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drm_connector.c

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  • drm_connector.c 105.42 KiB
    /*
     * 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/drm_auth.h>
    #include <drm/drm_connector.h>
    #include <drm/drm_drv.h>
    #include <drm/drm_edid.h>
    #include <drm/drm_encoder.h>
    #include <drm/drm_file.h>
    #include <drm/drm_managed.h>
    #include <drm/drm_panel.h>
    #include <drm/drm_print.h>
    #include <drm/drm_privacy_screen_consumer.h>
    #include <drm/drm_sysfs.h>
    #include <drm/drm_utils.h>
    
    #include <linux/property.h>
    #include <linux/uaccess.h>
    
    #include <video/cmdline.h>
    
    #include "drm_crtc_internal.h"
    #include "drm_internal.h"
    
    /**
     * DOC: overview
     *
     * In DRM connectors are the general abstraction for display sinks, and include
     * also 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_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().
     */
    
    /*
     * Global connector list for drm_connector_find_by_fwnode().
     * Note drm_connector_[un]register() first take connector->lock and then
     * take the connector_list_lock.
     */
    static DEFINE_MUTEX(connector_list_lock);
    static LIST_HEAD(connector_list);
    
    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" },
    	{ DRM_MODE_CONNECTOR_WRITEBACK, "Writeback" },
    	{ DRM_MODE_CONNECTOR_SPI, "SPI" },
    	{ DRM_MODE_CONNECTOR_USB, "USB" },
    };
    
    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_get_connector_type_name - return a string for connector type
     * @type: The connector type (DRM_MODE_CONNECTOR_*)
     *
     * Returns: the name of the connector type, or NULL if the type is not valid.
     */
    const char *drm_get_connector_type_name(unsigned int type)
    {
    	if (type < ARRAY_SIZE(drm_connector_enum_list))
    		return drm_connector_enum_list[type].name;
    
    	return NULL;
    }
    EXPORT_SYMBOL(drm_get_connector_type_name);
    
    /**
     * drm_connector_get_cmdline_mode - reads the user's cmdline mode
     * @connector: connector to query
     *
     * 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;
    	const char *option;
    
    	option = video_get_options(connector->name);
    	if (!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;
    	}
    
    	if (mode->panel_orientation != DRM_MODE_PANEL_ORIENTATION_UNKNOWN) {
    		DRM_INFO("cmdline forces connector %s panel_orientation to %d\n",
    			 connector->name, mode->panel_orientation);
    		drm_connector_set_panel_orientation(connector,
    						    mode->panel_orientation);
    	}
    
    	DRM_DEBUG_KMS("cmdline mode for connector %s %s %dx%d@%dHz%s%s%s\n",
    		      connector->name, mode->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);
    	}
    }
    
    static int __drm_connector_init(struct drm_device *dev,
    				struct drm_connector *connector,
    				const struct drm_connector_funcs *funcs,
    				int connector_type,
    				struct i2c_adapter *ddc)
    {
    	struct drm_mode_config *config = &dev->mode_config;
    	int ret;
    	struct ida *connector_ida =
    		&drm_connector_enum_list[connector_type].ida;
    
    	WARN_ON(drm_drv_uses_atomic_modeset(dev) &&
    		(!funcs->atomic_destroy_state ||
    		 !funcs->atomic_duplicate_state));
    
    	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;
    
    	/* connector index is used with 32bit bitmasks */
    	ret = ida_alloc_max(&config->connector_ida, 31, GFP_KERNEL);
    	if (ret < 0) {
    		DRM_DEBUG_KMS("Failed to allocate %s connector index: %d\n",
    			      drm_connector_enum_list[connector_type].name,
    			      ret);
    		goto out_put;
    	}
    	connector->index = ret;
    	ret = 0;
    
    	connector->connector_type = connector_type;
    	connector->connector_type_id =
    		ida_alloc_min(connector_ida, 1, 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;
    	}
    
    	/* provide ddc symlink in sysfs */
    	connector->ddc = ddc;
    
    	INIT_LIST_HEAD(&connector->global_connector_list_entry);
    	INIT_LIST_HEAD(&connector->probed_modes);
    	INIT_LIST_HEAD(&connector->modes);
    	mutex_init(&connector->mutex);
    	mutex_init(&connector->edid_override_mutex);
    	connector->edid_blob_ptr = NULL;
    	connector->epoch_counter = 0;
    	connector->tile_blob_ptr = NULL;
    	connector->status = connector_status_unknown;
    	connector->display_info.panel_orientation =
    		DRM_MODE_PANEL_ORIENTATION_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 &&
    	    connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
    		drm_connector_attach_edid_property(connector);
    
    	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);
    	drm_object_attach_property(&connector->base,
    				   config->tile_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_free(connector_ida, connector->connector_type_id);
    out_put_id:
    	if (ret)
    		ida_free(&config->connector_ida, connector->index);
    out_put:
    	if (ret)
    		drm_mode_object_unregister(dev, &connector->base);
    
    	return ret;
    }
    
    /**
     * 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.
     *
     * At driver unload time the driver's &drm_connector_funcs.destroy hook
     * should call drm_connector_cleanup() and free the connector structure.
     * The connector structure should not be allocated with devm_kzalloc().
     *
     * Note: consider using drmm_connector_init() instead of
     * drm_connector_init() to let the DRM managed resource infrastructure
     * take care of cleanup and deallocation.
     *
     * 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)
    {
    	if (drm_WARN_ON(dev, !(funcs && funcs->destroy)))
    		return -EINVAL;
    
    	return __drm_connector_init(dev, connector, funcs, connector_type, NULL);
    }
    EXPORT_SYMBOL(drm_connector_init);
    
    /**
     * drm_connector_init_with_ddc - 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
     * @ddc: pointer to the associated ddc adapter
     *
     * Initialises a preallocated connector. Connectors should be
     * subclassed as part of driver connector objects.
     *
     * At driver unload time the driver's &drm_connector_funcs.destroy hook
     * should call drm_connector_cleanup() and free the connector structure.
     * The connector structure should not be allocated with devm_kzalloc().
     *
     * Ensures that the ddc field of the connector is correctly set.
     *
     * Note: consider using drmm_connector_init() instead of
     * drm_connector_init_with_ddc() to let the DRM managed resource
     * infrastructure take care of cleanup and deallocation.
     *
     * Returns:
     * Zero on success, error code on failure.
     */
    int drm_connector_init_with_ddc(struct drm_device *dev,
    				struct drm_connector *connector,
    				const struct drm_connector_funcs *funcs,
    				int connector_type,
    				struct i2c_adapter *ddc)
    {
    	if (drm_WARN_ON(dev, !(funcs && funcs->destroy)))
    		return -EINVAL;
    
    	return __drm_connector_init(dev, connector, funcs, connector_type, ddc);
    }
    EXPORT_SYMBOL(drm_connector_init_with_ddc);
    
    static void drm_connector_cleanup_action(struct drm_device *dev,
    					 void *ptr)
    {
    	struct drm_connector *connector = ptr;
    
    	drm_connector_cleanup(connector);
    }
    
    /**
     * drmm_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
     * @ddc: optional pointer to the associated ddc adapter
     *
     * Initialises a preallocated connector. Connectors should be
     * subclassed as part of driver connector objects.
     *
     * Cleanup is automatically handled with a call to
     * drm_connector_cleanup() in a DRM-managed action.
     *
     * The connector structure should be allocated with drmm_kzalloc().
     *
     * Returns:
     * Zero on success, error code on failure.
     */
    int drmm_connector_init(struct drm_device *dev,
    			struct drm_connector *connector,
    			const struct drm_connector_funcs *funcs,
    			int connector_type,
    			struct i2c_adapter *ddc)
    {
    	int ret;
    
    	if (drm_WARN_ON(dev, funcs && funcs->destroy))
    		return -EINVAL;
    
    	ret = __drm_connector_init(dev, connector, funcs, connector_type, ddc);
    	if (ret)
    		return ret;
    
    	ret = drmm_add_action_or_reset(dev, drm_connector_cleanup_action,
    				       connector);
    	if (ret)
    		return ret;
    
    	return 0;
    }
    EXPORT_SYMBOL(drmm_connector_init);
    
    /**
     * drm_connector_attach_edid_property - attach edid property.
     * @connector: the connector
     *
     * Some connector types like DRM_MODE_CONNECTOR_VIRTUAL do not get a
     * edid property attached by default.  This function can be used to
     * explicitly enable the edid property in these cases.
     */
    void drm_connector_attach_edid_property(struct drm_connector *connector)
    {
    	struct drm_mode_config *config = &connector->dev->mode_config;
    
    	drm_object_attach_property(&connector->base,
    				   config->edid_property,
    				   0);
    }
    EXPORT_SYMBOL(drm_connector_attach_edid_property);
    
    /**
     * drm_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_connector_attach_encoder(struct drm_connector *connector,
    				 struct drm_encoder *encoder)
    {
    	/*
    	 * 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;
    
    	connector->possible_encoders |= drm_encoder_mask(encoder);
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_encoder);
    
