Re: [PATCH v7 2/3] dt-bindings: mfd: aspeed,ast2x00-scu: Describe AST2700 SCU0

[Rob Herring <robh@kernel.org>]

On Thu, Apr 16, 2026 at 03:29:44PM +0800, Billy Tsai wrote:
> AST2700 consists of two interconnected SoC instances, each with its own
> System Control Unit (SCU). The SCU0 provides pin control, interrupt
> controllers, clocks, resets, and address-space mappings for the
> Secondary and Tertiary Service Processors (SSP and TSP).
> 
> Describe the SSP/TSP address mappings using the standard
> memory-region and memory-region-names properties.
> 
> Disallow legacy child nodes that are not present on AST2700, including
> p2a-control and smp-memram. The latter is unnecessary as software can
> access the scratch registers via the SCU syscon.
> 
> Also allow the AST2700 SoC0 pin controller to be described as a child
> node of the SCU0, and add an example illustrating the SCU0 layout,
> including reserved-memory, interrupt controllers, and pinctrl.
> 
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../bindings/mfd/aspeed,ast2x00-scu.yaml           | 113 +++++++++++++++++++++
>  1 file changed, 113 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml b/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> index a87f31fce019..215ff59b38ea 100644
> --- a/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> +++ b/Documentation/devicetree/bindings/mfd/aspeed,ast2x00-scu.yaml
> @@ -46,6 +46,17 @@ properties:
>    '#reset-cells':
>      const: 1
>  
> +  memory-region:
> +    items:
> +      - description: Region mapped through the first SSP address window.
> +      - description: Region mapped through the second SSP address window.
> +      - description: Region mapped through the TSP address window.

blank line

> +  memory-region-names:
> +    items:
> +      - const: ssp-0
> +      - const: ssp-1
> +      - const: tsp
> +
>  patternProperties:
>    '^p2a-control@[0-9a-f]+$':
>      description: >
> @@ -87,6 +98,7 @@ patternProperties:
>              - aspeed,ast2400-pinctrl
>              - aspeed,ast2500-pinctrl
>              - aspeed,ast2600-pinctrl
> +            - aspeed,ast2700-soc0-pinctrl
>  
>      required:
>        - compatible
> @@ -156,6 +168,30 @@ required:
>    - '#clock-cells'
>    - '#reset-cells'
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            anyOf:
> +              - const: aspeed,ast2700-scu0
> +              - const: aspeed,ast2700-scu1

More simply expressed as:

contains:
  enum:
    - aspeed,ast2700-scu0
    - aspeed,ast2700-scu1


> +    then:
> +      patternProperties:
> +        '^p2a-control@[0-9a-f]+$': false
> +        '^smp-memram@[0-9a-f]+$': false