Re: [PATCH 2/3] dt-bindings: usb: mtk-xhci: Allow middle optional clocks to be missing

[Krzysztof Kozlowski]

On 17/06/2022 15:29, Nícolas F. R. A. Prado wrote:
> The current clock list in the binding doesn't allow for one of the
> optional clocks to be missing and a subsequent clock to be present. An
> example where this is an issue is in mt8192.dtsi, which has "sys_ck",
> "ref_ck", "xhci_ck" and would cause dtbs_check warnings.
> 
> Change the clock list in a way that allows the middle optional clocks to
> be missing, while still guaranteeing a fixed order. The "ref_ck" is kept
> as a const even though it is optional for simplicity, since it is
> present in all current dts files.
> 
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
> ---
> 
>  .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml       | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> index 63cbc2b62d18..99a1b233ec90 100644
> --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> @@ -80,8 +80,13 @@ properties:
>      items:
>        - const: sys_ck  # required, the following ones are optional
>        - const: ref_ck
> -      - const: mcu_ck
> -      - const: dma_ck
> +      - enum:
> +          - mcu_ck
> +          - dma_ck
> +          - xhci_ck
> +      - enum:
> +          - dma_ck
> +          - xhci_ck
>        - const: xhci_ck

You allow now almost any order here, including incorrect like
sys,ref,xhci,xhci,xhci.

The order of clocks has to be fixed and we cannot allow flexibility. Are
you sure that these clocks are actually optional (not wired to the device)?


Best regards,
Krzysztof