCMI_SYSPOWER_REBOOTING;
+		break;
+	case SYS_RESTART:
+		if (sc->required_transition == SCMI_SYSTEM_COLDRESET ||
+		    sc->required_transition == SCMI_SYSTEM_WARMRESET)
+			sc->state = SCMI_SYSPOWER_REBOOTING;
+		break;
+	default:
+		break;
+	}
+
+	if (sc->state == SCMI_SYSPOWER_REBOOTING) {
+		dev_dbg(sc->dev, "Reboot in progress...cancel delayed work.\n");
+		cancel_delayed_work_sync(&sc->forceful_work);
+	}
+	mutex_unlock(&sc->state_mtx);
+
+	return NOTIFY_OK;
+}
+
+/**
+ * scmi_request_forceful_transition  - Request forceful SystemPower transition
+ * @sc: A reference to the configuration data
+ *
+ * Initiates the required SystemPower transition without involving userspace:
+ * just trigger the action at the kernel level after issuing an emergency
+ * sync. (if possible at all)
+ */
+static inline void
+scmi_request_forceful_transition(struct scmi_syspower_conf *sc)
+{
+	dev_dbg(sc->dev, "Serving forceful request:%d\n",
+		sc->required_transition);
+
+#ifndef MODULE
+	emergency_sync();
+#endif
+	switch (sc->required_transition) {
+	case SCMI_SYSTEM_SHUTDOWN:
+		kernel_power_off();
+		break;
+	case SCMI_SYSTEM_COLDRESET:
+	case SCMI_SYSTEM_WARMRESET:
+		kernel_restart(NULL);
+		break;
+	default:
+		break;
+	}
+}
+
+static void scmi_forceful_work_func(struct work_struct *work)
+{
+	struct scmi_syspower_conf *sc;
+	struct delayed_work *dwork;
+
+	if (system_state > SYSTEM_RUNNING)
+		return;
+
+	dwork = to_delayed_work(work);
+	sc = dwork_to_sconf(dwork);
+
+	dev_dbg(sc->dev, "Graceful request timed out...forcing !\n");
+	mutex_lock(&sc->state_mtx);
+	/* avoid deadlock by unregistering reboot notifier first */
+	unregister_reboot_notifier(&sc->reboot_nb);
+	if (sc->state == SCMI_SYSPOWER_IN_PROGRESS)
+		scmi_request_forceful_transition(sc);
+	mutex_unlock(&sc->state_mtx);
+}
+
+/**
+ * scmi_request_graceful_transition  - Request graceful SystemPower transition
+ * @sc: A reference to the configuration data
+ * @timeout_ms: The desired timeout to wait for the shutdown to complete before
+ *		system is forcibly shutdown.
+ *
+ * Initiates the required SystemPower transition, requesting userspace
+ * co-operation: it uses the same orderly_ methods used by ACPI Shutdown event
+ * processing.
+ *
+ * Takes care also to register a reboot notifier and to schedule a delayed work
+ * in order to detect if userspace actions are taking too long and in such a
+ * case to trigger a forceful transition.
+ */
+static void scmi_request_graceful_transition(struct scmi_syspower_conf *sc,
+					     unsigned int timeout_ms)
+{
+	unsigned int adj_timeout_ms = 0;
+
+	if (timeout_ms) {
+		int ret;
+
+		sc->reboot_nb.notifier_call = &scmi_reboot_notifier;
+		ret = register_reboot_notifier(&sc->reboot_nb);
+		if (!ret) {
+			/* Wait only up to 75% of the advertised timeout */
+			adj_timeout_ms = mult_frac(timeout_ms, 3, 4);
+			INIT_DELAYED_WORK(&sc->forceful_work,
+					  scmi_forceful_work_func);
+			schedule_delayed_work(&sc->forceful_work,
+					      msecs_to_jiffies(adj_timeout_ms));
+		} else {
+			/* Carry on best effort even without a reboot notifier */
+			dev_warn(sc->dev,
+				 "Cannot register reboot notifier !\n");
+		}
+	}
+
+	dev_dbg(sc->dev,
+		"Serving graceful req:%d (timeout_ms:%u  adj_timeout_ms:%u)\n",
+		sc->required_transition, timeout_ms, adj_timeout_ms);
+
+	switch (sc->required_transition) {
+	case SCMI_SYSTEM_SHUTDOWN:
+		/*
+		 * When triggered early at boot-time the 'orderly' call will
+		 * partially fail due to the lack of userspace itself, but
+		 * the force=true argument will start anyway a successful
+		 * forced shutdown.
+		 */
+		orderly_poweroff(true);
+		break;
+	case SCMI_SYSTEM_COLDRESET:
+	case SCMI_SYSTEM_WARMRESET:
+		orderly_reboot();
+		break;
+	case SCMI_SYSTEM_SUSPEND:
+		schedule_work(&sc->suspend_work);
+		break;
+	default:
+		break;
+	}
+}
+
+/**
+ * scmi_userspace_notifier  - Notifier callback to act on SystemPower
+ * Notifications
+ * @nb: Reference to the related notifier block
+ * @event: The SystemPower notification event id
+ * @data: The SystemPower event report
+ *
+ * This callback is in charge of decoding the received SystemPower report
+ * and act accordingly triggering a graceful or forceful system transition.
+ *
+ * Note that once a valid SCMI SystemPower event starts being served, any
+ * other following SystemPower notification received from the same SCMI
+ * instance (handle) will be ignored.
+ *
+ * Return: NOTIFY_OK once a valid SystemPower event has been successfully
+ * processed.
+ */
+static int scmi_userspace_notifier(struct notifier_block *nb,
+				   unsigned long event, void *data)
+{
+	struct scmi_system_power_state_notifier_report *er = data;
+	struct scmi_syspower_conf *sc = userspace_nb_to_sconf(nb);
+
+	if (er->system_state >= SCMI_SYSTEM_MAX ||
+	    er->system_state == SCMI_SYSTEM_POWERUP) {
+		dev_err(sc->dev, "Ignoring unsupported system_state: 0x%X\n",
+			er->system_state);
+		return NOTIFY_DONE;
+	}
+
+	if (!SCMI_SYSPOWER_IS_REQUEST_GRACEFUL(er->flags)) {
+		dev_err(sc->dev, "Ignoring forceful notification.\n");
+		return NOTIFY_DONE;
+	}
+
+	/*
+	 * Bail out if system is already shutting down or an SCMI SystemPower
+	 * requested is already being served.
+	 */
+	if (system_state > SYSTEM_RUNNING)
+		return NOTIFY_DONE;
+	mutex_lock(&sc->state_mtx);
+	if (sc->state != SCMI_SYSPOWER_IDLE) {
+		dev_dbg(sc->dev,
+			"Transition already in progress...ignore.\n");
+		mutex_unlock(&sc->state_mtx);
+		return NOTIFY_DONE;
+	}
+	sc->state = SCMI_SYSPOWER_IN_PROGRESS;
+	mutex_unlock(&sc->state_mtx);
+
+	sc->required_transition = er->system_state;
+
+	/* Leaving a trace in logs of who triggered the shutdown/reboot. */
+	dev_info(sc->dev, "Serving shutdown/reboot request: %d\n",
+		 sc->required_transition);
+
+	scmi_request_graceful_transition(sc, er->timeout);
+
+	return NOTIFY_OK;
+}
+
+static void scmi_suspend_work_func(struct work_struct *work)
+{
+	pm_suspend(PM_SUSPEND_MEM);
+}
+
+static int scmi_syspower_probe(struct scmi_device *sdev)
+{
+	int ret;
+	struct scmi_syspower_conf *sc;
+	struct scmi_handle *handle = sdev->handle;
+
+	if (!handle)
+		return -ENODEV;
+
+	ret = handle->devm_protocol_acquire(sdev, SCMI_PROTOCOL_SYSTEM);
+	if (ret)
+		return ret;
+
+	sc = devm_kzalloc(&sdev->dev, sizeof(*sc), GFP_KERNEL);
+	if (!sc)
+		return -ENOMEM;
+
+	sc->state = SCMI_SYSPOWER_IDLE;
+	mutex_init(&sc->state_mtx);
+	sc->required_transition = SCMI_SYSTEM_MAX;
+	sc->userspace_nb.notifier_call = &scmi_userspace_notifier;
+	sc->dev = &sdev->dev;
+	dev_set_drvdata(&sdev->dev, sc);
+
+	INIT_WORK(&sc->suspend_work, scmi_suspend_work_func);
+
+	return handle->notify_ops->devm_event_notifier_register(sdev,
+							   SCMI_PROTOCOL_SYSTEM,
+					 SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
+						       NULL, &sc->userspace_nb);
+}
+
+static int scmi_system_power_resume(struct device *dev)
+{
+	struct scmi_syspower_conf *sc = dev_get_drvdata(dev);
+
+	sc->state = SCMI_SYSPOWER_IDLE;
+	return 0;
+}
+
+static const struct dev_pm_ops scmi_system_power_pmops = {
+	SYSTEM_SLEEP_PM_OPS(NULL, scmi_system_power_resume)
+};
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_SYSTEM, "syspower" },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_system_power_driver = {
+	.driver	= {
+		.pm = pm_sleep_ptr(&scmi_system_power_pmops),
+	},
+	.name = "scmi-system-power",
+	.probe = scmi_syspower_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_system_power_driver);
+
+MODULE_AUTHOR("Cristian Marussi <cristian.marussi@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI SystemPower Control driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/shmem.c

@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * For transport using shared mem structure.
+ *
+ * Copyright (C) 2019-2024 ARM Ltd.
+ */
+
+#include <linux/ktime.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/processor.h>
+#include <linux/types.h>
+
+#include <linux/bug.h>
+
+#include "common.h"
+
+#define SCMI_SHMEM_LAYOUT_OVERHEAD	24
+
+/*
+ * SCMI specification requires all parameters, message headers, return
+ * arguments or any protocol data to be expressed in little endian
+ * format only.
+ */
+struct scmi_shared_mem {
+	__le32 reserved;
+	__le32 channel_status;
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR	BIT(1)
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE	BIT(0)
+	__le32 reserved1[2];
+	__le32 flags;
+#define SCMI_SHMEM_FLAG_INTR_ENABLED	BIT(0)
+	__le32 length;
+	__le32 msg_header;
+	u8 msg_payload[];
+};
+
+static inline void shmem_memcpy_fromio32(void *to,
+					 const void __iomem *from,
+					 size_t count)
+{
+	WARN_ON(!IS_ALIGNED((unsigned long)from, 4) ||
+		!IS_ALIGNED((unsigned long)to, 4) ||
+		count % 4);
+
+	__ioread32_copy(to, from, count / 4);
+}
+
+static inline void shmem_memcpy_toio32(void __iomem *to,
+				       const void *from,
+				       size_t count)
+{
+	WARN_ON(!IS_ALIGNED((unsigned long)to, 4) ||
+		!IS_ALIGNED((unsigned long)from, 4) ||
+		count % 4);
+
+	__iowrite32_copy(to, from, count / 4);
+}
+
+static struct scmi_shmem_io_ops shmem_io_ops32 = {
+	.fromio	= shmem_memcpy_fromio32,
+	.toio	= shmem_memcpy_toio32,
+};
+
+/* Wrappers are needed for proper memcpy_{from,to}_io expansion by the
+ * pre-processor.
+ */
+static inline void shmem_memcpy_fromio(void *to,
+				       const void __iomem *from,
+				       size_t count)
+{
+	memcpy_fromio(to, from, count);
+}
+
+static inline void shmem_memcpy_toio(void __iomem *to,
+				     const void *from,
+				     size_t count)
+{
+	memcpy_toio(to, from, count);
+}
+
+static struct scmi_shmem_io_ops shmem_io_ops_default = {
+	.fromio = shmem_memcpy_fromio,
+	.toio	= shmem_memcpy_toio,
+};
+
+static void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
+			     struct scmi_xfer *xfer,
+			     struct scmi_chan_info *cinfo,
+			     shmem_copy_toio_t copy_toio)
+{
+	ktime_t stop;
+
+	/*
+	 * Ideally channel must be free by now unless OS timeout last
+	 * request and platform continued to process the same, wait
+	 * until it releases the shared memory, otherwise we may endup
+	 * overwriting its response with new message payload or vice-versa.
+	 * Giving up anyway after twice the expected channel timeout so as
+	 * not to bail-out on intermittent issues where the platform is
+	 * occasionally a bit slower to answer.
+	 *
+	 * Note that after a timeout is detected we bail-out and carry on but
+	 * the transport functionality is probably permanently compromised:
+	 * this is just to ease debugging and avoid complete hangs on boot
+	 * due to a misbehaving SCMI firmware.
+	 */
+	stop = ktime_add_ms(ktime_get(), 2 * cinfo->rx_timeout_ms);
+	spin_until_cond((ioread32(&shmem->channel_status) &
+			 SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE) ||
+			 ktime_after(ktime_get(), stop));
+	if (!(ioread32(&shmem->channel_status) &
+	      SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE)) {
+		WARN_ON_ONCE(1);
+		dev_err(cinfo->dev,
+			"Timeout waiting for a free TX channel !\n");
+		return;
+	}
+
+	/* Mark channel busy + clear error */
+	iowrite32(0x0, &shmem->channel_status);
+	iowrite32(xfer->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,
+		  &shmem->flags);
+	iowrite32(sizeof(shmem->msg_header) + xfer->tx.len, &shmem->length);
+	iowrite32(pack_scmi_header(&xfer->hdr), &shmem->msg_header);
+	if (xfer->tx.buf)
+		copy_toio(shmem->msg_payload, xfer->tx.buf, xfer->tx.len);
+}
+
+static u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem)
+{
+	return ioread32(&shmem->msg_header);
+}
+
+static void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
+				 struct scmi_xfer *xfer,
+				 shmem_copy_fromio_t copy_fromio)
+{
+	size_t len = ioread32(&shmem->length);
+
+	xfer->hdr.status = ioread32(shmem->msg_payload);
+	/* Skip the length of header and status in shmem area i.e 8 bytes */
+	xfer->rx.len = min_t(size_t, xfer->rx.len, len > 8 ? len - 8 : 0);
+
+	/* Take a copy to the rx buffer.. */
+	copy_fromio(xfer->rx.buf, shmem->msg_payload + 4, xfer->rx.len);
+}
+
+static void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
+				     size_t max_len, struct scmi_xfer *xfer,
+				     shmem_copy_fromio_t copy_fromio)
+{
+	size_t len = ioread32(&shmem->length);
+
+	/* Skip only the length of header in shmem area i.e 4 bytes */
+	xfer->rx.len = min_t(size_t, max_len, len > 4 ? len - 4 : 0);
+
+	/* Take a copy to the rx buffer.. */
+	copy_fromio(xfer->rx.buf, shmem->msg_payload, xfer->rx.len);
+}
+
+static void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem)
+{
+	iowrite32(SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE, &shmem->channel_status);
+}
+
+static bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
+			    struct scmi_xfer *xfer)
+{
+	u16 xfer_id;
+
+	xfer_id = MSG_XTRACT_TOKEN(ioread32(&shmem->msg_header));
+
+	if (xfer->hdr.seq != xfer_id)
+		return false;
+
+	return ioread32(&shmem->channel_status) &
+		(SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR |
+		 SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
+}
+
+static bool shmem_channel_free(struct scmi_shared_mem __iomem *shmem)
+{
+	return (ioread32(&shmem->channel_status) &
+			SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
+}
+
+static bool shmem_channel_intr_enabled(struct scmi_shared_mem __iomem *shmem)
+{
+	return ioread32(&shmem->flags) & SCMI_SHMEM_FLAG_INTR_ENABLED;
+}
+
+static void __iomem *shmem_setup_iomap(struct scmi_chan_info *cinfo,
+				       struct device *dev, bool tx,
+				       struct resource *res,
+				       struct scmi_shmem_io_ops **ops)
+{
+	const char *desc = tx ? "Tx" : "Rx";
+	int ret, idx = tx ? 0 : 1;
+	struct device *cdev = cinfo->dev;
+	struct resource lres = {};
+	resource_size_t size;
+	void __iomem *addr;
+	u32 reg_io_width;
+
+	struct device_node *shmem __free(device_node) = of_parse_phandle(cdev->of_node,
+		"shmem", idx);
+
+	if (!shmem)
+		return IOMEM_ERR_PTR(-ENODEV);
+
+	if (!of_device_is_compatible(shmem, "arm,scmi-shmem"))
+		return IOMEM_ERR_PTR(-ENXIO);
+
+	/* Use a local on-stack as a working area when not provided */
+	if (!res)
+		res = &lres;
+
+	ret = of_address_to_resource(shmem, 0, res);
+	if (ret) {
+		dev_err(cdev, "failed to get SCMI %s shared memory\n", desc);
+		return IOMEM_ERR_PTR(ret);
+	}
+
+	size = resource_size(res);
+	if (cinfo->max_msg_size + SCMI_SHMEM_LAYOUT_OVERHEAD > size) {
+		dev_err(dev, "misconfigured SCMI shared memory\n");
+		return IOMEM_ERR_PTR(-ENOSPC);
+	}
+
+	addr = devm_ioremap(dev, res->start, size);
+	if (!addr) {
+		dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc);
+		return IOMEM_ERR_PTR(-EADDRNOTAVAIL);
+	}
+
+	of_property_read_u32(shmem, "reg-io-width", &reg_io_width);
+	switch (reg_io_width) {
+	case 4:
+		*ops = &shmem_io_ops32;
+		break;
+	default:
+		*ops = &shmem_io_ops_default;
+		break;
+	}
+
+	return addr;
+}
+
+static const struct scmi_shared_mem_operations scmi_shmem_ops = {
+	.tx_prepare = shmem_tx_prepare,
+	.read_header = shmem_read_header,
+	.fetch_response = shmem_fetch_response,
+	.fetch_notification = shmem_fetch_notification,
+	.clear_channel = shmem_clear_channel,
+	.poll_done = shmem_poll_done,
+	.channel_free = shmem_channel_free,
+	.channel_intr_enabled = shmem_channel_intr_enabled,
+	.setup_iomap = shmem_setup_iomap,
+};
+
+const struct scmi_shared_mem_operations *scmi_shared_mem_operations_get(void)
+{
+	return &scmi_shmem_ops;
+}

linux-7.2.3/drivers/firmware/arm_scmi/system.c

@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) System Power Protocol
+ *
+ * Copyright (C) 2020-2022 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
+
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+
+#include "protocols.h"
+#include "notify.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x20001
+
+#define SCMI_SYSTEM_NUM_SOURCES		1
+
+enum scmi_system_protocol_cmd {
+	SYSTEM_POWER_STATE_NOTIFY = 0x5,
+};
+
+struct scmi_system_power_state_notify {
+	__le32 notify_enable;
+};
+
+struct scmi_system_power_state_notifier_payld {
+	__le32 agent_id;
+	__le32 flags;
+	__le32 system_state;
+	__le32 timeout;
+};
+
+struct scmi_system_info {
+	bool graceful_timeout_supported;
+	bool power_state_notify_cmd;
+};
+
+static bool scmi_system_notify_supported(const struct scmi_protocol_handle *ph,
+					 u8 evt_id, u32 src_id)
+{
+	struct scmi_system_info *pinfo = ph->get_priv(ph);
+
+	if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER)
+		return false;
+
+	return pinfo->power_state_notify_cmd;
+}
+
+static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
+				      bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_system_power_state_notify *notify;
+
+	ret = ph->xops->xfer_get_init(ph, SYSTEM_POWER_STATE_NOTIFY,
+				      sizeof(*notify), 0, &t);
+	if (ret)
+		return ret;
+
+	notify = t->tx.buf;
+	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_system_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					  u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_system_request_notify(ph, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
+
+	return ret;
+}
+
+static void *
+scmi_system_fill_custom_report(const struct scmi_protocol_handle *ph,
+			       u8 evt_id, ktime_t timestamp,
+			       const void *payld, size_t payld_sz,
+			       void *report, u32 *src_id)
+{
+	size_t expected_sz;
+	const struct scmi_system_power_state_notifier_payld *p = payld;
+	struct scmi_system_power_state_notifier_report *r = report;
+	struct scmi_system_info *pinfo = ph->get_priv(ph);
+
+	expected_sz = pinfo->graceful_timeout_supported ?
+			sizeof(*p) : sizeof(*p) - sizeof(__le32);
+	if (evt_id != SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER ||
+	    payld_sz != expected_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->agent_id = le32_to_cpu(p->agent_id);
+	r->flags = le32_to_cpu(p->flags);
+	r->system_state = le32_to_cpu(p->system_state);
+	if (pinfo->graceful_timeout_supported &&
+	    r->system_state == SCMI_SYSTEM_SHUTDOWN &&
+	    SCMI_SYSPOWER_IS_REQUEST_GRACEFUL(r->flags))
+		r->timeout = le32_to_cpu(p->timeout);
+	else
+		r->timeout = 0x00;
+	*src_id = 0;
+
+	return r;
+}
+
+static const struct scmi_event system_events[] = {
+	{
+		.id = SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
+		.max_payld_sz =
+			sizeof(struct scmi_system_power_state_notifier_payld),
+		.max_report_sz =
+			sizeof(struct scmi_system_power_state_notifier_report),
+	},
+};
+
+static const struct scmi_event_ops system_event_ops = {
+	.is_notify_supported = scmi_system_notify_supported,
+	.set_notify_enabled = scmi_system_set_notify_enabled,
+	.fill_custom_report = scmi_system_fill_custom_report,
+};
+
+static const struct scmi_protocol_events system_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &system_event_ops,
+	.evts = system_events,
+	.num_events = ARRAY_SIZE(system_events),
+	.num_sources = SCMI_SYSTEM_NUM_SOURCES,
+};
+
+static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_system_info *pinfo;
+
+	dev_dbg(ph->dev, "System Power Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	if (PROTOCOL_REV_MAJOR(ph->version) >= 0x2)
+		pinfo->graceful_timeout_supported = true;
+
+	if (!ph->hops->protocol_msg_check(ph, SYSTEM_POWER_STATE_NOTIFY, NULL))
+		pinfo->power_state_notify_cmd = true;
+
+	return ph->set_priv(ph, pinfo);
+}
+
+static const struct scmi_protocol scmi_system = {
+	.id = SCMI_PROTOCOL_SYSTEM,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_system_protocol_init,
+	.ops = NULL,
+	.events = &system_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)

