Re: [PATCH 1/2] dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Add vdda-refgen supply for Glymur

[Qiang Yu]

On Mon, Feb 09, 2026 at 09:06:23AM +0100, Krzysztof Kozlowski wrote:
> On Sun, Feb 08, 2026 at 08:49:39PM -0800, Qiang Yu wrote:
> > The PCIe QMP PHYs on Glymur require stable reference voltage provided by
> > refgen. The refgen itself requires two separate power supplies:
> > vdda-refgen0p9 and vdda-refgen1p2.
> > 
> > Since there is no dedicated driver for REFGEN, add vdda-refgen0p9-supply
> 
> How does the driver matter for the bindings? If I add dedicated driver
> for refgen, then I change the bindings?

Yeah, I know that dt-bindings should describe hardware, not software. But
what I meant to say is that the refgen is different from qref which is
controlled via TCSR registers and its LDOs are requested to vote in
tcsrcc driver. The refgen doesn't required register setting and it doesn't
have dedicated driver, so we vote its LDOs in phy driver. I will avoid
this statement in next version.

> 
> There is qcom,sc8280xp-refgen-regulator so why there cannot be
> qcom,x1e-refgen-regulator?

I think we can and it seems better because the refgen for pcie phy also
supplies reference voltage to other modules like usb. But I checked the
qcom-refgen-regulator.c, it contains some register settings and there is
no LDOs voting. I'm not sure what does those register do, maybe Konrad
can provide some backgroud. But on Glymur, we only need to vote LDOs. So
what if we use a fixed regulator in the device tree to represent refgen?
We could set refgen0p9 and refgen1p2 as its input supplies, then the PCIe
PHY would just need one refgen supply reference.

- Qiang Yu
> 
> 
> > and vdda-refgen1p2-supply properties to the PCIe PHY dt-bindings. Use
> > conditional schema to restrict these properties to only Glymur PCIe QMP
> > PHYs.
> 
> Best regards,
> Krzysztof
>