On Wed, Jun 22, 2011 at 10:36:59AM -0500, Chris Bagwell wrote: > On Wed, Jun 22, 2011 at 9:24 AM, Julian Squires <jul...@cipht.net> wrote: > > Hi, > > > > I'm currently working on getting the current xf86-input-wacom driver > > to support my old Wacom Digitizer II. > > > > I've looked at the previous approach of dropping wcmSerial.* back in > > and hacking around until it works, and I am wondering if it would be > > cleaner to move some of the code to the Linux kernel input subsystem > > and try to create a clean implementation based on the current wcmISDV4 > > module (obviously, using the old wcmSerial code as a reference). Then > > detection would be a lot cleaner -- users would use inputattach to > > signal that they have a legacy serial tablet on a given serial port > > and it would fit in with the current udev and InputClass detection > > scheme. > > > > Does this sound like an appropriate way to approach the problem, and > > if so, would serial support be accepted back into xf86-input-wacom? I > > think it would be a travesty to lose support for these great devices. > > > > I know just enough to get myself in trouble in this serial area so be > careful with my suggestions. > > Please look at linux kernel driver > drivers/input/touchscreen/wacom_w8001.c. It is a serial touchscreen > driver to use as example of what you described with inputattach > approach. Since its also a Wacom device, you can probably reuse a lot > of processing logic related to PEN packets.
w8001 is ISDV4 and I believe that the old serial tablets have a different type of protocol. So while certainly a template for coding, i'm not sure how much overlap there is. > If you take this approach then no modifications are required to > xf86-input-wacom. It would be treated same as a USB tablet since its > talking the generic evdev events. > > On opposite side, I don't believe Peter had overly strong objection to > re-merging the serial driver into xf86-input-wacom if someone was > willing to produce patches at quality level or better than the > wcmISDV4 code. Its come up several times in last year but so far no > one is willing to go that far. IMO putting this code into the kernel is the best approach, that's where it should live anyway. Even the ISDV4 code shouldn't be in our driver (and these days you can drive ISDV4 tablets with w8001). putting the old serial driver back in is just a stopgap measure anyway, long-term this should all live in the kernel. One thing I can definitely recommend is to analyse the old code and put a protocol description up on our wiki. Once that's done and double-checked, you can start with the kernel driver. That way it's much easier find bugs in the implementation. Cheers, Peter ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
