Re: [RFC PATCH 1/2] dt-bindings: pwm: Convert PWM bindings to json-schema

From: Krzysztof Kozlowski
Date: Tue Sep 10 2019 - 04:44:06 EST

On Tue, 10 Sep 2019 at 10:33, Rob Herring <robh+dt@xxxxxxxxxx> wrote:
>
> On Mon, Sep 9, 2019 at 7:35 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> >
> > Convert generic PWM bindings to DT schema format using json-schema. The
> > consumer bindings are split to separate file.
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > ---
> > .../devicetree/bindings/clock/pwm-clock.txt | 2 +-
> > .../bindings/display/bridge/ti,sn65dsi86.txt | 2 +-
> > .../devicetree/bindings/display/ssd1307fb.txt | 2 +-
> > .../bindings/leds/backlight/pwm-backlight.txt | 2 +-
> > .../devicetree/bindings/leds/leds-pwm.txt | 2 +-
> > .../devicetree/bindings/mfd/max77693.txt | 2 +-
> > .../bindings/pwm/atmel-hlcdc-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/atmel-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/atmel-tcb-pwm.txt | 2 +-
> > .../bindings/pwm/brcm,bcm7038-pwm.txt | 2 +-
> > .../bindings/pwm/brcm,iproc-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/brcm,kona-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/img-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/imx-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/imx-tpm-pwm.txt | 2 +-
> > .../bindings/pwm/lpc1850-sct-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/mxs-pwm.txt | 2 +-
> > .../bindings/pwm/nvidia,tegra20-pwm.txt | 2 +-
> > .../bindings/pwm/nxp,pca9685-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-bcm2835.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-berlin.txt | 2 +-
> > .../bindings/pwm/pwm-consumers.yaml | 76 +++++++++++++++++++
> > .../devicetree/bindings/pwm/pwm-fsl-ftm.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-hibvt.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-lp3943.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-mediatek.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-meson.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-mtk-disp.txt | 2 +-
> > .../bindings/pwm/pwm-omap-dmtimer.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-rockchip.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-sifive.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-stm32-lp.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-stm32.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-tiecap.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-tiehrpwm.txt | 2 +-
> > .../devicetree/bindings/pwm/pwm-zx.txt | 2 +-
> > Documentation/devicetree/bindings/pwm/pwm.txt | 69 -----------------
> > .../devicetree/bindings/pwm/pwm.yaml | 30 ++++++++
> > .../bindings/pwm/renesas,pwm-rcar.txt | 2 +-
> > .../bindings/pwm/renesas,tpu-pwm.txt | 4 +-
> > .../devicetree/bindings/pwm/spear-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/st,stmpe-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/ti,twl-pwm.txt | 2 +-
> > .../devicetree/bindings/pwm/ti,twl-pwmled.txt | 2 +-
> > .../devicetree/bindings/pwm/vt8500-pwm.txt | 2 +-
> > .../bindings/regulator/pwm-regulator.txt | 2 +-
> > .../devicetree/bindings/timer/ingenic,tcu.txt | 2 +-
>
> We've been leaving the .txt file with a reference to the schema file
> to avoid doing all the updates. But as you've done it already, that's
> good.
>
> > 47 files changed, 151 insertions(+), 114 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
> > delete mode 100644 Documentation/devicetree/bindings/pwm/pwm.txt
> > create mode 100644 Documentation/devicetree/bindings/pwm/pwm.yaml
>
> [...]
>
> > diff --git a/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml b/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
> > new file mode 100644
> > index 000000000000..39c844fe6338
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/pwm-consumers.yaml
>
> We already have a PWM consumer schema in dt-schema repository. It
> doesn't have the descriptions because we need permission to relicense.
> My aim is to have all common schema in the dt-schema repo, but we have
> a mixture because of needing to relicense.

I forgot to check it. In such case the pwm-consumers here do not offer
much more, except some description and examples. I guess it can be
just dropped then?

> > @@ -0,0 +1,76 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/pwm-consumers.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Specifying PWM information for devices
> > +
> > +maintainers:
> > + - Thierry Reding <thierry.reding@xxxxxxxxx>
> > +
> > +description: |
> > + PWM properties should be named "pwms". The exact meaning of each pwms
> > + property must be documented in the device tree binding for each device.
> > + An optional property "pwm-names" may contain a list of strings to label
> > + each of the PWM devices listed in the "pwms" property. If no "pwm-names"
> > + property is given, the name of the user node will be used as fallback.
> > +
> > + Drivers for devices that use more than a single PWM device can use the
> > + "pwm-names" property to map the name of the PWM device requested by the
> > + pwm_get() call to an index into the list given by the "pwms" property.
> > +
> > +properties:
> > + pwms:
> > + $ref: /schemas/types.yaml#/definitions/phandle-array
> > + description: |
> > + Phandle to PWM controller node and pwm-specifier (controller specific).
> > + pwm-specifier typically encodes the chip-relative PWM number and the PWM
> > + period in nanoseconds.
> > + Optionally, the pwm-specifier can encode a number of flags (defined in
> > + <dt-bindings/pwm/pwm.h>) in a third cell:
> > + - PWM_POLARITY_INVERTED: invert the PWM signal polarity
> > +
> > + pwm-names:
> > + $ref: /schemas/types.yaml#/definitions/string-array
> > + description:
> > + A list of strings to label each of the PWM devices listed in the "pwms"
> > + property. If no "pwm-names" property is given, the name of the user node
> > + will be used as fallback.
> > +
> > +required:
> > + - pwms
>
> Doing this means every consumer has to include this file where as I do
> 'select: true' some every occurrence of these properties is checked.
> We're generally only including other schema on the provider side.
>
> > +
> > +dependencies:
> > + pwm-names: [ pwms ]
> > +
> > +examples:
> > + - |
> > + // The following example could be used to describe a PWM-based
> > + // backlight device:
> > +
> > + pwm: pwm {
> > + #pwm-cells = <2>;
> > + };
> > +
> > + bl: backlight {
> > + pwms = <&pwm 0 5000000>;
> > + pwm-names = "backlight";
> > + };
> > +
> > + // Note that in the example above, specifying the "pwm-names" is redundant
> > + // because the name "backlight" would be used as fallback anyway.
> > +
> > + - |
> > + // Example with optional PWM specifier for inverse polarity
> > +
> > + #include <dt-bindings/pwm/pwm.h>
> > +
> > + pwm2: pwm {
> > + #pwm-cells = <3>;
> > + };
> > +
> > + backlight {
> > + pwms = <&pwm2 0 5000000 PWM_POLARITY_INVERTED>;
> > + pwm-names = "backlight";
> > + };
>
> > diff --git a/Documentation/devicetree/bindings/pwm/pwm.yaml b/Documentation/devicetree/bindings/pwm/pwm.yaml
> > new file mode 100644
> > index 000000000000..5d8029f11ccc
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pwm/pwm.yaml
> > @@ -0,0 +1,30 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pwm/pwm.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: PWM controllers (providers)
> > +
> > +maintainers:
> > + - Thierry Reding <thierry.reding@xxxxxxxxx>
> > +
> > +properties:
> > + $nodename:
> > + pattern: "^pwm(@.*)?$"
>
> Copy the pattern for spi. We allow for 'pwm-[0-9]' for cases like GPIO PWMs.

Sure

>
> > +
> > + "#pwm-cells":
> > + $ref: /schemas/types.yaml#/definitions/uint32
>
> You don't actually need to define the type as we already have for '#.*-cells'

OK.

Best regards,
Krzysztof