[media] V4L: Add camera exposure bias control

The camera may in some conditions incorrectly determine the exposure,
and a manual automatic exposure correction may be needed. This patch
adds V4L2_CID_AUTO_EXPOSURE_BIAS control which allows to add some
offset in the automatic exposure control loop, to compensate for
frame under- or over-exposure.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index fdcb9e2..5bfef90 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -604,6 +604,7 @@
 	case V4L2_CID_PRIVACY:			return "Privacy";
 	case V4L2_CID_IRIS_ABSOLUTE:		return "Iris, Absolute";
 	case V4L2_CID_IRIS_RELATIVE:		return "Iris, Relative";
+	case V4L2_CID_AUTO_EXPOSURE_BIAS:	return "Auto Exposure, Bias";
 
 	/* FM Radio Modulator control */
 	/* Keep the order of the 'case's the same as in videodev2.h! */
@@ -760,6 +761,9 @@
 	case V4L2_CID_RDS_TX_RADIO_TEXT:
 		*type = V4L2_CTRL_TYPE_STRING;
 		break;
+	case V4L2_CID_AUTO_EXPOSURE_BIAS:
+		*type = V4L2_CTRL_TYPE_INTEGER_MENU;
+		break;
 	case V4L2_CID_USER_CLASS:
 	case V4L2_CID_CAMERA_CLASS:
 	case V4L2_CID_MPEG_CLASS: