touchpad: always init the left/right palm edge to INT_MIN/MAX
[platform/upstream/libinput.git] / src / evdev-mt-touchpad.c
index 6c63cb6..5db204f 100644 (file)
 #include <assert.h>
 #include <math.h>
 #include <stdbool.h>
+#include <limits.h>
 
 #include "evdev-mt-touchpad.h"
 
-#define DEFAULT_CONSTANT_ACCEL_NUMERATOR 100
-#define DEFAULT_MIN_ACCEL_FACTOR 0.20
-#define DEFAULT_MAX_ACCEL_FACTOR 0.40
+#define DEFAULT_ACCEL_NUMERATOR 1200.0
 #define DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR 700.0
 
 static inline int
@@ -42,30 +41,8 @@ tp_hysteresis(int in, int center, int margin)
 
        if (diff > margin)
                return center + diff - margin;
-       else if (diff < -margin)
+       else
                return center + diff + margin;
-       return center + diff;
-}
-
-static double
-tp_accel_profile(struct motion_filter *filter,
-                void *data,
-                double velocity,
-                uint32_t time)
-{
-       struct tp_dispatch *tp =
-               (struct tp_dispatch *) data;
-
-       double accel_factor;
-
-       accel_factor = velocity * tp->accel.constant_factor;
-
-       if (accel_factor > tp->accel.max_factor)
-               accel_factor = tp->accel.max_factor;
-       else if (accel_factor < tp->accel.min_factor)
-               accel_factor = tp->accel.min_factor;
-
-       return accel_factor;
 }
 
 static inline struct tp_motion *
@@ -80,14 +57,15 @@ tp_motion_history_offset(struct tp_touch *t, int offset)
 
 static void
 tp_filter_motion(struct tp_dispatch *tp,
-                double *dx, double *dy, uint32_t time)
+                double *dx, double *dy, uint64_t time)
 {
        struct motion_params motion;
 
-       motion.dx = *dx;
-       motion.dy = *dy;
+       motion.dx = *dx * tp->accel.x_scale_coeff;
+       motion.dy = *dy * tp->accel.y_scale_coeff;
 
-       filter_dispatch(tp->filter, &motion, tp, time);
+       if (motion.dx != 0.0 || motion.dy != 0.0)
+               filter_dispatch(tp->filter, &motion, tp, time);
 
        *dx = motion.dx;
        *dy = motion.dy;
@@ -139,7 +117,7 @@ tp_motion_history_reset(struct tp_touch *t)
 static inline struct tp_touch *
 tp_current_touch(struct tp_dispatch *tp)
 {
-       return &tp->touches[min(tp->slot, tp->ntouches)];
+       return &tp->touches[min(tp->slot, tp->ntouches - 1)];
 }
 
 static inline struct tp_touch *
@@ -152,24 +130,14 @@ tp_get_touch(struct tp_dispatch *tp, unsigned int slot)
 static inline void
 tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t)
 {
-       struct tp_touch *tmp = NULL;
-
        if (t->state != TOUCH_UPDATE) {
                tp_motion_history_reset(t);
                t->dirty = true;
                t->state = TOUCH_BEGIN;
+               t->pinned.is_pinned = false;
                tp->nfingers_down++;
                assert(tp->nfingers_down >= 1);
                tp->queued |= TOUCHPAD_EVENT_MOTION;
-
-               tp_for_each_touch(tp, tmp) {
-                       if (tmp->is_pointer)
-                               break;
-               }
-
-               if (!tmp->is_pointer) {
-                       t->is_pointer = true;
-               }
        }
 }
 
@@ -181,7 +149,9 @@ tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t)
 
        t->dirty = true;
        t->is_pointer = false;
+       t->palm.is_palm = false;
        t->state = TOUCH_END;
+       t->pinned.is_pinned = false;
        assert(tp->nfingers_down >= 1);
        tp->nfingers_down--;
        tp->queued |= TOUCHPAD_EVENT_MOTION;
@@ -215,7 +185,7 @@ tp_get_delta(struct tp_touch *t, double *dx, double *dy)
 static void
 tp_process_absolute(struct tp_dispatch *tp,
                    const struct input_event *e,
-                   uint32_t time)
+                   uint64_t time)
 {
        struct tp_touch *t = tp_current_touch(tp);
 
