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

[Qiang Yu]

On Fri, Feb 13, 2026 at 07:47:36PM +0200, Dmitry Baryshkov wrote:
> 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.

Hi Konrad, Dmitry

I tried to model the reference voltage as a fixed regulator but the fixed
regulator driver only supports a single vin-supply. However, the refgen
block requires two separate power supplies (1.2V and 0.9V LDOs).

Would it be appropriate to modify the qcom-refgen-regulator.c driver to
handle LDO voting for both the 1.2V and 0.9V supplies? In the regulator's
enable/disable callbacks, we could vote for and unvote these two LDOs
instead of performing register operations.

- Qiang Yu
> 
> > 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