About the bindings:
There are bindings for the MIPI CSI-2 receiver:
Documentation/devicetree/bindings/media/imx.txt
I think here it's not necessary to make the bus-type property mandatory
as the imx6-mipi-csi2 driver enforces V4L2_MBUS_CSI2_DPHY anyhow
(see drivers/staging/media/imx/imx6-mipi-csi2.c#L677).
For the case of a camera with parallel bus, the camera endpoint is
connected to a video-mux and not directly to the CSI. Therefore, we cannot
make the bus-type property mandatory on this endpoint as it this wouldn't
apply to other use-cases of video-mux.
> >
> > >
> > > >
> > > > > > int ret;
> > > > > >
> > > > > > if (!priv->src_sd)
> > > > > > @@ -210,11 +212,37 @@ static int csi_get_upstream_mbus_config(struct csi_priv *priv,
> > > > > >
> > > > > > ret = v4l2_subdev_call(remote_sd, pad, get_mbus_config,
> > > > > > remote_pad->index, mbus_cfg);
> > > > > > - if (ret == -ENOIOCTLCMD)
> > > > > > - v4l2_err(&priv->sd,
> > > > > > - "entity %s does not implement get_mbus_config()\n",
> > > > > > - remote_pad->entity->name);
> > > > > > + if (ret == -ENOIOCTLCMD) {
> > > > >
> > > > > if (!ret)
> > > > > return 0;
> > > > >
> > > > > And you can unindent the rest.
> > > >
> > > > I was going to say this too but then I thought actually this needs to
> > > > be:
> > > >
> > > > if (ret != -ENOIOCTLCMD)
> > > > return ret;
> > > >
> > > > Which is weird. Better to break all the new code into a separate
> > > > helper function.
> > > >
> > > > if (ret == -ENOIOCTLCMD)
> > > > ret = parse_fw_link_config_stuff();
> > > >
> > > > return ret;
> >
> > Good point. I factored out a helper function as suggested.
> >
> > >
> > > Indeed. get_mbus_config() presumably wouldn't return an error but
> > > correctness is usually a good idea.
> > >
>
> --
> Regards,
>
> Sakari Ailus
Best regards,
Mathis Foerst
