Super I/O driver [generic gpio driver]

[Sam Leffler]

Andriy Gapon wrote:
> Do we have any drivers for special functions provided by ISA/LPC Super
> I/Os. I mean many of them have watchdog capabilities, GPIO, etc. I do
> not meant fdc, lpt, sio/uart and hwm which are 9or can be) handled as
> the devices of their own.
>
> I have some quite hairy code for Winbond W83977EF that provides watchdog
> and led interfaces (the latter is for power led).
> I'd like to understand what is the best/canonical way to access
> superio's ports, enter configuration mode, etc.
> Also, it would be interesting to see how various configurations/wirings
> of the same superio could be handled.
>
> I looked at some Linux drivers but their coding ways are quite different
> and they typically handle only one wiring type (probably the one that
> was found on author's motherboard).
>
> I also would be interested in a general discussion on this topic (superios).
>
> BTW, do we have some interface to userland or GPIO? Something similar to
> led(4), but more generic (and supporting 'I' as well 'O').
>   

There's been some discussion amongst embedded folks but nothing yet.  I 
noticed openbsd commit something recently but don't know if we can reuse 
anything they've done.

    Sam