Re: [PATCH RFC v2 1/2] dt-bindings: power: add nexus map for power-domains

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 28 May 2025 at 23:59, Kevin Hilman <khilman@baylibre.com> wrote:
>
> Add support for nexus map to be able to support hierarchical power
> domains for providers with #power-domain-cells > 0.
>
> Suggested-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Kevin Hilman <khilman@baylibre.com>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  Documentation/devicetree/bindings/power/power-domain.yaml | 35 +++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/power/power-domain.yaml b/Documentation/devicetree/bindings/power/power-domain.yaml
> index 8fdb529d560b..9f099d326aee 100644
> --- a/Documentation/devicetree/bindings/power/power-domain.yaml
> +++ b/Documentation/devicetree/bindings/power/power-domain.yaml
> @@ -68,6 +68,15 @@ properties:
>        by the given provider should be subdomains of the domain specified
>        by this binding.
>
> +  power-domains-map:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description:
> +      Nexus node mapping property that establishes parent-child relationships
> +      for PM domains using the format defined in the Device Tree specification
> +      section 2.5.1. Each map entry consists of child domain specifier,
> +      parent phandle, and optional parent specifier arguments. This property
> +      is only supported for onecell providers (#power-domain-cells = 1).
> +
>  required:
>    - "#power-domain-cells"
>
> @@ -133,3 +142,29 @@ examples:
>              min-residency-us = <7000>;
>          };
>      };
> +
> +  - |
> +    // Example using power-domains-map for Nexus mapping
> +    main_pd: power-controller@12370000 {
> +        compatible = "foo,power-controller";
> +        reg = <0x12370000 0x1000>;
> +        #power-domain-cells = <0>;
> +    };
> +
> +    wkup_pd: power-controller@12380000 {
> +        compatible = "foo,power-controller";
> +        reg = <0x12380000 0x1000>;
> +        #power-domain-cells = <0>;
> +    };
> +
> +    scmi_pds protocol@11 {
> +        compatible = "arm,scmi-power-domain";
> +        reg = <0x11>;
> +        #power-domain-cells = <1>;
> +        power-domains-map = <15 &main_pd>,
> +                            <19 &wkup_pd>;
> +    };
> +
> +    // In this example using Nexus node mapping:
> +    // - Child domain 15 (scmi_pds 15) becomes a subdomain of main_pd
> +    // - Child domain 19 (scmi_pds 19) becomes a subdomain of wkup_pd
>
> --
> 2.49.0
>