linux-kernel - Re: [PATCH/RFC] ARM: amba: Remove AMBA level regulator support

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Date:	Mon, 2 Apr 2012 01:02:36 +0530
From:	Rabin Vincent <rabin@....in>
To:	Linus Walleij <linus.walleij@...aro.org>
Cc:	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	spi-devel-general@...ts.sourceforge.net,
	Russell King <linux@....linux.org.uk>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH/RFC] ARM: amba: Remove AMBA level regulator support

On Sun, Apr 1, 2012 at 22:52, Linus Walleij <linus.walleij@...aro.org> wrote:
> On Sun, Apr 1, 2012 at 5:29 PM, Mark Brown
> <broonie@...nsource.wolfsonmicro.com> wrote:
>> The impact should be minimal since currently there are no mainline
>> systems which actually provide a vcore regulator so none need updating.
>
> Oh yes there are:
> drivers/mfd/db8500-prcmu.c
>
> This driver registers a number of voltage domain regulators,
> among those:
>
> static struct regulator_consumer_supply db8500_vape_consumers[] = {
>       (...)
>        REGULATOR_SUPPLY("vcore", "sdi0"),
>        REGULATOR_SUPPLY("vcore", "sdi1"),
>        REGULATOR_SUPPLY("vcore", "sdi2"),
>        REGULATOR_SUPPLY("vcore", "sdi3"),
>        REGULATOR_SUPPLY("vcore", "sdi4"),
>        (...)
>        REGULATOR_SUPPLY("vcore", "uart0"),
>        REGULATOR_SUPPLY("vcore", "uart1"),
>        REGULATOR_SUPPLY("vcore", "uart2"),
>
> IIRC the machine will not boot (i.e. these drivers cannot even
> probe) without these regulators in place, so they get enabled by
> the AMBA bus code.

These vcore "regulators" do nothing but increment a variable which is
write-only in mainline, so the machine will boot and drivers will probe
fine with Mark's patch.
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