text: /*
   * Copyright (c) 2016 Intel Corporation
   *
   * Permission to use, copy, modify, distribute, and sell this software and its
   * documentation for any purpose is hereby granted without fee, provided that
   * the above copyright notice appear in all copies and that both that copyright
   * notice and this permission notice appear in supporting documentation, and
   * that the name of the copyright holders not be used in advertising or
   * publicity pertaining to distribution of the software without specific,
   * written prior permission.  The copyright holders make no representations
   * about the suitability of this software for any purpose.  It is provided "as
   * is" without express or implied warranty.
   *
   * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
   * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
   * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
   * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
   * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   * OF THIS SOFTWARE.
   */
  
  #include <drm/drmP.h>
  #include <drm/drm_connector.h>
  #include <drm/drm_edid.h>
  #include <drm/drm_encoder.h>
  
  #include "drm_crtc_internal.h"
  #include "drm_internal.h"
  
  /**
   * DOC: overview
   *
   * In DRM connectors are the general abstraction for display sinks, and include
   * als fixed panels or anything else that can display pixels in some form. As
   * opposed to all other KMS objects representing hardware (like CRTC, encoder or
   * plane abstractions) connectors can be hotplugged and unplugged at runtime.
   * Hence they are reference-counted using drm_connector_get() and
   * drm_connector_put().
   *
   * KMS driver must create, initialize, register and attach at a &struct
   * drm_connector for each such sink. The instance is created as other KMS
   * objects and initialized by setting the following fields. The connector is
   * initialized with a call to drm_connector_init() with a pointer to the
   * &struct drm_connector_funcs and a connector type, and then exposed to
   * userspace with a call to drm_connector_register().
   *
   * Connectors must be attached to an encoder to be used. For devices that map
   * connectors to encoders 1:1, the connector should be attached at
   * initialization time with a call to drm_mode_connector_attach_encoder(). The
   * driver must also set the &drm_connector.encoder field to point to the
   * attached encoder.
   *
   * For connectors which are not fixed (like built-in panels) the driver needs to
   * support hotplug notifications. The simplest way to do that is by using the
   * probe helpers, see drm_kms_helper_poll_init() for connectors which don't have
   * hardware support for hotplug interrupts. Connectors with hardware hotplug
   * support can instead use e.g. drm_helper_hpd_irq_event().
   */
  
  struct drm_conn_prop_enum_list {
  	int type;
  	const char *name;
  	struct ida ida;
  };
  
  /*
   * Connector and encoder types.
   */
  static struct drm_conn_prop_enum_list drm_connector_enum_list[] = {
  	{ DRM_MODE_CONNECTOR_Unknown, "Unknown" },
  	{ DRM_MODE_CONNECTOR_VGA, "VGA" },
  	{ DRM_MODE_CONNECTOR_DVII, "DVI-I" },
  	{ DRM_MODE_CONNECTOR_DVID, "DVI-D" },
  	{ DRM_MODE_CONNECTOR_DVIA, "DVI-A" },
  	{ DRM_MODE_CONNECTOR_Composite, "Composite" },
  	{ DRM_MODE_CONNECTOR_SVIDEO, "SVIDEO" },
  	{ DRM_MODE_CONNECTOR_LVDS, "LVDS" },
  	{ DRM_MODE_CONNECTOR_Component, "Component" },
  	{ DRM_MODE_CONNECTOR_9PinDIN, "DIN" },
  	{ DRM_MODE_CONNECTOR_DisplayPort, "DP" },
  	{ DRM_MODE_CONNECTOR_HDMIA, "HDMI-A" },
  	{ DRM_MODE_CONNECTOR_HDMIB, "HDMI-B" },
  	{ DRM_MODE_CONNECTOR_TV, "TV" },
  	{ DRM_MODE_CONNECTOR_eDP, "eDP" },
  	{ DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },
  	{ DRM_MODE_CONNECTOR_DSI, "DSI" },
  	{ DRM_MODE_CONNECTOR_DPI, "DPI" },
  };
  
  void drm_connector_ida_init(void)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
  		ida_init(&drm_connector_enum_list[i].ida);
  }
  
  void drm_connector_ida_destroy(void)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
  		ida_destroy(&drm_connector_enum_list[i].ida);
  }
  
  /**
   * drm_connector_get_cmdline_mode - reads the user's cmdline mode
   * @connector: connector to quwery
   *
   * The kernel supports per-connector configuration of its consoles through
   * use of the video= parameter. This function parses that option and
   * extracts the user's specified mode (or enable/disable status) for a
   * particular connector. This is typically only used during the early fbdev
   * setup.
   */
  static void drm_connector_get_cmdline_mode(struct drm_connector *connector)
  {
  	struct drm_cmdline_mode *mode = &connector->cmdline_mode;
  	char *option = NULL;
  
  	if (fb_get_options(connector->name, &option))
  		return;
  
  	if (!drm_mode_parse_command_line_for_connector(option,
  						       connector,
  						       mode))
  		return;
  
  	if (mode->force) {
  		DRM_INFO("forcing %s connector %s\n", connector->name,
  			 drm_get_connector_force_name(mode->force));
  		connector->force = mode->force;
  	}
  
  	DRM_DEBUG_KMS("cmdline mode for connector %s %dx%d@%dHz%s%s%s\n",
  		      connector->name,
  		      mode->xres, mode->yres,
  		      mode->refresh_specified ? mode->refresh : 60,
  		      mode->rb ? " reduced blanking" : "",
  		      mode->margins ? " with margins" : "",
  		      mode->interlace ?  " interlaced" : "");
  }
  
  static void drm_connector_free(struct kref *kref)
  {
  	struct drm_connector *connector =
  		container_of(kref, struct drm_connector, base.refcount);
  	struct drm_device *dev = connector->dev;
  
  	drm_mode_object_unregister(dev, &connector->base);
  	connector->funcs->destroy(connector);
  }
  
  void drm_connector_free_work_fn(struct work_struct *work)
  {
  	struct drm_connector *connector, *n;
  	struct drm_device *dev =
  		container_of(work, struct drm_device, mode_config.connector_free_work);
  	struct drm_mode_config *config = &dev->mode_config;
  	unsigned long flags;
  	struct llist_node *freed;
  
  	spin_lock_irqsave(&config->connector_list_lock, flags);
  	freed = llist_del_all(&config->connector_free_list);
  	spin_unlock_irqrestore(&config->connector_list_lock, flags);
  
  	llist_for_each_entry_safe(connector, n, freed, free_node) {
  		drm_mode_object_unregister(dev, &connector->base);
  		connector->funcs->destroy(connector);
  	}
  }
  
  /**
   * drm_connector_init - Init a preallocated connector
   * @dev: DRM device
   * @connector: the connector to init
   * @funcs: callbacks for this connector
   * @connector_type: user visible type of the connector
   *
   * Initialises a preallocated connector. Connectors should be
   * subclassed as part of driver connector objects.
   *
   * Returns:
   * Zero on success, error code on failure.
   */
  int drm_connector_init(struct drm_device *dev,
  		       struct drm_connector *connector,
  		       const struct drm_connector_funcs *funcs,
  		       int connector_type)
  {
  	struct drm_mode_config *config = &dev->mode_config;
  	int ret;
  	struct ida *connector_ida =
  		&drm_connector_enum_list[connector_type].ida;
  
  	ret = __drm_mode_object_add(dev, &connector->base,
  				    DRM_MODE_OBJECT_CONNECTOR,
  				    false, drm_connector_free);
  	if (ret)
  		return ret;
  
  	connector->base.properties = &connector->properties;
  	connector->dev = dev;
  	connector->funcs = funcs;
  
  	ret = ida_simple_get(&config->connector_ida, 0, 0, GFP_KERNEL);
  	if (ret < 0)
  		goto out_put;
  	connector->index = ret;
  	ret = 0;
  
  	connector->connector_type = connector_type;
  	connector->connector_type_id =
  		ida_simple_get(connector_ida, 1, 0, GFP_KERNEL);
  	if (connector->connector_type_id < 0) {
  		ret = connector->connector_type_id;
  		goto out_put_id;
  	}
  	connector->name =
  		kasprintf(GFP_KERNEL, "%s-%d",
  			  drm_connector_enum_list[connector_type].name,
  			  connector->connector_type_id);
  	if (!connector->name) {
  		ret = -ENOMEM;
  		goto out_put_type_id;
  	}
  
  	INIT_LIST_HEAD(&connector->probed_modes);
  	INIT_LIST_HEAD(&connector->modes);
  	lockinit(&connector->mutex, "drmcm", 0, LK_CANRECURSE);
  	connector->edid_blob_ptr = NULL;
  	connector->status = connector_status_unknown;
  
  	drm_connector_get_cmdline_mode(connector);
  
  	/* We should add connectors at the end to avoid upsetting the connector
  	 * index too much. */
  	spin_lock_irq(&config->connector_list_lock);
  	list_add_tail(&connector->head, &config->connector_list);
  	config->num_connector++;
  	spin_unlock_irq(&config->connector_list_lock);
  
  	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)
  		drm_object_attach_property(&connector->base,
  					      config->edid_property,
  					      0);
  
  	drm_object_attach_property(&connector->base,
  				      config->dpms_property, 0);
  
  	drm_object_attach_property(&connector->base,
  				   config->link_status_property,
  				   0);
  
  	drm_object_attach_property(&connector->base,
  				   config->non_desktop_property,
  				   0);
  
  	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
  		drm_object_attach_property(&connector->base, config->prop_crtc_id, 0);
  	}
  
  	connector->debugfs_entry = NULL;
  out_put_type_id:
  	if (ret)
  		ida_simple_remove(connector_ida, connector->connector_type_id);
  out_put_id:
  	if (ret)
  		ida_simple_remove(&config->connector_ida, connector->index);
  out_put:
  	if (ret)
  		drm_mode_object_unregister(dev, &connector->base);
  
  	return ret;
  }
  EXPORT_SYMBOL(drm_connector_init);
  
  /**
   * drm_mode_connector_attach_encoder - attach a connector to an encoder
   * @connector: connector to attach
   * @encoder: encoder to attach @connector to
   *
   * This function links up a connector to an encoder. Note that the routing
   * restrictions between encoders and crtcs are exposed to userspace through the
   * possible_clones and possible_crtcs bitmasks.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_mode_connector_attach_encoder(struct drm_connector *connector,
  				      struct drm_encoder *encoder)
  {
  	int i;
  
  	/*
  	 * In the past, drivers have attempted to model the static association
  	 * of connector to encoder in simple connector/encoder devices using a
  	 * direct assignment of connector->encoder = encoder. This connection
  	 * is a logical one and the responsibility of the core, so drivers are
  	 * expected not to mess with this.
  	 *
  	 * Note that the error return should've been enough here, but a large
  	 * majority of drivers ignores the return value, so add in a big WARN
  	 * to get people's attention.
  	 */
  	if (WARN_ON(connector->encoder))
  		return -EINVAL;
  
  	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
  		if (connector->encoder_ids[i] == 0) {
  			connector->encoder_ids[i] = encoder->base.id;
  			return 0;
  		}
  	}
  	return -ENOMEM;
  }
  EXPORT_SYMBOL(drm_mode_connector_attach_encoder);
  
  static void drm_mode_remove(struct drm_connector *connector,
  			    struct drm_display_mode *mode)
  {
  	list_del(&mode->head);
  	drm_mode_destroy(connector->dev, mode);
  }
  
  /**
   * drm_connector_cleanup - cleans up an initialised connector
   * @connector: connector to cleanup
   *
   * Cleans up the connector but doesn't free the object.
   */
  void drm_connector_cleanup(struct drm_connector *connector)
  {
  	struct drm_device *dev = connector->dev;
  	struct drm_display_mode *mode, *t;
  
  	/* The connector should have been removed from userspace long before
  	 * it is finally destroyed.
  	 */
  	if (WARN_ON(connector->registered))
  		drm_connector_unregister(connector);
  
  	if (connector->tile_group) {
  		drm_mode_put_tile_group(dev, connector->tile_group);
  		connector->tile_group = NULL;
  	}
  
  	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
  		drm_mode_remove(connector, mode);
  
  	list_for_each_entry_safe(mode, t, &connector->modes, head)
  		drm_mode_remove(connector, mode);
  
  	ida_simple_remove(&drm_connector_enum_list[connector->connector_type].ida,
  			  connector->connector_type_id);
  
  	ida_simple_remove(&dev->mode_config.connector_ida,
  			  connector->index);
  
  	kfree(connector->display_info.bus_formats);
  	drm_mode_object_unregister(dev, &connector->base);
  	kfree(connector->name);
  	connector->name = NULL;
  	spin_lock_irq(&dev->mode_config.connector_list_lock);
  	list_del(&connector->head);
  	dev->mode_config.num_connector--;
  	spin_unlock_irq(&dev->mode_config.connector_list_lock);
  
  	WARN_ON(connector->state && !connector->funcs->atomic_destroy_state);
  	if (connector->state && connector->funcs->atomic_destroy_state)
  		connector->funcs->atomic_destroy_state(connector,
  						       connector->state);
  
  	mutex_destroy(&connector->mutex);
  
  	memset(connector, 0, sizeof(*connector));
  }
  EXPORT_SYMBOL(drm_connector_cleanup);
  
  /**
   * drm_connector_register - register a connector
   * @connector: the connector to register
   *
   * Register userspace interfaces for a connector
   *
   * Returns:
   * Zero on success, error code on failure.
   */
  int drm_connector_register(struct drm_connector *connector)
  {
  	int ret = 0;
  
  	if (!connector->dev->registered)
  		return 0;
  
  	mutex_lock(&connector->mutex);
  	if (connector->registered)
  		goto unlock;
  
  	ret = drm_sysfs_connector_add(connector);
  	if (ret)
  		goto unlock;
  
  	ret = drm_debugfs_connector_add(connector);
  	if (ret) {
  		goto err_sysfs;
  	}
  
  	if (connector->funcs->late_register) {
  		ret = connector->funcs->late_register(connector);
  		if (ret)
  			goto err_debugfs;
  	}
  
  	drm_mode_object_register(connector->dev, &connector->base);
  
  	connector->registered = true;
  	goto unlock;
  
  err_debugfs:
  	drm_debugfs_connector_remove(connector);
  err_sysfs:
  	drm_sysfs_connector_remove(connector);
  unlock:
  	mutex_unlock(&connector->mutex);
  	return ret;
  }
  EXPORT_SYMBOL(drm_connector_register);
  
