OSCL-LXR linux-6.0.1/​drivers/​gpu/​drm/​drm_connector.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  * 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_edid.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_panel.h>
 #include <drm/drm_utils.h>
 #include <drm/drm_print.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_sysfs.h>
 
 #include <linux/fb.h>
 #include <linux/uaccess.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;
     char *option = NULL;
 
     if (fb_get_options(connector->name, &option))
         return;
 
     if (!drm_mode_parse_command_line_for_connector(option,
                                connector,
                                mode))
         return;
 
     if (mode->force) {
         DRM_INFO("forcing %s connector %s\n", connector->name,
              drm_get_connector_force_name(mode->force));
         connector->force = mode->force;
     }
 
     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);
     }
 }
 
 /**
  * drm_connector_init - Init a preallocated connector
  * @dev: DRM device
  * @connector: the connector to init
  * @funcs: callbacks for this connector
  * @connector_type: user visible type of the connector
  *
  * Initialises a preallocated connector. Connectors should be
  * subclassed as part of driver connector objects.
  *
  * Returns:
  * Zero on success, error code on failure.
  */
 int drm_connector_init(struct drm_device *dev,
                struct drm_connector *connector,
                const struct drm_connector_funcs *funcs,
                int connector_type)
 {
     struct drm_mode_config *config = &dev->mode_config;
     int ret;
     struct ida *connector_ida =
         &drm_connector_enum_list[connector_type].ida;
 
     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;
     }
 
     INIT_LIST_HEAD(&connector->global_connector_list_entry);
     INIT_LIST_HEAD(&connector->probed_modes);
     INIT_LIST_HEAD(&connector->modes);
     mutex_init(&connector->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;
 }
 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.
  *
  * Ensures that the ddc field of the connector is correctly set.
  *
  * 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)
 {
     int ret;
 
     ret = drm_connector_init(dev, connector, funcs, connector_type);
     if (ret)
         return ret;
 
     /* provide ddc symlink in sysfs */
     connector->ddc = ddc;
 
     return ret;
 }
 EXPORT_SYMBOL(drm_connector_init_with_ddc);
 
 /**
  * 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);
     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));
 }
 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().
  *
  * 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;
     }
 
     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_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 registered explicitly by calling drm_dev_register(),
  * since connectors are unregistered automatically when drm_dev_unregister() is
  * called.
  */
 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);
 
     if (connector->funcs->early_unregister)
         connector->funcs->early_unregister(connector);
 
     drm_sysfs_connector_remove(connector);
     drm_debugfs_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_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 struct drm_prop_enum_list hdmi_colorspaces[] = {
     /* 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" },
 };
 
 /*
  * As per DP 1.4a spec, 2.2.5.7.5 VSC SDP Payload for Pixel Encoding/Colorimetry
  * Format Table 2-120
  */
 static const struct drm_prop_enum_list dp_colorspaces[] = {
     /* For Default case, driver will set the colorspace */
     { DRM_MODE_COLORIMETRY_DEFAULT, "Default" },
     { DRM_MODE_COLORIMETRY_RGB_WIDE_FIXED, "RGB_Wide_Gamut_Fixed_Point" },
     /* Colorimetry based on scRGB (IEC 61966-2-2) */
     { DRM_MODE_COLORIMETRY_RGB_WIDE_FLOAT, "RGB_Wide_Gamut_Floating_Point" },
     /* Colorimetry based on IEC 61966-2-5 */
     { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
     /* Colorimetry based on SMPTE RP 431-2 */
     { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
     /* Colorimetry based on ITU-R BT.2020 */
     { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
     { DRM_MODE_COLORIMETRY_BT601_YCC, "BT601_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 ITU-R BT.2020 */
     { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
     /* Colorimetry based on ITU-R BT.2020 */
     { DRM_MODE_COLORIMETRY_BT2020_YCC, "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.
  * 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.
  */
 
 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().
  */
 
 /**
  * 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().
  *
  * 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 - 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.
  *
  * Returns:
  * 0 on success or a negative error code on failure.
  */
 int drm_mode_create_tv_properties(struct drm_device *dev,
                   unsigned int num_modes,
                   const char * const modes[])
 {
     struct drm_property *tv_selector;
     struct drm_property *tv_subconnector;
     unsigned int i;
 
     if (dev->mode_config.tv_select_subconnector_property)
         return 0;
 
