Resguardo inicial

linux-7.2.3/drivers/platform/surface/aggregator/Kconfig

@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+
+menuconfig SURFACE_AGGREGATOR
+	tristate "Microsoft Surface System Aggregator Module Subsystem and Drivers"
+	depends on SERIAL_DEV_BUS
+	depends on ACPI && !RISCV
+	select CRC_ITU_T
+	help
+	  The Surface System Aggregator Module (Surface SAM or SSAM) is an
+	  embedded controller (EC) found on 5th- and later-generation Microsoft
+	  Surface devices (i.e. Surface Pro 5, Surface Book 2, Surface Laptop,
+	  and newer, with exception of Surface Go series devices).
+
+	  Depending on the device in question, this EC provides varying
+	  functionality, including:
+	  - EC access from ACPI via Surface ACPI Notify (5th- and 6th-generation)
+	  - battery status information (all devices)
+	  - thermal sensor access (all devices)
+	  - performance mode / cooling mode control (all devices)
+	  - clipboard detachment system control (Surface Book 2 and 3)
+	  - HID / keyboard input (Surface Laptops, Surface Book 3)
+
+	  This option controls whether the Surface SAM subsystem core will be
+	  built. This includes a driver for the Surface Serial Hub (SSH), which
+	  is the device responsible for the communication with the EC, and a
+	  basic kernel interface exposing the EC functionality to other client
+	  drivers, i.e. allowing them to make requests to the EC and receive
+	  events from it. Selecting this option alone will not provide any
+	  client drivers and therefore no functionality beyond the in-kernel
+	  interface. Said functionality is the responsibility of the respective
+	  client drivers.
+
+	  Note: While 4th-generation Surface devices also make use of a SAM EC,
+	  due to a difference in the communication interface of the controller,
+	  only 5th and later generations are currently supported. Specifically,
+	  devices using SAM-over-SSH are supported, whereas devices using
+	  SAM-over-HID, which is used on the 4th generation, are currently not
+	  supported.
+
+	  Choose m if you want to build the SAM subsystem core and SSH driver as
+	  module, y if you want to build it into the kernel and n if you don't
+	  want it at all.
+
+config SURFACE_AGGREGATOR_BUS
+	bool "Surface System Aggregator Module Bus"
+	depends on SURFACE_AGGREGATOR
+	default y
+	help
+	  Expands the Surface System Aggregator Module (SSAM) core driver by
+	  providing a dedicated bus and client-device type.
+
+	  This bus and device type are intended to provide and simplify support
+	  for non-platform and non-ACPI SSAM devices, i.e. SSAM devices that are
+	  not auto-detectable via the conventional means (e.g. ACPI).
+
+config SURFACE_AGGREGATOR_ERROR_INJECTION
+	bool "Surface System Aggregator Module Error Injection Capabilities"
+	depends on SURFACE_AGGREGATOR
+	depends on FUNCTION_ERROR_INJECTION
+	help
+	  Provides error-injection capabilities for the Surface System
+	  Aggregator Module subsystem and Surface Serial Hub driver.
+
+	  Specifically, exports error injection hooks to be used with the
+	  kernel's function error injection capabilities to simulate underlying
+	  transport and communication problems, such as invalid data sent to or
+	  received from the EC, dropped data, and communication timeouts.
+	  Intended for development and debugging.

linux-7.2.3/drivers/platform/surface/aggregator/Makefile

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+
+# For include/trace/define_trace.h to include trace.h
+CFLAGS_core.o = -I$(src)
+
+obj-$(CONFIG_SURFACE_AGGREGATOR) += surface_aggregator.o
+
+surface_aggregator-y := core.o
+surface_aggregator-y += ssh_parser.o
+surface_aggregator-y += ssh_packet_layer.o
+surface_aggregator-y += ssh_request_layer.o
+surface_aggregator-$(CONFIG_SURFACE_AGGREGATOR_BUS) += bus.o
+surface_aggregator-y += controller.o

linux-7.2.3/drivers/platform/surface/aggregator/bus.c

@@ -0,0 +1,527 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Surface System Aggregator Module bus and device integration.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+#include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/device.h>
+
+#include "bus.h"
+#include "controller.h"
+
+
+/* -- Device and bus functions. --------------------------------------------- */
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct ssam_device *sdev = to_ssam_device(dev);
+
+	return sysfs_emit(buf, "ssam:d%02Xc%02Xt%02Xi%02Xf%02X\n",
+			sdev->uid.domain, sdev->uid.category, sdev->uid.target,
+			sdev->uid.instance, sdev->uid.function);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *ssam_device_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ssam_device);
+
+static const struct bus_type ssam_bus_type;
+
+static int ssam_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct ssam_device *sdev = to_ssam_device(dev);
+
+	return add_uevent_var(env, "MODALIAS=ssam:d%02Xc%02Xt%02Xi%02Xf%02X",
+			      sdev->uid.domain, sdev->uid.category,
+			      sdev->uid.target, sdev->uid.instance,
+			      sdev->uid.function);
+}
+
+static void ssam_device_release(struct device *dev)
+{
+	struct ssam_device *sdev = to_ssam_device(dev);
+
+	ssam_controller_put(sdev->ctrl);
+	fwnode_handle_put(sdev->dev.fwnode);
+	kfree(sdev);
+}
+
+const struct device_type ssam_device_type = {
+	.name    = "surface_aggregator_device",
+	.groups  = ssam_device_groups,
+	.uevent  = ssam_device_uevent,
+	.release = ssam_device_release,
+};
+EXPORT_SYMBOL_GPL(ssam_device_type);
+
+/**
+ * ssam_device_alloc() - Allocate and initialize a SSAM client device.
+ * @ctrl: The controller under which the device should be added.
+ * @uid:  The UID of the device to be added.
+ *
+ * Allocates and initializes a new client device. The parent of the device
+ * will be set to the controller device and the name will be set based on the
+ * UID. Note that the device still has to be added via ssam_device_add().
+ * Refer to that function for more details.
+ *
+ * Return: Returns the newly allocated and initialized SSAM client device, or
+ * %NULL if it could not be allocated.
+ */
+struct ssam_device *ssam_device_alloc(struct ssam_controller *ctrl,
+				      struct ssam_device_uid uid)
+{
+	struct ssam_device *sdev;
+
+	sdev = kzalloc_obj(*sdev);
+	if (!sdev)
+		return NULL;
+
+	device_initialize(&sdev->dev);
+	sdev->dev.bus = &ssam_bus_type;
+	sdev->dev.type = &ssam_device_type;
+	sdev->dev.parent = ssam_controller_device(ctrl);
+	sdev->ctrl = ssam_controller_get(ctrl);
+	sdev->uid = uid;
+
+	dev_set_name(&sdev->dev, "%02x:%02x:%02x:%02x:%02x",
+		     sdev->uid.domain, sdev->uid.category, sdev->uid.target,
+		     sdev->uid.instance, sdev->uid.function);
+
+	return sdev;
+}
+EXPORT_SYMBOL_GPL(ssam_device_alloc);
+
+/**
+ * ssam_device_add() - Add a SSAM client device.
+ * @sdev: The SSAM client device to be added.
+ *
+ * Added client devices must be guaranteed to always have a valid and active
+ * controller. Thus, this function will fail with %-ENODEV if the controller
+ * of the device has not been initialized yet, has been suspended, or has been
+ * shut down.
+ *
+ * The caller of this function should ensure that the corresponding call to
+ * ssam_device_remove() is issued before the controller is shut down. If the
+ * added device is a direct child of the controller device (default), it will
+ * be automatically removed when the controller is shut down.
+ *
+ * By default, the controller device will become the parent of the newly
+ * created client device. The parent may be changed before ssam_device_add is
+ * called, but care must be taken that a) the correct suspend/resume ordering
+ * is guaranteed and b) the client device does not outlive the controller,
+ * i.e. that the device is removed before the controller is being shut down.
+ * In case these guarantees have to be manually enforced, please refer to the
+ * ssam_client_link() and ssam_client_bind() functions, which are intended to
+ * set up device-links for this purpose.
+ *
+ * Return: Returns zero on success, a negative error code on failure.
+ */
+int ssam_device_add(struct ssam_device *sdev)
+{
+	int status;
+
+	/*
+	 * Ensure that we can only add new devices to a controller if it has
+	 * been started and is not going away soon. This works in combination
+	 * with ssam_controller_remove_clients to ensure driver presence for the
+	 * controller device, i.e. it ensures that the controller (sdev->ctrl)
+	 * is always valid and can be used for requests as long as the client
+	 * device we add here is registered as child under it. This essentially
+	 * guarantees that the client driver can always expect the preconditions
+	 * for functions like ssam_request_do_sync() (controller has to be
+	 * started and is not suspended) to hold and thus does not have to check
+	 * for them.
+	 *
+	 * Note that for this to work, the controller has to be a parent device.
+	 * If it is not a direct parent, care has to be taken that the device is
+	 * removed via ssam_device_remove(), as device_unregister does not
+	 * remove child devices recursively.
+	 */
+	ssam_controller_statelock(sdev->ctrl);
+
+	if (sdev->ctrl->state != SSAM_CONTROLLER_STARTED) {
+		ssam_controller_stateunlock(sdev->ctrl);
+		return -ENODEV;
+	}
+
+	status = device_add(&sdev->dev);
+
+	ssam_controller_stateunlock(sdev->ctrl);
+	return status;
+}
+EXPORT_SYMBOL_GPL(ssam_device_add);
+
+/**
+ * ssam_device_remove() - Remove a SSAM client device.
+ * @sdev: The device to remove.
+ *
+ * Removes and unregisters the provided SSAM client device.
+ */
+void ssam_device_remove(struct ssam_device *sdev)
+{
+	device_unregister(&sdev->dev);
+}
+EXPORT_SYMBOL_GPL(ssam_device_remove);
+
+/**
+ * ssam_device_id_compatible() - Check if a device ID matches a UID.
+ * @id:  The device ID as potential match.
+ * @uid: The device UID matching against.
+ *
+ * Check if the given ID is a match for the given UID, i.e. if a device with
+ * the provided UID is compatible to the given ID following the match rules
+ * described in its &ssam_device_id.match_flags member.
+ *
+ * Return: Returns %true if the given UID is compatible to the match rule
+ * described by the given ID, %false otherwise.
+ */
+static bool ssam_device_id_compatible(const struct ssam_device_id *id,
+				      struct ssam_device_uid uid)
+{
+	if (id->domain != uid.domain || id->category != uid.category)
+		return false;
+
+	if ((id->match_flags & SSAM_MATCH_TARGET) && id->target != uid.target)
+		return false;
+
+	if ((id->match_flags & SSAM_MATCH_INSTANCE) && id->instance != uid.instance)
+		return false;
+
+	if ((id->match_flags & SSAM_MATCH_FUNCTION) && id->function != uid.function)
+		return false;
+
+	return true;
+}
+
+/**
+ * ssam_device_id_is_null() - Check if a device ID is null.
+ * @id: The device ID to check.
+ *
+ * Check if a given device ID is null, i.e. all zeros. Used to check for the
+ * end of ``MODULE_DEVICE_TABLE(ssam, ...)`` or similar lists.
+ *
+ * Return: Returns %true if the given ID represents a null ID, %false
+ * otherwise.
+ */
+static bool ssam_device_id_is_null(const struct ssam_device_id *id)
+{
+	return id->match_flags == 0 &&
+		id->domain == 0 &&
+		id->category == 0 &&
+		id->target == 0 &&
+		id->instance == 0 &&
+		id->function == 0 &&
+		id->driver_data == 0;
+}
+
+/**
+ * ssam_device_id_match() - Find the matching ID table entry for the given UID.
+ * @table: The table to search in.
+ * @uid:   The UID to matched against the individual table entries.
+ *
+ * Find the first match for the provided device UID in the provided ID table
+ * and return it. Returns %NULL if no match could be found.
+ */
+const struct ssam_device_id *ssam_device_id_match(const struct ssam_device_id *table,
+						  const struct ssam_device_uid uid)
+{
+	const struct ssam_device_id *id;
+
+	for (id = table; !ssam_device_id_is_null(id); ++id)
+		if (ssam_device_id_compatible(id, uid))
+			return id;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(ssam_device_id_match);
+
+/**
+ * ssam_device_get_match() - Find and return the ID matching the device in the
+ * ID table of the bound driver.
+ * @dev: The device for which to get the matching ID table entry.
+ *
+ * Find the fist match for the UID of the device in the ID table of the
+ * currently bound driver and return it. Returns %NULL if the device does not
+ * have a driver bound to it, the driver does not have match_table (i.e. it is
+ * %NULL), or there is no match in the driver's match_table.
+ *
+ * This function essentially calls ssam_device_id_match() with the ID table of
+ * the bound device driver and the UID of the device.
+ *
+ * Return: Returns the first match for the UID of the device in the device
+ * driver's match table, or %NULL if no such match could be found.
+ */
+const struct ssam_device_id *ssam_device_get_match(const struct ssam_device *dev)
+{
+	const struct ssam_device_driver *sdrv;
+
+	sdrv = to_ssam_device_driver(dev->dev.driver);
+	if (!sdrv)
+		return NULL;
+
+	if (!sdrv->match_table)
+		return NULL;
+
+	return ssam_device_id_match(sdrv->match_table, dev->uid);
+}
+EXPORT_SYMBOL_GPL(ssam_device_get_match);
+
+/**
+ * ssam_device_get_match_data() - Find the ID matching the device in the
+ * ID table of the bound driver and return its ``driver_data`` member.
+ * @dev: The device for which to get the match data.
+ *
+ * Find the fist match for the UID of the device in the ID table of the
+ * corresponding driver and return its driver_data. Returns %NULL if the
+ * device does not have a driver bound to it, the driver does not have
+ * match_table (i.e. it is %NULL), there is no match in the driver's
+ * match_table, or the match does not have any driver_data.
+ *
+ * This function essentially calls ssam_device_get_match() and, if any match
+ * could be found, returns its ``struct ssam_device_id.driver_data`` member.
+ *
+ * Return: Returns the driver data associated with the first match for the UID
+ * of the device in the device driver's match table, or %NULL if no such match
+ * could be found.
+ */
+const void *ssam_device_get_match_data(const struct ssam_device *dev)
+{
+	const struct ssam_device_id *id;
+
+	id = ssam_device_get_match(dev);
+	if (!id)
+		return NULL;
+
+	return (const void *)id->driver_data;
+}
+EXPORT_SYMBOL_GPL(ssam_device_get_match_data);
+
+static int ssam_bus_match(struct device *dev, const struct device_driver *drv)
+{
+	const struct ssam_device_driver *sdrv = to_ssam_device_driver(drv);
+	struct ssam_device *sdev = to_ssam_device(dev);
+
+	if (!is_ssam_device(dev))
+		return 0;
+
+	return !!ssam_device_id_match(sdrv->match_table, sdev->uid);
+}
+
+static int ssam_bus_probe(struct device *dev)
+{
+	return to_ssam_device_driver(dev->driver)
+		->probe(to_ssam_device(dev));
+}
+
+static void ssam_bus_remove(struct device *dev)
+{
+	struct ssam_device_driver *sdrv = to_ssam_device_driver(dev->driver);
+
+	if (sdrv->remove)
+		sdrv->remove(to_ssam_device(dev));
+}
+
+static const struct bus_type ssam_bus_type = {
+	.name   = "surface_aggregator",
+	.match  = ssam_bus_match,
+	.probe  = ssam_bus_probe,
+	.remove = ssam_bus_remove,
+};
+
+/**
+ * __ssam_device_driver_register() - Register a SSAM client device driver.
+ * @sdrv:  The driver to register.
+ * @owner: The module owning the provided driver.
+ *
+ * Please refer to the ssam_device_driver_register() macro for the normal way
+ * to register a driver from inside its owning module.
+ */
+int __ssam_device_driver_register(struct ssam_device_driver *sdrv,
+				  struct module *owner)
+{
+	sdrv->driver.owner = owner;
+	sdrv->driver.bus = &ssam_bus_type;
+
+	/* force drivers to async probe so I/O is possible in probe */
+	sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS;
+
+	return driver_register(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(__ssam_device_driver_register);
+
+/**
+ * ssam_device_driver_unregister - Unregister a SSAM device driver.
+ * @sdrv: The driver to unregister.
+ */
+void ssam_device_driver_unregister(struct ssam_device_driver *sdrv)
+{
+	driver_unregister(&sdrv->driver);
+}
+EXPORT_SYMBOL_GPL(ssam_device_driver_unregister);
+
+
+/* -- Bus registration. ----------------------------------------------------- */
+
+/**
+ * ssam_bus_register() - Register and set-up the SSAM client device bus.
+ */
+int ssam_bus_register(void)
+{
+	return bus_register(&ssam_bus_type);
+}
+
+/**
+ * ssam_bus_unregister() - Unregister the SSAM client device bus.
+ */
+void ssam_bus_unregister(void)
+{
+	return bus_unregister(&ssam_bus_type);
+}
+
+
+/* -- Helpers for controller and hub devices. ------------------------------- */
+
+static int ssam_device_uid_from_string(const char *str, struct ssam_device_uid *uid)
+{
+	u8 d, tc, tid, iid, fn;
+	int n;
+
+	n = sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx", &d, &tc, &tid, &iid, &fn);
+	if (n != 5)
+		return -EINVAL;
+
+	uid->domain = d;
+	uid->category = tc;
+	uid->target = tid;
+	uid->instance = iid;
+	uid->function = fn;
+
+	return 0;
+}
+
+static int ssam_get_uid_for_node(struct fwnode_handle *node, struct ssam_device_uid *uid)
+{
+	const char *str = fwnode_get_name(node);
+
+	/*
+	 * To simplify definitions of firmware nodes, we set the device name
+	 * based on the UID of the device, prefixed with "ssam:".
+	 */
+	if (strncmp(str, "ssam:", strlen("ssam:")) != 0)
+		return -ENODEV;
+
+	str += strlen("ssam:");
+	return ssam_device_uid_from_string(str, uid);
+}
+
+static int ssam_add_client_device(struct device *parent, struct ssam_controller *ctrl,
+				  struct fwnode_handle *node)
+{
+	struct ssam_device_uid uid;
+	struct ssam_device *sdev;
+	int status;
+
+	status = ssam_get_uid_for_node(node, &uid);
+	if (status)
+		return status;
+
+	sdev = ssam_device_alloc(ctrl, uid);
+	if (!sdev)
+		return -ENOMEM;
+
+	sdev->dev.parent = parent;
+	sdev->dev.fwnode = fwnode_handle_get(node);
+	sdev->dev.of_node = to_of_node(node);
+
+	status = ssam_device_add(sdev);
+	if (status)
+		ssam_device_put(sdev);
+
+	return status;
+}
+
+/**
+ * __ssam_register_clients() - Register client devices defined under the
+ * given firmware node as children of the given device.
+ * @parent: The parent device under which clients should be registered.
+ * @ctrl: The controller with which client should be registered.
+ * @node: The firmware node holding definitions of the devices to be added.
+ *
+ * Register all clients that have been defined as children of the given root
+ * firmware node as children of the given parent device. The respective child
+ * firmware nodes will be associated with the correspondingly created child
+ * devices.
+ *
+ * The given controller will be used to instantiate the new devices. See
+ * ssam_device_add() for details.
+ *
+ * Note that, generally, the use of either ssam_device_register_clients() or
+ * ssam_register_clients() should be preferred as they directly use the
+ * firmware node and/or controller associated with the given device. This
+ * function is only intended for use when different device specifications (e.g.
+ * ACPI and firmware nodes) need to be combined (as is done in the platform hub
+ * of the device registry).
+ *
+ * Return: Returns zero on success, nonzero on failure.
+ */
+int __ssam_register_clients(struct device *parent, struct ssam_controller *ctrl,
+			    struct fwnode_handle *node)
+{
+	struct fwnode_handle *child;
+	int status;
+
+	fwnode_for_each_child_node(node, child) {
+		/*
+		 * Try to add the device specified in the firmware node. If
+		 * this fails with -ENODEV, the node does not specify any SSAM
+		 * device, so ignore it and continue with the next one.
+		 */
+		status = ssam_add_client_device(parent, ctrl, child);
+		if (status && status != -ENODEV) {
+			fwnode_handle_put(child);
+			goto err;
+		}
+	}
+
+	return 0;
+err:
+	ssam_remove_clients(parent);
+	return status;
+}
+EXPORT_SYMBOL_GPL(__ssam_register_clients);
+
+static int ssam_remove_device(struct device *dev, void *_data)
+{
+	struct ssam_device *sdev = to_ssam_device(dev);
+
+	if (is_ssam_device(dev))
+		ssam_device_remove(sdev);
+
+	return 0;
+}
+
+/**
+ * ssam_remove_clients() - Remove SSAM client devices registered as direct
+ * children under the given parent device.
+ * @dev: The (parent) device to remove all direct clients for.
+ *
+ * Remove all SSAM client devices registered as direct children under the given
+ * device. Note that this only accounts for direct children of the device.
+ * Refer to ssam_device_add()/ssam_device_remove() for more details.
+ */
+void ssam_remove_clients(struct device *dev)
+{
+	device_for_each_child_reverse(dev, NULL, ssam_remove_device);
+}
+EXPORT_SYMBOL_GPL(ssam_remove_clients);

linux-7.2.3/drivers/platform/surface/aggregator/bus.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Surface System Aggregator Module bus and device integration.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_BUS_H
+#define _SURFACE_AGGREGATOR_BUS_H
+
+#include <linux/surface_aggregator/controller.h>
+
+#ifdef CONFIG_SURFACE_AGGREGATOR_BUS
+
+int ssam_bus_register(void);
+void ssam_bus_unregister(void);
+
+#else /* CONFIG_SURFACE_AGGREGATOR_BUS */
+
+static inline int ssam_bus_register(void) { return 0; }
+static inline void ssam_bus_unregister(void) {}
+
+#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */
+#endif /* _SURFACE_AGGREGATOR_BUS_H */

linux-7.2.3/drivers/platform/surface/aggregator/controller.h

@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Main SSAM/SSH controller structure and functionality.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_CONTROLLER_H
+#define _SURFACE_AGGREGATOR_CONTROLLER_H
+
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/serdev.h>
+#include <linux/spinlock.h>
+#include <linux/srcu.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/serial_hub.h>
+
+#include "ssh_request_layer.h"
+
+
+/* -- Safe counters. -------------------------------------------------------- */
+
+/**
+ * struct ssh_seq_counter - Safe counter for SSH sequence IDs.
+ * @value: The current counter value.
+ */
+struct ssh_seq_counter {
+	u8 value;
+};
+
+/**
+ * struct ssh_rqid_counter - Safe counter for SSH request IDs.
+ * @value: The current counter value.
+ */
+struct ssh_rqid_counter {
+	u16 value;
+};
+
+
+/* -- Event/notification system. -------------------------------------------- */
+
+/**
+ * struct ssam_nf_head - Notifier head for SSAM events.
+ * @srcu: The SRCU struct for synchronization.
+ * @head: List-head for notifier blocks registered under this head.
+ */
+struct ssam_nf_head {
+	struct srcu_struct srcu;
+	struct list_head head;
+};
+
+/**
+ * struct ssam_nf - Notifier callback- and activation-registry for SSAM events.
+ * @lock:     Lock guarding (de-)registration of notifier blocks. Note: This
+ *            lock does not need to be held for notifier calls, only
+ *            registration and deregistration.
+ * @refcount: The root of the RB-tree used for reference-counting enabled
+ *            events/notifications.
+ * @head:     The list of notifier heads for event/notification callbacks.
+ */
+struct ssam_nf {
+	struct mutex lock;
+	struct rb_root refcount;
+	struct ssam_nf_head head[SSH_NUM_EVENTS];
+};
+
+
+/* -- Event/async request completion system. -------------------------------- */
+
+struct ssam_cplt;
+
+/**
+ * struct ssam_event_item - Struct for event queuing and completion.
+ * @node:     The node in the queue.
+ * @rqid:     The request ID of the event.
+ * @ops:      Instance specific functions.
+ * @ops.free: Callback for freeing this event item.
+ * @event:    Actual event data.
+ */
+struct ssam_event_item {
+	struct list_head node;
+	u16 rqid;
+
+	struct {
+		void (*free)(struct ssam_event_item *event);
+	} ops;
+
+	struct ssam_event event;	/* must be last */
+};
+
+/**
+ * struct ssam_event_queue - Queue for completing received events.
+ * @cplt: Reference to the completion system on which this queue is active.
+ * @lock: The lock for any operation on the queue.
+ * @head: The list-head of the queue.
+ * @work: The &struct work_struct performing completion work for this queue.
+ */
+struct ssam_event_queue {
+	struct ssam_cplt *cplt;
+
+	spinlock_t lock;
+	struct list_head head;
+	struct work_struct work;
+};
+
+/**
+ * struct ssam_event_target - Set of queues for a single SSH target ID.
+ * @queue: The array of queues, one queue per event ID.
+ */
+struct ssam_event_target {
+	struct ssam_event_queue queue[SSH_NUM_EVENTS];
+};
+
+/**
+ * struct ssam_cplt - SSAM event/async request completion system.
+ * @dev:          The device with which this system is associated. Only used
+ *                for logging.
+ * @wq:           The &struct workqueue_struct on which all completion work
+ *                items are queued.
+ * @event:        Event completion management.
+ * @event.target: Array of &struct ssam_event_target, one for each target.
+ * @event.notif:  Notifier callbacks and event activation reference counting.
+ */
+struct ssam_cplt {
+	struct device *dev;
+	struct workqueue_struct *wq;
+
+	struct {
+		struct ssam_event_target target[SSH_NUM_TARGETS];
+		struct ssam_nf notif;
+	} event;
+};
+
+
+/* -- Main SSAM device structures. ------------------------------------------ */
+
+/**
+ * enum ssam_controller_state - State values for &struct ssam_controller.
+ * @SSAM_CONTROLLER_UNINITIALIZED:
+ *	The controller has not been initialized yet or has been deinitialized.
+ * @SSAM_CONTROLLER_INITIALIZED:
+ *	The controller is initialized, but has not been started yet.
+ * @SSAM_CONTROLLER_STARTED:
+ *	The controller has been started and is ready to use.
+ * @SSAM_CONTROLLER_STOPPED:
+ *	The controller has been stopped.
+ * @SSAM_CONTROLLER_SUSPENDED:
+ *	The controller has been suspended.
+ */
+enum ssam_controller_state {
+	SSAM_CONTROLLER_UNINITIALIZED,
+	SSAM_CONTROLLER_INITIALIZED,
+	SSAM_CONTROLLER_STARTED,
+	SSAM_CONTROLLER_STOPPED,
+	SSAM_CONTROLLER_SUSPENDED,
+};
+
+/**
+ * struct ssam_controller_caps - Controller device capabilities.
+ * @ssh_power_profile:             SSH power profile.
+ * @ssh_buffer_size:               SSH driver UART buffer size.
+ * @screen_on_sleep_idle_timeout:  SAM UART screen-on sleep idle timeout.
+ * @screen_off_sleep_idle_timeout: SAM UART screen-off sleep idle timeout.
+ * @d3_closes_handle:              SAM closes UART handle in D3.
+ *
+ * Controller and SSH device capabilities found in ACPI.
+ */
+struct ssam_controller_caps {
+	u32 ssh_power_profile;
+	u32 ssh_buffer_size;
+	u32 screen_on_sleep_idle_timeout;
+	u32 screen_off_sleep_idle_timeout;
+	u32 d3_closes_handle:1;
+};
+
+/**
+ * struct ssam_controller - SSAM controller device.
+ * @kref:  Reference count of the controller.
+ * @lock:  Main lock for the controller, used to guard state changes.
+ * @state: Controller state.
+ * @rtl:   Request transport layer for SSH I/O.
+ * @cplt:  Completion system for SSH/SSAM events and asynchronous requests.
+ * @counter:      Safe SSH message ID counters.
+ * @counter.seq:  Sequence ID counter.
+ * @counter.rqid: Request ID counter.
+ * @irq:          Wakeup IRQ resources.
+ * @irq.num:      The wakeup IRQ number.
+ * @irq.wakeup_enabled: Whether wakeup by IRQ is enabled during suspend.
+ * @caps: The controller device capabilities.
+ */
+struct ssam_controller {
+	struct kref kref;
+
+	struct rw_semaphore lock;
+	enum ssam_controller_state state;
+
+	struct ssh_rtl rtl;
+	struct ssam_cplt cplt;
+
+	struct {
+		struct ssh_seq_counter seq;
+		struct ssh_rqid_counter rqid;
+	} counter;
+
+	struct {
+		int num;
+		bool wakeup_enabled;
+	} irq;
+
+	struct ssam_controller_caps caps;
+};
+
+#define to_ssam_controller(ptr, member) \
+	container_of(ptr, struct ssam_controller, member)
+
+#define ssam_dbg(ctrl, fmt, ...)  rtl_dbg(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
+#define ssam_info(ctrl, fmt, ...) rtl_info(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
+#define ssam_warn(ctrl, fmt, ...) rtl_warn(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
+#define ssam_err(ctrl, fmt, ...)  rtl_err(&(ctrl)->rtl, fmt, ##__VA_ARGS__)
+
+/**
+ * ssam_controller_receive_buf() - Provide input-data to the controller.
+ * @ctrl: The controller.
+ * @buf:  The input buffer.
+ * @n:    The number of bytes in the input buffer.
+ *
+ * Provide input data to be evaluated by the controller, which has been
+ * received via the lower-level transport.
+ *
+ * Return: Returns the number of bytes consumed, or, if the packet transport
+ * layer of the controller has been shut down, %-ESHUTDOWN.
+ */
+static inline
+ssize_t ssam_controller_receive_buf(struct ssam_controller *ctrl, const u8 *buf,
+				    size_t n)
+{
+	return ssh_ptl_rx_rcvbuf(&ctrl->rtl.ptl, buf, n);
+}
+
+/**
+ * ssam_controller_write_wakeup() - Notify the controller that the underlying
+ * device has space available for data to be written.
+ * @ctrl: The controller.
+ */
+static inline void ssam_controller_write_wakeup(struct ssam_controller *ctrl)
+{
+	ssh_ptl_tx_wakeup_transfer(&ctrl->rtl.ptl);
+}
+
+int ssam_controller_init(struct ssam_controller *ctrl, struct serdev_device *s);
+int ssam_controller_start(struct ssam_controller *ctrl);
+void ssam_controller_shutdown(struct ssam_controller *ctrl);
+void ssam_controller_destroy(struct ssam_controller *ctrl);
+
+int ssam_notifier_disable_registered(struct ssam_controller *ctrl);
+void ssam_notifier_restore_registered(struct ssam_controller *ctrl);
+
+int ssam_irq_setup(struct ssam_controller *ctrl);
+void ssam_irq_free(struct ssam_controller *ctrl);
+int ssam_irq_arm_for_wakeup(struct ssam_controller *ctrl);
+void ssam_irq_disarm_wakeup(struct ssam_controller *ctrl);
+
+void ssam_controller_lock(struct ssam_controller *c);
+void ssam_controller_unlock(struct ssam_controller *c);
+
+int ssam_get_firmware_version(struct ssam_controller *ctrl, u32 *version);
+int ssam_ctrl_notif_display_off(struct ssam_controller *ctrl);
+int ssam_ctrl_notif_display_on(struct ssam_controller *ctrl);
+int ssam_ctrl_notif_d0_exit(struct ssam_controller *ctrl);
+int ssam_ctrl_notif_d0_entry(struct ssam_controller *ctrl);
+
+int ssam_controller_suspend(struct ssam_controller *ctrl);
+int ssam_controller_resume(struct ssam_controller *ctrl);
+
+int ssam_event_item_cache_init(void);
+void ssam_event_item_cache_destroy(void);
+
+#endif /* _SURFACE_AGGREGATOR_CONTROLLER_H */

linux-7.2.3/drivers/platform/surface/aggregator/core.c

@@ -0,0 +1,894 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Surface Serial Hub (SSH) driver for communication with the Surface/System
+ * Aggregator Module (SSAM/SAM).
+ *
+ * Provides access to a SAM-over-SSH connected EC via a controller device.
+ * Handles communication via requests as well as enabling, disabling, and
+ * relaying of events.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/atomic.h>
+#include <linux/completion.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/serdev.h>
+#include <linux/sysfs.h>
+#include <linux/units.h>
+
+#include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/device.h>
+
+#include "bus.h"
+#include "controller.h"
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+
+/* -- Static controller reference. ------------------------------------------ */
+
+/*
+ * Main controller reference. The corresponding lock must be held while
+ * accessing (reading/writing) the reference.
+ */
+static struct ssam_controller *__ssam_controller;
+static DEFINE_SPINLOCK(__ssam_controller_lock);
+
+/**
+ * ssam_get_controller() - Get reference to SSAM controller.
+ *
+ * Returns a reference to the SSAM controller of the system or %NULL if there
+ * is none, it hasn't been set up yet, or it has already been unregistered.
+ * This function automatically increments the reference count of the
+ * controller, thus the calling party must ensure that ssam_controller_put()
+ * is called when it doesn't need the controller any more.
+ */
+struct ssam_controller *ssam_get_controller(void)
+{
+	struct ssam_controller *ctrl;
+
+	spin_lock(&__ssam_controller_lock);
+
+	ctrl = __ssam_controller;
+	if (!ctrl)
+		goto out;
+
+	if (WARN_ON(!kref_get_unless_zero(&ctrl->kref)))
+		ctrl = NULL;
+
+out:
+	spin_unlock(&__ssam_controller_lock);
+	return ctrl;
+}
+EXPORT_SYMBOL_GPL(ssam_get_controller);
+
+/**
+ * ssam_try_set_controller() - Try to set the main controller reference.
+ * @ctrl: The controller to which the reference should point.
+ *
+ * Set the main controller reference to the given pointer if the reference
+ * hasn't been set already.
+ *
+ * Return: Returns zero on success or %-EEXIST if the reference has already
+ * been set.
+ */
+static int ssam_try_set_controller(struct ssam_controller *ctrl)
+{
+	int status = 0;
+
+	spin_lock(&__ssam_controller_lock);
+	if (!__ssam_controller)
+		__ssam_controller = ctrl;
+	else
+		status = -EEXIST;
+	spin_unlock(&__ssam_controller_lock);
+
+	return status;
+}
+
+/**
+ * ssam_clear_controller() - Remove/clear the main controller reference.
+ *
+ * Clears the main controller reference, i.e. sets it to %NULL. This function
+ * should be called before the controller is shut down.
+ */
+static void ssam_clear_controller(void)
+{
+	spin_lock(&__ssam_controller_lock);
+	__ssam_controller = NULL;
+	spin_unlock(&__ssam_controller_lock);
+}
+
+/**
+ * ssam_client_link() - Link an arbitrary client device to the controller.
+ * @c: The controller to link to.
+ * @client: The client device.
+ *
+ * Link an arbitrary client device to the controller by creating a device link
+ * between it as consumer and the controller device as provider. This function
+ * can be used for non-SSAM devices (or SSAM devices not registered as child
+ * under the controller) to guarantee that the controller is valid for as long
+ * as the driver of the client device is bound, and that proper suspend and
+ * resume ordering is guaranteed.
+ *
+ * The device link does not have to be destructed manually. It is removed
+ * automatically once the driver of the client device unbinds.
+ *
+ * Return: Returns zero on success, %-ENODEV if the controller is not ready or
+ * going to be removed soon, or %-ENOMEM if the device link could not be
+ * created for other reasons.
+ */
+int ssam_client_link(struct ssam_controller *c, struct device *client)
+{
+	const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_CONSUMER;
+	struct device_link *link;
+	struct device *ctrldev;
+
+	ssam_controller_statelock(c);
+
+	if (c->state != SSAM_CONTROLLER_STARTED) {
+		ssam_controller_stateunlock(c);
+		return -ENODEV;
+	}
+
+	ctrldev = ssam_controller_device(c);
+	if (!ctrldev) {
+		ssam_controller_stateunlock(c);
+		return -ENODEV;
+	}
+
+	link = device_link_add(client, ctrldev, flags);
+	if (!link) {
+		ssam_controller_stateunlock(c);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Return -ENODEV if supplier driver is on its way to be removed. In
+	 * this case, the controller won't be around for much longer and the
+	 * device link is not going to save us any more, as unbinding is
+	 * already in progress.
+	 */
+	if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) {
+		ssam_controller_stateunlock(c);
+		return -ENODEV;
+	}
+
+	ssam_controller_stateunlock(c);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ssam_client_link);
+
+/**
+ * ssam_client_bind() - Bind an arbitrary client device to the controller.
+ * @client: The client device.
+ *
+ * Link an arbitrary client device to the controller by creating a device link
+ * between it as consumer and the main controller device as provider. This
+ * function can be used for non-SSAM devices to guarantee that the controller
+ * returned by this function is valid for as long as the driver of the client
+ * device is bound, and that proper suspend and resume ordering is guaranteed.
+ *
+ * This function does essentially the same as ssam_client_link(), except that
+ * it first fetches the main controller reference, then creates the link, and
+ * finally returns this reference. Note that this function does not increment
+ * the reference counter of the controller, as, due to the link, the
+ * controller lifetime is assured as long as the driver of the client device
+ * is bound.
+ *
+ * It is not valid to use the controller reference obtained by this method
+ * outside of the driver bound to the client device at the time of calling
+ * this function, without first incrementing the reference count of the
+ * controller via ssam_controller_get(). Even after doing this, care must be
+ * taken that requests are only submitted and notifiers are only
+ * (un-)registered when the controller is active and not suspended. In other
+ * words: The device link only lives as long as the client driver is bound and
+ * any guarantees enforced by this link (e.g. active controller state) can
+ * only be relied upon as long as this link exists and may need to be enforced
+ * in other ways afterwards.
+ *
+ * The created device link does not have to be destructed manually. It is
+ * removed automatically once the driver of the client device unbinds.
+ *
+ * Return: Returns the controller on success, an error pointer with %-ENODEV
+ * if the controller is not present, not ready or going to be removed soon, or
+ * %-ENOMEM if the device link could not be created for other reasons.
+ */
+struct ssam_controller *ssam_client_bind(struct device *client)
+{
+	struct ssam_controller *c;
+	int status;
+
+	c = ssam_get_controller();
+	if (!c)
+		return ERR_PTR(-ENODEV);
+
+	status = ssam_client_link(c, client);
+
+	/*
+	 * Note that we can drop our controller reference in both success and
+	 * failure cases: On success, we have bound the controller lifetime
+	 * inherently to the client driver lifetime, i.e. it the controller is
+	 * now guaranteed to outlive the client driver. On failure, we're not
+	 * going to use the controller any more.
+	 */
+	ssam_controller_put(c);
+
+	return status >= 0 ? c : ERR_PTR(status);
+}
+EXPORT_SYMBOL_GPL(ssam_client_bind);
+
+
+/* -- Glue layer (serdev_device -> ssam_controller). ------------------------ */
+
+static size_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
+			       size_t n)
+{
+	struct ssam_controller *ctrl;
+	int ret;
+
+	ctrl = serdev_device_get_drvdata(dev);
+	ret = ssam_controller_receive_buf(ctrl, buf, n);
+
+	return ret < 0 ? 0 : ret;
+}
+
+static void ssam_write_wakeup(struct serdev_device *dev)
+{
+	ssam_controller_write_wakeup(serdev_device_get_drvdata(dev));
+}
+
+static const struct serdev_device_ops ssam_serdev_ops = {
+	.receive_buf = ssam_receive_buf,
+	.write_wakeup = ssam_write_wakeup,
+};
+
+
+/* -- SysFS and misc. ------------------------------------------------------- */
+
+static int ssam_log_firmware_version(struct ssam_controller *ctrl)
+{
+	u32 version, a, b, c;
+	int status;
+
+	status = ssam_get_firmware_version(ctrl, &version);
+	if (status)
+		return status;
+
+	a = (version >> 24) & 0xff;
+	b = ((version >> 8) & 0xffff);
+	c = version & 0xff;
+
+	ssam_info(ctrl, "SAM firmware version: %u.%u.%u\n", a, b, c);
+	return 0;
+}
+
+static ssize_t firmware_version_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct ssam_controller *ctrl = dev_get_drvdata(dev);
+	u32 version, a, b, c;
+	int status;
+
+	status = ssam_get_firmware_version(ctrl, &version);
+	if (status < 0)
+		return status;
+
+	a = (version >> 24) & 0xff;
+	b = ((version >> 8) & 0xffff);
+	c = version & 0xff;
+
+	return sysfs_emit(buf, "%u.%u.%u\n", a, b, c);
+}
+static DEVICE_ATTR_RO(firmware_version);
+
+static struct attribute *ssam_sam_attrs[] = {
+	&dev_attr_firmware_version.attr,
+	NULL
+};
+
+static const struct attribute_group ssam_sam_group = {
+	.name = "sam",
+	.attrs = ssam_sam_attrs,
+};
+
+
+/* -- Serial device setup. -------------------------------------------------- */
+
+static acpi_status ssam_serdev_setup_via_acpi_crs(struct acpi_resource *rsc,
+						  void *ctx)
+{
+	struct serdev_device *serdev = ctx;
+	struct acpi_resource_uart_serialbus *uart;
+	bool flow_control;
+	int status = 0;
+
+	if (!serdev_acpi_get_uart_resource(rsc, &uart))
+		return AE_OK;
+
+	/* Set up serdev device. */
+	serdev_device_set_baudrate(serdev, uart->default_baud_rate);
+
+	/* serdev currently only supports RTSCTS flow control. */
+	if (uart->flow_control & (~((u8)ACPI_UART_FLOW_CONTROL_HW))) {
+		dev_warn(&serdev->dev, "setup: unsupported flow control (value: %#04x)\n",
+			 uart->flow_control);
+	}
+
+	/* Set RTSCTS flow control. */
+	flow_control = uart->flow_control & ACPI_UART_FLOW_CONTROL_HW;
+	serdev_device_set_flow_control(serdev, flow_control);
+
+	/* serdev currently only supports EVEN/ODD parity. */
+	switch (uart->parity) {
+	case ACPI_UART_PARITY_NONE:
+		status = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+		break;
+	case ACPI_UART_PARITY_EVEN:
+		status = serdev_device_set_parity(serdev, SERDEV_PARITY_EVEN);
+		break;
+	case ACPI_UART_PARITY_ODD:
+		status = serdev_device_set_parity(serdev, SERDEV_PARITY_ODD);
+		break;
+	default:
+		dev_warn(&serdev->dev, "setup: unsupported parity (value: %#04x)\n",
+			 uart->parity);
+		break;
+	}
+
+	if (status) {
+		dev_err(&serdev->dev, "setup: failed to set parity (value: %#04x, error: %d)\n",
+			uart->parity, status);
+		return AE_ERROR;
+	}
+
+	/* We've found the resource and are done. */
+	return AE_CTRL_TERMINATE;
+}
+
+static int ssam_serdev_setup_via_acpi(struct serdev_device *serdev, acpi_handle handle)
+{
+	acpi_status status;
+
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     ssam_serdev_setup_via_acpi_crs, serdev);
+
+	return status ? -ENXIO : 0;
+}
+
+static int ssam_serdev_setup(struct acpi_device *ssh, struct serdev_device *serdev)
+{
+	if (ssh)
+		return ssam_serdev_setup_via_acpi(serdev, ssh->handle);
+
+	/* TODO: these values may differ per board/implementation */
+	serdev_device_set_baudrate(serdev, 4 * HZ_PER_MHZ);
+	serdev_device_set_flow_control(serdev, true);
+	serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+
+	return 0;
+}
+
+/* -- Power management. ----------------------------------------------------- */
+
+static void ssam_serial_hub_shutdown(struct serdev_device *serdev)
+{
+	struct ssam_controller *c = dev_get_drvdata(&serdev->dev);
+	int status;
+
+	/*
+	 * Try to disable notifiers, signal display-off and D0-exit, ignore any
+	 * errors.
+	 *
+	 * Note: It has not been established yet if this is actually
+	 * necessary/useful for shutdown.
+	 */
+
+	status = ssam_notifier_disable_registered(c);
+	if (status) {
+		ssam_err(c, "pm: failed to disable notifiers for shutdown: %d\n",
+			 status);
+	}
+
+	status = ssam_ctrl_notif_display_off(c);
+	if (status)
+		ssam_err(c, "pm: display-off notification failed: %d\n", status);
+
+	status = ssam_ctrl_notif_d0_exit(c);
+	if (status)
+		ssam_err(c, "pm: D0-exit notification failed: %d\n", status);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ssam_serial_hub_pm_prepare(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * Try to signal display-off, This will quiesce events.
+	 *
+	 * Note: Signaling display-off/display-on should normally be done from
+	 * some sort of display state notifier. As that is not available,
+	 * signal it here.
+	 */
+
+	status = ssam_ctrl_notif_display_off(c);
+	if (status)
+		ssam_err(c, "pm: display-off notification failed: %d\n", status);
+
+	return status;
+}
+
+static void ssam_serial_hub_pm_complete(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * Try to signal display-on. This will restore events.
+	 *
+	 * Note: Signaling display-off/display-on should normally be done from
+	 * some sort of display state notifier. As that is not available,
+	 * signal it here.
+	 */
+
+	status = ssam_ctrl_notif_display_on(c);
+	if (status)
+		ssam_err(c, "pm: display-on notification failed: %d\n", status);
+}
+
+static int ssam_serial_hub_pm_suspend(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * Try to signal D0-exit, enable IRQ wakeup if specified. Abort on
+	 * error.
+	 */
+
+	status = ssam_ctrl_notif_d0_exit(c);
+	if (status) {
+		ssam_err(c, "pm: D0-exit notification failed: %d\n", status);
+		goto err_notif;
+	}
+
+	status = ssam_irq_arm_for_wakeup(c);
+	if (status)
+		goto err_irq;
+
+	WARN_ON(ssam_controller_suspend(c));
+	return 0;
+
+err_irq:
+	ssam_ctrl_notif_d0_entry(c);
+err_notif:
+	ssam_ctrl_notif_display_on(c);
+	return status;
+}
+
+static int ssam_serial_hub_pm_resume(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	WARN_ON(ssam_controller_resume(c));
+
+	/*
+	 * Try to disable IRQ wakeup (if specified) and signal D0-entry. In
+	 * case of errors, log them and try to restore normal operation state
+	 * as far as possible.
+	 *
+	 * Note: Signaling display-off/display-on should normally be done from
+	 * some sort of display state notifier. As that is not available,
+	 * signal it here.
+	 */
+
+	ssam_irq_disarm_wakeup(c);
+
+	status = ssam_ctrl_notif_d0_entry(c);
+	if (status)
+		ssam_err(c, "pm: D0-entry notification failed: %d\n", status);
+
+	return 0;
+}
+
+static int ssam_serial_hub_pm_freeze(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * During hibernation image creation, we only have to ensure that the
+	 * EC doesn't send us any events. This is done via the display-off
+	 * and D0-exit notifications. Note that this sets up the wakeup IRQ
+	 * on the EC side, however, we have disabled it by default on our side
+	 * and won't enable it here.
+	 *
+	 * See ssam_serial_hub_poweroff() for more details on the hibernation
+	 * process.
+	 */
+
+	status = ssam_ctrl_notif_d0_exit(c);
+	if (status) {
+		ssam_err(c, "pm: D0-exit notification failed: %d\n", status);
+		ssam_ctrl_notif_display_on(c);
+		return status;
+	}
+
+	WARN_ON(ssam_controller_suspend(c));
+	return 0;
+}
+
+static int ssam_serial_hub_pm_thaw(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	WARN_ON(ssam_controller_resume(c));
+
+	status = ssam_ctrl_notif_d0_entry(c);
+	if (status)
+		ssam_err(c, "pm: D0-exit notification failed: %d\n", status);
+
+	return status;
+}
+
+static int ssam_serial_hub_pm_poweroff(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * When entering hibernation and powering off the system, the EC, at
+	 * least on some models, may disable events. Without us taking care of
+	 * that, this leads to events not being enabled/restored when the
+	 * system resumes from hibernation, resulting SAM-HID subsystem devices
+	 * (i.e. keyboard, touchpad) not working, AC-plug/AC-unplug events being
+	 * gone, etc.
+	 *
+	 * To avoid these issues, we disable all registered events here (this is
+	 * likely not actually required) and restore them during the drivers PM
+	 * restore callback.
+	 *
+	 * Wakeup from the EC interrupt is not supported during hibernation,
+	 * so don't arm the IRQ here.
+	 */
+
+	status = ssam_notifier_disable_registered(c);
+	if (status) {
+		ssam_err(c, "pm: failed to disable notifiers for hibernation: %d\n",
+			 status);
+		return status;
+	}
+
+	status = ssam_ctrl_notif_d0_exit(c);
+	if (status) {
+		ssam_err(c, "pm: D0-exit notification failed: %d\n", status);
+		ssam_notifier_restore_registered(c);
+		return status;
+	}
+
+	WARN_ON(ssam_controller_suspend(c));
+	return 0;
+}
+
+static int ssam_serial_hub_pm_restore(struct device *dev)
+{
+	struct ssam_controller *c = dev_get_drvdata(dev);
+	int status;
+
+	/*
+	 * Ignore but log errors, try to restore state as much as possible in
+	 * case of failures. See ssam_serial_hub_poweroff() for more details on
+	 * the hibernation process.
+	 */
+
+	WARN_ON(ssam_controller_resume(c));
+
+	status = ssam_ctrl_notif_d0_entry(c);
+	if (status)
+		ssam_err(c, "pm: D0-entry notification failed: %d\n", status);
+
+	ssam_notifier_restore_registered(c);
+	return 0;
+}
+
+static const struct dev_pm_ops ssam_serial_hub_pm_ops = {
+	.prepare  = ssam_serial_hub_pm_prepare,
+	.complete = ssam_serial_hub_pm_complete,
+	.suspend  = ssam_serial_hub_pm_suspend,
+	.resume   = ssam_serial_hub_pm_resume,
+	.freeze   = ssam_serial_hub_pm_freeze,
+	.thaw     = ssam_serial_hub_pm_thaw,
+	.poweroff = ssam_serial_hub_pm_poweroff,
+	.restore  = ssam_serial_hub_pm_restore,
+};
+
+#else /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops ssam_serial_hub_pm_ops = { };
+
+#endif /* CONFIG_PM_SLEEP */
+
+
+/* -- Device/driver setup. -------------------------------------------------- */
+
+static const struct acpi_gpio_params gpio_ssam_wakeup_int = { 0, 0, false };
+static const struct acpi_gpio_params gpio_ssam_wakeup     = { 1, 0, false };
+
+static const struct acpi_gpio_mapping ssam_acpi_gpios[] = {
+	{ "ssam_wakeup-int-gpio", &gpio_ssam_wakeup_int, 1 },
+	{ "ssam_wakeup-gpio",     &gpio_ssam_wakeup,     1 },
+	{ },
+};
+
+static int ssam_serial_hub_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	struct acpi_device *ssh = ACPI_COMPANION(dev);
+	struct ssam_controller *ctrl;
+	int status;
+
+	if (ssh) {
+		status = gpiod_count(dev, NULL);
+		if (status < 0)
+			return dev_err_probe(dev, status, "no GPIO found\n");
+
+		status = devm_acpi_dev_add_driver_gpios(dev, ssam_acpi_gpios);
+		if (status)
+			return status;
+	}
+
+	/* Allocate controller. */
+	ctrl = kzalloc_obj(*ctrl);
+	if (!ctrl)
+		return -ENOMEM;
+
+	/* Initialize controller. */
+	status = ssam_controller_init(ctrl, serdev);
+	if (status) {
+		dev_err_probe(dev, status, "failed to initialize ssam controller\n");
+		goto err_ctrl_init;
+	}
+
+	ssam_controller_lock(ctrl);
+
+	/* Set up serdev device. */
+	serdev_device_set_drvdata(serdev, ctrl);
+	serdev_device_set_client_ops(serdev, &ssam_serdev_ops);
+	status = serdev_device_open(serdev);
+	if (status) {
+		dev_err_probe(dev, status, "failed to open serdev device\n");
+		goto err_devopen;
+	}
+
+	status = ssam_serdev_setup(ssh, serdev);
+	if (status) {
+		dev_err_probe(dev, status, "failed to setup serdev\n");
+		goto err_devinit;
+	}
+
+	/* Start controller. */
+	status = ssam_controller_start(ctrl);
+	if (status)
+		goto err_devinit;
+
+	ssam_controller_unlock(ctrl);
+
+	/*
+	 * Initial SAM requests: Log version and notify default/init power
+	 * states.
+	 */
+	status = ssam_log_firmware_version(ctrl);
+	if (status) {
+		dev_err_probe(dev, status, "failed to get firmware version\n");
+		goto err_initrq;
+	}
+
+	status = ssam_ctrl_notif_d0_entry(ctrl);
+	if (status) {
+		dev_err_probe(dev, status, "D0-entry notification failed\n");
+		goto err_initrq;
+	}
+
+	status = ssam_ctrl_notif_display_on(ctrl);
+	if (status) {
+		dev_err_probe(dev, status, "display-on notification failed\n");
+		goto err_initrq;
+	}
+
+	status = sysfs_create_group(&dev->kobj, &ssam_sam_group);
+	if (status)
+		goto err_initrq;
+
+	/* Set up IRQ. */
+	status = ssam_irq_setup(ctrl);
+	if (status) {
+		dev_err_probe(dev, status, "failed to setup IRQ\n");
+		goto err_irq;
+	}
+
+	/* Finally, set main controller reference. */
+	status = ssam_try_set_controller(ctrl);
+	if (WARN_ON(status))	/* Currently, we're the only provider. */
+		goto err_mainref;
+
+	/*
+	 * TODO: The EC can wake up the system via the associated GPIO interrupt
+	 *       in multiple situations. One of which is the remaining battery
+	 *       capacity falling below a certain threshold. Normally, we should
+	 *       use the device_init_wakeup function, however, the EC also seems
+	 *       to have other reasons for waking up the system and it seems
+	 *       that Windows has additional checks whether the system should be
+	 *       resumed. In short, this causes some spurious unwanted wake-ups.
+	 *       For now let's thus default power/wakeup to false.
+	 */
+	device_set_wakeup_capable(dev, true);
+
+	/*
+	 * When using DT, we have to register the platform hub driver manually,
+	 * as it can't be matched based on top-level board compatible (like it
+	 * does the ACPI case).
+	 */
+	if (!ssh) {
+		struct platform_device *ph_pdev =
+			platform_device_register_simple("surface_aggregator_platform_hub",
+							0, NULL, 0);
+		if (IS_ERR(ph_pdev))
+			return dev_err_probe(dev, PTR_ERR(ph_pdev),
+					     "Failed to register the platform hub driver\n");
+	}
+
+	if (ssh)
+		acpi_dev_clear_dependencies(ssh);
+
+	return 0;
+
+err_mainref:
+	ssam_irq_free(ctrl);
+err_irq:
+	sysfs_remove_group(&dev->kobj, &ssam_sam_group);
+err_initrq:
+	ssam_controller_lock(ctrl);
+	ssam_controller_shutdown(ctrl);
+err_devinit:
+	serdev_device_close(serdev);
+err_devopen:
+	ssam_controller_destroy(ctrl);
+	ssam_controller_unlock(ctrl);
+err_ctrl_init:
+	kfree(ctrl);
+	return status;
+}
+
+static void ssam_serial_hub_remove(struct serdev_device *serdev)
+{
+	struct ssam_controller *ctrl = serdev_device_get_drvdata(serdev);
+	int status;
+
+	/* Clear static reference so that no one else can get a new one. */
+	ssam_clear_controller();
+
+	/* Disable and free IRQ. */
+	ssam_irq_free(ctrl);
+
+	sysfs_remove_group(&serdev->dev.kobj, &ssam_sam_group);
+	ssam_controller_lock(ctrl);
+
+	/* Remove all client devices. */
+	ssam_remove_clients(&serdev->dev);
+
+	/* Act as if suspending to silence events. */
+	status = ssam_ctrl_notif_display_off(ctrl);
+	if (status) {
+		dev_err(&serdev->dev, "display-off notification failed: %d\n",
+			status);
+	}
+
+	status = ssam_ctrl_notif_d0_exit(ctrl);
+	if (status) {
+		dev_err(&serdev->dev, "D0-exit notification failed: %d\n",
+			status);
+	}
+
+	/* Shut down controller and remove serdev device reference from it. */
+	ssam_controller_shutdown(ctrl);
+
+	/* Shut down actual transport. */
+	serdev_device_wait_until_sent(serdev, 0);
+	serdev_device_close(serdev);
+
+	/* Drop our controller reference. */
+	ssam_controller_unlock(ctrl);
+	ssam_controller_put(ctrl);
+
+	device_set_wakeup_capable(&serdev->dev, false);
+}
+
+static const struct acpi_device_id ssam_serial_hub_acpi_match[] = {
+	{ "MSHW0084", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, ssam_serial_hub_acpi_match);
+
+#ifdef CONFIG_OF
+static const struct of_device_id ssam_serial_hub_of_match[] = {
+	{ .compatible = "microsoft,surface-sam", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ssam_serial_hub_of_match);
+#endif
+
+static struct serdev_device_driver ssam_serial_hub = {
+	.probe = ssam_serial_hub_probe,
+	.remove = ssam_serial_hub_remove,
+	.shutdown = ssam_serial_hub_shutdown,
+	.driver = {
+		.name = "surface_serial_hub",
+		.acpi_match_table = ACPI_PTR(ssam_serial_hub_acpi_match),
+		.of_match_table = of_match_ptr(ssam_serial_hub_of_match),
+		.pm = &ssam_serial_hub_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+
+/* -- Module setup. --------------------------------------------------------- */
+
+static int __init ssam_core_init(void)
+{
+	int status;
+
+	status = ssam_bus_register();
+	if (status)
+		goto err_bus;
+
+	status = ssh_ctrl_packet_cache_init();
+	if (status)
+		goto err_cpkg;
+
+	status = ssam_event_item_cache_init();
+	if (status)
+		goto err_evitem;
+
+	status = serdev_device_driver_register(&ssam_serial_hub);
+	if (status)
+		goto err_register;
+
+	return 0;
+
+err_register:
+	ssam_event_item_cache_destroy();
+err_evitem:
+	ssh_ctrl_packet_cache_destroy();
+err_cpkg:
+	ssam_bus_unregister();
+err_bus:
+	return status;
+}
+subsys_initcall(ssam_core_init);
+
+static void __exit ssam_core_exit(void)
+{
+	serdev_device_driver_unregister(&ssam_serial_hub);
+	ssam_event_item_cache_destroy();
+	ssh_ctrl_packet_cache_destroy();
+	ssam_bus_unregister();
+}
+module_exit(ssam_core_exit);
+
+MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
+MODULE_DESCRIPTION("Subsystem and Surface Serial Hub driver for Surface System Aggregator Module");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/platform/surface/aggregator/ssh_msgb.h

@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * SSH message builder functions.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_SSH_MSGB_H
+#define _SURFACE_AGGREGATOR_SSH_MSGB_H
+
+#include <linux/unaligned.h>
+#include <linux/types.h>
+
+#include <linux/surface_aggregator/controller.h>
+#include <linux/surface_aggregator/serial_hub.h>
+
+/**
+ * struct msgbuf - Buffer struct to construct SSH messages.
+ * @begin: Pointer to the beginning of the allocated buffer space.
+ * @end:   Pointer to the end (one past last element) of the allocated buffer
+ *         space.
+ * @ptr:   Pointer to the first free element in the buffer.
+ */
+struct msgbuf {
+	u8 *begin;
+	u8 *end;
+	u8 *ptr;
+};
+
+/**
+ * msgb_init() - Initialize the given message buffer struct.
+ * @msgb: The buffer struct to initialize
+ * @ptr:  Pointer to the underlying memory by which the buffer will be backed.
+ * @cap:  Size of the underlying memory.
+ *
+ * Initialize the given message buffer struct using the provided memory as
+ * backing.
+ */
+static inline void msgb_init(struct msgbuf *msgb, u8 *ptr, size_t cap)
+{
+	msgb->begin = ptr;
+	msgb->end = ptr + cap;
+	msgb->ptr = ptr;
+}
+
+/**
+ * msgb_bytes_used() - Return the current number of bytes used in the buffer.
+ * @msgb: The message buffer.
+ */
+static inline size_t msgb_bytes_used(const struct msgbuf *msgb)
+{
+	return msgb->ptr - msgb->begin;
+}
+
+static inline void __msgb_push_u8(struct msgbuf *msgb, u8 value)
+{
+	*msgb->ptr = value;
+	msgb->ptr += sizeof(u8);
+}
+
+static inline void __msgb_push_u16(struct msgbuf *msgb, u16 value)
+{
+	put_unaligned_le16(value, msgb->ptr);
+	msgb->ptr += sizeof(u16);
+}
+
+/**
+ * msgb_push_u16() - Push a u16 value to the buffer.
+ * @msgb:  The message buffer.
+ * @value: The value to push to the buffer.
+ */
+static inline void msgb_push_u16(struct msgbuf *msgb, u16 value)
+{
+	if (WARN_ON(msgb->ptr + sizeof(u16) > msgb->end))
+		return;
+
+	__msgb_push_u16(msgb, value);
+}
+
+/**
+ * msgb_push_syn() - Push SSH SYN bytes to the buffer.
+ * @msgb: The message buffer.
+ */
+static inline void msgb_push_syn(struct msgbuf *msgb)
+{
+	msgb_push_u16(msgb, SSH_MSG_SYN);
+}
+
+/**
+ * msgb_push_buf() - Push raw data to the buffer.
+ * @msgb: The message buffer.
+ * @buf:  The data to push to the buffer.
+ * @len:  The length of the data to push to the buffer.
+ */
+static inline void msgb_push_buf(struct msgbuf *msgb, const u8 *buf, size_t len)
+{
+	msgb->ptr = memcpy(msgb->ptr, buf, len) + len;
+}
+
+/**
+ * msgb_push_crc() - Compute CRC and push it to the buffer.
+ * @msgb: The message buffer.
+ * @buf:  The data for which the CRC should be computed.
+ * @len:  The length of the data for which the CRC should be computed.
+ */
+static inline void msgb_push_crc(struct msgbuf *msgb, const u8 *buf, size_t len)
+{
+	msgb_push_u16(msgb, ssh_crc(buf, len));
+}
+
+/**
+ * msgb_push_frame() - Push a SSH message frame header to the buffer.
+ * @msgb: The message buffer
+ * @ty:   The type of the frame.
+ * @len:  The length of the payload of the frame.
+ * @seq:  The sequence ID of the frame/packet.
+ */
+static inline void msgb_push_frame(struct msgbuf *msgb, u8 ty, u16 len, u8 seq)
+{
+	u8 *const begin = msgb->ptr;
+
+	if (WARN_ON(msgb->ptr + sizeof(struct ssh_frame) > msgb->end))
+		return;
+
+	__msgb_push_u8(msgb, ty);	/* Frame type. */
+	__msgb_push_u16(msgb, len);	/* Frame payload length. */
+	__msgb_push_u8(msgb, seq);	/* Frame sequence ID. */
+
+	msgb_push_crc(msgb, begin, msgb->ptr - begin);
+}
+
+/**
+ * msgb_push_ack() - Push a SSH ACK frame to the buffer.
+ * @msgb: The message buffer
+ * @seq:  The sequence ID of the frame/packet to be ACKed.
+ */
+static inline void msgb_push_ack(struct msgbuf *msgb, u8 seq)
+{
+	/* SYN. */
+	msgb_push_syn(msgb);
+
+	/* ACK-type frame + CRC. */
+	msgb_push_frame(msgb, SSH_FRAME_TYPE_ACK, 0x00, seq);
+
+	/* Payload CRC (ACK-type frames do not have a payload). */
+	msgb_push_crc(msgb, msgb->ptr, 0);
+}
+
+/**
+ * msgb_push_nak() - Push a SSH NAK frame to the buffer.
+ * @msgb: The message buffer
+ */
+static inline void msgb_push_nak(struct msgbuf *msgb)
+{
+	/* SYN. */
+	msgb_push_syn(msgb);
+
+	/* NAK-type frame + CRC. */
+	msgb_push_frame(msgb, SSH_FRAME_TYPE_NAK, 0x00, 0x00);
+
+	/* Payload CRC (ACK-type frames do not have a payload). */
+	msgb_push_crc(msgb, msgb->ptr, 0);
+}
+
+/**
+ * msgb_push_cmd() - Push a SSH command frame with payload to the buffer.
+ * @msgb: The message buffer.
+ * @seq:  The sequence ID (SEQ) of the frame/packet.
+ * @rqid: The request ID (RQID) of the request contained in the frame.
+ * @rqst: The request to wrap in the frame.
+ */
+static inline void msgb_push_cmd(struct msgbuf *msgb, u8 seq, u16 rqid,
+				 const struct ssam_request *rqst)
+{
+	const u8 type = SSH_FRAME_TYPE_DATA_SEQ;
+	u8 *cmd;
+
+	/* SYN. */
+	msgb_push_syn(msgb);
+
+	/* Command frame + CRC. */
+	msgb_push_frame(msgb, type, sizeof(struct ssh_command) + rqst->length, seq);
+
+	/* Frame payload: Command struct + payload. */
+	if (WARN_ON(msgb->ptr + sizeof(struct ssh_command) > msgb->end))
+		return;
+
+	cmd = msgb->ptr;
+
+	__msgb_push_u8(msgb, SSH_PLD_TYPE_CMD);		/* Payload type. */
+	__msgb_push_u8(msgb, rqst->target_category);	/* Target category. */
+	__msgb_push_u8(msgb, rqst->target_id);		/* Target ID. */
+	__msgb_push_u8(msgb, SSAM_SSH_TID_HOST);	/* Source ID. */
+	__msgb_push_u8(msgb, rqst->instance_id);	/* Instance ID. */
+	__msgb_push_u16(msgb, rqid);			/* Request ID. */
+	__msgb_push_u8(msgb, rqst->command_id);		/* Command ID. */
+
+	/* Command payload. */
+	msgb_push_buf(msgb, rqst->payload, rqst->length);
+
+	/* CRC for command struct + payload. */
+	msgb_push_crc(msgb, cmd, msgb->ptr - cmd);
+}
+
+#endif /* _SURFACE_AGGREGATOR_SSH_MSGB_H */

linux-7.2.3/drivers/platform/surface/aggregator/ssh_packet_layer.h

@@ -0,0 +1,190 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * SSH packet transport layer.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_SSH_PACKET_LAYER_H
+#define _SURFACE_AGGREGATOR_SSH_PACKET_LAYER_H
+
+#include <linux/atomic.h>
+#include <linux/kfifo.h>
+#include <linux/ktime.h>
+#include <linux/list.h>
+#include <linux/serdev.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#include <linux/surface_aggregator/serial_hub.h>
+#include "ssh_parser.h"
+
+/**
+ * enum ssh_ptl_state_flags - State-flags for &struct ssh_ptl.
+ *
+ * @SSH_PTL_SF_SHUTDOWN_BIT:
+ *	Indicates that the packet transport layer has been shut down or is
+ *	being shut down and should not accept any new packets/data.
+ */
+enum ssh_ptl_state_flags {
+	SSH_PTL_SF_SHUTDOWN_BIT,
+};
+
+/**
+ * struct ssh_ptl_ops - Callback operations for packet transport layer.
+ * @data_received: Function called when a data-packet has been received. Both,
+ *                 the packet layer on which the packet has been received and
+ *                 the packet's payload data are provided to this function.
+ */
+struct ssh_ptl_ops {
+	void (*data_received)(struct ssh_ptl *p, const struct ssam_span *data);
+};
+
+/**
+ * struct ssh_ptl - SSH packet transport layer.
+ * @serdev:        Serial device providing the underlying data transport.
+ * @state:         State(-flags) of the transport layer.
+ * @queue:         Packet submission queue.
+ * @queue.lock:    Lock for modifying the packet submission queue.
+ * @queue.head:    List-head of the packet submission queue.
+ * @pending:       Set/list of pending packets.
+ * @pending.lock:  Lock for modifying the pending set.
+ * @pending.head:  List-head of the pending set/list.
+ * @pending.count: Number of currently pending packets.
+ * @tx:            Transmitter subsystem.
+ * @tx.running:    Flag indicating (desired) transmitter thread state.
+ * @tx.thread:     Transmitter thread.
+ * @tx.thread_cplt_tx:  Completion for transmitter thread waiting on transfer.
+ * @tx.thread_cplt_pkt: Completion for transmitter thread waiting on packets.
+ * @tx.packet_wq:  Waitqueue-head for packet transmit completion.
+ * @rx:            Receiver subsystem.
+ * @rx.thread:     Receiver thread.
+ * @rx.wq:         Waitqueue-head for receiver thread.
+ * @rx.fifo:       Buffer for receiving data/pushing data to receiver thread.
+ * @rx.buf:        Buffer for evaluating data on receiver thread.
+ * @rx.blocked:    List of recent/blocked sequence IDs to detect retransmission.
+ * @rx.blocked.seqs:   Array of blocked sequence IDs.
+ * @rx.blocked.offset: Offset indicating where a new ID should be inserted.
+ * @rtx_timeout:   Retransmission timeout subsystem.
+ * @rtx_timeout.lock:    Lock for modifying the retransmission timeout reaper.
+ * @rtx_timeout.timeout: Timeout interval for retransmission.
+ * @rtx_timeout.expires: Time specifying when the reaper work is next scheduled.
+ * @rtx_timeout.reaper:  Work performing timeout checks and subsequent actions.
+ * @ops:           Packet layer operations.
+ */
+struct ssh_ptl {
+	struct serdev_device *serdev;
+	unsigned long state;
+
+	struct {
+		spinlock_t lock;
+		struct list_head head;
+	} queue;
+
+	struct {
+		spinlock_t lock;
+		struct list_head head;
+		atomic_t count;
+	} pending;
+
+	struct {
+		atomic_t running;
+		struct task_struct *thread;
+		struct completion thread_cplt_tx;
+		struct completion thread_cplt_pkt;
+		struct wait_queue_head packet_wq;
+	} tx;
+
+	struct {
+		struct task_struct *thread;
+		struct wait_queue_head wq;
+		struct kfifo fifo;
+		struct sshp_buf buf;
+
+		struct {
+			u16 seqs[8];
+			u16 offset;
+		} blocked;
+	} rx;
+
+	struct {
+		spinlock_t lock;
+		ktime_t timeout;
+		ktime_t expires;
+		struct delayed_work reaper;
+	} rtx_timeout;
+
+	struct ssh_ptl_ops ops;
+};
+
+#define __ssam_prcond(func, p, fmt, ...)		\
+	do {						\
+		typeof(p) __p = (p);			\
+							\
+		if (__p)				\
+			func(__p, fmt, ##__VA_ARGS__);	\
+	} while (0)
+
+#define ptl_dbg(p, fmt, ...)  dev_dbg(&(p)->serdev->dev, fmt, ##__VA_ARGS__)
+#define ptl_info(p, fmt, ...) dev_info(&(p)->serdev->dev, fmt, ##__VA_ARGS__)
+#define ptl_warn(p, fmt, ...) dev_warn(&(p)->serdev->dev, fmt, ##__VA_ARGS__)
+#define ptl_err(p, fmt, ...)  dev_err(&(p)->serdev->dev, fmt, ##__VA_ARGS__)
+#define ptl_dbg_cond(p, fmt, ...) __ssam_prcond(ptl_dbg, p, fmt, ##__VA_ARGS__)
+
+#define to_ssh_ptl(ptr, member) \
+	container_of(ptr, struct ssh_ptl, member)
+
+int ssh_ptl_init(struct ssh_ptl *ptl, struct serdev_device *serdev,
+		 struct ssh_ptl_ops *ops);
+
+void ssh_ptl_destroy(struct ssh_ptl *ptl);
+
+/**
+ * ssh_ptl_get_device() - Get device associated with packet transport layer.
+ * @ptl: The packet transport layer.
+ *
+ * Return: Returns the device on which the given packet transport layer builds
+ * upon.
+ */
+static inline struct device *ssh_ptl_get_device(struct ssh_ptl *ptl)
+{
+	return ptl->serdev ? &ptl->serdev->dev : NULL;
+}
+
+int ssh_ptl_tx_start(struct ssh_ptl *ptl);
+int ssh_ptl_tx_stop(struct ssh_ptl *ptl);
+int ssh_ptl_rx_start(struct ssh_ptl *ptl);
+int ssh_ptl_rx_stop(struct ssh_ptl *ptl);
+void ssh_ptl_shutdown(struct ssh_ptl *ptl);
+
+int ssh_ptl_submit(struct ssh_ptl *ptl, struct ssh_packet *p);
+void ssh_ptl_cancel(struct ssh_packet *p);
+
+ssize_t ssh_ptl_rx_rcvbuf(struct ssh_ptl *ptl, const u8 *buf, size_t n);
+
+/**
+ * ssh_ptl_tx_wakeup_transfer() - Wake up packet transmitter thread for
+ * transfer.
+ * @ptl: The packet transport layer.
+ *
+ * Wakes up the packet transmitter thread, notifying it that the underlying
+ * transport has more space for data to be transmitted. If the packet
+ * transport layer has been shut down, calls to this function will be ignored.
+ */
+static inline void ssh_ptl_tx_wakeup_transfer(struct ssh_ptl *ptl)
+{
+	if (test_bit(SSH_PTL_SF_SHUTDOWN_BIT, &ptl->state))
+		return;
+
+	complete(&ptl->tx.thread_cplt_tx);
+}
+
+void ssh_packet_init(struct ssh_packet *packet, unsigned long type,
+		     u8 priority, const struct ssh_packet_ops *ops);
+
+int ssh_ctrl_packet_cache_init(void);
+void ssh_ctrl_packet_cache_destroy(void);
+
+#endif /* _SURFACE_AGGREGATOR_SSH_PACKET_LAYER_H */