@@ -247,7 +217,7 @@ tp_process_absolute(struct tp_dispatch *tp,
 static void
 tp_process_absolute_st(struct tp_dispatch *tp,
                       const struct input_event *e,
-                      uint32_t time)
+                      uint64_t time)
 {
        struct tp_touch *t = tp_current_touch(tp);
 
@@ -270,7 +240,7 @@ tp_process_absolute_st(struct tp_dispatch *tp,
 static void
 tp_process_fake_touch(struct tp_dispatch *tp,
                      const struct input_event *e,
-                     uint32_t time)
+                     uint64_t time)
 {
        struct tp_touch *t;
        unsigned int fake_touches;
@@ -318,22 +288,13 @@ tp_process_fake_touch(struct tp_dispatch *tp,
 static void
 tp_process_key(struct tp_dispatch *tp,
               const struct input_event *e,
-              uint32_t time)
+              uint64_t time)
 {
-       uint32_t mask;
-
        switch (e->code) {
                case BTN_LEFT:
                case BTN_MIDDLE:
                case BTN_RIGHT:
-                       mask = 1 << (e->code - BTN_LEFT);
-                       if (e->value) {
-                               tp->buttons.state |= mask;
-                               tp->queued |= TOUCHPAD_EVENT_BUTTON_PRESS;
-                       } else {
-                               tp->buttons.state &= ~mask;
-                               tp->queued |= TOUCHPAD_EVENT_BUTTON_RELEASE;
-                       }
+                       tp_process_button(tp, e, time);
                        break;
                case BTN_TOUCH:
                case BTN_TOOL_DOUBLETAP:
@@ -346,54 +307,102 @@ tp_process_key(struct tp_dispatch *tp,
 }
 
 static void
-tp_unpin_finger(struct tp_dispatch *tp)
+tp_unpin_finger(struct tp_dispatch *tp, struct tp_touch *t)
 {
-       struct tp_touch *t;
-       tp_for_each_touch(tp, t) {
-               if (t->is_pinned) {
-                       t->is_pinned = false;
+       unsigned int xdist, ydist;
 
-                       if (t->state != TOUCH_END &&
-                           tp->nfingers_down == 1)
-                               t->is_pointer = true;
-                       break;
-               }
+       if (!t->pinned.is_pinned)
+               return;
+
+       xdist = abs(t->x - t->pinned.center_x);
+       ydist = abs(t->y - t->pinned.center_y);
+
+       if (xdist * xdist + ydist * ydist >=
+                       tp->buttons.motion_dist * tp->buttons.motion_dist) {
+               t->pinned.is_pinned = false;
+               tp_set_pointer(tp, t);
        }
 }
 
 static void
-tp_pin_finger(struct tp_dispatch *tp)
+tp_pin_fingers(struct tp_dispatch *tp)
 {
-       struct tp_touch *t,
-                       *pinned = NULL;
+       struct tp_touch *t;
 
        tp_for_each_touch(tp, t) {
-               if (t->is_pinned) {
-                       pinned = t;
-                       break;
-               }
+               t->is_pointer = false;
+               t->pinned.is_pinned = true;
+               t->pinned.center_x = t->x;
+               t->pinned.center_y = t->y;
        }
+}
 
-       assert(!pinned);
+static int
+tp_touch_active(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       return (t->state == TOUCH_BEGIN || t->state == TOUCH_UPDATE) &&
+               !t->palm.is_palm &&
+               !t->pinned.is_pinned && tp_button_touch_active(tp, t);
+}
 
-       pinned = tp_current_touch(tp);
+void
+tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       struct tp_touch *tmp = NULL;
 
-       if (tp->nfingers_down != 1) {
-               tp_for_each_touch(tp, t) {
-                       if (t == pinned)
-                               continue;
+       /* Only set the touch as pointer if we don't have one yet */
+       tp_for_each_touch(tp, tmp) {
+               if (tmp->is_pointer)
+                       return;
+       }
 
