Date: Fri, 16 Nov 2012 19:04:39 +0000 (UTC) From: wpaul@FreeBSD.ORG (Bill Paul) To: freebsd-questions@freebsd.org Subject: Re: eGalax USB touch panel on ExoPC Slate vs. FreeBSD and X11 Message-ID: <20121116190439.B2D87B0@hub.freebsd.org>
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Well... apparently I was able to get this to work on my own. To recap, I
have an ExoPC Slate running FreeBSD 9.0 and xorg 1.7 with an eGalax
USB HID touch screen. Out of the box, ums(4) claims it but doesn't
like it.
After investigating a bit more, I found that the screen has multiple HID
collections associated with it:
Collection type=Application page=Digitizer usage=Touch_Screen
Collection type=Physical page=Digitizer usage=Finger
Collection type=Application page=Generic_Desktop usage=Pointer
Collection type=Physical page=Generic_Desktop usage=Pointer
Collection type=Application page=Microsoft usage=0x0001
Collection type=Application page=Digitizer usage=Touch_Screen
Collection type=Physical page=Digitizer usage=Stylus
Collection type=Application page=Digitizer usage=Device_Configuration
Collection type=Physical page=Digitizer usage=Finger
The ums(4) driver is trying to use the 'Pointer' collection, but I think
it may be getting confused by the X/Y ranges:
Collection type=Application page=Generic_Desktop usage=Pointer
Collection type=Physical page=Generic_Desktop usage=Pointer
Input rid=1 size=1 count=1 page=Button usage=Button_1, logical range 0..1, physical range 1..2047
Input rid=1 size=1 count=1 page=Button usage=Button_2, logical range 0..1, physical range 1..2047
Input rid=1 size=16 count=1 page=Generic_Desktop usage=X, logical range 0..4095, physical range 0..4095
Input rid=1 size=16 count=1 page=Generic_Desktop usage=Y, logical range 0..4095, physical range 0..4095
End collection
End collection
There are two problems. First, the ranges are a little unusual. I think
other mouse devices only have ranges from -127 to +127. Second, the input
flags for the X and Y axis entries are 0x2 (HI_VARIABLE) and not HI_RELATIVE,
which is what the usm(4) driver expects. This causes it to ignore the X and Y
axis entries and only handle the button entries. I tried changing the code to
accept just the HI_VARIABLE flag, but that still didn't make the cursor move.
In any case, I was wrong that the problem is that the FreeBSD ums(4) driver
doesn't handle gestures: it's just not flexible enough to handle this
oddball pointer design.
Anyway, go get it to work with X as a standard pointer device, I finally
ended up doing the following:
1) Edited the uhid_probe() function in sys/dev/usb/input/uhid.c to comment
out the code that excludes UIPROTO_MOUSE devices:
/*
* Don't attach to mouse and keyboard devices, hence then no
* "nomatch" event is generated and then ums and ukbd won't
* attach properly when loaded.
*/
if ((uaa->info.bInterfaceClass == UICLASS_HID) &&
(uaa->info.bInterfaceSubClass == UISUBCLASS_BOOT) &&
((uaa->info.bInterfaceProtocol == UIPROTO_BOOT_KEYBOARD)/* ||
(uaa->info.bInterfaceProtocol == UIPROTO_MOUSE) */)) {
return (ENXIO);
}
Note: this will make it match all mice. I could have fixed it to
be more selective, but for now I just wanted things to work.
2) Recompiled the kernel with the ums(4) and uhid(4) drivers removed.
3) Edited /boot/loader.conf to load the uhid(4) module:
uhid_load="YES"
4) Renamed /boot/kernel/ums.ko to something else so that the system would
stop trying to automatically load it all the time. (Grrr...)
5) Installed the ports collection.
6) Downloaded the following file:
http://people.freebsd.org/~mav/patch-zz-input-mouse9
6) Copied it to /usr/ports/x11-drivers/xf86-input-mouse/files
7) Recompiled and re-installed the xf86-input-mouse driver:
# cd /usr/ports/x11-drivers/xf86-input-mouse
# make
# make deinstall
# make install
8) Edited my xorg.conf to include the following:
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Collection" "2"
Option "Protocol" "usb"
Option "Device" "/dev/uhid0"
Option "Emulate3Timeout" "10"
EndSection
The touch panel is now detected as uhid0 instead of ums0 and the mouse
input driver now handles it directly instead of going through /dev/sysmouse.
Note that the '"Collection" "2"' option line is critical here. The driver
defaults to using collection 1, which is the touch screen. However this
doesn't provide a working pointer. Collection 2 is for the mouse emulation
mode, which is not ideal, but at least it allows me to move the cursor with
my finger now.
Button presses are a little tricky. There are 3 possible results:
1) Quick press -- button 1
2) Press and hold for a few seconds - button 2
3) Tap, release for a second, then press and hold -- button 3
I put the complete output of usbuhidctl -r and my xorg.conf file here:
http://people.freebsd.org/~wpaul/expoc
Note that I'm using the VESA driver for now as the Intel driver seems to
lock up when used with the Intel Pineview graphics controller in this
tablet.
Also note that it looks like you can use pretty much any other USB mouse
this way too, just remember to remove the '"Collection" "2"' line. For
example, I plugged in a Dell USB mouse which was detected as /dev/uhid2, and
modified the xorg.conf file to use it, and it worked fine.
Long story short, the ums(4) driver just isn't smart enough to seamlessly
handle the mouse emulation mode of the eGalax touch streen correctly. Maybe
some day someone will fix it. I might take a look at it again if I can
figure out how it works.
-Bill
--
=============================================================================
-Bill Paul (510) 749-2329 | Member of Technical Staff,
wpaul@windriver.com | Master of Unix-Fu - Wind River Systems
=============================================================================
"I put a dollar in a change machine. Nothing changed." - George Carlin
=============================================================================
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