linux-7.2.3/drivers/platform/surface/aggregator/ssh_parser.c

@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SSH message parser.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <linux/unaligned.h>
+#include <linux/compiler.h>
+#include <linux/device.h>
+#include <linux/types.h>
+
+#include <linux/surface_aggregator/serial_hub.h>
+#include "ssh_parser.h"
+
+/**
+ * sshp_validate_crc() - Validate a CRC in raw message data.
+ * @src: The span of data over which the CRC should be computed.
+ * @crc: The pointer to the expected u16 CRC value.
+ *
+ * Computes the CRC of the provided data span (@src), compares it to the CRC
+ * stored at the given address (@crc), and returns the result of this
+ * comparison, i.e. %true if equal. This function is intended to run on raw
+ * input/message data.
+ *
+ * Return: Returns %true if the computed CRC matches the stored CRC, %false
+ * otherwise.
+ */
+static bool sshp_validate_crc(const struct ssam_span *src, const u8 *crc)
+{
+	u16 actual = ssh_crc(src->ptr, src->len);
+	u16 expected = get_unaligned_le16(crc);
+
+	return actual == expected;
+}
+
+/**
+ * sshp_starts_with_syn() - Check if the given data starts with SSH SYN bytes.
+ * @src: The data span to check the start of.
+ */
+static bool sshp_starts_with_syn(const struct ssam_span *src)
+{
+	return src->len >= 2 && get_unaligned_le16(src->ptr) == SSH_MSG_SYN;
+}
+
+/**
+ * sshp_find_syn() - Find SSH SYN bytes in the given data span.
+ * @src: The data span to search in.
+ * @rem: The span (output) indicating the remaining data, starting with SSH
+ *       SYN bytes, if found.
+ *
+ * Search for SSH SYN bytes in the given source span. If found, set the @rem
+ * span to the remaining data, starting with the first SYN bytes and capped by
+ * the source span length, and return %true. This function does not copy any
+ * data, but rather only sets pointers to the respective start addresses and
+ * length values.
+ *
+ * If no SSH SYN bytes could be found, set the @rem span to the zero-length
+ * span at the end of the source span and return %false.
+ *
+ * If partial SSH SYN bytes could be found at the end of the source span, set
+ * the @rem span to cover these partial SYN bytes, capped by the end of the
+ * source span, and return %false. This function should then be re-run once
+ * more data is available.
+ *
+ * Return: Returns %true if a complete SSH SYN sequence could be found,
+ * %false otherwise.
+ */
+bool sshp_find_syn(const struct ssam_span *src, struct ssam_span *rem)
+{
+	size_t i;
+
+	for (i = 0; i < src->len - 1; i++) {
+		if (likely(get_unaligned_le16(src->ptr + i) == SSH_MSG_SYN)) {
+			rem->ptr = src->ptr + i;
+			rem->len = src->len - i;
+			return true;
+		}
+	}
+
+	if (unlikely(src->ptr[src->len - 1] == (SSH_MSG_SYN & 0xff))) {
+		rem->ptr = src->ptr + src->len - 1;
+		rem->len = 1;
+		return false;
+	}
+
+	rem->ptr = src->ptr + src->len;
+	rem->len = 0;
+	return false;
+}
+
+/**
+ * sshp_parse_frame() - Parse SSH frame.
+ * @dev: The device used for logging.
+ * @source: The source to parse from.
+ * @frame: The parsed frame (output).
+ * @payload: The parsed payload (output).
+ * @maxlen: The maximum supported message length.
+ *
+ * Parses and validates a SSH frame, including its payload, from the given
+ * source. Sets the provided @frame pointer to the start of the frame and
+ * writes the limits of the frame payload to the provided @payload span
+ * pointer.
+ *
+ * This function does not copy any data, but rather only validates the message
+ * data and sets pointers (and length values) to indicate the respective parts.
+ *
+ * If no complete SSH frame could be found, the frame pointer will be set to
+ * the %NULL pointer and the payload span will be set to the null span (start
+ * pointer %NULL, size zero).
+ *
+ * Return: Returns zero on success or if the frame is incomplete, %-ENOMSG if
+ * the start of the message is invalid, %-EBADMSG if any (frame-header or
+ * payload) CRC is invalid, or %-EMSGSIZE if the SSH message is bigger than
+ * the maximum message length specified in the @maxlen parameter.
+ */
+int sshp_parse_frame(const struct device *dev, const struct ssam_span *source,
+		     struct ssh_frame **frame, struct ssam_span *payload,
+		     size_t maxlen)
+{
+	struct ssam_span sf;
+	struct ssam_span sp;
+
+	/* Initialize output. */
+	*frame = NULL;
+	payload->ptr = NULL;
+	payload->len = 0;
+
+	if (!sshp_starts_with_syn(source)) {
+		dev_warn(dev, "rx: parser: invalid start of frame\n");
+		return -ENOMSG;
+	}
+
+	/* Check for minimum packet length. */
+	if (unlikely(source->len < SSH_MESSAGE_LENGTH(0))) {
+		dev_dbg(dev, "rx: parser: not enough data for frame\n");
+		return 0;
+	}
+
+	/* Pin down frame. */
+	sf.ptr = source->ptr + sizeof(u16);
+	sf.len = sizeof(struct ssh_frame);
+
+	/* Validate frame CRC. */
+	if (unlikely(!sshp_validate_crc(&sf, sf.ptr + sf.len))) {
+		dev_warn(dev, "rx: parser: invalid frame CRC\n");
+		return -EBADMSG;
+	}
+
+	/* Ensure packet does not exceed maximum length. */
+	sp.len = get_unaligned_le16(&((struct ssh_frame *)sf.ptr)->len);
+	if (unlikely(SSH_MESSAGE_LENGTH(sp.len) > maxlen)) {
+		dev_warn(dev, "rx: parser: frame too large: %llu bytes\n",
+			 SSH_MESSAGE_LENGTH(sp.len));
+		return -EMSGSIZE;
+	}
+
+	/* Pin down payload. */
+	sp.ptr = sf.ptr + sf.len + sizeof(u16);
+
+	/* Check for frame + payload length. */
+	if (source->len < SSH_MESSAGE_LENGTH(sp.len)) {
+		dev_dbg(dev, "rx: parser: not enough data for payload\n");
+		return 0;
+	}
+
+	/* Validate payload CRC. */
+	if (unlikely(!sshp_validate_crc(&sp, sp.ptr + sp.len))) {
+		dev_warn(dev, "rx: parser: invalid payload CRC\n");
+		return -EBADMSG;
+	}
+
+	*frame = (struct ssh_frame *)sf.ptr;
+	*payload = sp;
+
+	dev_dbg(dev, "rx: parser: valid frame found (type: %#04x, len: %u)\n",
+		(*frame)->type, (*frame)->len);
+
+	return 0;
+}
+
+/**
+ * sshp_parse_command() - Parse SSH command frame payload.
+ * @dev: The device used for logging.
+ * @source: The source to parse from.
+ * @command: The parsed command (output).
+ * @command_data: The parsed command data/payload (output).
+ *
+ * Parses and validates a SSH command frame payload. Sets the @command pointer
+ * to the command header and the @command_data span to the command data (i.e.
+ * payload of the command). This will result in a zero-length span if the
+ * command does not have any associated data/payload. This function does not
+ * check the frame-payload-type field, which should be checked by the caller
+ * before calling this function.
+ *
+ * The @source parameter should be the complete frame payload, e.g. returned
+ * by the sshp_parse_frame() command.
+ *
+ * This function does not copy any data, but rather only validates the frame
+ * payload data and sets pointers (and length values) to indicate the
+ * respective parts.
+ *
+ * Return: Returns zero on success or %-ENOMSG if @source does not represent a
+ * valid command-type frame payload, i.e. is too short.
+ */
+int sshp_parse_command(const struct device *dev, const struct ssam_span *source,
+		       struct ssh_command **command,
+		       struct ssam_span *command_data)
+{
+	/* Check for minimum length. */
+	if (unlikely(source->len < sizeof(struct ssh_command))) {
+		*command = NULL;
+		command_data->ptr = NULL;
+		command_data->len = 0;
+
+		dev_err(dev, "rx: parser: command payload is too short\n");
+		return -ENOMSG;
+	}
+
+	*command = (struct ssh_command *)source->ptr;
+	command_data->ptr = source->ptr + sizeof(struct ssh_command);
+	command_data->len = source->len - sizeof(struct ssh_command);
+
+	dev_dbg(dev, "rx: parser: valid command found (tc: %#04x, cid: %#04x)\n",
+		(*command)->tc, (*command)->cid);
+
+	return 0;
+}

linux-7.2.3/drivers/platform/surface/aggregator/ssh_parser.h

@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * SSH message parser.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_SSH_PARSER_H
+#define _SURFACE_AGGREGATOR_SSH_PARSER_H
+
+#include <linux/device.h>
+#include <linux/kfifo.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/surface_aggregator/serial_hub.h>
+
+/**
+ * struct sshp_buf - Parser buffer for SSH messages.
+ * @ptr: Pointer to the beginning of the buffer.
+ * @len: Number of bytes used in the buffer.
+ * @cap: Maximum capacity of the buffer.
+ */
+struct sshp_buf {
+	u8    *ptr;
+	size_t len;
+	size_t cap;
+};
+
+/**
+ * sshp_buf_init() - Initialize a SSH parser buffer.
+ * @buf: The buffer to initialize.
+ * @ptr: The memory backing the buffer.
+ * @cap: The length of the memory backing the buffer, i.e. its capacity.
+ *
+ * Initializes the buffer with the given memory as backing and set its used
+ * length to zero.
+ */
+static inline void sshp_buf_init(struct sshp_buf *buf, u8 *ptr, size_t cap)
+{
+	buf->ptr = ptr;
+	buf->len = 0;
+	buf->cap = cap;
+}
+
+/**
+ * sshp_buf_alloc() - Allocate and initialize a SSH parser buffer.
+ * @buf:   The buffer to initialize/allocate to.
+ * @cap:   The desired capacity of the buffer.
+ * @flags: The flags used for allocating the memory.
+ *
+ * Allocates @cap bytes and initializes the provided buffer struct with the
+ * allocated memory.
+ *
+ * Return: Returns zero on success and %-ENOMEM if allocation failed.
+ */
+static inline int sshp_buf_alloc(struct sshp_buf *buf, size_t cap, gfp_t flags)
+{
+	u8 *ptr;
+
+	ptr = kzalloc(cap, flags);
+	if (!ptr)
+		return -ENOMEM;
+
+	sshp_buf_init(buf, ptr, cap);
+	return 0;
+}
+
+/**
+ * sshp_buf_free() - Free a SSH parser buffer.
+ * @buf: The buffer to free.
+ *
+ * Frees a SSH parser buffer by freeing the memory backing it and then
+ * resetting its pointer to %NULL and length and capacity to zero. Intended to
+ * free a buffer previously allocated with sshp_buf_alloc().
+ */
+static inline void sshp_buf_free(struct sshp_buf *buf)
+{
+	kfree(buf->ptr);
+	buf->ptr = NULL;
+	buf->len = 0;
+	buf->cap = 0;
+}
+
+/**
+ * sshp_buf_drop() - Drop data from the beginning of the buffer.
+ * @buf: The buffer to drop data from.
+ * @n:   The number of bytes to drop.
+ *
+ * Drops the first @n bytes from the buffer. Re-aligns any remaining data to
+ * the beginning of the buffer.
+ */
+static inline void sshp_buf_drop(struct sshp_buf *buf, size_t n)
+{
+	memmove(buf->ptr, buf->ptr + n, buf->len - n);
+	buf->len -= n;
+}
+
+/**
+ * sshp_buf_read_from_fifo() - Transfer data from a fifo to the buffer.
+ * @buf:  The buffer to write the data into.
+ * @fifo: The fifo to read the data from.
+ *
+ * Transfers the data contained in the fifo to the buffer, removing it from
+ * the fifo. This function will try to transfer as much data as possible,
+ * limited either by the remaining space in the buffer or by the number of
+ * bytes available in the fifo.
+ *
+ * Return: Returns the number of bytes transferred.
+ */
+static inline size_t sshp_buf_read_from_fifo(struct sshp_buf *buf,
+					     struct kfifo *fifo)
+{
+	size_t n;
+
+	n =  kfifo_out(fifo, buf->ptr + buf->len, buf->cap - buf->len);
+	buf->len += n;
+
+	return n;
+}
+
+/**
+ * sshp_buf_span_from() - Initialize a span from the given buffer and offset.
+ * @buf:    The buffer to create the span from.
+ * @offset: The offset in the buffer at which the span should start.
+ * @span:   The span to initialize (output).
+ *
+ * Initializes the provided span to point to the memory at the given offset in
+ * the buffer, with the length of the span being capped by the number of bytes
+ * used in the buffer after the offset (i.e. bytes remaining after the
+ * offset).
+ *
+ * Warning: This function does not validate that @offset is less than or equal
+ * to the number of bytes used in the buffer or the buffer capacity. This must
+ * be guaranteed by the caller.
+ */
+static inline void sshp_buf_span_from(struct sshp_buf *buf, size_t offset,
+				      struct ssam_span *span)
+{
+	span->ptr = buf->ptr + offset;
+	span->len = buf->len - offset;
+}
+
+bool sshp_find_syn(const struct ssam_span *src, struct ssam_span *rem);
+
+int sshp_parse_frame(const struct device *dev, const struct ssam_span *source,
+		     struct ssh_frame **frame, struct ssam_span *payload,
+		     size_t maxlen);
+
+int sshp_parse_command(const struct device *dev, const struct ssam_span *source,
+		       struct ssh_command **command,
+		       struct ssam_span *command_data);
+
+#endif /* _SURFACE_AGGREGATOR_SSH_PARSER_h */

linux-7.2.3/drivers/platform/surface/aggregator/ssh_request_layer.h

@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * SSH request transport layer.
+ *
+ * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H
+#define _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H
+
+#include <linux/atomic.h>
+#include <linux/ktime.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+
+#include <linux/surface_aggregator/serial_hub.h>
+#include <linux/surface_aggregator/controller.h>
+
+#include "ssh_packet_layer.h"
+
+/**
+ * enum ssh_rtl_state_flags - State-flags for &struct ssh_rtl.
+ *
+ * @SSH_RTL_SF_SHUTDOWN_BIT:
+ *	Indicates that the request transport layer has been shut down or is
+ *	being shut down and should not accept any new requests.
+ */
+enum ssh_rtl_state_flags {
+	SSH_RTL_SF_SHUTDOWN_BIT,
+};
+
+/**
+ * struct ssh_rtl_ops - Callback operations for request transport layer.
+ * @handle_event: Function called when a SSH event has been received. The
+ *                specified function takes the request layer, received command
+ *                struct, and corresponding payload as arguments. If the event
+ *                has no payload, the payload span is empty (not %NULL).
+ */
+struct ssh_rtl_ops {
+	void (*handle_event)(struct ssh_rtl *rtl, const struct ssh_command *cmd,
+			     const struct ssam_span *data);
+};
+
+/**
+ * struct ssh_rtl - SSH request transport layer.
+ * @ptl:           Underlying packet transport layer.
+ * @state:         State(-flags) of the transport layer.
+ * @queue:         Request submission queue.
+ * @queue.lock:    Lock for modifying the request submission queue.
+ * @queue.head:    List-head of the request submission queue.
+ * @pending:       Set/list of pending requests.
+ * @pending.lock:  Lock for modifying the request set.
+ * @pending.head:  List-head of the pending set/list.
+ * @pending.count: Number of currently pending requests.
+ * @tx:            Transmitter subsystem.
+ * @tx.work:       Transmitter work item.
+ * @rtx_timeout:   Retransmission timeout subsystem.
+ * @rtx_timeout.lock:    Lock for modifying the retransmission timeout reaper.
+ * @rtx_timeout.timeout: Timeout interval for retransmission.
+ * @rtx_timeout.expires: Time specifying when the reaper work is next scheduled.
+ * @rtx_timeout.reaper:  Work performing timeout checks and subsequent actions.
+ * @ops:           Request layer operations.
+ */
+struct ssh_rtl {
+	struct ssh_ptl ptl;
+	unsigned long state;
+
+	struct {
+		spinlock_t lock;
+		struct list_head head;
+	} queue;
+
+	struct {
+		spinlock_t lock;
+		struct list_head head;
+		atomic_t count;
+	} pending;
+
+	struct {
+		struct work_struct work;
+	} tx;
+
+	struct {
+		spinlock_t lock;
+		ktime_t timeout;
+		ktime_t expires;
+		struct delayed_work reaper;
+	} rtx_timeout;
+
+	struct ssh_rtl_ops ops;
+};
+
+#define rtl_dbg(r, fmt, ...)  ptl_dbg(&(r)->ptl, fmt, ##__VA_ARGS__)
+#define rtl_info(p, fmt, ...) ptl_info(&(p)->ptl, fmt, ##__VA_ARGS__)
+#define rtl_warn(r, fmt, ...) ptl_warn(&(r)->ptl, fmt, ##__VA_ARGS__)
+#define rtl_err(r, fmt, ...)  ptl_err(&(r)->ptl, fmt, ##__VA_ARGS__)
+#define rtl_dbg_cond(r, fmt, ...) __ssam_prcond(rtl_dbg, r, fmt, ##__VA_ARGS__)
+
+#define to_ssh_rtl(ptr, member) \
+	container_of(ptr, struct ssh_rtl, member)
+
+/**
+ * ssh_rtl_get_device() - Get device associated with request transport layer.
+ * @rtl: The request transport layer.
+ *
+ * Return: Returns the device on which the given request transport layer
+ * builds upon.
+ */
+static inline struct device *ssh_rtl_get_device(struct ssh_rtl *rtl)
+{
+	return ssh_ptl_get_device(&rtl->ptl);
+}
+
+/**
+ * ssh_request_rtl() - Get request transport layer associated with request.
+ * @rqst: The request to get the request transport layer reference for.
+ *
+ * Return: Returns the &struct ssh_rtl associated with the given SSH request.
+ */
+static inline struct ssh_rtl *ssh_request_rtl(struct ssh_request *rqst)
+{
+	struct ssh_ptl *ptl;
+
+	ptl = READ_ONCE(rqst->packet.ptl);
+	return likely(ptl) ? to_ssh_rtl(ptl, ptl) : NULL;
+}
+
+int ssh_rtl_submit(struct ssh_rtl *rtl, struct ssh_request *rqst);
+bool ssh_rtl_cancel(struct ssh_request *rqst, bool pending);
+
+int ssh_rtl_init(struct ssh_rtl *rtl, struct serdev_device *serdev,
+		 const struct ssh_rtl_ops *ops);
+
+int ssh_rtl_start(struct ssh_rtl *rtl);
+int ssh_rtl_flush(struct ssh_rtl *rtl, unsigned long timeout);
+void ssh_rtl_shutdown(struct ssh_rtl *rtl);
+void ssh_rtl_destroy(struct ssh_rtl *rtl);
+
+int ssh_request_init(struct ssh_request *rqst, enum ssam_request_flags flags,
+		     const struct ssh_request_ops *ops);
+
+#endif /* _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H */