    /**
     * drm_connector_has_possible_encoder - check if the connector and encoder are
     * associated with each other
     * @connector: the connector
     * @encoder: the encoder
     *
     * Returns:
     * True if @encoder is one of the possible encoders for @connector.
     */
    bool drm_connector_has_possible_encoder(struct drm_connector *connector,
    					struct drm_encoder *encoder)
    {
    	return connector->possible_encoders & drm_encoder_mask(encoder);
    }
    EXPORT_SYMBOL(drm_connector_has_possible_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->registration_state ==
    		    DRM_CONNECTOR_REGISTERED))
    		drm_connector_unregister(connector);
    
    	if (connector->privacy_screen) {
    		drm_privacy_screen_put(connector->privacy_screen);
    		connector->privacy_screen = NULL;
    	}
    
    	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_free(&drm_connector_enum_list[connector->connector_type].ida,
    			  connector->connector_type_id);
    
    	ida_free(&dev->mode_config.connector_ida, connector->index);
    
    	kfree(connector->display_info.bus_formats);
    	kfree(connector->display_info.vics);
    	drm_mode_object_unregister(dev, &connector->base);
    	kfree(connector->name);
    	connector->name = NULL;
    	fwnode_handle_put(connector->fwnode);
    	connector->fwnode = 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));
    
    	if (dev->registered)
    		drm_sysfs_hotplug_event(dev);
    }
    EXPORT_SYMBOL(drm_connector_cleanup);
    
    /**
     * drm_connector_register - register a connector
     * @connector: the connector to register
     *
     * Register userspace interfaces for a connector. Only call this for connectors
     * which can be hotplugged after drm_dev_register() has been called already,
     * e.g. DP MST connectors. All other connectors will be registered automatically
     * when calling drm_dev_register().
     *
     * When the connector is no longer available, callers must call
     * drm_connector_unregister().
     *
     * 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->registration_state != DRM_CONNECTOR_INITIALIZING)
    		goto unlock;
    
    	ret = drm_sysfs_connector_add(connector);
    	if (ret)
    		goto unlock;
    
    	drm_debugfs_connector_add(connector);
    
    	if (connector->funcs->late_register) {
    		ret = connector->funcs->late_register(connector);
    		if (ret)
    			goto err_debugfs;
    	}
    
    	ret = drm_sysfs_connector_add_late(connector);
    	if (ret)
    		goto err_late_register;
    
    	drm_mode_object_register(connector->dev, &connector->base);
    
    	connector->registration_state = DRM_CONNECTOR_REGISTERED;
    
    	/* Let userspace know we have a new connector */
    	drm_sysfs_connector_hotplug_event(connector);
    
    	if (connector->privacy_screen)
    		drm_privacy_screen_register_notifier(connector->privacy_screen,
    					   &connector->privacy_screen_notifier);
    
    	mutex_lock(&connector_list_lock);
    	list_add_tail(&connector->global_connector_list_entry, &connector_list);
    	mutex_unlock(&connector_list_lock);
    	goto unlock;
    
    err_late_register:
    	if (connector->funcs->early_unregister)
    		connector->funcs->early_unregister(connector);
    err_debugfs:
    	drm_debugfs_connector_remove(connector);
    	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. Only call this for
     * connectors which have been registered explicitly by calling
     * drm_connector_register().
     */
    void drm_connector_unregister(struct drm_connector *connector)
    {
    	mutex_lock(&connector->mutex);
    	if (connector->registration_state != DRM_CONNECTOR_REGISTERED) {
    		mutex_unlock(&connector->mutex);
    		return;
    	}
    
    	mutex_lock(&connector_list_lock);
    	list_del_init(&connector->global_connector_list_entry);
    	mutex_unlock(&connector_list_lock);
    
    	if (connector->privacy_screen)
    		drm_privacy_screen_unregister_notifier(
    					connector->privacy_screen,
    					&connector->privacy_screen_notifier);
    
    	drm_sysfs_connector_remove_early(connector);
    
    	if (connector->funcs->early_unregister)
    		connector->funcs->early_unregister(connector);
    
    	drm_debugfs_connector_remove(connector);
    	drm_sysfs_connector_remove(connector);
    
    	connector->registration_state = DRM_CONNECTOR_UNREGISTERED;
    	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.
     *
     * Returns: connector status string
     */
    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: connector_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, _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.
     *
     * Returns: string describing an enumerated subpixel property
     */
    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.
     *
     * Returns:
     * 0 on success or a negative error code on failure.
     */
    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_content_type_enum_list[] = {
    	{ DRM_MODE_CONTENT_TYPE_NO_DATA, "No Data" },
    	{ DRM_MODE_CONTENT_TYPE_GRAPHICS, "Graphics" },
    	{ DRM_MODE_CONTENT_TYPE_PHOTO, "Photo" },
    	{ DRM_MODE_CONTENT_TYPE_CINEMA, "Cinema" },
    	{ DRM_MODE_CONTENT_TYPE_GAME, "Game" },
    };
    
    static const struct drm_prop_enum_list drm_panel_orientation_enum_list[] = {
    	{ DRM_MODE_PANEL_ORIENTATION_NORMAL,	"Normal"	},
    	{ DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP,	"Upside Down"	},
    	{ DRM_MODE_PANEL_ORIENTATION_LEFT_UP,	"Left Side Up"	},
    	{ DRM_MODE_PANEL_ORIENTATION_RIGHT_UP,	"Right Side Up"	},
    };
    
    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, TV-out and DP */
    	{ 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_mode_enum_list[] = {
    	{ DRM_MODE_TV_MODE_NTSC, "NTSC" },
    	{ DRM_MODE_TV_MODE_NTSC_443, "NTSC-443" },
    	{ DRM_MODE_TV_MODE_NTSC_J, "NTSC-J" },
    	{ DRM_MODE_TV_MODE_PAL, "PAL" },
    	{ DRM_MODE_TV_MODE_PAL_M, "PAL-M" },
    	{ DRM_MODE_TV_MODE_PAL_N, "PAL-N" },
    	{ DRM_MODE_TV_MODE_SECAM, "SECAM" },
    };
    DRM_ENUM_NAME_FN(drm_get_tv_mode_name, drm_tv_mode_enum_list)
    
    /**
     * drm_get_tv_mode_from_name - Translates a TV mode name into its enum value
     * @name: TV Mode name we want to convert
     * @len: Length of @name
     *
     * Translates @name into an enum drm_connector_tv_mode.
     *
     * Returns: the enum value on success, a negative errno otherwise.
     */
    int drm_get_tv_mode_from_name(const char *name, size_t len)
    {
    	unsigned int i;
    
    	for (i = 0; i < ARRAY_SIZE(drm_tv_mode_enum_list); i++) {
    		const struct drm_prop_enum_list *item = &drm_tv_mode_enum_list[i];
    
    		if (strlen(item->name) == len && !strncmp(item->name, name, len))
    			return item->type;
    	}
    
    	return -EINVAL;
    }
    EXPORT_SYMBOL(drm_get_tv_mode_from_name);
    
    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, TV-out and DP */
    	{ 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)
    
    static const struct drm_prop_enum_list drm_dp_subconnector_enum_list[] = {
    	{ DRM_MODE_SUBCONNECTOR_Unknown,     "Unknown"   }, /* DVI-I, TV-out and DP */
    	{ DRM_MODE_SUBCONNECTOR_VGA,	     "VGA"       }, /* DP */
    	{ DRM_MODE_SUBCONNECTOR_DVID,	     "DVI-D"     }, /* DP */
    	{ DRM_MODE_SUBCONNECTOR_HDMIA,	     "HDMI"      }, /* DP */
    	{ DRM_MODE_SUBCONNECTOR_DisplayPort, "DP"        }, /* DP */
    	{ DRM_MODE_SUBCONNECTOR_Wireless,    "Wireless"  }, /* DP */
    	{ DRM_MODE_SUBCONNECTOR_Native,	     "Native"    }, /* DP */
    };
    
