New multitouch touchscreen over serial support

New multitouch touchscreen over serial support

[Chase Douglas]

Ping,

I've got one of the new HP Mini 5102 touchscreen netbooks, which has a
wacom multitouch touchscreen over serial. I haven't found any support
for this device in the kernel, it seems X reads from it directly using
xf86-input-wacom. IMHO, the best support for this driver would be as a
kernel module that could use the input subsystem to send multitouch
events up through the evdev interface.

Do you have any information on this device? Would it be possible to
write a driver?

Thanks,

-- Chase

Re: New multitouch touchscreen over serial support

[Ping Cheng]

On Wed, May 26, 2010 at 3:29 PM, Chase Douglas
<chase.douglas@canonical.com> wrote:
> Ping,
>
> I've got one of the new HP Mini 5102 touchscreen netbooks, which has a
> wacom multitouch touchscreen over serial. I haven't found any support
> for this device in the kernel, it seems X reads from it directly using
> xf86-input-wacom.

You are right.  There is no Wacom kernel driver for the Wacom serial
ISD version 4 device you are using.  Everything is in the Wacom X
driver.

> IMHO, the best support for this driver would be as a
> kernel module that could use the input subsystem to send multitouch
> events up through the evdev interface.

Sure, you can add yours and a bunch of the other serial WACfxxx
devices into the kernel under input/touchscreen (I believe Jaya Kumar
<jayakumar.lkml@gmail.com> has added the pen-only one there already).
But you would need to update the Wacom X driver as well.  Without the
proper X driver to work with it, kernel driver is pretty much useless.
 Or you may be able to let X evdev driver take care of it as a generic
touch screen device. I don't know how good the X evdev driver handles
the touch events though.

> Do you have any information on this device?

What kind of information do you need?  I have the protocol and you can
get one if you sign an NDA with Wacom.

> Would it be possible to write a driver?

Anything is possible on Linux :).  Someone has to do the work though.
I do not have time to work on it. That is the reality.

Ping

Re: New multitouch touchscreen over serial support

[Chase Douglas]

On Wed, 2010-05-26 at 15:52 -0700, Ping Cheng wrote:
> On Wed, May 26, 2010 at 3:29 PM, Chase Douglas
> <chase.douglas@canonical.com> wrote:
> > IMHO, the best support for this driver would be as a
> > kernel module that could use the input subsystem to send multitouch
> > events up through the evdev interface.
> 
> Sure, you can add yours and a bunch of the other serial WACfxxx
> devices into the kernel under input/touchscreen (I believe Jaya Kumar
> <jayakumar.lkml@gmail.com> has added the pen-only one there already).
> But you would need to update the Wacom X driver as well.  Without the
> proper X driver to work with it, kernel driver is pretty much useless.
>  Or you may be able to let X evdev driver take care of it as a generic
> touch screen device. I don't know how good the X evdev driver handles
> the touch events though.

This is actually why I think it should be in the kernel instead of in X.
The kernel has an interface for multitouch events through evdev. It's
standardized, and the X multitouch support will be predicated on it. So
if we want any multitouch support for these devices in linux, it will
have to go through the kernel input subsystem one way or another.

Also, an evdev based driver shouldn't require any new X support.

(I'm new to linux input stuff, if anyone feels I've mischaracterized
multitouch support in linux, please speak up :)

> > Do you have any information on this device?
> 
> What kind of information do you need?  I have the protocol and you can
> get one if you sign an NDA with Wacom.
> 
> > Would it be possible to write a driver?
> 
> Anything is possible on Linux :).  Someone has to do the work though.
> I do not have time to work on it. That is the reality.

Sure. I am personally interested in writing the driver. I need to do
some work on my end before I can commit to anything, but I will get back
to you with more details.

Thanks,

-- Chase