From 5680fe45d66bbef32a902c04889a523fa4fc33ba Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 14 Jun 2022 20:11:09 +0100 Subject: media: mc-entity: Add a new helper function to get a remote pad The media_entity_remote_pad_first() helper function returns the first remote pad it finds connected to a given pad. Beside being possibly non-deterministic (as it stops at the first enabled link), the fact that it returns the first match makes it unsuitable for drivers that need to guarantee that a single link is enabled, for instance when an entity can process data from one of multiple sources at a time. For those use cases, add a new helper function, media_entity_remote_pad_unique(), that operates on an entity and returns a remote pad, with a guarantee that only one link is enabled. To ease its use in drivers, also add an inline wrapper that locates source pads specifically. A wrapper that locates sink pads can easily be added when needed. Signed-off-by: Laurent Pinchart Acked-by: Hans Verkuil Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- Documentation/driver-api/media/mc-core.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'Documentation/driver-api') diff --git a/Documentation/driver-api/media/mc-core.rst b/Documentation/driver-api/media/mc-core.rst index 6eea6a3b6441..66801506b2dd 100644 --- a/Documentation/driver-api/media/mc-core.rst +++ b/Documentation/driver-api/media/mc-core.rst @@ -186,7 +186,8 @@ 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()` and :c:func:`media_pad_remote_pad_first()`. +(:c:func:`media_entity_find_link()`, :c:func:`media_pad_remote_pad_first()` and +:c:func:`media_entity_remote_source_pad_unique()`). Use count and power handling ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -- cgit v1.2.3