Re: [PATCH v2 1/3] dt-bindings: usb: qcom,dwc3: Add multi-pd bindings for dwc3 qcom

Bjorn Andersson
2021-10-25T19:09:01Z

On Mon 25 Oct 02:07 PDT 2021, Sandeep Maheswaram wrote:

> Add multi pd bindings to set performance state for cx domain
> to maintain minimum corner voltage for USB clocks.
>
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> ---
> v2:
> Make cx domain mandatory.
>
> Documentation/devicetree/bindings/usb/qcom,dwc3.yaml | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> index 2bdaba0..fd595a8 100644
> --- a/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> +++ b/Documentation/devicetree/bindings/usb/qcom,dwc3.yaml
> @@ -42,7 +42,13 @@ properties:
>
> power-domains:
> description: specifies a phandle to PM domain provider node
> - maxItems: 1
> + minItems: 2
> + items:
> + - description: cx power domain
> + - description: USB gdsc power domain
> +
> + required-opps:
> + description: specifies the performance state to power domain

I'm still worried about the fact that we can't just rely on the USB GDSC
being a subdomin of CX in order to just "turn on" CX.

Afaict accepting this path forward means that for any device that sits
in a GDSC power domain we will have to replicate this series for the
related driver.

I mentioned this in v1, but I don't think we reached a conclusion.

Regards,
Bjorn

>
> clocks:
> description:
> --
> 2.7.4
>