[PATCH 1/2] of: Add helper to lookup non port child node

[Jagan Teki]

Hi Rob and Laurent,

On Wed, Dec 8, 2021 at 11:56 AM Jagan Teki <jagan at amarulasolutions.com> wrote:
>
> On Wed, Dec 8, 2021 at 2:20 AM Rob Herring <robh+dt at kernel.org> wrote:
> >
> > On Mon, Dec 6, 2021 at 11:49 PM Jagan Teki <jagan at amarulasolutions.com> wrote:
> > >
> > > Add of_get_non_port_child() helper that can be used to lookup
> > > non port child nodes.
> > >
> > > Some OF graphs don't require 'ports' to represent the next output
> > > instead, it simply adds a child node on a given parent node. This
> > > helper lookup that child node, however that child node is not a
> > > 'port' on given parent as 'port' based nodes are looked up via
> > > of_graph_get_remote_node().
> > >
> > > Example OF graph representation of DSI host, which doesn't
> > > have 'ports'.
> >
> > This seems pretty specific to DSI and also can't handle there being
> > more than 1 non-port node. That's allowed for DSI too, but I don't
> > think I've ever seen a case. Anyways, I'd just move this to DRM rather
> > than common DT code. One comment on the implementation that will
> > shrink it.
>
> I think it can be possible to OF graph even for non-DSI, however if
> the end-node outputs to a panel or bridge. At the moment, I can one
> use case on the non-DSI side is rcar du encoder.
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/gpu/drm/rcar-du/rcar_du_encoder.c#n68

Do you see any point to make this helper in of/base based on above
rcar_du_encoder usage? if not i can directly use this functionality in
panel_or_bridge finding code itself.

Please let me know.

Thanks,
Jagan.