From: <andrew-sh.cheng@mediatek.com>
To: unlisted-recipients:; (no To-header on input)
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
"Rob Herring" <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Viresh Kumar <viresh.kumar@linaro.org>,
Nishanth Menon <nm@ti.com>, "Stephen Boyd" <sboyd@kernel.org>,
Liam Girdwood <lgirdwood@gmail.com>, <linux-pm@vger.kernel.org>,
<devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <srv_heupstream@mediatek.com>
Subject: Re: [PATCH 09/12] devfreq: add mediatek cci devfreq
Date: Thu, 21 May 2020 16:52:35 +0800 [thread overview]
Message-ID: <1590051155.14062.3.camel@mtksdaap41> (raw)
In-Reply-To: <20200520123135.GD4823@sirena.org.uk>
On Wed, 2020-05-20 at 13:31 +0100, Mark Brown wrote:
> On Wed, May 20, 2020 at 11:43:04AM +0800, Andrew-sh.Cheng wrote:
>
> > + cci_df->proc_reg = devm_regulator_get_optional(cci_dev, "proc");
> > + ret = PTR_ERR_OR_ZERO(cci_df->proc_reg);
> > + if (ret) {
> > + if (ret != -EPROBE_DEFER)
> > + dev_err(cci_dev, "failed to get regulator for CCI: %d\n",
> > + ret);
> > + return ret;
> > + }
> > + ret = regulator_enable(cci_df->proc_reg);
>
> The code appears to require a regulator (and I'm guessing the device
> needs power) so why is this using regulator_get_optional()?
Hi Mark,
Do you mean, why not use regulator_get_exclusive() or regulator_get()?
Because cci and cpu litter core shared buck, it cannot use
regulator_get_exclusive().
Because both cci and cpu want to tune voltage, it cannot use
regulator_get(), otherwise it will get dummy regulator even this buck
doesn't register.as regulator.
BR,
Andrew-sh.Cheng
next prev parent reply other threads:[~2020-05-21 8:52 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200520034324epcas1p3affbd24bd1f3fe40d51baade07c1abba@epcas1p3.samsung.com>
[not found] ` <20200520034307.20435-1-andrew-sh.cheng@mediatek.com>
2020-05-20 4:10 ` [PATCH 00/12] Add cpufreq and cci devfreq for mt8183, and SVS support Chanwoo Choi
[not found] ` <1589953015.8243.2.camel@mtksdaap41>
2020-05-20 6:24 ` Chanwoo Choi
[not found] ` <1589958625.23971.2.camel@mtksdaap41>
2020-05-20 14:53 ` Matthias Brugger
[not found] ` <20200520034307.20435-2-andrew-sh.cheng@mediatek.com>
2020-05-20 14:54 ` [PATCH 01/12] OPP: Allow required-opps even if the device doesn't have power-domains Matthias Brugger
[not found] ` <CGME20200520034335epcas1p45a321a1a878fb7cd7b9c9ada0a474ef7@epcas1p4.samsung.com>
[not found] ` <20200520034307.20435-7-andrew-sh.cheng@mediatek.com>
2020-05-28 5:03 ` [PATCH 06/12] PM / devfreq: Add cpu based scaling support to passive_governor Chanwoo Choi
2020-05-28 6:14 ` Chanwoo Choi
2020-05-28 7:17 ` Chanwoo Choi
[not found] ` <1591100614.1804.1.camel@mtksdaap41>
2020-06-03 4:12 ` Chanwoo Choi
[not found] ` <1591098190.30729.15.camel@mtksdaap41>
2020-06-03 4:07 ` Chanwoo Choi
[not found] ` <20200520034307.20435-10-andrew-sh.cheng@mediatek.com>
2020-05-20 12:31 ` [PATCH 09/12] devfreq: add mediatek cci devfreq Mark Brown
2020-05-21 8:52 ` andrew-sh.cheng [this message]
2020-05-28 7:35 ` Chanwoo Choi
2020-05-28 8:00 ` Chanwoo Choi
[not found] ` <CGME20200520034339epcas1p1524dea2d7089cb3492384bbe917dcffe@epcas1p1.samsung.com>
[not found] ` <20200520034307.20435-9-andrew-sh.cheng@mediatek.com>
2020-05-28 7:42 ` [PATCH 08/12] dt-bindings: devfreq: add compatible for mt8183 " Chanwoo Choi
2020-06-15 7:31 ` [PATCH 00/12] Add cpufreq and cci devfreq for mt8183, and SVS support Viresh Kumar
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