Resguardo inicial

linux-7.2.3/drivers/gpu/drm/display/Kconfig

@@ -0,0 +1,108 @@
+# SPDX-License-Identifier: MIT
+
+config DRM_DISPLAY_DP_AUX_BUS
+	tristate
+	depends on DRM
+	depends on OF
+
+config DRM_DISPLAY_HELPER
+	tristate
+	depends on DRM
+	select CEC_CORE if DRM_DISPLAY_DP_AUX_CEC || DRM_DISPLAY_HDMI_CEC_HELPER || CEC_NOTIFIER
+	help
+	  DRM helpers for display adapters.
+
+if DRM_DISPLAY_HELPER
+
+config DRM_BRIDGE_CONNECTOR
+	bool
+	select DRM_DISPLAY_HDMI_AUDIO_HELPER
+	select DRM_DISPLAY_HDMI_CEC_HELPER
+	select DRM_DISPLAY_HDMI_STATE_HELPER
+	help
+	  DRM connector implementation terminating DRM bridge chains.
+
+config DRM_DISPLAY_DP_AUX_CEC
+	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
+	select DRM_DISPLAY_DP_HELPER
+	help
+	  Choose this option if you want to enable HDMI CEC support for
+	  DisplayPort/USB-C to HDMI adapters.
+
+	  Note: not all adapters support this feature, and even for those
+	  that do support this they often do not hook up the CEC pin.
+
+config DRM_DISPLAY_DP_AUX_CHARDEV
+	bool "DRM DP AUX Interface"
+	select DRM_DISPLAY_DP_HELPER
+	help
+	  Choose this option to enable a /dev/drm_dp_auxN node that allows to
+	  read and write values to arbitrary DPCD registers on the DP aux
+	  channel.
+
+config DRM_DISPLAY_DP_HELPER
+	bool
+	help
+	  DRM display helpers for DisplayPort.
+
+config DRM_DISPLAY_DP_TUNNEL
+	bool
+	select DRM_DISPLAY_DP_HELPER
+	help
+	  Enable support for DisplayPort tunnels. This allows drivers to use
+	  DP tunnel features like the Bandwidth Allocation mode to maximize the
+	  BW utilization for display streams on Thunderbolt links.
+
+config DRM_DISPLAY_DP_TUNNEL_STATE_DEBUG
+	bool "Enable debugging the DP tunnel state"
+	depends on REF_TRACKER
+	depends on DRM_DISPLAY_DP_TUNNEL
+	depends on DEBUG_KERNEL
+	depends on EXPERT
+	help
+	  Enables debugging the DP tunnel manager's state, including the
+	  consistency of all managed tunnels' reference counting and the state of
+	  streams contained in tunnels.
+
+	  If in doubt, say "N".
+
+config DRM_DISPLAY_DSC_HELPER
+	bool
+	depends on DRM_DISPLAY_HELPER
+	help
+	  DRM display helpers for VESA DSC (used by DSI and DisplayPort).
+
+config DRM_DISPLAY_HDCP_HELPER
+	bool
+	help
+	  DRM display helpers for HDCP.
+
+config DRM_DISPLAY_HDMI_AUDIO_HELPER
+	bool
+	help
+	  DRM display helpers for HDMI Audio functionality (generic HDMI Codec
+	  implementation).
+
+config DRM_DISPLAY_HDMI_CEC_HELPER
+	bool
+	help
+	  DRM display helpers for HDMI CEC implementation.
+
+config DRM_DISPLAY_HDMI_CEC_NOTIFIER_HELPER
+	def_bool CEC_NOTIFIER
+	help
+	  DRM display helpers for HDMI CEC notifiers implementation.
+
+config DRM_DISPLAY_HDMI_HELPER
+	bool
+	help
+	  DRM display helpers for HDMI.
+
+config DRM_DISPLAY_HDMI_STATE_HELPER
+	bool
+	select DRM_DISPLAY_HDMI_AUDIO_HELPER
+	select DRM_DISPLAY_HDMI_HELPER
+	help
+	  DRM KMS state helpers for HDMI.
+
+endif # DRM_DISPLAY_HELPER

linux-7.2.3/drivers/gpu/drm/display/Makefile

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: MIT
+
+obj-$(CONFIG_DRM_DISPLAY_DP_AUX_BUS) += drm_dp_aux_bus.o
+
+drm_display_helper-y := drm_display_helper_mod.o
+drm_display_helper-$(CONFIG_DRM_BRIDGE_CONNECTOR) += \
+	drm_bridge_connector.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_HELPER) += \
+	drm_dp_dual_mode_helper.o \
+	drm_dp_helper.o \
+	drm_dp_mst_topology.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_TUNNEL) += \
+	drm_dp_tunnel.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_DSC_HELPER) += \
+	drm_dsc_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDCP_HELPER) += drm_hdcp_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_AUDIO_HELPER) += \
+	drm_hdmi_audio_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_CEC_HELPER) += \
+	drm_hdmi_cec_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_CEC_NOTIFIER_HELPER) += \
+	drm_hdmi_cec_notifier_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_HELPER) += \
+	drm_hdmi_helper.o \
+	drm_scdc_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_HDMI_STATE_HELPER) += \
+	drm_hdmi_state_helper.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_AUX_CHARDEV) += drm_dp_aux_dev.o
+drm_display_helper-$(CONFIG_DRM_DISPLAY_DP_AUX_CEC) += drm_dp_cec.o
+
+obj-$(CONFIG_DRM_DISPLAY_HELPER) += drm_display_helper.o

linux-7.2.3/drivers/gpu/drm/display/drm_display_helper_mod.c

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+
+#include <linux/module.h>
+
+#include "drm_dp_helper_internal.h"
+
+MODULE_DESCRIPTION("DRM display adapter helper");
+MODULE_LICENSE("GPL and additional rights");
+
+static int __init drm_display_helper_module_init(void)
+{
+	return drm_dp_aux_dev_init();
+}
+
+static void __exit drm_display_helper_module_exit(void)
+{
+	/* Call exit functions from specific dp helpers here */
+	drm_dp_aux_dev_exit();
+}
+
+module_init(drm_display_helper_module_init);
+module_exit(drm_display_helper_module_exit);

linux-7.2.3/drivers/gpu/drm/display/drm_dp_aux_bus.c

@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Google Inc.
+ *
+ * The DP AUX bus is used for devices that are connected over a DisplayPort
+ * AUX bus. The device on the far side of the bus is referred to as an
+ * endpoint in this code.
+ *
+ * There is only one device connected to the DP AUX bus: an eDP panel.
+ * Though historically panels (even DP panels) have been modeled as simple
+ * platform devices, putting them under the DP AUX bus allows the panel driver
+ * to perform transactions on that bus.
+ */
+
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/display/drm_dp_aux_bus.h>
+#include <drm/display/drm_dp_helper.h>
+
+struct dp_aux_ep_device_with_data {
+	struct dp_aux_ep_device aux_ep;
+	int (*done_probing)(struct drm_dp_aux *aux);
+};
+
+/**
+ * dp_aux_ep_match() - The match function for the dp_aux_bus.
+ * @dev: The device to match.
+ * @drv: The driver to try to match against.
+ *
+ * At the moment, we just match on device tree.
+ *
+ * Return: True if this driver matches this device; false otherwise.
+ */
+static int dp_aux_ep_match(struct device *dev, const struct device_driver *drv)
+{
+	return !!of_match_device(drv->of_match_table, dev);
+}
+
+/**
+ * dp_aux_ep_probe() - The probe function for the dp_aux_bus.
+ * @dev: The device to probe.
+ *
+ * Calls through to the endpoint driver probe.
+ *
+ * Return: 0 if no error or negative error code.
+ */
+static int dp_aux_ep_probe(struct device *dev)
+{
+	struct dp_aux_ep_driver *aux_ep_drv = to_dp_aux_ep_drv(dev->driver);
+	struct dp_aux_ep_device *aux_ep = to_dp_aux_ep_dev(dev);
+	struct dp_aux_ep_device_with_data *aux_ep_with_data =
+		container_of(aux_ep, struct dp_aux_ep_device_with_data, aux_ep);
+	int ret;
+
+	ret = dev_pm_domain_attach(dev, PD_FLAG_ATTACH_POWER_ON);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to attach to PM Domain\n");
+
+	ret = aux_ep_drv->probe(aux_ep);
+	if (ret)
+		goto err_attached;
+
+	if (aux_ep_with_data->done_probing) {
+		ret = aux_ep_with_data->done_probing(aux_ep->aux);
+		if (ret) {
+			/*
+			 * The done_probing() callback should not return
+			 * -EPROBE_DEFER to us. If it does, we treat it as an
+			 * error. Passing it on as-is would cause the _panel_
+			 * to defer.
+			 */
+			if (ret == -EPROBE_DEFER) {
+				dev_err(dev,
+					"DP AUX done_probing() can't defer\n");
+				ret = -EINVAL;
+			}
+			goto err_probed;
+		}
+	}
+
+	return 0;
+err_probed:
+	if (aux_ep_drv->remove)
+		aux_ep_drv->remove(aux_ep);
+err_attached:
+	dev_pm_domain_detach(dev, true);
+
+	return ret;
+}
+
+/**
+ * dp_aux_ep_remove() - The remove function for the dp_aux_bus.
+ * @dev: The device to remove.
+ *
+ * Calls through to the endpoint driver remove.
+ */
+static void dp_aux_ep_remove(struct device *dev)
+{
+	struct dp_aux_ep_driver *aux_ep_drv = to_dp_aux_ep_drv(dev->driver);
+	struct dp_aux_ep_device *aux_ep = to_dp_aux_ep_dev(dev);
+
+	if (aux_ep_drv->remove)
+		aux_ep_drv->remove(aux_ep);
+	dev_pm_domain_detach(dev, true);
+}
+
+/**
+ * dp_aux_ep_shutdown() - The shutdown function for the dp_aux_bus.
+ * @dev: The device to shutdown.
+ *
+ * Calls through to the endpoint driver shutdown.
+ */
+static void dp_aux_ep_shutdown(struct device *dev)
+{
+	struct dp_aux_ep_driver *aux_ep_drv;
+
+	if (!dev->driver)
+		return;
+
+	aux_ep_drv = to_dp_aux_ep_drv(dev->driver);
+	if (aux_ep_drv->shutdown)
+		aux_ep_drv->shutdown(to_dp_aux_ep_dev(dev));
+}
+
+static const struct bus_type dp_aux_bus_type = {
+	.name		= "dp-aux",
+	.match		= dp_aux_ep_match,
+	.probe		= dp_aux_ep_probe,
+	.remove		= dp_aux_ep_remove,
+	.shutdown	= dp_aux_ep_shutdown,
+};
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	return of_device_modalias(dev, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *dp_aux_ep_dev_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(dp_aux_ep_dev);
+
+/**
+ * dp_aux_ep_dev_release() - Free memory for the dp_aux_ep device
+ * @dev: The device to free.
+ */
+static void dp_aux_ep_dev_release(struct device *dev)
+{
+	struct dp_aux_ep_device *aux_ep = to_dp_aux_ep_dev(dev);
+	struct dp_aux_ep_device_with_data *aux_ep_with_data =
+		container_of(aux_ep, struct dp_aux_ep_device_with_data, aux_ep);
+
+	kfree(aux_ep_with_data);
+}
+
+static int dp_aux_ep_dev_modalias(const struct device *dev, struct kobj_uevent_env *env)
+{
+	return of_device_uevent_modalias(dev, env);
+}
+
+static struct device_type dp_aux_device_type_type = {
+	.groups		= dp_aux_ep_dev_groups,
+	.uevent		= dp_aux_ep_dev_modalias,
+	.release	= dp_aux_ep_dev_release,
+};
+
+/**
+ * of_dp_aux_ep_destroy() - Destroy an DP AUX endpoint device
+ * @dev: The device to destroy.
+ * @data: Not used
+ *
+ * This is just used as a callback by of_dp_aux_depopulate_bus() and
+ * is called for _all_ of the child devices of the device providing the AUX bus.
+ * We'll only act on those that are of type "dp_aux_bus_type".
+ *
+ * This function is effectively an inverse of what's in
+ * of_dp_aux_populate_bus(). NOTE: since we only populate one child
+ * then it's expected that only one device will match all the "if" tests in
+ * this function and get to the device_unregister().
+ *
+ * Return: 0 if no error or negative error code.
+ */
+static int of_dp_aux_ep_destroy(struct device *dev, void *data)
+{
+	struct device_node *np = dev->of_node;
+
+	if (dev->bus != &dp_aux_bus_type)
+		return 0;
+
+	if (!of_node_check_flag(np, OF_POPULATED))
+		return 0;
+
+	of_node_clear_flag(np, OF_POPULATED);
+	of_node_put(np);
+
+	device_unregister(dev);
+
+	return 0;
+}
+
+/**
+ * of_dp_aux_depopulate_bus() - Undo of_dp_aux_populate_bus
+ * @aux: The AUX channel whose device we want to depopulate
+ *
+ * This will destroy the device that was created
+ * by of_dp_aux_populate_bus().
+ */
+void of_dp_aux_depopulate_bus(struct drm_dp_aux *aux)
+{
+	device_for_each_child_reverse(aux->dev, NULL, of_dp_aux_ep_destroy);
+}
+EXPORT_SYMBOL_GPL(of_dp_aux_depopulate_bus);
+
+/**
+ * of_dp_aux_populate_bus() - Populate the endpoint device on the DP AUX
+ * @aux: The AUX channel whose device we want to populate. It is required that
+ *       drm_dp_aux_init() has already been called for this AUX channel.
+ * @done_probing: Callback functions to call after EP device finishes probing.
+ *                Will not be called if there are no EP devices and this
+ *                function will return -ENODEV.
+ *
+ * This will populate the device (expected to be an eDP panel) under the
+ * "aux-bus" node of the device providing the AUX channel (AKA aux->dev).
+ *
+ * When this function finishes, it is _possible_ (but not guaranteed) that
+ * our sub-device will have finished probing. It should be noted that if our
+ * sub-device returns -EPROBE_DEFER or is probing asynchronously for some
+ * reason that we will not return any error codes ourselves but our
+ * sub-device will _not_ have actually probed successfully yet.
+ *
+ * In many cases it's important for the caller of this function to be notified
+ * when our sub device finishes probing. Our sub device is expected to be an
+ * eDP panel and the caller is expected to be an eDP controller. The eDP
+ * controller needs to be able to get a reference to the panel when it finishes
+ * probing. For this reason the caller can pass in a function pointer that
+ * will be called when our sub-device finishes probing.
+ *
+ * If this function succeeds you should later make sure you call
+ * of_dp_aux_depopulate_bus() to undo it, or just use the devm version
+ * of this function.
+ *
+ * Return: 0 if no error or negative error code; returns -ENODEV if there are
+ *         no children. The done_probing() function won't be called in that
+ *         case.
+ */
+int of_dp_aux_populate_bus(struct drm_dp_aux *aux,
+			   int (*done_probing)(struct drm_dp_aux *aux))
+{
+	struct device_node *bus = NULL, *np = NULL;
+	struct dp_aux_ep_device *aux_ep;
+	struct dp_aux_ep_device_with_data *aux_ep_with_data;
+	int ret;
+
+	/* drm_dp_aux_init() should have been called already; warn if not */
+	WARN_ON_ONCE(!aux->ddc.algo);
+
+	if (!aux->dev->of_node)
+		return -ENODEV;
+	bus = of_get_child_by_name(aux->dev->of_node, "aux-bus");
+	if (!bus)
+		return -ENODEV;
+
+	np = of_get_next_available_child(bus, NULL);
+	of_node_put(bus);
+	if (!np)
+		return -ENODEV;
+
+	if (of_node_test_and_set_flag(np, OF_POPULATED)) {
+		dev_err(aux->dev, "DP AUX EP device already populated\n");
+		ret = -EINVAL;
+		goto err_did_get_np;
+	}
+
+	aux_ep_with_data = kzalloc_obj(*aux_ep_with_data);
+	if (!aux_ep_with_data) {
+		ret = -ENOMEM;
+		goto err_did_set_populated;
+	}
+
+	aux_ep_with_data->done_probing = done_probing;
+
+	aux_ep = &aux_ep_with_data->aux_ep;
+	aux_ep->aux = aux;
+	aux_ep->dev.parent = aux->dev;
+	aux_ep->dev.bus = &dp_aux_bus_type;
+	aux_ep->dev.type = &dp_aux_device_type_type;
+	device_set_node(&aux_ep->dev, of_fwnode_handle(of_node_get(np)));
+	dev_set_name(&aux_ep->dev, "aux-%s", dev_name(aux->dev));
+
+	ret = device_register(&aux_ep->dev);
+	if (ret) {
+		dev_err(aux->dev, "Failed to create AUX EP for %pOF: %d\n", np, ret);
+
+		/*
+		 * As per docs of device_register(), call this instead
+		 * of kfree() directly for error cases.
+		 */
+		put_device(&aux_ep->dev);
+
+		goto err_did_set_populated;
+	}
+
+	return 0;
+
+err_did_set_populated:
+	of_node_clear_flag(np, OF_POPULATED);
+
+err_did_get_np:
+	of_node_put(np);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_dp_aux_populate_bus);
+
+static void of_dp_aux_depopulate_bus_void(void *data)
+{
+	of_dp_aux_depopulate_bus(data);
+}
+
+/**
+ * devm_of_dp_aux_populate_bus() - devm wrapper for of_dp_aux_populate_bus()
+ * @aux: The AUX channel whose device we want to populate
+ * @done_probing: Callback functions to call after EP device finishes probing.
+ *                Will not be called if there are no EP devices and this
+ *                function will return -ENODEV.
+ *
+ * Handles freeing w/ devm on the device "aux->dev".
+ *
+ * Return: 0 if no error or negative error code; returns -ENODEV if there are
+ *         no children. The done_probing() function won't be called in that
+ *         case.
+ */
+int devm_of_dp_aux_populate_bus(struct drm_dp_aux *aux,
+				int (*done_probing)(struct drm_dp_aux *aux))
+{
+	int ret;
+
+	ret = of_dp_aux_populate_bus(aux, done_probing);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(aux->dev,
+					of_dp_aux_depopulate_bus_void, aux);
+}
+EXPORT_SYMBOL_GPL(devm_of_dp_aux_populate_bus);
+
+int __dp_aux_dp_driver_register(struct dp_aux_ep_driver *drv, struct module *owner)
+{
+	drv->driver.owner = owner;
+	drv->driver.bus = &dp_aux_bus_type;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__dp_aux_dp_driver_register);
+
+void dp_aux_dp_driver_unregister(struct dp_aux_ep_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(dp_aux_dp_driver_unregister);
+
+static int __init dp_aux_bus_init(void)
+{
+	int ret;
+
+	ret = bus_register(&dp_aux_bus_type);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void __exit dp_aux_bus_exit(void)
+{
+	bus_unregister(&dp_aux_bus_type);
+}
+
+subsys_initcall(dp_aux_bus_init);
+module_exit(dp_aux_bus_exit);
+
+MODULE_AUTHOR("Douglas Anderson <dianders@chromium.org>");
+MODULE_DESCRIPTION("DRM DisplayPort AUX bus");
+MODULE_LICENSE("GPL v2");

