Re: [PATCH] gpio: tqmx86: Add GPIO driver for this IO controller

[Andrew Lunn <andrew@xxxxxxx>]

On Sun, Dec 09, 2018 at 12:01:52PM +0100, Linus Walleij wrote:
> Hi Andrew! Thanks for your patch!
> 
> On Sat, Dec 8, 2018 at 5:18 PM Andrew Lunn <andrew@xxxxxxx> wrote:
> 
> > Some TQ-Systems ComExpress modules contain an IO controller with 8
> > GPIO lines.
> >
> > Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
> 
> > +config GPIO_TQMX86
> > +       tristate "TQ-Systems QTMX86 GPIO"
> > +       depends on MFD_TQMX86
> > +       select GENERIC_IRQ_CHIP
> 
> I'd say probably remove that and add:
> 
> select GPIO_GENERIC

Hi Linus

I've been looking at the generic code. As far as i can see, it does
not work for this device. I see two problems:

1) This is not a mmio device, it is an ioport device. None of the
   accessors available in bgpio_setup_accessors() will work.

2) There does not appear to support the concept of some pins being GPO
   and some being GPI.

If the problem was just 1), i could probably add the needed accessors,
and add a new flag, to indicate ioport, not mmio. But handling the mix
of GPI and GPO does not look too easy.

Do you agree?

Thanks
	Andrew