    DRM_ENUM_NAME_FN(drm_get_dp_subconnector_name,
    		 drm_dp_subconnector_enum_list)
    
    
    static const char * const colorspace_names[] = {
    	/* For Default case, driver will set the colorspace */
    	[DRM_MODE_COLORIMETRY_DEFAULT] = "Default",
    	/* Standard Definition Colorimetry based on CEA 861 */
    	[DRM_MODE_COLORIMETRY_SMPTE_170M_YCC] = "SMPTE_170M_YCC",
    	[DRM_MODE_COLORIMETRY_BT709_YCC] = "BT709_YCC",
    	/* Standard Definition Colorimetry based on IEC 61966-2-4 */
    	[DRM_MODE_COLORIMETRY_XVYCC_601] = "XVYCC_601",
    	/* High Definition Colorimetry based on IEC 61966-2-4 */
    	[DRM_MODE_COLORIMETRY_XVYCC_709] = "XVYCC_709",
    	/* Colorimetry based on IEC 61966-2-1/Amendment 1 */
    	[DRM_MODE_COLORIMETRY_SYCC_601] = "SYCC_601",
    	/* Colorimetry based on IEC 61966-2-5 [33] */
    	[DRM_MODE_COLORIMETRY_OPYCC_601] = "opYCC_601",
    	/* Colorimetry based on IEC 61966-2-5 */
    	[DRM_MODE_COLORIMETRY_OPRGB] = "opRGB",
    	/* Colorimetry based on ITU-R BT.2020 */
    	[DRM_MODE_COLORIMETRY_BT2020_CYCC] = "BT2020_CYCC",
    	/* Colorimetry based on ITU-R BT.2020 */
    	[DRM_MODE_COLORIMETRY_BT2020_RGB] = "BT2020_RGB",
    	/* Colorimetry based on ITU-R BT.2020 */
    	[DRM_MODE_COLORIMETRY_BT2020_YCC] = "BT2020_YCC",
    	/* Added as part of Additional Colorimetry Extension in 861.G */
    	[DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65] = "DCI-P3_RGB_D65",
    	[DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER] = "DCI-P3_RGB_Theater",
    	[DRM_MODE_COLORIMETRY_RGB_WIDE_FIXED] = "RGB_WIDE_FIXED",
    	/* Colorimetry based on scRGB (IEC 61966-2-2) */
    	[DRM_MODE_COLORIMETRY_RGB_WIDE_FLOAT] = "RGB_WIDE_FLOAT",
    	[DRM_MODE_COLORIMETRY_BT601_YCC] = "BT601_YCC",
    };
    
    /**
     * drm_get_colorspace_name - return a string for color encoding
     * @colorspace: color space 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_colorspace_name(enum drm_colorspace colorspace)
    {
    	if (colorspace < ARRAY_SIZE(colorspace_names) && colorspace_names[colorspace])
    		return colorspace_names[colorspace];
    	else
    		return "(null)";
    }
    
    static const u32 hdmi_colorspaces =
    	BIT(DRM_MODE_COLORIMETRY_SMPTE_170M_YCC) |
    	BIT(DRM_MODE_COLORIMETRY_BT709_YCC) |
    	BIT(DRM_MODE_COLORIMETRY_XVYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_XVYCC_709) |
    	BIT(DRM_MODE_COLORIMETRY_SYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_OPYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_OPRGB) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_CYCC) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_RGB) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_YCC) |
    	BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65) |
    	BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER);
    
    /*
     * As per DP 1.4a spec, 2.2.5.7.5 VSC SDP Payload for Pixel Encoding/Colorimetry
     * Format Table 2-120
     */
    static const u32 dp_colorspaces =
    	BIT(DRM_MODE_COLORIMETRY_RGB_WIDE_FIXED) |
    	BIT(DRM_MODE_COLORIMETRY_RGB_WIDE_FLOAT) |
    	BIT(DRM_MODE_COLORIMETRY_OPRGB) |
    	BIT(DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_RGB) |
    	BIT(DRM_MODE_COLORIMETRY_BT601_YCC) |
    	BIT(DRM_MODE_COLORIMETRY_BT709_YCC) |
    	BIT(DRM_MODE_COLORIMETRY_XVYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_XVYCC_709) |
    	BIT(DRM_MODE_COLORIMETRY_SYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_OPYCC_601) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_CYCC) |
    	BIT(DRM_MODE_COLORIMETRY_BT2020_YCC);
    
