drivers/gpu/drm/drm_sysfs.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only

 /*
  * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
  *               extra sysfs attribute from DRM. Normal drm_sysfs_class
  *               does not allow adding attributes.
  *
  * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
  * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
  * Copyright (c) 2003-2004 IBM Corp.
  */

 #include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <linux/i2c.h>
 #include <linux/kdev_t.h>
 #include <linux/slab.h>

 #include <drm/drm_connector.h>
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>
 #include <drm/drm_modes.h>
 #include <drm/drm_print.h>
 #include <drm/drm_property.h>
 #include <drm/drm_sysfs.h>

 #include "drm_internal.h"
 #include "drm_crtc_internal.h"

 #define to_drm_minor(d) dev_get_drvdata(d)
 #define to_drm_connector(d) dev_get_drvdata(d)

 /**
  * DOC: overview
  *
  * DRM provides very little additional support to drivers for sysfs
  * interactions, beyond just all the standard stuff. Drivers who want to expose
  * additional sysfs properties and property groups can attach them at either
  * &drm_device.dev or &drm_connector.kdev.
  *
  * Registration is automatically handled when calling drm_dev_register(), or
  * drm_connector_register() in case of hot-plugged connectors. Unregistration is
  * also automatically handled by drm_dev_unregister() and
  * drm_connector_unregister().
  */

 static struct device_type drm_sysfs_device_minor = {
 	.name = "drm_minor"
 };

 static struct device_type drm_sysfs_device_connector = {
 	.name = "drm_connector",
 };

 struct class *drm_class;

 #ifdef CONFIG_ACPI
 static bool drm_connector_acpi_bus_match(struct device *dev)
 {
 	return dev->type == &drm_sysfs_device_connector;
 }

 static struct acpi_device *drm_connector_acpi_find_companion(struct device *dev)
 {
 	struct drm_connector *connector = to_drm_connector(dev);

 	return to_acpi_device_node(connector->fwnode);
 }

 static struct acpi_bus_type drm_connector_acpi_bus = {
 	.name = "drm_connector",
 	.match = drm_connector_acpi_bus_match,
 	.find_companion = drm_connector_acpi_find_companion,
 };

 static void drm_sysfs_acpi_register(void)
 {
 	register_acpi_bus_type(&drm_connector_acpi_bus);
 }

 static void drm_sysfs_acpi_unregister(void)
 {
 	unregister_acpi_bus_type(&drm_connector_acpi_bus);
 }
 #else
 static void drm_sysfs_acpi_register(void) { }
 static void drm_sysfs_acpi_unregister(void) { }
 #endif

 static char *drm_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
 }

 static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");

 /**
  * drm_sysfs_init - initialize sysfs helpers
  *
  * This is used to create the DRM class, which is the implicit parent of any
  * other top-level DRM sysfs objects.
  *
  * You must call drm_sysfs_destroy() to release the allocated resources.
  *
  * Return: 0 on success, negative error code on failure.
  */
 int drm_sysfs_init(void)
 {
 	int err;

 	drm_class = class_create(THIS_MODULE, "drm");
 	if (IS_ERR(drm_class))
 		return PTR_ERR(drm_class);

 	err = class_create_file(drm_class, &class_attr_version.attr);
 	if (err) {
 		class_destroy(drm_class);
 		drm_class = NULL;
 		return err;
 	}

 	drm_class->devnode = drm_devnode;

 	drm_sysfs_acpi_register();
 	return 0;
 }

 /**
  * drm_sysfs_destroy - destroys DRM class
  *
  * Destroy the DRM device class.
  */
 void drm_sysfs_destroy(void)
 {
 	if (IS_ERR_OR_NULL(drm_class))
 		return;
 	drm_sysfs_acpi_unregister();
 	class_remove_file(drm_class, &class_attr_version.attr);
 	class_destroy(drm_class);
 	drm_class = NULL;
 }

 static void drm_sysfs_release(struct device *dev)
 {
 	kfree(dev);
 }

 /*
  * Connector properties
  */
 static ssize_t status_store(struct device *device,
 			   struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
 	struct drm_connector *connector = to_drm_connector(device);
 	struct drm_device *dev = connector->dev;
 	enum drm_connector_force old_force;
 	int ret;