  /**
   * drm_connector_unregister - unregister a connector
   * @connector: the connector to unregister
   *
   * Unregister userspace interfaces for a connector
   */
  void drm_connector_unregister(struct drm_connector *connector)
  {
  	mutex_lock(&connector->mutex);
  	if (!connector->registered) {
  		mutex_unlock(&connector->mutex);
  		return;
  	}
  
  	if (connector->funcs->early_unregister)
  		connector->funcs->early_unregister(connector);
  
  	drm_sysfs_connector_remove(connector);
  	drm_debugfs_connector_remove(connector);
  
  	connector->registered = false;
  	mutex_unlock(&connector->mutex);
  }
  EXPORT_SYMBOL(drm_connector_unregister);
  
  void drm_connector_unregister_all(struct drm_device *dev)
  {
  	struct drm_connector *connector;
  	struct drm_connector_list_iter conn_iter;
  
  	drm_connector_list_iter_begin(dev, &conn_iter);
  	drm_for_each_connector_iter(connector, &conn_iter)
  		drm_connector_unregister(connector);
  	drm_connector_list_iter_end(&conn_iter);
  }
  
  int drm_connector_register_all(struct drm_device *dev)
  {
  	struct drm_connector *connector;
  	struct drm_connector_list_iter conn_iter;
  	int ret = 0;
  
  	drm_connector_list_iter_begin(dev, &conn_iter);
  	drm_for_each_connector_iter(connector, &conn_iter) {
  		ret = drm_connector_register(connector);
  		if (ret)
  			break;
  	}
  	drm_connector_list_iter_end(&conn_iter);
  
  	if (ret)
  		drm_connector_unregister_all(dev);
  	return ret;
  }
  
  /**
   * drm_get_connector_status_name - return a string for connector status
   * @status: connector status to compute name of
   *
   * In contrast to the other drm_get_*_name functions this one here returns a
   * const pointer and hence is threadsafe.
   */
  const char *drm_get_connector_status_name(enum drm_connector_status status)
  {
  	if (status == connector_status_connected)
  		return "connected";
  	else if (status == connector_status_disconnected)
  		return "disconnected";
  	else
  		return "unknown";
  }
  EXPORT_SYMBOL(drm_get_connector_status_name);
  
  /**
   * drm_get_connector_force_name - return a string for connector force
   * @force: connector force to get name of
   *
   * Returns: const pointer to name.
   */
  const char *drm_get_connector_force_name(enum drm_connector_force force)
  {
  	switch (force) {
  	case DRM_FORCE_UNSPECIFIED:
  		return "unspecified";
  	case DRM_FORCE_OFF:
  		return "off";
  	case DRM_FORCE_ON:
  		return "on";
  	case DRM_FORCE_ON_DIGITAL:
  		return "digital";
  	default:
  		return "unknown";
  	}
  }
  
  #ifdef CONFIG_LOCKDEP
  static struct lockdep_map connector_list_iter_dep_map = {
  	.name = "drm_connector_list_iter"
  };
  #endif
  
  /**
   * drm_connector_list_iter_begin - initialize a connector_list iterator
   * @dev: DRM device
   * @iter: connector_list iterator
   *
   * Sets @iter up to walk the &drm_mode_config.connector_list of @dev. @iter
   * must always be cleaned up again by calling drm_connector_list_iter_end().
   * Iteration itself happens using drm_connector_list_iter_next() or
   * drm_for_each_connector_iter().
   */
  void drm_connector_list_iter_begin(struct drm_device *dev,
  				   struct drm_connector_list_iter *iter)
  {
  	iter->dev = dev;
  	iter->conn = NULL;
  	lock_acquire_shared_recursive(&connector_list_iter_dep_map, 0, 1, NULL, _RET_IP_);
  }
  EXPORT_SYMBOL(drm_connector_list_iter_begin);
  
  /*
   * Extra-safe connector put function that works in any context. Should only be
   * used from the connector_iter functions, where we never really expect to
   * actually release the connector when dropping our final reference.
   */
  static void
  __drm_connector_put_safe(struct drm_connector *conn)
  {
  	struct drm_mode_config *config = &conn->dev->mode_config;
  
  	lockdep_assert_held(&config->connector_list_lock);
  
  	if (!refcount_dec_and_test(&conn->base.refcount.refcount))
  		return;
  
  	llist_add(&conn->free_node, &config->connector_free_list);
  	schedule_work(&config->connector_free_work);
  }
  
  /**
   * drm_connector_list_iter_next - return next connector
   * @iter: connectr_list iterator
   *
   * Returns the next connector for @iter, or NULL when the list walk has
   * completed.
   */
  struct drm_connector *
  drm_connector_list_iter_next(struct drm_connector_list_iter *iter)
  {
  	struct drm_connector *old_conn = iter->conn;
  	struct drm_mode_config *config = &iter->dev->mode_config;
  	struct list_head *lhead;
  	unsigned long flags;
  
  	spin_lock_irqsave(&config->connector_list_lock, flags);
  	lhead = old_conn ? &old_conn->head : &config->connector_list;
  
  	do {
  		if (lhead->next == &config->connector_list) {
  			iter->conn = NULL;
  			break;
  		}
  
  		lhead = lhead->next;
  		iter->conn = list_entry(lhead, struct drm_connector, head);
  
  		/* loop until it's not a zombie connector */
  	} while (!kref_get_unless_zero(&iter->conn->base.refcount));
  
  	if (old_conn)
  		__drm_connector_put_safe(old_conn);
  	spin_unlock_irqrestore(&config->connector_list_lock, flags);
  
  	return iter->conn;
  }
  EXPORT_SYMBOL(drm_connector_list_iter_next);
  
  /**
   * drm_connector_list_iter_end - tear down a connector_list iterator
   * @iter: connector_list iterator
   *
   * Tears down @iter and releases any resources (like &drm_connector references)
   * acquired while walking the list. This must always be called, both when the
   * iteration completes fully or when it was aborted without walking the entire
   * list.
   */
  void drm_connector_list_iter_end(struct drm_connector_list_iter *iter)
  {
  	struct drm_mode_config *config = &iter->dev->mode_config;
  	unsigned long flags;
  
  	iter->dev = NULL;
  	if (iter->conn) {
  		spin_lock_irqsave(&config->connector_list_lock, flags);
  		__drm_connector_put_safe(iter->conn);
  		spin_unlock_irqrestore(&config->connector_list_lock, flags);
  	}
  	lock_release(&connector_list_iter_dep_map, 0, _RET_IP_);
  }
  EXPORT_SYMBOL(drm_connector_list_iter_end);
  
  static const struct drm_prop_enum_list drm_subpixel_enum_list[] = {
  	{ SubPixelUnknown, "Unknown" },
  	{ SubPixelHorizontalRGB, "Horizontal RGB" },
  	{ SubPixelHorizontalBGR, "Horizontal BGR" },
  	{ SubPixelVerticalRGB, "Vertical RGB" },
  	{ SubPixelVerticalBGR, "Vertical BGR" },
  	{ SubPixelNone, "None" },
  };
  
