libcamera: camera_sensor: Add V4L2 control operations

Add operations to get and set control and to retrieve the informations
on a V4L2 control. For simple camera sensors, the operations are
directly called on the underlying V4L2 subdevice.

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

src/libcamera/include/camera_sensor.h

@@ -17,6 +17,8 @@
 namespace libcamera {
 
 class MediaEntity;
+class V4L2ControlInfo;
+class V4L2ControlList;
 class V4L2Subdevice;
 
 struct V4L2SubdeviceFormat;
@@ -41,6 +43,10 @@ public:
 				      const Size &size) const;
 	int setFormat(V4L2SubdeviceFormat *format);
 
+	const V4L2ControlInfo *getControlInfo(unsigned int id) const;
+	int getControls(V4L2ControlList *ctrls);
+	int setControls(V4L2ControlList *ctrls);
+
 protected:
 	std::string logPrefix() const;