Re: [PATCH v6 1/1] mfd: arizona: Export functions to control subsystem DVFS

From: Richard Fitzgerald
Date: Tue May 26 2015 - 11:45:27 EST


On Tue, May 26, 2015 at 04:29:42PM +0100, Mark Brown wrote:
> On Tue, May 26, 2015 at 02:52:05PM +0100, Lee Jones wrote:
>
> > Shouldn't this DVFS dump live in drivers/cpufreq?
>
> cpufreq is specifically for CPUs (with the governors and everything) and
> has its own problems here. There is devfreq which was crated for this
> sort of thing (though more on a SoC level) though, not sure if it's a
> good fit or not.

The only codecs that have DVFS are WM8997, WM8998 and WM5102. No newer
codecs have it so it feels like unnecessary effort to create a whole
new driver for these three codecs. In any case, all we're really doing
here is setting the state of a single bit which tells the codec whether
we're feeding it enough DCVDD for it to do its internal DVFS. Most of
the additional complexity here is around co-operating with the
runtime_suspend/resume code in the MFD driver,
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