[media] V4L: Add camera exposure metering control

The V4L2_CID_EXPOSURE_METERING control allows to determine
a method used by the camera for measuring the amount of light
available for automatic 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 debaf9f..55dd813 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -230,6 +230,12 @@
 		"Aperture Priority Mode",
 		NULL
 	};
+	static const char * const camera_exposure_metering[] = {
+		"Average",
+		"Center Weighted",
+		"Spot",
+		NULL
+	};
 	static const char * const colorfx[] = {
 		"None",
 		"Black & White",
@@ -434,6 +440,8 @@
 		return camera_power_line_frequency;
 	case V4L2_CID_EXPOSURE_AUTO:
 		return camera_exposure_auto;
+	case V4L2_CID_EXPOSURE_METERING:
+		return camera_exposure_metering;
 	case V4L2_CID_COLORFX:
 		return colorfx;
 	case V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE:
@@ -632,6 +640,7 @@
 	case V4L2_CID_IMAGE_STABILIZATION:	return "Image Stabilization";
 	case V4L2_CID_ISO_SENSITIVITY:		return "ISO Sensitivity";
 	case V4L2_CID_ISO_SENSITIVITY_AUTO:	return "ISO Sensitivity, Auto";
+	case V4L2_CID_EXPOSURE_METERING:	return "Exposure, Metering Mode";
 
 	/* FM Radio Modulator control */
 	/* Keep the order of the 'case's the same as in videodev2.h! */
@@ -783,6 +792,7 @@
 	case V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE:
 	case V4L2_CID_JPEG_CHROMA_SUBSAMPLING:
 	case V4L2_CID_ISO_SENSITIVITY_AUTO:
+	case V4L2_CID_EXPOSURE_METERING:
 		*type = V4L2_CTRL_TYPE_MENU;
 		break;
 	case V4L2_CID_LINK_FREQ: