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

[Dmitry Baryshkov]

On Wed, Feb 11, 2026 at 07:32:23PM -0800, Qiang Yu wrote:
> 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.

I must admit, I could not find references to the refgen in any of Glymur
PCIe-related HPGs.

> 
> > 
> > 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.

Those regs provide voting for refgen, because on those platforms DSI
block doesn't have a hardware vote for refgen.

> 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
> > 

-- 
With best wishes
Dmitry