Re: Which CAN driver to port to for PPC

David Jander wrote:

Hi again,

On Wednesday 28 December 2005 11:44, Wolfgang Grandegger wrote:

quoted

AFAIK, there is no _generic_ embedded CAN driver available which even
supports real-time extensions.

Yes, lincan does. Well, it supports RTlinux and OCERA's RTlinux (GPL) modifications, which somehow reinvent ADEOS (or is it the other way around?), but since RTlinux is an option only for i386, and anyway almost dead right now, you could say it doesn't support real-time extensions.

Well, ADEOS uses a different method of handling interrupts and exceptions to avoid the infamous RTLinux patent. Better let's say: it doesn't support really "free" real-time extensions.

The problem of saying "Peak-CAN for SJA1000" and "OCAN for intel" is that you can basically forget about writing portable code because they are both very different.

I agree.

Maybe you should have a look at Pavel Pisa's lincan. After trying it out you might end up as confused as I am, because it doesn't look that bad at all, it's almost platform independent, supports all kernels (2.2 to latest 2.6), and supports a great amount of cards with intel and/or philips chips (yes, both of them on one card is also an option). The driver is designed with performance and throughput in mind, but I am not so sure about the API which is still a little too simple (maybe that's actually good) and doesn't support properly checking chip- or  bus-status yet. Also honorable is their effort of staying compatible with at least one other player: can4linux.

In the meantime I had a closer look and it looks like the most advanced in terms of portability, indeed. My experience is, that the chip- or bus-status, apart from the bus-off state, is very hardware specific and it's difficult to provide a generic API. Still need to dig more in lincan to make a reasonable judgment, though.

Greetings, and thanks for the comments,

Btw, how's ELDK-4 coming along?

Please ask Wolfgang Denk directly.

Wolfgang.