Re: [PATCH v10 4/5] dt-bindings: arm-smmu: add binding for Tegra194 SMMU

[Rob Herring]

On Tue, Jul 07, 2020 at 10:00:16PM -0700, Krishna Reddy wrote:
> Add binding for NVIDIA's Tegra194 SoC SMMU.
> 
> Signed-off-by: Krishna Reddy <vdumpa@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/iommu/arm,smmu.yaml    | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
> index d7ceb4c34423..ac1f526c3424 100644
> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml
> @@ -38,6 +38,11 @@ properties:
>                - qcom,sc7180-smmu-500
>                - qcom,sdm845-smmu-500
>            - const: arm,mmu-500
> +      - description: NVIDIA SoCs that program two ARM MMU-500s identically
> +        items:
> +          - enum:
> +              - nvidia,tegra194-smmu
> +          - const: nvidia,smmu-500
>        - items:
>            - const: arm,mmu-500
>            - const: arm,smmu-v2
> @@ -138,6 +143,19 @@ required:
>  
>  additionalProperties: false
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - nvidia,tegra194-smmu
> +    then:
> +      properties:
> +        reg:
> +          minItems: 2
> +          maxItems: 2

This doesn't work. The main part of the schema already said there's only 
1 reg region. This part is ANDed with that, not an override. You need to 
add an else clause with 'maxItems: 1' and change the base schema to 
{minItems: 1, maxItems: 2}.

Rob