drm/sysfs: introduce drm_sysfs_connector_hotplug_event

This function sends a hotplug uevent with a CONNECTOR property.
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211018084707.32253-2-contact@emersion.fr

drivers/gpu/drm/drm_sysfs.c

@@ -409,6 +409,31 @@ void drm_sysfs_hotplug_event(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 
+/**
+ * drm_sysfs_connector_hotplug_event - generate a DRM uevent for any connector
+ * change
+ * @connector: connector which has changed
+ *
+ * Send a uevent for the DRM connector specified by @connector. This will send
+ * a uevent with the properties HOTPLUG=1 and CONNECTOR.
+ */
+void drm_sysfs_connector_hotplug_event(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	char hotplug_str[] = "HOTPLUG=1", conn_id[21];
+	char *envp[] = { hotplug_str, conn_id, NULL };
+
+	snprintf(conn_id, sizeof(conn_id),
+		 "CONNECTOR=%u", connector->base.id);
+
+	drm_dbg_kms(connector->dev,
+		    "[CONNECTOR:%d:%s] generating connector hotplug event\n",
+		    connector->base.id, connector->name);
+
+	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
+}
+EXPORT_SYMBOL(drm_sysfs_connector_hotplug_event);
+
 /**
  * drm_sysfs_connector_status_event - generate a DRM uevent for connector
  * property status change

include/drm/drm_sysfs.h

@@ -11,6 +11,7 @@ int drm_class_device_register(struct device *dev);
 void drm_class_device_unregister(struct device *dev);
 
 void drm_sysfs_hotplug_event(struct drm_device *dev);
+void drm_sysfs_connector_hotplug_event(struct drm_connector *connector);
 void drm_sysfs_connector_status_event(struct drm_connector *connector,
 				      struct drm_property *property);
 #endif