touchpad: always init the left/right palm edge to INT_MIN/MAX
[platform/upstream/libinput.git] / src / evdev-mt-touchpad.c
index a360651..5db204f 100644 (file)
 
 #include "config.h"
 
-#include "evdev.h"
+#include <assert.h>
+#include <math.h>
+#include <stdbool.h>
+#include <limits.h>
 
-struct touchpad_dispatch {
-       struct evdev_dispatch base;
-       struct evdev_device *device;
-};
+#include "evdev-mt-touchpad.h"
+
+#define DEFAULT_ACCEL_NUMERATOR 1200.0
+#define DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR 700.0
+
+static inline int
+tp_hysteresis(int in, int center, int margin)
+{
+       int diff = in - center;
+       if (abs(diff) <= margin)
+               return center;
+
+       if (diff > margin)
+               return center + diff - margin;
+       else
+               return center + diff + margin;
+}
+
+static inline struct tp_motion *
+tp_motion_history_offset(struct tp_touch *t, int offset)
+{
+       int offset_index =
+               (t->history.index - offset + TOUCHPAD_HISTORY_LENGTH) %
+               TOUCHPAD_HISTORY_LENGTH;
+
+       return &t->history.samples[offset_index];
+}
+
+static void
+tp_filter_motion(struct tp_dispatch *tp,
+                double *dx, double *dy, uint64_t time)
+{
+       struct motion_params motion;
+
+       motion.dx = *dx * tp->accel.x_scale_coeff;
+       motion.dy = *dy * tp->accel.y_scale_coeff;
+
+       if (motion.dx != 0.0 || motion.dy != 0.0)
+               filter_dispatch(tp->filter, &motion, tp, time);
+
+       *dx = motion.dx;
+       *dy = motion.dy;
+}
+
+static inline void
+tp_motion_history_push(struct tp_touch *t)
+{
+       int motion_index = (t->history.index + 1) % TOUCHPAD_HISTORY_LENGTH;
+
+       if (t->history.count < TOUCHPAD_HISTORY_LENGTH)
+               t->history.count++;
+
+       t->history.samples[motion_index].x = t->x;
+       t->history.samples[motion_index].y = t->y;
+       t->history.index = motion_index;
+}
+
+static inline void
+tp_motion_hysteresis(struct tp_dispatch *tp,
+                    struct tp_touch *t)
+{
+       int x = t->x,
+           y = t->y;
+
+       if (t->history.count == 0) {
+               t->hysteresis.center_x = t->x;
+               t->hysteresis.center_y = t->y;
+       } else {
+               x = tp_hysteresis(x,
+                                 t->hysteresis.center_x,
+                                 tp->hysteresis.margin_x);
+               y = tp_hysteresis(y,
+                                 t->hysteresis.center_y,
+                                 tp->hysteresis.margin_y);
+               t->hysteresis.center_x = x;
+               t->hysteresis.center_y = y;
+               t->x = x;
+               t->y = y;
+       }
+}
+
+static inline void
+tp_motion_history_reset(struct tp_touch *t)
+{
+       t->history.count = 0;
+}
+
+static inline struct tp_touch *
+tp_current_touch(struct tp_dispatch *tp)
+{
+       return &tp->touches[min(tp->slot, tp->ntouches - 1)];
+}
+
+static inline struct tp_touch *
+tp_get_touch(struct tp_dispatch *tp, unsigned int slot)
+{
+       assert(slot < tp->ntouches);
+       return &tp->touches[slot];
+}
+
+static inline void
+tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       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;
+       }
+}
+
+static inline void
+tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       if (t->state == TOUCH_NONE)
+               return;
+
+       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;
+}
+
+static double
+tp_estimate_delta(int x0, int x1, int x2, int x3)
+{
+       return (x0 + x1 - x2 - x3) / 4;
+}
+
+void
+tp_get_delta(struct tp_touch *t, double *dx, double *dy)
+{
+       if (t->history.count < 4) {
+               *dx = 0;
+               *dy = 0;
+               return;
+       }
+
+       *dx = tp_estimate_delta(tp_motion_history_offset(t, 0)->x,
+                               tp_motion_history_offset(t, 1)->x,
+                               tp_motion_history_offset(t, 2)->x,
+                               tp_motion_history_offset(t, 3)->x);
+       *dy = tp_estimate_delta(tp_motion_history_offset(t, 0)->y,
+                               tp_motion_history_offset(t, 1)->y,
+                               tp_motion_history_offset(t, 2)->y,