    /**
     * 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_connector_update_edid_property(), usually after having parsed
     * 	the EDID using drm_add_edid_modes(). Userspace cannot change this
     * 	property.
     *
     * 	User-space should not parse the EDID to obtain information exposed via
     * 	other KMS properties (because the kernel might apply limits, quirks or
     * 	fixups to the EDID). For instance, user-space should not try to parse
     * 	mode lists from the EDID.
     * 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.
     *
     * 	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_connector_set_path_property(), in the case of DP MST with the
     * 	path property the MST manager created. Userspace cannot change this
     * 	property.
     *
     * 	In the case of DP MST, the property has the format
     * 	``mst:<parent>-<ports>`` where ``<parent>`` is the KMS object ID of the
     * 	parent connector and ``<ports>`` is a hyphen-separated list of DP MST
     * 	port numbers. Note, KMS object IDs are not guaranteed to be stable
     * 	across reboots.
     * 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 virtualise both &drm_crtc and &drm_plane if needed. Drivers
     * 	should update this value using drm_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_connector_set_link_status_property().
     *
     *      When user-space receives the hotplug uevent and detects a "BAD"
     *      link-status, the sink doesn't receive pixels anymore (e.g. the screen
     *      becomes completely black). The list of available modes may have
     *      changed. User-space is expected to pick a new mode if the current one
     *      has disappeared and perform a new modeset with link-status set to
     *      "GOOD" to re-enable the connector.
     *
     *      If multiple connectors share the same CRTC and one of them gets a "BAD"
     *      link-status, the other are unaffected (ie. the sinks still continue to
     *      receive pixels).
     *
     *      When user-space performs an atomic commit on a connector with a "BAD"
     *      link-status without resetting the property to "GOOD", the sink may
     *      still not receive pixels. When user-space performs an atomic commit
     *      which resets the link-status property to "GOOD" without the
     *      ALLOW_MODESET flag set, it might fail because a modeset is required.
     *
     *      User-space can only change link-status to "GOOD", changing it to "BAD"
     *      is a no-op.
     *
     *      For backwards compatibility with non-atomic userspace the kernel
     *      tries to automatically set the link-status back to "GOOD" in the
     *      SETCRTC IOCTL. This might fail if the mode is no longer valid, similar
     *      to how it might fail if a different screen has been connected in the
     *      interim.
     * 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.
     * Content Protection:
     *	This property is used by userspace to request the kernel protect future
     *	content communicated over the link. When requested, kernel will apply
     *	the appropriate means of protection (most often HDCP), and use the
     *	property to tell userspace the protection is active.
     *
     *	Drivers can set this up by calling
     *	drm_connector_attach_content_protection_property() on initialization.
     *
     *	The value of this property can be one of the following:
     *
     *	DRM_MODE_CONTENT_PROTECTION_UNDESIRED = 0
     *		The link is not protected, content is transmitted in the clear.
     *	DRM_MODE_CONTENT_PROTECTION_DESIRED = 1
     *		Userspace has requested content protection, but the link is not
     *		currently protected. When in this state, kernel should enable
     *		Content Protection as soon as possible.
     *	DRM_MODE_CONTENT_PROTECTION_ENABLED = 2
     *		Userspace has requested content protection, and the link is
     *		protected. Only the driver can set the property to this value.
     *		If userspace attempts to set to ENABLED, kernel will return
     *		-EINVAL.
     *
     *	A few guidelines:
     *
     *	- DESIRED state should be preserved until userspace de-asserts it by
     *	  setting the property to UNDESIRED. This means ENABLED should only
     *	  transition to UNDESIRED when the user explicitly requests it.
     *	- If the state is DESIRED, kernel should attempt to re-authenticate the
     *	  link whenever possible. This includes across disable/enable, dpms,
     *	  hotplug, downstream device changes, link status failures, etc..
     *	- Kernel sends uevent with the connector id and property id through
     *	  @drm_hdcp_update_content_protection, upon below kernel triggered
     *	  scenarios:
     *
     *		- DESIRED -> ENABLED (authentication success)
     *		- ENABLED -> DESIRED (termination of authentication)
     *	- Please note no uevents for userspace triggered property state changes,
     *	  which can't fail such as
     *
     *		- DESIRED/ENABLED -> UNDESIRED
     *		- UNDESIRED -> DESIRED
     *	- Userspace is responsible for polling the property or listen to uevents
     *	  to determine when the value transitions from ENABLED to DESIRED.
     *	  This signifies the link is no longer protected and userspace should
     *	  take appropriate action (whatever that might be).
     *
     * HDCP Content Type:
     *	This Enum property is used by the userspace to declare the content type
     *	of the display stream, to kernel. Here display stream stands for any
     *	display content that userspace intended to display through HDCP
     *	encryption.
     *
     *	Content Type of a stream is decided by the owner of the stream, as
     *	"HDCP Type0" or "HDCP Type1".
     *
     *	The value of the property can be one of the below:
     *	  - "HDCP Type0": DRM_MODE_HDCP_CONTENT_TYPE0 = 0
     *	  - "HDCP Type1": DRM_MODE_HDCP_CONTENT_TYPE1 = 1
     *
     *	When kernel starts the HDCP authentication (see "Content Protection"
     *	for details), it uses the content type in "HDCP Content Type"
     *	for performing the HDCP authentication with the display sink.
     *
     *	Please note in HDCP spec versions, a link can be authenticated with
     *	HDCP 2.2 for Content Type 0/Content Type 1. Where as a link can be
     *	authenticated with HDCP1.4 only for Content Type 0(though it is implicit
     *	in nature. As there is no reference for Content Type in HDCP1.4).
     *
     *	HDCP2.2 authentication protocol itself takes the "Content Type" as a
     *	parameter, which is a input for the DP HDCP2.2 encryption algo.
     *
     *	In case of Type 0 content protection request, kernel driver can choose
     *	either of HDCP spec versions 1.4 and 2.2. When HDCP2.2 is used for
     *	"HDCP Type 0", a HDCP 2.2 capable repeater in the downstream can send
     *	that content to a HDCP 1.4 authenticated HDCP sink (Type0 link).
     *	But if the content is classified as "HDCP Type 1", above mentioned
     *	HDCP 2.2 repeater wont send the content to the HDCP sink as it can't
     *	authenticate the HDCP1.4 capable sink for "HDCP Type 1".
     *
     *	Please note userspace can be ignorant of the HDCP versions used by the
     *	kernel driver to achieve the "HDCP Content Type".
     *
     *	At current scenario, classifying a content as Type 1 ensures that the
     *	content will be displayed only through the HDCP2.2 encrypted link.
     *
     *	Note that the HDCP Content Type property is introduced at HDCP 2.2, and
     *	defaults to type 0. It is only exposed by drivers supporting HDCP 2.2
     *	(hence supporting Type 0 and Type 1). Based on how next versions of
     *	HDCP specs are defined content Type could be used for higher versions
     *	too.
     *
     *	If content type is changed when "Content Protection" is not UNDESIRED,
     *	then kernel will disable the HDCP and re-enable with new type in the
     *	same atomic commit. And when "Content Protection" is ENABLED, it means
     *	that link is HDCP authenticated and encrypted, for the transmission of
     *	the Type of stream mentioned at "HDCP Content Type".
     *
     * HDR_OUTPUT_METADATA:
     *	Connector property to enable userspace to send HDR Metadata to
     *	driver. This metadata is based on the composition and blending
     *	policies decided by user, taking into account the hardware and
     *	sink capabilities. The driver gets this metadata and creates a
     *	Dynamic Range and Mastering Infoframe (DRM) in case of HDMI,
     *	SDP packet (Non-audio INFOFRAME SDP v1.3) for DP. This is then
     *	sent to sink. This notifies the sink of the upcoming frame's Color
     *	Encoding and Luminance parameters.
     *
     *	Userspace first need to detect the HDR capabilities of sink by
     *	reading and parsing the EDID. Details of HDR metadata for HDMI
     *	are added in CTA 861.G spec. For DP , its defined in VESA DP
     *	Standard v1.4. It needs to then get the metadata information
     *	of the video/game/app content which are encoded in HDR (basically
     *	using HDR transfer functions). With this information it needs to
     *	decide on a blending policy and compose the relevant
     *	layers/overlays into a common format. Once this blending is done,
     *	userspace will be aware of the metadata of the composed frame to
     *	be send to sink. It then uses this property to communicate this
     *	metadata to driver which then make a Infoframe packet and sends
     *	to sink based on the type of encoder connected.
     *
     *	Userspace will be responsible to do Tone mapping operation in case:
     *		- Some layers are HDR and others are SDR
     *		- HDR layers luminance is not same as sink
     *
     *	It will even need to do colorspace conversion and get all layers
     *	to one common colorspace for blending. It can use either GL, Media
     *	or display engine to get this done based on the capabilities of the
     *	associated hardware.
     *
     *	Driver expects metadata to be put in &struct hdr_output_metadata
     *	structure from userspace. This is received as blob and stored in
     *	&drm_connector_state.hdr_output_metadata. It parses EDID and saves the
     *	sink metadata in &struct hdr_sink_metadata, as
     *	&drm_connector.hdr_sink_metadata.  Driver uses
     *	drm_hdmi_infoframe_set_hdr_metadata() helper to set the HDR metadata,
     *	hdmi_drm_infoframe_pack() to pack the infoframe as per spec, in case of
     *	HDMI encoder.
     *
     * max bpc:
     *	This range property is used by userspace to limit the bit depth. When
     *	used the driver would limit the bpc in accordance with the valid range
     *	supported by the hardware and sink. Drivers to use the function
     *	drm_connector_attach_max_bpc_property() to create and attach the
     *	property to the connector during initialization.
     *
     * Connectors also have one standardized atomic property:
     *
     * CRTC_ID:
     * 	Mode object ID of the &drm_crtc this connector should be connected to.
     *
     * Connectors for LCD panels may also have one standardized property:
     *
     * panel orientation:
     *	On some devices the LCD panel is mounted in the casing in such a way
     *	that the up/top side of the panel does not match with the top side of
     *	the device. Userspace can use this property to check for this.
     *	Note that input coordinates from touchscreens (input devices with
     *	INPUT_PROP_DIRECT) will still map 1:1 to the actual LCD panel
     *	coordinates, so if userspace rotates the picture to adjust for
     *	the orientation it must also apply the same transformation to the
     *	touchscreen input coordinates. This property is initialized by calling
     *	drm_connector_set_panel_orientation() or
     *	drm_connector_set_panel_orientation_with_quirk()
     *
     * scaling mode:
     *	This property defines how a non-native mode is upscaled to the native
     *	mode of an LCD panel:
     *
     *	None:
     *		No upscaling happens, scaling is left to the panel. Not all
     *		drivers expose this mode.
     *	Full:
     *		The output is upscaled to the full resolution of the panel,
     *		ignoring the aspect ratio.
     *	Center:
     *		No upscaling happens, the output is centered within the native
     *		resolution the panel.
     *	Full aspect:
     *		The output is upscaled to maximize either the width or height
     *		while retaining the aspect ratio.
     *
     *	This property should be set up by calling
     *	drm_connector_attach_scaling_mode_property(). Note that drivers
     *	can also expose this property to external outputs, in which case they
     *	must support "None", which should be the default (since external screens
     *	have a built-in scaler).
     *
     * subconnector:
     *	This property is used by DVI-I, TVout and DisplayPort to indicate different
     *	connector subtypes. Enum values more or less match with those from main
     *	connector types.
     *	For DVI-I and TVout there is also a matching property "select subconnector"
     *	allowing to switch between signal types.
     *	DP subconnector corresponds to a downstream port.
     *
     * privacy-screen sw-state, privacy-screen hw-state:
     *	These 2 optional properties can be used to query the state of the
     *	electronic privacy screen that is available on some displays; and in
     *	some cases also control the state. If a driver implements these
     *	properties then both properties must be present.
     *
     *	"privacy-screen hw-state" is read-only and reflects the actual state
     *	of the privacy-screen, possible values: "Enabled", "Disabled,
     *	"Enabled-locked", "Disabled-locked". The locked states indicate
     *	that the state cannot be changed through the DRM API. E.g. there
     *	might be devices where the firmware-setup options, or a hardware
     *	slider-switch, offer always on / off modes.
     *
     *	"privacy-screen sw-state" can be set to change the privacy-screen state
     *	when not locked. In this case the driver must update the hw-state
     *	property to reflect the new state on completion of the commit of the
     *	sw-state property. Setting the sw-state property when the hw-state is
     *	locked must be interpreted by the driver as a request to change the
     *	state to the set state when the hw-state becomes unlocked. E.g. if
     *	"privacy-screen hw-state" is "Enabled-locked" and the sw-state
     *	gets set to "Disabled" followed by the user unlocking the state by
     *	changing the slider-switch position, then the driver must set the
     *	state to "Disabled" upon receiving the unlock event.
     *
     *	In some cases the privacy-screen's actual state might change outside of
     *	control of the DRM code. E.g. there might be a firmware handled hotkey
     *	which toggles the actual state, or the actual state might be changed
     *	through another userspace API such as writing /proc/acpi/ibm/lcdshadow.
     *	In this case the driver must update both the hw-state and the sw-state
     *	to reflect the new value, overwriting any pending state requests in the
     *	sw-state. Any pending sw-state requests are thus discarded.
     *
     *	Note that the ability for the state to change outside of control of
     *	the DRM master process means that userspace must not cache the value
     *	of the sw-state. Caching the sw-state value and including it in later
     *	atomic commits may lead to overriding a state change done through e.g.
     *	a firmware handled hotkey. Therefor userspace must not include the
     *	privacy-screen sw-state in an atomic commit unless it wants to change
     *	its value.
     *
     * left margin, right margin, top margin, bottom margin:
     *	Add margins to the connector's viewport. This is typically used to
     *	mitigate overscan on TVs.
     *
     *	The value is the size in pixels of the black border which will be
     *	added. The attached CRTC's content will be scaled to fill the whole
     *	area inside the margin.
     *
     *	The margins configuration might be sent to the sink, e.g. via HDMI AVI
     *	InfoFrames.
     *
     *	Drivers can set up these properties by calling
     *	drm_mode_create_tv_margin_properties().
     */
    