  /**
   * drm_get_subpixel_order_name - return a string for a given subpixel enum
   * @order: enum of subpixel_order
   *
   * Note you could abuse this and return something out of bounds, but that
   * would be a caller error.  No unscrubbed user data should make it here.
   */
  const char *drm_get_subpixel_order_name(enum subpixel_order order)
  {
  	return drm_subpixel_enum_list[order].name;
  }
  EXPORT_SYMBOL(drm_get_subpixel_order_name);
  
  static const struct drm_prop_enum_list drm_dpms_enum_list[] = {
  	{ DRM_MODE_DPMS_ON, "On" },
  	{ DRM_MODE_DPMS_STANDBY, "Standby" },
  	{ DRM_MODE_DPMS_SUSPEND, "Suspend" },
  	{ DRM_MODE_DPMS_OFF, "Off" }
  };
  DRM_ENUM_NAME_FN(drm_get_dpms_name, drm_dpms_enum_list)
  
  static const struct drm_prop_enum_list drm_link_status_enum_list[] = {
  	{ DRM_MODE_LINK_STATUS_GOOD, "Good" },
  	{ DRM_MODE_LINK_STATUS_BAD, "Bad" },
  };
  
  /**
   * drm_display_info_set_bus_formats - set the supported bus formats
   * @info: display info to store bus formats in
   * @formats: array containing the supported bus formats
   * @num_formats: the number of entries in the fmts array
   *
   * Store the supported bus formats in display info structure.
   * See MEDIA_BUS_FMT_* definitions in include/uapi/linux/media-bus-format.h for
   * a full list of available formats.
   */
  int drm_display_info_set_bus_formats(struct drm_display_info *info,
  				     const u32 *formats,
  				     unsigned int num_formats)
  {
  	u32 *fmts = NULL;
  
  	if (!formats && num_formats)
  		return -EINVAL;
  
  	if (formats && num_formats) {
  		fmts = kmemdup(formats, sizeof(*formats) * num_formats,
  			       GFP_KERNEL);
  		if (!fmts)
  			return -ENOMEM;
  	}
  
  	kfree(info->bus_formats);
  	info->bus_formats = fmts;
  	info->num_bus_formats = num_formats;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_display_info_set_bus_formats);
  
  /* Optional connector properties. */
  static const struct drm_prop_enum_list drm_scaling_mode_enum_list[] = {
  	{ DRM_MODE_SCALE_NONE, "None" },
  	{ DRM_MODE_SCALE_FULLSCREEN, "Full" },
  	{ DRM_MODE_SCALE_CENTER, "Center" },
  	{ DRM_MODE_SCALE_ASPECT, "Full aspect" },
  };
  
  static const struct drm_prop_enum_list drm_aspect_ratio_enum_list[] = {
  	{ DRM_MODE_PICTURE_ASPECT_NONE, "Automatic" },
  	{ DRM_MODE_PICTURE_ASPECT_4_3, "4:3" },
  	{ DRM_MODE_PICTURE_ASPECT_16_9, "16:9" },
  };
  
  static const struct drm_prop_enum_list drm_dvi_i_select_enum_list[] = {
  	{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
  	{ DRM_MODE_SUBCONNECTOR_DVID,      "DVI-D"     }, /* DVI-I  */
  	{ DRM_MODE_SUBCONNECTOR_DVIA,      "DVI-A"     }, /* DVI-I  */
  };
  DRM_ENUM_NAME_FN(drm_get_dvi_i_select_name, drm_dvi_i_select_enum_list)
  
  static const struct drm_prop_enum_list drm_dvi_i_subconnector_enum_list[] = {
  	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
  	{ DRM_MODE_SUBCONNECTOR_DVID,      "DVI-D"     }, /* DVI-I  */
  	{ DRM_MODE_SUBCONNECTOR_DVIA,      "DVI-A"     }, /* DVI-I  */
  };
  DRM_ENUM_NAME_FN(drm_get_dvi_i_subconnector_name,
  		 drm_dvi_i_subconnector_enum_list)
  
  static const struct drm_prop_enum_list drm_tv_select_enum_list[] = {
  	{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
  	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_SVIDEO,    "SVIDEO"    }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_Component, "Component" }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_SCART,     "SCART"     }, /* TV-out */
  };
  DRM_ENUM_NAME_FN(drm_get_tv_select_name, drm_tv_select_enum_list)
  
  static const struct drm_prop_enum_list drm_tv_subconnector_enum_list[] = {
  	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
  	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_SVIDEO,    "SVIDEO"    }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_Component, "Component" }, /* TV-out */
  	{ DRM_MODE_SUBCONNECTOR_SCART,     "SCART"     }, /* TV-out */
  };
  DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
  		 drm_tv_subconnector_enum_list)
  
  /**
   * DOC: standard connector properties
   *
   * DRM connectors have a few standardized properties:
   *
   * EDID:
   * 	Blob property which contains the current EDID read from the sink. This
   * 	is useful to parse sink identification information like vendor, model
   * 	and serial. Drivers should update this property by calling
   * 	drm_mode_connector_update_edid_property(), usually after having parsed
   * 	the EDID using drm_add_edid_modes(). Userspace cannot change this
   * 	property.
   * DPMS:
   * 	Legacy property for setting the power state of the connector. For atomic
   * 	drivers this is only provided for backwards compatibility with existing
   * 	drivers, it remaps to controlling the "ACTIVE" property on the CRTC the
   * 	connector is linked to. Drivers should never set this property directly,
   * 	it is handled by the DRM core by calling the &drm_connector_funcs.dpms
   * 	callback. For atomic drivers the remapping to the "ACTIVE" property is
   * 	implemented in the DRM core.  This is the only standard connector
   * 	property that userspace can change.
   *
   * 	Note that this property cannot be set through the MODE_ATOMIC ioctl,
   * 	userspace must use "ACTIVE" on the CRTC instead.
   *
   * 	WARNING:
   *
   * 	For userspace also running on legacy drivers the "DPMS" semantics are a
   * 	lot more complicated. First, userspace cannot rely on the "DPMS" value
   * 	returned by the GETCONNECTOR actually reflecting reality, because many
   * 	drivers fail to update it. For atomic drivers this is taken care of in
   * 	drm_atomic_helper_update_legacy_modeset_state().
   *
   * 	The second issue is that the DPMS state is only well-defined when the
   * 	connector is connected to a CRTC. In atomic the DRM core enforces that
   * 	"ACTIVE" is off in such a case, no such checks exists for "DPMS".
   *
   * 	Finally, when enabling an output using the legacy SETCONFIG ioctl then
   * 	"DPMS" is forced to ON. But see above, that might not be reflected in
   * 	the software value on legacy drivers.
   *
   * 	Summarizing: Only set "DPMS" when the connector is known to be enabled,
   * 	assume that a successful SETCONFIG call also sets "DPMS" to on, and
   * 	never read back the value of "DPMS" because it can be incorrect.
   * PATH:
   * 	Connector path property to identify how this sink is physically
   * 	connected. Used by DP MST. This should be set by calling
   * 	drm_mode_connector_set_path_property(), in the case of DP MST with the
   * 	path property the MST manager created. Userspace cannot change this
   * 	property.
   * TILE:
   * 	Connector tile group property to indicate how a set of DRM connector
   * 	compose together into one logical screen. This is used by both high-res
   * 	external screens (often only using a single cable, but exposing multiple
   * 	DP MST sinks), or high-res integrated panels (like dual-link DSI) which
   * 	are not gen-locked. Note that for tiled panels which are genlocked, like
   * 	dual-link LVDS or dual-link DSI, the driver should try to not expose the
   * 	tiling and virtualize both &drm_crtc and &drm_plane if needed. Drivers
   * 	should update this value using drm_mode_connector_set_tile_property().
   * 	Userspace cannot change this property.
   * link-status:
   *      Connector link-status property to indicate the status of link. The default
   *      value of link-status is "GOOD". If something fails during or after modeset,
   *      the kernel driver may set this to "BAD" and issue a hotplug uevent. Drivers
   *      should update this value using drm_mode_connector_set_link_status_property().
   * non_desktop:
   * 	Indicates the output should be ignored for purposes of displaying a
   * 	standard desktop environment or console. This is most likely because
   * 	the output device is not rectilinear.
   *
   * Connectors also have one standardized atomic property:
   *
   * CRTC_ID:
   * 	Mode object ID of the &drm_crtc this connector should be connected to.
   */
  
