Hi Steve,
Thank you for the patch.
On Tue, Mar 03, 2020 at 03:42:48PM -0800, Steve Longerbeam wrote:
> Implement a notifier bound op to register media links from the remote
> sub-device's source pad(s) to the video-mux sink pad(s).
>
> Signed-off-by: Steve Longerbeam <slongerbeam@xxxxxxxxx>
> ---
> Changes in v3:
> - this version does the work inline. The previous version called
> a media_create_fwnode_links() which is removed in v3.
> ---
> drivers/media/platform/video-mux.c | 92 ++++++++++++++++++++++++++++++
> 1 file changed, 92 insertions(+)
>
> diff --git a/drivers/media/platform/video-mux.c b/drivers/media/platform/video-mux.c
> index f446ada82176..3991b1ea671c 100644
> --- a/drivers/media/platform/video-mux.c
> +++ b/drivers/media/platform/video-mux.c
> @@ -36,6 +36,12 @@ static const struct v4l2_mbus_framefmt video_mux_format_mbus_default = {
> .field = V4L2_FIELD_NONE,
> };
>
> +static inline struct video_mux *
> +notifier_to_video_mux(struct v4l2_async_notifier *n)
> +{
> + return container_of(n, struct video_mux, notifier);
> +}
> +
> static inline struct video_mux *v4l2_subdev_to_video_mux(struct v4l2_subdev *sd)
> {
> return container_of(sd, struct video_mux, subdev);
> @@ -360,6 +366,90 @@ static const struct v4l2_subdev_ops video_mux_subdev_ops = {
> .video = &video_mux_subdev_video_ops,
> };
>
> +static int video_mux_notify_bound(struct v4l2_async_notifier *notifier,
> + struct v4l2_subdev *sd,
> + struct v4l2_async_subdev *asd)
> +{
> + struct video_mux *vmux = notifier_to_video_mux(notifier);
> + struct fwnode_handle *vmux_fwnode = dev_fwnode(vmux->subdev.dev);
> + struct fwnode_handle *sd_fwnode = dev_fwnode(sd->dev);
> + struct fwnode_handle *vmux_ep;
There doesn't seem to be anything in this function that is specific to
the video_mux driver. I think it would make sense to turn it into a
generic helper that creates links between two subdevs based on their
fwnode connections.
I also wonder if it wouldn't be more efficient to create links at
complete() time instead of bound() time, in which case the helper would
create all links for a given subdevice, not links between two specific
subdevices (or maybe all links for a given pad direction, to be able to
remove the existing link check below).
> +
> + fwnode_graph_for_each_endpoint(vmux_fwnode, vmux_ep) {
> + struct fwnode_handle *remote_ep, *sd_ep;
> + struct media_pad *src_pad, *sink_pad;
> + struct fwnode_endpoint fwep;
> + int src_idx, sink_idx, ret;
> + bool remote_ep_belongs;
> +
> + ret = fwnode_graph_parse_endpoint(vmux_ep, &fwep);
> + if (ret)
> + continue;
> +
> + /* only create links to the vmux sink pads */
> + if (fwep.port >= vmux->subdev.entity.num_pads - 1)
> + continue;
> +
> + sink_idx = fwep.port;
> + sink_pad = &vmux->subdev.entity.pads[sink_idx];
> +
> + remote_ep = fwnode_graph_get_remote_endpoint(vmux_ep);
> + if (!remote_ep)
> + continue;
> +
> + /*
> + * verify that this remote endpoint is owned by the
> + * sd, in case the sd does not check for that in its
> + * .get_fwnode_pad operation or does not implement it.
> + */
> + remote_ep_belongs = false;
> + fwnode_graph_for_each_endpoint(sd_fwnode, sd_ep) {
> + if (sd_ep == remote_ep) {
> + remote_ep_belongs = true;
> + fwnode_handle_put(sd_ep);
> + break;
> + }
> + }
> + if (!remote_ep_belongs)
> + continue;
> +
> + src_idx = media_entity_get_fwnode_pad(&sd->entity, remote_ep,
> + MEDIA_PAD_FL_SOURCE);
> + fwnode_handle_put(remote_ep);
> +
> + if (src_idx < 0)
> + continue;
> +
> + src_pad = &sd->entity.pads[src_idx];
> +
> + /* skip this link if it already exists */
> + if (media_entity_find_link(src_pad, sink_pad))
> + continue;
Have you encountered this in practice ? If we only create links for sink
pads this shouldn't happen.
> +
> + ret = media_create_pad_link(&sd->entity, src_idx,
> + &vmux->subdev.entity,
> + sink_idx, 0);
> + if (ret) {
> + dev_err(vmux->subdev.dev,
> + "%s:%d -> %s:%d failed with %d\n",
> + sd->entity.name, src_idx,
> + vmux->subdev.entity.name, sink_idx, ret);
> + fwnode_handle_put(vmux_ep);
> + return ret;
> + }
> +
> + dev_dbg(vmux->subdev.dev, "%s:%d -> %s:%d\n",
> + sd->entity.name, src_idx,
> + vmux->subdev.entity.name, sink_idx);
> + }
> +
> + return 0;
> +}
> +
> +static const struct v4l2_async_notifier_operations video_mux_notify_ops = {
> + .bound = video_mux_notify_bound,
> +};
> +
> static int video_mux_async_register(struct video_mux *vmux,
> unsigned int num_input_pads)
> {
> @@ -397,6 +487,8 @@ static int video_mux_async_register(struct video_mux *vmux,
> }
> }
>
> + vmux->notifier.ops = &video_mux_notify_ops;
> +
> ret = v4l2_async_subdev_notifier_register(&vmux->subdev,
> &vmux->notifier);
> if (ret)
--
Regards,
Laurent Pinchart
