Re: [PATCH v2] gpio: davinci: fix gpio selection for OF

From: Grygorii Strashko
Date: Mon Mar 17 2014 - 10:12:15 EST


On 03/17/2014 03:29 PM, Sekhar Nori wrote:
> On Friday 14 March 2014 04:32 PM, Linus Walleij wrote:
>> On Fri, Mar 14, 2014 at 11:08 AM, Alexander Holler <holler@xxxxxxxxxxxxx> wrote:
>>> Am 11.03.2014 11:15, schrieb Linus Walleij:
>>>> On Wed, Mar 5, 2014 at 12:21 PM, Alexander Holler <holler@xxxxxxxxxxxxx> wrote:
>>>>
>>>>> The driver missed an of_xlate function to translate gpio numbers
>>>>> as found in the DT to the correct chip and number.
>>>>>
>>>>> While there I've set #gpio_cells to a fixed value of 2.
>>>>>
>>>>> I've used gpio-pxa.c as template for those changes and tested my changes
>>>>> successfully on a da850 board using entries for gpio-leds in a DT. So I didn't
>>>>> reinvent the wheel but just copied and tested stuff.
>>>>>
>>>>> Thanks to Grygorii Strashko for the hint to the existing code in gpio-pxa.
>>>>>
>>>>> Signed-off-by: Alexander Holler <holler@xxxxxxxxxxxxx>
>>>>> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
>>>>
>>>> This v2 version applied, thanks!
>>>
>>> Thanks, but actually that should have been a fix for 3.14 with which the
>>> OF functionality for davinci gpio gets introduced. I assum with the
>>> patch in for-next, 3.14 will appear with that functionality broken and
>>> it will become a candidate for -stable.
>>
>> I just get the impression that DT support for DaVinci in v3.14 is so risky
>> and unstable that noone except those implementing it (i.e. you) is really
>> using it, is that correct?
>>
>> In that case it is hardly a fix that we need to rush out to the entire world.
>
> One thing to note is that this driver is used by keystone too and all
> its users are DT-only. Although I do not see any in-kernel DT GPIO users
> even there.
>
> I can confirm the patch does not break my gpiolib based test module
> (test with and without DT), but then it did not have an issue even before.

The issues isn't observed on Keystone2 as it has <32 gpios as of now, also GPIO
support for keystone is going to be added in 3.15 (including DT changes).

Regards,
-grygorii

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