linux-7.2.3/drivers/gpu/drm/display/drm_dp_aux_dev.c

@@ -0,0 +1,354 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Rafael Antognolli <rafael.antognolli@intel.com>
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include <drm/display/drm_dp_helper.h>
+#include <drm/display/drm_dp_mst_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_print.h>
+
+#include "drm_dp_helper_internal.h"
+
+struct drm_dp_aux_dev {
+	unsigned index;
+	struct drm_dp_aux *aux;
+	struct device *dev;
+	struct kref refcount;
+	atomic_t usecount;
+};
+
+#define DRM_AUX_MINORS	256
+#define AUX_MAX_OFFSET	(1 << 20)
+static DEFINE_IDR(aux_idr);
+static DEFINE_MUTEX(aux_idr_mutex);
+static struct class *drm_dp_aux_dev_class;
+static int drm_dev_major = -1;
+
+static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_minor(unsigned index)
+{
+	struct drm_dp_aux_dev *aux_dev = NULL;
+
+	mutex_lock(&aux_idr_mutex);
+	aux_dev = idr_find(&aux_idr, index);
+	if (aux_dev && !kref_get_unless_zero(&aux_dev->refcount))
+		aux_dev = NULL;
+	mutex_unlock(&aux_idr_mutex);
+
+	return aux_dev;
+}
+
+static struct drm_dp_aux_dev *alloc_drm_dp_aux_dev(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	int index;
+
+	aux_dev = kzalloc_obj(*aux_dev);
+	if (!aux_dev)
+		return ERR_PTR(-ENOMEM);
+	aux_dev->aux = aux;
+	atomic_set(&aux_dev->usecount, 1);
+	kref_init(&aux_dev->refcount);
+
+	mutex_lock(&aux_idr_mutex);
+	index = idr_alloc(&aux_idr, aux_dev, 0, DRM_AUX_MINORS, GFP_KERNEL);
+	mutex_unlock(&aux_idr_mutex);
+	if (index < 0) {
+		kfree(aux_dev);
+		return ERR_PTR(index);
+	}
+	aux_dev->index = index;
+
+	return aux_dev;
+}
+
+static void release_drm_dp_aux_dev(struct kref *ref)
+{
+	struct drm_dp_aux_dev *aux_dev =
+		container_of(ref, struct drm_dp_aux_dev, refcount);
+
+	kfree(aux_dev);
+}
+
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	ssize_t res;
+	struct drm_dp_aux_dev *aux_dev =
+		drm_dp_aux_dev_get_by_minor(MINOR(dev->devt));
+
+	if (!aux_dev)
+		return -ENODEV;
+
+	res = sprintf(buf, "%s\n", aux_dev->aux->name);
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+
+	return res;
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *drm_dp_aux_attrs[] = {
+	&dev_attr_name.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(drm_dp_aux);
+
+static int auxdev_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	struct drm_dp_aux_dev *aux_dev;
+
+	aux_dev = drm_dp_aux_dev_get_by_minor(minor);
+	if (!aux_dev)
+		return -ENODEV;
+
+	file->private_data = aux_dev;
+	return 0;
+}
+
+static loff_t auxdev_llseek(struct file *file, loff_t offset, int whence)
+{
+	return fixed_size_llseek(file, offset, whence, AUX_MAX_OFFSET);
+}
+
+static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
+	loff_t pos = iocb->ki_pos;
+	ssize_t res = 0;
+
+	if (!atomic_inc_not_zero(&aux_dev->usecount))
+		return -ENODEV;
+
+	iov_iter_truncate(to, AUX_MAX_OFFSET - pos);
+
+	while (iov_iter_count(to)) {
+		uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
+		ssize_t todo = min(iov_iter_count(to), sizeof(buf));
+
+		if (signal_pending(current)) {
+			res = -ERESTARTSYS;
+			break;
+		}
+
+		res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo);
+
+		if (res <= 0)
+			break;
+
+		if (copy_to_iter(buf, res, to) != res) {
+			res = -EFAULT;
+			break;
+		}
+
+		pos += res;
+	}
+
+	if (pos != iocb->ki_pos)
+		res = pos - iocb->ki_pos;
+	iocb->ki_pos = pos;
+
+	if (atomic_dec_and_test(&aux_dev->usecount))
+		wake_up_var(&aux_dev->usecount);
+
+	return res;
+}
+
+static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
+	loff_t pos = iocb->ki_pos;
+	ssize_t res = 0;
+
+	if (!atomic_inc_not_zero(&aux_dev->usecount))
+		return -ENODEV;
+
+	iov_iter_truncate(from, AUX_MAX_OFFSET - pos);
+
+	while (iov_iter_count(from)) {
+		uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
+		ssize_t todo = min(iov_iter_count(from), sizeof(buf));
+
+		if (signal_pending(current)) {
+			res = -ERESTARTSYS;
+			break;
+		}
+
+		if (!copy_from_iter_full(buf, todo, from)) {
+			res = -EFAULT;
+			break;
+		}
+
+		res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo);
+
+		if (res <= 0)
+			break;
+
+		pos += res;
+	}
+
+	if (pos != iocb->ki_pos)
+		res = pos - iocb->ki_pos;
+	iocb->ki_pos = pos;
+
+	if (atomic_dec_and_test(&aux_dev->usecount))
+		wake_up_var(&aux_dev->usecount);
+
+	return res;
+}
+
+static int auxdev_release(struct inode *inode, struct file *file)
+{
+	struct drm_dp_aux_dev *aux_dev = file->private_data;
+
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+	return 0;
+}
+
+static const struct file_operations auxdev_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= auxdev_llseek,
+	.read_iter	= auxdev_read_iter,
+	.write_iter	= auxdev_write_iter,
+	.open		= auxdev_open,
+	.release	= auxdev_release,
+};
+
+#define to_auxdev(d) container_of(d, struct drm_dp_aux_dev, aux)
+
+static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_aux(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *iter, *aux_dev = NULL;
+	int id;
+
+	/* don't increase kref count here because this function should only be
+	 * used by drm_dp_aux_unregister_devnode. Thus, it will always have at
+	 * least one reference - the one that drm_dp_aux_register_devnode
+	 * created
+	 */
+	mutex_lock(&aux_idr_mutex);
+	idr_for_each_entry(&aux_idr, iter, id) {
+		if (iter->aux == aux) {
+			aux_dev = iter;
+			break;
+		}
+	}
+	mutex_unlock(&aux_idr_mutex);
+	return aux_dev;
+}
+
+void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	unsigned int minor;
+
+	aux_dev = drm_dp_aux_dev_get_by_aux(aux);
+	if (!aux_dev) /* attach must have failed */
+		return;
+
+	/*
+	 * As some AUX adapters may exist as platform devices which outlive their respective DRM
+	 * devices, we clear drm_dev to ensure that we never accidentally reference a stale pointer
+	 */
+	aux->drm_dev = NULL;
+
+	mutex_lock(&aux_idr_mutex);
+	idr_remove(&aux_idr, aux_dev->index);
+	mutex_unlock(&aux_idr_mutex);
+
+	atomic_dec(&aux_dev->usecount);
+	wait_var_event(&aux_dev->usecount, !atomic_read(&aux_dev->usecount));
+
+	minor = aux_dev->index;
+	if (aux_dev->dev)
+		device_destroy(drm_dp_aux_dev_class,
+			       MKDEV(drm_dev_major, minor));
+
+	DRM_DEBUG("drm_dp_aux_dev: aux [%s] unregistering\n", aux->name);
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+}
+
+int drm_dp_aux_register_devnode(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	int res;
+
+	aux_dev = alloc_drm_dp_aux_dev(aux);
+	if (IS_ERR(aux_dev))
+		return PTR_ERR(aux_dev);
+
+	aux_dev->dev = device_create(drm_dp_aux_dev_class, aux->dev,
+				     MKDEV(drm_dev_major, aux_dev->index), NULL,
+				     "drm_dp_aux%d", aux_dev->index);
+	if (IS_ERR(aux_dev->dev)) {
+		res = PTR_ERR(aux_dev->dev);
+		aux_dev->dev = NULL;
+		goto error;
+	}
+
+	DRM_DEBUG("drm_dp_aux_dev: aux [%s] registered as minor %d\n",
+		  aux->name, aux_dev->index);
+	return 0;
+error:
+	drm_dp_aux_unregister_devnode(aux);
+	return res;
+}
+
+int drm_dp_aux_dev_init(void)
+{
+	int res;
+
+	drm_dp_aux_dev_class = class_create("drm_dp_aux_dev");
+	if (IS_ERR(drm_dp_aux_dev_class)) {
+		return PTR_ERR(drm_dp_aux_dev_class);
+	}
+	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;
+
+	res = register_chrdev(0, "aux", &auxdev_fops);
+	if (res < 0)
+		goto out;
+	drm_dev_major = res;
+
+	return 0;
+out:
+	class_destroy(drm_dp_aux_dev_class);
+	return res;
+}
+
+void drm_dp_aux_dev_exit(void)
+{
+	unregister_chrdev(drm_dev_major, "aux");
+	class_destroy(drm_dp_aux_dev_class);
+}

