Re: [PATCH v2 0/3] phy: qcom: qmp-pcie: Add vdda-refgen supply support for Glymur

[Qiang Yu <qiang.yu@oss.qualcomm.com>]

On Mon, Jun 29, 2026 at 02:18:35PM +0200, Konrad Dybcio wrote:
> On 6/29/26 2:14 PM, Qiang Yu wrote:
> > On Mon, Jun 29, 2026 at 12:51:55PM +0200, Konrad Dybcio wrote:
> >> On 6/23/26 3:05 PM, Qiang Yu wrote:
> >>> The PCIe QMP PHYs on Glymur require both refgen for stable reference
> >>> voltage and qref for stable reference clock. The refgen requires two power
> >>> supplies: vdda-refgen0p9 and vdda-refgen1p2.
> >>>
> >>> can be extended in the future.
> >>>
> >>> This series creates a Glymur-specific supply list including the refgen
> >>> supplies and updates both Gen5x4 and Gen4x2 configurations to use it.
> >>>
> >>> Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com>
> >>>
> >>> Changes in v2:
> >>> - Add dts patch in this series.
> >>> - Reword commit msg of dtbinding patch.
> >>> - Link to v1: https://lore.kernel.org/all/20260208-refgen-v1-0-87ca84fd78b3@oss.qualcomm.com/ 
> >>>
> >>> ---
> >>
> >> Is this necessary (for Glymur) now that we correlated some of the
> >> TCSR clocks with the right nodes?
> > 
> > This patch is necessary for glymur and mahua and other Qualcomm targets,
> > which can be verified from the REFGEN page and power grid page on ipcat.
> > 
> > Take Glymur PCIe3 PHY as an example: it requires two REFGENs — REFGEN0 for
> > the PHY itself and REFGEN4 for QREF. In the TCSR driver, only the LDOs for
> > REFGEN4 are voted, not REFGEN0. This is intentional: each consumer is
> > responsible for voting the LDOs of the REFGEN it uses. Since QREF uses
> > REFGEN4, the TCSR driver votes the REFGEN4 LDOs; since the PHY uses
> > REFGEN0, the PHY driver votes the REFGEN0 LDOs.
> > 
> > For some PHY instances in power grid, you can only see one REFGEN, that
> > indicates the phy doesn't require QREF or the phy and the QREF it requires
> > share same REFGEN.
> >>
> >> Perhaps this would be necessary for Mahua since its clocks don't
> >> require QREF (or we can lie about it and handle them there)?
> > 
> > For Mahua PCIe5 PHY, it doesn't require QREF. So we don't need to vote
> > REFGEN LDOs for QREF in tcsr driver. But the PHY requires REFGEN. So we
> > still need to vote in PHY driver.
> 
> OK, I think I got my mental model of all of this straight. But expect
> me to make more mistakes and sorry for that!

No worries at all. Glad the REFGEN and QREF topology is clear now. Thanks
for the review.

- Qiang Yu

-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy