linux-kernel - Re: [PATCH V1 4/4] phy: qcom-qmp-ufs: read max-microamp values from device tree

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Message-ID: <fe2bc07c-8fe9-47fd-bcd7-c2f0ebbd596f@sirena.org.uk>
Date: Wed, 6 Aug 2025 17:51:04 +0100
From: Mark Brown <broonie@...nel.org>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: Nitin Rawat <quic_nitirawa@...cinc.com>, vkoul@...nel.org,
	kishon@...nel.org, mani@...nel.org, conor+dt@...nel.org,
	bvanassche@....org, andersson@...nel.org, neil.armstrong@...aro.org,
	dmitry.baryshkov@....qualcomm.com, konradybcio@...nel.org,
	krzk+dt@...nel.org, linux-arm-msm@...r.kernel.org,
	linux-phy@...ts.infradead.org, linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org
Subject: Re: [PATCH V1 4/4] phy: qcom-qmp-ufs: read max-microamp values from
 device tree

On Wed, Aug 06, 2025 at 05:58:30PM +0200, Konrad Dybcio wrote:
> On 8/6/25 5:43 PM, Nitin Rawat wrote:

> > Add support in QMP PHY driver to read optional vdda-phy-max-microamp
> > and vdda-pll-max-microamp properties from the device tree.

> > These properties define the expected maximum current (in microamps) for
> > each supply. The driver uses this information to configure regulators
> > more accurately and ensure they operate in the correct mode based on
> > client load requirements.

> > If the property is not present, the driver defaults load to
> > `QMP_VREG_UNUSED`.

> do you think having this in regulator core would make sense?

I'm not clear why the driver is trying to do this at all, the driver is
AFAICT making no other effort to manage the load at all.  We already
impose any constraints that are defined for a regulator while initially
parsing them so it's not clear to me what this is supposed to
accomplish, and it'll be broken if the supply is ever shared since it'll
set the load from this individual consumer to the maximum that's
permitted for the regulator as a whole.

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