+                               tp_motion_history_offset(t, 3)->y);
+}
+
+static void
+tp_process_absolute(struct tp_dispatch *tp,
+                   const struct input_event *e,
+                   uint64_t time)
+{
+       struct tp_touch *t = tp_current_touch(tp);
+
+       switch(e->code) {
+       case ABS_MT_POSITION_X:
+               t->x = e->value;
+               t->millis = time;
+               t->dirty = true;
+               tp->queued |= TOUCHPAD_EVENT_MOTION;
+               break;
+       case ABS_MT_POSITION_Y:
+               t->y = e->value;
+               t->millis = time;
+               t->dirty = true;
+               tp->queued |= TOUCHPAD_EVENT_MOTION;
+               break;
+       case ABS_MT_SLOT:
+               tp->slot = e->value;
+               break;
+       case ABS_MT_TRACKING_ID:
+               t->millis = time;
+               if (e->value != -1)
+                       tp_begin_touch(tp, t);
+               else
+                       tp_end_touch(tp, t);
+       }
+}
+
+static void
+tp_process_absolute_st(struct tp_dispatch *tp,
+                      const struct input_event *e,
+                      uint64_t time)
+{
+       struct tp_touch *t = tp_current_touch(tp);
+
+       switch(e->code) {
+       case ABS_X:
+               t->x = e->value;
+               t->millis = time;
+               t->dirty = true;
+               tp->queued |= TOUCHPAD_EVENT_MOTION;
+               break;
+       case ABS_Y:
+               t->y = e->value;
+               t->millis = time;
+               t->dirty = true;
+               tp->queued |= TOUCHPAD_EVENT_MOTION;
+               break;
+       }
+}
+
+static void
+tp_process_fake_touch(struct tp_dispatch *tp,
+                     const struct input_event *e,
+                     uint64_t time)
+{
+       struct tp_touch *t;
+       unsigned int fake_touches;
+       unsigned int nfake_touches;
+       unsigned int i;
+       unsigned int shift;
+
+       if (e->code != BTN_TOUCH &&
+           (e->code < BTN_TOOL_DOUBLETAP || e->code > BTN_TOOL_QUADTAP))
+               return;
+
+       shift = e->code == BTN_TOUCH ? 0 : (e->code - BTN_TOOL_DOUBLETAP + 1);
+
+       if (e->value)
+               tp->fake_touches |= 1 << shift;
+       else
+               tp->fake_touches &= ~(0x1 << shift);
+
+       fake_touches = tp->fake_touches;
+       nfake_touches = 0;
+       while (fake_touches) {
+               nfake_touches++;
+               fake_touches >>= 1;
+       }
+
+       for (i = 0; i < tp->ntouches; i++) {
+               t = tp_get_touch(tp, i);
+               if (i >= nfake_touches) {
+                       if (t->state != TOUCH_NONE) {
+                               tp_end_touch(tp, t);
+                               t->millis = time;
+                       }
+               } else if (t->state != TOUCH_UPDATE &&
+                          t->state != TOUCH_BEGIN) {
+                       t->state = TOUCH_NONE;
+                       tp_begin_touch(tp, t);
+                       t->millis = time;
+                       t->fake =true;
+               }
+       }
+
+       assert(tp->nfingers_down == nfake_touches);
+}
+
+static void
+tp_process_key(struct tp_dispatch *tp,
+              const struct input_event *e,
+              uint64_t time)
+{
+       switch (e->code) {
+               case BTN_LEFT:
+               case BTN_MIDDLE:
+               case BTN_RIGHT:
+                       tp_process_button(tp, e, time);
+                       break;
+               case BTN_TOUCH:
+               case BTN_TOOL_DOUBLETAP:
+               case BTN_TOOL_TRIPLETAP:
+               case BTN_TOOL_QUADTAP:
+                       if (!tp->has_mt)
+                               tp_process_fake_touch(tp, e, time);
+                       break;
+       }
+}
+
+static void
+tp_unpin_finger(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       unsigned int xdist, ydist;
+
+       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_fingers(struct tp_dispatch *tp)
+{
+       struct tp_touch *t;
+
+       tp_for_each_touch(tp, t) {
+               t->is_pointer = false;
+               t->pinned.is_pinned = true;
+               t->pinned.center_x = t->x;
