[media] uvcvideo: Add M420 format support

The M420 format is used by the Microsoft LifeCam Studio HD.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[laurent.pinchart@ideasonboard.com: split into v4l/uvcvideo patches]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/uvc/uvc_driver.c

@@ -83,6 +83,11 @@ static struct uvc_format_desc uvc_fmts[] = {
 		.guid		= UVC_GUID_FORMAT_I420,
 		.fcc		= V4L2_PIX_FMT_YUV420,
 	},
+	{
+		.name		= "YUV 4:2:0 (M420)",
+		.guid		= UVC_GUID_FORMAT_M420,
+		.fcc		= V4L2_PIX_FMT_M420,
+	},
 	{
 		.name		= "YUV 4:2:2 (UYVY)",
 		.guid		= UVC_GUID_FORMAT_UYVY,

drivers/media/video/uvc/uvcvideo.h

@@ -172,6 +172,9 @@ struct uvc_xu_control {
 #define UVC_GUID_FORMAT_RGBP \
 	{ 'R',  'G',  'B',  'P', 0x00, 0x00, 0x10, 0x00, \
 	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_M420 \
+	{ 'M',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
 
 /* ------------------------------------------------------------------------
  * Driver specific constants.