[PATCH:evdev] Add touchscreen ABS_RX/ABS_Z quirk.

[Peter Hutterer]

Many touchscreens (e.g. HP TouchSmart) send touch events through ABS_Z and
ABS_RX instead of X/Y. ABS_X and ABS_Y are in fact dead.
For these devices, we simply map those two axes to x/y.

This patch assumes that any device with ABS_RX but not ABS_RY needs this
quirk. I haven't seen evidence to the contrary yet.

Tested on a HP TouchSmart.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index 17c0f01..77fc770 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -92,6 +92,7 @@
 #define EVDEV_TABLET		(1 << 8) /* device looks like a tablet? */
 #define EVDEV_UNIGNORE_ABSOLUTE (1 << 9) /* explicitly unignore abs axes */
 #define EVDEV_UNIGNORE_RELATIVE (1 << 10) /* explicitly unignore rel axes */
+#define EVDEV_TOUCHSCREEN_QUIRK (1 << 11) /* ABS_Z/ABS_RX touchpad quirk */
 
 #define MIN_KEYCODE 8
 #define GLYPHS_PER_KEY 2
@@ -1149,6 +1150,14 @@ EvdevAddAbsClass(DeviceIntPtr device)
         i++;
     }
 
+    if (pEvdev->flags & EVDEV_TOUCHSCREEN_QUIRK)
+    {
+        pEvdev->axis_map[ABS_X] = -1;
+        pEvdev->axis_map[ABS_Y] = -1;
+        pEvdev->axis_map[ABS_Z] = 0;
+        pEvdev->axis_map[ABS_RX] = 1;
+    }
+
     EvdevInitAxesLabels(pEvdev, pEvdev->num_vals, atoms);
 
     if (!InitValuatorClassDeviceStruct(device, num_axes,
@@ -1864,6 +1873,14 @@ EvdevProbe(InputInfoPtr pInfo)
                     pEvdev->flags |= EVDEV_BUTTON_EVENTS;
                 }
             }
+
+            /* Touchscreens that send events through ABS_Z and ABS_RX. We
+             * assume that any device with RX but not RY falls into that
+             * category until a real-world device proves otherwise. */
+            if (TestBit(ABS_Z, pEvdev->abs_bitmask) &&
+                TestBit(ABS_RX, pEvdev->abs_bitmask) &&
+                !TestBit(ABS_RY, pEvdev->abs_bitmask))
+                pEvdev->flags |= EVDEV_TOUCHSCREEN_QUIRK;
         }
     }
 
-- 
1.6.5.2