 	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
 	if (ret)
 		return ret;

 	old_force = connector->force;

 	if (sysfs_streq(buf, "detect"))
 		connector->force = 0;
 	else if (sysfs_streq(buf, "on"))
 		connector->force = DRM_FORCE_ON;
 	else if (sysfs_streq(buf, "on-digital"))
 		connector->force = DRM_FORCE_ON_DIGITAL;
 	else if (sysfs_streq(buf, "off"))
 		connector->force = DRM_FORCE_OFF;
 	else
 		ret = -EINVAL;

 	if (old_force != connector->force || !connector->force) {
 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
 			      connector->base.id,
 			      connector->name,
 			      old_force, connector->force);

 		connector->funcs->fill_modes(connector,
 					     dev->mode_config.max_width,
 					     dev->mode_config.max_height);
 	}

 	mutex_unlock(&dev->mode_config.mutex);

 	return ret ? ret : count;
 }

 static ssize_t status_show(struct device *device,
 			   struct device_attribute *attr,
 			   char *buf)
 {
 	struct drm_connector *connector = to_drm_connector(device);
 	enum drm_connector_status status;

 	status = READ_ONCE(connector->status);

 	return sysfs_emit(buf, "%s\n",
 			  drm_get_connector_status_name(status));
 }

 static ssize_t dpms_show(struct device *device,
 			   struct device_attribute *attr,
 			   char *buf)
 {
 	struct drm_connector *connector = to_drm_connector(device);
 	int dpms;

 	dpms = READ_ONCE(connector->dpms);

 	return sysfs_emit(buf, "%s\n", drm_get_dpms_name(dpms));
 }

 static ssize_t enabled_show(struct device *device,
 			    struct device_attribute *attr,
 			   char *buf)
 {
 	struct drm_connector *connector = to_drm_connector(device);
 	bool enabled;

 	enabled = READ_ONCE(connector->encoder);

 	return sysfs_emit(buf, enabled ? "enabled\n" : "disabled\n");
 }

 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 			 struct bin_attribute *attr, char *buf, loff_t off,
 			 size_t count)
 {
 	struct device *connector_dev = kobj_to_dev(kobj);
 	struct drm_connector *connector = to_drm_connector(connector_dev);
 	unsigned char *edid;
 	size_t size;
 	ssize_t ret = 0;

 	mutex_lock(&connector->dev->mode_config.mutex);
 	if (!connector->edid_blob_ptr)
 		goto unlock;

 	edid = connector->edid_blob_ptr->data;
 	size = connector->edid_blob_ptr->length;
 	if (!edid)
 		goto unlock;

 	if (off >= size)
 		goto unlock;

 	if (off + count > size)
 		count = size - off;
 	memcpy(buf, edid + off, count);

 	ret = count;
 unlock:
 	mutex_unlock(&connector->dev->mode_config.mutex);

 	return ret;
 }

 static ssize_t modes_show(struct device *device,
 			   struct device_attribute *attr,
 			   char *buf)
 {
 	struct drm_connector *connector = to_drm_connector(device);
 	struct drm_display_mode *mode;
 	int written = 0;

 	mutex_lock(&connector->dev->mode_config.mutex);
 	list_for_each_entry(mode, &connector->modes, head) {
 		written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
 				    mode->name);
 	}
 	mutex_unlock(&connector->dev->mode_config.mutex);

 	return written;
 }

 static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(enabled);
 static DEVICE_ATTR_RO(dpms);
 static DEVICE_ATTR_RO(modes);

 static struct attribute *connector_dev_attrs[] = {
 	&dev_attr_status.attr,
 	&dev_attr_enabled.attr,
 	&dev_attr_dpms.attr,
 	&dev_attr_modes.attr,
 	NULL
 };