  int drm_connector_create_standard_properties(struct drm_device *dev)
  {
  	struct drm_property *prop;
  
  	prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
  				   DRM_MODE_PROP_IMMUTABLE,
  				   "EDID", 0);
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.edid_property = prop;
  
  	prop = drm_property_create_enum(dev, 0,
  				   "DPMS", drm_dpms_enum_list,
  				   ARRAY_SIZE(drm_dpms_enum_list));
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.dpms_property = prop;
  
  	prop = drm_property_create(dev,
  				   DRM_MODE_PROP_BLOB |
  				   DRM_MODE_PROP_IMMUTABLE,
  				   "PATH", 0);
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.path_property = prop;
  
  	prop = drm_property_create(dev,
  				   DRM_MODE_PROP_BLOB |
  				   DRM_MODE_PROP_IMMUTABLE,
  				   "TILE", 0);
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.tile_property = prop;
  
  	prop = drm_property_create_enum(dev, 0, "link-status",
  					drm_link_status_enum_list,
  					ARRAY_SIZE(drm_link_status_enum_list));
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.link_status_property = prop;
  
  	prop = drm_property_create_bool(dev, DRM_MODE_PROP_IMMUTABLE, "non-desktop");
  	if (!prop)
  		return -ENOMEM;
  	dev->mode_config.non_desktop_property = prop;
  
  	return 0;
  }
  
  /**
   * drm_mode_create_dvi_i_properties - create DVI-I specific connector properties
   * @dev: DRM device
   *
   * Called by a driver the first time a DVI-I connector is made.
   */
  int drm_mode_create_dvi_i_properties(struct drm_device *dev)
  {
  	struct drm_property *dvi_i_selector;
  	struct drm_property *dvi_i_subconnector;
  
  	if (dev->mode_config.dvi_i_select_subconnector_property)
  		return 0;
  
  	dvi_i_selector =
  		drm_property_create_enum(dev, 0,
  				    "select subconnector",
  				    drm_dvi_i_select_enum_list,
  				    ARRAY_SIZE(drm_dvi_i_select_enum_list));
  	dev->mode_config.dvi_i_select_subconnector_property = dvi_i_selector;
  
  	dvi_i_subconnector = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
  				    "subconnector",
  				    drm_dvi_i_subconnector_enum_list,
  				    ARRAY_SIZE(drm_dvi_i_subconnector_enum_list));
  	dev->mode_config.dvi_i_subconnector_property = dvi_i_subconnector;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_mode_create_dvi_i_properties);
  
  /**
   * drm_create_tv_properties - create TV specific connector properties
   * @dev: DRM device
   * @num_modes: number of different TV formats (modes) supported
   * @modes: array of pointers to strings containing name of each format
   *
   * Called by a driver's TV initialization routine, this function creates
   * the TV specific connector properties for a given device.  Caller is
   * responsible for allocating a list of format names and passing them to
   * this routine.
   */
  int drm_mode_create_tv_properties(struct drm_device *dev,
  				  unsigned int num_modes,
  				  const char * const modes[])
  {
  	struct drm_property *tv_selector;
  	struct drm_property *tv_subconnector;
  	unsigned int i;
  
  	if (dev->mode_config.tv_select_subconnector_property)
  		return 0;
  
  	/*
  	 * Basic connector properties
  	 */
  	tv_selector = drm_property_create_enum(dev, 0,
  					  "select subconnector",
  					  drm_tv_select_enum_list,
  					  ARRAY_SIZE(drm_tv_select_enum_list));
  	if (!tv_selector)
  		goto nomem;
  
  	dev->mode_config.tv_select_subconnector_property = tv_selector;
  
  	tv_subconnector =
  		drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
  				    "subconnector",
  				    drm_tv_subconnector_enum_list,
  				    ARRAY_SIZE(drm_tv_subconnector_enum_list));
  	if (!tv_subconnector)
  		goto nomem;
  	dev->mode_config.tv_subconnector_property = tv_subconnector;
  
  	/*
  	 * Other, TV specific properties: margins & TV modes.
  	 */
  	dev->mode_config.tv_left_margin_property =
  		drm_property_create_range(dev, 0, "left margin", 0, 100);
  	if (!dev->mode_config.tv_left_margin_property)
  		goto nomem;
  
  	dev->mode_config.tv_right_margin_property =
  		drm_property_create_range(dev, 0, "right margin", 0, 100);
  	if (!dev->mode_config.tv_right_margin_property)
  		goto nomem;
  
  	dev->mode_config.tv_top_margin_property =
  		drm_property_create_range(dev, 0, "top margin", 0, 100);
  	if (!dev->mode_config.tv_top_margin_property)
  		goto nomem;
  
  	dev->mode_config.tv_bottom_margin_property =
  		drm_property_create_range(dev, 0, "bottom margin", 0, 100);
  	if (!dev->mode_config.tv_bottom_margin_property)
  		goto nomem;
  
  	dev->mode_config.tv_mode_property =
  		drm_property_create(dev, DRM_MODE_PROP_ENUM,
  				    "mode", num_modes);
  	if (!dev->mode_config.tv_mode_property)
  		goto nomem;
  
  	for (i = 0; i < num_modes; i++)
  		drm_property_add_enum(dev->mode_config.tv_mode_property, i,
  				      i, modes[i]);
  
  	dev->mode_config.tv_brightness_property =
  		drm_property_create_range(dev, 0, "brightness", 0, 100);
  	if (!dev->mode_config.tv_brightness_property)
  		goto nomem;
  
  	dev->mode_config.tv_contrast_property =
  		drm_property_create_range(dev, 0, "contrast", 0, 100);
  	if (!dev->mode_config.tv_contrast_property)
  		goto nomem;
  
  	dev->mode_config.tv_flicker_reduction_property =
  		drm_property_create_range(dev, 0, "flicker reduction", 0, 100);
  	if (!dev->mode_config.tv_flicker_reduction_property)
  		goto nomem;
  
  	dev->mode_config.tv_overscan_property =
  		drm_property_create_range(dev, 0, "overscan", 0, 100);
  	if (!dev->mode_config.tv_overscan_property)
  		goto nomem;
  
  	dev->mode_config.tv_saturation_property =
  		drm_property_create_range(dev, 0, "saturation", 0, 100);
  	if (!dev->mode_config.tv_saturation_property)
  		goto nomem;
  
  	dev->mode_config.tv_hue_property =
  		drm_property_create_range(dev, 0, "hue", 0, 100);
  	if (!dev->mode_config.tv_hue_property)
  		goto nomem;
  
  	return 0;
  nomem:
  	return -ENOMEM;
  }
  EXPORT_SYMBOL(drm_mode_create_tv_properties);
  