linux-7.2.3/drivers/gpu/drm/display/drm_dp_cec.c

@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DisplayPort CEC-Tunneling-over-AUX support
+ *
+ * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <media/cec.h>
+
+#include <drm/display/drm_dp_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_device.h>
+#include <drm/drm_edid.h>
+
+/*
+ * Unfortunately it turns out that we have a chicken-and-egg situation
+ * here. Quite a few active (mini-)DP-to-HDMI or USB-C-to-HDMI adapters
+ * have a converter chip that supports CEC-Tunneling-over-AUX (usually the
+ * Parade PS176), but they do not wire up the CEC pin, thus making CEC
+ * useless. Note that MegaChips 2900-based adapters appear to have good
+ * support for CEC tunneling. Those adapters that I have tested using
+ * this chipset all have the CEC line connected.
+ *
+ * Sadly there is no way for this driver to know this. What happens is
+ * that a /dev/cecX device is created that is isolated and unable to see
+ * any of the other CEC devices. Quite literally the CEC wire is cut
+ * (or in this case, never connected in the first place).
+ *
+ * The reason so few adapters support this is that this tunneling protocol
+ * was never supported by any OS. So there was no easy way of testing it,
+ * and no incentive to correctly wire up the CEC pin.
+ *
+ * Hopefully by creating this driver it will be easier for vendors to
+ * finally fix their adapters and test the CEC functionality.
+ *
+ * I keep a list of known working adapters here:
+ *
+ * https://hverkuil.home.xs4all.nl/cec-status.txt
+ *
+ * Please mail me (hverkuil@kernel.org) if you find an adapter that works
+ * and is not yet listed there.
+ *
+ * Note that the current implementation does not support CEC over an MST hub.
+ * As far as I can see there is no mechanism defined in the DisplayPort
+ * standard to transport CEC interrupts over an MST device. It might be
+ * possible to do this through polling, but I have not been able to get that
+ * to work.
+ */
+
+/**
+ * DOC: dp cec helpers
+ *
+ * These functions take care of supporting the CEC-Tunneling-over-AUX
+ * feature of DisplayPort-to-HDMI adapters.
+ */
+
+/*
+ * When the EDID is unset because the HPD went low, then the CEC DPCD registers
+ * typically can no longer be read (true for a DP-to-HDMI adapter since it is
+ * powered by the HPD). However, some displays toggle the HPD off and on for a
+ * short period for one reason or another, and that would cause the CEC adapter
+ * to be removed and added again, even though nothing else changed.
+ *
+ * This module parameter sets a delay in seconds before the CEC adapter is
+ * actually unregistered. Only if the HPD does not return within that time will
+ * the CEC adapter be unregistered.
+ *
+ * If it is set to a value >= NEVER_UNREG_DELAY, then the CEC adapter will never
+ * be unregistered for as long as the connector remains registered.
+ *
+ * If it is set to 0, then the CEC adapter will be unregistered immediately as
+ * soon as the HPD disappears.
+ *
+ * The default is one second to prevent short HPD glitches from unregistering
+ * the CEC adapter.
+ *
+ * Note that for integrated HDMI branch devices that support CEC the DPCD
+ * registers remain available even if the HPD goes low since it is not powered
+ * by the HPD. In that case the CEC adapter will never be unregistered during
+ * the life time of the connector. At least, this is the theory since I do not
+ * have hardware with an integrated HDMI branch device that supports CEC.
+ */
+#define NEVER_UNREG_DELAY 1000
+static unsigned int drm_dp_cec_unregister_delay = 1;
+module_param(drm_dp_cec_unregister_delay, uint, 0600);
+MODULE_PARM_DESC(drm_dp_cec_unregister_delay,
+		 "CEC unregister delay in seconds, 0: no delay, >= 1000: never unregister");
+
+static int drm_dp_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct drm_dp_aux *aux = cec_get_drvdata(adap);
+	u32 val = enable ? DP_CEC_TUNNELING_ENABLE : 0;
+	ssize_t err = 0;
+
+	err = drm_dp_dpcd_write_byte(aux, DP_CEC_TUNNELING_CONTROL, val);
+	return (enable && err < 0) ? err : 0;
+}
+
+static int drm_dp_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
+{
+	struct drm_dp_aux *aux = cec_get_drvdata(adap);
+	/* Bit 15 (logical address 15) should always be set */
+	u16 la_mask = 1 << CEC_LOG_ADDR_BROADCAST;
+	u8 mask[2];
+	ssize_t err;
+
+	if (addr != CEC_LOG_ADDR_INVALID)
+		la_mask |= adap->log_addrs.log_addr_mask | (1 << addr);
+	mask[0] = la_mask & 0xff;
+	mask[1] = la_mask >> 8;
+	err = drm_dp_dpcd_write_data(aux, DP_CEC_LOGICAL_ADDRESS_MASK, mask, 2);
+	return (addr != CEC_LOG_ADDR_INVALID && err < 0) ? err : 0;
+}
+
+static int drm_dp_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				    u32 signal_free_time, struct cec_msg *msg)
+{
+	struct drm_dp_aux *aux = cec_get_drvdata(adap);
+	unsigned int retries = min(5, attempts - 1);
+	ssize_t err;
+
+	err = drm_dp_dpcd_write_data(aux, DP_CEC_TX_MESSAGE_BUFFER,
+				     msg->msg, msg->len);
+	if (err < 0)
+		return err;
+
+	return drm_dp_dpcd_write_byte(aux, DP_CEC_TX_MESSAGE_INFO,
+				      (msg->len - 1) | (retries << 4) |
+				      DP_CEC_TX_MESSAGE_SEND);
+}
+
+static int drm_dp_cec_adap_monitor_all_enable(struct cec_adapter *adap,
+					      bool enable)
+{
+	struct drm_dp_aux *aux = cec_get_drvdata(adap);
+	ssize_t err;
+	u8 val;
+
+	if (!(adap->capabilities & CEC_CAP_MONITOR_ALL))
+		return 0;
+
+	err = drm_dp_dpcd_read_byte(aux, DP_CEC_TUNNELING_CONTROL, &val);
+	if (!err) {
+		if (enable)
+			val |= DP_CEC_SNOOPING_ENABLE;
+		else
+			val &= ~DP_CEC_SNOOPING_ENABLE;
+		err = drm_dp_dpcd_write_byte(aux, DP_CEC_TUNNELING_CONTROL, val);
+	}
+	return (enable && err < 0) ? err : 0;
+}
+
+static void drm_dp_cec_adap_status(struct cec_adapter *adap,
+				   struct seq_file *file)
+{
+	struct drm_dp_aux *aux = cec_get_drvdata(adap);
+	struct drm_dp_desc desc;
+	struct drm_dp_dpcd_ident *id = &desc.ident;
+
+	if (drm_dp_read_desc(aux, &desc, true))
+		return;
+	seq_printf(file, "OUI: %*phD\n",
+		   (int)sizeof(id->oui), id->oui);
+	seq_printf(file, "ID: %*pE\n",
+		   (int)strnlen(id->device_id, sizeof(id->device_id)),
+		   id->device_id);
+	seq_printf(file, "HW Rev: %d.%d\n", id->hw_rev >> 4, id->hw_rev & 0xf);
+	/*
+	 * Show this both in decimal and hex: at least one vendor
+	 * always reports this in hex.
+	 */
+	seq_printf(file, "FW/SW Rev: %d.%d (0x%02x.0x%02x)\n",
+		   id->sw_major_rev, id->sw_minor_rev,
+		   id->sw_major_rev, id->sw_minor_rev);
+}
+
+static const struct cec_adap_ops drm_dp_cec_adap_ops = {
+	.adap_enable = drm_dp_cec_adap_enable,
+	.adap_log_addr = drm_dp_cec_adap_log_addr,
+	.adap_transmit = drm_dp_cec_adap_transmit,
+	.adap_monitor_all_enable = drm_dp_cec_adap_monitor_all_enable,
+	.adap_status = drm_dp_cec_adap_status,
+};
+
+static int drm_dp_cec_received(struct drm_dp_aux *aux)
+{
+	struct cec_adapter *adap = aux->cec.adap;
+	struct cec_msg msg;
+	u8 rx_msg_info;
+	ssize_t err;
+
+	err = drm_dp_dpcd_read_byte(aux, DP_CEC_RX_MESSAGE_INFO, &rx_msg_info);
+	if (err < 0)
+		return err;
+
+	if (!(rx_msg_info & DP_CEC_RX_MESSAGE_ENDED))
+		return 0;
+
+	msg.len = (rx_msg_info & DP_CEC_RX_MESSAGE_LEN_MASK) + 1;
+	err = drm_dp_dpcd_read_data(aux, DP_CEC_RX_MESSAGE_BUFFER, msg.msg, msg.len);
+	if (err < 0)
+		return err;
+
+	cec_received_msg(adap, &msg);
+	return 0;
+}
+
+static void drm_dp_cec_handle_irq(struct drm_dp_aux *aux)
+{
+	struct cec_adapter *adap = aux->cec.adap;
+	u8 flags;
+
+	if (drm_dp_dpcd_read_byte(aux, DP_CEC_TUNNELING_IRQ_FLAGS, &flags) < 0)
+		return;
+
+	if (flags & DP_CEC_RX_MESSAGE_INFO_VALID)
+		drm_dp_cec_received(aux);
+
+	if (flags & DP_CEC_TX_MESSAGE_SENT)
+		cec_transmit_attempt_done(adap, CEC_TX_STATUS_OK);
+	else if (flags & DP_CEC_TX_LINE_ERROR)
+		cec_transmit_attempt_done(adap, CEC_TX_STATUS_ERROR |
+						CEC_TX_STATUS_MAX_RETRIES);
+	else if (flags &
+		 (DP_CEC_TX_ADDRESS_NACK_ERROR | DP_CEC_TX_DATA_NACK_ERROR))
+		cec_transmit_attempt_done(adap, CEC_TX_STATUS_NACK |
+						CEC_TX_STATUS_MAX_RETRIES);
+	drm_dp_dpcd_write_byte(aux, DP_CEC_TUNNELING_IRQ_FLAGS, flags);
+}
+
+/**
+ * drm_dp_cec_irq() - handle CEC interrupt, if any
+ * @aux: DisplayPort AUX channel
+ *
+ * Should be called when handling an IRQ_HPD request. If CEC-tunneling-over-AUX
+ * is present, then it will check for a CEC_IRQ and handle it accordingly.
+ */
+void drm_dp_cec_irq(struct drm_dp_aux *aux)
+{
+	u8 cec_irq;
+	int ret;
+
+	/* No transfer function was set, so not a DP connector */
+	if (!aux->transfer)
+		return;
+
+	mutex_lock(&aux->cec.lock);
+	if (!aux->cec.adap)
+		goto unlock;
+
+	ret = drm_dp_dpcd_read_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1,
+				    &cec_irq);
+	if (ret < 0 || !(cec_irq & DP_CEC_IRQ))
+		goto unlock;
+
+	drm_dp_cec_handle_irq(aux);
+	drm_dp_dpcd_write_byte(aux, DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1, DP_CEC_IRQ);
+unlock:
+	mutex_unlock(&aux->cec.lock);
+}
+EXPORT_SYMBOL(drm_dp_cec_irq);
+
+static bool drm_dp_cec_cap(struct drm_dp_aux *aux, u8 *cec_cap)
+{
+	u8 cap = 0;
+
+	if (drm_dp_dpcd_read_byte(aux, DP_CEC_TUNNELING_CAPABILITY, &cap) < 0 ||
+	    !(cap & DP_CEC_TUNNELING_CAPABLE))
+		return false;
+	if (cec_cap)
+		*cec_cap = cap;
+	return true;
+}
+
+/*
+ * Called if the HPD was low for more than drm_dp_cec_unregister_delay
+ * seconds. This unregisters the CEC adapter.
+ */
+static void drm_dp_cec_unregister_work(struct work_struct *work)
+{
+	struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,
+					      cec.unregister_work.work);
+
+	mutex_lock(&aux->cec.lock);
+	cec_unregister_adapter(aux->cec.adap);
+	aux->cec.adap = NULL;
+	mutex_unlock(&aux->cec.lock);
+}
+
+/*
+ * A new EDID is set. If there is no CEC adapter, then create one. If
+ * there was a CEC adapter, then check if the CEC adapter properties
+ * were unchanged and just update the CEC physical address. Otherwise
+ * unregister the old CEC adapter and create a new one.
+ */
+void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address)
+{
+	struct drm_connector *connector = aux->cec.connector;
+	u32 cec_caps = CEC_CAP_DEFAULTS | CEC_CAP_NEEDS_HPD |
+		       CEC_CAP_CONNECTOR_INFO;
+	struct cec_connector_info conn_info;
+	unsigned int num_las = 1;
+	u8 cap;
+
+	/* No transfer function was set, so not a DP connector */
+	if (!aux->transfer)
+		return;
+
+	cancel_delayed_work_sync(&aux->cec.unregister_work);
+
+	mutex_lock(&aux->cec.lock);
+	if (!drm_dp_cec_cap(aux, &cap)) {
+		/* CEC is not supported, unregister any existing adapter */
+		cec_unregister_adapter(aux->cec.adap);
+		aux->cec.adap = NULL;
+		goto unlock;
+	}
+
+	if (cap & DP_CEC_SNOOPING_CAPABLE)
+		cec_caps |= CEC_CAP_MONITOR_ALL;
+	if (cap & DP_CEC_MULTIPLE_LA_CAPABLE)
+		num_las = CEC_MAX_LOG_ADDRS;
+
+	if (aux->cec.adap) {
+		/* Check if the adapter properties have changed */
+		if ((aux->cec.adap->capabilities & CEC_CAP_MONITOR_ALL) ==
+		    (cec_caps & CEC_CAP_MONITOR_ALL) &&
+		    aux->cec.adap->available_log_addrs == num_las) {
+			/* Unchanged, so just set the phys addr */
+			cec_s_phys_addr(aux->cec.adap, source_physical_address, false);
+			goto unlock;
+		}
+		/*
+		 * The capabilities changed, so unregister the old
+		 * adapter first.
+		 */
+		cec_unregister_adapter(aux->cec.adap);
+	}
+
+	/* Create a new adapter */
+	aux->cec.adap = cec_allocate_adapter(&drm_dp_cec_adap_ops,
+					     aux, connector->name, cec_caps,
+					     num_las);
+	if (IS_ERR(aux->cec.adap)) {
+		aux->cec.adap = NULL;
+		goto unlock;
+	}
+
+	cec_fill_conn_info_from_drm(&conn_info, connector);
+	cec_s_conn_info(aux->cec.adap, &conn_info);
+
+	if (cec_register_adapter(aux->cec.adap, connector->dev->dev)) {
+		cec_delete_adapter(aux->cec.adap);
+		aux->cec.adap = NULL;
+	} else {
+		/*
+		 * Update the phys addr for the new CEC adapter. When called
+		 * from drm_dp_cec_register_connector() edid == NULL, so in
+		 * that case the phys addr is just invalidated.
+		 */
+		cec_s_phys_addr(aux->cec.adap, source_physical_address, false);
+	}
+unlock:
+	mutex_unlock(&aux->cec.lock);
+}
+EXPORT_SYMBOL(drm_dp_cec_attach);
+
+/*
+ * Note: Prefer calling drm_dp_cec_attach() with
+ * connector->display_info.source_physical_address if possible.
+ */
+void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid)
+{
+	u16 pa = CEC_PHYS_ADDR_INVALID;
+
+	if (edid && edid->extensions)
+		pa = cec_get_edid_phys_addr((const u8 *)edid,
+					    EDID_LENGTH * (edid->extensions + 1), NULL);
+
+	drm_dp_cec_attach(aux, pa);
+}
+EXPORT_SYMBOL(drm_dp_cec_set_edid);
+
+/*
+ * The EDID disappeared (likely because of the HPD going down).
+ */
+void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
+{
+	/* No transfer function was set, so not a DP connector */
+	if (!aux->transfer)
+		return;
+
+	cancel_delayed_work_sync(&aux->cec.unregister_work);
+
+	mutex_lock(&aux->cec.lock);
+	if (!aux->cec.adap)
+		goto unlock;
+
+	cec_phys_addr_invalidate(aux->cec.adap);
+	/*
+	 * We're done if we want to keep the CEC device
+	 * (drm_dp_cec_unregister_delay is >= NEVER_UNREG_DELAY) or if the
+	 * DPCD still indicates the CEC capability (expected for an integrated
+	 * HDMI branch device).
+	 */
+	if (drm_dp_cec_unregister_delay < NEVER_UNREG_DELAY &&
+	    !drm_dp_cec_cap(aux, NULL)) {
+		/*
+		 * Unregister the CEC adapter after drm_dp_cec_unregister_delay
+		 * seconds. This to debounce short HPD off-and-on cycles from
+		 * displays.
+		 */
+		schedule_delayed_work(&aux->cec.unregister_work,
+				      drm_dp_cec_unregister_delay * HZ);
+	}
+unlock:
+	mutex_unlock(&aux->cec.lock);
+}
+EXPORT_SYMBOL(drm_dp_cec_unset_edid);
+
+/**
+ * drm_dp_cec_register_connector() - register a new connector
+ * @aux: DisplayPort AUX channel
+ * @connector: drm connector
+ *
+ * A new connector was registered with associated CEC adapter name and
+ * CEC adapter parent device. After registering the name and parent
+ * drm_dp_cec_set_edid() is called to check if the connector supports
+ * CEC and to register a CEC adapter if that is the case.
+ */
+void drm_dp_cec_register_connector(struct drm_dp_aux *aux,
+				   struct drm_connector *connector)
+{
+	WARN_ON(aux->cec.adap);
+	if (WARN_ON(!aux->transfer))
+		return;
+	aux->cec.connector = connector;
+	INIT_DELAYED_WORK(&aux->cec.unregister_work,
+			  drm_dp_cec_unregister_work);
+}
+EXPORT_SYMBOL(drm_dp_cec_register_connector);
+
+/**
+ * drm_dp_cec_unregister_connector() - unregister the CEC adapter, if any
+ * @aux: DisplayPort AUX channel
+ */
+void drm_dp_cec_unregister_connector(struct drm_dp_aux *aux)
+{
+	if (!aux->cec.adap)
+		return;
+	cancel_delayed_work_sync(&aux->cec.unregister_work);
+	cec_unregister_adapter(aux->cec.adap);
+	aux->cec.adap = NULL;
+}
+EXPORT_SYMBOL(drm_dp_cec_unregister_connector);

