[PATCH v2 3/4] cpufreq: mediatek: add Mediatek cpufreq driver

Viresh Kumar viresh.kumar at linaro.org
Wed Mar 11 04:03:49 PDT 2015


On 11 March 2015 at 16:23, Mark Brown <broonie at kernel.org> wrote:
> On Tue, Mar 10, 2015 at 08:20:43AM +0530, Viresh Kumar wrote:
>
> Please don't send upstream e-mail to my work account, I use this address
> pretty consistently for upstream.  Upstream mail to my work account
> frequently ends up unread.

Sorry about that, I did exactly opposite of this earlier :(

>> On 6 March 2015 at 11:19, Pi-Cheng Chen <pi-cheng.chen at linaro.org> wrote:
>> > On 5 March 2015 at 17:55, Viresh Kumar <viresh.kumar at linaro.org> wrote:
>
>> > About putting
>> > those stuff into regulator driver, I think you mean creating a
>> > "virtual regulator
>> > device" and put all the voltage controlling complex into the driver, right?
>> > Maybe it's a good idea in this case, but I am sure if this kind of
>> > virtual regulator is acceptable.
>
>> @Mark: Is this allowed to create virtual regulator for a CPU ?
>
> I don't really know what the above means or what problem it's supposed
> to solve.

On mediatek platform, they need to configure two regulators in order to change
DVFS state of the big cluster. The generic cpufreq-dt driver and earlier OPP
bindings have support for a single regulator only and so what Pi-cheng tried
to do is,
- Configure one of the regulators using cpufreq-dt
- And other one using cpufreq frequency change notifiers

This looks awkward..

What I suggested was to create another virtual regulator for CPU which will
eventually configure both the regulators. And so the question that such
virtual regulators are allowed or not.



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