On 22/07/2021 14:12, David Plowman wrote: > 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@xxxxxxxxxxxxxxx> Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Regards, Hans > --- > .../media/v4l/ext-ctrls-image-source.rst | 25 +++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst > index de43f5c8486d..d50b56156a8e 100644 > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-image-source.rst > @@ -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. >