 static struct bin_attribute edid_attr = {
 	.attr.name = "edid",
 	.attr.mode = 0444,
 	.size = 0,
 	.read = edid_show,
 };

 static struct bin_attribute *connector_bin_attrs[] = {
 	&edid_attr,
 	NULL
 };

 static const struct attribute_group connector_dev_group = {
 	.attrs = connector_dev_attrs,
 	.bin_attrs = connector_bin_attrs,
 };

 static const struct attribute_group *connector_dev_groups[] = {
 	&connector_dev_group,
 	NULL
 };

 int drm_sysfs_connector_add(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
 	struct device *kdev;
 	int r;

 	if (connector->kdev)
 		return 0;

 	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 	if (!kdev)
 		return -ENOMEM;

 	device_initialize(kdev);
 	kdev->class = drm_class;
 	kdev->type = &drm_sysfs_device_connector;
 	kdev->parent = dev->primary->kdev;
 	kdev->groups = connector_dev_groups;
 	kdev->release = drm_sysfs_release;
 	dev_set_drvdata(kdev, connector);

 	r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
 	if (r)
 		goto err_free;

 	DRM_DEBUG("adding \"%s\" to sysfs\n",
 		  connector->name);

 	r = device_add(kdev);
 	if (r) {
 		drm_err(dev, "failed to register connector device: %d\n", r);
 		goto err_free;
 	}

 	connector->kdev = kdev;

 	if (connector->ddc)
 		return sysfs_create_link(&connector->kdev->kobj,
 				 &connector->ddc->dev.kobj, "ddc");
 	return 0;

 err_free:
 	put_device(kdev);
 	return r;
 }

 void drm_sysfs_connector_remove(struct drm_connector *connector)
 {
 	if (!connector->kdev)
 		return;

 	if (connector->ddc)
 		sysfs_remove_link(&connector->kdev->kobj, "ddc");

 	DRM_DEBUG("removing \"%s\" from sysfs\n",
 		  connector->name);

 	device_unregister(connector->kdev);
 	connector->kdev = NULL;
 }

 void drm_sysfs_lease_event(struct drm_device *dev)
 {
 	char *event_string = "LEASE=1";
 	char *envp[] = { event_string, NULL };

 	DRM_DEBUG("generating lease event\n");

 	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 }

 /**
  * drm_sysfs_hotplug_event - generate a DRM uevent
  * @dev: DRM device
  *
  * Send a uevent for the DRM device specified by @dev.  Currently we only
  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
  * deal with other types of events.
  *
  * Any new uapi should be using the drm_sysfs_connector_status_event()
  * for uevents on connector status change.
  */
 void drm_sysfs_hotplug_event(struct drm_device *dev)
 {
 	char *event_string = "HOTPLUG=1";
 	char *envp[] = { event_string, NULL };

 	DRM_DEBUG("generating hotplug event\n");

 	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 }
 EXPORT_SYMBOL(drm_sysfs_hotplug_event);

 /**
  * drm_sysfs_connector_status_event - generate a DRM uevent for connector
  * property status change
  * @connector: connector on which property status changed
  * @property: connector property whose status changed.
  *
  * Send a uevent for the DRM device specified by @dev.  Currently we
  * set HOTPLUG=1 and connector id along with the attached property id
  * related to the status change.
  */
 void drm_sysfs_connector_status_event(struct drm_connector *connector,
 				      struct drm_property *property)
 {
 	struct drm_device *dev = connector->dev;
 	char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
 	char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };

 	WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
 					   property->base.id));

 	snprintf(conn_id, ARRAY_SIZE(conn_id),
 		 "CONNECTOR=%u", connector->base.id);
 	snprintf(prop_id, ARRAY_SIZE(prop_id),
 		 "PROPERTY=%u", property->base.id);

 	DRM_DEBUG("generating connector status event\n");

