Re: [RFC v2 10/39] gpio: add HAS_IOPORT dependencies

[Niklas Schnelle <schnelle@linux.ibm.com>]

On Sun, 2022-05-01 at 23:55 +0200, Linus Walleij wrote:
> On Fri, Apr 29, 2022 at 5:37 PM William Breathitt Gray
> <william.gray@linaro.org> wrote:
> > On Fri, Apr 29, 2022 at 04:46:00PM +0200, Niklas Schnelle wrote:
> > > Good question. As far as I can see most (all?) of these have "select
> > > ISA_BUS_API" which is "def_bool ISA". Now "config ISA" seems to
> > > currently be repeated in architectures and doesn't have an explicit
> > > HAS_IOPORT dependency (it maybe should have one). But it does only make
> > > sense on architectures with HAS_IOPORT set.
> > 
> > There is such a thing as ISA DMA, but you'll still need to initialize
> > the device via the IO Port bus first, so perhaps setting HAS_IOPORT for
> > "config ISA" is the right thing to do: all ISA devices are expected to
> > communicate in some way via ioport.
> 
> Adding that dependency seems like the right solution to me.
> 
> Yours,
> Linus Walleij

One thing I forgot to mention, config HAS_IOPORT does have a "def_bool
ISA" but yes I agree an explicit "depends on HAS_IOPORT" for ISA seems
more logical. I also haven't found issues trying this out locally so
far.