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.

We can find it on ipcatalog. On Glymur, there are 6 refgen instances:
u_cm_phy_refgen_0_west supplies to pcie3/4/6.
u_cm_phy_refgen_3_east supplies to pcie5.
This two refgen also supply to other modules like usb and qref which
is required by PCIe phy for stable reference clk.

In previous targets, refgen was often ignored because it shares LDOs with
phy or qref. We typically only vote for vdda-phy, vdda-pll, and vdda-qref
supplies. However, on Glymur, there are more instances and less LDO
sharing between phy/qref/refgen.

> 
> > 
> > > 
> > > 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.
> 

Okay, for PCIe PHY, we don't need register settings for refgen.

- 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