 	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 }
 EXPORT_SYMBOL(drm_sysfs_connector_status_event);

 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 {
 	const char *minor_str;
 	struct device *kdev;
 	int r;

 	if (minor->type == DRM_MINOR_RENDER)
 		minor_str = "renderD%d";
 	else
 		minor_str = "card%d";

 	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 	if (!kdev)
 		return ERR_PTR(-ENOMEM);

 	device_initialize(kdev);
 	kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 	kdev->class = drm_class;
 	kdev->type = &drm_sysfs_device_minor;
 	kdev->parent = minor->dev->dev;
 	kdev->release = drm_sysfs_release;
 	dev_set_drvdata(kdev, minor);

 	r = dev_set_name(kdev, minor_str, minor->index);
 	if (r < 0)
 		goto err_free;

 	return kdev;

 err_free:
 	put_device(kdev);
 	return ERR_PTR(r);
 }

 /**
  * drm_class_device_register - register new device with the DRM sysfs class
  * @dev: device to register
  *
  * Registers a new &struct device within the DRM sysfs class. Essentially only
  * used by ttm to have a place for its global settings. Drivers should never use
  * this.
  */
 int drm_class_device_register(struct device *dev)
 {
 	if (!drm_class || IS_ERR(drm_class))
 		return -ENOENT;

 	dev->class = drm_class;
 	return device_register(dev);
 }
 EXPORT_SYMBOL_GPL(drm_class_device_register);

 /**
  * drm_class_device_unregister - unregister device with the DRM sysfs class
  * @dev: device to unregister
  *
  * Unregisters a &struct device from the DRM sysfs class. Essentially only used
  * by ttm to have a place for its global settings. Drivers should never use
  * this.
  */
 void drm_class_device_unregister(struct device *dev)
 {
 	return device_unregister(dev);
 }
 EXPORT_SYMBOL_GPL(drm_class_device_unregister);
	// SPDX-License-Identifier: GPL-2.0-only

	/*
	* drm_sysfs.c - Modifications to drm_sysfs_class.c to support
	* extra sysfs attribute from DRM. Normal drm_sysfs_class
	* does not allow adding attributes.
	*
	* Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
	* Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
	* Copyright (c) 2003-2004 IBM Corp.
	*/

	#include <linux/acpi.h>
	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/export.h>
	#include <linux/gfp.h>
	#include <linux/i2c.h>
	#include <linux/kdev_t.h>
	#include <linux/slab.h>

	#include <drm/drm_connector.h>
	#include <drm/drm_device.h>
	#include <drm/drm_file.h>
	#include <drm/drm_modes.h>
	#include <drm/drm_print.h>
	#include <drm/drm_property.h>
	#include <drm/drm_sysfs.h>

	#include "drm_internal.h"
	#include "drm_crtc_internal.h"

	#define to_drm_minor(d) dev_get_drvdata(d)
	#define to_drm_connector(d) dev_get_drvdata(d)

	/**
	* DOC: overview
	*
	* DRM provides very little additional support to drivers for sysfs
	* interactions, beyond just all the standard stuff. Drivers who want to expose
	* additional sysfs properties and property groups can attach them at either
	* &drm_device.dev or &drm_connector.kdev.
	*
	* Registration is automatically handled when calling drm_dev_register(), or
	* drm_connector_register() in case of hot-plugged connectors. Unregistration is
	* also automatically handled by drm_dev_unregister() and
	* drm_connector_unregister().
	*/

	static struct device_type drm_sysfs_device_minor = {
	.name = "drm_minor"
	};

	static struct device_type drm_sysfs_device_connector = {
	.name = "drm_connector",
	};

	struct class *drm_class;

	#ifdef CONFIG_ACPI
	static bool drm_connector_acpi_bus_match(struct device *dev)
	{
	return dev->type == &drm_sysfs_device_connector;
	}

	static struct acpi_device drm_connector_acpi_find_companion(struct device dev)
	{
	struct drm_connector *connector = to_drm_connector(dev);

	return to_acpi_device_node(connector->fwnode);
	}

	static struct acpi_bus_type drm_connector_acpi_bus = {
	.name = "drm_connector",
	.match = drm_connector_acpi_bus_match,
	.find_companion = drm_connector_acpi_find_companion,
	};

	static void drm_sysfs_acpi_register(void)
	{
	register_acpi_bus_type(&drm_connector_acpi_bus);
	}

	static void drm_sysfs_acpi_unregister(void)
	{
	unregister_acpi_bus_type(&drm_connector_acpi_bus);
	}
	#else
	static void drm_sysfs_acpi_register(void) { }
	static void drm_sysfs_acpi_unregister(void) { }
	#endif

	static char drm_devnode(struct device dev, umode_t *mode)
	{
	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
	}

	static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");

	/**
	* drm_sysfs_init - initialize sysfs helpers
	*
	* This is used to create the DRM class, which is the implicit parent of any
	* other top-level DRM sysfs objects.
	*
	* You must call drm_sysfs_destroy() to release the allocated resources.
	*
	* Return: 0 on success, negative error code on failure.
	*/
	int drm_sysfs_init(void)
	{
	int err;

	drm_class = class_create(THIS_MODULE, "drm");
	if (IS_ERR(drm_class))
	return PTR_ERR(drm_class);

	err = class_create_file(drm_class, &class_attr_version.attr);
	if (err) {
	class_destroy(drm_class);
	drm_class = NULL;
	return err;
	}

	drm_class->devnode = drm_devnode;

	drm_sysfs_acpi_register();
	return 0;
	}

	/**
	* drm_sysfs_destroy - destroys DRM class
	*
	* Destroy the DRM device class.
	*/
	void drm_sysfs_destroy(void)
	{
	if (IS_ERR_OR_NULL(drm_class))
	return;
	drm_sysfs_acpi_unregister();
	class_remove_file(drm_class, &class_attr_version.attr);
	class_destroy(drm_class);
	drm_class = NULL;
	}

	static void drm_sysfs_release(struct device *dev)
	{
	kfree(dev);
	}

	/*
	* Connector properties
	*/
	static ssize_t status_store(struct device *device,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct drm_connector *connector = to_drm_connector(device);
	struct drm_device *dev = connector->dev;
	enum drm_connector_force old_force;
	int ret;

	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
	if (ret)
	return ret;

	old_force = connector->force;

	if (sysfs_streq(buf, "detect"))
	connector->force = 0;
	else if (sysfs_streq(buf, "on"))
	connector->force = DRM_FORCE_ON;
	else if (sysfs_streq(buf, "on-digital"))
	connector->force = DRM_FORCE_ON_DIGITAL;
	else if (sysfs_streq(buf, "off"))
	connector->force = DRM_FORCE_OFF;
	else
	ret = -EINVAL;

	if (old_force != connector->force \|\| !connector->force) {
	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
	connector->base.id,
	connector->name,
	old_force, connector->force);

	connector->funcs->fill_modes(connector,
	dev->mode_config.max_width,
	dev->mode_config.max_height);
	}

	mutex_unlock(&dev->mode_config.mutex);

	return ret ? ret : count;
	}

	static ssize_t status_show(struct device *device,
	struct device_attribute *attr,
	char *buf)
	{
	struct drm_connector *connector = to_drm_connector(device);
	enum drm_connector_status status;

	status = READ_ONCE(connector->status);

	return sysfs_emit(buf, "%s\n",
	drm_get_connector_status_name(status));
	}

	static ssize_t dpms_show(struct device *device,
	struct device_attribute *attr,
	char *buf)
	{
	struct drm_connector *connector = to_drm_connector(device);
	int dpms;

	dpms = READ_ONCE(connector->dpms);

