From: mike@compulab.co.il (Mike Rapoport)
To: linux-arm-kernel@lists.infradead.org
Subject: Colibri PXA320 Power management question
Date: Thu, 02 Sep 2010 17:41:57 +0300 [thread overview]
Message-ID: <4C7FB7B5.2010301@compulab.co.il> (raw)
In-Reply-To: <20100902142203.GA8381@sirena.org.uk>
Mark Brown wrote:
> On Thu, Aug 12, 2010 at 02:02:17PM +0400, Yuri Ludkevich wrote:
>
>> I have a question about power management of Colibri PXA320 module:
>> I found that bits PVE and FVE in PVCR register are disabled,
>> so at frequency change voltage will not change.
>
>> If I turn on PVE and FVE with pxaregs tool - voltage changes just fine.
>> Where are suitable place in the kernel for PVCR initialization?
>
> The expectation in Linux is that voltage scaling will be done in
> software using cpufreq rather than autonomously by the CPU.
PXA3xx has ability to automatically control certain regulators (almost) without
software intervention. Setting the bits Yuri is talking about should enable CPU
initiated i2c transactions upon frequency scaling events.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2010-09-02 14:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-12 10:02 Colibri PXA320 Power management question Yuri Ludkevich
2010-08-14 6:53 ` [Openpxa-users] " Marek Vasut
2010-08-15 2:06 ` Eric Miao
2010-08-15 9:13 ` Igor Grinberg
2010-08-15 9:16 ` Eric Miao
2010-09-02 14:22 ` Mark Brown
2010-09-02 14:41 ` Mike Rapoport [this message]
2010-09-02 15:27 ` Mark Brown
2010-09-02 15:43 ` Mike Rapoport
2010-09-04 2:31 ` [Openpxa-users] " Marek Vasut
2010-09-06 10:13 ` Mark Brown
2010-09-06 11:06 ` Mike Rapoport
2010-09-06 11:09 ` Eric Miao
2010-09-06 11:30 ` Mark Brown
2010-09-06 11:42 ` Haojian Zhuang
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