cell-phone like keyboard driver anywhere?

[Holger Schurig]

I have to write a keyboard driver for a cell-phone like keyboard. I'm just 
wondering if this has been done before.

Basically, the keys are in some x/y matrix. How to decode that can be seen in 
drivers/char/asi_keyboard.c (after applying the patches

ftp://ftp.arm.linux.org.uk/pub/armlinux/source/kernel-patches/v2.4/patch-2.4.18-rmk7.bz2 
ftp://source.mvista.com/pub/xscale/pxa/diff-2.4.18-rmk7-pxa3.gz
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=1187/1

However, this file (as any other that I have seen) assumes that there are 
shift, ctrl, alt etc layers. But a cell-phone like keyboard operates 
differently, e.g.

1 pause -> send keycode for character "a"
1 1 pause -> send keycode for character "b"
1 1 1 pause -> send keycode for character "c"
2 pause -> send keycode for character "d"

and so on.

Has anybody done things in this area?

Holger