From mboxrd@z Thu Jan  1 00:00:00 1970
From: bilhuang <bilhuang@nvidia.com>
Subject: Re: [PATCH v3 2/2] cpufreq: tegra: Re-model Tegra cpufreq driver
Date: Wed, 18 Dec 2013 19:33:09 +0800
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To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Stephen Warren <swarren@wwwdotorg.org>, "thierry.reding@gmail.com" <thierry.reding@gmail.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, "cpufreq@vger.kernel.org" <cpufreq@vger.kernel.org>, "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>
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On 12/18/2013 07:11 PM, Viresh Kumar wrote:
> On 17 December 2013 16:22, bilhuang <bilhuang@nvidia.com> wrote:
>> Tegra20 DVFS is a little bit complicated due to the fact that we can't scale
>> VDD_CPU directly, there are constraints or relationship to other power rails
>> so I don't think it is a good idea to use generic cpufreq-cpu0 driver if
>> we're going to support voltage scaling.
>
> But why can't we handle that in a CPU specific regulator code?
>
cpufreq-cpu0 driver will call regulator_set_voltage_tol() directly 
according to the pre-defined OPP freq/volt pairs, the regulator drivers 
could be shared by other SoC so is not suitable to handle this, or do I 
misunderstand?