linux-7.2.3/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c

@@ -0,0 +1,537 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <drm/display/drm_dp_dual_mode_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+
+/**
+ * DOC: dp dual mode helpers
+ *
+ * Helper functions to deal with DP dual mode (aka. DP++) adaptors.
+ *
+ * Type 1:
+ * Adaptor registers (if any) and the sink DDC bus may be accessed via I2C.
+ *
+ * Type 2:
+ * Adaptor registers and sink DDC bus can be accessed either via I2C or
+ * I2C-over-AUX. Source devices may choose to implement either of these
+ * access methods.
+ */
+
+#define DP_DUAL_MODE_SLAVE_ADDRESS 0x40
+
+/**
+ * drm_dp_dual_mode_read - Read from the DP dual mode adaptor register(s)
+ * @adapter: I2C adapter for the DDC bus
+ * @offset: register offset
+ * @buffer: buffer for return data
+ * @size: size of the buffer
+ *
+ * Reads @size bytes from the DP dual mode adaptor registers
+ * starting at @offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+ssize_t drm_dp_dual_mode_read(struct i2c_adapter *adapter,
+			      u8 offset, void *buffer, size_t size)
+{
+	u8 zero = 0;
+	char *tmpbuf = NULL;
+	/*
+	 * As sub-addressing is not supported by all adaptors,
+	 * always explicitly read from the start and discard
+	 * any bytes that come before the requested offset.
+	 * This way, no matter whether the adaptor supports it
+	 * or not, we'll end up reading the proper data.
+	 */
+	struct i2c_msg msgs[] = {
+		{
+			.addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+			.flags = 0,
+			.len = 1,
+			.buf = &zero,
+		},
+		{
+			.addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+			.flags = I2C_M_RD,
+			.len = size + offset,
+			.buf = buffer,
+		},
+	};
+	int ret;
+
+	if (offset) {
+		tmpbuf = kmalloc(size + offset, GFP_KERNEL);
+		if (!tmpbuf)
+			return -ENOMEM;
+
+		msgs[1].buf = tmpbuf;
+	}
+
+	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
+	if (tmpbuf)
+		memcpy(buffer, tmpbuf + offset, size);
+
+	kfree(tmpbuf);
+
+	if (ret < 0)
+		return ret;
+	if (ret != ARRAY_SIZE(msgs))
+		return -EPROTO;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_read);
+
+/**
+ * drm_dp_dual_mode_write - Write to the DP dual mode adaptor register(s)
+ * @adapter: I2C adapter for the DDC bus
+ * @offset: register offset
+ * @buffer: buffer for write data
+ * @size: size of the buffer
+ *
+ * Writes @size bytes to the DP dual mode adaptor registers
+ * starting at @offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+ssize_t drm_dp_dual_mode_write(struct i2c_adapter *adapter,
+			       u8 offset, const void *buffer, size_t size)
+{
+	struct i2c_msg msg = {
+		.addr = DP_DUAL_MODE_SLAVE_ADDRESS,
+		.flags = 0,
+		.len = 1 + size,
+		.buf = NULL,
+	};
+	void *data;
+	int ret;
+
+	data = kmalloc(msg.len, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	msg.buf = data;
+
+	memcpy(data, &offset, 1);
+	memcpy(data + 1, buffer, size);
+
+	ret = i2c_transfer(adapter, &msg, 1);
+
+	kfree(data);
+
+	if (ret < 0)
+		return ret;
+	if (ret != 1)
+		return -EPROTO;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_write);
+
+static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
+{
+	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
+		"DP-HDMI ADAPTOR\x04";
+
+	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
+		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
+}
+
+static bool is_type1_adaptor(uint8_t adaptor_id)
+{
+	return adaptor_id == 0 || adaptor_id == 0xff;
+}
+
+static bool is_type2_adaptor(uint8_t adaptor_id)
+{
+	return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
+			      DP_DUAL_MODE_REV_TYPE2);
+}
+
+static bool is_lspcon_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN],
+			      const uint8_t adaptor_id)
+{
+	return is_hdmi_adaptor(hdmi_id) &&
+		(adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 |
+		 DP_DUAL_MODE_TYPE_HAS_DPCD));
+}
+
+/**
+ * drm_dp_dual_mode_detect - Identify the DP dual mode adaptor
+ * @dev: &drm_device to use
+ * @adapter: I2C adapter for the DDC bus
+ *
+ * Attempt to identify the type of the DP dual mode adaptor used.
+ *
+ * Note that when the answer is @DRM_DP_DUAL_MODE_UNKNOWN it's not
+ * certain whether we're dealing with a native HDMI port or
+ * a type 1 DVI dual mode adaptor. The driver will have to use
+ * some other hardware/driver specific mechanism to make that
+ * distinction.
+ *
+ * Returns:
+ * The type of the DP dual mode adaptor used
+ */
+enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(const struct drm_device *dev,
+						   struct i2c_adapter *adapter)
+{
+	char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] = {};
+	uint8_t adaptor_id = 0x00;
+	ssize_t ret;
+
+	/*
+	 * Let's see if the adaptor is there the by reading the
+	 * HDMI ID registers.
+	 *
+	 * Note that type 1 DVI adaptors are not required to implemnt
+	 * any registers, and that presents a problem for detection.
+	 * If the i2c transfer is nacked, we may or may not be dealing
+	 * with a type 1 DVI adaptor. Some other mechanism of detecting
+	 * the presence of the adaptor is required. One way would be
+	 * to check the state of the CONFIG1 pin, Another method would
+	 * simply require the driver to know whether the port is a DP++
+	 * port or a native HDMI port. Both of these methods are entirely
+	 * hardware/driver specific so we can't deal with them here.
+	 */
+	ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_HDMI_ID,
+				    hdmi_id, sizeof(hdmi_id));
+	drm_dbg_kms(dev, "DP dual mode HDMI ID: %*pE (err %zd)\n",
+		    ret ? 0 : (int)sizeof(hdmi_id), hdmi_id, ret);
+	if (ret)
+		return DRM_DP_DUAL_MODE_UNKNOWN;
+
+	ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID,
+				    &adaptor_id, sizeof(adaptor_id));
+	drm_dbg_kms(dev, "DP dual mode adaptor ID: %02x (err %zd)\n", adaptor_id, ret);
+	if (ret == 0) {
+		if (is_lspcon_adaptor(hdmi_id, adaptor_id))
+			return DRM_DP_DUAL_MODE_LSPCON;
+		if (is_type2_adaptor(adaptor_id)) {
+			if (is_hdmi_adaptor(hdmi_id))
+				return DRM_DP_DUAL_MODE_TYPE2_HDMI;
+			else
+				return DRM_DP_DUAL_MODE_TYPE2_DVI;
+		}
+		/*
+		 * If not a proper type 1 ID, still assume type 1, but let
+		 * the user know that we may have misdetected the type.
+		 */
+		if (!is_type1_adaptor(adaptor_id))
+			drm_err(dev, "Unexpected DP dual mode adaptor ID %02x\n", adaptor_id);
+
+	}
+
+	if (is_hdmi_adaptor(hdmi_id))
+		return DRM_DP_DUAL_MODE_TYPE1_HDMI;
+	else
+		return DRM_DP_DUAL_MODE_TYPE1_DVI;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_detect);
+
+/**
+ * drm_dp_dual_mode_max_tmds_clock - Max TMDS clock for DP dual mode adaptor
+ * @dev: &drm_device to use
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ *
+ * Determine the max TMDS clock the adaptor supports based on the
+ * type of the dual mode adaptor and the DP_DUAL_MODE_MAX_TMDS_CLOCK
+ * register (on type2 adaptors). As some type 1 adaptors have
+ * problems with registers (see comments in drm_dp_dual_mode_detect())
+ * we don't read the register on those, instead we simply assume
+ * a 165 MHz limit based on the specification.
+ *
+ * Returns:
+ * Maximum supported TMDS clock rate for the DP dual mode adaptor in kHz.
+ */
+int drm_dp_dual_mode_max_tmds_clock(const struct drm_device *dev, enum drm_dp_dual_mode_type type,
+				    struct i2c_adapter *adapter)
+{
+	uint8_t max_tmds_clock;
+	ssize_t ret;
+
+	/* native HDMI so no limit */
+	if (type == DRM_DP_DUAL_MODE_NONE)
+		return 0;
+
+	/*
+	 * Type 1 adaptors are limited to 165MHz
+	 * Type 2 adaptors can tells us their limit
+	 */
+	if (type < DRM_DP_DUAL_MODE_TYPE2_DVI)
+		return 165000;
+
+	ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_MAX_TMDS_CLOCK,
+				    &max_tmds_clock, sizeof(max_tmds_clock));
+	if (ret || max_tmds_clock == 0x00 || max_tmds_clock == 0xff) {
+		drm_dbg_kms(dev, "Failed to query max TMDS clock\n");
+		return 165000;
+	}
+
+	return max_tmds_clock * 5000 / 2;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_max_tmds_clock);
+
+/**
+ * drm_dp_dual_mode_get_tmds_output - Get the state of the TMDS output buffers in the DP dual mode adaptor
+ * @dev: &drm_device to use
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ * @enabled: current state of the TMDS output buffers
+ *
+ * Get the state of the TMDS output buffers in the adaptor. For
+ * type2 adaptors this is queried from the DP_DUAL_MODE_TMDS_OEN
+ * register. As some type 1 adaptors have problems with registers
+ * (see comments in drm_dp_dual_mode_detect()) we don't read the
+ * register on those, instead we simply assume that the buffers
+ * are always enabled.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+int drm_dp_dual_mode_get_tmds_output(const struct drm_device *dev,
+				     enum drm_dp_dual_mode_type type, struct i2c_adapter *adapter,
+				     bool *enabled)
+{
+	uint8_t tmds_oen;
+	ssize_t ret;
+
+	if (type < DRM_DP_DUAL_MODE_TYPE2_DVI) {
+		*enabled = true;
+		return 0;
+	}
+
+	ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN,
+				    &tmds_oen, sizeof(tmds_oen));
+	if (ret) {
+		drm_dbg_kms(dev, "Failed to query state of TMDS output buffers\n");
+		return ret;
+	}
+
+	*enabled = !(tmds_oen & DP_DUAL_MODE_TMDS_DISABLE);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_get_tmds_output);
+
+/**
+ * drm_dp_dual_mode_set_tmds_output - Enable/disable TMDS output buffers in the DP dual mode adaptor
+ * @dev: &drm_device to use
+ * @type: DP dual mode adaptor type
+ * @adapter: I2C adapter for the DDC bus
+ * @enable: enable (as opposed to disable) the TMDS output buffers
+ *
+ * Set the state of the TMDS output buffers in the adaptor. For
+ * type2 this is set via the DP_DUAL_MODE_TMDS_OEN register.
+ * Type1 adaptors do not support any register writes.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure
+ */
+int drm_dp_dual_mode_set_tmds_output(const struct drm_device *dev, enum drm_dp_dual_mode_type type,
+				     struct i2c_adapter *adapter, bool enable)
+{
+	uint8_t tmds_oen = enable ? 0 : DP_DUAL_MODE_TMDS_DISABLE;
+	ssize_t ret;
+	int retry;
+
+	if (type < DRM_DP_DUAL_MODE_TYPE2_DVI)
+		return 0;
+
+	/*
+	 * LSPCON adapters in low-power state may ignore the first write, so
+	 * read back and verify the written value a few times.
+	 */
+	for (retry = 0; retry < 3; retry++) {
+		uint8_t tmp;
+
+		ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_TMDS_OEN,
+					     &tmds_oen, sizeof(tmds_oen));
+		if (ret) {
+			drm_dbg_kms(dev, "Failed to %s TMDS output buffers (%d attempts)\n",
+				    enable ? "enable" : "disable", retry + 1);
+			return ret;
+		}
+
+		ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_TMDS_OEN,
+					    &tmp, sizeof(tmp));
+		if (ret) {
+			drm_dbg_kms(dev,
+				    "I2C read failed during TMDS output buffer %s (%d attempts)\n",
+				    enable ? "enabling" : "disabling", retry + 1);
+			return ret;
+		}
+
+		if (tmp == tmds_oen)
+			return 0;
+	}
+
+	drm_dbg_kms(dev, "I2C write value mismatch during TMDS output buffer %s\n",
+		    enable ? "enabling" : "disabling");
+
+	return -EIO;
+}
+EXPORT_SYMBOL(drm_dp_dual_mode_set_tmds_output);
+
+/**
+ * drm_dp_get_dual_mode_type_name - Get the name of the DP dual mode adaptor type as a string
+ * @type: DP dual mode adaptor type
+ *
+ * Returns:
+ * String representation of the DP dual mode adaptor type
+ */
+const char *drm_dp_get_dual_mode_type_name(enum drm_dp_dual_mode_type type)
+{
+	switch (type) {
+	case DRM_DP_DUAL_MODE_NONE:
+		return "none";
+	case DRM_DP_DUAL_MODE_TYPE1_DVI:
+		return "type 1 DVI";
+	case DRM_DP_DUAL_MODE_TYPE1_HDMI:
+		return "type 1 HDMI";
+	case DRM_DP_DUAL_MODE_TYPE2_DVI:
+		return "type 2 DVI";
+	case DRM_DP_DUAL_MODE_TYPE2_HDMI:
+		return "type 2 HDMI";
+	case DRM_DP_DUAL_MODE_LSPCON:
+		return "lspcon";
+	default:
+		WARN_ON(type != DRM_DP_DUAL_MODE_UNKNOWN);
+		return "unknown";
+	}
+}
+EXPORT_SYMBOL(drm_dp_get_dual_mode_type_name);
+
+/**
+ * drm_lspcon_get_mode: Get LSPCON's current mode of operation by
+ * reading offset (0x80, 0x41)
+ * @dev: &drm_device to use
+ * @adapter: I2C-over-aux adapter
+ * @mode: current lspcon mode of operation output variable
+ *
+ * Returns:
+ * 0 on success, sets the current_mode value to appropriate mode
+ * -error on failure
+ */
+int drm_lspcon_get_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
+			enum drm_lspcon_mode *mode)
+{
+	u8 data;
+	int ret = 0;
+	int retry;
+
+	if (!mode) {
+		drm_err(dev, "NULL input\n");
+		return -EINVAL;
+	}
+
+	/* Read Status: i2c over aux */
+	for (retry = 0; retry < 6; retry++) {
+		if (retry)
+			usleep_range(500, 1000);
+
+		ret = drm_dp_dual_mode_read(adapter,
+					    DP_DUAL_MODE_LSPCON_CURRENT_MODE,
+					    &data, sizeof(data));
+		if (!ret)
+			break;
+	}
+
+	if (ret < 0) {
+		drm_dbg_kms(dev, "LSPCON read(0x80, 0x41) failed\n");
+		return -EFAULT;
+	}
+
+	if (data & DP_DUAL_MODE_LSPCON_MODE_PCON)
+		*mode = DRM_LSPCON_MODE_PCON;
+	else
+		*mode = DRM_LSPCON_MODE_LS;
+	return 0;
+}
+EXPORT_SYMBOL(drm_lspcon_get_mode);
+
+/**
+ * drm_lspcon_set_mode: Change LSPCON's mode of operation by
+ * writing offset (0x80, 0x40)
+ * @dev: &drm_device to use
+ * @adapter: I2C-over-aux adapter
+ * @mode: required mode of operation
+ * @time_out: LSPCON mode change settle timeout
+ *
+ * Returns:
+ * 0 on success, -error on failure/timeout
+ */
+int drm_lspcon_set_mode(const struct drm_device *dev, struct i2c_adapter *adapter,
+			enum drm_lspcon_mode mode, int time_out)
+{
+	u8 data = 0;
+	int ret;
+	enum drm_lspcon_mode current_mode;
+
+	if (mode == DRM_LSPCON_MODE_PCON)
+		data = DP_DUAL_MODE_LSPCON_MODE_PCON;
+
+	/* Change mode */
+	ret = drm_dp_dual_mode_write(adapter, DP_DUAL_MODE_LSPCON_MODE_CHANGE,
+				     &data, sizeof(data));
+	if (ret < 0) {
+		drm_err(dev, "LSPCON mode change failed\n");
+		return ret;
+	}
+
+	/*
+	 * Confirm mode change by reading the status bit.
+	 * Sometimes, it takes a while to change the mode,
+	 * so wait and retry until time out or done.
+	 */
+	do {
+		ret = drm_lspcon_get_mode(dev, adapter, &current_mode);
+		if (ret) {
+			drm_err(dev, "can't confirm LSPCON mode change\n");
+			return ret;
+		} else {
+			if (current_mode != mode) {
+				msleep(10);
+				time_out -= 10;
+			} else {
+				drm_dbg_kms(dev, "LSPCON mode changed to %s\n",
+					    mode == DRM_LSPCON_MODE_LS ? "LS" : "PCON");
+				return 0;
+			}
+		}
+	} while (time_out);
+
+	drm_err(dev, "LSPCON mode change timed out\n");
+	return -ETIMEDOUT;
+}
+EXPORT_SYMBOL(drm_lspcon_set_mode);