linux-7.2.3/drivers/firmware/arm_scmi/transports/Kconfig

@@ -0,0 +1,123 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "SCMI Transport Drivers"
+
+config ARM_SCMI_HAVE_TRANSPORT
+	bool
+	help
+	  This declares whether at least one SCMI transport has been configured.
+	  Used to trigger a build bug when trying to build SCMI without any
+	  configured transport.
+
+config ARM_SCMI_HAVE_SHMEM
+	bool
+	help
+	  This declares whether a shared memory based transport for SCMI is
+	  available.
+
+config ARM_SCMI_HAVE_MSG
+	bool
+	help
+	  This declares whether a message passing based transport for SCMI is
+	  available.
+
+config ARM_SCMI_TRANSPORT_MAILBOX
+	tristate "SCMI transport based on Mailbox"
+	depends on MAILBOX
+	select ARM_SCMI_HAVE_TRANSPORT
+	select ARM_SCMI_HAVE_SHMEM
+	default y
+	help
+	  Enable mailbox based transport for SCMI.
+
+	  If you want the ARM SCMI PROTOCOL stack to include support for a
+	  transport based on mailboxes, answer Y.
+	  This driver can also be built as a module. If so, the module
+	  will be called scmi_transport_mailbox.
+
+config ARM_SCMI_TRANSPORT_SMC
+	tristate "SCMI transport based on SMC"
+	depends on HAVE_ARM_SMCCC_DISCOVERY
+	select ARM_SCMI_HAVE_TRANSPORT
+	select ARM_SCMI_HAVE_SHMEM
+	default y
+	help
+	  Enable SMC based transport for SCMI.
+
+	  If you want the ARM SCMI PROTOCOL stack to include support for a
+	  transport based on SMC, answer Y.
+	  This driver can also be built as a module. If so, the module
+	  will be called scmi_transport_smc.
+
+config ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE
+	bool "Enable atomic mode support for SCMI SMC transport"
+	depends on ARM_SCMI_TRANSPORT_SMC
+	help
+	  Enable support of atomic operation for SCMI SMC based transport.
+
+	  If you want the SCMI SMC based transport to operate in atomic
+	  mode, avoiding any kind of sleeping behaviour for selected
+	  transactions on the TX path, answer Y.
+	  Enabling atomic mode operations allows any SCMI driver using this
+	  transport to optionally ask for atomic SCMI transactions and operate
+	  in atomic context too, at the price of using a number of busy-waiting
+	  primitives all over instead. If unsure say N.
+
+config ARM_SCMI_TRANSPORT_OPTEE
+	tristate "SCMI transport based on OP-TEE service"
+	depends on OPTEE
+	select ARM_SCMI_HAVE_TRANSPORT
+	select ARM_SCMI_HAVE_SHMEM
+	select ARM_SCMI_HAVE_MSG
+	default y
+	help
+	  This enables the OP-TEE service based transport for SCMI.
+
+	  If you want the ARM SCMI PROTOCOL stack to include support for a
+	  transport based on OP-TEE SCMI service, answer Y.
+	  This driver can also be built as a module. If so, the module
+	  will be called scmi_transport_optee.
+
+config ARM_SCMI_TRANSPORT_VIRTIO
+	tristate "SCMI transport based on VirtIO"
+	depends on VIRTIO
+	select ARM_SCMI_HAVE_TRANSPORT
+	select ARM_SCMI_HAVE_MSG
+	help
+	  This enables the virtio based transport for SCMI.
+
+	  If you want the ARM SCMI PROTOCOL stack to include support for a
+	  transport based on VirtIO, answer Y.
+	  This driver can also be built as a module. If so, the module
+	  will be called scmi_transport_virtio.
+
+config ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE
+	bool "SCMI VirtIO transport Version 1 compliance"
+	depends on ARM_SCMI_TRANSPORT_VIRTIO
+	default y
+	help
+	  This enforces strict compliance with VirtIO Version 1 specification.
+
+	  If you want the ARM SCMI VirtIO transport layer to refuse to work
+	  with Legacy VirtIO backends and instead support only VirtIO Version 1
+	  devices (or above), answer Y.
+
+	  If you want instead to support also old Legacy VirtIO backends (like
+	  the ones implemented by kvmtool) and let the core Kernel VirtIO layer
+	  take care of the needed conversions, say N.
+
+config ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE
+	bool "Enable atomic mode for SCMI VirtIO transport"
+	depends on ARM_SCMI_TRANSPORT_VIRTIO
+	help
+	  Enable support of atomic operation for SCMI VirtIO based transport.
+
+	  If you want the SCMI VirtIO based transport to operate in atomic
+	  mode, avoiding any kind of sleeping behaviour for selected
+	  transactions on the TX path, answer Y.
+
+	  Enabling atomic mode operations allows any SCMI driver using this
+	  transport to optionally ask for atomic SCMI transactions and operate
+	  in atomic context too, at the price of using a number of busy-waiting
+	  primitives all over instead. If unsure say N.
+
+endmenu

linux-7.2.3/drivers/firmware/arm_scmi/transports/Makefile

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Keep before scmi_transport_mailbox.o to allow precedence
+# while matching the compatible.
+scmi_transport_smc-objs := smc.o
+obj-$(CONFIG_ARM_SCMI_TRANSPORT_SMC) += scmi_transport_smc.o
+scmi_transport_mailbox-objs := mailbox.o
+obj-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += scmi_transport_mailbox.o
+scmi_transport_optee-objs := optee.o
+obj-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) += scmi_transport_optee.o
+scmi_transport_virtio-objs := virtio.o
+obj-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += scmi_transport_virtio.o
+
+ifeq ($(CONFIG_THUMB2_KERNEL)$(CONFIG_CC_IS_CLANG),yy)
+# The use of R7 in the SMCCC conflicts with the compiler's use of R7 as a frame
+# pointer in Thumb2 mode, which is forcibly enabled by Clang when profiling
+# hooks are inserted via the -pg switch.
+CFLAGS_REMOVE_smc.o += $(CC_FLAGS_FTRACE)
+endif

linux-7.2.3/drivers/firmware/arm_scmi/transports/mailbox.c

@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Mailbox Transport
+ * driver.
+ *
+ * Copyright (C) 2019-2024 ARM Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/mailbox_client.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "../common.h"
+
+/**
+ * struct scmi_mailbox - Structure representing a SCMI mailbox transport
+ *
+ * @cl: Mailbox Client
+ * @chan: Transmit/Receive mailbox uni/bi-directional channel
+ * @chan_receiver: Optional Receiver mailbox unidirectional channel
+ * @chan_platform_receiver: Optional Platform Receiver mailbox unidirectional channel
+ * @cinfo: SCMI channel info
+ * @shmem: Transmit/Receive shared memory area
+ * @chan_lock: Lock that prevents multiple xfers from being queued
+ * @io_ops: Transport specific I/O operations
+ */
+struct scmi_mailbox {
+	struct mbox_client cl;
+	struct mbox_chan *chan;
+	struct mbox_chan *chan_receiver;
+	struct mbox_chan *chan_platform_receiver;
+	struct scmi_chan_info *cinfo;
+	struct scmi_shared_mem __iomem *shmem;
+	struct mutex chan_lock;
+	struct scmi_shmem_io_ops *io_ops;
+};
+
+#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)
+
+static struct scmi_transport_core_operations *core;
+
+static void tx_prepare(struct mbox_client *cl, void *m)
+{
+	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+
+	core->shmem->tx_prepare(smbox->shmem, m, smbox->cinfo,
+				smbox->io_ops->toio);
+}
+
+static void rx_callback(struct mbox_client *cl, void *m)
+{
+	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+
+	/*
+	 * An A2P IRQ is NOT valid when received while the platform still has
+	 * the ownership of the channel, because the platform at first releases
+	 * the SMT channel and then sends the completion interrupt.
+	 *
+	 * This addresses a possible race condition in which a spurious IRQ from
+	 * a previous timed-out reply which arrived late could be wrongly
+	 * associated with the next pending transaction.
+	 */
+	if (cl->knows_txdone &&
+	    !core->shmem->channel_free(smbox->shmem)) {
+		dev_warn(smbox->cinfo->dev, "Ignoring spurious A2P IRQ !\n");
+		core->bad_message_trace(smbox->cinfo,
+			     core->shmem->read_header(smbox->shmem),
+							     MSG_MBOX_SPURIOUS);
+		return;
+	}
+
+	core->rx_callback(smbox->cinfo,
+		      core->shmem->read_header(smbox->shmem), NULL);
+}
+
+static bool mailbox_chan_available(struct device_node *of_node, int idx)
+{
+	int num_mb;
+
+	/*
+	 * Just check if bidirrectional channels are involved, and check the
+	 * index accordingly; proper full validation will be made later
+	 * in mailbox_chan_setup().
+	 */
+	num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells");
+	if (num_mb == 3 && idx == 1)
+		idx = 2;
+
+	return !of_parse_phandle_with_args(of_node, "mboxes",
+					   "#mbox-cells", idx, NULL);
+}
+
+/**
+ * mailbox_chan_validate  - Validate transport configuration and map channels
+ *
+ * @cdev: Reference to the underlying transport device carrying the
+ *	  of_node descriptor to analyze.
+ * @a2p_rx_chan: A reference to an optional unidirectional channel to use
+ *		 for replies on the a2p channel. Set as zero if not present.
+ * @p2a_chan: A reference to the optional p2a channel.
+ *	      Set as zero if not present.
+ * @p2a_rx_chan: A reference to the optional p2a completion channel.
+ *	      Set as zero if not present.
+ *
+ * At first, validate the transport configuration as described in terms of
+ * 'mboxes' and 'shmem', then determin which mailbox channel indexes are
+ * appropriate to be use in the current configuration.
+ *
+ * Return: 0 on Success or error
+ */
+static int mailbox_chan_validate(struct device *cdev, int *a2p_rx_chan,
+				 int *p2a_chan, int *p2a_rx_chan)
+{
+	int num_mb, num_sh, ret = 0;
+	struct device_node *np = cdev->of_node;
+
+	num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+	num_sh = of_count_phandle_with_args(np, "shmem", NULL);
+	dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh);
+
+	/* Bail out if mboxes and shmem descriptors are inconsistent */
+	if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 4 ||
+	    (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2) ||
+	    (num_mb == 4 && num_sh != 2)) {
+		dev_warn(cdev,
+			 "Invalid channel descriptor for '%pOF' - mbs:%d  shm:%d\n",
+			 np, num_mb, num_sh);
+		return -EINVAL;
+	}
+
+	/* Bail out if provided shmem descriptors do not refer distinct areas  */
+	if (num_sh > 1) {
+		struct device_node *np_tx __free(device_node) =
+					of_parse_phandle(np, "shmem", 0);
+		struct device_node *np_rx __free(device_node) =
+					of_parse_phandle(np, "shmem", 1);
+
+		if (!np_tx || !np_rx || np_tx == np_rx) {
+			dev_warn(cdev, "Invalid shmem descriptor for '%pOF'\n", np);
+			ret = -EINVAL;
+		}
+	}
+
+	/* Calculate channels IDs to use depending on mboxes/shmem layout */
+	if (!ret) {
+		switch (num_mb) {
+		case 1:
+			*a2p_rx_chan = 0;
+			*p2a_chan = 0;
+			*p2a_rx_chan = 0;
+			break;
+		case 2:
+			if (num_sh == 2) {
+				*a2p_rx_chan = 0;
+				*p2a_chan = 1;
+			} else {
+				*a2p_rx_chan = 1;
+				*p2a_chan = 0;
+			}
+			*p2a_rx_chan = 0;
+			break;
+		case 3:
+			*a2p_rx_chan = 1;
+			*p2a_chan = 2;
+			*p2a_rx_chan = 0;
+			break;
+		case 4:
+			*a2p_rx_chan = 1;
+			*p2a_chan = 2;
+			*p2a_rx_chan = 3;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+			      bool tx)
+{
+	const char *desc = tx ? "Tx" : "Rx";
+	struct device *cdev = cinfo->dev;
+	struct scmi_mailbox *smbox;
+	int ret, a2p_rx_chan, p2a_chan, p2a_rx_chan;
+	struct mbox_client *cl;
+
+	ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan, &p2a_rx_chan);
+	if (ret)
+		return ret;
+
+	if (!tx && !p2a_chan)
+		return -ENODEV;
+
+	smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
+	if (!smbox)
+		return -ENOMEM;
+
+	smbox->shmem = core->shmem->setup_iomap(cinfo, dev, tx, NULL,
+						&smbox->io_ops);
+	if (IS_ERR(smbox->shmem))
+		return PTR_ERR(smbox->shmem);
+
+	cl = &smbox->cl;
+	cl->dev = cdev;
+	cl->tx_prepare = tx ? tx_prepare : NULL;
+	cl->rx_callback = rx_callback;
+	cl->tx_block = false;
+	cl->knows_txdone = tx;
+
+	smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan);
+	if (IS_ERR(smbox->chan)) {
+		ret = PTR_ERR(smbox->chan);
+		if (ret != -EPROBE_DEFER)
+			dev_err(cdev,
+				"failed to request SCMI %s mailbox\n", desc);
+		return ret;
+	}
+
+	/* Additional unidirectional channel for TX if needed */
+	if (tx && a2p_rx_chan) {
+		smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan);
+		if (IS_ERR(smbox->chan_receiver)) {
+			ret = PTR_ERR(smbox->chan_receiver);
+			if (ret != -EPROBE_DEFER)
+				dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n");
+			return ret;
+		}
+	}
+
+	if (!tx && p2a_rx_chan) {
+		smbox->chan_platform_receiver = mbox_request_channel(cl, p2a_rx_chan);
+		if (IS_ERR(smbox->chan_platform_receiver)) {
+			ret = PTR_ERR(smbox->chan_platform_receiver);
+			if (ret != -EPROBE_DEFER)
+				dev_err(cdev, "failed to request SCMI P2A Receiver mailbox\n");
+			return ret;
+		}
+	}
+
+	cinfo->transport_info = smbox;
+	smbox->cinfo = cinfo;
+	mutex_init(&smbox->chan_lock);
+
+	return 0;
+}
+
+static int mailbox_chan_free(int id, void *p, void *data)
+{
+	struct scmi_chan_info *cinfo = p;
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	if (smbox && !IS_ERR(smbox->chan)) {
+		mbox_free_channel(smbox->chan);
+		mbox_free_channel(smbox->chan_receiver);
+		mbox_free_channel(smbox->chan_platform_receiver);
+		cinfo->transport_info = NULL;
+		smbox->chan = NULL;
+		smbox->chan_receiver = NULL;
+		smbox->chan_platform_receiver = NULL;
+		smbox->cinfo = NULL;
+	}
+
+	return 0;
+}
+
+static int mailbox_send_message(struct scmi_chan_info *cinfo,
+				struct scmi_xfer *xfer)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+	int ret;
+
+	/*
+	 * The mailbox layer has its own queue. However the mailbox queue
+	 * confuses the per message SCMI timeouts since the clock starts when
+	 * the message is submitted into the mailbox queue. So when multiple
+	 * messages are queued up the clock starts on all messages instead of
+	 * only the one inflight.
+	 */
+	mutex_lock(&smbox->chan_lock);
+
+	ret = mbox_send_message(smbox->chan, xfer);
+	/* mbox_send_message returns non-negative value on success */
+	if (ret < 0) {
+		mutex_unlock(&smbox->chan_lock);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+				struct scmi_xfer *__unused)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	mbox_client_txdone(smbox->chan, ret);
+
+	/* Release channel */
+	mutex_unlock(&smbox->chan_lock);
+}
+
+static void mailbox_fetch_response(struct scmi_chan_info *cinfo,
+				   struct scmi_xfer *xfer)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	core->shmem->fetch_response(smbox->shmem, xfer, smbox->io_ops->fromio);
+}
+
+static void mailbox_fetch_notification(struct scmi_chan_info *cinfo,
+				       size_t max_len, struct scmi_xfer *xfer)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	core->shmem->fetch_notification(smbox->shmem, max_len, xfer,
+					smbox->io_ops->fromio);
+}
+
+static void mailbox_clear_channel(struct scmi_chan_info *cinfo)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+	struct mbox_chan *intr_chan;
+	int ret;
+
+	core->shmem->clear_channel(smbox->shmem);
+
+	if (!core->shmem->channel_intr_enabled(smbox->shmem))
+		return;
+
+	if (smbox->chan_platform_receiver)
+		intr_chan = smbox->chan_platform_receiver;
+	else if (smbox->chan)
+		intr_chan = smbox->chan;
+	else
+		return;
+
+	ret = mbox_send_message(intr_chan, NULL);
+	/* mbox_send_message returns non-negative value on success, so reset */
+	if (ret > 0)
+		ret = 0;
+
+	mbox_client_txdone(intr_chan, ret);
+}
+
+static bool
+mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	return core->shmem->poll_done(smbox->shmem, xfer);
+}
+
+static const struct scmi_transport_ops scmi_mailbox_ops = {
+	.chan_available = mailbox_chan_available,
+	.chan_setup = mailbox_chan_setup,
+	.chan_free = mailbox_chan_free,
+	.send_message = mailbox_send_message,
+	.mark_txdone = mailbox_mark_txdone,
+	.fetch_response = mailbox_fetch_response,
+	.fetch_notification = mailbox_fetch_notification,
+	.clear_channel = mailbox_clear_channel,
+	.poll_done = mailbox_poll_done,
+};
+
+static struct scmi_desc scmi_mailbox_desc = {
+	.ops = &scmi_mailbox_ops,
+	.max_rx_timeout_ms = 30, /* We may increase this if required */
+	.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
+	.max_msg_size = SCMI_SHMEM_MAX_PAYLOAD_SIZE,
+};
+
+static const struct of_device_id scmi_of_match[] = {
+	{ .compatible = "arm,scmi" },
+	{ /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, scmi_of_match);
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_mailbox, scmi_mailbox_driver,
+			     scmi_mailbox_desc, scmi_of_match, core);
+module_platform_driver(scmi_mailbox_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("SCMI Mailbox Transport driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/transports/optee.c

@@ -0,0 +1,649 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019-2021 Linaro Ltd.
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+#include <linux/uuid.h>
+#include <uapi/linux/tee.h>
+
+#include "../common.h"
+
+enum scmi_optee_pta_cmd {
+	/*
+	 * PTA_SCMI_CMD_CAPABILITIES - Get channel capabilities
+	 *
+	 * [out]    value[0].a: Capability bit mask (enum pta_scmi_caps)
+	 * [out]    value[0].b: Extended capabilities or 0
+	 */
+	PTA_SCMI_CMD_CAPABILITIES = 0,
+
+	/*
+	 * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL - Process SCMI message in SMT buffer
+	 *
+	 * [in]     value[0].a: Channel handle
+	 *
+	 * Shared memory used for SCMI message/response exhange is expected
+	 * already identified and bound to channel handle in both SCMI agent
+	 * and SCMI server (OP-TEE) parts.
+	 * The memory uses SMT header to carry SCMI meta-data (protocol ID and
+	 * protocol message ID).
+	 */
+	PTA_SCMI_CMD_PROCESS_SMT_CHANNEL = 1,
+
+	/*
+	 * PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE - Process SMT/SCMI message
+	 *
+	 * [in]     value[0].a: Channel handle
+	 * [in/out] memref[1]: Message/response buffer (SMT and SCMI payload)
+	 *
+	 * Shared memory used for SCMI message/response is a SMT buffer
+	 * referenced by param[1]. It shall be 128 bytes large to fit response
+	 * payload whatever message playload size.
+	 * The memory uses SMT header to carry SCMI meta-data (protocol ID and
+	 * protocol message ID).
+	 */
+	PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE = 2,
+
+	/*
+	 * PTA_SCMI_CMD_GET_CHANNEL - Get channel handle
+	 *
+	 * SCMI shm information are 0 if agent expects to use OP-TEE regular SHM
+	 *
+	 * [in]     value[0].a: Channel identifier
+	 * [out]    value[0].a: Returned channel handle
+	 * [in]     value[0].b: Requested capabilities mask (enum pta_scmi_caps)
+	 */
+	PTA_SCMI_CMD_GET_CHANNEL = 3,
+
+	/*
+	 * PTA_SCMI_CMD_PROCESS_MSG_CHANNEL - Process SCMI message in a MSG
+	 * buffer pointed by memref parameters
+	 *
+	 * [in]     value[0].a: Channel handle
+	 * [in]     memref[1]: Message buffer (MSG and SCMI payload)
+	 * [out]    memref[2]: Response buffer (MSG and SCMI payload)
+	 *
+	 * Shared memories used for SCMI message/response are MSG buffers
+	 * referenced by param[1] and param[2]. MSG transport protocol
+	 * uses a 32bit header to carry SCMI meta-data (protocol ID and
+	 * protocol message ID) followed by the effective SCMI message
+	 * payload.
+	 */
+	PTA_SCMI_CMD_PROCESS_MSG_CHANNEL = 4,
+};
+
+/*
+ * OP-TEE SCMI service capabilities bit flags (32bit)
+ *
+ * PTA_SCMI_CAPS_SMT_HEADER
+ * When set, OP-TEE supports command using SMT header protocol (SCMI shmem) in
+ * shared memory buffers to carry SCMI protocol synchronisation information.
+ *
+ * PTA_SCMI_CAPS_MSG_HEADER
+ * When set, OP-TEE supports command using MSG header protocol in an OP-TEE
+ * shared memory to carry SCMI protocol synchronisation information and SCMI
+ * message payload.
+ */
+#define PTA_SCMI_CAPS_NONE		0
+#define PTA_SCMI_CAPS_SMT_HEADER	BIT(0)
+#define PTA_SCMI_CAPS_MSG_HEADER	BIT(1)
+#define PTA_SCMI_CAPS_MASK		(PTA_SCMI_CAPS_SMT_HEADER | \
+					 PTA_SCMI_CAPS_MSG_HEADER)
+
+/**
+ * struct scmi_optee_channel - Description of an OP-TEE SCMI channel
+ *
+ * @channel_id: OP-TEE channel ID used for this transport
+ * @tee_session: TEE session identifier
+ * @caps: OP-TEE SCMI channel capabilities
+ * @rx_len: Response size
+ * @mu: Mutex protection on channel access
+ * @cinfo: SCMI channel information
+ * @req: union for SCMI interface
+ * @req.shmem: Virtual base address of the shared memory
+ * @req.msg: Shared memory protocol handle for SCMI request and
+ *   synchronous response
+ * @io_ops: Transport specific I/O operations
+ * @tee_shm: TEE shared memory handle @req or NULL if using IOMEM shmem
+ * @link: Reference in agent's channel list
+ */
+struct scmi_optee_channel {
+	u32 channel_id;
+	u32 tee_session;
+	u32 caps;
+	u32 rx_len;
+	struct mutex mu;
+	struct scmi_chan_info *cinfo;
+	union {
+		struct scmi_shared_mem __iomem *shmem;
+		struct scmi_msg_payld *msg;
+	} req;
+	struct scmi_shmem_io_ops *io_ops;
+	struct tee_shm *tee_shm;
+	struct list_head link;
+};
+
+/**
+ * struct scmi_optee_agent - OP-TEE transport private data
+ *
+ * @dev: Device used for communication with TEE
+ * @tee_ctx: TEE context used for communication
+ * @caps: Supported channel capabilities
+ * @mu: Mutex for protection of @channel_list
+ * @channel_list: List of all created channels for the agent
+ */
+struct scmi_optee_agent {
+	struct device *dev;
+	struct tee_context *tee_ctx;
+	u32 caps;
+	struct mutex mu;
+	struct list_head channel_list;
+};
+
+static struct scmi_transport_core_operations *core;
+
+/* There can be only 1 SCMI service in OP-TEE we connect to */
+static struct scmi_optee_agent *scmi_optee_private;
+
+static DEFINE_SCMI_TRANSPORT_SUPPLIER(scmi_optee_supplier);
+
+/* Open a session toward SCMI OP-TEE service with REE_KERNEL identity */
+static int open_session(struct scmi_optee_agent *agent, u32 *tee_session)
+{
+	struct device *dev = agent->dev;
+	struct tee_client_device *scmi_pta = to_tee_client_device(dev);
+	struct tee_ioctl_open_session_arg arg = { };
+	int ret;
+
+	memcpy(arg.uuid, scmi_pta->id.uuid.b, TEE_IOCTL_UUID_LEN);
+	arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+	ret = tee_client_open_session(agent->tee_ctx, &arg, NULL);
+	if (ret < 0 || arg.ret) {
+		dev_err(dev, "Can't open tee session: %d / %#x\n", ret, arg.ret);
+		return -EOPNOTSUPP;
+	}
+
+	*tee_session = arg.session;
+
+	return 0;
+}
+
+static void close_session(struct scmi_optee_agent *agent, u32 tee_session)
+{
+	tee_client_close_session(agent->tee_ctx, tee_session);
+}
+
+static int get_capabilities(struct scmi_optee_agent *agent)
+{
+	struct tee_ioctl_invoke_arg arg = { };
+	struct tee_param param[1] = { };
+	u32 caps;
+	u32 tee_session;
+	int ret;
+
+	ret = open_session(agent, &tee_session);
+	if (ret)
+		return ret;
+
+	arg.func = PTA_SCMI_CMD_CAPABILITIES;
+	arg.session = tee_session;
+	arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+	ret = tee_client_invoke_func(agent->tee_ctx, &arg, param);
+
+	close_session(agent, tee_session);
+
+	if (ret < 0 || arg.ret) {
+		dev_err(agent->dev, "Can't get capabilities: %d / %#x\n", ret, arg.ret);
+		return -EOPNOTSUPP;
+	}
+
+	caps = param[0].u.value.a;
+
+	if (!(caps & (PTA_SCMI_CAPS_SMT_HEADER | PTA_SCMI_CAPS_MSG_HEADER))) {
+		dev_err(agent->dev, "OP-TEE SCMI PTA doesn't support SMT and MSG\n");
+		return -EOPNOTSUPP;
+	}
+
+	agent->caps = caps;
+
+	return 0;
+}
+
+static int get_channel(struct scmi_optee_channel *channel)
+{
+	struct device *dev = scmi_optee_private->dev;
+	struct tee_ioctl_invoke_arg arg = { };
+	struct tee_param param[1] = { };
+	unsigned int caps = 0;
+	int ret;
+
+	if (channel->tee_shm)
+		caps = PTA_SCMI_CAPS_MSG_HEADER;
+	else
+		caps = PTA_SCMI_CAPS_SMT_HEADER;
+
+	arg.func = PTA_SCMI_CMD_GET_CHANNEL;
+	arg.session = channel->tee_session;
+	arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
+	param[0].u.value.a = channel->channel_id;
+	param[0].u.value.b = caps;
+
+	ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param);
+
+	if (ret || arg.ret) {
+		dev_err(dev, "Can't get channel with caps %#x: %d / %#x\n", caps, ret, arg.ret);
+		return -EOPNOTSUPP;
+	}
+
+	/* From now on use channel identifer provided by OP-TEE SCMI service */
+	channel->channel_id = param[0].u.value.a;
+	channel->caps = caps;
+
+	return 0;
+}
+
+static int invoke_process_smt_channel(struct scmi_optee_channel *channel)
+{
+	struct tee_ioctl_invoke_arg arg = {
+		.func = PTA_SCMI_CMD_PROCESS_SMT_CHANNEL,
+		.session = channel->tee_session,
+		.num_params = 1,
+	};
+	struct tee_param param[1] = { };
+	int ret;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = channel->channel_id;
+
+	ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param);
+	if (ret < 0 || arg.ret) {
+		dev_err(scmi_optee_private->dev, "Can't invoke channel %u: %d / %#x\n",
+			channel->channel_id, ret, arg.ret);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int invoke_process_msg_channel(struct scmi_optee_channel *channel, size_t msg_size)
+{
+	struct tee_ioctl_invoke_arg arg = {
+		.func = PTA_SCMI_CMD_PROCESS_MSG_CHANNEL,
+		.session = channel->tee_session,
+		.num_params = 3,
+	};
+	struct tee_param param[3] = { };
+	int ret;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = channel->channel_id;
+
+	param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[1].u.memref.shm = channel->tee_shm;
+	param[1].u.memref.size = msg_size;
+
+	param[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[2].u.memref.shm = channel->tee_shm;
+	param[2].u.memref.size = SCMI_SHMEM_MAX_PAYLOAD_SIZE;
+
+	ret = tee_client_invoke_func(scmi_optee_private->tee_ctx, &arg, param);
+	if (ret < 0 || arg.ret) {
+		dev_err(scmi_optee_private->dev, "Can't invoke channel %u: %d / %#x\n",
+			channel->channel_id, ret, arg.ret);
+		return -EIO;
+	}
+
+	/* Save response size */
+	channel->rx_len = param[2].u.memref.size;
+
+	return 0;
+}
+
+static bool scmi_optee_chan_available(struct device_node *of_node, int idx)
+{
+	u32 channel_id;
+
+	return !of_property_read_u32_index(of_node, "linaro,optee-channel-id",
+					   idx, &channel_id);
+}
+
+static void scmi_optee_clear_channel(struct scmi_chan_info *cinfo)
+{
+	struct scmi_optee_channel *channel = cinfo->transport_info;
+
+	if (!channel->tee_shm)
+		core->shmem->clear_channel(channel->req.shmem);
+}
+
+static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *channel)
+{
+	const size_t msg_size = SCMI_SHMEM_MAX_PAYLOAD_SIZE;
+	void *shbuf;
+
+	channel->tee_shm = tee_shm_alloc_kernel_buf(scmi_optee_private->tee_ctx, msg_size);
+	if (IS_ERR(channel->tee_shm)) {
+		dev_err(channel->cinfo->dev, "shmem allocation failed\n");
+		return -ENOMEM;
+	}
+
+	shbuf = tee_shm_get_va(channel->tee_shm, 0);
+	memset(shbuf, 0, msg_size);
+	channel->req.msg = shbuf;
+	channel->rx_len = msg_size;
+
+	return 0;
+}
+
+static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo,
+			      struct scmi_optee_channel *channel)
+{
+	channel->req.shmem = core->shmem->setup_iomap(cinfo, dev, true, NULL,
+						      &channel->io_ops);
+	if (IS_ERR(channel->req.shmem))
+		return PTR_ERR(channel->req.shmem);
+
+	return 0;
+}
+
+static int setup_shmem(struct device *dev, struct scmi_chan_info *cinfo,
+		       struct scmi_optee_channel *channel)
+{
+	if (of_property_present(cinfo->dev->of_node, "shmem"))
+		return setup_static_shmem(dev, cinfo, channel);
+	else
+		return setup_dynamic_shmem(dev, channel);
+}
+
+static int scmi_optee_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, bool tx)
+{
+	struct scmi_optee_channel *channel;
+	uint32_t channel_id;
+	int ret;
+
+	if (!tx)
+		return -ENODEV;
+
+	channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL);
+	if (!channel)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_index(cinfo->dev->of_node, "linaro,optee-channel-id",
+					 0, &channel_id);
+	if (ret)
+		return ret;
+
+	cinfo->transport_info = channel;
+	channel->cinfo = cinfo;
+	channel->channel_id = channel_id;
+	mutex_init(&channel->mu);
+
+	ret = setup_shmem(dev, cinfo, channel);
+	if (ret)
+		return ret;
+
+	ret = open_session(scmi_optee_private, &channel->tee_session);
+	if (ret)
+		goto err_free_shm;
+
+	ret = tee_client_system_session(scmi_optee_private->tee_ctx, channel->tee_session);
+	if (ret)
+		dev_warn(dev, "Could not switch to system session, do best effort\n");
+
+	ret = get_channel(channel);
+	if (ret)
+		goto err_close_sess;
+
+	/* Enable polling */
+	cinfo->no_completion_irq = true;
+
+	mutex_lock(&scmi_optee_private->mu);
+	list_add(&channel->link, &scmi_optee_private->channel_list);
+	mutex_unlock(&scmi_optee_private->mu);
+
+	return 0;
+
+err_close_sess:
+	close_session(scmi_optee_private, channel->tee_session);
+err_free_shm:
+	if (channel->tee_shm)
+		tee_shm_free(channel->tee_shm);
+
+	return ret;
+}
+
+static int scmi_optee_chan_free(int id, void *p, void *data)
+{
+	struct scmi_chan_info *cinfo = p;
+	struct scmi_optee_channel *channel = cinfo->transport_info;
+
+	/*
+	 * Different protocols might share the same chan info, so a previous
+	 * call might have already freed the structure.
+	 */
+	if (!channel)
+		return 0;
+
+	mutex_lock(&scmi_optee_private->mu);
+	list_del(&channel->link);
+	mutex_unlock(&scmi_optee_private->mu);
+
+	close_session(scmi_optee_private, channel->tee_session);
+
+	if (channel->tee_shm) {
+		tee_shm_free(channel->tee_shm);
+		channel->tee_shm = NULL;
+	}
+
+	cinfo->transport_info = NULL;
+	channel->cinfo = NULL;
+
+	return 0;
+}
+
+static int scmi_optee_send_message(struct scmi_chan_info *cinfo,
+				   struct scmi_xfer *xfer)
+{
+	struct scmi_optee_channel *channel = cinfo->transport_info;
+	int ret;
+
+	mutex_lock(&channel->mu);
+
+	if (channel->tee_shm) {
+		core->msg->tx_prepare(channel->req.msg, xfer);
+		ret = invoke_process_msg_channel(channel,
+						 core->msg->command_size(xfer));
+	} else {
+		core->shmem->tx_prepare(channel->req.shmem, xfer, cinfo,
+					channel->io_ops->toio);
+		ret = invoke_process_smt_channel(channel);
+	}
+
+	if (ret)
+		mutex_unlock(&channel->mu);
+
+	return ret;
+}
+
+static void scmi_optee_fetch_response(struct scmi_chan_info *cinfo,
+				      struct scmi_xfer *xfer)
+{
+	struct scmi_optee_channel *channel = cinfo->transport_info;
+
+	if (channel->tee_shm)
+		core->msg->fetch_response(channel->req.msg,
+					  channel->rx_len, xfer);
+	else
+		core->shmem->fetch_response(channel->req.shmem, xfer,
+					    channel->io_ops->fromio);
+}
+
+static void scmi_optee_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+				   struct scmi_xfer *__unused)
+{
+	struct scmi_optee_channel *channel = cinfo->transport_info;
+
+	mutex_unlock(&channel->mu);
+}
+
+static const struct scmi_transport_ops scmi_optee_ops = {
+	.chan_available = scmi_optee_chan_available,
+	.chan_setup = scmi_optee_chan_setup,
+	.chan_free = scmi_optee_chan_free,
+	.send_message = scmi_optee_send_message,
+	.mark_txdone = scmi_optee_mark_txdone,
+	.fetch_response = scmi_optee_fetch_response,
+	.clear_channel = scmi_optee_clear_channel,
+};
+
+static int scmi_optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	return ver->impl_id == TEE_IMPL_ID_OPTEE;
+}
+
+static struct scmi_desc scmi_optee_desc = {
+	.ops = &scmi_optee_ops,
+	.max_rx_timeout_ms = 30,
+	.max_msg = 20,
+	.max_msg_size = SCMI_SHMEM_MAX_PAYLOAD_SIZE,
+	.sync_cmds_completed_on_ret = true,
+};
+
+static const struct of_device_id scmi_of_match[] = {
+	{ .compatible = "linaro,scmi-optee", .data = &scmi_optee_supplier.th},
+	{ /* Sentinel */ },
+};
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_optee, scmi_optee_driver, scmi_optee_desc,
+			     scmi_of_match, core);
+
+static int scmi_optee_service_probe(struct tee_client_device *scmi_pta)
+{
+	struct device *dev = &scmi_pta->dev;
+	struct scmi_optee_agent *agent;
+	struct tee_context *tee_ctx;
+	int ret;
+
+	/* Only one SCMI OP-TEE device allowed */
+	if (scmi_optee_private) {
+		dev_err(dev, "An SCMI OP-TEE device was already initialized: only one allowed\n");
+		return -EBUSY;
+	}
+
+	tee_ctx = tee_client_open_context(NULL, scmi_optee_ctx_match, NULL, NULL);
+	if (IS_ERR(tee_ctx))
+		return -ENODEV;
+
+	agent = devm_kzalloc(dev, sizeof(*agent), GFP_KERNEL);
+	if (!agent) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	agent->dev = dev;
+	agent->tee_ctx = tee_ctx;
+	INIT_LIST_HEAD(&agent->channel_list);
+	mutex_init(&agent->mu);
+
+	ret = get_capabilities(agent);
+	if (ret)
+		goto err;
+
+	/* Ensure initialized scmi_optee_private is visible */
+	smp_mb();
+	scmi_optee_private = agent;
+
+	ret = scmi_transport_supplier_put(&scmi_optee_supplier.th, agent->dev);
+	if (ret)
+		goto err_put;
+
+	return 0;
+
+err_put:
+	/* Ensure cleared reference is visible before resources are released */
+	smp_store_mb(scmi_optee_private, NULL);
+
+err:
+	tee_client_close_context(tee_ctx);
+
+	return ret;
+}
+
+static void scmi_optee_service_remove(struct tee_client_device *scmi_pta)
+{
+	struct scmi_optee_agent *agent = scmi_optee_private;
+
+	if (!scmi_optee_private)
+		return;
+
+	if (!list_empty(&scmi_optee_private->channel_list))
+		return;
+
+	/* Ensure cleared reference is visible before resources are released */
+	smp_store_mb(scmi_optee_private, NULL);
+	scmi_transport_supplier_put(&scmi_optee_supplier.th, agent->dev);
+
+	tee_client_close_context(agent->tee_ctx);
+}
+
+static const struct tee_client_device_id scmi_optee_service_id[] = {
+	{
+		UUID_INIT(0xa8cfe406, 0xd4f5, 0x4a2e,
+			  0x9f, 0x8d, 0xa2, 0x5d, 0xc7, 0x54, 0xc0, 0x99)
+	},
+	{ }
+};
+
+MODULE_DEVICE_TABLE(tee, scmi_optee_service_id);
+
+static struct tee_client_driver scmi_optee_service_driver = {
+	.probe = scmi_optee_service_probe,
+	.remove = scmi_optee_service_remove,
+	.id_table = scmi_optee_service_id,
+	.driver = {
+		.name = "scmi-optee",
+	},
+};
+
+static int __init scmi_transport_optee_init(void)
+{
+	int ret;
+
+	ret = tee_client_driver_register(&scmi_optee_service_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&scmi_optee_driver);
+	if (ret) {
+		tee_client_driver_unregister(&scmi_optee_service_driver);
+		return ret;
+	}
+
+	return ret;
+}
+module_init(scmi_transport_optee_init);
+
+static void __exit scmi_transport_optee_exit(void)
+{
+	platform_driver_unregister(&scmi_optee_driver);
+	tee_client_driver_unregister(&scmi_optee_service_driver);
+}
+module_exit(scmi_transport_optee_exit);
+
+MODULE_AUTHOR("Etienne Carriere <etienne.carriere@foss.st.com>");
+MODULE_DESCRIPTION("SCMI OPTEE Transport driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/transports/smc.c

