@@ -72,3 +72,28 @@ Image Source Control IDs
* - __u32
- ``height``
- Height of the area.
+
+``V4L2_CID_NOTIFY_GAIN_RED (integer)``
+ Please refer to ``V4L2_CID_NOTIFY_GAIN_GREENB`` below.
+
+``V4L2_CID_NOTIFY_GAIN_GREENR (integer)``
+ Please refer to ``V4L2_CID_NOTIFY_GAIN_GREENB`` below.
+
+``V4L2_CID_NOTIFY_GAIN_BLUE (integer)``
+ Please refer to ``V4L2_CID_NOTIFY_GAIN_GREENB`` below.
+
+``V4L2_CID_NOTIFY_GAIN_GREENB (integer)``
+ Note: this description covers all four ``V4L2_CID_NOTIFY_GAIN``
+ controls, according to the Bayer channel indicated at the end of
+ the control name.
+
+ The sensor is notified what gain will be applied to this Bayer
+ channel by subsequent processing (such as by an ISP). The sensor
+ is merely informed of this value in case it performs processing
+ that requires it, but it does not apply it to the output pixels
+ themselves.
+
+ The units for the gain value are linear, with the default value
+ being shared between all four controls and representing a gain of
+ exactly 1. Other control properties, such as ranges, should also
+ be common.
Add documentation for each of the controls V4L2_CID_NOTIFY_GAIN_RED V4L2_CID_NOTIFY_GAIN_GREENR V4L2_CID_NOTIFY_GAIN_BLUE V4L2_CID_NOTIFY_GAIN_GREENB These controls are required by sensors that need to know what colour gains will be applied to pixels by downstream processing (such as by an ISP), though the sensor does not apply these gains itself. Signed-off-by: David Plowman <david.plowman@raspberrypi.com> --- .../media/v4l/ext-ctrls-image-source.rst | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+)