Hi Philippe,
I'm cleaning up old patches and I decided to mark this as Obsolete since
there has been no activity for a long time. If you still want to pursue this,
then post a v2.
In any case, this patch can only be accepted if there is also a driver in
the mainline kernel that uses it.
Regards,
Hans
On 01/02/2021 10:34, Philippe De Muyter wrote:
> Since V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN and
> V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC were added long ago, no other flag
> was introduced to indicate precisely the reference clock used for
> timestamps associated to v4l2 buffers. Add here the ability for drivers
> to use the realtime (= UTC) or TAI clock.
>
> Signed-off-by: Philippe De Muyter <phdm@xxxxxxxxx>
> ---
> Documentation/userspace-api/media/v4l/buffer.rst | 14 ++++++++++++++
> include/trace/events/v4l2.h | 2 ++
> include/uapi/linux/videodev2.h | 2 ++
> 3 files changed, 18 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> index 1b0fdc1..44cb59b 100644
> --- a/Documentation/userspace-api/media/v4l/buffer.rst
> +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> @@ -637,6 +637,20 @@ Buffer Flags
> - The buffer timestamp has been taken from the ``CLOCK_MONOTONIC``
> clock. To access the same clock outside V4L2, use
> :c:func:`clock_gettime`.
> + * .. _`V4L2-BUF-FLAG-TIMESTAMP-UTC`:
> +
> + - ``V4L2_BUF_FLAG_TIMESTAMP_UTC``
> + - 0x00008000
> + - The buffer timestamp has been taken from the ``CLOCK_REALTIME``
> + clock. To access the same clock outside V4L2, use
> + :c:func:`clock_gettime`.
> + * .. _`V4L2-BUF-FLAG-TIMESTAMP-TAI`:
> +
> + - ``V4L2_BUF_FLAG_TIMESTAMP_TAI``
> + - 0x0000a000
> + - The buffer timestamp has been taken from the ``CLOCK_TAI``
> + clock. To access the same clock outside V4L2, use
> + :c:func:`clock_gettime`.
> * .. _`V4L2-BUF-FLAG-TIMESTAMP-COPY`:
>
> - ``V4L2_BUF_FLAG_TIMESTAMP_COPY``
> diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h
> index 248bc09..ce93c88 100644
> --- a/include/trace/events/v4l2.h
> +++ b/include/trace/events/v4l2.h
> @@ -88,6 +88,8 @@
> { V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN, "TIMESTAMP_UNKNOWN" }, \
> { V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC, "TIMESTAMP_MONOTONIC" }, \
> { V4L2_BUF_FLAG_TIMESTAMP_COPY, "TIMESTAMP_COPY" }, \
> + { V4L2_BUF_FLAG_TIMESTAMP_UTC, "TIMESTAMP_UTC" }, \
> + { V4L2_BUF_FLAG_TIMESTAMP_TAI, "TIMESTAMP_TAI" }, \
> { V4L2_BUF_FLAG_LAST, "LAST" })
>
> #define show_timecode_flags(flags) \
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 79dbde3..87502ab 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1101,6 +1101,8 @@ static inline __u64 v4l2_timeval_to_ns(const struct timeval *tv)
> #define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x00000000
> #define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x00002000
> #define V4L2_BUF_FLAG_TIMESTAMP_COPY 0x00004000
> +#define V4L2_BUF_FLAG_TIMESTAMP_UTC 0x00008000
> +#define V4L2_BUF_FLAG_TIMESTAMP_TAI 0x0000a000
> /* Timestamp sources. */
> #define V4L2_BUF_FLAG_TSTAMP_SRC_MASK 0x00070000
> #define V4L2_BUF_FLAG_TSTAMP_SRC_EOF 0x00000000
