[v4,1/2] dt-bindings: pwm: Document clk based PWM controller

Add YAML devicetree binding for clk based PWM controller

Signed-off-by: Nikita Travkin <nikita@trvn.ru>
--
Changes in v2:
 - fix the file name.
Changes in v4:
 - Use generic node name in the dt bindings example.
---
 .../devicetree/bindings/pwm/clk-pwm.yaml      | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/clk-pwm.yaml

On 26/01/2022 13:58, Nikita Travkin wrote:
> Add YAML devicetree binding for clk based PWM controller
> 
> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
> --
> Changes in v2:
>  - fix the file name.
> Changes in v4:
>  - Use generic node name in the dt bindings example.
> ---
>  .../devicetree/bindings/pwm/clk-pwm.yaml      | 45 +++++++++++++++++++
>  1 file changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/clk-pwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/clk-pwm.yaml b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml
> new file mode 100644
> index 000000000000..d3416ba549b5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml
> @@ -0,0 +1,45 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/clk-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Clock based PWM controller
> +
> +maintainers:
> +  - Nikita Travkin <nikita@trvn.ru>
> +
> +description: |
> +  Some systems have clocks that can be exposed to external devices.
> +  (e.g. by muxing them to GPIO pins)
> +  It's often possible to control duty-cycle of such clocks which makes them
> +  suitable for generating PWM signal.
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +properties:
> +  compatible:
> +    const: clk-pwm
> +
> +  clocks:
> +    description: Clock used to generate the signal.
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 2
> +
> +unevaluatedProperties: false
> +
> +required:

You need a compatible. pwm-cells can be skipped as pwm.yaml will require
them.

> +  - clocks
> +
> +examples:
> +  - |
> +    pwm {
> +      compatible = "clk-pwm";
> +      #pwm-cells = <2>;
> +      clocks = <&gcc 0>;
> +      pinctrl-names = "default";
> +      pinctrl-0 = <&pwm_clk_flash_default>;
> +    };


Best regards,
Krzysztof

Krzysztof Kozlowski писал(а) 26.01.2022 18:14:
> On 26/01/2022 13:58, Nikita Travkin wrote:
>> Add YAML devicetree binding for clk based PWM controller
>>
>> Signed-off-by: Nikita Travkin <nikita@trvn.ru>
>> --
>> Changes in v2:
>>  - fix the file name.
>> Changes in v4:
>>  - Use generic node name in the dt bindings example.
>> ---
>>  .../devicetree/bindings/pwm/clk-pwm.yaml      | 45 +++++++++++++++++++
>>  1 file changed, 45 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pwm/clk-pwm.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/pwm/clk-pwm.yaml b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml
>> new file mode 100644
>> index 000000000000..d3416ba549b5
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pwm/clk-pwm.yaml
>> @@ -0,0 +1,45 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/pwm/clk-pwm.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Clock based PWM controller
>> +
>> +maintainers:
>> +  - Nikita Travkin <nikita@trvn.ru>
>> +
>> +description: |
>> +  Some systems have clocks that can be exposed to external devices.
>> +  (e.g. by muxing them to GPIO pins)
>> +  It's often possible to control duty-cycle of such clocks which makes them
>> +  suitable for generating PWM signal.
>> +
>> +allOf:
>> +  - $ref: pwm.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    const: clk-pwm
>> +
>> +  clocks:
>> +    description: Clock used to generate the signal.
>> +    maxItems: 1
>> +
>> +  "#pwm-cells":
>> +    const: 2
>> +
>> +unevaluatedProperties: false
>> +
>> +required:
> 
> You need a compatible. pwm-cells can be skipped as pwm.yaml will require
> them.
> 

Oops, thanks for noticing that, will add. (Though I'd assume compatible
to be implicitly required as the schema wouldn't even match otherwise...)

Nikita

>> +  - clocks
>> +
>> +examples:
>> +  - |
>> +    pwm {
>> +      compatible = "clk-pwm";
>> +      #pwm-cells = <2>;
>> +      clocks = <&gcc 0>;
>> +      pinctrl-names = "default";
>> +      pinctrl-0 = <&pwm_clk_flash_default>;
>> +    };
> 
> 
> Best regards,
> Krzysztof