[PATCH v2] ath79: add support for reset key on MikroTik RB912UAG-2HPnD

[Sergey Ryazanov]

On Wed, Jan 19, 2022 at 1:25 PM Denis Kalashnikov <denis281089 at gmail.com> wrote:
> On MikroTik RB91x board series a reset key shares SoC gpio
> line #15 with NAND ALE and NAND IO7. So we need a custom
> gpio driver to manage this non-trivial connection schema.
> Also rb91x-nand needs to have an ability to disable a polling
> of the key while it works with NAND.
>
> While we've been integrating rb91x-key into a firmware, we've
> figured out that:
> * In the gpio-latch driver we need to add a "cansleep" suffix to
> several gpiolib calls,
> * When gpio-latch and rb91x-nand fail to get a gpio and an error
> is -EPROBE_DEFER, they shouldn't report about this, since this
> actually is not an error and occurs when the gpio-latch probe
> function is called before the rb91x-key probe.
> We fix these related things here too.
>
> Signed-off-by: Denis Kalashnikov <denis281089 at gmail.com>

Reviewed-by: Sergey Ryazanov <ryazanov.s.a at gmail.com>