linux-7.2.3/drivers/gpu/drm/display/drm_dp_helper_internal.h

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef DRM_DP_HELPER_INTERNAL_H
+#define DRM_DP_HELPER_INTERNAL_H
+
+struct drm_dp_aux;
+
+#ifdef CONFIG_DRM_DISPLAY_DP_AUX_CHARDEV
+int drm_dp_aux_dev_init(void);
+void drm_dp_aux_dev_exit(void);
+int drm_dp_aux_register_devnode(struct drm_dp_aux *aux);
+void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux);
+#else
+static inline int drm_dp_aux_dev_init(void)
+{
+	return 0;
+}
+
+static inline void drm_dp_aux_dev_exit(void)
+{
+}
+
+static inline int drm_dp_aux_register_devnode(struct drm_dp_aux *aux)
+{
+	return 0;
+}
+
+static inline void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
+{
+}
+#endif
+
+#endif

linux-7.2.3/drivers/gpu/drm/display/drm_dp_mst_topology_internal.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Declarations for DP MST related functions which are only used in selftests
+ *
+ * Copyright © 2018 Red Hat
+ * Authors:
+ *     Lyude Paul <lyude@redhat.com>
+ */
+
+#ifndef _DRM_DP_MST_HELPER_INTERNAL_H_
+#define _DRM_DP_MST_HELPER_INTERNAL_H_
+
+struct drm_dp_sideband_msg_req_body;
+struct drm_dp_sideband_msg_tx;
+struct drm_printer;
+
+void
+drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
+			   struct drm_dp_sideband_msg_tx *raw);
+int drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
+			       struct drm_dp_sideband_msg_req_body *req);
+void
+drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
+				  int indent, struct drm_printer *printer);
+
+#endif /* !_DRM_DP_MST_HELPER_INTERNAL_H_ */

linux-7.2.3/drivers/gpu/drm/display/drm_hdcp_helper.c

@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Intel Corporation.
+ *
+ * Authors:
+ * Ramalingam C <ramalingam.c@intel.com>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/firmware.h>
+
+#include <drm/display/drm_hdcp_helper.h>
+#include <drm/drm_sysfs.h>
+#include <drm/drm_print.h>
+#include <drm/drm_device.h>
+#include <drm/drm_property.h>
+#include <drm/drm_mode_object.h>
+#include <drm/drm_connector.h>
+
+static inline void drm_hdcp_print_ksv(const u8 *ksv)
+{
+	DRM_DEBUG("\t%#02x, %#02x, %#02x, %#02x, %#02x\n",
+		  ksv[0], ksv[1], ksv[2], ksv[3], ksv[4]);
+}
+
+static u32 drm_hdcp_get_revoked_ksv_count(const u8 *buf, u32 vrls_length)
+{
+	u32 parsed_bytes = 0, ksv_count = 0, vrl_ksv_cnt, vrl_sz;
+
+	while (parsed_bytes < vrls_length) {
+		vrl_ksv_cnt = *buf;
+		ksv_count += vrl_ksv_cnt;
+
+		vrl_sz = (vrl_ksv_cnt * DRM_HDCP_KSV_LEN) + 1;
+		buf += vrl_sz;
+		parsed_bytes += vrl_sz;
+	}
+
+	/*
+	 * When vrls are not valid, ksvs are not considered.
+	 * Hence SRM will be discarded.
+	 */
+	if (parsed_bytes != vrls_length)
+		ksv_count = 0;
+
+	return ksv_count;
+}
+
+static u32 drm_hdcp_get_revoked_ksvs(const u8 *buf, u8 **revoked_ksv_list,
+				     u32 vrls_length)
+{
+	u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 0;
+	u32 parsed_bytes = 0, ksv_count = 0;
+
+	do {
+		vrl_ksv_cnt = *buf;
+		vrl_ksv_sz = vrl_ksv_cnt * DRM_HDCP_KSV_LEN;
+
+		buf++;
+
+		DRM_DEBUG("vrl: %d, Revoked KSVs: %d\n", vrl_idx++,
+			  vrl_ksv_cnt);
+		memcpy((*revoked_ksv_list) + (ksv_count * DRM_HDCP_KSV_LEN),
+		       buf, vrl_ksv_sz);
+
+		ksv_count += vrl_ksv_cnt;
+		buf += vrl_ksv_sz;
+
+		parsed_bytes += (vrl_ksv_sz + 1);
+	} while (parsed_bytes < vrls_length);
+
+	return ksv_count;
+}
+
+static inline u32 get_vrl_length(const u8 *buf)
+{
+	return drm_hdcp_be24_to_cpu(buf);
+}
+
+static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count,
+				    u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
+{
+	struct hdcp_srm_header *header;
+	u32 vrl_length, ksv_count;
+
+	if (count < (sizeof(struct hdcp_srm_header) +
+	    DRM_HDCP_1_4_VRL_LENGTH_SIZE + DRM_HDCP_1_4_DCP_SIG_SIZE)) {
+		DRM_ERROR("Invalid blob length\n");
+		return -EINVAL;
+	}
+
+	header = (struct hdcp_srm_header *)buf;
+	DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
+		  header->srm_id,
+		  be16_to_cpu(header->srm_version), header->srm_gen_no);
+
+	WARN_ON(header->reserved);
+
+	buf = buf + sizeof(*header);
+	vrl_length = get_vrl_length(buf);
+	if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
+	    vrl_length < (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
+			  DRM_HDCP_1_4_DCP_SIG_SIZE)) {
+		DRM_ERROR("Invalid blob length or vrl length\n");
+		return -EINVAL;
+	}
+
+	/* Length of the all vrls combined */
+	vrl_length -= (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
+		       DRM_HDCP_1_4_DCP_SIG_SIZE);
+
+	if (!vrl_length) {
+		DRM_ERROR("No vrl found\n");
+		return -EINVAL;
+	}
+
+	buf += DRM_HDCP_1_4_VRL_LENGTH_SIZE;
+	ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length);
+	if (!ksv_count) {
+		DRM_DEBUG("Revoked KSV count is 0\n");
+		return 0;
+	}
+
+	*revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
+	if (!*revoked_ksv_list) {
+		DRM_ERROR("Out of Memory\n");
+		return -ENOMEM;
+	}
+
+	if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list,
+				      vrl_length) != ksv_count) {
+		*revoked_ksv_cnt = 0;
+		kfree(*revoked_ksv_list);
+		return -EINVAL;
+	}
+
+	*revoked_ksv_cnt = ksv_count;
+	return 0;
+}
+
+static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count,
+				    u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
+{
+	struct hdcp_srm_header *header;
+	u32 vrl_length, ksv_count, ksv_sz;
+
+	if (count < (sizeof(struct hdcp_srm_header) +
+	    DRM_HDCP_2_VRL_LENGTH_SIZE + DRM_HDCP_2_DCP_SIG_SIZE)) {
+		DRM_ERROR("Invalid blob length\n");
+		return -EINVAL;
+	}
+
+	header = (struct hdcp_srm_header *)buf;
+	DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
+		  header->srm_id & DRM_HDCP_SRM_ID_MASK,
+		  be16_to_cpu(header->srm_version), header->srm_gen_no);
+
+	if (header->reserved)
+		return -EINVAL;
+
+	buf = buf + sizeof(*header);
+	vrl_length = get_vrl_length(buf);
+
+	if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
+	    vrl_length < (DRM_HDCP_2_VRL_LENGTH_SIZE +
+	    DRM_HDCP_2_DCP_SIG_SIZE)) {
+		DRM_ERROR("Invalid blob length or vrl length\n");
+		return -EINVAL;
+	}
+
+	/* Length of the all vrls combined */
+	vrl_length -= (DRM_HDCP_2_VRL_LENGTH_SIZE +
+		       DRM_HDCP_2_DCP_SIG_SIZE);
+
+	if (!vrl_length) {
+		DRM_ERROR("No vrl found\n");
+		return -EINVAL;
+	}
+
+	buf += DRM_HDCP_2_VRL_LENGTH_SIZE;
+	ksv_count = (*buf << 2) | DRM_HDCP_2_KSV_COUNT_2_LSBITS(*(buf + 1));
+	if (!ksv_count) {
+		DRM_DEBUG("Revoked KSV count is 0\n");
+		return 0;
+	}
+
+	*revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
+	if (!*revoked_ksv_list) {
+		DRM_ERROR("Out of Memory\n");
+		return -ENOMEM;
+	}
+
+	ksv_sz = ksv_count * DRM_HDCP_KSV_LEN;
+	buf += DRM_HDCP_2_NO_OF_DEV_PLUS_RESERVED_SZ;
+
+	DRM_DEBUG("Revoked KSVs: %d\n", ksv_count);
+	memcpy(*revoked_ksv_list, buf, ksv_sz);
+
+	*revoked_ksv_cnt = ksv_count;
+	return 0;
+}
+
+static inline bool is_srm_version_hdcp1(const u8 *buf)
+{
+	return *buf == (u8)(DRM_HDCP_1_4_SRM_ID << 4);
+}
+
+static inline bool is_srm_version_hdcp2(const u8 *buf)
+{
+	return *buf == (u8)(DRM_HDCP_2_SRM_ID << 4 | DRM_HDCP_2_INDICATOR);
+}
+
+static int drm_hdcp_srm_update(const u8 *buf, size_t count,
+			       u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
+{
+	if (count < sizeof(struct hdcp_srm_header))
+		return -EINVAL;
+
+	if (is_srm_version_hdcp1(buf))
+		return drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list,
+						revoked_ksv_cnt);
+	else if (is_srm_version_hdcp2(buf))
+		return drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list,
+						revoked_ksv_cnt);
+	else
+		return -EINVAL;
+}
+
+static int drm_hdcp_request_srm(struct drm_device *drm_dev,
+				u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
+{
+	char fw_name[36] = "display_hdcp_srm.bin";
+	const struct firmware *fw;
+	int ret;
+
+	ret = request_firmware_direct(&fw, (const char *)fw_name,
+				      drm_dev->dev);
+	if (ret < 0) {
+		*revoked_ksv_cnt = 0;
+		*revoked_ksv_list = NULL;
+		ret = 0;
+		goto exit;
+	}
+
+	if (fw->size && fw->data)
+		ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list,
+					  revoked_ksv_cnt);
+
+exit:
+	release_firmware(fw);
+	return ret;
+}
+
+/**
+ * drm_hdcp_check_ksvs_revoked - Check the revoked status of the IDs
+ *
+ * @drm_dev: drm_device for which HDCP revocation check is requested
+ * @ksvs: List of KSVs (HDCP receiver IDs)
+ * @ksv_count: KSV count passed in through @ksvs
+ *
+ * This function reads the HDCP System renewability Message(SRM Table)
+ * from userspace as a firmware and parses it for the revoked HDCP
+ * KSVs(Receiver IDs) detected by DCP LLC. Once the revoked KSVs are known,
+ * revoked state of the KSVs in the list passed in by display drivers are
+ * decided and response is sent.
+ *
+ * SRM should be presented in the name of "display_hdcp_srm.bin".
+ *
+ * Format of the SRM table, that userspace needs to write into the binary file,
+ * is defined at:
+ * 1. Renewability chapter on 55th page of HDCP 1.4 specification
+ * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Specification%20Rev1_4_Secure.pdf
+ * 2. Renewability chapter on 63rd page of HDCP 2.2 specification
+ * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf
+ *
+ * Returns:
+ * Count of the revoked KSVs or -ve error number in case of the failure.
+ */
+int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs,
+				u32 ksv_count)
+{
+	u32 revoked_ksv_cnt = 0, i, j;
+	u8 *revoked_ksv_list = NULL;
+	int ret = 0;
+
+	ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list,
+				   &revoked_ksv_cnt);
+	if (ret)
+		return ret;
+
+	/* revoked_ksv_cnt will be zero when above function failed */
+	for (i = 0; i < revoked_ksv_cnt; i++)
+		for  (j = 0; j < ksv_count; j++)
+			if (!memcmp(&ksvs[j * DRM_HDCP_KSV_LEN],
+				    &revoked_ksv_list[i * DRM_HDCP_KSV_LEN],
+				    DRM_HDCP_KSV_LEN)) {
+				DRM_DEBUG("Revoked KSV is ");
+				drm_hdcp_print_ksv(&ksvs[j * DRM_HDCP_KSV_LEN]);
+				ret++;
+			}
+
+	kfree(revoked_ksv_list);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked);
+
+static struct drm_prop_enum_list drm_cp_enum_list[] = {
+	{ DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" },
+	{ DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" },
+	{ DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" },
+};
+DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
+
+static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = {
+	{ DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" },
+	{ DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" },
+};
+DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
+		 drm_hdcp_content_type_enum_list)
+
+/**
+ * drm_connector_attach_content_protection_property - attach content protection
+ * property
+ *
+ * @connector: connector to attach CP property on.
+ * @hdcp_content_type: is HDCP Content Type property needed for connector
+ *
+ * This is used to add support for content protection on select connectors.
+ * Content Protection is intentionally vague to allow for different underlying
+ * technologies, however it is most implemented by HDCP.
+ *
+ * When hdcp_content_type is true enum property called HDCP Content Type is
+ * created (if it is not already) and attached to the connector.
+ *
+ * This property is used for sending the protected content's stream type
+ * from userspace to kernel on selected connectors. Protected content provider
+ * will decide their type of their content and declare the same to kernel.
+ *
+ * Content type will be used during the HDCP 2.2 authentication.
+ * Content type will be set to &drm_connector_state.hdcp_content_type.
+ *
+ * The content protection will be set to &drm_connector_state.content_protection
+ *
+ * When kernel triggered content protection state change like DESIRED->ENABLED
+ * and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update
+ * the content protection state of a connector.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_attach_content_protection_property(
+		struct drm_connector *connector, bool hdcp_content_type)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop =
+			dev->mode_config.content_protection_property;
+
+	if (!prop)
+		prop = drm_property_create_enum(dev, 0, "Content Protection",
+						drm_cp_enum_list,
+						ARRAY_SIZE(drm_cp_enum_list));
+	if (!prop)
+		return -ENOMEM;
+
+	drm_object_attach_property(&connector->base, prop,
+				   DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
+	dev->mode_config.content_protection_property = prop;
+
+	if (!hdcp_content_type)
+		return 0;
+
+	prop = dev->mode_config.hdcp_content_type_property;
+	if (!prop)
+		prop = drm_property_create_enum(dev, 0, "HDCP Content Type",
+					drm_hdcp_content_type_enum_list,
+					ARRAY_SIZE(
+					drm_hdcp_content_type_enum_list));
+	if (!prop)
+		return -ENOMEM;
+
+	drm_object_attach_property(&connector->base, prop,
+				   DRM_MODE_HDCP_CONTENT_TYPE0);
+	dev->mode_config.hdcp_content_type_property = prop;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
+
+/**
+ * drm_hdcp_update_content_protection - Updates the content protection state
+ * of a connector
+ *
+ * @connector: drm_connector on which content protection state needs an update
+ * @val: New state of the content protection property
+ *
+ * This function can be used by display drivers, to update the kernel triggered
+ * content protection state changes of a drm_connector such as DESIRED->ENABLED
+ * and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED,
+ * as userspace is triggering such state change and kernel performs it without
+ * fail.This function update the new state of the property into the connector's
+ * state and generate an uevent to notify the userspace.
+ */
+void drm_hdcp_update_content_protection(struct drm_connector *connector,
+					u64 val)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_connector_state *state = connector->state;
+
+	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+	if (state->content_protection == val)
+		return;
+
+	state->content_protection = val;
+	drm_sysfs_connector_property_event(connector,
+					   dev->mode_config.content_protection_property);
+}
+EXPORT_SYMBOL(drm_hdcp_update_content_protection);

