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

[Haojian Zhuang]

On Tue, Nov 6, 2012 at 1:31 AM, Vasily Khoruzhick <anarsoul at gmail.com> wrote:
> On Sat, Nov 3, 2012 at 12:29 AM, Vasily Khoruzhick <anarsoul at gmail.com> wrote:
>
>>>
>>> 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
>>
>> OK, one more question:
>>
>> On PXA2xx GPIO and PINMUX are not separate blocks. Each pin can be
>> either input or output and have 4 modes (gpio + 3 alternate functions)
>> == 8 states , so we have: gpio in, gpio out, 3 alt in, 3 alt out.
>> To control pin mode one should write to GPDR (direction register) and
>> GAFR (alternate function register). pxa-gpio driver controls both of
>> those registers, so does pxa2xx-mfp.
>>
>> I'm not sure what to do in this case. Should I move code controlling
>> GPDR and GAFR into some pinctrl-pxa2xx driver, and modify pxa-gpio
>> driver to use it?
>>
>> Regards
>> Vasily
>
> Daniel, Haojian, any suggestion?
>
> I'm stuck at the moment, and have no idea how to handle it...
> pinmux/gpio are connected in hardware
> and I don't see a way to handle them with 2 separate drivers (gpio and
> pinmux) in software...
>
> Regards
> Vasily

I checked the PXA25x spec. pinmux functions are contained in gpio registers.

It doesn't matter. You can still you pinmux register. You only need to control
GAFP in pinmux driver.