+               t->pinned.center_y = t->y;
+       }
+}
+
+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);
+}
+
+void
+tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t)
+{
+       struct tp_touch *tmp = NULL;
+
+       /* 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 (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;
+       }
+
+       /* 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, uint64_t time)
+{
+       struct tp_touch *t;
+       struct tp_touch *first = tp_get_touch(tp, 0);
+
+       tp_for_each_touch(tp, t) {
+               if (!tp->has_mt && t != first && first->fake) {
+                       t->x = first->x;
+                       t->y = first->y;
+                       if (!t->dirty)
+                               t->dirty = first->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);
+       }
+
+       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.is_clickpad)
+               tp_pin_fingers(tp);
+}
+
+static void
+tp_post_process_state(struct tp_dispatch *tp, uint64_t time)
+{
+       struct tp_touch *t;
+
+       tp_for_each_touch(tp, t) {
+               if (!t->dirty)
+                       continue;
+
+               if (t->state == TOUCH_END) {
+                       t->state = TOUCH_NONE;
+                       t->fake = false;
+               } else if (t->state == TOUCH_BEGIN)
+                       t->state = TOUCH_UPDATE;
+
+               t->dirty = false;
+       }
+
+       tp->buttons.old_state = tp->buttons.state;
+
+       tp->queued = TOUCHPAD_EVENT_NONE;
+}
+
+static void
+tp_post_twofinger_scroll(struct tp_dispatch *tp, uint64_t time)
+{
+       struct tp_touch *t;
+       int nchanged = 0;
+       double dx = 0, dy =0;
+       double tmpx, tmpy;
+
+       tp_for_each_touch(tp, t) {
+               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)
+               return;
+
+       dx /= nchanged;
+       dy /= nchanged;
+
+       tp_filter_motion(tp, &dx, &dy, time);
+
+       /* 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 (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_SCROLL_VERTICAL))) {
+               pointer_notify_axis(&tp->device->base,
+                                   time,
+                                   LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
+                                   dy);
+       }
+
+       if (dx != 0.0 &&
+           (tp->scroll.direction & (1 << LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL))) {
+               pointer_notify_axis(&tp->device->base,
+                                   time,
+                                   LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
+                                   dx);
+       }
+}
+
+static void
+tp_stop_scroll_events(struct tp_dispatch *tp, uint64_t time)
+{
+       /* 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);
+
+       tp->scroll.direction = 0;
+}
+
+static int
+tp_post_scroll_events(struct tp_dispatch *tp, uint64_t time)
+{
+       struct tp_touch *t;
+       int nfingers_down = 0;
+
+       /* Only count active touches for 2 finger scrolling */
+       tp_for_each_touch(tp, t) {
+               if (tp_touch_active(tp, t))
+                       nfingers_down++;
+       }
+
+       if (nfingers_down != 2) {
+               tp_stop_scroll_events(tp, time);
+               return 0;
+       }
+
+       tp_post_twofinger_scroll(tp, time);
+       return 1;
+}
+
+static void
+tp_post_events(struct tp_dispatch *tp, uint64_t time)
+{
+       struct tp_touch *t = tp_current_touch(tp);
+       double dx, dy;
+       int consumed = 0;
+
+       consumed |= tp_tap_handle_state(tp, time);
+       consumed |= tp_post_button_events(tp, time);
+
+       if (consumed) {
+               tp_stop_scroll_events(tp, time);
+               return;
+       }
+
+       if (tp_post_scroll_events(tp, time) != 0)
+               return;
+
+       if (!t->is_pointer) {
+               tp_for_each_touch(tp, t) {
+                       if (t->is_pointer)
+                               break;
+               }
+       }
+
+       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);
+
+       if (dx != 0.0 || dy != 0.0)
+               pointer_notify_motion(&tp->device->base, time, dx, dy);
+}
 