linux-7.2.3/drivers/gpu/drm/display/drm_hdmi_audio_helper.c

@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (c) 2024 Linaro Ltd
+ */
+
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_device.h>
+#include <drm/display/drm_hdmi_audio_helper.h>
+
+#include <sound/hdmi-codec.h>
+
+static int drm_connector_hdmi_audio_startup(struct device *dev, void *data)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_audio_funcs *funcs =
+		connector->hdmi_audio.funcs;
+
+	if (funcs->startup)
+		return funcs->startup(connector);
+
+	return 0;
+}
+
+static int drm_connector_hdmi_audio_prepare(struct device *dev, void *data,
+					    struct hdmi_codec_daifmt *fmt,
+					    struct hdmi_codec_params *hparms)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_audio_funcs *funcs =
+		connector->hdmi_audio.funcs;
+
+	return funcs->prepare(connector, fmt, hparms);
+}
+
+static void drm_connector_hdmi_audio_shutdown(struct device *dev, void *data)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_audio_funcs *funcs =
+		connector->hdmi_audio.funcs;
+
+	return funcs->shutdown(connector);
+}
+
+static int drm_connector_hdmi_audio_mute_stream(struct device *dev, void *data,
+						bool enable, int direction)
+{
+	struct drm_connector *connector = data;
+	const struct drm_connector_hdmi_audio_funcs *funcs =
+		connector->hdmi_audio.funcs;
+
+	if (funcs->mute_stream)
+		return funcs->mute_stream(connector, enable, direction);
+
+	return -ENOTSUPP;
+}
+
+static int drm_connector_hdmi_audio_get_dai_id(struct snd_soc_component *comment,
+					       struct device_node *endpoint,
+					       void *data)
+{
+	struct drm_connector *connector = data;
+	struct of_endpoint of_ep;
+	int ret;
+
+	if (connector->hdmi_audio.dai_port < 0)
+		return -ENOTSUPP;
+
+	ret = of_graph_parse_endpoint(endpoint, &of_ep);
+	if (ret < 0)
+		return ret;
+
+	if (of_ep.port == connector->hdmi_audio.dai_port)
+		return 0;
+
+	return -EINVAL;
+}
+
+static int drm_connector_hdmi_audio_get_eld(struct device *dev, void *data,
+					    uint8_t *buf, size_t len)
+{
+	struct drm_connector *connector = data;
+
+	mutex_lock(&connector->eld_mutex);
+	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+	mutex_unlock(&connector->eld_mutex);
+
+	return 0;
+}
+
+static int drm_connector_hdmi_audio_hook_plugged_cb(struct device *dev,
+						    void *data,
+						    hdmi_codec_plugged_cb fn,
+						    struct device *codec_dev)
+{
+	struct drm_connector *connector = data;
+
+	mutex_lock(&connector->hdmi_audio.lock);
+
+	connector->hdmi_audio.plugged_cb = fn;
+	connector->hdmi_audio.plugged_cb_dev = codec_dev;
+
+	if (fn)
+		fn(codec_dev, connector->hdmi_audio.last_state);
+
+	mutex_unlock(&connector->hdmi_audio.lock);
+
+	return 0;
+}
+
+void drm_connector_hdmi_audio_plugged_notify(struct drm_connector *connector,
+					     bool plugged)
+{
+	mutex_lock(&connector->hdmi_audio.lock);
+
+	connector->hdmi_audio.last_state = plugged;
+
+	if (connector->hdmi_audio.plugged_cb &&
+	    connector->hdmi_audio.plugged_cb_dev)
+		connector->hdmi_audio.plugged_cb(connector->hdmi_audio.plugged_cb_dev,
+						 connector->hdmi_audio.last_state);
+
+	mutex_unlock(&connector->hdmi_audio.lock);
+}
+EXPORT_SYMBOL(drm_connector_hdmi_audio_plugged_notify);
+
+static const struct hdmi_codec_ops drm_connector_hdmi_audio_ops = {
+	.audio_startup = drm_connector_hdmi_audio_startup,
+	.prepare = drm_connector_hdmi_audio_prepare,
+	.audio_shutdown = drm_connector_hdmi_audio_shutdown,
+	.mute_stream = drm_connector_hdmi_audio_mute_stream,
+	.get_eld = drm_connector_hdmi_audio_get_eld,
+	.get_dai_id = drm_connector_hdmi_audio_get_dai_id,
+	.hook_plugged_cb = drm_connector_hdmi_audio_hook_plugged_cb,
+};
+
+/**
+ * drm_connector_hdmi_audio_init - Initialize HDMI Codec device for the DRM connector
+ * @connector: A pointer to the connector to allocate codec for
+ * @hdmi_codec_dev: device to be used as a parent for the HDMI Codec
+ * @funcs: callbacks for this HDMI Codec
+ * @max_i2s_playback_channels: maximum number of playback I2S channels
+ * @i2s_formats: set of I2S formats (use 0 for a bus-specific set)
+ * @spdif_playback: set if HDMI codec has S/PDIF playback port
+ * @dai_port: sound DAI port, -1 if it is not enabled
+ *
+ * Create a HDMI codec device to be used with the specified connector.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_connector_hdmi_audio_init(struct drm_connector *connector,
+				  struct device *hdmi_codec_dev,
+				  const struct drm_connector_hdmi_audio_funcs *funcs,
+				  unsigned int max_i2s_playback_channels,
+				  u64 i2s_formats,
+				  bool spdif_playback,
+				  int dai_port)
+{
+	struct hdmi_codec_pdata codec_pdata = {
+		.ops = &drm_connector_hdmi_audio_ops,
+		.max_i2s_channels = max_i2s_playback_channels,
+		.i2s = !!max_i2s_playback_channels,
+		.i2s_formats = i2s_formats,
+		.spdif = spdif_playback,
+		.no_i2s_capture = true,
+		.no_spdif_capture = true,
+		.data = connector,
+	};
+	struct platform_device *pdev;
+
+	if (!funcs ||
+	    !funcs->prepare ||
+	    !funcs->shutdown)
+		return -EINVAL;
+
+	connector->hdmi_audio.funcs = funcs;
+	connector->hdmi_audio.dai_port = dai_port;
+
+	pdev = platform_device_register_data(hdmi_codec_dev,
+					     HDMI_CODEC_DRV_NAME,
+					     PLATFORM_DEVID_AUTO,
+					     &codec_pdata, sizeof(codec_pdata));
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	connector->hdmi_audio.codec_pdev = pdev;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_connector_hdmi_audio_init);

linux-7.2.3/drivers/gpu/drm/display/drm_hdmi_cec_helper.c

@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (c) 2024 Linaro Ltd
+ */
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_managed.h>
+#include <drm/display/drm_hdmi_cec_helper.h>
+
+#include <linux/export.h>
+#include <linux/mutex.h>
+
+#include <media/cec.h>
+
+struct drm_connector_hdmi_cec_data {
+	struct cec_adapter *adapter;
+	const struct drm_connector_hdmi_cec_funcs *funcs;
+};
+
+static int drm_connector_hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct drm_connector *connector = cec_get_drvdata(adap);
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	return data->funcs->enable(connector, enable);
+}
+
+static int drm_connector_hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct drm_connector *connector = cec_get_drvdata(adap);
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	return data->funcs->log_addr(connector, logical_addr);
+}
+
+static int drm_connector_hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+						u32 signal_free_time, struct cec_msg *msg)
+{
+	struct drm_connector *connector = cec_get_drvdata(adap);
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	return data->funcs->transmit(connector, attempts, signal_free_time, msg);
+}
+
+static const struct cec_adap_ops drm_connector_hdmi_cec_adap_ops = {
+	.adap_enable = drm_connector_hdmi_cec_adap_enable,
+	.adap_log_addr = drm_connector_hdmi_cec_adap_log_addr,
+	.adap_transmit = drm_connector_hdmi_cec_adap_transmit,
+};
+
+static void drm_connector_hdmi_cec_adapter_phys_addr_invalidate(struct drm_connector *connector)
+{
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_phys_addr_invalidate(data->adapter);
+}
+
+static void drm_connector_hdmi_cec_adapter_phys_addr_set(struct drm_connector *connector,
+							 u16 addr)
+{
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_s_phys_addr(data->adapter, addr, false);
+}
+
+static void drm_connector_hdmi_cec_adapter_unregister(struct drm_device *dev, void *res)
+{
+	struct drm_connector *connector = res;
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_unregister_adapter(data->adapter);
+
+	if (data->funcs->uninit)
+		data->funcs->uninit(connector);
+
+	kfree(data);
+	connector->cec.data = NULL;
+}
+
+static struct drm_connector_cec_funcs drm_connector_hdmi_cec_adapter_funcs = {
+	.phys_addr_invalidate = drm_connector_hdmi_cec_adapter_phys_addr_invalidate,
+	.phys_addr_set = drm_connector_hdmi_cec_adapter_phys_addr_set,
+};
+
+int drmm_connector_hdmi_cec_register(struct drm_connector *connector,
+				     const struct drm_connector_hdmi_cec_funcs *funcs,
+				     const char *name,
+				     u8 available_las,
+				     struct device *dev)
+{
+	struct drm_connector_hdmi_cec_data *data;
+	struct cec_connector_info conn_info;
+	struct cec_adapter *cec_adap;
+	int ret;
+
+	if (!funcs->init || !funcs->enable || !funcs->log_addr || !funcs->transmit)
+		return -EINVAL;
+
+	data = kzalloc_obj(*data);
+	if (!data)
+		return -ENOMEM;
+
+	data->funcs = funcs;
+
+	cec_adap = cec_allocate_adapter(&drm_connector_hdmi_cec_adap_ops, connector, name,
+					CEC_CAP_DEFAULTS | CEC_CAP_CONNECTOR_INFO,
+					available_las ? : CEC_MAX_LOG_ADDRS);
+	ret = PTR_ERR_OR_ZERO(cec_adap);
+	if (ret < 0)
+		goto err_free;
+
+	cec_fill_conn_info_from_drm(&conn_info, connector);
+	cec_s_conn_info(cec_adap, &conn_info);
+
+	data->adapter = cec_adap;
+
+	mutex_lock(&connector->cec.mutex);
+
+	connector->cec.data = data;
+	connector->cec.funcs = &drm_connector_hdmi_cec_adapter_funcs;
+
+	ret = funcs->init(connector);
+	if (ret < 0)
+		goto err_delete_adapter;
+
+	/*
+	 * NOTE: the CEC adapter will be unregistered by drmm cleanup from
+	 * drm_managed_release(), which is called from drm_dev_release()
+	 * during device unbind.
+	 *
+	 * However, the CEC framework cleans up the CEC adapter only when the
+	 * last user has closed its file descriptor, so we don't need to handle
+	 * it in DRM.
+	 *
+	 * Before that CEC framework makes sure that even if the userspace
+	 * still holds CEC device open, all calls will be shortcut via
+	 * cec_is_registered(), making sure that there is no access to the
+	 * freed memory.
+	 */
+	ret = cec_register_adapter(cec_adap, dev);
+	if (ret < 0)
+		goto err_delete_adapter;
+
+	mutex_unlock(&connector->cec.mutex);
+
+	return drmm_add_action_or_reset(connector->dev,
+					drm_connector_hdmi_cec_adapter_unregister,
+					connector);
+
+err_delete_adapter:
+	cec_delete_adapter(cec_adap);
+
+	connector->cec.data = NULL;
+
+	mutex_unlock(&connector->cec.mutex);
+
+err_free:
+	kfree(data);
+
+	return ret;
+}
+EXPORT_SYMBOL(drmm_connector_hdmi_cec_register);
+
+void drm_connector_hdmi_cec_received_msg(struct drm_connector *connector,
+					 struct cec_msg *msg)
+{
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_received_msg(data->adapter, msg);
+}
+EXPORT_SYMBOL(drm_connector_hdmi_cec_received_msg);
+
+void drm_connector_hdmi_cec_transmit_attempt_done(struct drm_connector *connector,
+						  u8 status)
+{
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_transmit_attempt_done(data->adapter, status);
+}
+EXPORT_SYMBOL(drm_connector_hdmi_cec_transmit_attempt_done);
+
+void drm_connector_hdmi_cec_transmit_done(struct drm_connector *connector,
+					  u8 status,
+					  u8 arb_lost_cnt, u8 nack_cnt,
+					  u8 low_drive_cnt, u8 error_cnt)
+{
+	struct drm_connector_hdmi_cec_data *data = connector->cec.data;
+
+	cec_transmit_done(data->adapter, status,
+			  arb_lost_cnt, nack_cnt, low_drive_cnt, error_cnt);
+}
+EXPORT_SYMBOL(drm_connector_hdmi_cec_transmit_done);

