libcamera: pipeline: raspberrypi: Update sensor's V4L2_CID_NOTIFY_GAINS control

If the sensor exposes the V4L2_CID_NOTIFY_GAINS control, assume it
means the sensor wants to be told the latest colour gains.

We store whether the control exists and if so its default value, to
save us checking for it on every frame.

Signed-off-by: David Plowman <>
Reviewed-by: Naushir Patuck <>
Reviewed-by: Laurent Pinchart <>
Signed-off-by: Laurent Pinchart <>
1 file changed