Re: [PATCH RFC 1/2] m68k: io_mm.h: conditionalize ISA address translation on Atari

[Brad Boyer <flar@allandria.com>]

On Sat, Jun 05, 2021 at 01:41:22PM +1200, Michael Schmitz wrote:
> Am 05.06.2021 um 10:49 schrieb Brad Boyer:
> >I don't see anything in drivers/pcmcia that is obviously an m68k
> >system even though I'm pretty sure I remember discussions of supporting
> >such hardware in the past.
> 
> There's the APNE driver (Amiga PCMCIA NE2000 clone), which is already
> catered for by the current code in io_mm.h. I remember seeing patches for
> that driver that would allow support of a variant of the APNE card that were
> hard to integrate in the current NE clone code framework. Didn't consider
> adding another isa_type for that card at the time - I'll revisit these
> patches if I can find them again.
> 
> Supporting PB190 PCMCIA hardware requires adding a new isa_type and the
> corresponding IO translation cases. Not much more, for all I can see.
> Existing chipset drivers from other architectures ought to work already.
> Maybe add a specific block_input() hook as for APNE (but I surmise that
> might just be code duplication from generic code in lib8390.c - didn't
> check).
> 
> Not sure what card socket code the APNE driver uses - must be one of the
> generic variants from drivers/pcmcia. If your PB190 needs something not
> already in there, we'd need to add that as well.

I had to look a bit, but I found it. The apne driver doesn't use the
normal PCMCIA infrastructure at all. There is a custom Amiga PCMCIA
thing found in arch/m68k/amiga/pcmcia.c. This could complicate things
if we are able to use the common PCMCIA code for trex and try to
build a kernel with both that and amiga/pcmcia + apne.

At least it does sound like the io macros won't be an issue.

	Brad Boyer
	flar@allandria.com