Hi Tomi,
Thank you for the patch.
On Tue, Oct 05, 2021 at 11:57:47AM +0300, Tomi Valkeinen wrote:
> Add two helper functions to make dealing with streams easier:
>
> v4l2_state_find_opposite_end - given a routing table and a pad + stream,
> return the pad + stream on the opposite side of the subdev.
>
> v4l2_state_get_opposite_stream_format - return a pointer to the format
> on the pad + stream on the opposite side from the given pad + stream.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-subdev.c | 42 +++++++++++++++++++++++++++
> include/media/v4l2-subdev.h | 32 ++++++++++++++++++++
> 2 files changed, 74 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 37e2e1f907fc..9eeadad997c8 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -1484,3 +1484,45 @@ v4l2_state_get_stream_format(struct v4l2_subdev_state *state, unsigned int pad,
> return NULL;
> }
> EXPORT_SYMBOL_GPL(v4l2_state_get_stream_format);
> +
> +int v4l2_state_find_opposite_end(struct v4l2_subdev_krouting *routing, u32 pad,
> + u32 stream, u32 *other_pad, u32 *other_stream)
This function should take a state pointer given its name. I would also
rename it to v4l2_subdev_state_find_opposite_end(). Same for
v4l2_state_get_opposite_stream_format() which should be
v4l2_subdev_state_get_opposite_stream_format().
> +{
> + unsigned int i;
> +
> + for (i = 0; i < routing->num_routes; ++i) {
> + struct v4l2_subdev_route *route = &routing->routes[i];
> +
> + if (route->source_pad == pad &&
> + route->source_stream == stream) {
> + *other_pad = route->sink_pad;
> + *other_stream = route->sink_stream;
Can we support other_stream being NULL ? When the subdev implements the
routing API without multiplexed streams, the other_stream number will
always be 0 and it would be nice if the caller didn't have to declare a
placeholder variable.
There are less use cases for other_pad being NULL, but maybe we could
also allow that for consistency reasons ? Up to you.
> + return 0;
> + }
> +
> + if (route->sink_pad == pad && route->sink_stream == stream) {
> + *other_pad = route->source_pad;
> + *other_stream = route->source_stream;
> + return 0;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_state_find_opposite_end);
> +
> +struct v4l2_mbus_framefmt *
> +v4l2_state_get_opposite_stream_format(struct v4l2_subdev_state *state, u32 pad,
> + u32 stream)
> +{
> + u32 other_pad, other_stream;
> + int ret;
> +
> + ret = v4l2_state_find_opposite_end(&state->routing, pad, stream,
> + &other_pad, &other_stream);
> + if (ret)
> + return NULL;
> +
> + return v4l2_state_get_stream_format(state, other_pad, other_stream);
> +}
> +EXPORT_SYMBOL_GPL(v4l2_state_get_opposite_stream_format);
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 1dc824416c1b..4b9520410783 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -1501,4 +1501,36 @@ struct v4l2_mbus_framefmt *
> v4l2_state_get_stream_format(struct v4l2_subdev_state *state, unsigned int pad,
> u32 stream);
>
> +/**
> + * v4l2_state_find_opposite_end() - Find the opposite stream
> + * @routing: routing used to find the opposite side
> + * @pad: pad id
> + * @stream: stream id
> + * @other_pad: pointer used to return the opposite pad
> + * @other_stream: pointer used to return the opposite stream
> + *
> + * This function uses the routing table to find the pad + stream which is
> + * opposite the given pad + stream.
> + *
> + * Returns 0 on success, or -EINVAL if no matching route is found.
> + */
> +int v4l2_state_find_opposite_end(struct v4l2_subdev_krouting *routing, u32 pad,
> + u32 stream, u32 *other_pad, u32 *other_stream);
> +
> +/**
> + * v4l2_state_get_opposite_stream_format() - Get pointer to opposite stream
> + * format
> + * @state: subdevice state
> + * @pad: pad id
> + * @stream: stream id
> + *
> + * This returns a pointer to &struct v4l2_mbus_framefmt for the pad + stream
> + * that is opposite the given pad + stream in the subdev state.
> + *
> + * If the state does not contain the given pad + stream, NULL is returned.
> + */
> +struct v4l2_mbus_framefmt *
> +v4l2_state_get_opposite_stream_format(struct v4l2_subdev_state *state, u32 pad,
> + u32 stream);
> +
> #endif
--
Regards,
Laurent Pinchart
