On 09/08/2021 11:34, David Plowman wrote: > Add documentation for the V4L2_CID_NOTIFY_GAINS control. > > This control is 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> > --- > .../media/v4l/ext-ctrls-image-source.rst | 15 +++++++++++++++ > 1 file changed, 15 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..c1793fda1429 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 +72,18 @@ Image Source Control IDs > * - __u32 > - ``height`` > - Height of the area. > + > +``V4L2_CID_NOTIFY_GAINS (integer)`` Say '(integer array)' here to clarify that this is an array. > + The sensor is notified what gains will be applied to the different > + colour channels by subsequent processing (such as by an ISP). The > + sensor is merely informed of these values in case it performs > + processing that requires them, but it does not apply them itself to > + the output pixels. > + > + For Bayer sensors this is an array control taking 4 gain values, > + being the gains for each of the Bayer channels. The gains are always > + in the order B, Gb, Gr and R, irrespective of the exact Bayer order > + of the sensor itself. > + > + The units for the gain values are linear, with the default value > + representing a gain of exactly 1. Add an example here to clarify this. Regards, Hans >
