Re: [RFC PATCH 2/2] dt-bindings: pwm: Convert Samsung PWM bindings to json-schema
From: Krzysztof Kozlowski
Date: Wed Sep 18 2019 - 07:54:11 EST
On Fri, 13 Sep 2019 at 16:36, Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Mon, Sep 09, 2019 at 08:34:36PM +0200, Krzysztof Kozlowski wrote:
> > Convert Samsung PWM (S3C, S5P and Exynos SoCs) bindings to DT schema
> > format using json-schema.
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > ---
> > .../devicetree/bindings/pwm/pwm-samsung.txt | 51 --------
> > .../devicetree/bindings/pwm/pwm-samsung.yaml | 111 ++++++++++++++++++
> > 2 files changed, 111 insertions(+), 51 deletions(-)
> > delete mode 100644 Documentation/devicetree/bindings/pwm/pwm-samsung.txt
> > create mode 100644 Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
>
>
> > diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
> > new file mode 100644
> > index 000000000000..90fb467bcdd5
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.yaml
> > @@ -0,0 +1,111 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/pwm-samsung.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Samsung SoC PWM timers
> > +
> > +maintainers:
> > + - Thierry Reding <thierry.reding@xxxxxxxxx>
> > + - Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > +
> > +description: |+
> > + Samsung SoCs contain PWM timer blocks which can be used for system clock source
> > + and clock event timers, as well as to drive SoC outputs with PWM signal. Each
> > + PWM timer block provides 5 PWM channels (not all of them can drive physical
> > + outputs - see SoC and board manual).
> > +
> > + Be aware that the clocksource driver supports only uniprocessor systems.
> > +
> > +allOf:
> > + - $ref: pwm.yaml#
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - samsung,s3c2410-pwm # 16-bit, S3C24xx
> > + - samsung,s3c6400-pwm # 32-bit, S3C64xx
> > + - samsung,s5p6440-pwm # 32-bit, S5P64x0
> > + - samsung,s5pc100-pwm # 32-bit, S5PC100, S5PV210, Exynos4210 rev0 SoCs
> > + - samsung,exynos4210-pwm # 32-bit, Exynos
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + clocks:
> > + minItems: 1
> > + maxItems: 3
> > +
> > + clock-names:
> > + description: |
> > + Should contain all following required clock names:
> > + - "timers" - PWM base clock used to generate PWM signals,
> > + and any subset of following optional clock names:
> > + - "pwm-tclk0" - first external PWM clock source,
> > + - "pwm-tclk1" - second external PWM clock source.
> > + Note that not all IP variants allow using all external clock sources.
> > + Refer to SoC documentation to learn which clock source configurations
> > + are available.
> > + oneOf:
> > + - items:
> > + - const: "timers"
> > + - items:
> > + - const: "timers"
> > + - const: "pwm-tclk0"
> > + - items:
> > + - const: "timers"
> > + - const: "pwm-tclk1"
> > + - items:
> > + - const: "timers"
> > + - const: "pwm-tclk0"
> > + - const: "pwm-tclk1"
> > +
> > + interrupts:
> > + description:
> > + One interrupt per timer, starting at timer 0.
> > + minItems: 1
> > + maxItems: 5
> > +
> > + "#pwm-cells":
> > + description:
> > + The only third cell flag supported by this binding
> > + is PWM_POLARITY_INVERTED.
> > + const: 3
> > +
> > + samsung,pwm-outputs:
> > + description:
> > + A list of PWM channels used as PWM outputs on particular platform.
> > + It is an array of up to 5 elements being indices of PWM channels
> > + (from 0 to 4), the order does not matter.
> > + # TODO: Values should not repeat
>
> uniqueItems: true
>
> Though it looks like we have to enable that keyword. (As silently
> ignoring unknown keywords (such as typos) is 'feature' of json-schema,
> we explicitly list keywords we use.)
This works fine.
>
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32-array
> > + # FIXME: min/max limit of items does not work
> > + - items:
> > + minItems: 1
> > + maxItems: 5
> > + - items:
> > + minimum: 0
> > + maximum: 4
>
> I think you want:
>
> minItems: 1
> maxItems: 2
> items:
> minimum: 0
> maximum: 4
This not. However I figured out it is not needed. Since these are
unique values from 0 to 4, then the size of array cannot be longer
than 5 or shorter than 1.
Best regards,
Krzysztof