  /**
   * drm_mode_create_scaling_mode_property - create scaling mode property
   * @dev: DRM device
   *
   * Called by a driver the first time it's needed, must be attached to desired
   * connectors.
   *
   * Atomic drivers should use drm_connector_attach_scaling_mode_property()
   * instead to correctly assign &drm_connector_state.picture_aspect_ratio
   * in the atomic state.
   */
  int drm_mode_create_scaling_mode_property(struct drm_device *dev)
  {
  	struct drm_property *scaling_mode;
  
  	if (dev->mode_config.scaling_mode_property)
  		return 0;
  
  	scaling_mode =
  		drm_property_create_enum(dev, 0, "scaling mode",
  				drm_scaling_mode_enum_list,
  				    ARRAY_SIZE(drm_scaling_mode_enum_list));
  
  	dev->mode_config.scaling_mode_property = scaling_mode;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
  
  /**
   * drm_connector_attach_scaling_mode_property - attach atomic scaling mode property
   * @connector: connector to attach scaling mode property on.
   * @scaling_mode_mask: or'ed mask of BIT(%DRM_MODE_SCALE_\*).
   *
   * This is used to add support for scaling mode to atomic drivers.
   * The scaling mode will be set to &drm_connector_state.picture_aspect_ratio
   * and can be used from &drm_connector_helper_funcs->atomic_check for validation.
   *
   * This is the atomic version of drm_mode_create_scaling_mode_property().
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_connector_attach_scaling_mode_property(struct drm_connector *connector,
  					       u32 scaling_mode_mask)
  {
  	struct drm_device *dev = connector->dev;
  	struct drm_property *scaling_mode_property;
  	int i, j = 0;
  	const unsigned valid_scaling_mode_mask =
  		(1U << ARRAY_SIZE(drm_scaling_mode_enum_list)) - 1;
  
  	if (WARN_ON(hweight32(scaling_mode_mask) < 2 ||
  		    scaling_mode_mask & ~valid_scaling_mode_mask))
  		return -EINVAL;
  
  	scaling_mode_property =
  		drm_property_create(dev, DRM_MODE_PROP_ENUM, "scaling mode",
  				    hweight32(scaling_mode_mask));
  
  	if (!scaling_mode_property)
  		return -ENOMEM;
  
  	for (i = 0; i < ARRAY_SIZE(drm_scaling_mode_enum_list); i++) {
  		int ret;
  
  		if (!(BIT(i) & scaling_mode_mask))
  			continue;
  
  		ret = drm_property_add_enum(scaling_mode_property, j++,
  					    drm_scaling_mode_enum_list[i].type,
  					    drm_scaling_mode_enum_list[i].name);
  
  		if (ret) {
  			drm_property_destroy(dev, scaling_mode_property);
  
  			return ret;
  		}
  	}
  
  	drm_object_attach_property(&connector->base,
  				   scaling_mode_property, 0);
  
  	connector->scaling_mode_property = scaling_mode_property;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_connector_attach_scaling_mode_property);
  
  /**
   * drm_mode_create_aspect_ratio_property - create aspect ratio property
   * @dev: DRM device
   *
   * Called by a driver the first time it's needed, must be attached to desired
   * connectors.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_mode_create_aspect_ratio_property(struct drm_device *dev)
  {
  	if (dev->mode_config.aspect_ratio_property)
  		return 0;
  
  	dev->mode_config.aspect_ratio_property =
  		drm_property_create_enum(dev, 0, "aspect ratio",
  				drm_aspect_ratio_enum_list,
  				ARRAY_SIZE(drm_aspect_ratio_enum_list));
  
  	if (dev->mode_config.aspect_ratio_property == NULL)
  		return -ENOMEM;
  
  	return 0;
  }
  EXPORT_SYMBOL(drm_mode_create_aspect_ratio_property);
  
  /**
   * drm_mode_create_suggested_offset_properties - create suggests offset properties
   * @dev: DRM device
   *
   * Create the the suggested x/y offset property for connectors.
   */
  int drm_mode_create_suggested_offset_properties(struct drm_device *dev)
  {
  	if (dev->mode_config.suggested_x_property && dev->mode_config.suggested_y_property)
  		return 0;
  
  	dev->mode_config.suggested_x_property =
  		drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "suggested X", 0, 0xffffffff);
  
  	dev->mode_config.suggested_y_property =
  		drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "suggested Y", 0, 0xffffffff);
  
  	if (dev->mode_config.suggested_x_property == NULL ||
  	    dev->mode_config.suggested_y_property == NULL)
  		return -ENOMEM;
  	return 0;
  }
  EXPORT_SYMBOL(drm_mode_create_suggested_offset_properties);
  
  /**
   * drm_mode_connector_set_path_property - set tile property on connector
   * @connector: connector to set property on.
   * @path: path to use for property; must not be NULL.
   *
   * This creates a property to expose to userspace to specify a
   * connector path. This is mainly used for DisplayPort MST where
   * connectors have a topology and we want to allow userspace to give
   * them more meaningful names.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_mode_connector_set_path_property(struct drm_connector *connector,
  					 const char *path)
  {
  	struct drm_device *dev = connector->dev;
  	int ret;
  
  	ret = drm_property_replace_global_blob(dev,
  	                                       &connector->path_blob_ptr,
  	                                       strlen(path) + 1,
  	                                       path,
  	                                       &connector->base,
  	                                       dev->mode_config.path_property);
  	return ret;
  }
  EXPORT_SYMBOL(drm_mode_connector_set_path_property);
  
  /**
   * drm_mode_connector_set_tile_property - set tile property on connector
   * @connector: connector to set property on.
   *
   * This looks up the tile information for a connector, and creates a
   * property for userspace to parse if it exists. The property is of
   * the form of 8 integers using ':' as a separator.
   *
   * Returns:
   * Zero on success, errno on failure.
   */
  int drm_mode_connector_set_tile_property(struct drm_connector *connector)
  {
  	struct drm_device *dev = connector->dev;
  	char tile[256];
  	int ret;
  
  	if (!connector->has_tile) {
  		ret  = drm_property_replace_global_blob(dev,
  		                                        &connector->tile_blob_ptr,
  		                                        0,
  		                                        NULL,
  		                                        &connector->base,
  		                                        dev->mode_config.tile_property);
  		return ret;
  	}
  
  	snprintf(tile, 256, "%d:%d:%d:%d:%d:%d:%d:%d",
  		 connector->tile_group->id, connector->tile_is_single_monitor,
  		 connector->num_h_tile, connector->num_v_tile,
  		 connector->tile_h_loc, connector->tile_v_loc,
  		 connector->tile_h_size, connector->tile_v_size);
  
  	ret = drm_property_replace_global_blob(dev,
  	                                       &connector->tile_blob_ptr,
  	                                       strlen(tile) + 1,
  	                                       tile,
  	                                       &connector->base,
  	                                       dev->mode_config.tile_property);
  	return ret;
  }
  EXPORT_SYMBOL(drm_mode_connector_set_tile_property);
  
