libcamera: Move IPA sensor controls validation to CameraSensor

The CameraSensor class validates that the sensor driver in use supports
the controls required for IPA modules to work correctly.

For in-tree IPA modules, whose pipeline handlers already use
CameraSensor there's no need to validate such controls again.

Remove controls validation from the IPU3 and RkISP1 IPA modules and rely
on CameraSensor doing that at initialization time.

The list of mandatory controls is expanded to add V4L2_CID_ANALOGUE_GAIN
without which IPA modules cannot function.

The new requirement only applies to RAW sensors, platforms like UVC and
Simple are not impacted by this change.

While at it, expand the sensor driver requirements documentation to
include V4L2_ANALOGUE_GAIN in the list of mandatory controls a sensor
driver has to support.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index 572a313a..ea373458 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -301,6 +301,7 @@ int CameraSensor::validateSensorDriver()
 	 * required by the CameraSensor class.
 	 */
 	static constexpr uint32_t mandatoryControls[] = {
+		V4L2_CID_ANALOGUE_GAIN,
 		V4L2_CID_EXPOSURE,
 		V4L2_CID_HBLANK,
 		V4L2_CID_PIXEL_RATE,