Re: [PATCH v1 1/1] pinctrl: add pinctrl/GPIO driver for Apple SoCs

[Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>]

> > Apple calls those four controllers "gpio", "nub-gpio", "smc-gpio"
> > and "aop-gpio". SMC is their system management controller and AOP
> > is their "always-on processor". No idea what "nub-gpio" is.
> 
> It's similar to what we have in Baytrail/Cherrytrail.
> AOP -> SUS
> SMC -> ...
> 
> nub is probably related to some type of hub (or maybe simple typo, or
> typo on purpose?).

Unlikely a typo. "nub" is an Apple term. In software, an XNU (macOS)
kernel driver has a "nub" for exposing its public API. I don't know what
it means for hardware but very likely intentional.