-                       if (t->y > pinned->y)
-                               pinned = t;
+       if (tp_touch_active(tp, t))
+               t->is_pointer = true;
+}
+
+static void
+tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
+{
+       const int PALM_TIMEOUT = 200; /* ms */
+       const int DIRECTIONS = NE|E|SE|SW|W|NW;
+
+       /* If labelled a touch as palm, we unlabel as palm when
+          we move out of the palm edge zone within the timeout, provided
+          the direction is within 45 degrees of the horizontal.
+        */
+       if (t->palm.is_palm) {
+               if (time < t->palm.time + PALM_TIMEOUT &&
+                   (t->x > tp->palm.left_edge && t->x < tp->palm.right_edge)) {
+                       int dirs = vector_get_direction(t->x - t->palm.x, t->y - t->palm.y);
+                       if ((dirs & DIRECTIONS) && !(dirs & ~DIRECTIONS)) {
+                               t->palm.is_palm = false;
+                               tp_set_pointer(tp, t);
+                       }
                }
+               return;
        }
 
-       pinned->is_pinned = true;
-       pinned->is_pointer = false;
+       /* palm must start in exclusion zone, it's ok to move into
+          the zone without being a palm */
+       if (t->state != TOUCH_BEGIN ||
+           (t->x > tp->palm.left_edge && t->x < tp->palm.right_edge))
+               return;
+
+       /* don't detect palm in software button areas, it's
+          likely that legitimate touches start in the area
+          covered by the exclusion zone */
+       if (tp->buttons.is_clickpad &&
+           tp_button_is_inside_softbutton_area(tp, t))
+               return;
+
+       t->palm.is_palm = true;
+       t->palm.time = time;
+       t->palm.x = t->x;
+       t->palm.y = t->y;
 }
 
 static void
-tp_process_state(struct tp_dispatch *tp, uint32_t time)
+tp_process_state(struct tp_dispatch *tp, uint64_t time)
 {
        struct tp_touch *t;
        struct tp_touch *first = tp_get_touch(tp, 0);
@@ -404,25 +413,33 @@ tp_process_state(struct tp_dispatch *tp, uint32_t time)
                        t->y = first->y;
                        if (!t->dirty)
                                t->dirty = first->dirty;
-               } else if (!t->dirty)
+               } else if (!t->dirty) {
                        continue;
+               }
+
+               tp_palm_detect(tp, t, time);
 
                tp_motion_hysteresis(tp, t);
                tp_motion_history_push(t);
+
+               tp_unpin_finger(tp, t);
        }
 
-       /* We have a physical button down event on a clickpad. For drag and
-          drop, this means we try to identify which finger pressed the
-          physical button and "pin" it, i.e. remove pointer-moving
-          capabilities from it.
+       tp_button_handle_state(tp, time);
+
+       /*
+        * We have a physical button down event on a clickpad. To avoid
+        * spurious pointer moves by the clicking finger we pin all fingers.
+        * We unpin fingers when they move more then a certain threshold to
+        * to allow drag and drop.
         */
        if ((tp->queued & TOUCHPAD_EVENT_BUTTON_PRESS) &&
-           !tp->buttons.has_buttons)
-               tp_pin_finger(tp);
+           tp->buttons.is_clickpad)
+               tp_pin_fingers(tp);
 }
 
 static void
-tp_post_process_state(struct tp_dispatch *tp, uint32_t time)
+tp_post_process_state(struct tp_dispatch *tp, uint64_t time)
 {
        struct tp_touch *t;
 
@@ -441,14 +458,11 @@ tp_post_process_state(struct tp_dispatch *tp, uint32_t time)
 
        tp->buttons.old_state = tp->buttons.state;
 
-       if (tp->queued & TOUCHPAD_EVENT_BUTTON_RELEASE)
-               tp_unpin_finger(tp);
-
        tp->queued = TOUCHPAD_EVENT_NONE;
 }
 
 static void
-tp_post_twofinger_scroll(struct tp_dispatch *tp, uint32_t time)
+tp_post_twofinger_scroll(struct tp_dispatch *tp, uint64_t time)
 {
        struct tp_touch *t;
        int nchanged = 0;
@@ -456,13 +470,15 @@ tp_post_twofinger_scroll(struct tp_dispatch *tp, uint32_t time)
        double tmpx, tmpy;
 
        tp_for_each_touch(tp, t) {
-               if (t->dirty) {
+               if (tp_touch_active(tp, t) && t->dirty) {
                        nchanged++;
                        tp_get_delta(t, &tmpx, &tmpy);
 
