linux-kernel - Re: [PATCH v2 1/3] mfd: sprd-sc27xx: Integrate power off and reboot support

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Message-ID: <20260108101520.GA302752@google.com>
Date: Thu, 8 Jan 2026 10:15:20 +0000
From: Lee Jones <lee@...nel.org>
To: Otto Pflüger <otto.pflueger@...cue.de>
Cc: Orson Zhai <orsonzhai@...il.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Chunyan Zhang <zhang.lyra@...il.com>,
	Mark Brown <broonie@...nel.org>, Sebastian Reichel <sre@...nel.org>,
	Rob Herring <robh@...nel.org>, linux-kernel@...r.kernel.org,
	linux-spi@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH v2 1/3] mfd: sprd-sc27xx: Integrate power off and reboot
 support

On Wed, 26 Nov 2025, Lee Jones wrote:

> On Sun, 23 Nov 2025, Otto Pflüger wrote:
> 
> > On Thu, Nov 20, 2025 at 03:30:24PM +0000, Lee Jones wrote:
> > > On Mon, 10 Nov 2025, Otto Pflüger wrote:
> > > 
> > > > The SC27xx PMICs allow restarting and powering off the device. Since
> > > > this functionality is rather simple and not configurable in any way,
> > > > make it part of the main PMIC driver.
> > > 
> > > This sounds like more of a drivers/power thing.
> > 
> > This was originally in drivers/power, but according to [1], it should
> > not be a separate device tree node. Using a separate driver without a
> > separate device tree node would still involve some code here that
> > instantiates a platform device and selects the right platform data for
> > it.
> > 
> > Registering the poweroff handler directly seemed less complex, and I
> > assumed it was okay since some other MFD drivers (e.g. rk8xx) also
> > implement the same functionality without a separate power driver.
> > 
> > Is it a good idea to use devm_mfd_add_devices here instead?
> > 
> > [1]: https://lore.kernel.org/all/20251002025344.GA2958334-robh@kernel.org/
> 
> Well that is quite the predicament.
> 
> Let me catch-up with Rob out-of-band and see if we can come up with a
> solution.

The discussion between Rob and I led to an "agree to disagree" moment.

I still think that a node to describe this device is the correct
approach, however without Rob's blessing, you're a bit stuck.

I think your best bet at this point is to remove the
devm_of_platform_populate() and replace it with mfd_add_devices().

-- 
Lee Jones [李琼斯]