    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;
    
    	prop = drm_property_create(dev, DRM_MODE_PROP_BLOB,
    				   "HDR_OUTPUT_METADATA", 0);
    	if (!prop)
    		return -ENOMEM;
    	dev->mode_config.hdr_output_metadata_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.
     *
     * Returns: %0
     */
    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_connector_attach_dp_subconnector_property - create subconnector property for DP
     * @connector: drm_connector to attach property
     *
     * Called by a driver when DP connector is created.
     */
    void drm_connector_attach_dp_subconnector_property(struct drm_connector *connector)
    {
    	struct drm_mode_config *mode_config = &connector->dev->mode_config;
    
    	if (!mode_config->dp_subconnector_property)
    		mode_config->dp_subconnector_property =
    			drm_property_create_enum(connector->dev,
    				DRM_MODE_PROP_IMMUTABLE,
    				"subconnector",
    				drm_dp_subconnector_enum_list,
    				ARRAY_SIZE(drm_dp_subconnector_enum_list));
    
    	drm_object_attach_property(&connector->base,
    				   mode_config->dp_subconnector_property,
    				   DRM_MODE_SUBCONNECTOR_Unknown);
    }
    EXPORT_SYMBOL(drm_connector_attach_dp_subconnector_property);
    
    /**
     * DOC: HDMI connector properties
     *
     * content type (HDMI specific):
     *	Indicates content type setting to be used in HDMI infoframes to indicate
     *	content type for the external device, so that it adjusts its display
     *	settings accordingly.
     *
     *	The value of this property can be one of the following:
     *
     *	No Data:
     *		Content type is unknown
     *	Graphics:
     *		Content type is graphics
     *	Photo:
     *		Content type is photo
     *	Cinema:
     *		Content type is cinema
     *	Game:
     *		Content type is game
     *
     *	The meaning of each content type is defined in CTA-861-G table 15.
     *
     *	Drivers can set up this property by calling
     *	drm_connector_attach_content_type_property(). Decoding to
     *	infoframe values is done through drm_hdmi_avi_infoframe_content_type().
     */
    
    /*
     * TODO: Document the properties:
     *   - brightness
     *   - contrast
     *   - flicker reduction
     *   - hue
     *   - mode
     *   - overscan
     *   - saturation
     *   - select subconnector
     */
    /**
     * DOC: Analog TV Connector Properties
     *
     * TV Mode:
     *	Indicates the TV Mode used on an analog TV connector. The value
     *	of this property can be one of the following:
     *
     *	NTSC:
     *		TV Mode is CCIR System M (aka 525-lines) together with
     *		the NTSC Color Encoding.
     *
     *	NTSC-443:
     *
     *		TV Mode is CCIR System M (aka 525-lines) together with
     *		the NTSC Color Encoding, but with a color subcarrier
     *		frequency of 4.43MHz
     *
     *	NTSC-J:
     *
     *		TV Mode is CCIR System M (aka 525-lines) together with
     *		the NTSC Color Encoding, but with a black level equal to
     *		the blanking level.
     *
     *	PAL:
     *
     *		TV Mode is CCIR System B (aka 625-lines) together with
     *		the PAL Color Encoding.
     *
     *	PAL-M:
     *
     *		TV Mode is CCIR System M (aka 525-lines) together with
     *		the PAL Color Encoding.
     *
     *	PAL-N:
     *
     *		TV Mode is CCIR System N together with the PAL Color
     *		Encoding, a color subcarrier frequency of 3.58MHz, the
     *		SECAM color space, and narrower channels than other PAL
     *		variants.
     *
     *	SECAM:
     *
     *		TV Mode is CCIR System B (aka 625-lines) together with
     *		the SECAM Color Encoding.
     *
     *	Drivers can set up this property by calling
     *	drm_mode_create_tv_properties().
     */
    
    /**
     * drm_connector_attach_content_type_property - attach content-type property
     * @connector: connector to attach content type property on.
     *
     * Called by a driver the first time a HDMI connector is made.
     *
     * Returns: %0
     */
    int drm_connector_attach_content_type_property(struct drm_connector *connector)
    {
    	if (!drm_mode_create_content_type_property(connector->dev))
    		drm_object_attach_property(&connector->base,
    					   connector->dev->mode_config.content_type_property,
    					   DRM_MODE_CONTENT_TYPE_NO_DATA);
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_content_type_property);
    
    /**
     * drm_connector_attach_tv_margin_properties - attach TV connector margin
     * 	properties
     * @connector: DRM connector
     *
     * Called by a driver when it needs to attach TV margin props to a connector.
     * Typically used on SDTV and HDMI connectors.
     */
    void drm_connector_attach_tv_margin_properties(struct drm_connector *connector)
    {
    	struct drm_device *dev = connector->dev;
    
    	drm_object_attach_property(&connector->base,
    				   dev->mode_config.tv_left_margin_property,
    				   0);
    	drm_object_attach_property(&connector->base,
    				   dev->mode_config.tv_right_margin_property,
    				   0);
    	drm_object_attach_property(&connector->base,
    				   dev->mode_config.tv_top_margin_property,
    				   0);
    	drm_object_attach_property(&connector->base,
    				   dev->mode_config.tv_bottom_margin_property,
    				   0);
    }
    EXPORT_SYMBOL(drm_connector_attach_tv_margin_properties);
    
    /**
     * drm_mode_create_tv_margin_properties - create TV connector margin properties
     * @dev: DRM device
     *
     * Called by a driver's HDMI connector initialization routine, this function
     * creates the TV margin properties for a given device. No need to call this
     * function for an SDTV connector, it's already called from
     * drm_mode_create_tv_properties_legacy().
     *
     * Returns:
     * 0 on success or a negative error code on failure.
     */
    int drm_mode_create_tv_margin_properties(struct drm_device *dev)
    {
    	if (dev->mode_config.tv_left_margin_property)
    		return 0;
    
    	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)
    		return -ENOMEM;
    
    	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)
    		return -ENOMEM;
    
    	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)
    		return -ENOMEM;
    
    	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)
    		return -ENOMEM;
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_mode_create_tv_margin_properties);
    
    /**
     * drm_mode_create_tv_properties_legacy - 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.
     *
     * NOTE: This functions registers the deprecated "mode" connector
     * property to select the analog TV mode (ie, NTSC, PAL, etc.). New
     * drivers must use drm_mode_create_tv_properties() instead.
     *
     * Returns:
     * 0 on success or a negative error code on failure.
     */
    int drm_mode_create_tv_properties_legacy(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.
    	 */
    	if (drm_mode_create_tv_margin_properties(dev))
    		goto nomem;
    
    	if (num_modes) {
    		dev->mode_config.legacy_tv_mode_property =
    			drm_property_create(dev, DRM_MODE_PROP_ENUM,
    					    "mode", num_modes);
    		if (!dev->mode_config.legacy_tv_mode_property)
    			goto nomem;
    
    		for (i = 0; i < num_modes; i++)
    			drm_property_add_enum(dev->mode_config.legacy_tv_mode_property,
    					      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_legacy);
    
    /**
     * drm_mode_create_tv_properties - create TV specific connector properties
     * @dev: DRM device
     * @supported_tv_modes: Bitmask of TV modes supported (See DRM_MODE_TV_MODE_*)
     *
     * Called by a driver's TV initialization routine, this function creates
     * the TV specific connector properties for a given device.
     *
     * Returns:
     * 0 on success or a negative error code on failure.
     */
    int drm_mode_create_tv_properties(struct drm_device *dev,
    				  unsigned int supported_tv_modes)
    {
    	struct drm_prop_enum_list tv_mode_list[DRM_MODE_TV_MODE_MAX];
    	struct drm_property *tv_mode;
    	unsigned int i, len = 0;
    
    	if (dev->mode_config.tv_mode_property)
    		return 0;
    
    	for (i = 0; i < DRM_MODE_TV_MODE_MAX; i++) {
    		if (!(supported_tv_modes & BIT(i)))
    			continue;
    
    		tv_mode_list[len].type = i;
    		tv_mode_list[len].name = drm_get_tv_mode_name(i);
    		len++;
    	}
    
    	tv_mode = drm_property_create_enum(dev, 0, "TV mode",
    					   tv_mode_list, len);
    	if (!tv_mode)
    		return -ENOMEM;
    
    	dev->mode_config.tv_mode_property = tv_mode;
    
    	return drm_mode_create_tv_properties_legacy(dev, 0, NULL);
    }
    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.scaling_mode
     * in the atomic state.
     *
     * Returns: %0
     */
    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);
    
