evdev: support for touchscreens not providing BTN_TOUCH

[Peter Korsgaard]

Hi,

I've recently tested a lumio crystaltouch touchscreen on Linux, and
xf86-input-evdev unfortunately gets confused and handles it as a mouse.

It provides the following events:

Input driver version is 1.0.1
Input device ID: bus 0x3 vendor 0x202e product 0x5 version 0x111
Input device name: "LUMIO Inc LUMIO CrystalTouch ver 1.1C"
Supported events:
  Event type 0 (Sync)
  Event type 1 (Key)
    Event code 272 (LeftBtn)
    Event code 273 (RightBtn)
    Event code 274 (MiddleBtn)
  Event type 2 (Relative)
    Event code 9 (Misc)
  Event type 3 (Absolute)
    Event code 0 (X)
      Value    650
      Min        0
      Max     4095
    Event code 1 (Y)
      Value   3221
      Min        0
      Max     4095
  Event type 4 (Misc)
    Event code 4 (ScanCode)
Testing ... (interrupt to exit)
Event: time 1305882024.934011, type 4 (Misc), code 4 (ScanCode), value 90001
Event: time 1305882024.934017, type 1 (Key), code 272 (LeftBtn), value 1
Event: time 1305882024.934029, type 3 (Absolute), code 0 (X), value 270
Event: time 1305882024.934034, type 3 (Absolute), code 1 (Y), value 1513
Event: time 1305882024.934039, type 2 (Relative), code 9 (Misc), value 1
Event: time 1305882024.934043, -------------- Report Sync ------------
Event: time 1305882024.943019, type 2 (Relative), code 9 (Misc), value 1
Event: time 1305882024.943025, -------------- Report Sync ------------
Event: time 1305882024.951998, type 3 (Absolute), code 0 (X), value 275
Event: time 1305882024.952006, type 3 (Absolute), code 1 (Y), value 1519
Event: time 1305882024.952010, type 2 (Relative), code 9 (Misc), value 1

Whichs leads to evdev configuring it as a mouse as there's no BTN_TOUCH:

[   563.001] (**) LUMIO Inc LUMIO CrystalTouch ver 1.1C: always reports core events
[   563.001] (**) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Device: "/dev/input/event17"
[   563.020] (--) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Found 3 mouse buttons
[   563.020] (--) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Found relative axes
[   563.020] (--) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Found absolute axes
[   563.020] (--) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Found x and y absolute axes
[   563.020] (II) LUMIO Inc LUMIO CrystalTouch ver 1.1C: Configuring as mouse
[   563.020] (**) LUMIO Inc LUMIO CrystalTouch ver 1.1C: YAxisMapping: buttons 4 and 5
[   563.020] (**) LUMIO Inc LUMIO CrystalTouch ver 1.1C: EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
[   563.020] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.2/input/input19/event17"
[   563.020] (II) XINPUT: Adding extended input device "LUMIO Inc LUMIO CrystalTouch ver 1.1C" (type: MOUSE)

So the absolute X/Y coordinates gets ignored and the REL_MISC event gets
handled as a relative motion of +1 in X direction - Not quite what we
want.