Re: Amiga PCMCIA network card support

[Andreas 'count' Kotes <count-vger.kernel.org+linux-m68k@flatline.de>]

Hello Kars,

On 25.10.19 09:25, Kars de Jong wrote:
> Op do 24 okt. 2019 om 22:56 schreef Andreas 'count' Kotes
> <count-vger.kernel.org+linux-
>> What needs to happen for stable, reliable support for existing PCMCIA
>> network cards people already have? How can we unblock those possible
>> Linux users?
> 
> That would involve quite a few things. I did most of this back in 2.6
> times, and had the standard pcnet_cs, 3c589_cs and serial_cs drivers
> working on my Amiga 1200. Some of it was a bit hackish though, changes
> to <asm/io.h> were discussed but never implemented. The need to be
> able to build a multi-machine kernel (with Atari, Q40 and Amiga
> support in a single kernel) was one of the things that interfered (it
> could probably be solved by adding an extra level of indirection ;-)).
> Then Real Life happened and I didn't touch my Amiga for 10+ years...

.. hmm, is this something that's likely to change? ;)

> 1) A proper driver for the PCMCIA slot, including hot plugging and
> proper controller reset. This involves rewriting part of the IRQ
> handling to make Gayle a separate IRQ controller instead of the hard
> coded hack that is used now. That shouldn't be too hard. Support for
> setting up different data path widths (IO_DATA_PATH_WIDTH_16 etc.)
> will require changes to <asm/io.h>, see point 2.
> 2) Rework <asm/io.h> so inb()/inw()/inl(), outb()/outw()/outl(),
> insb()/insw()/insl() and outsb()/outsw()/outsl() "just work" for
> PCMCIA address space without having to create ugly hacks in the
> generic drivers. This is not trivial because of the strange memory
> mapping of the Amiga PCMCIA slot.

ooooof. while neither sounds undoable (and looking at
http://www.ianstedman.co.uk/downloads/A1200FuncSpec.txt and
https://www.amigacoding.com/index.php/Amiga_memory_map), this is way
beyond my limited low-level experience and rusty Amiga coding experience
for me to do (by) myself - but I'd totally be willing to help kick off
and aid any serious effort for that ... or even let myself be mentored
into doing it.

I should also be able to set up an A1200 with a remotely switchable
power socket and remotely accessible Linux serial console and PLIP
network access that boots into alternating kernels to allow remote
development for interested people.

Kars, you sound like you're in Europe - will you be on the Chaos
Communcation Congress in Leipzig this year? Will there be a Linux m68k
table?

I don't know how well bounties (like
https://www.bountysource.com/issues/80706251-m68k-convert-the-backend-to-mode_cc-so-it-can-be-kept-in-future-releases)
work, but I'd certainly willing to chip in with money, time and
resources to get this addressed for good.

I think cleaning up the IRQ handling etc would also be (another?) good
showcase of linux-m68k and the Amiga platform being very much alive,
contrary to what Linus might think :D

all the best from Berlin,

  count