[alsa-devel] [PATCH 1/2] dt-bindings: sound: Convert Allwinner SPDIF binding to YAML

[Rob Herring]

On Wed, Apr 17, 2019 at 1:43 AM Maxime Ripard <maxime.ripard at bootlin.com> wrote:
>
> Hi Rob,
>
> On Tue, Apr 16, 2019 at 04:36:18PM -0500, Rob Herring wrote:
> > On Mon, Apr 15, 2019 at 7:07 AM Maxime Ripard <maxime.ripard at bootlin.com> wrote:
> > >
> > > The Allwinner SoCs feature an SPDIF controller across multiple SoC
> > > generations.
> > >
> > > However, earlier generations were a bit simpler than the subsequent ones,
> > > and for example would always have RX and TX capabilities, and no reset
> > > lines.
> > >
> > > In order to express this, let's create two YAML schemas instead of the free
> > > form text we had before.
> >
> > The only difference is 'reset' is required in one? Perhaps better to
> > just not make 'reset' required til we figure out how to handle a
> > conditional like this. Seems like we discussed this and I probably
> > said to split things?
>
> We indeed discussed this, and this was one of the solutions to support
> this. I wanted to get the discussion started as of how exactly we want
> to support this kind of construct.
>
> I looked it up a bit, and it looks like json schema 7 introduces
> conditionals that would allow us to deal with this nicely.
>
> https://json-schema.org/understanding-json-schema/reference/conditionals.html
>
> Is that something we can switch to while we have not a lot of schemas,
> or would that require some significant work?

We need check if the json-schema library supports this yet. I think it
should as there was an issue for it which is closed now.

We'll then need to update the meta-schema and maybe the schema fixups
to handle this case. We should have a test case in the library too.
Test cases are important given that if you get schemas wrong, the
result is silence.

Rob