[PATCH evdev 3/3] Add use_proximity bit for BTN_TOOL handling.

[Peter Hutterer]

Touchpads send garbage data between BTN_TOOL_FINGER and BTN_TOUCH. This
leads to cursor movement towards invalid positions (bottom left corner,
usually).

Add a new flag "use_proximity" as a delimiter for BTN_TOUCH handling. If
unset, the actual proximity bits are ignored, no proximity events are sent
and BTN_TOUCH is used for the tool handling.

Example event stream for synaptics:

Event: time 1292893041.002731, -------------- Report Sync ------------
Event: time 1292893041.015807, type 1 (Key), code 330 (Touch), value 0
Event: time 1292893041.015812, type 3 (Absolute), code 0 (X), value 4283
Event: time 1292893041.015813, type 3 (Absolute), code 1 (Y), value 4860
Event: time 1292893041.015815, type 3 (Absolute), code 24 (Pressure), value 23
Event: time 1292893041.015817, type 3 (Absolute), code 28 (Tool Width), value 5
Event: time 1292893041.027537, -------------- Report Sync ------------
Event: time 1292893041.038854, type 3 (Absolute), code 0 (X), value 1
Event: time 1292893041.038857, type 3 (Absolute), code 1 (Y), value 5855
Event: time 1292893041.038859, type 3 (Absolute), code 24 (Pressure), value 1
Event: time 1292893041.038861, type 3 (Absolute), code 28 (Tool Width), value 5
Event: time 1292893041.038864, -------------- Report Sync ------------
Event: time 1292893041.062432, type 3 (Absolute), code 24 (Pressure), value 0
Event: time 1292893041.062435, type 3 (Absolute), code 28 (Tool Width), value 0
Event: time 1292893041.062437, type 1 (Key), code 325 (ToolFinger), value 0
Event: time 1292893041.062438, -------------- Report Sync ------------

Reported-by: Dave Airlie <airlied at redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev.c |   13 ++++++++++++-
 src/evdev.h |    1 +
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index b6591ce..50847a8 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -486,6 +486,9 @@ EvdevProcessProximityEvent(InputInfoPtr pInfo, struct input_event *ev)
 {
     EvdevPtr pEvdev = pInfo->private;
 
+    if (!pEvdev->use_proximity)
+        return;
+
     pEvdev->prox_queued = 1;
 
     EvdevQueueProximityEvent(pInfo, ev->value);
@@ -679,7 +682,10 @@ EvdevProcessKeyEvent(InputInfoPtr pInfo, struct input_event *ev)
 
     switch (ev->code) {
         case BTN_TOUCH:
-            pEvdev->in_proximity = value ? ev->code : 0;
+            /* For devices that have but don't use proximity, use
+             * BTN_TOUCH as the proximity notifier */
+            if (!pEvdev->use_proximity)
+                pEvdev->in_proximity = value ? ev->code : 0;
             if (!(pEvdev->flags & (EVDEV_TOUCHSCREEN | EVDEV_TABLET)))
                 break;
             /* Treat BTN_TOUCH from devices that only have BTN_TOUCH as
@@ -1346,6 +1352,9 @@ EvdevAddAbsClass(DeviceIntPtr device)
 
     for (i = 0; i < ArrayLength(proximity_bits); i++)
     {
+        if (!pEvdev->use_proximity)
+            break;
+
         if (TestBit(proximity_bits[i], pEvdev->key_bitmask))
         {
             InitProximityClassDeviceStruct(device);
@@ -2039,6 +2048,7 @@ EvdevProbe(InputInfoPtr pInfo)
 	if (pEvdev->flags & EVDEV_TOUCHPAD) {
 	    xf86Msg(X_INFO, "%s: Configuring as touchpad\n", pInfo->name);
 	    pInfo->type_name = XI_TOUCHPAD;
+	    pEvdev->use_proximity = 0;
 	} else if (pEvdev->flags & EVDEV_TABLET) {
 	    xf86Msg(X_INFO, "%s: Configuring as tablet\n", pInfo->name);
 	    pInfo->type_name = XI_TABLET;
@@ -2205,6 +2215,7 @@ EvdevPreInit(InputDriverPtr drv, InputInfoPtr pInfo, int flags)
      * proximity will still report events.
      */
     pEvdev->in_proximity = 1;
+    pEvdev->use_proximity = 1;
 
     /* Grabbing the event device stops in-kernel event forwarding. In other
        words, it disables rfkill and the "Macintosh mouse button emulation".
diff --git a/src/evdev.h b/src/evdev.h
index b04f961..f640fdd 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -126,6 +126,7 @@ typedef struct {
 
     int flags;
     int in_proximity;           /* device in proximity */
+    int use_proximity;          /* using the proximity bit? */
     int num_buttons;            /* number of buttons */
     BOOL swap_axes;
     BOOL invert_x;
-- 
1.7.3.4