On Sun, Oct 10, 2021 at 05:15:15PM +0300, Laurent Pinchart wrote:
> 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().
Also, the state pointer passed to this function should be const.
> > +{
> > + 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
