Signed-off-by: NSylwester Nawrocki <snjw23@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This patch addresses several issues pointed by Randy Dunlap
<rdunlap@xenotime.net> at changeset ece722c:

- In the generated index.html file, "media" is listed first, but it
  should be listed in alphabetical order, not first.

- The generated files are (hidden) in .tmpmedia/

- The link from the top-level index.html file to "media" is to
  media/index.html, but the file is actually in .tmpmedia/media/index.html

- Please build docs with and without using "O=builddir" and test that.

- Would it be possible for media to have its own Makefile instead of
  merging into this one?

Due to the way cleandocs target works, I had to rename the media DocBook
to media_api, otherwise cleandocs would remove the /media directory.

Thanks-to: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Drivers often need to associate pipeline objects to entities, and to
take stream state into account when configuring entities and links. The
pipeline API helps drivers manage that information.

When starting streaming, drivers call media_entity_pipeline_start(). The
function marks all entities connected to the given entity through
enabled links, either directly or indirectly, as streaming. Similarly,
when stopping the stream, drivers call media_entity_pipeline_stop().

The media_entity_pipeline_start() function takes a pointer to a media
pipeline and stores it in every entity in the graph. Drivers should
embed the media_pipeline structure in higher-level pipeline structures
and can then access the pipeline through the media_entity structure.

Link configuration will fail with -EBUSY by default if either end of the
link is a streaming entity, unless the link is marked with the
MEDIA_LNK_FL_DYNAMIC flag.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Create the following two ioctls and implement them at the media device
level to enumerate entities, pads and links.

- MEDIA_IOC_ENUM_ENTITIES: Enumerate entities and their properties
- MEDIA_IOC_ENUM_LINKS: Enumerate all pads and links for a given entity

Entity IDs can be non-contiguous. Userspace applications should
enumerate entities using the MEDIA_ENT_ID_FLAG_NEXT flag. When the flag
is set in the entity ID, the MEDIA_IOC_ENUM_ENTITIES will return the
next entity with an ID bigger than the requested one.

Only forward links that originate at one of the entity's source pads are
returned during the enumeration process.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>