CardMan 5121 / RC632 driver and 14443-3 layer working

GREAT NEWS! The generic RC632 driver and the CM5121 backend is working, as is the ISO 14443-3 Type A (anti-collision)layer. This means that I'm actually talking to cards, etc.

The next big step is to code the 14443-4 (also known as T=CL) protocol, which is the last element in the chain to use industry standard ISO 7816-4 commands to talk to the chip.

I've also been thinking of what might be an appropriate interface for applications to interface the stack. It's probably because I'm having so much of a kernel-level networking background... but where is that whole RFID stack different from a network? You have packets being sent back and forth, you have anti-collision, you have multiple devices sharing a single 'ether', ...

The whole "7816-4 on top of 14443-4 on top of 14443-3 on top of 14443-2" issue also resembles the OSI model quite a lot, so this could actually map onto the different SOL (socket layers) in the stack.

And after all, why would a socket API like interface be so bad?

Of course this all comes with a severe disadvantage: who wants to have all this stuff in the kernel, if it also works from userspace? Well, the same was true for the first TCP implementations when they were in userspace...