linux-7.2.3/drivers/gpu/drm/display/drm_hdmi_cec_notifier_helper.c

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (c) 2024 Linaro Ltd
+ */
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_managed.h>
+#include <drm/display/drm_hdmi_cec_helper.h>
+
+#include <linux/export.h>
+#include <linux/mutex.h>
+
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+static void drm_connector_hdmi_cec_notifier_phys_addr_invalidate(struct drm_connector *connector)
+{
+	cec_notifier_phys_addr_invalidate(connector->cec.data);
+}
+
+static void drm_connector_hdmi_cec_notifier_phys_addr_set(struct drm_connector *connector,
+							  u16 addr)
+{
+	cec_notifier_set_phys_addr(connector->cec.data, addr);
+}
+
+static void drm_connector_hdmi_cec_notifier_unregister(struct drm_device *dev, void *res)
+{
+	struct drm_connector *connector = res;
+
+	cec_notifier_conn_unregister(connector->cec.data);
+	connector->cec.data = NULL;
+}
+
+static const struct drm_connector_cec_funcs drm_connector_cec_notifier_funcs = {
+	.phys_addr_invalidate = drm_connector_hdmi_cec_notifier_phys_addr_invalidate,
+	.phys_addr_set = drm_connector_hdmi_cec_notifier_phys_addr_set,
+};
+
+int drmm_connector_hdmi_cec_notifier_register(struct drm_connector *connector,
+					      const char *port_name,
+					      struct device *dev)
+{
+	struct cec_connector_info conn_info;
+	struct cec_notifier *notifier;
+
+	cec_fill_conn_info_from_drm(&conn_info, connector);
+
+	notifier = cec_notifier_conn_register(dev, port_name, &conn_info);
+	if (!notifier)
+		return -ENOMEM;
+
+	mutex_lock(&connector->cec.mutex);
+
+	connector->cec.data = notifier;
+	connector->cec.funcs = &drm_connector_cec_notifier_funcs;
+
+	mutex_unlock(&connector->cec.mutex);
+
+	return drmm_add_action_or_reset(connector->dev,
+					drm_connector_hdmi_cec_notifier_unregister,
+					connector);
+}
+EXPORT_SYMBOL(drmm_connector_hdmi_cec_notifier_register);

linux-7.2.3/drivers/gpu/drm/display/drm_hdmi_helper.c

@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: MIT
+
+#include <linux/export.h>
+#include <linux/module.h>
+
+#include <drm/display/drm_hdmi_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_print.h>
+#include <drm/drm_property.h>
+
+static inline bool is_eotf_supported(u8 output_eotf, u8 sink_eotf)
+{
+	return sink_eotf & BIT(output_eotf);
+}
+
+/**
+ * drm_hdmi_infoframe_set_hdr_metadata() - fill an HDMI DRM infoframe with
+ *                                         HDR metadata from userspace
+ * @frame: HDMI DRM infoframe
+ * @conn_state: Connector state containing HDR metadata
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int drm_hdmi_infoframe_set_hdr_metadata(struct hdmi_drm_infoframe *frame,
+					const struct drm_connector_state *conn_state)
+{
+	struct drm_connector *connector;
+	struct hdr_output_metadata *hdr_metadata;
+	int err;
+
+	if (!frame || !conn_state)
+		return -EINVAL;
+
+	connector = conn_state->connector;
+
+	if (!conn_state->hdr_output_metadata)
+		return -EINVAL;
+
+	hdr_metadata = conn_state->hdr_output_metadata->data;
+
+	if (!hdr_metadata || !connector)
+		return -EINVAL;
+
+	/* Sink EOTF is Bit map while infoframe is absolute values */
+	if (!is_eotf_supported(hdr_metadata->hdmi_metadata_type1.eotf,
+			       connector->display_info.hdr_sink_metadata.hdmi_type1.eotf))
+		DRM_DEBUG_KMS("Unknown EOTF %d\n", hdr_metadata->hdmi_metadata_type1.eotf);
+
+	err = hdmi_drm_infoframe_init(frame);
+	if (err < 0)
+		return err;
+
+	frame->eotf = hdr_metadata->hdmi_metadata_type1.eotf;
+	frame->metadata_type = hdr_metadata->hdmi_metadata_type1.metadata_type;
+
+	BUILD_BUG_ON(sizeof(frame->display_primaries) !=
+		     sizeof(hdr_metadata->hdmi_metadata_type1.display_primaries));
+	BUILD_BUG_ON(sizeof(frame->white_point) !=
+		     sizeof(hdr_metadata->hdmi_metadata_type1.white_point));
+
+	memcpy(&frame->display_primaries,
+	       &hdr_metadata->hdmi_metadata_type1.display_primaries,
+	       sizeof(frame->display_primaries));
+
+	memcpy(&frame->white_point,
+	       &hdr_metadata->hdmi_metadata_type1.white_point,
+	       sizeof(frame->white_point));
+
+	frame->max_display_mastering_luminance =
+		hdr_metadata->hdmi_metadata_type1.max_display_mastering_luminance;
+	frame->min_display_mastering_luminance =
+		hdr_metadata->hdmi_metadata_type1.min_display_mastering_luminance;
+	frame->max_fall = hdr_metadata->hdmi_metadata_type1.max_fall;
+	frame->max_cll = hdr_metadata->hdmi_metadata_type1.max_cll;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
+
+/* HDMI Colorspace Spec Definitions */
+#define FULL_COLORIMETRY_MASK		0x1FF
+#define NORMAL_COLORIMETRY_MASK		0x3
+#define EXTENDED_COLORIMETRY_MASK	0x7
+#define EXTENDED_ACE_COLORIMETRY_MASK	0xF
+
+#define C(x) ((x) << 0)
+#define EC(x) ((x) << 2)
+#define ACE(x) ((x) << 5)
+
+#define HDMI_COLORIMETRY_NO_DATA		0x0
+#define HDMI_COLORIMETRY_SMPTE_170M_YCC		(C(1) | EC(0) | ACE(0))
+#define HDMI_COLORIMETRY_BT709_YCC		(C(2) | EC(0) | ACE(0))
+#define HDMI_COLORIMETRY_XVYCC_601		(C(3) | EC(0) | ACE(0))
+#define HDMI_COLORIMETRY_XVYCC_709		(C(3) | EC(1) | ACE(0))
+#define HDMI_COLORIMETRY_SYCC_601		(C(3) | EC(2) | ACE(0))
+#define HDMI_COLORIMETRY_OPYCC_601		(C(3) | EC(3) | ACE(0))
+#define HDMI_COLORIMETRY_OPRGB			(C(3) | EC(4) | ACE(0))
+#define HDMI_COLORIMETRY_BT2020_CYCC		(C(3) | EC(5) | ACE(0))
+#define HDMI_COLORIMETRY_BT2020_RGB		(C(3) | EC(6) | ACE(0))
+#define HDMI_COLORIMETRY_BT2020_YCC		(C(3) | EC(6) | ACE(0))
+#define HDMI_COLORIMETRY_DCI_P3_RGB_D65		(C(3) | EC(7) | ACE(0))
+#define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER	(C(3) | EC(7) | ACE(1))
+
+static const u32 hdmi_colorimetry_val[] = {
+	[DRM_MODE_COLORIMETRY_NO_DATA] = HDMI_COLORIMETRY_NO_DATA,
+	[DRM_MODE_COLORIMETRY_SMPTE_170M_YCC] = HDMI_COLORIMETRY_SMPTE_170M_YCC,
+	[DRM_MODE_COLORIMETRY_BT709_YCC] = HDMI_COLORIMETRY_BT709_YCC,
+	[DRM_MODE_COLORIMETRY_XVYCC_601] = HDMI_COLORIMETRY_XVYCC_601,
+	[DRM_MODE_COLORIMETRY_XVYCC_709] = HDMI_COLORIMETRY_XVYCC_709,
+	[DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
+	[DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
+	[DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
+	[DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
+	[DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
+	[DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
+};
+
+#undef C
+#undef EC
+#undef ACE
+
+/**
+ * drm_hdmi_avi_infoframe_colorimetry() - fill the HDMI AVI infoframe
+ *                                       colorimetry information
+ * @frame: HDMI AVI infoframe
+ * @conn_state: connector state
+ */
+void drm_hdmi_avi_infoframe_colorimetry(struct hdmi_avi_infoframe *frame,
+					const struct drm_connector_state *conn_state)
+{
+	u32 colorimetry_val;
+	u32 colorimetry_index = conn_state->colorspace & FULL_COLORIMETRY_MASK;
+
+	if (colorimetry_index >= ARRAY_SIZE(hdmi_colorimetry_val))
+		colorimetry_val = HDMI_COLORIMETRY_NO_DATA;
+	else
+		colorimetry_val = hdmi_colorimetry_val[colorimetry_index];
+
+	frame->colorimetry = colorimetry_val & NORMAL_COLORIMETRY_MASK;
+	/*
+	 * ToDo: Extend it for ACE formats as well. Modify the infoframe
+	 * structure and extend it in drivers/video/hdmi
+	 */
+	frame->extended_colorimetry = (colorimetry_val >> 2) &
+					EXTENDED_COLORIMETRY_MASK;
+}
+EXPORT_SYMBOL(drm_hdmi_avi_infoframe_colorimetry);
+
+/**
+ * drm_hdmi_avi_infoframe_bars() - fill the HDMI AVI infoframe
+ *                                 bar information
+ * @frame: HDMI AVI infoframe
+ * @conn_state: connector state
+ */
+void drm_hdmi_avi_infoframe_bars(struct hdmi_avi_infoframe *frame,
+				 const struct drm_connector_state *conn_state)
+{
+	frame->right_bar = conn_state->tv.margins.right;
+	frame->left_bar = conn_state->tv.margins.left;
+	frame->top_bar = conn_state->tv.margins.top;
+	frame->bottom_bar = conn_state->tv.margins.bottom;
+}
+EXPORT_SYMBOL(drm_hdmi_avi_infoframe_bars);
+
+/**
+ * drm_hdmi_avi_infoframe_content_type() - fill the HDMI AVI infoframe
+ *                                         content type information, based
+ *                                         on correspondent DRM property.
+ * @frame: HDMI AVI infoframe
+ * @conn_state: DRM display connector state
+ *
+ */
+void drm_hdmi_avi_infoframe_content_type(struct hdmi_avi_infoframe *frame,
+					 const struct drm_connector_state *conn_state)
+{
+	switch (conn_state->content_type) {
+	case DRM_MODE_CONTENT_TYPE_GRAPHICS:
+		frame->content_type = HDMI_CONTENT_TYPE_GRAPHICS;
+		break;
+	case DRM_MODE_CONTENT_TYPE_CINEMA:
+		frame->content_type = HDMI_CONTENT_TYPE_CINEMA;
+		break;
+	case DRM_MODE_CONTENT_TYPE_GAME:
+		frame->content_type = HDMI_CONTENT_TYPE_GAME;
+		break;
+	case DRM_MODE_CONTENT_TYPE_PHOTO:
+		frame->content_type = HDMI_CONTENT_TYPE_PHOTO;
+		break;
+	default:
+		/* Graphics is the default(0) */
+		frame->content_type = HDMI_CONTENT_TYPE_GRAPHICS;
+	}
+
+	frame->itc = conn_state->content_type != DRM_MODE_CONTENT_TYPE_NO_DATA;
+}
+EXPORT_SYMBOL(drm_hdmi_avi_infoframe_content_type);
+
+/**
+ * drm_hdmi_compute_mode_clock() - Computes the TMDS Character Rate
+ * @mode: Display mode to compute the clock for
+ * @bpc: Bits per character
+ * @fmt: Output Pixel Format used
+ *
+ * Returns the TMDS Character Rate for a given mode, bpc count and output format.
+ *
+ * RETURNS:
+ * The TMDS Character Rate, in Hertz, or 0 on error.
+ */
+unsigned long long
+drm_hdmi_compute_mode_clock(const struct drm_display_mode *mode,
+			    unsigned int bpc,
+			    enum drm_output_color_format fmt)
+{
+	unsigned long long clock = mode->clock * 1000ULL;
+	unsigned int vic = drm_match_cea_mode(mode);
+
+	/*
+	 * CTA-861-G Spec, section 5.4 - Color Coding and Quantization
+	 * mandates that VIC 1 always uses 8 bpc.
+	 */
+	if (vic == 1 && bpc != 8)
+		return 0;
+
+	if (fmt == DRM_OUTPUT_COLOR_FORMAT_YCBCR422) {
+		/*
+		 * HDMI 1.0 Spec, section 6.5 - Pixel Encoding states that
+		 * YUV422 sends 24 bits over three channels, with Cb and Cr
+		 * components being sent on odd and even pixels, respectively.
+		 *
+		 * If fewer than 12 bpc are sent, data are left justified.
+		 */
+		if (bpc > 12)
+			return 0;
+
+		/*
+		 * HDMI 1.0 Spec, section 6.5 - Pixel Encoding
+		 * specifies that YUV422 sends two 12-bits components over
+		 * three TMDS channels per pixel clock, which is equivalent to
+		 * three 8-bits components over three channels used by RGB as
+		 * far as the clock rate goes.
+		 */
+		bpc = 8;
+	}
+
+	/*
+	 * HDMI 2.0 Spec, Section 7.1 - YCbCr 4:2:0 Pixel Encoding
+	 * specifies that YUV420 encoding is carried at a TMDS Character Rate
+	 * equal to half the pixel clock rate.
+	 */
+	if (fmt == DRM_OUTPUT_COLOR_FORMAT_YCBCR420)
+		clock = clock / 2;
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		clock = clock * 2;
+
+	return DIV_ROUND_CLOSEST_ULL(clock * bpc, 8);
+}
+EXPORT_SYMBOL(drm_hdmi_compute_mode_clock);
+
+struct drm_hdmi_acr_n_cts_entry {
+	unsigned int n;
+	unsigned int cts;
+};
+
+struct drm_hdmi_acr_data {
+	unsigned long tmds_clock_khz;
+	struct drm_hdmi_acr_n_cts_entry n_cts_32k,
+					n_cts_44k1,
+					n_cts_48k;
+};
+
+static const struct drm_hdmi_acr_data hdmi_acr_n_cts[] = {
+	{
+		/* "Other" entry */
+		.n_cts_32k =  { .n = 4096, },
+		.n_cts_44k1 = { .n = 6272, },
+		.n_cts_48k =  { .n = 6144, },
+	}, {
+		.tmds_clock_khz = 25175,
+		.n_cts_32k =  { .n = 4576,  .cts = 28125, },
+		.n_cts_44k1 = { .n = 7007,  .cts = 31250, },
+		.n_cts_48k =  { .n = 6864,  .cts = 28125, },
+	}, {
+		.tmds_clock_khz = 25200,
+		.n_cts_32k =  { .n = 4096,  .cts = 25200, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 28000, },
+		.n_cts_48k =  { .n = 6144,  .cts = 25200, },
+	}, {
+		.tmds_clock_khz = 27000,
+		.n_cts_32k =  { .n = 4096,  .cts = 27000, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 30000, },
+		.n_cts_48k =  { .n = 6144,  .cts = 27000, },
+	}, {
+		.tmds_clock_khz = 27027,
+		.n_cts_32k =  { .n = 4096,  .cts = 27027, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 30030, },
+		.n_cts_48k =  { .n = 6144,  .cts = 27027, },
+	}, {
+		.tmds_clock_khz = 54000,
+		.n_cts_32k =  { .n = 4096,  .cts = 54000, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 60000, },
+		.n_cts_48k =  { .n = 6144,  .cts = 54000, },
+	}, {
+		.tmds_clock_khz = 54054,
+		.n_cts_32k =  { .n = 4096,  .cts = 54054, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 60060, },
+		.n_cts_48k =  { .n = 6144,  .cts = 54054, },
+	}, {
+		.tmds_clock_khz = 74176,
+		.n_cts_32k =  { .n = 11648, .cts = 210937, }, /* and 210938 */
+		.n_cts_44k1 = { .n = 17836, .cts = 234375, },
+		.n_cts_48k =  { .n = 11648, .cts = 140625, },
+	}, {
+		.tmds_clock_khz = 74250,
+		.n_cts_32k =  { .n = 4096,  .cts = 74250, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 82500, },
+		.n_cts_48k =  { .n = 6144,  .cts = 74250, },
+	}, {
+		.tmds_clock_khz = 148352,
+		.n_cts_32k =  { .n = 11648, .cts = 421875, },
+		.n_cts_44k1 = { .n = 8918,  .cts = 234375, },
+		.n_cts_48k =  { .n = 5824,  .cts = 140625, },
+	}, {
+		.tmds_clock_khz = 148500,
+		.n_cts_32k =  { .n = 4096,  .cts = 148500, },
+		.n_cts_44k1 = { .n = 6272,  .cts = 165000, },
+		.n_cts_48k =  { .n = 6144,  .cts = 148500, },
+	}, {
+		.tmds_clock_khz = 296703,
+		.n_cts_32k =  { .n = 5824,  .cts = 421875, },
+		.n_cts_44k1 = { .n = 4459,  .cts = 234375, },
+		.n_cts_48k =  { .n = 5824,  .cts = 281250, },
+	}, {
+		.tmds_clock_khz = 297000,
+		.n_cts_32k =  { .n = 3072,  .cts = 222750, },
+		.n_cts_44k1 = { .n = 4704,  .cts = 247500, },
+		.n_cts_48k =  { .n = 5120,  .cts = 247500, },
+	}, {
+		.tmds_clock_khz = 593407,
+		.n_cts_32k =  { .n = 5824,  .cts = 843750, },
+		.n_cts_44k1 = { .n = 8918,  .cts = 937500, },
+		.n_cts_48k =  { .n = 5824,  .cts = 562500, },
+	}, {
+		.tmds_clock_khz = 594000,
+		.n_cts_32k =  { .n = 3072,  .cts = 445500, },
+		.n_cts_44k1 = { .n = 9408,  .cts = 990000, },
+		.n_cts_48k =  { .n = 6144,  .cts = 594000, },
+	},
+};
+
+static int drm_hdmi_acr_find_tmds_entry(unsigned long tmds_clock_khz)
+{
+	int i;
+
+	/* skip the "other" entry */
+	for (i = 1; i < ARRAY_SIZE(hdmi_acr_n_cts); i++) {
+		if (hdmi_acr_n_cts[i].tmds_clock_khz == tmds_clock_khz)
+			return i;
+	}
+
+	return 0;
+}
+
+/**
+ * drm_hdmi_acr_get_n_cts() - get N and CTS values for Audio Clock Regeneration
+ *
+ * @tmds_char_rate: TMDS clock (char rate) as used by the HDMI connector
+ * @sample_rate: audio sample rate
+ * @out_n: a pointer to write the N value
+ * @out_cts: a pointer to write the CTS value
+ *
+ * Get the N and CTS values (either by calculating them or by returning data
+ * from the tables. This follows the HDMI 1.4b Section 7.2 "Audio Sample Clock
+ * Capture and Regeneration".
+ *
+ * Note, @sample_rate corresponds to the Fs value, see sections 7.2.4 - 7.2.6
+ * on how to select Fs for non-L-PCM formats.
+ */
+void
+drm_hdmi_acr_get_n_cts(unsigned long long tmds_char_rate,
+		       unsigned int sample_rate,
+		       unsigned int *out_n,
+		       unsigned int *out_cts)
+{
+	/* be a bit more tolerant, especially for the 1.001 entries */
+	unsigned long tmds_clock_khz = DIV_ROUND_CLOSEST_ULL(tmds_char_rate, 1000);
+	const struct drm_hdmi_acr_n_cts_entry *entry;
+	unsigned int n, cts, mult;
+	int tmds_idx;
+
+	tmds_idx = drm_hdmi_acr_find_tmds_entry(tmds_clock_khz);
+
+	/*
+	 * Don't change the order, 192 kHz is divisible by 48k and 32k, but it
+	 * should use 48k entry.
+	 */
+	if (sample_rate % 48000 == 0) {
+		entry = &hdmi_acr_n_cts[tmds_idx].n_cts_48k;
+		mult = sample_rate / 48000;
+	} else if (sample_rate % 44100 == 0) {
+		entry = &hdmi_acr_n_cts[tmds_idx].n_cts_44k1;
+		mult = sample_rate / 44100;
+	} else if (sample_rate % 32000 == 0) {
+		entry = &hdmi_acr_n_cts[tmds_idx].n_cts_32k;
+		mult = sample_rate / 32000;
+	} else {
+		entry = NULL;
+	}
+
+	if (entry) {
+		n = entry->n * mult;
+		cts = entry->cts;
+	} else {
+		/* Recommended optimal value, HDMI 1.4b, Section 7.2.1 */
+		n = 128 * sample_rate / 1000;
+		cts = 0;
+	}
+
+	if (!cts)
+		cts = DIV_ROUND_CLOSEST_ULL(tmds_char_rate * n,
+					    128 * sample_rate);
+
+	*out_n = n;
+	*out_cts = cts;
+}
+EXPORT_SYMBOL(drm_hdmi_acr_get_n_cts);

