Re: [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x GPIO controller

[Michael Walle]

Hi,

Am 2021-04-26 12:29, schrieb Andy Shevchenko:
> On Mon, Apr 26, 2021 at 12:55 PM Thomas Bogendoerfer
> <tsbogend@xxxxxxxxxxxxxxxx> 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