    /**
     * DOC: Variable refresh properties
     *
     * Variable refresh rate capable displays can dynamically adjust their
     * refresh rate by extending the duration of their vertical front porch
     * until page flip or timeout occurs. This can reduce or remove stuttering
     * and latency in scenarios where the page flip does not align with the
     * vblank interval.
     *
     * An example scenario would be an application flipping at a constant rate
     * of 48Hz on a 60Hz display. The page flip will frequently miss the vblank
     * interval and the same contents will be displayed twice. This can be
     * observed as stuttering for content with motion.
     *
     * If variable refresh rate was active on a display that supported a
     * variable refresh range from 35Hz to 60Hz no stuttering would be observable
     * for the example scenario. The minimum supported variable refresh rate of
     * 35Hz is below the page flip frequency and the vertical front porch can
     * be extended until the page flip occurs. The vblank interval will be
     * directly aligned to the page flip rate.
     *
     * Not all userspace content is suitable for use with variable refresh rate.
     * Large and frequent changes in vertical front porch duration may worsen
     * perceived stuttering for input sensitive applications.
     *
     * Panel brightness will also vary with vertical front porch duration. Some
     * panels may have noticeable differences in brightness between the minimum
     * vertical front porch duration and the maximum vertical front porch duration.
     * Large and frequent changes in vertical front porch duration may produce
     * observable flickering for such panels.
     *
     * Userspace control for variable refresh rate is supported via properties
     * on the &drm_connector and &drm_crtc objects.
     *
     * "vrr_capable":
     *	Optional &drm_connector boolean property that drivers should attach
     *	with drm_connector_attach_vrr_capable_property() on connectors that
     *	could support variable refresh rates. Drivers should update the
     *	property value by calling drm_connector_set_vrr_capable_property().
     *
     *	Absence of the property should indicate absence of support.
     *
     * "VRR_ENABLED":
     *	Default &drm_crtc boolean property that notifies the driver that the
     *	content on the CRTC is suitable for variable refresh rate presentation.
     *	The driver will take this property as a hint to enable variable
     *	refresh rate support if the receiver supports it, ie. if the
     *	"vrr_capable" property is true on the &drm_connector object. The
     *	vertical front porch duration will be extended until page-flip or
     *	timeout when enabled.
     *
     *	The minimum vertical front porch duration is defined as the vertical
     *	front porch duration for the current mode.
     *
     *	The maximum vertical front porch duration is greater than or equal to
     *	the minimum vertical front porch duration. The duration is derived
     *	from the minimum supported variable refresh rate for the connector.
     *
     *	The driver may place further restrictions within these minimum
     *	and maximum bounds.
     */
    
    /**
     * drm_connector_attach_vrr_capable_property - creates the
     * vrr_capable property
     * @connector: connector to create the vrr_capable property on.
     *
     * This is used by atomic drivers to add support for querying
     * variable refresh rate capability for a connector.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_attach_vrr_capable_property(
    	struct drm_connector *connector)
    {
    	struct drm_device *dev = connector->dev;
    	struct drm_property *prop;
    
    	if (!connector->vrr_capable_property) {
    		prop = drm_property_create_bool(dev, DRM_MODE_PROP_IMMUTABLE,
    			"vrr_capable");
    		if (!prop)
    			return -ENOMEM;
    
    		connector->vrr_capable_property = prop;
    		drm_object_attach_property(&connector->base, prop, 0);
    	}
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_vrr_capable_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.scaling_mode
     * 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;
    	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,
    					    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);
    
    /**
     * DOC: standard connector properties
     *
     * Colorspace:
     *     This property helps select a suitable colorspace based on the sink
     *     capability. Modern sink devices support wider gamut like BT2020.
     *     This helps switch to BT2020 mode if the BT2020 encoded video stream
     *     is being played by the user, same for any other colorspace. Thereby
     *     giving a good visual experience to users.
     *
     *     The expectation from userspace is that it should parse the EDID
     *     and get supported colorspaces. Use this property and switch to the
     *     one supported. Sink supported colorspaces should be retrieved by
     *     userspace from EDID and driver will not explicitly expose them.
     *
     *     Basically the expectation from userspace is:
     *      - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink
     *        colorspace
     *      - Set this new property to let the sink know what it
     *        converted the CRTC output to.
     *      - This property is just to inform sink what colorspace
     *        source is trying to drive.
     *
     * Because between HDMI and DP have different colorspaces,
     * drm_mode_create_hdmi_colorspace_property() is used for HDMI connector and
     * drm_mode_create_dp_colorspace_property() is used for DP connector.
     */
    
    static int drm_mode_create_colorspace_property(struct drm_connector *connector,
    					u32 supported_colorspaces)
    {
    	struct drm_device *dev = connector->dev;
    	u32 colorspaces = supported_colorspaces | BIT(DRM_MODE_COLORIMETRY_DEFAULT);
    	struct drm_prop_enum_list enum_list[DRM_MODE_COLORIMETRY_COUNT];
    	int i, len;
    
    	if (connector->colorspace_property)
    		return 0;
    
    	if (!supported_colorspaces) {
    		drm_err(dev, "No supported colorspaces provded on [CONNECTOR:%d:%s]\n",
    			    connector->base.id, connector->name);
    		return -EINVAL;
    	}
    
    	if ((supported_colorspaces & -BIT(DRM_MODE_COLORIMETRY_COUNT)) != 0) {
    		drm_err(dev, "Unknown colorspace provded on [CONNECTOR:%d:%s]\n",
    			    connector->base.id, connector->name);
    		return -EINVAL;
    	}
    
    	len = 0;
    	for (i = 0; i < DRM_MODE_COLORIMETRY_COUNT; i++) {
    		if ((colorspaces & BIT(i)) == 0)
    			continue;
    
    		enum_list[len].type = i;
    		enum_list[len].name = colorspace_names[i];
    		len++;
    	}
    
    	connector->colorspace_property =
    		drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, "Colorspace",
    					enum_list,
    					len);
    
    	if (!connector->colorspace_property)
    		return -ENOMEM;
    
    	return 0;
    }
    
    /**
     * drm_mode_create_hdmi_colorspace_property - create hdmi colorspace property
     * @connector: connector to create the Colorspace property on.
     * @supported_colorspaces: bitmap of supported color spaces
     *
     * Called by a driver the first time it's needed, must be attached to desired
     * HDMI connectors.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_mode_create_hdmi_colorspace_property(struct drm_connector *connector,
    					     u32 supported_colorspaces)
    {
    	u32 colorspaces;
    
    	if (supported_colorspaces)
    		colorspaces = supported_colorspaces & hdmi_colorspaces;
    	else
    		colorspaces = hdmi_colorspaces;
    
    	return drm_mode_create_colorspace_property(connector, colorspaces);
    }
    EXPORT_SYMBOL(drm_mode_create_hdmi_colorspace_property);
    
    /**
     * drm_mode_create_dp_colorspace_property - create dp colorspace property
     * @connector: connector to create the Colorspace property on.
     * @supported_colorspaces: bitmap of supported color spaces
     *
     * Called by a driver the first time it's needed, must be attached to desired
     * DP connectors.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_mode_create_dp_colorspace_property(struct drm_connector *connector,
    					   u32 supported_colorspaces)
    {
    	u32 colorspaces;
    
    	if (supported_colorspaces)
    		colorspaces = supported_colorspaces & dp_colorspaces;
    	else
    		colorspaces = dp_colorspaces;
    
    	return drm_mode_create_colorspace_property(connector, colorspaces);
    }
    EXPORT_SYMBOL(drm_mode_create_dp_colorspace_property);
    
    /**
     * drm_mode_create_content_type_property - create content type 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_content_type_property(struct drm_device *dev)
    {
    	if (dev->mode_config.content_type_property)
    		return 0;
    
    	dev->mode_config.content_type_property =
    		drm_property_create_enum(dev, 0, "content type",
    					 drm_content_type_enum_list,
    					 ARRAY_SIZE(drm_content_type_enum_list));
    
    	if (dev->mode_config.content_type_property == NULL)
    		return -ENOMEM;
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_mode_create_content_type_property);
    
    /**
     * drm_mode_create_suggested_offset_properties - create suggests offset properties
     * @dev: DRM device
     *
     * Create the suggested x/y offset property for connectors.
     *
     * Returns:
     * 0 on success or a negative error code on failure.
     */
    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_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_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_connector_set_path_property);
    
    /**
     * drm_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.
     * This is used for dual port tiled displays with DisplayPort SST
     * or DisplayPort MST connectors.
     *
     * Returns:
     * Zero on success, errno on failure.
     */
    int drm_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_connector_set_tile_property);
    
    /**
     * drm_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_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_connector_set_link_status_property);
    
    /**
     * drm_connector_attach_max_bpc_property - attach "max bpc" property
     * @connector: connector to attach max bpc property on.
     * @min: The minimum bit depth supported by the connector.
     * @max: The maximum bit depth supported by the connector.
     *
     * This is used to add support for limiting the bit depth on a connector.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
    					  int min, int max)
    {
    	struct drm_device *dev = connector->dev;
    	struct drm_property *prop;
    
    	prop = connector->max_bpc_property;
    	if (!prop) {
    		prop = drm_property_create_range(dev, 0, "max bpc", min, max);
    		if (!prop)
    			return -ENOMEM;
    
    		connector->max_bpc_property = prop;
    	}
    
    	drm_object_attach_property(&connector->base, prop, max);
    	connector->state->max_requested_bpc = max;
    	connector->state->max_bpc = max;
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_max_bpc_property);
    
