This is my second strike to add drivers for Microchannel-based boards to the Linux kernel. This time, it's the IBM LAN Adapter/A for Ethernet, a 16/32 bit Ethernet Adapter based on National Semiconductor's SONIC-T network controller.
I received a LAN/A as part of a PS/2 Model 85. Since Microchannel Ethernet cards are a limited resource, making it usable under Linux was important for me (and I guess there are a couple of other people out there who will also benefit).
You may download the sources here. The driver was developed with kernel version 2.2.10 and tested on two different PS/2 machines. The current version is confirmed to run with 2.0, 2.2, 2.3 and pre-2.4 kernels. Of course, if you want to use it with 2.0, you first have apply the MCA patches patches available on www.dgmicro.com. A couple of PS/2 users have successfully tested it in the meantime, and I have submitted it for inclusion in the official kernel source tree. This will probably take place with the first real 2.4 kernel.
Configurations with more than one card should theoretically be possible, however I cannot confirm this due to lack of hardware.
The driver is GPL, so you are free to use and improve it, but like always, it comes without any warranty: If you smash something with it, you're the proud owner of all remaining chunks ;-)
Apart from the driver sources themselves, you will find a patch file to modify some other files in the Linux kernel tree. This way, the driver will show up as a configuration option just like all other network drivers. The patches are relative to a 2.2.10 source tree.
A big thank you to Bob Eager for helping me out with information about the adapter. It wouldn't have been possible without him since IBM proved to be somewhere between reluctant and clueless to my requests for documentation. I really hate to bash a company in public, since I definitely like the PS/2 architecture designed by IBM, but if their commitment to Linux was really meant as they always say, they should have reacted differently....
P.S.: If someone reads this and can help: I am interested in writing a driver for the MCA-based Etherstreamers and LANstreamers either, so if you have docs...