Re: [PATCH 1/4] dt-bindings: mtd: qcom,nandc: Add MDM9607 QPIC NAND controller
From: Stephan Gerhold
Date: Tue Jun 09 2026 - 04:13:12 EST
On Tue, Jun 09, 2026 at 09:52:51AM +0200, Miquel Raynal wrote:
> >> On MDM9607, there is only a single controllable clock for the NAND
> >> controller (RPM_SMD_QPIC_CLK). The same situation also applies e.g. for
> >> qcom,sdx55-nand, but the corresponding device tree (qcom-sdx55.dtsi) works
> >> around that by assigning a dummy clock (&nand_clk_dummy) to the second
> >> clock ("aon") that is required by the dt-bindings. This is not really
> >> useful, so avoid doing that for new platforms by excluding the second "aon"
> >> clock entry in the dt-bindings.
> >
> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxxxxx>
>
> What is the problem in giving twice the same clock? If this is what is
> done in the hardware routing, I do not see the reason for more
> complexity in the binding?
>
I had that in my first draft for this series, but this would be wrong
IMO. I suspect there is no QPIC/NAND related "aon" (always-on) clock on
this platform at all. I'm not sure about MDM9607 in particular (maybe
someone from Qualcomm can confirm), but a similar platform I was looking
into at some point actually had *3* separate clocks for QPIC in the
hardware and none of them were called "aon" ...
I think it's better to omit it and describe what we know for sure
instead of describing some dummy hardware resources that do not actually
exist.
Thanks,
Stephan