[media] v4l: Define video buffer flag for the COPY timestamp type

Define video buffer flag for the COPY timestamp. In this case the timestamp
value is copied from the OUTPUT to the corresponding CAPTURE buffer.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index e6c5855..2c4c068 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -1145,6 +1145,12 @@
 	    same clock outside V4L2, use
 	    <function>clock_gettime(2)</function> .</entry>
 	  </row>
+	  <row>
+	    <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_COPY</constant></entry>
+	    <entry>0x4000</entry>
+	    <entry>The CAPTURE buffer timestamp has been taken from the
+	    corresponding OUTPUT buffer. This flag applies only to mem2mem devices.</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 234d1d8..b5f5cdd 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -705,6 +705,7 @@
 #define V4L2_BUF_FLAG_TIMESTAMP_MASK		0xe000
 #define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN		0x0000
 #define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC	0x2000
+#define V4L2_BUF_FLAG_TIMESTAMP_COPY		0x4000
 
 /**
  * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor