Re: [RFC v4 01/10] dt-bindings: pwm: Document Synopsys DesignWare snps,pwm-dw-apb-timers-pwm2

[Krzysztof Kozlowski]

On 17/08/2022 00:14, Ben Dooks wrote:
> Add documentation for the bindings for Synopsys' DesignWare PWM block
> as we will be adding DT/platform support to the Linux driver soon.
> 
> Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxx>
> ---
> v4:
>  - fixed typos, added reg
> v3:
>  - add description and example
>  - merge the snps,pwm-number into this patch
>  - rename snps,pwm to snps,dw-apb-timers-pwm2
> v2:
>  - fix #pwm-cells to be 3
>  - fix indentation and ordering issues
> ---
>  .../bindings/pwm/snps,dw-apb-timers-pwm2.yaml | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> new file mode 100644
> index 000000000000..e7feae6d4404
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2022 SiFive, Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/snps,dw-apb-timers-pwm2.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DW-APB timers PWM controller
> +
> +maintainers:
> +  - Ben Dooks <ben.dooks@xxxxxxxxxx>
> +
> +description:
> +  This describes the DesignWare APB timers module when used in the PWM
> +  mode. The IP core can be generated with various options which can
> +  control the functionality, the number of PWMs available and other
> +  internal controls the designer requires.
> +
> +  The IP block has a version register so this can be used for detection
> +  instead of having to encode the IP version number in the device tree
> +  comaptible.
> +
> +allOf:
> +  - $ref: pwm.yaml#
> +
> +properties:
> +  compatible:
> +    const: snps,dw-apb-timers-pwm2
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +  clocks:
> +    items:
> +      - description: Interface bus clock
> +      - description: PWM reference clock
> +
> +  clock-names:
> +    items:
> +      - const: bus
> +      - const: timer
> +
> +  snps,pwm-number:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: The number of PWM channels configured for this instance
> +    enum: [1, 2, 3, 4, 5, 6, 7, 8]
> +
> +  reg:
> +    maxItems: 1
> +
> +required:
> +  - "#pwm-cells"
> +  - compatible
> +  - reg

Keep the same order as list of properties.

> +  - clocks
> +  - clock-names
> +
> +additionalProperties: false
> +
> +

Just one blank line.

> +examples:
> +  - |
> +    pwm: pwm@180000 {
> +      #pwm-cells = <3>;
> +      compatible = "snps,dw-apb-timers-pwm2";
> +      reg = <0x180000 0x200>;

The convention of DTS is: compatible, then reg, then rest of properties.

> +      clocks = <&bus &timer>;

You put here one item, not two. This has to be <&bus>, <&timer>

> +      clock-names = "bus", "timer";
> +    };


Best regards,
Krzysztof