                        dx += tmpx;
                        dy += tmpy;
                }
+               /* Stop spurious MOTION events at the end of scrolling */
+               t->is_pointer = false;
        }
 
        if (nchanged == 0)
@@ -473,195 +489,111 @@ tp_post_twofinger_scroll(struct tp_dispatch *tp, uint32_t time)
 
        tp_filter_motion(tp, &dx, &dy, time);
 
-       if (tp->scroll.state == SCROLL_STATE_NONE) {
-               /* Require at least one px scrolling to start */
-               if (dx <= -1.0 || dx >= 1.0) {
-                       tp->scroll.state = SCROLL_STATE_SCROLLING;
-                       tp->scroll.direction |= (1 << LIBINPUT_POINTER_AXIS_HORIZONTAL_SCROLL);
-               }
+       /* Require at least five px scrolling to start */
+       if (dy <= -5.0 || dy >= 5.0)
+               tp->scroll.direction |= (1 << LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
 
-               if (dy <= -1.0 || dy >= 1.0) {
-                       tp->scroll.state = SCROLL_STATE_SCROLLING;
-                       tp->scroll.direction |= (1 << LIBINPUT_POINTER_AXIS_VERTICAL_SCROLL);
-               }
-
-               if (tp->scroll.state == SCROLL_STATE_NONE)
-                       return;
-       }
+       if (dx <= -5.0 || dx >= 5.0)
+               tp->scroll.direction |= (1 << LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL);
 
        if (dy != 0.0 &&
-           (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_VERTICAL_SCROLL))) {
+           (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL))) {
                pointer_notify_axis(&tp->device->base,
                                    time,
-                                   LIBINPUT_POINTER_AXIS_VERTICAL_SCROLL,
-                                   li_fixed_from_double(dy));
+                                   LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
+                                   dy);
        }
 
        if (dx != 0.0 &&
-           (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_HORIZONTAL_SCROLL))) {
+           (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL))) {
                pointer_notify_axis(&tp->device->base,
                                    time,
-                                   LIBINPUT_POINTER_AXIS_HORIZONTAL_SCROLL,
-                                   li_fixed_from_double(dx));
+                                   LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
+                                   dx);
        }
 }
 
-static int
-tp_post_scroll_events(struct tp_dispatch *tp, uint32_t time)
+static void
+tp_stop_scroll_events(struct tp_dispatch *tp, uint64_t time)
 {
-       /* don't scroll if a clickpad is held down */
-       if (!tp->buttons.has_buttons &&
-           (tp->buttons.state || tp->buttons.old_state))
-               return 0;
+       /* terminate scrolling with a zero scroll event */
+       if (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL))
+               pointer_notify_axis(&tp->device->base,
+                                   time,
+                                   LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
+                                   0);
+       if (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL))
+               pointer_notify_axis(&tp->device->base,
+                                   time,
+                                   LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
+                                   0);
 
-       if (tp->nfingers_down != 2) {
-               /* terminate scrolling with a zero scroll event to notify
-                * caller that it really ended now */
-               if (tp->scroll.state != SCROLL_STATE_NONE) {
-                       tp->scroll.state = SCROLL_STATE_NONE;
-                       tp->scroll.direction = 0;
-                       if (tp->scroll.direction & LIBINPUT_POINTER_AXIS_VERTICAL_SCROLL)
-                               pointer_notify_axis(&tp->device->base,
-                                                   time,
-                                                   LIBINPUT_POINTER_AXIS_VERTICAL_SCROLL,
-                                                   0);
-                       if (tp->scroll.direction & LIBINPUT_POINTER_AXIS_HORIZONTAL_SCROLL)
-                               pointer_notify_axis(&tp->device->base,
-                                                   time,
-                                                   LIBINPUT_POINTER_AXIS_HORIZONTAL_SCROLL,
-                                                   0);
-               }
-       } else {
-               tp_post_twofinger_scroll(tp, time);
-               return 1;
-       }
-       return 0;
+       tp->scroll.direction = 0;
 }
 
 static int
-tp_post_clickfinger_buttons(struct tp_dispatch *tp, uint32_t time)
+tp_post_scroll_events(struct tp_dispatch *tp, uint64_t time)
 {
-       uint32_t current, old, button;
-       enum libinput_pointer_button_state state;
+       struct tp_touch *t;
+       int nfingers_down = 0;
 
-       current = tp->buttons.state;
-       old = tp->buttons.old_state;
+       /* Only count active touches for 2 finger scrolling */
+       tp_for_each_touch(tp, t) {
+               if (tp_touch_active(tp, t))
+                       nfingers_down++;
+       }
 
-       if (current == old)
+       if (nfingers_down != 2) {
+               tp_stop_scroll_events(tp, time);
                return 0;
-
-       switch (tp->nfingers_down) {
-               case 1: button = BTN_LEFT; break;
-               case 2: button = BTN_RIGHT; break;
-               case 3: button = BTN_MIDDLE; break;
-               default:
-                       return 0;
        }
 
-       if (current)
-               state = LIBINPUT_POINTER_BUTTON_STATE_PRESSED;
-       else
-               state = LIBINPUT_POINTER_BUTTON_STATE_RELEASED;
-
-       pointer_notify_button(&tp->device->base,
-                             time,
-                             button,
-                             state);
+       tp_post_twofinger_scroll(tp, time);
        return 1;
 }
 
-static int
-tp_post_physical_buttons(struct tp_dispatch *tp, uint32_t time)
-{
-       uint32_t current, old, button;
-
-       current = tp->buttons.state;
-       old = tp->buttons.old_state;
-       button = BTN_LEFT;
-
-       while (current || old) {
-               enum libinput_pointer_button_state state;
-
-               if ((current & 0x1) ^ (old & 0x1)) {
-                       if (!!(current & 0x1))
-                               state = LIBINPUT_POINTER_BUTTON_STATE_PRESSED;
-                       else
-                               state = LIBINPUT_POINTER_BUTTON_STATE_RELEASED;
-
-                       pointer_notify_button(&tp->device->base,
-                                             time,
-                                             button,
-                                             state);
-               }
-
-               button++;
-               current >>= 1;
-               old >>= 1;
-       }
-
-       return 0;
-}
-
-static int
-tp_post_button_events(struct tp_dispatch *tp, uint32_t time)
-{
-       int rc;
-
-       if ((tp->queued &
-               (TOUCHPAD_EVENT_BUTTON_PRESS|TOUCHPAD_EVENT_BUTTON_RELEASE)) == 0)
-                               return 0;
-
-       if (tp->buttons.has_buttons)
-               rc = tp_post_physical_buttons(tp, time);
-       else
-               rc = tp_post_clickfinger_buttons(tp, time);
-
-       return rc;
-}
-
 static void
-tp_post_events(struct tp_dispatch *tp, uint32_t time)
+tp_post_events(struct tp_dispatch *tp, uint64_t time)
 {
        struct tp_touch *t = tp_current_touch(tp);
        double dx, dy;
+       int consumed = 0;
 
-       if (tp_post_button_events(tp, time) != 0)
-               return;
+       consumed |= tp_tap_handle_state(tp, time);
+       consumed |= tp_post_button_events(tp, time);
 
-       if (tp_tap_handle_state(tp, time) != 0)
+       if (consumed) {
+               tp_stop_scroll_events(tp, time);
                return;
+       }
 
        if (tp_post_scroll_events(tp, time) != 0)
                return;
 
-       if (t->history.count >= TOUCHPAD_MIN_SAMPLES) {
-               if (!t->is_pointer) {
-                       tp_for_each_touch(tp, t) {
-                               if (t->is_pointer)
-                                       break;
-                       }
+       if (!t->is_pointer) {
+               tp_for_each_touch(tp, t) {
+                       if (t->is_pointer)
+                               break;
                }
+       }
 
-               if (!t->is_pointer)
-                       return;
+       if (!t->is_pointer ||
+           !t->dirty ||
+           t->history.count < TOUCHPAD_MIN_SAMPLES)
+               return;
 
