Re: [PATCH v3 1/2] dt-bindings: PCI: qcom: Add SM8550 compatible

[Krzysztof Kozlowski]

On 19/01/2023 12:24, Abel Vesa wrote:
> Add the SM8550 platform to the binding.
> 
> Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> ---
> 
> The v2 was here:
> https://lore.kernel.org/all/20230118111704.3553542-1-abel.vesa@xxxxxxxxxx/
> 
> Changes since v2:
>  * dropped the pipe from clock-names
>  * removed the pcie instance number from aggre clock-names comment
>  * renamed aggre clock-names to noc_aggr
>  * dropped the _pcie infix from cnoc_pcie_sf_axi
>  * renamed pcie_1_link_down_reset to simply link_down
>  * added enable-gpios back, since pcie1 node will use it
> 
> Changes since v1:
>  * Switched to single compatible for both PCIes (qcom,pcie-sm8550)
>  * dropped enable-gpios property
>  * dropped interconnects related properties, the power-domains
>  * properties
>    and resets related properties the sm8550 specific allOf:if:then
>  * dropped pipe_mux, phy_pipe and ref clocks from the sm8550 specific
>    allOf:if:then clock-names array and decreased the minItems and
>    maxItems for clocks property accordingly
>  * added "minItems: 1" to interconnects, since sm8550 pcie uses just one,
>    same for interconnect-names
> 
> 
>  .../devicetree/bindings/pci/qcom,pcie.yaml    | 44 +++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> index a5859bb3dc28..93e86dfdd6fe 100644
> --- a/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> +++ b/Documentation/devicetree/bindings/pci/qcom,pcie.yaml
> @@ -34,6 +34,7 @@ properties:
>        - qcom,pcie-sm8250
>        - qcom,pcie-sm8450-pcie0
>        - qcom,pcie-sm8450-pcie1
> +      - qcom,pcie-sm8550
>        - qcom,pcie-ipq6018
>  
>    reg:
> @@ -65,9 +66,11 @@ properties:
>    dma-coherent: true
>  
>    interconnects:
> +    minItems: 1
>      maxItems: 2

1. Why do you skip cpu-pcie interconnect on SM8550?
2. This should not be allowed on other variants.

>  
>    interconnect-names:
> +    minItems: 1
>      items:
>        - const: pcie-mem
>        - const: cpu-pcie
> @@ -102,6 +105,10 @@ properties:
>    power-domains:
>      maxItems: 1
>  
> +  enable-gpios:
> +    description: GPIO controlled connection to ENABLE# signal
> +    maxItems: 1
> +
>    perst-gpios:
>      description: GPIO controlled connection to PERST# signal
>      maxItems: 1
> @@ -197,6 +204,7 @@ allOf:
>                - qcom,pcie-sm8250
>                - qcom,pcie-sm8450-pcie0
>                - qcom,pcie-sm8450-pcie1
> +              - qcom,pcie-sm8550
>      then:
>        properties:
>          reg:
> @@ -611,6 +619,41 @@ allOf:
>            items:
>              - const: pci # PCIe core reset
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - qcom,pcie-sm8550
> +    then:
> +      properties:
> +        clocks:
> +          minItems: 7
> +          maxItems: 8
> +        clock-names:
> +          minItems: 7
> +          items:
> +            - const: aux # Auxiliary clock
> +            - const: cfg # Configuration clock
> +            - const: bus_master # Master AXI clock
> +            - const: bus_slave # Slave AXI clock
> +            - const: slave_q2a # Slave Q2A clock
> +            - const: ddrss_sf_tbu # PCIe SF TBU clock
> +            - const: noc_aggr # Aggre NoC PCIe AXI clock
> +            - const: cnoc_sf_axi # Config NoC PCIe1 AXI clock
> +        iommus:
> +          maxItems: 1
> +        iommu-map:
> +          maxItems: 2

1. Don't define new properties in allOf. It makes the binding
unmaintainable.

2. Why only SM8550?

> +        resets:
> +          minItems: 1

Why second reset is optional?

> +          maxItems: 2
> +        reset-names:
> +          minItems: 1
> +          items:
> +            - const: pci # PCIe core reset
> +            - const: link_down # PCIe link down reset
> +
>    - if:
>        properties:
>          compatible:
> @@ -694,6 +737,7 @@ allOf:
>                - qcom,pcie-sm8250
>                - qcom,pcie-sm8450-pcie0
>                - qcom,pcie-sm8450-pcie1
> +              - qcom,pcie-sm8550
>      then:
>        oneOf:
>          - properties:

Best regards,
Krzysztof