@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message SMC/HVC
+ * Transport driver
+ *
+ * Copyright 2020 NXP
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/limits.h>
+#include <linux/platform_device.h>
+#include <linux/processor.h>
+#include <linux/slab.h>
+
+#include "../common.h"
+
+/*
+ * The shmem address is split into 4K page and offset.
+ * This is to make sure the parameters fit in 32bit arguments of the
+ * smc/hvc call to keep it uniform across smc32/smc64 conventions.
+ * This however limits the shmem address to 44 bit.
+ *
+ * These optional parameters can be used to distinguish among multiple
+ * scmi instances that are using the same smc-id.
+ * The page parameter is passed in r1/x1/w1 register and the offset parameter
+ * is passed in r2/x2/w2 register.
+ */
+
+#define SHMEM_SIZE (SZ_4K)
+#define SHMEM_SHIFT 12
+#define SHMEM_PAGE(x) (_UL((x) >> SHMEM_SHIFT))
+#define SHMEM_OFFSET(x) ((x) & (SHMEM_SIZE - 1))
+
+/**
+ * struct scmi_smc - Structure representing a SCMI smc transport
+ *
+ * @irq: An optional IRQ for completion
+ * @cinfo: SCMI channel info
+ * @shmem: Transmit/Receive shared memory area
+ * @io_ops: Transport specific I/O operations
+ * @shmem_lock: Lock to protect access to Tx/Rx shared memory area.
+ *		Used when NOT operating in atomic mode.
+ * @inflight: Atomic flag to protect access to Tx/Rx shared memory area.
+ *	      Used when operating in atomic mode.
+ * @func_id: smc/hvc call function id
+ * @param_page: 4K page number of the shmem channel
+ * @param_offset: Offset within the 4K page of the shmem channel
+ * @cap_id: smc/hvc doorbell's capability id to be used on Qualcomm virtual
+ *	    platforms
+ */
+
+struct scmi_smc {
+	int irq;
+	struct scmi_chan_info *cinfo;
+	struct scmi_shared_mem __iomem *shmem;
+	struct scmi_shmem_io_ops *io_ops;
+	/* Protect access to shmem area */
+	struct mutex shmem_lock;
+#define INFLIGHT_NONE	MSG_TOKEN_MAX
+	atomic_t inflight;
+	unsigned long func_id;
+	unsigned long param_page;
+	unsigned long param_offset;
+	unsigned long cap_id;
+};
+
+static struct scmi_transport_core_operations *core;
+
+static irqreturn_t smc_msg_done_isr(int irq, void *data)
+{
+	struct scmi_smc *scmi_info = data;
+
+	core->rx_callback(scmi_info->cinfo,
+			  core->shmem->read_header(scmi_info->shmem), NULL);
+
+	return IRQ_HANDLED;
+}
+
+static bool smc_chan_available(struct device_node *of_node, int idx)
+{
+	struct device_node *np __free(device_node) =
+					of_parse_phandle(of_node, "shmem", 0);
+	if (!np)
+		return false;
+
+	return true;
+}
+
+static inline void smc_channel_lock_init(struct scmi_smc *scmi_info)
+{
+	if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
+		atomic_set(&scmi_info->inflight, INFLIGHT_NONE);
+	else
+		mutex_init(&scmi_info->shmem_lock);
+}
+
+static bool smc_xfer_inflight(struct scmi_xfer *xfer, atomic_t *inflight)
+{
+	int ret;
+
+	ret = atomic_cmpxchg(inflight, INFLIGHT_NONE, xfer->hdr.seq);
+
+	return ret == INFLIGHT_NONE;
+}
+
+static inline void
+smc_channel_lock_acquire(struct scmi_smc *scmi_info,
+			 struct scmi_xfer *xfer __maybe_unused)
+{
+	if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
+		spin_until_cond(smc_xfer_inflight(xfer, &scmi_info->inflight));
+	else
+		mutex_lock(&scmi_info->shmem_lock);
+}
+
+static inline void smc_channel_lock_release(struct scmi_smc *scmi_info)
+{
+	if (IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE))
+		atomic_set(&scmi_info->inflight, INFLIGHT_NONE);
+	else
+		mutex_unlock(&scmi_info->shmem_lock);
+}
+
+static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+			  bool tx)
+{
+	struct device *cdev = cinfo->dev;
+	unsigned long cap_id = ULONG_MAX;
+	struct scmi_smc *scmi_info;
+	struct resource res = {};
+	u32 func_id;
+	int ret;
+
+	if (!tx)
+		return -ENODEV;
+
+	scmi_info = devm_kzalloc(dev, sizeof(*scmi_info), GFP_KERNEL);
+	if (!scmi_info)
+		return -ENOMEM;
+
+	scmi_info->shmem = core->shmem->setup_iomap(cinfo, dev, tx, &res,
+						    &scmi_info->io_ops);
+	if (IS_ERR(scmi_info->shmem))
+		return PTR_ERR(scmi_info->shmem);
+
+	ret = of_property_read_u32(dev->of_node, "arm,smc-id", &func_id);
+	if (ret < 0)
+		return ret;
+
+	if (of_device_is_compatible(dev->of_node, "qcom,scmi-smc")) {
+		resource_size_t size = resource_size(&res);
+		void __iomem *ptr = (void __iomem *)scmi_info->shmem + size - 8;
+		/* The capability-id is kept in last 8 bytes of shmem.
+		 *     +-------+ <-- 0
+		 *     | shmem |
+		 *     +-------+ <-- size - 8
+		 *     | capId |
+		 *     +-------+ <-- size
+		 */
+		memcpy_fromio(&cap_id, ptr, sizeof(cap_id));
+	}
+
+	if (of_device_is_compatible(dev->of_node, "arm,scmi-smc-param")) {
+		scmi_info->param_page = SHMEM_PAGE(res.start);
+		scmi_info->param_offset = SHMEM_OFFSET(res.start);
+	}
+	/*
+	 * If there is an interrupt named "a2p", then the service and
+	 * completion of a message is signaled by an interrupt rather than by
+	 * the return of the SMC call.
+	 */
+	scmi_info->irq = of_irq_get_byname(cdev->of_node, "a2p");
+	if (scmi_info->irq > 0) {
+		ret = request_irq(scmi_info->irq, smc_msg_done_isr,
+				  IRQF_NO_SUSPEND, dev_name(dev), scmi_info);
+		if (ret) {
+			dev_err(dev, "failed to setup SCMI smc irq\n");
+			return ret;
+		}
+	} else {
+		cinfo->no_completion_irq = true;
+	}
+
+	scmi_info->func_id = func_id;
+	scmi_info->cap_id = cap_id;
+	scmi_info->cinfo = cinfo;
+	smc_channel_lock_init(scmi_info);
+	cinfo->transport_info = scmi_info;
+
+	return 0;
+}
+
+static int smc_chan_free(int id, void *p, void *data)
+{
+	struct scmi_chan_info *cinfo = p;
+	struct scmi_smc *scmi_info = cinfo->transport_info;
+
+	/*
+	 * Different protocols might share the same chan info, so a previous
+	 * smc_chan_free call might have already freed the structure.
+	 */
+	if (!scmi_info)
+		return 0;
+
+	/* Ignore any possible further reception on the IRQ path */
+	if (scmi_info->irq > 0)
+		free_irq(scmi_info->irq, scmi_info);
+
+	cinfo->transport_info = NULL;
+	scmi_info->cinfo = NULL;
+
+	return 0;
+}
+
+static int smc_send_message(struct scmi_chan_info *cinfo,
+			    struct scmi_xfer *xfer)
+{
+	struct scmi_smc *scmi_info = cinfo->transport_info;
+	struct arm_smccc_res res;
+
+	/*
+	 * Channel will be released only once response has been
+	 * surely fully retrieved, so after .mark_txdone()
+	 */
+	smc_channel_lock_acquire(scmi_info, xfer);
+
+	core->shmem->tx_prepare(scmi_info->shmem, xfer, cinfo,
+				scmi_info->io_ops->toio);
+
+	if (scmi_info->cap_id != ULONG_MAX)
+		arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->cap_id, 0,
+				     0, 0, 0, 0, 0, &res);
+	else
+		arm_smccc_1_1_invoke(scmi_info->func_id, scmi_info->param_page,
+				     scmi_info->param_offset, 0, 0, 0, 0, 0,
+				     &res);
+
+	/* Only SMCCC_RET_NOT_SUPPORTED is valid error code */
+	if (res.a0) {
+		smc_channel_lock_release(scmi_info);
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static void smc_fetch_response(struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer)
+{
+	struct scmi_smc *scmi_info = cinfo->transport_info;
+
+	core->shmem->fetch_response(scmi_info->shmem, xfer,
+				    scmi_info->io_ops->fromio);
+}
+
+static void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+			    struct scmi_xfer *__unused)
+{
+	struct scmi_smc *scmi_info = cinfo->transport_info;
+
+	smc_channel_lock_release(scmi_info);
+}
+
+static const struct scmi_transport_ops scmi_smc_ops = {
+	.chan_available = smc_chan_available,
+	.chan_setup = smc_chan_setup,
+	.chan_free = smc_chan_free,
+	.send_message = smc_send_message,
+	.mark_txdone = smc_mark_txdone,
+	.fetch_response = smc_fetch_response,
+};
+
+static struct scmi_desc scmi_smc_desc = {
+	.ops = &scmi_smc_ops,
+	.max_rx_timeout_ms = 30,
+	.max_msg = 20,
+	.max_msg_size = SCMI_SHMEM_MAX_PAYLOAD_SIZE,
+	/*
+	 * Setting .sync_cmds_atomic_replies to true for SMC assumes that,
+	 * once the SMC instruction has completed successfully, the issued
+	 * SCMI command would have been already fully processed by the SCMI
+	 * platform firmware and so any possible response value expected
+	 * for the issued command will be immmediately ready to be fetched
+	 * from the shared memory area.
+	 */
+	.sync_cmds_completed_on_ret = true,
+	.atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE),
+};
+
+static const struct of_device_id scmi_of_match[] = {
+	{ .compatible = "arm,scmi-smc" },
+	{ .compatible = "arm,scmi-smc-param" },
+	{ .compatible = "qcom,scmi-smc" },
+	{ /* Sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, scmi_of_match);
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_smc, scmi_smc_driver, scmi_smc_desc,
+			     scmi_of_match, core);
+module_platform_driver(scmi_smc_driver);
+
+MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
+MODULE_AUTHOR("Nikunj Kela <quic_nkela@quicinc.com>");
+MODULE_DESCRIPTION("SCMI SMC Transport driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/transports/virtio.c

@@ -0,0 +1,979 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Virtio Transport driver for Arm System Control and Management Interface
+ * (SCMI).
+ *
+ * Copyright (C) 2020-2022 OpenSynergy.
+ * Copyright (C) 2021-2026 ARM Ltd.
+ */
+
+/**
+ * DOC: Theory of Operation
+ *
+ * The scmi-virtio transport implements a driver for the virtio SCMI device.
+ *
+ * There is one Tx channel (virtio cmdq, A2P channel) and at most one Rx
+ * channel (virtio eventq, P2A channel). Each channel is implemented through a
+ * virtqueue. Access to each virtqueue is protected by spinlocks.
+ */
+
+#include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/refcount.h>
+#include <linux/slab.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+
+#include <uapi/linux/virtio_ids.h>
+#include <uapi/linux/virtio_scmi.h>
+
+#include "../common.h"
+
+#define VIRTIO_MAX_RX_TIMEOUT_MS	60000
+#define VIRTIO_SCMI_MAX_MSG_SIZE 128 /* Value may be increased. */
+#define VIRTIO_SCMI_MAX_PDU_SIZE(ci) \
+	((ci)->max_msg_size + SCMI_MSG_MAX_PROT_OVERHEAD)
+#define DESCRIPTORS_PER_TX_MSG 2
+
+/**
+ * struct scmi_vio_channel - Transport channel information
+ *
+ * @vqueue: Associated virtqueue
+ * @cinfo: SCMI Tx or Rx channel
+ * @free_lock: Protects access to the @free_list.
+ * @free_list: List of unused scmi_vio_msg, maintained for Tx channels only
+ * @deferred_tx_work: Worker for TX deferred replies processing
+ * @deferred_tx_wq: Workqueue for TX deferred replies
+ * @pending_lock: Protects access to the @pending_cmds_list.
+ * @pending_cmds_list: List of pre-fetched commands queueud for later processing
+ * @is_rx: Whether channel is an Rx channel
+ * @max_msg: Maximum number of pending messages for this channel.
+ * @lock: Protects access to all members except users, free_list and
+ *	  pending_cmds_list.
+ * @shutdown_done: A reference to a completion used when freeing this channel.
+ * @users: A reference count to currently active users of this channel.
+ */
+struct scmi_vio_channel {
+	struct virtqueue *vqueue;
+	struct scmi_chan_info *cinfo;
+	/* lock to protect access to the free list. */
+	spinlock_t free_lock;
+	struct list_head free_list;
+	/* lock to protect access to the pending list. */
+	spinlock_t pending_lock;
+	struct list_head pending_cmds_list;
+	struct work_struct deferred_tx_work;
+	struct workqueue_struct *deferred_tx_wq;
+	bool is_rx;
+	unsigned int max_msg;
+	/*
+	 * Lock to protect access to all members except users, free_list and
+	 * pending_cmds_list
+	 */
+	spinlock_t lock;
+	struct completion *shutdown_done;
+	refcount_t users;
+};
+
+enum poll_states {
+	VIO_MSG_NOT_POLLED,
+	VIO_MSG_POLL_TIMEOUT,
+	VIO_MSG_POLLING,
+	VIO_MSG_POLL_DONE,
+};
+
+/**
+ * struct scmi_vio_msg - Transport PDU information
+ *
+ * @request: SDU used for commands
+ * @input: SDU used for (delayed) responses and notifications
+ * @list: List which scmi_vio_msg may be part of
+ * @rx_len: Input SDU size in bytes, once input has been received
+ * @max_len: Maximumm allowed SDU size in bytes
+ * @poll_idx: Last used index registered for polling purposes if this message
+ *	      transaction reply was configured for polling.
+ * @poll_status: Polling state for this message.
+ * @poll_lock: A lock to protect @poll_status
+ * @users: A reference count to track this message users and avoid premature
+ *	   freeing (and reuse) when polling and IRQ execution paths interleave.
+ */
+struct scmi_vio_msg {
+	struct scmi_msg_payld *request;
+	struct scmi_msg_payld *input;
+	struct list_head list;
+	unsigned int rx_len;
+	unsigned int max_len;
+	unsigned int poll_idx;
+	enum poll_states poll_status;
+	/* Lock to protect access to poll_status */
+	spinlock_t poll_lock;
+	refcount_t users;
+};
+
+static struct scmi_transport_core_operations *core;
+
+/* Only one SCMI VirtIO device can possibly exist */
+static struct virtio_device *scmi_vdev;
+
+static DEFINE_SCMI_TRANSPORT_SUPPLIER(scmi_virtio_supplier);
+
+static void scmi_vio_channel_ready(struct scmi_vio_channel *vioch,
+				   struct scmi_chan_info *cinfo)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&vioch->lock, flags);
+	cinfo->transport_info = vioch;
+	/* Indirectly setting channel not available any more */
+	vioch->cinfo = cinfo;
+	spin_unlock_irqrestore(&vioch->lock, flags);
+
+	refcount_set(&vioch->users, 1);
+}
+
+static inline bool scmi_vio_channel_acquire(struct scmi_vio_channel *vioch)
+{
+	return refcount_inc_not_zero(&vioch->users);
+}
+
+static inline void scmi_vio_channel_release(struct scmi_vio_channel *vioch)
+{
+	if (refcount_dec_and_test(&vioch->users)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&vioch->lock, flags);
+		if (vioch->shutdown_done) {
+			vioch->cinfo = NULL;
+			complete(vioch->shutdown_done);
+		}
+		spin_unlock_irqrestore(&vioch->lock, flags);
+	}
+}
+
+static void scmi_vio_channel_cleanup_sync(struct scmi_vio_channel *vioch)
+{
+	unsigned long flags;
+	DECLARE_COMPLETION_ONSTACK(vioch_shutdown_done);
+
+	/*
+	 * Prepare to wait for the last release if not already released
+	 * or in progress.
+	 */
+	spin_lock_irqsave(&vioch->lock, flags);
+	if (!vioch->cinfo || vioch->shutdown_done) {
+		spin_unlock_irqrestore(&vioch->lock, flags);
+		return;
+	}
+
+	vioch->shutdown_done = &vioch_shutdown_done;
+	if (!vioch->is_rx && vioch->deferred_tx_wq)
+		/* Cannot be kicked anymore after this...*/
+		vioch->deferred_tx_wq = NULL;
+	spin_unlock_irqrestore(&vioch->lock, flags);
+
+	scmi_vio_channel_release(vioch);
+
+	/* Let any possibly concurrent RX path release the channel */
+	wait_for_completion(vioch->shutdown_done);
+}
+
+/* Assumes to be called with vio channel acquired already */
+static struct scmi_vio_msg *
+scmi_virtio_get_free_msg(struct scmi_vio_channel *vioch)
+{
+	unsigned long flags;
+	struct scmi_vio_msg *msg;
+
+	spin_lock_irqsave(&vioch->free_lock, flags);
+	if (list_empty(&vioch->free_list)) {
+		spin_unlock_irqrestore(&vioch->free_lock, flags);
+		return NULL;
+	}
+
+	msg = list_first_entry(&vioch->free_list, typeof(*msg), list);
+	list_del_init(&msg->list);
+	spin_unlock_irqrestore(&vioch->free_lock, flags);
+
+	/* Still no users, no need to acquire poll_lock */
+	msg->poll_status = VIO_MSG_NOT_POLLED;
+	refcount_set(&msg->users, 1);
+
+	return msg;
+}
+
+static inline bool scmi_vio_msg_acquire(struct scmi_vio_msg *msg)
+{
+	return refcount_inc_not_zero(&msg->users);
+}
+
+/* Assumes to be called with vio channel acquired already */
+static inline bool scmi_vio_msg_release(struct scmi_vio_channel *vioch,
+					struct scmi_vio_msg *msg)
+{
+	bool ret;
+
+	ret = refcount_dec_and_test(&msg->users);
+	if (ret) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&vioch->free_lock, flags);
+		list_add_tail(&msg->list, &vioch->free_list);
+		spin_unlock_irqrestore(&vioch->free_lock, flags);
+	}
+
+	return ret;
+}
+
+static bool scmi_vio_have_vq_rx(struct virtio_device *vdev)
+{
+	return virtio_has_feature(vdev, VIRTIO_SCMI_F_P2A_CHANNELS);
+}
+
+static int scmi_vio_feed_vq_rx(struct scmi_vio_channel *vioch,
+			       struct scmi_vio_msg *msg)
+{
+	struct scatterlist sg_in;
+	int rc;
+	unsigned long flags;
+	struct device *dev = &vioch->vqueue->vdev->dev;
+
+	sg_init_one(&sg_in, msg->input, msg->max_len);
+
+	spin_lock_irqsave(&vioch->lock, flags);
+
+	rc = virtqueue_add_inbuf(vioch->vqueue, &sg_in, 1, msg, GFP_ATOMIC);
+	if (rc)
+		dev_err(dev, "failed to add to RX virtqueue (%d)\n", rc);
+	else
+		virtqueue_kick(vioch->vqueue);
+
+	spin_unlock_irqrestore(&vioch->lock, flags);
+
+	return rc;
+}
+
+/*
+ * Assume to be called with channel already acquired or not ready at all;
+ * vioch->lock MUST NOT have been already acquired.
+ */
+static void scmi_finalize_message(struct scmi_vio_channel *vioch,
+				  struct scmi_vio_msg *msg)
+{
+	if (vioch->is_rx)
+		scmi_vio_feed_vq_rx(vioch, msg);
+	else
+		scmi_vio_msg_release(vioch, msg);
+}
+
+static void scmi_vio_complete_cb(struct virtqueue *vqueue)
+{
+	unsigned long flags;
+	unsigned int length;
+	struct scmi_vio_channel *vioch;
+	struct scmi_vio_msg *msg;
+	bool cb_enabled = true;
+
+	if (WARN_ON_ONCE(!vqueue->vdev->priv))
+		return;
+	vioch = &((struct scmi_vio_channel *)vqueue->vdev->priv)[vqueue->index];
+
+	for (;;) {
+		if (!scmi_vio_channel_acquire(vioch))
+			return;
+
+		spin_lock_irqsave(&vioch->lock, flags);
+		if (cb_enabled) {
+			virtqueue_disable_cb(vqueue);
+			cb_enabled = false;
+		}
+
+		msg = virtqueue_get_buf(vqueue, &length);
+		if (!msg) {
+			if (virtqueue_enable_cb(vqueue)) {
+				spin_unlock_irqrestore(&vioch->lock, flags);
+				scmi_vio_channel_release(vioch);
+				return;
+			}
+			cb_enabled = true;
+		}
+		spin_unlock_irqrestore(&vioch->lock, flags);
+
+		if (msg) {
+			msg->rx_len = length;
+			core->rx_callback(vioch->cinfo,
+					  core->msg->read_header(msg->input),
+					  msg);
+
+			scmi_finalize_message(vioch, msg);
+		}
+
+		/*
+		 * Release vio channel between loop iterations to allow
+		 * virtio_chan_free() to eventually fully release it when
+		 * shutting down; in such a case, any outstanding message will
+		 * be ignored since this loop will bail out at the next
+		 * iteration.
+		 */
+		scmi_vio_channel_release(vioch);
+	}
+}
+
+static void scmi_vio_deferred_tx_worker(struct work_struct *work)
+{
+	unsigned long flags;
+	struct scmi_vio_channel *vioch;
+	struct scmi_vio_msg *msg, *tmp;
+
+	vioch = container_of(work, struct scmi_vio_channel, deferred_tx_work);
+
+	if (!scmi_vio_channel_acquire(vioch))
+		return;
+
+	/*
+	 * Process pre-fetched messages: these could be non-polled messages or
+	 * late timed-out replies to polled messages dequeued by chance while
+	 * polling for some other messages: this worker is in charge to process
+	 * the valid non-expired messages and anyway finally free all of them.
+	 */
+	spin_lock_irqsave(&vioch->pending_lock, flags);
+
+	/* Scan the list of possibly pre-fetched messages during polling. */
+	list_for_each_entry_safe(msg, tmp, &vioch->pending_cmds_list, list) {
+		list_del(&msg->list);
+
+		/*
+		 * Channel is acquired here (cannot vanish) and this message
+		 * is no more processed elsewhere so no poll_lock needed.
+		 */
+		if (msg->poll_status == VIO_MSG_NOT_POLLED)
+			core->rx_callback(vioch->cinfo,
+					  core->msg->read_header(msg->input),
+					  msg);
+
+		/* Free the processed message once done */
+		scmi_vio_msg_release(vioch, msg);
+	}
+
+	spin_unlock_irqrestore(&vioch->pending_lock, flags);
+
+	/* Process possibly still pending messages */
+	scmi_vio_complete_cb(vioch->vqueue);
+
+	scmi_vio_channel_release(vioch);
+}
+
+static struct virtqueue_info scmi_vio_vqs_info[] = {
+	{ "tx", scmi_vio_complete_cb },
+	{ "rx", scmi_vio_complete_cb },
+};
+
+static unsigned int virtio_get_max_msg(struct scmi_chan_info *base_cinfo)
+{
+	struct scmi_vio_channel *vioch = base_cinfo->transport_info;
+
+	return vioch->max_msg;
+}
+
+static bool virtio_chan_available(struct device_node *of_node, int idx)
+{
+	struct scmi_vio_channel *channels, *vioch = NULL;
+
+	if (WARN_ON_ONCE(!scmi_vdev))
+		return false;
+
+	channels = (struct scmi_vio_channel *)scmi_vdev->priv;
+
+	switch (idx) {
+	case VIRTIO_SCMI_VQ_TX:
+		vioch = &channels[VIRTIO_SCMI_VQ_TX];
+		break;
+	case VIRTIO_SCMI_VQ_RX:
+		if (scmi_vio_have_vq_rx(scmi_vdev))
+			vioch = &channels[VIRTIO_SCMI_VQ_RX];
+		break;
+	default:
+		return false;
+	}
+
+	dev_dbg(&scmi_vdev->dev, "%s Channel %sAVAILABLE on SCMI Virtio device.\n",
+		idx == VIRTIO_SCMI_VQ_TX ? "TX" : "RX",
+		(vioch && !vioch->cinfo) ? "" : "NOT ");
+
+	return vioch && !vioch->cinfo;
+}
+
+static void scmi_destroy_tx_workqueue(void *deferred_tx_wq)
+{
+	destroy_workqueue(deferred_tx_wq);
+}
+
+static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+			     bool tx)
+{
+	struct scmi_vio_channel *vioch;
+	int index = tx ? VIRTIO_SCMI_VQ_TX : VIRTIO_SCMI_VQ_RX;
+	int i;
+
+	if (!scmi_vdev)
+		return -EINVAL;
+
+	vioch = &((struct scmi_vio_channel *)scmi_vdev->priv)[index];
+
+	/* Setup a deferred worker for polling. */
+	if (tx && !vioch->deferred_tx_wq) {
+		int ret;
+
+		vioch->deferred_tx_wq =
+			alloc_workqueue(dev_name(&scmi_vdev->dev),
+					WQ_UNBOUND | WQ_FREEZABLE | WQ_SYSFS,
+					0);
+		if (!vioch->deferred_tx_wq)
+			return -ENOMEM;
+
+		ret = devm_add_action_or_reset(dev, scmi_destroy_tx_workqueue,
+					       vioch->deferred_tx_wq);
+		if (ret)
+			return ret;
+
+		INIT_WORK(&vioch->deferred_tx_work,
+			  scmi_vio_deferred_tx_worker);
+	}
+
+	for (i = 0; i < vioch->max_msg; i++) {
+		struct scmi_vio_msg *msg;
+
+		msg = devm_kzalloc(dev, sizeof(*msg), GFP_KERNEL);
+		if (!msg)
+			return -ENOMEM;
+
+		msg->max_len = VIRTIO_SCMI_MAX_PDU_SIZE(cinfo);
+		if (tx) {
+			msg->request = devm_kzalloc(dev, msg->max_len,
+						    GFP_KERNEL);
+			if (!msg->request)
+				return -ENOMEM;
+			spin_lock_init(&msg->poll_lock);
+			refcount_set(&msg->users, 1);
+		}
+
+		msg->input = devm_kzalloc(dev, msg->max_len, GFP_KERNEL);
+		if (!msg->input)
+			return -ENOMEM;
+
+		scmi_finalize_message(vioch, msg);
+	}
+
+	scmi_vio_channel_ready(vioch, cinfo);
+
+	dev_dbg(&scmi_vdev->dev, "%s Channel SETUP on SCMI Virtio device.\n",
+		tx ? "TX" : "RX");
+
+	return 0;
+}
+
+static int virtio_chan_free(int id, void *p, void *data)
+{
+	struct scmi_chan_info *cinfo = p;
+	struct scmi_vio_channel *vioch = cinfo->transport_info;
+
+	/*
+	 * Break device to inhibit further traffic flowing while shutting down
+	 * the channels: doing it later holding vioch->lock creates unsafe
+	 * locking dependency chains as reported by LOCKDEP.
+	 */
+	virtio_break_device(vioch->vqueue->vdev);
+	scmi_vio_channel_cleanup_sync(vioch);
+
+	return 0;
+}
+
+static int virtio_send_message(struct scmi_chan_info *cinfo,
+			       struct scmi_xfer *xfer)
+{
+	struct scmi_vio_channel *vioch = cinfo->transport_info;
+	struct scatterlist sg_out;
+	struct scatterlist sg_in;
+	struct scatterlist *sgs[DESCRIPTORS_PER_TX_MSG] = { &sg_out, &sg_in };
+	unsigned long flags;
+	int rc;
+	struct scmi_vio_msg *msg;
+
+	if (!scmi_vio_channel_acquire(vioch))
+		return -EINVAL;
+
+	msg = scmi_virtio_get_free_msg(vioch);
+	if (!msg) {
+		scmi_vio_channel_release(vioch);
+		return -EBUSY;
+	}
+
+	core->msg->tx_prepare(msg->request, xfer);
+
+	sg_init_one(&sg_out, msg->request, core->msg->command_size(xfer));
+	sg_init_one(&sg_in, msg->input, core->msg->response_size(xfer));
+
+	spin_lock_irqsave(&vioch->lock, flags);
+
+	/*
+	 * If polling was requested for this transaction:
+	 *  - retrieve last used index (will be used as polling reference)
+	 *  - bind the polled message to the xfer via .priv
+	 *  - grab an additional msg refcount for the poll-path
+	 */
+	if (xfer->hdr.poll_completion) {
+		msg->poll_idx = virtqueue_enable_cb_prepare(vioch->vqueue);
+		/* Still no users, no need to acquire poll_lock */
+		msg->poll_status = VIO_MSG_POLLING;
+		scmi_vio_msg_acquire(msg);
+		/* Ensure initialized msg is visibly bound to xfer */
+		smp_store_mb(xfer->priv, msg);
+	}
+
+	rc = virtqueue_add_sgs(vioch->vqueue, sgs, 1, 1, msg, GFP_ATOMIC);
+	if (rc)
+		dev_err(vioch->cinfo->dev,
+			"failed to add to TX virtqueue (%d)\n", rc);
+	else
+		virtqueue_kick(vioch->vqueue);
+
+	spin_unlock_irqrestore(&vioch->lock, flags);
+
+	if (rc) {
+		/* Ensure order between xfer->priv clear and vq feeding */
+		smp_store_mb(xfer->priv, NULL);
+		if (xfer->hdr.poll_completion)
+			scmi_vio_msg_release(vioch, msg);
+		scmi_vio_msg_release(vioch, msg);
+	}
+
+	scmi_vio_channel_release(vioch);
+
+	return rc;
+}
+
+static void virtio_fetch_response(struct scmi_chan_info *cinfo,
+				  struct scmi_xfer *xfer)
+{
+	struct scmi_vio_msg *msg = xfer->priv;
+
+	if (msg)
+		core->msg->fetch_response(msg->input, msg->rx_len, xfer);
+}
+
+static void virtio_fetch_notification(struct scmi_chan_info *cinfo,
+				      size_t max_len, struct scmi_xfer *xfer)
+{
+	struct scmi_vio_msg *msg = xfer->priv;
+
+	if (msg)
+		core->msg->fetch_notification(msg->input, msg->rx_len,
+					      max_len, xfer);
+}
+
+/**
+ * virtio_mark_txdone  - Mark transmission done
+ *
+ * Free only completed polling transfer messages.
+ *
+ * Note that in the SCMI VirtIO transport we never explicitly release still
+ * outstanding but timed-out messages by forcibly re-adding them to the
+ * free-list inside the TX code path; we instead let IRQ/RX callbacks, or the
+ * TX deferred worker, eventually clean up such messages once, finally, a late
+ * reply is received and discarded (if ever).
+ *
+ * This approach was deemed preferable since those pending timed-out buffers are
+ * still effectively owned by the SCMI platform VirtIO device even after timeout
+ * expiration: forcibly freeing and reusing them before they had been returned
+ * explicitly by the SCMI platform could lead to subtle bugs due to message
+ * corruption.
+ * An SCMI platform VirtIO device which never returns message buffers is
+ * anyway broken and it will quickly lead to exhaustion of available messages.
+ *
+ * For this same reason, here, we take care to free only the polled messages
+ * that had been somehow replied (only if not by chance already processed on the
+ * IRQ path - the initial scmi_vio_msg_release() takes care of this) and also
+ * any timed-out polled message if that indeed appears to have been at least
+ * dequeued from the virtqueues (VIO_MSG_POLL_DONE): this is needed since such
+ * messages won't be freed elsewhere. Any other polled message is marked as
+ * VIO_MSG_POLL_TIMEOUT.
+ *
+ * Possible late replies to timed-out polled messages will be eventually freed
+ * by RX callbacks if delivered on the IRQ path or by the deferred TX worker if
+ * dequeued on some other polling path.
+ *
+ * @cinfo: SCMI channel info
+ * @ret: Transmission return code
+ * @xfer: Transfer descriptor
+ */
+static void virtio_mark_txdone(struct scmi_chan_info *cinfo, int ret,
+			       struct scmi_xfer *xfer)
+{
+	unsigned long flags;
+	struct scmi_vio_channel *vioch = cinfo->transport_info;
+	struct scmi_vio_msg *msg = xfer->priv;
+
+	if (!msg || !scmi_vio_channel_acquire(vioch))
+		return;
+
+	/* Ensure msg is unbound from xfer anyway at this point */
+	smp_store_mb(xfer->priv, NULL);
+
+	/* Must be a polled xfer and not already freed on the IRQ path */
+	if (!xfer->hdr.poll_completion || scmi_vio_msg_release(vioch, msg)) {
+		scmi_vio_channel_release(vioch);
+		return;
+	}
+
+	spin_lock_irqsave(&msg->poll_lock, flags);
+	/* Do not free timedout polled messages only if still inflight */
+	if (ret != -ETIMEDOUT || msg->poll_status == VIO_MSG_POLL_DONE)
+		scmi_vio_msg_release(vioch, msg);
+	else if (msg->poll_status == VIO_MSG_POLLING)
+		msg->poll_status = VIO_MSG_POLL_TIMEOUT;
+	spin_unlock_irqrestore(&msg->poll_lock, flags);
+
+	scmi_vio_channel_release(vioch);
+}
+
+/**
+ * virtio_poll_done  - Provide polling support for VirtIO transport
+ *
+ * @cinfo: SCMI channel info
+ * @xfer: Reference to the transfer being poll for.
+ *
+ * VirtIO core provides a polling mechanism based only on last used indexes:
+ * this means that it is possible to poll the virtqueues waiting for something
+ * new to arrive from the host side, but the only way to check if the freshly
+ * arrived buffer was indeed what we were waiting for is to compare the newly
+ * arrived message descriptor with the one we are polling on.
+ *
+ * As a consequence it can happen to dequeue something different from the buffer
+ * we were poll-waiting for: if that is the case such early fetched buffers are
+ * then added to a the @pending_cmds_list list for later processing by a
+ * dedicated deferred worker.
+ *
+ * So, basically, once something new is spotted we proceed to de-queue all the
+ * freshly received used buffers until we found the one we were polling on, or,
+ * we have 'seemingly' emptied the virtqueue; if some buffers are still pending
+ * in the vqueue at the end of the polling loop (possible due to inherent races
+ * in virtqueues handling mechanisms), we similarly kick the deferred worker
+ * and let it process those, to avoid indefinitely looping in the .poll_done
+ * busy-waiting helper.
+ *
+ * Finally, we delegate to the deferred worker also the final free of any timed
+ * out reply to a polled message that we should dequeue.
+ *
+ * Note that, since we do NOT have per-message suppress notification mechanism,
+ * the message we are polling for could be alternatively delivered via usual
+ * IRQs callbacks on another core which happened to have IRQs enabled while we
+ * are actively polling for it here: in such a case it will be handled as such
+ * by rx_callback() and the polling loop in the SCMI Core TX path will be
+ * transparently terminated anyway.
+ *
+ * Return: True once polling has successfully completed.
+ */
+static bool virtio_poll_done(struct scmi_chan_info *cinfo,
+			     struct scmi_xfer *xfer)
+{
+	bool pending, found = false;
+	unsigned int length, any_prefetched = 0;
+	unsigned long flags;
+	struct scmi_vio_msg *next_msg, *msg = xfer->priv;
+	struct scmi_vio_channel *vioch = cinfo->transport_info;
+
+	if (!msg)
+		return true;
+
+	/*
+	 * Processed already by other polling loop on another CPU ?
+	 *
+	 * Note that this message is acquired on the poll path so cannot vanish
+	 * while inside this loop iteration even if concurrently processed on
+	 * the IRQ path.
+	 *
+	 * Avoid to acquire poll_lock since polled_status can be changed
+	 * in a relevant manner only later in this same thread of execution:
+	 * any other possible changes made concurrently by other polling loops
+	 * or by a reply delivered on the IRQ path have no meaningful impact on
+	 * this loop iteration: in other words it is harmless to allow this
+	 * possible race but let has avoid spinlocking with irqs off in this
+	 * initial part of the polling loop.
+	 */
+	if (msg->poll_status == VIO_MSG_POLL_DONE)
+		return true;
+
+	if (!scmi_vio_channel_acquire(vioch))
+		return true;
+
+	/* Has cmdq index moved at all ? */
+	pending = virtqueue_poll(vioch->vqueue, msg->poll_idx);
+	if (!pending) {
+		scmi_vio_channel_release(vioch);
+		return false;
+	}
+
+	spin_lock_irqsave(&vioch->lock, flags);
+	virtqueue_disable_cb(vioch->vqueue);
+
+	/*
+	 * Process all new messages till the polled-for message is found OR
+	 * the vqueue is empty.
+	 */
+	while ((next_msg = virtqueue_get_buf(vioch->vqueue, &length))) {
+		bool next_msg_done = false;
+
+		/*
+		 * Mark any dequeued buffer message as VIO_MSG_POLL_DONE so
+		 * that can be properly freed even on timeout in mark_txdone.
+		 */
+		spin_lock(&next_msg->poll_lock);
+		if (next_msg->poll_status == VIO_MSG_POLLING) {
+			next_msg->poll_status = VIO_MSG_POLL_DONE;
+			next_msg_done = true;
+		}
+		spin_unlock(&next_msg->poll_lock);
+
+		next_msg->rx_len = length;
+		/* Is the message we were polling for ? */
+		if (next_msg == msg) {
+			found = true;
+			break;
+		} else if (next_msg_done) {
+			/* Skip the rest if this was another polled msg */
+			continue;
+		}
+
+		/*
+		 * Enqueue for later processing any non-polled message and any
+		 * timed-out polled one that we happen to have dequeued.
+		 */
+		spin_lock(&next_msg->poll_lock);
+		if (next_msg->poll_status == VIO_MSG_NOT_POLLED ||
+		    next_msg->poll_status == VIO_MSG_POLL_TIMEOUT) {
+			spin_unlock(&next_msg->poll_lock);
+
+			any_prefetched++;
+			spin_lock(&vioch->pending_lock);
+			list_add_tail(&next_msg->list,
+				      &vioch->pending_cmds_list);
+			spin_unlock(&vioch->pending_lock);
+		} else {
+			spin_unlock(&next_msg->poll_lock);
+		}
+	}
+
+	/*
+	 * When the polling loop has successfully terminated if something
+	 * else was queued in the meantime, it will be served by a deferred
+	 * worker OR by the normal IRQ/callback OR by other poll loops.
+	 *
+	 * If we are still looking for the polled reply, the polling index has
+	 * to be updated to the current vqueue last used index.
+	 */
+	if (found) {
+		pending = !virtqueue_enable_cb(vioch->vqueue);
+	} else {
+		msg->poll_idx = virtqueue_enable_cb_prepare(vioch->vqueue);
+		pending = virtqueue_poll(vioch->vqueue, msg->poll_idx);
+	}
+
+	if (vioch->deferred_tx_wq && (any_prefetched || pending))
+		queue_work(vioch->deferred_tx_wq, &vioch->deferred_tx_work);
+
+	spin_unlock_irqrestore(&vioch->lock, flags);
+
+	scmi_vio_channel_release(vioch);
+
+	return found;
+}
+
+static const struct scmi_transport_ops scmi_virtio_ops = {
+	.chan_available = virtio_chan_available,
+	.chan_setup = virtio_chan_setup,
+	.chan_free = virtio_chan_free,
+	.get_max_msg = virtio_get_max_msg,
+	.send_message = virtio_send_message,
+	.fetch_response = virtio_fetch_response,
+	.fetch_notification = virtio_fetch_notification,
+	.mark_txdone = virtio_mark_txdone,
+	.poll_done = virtio_poll_done,
+};
+
+static struct scmi_desc scmi_virtio_desc = {
+	.ops = &scmi_virtio_ops,
+	/* for non-realtime virtio devices */
+	.max_rx_timeout_ms = VIRTIO_MAX_RX_TIMEOUT_MS,
+	.max_msg = 0, /* overridden by virtio_get_max_msg() */
+	.max_msg_size = VIRTIO_SCMI_MAX_MSG_SIZE,
+	.atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_ATOMIC_ENABLE),
+};
+
+static const struct of_device_id scmi_of_match[] = {
+	{ .compatible = "arm,scmi-virtio", .data = &scmi_virtio_supplier.th},
+	{ /* Sentinel */ },
+};
+
+DEFINE_SCMI_TRANSPORT_DRIVER(scmi_virtio, scmi_virtio_driver, scmi_virtio_desc,
+			     scmi_of_match, core);
+
+static int scmi_vio_probe(struct virtio_device *vdev)
+{
+	struct device *dev = &vdev->dev;
+	struct scmi_vio_channel *channels;
+	bool have_vq_rx;
+	int vq_cnt;
+	int i;
+	int ret;
+	struct virtqueue *vqs[VIRTIO_SCMI_VQ_MAX_CNT];
+
+	/* Only one SCMI VirtiO device allowed */
+	if (scmi_vdev) {
+		dev_err(dev,
+			"One SCMI Virtio device was already initialized: only one allowed.\n");
+		return -EBUSY;
+	}
+
+	have_vq_rx = scmi_vio_have_vq_rx(vdev);
+	vq_cnt = have_vq_rx ? VIRTIO_SCMI_VQ_MAX_CNT : 1;
+
+	channels = devm_kcalloc(dev, vq_cnt, sizeof(*channels), GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	if (have_vq_rx)
+		channels[VIRTIO_SCMI_VQ_RX].is_rx = true;
+
+	ret = virtio_find_vqs(vdev, vq_cnt, vqs, scmi_vio_vqs_info, NULL);
+	if (ret) {
+		dev_err(dev, "Failed to get %d virtqueue(s)\n", vq_cnt);
+		return ret;
+	}
+
+	for (i = 0; i < vq_cnt; i++) {
+		unsigned int sz;
+
+		spin_lock_init(&channels[i].lock);
+		spin_lock_init(&channels[i].free_lock);
+		INIT_LIST_HEAD(&channels[i].free_list);
+		spin_lock_init(&channels[i].pending_lock);
+		INIT_LIST_HEAD(&channels[i].pending_cmds_list);
+		channels[i].vqueue = vqs[i];
+
+		sz = virtqueue_get_vring_size(channels[i].vqueue);
+		/* Tx messages need multiple descriptors. */
+		if (!channels[i].is_rx)
+			sz /= DESCRIPTORS_PER_TX_MSG;
+
+		if (sz > MSG_TOKEN_MAX) {
+			dev_info(dev,
+				 "%s virtqueue could hold %d messages. Only %ld allowed to be pending.\n",
+				 channels[i].is_rx ? "rx" : "tx",
+				 sz, MSG_TOKEN_MAX);
+			sz = MSG_TOKEN_MAX;
+		}
+		channels[i].max_msg = sz;
+		dev_dbg(dev, "VQ%d initialized with max_msg: %d\n", i, sz);
+	}
+
+	vdev->priv = channels;
+	/* Ensure initialized scmi_vdev is visible */
+	smp_store_mb(scmi_vdev, vdev);
+
+	/* Set device ready */
+	virtio_device_ready(vdev);
+
+	ret = scmi_transport_supplier_put(&scmi_virtio_supplier.th, &vdev->dev);
+	if (ret) {
+		virtio_reset_device(vdev);
+		vdev->priv = NULL;
+		vdev->config->del_vqs(vdev);
+		/* Ensure NULLified scmi_vdev is visible */
+		smp_store_mb(scmi_vdev, NULL);
+		return ret;
+	}
+
+	dev_dbg(dev, "Probed and initialized SCMI Virtio device.\n");
+
+	return 0;
+}
+
+static void scmi_vio_remove(struct virtio_device *vdev)
+{
+	/*
+	 * Once we get here, virtio_chan_free() will have already been called by
+	 * the SCMI core for any existing channel and, as a consequence, all the
+	 * virtio channels will have been already marked NOT ready, causing any
+	 * outstanding message on any vqueue to be ignored by complete_cb: now
+	 * we can just stop processing buffers and destroy the vqueues.
+	 */
+	virtio_reset_device(vdev);
+	vdev->config->del_vqs(vdev);
+
+	/* Ensure scmi_vdev is visible as NULL */
+	smp_store_mb(scmi_vdev, NULL);
+	scmi_transport_supplier_put(&scmi_virtio_supplier.th, &vdev->dev);
+}
+
+static int scmi_vio_validate(struct virtio_device *vdev)
+{
+#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO_VERSION1_COMPLIANCE
+	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
+		dev_err(&vdev->dev,
+			"device does not comply with spec version 1.x\n");
+		return -EINVAL;
+	}
+#endif
+	return 0;
+}
+
+static unsigned int features[] = {
+	VIRTIO_SCMI_F_P2A_CHANNELS,
+};
+
+static const struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_SCMI, VIRTIO_DEV_ANY_ID },
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(virtio, id_table);
+
+static struct virtio_driver virtio_scmi_driver = {
+	.driver.name = "scmi-virtio",
+	.feature_table = features,
+	.feature_table_size = ARRAY_SIZE(features),
+	.id_table = id_table,
+	.probe = scmi_vio_probe,
+	.remove = scmi_vio_remove,
+	.validate = scmi_vio_validate,
+};
+
+static int __init scmi_transport_virtio_init(void)
+{
+	int ret;
+
+	ret = register_virtio_driver(&virtio_scmi_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&scmi_virtio_driver);
+	if (ret) {
+		unregister_virtio_driver(&virtio_scmi_driver);
+		return ret;
+	}
+
+	return ret;
+}
+module_init(scmi_transport_virtio_init);
+
+static void __exit scmi_transport_virtio_exit(void)
+{
+	platform_driver_unregister(&scmi_virtio_driver);
+	unregister_virtio_driver(&virtio_scmi_driver);
+}
+module_exit(scmi_transport_virtio_exit);
+
+MODULE_AUTHOR("Igor Skalkin <igor.skalkin@opensynergy.com>");
+MODULE_AUTHOR("Peter Hilber <peter.hilber@opensynergy.com>");
+MODULE_AUTHOR("Cristian Marussi <cristian.marussi@arm.com>");
+MODULE_DESCRIPTION("SCMI VirtIO Transport driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/Kconfig

