[media] v4l: Define video buffer flags for timestamp types

Define video buffer flags for different timestamp types. Everything up to
now have used either realtime clock or monotonic clock, without a way to
tell which clock the timestamp was taken from.
Also document that the clock source of the timestamp in the timestamp field
depends on buffer flags.

[mchehab@redhat.com: fix a few wrong references to Kernel 3.8 - as this patch
 is meant for 3.9]
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 39d2cecdf38c..94cbe26e9f00 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -701,6 +701,10 @@ struct v4l2_buffer {
 /* Cache handling flags */
 #define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE       0x0800
 #define V4L2_BUF_FLAG_NO_CACHE_CLEAN            0x1000
+/* Timestamp type */
+#define V4L2_BUF_FLAG_TIMESTAMP_MASK            0xe000
+#define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN         0x0000
+#define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC       0x2000
 
 /**
  * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor