Commit 4e4dab4b authored by Daniel Scally's avatar Daniel Scally Committed by Mauro Carvalho Chehab
Browse files

media: media.h: Add new media link type 



To describe in the kernel the connection between devices and their
supporting peripherals (for example, a camera sensor and the vcm
driving the focusing lens for it), add a new type of media link
to introduce the concept of these ancillary links.

Add some elements to the uAPI documentation to explain the new link
type, their purpose and some aspects of their current implementation.

Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarDaniel Scally <djrscally@gmail.com>
Reviewed-by: default avatarJean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent af3ed78e

Documentation/userspace-api/media/mediactl/media-controller-model.rst

+6 −0
Original line number Diff line number Diff line
@@ -33,3 +33,9 @@ are: 


-  An **interface link** is a point-to-point bidirectional control

   connection between a Linux Kernel interface and an entity.



- An **ancillary link** is a point-to-point connection denoting that two

  entities form a single logical unit. For example this could represent the

  fact that a particular camera sensor and lens controller form a single

  physical module, meaning this lens controller drives the lens for this

  camera sensor.
 
 No newline at end of file

Documentation/userspace-api/media/mediactl/media-types.rst

+12 −5
Original line number Diff line number Diff line
@@ -412,14 +412,21 @@ must be set for every pad. 
	  is set by drivers and is read-only for applications.



    *  -  ``MEDIA_LNK_FL_LINK_TYPE``

       -  This is a bitmask that defines the type of the link. Currently,

	  two types of links are supported:

       -  This is a bitmask that defines the type of the link. The following

	  link types are currently supported:



	  .. _MEDIA-LNK-FL-DATA-LINK:



	  ``MEDIA_LNK_FL_DATA_LINK`` if the link is between two pads

	  ``MEDIA_LNK_FL_DATA_LINK`` for links that represent a data connection

	  between two pads.



	  .. _MEDIA-LNK-FL-INTERFACE-LINK:



	  ``MEDIA_LNK_FL_INTERFACE_LINK`` if the link is between an

	  interface and an entity
 
	  ``MEDIA_LNK_FL_INTERFACE_LINK`` for links that associate an entity to its

	  interface.



	  .. _MEDIA-LNK-FL-ANCILLARY-LINK:



	  ``MEDIA_LNK_FL_ANCILLARY_LINK`` for links that represent a physical

	  relationship between two entities. The link may or may not be

	  immutable, so applications must not assume either case.

include/uapi/linux/media.h

+1 −0
Original line number Diff line number Diff line
@@ -226,6 +226,7 @@ struct media_pad_desc { 
#define MEDIA_LNK_FL_LINK_TYPE			(0xf << 28)

#  define MEDIA_LNK_FL_DATA_LINK		(0 << 28)

#  define MEDIA_LNK_FL_INTERFACE_LINK		(1 << 28)

#  define MEDIA_LNK_FL_ANCILLARY_LINK		(2 << 28)



struct media_link_desc {

	struct media_pad_desc source;