Re: [PATCH 2/2] arm64: dts: qcom: Add X1E001DE Snapdragon Devkit for Windows

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Tue, Oct 01, 2024 at 09:56:30AM +0300, Dmitry Baryshkov wrote:
> On October 1, 2024 5:42:35 AM GMT+03:00, Bjorn Andersson <andersson@kernel.org> wrote:
> >On Wed, Sep 11, 2024 at 10:55:05AM GMT, Dmitry Baryshkov wrote:
> >> On Wed, Sep 11, 2024 at 01:03:37PM GMT, Sibi Sankar wrote:
> >[..]
> >> > diff --git a/arch/arm64/boot/dts/qcom/x1e001de-devkit.dts b/arch/arm64/boot/dts/qcom/x1e001de-devkit.dts
> >[..]
> >> > +
> >> > +&pcie5 {
> >> > +	perst-gpios = <&tlmm 149 GPIO_ACTIVE_LOW>;
> >> > +	wake-gpios = <&tlmm 151 GPIO_ACTIVE_LOW>;
> >> > +
> >> > +	vddpe-3v3-supply = <&vreg_wwan>;
> >> 
> >> Please use pwrseq instead.
> >> 
> >
> >What benefit is there to wrap a single 3.3V regulator in pwrseq driver?
> 
> First of all, is it really just a 3.3V? Second, is it actually powering up the host controller (as expressed in the device tree? Is it a power supply to the slot (in this case, I think, it should be expressed differently)? Or is it a power supply to the card itself?
> 

Yeah, we should get into the details here. We were not paying attention till
now, but with the advent of pwrseq, we should describe the power supply properly
in DT.

Here I believe the supply is to the PCIe Mini Card connector where a modem is
connected. In that case, 3.3v supply should be connected to 3.3Vaux of the
connector and we should have a generic pwrseq driver for the mini cards.

Sibi, please verify the above in schematics.

- Mani
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