linux-7.2.3/drivers/platform/surface/aggregator/trace.h

@@ -0,0 +1,703 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Trace points for SSAM/SSH.
+ *
+ * Copyright (C) 2020-2022 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM surface_aggregator
+
+#if !defined(_SURFACE_AGGREGATOR_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _SURFACE_AGGREGATOR_TRACE_H
+
+#include <linux/surface_aggregator/serial_hub.h>
+
+#include <linux/unaligned.h>
+#include <linux/tracepoint.h>
+
+TRACE_DEFINE_ENUM(SSH_FRAME_TYPE_DATA_SEQ);
+TRACE_DEFINE_ENUM(SSH_FRAME_TYPE_DATA_NSQ);
+TRACE_DEFINE_ENUM(SSH_FRAME_TYPE_ACK);
+TRACE_DEFINE_ENUM(SSH_FRAME_TYPE_NAK);
+
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_LOCKED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_QUEUED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_PENDING_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_TRANSMITTING_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_TRANSMITTED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_ACKED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_CANCELED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_SF_COMPLETED_BIT);
+
+TRACE_DEFINE_ENUM(SSH_PACKET_TY_FLUSH_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_TY_SEQUENCED_BIT);
+TRACE_DEFINE_ENUM(SSH_PACKET_TY_BLOCKING_BIT);
+
+TRACE_DEFINE_ENUM(SSH_PACKET_FLAGS_SF_MASK);
+TRACE_DEFINE_ENUM(SSH_PACKET_FLAGS_TY_MASK);
+
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_LOCKED_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_QUEUED_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_PENDING_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_TRANSMITTING_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_TRANSMITTED_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_RSPRCVD_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_CANCELED_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_SF_COMPLETED_BIT);
+
+TRACE_DEFINE_ENUM(SSH_REQUEST_TY_FLUSH_BIT);
+TRACE_DEFINE_ENUM(SSH_REQUEST_TY_HAS_RESPONSE_BIT);
+
+TRACE_DEFINE_ENUM(SSH_REQUEST_FLAGS_SF_MASK);
+TRACE_DEFINE_ENUM(SSH_REQUEST_FLAGS_TY_MASK);
+
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SAM);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_BAT);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_TMP);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_PMC);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_FAN);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_PoM);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_DBG);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_KBD);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_FWU);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_UNI);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_LPC);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_TCL);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SFL);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_KIP);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_EXT);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_BLD);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_BAS);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SEN);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SRQ);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_MCU);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_HID);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_TCH);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_BKL);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_TAM);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_ACC0);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_UFI);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_USC);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_PEN);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_VID);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_AUD);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SMC);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_KPD);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_REG);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SPT);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SYS);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_ACC1);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_SHB);
+TRACE_DEFINE_ENUM(SSAM_SSH_TC_POS);
+
+#define SSAM_PTR_UID_LEN		9
+#define SSAM_U8_FIELD_NOT_APPLICABLE	((u16)-1)
+#define SSAM_SEQ_NOT_APPLICABLE		((u16)-1)
+#define SSAM_RQID_NOT_APPLICABLE	((u32)-1)
+#define SSAM_SSH_TC_NOT_APPLICABLE	0
+#define SSAM_SSH_TID_NOT_APPLICABLE	((u8)-1)
+
+#ifndef _SURFACE_AGGREGATOR_TRACE_HELPERS
+#define _SURFACE_AGGREGATOR_TRACE_HELPERS
+
+/**
+ * ssam_trace_ptr_uid() - Convert the pointer to a non-pointer UID string.
+ * @ptr: The pointer to convert.
+ * @uid_str: A buffer of length SSAM_PTR_UID_LEN where the UID will be stored.
+ *
+ * Converts the given pointer into a UID string that is safe to be shared
+ * with userspace and logs, i.e. doesn't give away the real memory location.
+ */
+static inline void ssam_trace_ptr_uid(const void *ptr, char *uid_str)
+{
+	char buf[2 * sizeof(void *) + 1];
+
+	BUILD_BUG_ON(ARRAY_SIZE(buf) < SSAM_PTR_UID_LEN);
+
+	snprintf(buf, ARRAY_SIZE(buf), "%p", ptr);
+	memcpy(uid_str, &buf[ARRAY_SIZE(buf) - SSAM_PTR_UID_LEN],
+	       SSAM_PTR_UID_LEN);
+}
+
+/**
+ * ssam_trace_get_packet_seq() - Read the packet's sequence ID.
+ * @p: The packet.
+ *
+ * Return: Returns the packet's sequence ID (SEQ) field if present, or
+ * %SSAM_SEQ_NOT_APPLICABLE if not (e.g. flush packet).
+ */
+static inline u16 ssam_trace_get_packet_seq(const struct ssh_packet *p)
+{
+	if (!p->data.ptr || p->data.len < SSH_MESSAGE_LENGTH(0))
+		return SSAM_SEQ_NOT_APPLICABLE;
+
+	return p->data.ptr[SSH_MSGOFFSET_FRAME(seq)];
+}
+
+/**
+ * ssam_trace_get_request_id() - Read the packet's request ID.
+ * @p: The packet.
+ *
+ * Return: Returns the packet's request ID (RQID) field if the packet
+ * represents a request with command data, or %SSAM_RQID_NOT_APPLICABLE if not
+ * (e.g. flush request, control packet).
+ */
+static inline u32 ssam_trace_get_request_id(const struct ssh_packet *p)
+{
+	if (!p->data.ptr || p->data.len < SSH_COMMAND_MESSAGE_LENGTH(0))
+		return SSAM_RQID_NOT_APPLICABLE;
+
+	return get_unaligned_le16(&p->data.ptr[SSH_MSGOFFSET_COMMAND(rqid)]);
+}
+
+/**
+ * ssam_trace_get_request_tid() - Read the packet's request target ID.
+ * @p: The packet.
+ *
+ * Return: Returns the packet's request target ID (TID) field if the packet
+ * represents a request with command data, or %SSAM_SSH_TID_NOT_APPLICABLE
+ * if not (e.g. flush request, control packet).
+ */
+static inline u32 ssam_trace_get_request_tid(const struct ssh_packet *p)
+{
+	if (!p->data.ptr || p->data.len < SSH_COMMAND_MESSAGE_LENGTH(0))
+		return SSAM_SSH_TID_NOT_APPLICABLE;
+
+	return get_unaligned_le16(&p->data.ptr[SSH_MSGOFFSET_COMMAND(tid)]);
+}
+
+/**
+ * ssam_trace_get_request_sid() - Read the packet's request source ID.
+ * @p: The packet.
+ *
+ * Return: Returns the packet's request source ID (SID) field if the packet
+ * represents a request with command data, or %SSAM_SSH_TID_NOT_APPLICABLE
+ * if not (e.g. flush request, control packet).
+ */
+static inline u32 ssam_trace_get_request_sid(const struct ssh_packet *p)
+{
+	if (!p->data.ptr || p->data.len < SSH_COMMAND_MESSAGE_LENGTH(0))
+		return SSAM_SSH_TID_NOT_APPLICABLE;
+
+	return get_unaligned_le16(&p->data.ptr[SSH_MSGOFFSET_COMMAND(sid)]);
+}
+
+/**
+ * ssam_trace_get_request_tc() - Read the packet's request target category.
+ * @p: The packet.
+ *
+ * Return: Returns the packet's request target category (TC) field if the
+ * packet represents a request with command data, or %SSAM_SSH_TC_NOT_APPLICABLE
+ * if not (e.g. flush request, control packet).
+ */
+static inline u32 ssam_trace_get_request_tc(const struct ssh_packet *p)
+{
+	if (!p->data.ptr || p->data.len < SSH_COMMAND_MESSAGE_LENGTH(0))
+		return SSAM_SSH_TC_NOT_APPLICABLE;
+
+	return get_unaligned_le16(&p->data.ptr[SSH_MSGOFFSET_COMMAND(tc)]);
+}
+
+#endif /* _SURFACE_AGGREGATOR_TRACE_HELPERS */
+
+#define ssam_trace_get_command_field_u8(packet, field) \
+	((!(packet) || (packet)->data.len < SSH_COMMAND_MESSAGE_LENGTH(0)) \
+	 ? 0 : (packet)->data.ptr[SSH_MSGOFFSET_COMMAND(field)])
+
+#define ssam_show_generic_u8_field(value)				\
+	__print_symbolic(value,						\
+		{ SSAM_U8_FIELD_NOT_APPLICABLE,		"N/A" }		\
+	)
+
+#define ssam_show_frame_type(ty)					\
+	__print_symbolic(ty,						\
+		{ SSH_FRAME_TYPE_DATA_SEQ,		"DSEQ" },	\
+		{ SSH_FRAME_TYPE_DATA_NSQ,		"DNSQ" },	\
+		{ SSH_FRAME_TYPE_ACK,			"ACK"  },	\
+		{ SSH_FRAME_TYPE_NAK,			"NAK"  }	\
+	)
+
+#define ssam_show_packet_type(type)					\
+	__print_flags(flags & SSH_PACKET_FLAGS_TY_MASK, "",		\
+		{ BIT(SSH_PACKET_TY_FLUSH_BIT),		"F" },		\
+		{ BIT(SSH_PACKET_TY_SEQUENCED_BIT),	"S" },		\
+		{ BIT(SSH_PACKET_TY_BLOCKING_BIT),	"B" }		\
+	)
+
+#define ssam_show_packet_state(state)					\
+	__print_flags(flags & SSH_PACKET_FLAGS_SF_MASK, "",		\
+		{ BIT(SSH_PACKET_SF_LOCKED_BIT),	"L" },		\
+		{ BIT(SSH_PACKET_SF_QUEUED_BIT),	"Q" },		\
+		{ BIT(SSH_PACKET_SF_PENDING_BIT),	"P" },		\
+		{ BIT(SSH_PACKET_SF_TRANSMITTING_BIT),	"S" },		\
+		{ BIT(SSH_PACKET_SF_TRANSMITTED_BIT),	"T" },		\
+		{ BIT(SSH_PACKET_SF_ACKED_BIT),		"A" },		\
+		{ BIT(SSH_PACKET_SF_CANCELED_BIT),	"C" },		\
+		{ BIT(SSH_PACKET_SF_COMPLETED_BIT),	"F" }		\
+	)
+
+#define ssam_show_packet_seq(seq)					\
+	__print_symbolic(seq,						\
+		{ SSAM_SEQ_NOT_APPLICABLE,		"N/A" }		\
+	)
+
+#define ssam_show_request_type(flags)					\
+	__print_flags((flags) & SSH_REQUEST_FLAGS_TY_MASK, "",		\
+		{ BIT(SSH_REQUEST_TY_FLUSH_BIT),	"F" },		\
+		{ BIT(SSH_REQUEST_TY_HAS_RESPONSE_BIT),	"R" }		\
+	)
+
+#define ssam_show_request_state(flags)					\
+	__print_flags((flags) & SSH_REQUEST_FLAGS_SF_MASK, "",		\
+		{ BIT(SSH_REQUEST_SF_LOCKED_BIT),	"L" },		\
+		{ BIT(SSH_REQUEST_SF_QUEUED_BIT),	"Q" },		\
+		{ BIT(SSH_REQUEST_SF_PENDING_BIT),	"P" },		\
+		{ BIT(SSH_REQUEST_SF_TRANSMITTING_BIT),	"S" },		\
+		{ BIT(SSH_REQUEST_SF_TRANSMITTED_BIT),	"T" },		\
+		{ BIT(SSH_REQUEST_SF_RSPRCVD_BIT),	"A" },		\
+		{ BIT(SSH_REQUEST_SF_CANCELED_BIT),	"C" },		\
+		{ BIT(SSH_REQUEST_SF_COMPLETED_BIT),	"F" }		\
+	)
+
+#define ssam_show_request_id(rqid)					\
+	__print_symbolic(rqid,						\
+		{ SSAM_RQID_NOT_APPLICABLE,		"N/A" }		\
+	)
+
+#define ssam_show_ssh_tid(tid)						\
+	__print_symbolic(tid,						\
+		{ SSAM_SSH_TID_NOT_APPLICABLE,		"N/A"      },	\
+		{ SSAM_SSH_TID_HOST,			"Host"     },	\
+		{ SSAM_SSH_TID_SAM,			"SAM"      },	\
+		{ SSAM_SSH_TID_KIP,			"KIP"      },	\
+		{ SSAM_SSH_TID_DEBUG,			"Debug"    },	\
+		{ SSAM_SSH_TID_SURFLINK,		"SurfLink" }	\
+	)
+
+#define ssam_show_ssh_tc(tc)						\
+	__print_symbolic(tc,						\
+		{ SSAM_SSH_TC_NOT_APPLICABLE,		"N/A"  },	\
+		{ SSAM_SSH_TC_SAM,			"SAM"  },	\
+		{ SSAM_SSH_TC_BAT,			"BAT"  },	\
+		{ SSAM_SSH_TC_TMP,			"TMP"  },	\
+		{ SSAM_SSH_TC_PMC,			"PMC"  },	\
+		{ SSAM_SSH_TC_FAN,			"FAN"  },	\
+		{ SSAM_SSH_TC_PoM,			"PoM"  },	\
+		{ SSAM_SSH_TC_DBG,			"DBG"  },	\
+		{ SSAM_SSH_TC_KBD,			"KBD"  },	\
+		{ SSAM_SSH_TC_FWU,			"FWU"  },	\
+		{ SSAM_SSH_TC_UNI,			"UNI"  },	\
+		{ SSAM_SSH_TC_LPC,			"LPC"  },	\
+		{ SSAM_SSH_TC_TCL,			"TCL"  },	\
+		{ SSAM_SSH_TC_SFL,			"SFL"  },	\
+		{ SSAM_SSH_TC_KIP,			"KIP"  },	\
+		{ SSAM_SSH_TC_EXT,			"EXT"  },	\
+		{ SSAM_SSH_TC_BLD,			"BLD"  },	\
+		{ SSAM_SSH_TC_BAS,			"BAS"  },	\
+		{ SSAM_SSH_TC_SEN,			"SEN"  },	\
+		{ SSAM_SSH_TC_SRQ,			"SRQ"  },	\
+		{ SSAM_SSH_TC_MCU,			"MCU"  },	\
+		{ SSAM_SSH_TC_HID,			"HID"  },	\
+		{ SSAM_SSH_TC_TCH,			"TCH"  },	\
+		{ SSAM_SSH_TC_BKL,			"BKL"  },	\
+		{ SSAM_SSH_TC_TAM,			"TAM"  },	\
+		{ SSAM_SSH_TC_ACC0,			"ACC0" },	\
+		{ SSAM_SSH_TC_UFI,			"UFI"  },	\
+		{ SSAM_SSH_TC_USC,			"USC"  },	\
+		{ SSAM_SSH_TC_PEN,			"PEN"  },	\
+		{ SSAM_SSH_TC_VID,			"VID"  },	\
+		{ SSAM_SSH_TC_AUD,			"AUD"  },	\
+		{ SSAM_SSH_TC_SMC,			"SMC"  },	\
+		{ SSAM_SSH_TC_KPD,			"KPD"  },	\
+		{ SSAM_SSH_TC_REG,			"REG"  },	\
+		{ SSAM_SSH_TC_SPT,			"SPT"  },	\
+		{ SSAM_SSH_TC_SYS,			"SYS"  },	\
+		{ SSAM_SSH_TC_ACC1,			"ACC1" },	\
+		{ SSAM_SSH_TC_SHB,			"SMB"  },	\
+		{ SSAM_SSH_TC_POS,			"POS"  }	\
+	)
+
+DECLARE_EVENT_CLASS(ssam_frame_class,
+	TP_PROTO(const struct ssh_frame *frame),
+
+	TP_ARGS(frame),
+
+	TP_STRUCT__entry(
+		__field(u8, type)
+		__field(u8, seq)
+		__field(u16, len)
+	),
+
+	TP_fast_assign(
+		__entry->type = frame->type;
+		__entry->seq = frame->seq;
+		__entry->len = get_unaligned_le16(&frame->len);
+	),
+
+	TP_printk("ty=%s, seq=%#04x, len=%u",
+		ssam_show_frame_type(__entry->type),
+		__entry->seq,
+		__entry->len
+	)
+);
+
+#define DEFINE_SSAM_FRAME_EVENT(name)				\
+	DEFINE_EVENT(ssam_frame_class, ssam_##name,		\
+		TP_PROTO(const struct ssh_frame *frame),	\
+		TP_ARGS(frame)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_command_class,
+	TP_PROTO(const struct ssh_command *cmd, u16 len),
+
+	TP_ARGS(cmd, len),
+
+	TP_STRUCT__entry(
+		__field(u16, rqid)
+		__field(u16, len)
+		__field(u8, tid)
+		__field(u8, sid)
+		__field(u8, tc)
+		__field(u8, cid)
+		__field(u8, iid)
+	),
+
+	TP_fast_assign(
+		__entry->rqid = get_unaligned_le16(&cmd->rqid);
+		__entry->tid = cmd->tid;
+		__entry->sid = cmd->sid;
+		__entry->tc = cmd->tc;
+		__entry->cid = cmd->cid;
+		__entry->iid = cmd->iid;
+		__entry->len = len;
+	),
+
+	TP_printk("rqid=%#06x, tid=%s, sid=%s, tc=%s, cid=%#04x, iid=%#04x, len=%u",
+		__entry->rqid,
+		ssam_show_ssh_tid(__entry->tid),
+		ssam_show_ssh_tid(__entry->sid),
+		ssam_show_ssh_tc(__entry->tc),
+		__entry->cid,
+		__entry->iid,
+		__entry->len
+	)
+);
+
+#define DEFINE_SSAM_COMMAND_EVENT(name)					\
+	DEFINE_EVENT(ssam_command_class, ssam_##name,			\
+		TP_PROTO(const struct ssh_command *cmd, u16 len),	\
+		TP_ARGS(cmd, len)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_packet_class,
+	TP_PROTO(const struct ssh_packet *packet),
+
+	TP_ARGS(packet),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__array(char, uid, SSAM_PTR_UID_LEN)
+		__field(u8, priority)
+		__field(u16, length)
+		__field(u16, seq)
+	),
+
+	TP_fast_assign(
+		__entry->state = READ_ONCE(packet->state);
+		ssam_trace_ptr_uid(packet, __entry->uid);
+		__entry->priority = READ_ONCE(packet->priority);
+		__entry->length = packet->data.len;
+		__entry->seq = ssam_trace_get_packet_seq(packet);
+	),
+
+	TP_printk("uid=%s, seq=%s, ty=%s, pri=%#04x, len=%u, sta=%s",
+		__entry->uid,
+		ssam_show_packet_seq(__entry->seq),
+		ssam_show_packet_type(__entry->state),
+		__entry->priority,
+		__entry->length,
+		ssam_show_packet_state(__entry->state)
+	)
+);
+
+#define DEFINE_SSAM_PACKET_EVENT(name)				\
+	DEFINE_EVENT(ssam_packet_class, ssam_##name,		\
+		TP_PROTO(const struct ssh_packet *packet),	\
+		TP_ARGS(packet)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_packet_status_class,
+	TP_PROTO(const struct ssh_packet *packet, int status),
+
+	TP_ARGS(packet, status),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__field(int, status)
+		__array(char, uid, SSAM_PTR_UID_LEN)
+		__field(u8, priority)
+		__field(u16, length)
+		__field(u16, seq)
+	),
+
+	TP_fast_assign(
+		__entry->state = READ_ONCE(packet->state);
+		__entry->status = status;
+		ssam_trace_ptr_uid(packet, __entry->uid);
+		__entry->priority = READ_ONCE(packet->priority);
+		__entry->length = packet->data.len;
+		__entry->seq = ssam_trace_get_packet_seq(packet);
+	),
+
+	TP_printk("uid=%s, seq=%s, ty=%s, pri=%#04x, len=%u, sta=%s, status=%d",
+		__entry->uid,
+		ssam_show_packet_seq(__entry->seq),
+		ssam_show_packet_type(__entry->state),
+		__entry->priority,
+		__entry->length,
+		ssam_show_packet_state(__entry->state),
+		__entry->status
+	)
+);
+
+#define DEFINE_SSAM_PACKET_STATUS_EVENT(name)				\
+	DEFINE_EVENT(ssam_packet_status_class, ssam_##name,		\
+		TP_PROTO(const struct ssh_packet *packet, int status),	\
+		TP_ARGS(packet, status)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_request_class,
+	TP_PROTO(const struct ssh_request *request),
+
+	TP_ARGS(request),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__field(u32, rqid)
+		__array(char, uid, SSAM_PTR_UID_LEN)
+		__field(u8, tc)
+		__field(u16, cid)
+		__field(u16, iid)
+		__field(u8, tid)
+		__field(u8, sid)
+	),
+
+	TP_fast_assign(
+		const struct ssh_packet *p = &request->packet;
+
+		/* Use packet for UID so we can match requests to packets. */
+		__entry->state = READ_ONCE(request->state);
+		__entry->rqid = ssam_trace_get_request_id(p);
+		ssam_trace_ptr_uid(p, __entry->uid);
+		__entry->tid = ssam_trace_get_request_tid(p);
+		__entry->sid = ssam_trace_get_request_sid(p);
+		__entry->tc = ssam_trace_get_request_tc(p);
+		__entry->cid = ssam_trace_get_command_field_u8(p, cid);
+		__entry->iid = ssam_trace_get_command_field_u8(p, iid);
+	),
+
+	TP_printk("uid=%s, rqid=%s, ty=%s, sta=%s, tid=%s, sid=%s, tc=%s, cid=%s, iid=%s",
+		__entry->uid,
+		ssam_show_request_id(__entry->rqid),
+		ssam_show_request_type(__entry->state),
+		ssam_show_request_state(__entry->state),
+		ssam_show_ssh_tid(__entry->tid),
+		ssam_show_ssh_tid(__entry->sid),
+		ssam_show_ssh_tc(__entry->tc),
+		ssam_show_generic_u8_field(__entry->cid),
+		ssam_show_generic_u8_field(__entry->iid)
+	)
+);
+
+#define DEFINE_SSAM_REQUEST_EVENT(name)				\
+	DEFINE_EVENT(ssam_request_class, ssam_##name,		\
+		TP_PROTO(const struct ssh_request *request),	\
+		TP_ARGS(request)				\
+	)
+
+DECLARE_EVENT_CLASS(ssam_request_status_class,
+	TP_PROTO(const struct ssh_request *request, int status),
+
+	TP_ARGS(request, status),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__field(u32, rqid)
+		__field(int, status)
+		__array(char, uid, SSAM_PTR_UID_LEN)
+		__field(u8, tc)
+		__field(u16, cid)
+		__field(u16, iid)
+		__field(u8, tid)
+		__field(u8, sid)
+	),
+
+	TP_fast_assign(
+		const struct ssh_packet *p = &request->packet;
+
+		/* Use packet for UID so we can match requests to packets. */
+		__entry->state = READ_ONCE(request->state);
+		__entry->rqid = ssam_trace_get_request_id(p);
+		__entry->status = status;
+		ssam_trace_ptr_uid(p, __entry->uid);
+		__entry->tid = ssam_trace_get_request_tid(p);
+		__entry->sid = ssam_trace_get_request_sid(p);
+		__entry->tc = ssam_trace_get_request_tc(p);
+		__entry->cid = ssam_trace_get_command_field_u8(p, cid);
+		__entry->iid = ssam_trace_get_command_field_u8(p, iid);
+	),
+
+	TP_printk("uid=%s, rqid=%s, ty=%s, sta=%s, tid=%s, sid=%s, tc=%s, cid=%s, iid=%s, status=%d",
+		__entry->uid,
+		ssam_show_request_id(__entry->rqid),
+		ssam_show_request_type(__entry->state),
+		ssam_show_request_state(__entry->state),
+		ssam_show_ssh_tid(__entry->tid),
+		ssam_show_ssh_tid(__entry->sid),
+		ssam_show_ssh_tc(__entry->tc),
+		ssam_show_generic_u8_field(__entry->cid),
+		ssam_show_generic_u8_field(__entry->iid),
+		__entry->status
+	)
+);
+
+#define DEFINE_SSAM_REQUEST_STATUS_EVENT(name)				\
+	DEFINE_EVENT(ssam_request_status_class, ssam_##name,		\
+		TP_PROTO(const struct ssh_request *request, int status),\
+		TP_ARGS(request, status)				\
+	)
+
+DECLARE_EVENT_CLASS(ssam_alloc_class,
+	TP_PROTO(void *ptr, size_t len),
+
+	TP_ARGS(ptr, len),
+
+	TP_STRUCT__entry(
+		__field(size_t, len)
+		__array(char, uid, SSAM_PTR_UID_LEN)
+	),
+
+	TP_fast_assign(
+		__entry->len = len;
+		ssam_trace_ptr_uid(ptr, __entry->uid);
+	),
+
+	TP_printk("uid=%s, len=%zu", __entry->uid, __entry->len)
+);
+
+#define DEFINE_SSAM_ALLOC_EVENT(name)					\
+	DEFINE_EVENT(ssam_alloc_class, ssam_##name,			\
+		TP_PROTO(void *ptr, size_t len),			\
+		TP_ARGS(ptr, len)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_free_class,
+	TP_PROTO(void *ptr),
+
+	TP_ARGS(ptr),
+
+	TP_STRUCT__entry(
+		__array(char, uid, SSAM_PTR_UID_LEN)
+	),
+
+	TP_fast_assign(
+		ssam_trace_ptr_uid(ptr, __entry->uid);
+	),
+
+	TP_printk("uid=%s", __entry->uid)
+);
+
+#define DEFINE_SSAM_FREE_EVENT(name)					\
+	DEFINE_EVENT(ssam_free_class, ssam_##name,			\
+		TP_PROTO(void *ptr),					\
+		TP_ARGS(ptr)						\
+	)
+
+DECLARE_EVENT_CLASS(ssam_pending_class,
+	TP_PROTO(unsigned int pending),
+
+	TP_ARGS(pending),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, pending)
+	),
+
+	TP_fast_assign(
+		__entry->pending = pending;
+	),
+
+	TP_printk("pending=%u", __entry->pending)
+);
+
+#define DEFINE_SSAM_PENDING_EVENT(name)					\
+	DEFINE_EVENT(ssam_pending_class, ssam_##name,			\
+		TP_PROTO(unsigned int pending),				\
+		TP_ARGS(pending)					\
+	)
+
+DECLARE_EVENT_CLASS(ssam_data_class,
+	TP_PROTO(size_t length),
+
+	TP_ARGS(length),
+
+	TP_STRUCT__entry(
+		__field(size_t, length)
+	),
+
+	TP_fast_assign(
+		__entry->length = length;
+	),
+
+	TP_printk("length=%zu", __entry->length)
+);
+
+#define DEFINE_SSAM_DATA_EVENT(name)					\
+	DEFINE_EVENT(ssam_data_class, ssam_##name,			\
+		TP_PROTO(size_t length),				\
+		TP_ARGS(length)						\
+	)
+
+DEFINE_SSAM_FRAME_EVENT(rx_frame_received);
+DEFINE_SSAM_COMMAND_EVENT(rx_response_received);
+DEFINE_SSAM_COMMAND_EVENT(rx_event_received);
+
+DEFINE_SSAM_PACKET_EVENT(packet_release);
+DEFINE_SSAM_PACKET_EVENT(packet_submit);
+DEFINE_SSAM_PACKET_EVENT(packet_resubmit);
+DEFINE_SSAM_PACKET_EVENT(packet_timeout);
+DEFINE_SSAM_PACKET_EVENT(packet_cancel);
+DEFINE_SSAM_PACKET_STATUS_EVENT(packet_complete);
+DEFINE_SSAM_PENDING_EVENT(ptl_timeout_reap);
+
+DEFINE_SSAM_REQUEST_EVENT(request_submit);
+DEFINE_SSAM_REQUEST_EVENT(request_timeout);
+DEFINE_SSAM_REQUEST_EVENT(request_cancel);
+DEFINE_SSAM_REQUEST_STATUS_EVENT(request_complete);
+DEFINE_SSAM_PENDING_EVENT(rtl_timeout_reap);
+
+DEFINE_SSAM_PACKET_EVENT(ei_tx_drop_ack_packet);
+DEFINE_SSAM_PACKET_EVENT(ei_tx_drop_nak_packet);
+DEFINE_SSAM_PACKET_EVENT(ei_tx_drop_dsq_packet);
+DEFINE_SSAM_PACKET_STATUS_EVENT(ei_tx_fail_write);
+DEFINE_SSAM_PACKET_EVENT(ei_tx_corrupt_data);
+DEFINE_SSAM_DATA_EVENT(ei_rx_corrupt_syn);
+DEFINE_SSAM_FRAME_EVENT(ei_rx_corrupt_data);
+DEFINE_SSAM_REQUEST_EVENT(ei_rx_drop_response);
+
+DEFINE_SSAM_ALLOC_EVENT(ctrl_packet_alloc);
+DEFINE_SSAM_FREE_EVENT(ctrl_packet_free);
+
+DEFINE_SSAM_ALLOC_EVENT(event_item_alloc);
+DEFINE_SSAM_FREE_EVENT(event_item_free);
+
+#endif /* _SURFACE_AGGREGATOR_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+
+#include <trace/define_trace.h>