From mboxrd@z Thu Jan 1 00:00:00 1970 From: haojian.zhuang@gmail.com (Haojian Zhuang) Date: Wed, 31 Oct 2012 23:31:30 +0800 Subject: [PATCH 2/5] ARM: PXA: Zipit Z2: Add USB host and device support In-Reply-To: <509032F6.1050301@gmail.com> References: <1351438555-4668-1-git-send-email-anarsoul@gmail.com> <1351438555-4668-2-git-send-email-anarsoul@gmail.com> <201210282259.46491.marex@denx.de> <508E4F7F.7010607@gmail.com> <508E5DFB.3060002@gmail.com> <508E61E7.7090502@gmail.com> <508E651A.5070009@gmail.com> <509032F6.1050301@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Oct 31, 2012 at 4:05 AM, Daniel Mack wrote: > > On 30.10.2012 21:01, Vasily Khoruzhick wrote: > > On Mon, Oct 29, 2012 at 2:14 PM, Daniel Mack wrote: > >> On 29.10.2012 12:12, Vasily Khoruzhick wrote: > >>> On Mon, Oct 29, 2012 at 2:00 PM, Daniel Mack wrote: > >>> > >>>>> Well, there's an issue - Z2 does not preserve memory contents in deep sleep > >>>>> (but it does in sleep), so userspace can't be fixed here unfortunatelly. > >>>>> There's no another possibility to turn Z2 off, and plain sleep is too > >>>>> power hungry. > >>>>> So the only way to keep Z2 in low-power mode is fake power off, which just puts > >>>>> Z2 in deep sleep. > >>>> > >>>> Why can't the userspace trigger a deep sleep then instead of powering > >>>> off? Which details do I lack? > >>> > >>> How? echo mem >/sys/power/state puts system into non-deep sleep. Anyway, kernel > >>> is not ready for fake power off instead of suspend (we can't resume > >>> from deep sleep, > >>> memory content is not preserved), so there can be some data loss. > >>> Adding some sysfs file to control sleep type does not look like a good > >>> idea to me. > >>> > >>> Btw, how other DT-capable boards handle power off? > >> > >> No idea. I never actually used that kind of power state. > > > > Hi Daniel, > > > > One more question: what should I use instead of pxa2xx_mfp_config in > > DT board to configure pin modes? > > Haojian was working on the PXA pinctrl drivers, but I don't know how far > that is yet. > > If that's not yet there, have a look at the pinctrl-single driver. It's > admittedly not as nice to use as the constants in the board file as DT > lacks defines for numerical constants, but's at least a workaround. > > On a more general note, it's arguable whether this kind of setup should > be done in the bootloader after all. > > > Daniel > I prefer to use pinctrl-single driver instead. I'm updating mmp pinctrol driver to pinctrl-single driver framework. You can find them in mailist. I'm submitting a third round in these days. Regards Haojian