Re: [PATCH v6 3/4] dt-bindings: pwm: add IPQ6018 binding

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Thu 22 Jul 05:01 CDT 2021, Baruch Siach wrote:

> DT binding for the PWM block in Qualcomm IPQ6018 SoC.
> 
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> ---
> v6:
> 
>   Device node is child of TCSR; remove phandle (Rob Herring)
> 
>   Add assigned-clocks/assigned-clock-rates (Uwe Kleine-König)
> 
> v5: Use qcom,pwm-regs for phandle instead of direct regs (Bjorn
>     Andersson, Kathiravan T)
> 
> v4: Update the binding example node as well (Rob Herring's bot)
> 
> v3: s/qcom,pwm-ipq6018/qcom,ipq6018-pwm/ (Rob Herring)
> 
> v2: Make #pwm-cells const (Rob Herring)
> ---
>  .../devicetree/bindings/pwm/ipq-pwm.yaml      | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/ipq-pwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/ipq-pwm.yaml b/Documentation/devicetree/bindings/pwm/ipq-pwm.yaml
> new file mode 100644
> index 000000000000..ee2bb03a1223
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/ipq-pwm.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/ipq-pwm.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm IPQ6018 PWM controller
> +
> +maintainers:
> +  - Baruch Siach <baruch@tkos.co.il>
> +
> +properties:
> +  "#pwm-cells":
> +    const: 2
> +
> +  compatible:
> +    const: qcom,ipq6018-pwm
> +
> +  offset:
> +    description: |

'|' maintains the formatting of the text, you don't need that.

> +      Offset of PWM register in the TCSR block.
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    const: core

With a single clock, it's nice to skip the -names.

> +
> +  assigned-clocks:
> +    maxItems: 1
> +
> +  assigned-clock-rates:
> +    maxItems: 1

These (assigned-*) are generic properties that may be used on a lot of
nodes, should they really be part of the individual binding, Rob?

> +
> +required:
> +  - "#pwm-cells"
> +  - compatible
> +  - clocks
> +  - clock-names
> +  - assigned-clocks
> +  - assigned-clock-rates
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/qcom,gcc-ipq6018.h>
> +
> +    soc {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +

Skip soc and *-cells...

> +        tcsr: syscon@1937000 {
> +            compatible = "syscon", "simple-mfd";
> +            reg = <0x0 0x01937000 0x0 0x21000>;
> +

..and just make this "reg = <0x01937000 0x21000>", in the example. Then
as we put this in the particular dts we adjust for whatever *-cells that
has defined for the parent bus.

> +            pwm: pwm {
> +                #pwm-cells = <2>;

I know it's important that this is a pwm thing, but I would prefer to
see the node start with compatible, offset/reg, clocks. And then end
with whatever is exposed (i.e. #pwm-cells)

Regards,
Bjorn

> +                compatible = "qcom,ipq6018-pwm";
> +                offset = <0xa010>;
> +                clocks = <&gcc GCC_ADSS_PWM_CLK>;
> +                clock-names = "core";
> +                assigned-clocks = <&gcc GCC_ADSS_PWM_CLK>;
> +                assigned-clock-rates = <100000000>;
> +                status = "disabled";
> +            };
> +        };
> +    };
> -- 
> 2.30.2
>