    /**
     * drm_connector_attach_hdr_output_metadata_property - attach "HDR_OUTPUT_METADA" property
     * @connector: connector to attach the property on.
     *
     * This is used to allow the userspace to send HDR Metadata to the
     * driver.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_attach_hdr_output_metadata_property(struct drm_connector *connector)
    {
    	struct drm_device *dev = connector->dev;
    	struct drm_property *prop = dev->mode_config.hdr_output_metadata_property;
    
    	drm_object_attach_property(&connector->base, prop, 0);
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_hdr_output_metadata_property);
    
    /**
     * drm_connector_attach_colorspace_property - attach "Colorspace" property
     * @connector: connector to attach the property on.
     *
     * This is used to allow the userspace to signal the output colorspace
     * to the driver.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_attach_colorspace_property(struct drm_connector *connector)
    {
    	struct drm_property *prop = connector->colorspace_property;
    
    	drm_object_attach_property(&connector->base, prop, DRM_MODE_COLORIMETRY_DEFAULT);
    
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_attach_colorspace_property);
    
    /**
     * drm_connector_atomic_hdr_metadata_equal - checks if the hdr metadata changed
     * @old_state: old connector state to compare
     * @new_state: new connector state to compare
     *
     * This is used by HDR-enabled drivers to test whether the HDR metadata
     * have changed between two different connector state (and thus probably
     * requires a full blown mode change).
     *
     * Returns:
     * True if the metadata are equal, False otherwise
     */
    bool drm_connector_atomic_hdr_metadata_equal(struct drm_connector_state *old_state,
    					     struct drm_connector_state *new_state)
    {
    	struct drm_property_blob *old_blob = old_state->hdr_output_metadata;
    	struct drm_property_blob *new_blob = new_state->hdr_output_metadata;
    
    	if (!old_blob || !new_blob)
    		return old_blob == new_blob;
    
    	if (old_blob->length != new_blob->length)
    		return false;
    
    	return !memcmp(old_blob->data, new_blob->data, old_blob->length);
    }
    EXPORT_SYMBOL(drm_connector_atomic_hdr_metadata_equal);
    
    /**
     * drm_connector_set_vrr_capable_property - sets the variable refresh rate
     * capable property for a connector
     * @connector: drm connector
     * @capable: True if the connector is variable refresh rate capable
     *
     * Should be used by atomic drivers to update the indicated support for
     * variable refresh rate over a connector.
     */
    void drm_connector_set_vrr_capable_property(
    		struct drm_connector *connector, bool capable)
    {
    	if (!connector->vrr_capable_property)
    		return;
    
    	drm_object_property_set_value(&connector->base,
    				      connector->vrr_capable_property,
    				      capable);
    }
    EXPORT_SYMBOL(drm_connector_set_vrr_capable_property);
    
    /**
     * drm_connector_set_panel_orientation - sets the connector's panel_orientation
     * @connector: connector for which to set the panel-orientation property.
     * @panel_orientation: drm_panel_orientation value to set
     *
     * This function sets the connector's panel_orientation and attaches
     * a "panel orientation" property to the connector.
     *
     * Calling this function on a connector where the panel_orientation has
     * already been set is a no-op (e.g. the orientation has been overridden with
     * a kernel commandline option).
     *
     * It is allowed to call this function with a panel_orientation of
     * DRM_MODE_PANEL_ORIENTATION_UNKNOWN, in which case it is a no-op.
     *
     * The function shouldn't be called in panel after drm is registered (i.e.
     * drm_dev_register() is called in drm).
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_set_panel_orientation(
    	struct drm_connector *connector,
    	enum drm_panel_orientation panel_orientation)
    {
    	struct drm_device *dev = connector->dev;
    	struct drm_display_info *info = &connector->display_info;
    	struct drm_property *prop;
    
    	/* Already set? */
    	if (info->panel_orientation != DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
    		return 0;
    
    	/* Don't attach the property if the orientation is unknown */
    	if (panel_orientation == DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
    		return 0;
    
    	info->panel_orientation = panel_orientation;
    
    	prop = dev->mode_config.panel_orientation_property;
    	if (!prop) {
    		prop = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
    				"panel orientation",
    				drm_panel_orientation_enum_list,
    				ARRAY_SIZE(drm_panel_orientation_enum_list));
    		if (!prop)
    			return -ENOMEM;
    
    		dev->mode_config.panel_orientation_property = prop;
    	}
    
    	drm_object_attach_property(&connector->base, prop,
    				   info->panel_orientation);
    	return 0;
    }
    EXPORT_SYMBOL(drm_connector_set_panel_orientation);
    
    /**
     * drm_connector_set_panel_orientation_with_quirk - set the
     *	connector's panel_orientation after checking for quirks
     * @connector: connector for which to init the panel-orientation property.
     * @panel_orientation: drm_panel_orientation value to set
     * @width: width in pixels of the panel, used for panel quirk detection
     * @height: height in pixels of the panel, used for panel quirk detection
     *
     * Like drm_connector_set_panel_orientation(), but with a check for platform
     * specific (e.g. DMI based) quirks overriding the passed in panel_orientation.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_set_panel_orientation_with_quirk(
    	struct drm_connector *connector,
    	enum drm_panel_orientation panel_orientation,
    	int width, int height)
    {
    	int orientation_quirk;
    
    	orientation_quirk = drm_get_panel_orientation_quirk(width, height);
    	if (orientation_quirk != DRM_MODE_PANEL_ORIENTATION_UNKNOWN)
    		panel_orientation = orientation_quirk;
    
    	return drm_connector_set_panel_orientation(connector,
    						   panel_orientation);
    }
    EXPORT_SYMBOL(drm_connector_set_panel_orientation_with_quirk);
    
    /**
     * drm_connector_set_orientation_from_panel -
     *	set the connector's panel_orientation from panel's callback.
     * @connector: connector for which to init the panel-orientation property.
     * @panel: panel that can provide orientation information.
     *
     * Drm drivers should call this function before drm_dev_register().
     * Orientation is obtained from panel's .get_orientation() callback.
     *
     * Returns:
     * Zero on success, negative errno on failure.
     */
    int drm_connector_set_orientation_from_panel(
    	struct drm_connector *connector,
    	struct drm_panel *panel)
    {
    	enum drm_panel_orientation orientation;
    
    	if (panel && panel->funcs && panel->funcs->get_orientation)
    		orientation = panel->funcs->get_orientation(panel);
    	else
    		orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
    
    	return drm_connector_set_panel_orientation(connector, orientation);
    }
    EXPORT_SYMBOL(drm_connector_set_orientation_from_panel);
    
    static const struct drm_prop_enum_list privacy_screen_enum[] = {
    	{ PRIVACY_SCREEN_DISABLED,		"Disabled" },
    	{ PRIVACY_SCREEN_ENABLED,		"Enabled" },
    	{ PRIVACY_SCREEN_DISABLED_LOCKED,	"Disabled-locked" },
    	{ PRIVACY_SCREEN_ENABLED_LOCKED,	"Enabled-locked" },
    };
    
    /**
     * drm_connector_create_privacy_screen_properties - create the drm connecter's
     *    privacy-screen properties.
     * @connector: connector for which to create the privacy-screen properties
     *
     * This function creates the "privacy-screen sw-state" and "privacy-screen
     * hw-state" properties for the connector. They are not attached.
     */
    void
    drm_connector_create_privacy_screen_properties(struct drm_connector *connector)
    {
    	if (connector->privacy_screen_sw_state_property)
    		return;
    
    	/* Note sw-state only supports the first 2 values of the enum */
    	connector->privacy_screen_sw_state_property =
    		drm_property_create_enum(connector->dev, DRM_MODE_PROP_ENUM,
    				"privacy-screen sw-state",
    				privacy_screen_enum, 2);
    
    	connector->privacy_screen_hw_state_property =
    		drm_property_create_enum(connector->dev,
    				DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_ENUM,
    				"privacy-screen hw-state",
    				privacy_screen_enum,
    				ARRAY_SIZE(privacy_screen_enum));
    }
    EXPORT_SYMBOL(drm_connector_create_privacy_screen_properties);
    
    /**
     * drm_connector_attach_privacy_screen_properties - attach the drm connecter's
     *    privacy-screen properties.
     * @connector: connector on which to attach the privacy-screen properties
     *
     * This function attaches the "privacy-screen sw-state" and "privacy-screen
     * hw-state" properties to the connector. The initial state of both is set
     * to "Disabled".
     */
    void
    drm_connector_attach_privacy_screen_properties(struct drm_connector *connector)
    {
    	if (!connector->privacy_screen_sw_state_property)
    		return;
    
    	drm_object_attach_property(&connector->base,
    				   connector->privacy_screen_sw_state_property,
    				   PRIVACY_SCREEN_DISABLED);
    
    	drm_object_attach_property(&connector->base,
    				   connector->privacy_screen_hw_state_property,
    				   PRIVACY_SCREEN_DISABLED);
    }
    EXPORT_SYMBOL(drm_connector_attach_privacy_screen_properties);
    
    static void drm_connector_update_privacy_screen_properties(
    	struct drm_connector *connector, bool set_sw_state)
    {
    	enum drm_privacy_screen_status sw_state, hw_state;
    
    	drm_privacy_screen_get_state(connector->privacy_screen,
    				     &sw_state, &hw_state);
    
    	if (set_sw_state)
    		connector->state->privacy_screen_sw_state = sw_state;
    	drm_object_property_set_value(&connector->base,
    			connector->privacy_screen_hw_state_property, hw_state);
    }
    
    static int drm_connector_privacy_screen_notifier(
    	struct notifier_block *nb, unsigned long action, void *data)
    {
    	struct drm_connector *connector =
    		container_of(nb, struct drm_connector, privacy_screen_notifier);
    	struct drm_device *dev = connector->dev;
    
