Commit 03b28286 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab
Browse files

media: mc-entity: Add a new helper function to get a remote pad for a pad 



The newly added media_entity_remote_source_pad_unique() helper function
handles use cases where the entity has a link enabled uniqueness
constraint covering all pads. There are use cases where the constraint
covers a specific pad only. Add a new media_pad_remote_pad_unique()
function to handle this. It operates as
media_entity_remote_source_pad_unique(), but on a given pad instead of
on the entity.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 5680fe45

Documentation/driver-api/media/mc-core.rst

+3 −2
Original line number Diff line number Diff line
@@ -186,8 +186,9 @@ is required and the graph structure can be freed normally. 


Helper functions can be used to find a link between two given pads, or a pad

connected to another pad through an enabled link

(:c:func:`media_entity_find_link()`, :c:func:`media_pad_remote_pad_first()` and

:c:func:`media_entity_remote_source_pad_unique()`).

(:c:func:`media_entity_find_link()`, :c:func:`media_pad_remote_pad_first()`n

:c:func:`media_entity_remote_source_pad_unique()` and

:c:func:`media_pad_remote_pad_unique()`).



Use count and power handling

^^^^^^^^^^^^^^^^^^^^^^^^^^^^

drivers/media/mc/mc-entity.c

+31 −0
Original line number Diff line number Diff line
@@ -960,6 +960,37 @@ media_entity_remote_pad_unique(const struct media_entity *entity, 
}

EXPORT_SYMBOL_GPL(media_entity_remote_pad_unique);



struct media_pad *media_pad_remote_pad_unique(const struct media_pad *pad)

{

	struct media_pad *found_pad = NULL;

	struct media_link *link;



	list_for_each_entry(link, &pad->entity->links, list) {

		struct media_pad *remote_pad;



		if (!(link->flags & MEDIA_LNK_FL_ENABLED))

			continue;



		if (link->sink == pad)

			remote_pad = link->source;

		else if (link->source == pad)

			remote_pad = link->sink;

		else

			continue;



		if (found_pad)

			return ERR_PTR(-ENOTUNIQ);



		found_pad = remote_pad;

	}



	if (!found_pad)

		return ERR_PTR(-ENOLINK);



	return found_pad;

}

EXPORT_SYMBOL_GPL(media_pad_remote_pad_unique);



static void media_interface_init(struct media_device *mdev,

				 struct media_interface *intf,

				 u32 gobj_type,

include/media/media-entity.h

+18 −0
Original line number Diff line number Diff line
@@ -859,6 +859,24 @@ struct media_link *media_entity_find_link(struct media_pad *source, 
 */

struct media_pad *media_pad_remote_pad_first(const struct media_pad *pad);



/**

 * media_pad_remote_pad_unique - Find a remote pad connected to a pad

 * @pad: The pad

 *

 * Search for and return a remote pad connected to @pad through an enabled

 * link. If multiple (or no) remote pads are found, an error is returned.

 *

 * The uniqueness constraint makes this helper function suitable for entities

 * that support a single active source at a time on a given pad.

 *

 * Return: A pointer to the remote pad, or one of the following error pointers

 * if an error occurs:

 *

 * * -ENOTUNIQ - Multiple links are enabled

 * * -ENOLINK - No connected pad found

 */

struct media_pad *media_pad_remote_pad_unique(const struct media_pad *pad);



/**

 * media_entity_remote_pad_unique - Find a remote pad connected to an entity

 * @entity: The entity