Re: [PATCH v4 3/4] dt-bindings: arm: Add new compatible for smc/hvc transport for SCMI

[Sudeep Holla <sudeep.holla@arm.com>]

On Mon, Sep 11, 2023 at 12:43:58PM -0700, Nikunj Kela wrote:
> Introduce compatible "qcom,scmi-hvc-shmem" for SCMI smc/hvc
> transport channel for Qualcomm virtual platforms.
> The compatible mandates a shared memory channel.
> 
> Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com>
> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  .../devicetree/bindings/firmware/arm,scmi.yaml       | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> index 8d54ea768d38..4090240f45b1 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

Can it be simply "qcom,scmi-smc" for 2 reasons ?
1. We don't support SMC/HVC without shmem, so what is your argument to add
   '-shmem' in the compatible here ?
2. The exact conduit(SMC/HVC) used is detected runtime, so I prefer to keep
  '-smc' instead of '-hvc' in the compatible just to avoid giving an illusion
  that HVC is the conduit chosen here based on the compatible. It can be true
  for other reason but I don't want to mislead here by using HVC.
>
>    interrupts:
>      description:
> @@ -320,6 +323,15 @@ allOf:
>        required:
>          - linaro,optee-channel-id
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: qcom,scmi-hvc-shmem
> +    then:
> +      required:
> +        - shmem
> +
>  examples:
>    - |
>      firmware {
> -- 
> 2.17.1
> 

-- 
Regards,
Sudeep