From mboxrd@z Thu Jan  1 00:00:00 1970
From: Liam Girdwood <lrg@slimlogic.co.uk>
Subject: Re: how can we modify voltage on DVFS through Linux
Date: Sat, 17 Oct 2009 20:18:10 +0100
Message-ID: <1255807090.19139.289.camel@vega>
References: <9c3f89cc0910161227l599965c9me23d563642592cfc@mail.gmail.com>
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To: Priya Sehgal <priya.sehgal@gmail.com>
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List-Id: linux-pm@vger.kernel.org

On Fri, 2009-10-16 at 15:27 -0400, Priya Sehgal wrote:
> Hello,
> I am working on DVFS capable CPU - Nehalem quad core and I need to
> modify the
> CPU speed and voltage. I disabled cpuspeed service on my machine and
> modified 
> some piece of cpuspeed code, to change the frequency of all the CPUs
> the way I want.
> 
> I am curious whether the voltage gets increased and decreased in
> proportion to the 
> frequency, or can we control the voltage separately. I could not
> locate any /sys entries for voltage
> only for frequency.
> 

Have a look at voltage regulator framework in include/linux/regulator.
It's used for CPU DVFS on ARM atm. 

Liam