Re: [RFC 5/9] dt-bindings: arm: samsung: Convert Exynos PMU bindings to json-schema

[Rob Herring]

On Tue, Sep 3, 2019 at 8:58 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> On Mon, 26 Aug 2019 at 13:54, Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> >
> > On Fri, Aug 23, 2019 at 9:54 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> > >
> > > Convert Samsung Exynos Power Management Unit (PMU) bindings to DT schema
> > > format using json-schema.
> > >
> > > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > > ---
> > >  .../devicetree/bindings/arm/samsung/pmu.txt   | 72 --------------
> > >  .../devicetree/bindings/arm/samsung/pmu.yaml  | 93 +++++++++++++++++++
> > >  2 files changed, 93 insertions(+), 72 deletions(-)
> > >  delete mode 100644 Documentation/devicetree/bindings/arm/samsung/pmu.txt
> > >  create mode 100644 Documentation/devicetree/bindings/arm/samsung/pmu.yaml
> >
> >
> > > diff --git a/Documentation/devicetree/bindings/arm/samsung/pmu.yaml b/Documentation/devicetree/bindings/arm/samsung/pmu.yaml
> > > new file mode 100644
> > > index 000000000000..818c6f3488ef
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/arm/samsung/pmu.yaml
> > > @@ -0,0 +1,93 @@
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/arm/samsung/pmu.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Samsung Exynos SoC series Power Management Unit (PMU)
> > > +
> > > +maintainers:
> > > +  - Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > > +
> > > +properties:
> > > +  compatible:
> > > +    items:
> > > +      - enum:
> > > +          - samsung,exynos3250-pmu
> > > +          - samsung,exynos4210-pmu
> > > +          - samsung,exynos4412-pmu
> > > +          - samsung,exynos5250-pmu
> > > +          - samsung,exynos5260-pmu
> > > +          - samsung,exynos5410-pmu
> > > +          - samsung,exynos5420-pmu
> > > +          - samsung,exynos5433-pmu
> > > +          - samsung,exynos7-pmu
> > > +      - const: syscon
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  '#clock-cells':
> > > +    const: 1
> > > +
> > > +  clock-names:
> > > +    description:
> > > +      list of clock names for particular CLKOUT mux inputs
> > > +    # TODO: what is the maximum number of elements (mux inputs)?
> > > +    minItems: 1
> > > +    maxItems: 32
> > > +    items:
> > > +      - enum:
> >
> > This isn't correct as you are only defining possible names for the
> > first item. Drop the '-' (making items a schema instead of a list) and
> > then it applies to all. However, doing that will cause a meta-schema
> > error which I need to fix to allow. Or if there's a small set of
> > possibilities of number of inputs, you can list them under a 'oneOf'
> > list.
>
> Mhmm, I cannot test it or I have an error in the schema. if I
> understand correctly, this would be:
>
>   clock-names:
>     description:
>       List of clock names for particular CLKOUT mux inputs
>     minItems: 1
>     maxItems: 16
>     items:
>       clkout0
>       clkout1
>       clkout2
>       clkout3
>       clkout4
>       clkout5
>       clkout6
>       clkout7
>       clkout8
>       clkout9
>       clkout10
>       clkout11
>       clkout12
>       clkout13
>       clkout14
>       clkout15
>       clkout16
>
> Now it produces the error "ignoring, error in schema 'items'" but
> maybe it is expected with current meta-schema?

'make dt_binding_check' will give more detailed errors.

Are the inputs always contiguous 0-N? If so, you want:

items:
  - const: clkout0
  - const: clkout1
  - const: clkout2
  ...

If you want to express any number and order of strings is valid, then you need:

items:
  enum:
    - clkout0
    - clkout1
    - clkout2

Doing that is discouraged for bindings though. Currently, it will
generate an error from the meta-schema, but we could change that.

Rob