	return sysfs_emit(buf, "%s\n", drm_get_dpms_name(dpms));
	}

	static ssize_t enabled_show(struct device *device,
	struct device_attribute *attr,
	char *buf)
	{
	struct drm_connector *connector = to_drm_connector(device);
	bool enabled;

	enabled = READ_ONCE(connector->encoder);

	return sysfs_emit(buf, enabled ? "enabled\n" : "disabled\n");
	}

	static ssize_t edid_show(struct file filp, struct kobject kobj,
	struct bin_attribute attr, char buf, loff_t off,
	size_t count)
	{
	struct device *connector_dev = kobj_to_dev(kobj);
	struct drm_connector *connector = to_drm_connector(connector_dev);
	unsigned char *edid;
	size_t size;
	ssize_t ret = 0;

	mutex_lock(&connector->dev->mode_config.mutex);
	if (!connector->edid_blob_ptr)
	goto unlock;

	edid = connector->edid_blob_ptr->data;
	size = connector->edid_blob_ptr->length;
	if (!edid)
	goto unlock;

	if (off >= size)
	goto unlock;

	if (off + count > size)
	count = size - off;
	memcpy(buf, edid + off, count);

	ret = count;
	unlock:
	mutex_unlock(&connector->dev->mode_config.mutex);

	return ret;
	}

	static ssize_t modes_show(struct device *device,
	struct device_attribute *attr,
	char *buf)
	{
	struct drm_connector *connector = to_drm_connector(device);
	struct drm_display_mode *mode;
	int written = 0;

	mutex_lock(&connector->dev->mode_config.mutex);
	list_for_each_entry(mode, &connector->modes, head) {
	written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
	mode->name);
	}
	mutex_unlock(&connector->dev->mode_config.mutex);

	return written;
	}

	static DEVICE_ATTR_RW(status);
	static DEVICE_ATTR_RO(enabled);
	static DEVICE_ATTR_RO(dpms);
	static DEVICE_ATTR_RO(modes);

	static struct attribute *connector_dev_attrs[] = {
	&dev_attr_status.attr,
	&dev_attr_enabled.attr,
	&dev_attr_dpms.attr,
	&dev_attr_modes.attr,
	NULL
	};

	static struct bin_attribute edid_attr = {
	.attr.name = "edid",
	.attr.mode = 0444,
	.size = 0,
	.read = edid_show,
	};

	static struct bin_attribute *connector_bin_attrs[] = {
	&edid_attr,
	NULL
	};

	static const struct attribute_group connector_dev_group = {
	.attrs = connector_dev_attrs,
	.bin_attrs = connector_bin_attrs,
	};

	static const struct attribute_group *connector_dev_groups[] = {
	&connector_dev_group,
	NULL
	};

	int drm_sysfs_connector_add(struct drm_connector *connector)
	{
	struct drm_device *dev = connector->dev;
	struct device *kdev;
	int r;

	if (connector->kdev)
	return 0;

	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
	if (!kdev)
	return -ENOMEM;

	device_initialize(kdev);
	kdev->class = drm_class;
	kdev->type = &drm_sysfs_device_connector;
	kdev->parent = dev->primary->kdev;
	kdev->groups = connector_dev_groups;
	kdev->release = drm_sysfs_release;
	dev_set_drvdata(kdev, connector);

	r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
	if (r)
	goto err_free;

	DRM_DEBUG("adding \"%s\" to sysfs\n",
	connector->name);

	r = device_add(kdev);
	if (r) {
	drm_err(dev, "failed to register connector device: %d\n", r);
	goto err_free;
	}

	connector->kdev = kdev;

	if (connector->ddc)
	return sysfs_create_link(&connector->kdev->kobj,
	&connector->ddc->dev.kobj, "ddc");
	return 0;

	err_free:
	put_device(kdev);
	return r;
	}

	void drm_sysfs_connector_remove(struct drm_connector *connector)
	{
	if (!connector->kdev)
	return;

	if (connector->ddc)
	sysfs_remove_link(&connector->kdev->kobj, "ddc");

	DRM_DEBUG("removing \"%s\" from sysfs\n",
	connector->name);

	device_unregister(connector->kdev);
	connector->kdev = NULL;
	}

	void drm_sysfs_lease_event(struct drm_device *dev)
	{
	char *event_string = "LEASE=1";
	char *envp[] = { event_string, NULL };

	DRM_DEBUG("generating lease event\n");

	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
	}

	/**
	* drm_sysfs_hotplug_event - generate a DRM uevent
	* @dev: DRM device
	*
	* Send a uevent for the DRM device specified by @dev. Currently we only
	* set HOTPLUG=1 in the uevent environment, but this could be expanded to
	* deal with other types of events.
	*
	* Any new uapi should be using the drm_sysfs_connector_status_event()
	* for uevents on connector status change.
	*/
	void drm_sysfs_hotplug_event(struct drm_device *dev)
	{
	char *event_string = "HOTPLUG=1";
	char *envp[] = { event_string, NULL };

	DRM_DEBUG("generating hotplug event\n");

	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
	}
	EXPORT_SYMBOL(drm_sysfs_hotplug_event);

	/**
	* drm_sysfs_connector_status_event - generate a DRM uevent for connector
	* property status change
	* @connector: connector on which property status changed
	* @property: connector property whose status changed.
	*
	* Send a uevent for the DRM device specified by @dev. Currently we
	* set HOTPLUG=1 and connector id along with the attached property id
	* related to the status change.
	*/
	void drm_sysfs_connector_status_event(struct drm_connector *connector,
	struct drm_property *property)
	{
	struct drm_device *dev = connector->dev;
	char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
	char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };

	WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
	property->base.id));

	snprintf(conn_id, ARRAY_SIZE(conn_id),
	"CONNECTOR=%u", connector->base.id);
	snprintf(prop_id, ARRAY_SIZE(prop_id),
	"PROPERTY=%u", property->base.id);

	DRM_DEBUG("generating connector status event\n");

	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
	}
	EXPORT_SYMBOL(drm_sysfs_connector_status_event);

	struct device drm_sysfs_minor_alloc(struct drm_minor minor)
	{
	const char *minor_str;
	struct device *kdev;
	int r;

	if (minor->type == DRM_MINOR_RENDER)
	minor_str = "renderD%d";
	else
	minor_str = "card%d";

	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
	if (!kdev)
	return ERR_PTR(-ENOMEM);

	device_initialize(kdev);
	kdev->devt = MKDEV(DRM_MAJOR, minor->index);
	kdev->class = drm_class;
	kdev->type = &drm_sysfs_device_minor;
	kdev->parent = minor->dev->dev;
	kdev->release = drm_sysfs_release;
	dev_set_drvdata(kdev, minor);

	r = dev_set_name(kdev, minor_str, minor->index);
	if (r < 0)
	goto err_free;

	return kdev;

	err_free:
	put_device(kdev);
	return ERR_PTR(r);
	}

	/**
	* drm_class_device_register - register new device with the DRM sysfs class
	* @dev: device to register
	*
	* Registers a new &struct device within the DRM sysfs class. Essentially only
	* used by ttm to have a place for its global settings. Drivers should never use
	* this.
	*/
	int drm_class_device_register(struct device *dev)
	{
	if (!drm_class \|\| IS_ERR(drm_class))
	return -ENOENT;

	dev->class = drm_class;
	return device_register(dev);
	}
	EXPORT_SYMBOL_GPL(drm_class_device_register);

	/**
	* drm_class_device_unregister - unregister device with the DRM sysfs class
	* @dev: device to unregister
	*
	* Unregisters a &struct device from the DRM sysfs class. Essentially only used
	* by ttm to have a place for its global settings. Drivers should never use
	* this.
	*/
	void drm_class_device_unregister(struct device *dev)
	{
	return device_unregister(dev);
	}
	EXPORT_SYMBOL_GPL(drm_class_device_unregister);