Make acecad driver work with 2.6.x kernels

[Giuseppe Bilotta]

On 4/24/07, Zephaniah E. Hull <warp at aehallh.com> wrote:
> Just a brief few questions.
>
> What version of xf86-input-evdev are you trying to use?
>
> The current release should work, and current git should _definitely_
> work.

I was absolutely unable to use the driver version 1.1.0-1 from the
Debian unstable distribution:

http://packages.debian.org/unstable/x11/xserver-xorg-input-acecad

Yesterday, I checked out what I believe to be git version, from

http://gitweb.freedesktop.org/?p=xorg/driver/xf86-input-acecad.git;a=summary

This, too, has not been updated for over a year, but I haven't found
any other git repository concerned with the acecad driver for xorg. If
this isn't the 'latest and greatest' git version of the acecad driver,
however, I must say that the proper git versions are badly advertised
on the site ... these are the only I could find.

Now, concerning the 1.1.0 version I checked out, it didn't work either.

First problem: it won't compile with LINUX_INPUT, because errno is not
defined. This is easily fixed by adding an #ifdef LINUX_INPUT-wrapped
#include.

Secondly, it still has the problem with the inability to work on 2.6.x
kernels, because it doesn't use EV_SYN to check for event finish, but
for EV_ABS/ABS_MISC.

What I've done is write a patch that (1) allows compilation with
LINUX_INPUT (necessary to use the the USB version) (2) fixes the
EV_SYN problem in a very 'raw' way (probably wrong, which is why I
wanted someone to tutor me on this)  (3) fixes most of the message to
use the proper X_{ERROR,CONFIG,PROBED,DEFAULT,INFO} MessageType.

Now, assuming that what I've been hacking on is indeed the git-latest
version of the acecad input driver, and that your reply is an implicit
offer to help, here comes the first question :D

What is the best way to check which version of the kernel-side input
layer we are dealing with, at runtime?

-- 
Giuseppe "Oblomov" Bilotta