[media] V4L: Add camera wide dynamic range control

Add V4L2_CID_WIDE_DYNAMIC_RANGE camera class control for the
camera wide dynamic range (WDR, HDR) feature. This control
can be used to enable/disable wide dynamic range. It might
get converted to a menu control in future if more options
are needed.

Signed-off-by: HeungJun Kim <riverful.kim@samsung.com>
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>

Documentation/DocBook/media/v4l/controls.xml

@@ -3092,6 +3092,21 @@ sky. It corresponds approximately to 9000...10000 K color temperature.
 	  </row>
 	  <row><entry></entry></row>
 
+	  <row id="v4l2-wide-dynamic-range">
+	    <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
+	    <entry>boolean</entry>
+	  </row>
+	  <row>
+	    <entry spanname="descr">Enables or disables the camera's wide dynamic
+range feature. This feature allows to obtain clear images in situations where
+intensity of the illumination varies significantly throughout the scene, i.e.
+there are simultaneously very dark and very bright areas. It is most commonly
+realized in cameras by combining two subsequent frames with different exposure
+times. <footnote id="ctypeconv"><para> This control may be changed to a menu
+control in the future, if more options are required.</para></footnote></entry>
+	  </row>
+	  <row><entry></entry></row>
+
 	</tbody>
       </tgroup>
     </table>

drivers/media/video/v4l2-ctrls.c

@@ -621,6 +621,7 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_IRIS_RELATIVE:		return "Iris, Relative";
 	case V4L2_CID_AUTO_EXPOSURE_BIAS:	return "Auto Exposure, Bias";
 	case V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE: return "White Balance, Auto & Preset";
+	case V4L2_CID_WIDE_DYNAMIC_RANGE:	return "Wide Dynamic Range";
 
 	/* FM Radio Modulator control */
 	/* Keep the order of the 'case's the same as in videodev2.h! */
@@ -723,6 +724,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 	case V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM:
 	case V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE:
 	case V4L2_CID_MPEG_VIDEO_MPEG4_QPEL:
+	case V4L2_CID_WIDE_DYNAMIC_RANGE:
 		*type = V4L2_CTRL_TYPE_BOOLEAN;
 		*min = 0;
 		*max = *step = 1;

include/linux/videodev2.h

@@ -1723,6 +1723,8 @@ enum v4l2_auto_n_preset_white_balance {
 	V4L2_WHITE_BALANCE_SHADE		= 9,
 };
 
+#define V4L2_CID_WIDE_DYNAMIC_RANGE		(V4L2_CID_CAMERA_CLASS_BASE+21)
+
 /* FM Modulator class control IDs */
 #define V4L2_CID_FM_TX_CLASS_BASE		(V4L2_CTRL_CLASS_FM_TX | 0x900)
 #define V4L2_CID_FM_TX_CLASS			(V4L2_CTRL_CLASS_FM_TX | 1)