  /**
   * drm_mode_connector_update_edid_property - update the edid property of a connector
   * @connector: drm connector
   * @edid: new value of the edid property
   *
   * This function creates a new blob modeset object and assigns its id to the
   * connector's edid property.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_mode_connector_update_edid_property(struct drm_connector *connector,
  					    const struct edid *edid)
  {
  	struct drm_device *dev = connector->dev;
  	size_t size = 0;
  	int ret;
  
  	/* ignore requests to set edid when overridden */
  	if (connector->override_edid)
  		return 0;
  
  	if (edid)
  		size = EDID_LENGTH * (1 + edid->extensions);
  
  	/* Set the display info, using edid if available, otherwise
  	 * reseting the values to defaults. This duplicates the work
  	 * done in drm_add_edid_modes, but that function is not
  	 * consistently called before this one in all drivers and the
  	 * computation is cheap enough that it seems better to
  	 * duplicate it rather than attempt to ensure some arbitrary
  	 * ordering of calls.
  	 */
  	if (edid)
  		drm_add_display_info(connector, edid);
  	else
  		drm_reset_display_info(connector);
  
  	drm_object_property_set_value(&connector->base,
  				      dev->mode_config.non_desktop_property,
  				      connector->display_info.non_desktop);
  
  	ret = drm_property_replace_global_blob(dev,
  					       &connector->edid_blob_ptr,
  	                                       size,
  	                                       edid,
  	                                       &connector->base,
  	                                       dev->mode_config.edid_property);
  	return ret;
  }
  EXPORT_SYMBOL(drm_mode_connector_update_edid_property);
  
  /**
   * drm_mode_connector_set_link_status_property - Set link status property of a connector
   * @connector: drm connector
   * @link_status: new value of link status property (0: Good, 1: Bad)
   *
   * In usual working scenario, this link status property will always be set to
   * "GOOD". If something fails during or after a mode set, the kernel driver
   * may set this link status property to "BAD". The caller then needs to send a
   * hotplug uevent for userspace to re-check the valid modes through
   * GET_CONNECTOR_IOCTL and retry modeset.
   *
   * Note: Drivers cannot rely on userspace to support this property and
   * issue a modeset. As such, they may choose to handle issues (like
   * re-training a link) without userspace's intervention.
   *
   * The reason for adding this property is to handle link training failures, but
   * it is not limited to DP or link training. For example, if we implement
   * asynchronous setcrtc, this property can be used to report any failures in that.
   */
  void drm_mode_connector_set_link_status_property(struct drm_connector *connector,
  						 uint64_t link_status)
  {
  	struct drm_device *dev = connector->dev;
  
  	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
  	connector->state->link_status = link_status;
  	drm_modeset_unlock(&dev->mode_config.connection_mutex);
  }
  EXPORT_SYMBOL(drm_mode_connector_set_link_status_property);
  
  int drm_mode_connector_set_obj_prop(struct drm_mode_object *obj,
  				    struct drm_property *property,
  				    uint64_t value)
  {
  	int ret = -EINVAL;
  	struct drm_connector *connector = obj_to_connector(obj);
  
  	/* Do DPMS ourselves */
  	if (property == connector->dev->mode_config.dpms_property) {
  		ret = (*connector->funcs->dpms)(connector, (int)value);
  	} else if (connector->funcs->set_property)
  		ret = connector->funcs->set_property(connector, property, value);
  
  	if (!ret)
  		drm_object_property_set_value(&connector->base, property, value);
  	return ret;
  }
  
  int drm_mode_connector_property_set_ioctl(struct drm_device *dev,
  				       void *data, struct drm_file *file_priv)
  {
  	struct drm_mode_connector_set_property *conn_set_prop = data;
  	struct drm_mode_obj_set_property obj_set_prop = {
  		.value = conn_set_prop->value,
  		.prop_id = conn_set_prop->prop_id,
  		.obj_id = conn_set_prop->connector_id,
  		.obj_type = DRM_MODE_OBJECT_CONNECTOR
  	};
  
  	/* It does all the locking and checking we need */
  	return drm_mode_obj_set_property_ioctl(dev, &obj_set_prop, file_priv);
  }
  
  static struct drm_encoder *drm_connector_get_encoder(struct drm_connector *connector)
  {
  	/* For atomic drivers only state objects are synchronously updated and
  	 * protected by modeset locks, so check those first. */
  	if (connector->state)
  		return connector->state->best_encoder;
  	return connector->encoder;
  }
  
  static bool drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
  					 const struct drm_file *file_priv)
  {
  	/*
  	 * If user-space hasn't configured the driver to expose the stereo 3D
  	 * modes, don't expose them.
  	 */
  	if (!file_priv->stereo_allowed && drm_mode_is_stereo(mode))
  		return false;
  
  	return true;
  }
  
  int drm_mode_getconnector(struct drm_device *dev, void *data,
  			  struct drm_file *file_priv)
  {
  	struct drm_mode_get_connector *out_resp = data;
  	struct drm_connector *connector;
  	struct drm_encoder *encoder;
  	struct drm_display_mode *mode;
  	int mode_count = 0;
  	int encoders_count = 0;
  	int ret = 0;
  	int copied = 0;
  	int i;
  	struct drm_mode_modeinfo u_mode;
  	struct drm_mode_modeinfo __user *mode_ptr;
  	uint32_t __user *encoder_ptr;
  
  	if (!drm_core_check_feature(dev, DRIVER_MODESET))
  		return -EINVAL;
  
  	memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
  
  	connector = drm_connector_lookup(dev, file_priv, out_resp->connector_id);
  	if (!connector)
  		return -ENOENT;
  
  	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
  		if (connector->encoder_ids[i] != 0)
  			encoders_count++;
  
  	if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
  		copied = 0;
  		encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
  		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
  			if (connector->encoder_ids[i] != 0) {
  				if (put_user(connector->encoder_ids[i],
  					     encoder_ptr + copied)) {
  					ret = -EFAULT;
  					goto out;
  				}
  				copied++;
  			}
  		}
  	}
  	out_resp->count_encoders = encoders_count;
  
  	out_resp->connector_id = connector->base.id;
  	out_resp->connector_type = connector->connector_type;
  	out_resp->connector_type_id = connector->connector_type_id;
  
  	mutex_lock(&dev->mode_config.mutex);
  	if (out_resp->count_modes == 0) {
  		connector->funcs->fill_modes(connector,
  					     dev->mode_config.max_width,
  					     dev->mode_config.max_height);
  	}
  
  	out_resp->mm_width = connector->display_info.width_mm;
  	out_resp->mm_height = connector->display_info.height_mm;
  	out_resp->subpixel = connector->display_info.subpixel_order;
  	out_resp->connection = connector->status;
  
