Re: [PATCH v2 14/34] dt-bindings: arm: Convert Amlogic board/soc bindings to json-schema

[Rob Herring]

On Tue, Dec 4, 2018 at 8:44 AM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Tue, Dec 4, 2018 at 2:39 AM Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
> >
> > Hi Rob,
> >
> > You forgot linux-amlogic in CC...
> >
> > On 03/12/2018 22:32, Rob Herring wrote:
> > > Convert Amlogic SoC bindings to DT schema format using json-schema.
> > >
> > > Cc: Carlo Caione <carlo@xxxxxxxxxx>
> > > Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
> > > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > > Cc: devicetree@xxxxxxxxxxxxxxx
> > > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> > > ---
>
> [...]
>
> > > +      - items:
> > > +          - enum:
> > > +              - amlogic,s400
> > > +          - const: amlogic,a113d
> > > +          - const: amlogic,meson-axg
> > > +      - items:
> > > +          - enum:
> > > +              - amlogic,u200
> > > +          - const: amlogic,g12a
> >
> > but all this feels wrong for me.
> >
> > First of all, this yaml description is not human friendly and not intuitive at all,
> > and secondly with this conversion we loose all the comments about the SoC family relationship
> > with the compatible strings !
> >
> > I really understand the point to have automated verification, but really it's a pain to read
> > (I can't imagine newcomers... the actual DT bindings are already hard to read...) and
> > I feel it will be a real pain to write !
>
> What do you suggest that would be easier? Is it the YAML itself or the
> json-schema vocabulary? For the former, we could use {} and [] to make
> things more json style. But I imagine it is the latter.
>
> There is some learning curve for json-schema and is certainly a
> concern I have, but there would be a learning curve for anything. Our
> choices are use some existing schema language or invent one. All the
> previous efforts (there's been about 5 since 2013) have been inventing
> one, and they've not gone far. There will be far few resources
> available to train people with if we do something custom.
>
> > Can't we mix an "humam text" with a "yaml" part on a same document ? we are in 2018 (nearly 2019),
> > and it should be easy to extract a yaml description from a text document without pain and
> > keep all the human description, no ?
>
> Yes. Please go look at the annotated example in patch 2.

How's this?:

  compatible:
    oneOf:
      - description: Boards with the Amlogic Meson6 SoC
        items:
          - enum:
              - geniatech,atv1200
          - const: amlogic,meson6

      - description: Boards with the Amlogic Meson8 SoC
        items:
          - enum:
              - minix,neo-x8
          - const: amlogic,meson8

      - description: Boards with the Amlogic Meson8m2 SoC
        items:
          - enum:
              - tronsmart,mxiii-plus
          - const: amlogic,meson8m2