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "ARM SCMI NXP i.MX Vendor Protocols"
+
+config IMX_SCMI_BBM_EXT
+	tristate "i.MX SCMI BBM EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System BBM control logic which supports RTC
+	  and BUTTON.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-bbm.
+
+config IMX_SCMI_CPU_EXT
+	tristate "i.MX SCMI CPU EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_CPU_DRV
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System CPU Protocol to manage cpu
+	  start, stop and etc.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-cpu.
+
+config IMX_SCMI_LMM_EXT
+	tristate "i.MX SCMI LMM EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_LMM_DRV
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System Logical Machine Protocol to
+	  manage Logical Machines boot, shutdown and etc.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-lmm.
+
+config IMX_SCMI_MISC_EXT
+	tristate "i.MX SCMI MISC EXTENSION"
+	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_MISC_DRV
+	default y if ARCH_MXC
+	help
+	  This enables i.MX System MISC control logic such as gpio expander
+	  wakeup
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx-sm-misc.
+endmenu

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/Makefile

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_IMX_SCMI_BBM_EXT) += imx-sm-bbm.o
+obj-$(CONFIG_IMX_SCMI_CPU_EXT) += imx-sm-cpu.o
+obj-$(CONFIG_IMX_SCMI_LMM_EXT) += imx-sm-lmm.o
+obj-$(CONFIG_IMX_SCMI_MISC_EXT) += imx-sm-misc.o

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/imx-sm-bbm.c

@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) NXP BBM Protocol
+ *
+ * Copyright 2024 NXP
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications BBM - " fmt
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+enum scmi_imx_bbm_protocol_cmd {
+	IMX_BBM_GPR_SET = 0x3,
+	IMX_BBM_GPR_GET = 0x4,
+	IMX_BBM_RTC_ATTRIBUTES = 0x5,
+	IMX_BBM_RTC_TIME_SET = 0x6,
+	IMX_BBM_RTC_TIME_GET = 0x7,
+	IMX_BBM_RTC_ALARM_SET = 0x8,
+	IMX_BBM_BUTTON_GET = 0x9,
+	IMX_BBM_RTC_NOTIFY = 0xA,
+	IMX_BBM_BUTTON_NOTIFY = 0xB,
+};
+
+#define GET_RTCS_NR(x)	le32_get_bits((x), GENMASK(23, 16))
+#define GET_GPRS_NR(x)	le32_get_bits((x), GENMASK(15, 0))
+
+#define SCMI_IMX_BBM_NOTIFY_RTC_UPDATED		BIT(2)
+#define SCMI_IMX_BBM_NOTIFY_RTC_ROLLOVER	BIT(1)
+#define SCMI_IMX_BBM_NOTIFY_RTC_ALARM		BIT(0)
+
+#define SCMI_IMX_BBM_RTC_ALARM_ENABLE_FLAG	BIT(0)
+
+#define SCMI_IMX_BBM_NOTIFY_RTC_FLAG	\
+	(SCMI_IMX_BBM_NOTIFY_RTC_UPDATED | SCMI_IMX_BBM_NOTIFY_RTC_ROLLOVER | \
+	 SCMI_IMX_BBM_NOTIFY_RTC_ALARM)
+
+#define SCMI_IMX_BBM_EVENT_RTC_MASK		GENMASK(31, 24)
+
+struct scmi_imx_bbm_info {
+	int nr_rtc;
+	int nr_gpr;
+};
+
+struct scmi_msg_imx_bbm_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_imx_bbm_set_time {
+	__le32 id;
+	__le32 flags;
+	__le32 value_low;
+	__le32 value_high;
+};
+
+struct scmi_imx_bbm_get_time {
+	__le32 id;
+	__le32 flags;
+};
+
+struct scmi_imx_bbm_alarm_time {
+	__le32 id;
+	__le32 flags;
+	__le32 value_low;
+	__le32 value_high;
+};
+
+struct scmi_msg_imx_bbm_rtc_notify {
+	__le32 rtc_id;
+	__le32 flags;
+};
+
+struct scmi_msg_imx_bbm_button_notify {
+	__le32 flags;
+};
+
+struct scmi_imx_bbm_notify_payld {
+	__le32 flags;
+};
+
+static int scmi_imx_bbm_attributes_get(const struct scmi_protocol_handle *ph,
+				       struct scmi_imx_bbm_info *pi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_imx_bbm_protocol_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		pi->nr_rtc = GET_RTCS_NR(attr->attributes);
+		pi->nr_gpr = GET_GPRS_NR(attr->attributes);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_bbm_notify(const struct scmi_protocol_handle *ph,
+			       u32 src_id, int message_id, bool enable)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	if (message_id == IMX_BBM_RTC_NOTIFY) {
+		struct scmi_msg_imx_bbm_rtc_notify *rtc_notify;
+
+		ret = ph->xops->xfer_get_init(ph, message_id,
+					      sizeof(*rtc_notify), 0, &t);
+		if (ret)
+			return ret;
+
+		rtc_notify = t->tx.buf;
+		rtc_notify->rtc_id = cpu_to_le32(0);
+		rtc_notify->flags =
+			cpu_to_le32(enable ? SCMI_IMX_BBM_NOTIFY_RTC_FLAG : 0);
+	} else if (message_id == IMX_BBM_BUTTON_NOTIFY) {
+		struct scmi_msg_imx_bbm_button_notify *button_notify;
+
+		ret = ph->xops->xfer_get_init(ph, message_id,
+					      sizeof(*button_notify), 0, &t);
+		if (ret)
+			return ret;
+
+		button_notify = t->tx.buf;
+		button_notify->flags = cpu_to_le32(enable ? 1 : 0);
+	} else {
+		return -EINVAL;
+	}
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static enum scmi_imx_bbm_protocol_cmd evt_2_cmd[] = {
+	IMX_BBM_RTC_NOTIFY,
+	IMX_BBM_BUTTON_NOTIFY
+};
+
+static int scmi_imx_bbm_set_notify_enabled(const struct scmi_protocol_handle *ph,
+					   u8 evt_id, u32 src_id, bool enable)
+{
+	int ret, cmd_id;
+
+	if (evt_id >= ARRAY_SIZE(evt_2_cmd))
+		return -EINVAL;
+
+	cmd_id = evt_2_cmd[evt_id];
+	ret = scmi_imx_bbm_notify(ph, src_id, cmd_id, enable);
+	if (ret)
+		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
+			 evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *scmi_imx_bbm_fill_custom_report(const struct scmi_protocol_handle *ph,
+					     u8 evt_id, ktime_t timestamp,
+					     const void *payld, size_t payld_sz,
+					     void *report, u32 *src_id)
+{
+	const struct scmi_imx_bbm_notify_payld *p = payld;
+	struct scmi_imx_bbm_notif_report *r = report;
+
+	if (sizeof(*p) != payld_sz)
+		return NULL;
+
+	if (evt_id == SCMI_EVENT_IMX_BBM_RTC) {
+		r->is_rtc = true;
+		r->is_button = false;
+		r->timestamp = timestamp;
+		r->rtc_id = le32_get_bits(p->flags, SCMI_IMX_BBM_EVENT_RTC_MASK);
+		r->rtc_evt = le32_get_bits(p->flags, SCMI_IMX_BBM_NOTIFY_RTC_FLAG);
+		dev_dbg(ph->dev, "RTC: %d evt: %x\n", r->rtc_id, r->rtc_evt);
+		*src_id = r->rtc_evt;
+	} else if (evt_id == SCMI_EVENT_IMX_BBM_BUTTON) {
+		r->is_rtc = false;
+		r->is_button = true;
+		r->timestamp = timestamp;
+		dev_dbg(ph->dev, "BBM Button\n");
+		*src_id = 0;
+	} else {
+		WARN_ON_ONCE(1);
+		return NULL;
+	}
+
+	return r;
+}
+
+static const struct scmi_event scmi_imx_bbm_events[] = {
+	{
+		.id = SCMI_EVENT_IMX_BBM_RTC,
+		.max_payld_sz = sizeof(struct scmi_imx_bbm_notify_payld),
+		.max_report_sz = sizeof(struct scmi_imx_bbm_notif_report),
+	},
+	{
+		.id = SCMI_EVENT_IMX_BBM_BUTTON,
+		.max_payld_sz = sizeof(struct scmi_imx_bbm_notify_payld),
+		.max_report_sz = sizeof(struct scmi_imx_bbm_notif_report),
+	},
+};
+
+static const struct scmi_event_ops scmi_imx_bbm_event_ops = {
+	.set_notify_enabled = scmi_imx_bbm_set_notify_enabled,
+	.fill_custom_report = scmi_imx_bbm_fill_custom_report,
+};
+
+static const struct scmi_protocol_events scmi_imx_bbm_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &scmi_imx_bbm_event_ops,
+	.evts = scmi_imx_bbm_events,
+	.num_events = ARRAY_SIZE(scmi_imx_bbm_events),
+	.num_sources = 1,
+};
+
+static int scmi_imx_bbm_rtc_time_set(const struct scmi_protocol_handle *ph,
+				     u32 rtc_id, u64 sec)
+{
+	struct scmi_imx_bbm_info *pi = ph->get_priv(ph);
+	struct scmi_imx_bbm_set_time *cfg;
+	struct scmi_xfer *t;
+	int ret;
+
+	if (rtc_id >= pi->nr_rtc)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, IMX_BBM_RTC_TIME_SET, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(rtc_id);
+	cfg->flags = 0;
+	cfg->value_low = cpu_to_le32(lower_32_bits(sec));
+	cfg->value_high = cpu_to_le32(upper_32_bits(sec));
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_bbm_rtc_time_get(const struct scmi_protocol_handle *ph,
+				     u32 rtc_id, u64 *value)
+{
+	struct scmi_imx_bbm_info *pi = ph->get_priv(ph);
+	struct scmi_imx_bbm_get_time *cfg;
+	struct scmi_xfer *t;
+	int ret;
+
+	if (rtc_id >= pi->nr_rtc)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, IMX_BBM_RTC_TIME_GET, sizeof(*cfg),
+				      sizeof(u64), &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(rtc_id);
+	cfg->flags = 0;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		*value = get_unaligned_le64(t->rx.buf);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_bbm_rtc_alarm_set(const struct scmi_protocol_handle *ph,
+				      u32 rtc_id, bool enable, u64 sec)
+{
+	struct scmi_imx_bbm_info *pi = ph->get_priv(ph);
+	struct scmi_imx_bbm_alarm_time *cfg;
+	struct scmi_xfer *t;
+	int ret;
+
+	if (rtc_id >= pi->nr_rtc)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, IMX_BBM_RTC_ALARM_SET, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->id = cpu_to_le32(rtc_id);
+	cfg->flags = enable ?
+		     cpu_to_le32(SCMI_IMX_BBM_RTC_ALARM_ENABLE_FLAG) : 0;
+	cfg->value_low = cpu_to_le32(lower_32_bits(sec));
+	cfg->value_high = cpu_to_le32(upper_32_bits(sec));
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_bbm_button_get(const struct scmi_protocol_handle *ph, u32 *state)
+{
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, IMX_BBM_BUTTON_GET, 0, sizeof(u32), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		*state = get_unaligned_le32(t->rx.buf);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_bbm_proto_ops scmi_imx_bbm_proto_ops = {
+	.rtc_time_get = scmi_imx_bbm_rtc_time_get,
+	.rtc_time_set = scmi_imx_bbm_rtc_time_set,
+	.rtc_alarm_set = scmi_imx_bbm_rtc_alarm_set,
+	.button_get = scmi_imx_bbm_button_get,
+};
+
+static int scmi_imx_bbm_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int ret;
+	struct scmi_imx_bbm_info *binfo;
+
+	dev_info(ph->dev, "NXP SM BBM Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	binfo = devm_kzalloc(ph->dev, sizeof(*binfo), GFP_KERNEL);
+	if (!binfo)
+		return -ENOMEM;
+
+	ret = scmi_imx_bbm_attributes_get(ph, binfo);
+	if (ret)
+		return ret;
+
+	return ph->set_priv(ph, binfo);
+}
+
+static const struct scmi_protocol scmi_imx_bbm = {
+	.id = SCMI_PROTOCOL_IMX_BBM,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_bbm_protocol_init,
+	.ops = &scmi_imx_bbm_proto_ops,
+	.events = &scmi_imx_bbm_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_bbm);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_BBM) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI BBM driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c

@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System control and Management Interface (SCMI) NXP CPU Protocol
+ *
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+enum scmi_imx_cpu_protocol_cmd {
+	SCMI_IMX_CPU_ATTRIBUTES	= 0x3,
+	SCMI_IMX_CPU_START = 0x4,
+	SCMI_IMX_CPU_STOP = 0x5,
+	SCMI_IMX_CPU_RESET_VECTOR_SET = 0x6,
+	SCMI_IMX_CPU_INFO_GET = 0xC,
+};
+
+struct scmi_imx_cpu_info {
+	u32 nr_cpu;
+};
+
+#define SCMI_IMX_CPU_NR_CPU_MASK	GENMASK(15, 0)
+struct scmi_msg_imx_cpu_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_msg_imx_cpu_attributes_out {
+	__le32 attributes;
+#define	CPU_MAX_NAME	16
+	u8 name[CPU_MAX_NAME];
+};
+
+struct scmi_imx_cpu_reset_vector_set_in {
+	__le32 cpuid;
+#define	CPU_VEC_FLAGS_RESUME	BIT(31)
+#define	CPU_VEC_FLAGS_START	BIT(30)
+#define	CPU_VEC_FLAGS_BOOT	BIT(29)
+	__le32 flags;
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+struct scmi_imx_cpu_info_get_out {
+#define	CPU_RUN_MODE_START	0
+#define	CPU_RUN_MODE_HOLD	1
+#define	CPU_RUN_MODE_STOP	2
+#define	CPU_RUN_MODE_SLEEP	3
+	__le32 runmode;
+	__le32 sleepmode;
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+static int scmi_imx_cpu_validate_cpuid(const struct scmi_protocol_handle *ph,
+				       u32 cpuid)
+{
+	struct scmi_imx_cpu_info *info = ph->get_priv(ph);
+
+	if (cpuid >= info->nr_cpu)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_imx_cpu_start(const struct scmi_protocol_handle *ph,
+			      u32 cpuid, bool start)
+{
+	struct scmi_xfer *t;
+	u8 msg_id;
+	int ret;
+
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	if (start)
+		msg_id = SCMI_IMX_CPU_START;
+	else
+		msg_id = SCMI_IMX_CPU_STOP;
+
+	ret = ph->xops->xfer_get_init(ph, msg_id, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_reset_vector_set(const struct scmi_protocol_handle *ph,
+					 u32 cpuid, u64 vector, bool start,
+					 bool boot, bool resume)
+{
+	struct scmi_imx_cpu_reset_vector_set_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_RESET_VECTOR_SET, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->cpuid = cpu_to_le32(cpuid);
+	in->flags = cpu_to_le32(0);
+	if (start)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_START);
+	if (boot)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_BOOT);
+	if (resume)
+		in->flags |= le32_encode_bits(1, CPU_VEC_FLAGS_RESUME);
+	in->resetvectorlow = cpu_to_le32(lower_32_bits(vector));
+	in->resetvectorhigh = cpu_to_le32(upper_32_bits(vector));
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_started(const struct scmi_protocol_handle *ph, u32 cpuid,
+				bool *started)
+{
+	struct scmi_imx_cpu_info_get_out *out;
+	struct scmi_xfer *t;
+	u32 mode;
+	int ret;
+
+	if (!started)
+		return -EINVAL;
+
+	*started = false;
+	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_INFO_GET, sizeof(u32),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		mode = le32_to_cpu(out->runmode);
+		if (mode == CPU_RUN_MODE_START || mode == CPU_RUN_MODE_SLEEP)
+			*started = true;
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_cpu_proto_ops scmi_imx_cpu_proto_ops = {
+	.cpu_reset_vector_set = scmi_imx_cpu_reset_vector_set,
+	.cpu_start = scmi_imx_cpu_start,
+	.cpu_started = scmi_imx_cpu_started,
+};
+
+static int scmi_imx_cpu_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+						struct scmi_imx_cpu_info *info)
+{
+	struct scmi_msg_imx_cpu_protocol_attributes *attr;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		info->nr_cpu = le32_get_bits(attr->attributes, SCMI_IMX_CPU_NR_CPU_MASK);
+		dev_info(ph->dev, "i.MX SM CPU: %d cpus\n",
+			 info->nr_cpu);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_attributes_get(const struct scmi_protocol_handle *ph,
+				       u32 cpuid)
+{
+	struct scmi_msg_imx_cpu_attributes_out *out;
+	char name[SCMI_SHORT_NAME_MAX_SIZE] = {'\0'};
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_ATTRIBUTES, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(cpuid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		strscpy(name, out->name, SCMI_SHORT_NAME_MAX_SIZE);
+		dev_info(ph->dev, "i.MX CPU: name: %s\n", name);
+	} else {
+		dev_err(ph->dev, "i.MX cpu: Failed to get info of cpu(%u)\n", cpuid);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_cpu_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_cpu_info *info;
+	int ret, i;
+
+	dev_info(ph->dev, "NXP SM CPU Protocol Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	info = devm_kzalloc(ph->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = scmi_imx_cpu_protocol_attributes_get(ph, info);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < info->nr_cpu; i++) {
+		ret = scmi_imx_cpu_attributes_get(ph, i);
+		if (ret)
+			return ret;
+	}
+
+	return ph->set_priv(ph, info);
+}
+
+static const struct scmi_protocol scmi_imx_cpu = {
+	.id = SCMI_PROTOCOL_IMX_CPU,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_cpu_protocol_init,
+	.ops = &scmi_imx_cpu_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_cpu);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_CPU) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI CPU driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/imx-sm-lmm.c