     /*
      * Basic connector properties
      */
     tv_selector = drm_property_create_enum(dev, 0,
                       "select subconnector",
                       drm_tv_select_enum_list,
                       ARRAY_SIZE(drm_tv_select_enum_list));
     if (!tv_selector)
         goto nomem;
 
     dev->mode_config.tv_select_subconnector_property = tv_selector;
 
     tv_subconnector =
         drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
                     "subconnector",
                     drm_tv_subconnector_enum_list,
                     ARRAY_SIZE(drm_tv_subconnector_enum_list));
     if (!tv_subconnector)
         goto nomem;
     dev->mode_config.tv_subconnector_property = tv_subconnector;
 
     /*
      * Other, TV specific properties: margins & TV modes.
      */
     if (drm_mode_create_tv_margin_properties(dev))
         goto nomem;
 
     dev->mode_config.tv_mode_property =
         drm_property_create(dev, DRM_MODE_PROP_ENUM,
                     "mode", num_modes);
     if (!dev->mode_config.tv_mode_property)
         goto nomem;
 
     for (i = 0; i < num_modes; i++)
         drm_property_add_enum(dev->mode_config.tv_mode_property,
                       i, modes[i]);
 
     dev->mode_config.tv_brightness_property =
         drm_property_create_range(dev, 0, "brightness", 0, 100);
     if (!dev->mode_config.tv_brightness_property)
         goto nomem;
 
     dev->mode_config.tv_contrast_property =
         drm_property_create_range(dev, 0, "contrast", 0, 100);
     if (!dev->mode_config.tv_contrast_property)
         goto nomem;
 
     dev->mode_config.tv_flicker_reduction_property =
         drm_property_create_range(dev, 0, "flicker reduction", 0, 100);
     if (!dev->mode_config.tv_flicker_reduction_property)
         goto nomem;
 
     dev->mode_config.tv_overscan_property =
         drm_property_create_range(dev, 0, "overscan", 0, 100);
     if (!dev->mode_config.tv_overscan_property)
         goto nomem;
 
     dev->mode_config.tv_saturation_property =
         drm_property_create_range(dev, 0, "saturation", 0, 100);
     if (!dev->mode_config.tv_saturation_property)
         goto nomem;
 
     dev->mode_config.tv_hue_property =
         drm_property_create_range(dev, 0, "hue", 0, 100);
     if (!dev->mode_config.tv_hue_property)
         goto nomem;
 
     return 0;
 nomem:
     return -ENOMEM;
 }
 EXPORT_SYMBOL(drm_mode_create_tv_properties);
 
 /**
  * drm_mode_create_scaling_mode_property - create scaling mode property
  * @dev: DRM device
  *
  * Called by a driver the first time it's needed, must be attached to desired
  * connectors.
  *
  * Atomic drivers should use drm_connector_attach_scaling_mode_property()
  * instead to correctly assign &drm_connector_state.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.
  */
 
 /**
  * drm_mode_create_hdmi_colorspace_property - create hdmi colorspace property
  * @connector: connector to create the Colorspace property on.
  *
  * 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)
 {
     struct drm_device *dev = connector->dev;
 
     if (connector->colorspace_property)
         return 0;
 
     connector->colorspace_property =
         drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, "Colorspace",
                      hdmi_colorspaces,
                      ARRAY_SIZE(hdmi_colorspaces));
 
     if (!connector->colorspace_property)
         return -ENOMEM;
 
     return 0;
 }
 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.
  *
  * 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)
 {
     struct drm_device *dev = connector->dev;
 
     if (connector->colorspace_property)
         return 0;
 
     connector->colorspace_property =
         drm_property_create_enum(dev, DRM_MODE_PROP_ENUM, "Colorspace",
                      dp_colorspaces,
                      ARRAY_SIZE(dp_colorspaces));
 
     if (!connector->colorspace_property)
         return -ENOMEM;
 
     return 0;
 }
 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_status_event(connector,
                 connector->privacy_screen_sw_state_property);
     drm_sysfs_connector_status_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",
                     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
  *
  * 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)
 {
     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);
 
     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);

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