    	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
    	drm_connector_update_privacy_screen_properties(connector, true);
    	drm_modeset_unlock(&dev->mode_config.connection_mutex);
    
    	drm_sysfs_connector_property_event(connector,
    					   connector->privacy_screen_sw_state_property);
    	drm_sysfs_connector_property_event(connector,
    					   connector->privacy_screen_hw_state_property);
    
    	return NOTIFY_DONE;
    }
    
    /**
     * drm_connector_attach_privacy_screen_provider - attach a privacy-screen to
     *    the connector
     * @connector: connector to attach the privacy-screen to
     * @priv: drm_privacy_screen to attach
     *
     * Create and attach the standard privacy-screen properties and register
     * a generic notifier for generating sysfs-connector-status-events
     * on external changes to the privacy-screen status.
     * This function takes ownership of the passed in drm_privacy_screen and will
     * call drm_privacy_screen_put() on it when the connector is destroyed.
     */
    void drm_connector_attach_privacy_screen_provider(
    	struct drm_connector *connector, struct drm_privacy_screen *priv)
    {
    	connector->privacy_screen = priv;
    	connector->privacy_screen_notifier.notifier_call =
    		drm_connector_privacy_screen_notifier;
    
    	drm_connector_create_privacy_screen_properties(connector);
    	drm_connector_update_privacy_screen_properties(connector, true);
    	drm_connector_attach_privacy_screen_properties(connector);
    }
    EXPORT_SYMBOL(drm_connector_attach_privacy_screen_provider);
    
    /**
     * drm_connector_update_privacy_screen - update connector's privacy-screen sw-state
     * @connector_state: connector-state to update the privacy-screen for
     *
     * This function calls drm_privacy_screen_set_sw_state() on the connector's
     * privacy-screen.
     *
     * If the connector has no privacy-screen, then this is a no-op.
     */
    void drm_connector_update_privacy_screen(const struct drm_connector_state *connector_state)
    {
    	struct drm_connector *connector = connector_state->connector;
    	int ret;
    
    	if (!connector->privacy_screen)
    		return;
    
    	ret = drm_privacy_screen_set_sw_state(connector->privacy_screen,
    					      connector_state->privacy_screen_sw_state);
    	if (ret) {
    		drm_err(connector->dev, "Error updating privacy-screen sw_state\n");
    		return;
    	}
    
    	/* The hw_state property value may have changed, update it. */
    	drm_connector_update_privacy_screen_properties(connector, false);
    }
    EXPORT_SYMBOL(drm_connector_update_privacy_screen);
    
    int drm_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_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 list_head *modes,
    			     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;
    	/*
    	 * If user-space hasn't configured the driver to expose the modes
    	 * with aspect-ratio, don't expose them. However if such a mode
    	 * is unique, let it be exposed, but reset the aspect-ratio flags
    	 * while preparing the list of user-modes.
    	 */
    	if (!file_priv->aspect_ratio_allowed) {
    		const struct drm_display_mode *mode_itr;
    
    		list_for_each_entry(mode_itr, modes, head) {
    			if (mode_itr->expose_to_userspace &&
    			    drm_mode_match(mode_itr, mode,
    					   DRM_MODE_MATCH_TIMINGS |
    					   DRM_MODE_MATCH_CLOCK |
    					   DRM_MODE_MATCH_FLAGS |
    					   DRM_MODE_MATCH_3D_FLAGS))
    				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;
    	struct drm_mode_modeinfo u_mode;
    	struct drm_mode_modeinfo __user *mode_ptr;
    	uint32_t __user *encoder_ptr;
    	bool is_current_master;
    
    	if (!drm_core_check_feature(dev, DRIVER_MODESET))
    		return -EOPNOTSUPP;
    
    	memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
    
    	connector = drm_connector_lookup(dev, file_priv, out_resp->connector_id);
    	if (!connector)
    		return -ENOENT;
    
    	encoders_count = hweight32(connector->possible_encoders);
    
    	if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
    		copied = 0;
    		encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
    
    		drm_connector_for_each_possible_encoder(connector, encoder) {
    			if (put_user(encoder->base.id, 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;
    
    	is_current_master = drm_is_current_master(file_priv);
    
    	mutex_lock(&dev->mode_config.mutex);
    	if (out_resp->count_modes == 0) {
    		if (is_current_master)
    			connector->funcs->fill_modes(connector,
    						     dev->mode_config.max_width,
    						     dev->mode_config.max_height);
    		else
    			drm_dbg_kms(dev, "User-space requested a forced probe on [CONNECTOR:%d:%s] but is not the DRM master, demoting to read-only probe\n",
    				    connector->base.id, connector->name);
    	}
    
    	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) {
    		WARN_ON(mode->expose_to_userspace);
    
    		if (drm_mode_expose_to_userspace(mode, &connector->modes,
    						 file_priv)) {
    			mode->expose_to_userspace = true;
    			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 (!mode->expose_to_userspace)
    				continue;
    
    			/* Clear the tag for the next time around */
    			mode->expose_to_userspace = false;
    
    			drm_mode_convert_to_umode(&u_mode, mode);
    			/*
    			 * Reset aspect ratio flags of user-mode, if modes with
    			 * aspect-ratio are not supported.
    			 */
    			if (!file_priv->aspect_ratio_allowed)
    				u_mode.flags &= ~DRM_MODE_FLAG_PIC_AR_MASK;
    			if (copy_to_user(mode_ptr + copied,
    					 &u_mode, sizeof(u_mode))) {
    				ret = -EFAULT;
    
    				/*
    				 * Clear the tag for the rest of
    				 * the modes for the next time around.
    				 */
    				list_for_each_entry_continue(mode, &connector->modes, head)
    					mode->expose_to_userspace = false;
    
    				mutex_unlock(&dev->mode_config.mutex);
    
    				goto out;
    			}
    			copied++;
    		}
    	} else {
    		/* Clear the tag for the next time around */
    		list_for_each_entry(mode, &connector->modes, head)
    			mode->expose_to_userspace = false;
    	}
    
    	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;
    }
    
    /**
     * drm_connector_find_by_fwnode - Find a connector based on the associated fwnode
     * @fwnode: fwnode for which to find the matching drm_connector
     *
     * This functions looks up a drm_connector based on its associated fwnode. When
     * a connector is found a reference to the connector is returned. The caller must
     * call drm_connector_put() to release this reference when it is done with the
     * connector.
     *
     * Returns: A reference to the found connector or an ERR_PTR().
     */
    struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
    {
    	struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
    
    	if (!fwnode)
    		return ERR_PTR(-ENODEV);
    
    	mutex_lock(&connector_list_lock);
    
    	list_for_each_entry(connector, &connector_list, global_connector_list_entry) {
    		if (connector->fwnode == fwnode ||
    		    (connector->fwnode && connector->fwnode->secondary == fwnode)) {
    			drm_connector_get(connector);
    			found = connector;
    			break;
    		}
    	}
    
    	mutex_unlock(&connector_list_lock);
    
    	return found;
    }
    
    /**
     * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
     * @connector_fwnode: fwnode_handle to report the event on
     * @status: hot plug detect logical state
     *
     * On some hardware a hotplug event notification may come from outside the display
     * driver / device. An example of this is some USB Type-C setups where the hardware
     * muxes the DisplayPort data and aux-lines but does not pass the altmode HPD
     * status bit to the GPU's DP HPD pin.
     *
     * This function can be used to report these out-of-band events after obtaining
     * a drm_connector reference through calling drm_connector_find_by_fwnode().
     */
    void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
    				     enum drm_connector_status status)
    {
    	struct drm_connector *connector;
    
    	connector = drm_connector_find_by_fwnode(connector_fwnode);
    	if (IS_ERR(connector))
    		return;
    
    	if (connector->funcs->oob_hotplug_event)
    		connector->funcs->oob_hotplug_event(connector, status);
    
    	drm_connector_put(connector);
    }
    EXPORT_SYMBOL(drm_connector_oob_hotplug_event);
    
    
    /**
     * 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,
    					       const 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 NULL.
     */
    struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
    						  const char topology[8])
    {
    	struct drm_tile_group *tg;
    	int ret;
    
    	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
    	if (!tg)
    		return NULL;
    
    	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 = NULL;
    	}
    
    	mutex_unlock(&dev->mode_config.idr_mutex);
    	return tg;
    }
    EXPORT_SYMBOL(drm_mode_create_tile_group);