From: NeilBrown <neilb@suse.de>
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: linux-serial@vger.kernel.org, linux-pm@vger.kernel.org,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: Question: How to power-manage UART-attached devices.
Date: Tue, 1 May 2012 09:35:59 +1000 [thread overview]
Message-ID: <20120501093559.5c14087d@notabene.brown> (raw)
In-Reply-To: <20120430223322.GA3951@sirena.org.uk>
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On Mon, 30 Apr 2012 23:33:22 +0100 Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
> On Tue, May 01, 2012 at 08:22:09AM +1000, NeilBrown wrote:
>
> > The question is how can user-space tell the kernel that these devices are
> > 'inactive'?
>
> > I would like to integrate this into Linux in the most "natural" way that I
> > can but am having trouble. My current approach involves using "rfkill" but
> > that doesn't work very well for reasons that are probably not very relevant
> > here. It probably does make sense for powering the GPS antenna, but not
> > much else.
>
> The userspace consumer was added for users like this that live entirely
> in userspace.
Hi Mark,
thanks for the reply.
I assume you mean REGULATOR_VIRTUAL_CONSUMER (drivers/regulator/virtual.c)?
The one where the Kconfig entry says:
This is mainly useful for test purposes.
That certainly was useful for test purposes but I want to move beyond
testing.
One of the purposes of an operating system is to provide useful abstractions
and hide irrelevant details, so I don't want user-space to have to
explicitly enable a regulator.
I could cope with an 'on/off switch' abstraction. It might then enable a
regulator. In the case of the GPS device it would need to both enable a
regulator and toggle a GPIO line. I really don't want user-space to "know"
that it has to turn on a regulator and toggle a gpio line...
So I'm still hoping for something more abstract.
Thanks,
NeilBrown
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next prev parent reply other threads:[~2012-04-30 23:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-30 22:22 Question: How to power-manage UART-attached devices NeilBrown
2012-04-30 22:33 ` Mark Brown
2012-04-30 23:35 ` NeilBrown [this message]
2012-05-01 16:33 ` Mark Brown
2012-05-01 23:15 ` NeilBrown
2012-05-02 9:02 ` Mark Brown
2012-04-30 22:51 ` H. Peter Anvin
2012-04-30 23:34 ` Alan Cox
2012-05-01 0:12 ` NeilBrown
2012-04-30 23:47 ` NeilBrown
2012-04-30 23:50 ` H. Peter Anvin
2012-05-01 0:27 ` NeilBrown
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