  	/* delayed so we get modes regardless of pre-fill_modes state */
  	list_for_each_entry(mode, &connector->modes, head)
  		if (drm_mode_expose_to_userspace(mode, file_priv))
  			mode_count++;
  
  	/*
  	 * This ioctl is called twice, once to determine how much space is
  	 * needed, and the 2nd time to fill it.
  	 */
  	if ((out_resp->count_modes >= mode_count) && mode_count) {
  		copied = 0;
  		mode_ptr = (struct drm_mode_modeinfo __user *)(unsigned long)out_resp->modes_ptr;
  		list_for_each_entry(mode, &connector->modes, head) {
  			if (!drm_mode_expose_to_userspace(mode, file_priv))
  				continue;
  
  			drm_mode_convert_to_umode(&u_mode, mode);
  			if (copy_to_user(mode_ptr + copied,
  					 &u_mode, sizeof(u_mode))) {
  				ret = -EFAULT;
  				mutex_unlock(&dev->mode_config.mutex);
  
  				goto out;
  			}
  			copied++;
  		}
  	}
  	out_resp->count_modes = mode_count;
  	mutex_unlock(&dev->mode_config.mutex);
  
  	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
  	encoder = drm_connector_get_encoder(connector);
  	if (encoder)
  		out_resp->encoder_id = encoder->base.id;
  	else
  		out_resp->encoder_id = 0;
  
  	/* Only grab properties after probing, to make sure EDID and other
  	 * properties reflect the latest status. */
  	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
  			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
  			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
  			&out_resp->count_props);
  	drm_modeset_unlock(&dev->mode_config.connection_mutex);
  
  out:
  	drm_connector_put(connector);
  
  	return ret;
  }
  
  
  /**
   * DOC: Tile group
   *
   * Tile groups are used to represent tiled monitors with a unique integer
   * identifier. Tiled monitors using DisplayID v1.3 have a unique 8-byte handle,
   * we store this in a tile group, so we have a common identifier for all tiles
   * in a monitor group. The property is called "TILE". Drivers can manage tile
   * groups using drm_mode_create_tile_group(), drm_mode_put_tile_group() and
   * drm_mode_get_tile_group(). But this is only needed for internal panels where
   * the tile group information is exposed through a non-standard way.
   */
  
  static void drm_tile_group_free(struct kref *kref)
  {
  	struct drm_tile_group *tg = container_of(kref, struct drm_tile_group, refcount);
  	struct drm_device *dev = tg->dev;
  	mutex_lock(&dev->mode_config.idr_mutex);
  	idr_remove(&dev->mode_config.tile_idr, tg->id);
  	mutex_unlock(&dev->mode_config.idr_mutex);
  	kfree(tg);
  }
  
  /**
   * drm_mode_put_tile_group - drop a reference to a tile group.
   * @dev: DRM device
   * @tg: tile group to drop reference to.
   *
   * drop reference to tile group and free if 0.
   */
  void drm_mode_put_tile_group(struct drm_device *dev,
  			     struct drm_tile_group *tg)
  {
  	kref_put(&tg->refcount, drm_tile_group_free);
  }
  EXPORT_SYMBOL(drm_mode_put_tile_group);
  
  /**
   * drm_mode_get_tile_group - get a reference to an existing tile group
   * @dev: DRM device
   * @topology: 8-bytes unique per monitor.
   *
   * Use the unique bytes to get a reference to an existing tile group.
   *
   * RETURNS:
   * tile group or NULL if not found.
   */
  struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
  					       char topology[8])
  {
  	struct drm_tile_group *tg;
  	int id;
  	mutex_lock(&dev->mode_config.idr_mutex);
  	idr_for_each_entry(&dev->mode_config.tile_idr, tg, id) {
  		if (!memcmp(tg->group_data, topology, 8)) {
  			if (!kref_get_unless_zero(&tg->refcount))
  				tg = NULL;
  			mutex_unlock(&dev->mode_config.idr_mutex);
  			return tg;
  		}
  	}
  	mutex_unlock(&dev->mode_config.idr_mutex);
  	return NULL;
  }
  EXPORT_SYMBOL(drm_mode_get_tile_group);
  
  /**
   * drm_mode_create_tile_group - create a tile group from a displayid description
   * @dev: DRM device
   * @topology: 8-bytes unique per monitor.
   *
   * Create a tile group for the unique monitor, and get a unique
   * identifier for the tile group.
   *
   * RETURNS:
   * new tile group or error.
   */
  struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
  						  char topology[8])
  {
  	struct drm_tile_group *tg;
  	int ret;
  
  	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
  	if (!tg)
  		return ERR_PTR(-ENOMEM);
  
  	kref_init(&tg->refcount);
  	memcpy(tg->group_data, topology, 8);
  	tg->dev = dev;
  
  	mutex_lock(&dev->mode_config.idr_mutex);
  	ret = idr_alloc(&dev->mode_config.tile_idr, tg, 1, 0, GFP_KERNEL);
  	if (ret >= 0) {
  		tg->id = ret;
  	} else {
  		kfree(tg);
  		tg = ERR_PTR(ret);
  	}
  
  	mutex_unlock(&dev->mode_config.idr_mutex);
  	return tg;
  }
  EXPORT_SYMBOL(drm_mode_create_tile_group);
  
  /**
   * drm_connector_update_edid_property - update the edid property of a connector
   * @connector: drm connector
   * @edid: new value of the edid property
   *
   * This function creates a new blob modeset object and assigns its id to the
   * connector's edid property.
   *
   * Returns:
   * Zero on success, negative errno on failure.
   */
  int drm_connector_update_edid_property(struct drm_connector *connector,
  				       const struct edid *edid)
  {
  	struct drm_device *dev = connector->dev;
  	size_t size = 0;
  	int ret;
  
  	/* ignore requests to set edid when overridden */
  	if (connector->override_edid)
  		return 0;
  
  	if (edid)
  		size = EDID_LENGTH * (1 + edid->extensions);
  
  	/* Set the display info, using edid if available, otherwise
  	 * reseting the values to defaults. This duplicates the work
  	 * done in drm_add_edid_modes, but that function is not
  	 * consistently called before this one in all drivers and the
  	 * computation is cheap enough that it seems better to
  	 * duplicate it rather than attempt to ensure some arbitrary
  	 * ordering of calls.
  	 */
  	if (edid)
  		drm_add_display_info(connector, edid);
  	else
  		drm_reset_display_info(connector);
  
  	drm_object_property_set_value(&connector->base,
  				      dev->mode_config.non_desktop_property,
  				      connector->display_info.non_desktop);
  
  	ret = drm_property_replace_global_blob(dev,
  					       &connector->edid_blob_ptr,
  	                                       size,
  	                                       edid,
  	                                       &connector->base,
  	                                       dev->mode_config.edid_property);
  	return ret;
  }
  EXPORT_SYMBOL(drm_connector_update_edid_property);
  