Re: [PATCH] pinctrl: baytrail: explicitly set gpio chip base

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Mon, May 4, 2015 at 1:36 PM, Antonio Ospite <ao2@xxxxxx> wrote:
> On Mon, 4 May 2015 13:40:00 +0300 Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote:

>> Well, if you happen to have another GPIO chip (a GPIO expander for
>> example) and it somehow gets loaded before this driver. It may take the
>> range you have reserved for the BYT driver.
>>
>> Not sure how realistic case that is, though...
>
> Indeed, being this for the SoC gpio controller I thought it was
> unlikely, however I do not have a huge experience on these matters.
>
> I have no strong opinion on this, Mika, so whether or not you merge the
> change it'll be fine by me.

The ability to set .base is basically there for legacy reasons,
and the critical legacy case is usually when setting it to 0
for the on-SoC GPIO.

In the long run we want to get rid of static GPIO numbers
altogether so I prefer if you construct your userspace to
traverse sysfs to get the GPIOs you need to get at,
sysfs is horrible and unreliable for GPIO.

Yours,
Linus Walleij
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