drm/probe-helper: add drm_kms_helper_connector_hotplug_event

This function is the same as drm_kms_helper_hotplug_event, but takes
a connector instead of a device.
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/20211018084707.32253-3-contact@emersion.fr

drivers/gpu/drm/drm_probe_helper.c

@@ -604,6 +604,9 @@ EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
  *
  * This function must be called from process context with no mode
  * setting locks held.
+ *
+ * If only a single connector has changed, consider calling
+ * drm_kms_helper_connector_hotplug_event() instead.
  */
 void drm_kms_helper_hotplug_event(struct drm_device *dev)
 {
@@ -616,6 +619,26 @@ void drm_kms_helper_hotplug_event(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 
+/**
+ * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
+ * @connector: drm_connector which has changed
+ *
+ * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
+ * fine-grained uevent for a single connector.
+ */
+void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+
+	/* send a uevent + call fbdev */
+	drm_sysfs_connector_hotplug_event(connector);
+	if (dev->mode_config.funcs->output_poll_changed)
+		dev->mode_config.funcs->output_poll_changed(dev);
+
+	drm_client_dev_hotplug(dev);
+}
+EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
+
 static void output_poll_execute(struct work_struct *work)
 {
 	struct delayed_work *delayed_work = to_delayed_work(work);

include/drm/drm_probe_helper.h

@@ -20,6 +20,7 @@ void drm_kms_helper_poll_fini(struct drm_device *dev);
 bool drm_helper_hpd_irq_event(struct drm_device *dev);
 bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector);
 void drm_kms_helper_hotplug_event(struct drm_device *dev);
+void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector);
 
 void drm_kms_helper_poll_disable(struct drm_device *dev);
 void drm_kms_helper_poll_enable(struct drm_device *dev);