Driver problems: t213 on i8042 port

[Alex Hudson <home@alexhudson.com>]

Hi all,

I'm having some trouble with the serio support for a touchit213 device,
and I'm hoping by describing what's going on someone can offer some
clues.

The PC in question is a tablet PC with the touchscreen apparently
connected to the fourth serial/ps2 port on the i8042 internally, rather
than ttyS0 or something.

The manufacturer provides an xf86 driver which is extremely ropey, and
requires raw access the port. This works:

	echo -n "serio_raw" > /sys/bus/serio/devices/serio4/drvctl

.. and /dev/serio_raw0 is created.

Now, there is a serio driver for the touchit213 series, but the obvious:

	echo -n "touchit213" > /sys/bus/serio/devices/serio4/drvctl

.. doesn't work. I don't see anything in the logs; whereas if I use
inputattach to connect the driver to ttyS0 (which doesn't have the
device, obviously) I can see that the driver is enabled
in /var/log/messages and a touch /dev/input/event device is created.

I've looked through the source for the touchit213 driver, and it's nice
simple code - and I'm assuming that it's failing somewhere in the
connect function. However, I'm struggling to get much further than this.

I guess the first question is, should this work? Attaching touchit213 to
a 'real' serial port appears to work, so I'm making the guess that this
is something to do with it being a port on the i8042. However, I don't
really know much serio and haven't been able to find any good
documentation about it - it could be I'm just missing an appropriate
incantation?

Second question is, if it's supposed to work - does anyone have some
good ideas for debugging this? I think otherwise I'm going to be
sprinkling kprintfs() in the driver and seeing what happens - are there
any better ways than this?

Thanks for any help you can offer,

Alex.


--
This message was scanned by Better Hosted and is believed to be clean.
http://www.betterhosted.com