[PATCH 2/5] ARM: PXA: Zipit Z2: Add USB host and device support

[haojian.zhuang@gmail.com (Haojian Zhuang)]

On Wed, Oct 31, 2012 at 4:05 AM, Daniel Mack <zonque@gmail.com> wrote:

> On 30.10.2012 21:01, Vasily Khoruzhick wrote:
> > On Mon, Oct 29, 2012 at 2:14 PM, Daniel Mack <zonque@gmail.com> wrote:
> >> On 29.10.2012 12:12, Vasily Khoruzhick wrote:
> >>> On Mon, Oct 29, 2012 at 2:00 PM, Daniel Mack <zonque@gmail.com> 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
>
>
Using pinctrl-single driver is preferred. I'm converting mmp pinctrl driver
into pinctrl-single
driver. I'll submit a new round in these days.

Thanks
Haojian
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