Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol

From	Robert Jarzmik <robert.jarzmik@free.fr>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol
Date	2015-12-10 18:40 +0100
Message-ID	<qEdmc-OR-59@gated-at.bofh.it> (permalink)
References	<qzVxw-5SR-5@gated-at.bofh.it> <qDVSi-65j-15@gated-at.bofh.it> <qE3PQ-2Xo-19@gated-at.bofh.it> <qEb11-7RF-29@gated-at.bofh.it>
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Linus Walleij <linus.walleij@linaro.org> writes:

>>    - the GPDR (gpio direction register) shared access bothers me a bit
>
> How is it shared and between what users?
It's shared between the pin controller and the gpio controller.

The odd thing with the pxa architecture is that the GPDR bit selects between 2
different alternate functions, even when the pin is not a GPIO. Strange design,
isn't it ?

As a consequence, both the gpio driver and pinctrl have to modify it, for
different purposes :
 - pinctrl will modify it to select a specific alternate function
 - gpio driver will modify it when the pin is a GPIO, to modify its direction.

Cheers.

-- 
Robert
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Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol Linus Walleij <linus.walleij@linaro.org> - 2015-12-10 00:00 +0100
  Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol Robert Jarzmik <robert.jarzmik@free.fr> - 2015-12-10 08:30 +0100
    Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol Linus Walleij <linus.walleij@linaro.org> - 2015-12-10 16:10 +0100
      Re: [PATCH 0/4] gpio: pxa: integrate with pincontrol Robert Jarzmik <robert.jarzmik@free.fr> - 2015-12-10 18:40 +0100

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