Re: [PATCH 1/2] dt-bindings: arm: Add qcom specific hvc transport for SCMI

[Nikunj Kela]

On 7/18/2023 11:12 AM, Krzysztof Kozlowski wrote:
> On 18/07/2023 18:08, Nikunj Kela wrote:
> > Introduce compatible "qcom,scmi-hvc-shmem" for SCMI
> > transport channel for Qualcomm virtual platforms.
> > The compatible mandates a shared memory channel.
> >
> > Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
> > ---
> >   .../bindings/firmware/arm,scmi.yaml           | 69 +++++++++++++++++++
> >   1 file changed, 69 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > index b138f3d23df8..605b1e997a85 100644
> > --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> > @@ -45,6 +45,9 @@ properties:
> >         - description: SCMI compliant firmware with OP-TEE transport
> >           items:
> >             - const: linaro,scmi-optee
> > +      - description: SCMI compliant firmware with Qualcomm hvc/shmem transport
> > +        items:
> > +          - const: qcom,scmi-hvc-shmem
> >   
> >     interrupts:
> >       description:
> > @@ -321,6 +324,16 @@ else:
> >         required:
> >           - linaro,optee-channel-id
> >   
> > +    else:
> > +      if:
> > +        properties:
> > +          compatible:
> > +            contains:
> > +              const: qcom,scmi-hvc-shmem
> > +      then:
> > +        required:
> > +          - shmem
> Unfortunately this pattern if-else-if-else-if-else does not scale well.
> Please convert all entries first to allOf:if:then,if:then,if:then (in
> new patch), and then add new if:then:
Ok!
> > +
> >   examples:
> >     - |
> >       firmware {
> > @@ -444,6 +457,62 @@ examples:
> >           };
> >       };
> >   
> > +  - |
> > +    firmware {
> > +        scmi_dpu {
> No underscores in node names.
>
> Node names should be generic. See also an explanation and list of
> examples (not exhaustive) in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
ACK!
> > +            compatible = "qcom,scmi-hvc-shmem";
> > +            shmem = <&shmem_dpu>;
> > +
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +
> > +            scmi_pd_dpu: protocol@11 {
> > +                reg = <0x11>;
> > +                #power-domain-cells = <1>;
> > +            };
> > +        };
> > +
> Add only one example, but then only if it differs significantly. I see
> no differences - except compatible - so maybe no point of examples.
Other than the compatible, it also doesn't require smc-id, we read it 
from shmem region.  Will remove examples.
> > +        scmi_gpu {
> > +            compatible = "qcom,scmi-hvc-shmem";
> > +            shmem = <&shmem_gpu>;
> This example for sure is not needed - you duplicate above.
Right, will remove this example.
> > +
> > +            interrupts = <GIC_SPI 931 IRQ_TYPE_EDGE_RISING>;
> > +            interrupt-names = "a2p";
> > +
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +
> > +            scmi_pd_gpu: protocol@11 {
> > +                reg = <0x11>;
> > +                #power-domain-cells = <1>;
> > +            };
> > +        };
> > +    };
> > +
> > +    soc {
> > +        #address-cells = <1>;
> > +        #size-cells = <1>;
> > +
> > +        sram@95c00000 {
> > +            compatible = "mmio-sram";
> > +            reg = <0x95c00000 0x10000>;
> > +
> > +            #address-cells = <1>;
> > +            #size-cells = <1>;
> > +            ranges;
> > +
> > +            shmem_dpu: scmi-sram-dpu@95c00000 {
> > +                compatible = "arm,scmi-shmem";
> > +                reg = <0x95c00000 0x3f0>;
> > +            };
> How does these differ from existing example?

It doesn't. Will remove the example as suggested. Thanks


> Best regards,
> Krzysztof