[media] media: Add video statistics computation functions

The video statistics function describes entities such as video histogram
engines or 3A statistics engines.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/DocBook/media/v4l/media-types.xml

@@ -176,6 +176,15 @@
 		   skipping are considered as scaling.
 	    </entry>
 	  </row>
+	  <row>
+	    <entry><constant>MEDIA_ENT_F_PROC_VIDEO_STATISTICS</constant></entry>
+	    <entry>Video statistics computation (histogram, 3A, ...). An entity
+		   capable of statistics computation must have one sink pad and
+		   one source pad. It computes statistics over the frames
+		   received on its sink pad and outputs the statistics data on
+		   its source pad.
+	    </entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>

include/uapi/linux/media.h

@@ -102,6 +102,7 @@ struct media_device_info {
 #define MEDIA_ENT_F_PROC_VIDEO_PIXEL_ENC_CONV	(MEDIA_ENT_F_BASE + 0x4003)
 #define MEDIA_ENT_F_PROC_VIDEO_LUT		(MEDIA_ENT_F_BASE + 0x4004)
 #define MEDIA_ENT_F_PROC_VIDEO_SCALER		(MEDIA_ENT_F_BASE + 0x4005)
+#define MEDIA_ENT_F_PROC_VIDEO_STATISTICS	(MEDIA_ENT_F_BASE + 0x4006)
 
 /*
  * Connectors