@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System control and Management Interface (SCMI) NXP LMM Protocol
+ *
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+enum scmi_imx_lmm_protocol_cmd {
+	SCMI_IMX_LMM_ATTRIBUTES	= 0x3,
+	SCMI_IMX_LMM_BOOT = 0x4,
+	SCMI_IMX_LMM_RESET = 0x5,
+	SCMI_IMX_LMM_SHUTDOWN = 0x6,
+	SCMI_IMX_LMM_WAKE = 0x7,
+	SCMI_IMX_LMM_SUSPEND = 0x8,
+	SCMI_IMX_LMM_NOTIFY = 0x9,
+	SCMI_IMX_LMM_RESET_REASON = 0xA,
+	SCMI_IMX_LMM_POWER_ON = 0xB,
+	SCMI_IMX_LMM_RESET_VECTOR_SET = 0xC,
+};
+
+struct scmi_imx_lmm_priv {
+	u32 nr_lmm;
+};
+
+#define SCMI_IMX_LMM_NR_LM_MASK	GENMASK(5, 0)
+#define SCMI_IMX_LMM_NR_MAX	16
+struct scmi_msg_imx_lmm_protocol_attributes {
+	__le32 attributes;
+};
+
+struct scmi_msg_imx_lmm_attributes_out {
+	__le32 lmid;
+	__le32 attributes;
+	__le32 state;
+	__le32 errstatus;
+	u8 name[LMM_MAX_NAME];
+};
+
+struct scmi_imx_lmm_reset_vector_set_in {
+	__le32 lmid;
+	__le32 cpuid;
+	__le32 flags; /* reserved for future extension */
+	__le32 resetvectorlow;
+	__le32 resetvectorhigh;
+};
+
+struct scmi_imx_lmm_shutdown_in {
+	__le32 lmid;
+#define SCMI_IMX_LMM_SHUTDOWN_GRACEFUL	BIT(0)
+	__le32 flags;
+};
+
+static int scmi_imx_lmm_validate_lmid(const struct scmi_protocol_handle *ph, u32 lmid)
+{
+	struct scmi_imx_lmm_priv *priv = ph->get_priv(ph);
+
+	if (lmid >= priv->nr_lmm)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_imx_lmm_attributes(const struct scmi_protocol_handle *ph,
+				   u32 lmid, struct scmi_imx_lmm_info *info)
+{
+	struct scmi_msg_imx_lmm_attributes_out *out;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_ATTRIBUTES, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(lmid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		info->lmid = le32_to_cpu(out->lmid);
+		info->state = le32_to_cpu(out->state);
+		info->errstatus = le32_to_cpu(out->errstatus);
+		strscpy(info->name, out->name);
+		dev_dbg(ph->dev, "i.MX LMM: Logical Machine(%d), name: %s\n",
+			info->lmid, info->name);
+	} else {
+		dev_err(ph->dev, "i.MX LMM: Failed to get info of Logical Machine(%u)\n", lmid);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int
+scmi_imx_lmm_power_boot(const struct scmi_protocol_handle *ph, u32 lmid, bool boot)
+{
+	struct scmi_xfer *t;
+	u8 msg_id;
+	int ret;
+
+	ret = scmi_imx_lmm_validate_lmid(ph, lmid);
+	if (ret)
+		return ret;
+
+	if (boot)
+		msg_id = SCMI_IMX_LMM_BOOT;
+	else
+		msg_id = SCMI_IMX_LMM_POWER_ON;
+
+	ret = ph->xops->xfer_get_init(ph, msg_id, sizeof(u32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(lmid, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_reset_vector_set(const struct scmi_protocol_handle *ph,
+					 u32 lmid, u32 cpuid, u32 flags, u64 vector)
+{
+	struct scmi_imx_lmm_reset_vector_set_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_RESET_VECTOR_SET, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->lmid = cpu_to_le32(lmid);
+	in->cpuid = cpu_to_le32(cpuid);
+	in->flags = cpu_to_le32(0);
+	in->resetvectorlow = cpu_to_le32(lower_32_bits(vector));
+	in->resetvectorhigh = cpu_to_le32(upper_32_bits(vector));
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_shutdown(const struct scmi_protocol_handle *ph, u32 lmid,
+				 u32 flags)
+{
+	struct scmi_imx_lmm_shutdown_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = scmi_imx_lmm_validate_lmid(ph, lmid);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_LMM_SHUTDOWN, sizeof(*in),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->lmid = cpu_to_le32(lmid);
+	if (flags & SCMI_IMX_LMM_SHUTDOWN_GRACEFUL)
+		in->flags = cpu_to_le32(SCMI_IMX_LMM_SHUTDOWN_GRACEFUL);
+	else
+		in->flags = cpu_to_le32(0);
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_lmm_proto_ops scmi_imx_lmm_proto_ops = {
+	.lmm_power_boot = scmi_imx_lmm_power_boot,
+	.lmm_info = scmi_imx_lmm_attributes,
+	.lmm_reset_vector_set = scmi_imx_lmm_reset_vector_set,
+	.lmm_shutdown = scmi_imx_lmm_shutdown,
+};
+
+static int scmi_imx_lmm_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+						struct scmi_imx_lmm_priv *priv)
+{
+	struct scmi_msg_imx_lmm_protocol_attributes *attr;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		priv->nr_lmm = le32_get_bits(attr->attributes, SCMI_IMX_LMM_NR_LM_MASK);
+		if (priv->nr_lmm > SCMI_IMX_LMM_NR_MAX) {
+			dev_err(ph->dev, "i.MX LMM: %d:Exceed max supported Logical Machines\n",
+				priv->nr_lmm);
+			ret = -EINVAL;
+		} else {
+			dev_info(ph->dev, "i.MX LMM: %d Logical Machines\n", priv->nr_lmm);
+		}
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_lmm_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_lmm_priv *info;
+	int ret;
+
+	dev_info(ph->dev, "NXP SM LMM Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	info = devm_kzalloc(ph->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = scmi_imx_lmm_protocol_attributes_get(ph, info);
+	if (ret)
+		return ret;
+
+	return ph->set_priv(ph, info);
+}
+
+static const struct scmi_protocol scmi_imx_lmm = {
+	.id = SCMI_PROTOCOL_IMX_LMM,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_lmm_protocol_init,
+	.ops = &scmi_imx_lmm_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_lmm);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_LMM) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI LMM driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/vendors/imx/imx-sm-misc.c

@@ -0,0 +1,593 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System control and Management Interface (SCMI) NXP MISC Protocol
+ *
+ * Copyright 2024 NXP
+ */
+
+#define pr_fmt(fmt) "SCMI Notifications MISC - " fmt
+
+#include <linux/bits.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/scmi_protocol.h>
+#include <linux/scmi_imx_protocol.h>
+
+#include "../../protocols.h"
+#include "../../notify.h"
+
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
+
+#define MAX_MISC_CTRL_SOURCES			GENMASK(15, 0)
+
+enum scmi_imx_misc_protocol_cmd {
+	SCMI_IMX_MISC_CTRL_SET	= 0x3,
+	SCMI_IMX_MISC_CTRL_GET	= 0x4,
+	SCMI_IMX_MISC_DISCOVER_BUILD_INFO = 0x6,
+	SCMI_IMX_MISC_CTRL_NOTIFY = 0x8,
+	SCMI_IMX_MISC_RESET_REASON_GET = 0xA,
+	SCMI_IMX_MISC_CFG_INFO_GET = 0xC,
+	SCMI_IMX_MISC_SYSLOG_GET = 0xD,
+	SCMI_IMX_MISC_BOARD_INFO = 0xE,
+};
+
+struct scmi_imx_misc_info {
+	u32 nr_dev_ctrl;
+	u32 nr_brd_ctrl;
+	u32 nr_reason;
+};
+
+struct scmi_msg_imx_misc_protocol_attributes {
+	__le32 attributes;
+};
+
+#define GET_BRD_CTRLS_NR(x)	le32_get_bits((x), GENMASK(31, 24))
+#define GET_REASONS_NR(x)	le32_get_bits((x), GENMASK(23, 16))
+#define GET_DEV_CTRLS_NR(x)	le32_get_bits((x), GENMASK(15, 0))
+#define BRD_CTRL_START_ID	BIT(15)
+
+struct scmi_imx_misc_ctrl_set_in {
+	__le32 id;
+	__le32 num;
+	__le32 value[];
+};
+
+struct scmi_imx_misc_ctrl_notify_in {
+	__le32 ctrl_id;
+	__le32 flags;
+};
+
+struct scmi_imx_misc_ctrl_notify_payld {
+	__le32 ctrl_id;
+	__le32 flags;
+};
+
+struct scmi_imx_misc_ctrl_get_out {
+	__le32 num;
+	__le32 val[];
+};
+
+struct scmi_imx_misc_buildinfo_out {
+	__le32 buildnum;
+	__le32 buildcommit;
+#define MISC_MAX_BUILDDATE	16
+	u8 builddate[MISC_MAX_BUILDDATE];
+#define MISC_MAX_BUILDTIME	16
+	u8 buildtime[MISC_MAX_BUILDTIME];
+};
+
+struct scmi_imx_misc_board_info_out {
+	__le32 attributes;
+#define MISC_MAX_BRDNAME	16
+	u8 brdname[MISC_MAX_BRDNAME];
+};
+
+struct scmi_imx_misc_cfg_info_out {
+	__le32 msel;
+#define MISC_MAX_CFGNAME	16
+	u8 cfgname[MISC_MAX_CFGNAME];
+};
+
+struct scmi_imx_misc_reset_reason_in {
+#define MISC_REASON_FLAG_SYSTEM	BIT(0)
+	__le32 flags;
+};
+
+struct scmi_imx_misc_reset_reason_out {
+	/* Boot reason flags */
+#define MISC_BOOT_FLAG_VLD		BIT(31)
+#define MISC_BOOT_FLAG_ORG_VLD		BIT(28)
+#define MISC_BOOT_FLAG_ORIGIN		GENMASK(27, 24)
+#define MISC_BOOT_FLAG_O_SHIFT		24
+#define MISC_BOOT_FLAG_ERR_VLD		BIT(23)
+#define MISC_BOOT_FLAG_ERR_ID		GENMASK(22, 8)
+#define MISC_BOOT_FLAG_E_SHIFT		8
+#define MISC_BOOT_FLAG_REASON		GENMASK(7, 0)
+	__le32 b_flags;
+	/* Shutdown reason flags */
+#define MISC_SHUTDOWN_FLAG_VLD		BIT(31)
+#define MISC_SHUTDOWN_FLAG_EXT_LEN	GENMASK(30, 29)
+#define MISC_SHUTDOWN_FLAG_ORG_VLD	BIT(28)
+#define MISC_SHUTDOWN_FLAG_ORIGIN	GENMASK(27, 24)
+#define MISC_SHUTDOWN_FLAG_O_SHIFT	24
+#define MISC_SHUTDOWN_FLAG_ERR_VLD	BIT(23)
+#define MISC_SHUTDOWN_FLAG_ERR_ID	GENMASK(22, 8)
+#define MISC_SHUTDOWN_FLAG_E_SHIFT	8
+#define MISC_SHUTDOWN_FLAG_REASON	GENMASK(7, 0)
+	__le32 s_flags;
+	/* Array of extended info words */
+	__le32 extinfo[MISC_EXT_INFO_LEN_MAX];
+};
+
+struct scmi_imx_misc_syslog_in {
+	__le32 flags;
+	__le32 index;
+};
+
+#define REMAINING(x)	le32_get_bits((x), GENMASK(31, 20))
+#define RETURNED(x)	le32_get_bits((x), GENMASK(11, 0))
+
+struct scmi_imx_misc_syslog_out {
+	__le32 numlogflags;
+	__le32 syslog[];
+};
+
+static int scmi_imx_misc_attributes_get(const struct scmi_protocol_handle *ph,
+					struct scmi_imx_misc_info *mi)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct scmi_msg_imx_misc_protocol_attributes *attr;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
+	if (ret)
+		return ret;
+
+	attr = t->rx.buf;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		mi->nr_dev_ctrl = GET_DEV_CTRLS_NR(attr->attributes);
+		mi->nr_brd_ctrl = GET_BRD_CTRLS_NR(attr->attributes);
+		mi->nr_reason = GET_REASONS_NR(attr->attributes);
+		dev_info(ph->dev, "i.MX MISC NUM DEV CTRL: %d, NUM BRD CTRL: %d,NUM Reason: %d\n",
+			 mi->nr_dev_ctrl, mi->nr_brd_ctrl, mi->nr_reason);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_misc_ctrl_validate_id(const struct scmi_protocol_handle *ph,
+					  u32 ctrl_id)
+{
+	struct scmi_imx_misc_info *mi = ph->get_priv(ph);
+
+	/*
+	 * [0,      BRD_CTRL_START_ID) is for Dev Ctrl which is SOC related
+	 * [BRD_CTRL_START_ID, 0xffff) is for Board Ctrl which is board related
+	 */
+	if (ctrl_id < BRD_CTRL_START_ID && ctrl_id > mi->nr_dev_ctrl)
+		return -EINVAL;
+	if (ctrl_id >= BRD_CTRL_START_ID + mi->nr_brd_ctrl)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int scmi_imx_misc_ctrl_notify(const struct scmi_protocol_handle *ph,
+				     u32 ctrl_id, u32 evt_id, u32 flags)
+{
+	struct scmi_imx_misc_ctrl_notify_in *in;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = scmi_imx_misc_ctrl_validate_id(ph, ctrl_id);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_CTRL_NOTIFY,
+				      sizeof(*in), 0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->ctrl_id = cpu_to_le32(ctrl_id);
+	in->flags = cpu_to_le32(flags);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int
+scmi_imx_misc_ctrl_set_notify_enabled(const struct scmi_protocol_handle *ph,
+				      u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	/* misc_ctrl_req_notify is for enablement */
+	if (enable)
+		return 0;
+
+	ret = scmi_imx_misc_ctrl_notify(ph, src_id, evt_id, 0);
+	if (ret)
+		dev_err(ph->dev, "FAIL_ENABLED - evt[%X] src[%d] - ret:%d\n",
+			evt_id, src_id, ret);
+
+	return ret;
+}
+
+static void *
+scmi_imx_misc_ctrl_fill_custom_report(const struct scmi_protocol_handle *ph,
+				      u8 evt_id, ktime_t timestamp,
+				      const void *payld, size_t payld_sz,
+				      void *report, u32 *src_id)
+{
+	const struct scmi_imx_misc_ctrl_notify_payld *p = payld;
+	struct scmi_imx_misc_ctrl_notify_report *r = report;
+
+	if (sizeof(*p) != payld_sz)
+		return NULL;
+
+	r->timestamp = timestamp;
+	r->ctrl_id = le32_to_cpu(p->ctrl_id);
+	r->flags = le32_to_cpu(p->flags);
+	if (src_id)
+		*src_id = r->ctrl_id;
+	dev_dbg(ph->dev, "%s: ctrl_id: %d flags: %d\n", __func__,
+		r->ctrl_id, r->flags);
+
+	return r;
+}
+
+static const struct scmi_event_ops scmi_imx_misc_event_ops = {
+	.set_notify_enabled = scmi_imx_misc_ctrl_set_notify_enabled,
+	.fill_custom_report = scmi_imx_misc_ctrl_fill_custom_report,
+};
+
+static const struct scmi_event scmi_imx_misc_events[] = {
+	{
+		.id = SCMI_EVENT_IMX_MISC_CONTROL,
+		.max_payld_sz = sizeof(struct scmi_imx_misc_ctrl_notify_payld),
+		.max_report_sz = sizeof(struct scmi_imx_misc_ctrl_notify_report),
+	},
+};
+
+static struct scmi_protocol_events scmi_imx_misc_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &scmi_imx_misc_event_ops,
+	.evts = scmi_imx_misc_events,
+	.num_events = ARRAY_SIZE(scmi_imx_misc_events),
+	.num_sources = MAX_MISC_CTRL_SOURCES,
+};
+
+static int scmi_imx_misc_ctrl_get(const struct scmi_protocol_handle *ph,
+				  u32 ctrl_id, u32 *num, u32 *val)
+{
+	struct scmi_imx_misc_ctrl_get_out *out;
+	struct scmi_xfer *t;
+	int ret, i;
+	int max_msg_size = ph->hops->get_max_msg_size(ph);
+	int max_num = (max_msg_size - sizeof(*out)) / sizeof(__le32);
+
+	ret = scmi_imx_misc_ctrl_validate_id(ph, ctrl_id);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_CTRL_GET, sizeof(u32),
+				      0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(ctrl_id, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		*num = le32_to_cpu(out->num);
+
+		if (*num >= max_num ||
+		    *num * sizeof(__le32) > t->rx.len - sizeof(__le32)) {
+			ph->xops->xfer_put(ph, t);
+			return -EINVAL;
+		}
+
+		for (i = 0; i < *num; i++)
+			val[i] = le32_to_cpu(out->val[i]);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_misc_ctrl_set(const struct scmi_protocol_handle *ph,
+				  u32 ctrl_id, u32 num, u32 *val)
+{
+	struct scmi_imx_misc_ctrl_set_in *in;
+	struct scmi_xfer *t;
+	int ret, i;
+	int max_msg_size = ph->hops->get_max_msg_size(ph);
+	int max_num = (max_msg_size - sizeof(*in)) / sizeof(__le32);
+
+	ret = scmi_imx_misc_ctrl_validate_id(ph, ctrl_id);
+	if (ret)
+		return ret;
+
+	if (num > max_num)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_CTRL_SET,
+				      sizeof(*in) + num * sizeof(__le32), 0, &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	in->id = cpu_to_le32(ctrl_id);
+	in->num = cpu_to_le32(num);
+	for (i = 0; i < num; i++)
+		in->value[i] = cpu_to_le32(val[i]);
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_misc_build_info_discover(const struct scmi_protocol_handle *ph)
+{
+	char date[MISC_MAX_BUILDDATE], time[MISC_MAX_BUILDTIME];
+	struct scmi_imx_misc_buildinfo_out *out;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_DISCOVER_BUILD_INFO, 0,
+				      sizeof(*out), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		strscpy(date, out->builddate, MISC_MAX_BUILDDATE);
+		strscpy(time, out->buildtime, MISC_MAX_BUILDTIME);
+		dev_info(ph->dev, "SM Version\t= Build %u, Commit %08x %s %s\n",
+			 le32_to_cpu(out->buildnum), le32_to_cpu(out->buildcommit),
+			 date, time);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_misc_board_info(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_misc_board_info_out *out;
+	char name[MISC_MAX_BRDNAME];
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_BOARD_INFO, 0, sizeof(*out), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		strscpy(name, out->brdname, MISC_MAX_BRDNAME);
+		dev_info(ph->dev, "Board\t\t= %s, attr=0x%08x\n",
+			 name, le32_to_cpu(out->attributes));
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static int scmi_imx_misc_cfg_info_get(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_misc_cfg_info_out *out;
+	char name[MISC_MAX_CFGNAME];
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_CFG_INFO_GET, 0, sizeof(*out), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		strscpy(name, out->cfgname, MISC_MAX_CFGNAME);
+		dev_info(ph->dev, "SM Config\t= %s, mSel = %u\n",
+			 name, le32_to_cpu(out->msel));
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+struct scmi_imx_misc_syslog_ipriv {
+	u32 *array;
+	u16 *size;
+};
+
+static void iter_misc_syslog_prepare_message(void *message, u32 desc_index,
+					     const void *priv)
+{
+	struct scmi_imx_misc_syslog_in *msg = message;
+
+	msg->flags = cpu_to_le32(0);
+	msg->index = cpu_to_le32(desc_index);
+}
+
+static int iter_misc_syslog_update_state(struct scmi_iterator_state *st,
+					 const void *response, void *priv)
+{
+	const struct scmi_imx_misc_syslog_out *r = response;
+	struct scmi_imx_misc_syslog_ipriv *p = priv;
+
+	st->num_returned = RETURNED(r->numlogflags);
+	st->num_remaining = REMAINING(r->numlogflags);
+	*p->size = st->num_returned + st->num_remaining;
+
+	return 0;
+}
+
+static int
+iter_misc_syslog_process_response(const struct scmi_protocol_handle *ph,
+				  const void *response,
+				  struct scmi_iterator_state *st, void *priv)
+{
+	const struct scmi_imx_misc_syslog_out *r = response;
+	struct scmi_imx_misc_syslog_ipriv *p = priv;
+
+	p->array[st->desc_index + st->loop_idx] =
+		le32_to_cpu(r->syslog[st->loop_idx]);
+
+	return 0;
+}
+
+static int scmi_imx_misc_syslog_get(const struct scmi_protocol_handle *ph, u16 *size,
+				    void *array)
+{
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_misc_syslog_prepare_message,
+		.update_state = iter_misc_syslog_update_state,
+		.process_response = iter_misc_syslog_process_response,
+	};
+	struct scmi_imx_misc_syslog_ipriv ipriv = {
+		.array = array,
+		.size = size,
+	};
+	void *iter;
+
+	if (!array || !size || !*size)
+		return -EINVAL;
+
+	iter = ph->hops->iter_response_init(ph, &ops, *size, SCMI_IMX_MISC_SYSLOG_GET,
+					    sizeof(struct scmi_imx_misc_syslog_in),
+					    &ipriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	/* If firmware return NOT SUPPORTED, propagate value to caller */
+	return ph->hops->iter_response_run(iter);
+}
+
+static int scmi_imx_misc_reset_reason(const struct scmi_protocol_handle *ph, bool system,
+				      struct scmi_imx_misc_reset_reason *boot_r,
+				      struct scmi_imx_misc_reset_reason *shut_r,
+				      u32 *extinfo)
+{
+	struct scmi_imx_misc_reset_reason_in *in;
+	struct scmi_imx_misc_reset_reason_out *out;
+	struct scmi_xfer *t;
+	int ret;
+
+	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_MISC_RESET_REASON_GET, sizeof(*in),
+				      sizeof(*out), &t);
+	if (ret)
+		return ret;
+
+	in = t->tx.buf;
+	if (system)
+		in->flags = le32_encode_bits(1, MISC_REASON_FLAG_SYSTEM);
+	else
+		in->flags = cpu_to_le32(0);
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret) {
+		out = t->rx.buf;
+		if (boot_r) {
+			boot_r->valid = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_VLD);
+			boot_r->orig_valid = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_ORG_VLD);
+			boot_r->err_valid = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_ERR_VLD);
+			boot_r->reason = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_REASON);
+			boot_r->origin = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_ORIGIN);
+			boot_r->errid = le32_get_bits(out->b_flags, MISC_BOOT_FLAG_ERR_ID);
+		}
+
+		if (shut_r) {
+			shut_r->valid = le32_get_bits(out->s_flags, MISC_SHUTDOWN_FLAG_VLD);
+			shut_r->orig_valid = le32_get_bits(out->s_flags,
+							   MISC_SHUTDOWN_FLAG_ORG_VLD);
+			shut_r->err_valid = le32_get_bits(out->s_flags,
+							  MISC_SHUTDOWN_FLAG_ERR_VLD);
+			shut_r->reason = le32_get_bits(out->s_flags, MISC_SHUTDOWN_FLAG_REASON);
+			shut_r->origin = le32_get_bits(out->s_flags, MISC_SHUTDOWN_FLAG_ORIGIN);
+			shut_r->errid = le32_get_bits(out->s_flags, MISC_SHUTDOWN_FLAG_ERR_ID);
+		}
+
+		if (extinfo)
+			memcpy_from_le32(extinfo, out->extinfo, MISC_EXT_INFO_LEN_MAX);
+	}
+
+	ph->xops->xfer_put(ph, t);
+
+	return ret;
+}
+
+static const struct scmi_imx_misc_proto_ops scmi_imx_misc_proto_ops = {
+	.misc_ctrl_set = scmi_imx_misc_ctrl_set,
+	.misc_ctrl_get = scmi_imx_misc_ctrl_get,
+	.misc_ctrl_req_notify = scmi_imx_misc_ctrl_notify,
+	.misc_syslog = scmi_imx_misc_syslog_get,
+	.misc_reset_reason = scmi_imx_misc_reset_reason,
+};
+
+static int scmi_imx_misc_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_imx_misc_info *minfo;
+	int ret;
+
+	dev_info(ph->dev, "NXP SM MISC Version %d.%d\n",
+		 PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	minfo = devm_kzalloc(ph->dev, sizeof(*minfo), GFP_KERNEL);
+	if (!minfo)
+		return -ENOMEM;
+
+	ret = scmi_imx_misc_attributes_get(ph, minfo);
+	if (ret)
+		return ret;
+
+	ret = scmi_imx_misc_build_info_discover(ph);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	ret = scmi_imx_misc_board_info(ph);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	ret = scmi_imx_misc_cfg_info_get(ph);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	return ph->set_priv(ph, minfo);
+}
+
+static const struct scmi_protocol scmi_imx_misc = {
+	.id = SCMI_PROTOCOL_IMX_MISC,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_imx_misc_protocol_init,
+	.ops = &scmi_imx_misc_proto_ops,
+	.events = &scmi_imx_misc_protocol_events,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+	.vendor_id = SCMI_IMX_VENDOR,
+	.sub_vendor_id = SCMI_IMX_SUBVENDOR,
+};
+module_scmi_protocol(scmi_imx_misc);
+
+MODULE_ALIAS("scmi-protocol-" __stringify(SCMI_PROTOCOL_IMX_MISC) "-" SCMI_IMX_VENDOR);
+MODULE_DESCRIPTION("i.MX SCMI MISC driver");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/firmware/arm_scmi/voltage.c

