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Date:   Wed, 28 Apr 2021 00:51:41 +0200
From:   Michael Walle <michael@walle.cc>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>
Subject: Re: [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x GPIO
 controller
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References: <20210426095426.118356-1-tsbogend@alpha.franken.de>
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Hi,

Am 2021-04-26 12:29, schrieb Andy Shevchenko:
> On Mon, Apr 26, 2021 at 12:55 PM Thomas Bogendoerfer
> <tsbogend@alpha.franken.de> wrote:
> 
> 2) there is gpio-regmap generic code, that may be worth
> considering.

This driver uses memory mapped registers. While that is
also possible with gpio-regmap, there is one drawback:
it assumes gpiochip->can_sleep = true for now, see [1].
Unfortunately, there is no easy way to ask the regmap
if its mmio/fastio.

-michael

[1] 
https://elixir.bootlin.com/linux/v5.12/source/drivers/gpio/gpio-regmap.c#L257