[media] videodev2.h: add V4L2_CTRL_FLAG_VOLATILE

Add a new VOLATILE control flag that is set for volatile controls.
That way applications know whether the value of the control is volatile
(i.e. can change continuously) or not.

Until now this was an internal property, but it is useful to know in
userspace as well.

A typical use case is the gain value when autogain is on. In that case the
hardware will continuously adjust the gain based various environmental
factors.

This patch just adds and documents the flag, it's not yet used.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml
index 0d05e8747c12..40132c277647 100644
--- a/Documentation/DocBook/media/v4l/v4l2.xml
+++ b/Documentation/DocBook/media/v4l/v4l2.xml
@@ -128,6 +128,13 @@ structs, ioctls) must be noted in more detail in the history chapter
 applications. -->
 
       <revision>
+        <revnumber>3.2</revnumber>
+        <date>2011-08-26</date>
+        <authorinitials>hv</authorinitials>
+        <revremark>Added V4L2_CTRL_FLAG_VOLATILE.</revremark>
+      </revision>
+
+      <revision>
         <revnumber>3.1</revnumber>
         <date>2011-06-27</date>
         <authorinitials>mcc, po, hv</authorinitials>
@@ -410,7 +417,7 @@ and discussions on the V4L mailing list.</revremark>
 </partinfo>
 
 <title>Video for Linux Two API Specification</title>
- <subtitle>Revision 3.1</subtitle>
+ <subtitle>Revision 3.2</subtitle>
 
   <chapter id="common">
     &sub-common;