V4L/DVB: videodev2: introduce a common control for chroma gain

Introduce a new control for modifying the chroma gain.  This allows for user
intervention in abnormal signal conditions cases where the decoder's chroma
AGC cannot compensate and the value needs to be adjusted manually.

This work was sponsored by EyeMagnet Limited.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/DocBook/v4l/controls.xml b/Documentation/DocBook/v4l/controls.xml
index f46450610412..e1bdbb6eff84 100644
--- a/Documentation/DocBook/v4l/controls.xml
+++ b/Documentation/DocBook/v4l/controls.xml
@@ -267,6 +267,12 @@ minimum value disables backlight compensation.</entry>
             <entry>Chroma automatic gain control.</entry>
           </row>
           <row>
+            <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
+            <entry>integer</entry>
+            <entry>Adjusts the Chroma gain control (for use when chroma AGC
+            is disabled).</entry>
+          </row>
+          <row>
             <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
             <entry>boolean</entry>
             <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>