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

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Pi-Cheng Chen <pi-cheng.chen@linaro.org>,
	Mark Brown <broonie@linaro.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	"Joe.C" <yingjoe.chen@mediatek.com>,
	Eddie Huang <eddie.huang@mediatek.com>,
	Howard Chen <ibanezchen@gmail.com>,
	Ashwin Chaugule <ashwin.chaugule@linaro.org>,
	Mike Turquette <mturquette@linaro.org>,
	Chen Fan <fan.chen@mediatek.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	Linaro Kernel Mailman List <linaro-kernel@lists.linaro.org>,
	linux-mediatek@lists.infradead.org,
	Sascha Hauer <s.hauer@pengutronix.de>
Subject: Re: [PATCH v2 3/4] cpufreq: mediatek: add Mediatek cpufreq driver
Date: Tue, 10 Mar 2015 08:20:43 +0530	[thread overview]
Message-ID: <CAKohpokT7fSniPGX2BfM61AtMoMCxEP8WDtbZ34bozUXscEWyg@mail.gmail.com> (raw)
In-Reply-To: <CALx668VFRdeWcK_gKhJrJehnaH5uDpA0m2OfHLqPVUq8oocXaw@mail.gmail.com>

On 6 March 2015 at 11:19, Pi-Cheng Chen <pi-cheng.chen@linaro.org> wrote:
> On 5 March 2015 at 17:55, Viresh Kumar <viresh.kumar@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 ?

> And the flexibility might be an issue, since we might
> use different
> PMIC for same SoC on different board.

We can talk about that separately once Mark replies to my query.

> Combining comments and suggestions from you and Sascha[1], I conclude some
> architectural changes are going to be made in the next version:
>
> 1. Use set_rate hook instead of determine_rate in clk driver, and
> switch to intermeidate
>     PLL parent and back to original CPU PLL parent explicitly in set_rate

Lets wait for Russell's answer to the query I posted before making any
progress here.