[PATCH 04/31] media: Media Controller enable/disable source handler API

[Shuah Khan <shuahkh@osg.samsung.com>]

Add new fields to struct media_device to add enable_source, and
disable_source handlers, and source_priv to stash driver private
data that is need to run these handlers. The enable_source handler
finds source entity for the passed in entity and check if it is
available, and activate the link using __media_entity_setup_link()
interface. Bridge driver is expected to implement and set these
handlers and private data when media_device is registered or when
bridge driver finds the media_device during probe. This is to enable
the use-case to find tuner entity connected to the decoder entity and
check if it is available, and activate it and start pipeline between
the source and the entity. The disable_source handler deactivates the
link and stops the pipeline. This handler can be invoked from the
media core (v4l-core, dvb-core) as well as other drivers such as ALSA
that control the media device.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
 include/media/media-device.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/include/media/media-device.h b/include/media/media-device.h
index 6520d1c..04b6c2e 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -333,6 +333,25 @@ struct media_device {
 	/* Serializes graph operations. */
 	struct mutex graph_mutex;
 
+	/* Handlers to find source entity for the sink entity and
+	 * check if it is available, and activate the link using
+	 * media_entity_setup_link() interface and start pipeline
+	 * from the source to the entity.
+	 * Bridge driver is expected to implement and set the
+	 * handler when media_device is registered or when
+	 * bridge driver finds the media_device during probe.
+	 * Bridge driver sets source_priv with information
+	 * necessary to run enable/disable source handlers.
+	 *
+	 * Use-case: find tuner entity connected to the decoder
+	 * entity and check if it is available, and activate the
+	 * using media_entity_setup_link() if it is available.
+	*/
+	void *source_priv;
+	int (*enable_source)(struct media_entity *entity,
+			     struct media_pipeline *pipe);
+	void (*disable_source)(struct media_entity *entity);
+
 	int (*link_notify)(struct media_link *link, u32 flags,
 			   unsigned int notification);
 };
-- 
2.5.0