[media] media: Entities, pads and links enumeration

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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/DocBook/media-entities.tmpl b/Documentation/DocBook/media-entities.tmpl
index 034f891399ed..2bd7b27f8553 100644
--- a/Documentation/DocBook/media-entities.tmpl
+++ b/Documentation/DocBook/media-entities.tmpl
@@ -92,6 +92,8 @@
 <!ENTITY VIDIOC-UNSUBSCRIBE-EVENT "<link linkend='vidioc-subscribe-event'><constant>VIDIOC_UNSUBSCRIBE_EVENT</constant></link>">
 
 <!ENTITY MEDIA-IOC-DEVICE-INFO "<link linkend='media-ioc-device-info'><constant>MEDIA_IOC_DEVICE_INFO</constant></link>">
+<!ENTITY MEDIA-IOC-ENUM-ENTITIES "<link linkend='media-ioc-enum-entities'><constant>MEDIA_IOC_ENUM_ENTITIES</constant></link>">
+<!ENTITY MEDIA-IOC-ENUM-LINKS "<link linkend='media-ioc-enum-links'><constant>MEDIA_IOC_ENUM_LINKS</constant></link>">
 
 <!-- Types -->
 <!ENTITY v4l2-std-id "<link linkend='v4l2-std-id'>v4l2_std_id</link>">
@@ -191,6 +193,10 @@
 <!ENTITY v4l2-window "struct&nbsp;<link linkend='v4l2-window'>v4l2_window</link>">
 
 <!ENTITY media-device-info "struct&nbsp;<link linkend='media-device-info'>media_device_info</link>">
+<!ENTITY media-entity-desc "struct&nbsp;<link linkend='media-entity-desc'>media_entity_desc</link>">
+<!ENTITY media-links-enum "struct&nbsp;<link linkend='media-links-enum'>media_links_enum</link>">
+<!ENTITY media-pad-desc "struct&nbsp;<link linkend='media-pad-desc'>media_pad_desc</link>">
+<!ENTITY media-link-desc "struct&nbsp;<link linkend='media-link-desc'>media_link_desc</link>">
 
 <!-- Error Codes -->
 <!ENTITY EACCES "<errorcode>EACCES</errorcode> error code">
@@ -340,6 +346,8 @@
 <!ENTITY sub-media-close SYSTEM "v4l/media-func-close.xml">
 <!ENTITY sub-media-ioctl SYSTEM "v4l/media-func-ioctl.xml">
 <!ENTITY sub-media-ioc-device-info SYSTEM "v4l/media-ioc-device-info.xml">
+<!ENTITY sub-media-ioc-enum-entities SYSTEM "v4l/media-ioc-enum-entities.xml">
+<!ENTITY sub-media-ioc-enum-links SYSTEM "v4l/media-ioc-enum-links.xml">
 
 <!-- Function Reference -->
 <!ENTITY close SYSTEM "v4l/func-close.xml">