-               tp_get_delta(t, &dx, &dy);
-               tp_filter_motion(tp, &dx, &dy, time);
+       tp_get_delta(t, &dx, &dy);
+       tp_filter_motion(tp, &dx, &dy, time);
 
-               if (dx != 0 || dy != 0)
-                       pointer_notify_motion(
-                               &tp->device->base,
-                               time,
-                               li_fixed_from_double(dx),
-                               li_fixed_from_double(dy));
-       }
+       if (dx != 0.0 || dy != 0.0)
+               pointer_notify_motion(&tp->device->base, time, dx, dy);
 }
 
 static void
 tp_process(struct evdev_dispatch *dispatch,
           struct evdev_device *device,
           struct input_event *e,
-          uint32_t time)
+          uint64_t time)
 {
        struct tp_dispatch *tp =
                (struct tp_dispatch *)dispatch;
@@ -691,9 +623,9 @@ tp_destroy(struct evdev_dispatch *dispatch)
                (struct tp_dispatch*)dispatch;
 
        tp_destroy_tap(tp);
+       tp_destroy_buttons(tp);
 
-       if (tp->filter)
-               tp->filter->interface->destroy(tp->filter);
+       filter_destroy(tp->filter);
        free(tp->touches);
        free(tp);
 }
@@ -703,10 +635,18 @@ static struct evdev_dispatch_interface tp_interface = {
        tp_destroy
 };
 
+static void
+tp_init_touch(struct tp_dispatch *tp,
+             struct tp_touch *t)
+{
+       t->tp = tp;
+}
+
 static int
 tp_init_slots(struct tp_dispatch *tp,
              struct evdev_device *device)
 {
+       size_t i;
        const struct input_absinfo *absinfo;
 
        absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_SLOT);
@@ -715,33 +655,87 @@ tp_init_slots(struct tp_dispatch *tp,
                tp->slot = absinfo->value;
                tp->has_mt = true;
        } else {
-               tp->ntouches = 5; /* FIXME: based on DOUBLETAP, etc. */
+               struct map {
+                       unsigned int code;
+                       int ntouches;
+               } max_touches[] = {
+                       { BTN_TOOL_QUINTTAP, 5 },
+                       { BTN_TOOL_QUADTAP, 4 },
+                       { BTN_TOOL_TRIPLETAP, 3 },
+                       { BTN_TOOL_DOUBLETAP, 2 },
+               };
+               struct map *m;
+
                tp->slot = 0;
                tp->has_mt = false;
+               tp->ntouches = 1;
+
+               ARRAY_FOR_EACH(max_touches, m) {
+                       if (libevdev_has_event_code(device->evdev,
+                                                   EV_KEY,
+                                                   m->code)) {
+                               tp->ntouches = m->ntouches;
+                               break;
+                       }
+               }
        }
        tp->touches = calloc(tp->ntouches,
                             sizeof(struct tp_touch));
        if (!tp->touches)
                return -1;
 
+       for (i = 0; i < tp->ntouches; i++)
+               tp_init_touch(tp, &tp->touches[i]);
+
        return 0;
 }
 
 static int
-tp_init_accel(struct tp_dispatch *touchpad, double diagonal)
+tp_init_accel(struct tp_dispatch *tp, double diagonal)
 {
        struct motion_filter *accel;
+       int res_x, res_y;
 
-       touchpad->accel.constant_factor =
-               DEFAULT_CONSTANT_ACCEL_NUMERATOR / diagonal;
-       touchpad->accel.min_factor = DEFAULT_MIN_ACCEL_FACTOR;
-       touchpad->accel.max_factor = DEFAULT_MAX_ACCEL_FACTOR;
+       if (tp->has_mt) {
+               res_x = libevdev_get_abs_resolution(tp->device->evdev,
+                                                   ABS_MT_POSITION_X);
+               res_y = libevdev_get_abs_resolution(tp->device->evdev,
+                                                   ABS_MT_POSITION_Y);
+       } else {
+               res_x = libevdev_get_abs_resolution(tp->device->evdev,
+                                                   ABS_X);
+               res_y = libevdev_get_abs_resolution(tp->device->evdev,
+                                                   ABS_Y);
+       }
 
