linux-kernel - Re: [PATCH] regulator: qcom-rpmh: Add support for regulator-off-on-delay-us

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Message-ID: <2b8945c1-4372-4023-a15b-9187b9f23418@sirena.org.uk>
Date: Tue, 27 Jan 2026 17:35:56 +0000
From: Mark Brown <broonie@...nel.org>
To: Saikiran <bjsaikiran@...il.com>
Cc: lgirdwood@...il.com, andersson@...nel.org, konrad.dybcio@...aro.org,
	linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] regulator: qcom-rpmh: Add support for
 regulator-off-on-delay-us

On Tue, Jan 27, 2026 at 10:57:57PM +0530, Saikiran wrote:

> Some Qualcomm platforms require a significant delay after powering off a
> rail before it can be powered on again, especially for regulators that
> depend on passive discharge.

> The core regulator framework supports this via the 'regulator-off-on-delay-us'
> property, but the RPMh regulator driver currently ignores it.

The core regulator framework does not support this, this is specifically
a property supported by the fixed voltage regulator.

> Add support for parsing this generic property from device tree and
> populating the regulator descriptor. This allows board-specific DTS files
> to specify required discharge delays for RPMh-controlled regulators.

This would at a minimum need the bindings for the regulators on the
affected platforms to be updated.  What exactly are we talking about in
terms of the actual configuration here, what goes wrong if we don't
leave the regulator powered off and how sure are we that this is
platform specific rather than regulator specific?  I'm guessing these
are LDOs?

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