Date: Mon, 30 Sep 2013 23:09:44 +0200 From: Bernd Walter <ticso@cicely7.cicely.de> To: Jia-Shiun Li <jiashiun@gmail.com> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org>, ticso@cicely.de Subject: Re: BBB CPU clock (was: Re: FreeBSD on Cubieboard 2, UDOO and Galaxy Note 10.1 (Exynos). Message-ID: <20130930210944.GH93103@cicely7.cicely.de> In-Reply-To: <CAHNYxxM5Lhytd8J-A7TvaXm05sMjFM1ghROhLthyV9uCVGishQ@mail.gmail.com> References: <CAHNYxxPtD5vgrohumwccoC_5bZv7fuV3RYK2vgLUpyEZCmOgqg@mail.gmail.com> <B8966F22-1169-4FE5-B105-4D104909723E@freebsd.org> <CAHNYxxM5Lhytd8J-A7TvaXm05sMjFM1ghROhLthyV9uCVGishQ@mail.gmail.com>
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On Tue, Oct 01, 2013 at 05:04:29AM +0800, Jia-Shiun Li wrote: > On Mon, Sep 30, 2013 at 11:26 AM, Tim Kientzle <kientzle@freebsd.org> wrote: > > > > My understanding: > > > > * We should query the PMIC to determine whether we're running from 5V supply or USB. > > > > * Based on that, we should adjust the CPU clocks. We should be able to run 1GHz from 5v supply. > > > > Connecting cpufreq would be a nice addition. > > Hi Tim, > > Yes you are right. I digged a bit the PMIC docs. > I didn't realize that DCDC2/3 output to MPC/core are adjustable. > > The PMIC capped USB input at 500mA by default, so if not changed otherwise, > or to be safe with what most USB power supplies are, it is correct to only go up > to 1GHz on DC input. > > I played for a while manually setting PMIC from u-boot prompt, setting MPU volt > to 1.325v, raise USB current limit, etc. but still cannot get it run > above 800MHz. > It always stopped booting at initing uhub. Looks like I need a bigger > DC adapter. I can do some tests with a lab supply. But right now I'm doing some tests with another board. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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