Digitizer support

[Peter Hutterer]

On Mon, May 20, 2024 at 09:16:01AM -0400, Adam Jackson wrote:
> The calcomp driver didn't stay supported for long after modularisation, and
> it certainly no longer builds, but it's still in the archive:
> 
> https://gitlab.freedesktop.org/xorg/driver/xf86-input-calcomp/-/tree/master
> 
> I expect the build failures are mostly API drift, so if you have hardware
> that the driver would support, it ought to work as well as it ever did.
> Which, these days, might imply things like "you need to set it up with
> xorg.conf because neither the kernel nor libinput know it's there".

Best choice here is probably looking at the wacom w8001 kernel driver
drivers/input/touchscreen/wacom_w8001.c
which is an old wacom driver for serial tablets. That driver is loaded
via systemd + udev, thus presents an evdev node and the rest of
userspace is blissfully unaware of the fact that serial devices ever
existed.

grep for inputattach in the xf86-input-wacom repo and you'll find the
various pieces.

theory goes you should be able to look at the xf86-input-calcomp 
sources, write something like the w8001 driver, then create a similar
kernel driver and thus be ready for the next millennium without having
to actually resurrect, update, maintain and configure an X input driver
that's been unmaintained for 15 years.

Cheers,
  Peter


> On Mon, May 20, 2024 at 6:01 AM Russ Bixby <bixbyru at gmail.com> wrote:
> 
> > Hey all -
> >
> > So "calcomp" is a reserved word under the legacy XFree86 stuff in the
> > x.org source tree, but the driver seems not to actually exist under any
> > version of x.org which I can find.
> >
> > Anyone have any pointers regarding where I might best find a starting
> > point if I wish to use a real (E size) digitizer for actually digitizing
> > stuff, rather than using a Wacom tablet like a mouse with a hard pad? I'm
> > happy to code, but there's no point reinventing the axle; the most recent
> > version of a driver suitable for my uses would be a great place to start,
> > so I can update and then fold it into the current version of X.
> >
> > Thanks!
> >