 static void
-touchpad_process(struct evdev_dispatch *dispatch,
-                struct evdev_device *device,
-                struct input_event *e,
-                uint32_t time)
+tp_process(struct evdev_dispatch *dispatch,
+          struct evdev_device *device,
+          struct input_event *e,
+          uint64_t time)
 {
+       struct tp_dispatch *tp =
+               (struct tp_dispatch *)dispatch;
+
+       switch (e->type) {
+       case EV_ABS:
+               if (tp->has_mt)
+                       tp_process_absolute(tp, e, time);
+               else
+                       tp_process_absolute_st(tp, e, time);
+               break;
+       case EV_KEY:
+               tp_process_key(tp, e, time);
+               break;
+       case EV_SYN:
+               tp_process_state(tp, time);
+               tp_post_events(tp, time);
+               tp_post_process_state(tp, time);
+               break;
+       }
 }
 
 static void
-touchpad_destroy(struct evdev_dispatch *dispatch)
+tp_destroy(struct evdev_dispatch *dispatch)
 {
-       free(dispatch);
+       struct tp_dispatch *tp =
+               (struct tp_dispatch*)dispatch;
+
+       tp_destroy_tap(tp);
+       tp_destroy_buttons(tp);
+
+       filter_destroy(tp->filter);
+       free(tp->touches);
+       free(tp);
 }
 
-static struct evdev_dispatch_interface touchpad_interface = {
-       touchpad_process,
-       touchpad_destroy
+static struct evdev_dispatch_interface tp_interface = {
+       tp_process,
+       tp_destroy
 };
 
+static void
+tp_init_touch(struct tp_dispatch *tp,
+             struct tp_touch *t)
+{
+       t->tp = tp;
+}
+
 static int
-touchpad_init(struct touchpad_dispatch *touchpad,
+tp_init_slots(struct tp_dispatch *tp,
              struct evdev_device *device)
 {
-       touchpad->base.interface = &touchpad_interface;
-       touchpad->device = device;
+       size_t i;
+       const struct input_absinfo *absinfo;
+
+       absinfo = libevdev_get_abs_info(device->evdev, ABS_MT_SLOT);
+       if (absinfo) {
+               tp->ntouches = absinfo->maximum + 1;
+               tp->slot = absinfo->value;
+               tp->has_mt = true;
+       } else {
+               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 *tp, double diagonal)
+{
+       struct motion_filter *accel;
+       int res_x, res_y;
+
+       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);
+       }
+
+       /*
+        * 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;
+
+       tp->filter = accel;
+
+       return 0;
+}
+
+static int
+tp_init_scroll(struct tp_dispatch *tp)
+{
+       tp->scroll.direction = 0;
+
+       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)
+{
+       int width, height;
+       double diagonal;
+
+       tp->base.interface = &tp_interface;
+       tp->device = device;
+
+       if (tp_init_slots(tp, device) != 0)
+               return -1;
+
+       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 =
+               diagonal / DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR;
+       tp->hysteresis.margin_y =
+               diagonal / DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR;
+
+       if (tp_init_scroll(tp) != 0)
+               return -1;
+
+       if (tp_init_accel(tp, diagonal) != 0)
+               return -1;
+
+       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;
 }
@@ -61,16 +822,16 @@ touchpad_init(struct touchpad_dispatch *touchpad,
 struct evdev_dispatch *
 evdev_mt_touchpad_create(struct evdev_device *device)
 {
-       struct touchpad_dispatch *touchpad;
+       struct tp_dispatch *tp;
 
-       touchpad = zalloc(sizeof *touchpad);
-       if (!touchpad)
+       tp = zalloc(sizeof *tp);
+       if (!tp)
                return NULL;
 
-       if (touchpad_init(touchpad, device) != 0) {
-               free(touchpad);
+       if (tp_init(tp, device) != 0) {
+               tp_destroy(&tp->base);
                return NULL;
        }
 
-       return  &touchpad->base;
+       return  &tp->base;
 }