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authorHans de Goede <hdegoede@redhat.com>2021-08-17 23:51:57 +0200
committerHans de Goede <hdegoede@redhat.com>2021-08-20 12:35:59 +0200
commit72ad49682dde3d9de5708b8699dc8e0b44962322 (patch)
tree2ca65eeea898e7ce78dd668180e9eb0bf7c9398f /drivers/gpu/drm/drm_connector.c
parent3d3f7c1e68691574c1d87cd0f9f2348323bc0199 (diff)
drm/connector: Add support for out-of-band hotplug notification (v3)
Add a new drm_connector_oob_hotplug_event() function and oob_hotplug_event drm_connector_funcs member. 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. In cases like this the new drm_connector_oob_hotplug_event() function can be used to report these out-of-band events. Changes in v2: - Make drm_connector_oob_hotplug_event() take a fwnode as argument and have it call drm_connector_find_by_fwnode() internally. This allows making drm_connector_find_by_fwnode() a drm-internal function and avoids code outside the drm subsystem potentially holding on the a drm_connector reference for a longer period. Changes in v3: - Drop the data argument to the drm_connector_oob_hotplug_event function since it is not used atm. This can be re-added later when a use for it actually arises. Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://lore.kernel.org/r/20210817215201.795062-5-hdegoede@redhat.com
Diffstat (limited to 'drivers/gpu/drm/drm_connector.c')
-rw-r--r--drivers/gpu/drm/drm_connector.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 7d72bcefa4d6..e0a30e0ee86a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2595,6 +2595,33 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
return found;
}
+/**
+ * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
+ * @connector: connector 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