[media] media: Links setup

Create the following ioctl and implement it at the media device level to
setup links.

- MEDIA_IOC_SETUP_LINK: Modify the properties of a given link

The only property that can currently be modified is the ENABLED link
flag to enable/disable a link. Links marked with the IMMUTABLE link flag
can not be enabled or disabled.

Enabling or disabling a link has effects on entities' use count. Those
changes are automatically propagated through the graph.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.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, 2 insertions, 0 deletions

diff --git a/Documentation/DocBook/media-entities.tmpl b/Documentation/DocBook/media-entities.tmpl
index 2bd7b27f8553..121db1549244 100644
--- a/Documentation/DocBook/media-entities.tmpl
+++ b/Documentation/DocBook/media-entities.tmpl
@@ -94,6 +94,7 @@
 <!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>">
+<!ENTITY MEDIA-IOC-SETUP-LINK "<link linkend='media-ioc-setup-link'><constant>MEDIA_IOC_SETUP_LINK</constant></link>">
 
 <!-- Types -->
 <!ENTITY v4l2-std-id "<link linkend='v4l2-std-id'>v4l2_std_id</link>">
@@ -348,6 +349,7 @@
 <!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">
+<!ENTITY sub-media-ioc-setup-link SYSTEM "v4l/media-ioc-setup-link.xml">
 
 <!-- Function Reference -->
 <!ENTITY close SYSTEM "v4l/func-close.xml">