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

[Abel Vesa <abel.vesa@linaro.org>]

On 23-01-20 09:37:32, Krzysztof Kozlowski wrote:
> On 19/01/2023 12:24, Abel Vesa wrote:
> > Add the SM8550 platform to the binding.
> > 
> > Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> > ---
> > 
> > The v2 was here:
> > https://lore.kernel.org/all/20230118111704.3553542-1-abel.vesa@linaro.org/
> > 
> > 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.

That is a good point. Will add the cpu-pcie in v5.

> 
> >  
> >    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?

Good point again. Will make both iommus and iommu-map properties global
as even SM8450 has them.

> 
> > +        resets:
> > +          minItems: 1
> 
> Why second reset is optional?

link_down reset is needed only by g4x2 pcie, AFAICT.

> 
> > +          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
>