@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Voltage Protocol
+ *
+ * Copyright (C) 2020-2022 ARM Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/scmi_protocol.h>
+
+#include "protocols.h"
+
+/* Updated only after ALL the mandatory features for that version are merged */
+#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x20001
+
+#define VOLTAGE_DOMS_NUM_MASK		GENMASK(15, 0)
+#define REMAINING_LEVELS_MASK		GENMASK(31, 16)
+#define RETURNED_LEVELS_MASK		GENMASK(11, 0)
+
+enum scmi_voltage_protocol_cmd {
+	VOLTAGE_DOMAIN_ATTRIBUTES = 0x3,
+	VOLTAGE_DESCRIBE_LEVELS = 0x4,
+	VOLTAGE_CONFIG_SET = 0x5,
+	VOLTAGE_CONFIG_GET = 0x6,
+	VOLTAGE_LEVEL_SET = 0x7,
+	VOLTAGE_LEVEL_GET = 0x8,
+	VOLTAGE_DOMAIN_NAME_GET = 0x09,
+};
+
+#define NUM_VOLTAGE_DOMAINS(x)	((u16)(FIELD_GET(VOLTAGE_DOMS_NUM_MASK, (x))))
+
+struct scmi_msg_resp_domain_attributes {
+	__le32 attr;
+#define SUPPORTS_ASYNC_LEVEL_SET(x)	((x) & BIT(31))
+#define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(30))
+	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
+};
+
+struct scmi_msg_cmd_describe_levels {
+	__le32 domain_id;
+	__le32 level_index;
+};
+
+struct scmi_msg_resp_describe_levels {
+	__le32 flags;
+#define NUM_REMAINING_LEVELS(f)	((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
+#define NUM_RETURNED_LEVELS(f)	((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
+#define SUPPORTS_SEGMENTED_LEVELS(f)	((f) & BIT(12))
+	__le32 voltage[];
+};
+
+struct scmi_msg_cmd_config_set {
+	__le32 domain_id;
+	__le32 config;
+};
+
+struct scmi_msg_cmd_level_set {
+	__le32 domain_id;
+	__le32 flags;
+	__le32 voltage_level;
+};
+
+struct scmi_resp_voltage_level_set_complete {
+	__le32 domain_id;
+	__le32 voltage_level;
+};
+
+struct voltage_info {
+	unsigned int num_domains;
+	struct scmi_voltage_info *domains;
+};
+
+static int scmi_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+					struct voltage_info *vinfo)
+{
+	int ret;
+	struct scmi_xfer *t;
+
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(__le32), &t);
+	if (ret)
+		return ret;
+
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		vinfo->num_domains =
+			NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_init_voltage_levels(struct device *dev,
+				    struct scmi_voltage_info *v,
+				    u32 num_returned, u32 num_remaining,
+				    bool segmented)
+{
+	u32 num_levels;
+
+	num_levels = num_returned + num_remaining;
+	/*
+	 * segmented levels entries are represented by a single triplet
+	 * returned all in one go.
+	 */
+	if (!num_levels ||
+	    (segmented && (num_remaining || num_returned != 3))) {
+		dev_err(dev,
+			"Invalid level descriptor(%d/%d/%d) for voltage dom %d\n",
+			num_levels, num_returned, num_remaining, v->id);
+		return -EINVAL;
+	}
+
+	v->levels_uv = devm_kcalloc(dev, num_levels, sizeof(u32), GFP_KERNEL);
+	if (!v->levels_uv)
+		return -ENOMEM;
+
+	v->num_levels = num_levels;
+	v->segmented = segmented;
+
+	return 0;
+}
+
+struct scmi_volt_ipriv {
+	struct device *dev;
+	struct scmi_voltage_info *v;
+};
+
+static void iter_volt_levels_prepare_message(void *message,
+					     unsigned int desc_index,
+					     const void *priv)
+{
+	struct scmi_msg_cmd_describe_levels *msg = message;
+	const struct scmi_volt_ipriv *p = priv;
+
+	msg->domain_id = cpu_to_le32(p->v->id);
+	msg->level_index = cpu_to_le32(desc_index);
+}
+
+static int iter_volt_levels_update_state(struct scmi_iterator_state *st,
+					 const void *response, void *priv)
+{
+	int ret = 0;
+	u32 flags;
+	const struct scmi_msg_resp_describe_levels *r = response;
+	struct scmi_volt_ipriv *p = priv;
+
+	flags = le32_to_cpu(r->flags);
+	st->num_returned = NUM_RETURNED_LEVELS(flags);
+	st->num_remaining = NUM_REMAINING_LEVELS(flags);
+
+	/* Allocate space for num_levels if not already done */
+	if (!p->v->num_levels) {
+		ret = scmi_init_voltage_levels(p->dev, p->v, st->num_returned,
+					       st->num_remaining,
+					      SUPPORTS_SEGMENTED_LEVELS(flags));
+		if (!ret)
+			st->max_resources = p->v->num_levels;
+	}
+
+	return ret;
+}
+
+static int
+iter_volt_levels_process_response(const struct scmi_protocol_handle *ph,
+				  const void *response,
+				  struct scmi_iterator_state *st, void *priv)
+{
+	s32 val;
+	const struct scmi_msg_resp_describe_levels *r = response;
+	struct scmi_volt_ipriv *p = priv;
+
+	val = (s32)le32_to_cpu(r->voltage[st->loop_idx]);
+	p->v->levels_uv[st->desc_index + st->loop_idx] = val;
+	if (val < 0)
+		p->v->negative_volts_allowed = true;
+
+	return 0;
+}
+
+static int scmi_voltage_levels_get(const struct scmi_protocol_handle *ph,
+				   struct scmi_voltage_info *v)
+{
+	int ret;
+	void *iter;
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_volt_levels_prepare_message,
+		.update_state = iter_volt_levels_update_state,
+		.process_response = iter_volt_levels_process_response,
+	};
+	struct scmi_volt_ipriv vpriv = {
+		.dev = ph->dev,
+		.v = v,
+	};
+
+	iter = ph->hops->iter_response_init(ph, &ops, v->num_levels,
+					    VOLTAGE_DESCRIBE_LEVELS,
+					    sizeof(struct scmi_msg_cmd_describe_levels),
+					    &vpriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	ret = ph->hops->iter_response_run(iter);
+	if (ret) {
+		v->num_levels = 0;
+		devm_kfree(ph->dev, v->levels_uv);
+	}
+
+	return ret;
+}
+
+static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
+					struct voltage_info *vinfo)
+{
+	int ret, dom;
+	struct scmi_xfer *td;
+	struct scmi_msg_resp_domain_attributes *resp_dom;
+
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_DOMAIN_ATTRIBUTES,
+				      sizeof(__le32), sizeof(*resp_dom), &td);
+	if (ret)
+		return ret;
+	resp_dom = td->rx.buf;
+
+	for (dom = 0; dom < vinfo->num_domains; dom++) {
+		u32 attributes;
+		struct scmi_voltage_info *v;
+
+		/* Retrieve domain attributes at first ... */
+		put_unaligned_le32(dom, td->tx.buf);
+		/* Skip domain on comms error */
+		if (ph->xops->do_xfer(ph, td)) {
+			ph->xops->reset_rx_to_maxsz(ph, td);
+			continue;
+		}
+
+		v = vinfo->domains + dom;
+		v->id = dom;
+		attributes = le32_to_cpu(resp_dom->attr);
+		strscpy(v->name, resp_dom->name, SCMI_SHORT_NAME_MAX_SIZE);
+
+		/*
+		 * If supported overwrite short name with the extended one;
+		 * on error just carry on and use already provided short name.
+		 */
+		if (PROTOCOL_REV_MAJOR(ph->version) >= 0x2) {
+			if (SUPPORTS_EXTENDED_NAMES(attributes))
+				ph->hops->extended_name_get(ph,
+							VOLTAGE_DOMAIN_NAME_GET,
+							v->id, NULL, v->name,
+							SCMI_MAX_STR_SIZE);
+			if (SUPPORTS_ASYNC_LEVEL_SET(attributes))
+				v->async_level_set = true;
+		}
+
+		/* Skip invalid voltage descriptors */
+		scmi_voltage_levels_get(ph, v);
+	}
+
+	ph->xops->xfer_put(ph, td);
+
+	return ret;
+}
+
+static int __scmi_voltage_get_u32(const struct scmi_protocol_handle *ph,
+				  u8 cmd_id, u32 domain_id, u32 *value)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct voltage_info *vinfo = ph->get_priv(ph);
+
+	if (domain_id >= vinfo->num_domains)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, cmd_id, sizeof(__le32), 0, &t);
+	if (ret)
+		return ret;
+
+	put_unaligned_le32(domain_id, t->tx.buf);
+	ret = ph->xops->do_xfer(ph, t);
+	if (!ret)
+		*value = get_unaligned_le32(t->rx.buf);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_voltage_config_set(const struct scmi_protocol_handle *ph,
+				   u32 domain_id, u32 config)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct voltage_info *vinfo = ph->get_priv(ph);
+	struct scmi_msg_cmd_config_set *cmd;
+
+	if (domain_id >= vinfo->num_domains)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_CONFIG_SET,
+				     sizeof(*cmd), 0, &t);
+	if (ret)
+		return ret;
+
+	cmd = t->tx.buf;
+	cmd->domain_id = cpu_to_le32(domain_id);
+	cmd->config = cpu_to_le32(config & GENMASK(3, 0));
+
+	ret = ph->xops->do_xfer(ph, t);
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_voltage_config_get(const struct scmi_protocol_handle *ph,
+				   u32 domain_id, u32 *config)
+{
+	return __scmi_voltage_get_u32(ph, VOLTAGE_CONFIG_GET,
+				      domain_id, config);
+}
+
+static int scmi_voltage_level_set(const struct scmi_protocol_handle *ph,
+				  u32 domain_id,
+				  enum scmi_voltage_level_mode mode,
+				  s32 volt_uV)
+{
+	int ret;
+	struct scmi_xfer *t;
+	struct voltage_info *vinfo = ph->get_priv(ph);
+	struct scmi_msg_cmd_level_set *cmd;
+	struct scmi_voltage_info *v;
+
+	if (domain_id >= vinfo->num_domains)
+		return -EINVAL;
+
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_LEVEL_SET,
+				      sizeof(*cmd), 0, &t);
+	if (ret)
+		return ret;
+
+	v = vinfo->domains + domain_id;
+
+	cmd = t->tx.buf;
+	cmd->domain_id = cpu_to_le32(domain_id);
+	cmd->voltage_level = cpu_to_le32(volt_uV);
+
+	if (!v->async_level_set || mode != SCMI_VOLTAGE_LEVEL_SET_AUTO) {
+		cmd->flags = cpu_to_le32(0x0);
+		ret = ph->xops->do_xfer(ph, t);
+	} else {
+		cmd->flags = cpu_to_le32(0x1);
+		ret = ph->xops->do_xfer_with_response(ph, t);
+		if (!ret) {
+			struct scmi_resp_voltage_level_set_complete *resp;
+
+			resp = t->rx.buf;
+			if (le32_to_cpu(resp->domain_id) == domain_id)
+				dev_dbg(ph->dev,
+					"Voltage domain %d set async to %d\n",
+					v->id,
+					le32_to_cpu(resp->voltage_level));
+			else
+				ret = -EPROTO;
+		}
+	}
+
+	ph->xops->xfer_put(ph, t);
+	return ret;
+}
+
+static int scmi_voltage_level_get(const struct scmi_protocol_handle *ph,
+				  u32 domain_id, s32 *volt_uV)
+{
+	return __scmi_voltage_get_u32(ph, VOLTAGE_LEVEL_GET,
+				      domain_id, (u32 *)volt_uV);
+}
+
+static const struct scmi_voltage_info * __must_check
+scmi_voltage_info_get(const struct scmi_protocol_handle *ph, u32 domain_id)
+{
+	struct voltage_info *vinfo = ph->get_priv(ph);
+
+	if (domain_id >= vinfo->num_domains ||
+	    !vinfo->domains[domain_id].num_levels)
+		return NULL;
+
+	return vinfo->domains + domain_id;
+}
+
+static int scmi_voltage_domains_num_get(const struct scmi_protocol_handle *ph)
+{
+	struct voltage_info *vinfo = ph->get_priv(ph);
+
+	return vinfo->num_domains;
+}
+
+static const struct scmi_voltage_proto_ops voltage_proto_ops = {
+	.num_domains_get = scmi_voltage_domains_num_get,
+	.info_get = scmi_voltage_info_get,
+	.config_set = scmi_voltage_config_set,
+	.config_get = scmi_voltage_config_get,
+	.level_set = scmi_voltage_level_set,
+	.level_get = scmi_voltage_level_get,
+};
+
+static int scmi_voltage_protocol_init(const struct scmi_protocol_handle *ph)
+{
+	int ret;
+	struct voltage_info *vinfo;
+
+	dev_dbg(ph->dev, "Voltage Version %d.%d\n",
+		PROTOCOL_REV_MAJOR(ph->version), PROTOCOL_REV_MINOR(ph->version));
+
+	vinfo = devm_kzalloc(ph->dev, sizeof(*vinfo), GFP_KERNEL);
+	if (!vinfo)
+		return -ENOMEM;
+
+	ret = scmi_protocol_attributes_get(ph, vinfo);
+	if (ret)
+		return ret;
+
+	if (vinfo->num_domains) {
+		vinfo->domains = devm_kcalloc(ph->dev, vinfo->num_domains,
+					      sizeof(*vinfo->domains),
+					      GFP_KERNEL);
+		if (!vinfo->domains)
+			return -ENOMEM;
+		ret = scmi_voltage_descriptors_get(ph, vinfo);
+		if (ret)
+			return ret;
+	} else {
+		dev_warn(ph->dev, "No Voltage domains found.\n");
+	}
+
+	return ph->set_priv(ph, vinfo);
+}
+
+static const struct scmi_protocol scmi_voltage = {
+	.id = SCMI_PROTOCOL_VOLTAGE,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_voltage_protocol_init,
+	.ops = &voltage_proto_ops,
+	.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(voltage, scmi_voltage)