-       accel = create_pointer_accelator_filter(tp_accel_profile);
+       /*
+        * Not all touchpads report the same amount of units/mm (resolution).
+        * Normalize motion events to a resolution of 15.74 units/mm
+        * (== 400 dpi) as base (unaccelerated) speed. This also evens out any
+        * differences in x and y resolution, so that a circle on the
+        * touchpad does not turn into an elipse on the screen.
+        *
+        * We pick 400dpi as thats one of the many default resolutions
+        * for USB mice, so we end up with a similar base speed on the device.
+        */
+       if (res_x > 1 && res_y > 1) {
+               tp->accel.x_scale_coeff = (400/25.4) / res_x;
+               tp->accel.y_scale_coeff = (400/25.4) / res_y;
+       } else {
+       /*
+        * For touchpads where the driver does not provide resolution, fall
+        * back to scaling motion events based on the diagonal size in units.
+        */
+               tp->accel.x_scale_coeff = DEFAULT_ACCEL_NUMERATOR / diagonal;
+               tp->accel.y_scale_coeff = DEFAULT_ACCEL_NUMERATOR / diagonal;
+       }
+
+       accel = create_pointer_accelator_filter(
+                       pointer_accel_profile_smooth_simple);
        if (accel == NULL)
                return -1;
 
-       touchpad->filter = accel;
+       tp->filter = accel;
 
        return 0;
 }
@@ -750,12 +744,40 @@ static int
 tp_init_scroll(struct tp_dispatch *tp)
 {
        tp->scroll.direction = 0;
-       tp->scroll.state = SCROLL_STATE_NONE;
 
        return 0;
 }
 
 static int
+tp_init_palmdetect(struct tp_dispatch *tp,
+                  struct evdev_device *device)
+{
+       int width;
+
+       tp->palm.right_edge = INT_MAX;
+       tp->palm.left_edge = INT_MIN;
+
+       /* We don't know how big the touchpad is */
+       if (device->abs.absinfo_x->resolution == 1)
+               return 0;
+
+       width = abs(device->abs.absinfo_x->maximum -
+                   device->abs.absinfo_x->minimum);
+
+       /* Enable palm detection on touchpads >= 80 mm. Anything smaller
+          probably won't need it, until we find out it does */
+       if (width/device->abs.absinfo_x->resolution < 80)
+               return 0;
+
+       /* palm edges are 5% of the width on each side */
+       tp->palm.right_edge = device->abs.absinfo_x->maximum - width * 0.05;
+       tp->palm.left_edge = device->abs.absinfo_x->minimum + width * 0.05;
+
+       return 0;
+}
+
+
+static int
 tp_init(struct tp_dispatch *tp,
        struct evdev_device *device)
 {
@@ -764,13 +786,14 @@ tp_init(struct tp_dispatch *tp,
 
        tp->base.interface = &tp_interface;
        tp->device = device;
-       tp->tap.timer_fd = -1;
 
        if (tp_init_slots(tp, device) != 0)
                return -1;
 
-       width = abs(device->abs.max_x - device->abs.min_x);
-       height = abs(device->abs.max_y - device->abs.min_y);
+       width = abs(device->abs.absinfo_x->maximum -
+                   device->abs.absinfo_x->minimum);
+       height = abs(device->abs.absinfo_y->maximum -
+                    device->abs.absinfo_y->minimum);
        diagonal = sqrt(width*width + height*height);
 
        tp->hysteresis.margin_x =
@@ -778,10 +801,6 @@ tp_init(struct tp_dispatch *tp,
        tp->hysteresis.margin_y =
                diagonal / DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR;
 
-       if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_MIDDLE) ||
-           libevdev_has_event_code(device->evdev, EV_KEY, BTN_RIGHT))
-               tp->buttons.has_buttons = true;
-
        if (tp_init_scroll(tp) != 0)
                return -1;
 
@@ -791,6 +810,12 @@ tp_init(struct tp_dispatch *tp,
        if (tp_init_tap(tp) != 0)
                return -1;
 
+       if (tp_init_buttons(tp, device) != 0)
+               return -1;
+
+       if (tp_init_palmdetect(tp, device) != 0)
+               return -1;
+
        return 0;
 }