From mboxrd@z Thu Jan 1 00:00:00 1970 From: zonque@gmail.com (Daniel Mack) Date: Tue, 30 Oct 2012 21:05:10 +0100 Subject: [PATCH 2/5] ARM: PXA: Zipit Z2: Add USB host and device support In-Reply-To: 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> Message-ID: <509032F6.1050301@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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