Re: [PATCH 4/4] dt-bindings: cache: Add docs for StarFive StarLink-500 cache controller

[Rob Herring <robh@xxxxxxxxxx>]

On Thu, Mar 14, 2024 at 02:12:05PM +0800, Joshua Yeong wrote:
> Add DT binding documentation used by StarFive's
> Starlink-500 cache controller.
> 
> Signed-off-by: Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> ---
>  .../cache/starfive,starlink-500-cache.yaml    | 62 +++++++++++++++++++
>  1 file changed, 62 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cache/starfive,starlink-500-cache.yaml
> 
> diff --git a/Documentation/devicetree/bindings/cache/starfive,starlink-500-cache.yaml b/Documentation/devicetree/bindings/cache/starfive,starlink-500-cache.yaml
> new file mode 100644
> index 000000000000..97ddf7db39e9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cache/starfive,starlink-500-cache.yaml
> @@ -0,0 +1,62 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/cache/starfive,starlink-500-cache.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: StarFive StarLink-500 Cache Controller
> +
> +maintainers:
> +  - Joshua Yeong <joshua.yeong@xxxxxxxxxxxxxxxx>
> +
> +description:
> +  StarFive's StarLink-500 controller manages cache shared between clusters of
> +  CPU cores. The cache driver provides mechanism to perform invalidate and write
> +  back functionality to the shared memory.

What a driver does is not relevant to the binding. You could describe 
what the registers control though.

> +
> +allOf:
> +  - $ref: /schemas/cache-controller.yaml#
> +
> +# We need a select here so we don't match all nodes with 'cache'
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        enum:
> +          - starfive,starlink-500-cache
> +
> +  required:
> +    - compatible
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: starfive,starlink-500-cache
> +      - const: cache
> +
> +  reg:
> +    maxItems: 1
> +
> +  cache-size: true
> +  cache-sets: true
> +  cache-block-size: true
> +  cache-level: true
> +  cache-unified: true

Drop these and...

> +
> +additionalProperties: false

... use 'unevaluatedProperties' instead.

> +
> +required:
> +  - compatible
> +  - reg

cache-unified should be required as I imagine the cache is always 
unified. Perhaps other properties too (cache-level already is)?

> +
> +examples:
> +  - |
> +      cache-controller@15000000 {
> +        compatible = "starfive,starlink-500-cache", "cache";
> +        reg = <0x15000000 0x278>;
> +        cache-block-size = <64>;
> +        cache-level = <3>;
> +        cache-sets = <8192>;
> +        cache-size = <0x400000>;
> +        cache-unified;
> +      };
> -- 
> 2.25.1
>