Re: [PATCH v4 1/2] driver: reset: spacemit-p1: add driver for poweroff/reboot

From: Andreas Schwab <schwab@suse.de>
To: Yao Zi <ziyao@disroot.org>
Cc: Troy Mitchell <troy.mitchell@linux.spacemit.com>,
	 Aurelien Jarno <aurelien@aurel32.net>,
	 linux-kernel@vger.kernel.org,  Lee Jones <lee@kernel.org>,
	 Sebastian Reichel <sre@kernel.org>,  Yixun Lan <dlan@gentoo.org>,
	 Paul Walmsley <pjw@kernel.org>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	 Albert Ou <aou@eecs.berkeley.edu>,
	 Alexandre Ghiti <alex@ghiti.fr>,
	 "open list:RISC-V ARCHITECTURE:Keyword:riscv"
	<linux-riscv@lists.infradead.org>,
	 "open list:RISC-V SPACEMIT SoC Support:Keyword:spacemit"
	<spacemit@lists.linux.dev>,
	 "open list:SYSTEM RESET/SHUTDOWN DRIVERS"
	<linux-pm@vger.kernel.org>
Subject: Re: [PATCH v4 1/2] driver: reset: spacemit-p1: add driver for poweroff/reboot
Date: Mon, 27 Oct 2025 10:03:44 +0100	[thread overview]
Message-ID: <mvmh5vk67in.fsf@suse.de> (raw)
In-Reply-To: <aP8QHwsYDlbQxQJo@pie> (Yao Zi's message of "Mon, 27 Oct 2025 06:24:31 +0000")

On Okt 27 2025, Yao Zi wrote:

> On Mon, Oct 27, 2025 at 11:20:33AM +0800, Troy Mitchell wrote:
>> On Sun, Oct 26, 2025 at 11:41:14PM +0100, Aurelien Jarno wrote:
>> > This driver implements poweroff/reboot support for the SpacemiT P1 PMIC
>> > chip, which is commonly paired with the SpacemiT K1 SoC.
>> > 
>> > The SpacemiT P1 support is implemented as a MFD driver, so the access is
>> > done directly through the regmap interface. Reboot or poweroff is
>> > triggered by setting a specific bit in a control register, which is
>> > automatically cleared by the hardware afterwards.
>> > 
>> > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
>> > ---
>> > v2:
>> >  - Replace the "select" by a "depends on"
>> >  - Remove outdated Reviewed-by
>> > 
>> >  drivers/power/reset/Kconfig              |  9 +++
>> >  drivers/power/reset/Makefile             |  1 +
>> >  drivers/power/reset/spacemit-p1-reboot.c | 88 ++++++++++++++++++++++++
>> >  3 files changed, 98 insertions(+)
>> >  create mode 100644 drivers/power/reset/spacemit-p1-reboot.c
>> > 
>> > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
>> > index 8248895ca9038..61c16f3d5abc7 100644
>> > --- a/drivers/power/reset/Kconfig
>> > +++ b/drivers/power/reset/Kconfig
>> > @@ -283,6 +283,15 @@ config POWER_RESET_KEYSTONE
>> >  	help
>> >  	  Reboot support for the KEYSTONE SoCs.
>> >  
>> > +config POWER_RESET_SPACEMIT_P1
>> > +	tristate "SpacemiT P1 poweroff and reset driver"
>> > +	depends on ARCH_SPACEMIT || COMPILE_TEST
>> > +	depends on MFD_SPACEMIT_P1
>> > +	default m
>> default m if ARCH_SPACEMIT? Or default ARCH_SPACEMIT?
>> I believe that reboot and shutdown are actually essential functionalities,
>> so it might make more sense: default ARCH_SPACEMIT?
>
> I don't think there's anything preventing it to be built as module by
> default: even though it's "essential", it's unnecessary during kernel
> and userspace startup, thus I see no reason to build it in the image.

Wouldn't it be needed in a reboot-on-panic situation?

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."