linux-7.2.3/drivers/gpu/drm/display/drm_scdc_helper.c

@@ -0,0 +1,278 @@
+/*
+ * Copyright (c) 2015 NVIDIA Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <linux/export.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+#include <drm/display/drm_scdc_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+
+/**
+ * DOC: scdc helpers
+ *
+ * Status and Control Data Channel (SCDC) is a mechanism introduced by the
+ * HDMI 2.0 specification. It is a point-to-point protocol that allows the
+ * HDMI source and HDMI sink to exchange data. The same I2C interface that
+ * is used to access EDID serves as the transport mechanism for SCDC.
+ *
+ * Note: The SCDC status is going to be lost when the display is
+ * disconnected. This can happen physically when the user disconnects
+ * the cable, but also when a display is switched on (such as waking up
+ * a TV).
+ *
+ * This is further complicated by the fact that, upon a disconnection /
+ * reconnection, KMS won't change the mode on its own. This means that
+ * one can't just rely on setting the SCDC status on enable, but also
+ * has to track the connector status changes using interrupts and
+ * restore the SCDC status. The typical solution for this is to trigger an
+ * empty modeset in drm_connector_helper_funcs.detect_ctx(), like what vc4 does
+ * in vc4_hdmi_reset_link().
+ */
+
+#define SCDC_I2C_SLAVE_ADDRESS 0x54
+
+/**
+ * drm_scdc_read - read a block of data from SCDC
+ * @adapter: I2C controller
+ * @offset: start offset of block to read
+ * @buffer: return location for the block to read
+ * @size: size of the block to read
+ *
+ * Reads a block of data from SCDC, starting at a given offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure.
+ */
+ssize_t drm_scdc_read(struct i2c_adapter *adapter, u8 offset, void *buffer,
+		      size_t size)
+{
+	int ret;
+	struct i2c_msg msgs[2] = {
+		{
+			.addr = SCDC_I2C_SLAVE_ADDRESS,
+			.flags = 0,
+			.len = 1,
+			.buf = &offset,
+		}, {
+			.addr = SCDC_I2C_SLAVE_ADDRESS,
+			.flags = I2C_M_RD,
+			.len = size,
+			.buf = buffer,
+		}
+	};
+
+	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret < 0)
+		return ret;
+	if (ret != ARRAY_SIZE(msgs))
+		return -EPROTO;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_scdc_read);
+
+/**
+ * drm_scdc_write - write a block of data to SCDC
+ * @adapter: I2C controller
+ * @offset: start offset of block to write
+ * @buffer: block of data to write
+ * @size: size of the block to write
+ *
+ * Writes a block of data to SCDC, starting at a given offset.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure.
+ */
+ssize_t drm_scdc_write(struct i2c_adapter *adapter, u8 offset,
+		       const void *buffer, size_t size)
+{
+	struct i2c_msg msg = {
+		.addr = SCDC_I2C_SLAVE_ADDRESS,
+		.flags = 0,
+		.len = 1 + size,
+		.buf = NULL,
+	};
+	void *data;
+	int err;
+
+	data = kmalloc(1 + size, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	msg.buf = data;
+
+	memcpy(data, &offset, sizeof(offset));
+	memcpy(data + 1, buffer, size);
+
+	err = i2c_transfer(adapter, &msg, 1);
+
+	kfree(data);
+
+	if (err < 0)
+		return err;
+	if (err != 1)
+		return -EPROTO;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_scdc_write);
+
+/**
+ * drm_scdc_get_scrambling_status - what is status of scrambling?
+ * @connector: connector
+ *
+ * Reads the scrambler status over SCDC, and checks the
+ * scrambling status.
+ *
+ * Returns:
+ * True if the scrambling is enabled, false otherwise.
+ */
+bool drm_scdc_get_scrambling_status(struct drm_connector *connector)
+{
+	u8 status;
+	int ret;
+
+	ret = drm_scdc_readb(connector->ddc, SCDC_SCRAMBLER_STATUS, &status);
+	if (ret < 0) {
+		drm_dbg_kms(connector->dev,
+			    "[CONNECTOR:%d:%s] Failed to read scrambling status: %d\n",
+			    connector->base.id, connector->name, ret);
+		return false;
+	}
+
+	return status & SCDC_SCRAMBLING_STATUS;
+}
+EXPORT_SYMBOL(drm_scdc_get_scrambling_status);
+
+/**
+ * drm_scdc_set_scrambling - enable scrambling
+ * @connector: connector
+ * @enable: bool to indicate if scrambling is to be enabled/disabled
+ *
+ * Writes the TMDS config register over SCDC channel, and:
+ * enables scrambling when enable = 1
+ * disables scrambling when enable = 0
+ *
+ * Returns:
+ * True if scrambling is set/reset successfully, false otherwise.
+ */
+bool drm_scdc_set_scrambling(struct drm_connector *connector,
+			     bool enable)
+{
+	u8 config;
+	int ret;
+
+	ret = drm_scdc_readb(connector->ddc, SCDC_TMDS_CONFIG, &config);
+	if (ret < 0) {
+		drm_dbg_kms(connector->dev,
+			    "[CONNECTOR:%d:%s] Failed to read TMDS config: %d\n",
+			    connector->base.id, connector->name, ret);
+		return false;
+	}
+
+	if (enable)
+		config |= SCDC_SCRAMBLING_ENABLE;
+	else
+		config &= ~SCDC_SCRAMBLING_ENABLE;
+
+	ret = drm_scdc_writeb(connector->ddc, SCDC_TMDS_CONFIG, config);
+	if (ret < 0) {
+		drm_dbg_kms(connector->dev,
+			    "[CONNECTOR:%d:%s] Failed to enable scrambling: %d\n",
+			    connector->base.id, connector->name, ret);
+		return false;
+	}
+
+	return true;
+}
+EXPORT_SYMBOL(drm_scdc_set_scrambling);
+
+/**
+ * drm_scdc_set_high_tmds_clock_ratio - set TMDS clock ratio
+ * @connector: connector
+ * @set: ret or reset the high clock ratio
+ *
+ *
+ *	TMDS clock ratio calculations go like this:
+ *		TMDS character = 10 bit TMDS encoded value
+ *
+ *		TMDS character rate = The rate at which TMDS characters are
+ *		transmitted (Mcsc)
+ *
+ *		TMDS bit rate = 10x TMDS character rate
+ *
+ *	As per the spec:
+ *		TMDS clock rate for pixel clock < 340 MHz = 1x the character
+ *		rate = 1/10 pixel clock rate
+ *
+ *		TMDS clock rate for pixel clock > 340 MHz = 0.25x the character
+ *		rate = 1/40 pixel clock rate
+ *
+ *	Writes to the TMDS config register over SCDC channel, and:
+ *		sets TMDS clock ratio to 1/40 when set = 1
+ *
+ *		sets TMDS clock ratio to 1/10 when set = 0
+ *
+ * Returns:
+ * True if write is successful, false otherwise.
+ */
+bool drm_scdc_set_high_tmds_clock_ratio(struct drm_connector *connector,
+					bool set)
+{
+	u8 config;
+	int ret;
+
+	ret = drm_scdc_readb(connector->ddc, SCDC_TMDS_CONFIG, &config);
+	if (ret < 0) {
+		drm_dbg_kms(connector->dev,
+			    "[CONNECTOR:%d:%s] Failed to read TMDS config: %d\n",
+			    connector->base.id, connector->name, ret);
+		return false;
+	}
+
+	if (set)
+		config |= SCDC_TMDS_BIT_CLOCK_RATIO_BY_40;
+	else
+		config &= ~SCDC_TMDS_BIT_CLOCK_RATIO_BY_40;
+
+	ret = drm_scdc_writeb(connector->ddc, SCDC_TMDS_CONFIG, config);
+	if (ret < 0) {
+		drm_dbg_kms(connector->dev,
+			    "[CONNECTOR:%d:%s] Failed to set TMDS clock ratio: %d\n",
+			    connector->base.id, connector->name, ret);
+		return false;
+	}
+
+	/*
+	 * The spec says that a source should wait minimum 1ms and maximum
+	 * 100ms after writing the TMDS config for clock ratio. Lets allow a
+	 * wait of up to 2ms here.
+	 */
+	usleep_range(1000, 2000);
+	return true;
+}
+EXPORT_SYMBOL(drm_scdc_set_high_tmds_clock_ratio);