Re: [PATCH v4 7/7] arm64: dts: qcom: mahua: Switch pcie5_phy ref clock to RPMH_CXO_CLK

From: Konrad Dybcio

Date: Tue Jun 09 2026 - 09:13:18 EST


On 5/28/26 4:29 AM, Qiang Yu wrote:
> PCIe5 PHY on Mahua gets refclk from CXO0 pad directly, so no QREF
> clkref_en voting is required. Override the clock list to use RPMH_CXO_CLK
> directly instead.

This is the last piece of the puzzle that this series is missing.
There's no QREF clkref_en, but there is a refgen that needs to be
powered. For PCIe5 on Mahua this would be L2F_E0 (0p9) and L4H_E0
(1p2).

I think the easiest (laziest?) solution would be to add dummy clocks
in the clkref driver and only toggle the required regulators. Another
option is to defer back to individual drivers (such as PCIe QMPPHY).

I kinda like the "one central node to drive power" approach, but I'm
not sure others agree, since it stretches truth just a tiny bit
(although not as much as one would think since there are *some*
controls for the transparent-to-the-OS hw pieces in these paths still
in TCSR).. Dmitry, Krzysztof, would you object to that?

Konrad