Re: [PATCH 1/4] dt-bindings: arm: qcom: Document Shikra and its EVK boards

[Krzysztof Kozlowski <krzk@kernel.org>]

On Tue, May 12, 2026 at 09:38:04AM +0530, Komal Bajaj wrote:
> Shikra is a Qualcomm IoT SoC available in a System-on-Module (SoM)
> form factor. The SoM integrates the Shikra SoC, PMICs, and essential
> passives, and is designed to be mounted on carrier boards.
> 
> One SoM variant is introduced:
>   - CQM: retail variant with integrated modem (PM4125 PMIC)
> 
> Two EVK boards are supported:
>   - shikra-cqm-evk: pairs with the CQM SoM
>   - shikra-cqs-evk: pairs with the CQM SoM, with no modem support

s/CQM/CQS/

but anyway I would prefer to use full product names from
include/dt-bindings/arm/qcom,ids.h (so CQXXXXM).

> 
> Each EVK provides debug UART, USB, and other peripheral interfaces.
> 
> Add compatible strings for the CQM SoM variant and its two
> corresponding EVK boards.
> 
> Signed-off-by: Komal Bajaj <komal.bajaj@oss.qualcomm.com>
> ---
>  Documentation/devicetree/bindings/arm/qcom.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
> index 2741c07e9f41..f041d71d7957 100644
> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
> @@ -963,6 +963,13 @@ properties:
>            - const: qcom,qcs9100
>            - const: qcom,sa8775p
>  
> +      - items:
> +          - enum:
> +              - qcom,shikra-cqm-evk
> +              - qcom,shikra-cqs-evk
> +          - const: qcom,shikra-cqm-som

This is not accurate. The SoM has physically different SoC - either CQM
or CQS. You either need two lists, like Toradex is doing (e.g.
toradex,verdin-imx95), or enum in the middle of the lists, like Renesas
is doing (e.g. renesas,rzt2h-evk).

I prefer the first option, so Toradex choice.

But for sure you do not get the third solution... Really, you are not
supposed to invent these things, but look at existing solutions (and I
was mentioning Toradex during internal meetings whenever someone asked
me how the SoM and carrier should be organized).

Best regards,
Krzysztof