Hi Kieran,
Thanks for your comments,
On 2017-12-14 23:27:57 +0000, Kieran Bingham wrote:
> Hi Niklas,
>
> On 14/12/17 19:08, Niklas Söderlund wrote:
> > To support multiplexed streams the internal routing between the
> > adv748x sink pad and its source pad needs to be described.
>
> The adv748x has quite a few sink and source pads... I presume here you mean the
> adv748x csi2 sink and source pad :D
Yes :-) Will fix for next version, thanks.
>
> >
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> > ---
> > drivers/media/i2c/adv748x/adv748x-csi2.c | 22 ++++++++++++++++++++++
> > 1 file changed, 22 insertions(+)
> >
> > diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > index 291b35bef49d41fb..dbefb53f5b8c414d 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
> > @@ -262,10 +262,32 @@ static int adv748x_csi2_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> > return 0;
> > }
> >
> > +static int adv748x_csi2_get_routing(struct v4l2_subdev *subdev,
> > + struct v4l2_subdev_routing *routing)
> > +{
> > + struct v4l2_subdev_route *r = routing->routes;
> > +
> > + if (routing->num_routes < 1) {
> > + routing->num_routes = 1;
> > + return -ENOSPC;
> > + }
> > +
> > + routing->num_routes = 1;
> > +
> > + r->sink_pad = ADV748X_CSI2_SINK;
> > + r->sink_stream = 0;
> > + r->source_pad = ADV748X_CSI2_SOURCE;
> > + r->source_stream = 0;
> > + r->flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE | V4L2_SUBDEV_ROUTE_FL_IMMUTABLE;
> > +
> > + return 0;
> > +}
> > +
>
> So - I think this is fine - but it seems a lot of code to define a static
> default route which describes a single link between it's sink pad - and its
> source pad ...
>
> I suspect this should/could be wrapped by some helpers in core for cases like
> this, as it's the simple case - but as we don't currently have that I guess we
> have to put this in here for now ?
Yes for now we need to fill in the information here.
>
> Maybe we should have a helper to make this
I'm sure there could be v4l2 helpers for such a case. I don't even think
you wound need to prime it with any information. If there is only one
source and one sink I'm sure a helper function can figure it out :-)
>
> return v4l2_subdev_single_route(subdev, routing,
> ADV748X_CS2_SINK, 0,
> ADV748X_CSI2_SOURCE, 0,
> V4L2_SUBDEV_ROUTE_FL_ACTIVE | V4L2_SUBDEV_ROUTE_FL_IMMUTABLE);
>
> Or maybe even define these static routes in a struct somehow?
For more complex setups a struct could be used together with a helper
function to decode it. But then again maybe it's easier to just define a
const v4l2_subdev_route array and 'routing->routes = my_const_routes' ?
>
> > static const struct v4l2_subdev_pad_ops adv748x_csi2_pad_ops = {
> > .get_fmt = adv748x_csi2_get_format,
> > .set_fmt = adv748x_csi2_set_format,
> > .get_frame_desc = adv748x_csi2_get_frame_desc,
> > + .get_routing = adv748x_csi2_get_routing,
> > .s_stream = adv748x_csi2_s_stream,
> > };
> >
> >
--
Regards,
Niklas Söderlund
