src/evdev-touchpad.c

   1 /*
   2  * Copyright © 2012 Jonas Ådahl
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name of the copyright holders not be used in
   9  * advertising or publicity pertaining to distribution of the software
  10  * without specific, written prior permission.  The copyright holders make
  11  * no representations about the suitability of this software for any
  12  * purpose.  It is provided "as is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
  15  * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  16  * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
  17  * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
  18  * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
  19  * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  20  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  21  */
  22
  23 #include <stdlib.h>
  24 #include <math.h>
  25 #include <string.h>
  26 #include <stdbool.h>
  27 #include <linux/input.h>
  28
  29 #include "filter.h"
  30 #include "evdev.h"
  31
  32 /* Default values */
  33 #define DEFAULT_CONSTANT_ACCEL_NUMERATOR 50
  34 #define DEFAULT_MIN_ACCEL_FACTOR 0.16
  35 #define DEFAULT_MAX_ACCEL_FACTOR 1.0
  36 #define DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR 700.0
  37
  38 #define DEFAULT_TOUCHPAD_SINGLE_TAP_BUTTON BTN_LEFT
  39 #define DEFAULT_TOUCHPAD_SINGLE_TAP_TIMEOUT 100
  40
  41 enum touchpad_model {
  42         TOUCHPAD_MODEL_UNKNOWN = 0,
  43         TOUCHPAD_MODEL_SYNAPTICS,
  44         TOUCHPAD_MODEL_ALPS,
  45         TOUCHPAD_MODEL_APPLETOUCH,
  46         TOUCHPAD_MODEL_ELANTECH
  47 };
  48
  49 enum touchpad_event {
  50         TOUCHPAD_EVENT_NONE         = 0,
  51         TOUCHPAD_EVENT_ABSOLUTE_ANY = (1 << 0),
  52         TOUCHPAD_EVENT_ABSOLUTE_X   = (1 << 1),
  53         TOUCHPAD_EVENT_ABSOLUTE_Y   = (1 << 2),
  54         TOUCHPAD_EVENT_REPORT       = (1 << 3)
  55 };
  56
  57 struct touchpad_model_spec {
  58         short vendor;
  59         short product;
  60         enum touchpad_model model;
  61 };
  62
  63 static struct touchpad_model_spec touchpad_spec_table[] = {
  64         {0x0002, 0x0007, TOUCHPAD_MODEL_SYNAPTICS},
  65         {0x0002, 0x0008, TOUCHPAD_MODEL_ALPS},
  66         {0x05ac, 0x0000, TOUCHPAD_MODEL_APPLETOUCH},
  67         {0x0002, 0x000e, TOUCHPAD_MODEL_ELANTECH},
  68         {0x0000, 0x0000, TOUCHPAD_MODEL_UNKNOWN}
  69 };
  70
  71 enum touchpad_state {
  72         TOUCHPAD_STATE_NONE  = 0,
  73         TOUCHPAD_STATE_TOUCH = (1 << 0),
  74         TOUCHPAD_STATE_MOVE  = (1 << 1)
  75 };
  76
  77 #define TOUCHPAD_HISTORY_LENGTH 4
  78
  79 struct touchpad_motion {
  80         int32_t x;
  81         int32_t y;
  82 };
  83
  84 enum touchpad_fingers_state {
  85         TOUCHPAD_FINGERS_ONE   = (1 << 0),
  86         TOUCHPAD_FINGERS_TWO   = (1 << 1),
  87         TOUCHPAD_FINGERS_THREE = (1 << 2)
  88 };
  89
  90 enum fsm_event {
  91         FSM_EVENT_TOUCH,
  92         FSM_EVENT_RELEASE,
  93         FSM_EVENT_MOTION,
  94         FSM_EVENT_TIMEOUT
  95 };
  96
  97 enum fsm_state {
  98         FSM_IDLE,
  99         FSM_TOUCH,
 100         FSM_TAP,
 101         FSM_TAP_2,
 102         FSM_DRAG
 103 };
 104
 105 struct touchpad_dispatch {
 106         struct evdev_dispatch base;
 107         struct evdev_device *device;
 108
 109         enum touchpad_model model;
 110         unsigned int state;
 111         int finger_state;
 112         int last_finger_state;
 113
 114         double constant_accel_factor;
 115         double min_accel_factor;
 116         double max_accel_factor;
 117
 118         unsigned int event_mask;
 119         unsigned int event_mask_filter;
 120
 121         int reset;
 122
 123         struct {
 124                 struct wl_array events;
 125                 enum fsm_state state;
 126                 struct wl_event_source *timer_source;
 127         } fsm;
 128
 129         struct {
 130                 int32_t x;
 131                 int32_t y;
 132         } hw_abs;
 133
 134         int has_pressure;
 135         struct {
 136                 int32_t touch_low;
 137                 int32_t touch_high;
 138         } pressure;
 139
 140         struct {
 141                 int32_t margin_x;
 142                 int32_t margin_y;
 143                 int32_t center_x;
 144                 int32_t center_y;
 145         } hysteresis;
 146
 147         struct touchpad_motion motion_history[TOUCHPAD_HISTORY_LENGTH];
 148         int motion_index;
 149         unsigned int motion_count;
 150
 151         struct weston_motion_filter *filter;
 152 };
 153
 154 static enum touchpad_model
 155 get_touchpad_model(struct evdev_device *device)
 156 {
 157         struct input_id id;
 158         unsigned int i;
 159
 160         if (ioctl(device->fd, EVIOCGID, &id) < 0)
 161                 return TOUCHPAD_MODEL_UNKNOWN;
 162
 163         for (i = 0; i < ARRAY_LENGTH(touchpad_spec_table); i++)
 164                 if (touchpad_spec_table[i].vendor == id.vendor &&
 165                     (!touchpad_spec_table[i].product ||
 166                      touchpad_spec_table[i].product == id.product))
 167                         return touchpad_spec_table[i].model;
 168
 169         return TOUCHPAD_MODEL_UNKNOWN;
 170 }
 171
 172 static void
 173 configure_touchpad_pressure(struct touchpad_dispatch *touchpad,
 174                             int32_t pressure_min, int32_t pressure_max)
 175 {
 176         int32_t range = pressure_max - pressure_min + 1;
 177
 178         touchpad->has_pressure = 1;
 179
 180         /* Magic numbers from xf86-input-synaptics */
 181         switch (touchpad->model) {
 182         case TOUCHPAD_MODEL_ELANTECH:
 183                 touchpad->pressure.touch_low = pressure_min + 1;
 184                 touchpad->pressure.touch_high = pressure_min + 1;
 185                 break;
 186         default:
 187                 touchpad->pressure.touch_low =
 188                         pressure_min + range * (25.0/256.0);
 189                 touchpad->pressure.touch_high =
 190                         pressure_min + range * (30.0/256.0);
 191         }
 192 }
 193
 194 static double
 195 touchpad_profile(struct weston_motion_filter *filter,
 196                  void *data,
 197                  double velocity,
 198                  uint32_t time)
 199 {
 200         struct touchpad_dispatch *touchpad =
 201                 (struct touchpad_dispatch *) data;
 202
 203         double accel_factor;
 204
 205         accel_factor = velocity * touchpad->constant_accel_factor;
 206
 207         if (accel_factor > touchpad->max_accel_factor)
 208                 accel_factor = touchpad->max_accel_factor;
 209         else if (accel_factor < touchpad->min_accel_factor)
 210                 accel_factor = touchpad->min_accel_factor;
 211
 212         return accel_factor;
 213 }
 214
 215 static inline struct touchpad_motion *
 216 motion_history_offset(struct touchpad_dispatch *touchpad, int offset)
 217 {
 218         int offset_index =
 219                 (touchpad->motion_index - offset + TOUCHPAD_HISTORY_LENGTH) %
 220                 TOUCHPAD_HISTORY_LENGTH;
 221
 222         return &touchpad->motion_history[offset_index];
 223 }
 224
 225 static double
 226 estimate_delta(int x0, int x1, int x2, int x3)
 227 {
 228         return (x0 + x1 - x2 - x3) / 4;
 229 }
 230
 231 static int
 232 hysteresis(int in, int center, int margin)
 233 {
 234         int diff = in - center;
 235         if (abs(diff) <= margin)
 236                 return center;
 237
 238         if (diff > margin)
 239                 return center + diff - margin;
 240         else if (diff < -margin)
 241                 return center + diff + margin;
 242         return center + diff;
 243 }
 244
 245 static void
 246 touchpad_get_delta(struct touchpad_dispatch *touchpad, double *dx, double *dy)
 247 {
 248         *dx = estimate_delta(motion_history_offset(touchpad, 0)->x,
 249                              motion_history_offset(touchpad, 1)->x,
 250                              motion_history_offset(touchpad, 2)->x,
 251                              motion_history_offset(touchpad, 3)->x);
 252         *dy = estimate_delta(motion_history_offset(touchpad, 0)->y,
 253                              motion_history_offset(touchpad, 1)->y,
 254                              motion_history_offset(touchpad, 2)->y,
 255                              motion_history_offset(touchpad, 3)->y);
 256 }
 257
 258 static void
 259 filter_motion(struct touchpad_dispatch *touchpad,
 260               double *dx, double *dy, uint32_t time)
 261 {
 262         struct weston_motion_params motion;
 263
 264         motion.dx = *dx;
 265         motion.dy = *dy;
 266
 267         weston_filter_dispatch(touchpad->filter, &motion, touchpad, time);
 268
 269         *dx = motion.dx;
 270         *dy = motion.dy;
 271 }
 272
 273 static void
 274 notify_button_pressed(struct touchpad_dispatch *touchpad, uint32_t time)
 275 {
 276         notify_button(touchpad->device->seat, time,
 277                       DEFAULT_TOUCHPAD_SINGLE_TAP_BUTTON,
 278                       WL_POINTER_BUTTON_STATE_PRESSED);
 279 }
 280
 281 static void
 282 notify_button_released(struct touchpad_dispatch *touchpad, uint32_t time)
 283 {
 284         notify_button(touchpad->device->seat, time,
 285                       DEFAULT_TOUCHPAD_SINGLE_TAP_BUTTON,
 286                       WL_POINTER_BUTTON_STATE_RELEASED);
 287 }
 288
 289 static void
 290 notify_tap(struct touchpad_dispatch *touchpad, uint32_t time)
 291 {
 292         notify_button_pressed(touchpad, time);
 293         notify_button_released(touchpad, time);
 294 }
 295
 296 static void
 297 process_fsm_events(struct touchpad_dispatch *touchpad, uint32_t time)
 298 {
 299         uint32_t timeout = UINT32_MAX;
 300         enum fsm_event *pevent;
 301         enum fsm_event event;
 302
 303         if (touchpad->fsm.events.size == 0)
 304                 return;
 305
 306         wl_array_for_each(pevent, &touchpad->fsm.events) {
 307                 event = *pevent;
 308                 timeout = 0;
 309
 310                 switch (touchpad->fsm.state) {
 311                 case FSM_IDLE:
 312                         switch (event) {
 313                         case FSM_EVENT_TOUCH:
 314                                 touchpad->fsm.state = FSM_TOUCH;
 315                                 break;
 316                         default:
 317                                 break;
 318                         }
 319                         break;
 320                 case FSM_TOUCH:
 321                         switch (event) {
 322                         case FSM_EVENT_RELEASE:
 323                                 timeout = DEFAULT_TOUCHPAD_SINGLE_TAP_TIMEOUT;
 324                                 touchpad->fsm.state = FSM_TAP;
 325                                 break;
 326                         default:
 327                                 touchpad->fsm.state = FSM_IDLE;
 328                                 break;
 329                         }
 330                         break;
 331                 case FSM_TAP:
 332                         switch (event) {
 333                         case FSM_EVENT_TIMEOUT:
 334                                 notify_tap(touchpad, time);
 335                                 touchpad->fsm.state = FSM_IDLE;
 336                                 break;
 337                         case FSM_EVENT_TOUCH:
 338                                 notify_button_pressed(touchpad, time);
 339                                 touchpad->fsm.state = FSM_TAP_2;
 340                                 break;
 341                         default:
 342                                 touchpad->fsm.state = FSM_IDLE;
 343                                 break;
 344                         }
 345                         break;
 346                 case FSM_TAP_2:
 347                         switch (event) {
 348                         case FSM_EVENT_MOTION:
 349                                 touchpad->fsm.state = FSM_DRAG;
 350                                 break;
 351                         case FSM_EVENT_RELEASE:
 352                                 notify_button_released(touchpad, time);
 353                                 notify_tap(touchpad, time);
 354                                 touchpad->fsm.state = FSM_IDLE;
 355                                 break;
 356                         default:
 357                                 touchpad->fsm.state = FSM_IDLE;
 358                                 break;
 359                         }
 360                         break;
 361                 case FSM_DRAG:
 362                         switch (event) {
 363                         case FSM_EVENT_RELEASE:
 364                                 notify_button_released(touchpad, time);
 365                                 touchpad->fsm.state = FSM_IDLE;
 366                                 break;
 367                         default:
 368                                 touchpad->fsm.state = FSM_IDLE;
 369                                 break;
 370                         }
 371                         break;
 372                 default:
 373                         weston_log("evdev-touchpad: Unknown state %d",
 374                                    touchpad->fsm.state);
 375                         touchpad->fsm.state = FSM_IDLE;
 376                         break;
 377                 }
 378         }
 379
 380         if (timeout != UINT32_MAX)
 381                 wl_event_source_timer_update(touchpad->fsm.timer_source,
 382                                              timeout);
 383
 384         wl_array_release(&touchpad->fsm.events);
 385         wl_array_init(&touchpad->fsm.events);
 386 }
 387
 388 static void
 389 push_fsm_event(struct touchpad_dispatch *touchpad,
 390                enum fsm_event event)
 391 {
 392         enum fsm_event *pevent;
 393
 394         pevent = wl_array_add(&touchpad->fsm.events, sizeof event);
 395         if (pevent)
 396                 *pevent = event;
 397         else
 398                 touchpad->fsm.state = FSM_IDLE;
 399 }
 400
 401 static int
 402 fsm_timout_handler(void *data)
 403 {
 404         struct touchpad_dispatch *touchpad = data;
 405
 406         if (touchpad->fsm.events.size == 0) {
 407                 push_fsm_event(touchpad, FSM_EVENT_TIMEOUT);
 408                 process_fsm_events(touchpad, weston_compositor_get_time());
 409         }
 410
 411         return 1;
 412 }
 413
 414 static void
 415 touchpad_update_state(struct touchpad_dispatch *touchpad, uint32_t time)
 416 {
 417         int motion_index;
 418         int center_x, center_y;
 419         double dx = 0.0, dy = 0.0;
 420
 421         if (touchpad->reset ||
 422             touchpad->last_finger_state != touchpad->finger_state) {
 423                 touchpad->reset = 0;
 424                 touchpad->motion_count = 0;
 425                 touchpad->event_mask = TOUCHPAD_EVENT_NONE;
 426                 touchpad->event_mask_filter =
 427                         TOUCHPAD_EVENT_ABSOLUTE_X | TOUCHPAD_EVENT_ABSOLUTE_Y;
 428
 429                 touchpad->last_finger_state = touchpad->finger_state;
 430
 431                 process_fsm_events(touchpad, time);
 432
 433                 return;
 434         }
 435         touchpad->last_finger_state = touchpad->finger_state;
 436
 437         if (!(touchpad->event_mask & TOUCHPAD_EVENT_REPORT))
 438                 return;
 439         else
 440                 touchpad->event_mask &= ~TOUCHPAD_EVENT_REPORT;
 441
 442         if ((touchpad->event_mask & touchpad->event_mask_filter) !=
 443             touchpad->event_mask_filter)
 444                 return;
 445
 446         touchpad->event_mask_filter = TOUCHPAD_EVENT_ABSOLUTE_ANY;
 447         touchpad->event_mask = 0;
 448
 449         /* Avoid noice by moving center only when delta reaches a threshold
 450          * distance from the old center. */
 451         if (touchpad->motion_count > 0) {
 452                 center_x = hysteresis(touchpad->hw_abs.x,
 453                                       touchpad->hysteresis.center_x,
 454                                       touchpad->hysteresis.margin_x);
 455                 center_y = hysteresis(touchpad->hw_abs.y,
 456                                       touchpad->hysteresis.center_y,
 457                                       touchpad->hysteresis.margin_y);
 458         } else {
 459                 center_x = touchpad->hw_abs.x;
 460                 center_y = touchpad->hw_abs.y;
 461         }
 462         touchpad->hysteresis.center_x = center_x;
 463         touchpad->hysteresis.center_y = center_y;
 464         touchpad->hw_abs.x = center_x;
 465         touchpad->hw_abs.y = center_y;
 466
 467         /* Update motion history tracker */
 468         motion_index = (touchpad->motion_index + 1) % TOUCHPAD_HISTORY_LENGTH;
 469         touchpad->motion_index = motion_index;
 470         touchpad->motion_history[motion_index].x = touchpad->hw_abs.x;
 471         touchpad->motion_history[motion_index].y = touchpad->hw_abs.y;
 472         if (touchpad->motion_count < 4)
 473                 touchpad->motion_count++;
 474
 475         if (touchpad->motion_count >= 4) {
 476                 touchpad_get_delta(touchpad, &dx, &dy);
 477
 478                 filter_motion(touchpad, &dx, &dy, time);
 479
 480                 if (touchpad->finger_state == TOUCHPAD_FINGERS_ONE) {
 481                         touchpad->device->rel.dx = wl_fixed_from_double(dx);
 482                         touchpad->device->rel.dy = wl_fixed_from_double(dy);
 483                         touchpad->device->pending_events |=
 484                                 EVDEV_RELATIVE_MOTION;
 485                 } else if (touchpad->finger_state == TOUCHPAD_FINGERS_TWO) {
 486                         if (dx != 0.0)
 487                                 notify_axis(touchpad->device->seat,
 488                                             time,
 489                                             WL_POINTER_AXIS_HORIZONTAL_SCROLL,
 490                                             wl_fixed_from_double(dx));
 491                         if (dy != 0.0)
 492                                 notify_axis(touchpad->device->seat,
 493                                             time,
 494                                             WL_POINTER_AXIS_VERTICAL_SCROLL,
 495                                             wl_fixed_from_double(dy));
 496                 }
 497         }
 498
 499         if (!(touchpad->state & TOUCHPAD_STATE_MOVE) &&
 500             ((int)dx || (int)dy)) {
 501                 touchpad->state |= TOUCHPAD_STATE_MOVE;
 502                 push_fsm_event(touchpad, FSM_EVENT_MOTION);
 503         }
 504
 505         process_fsm_events(touchpad, time);
 506 }
 507
 508 static void
 509 on_touch(struct touchpad_dispatch *touchpad)
 510 {
 511         touchpad->state |= TOUCHPAD_STATE_TOUCH;
 512
 513         push_fsm_event(touchpad, FSM_EVENT_TOUCH);
 514 }
 515
 516 static void
 517 on_release(struct touchpad_dispatch *touchpad)
 518 {
 519
 520         touchpad->reset = 1;
 521         touchpad->state &= ~(TOUCHPAD_STATE_MOVE | TOUCHPAD_STATE_TOUCH);
 522
 523         push_fsm_event(touchpad, FSM_EVENT_RELEASE);
 524 }
 525
 526 static inline void
 527 process_absolute(struct touchpad_dispatch *touchpad,
 528                  struct evdev_device *device,
 529                  struct input_event *e)
 530 {
 531         switch (e->code) {
 532         case ABS_PRESSURE:
 533                 if (e->value > touchpad->pressure.touch_high &&
 534                     !(touchpad->state & TOUCHPAD_STATE_TOUCH))
 535                         on_touch(touchpad);
 536                 else if (e->value < touchpad->pressure.touch_low &&
 537                          touchpad->state & TOUCHPAD_STATE_TOUCH)
 538                         on_release(touchpad);
 539
 540                 break;
 541         case ABS_X:
 542                 if (touchpad->state & TOUCHPAD_STATE_TOUCH) {
 543                         touchpad->hw_abs.x = e->value;
 544                         touchpad->event_mask |= TOUCHPAD_EVENT_ABSOLUTE_ANY;
 545                         touchpad->event_mask |= TOUCHPAD_EVENT_ABSOLUTE_X;
 546                 }
 547                 break;
 548         case ABS_Y:
 549                 if (touchpad->state & TOUCHPAD_STATE_TOUCH) {
 550                         touchpad->hw_abs.y = e->value;
 551                         touchpad->event_mask |= TOUCHPAD_EVENT_ABSOLUTE_ANY;
 552                         touchpad->event_mask |= TOUCHPAD_EVENT_ABSOLUTE_Y;
 553                 }
 554                 break;
 555         }
 556 }
 557
 558 static inline void
 559 process_key(struct touchpad_dispatch *touchpad,
 560             struct evdev_device *device,
 561             struct input_event *e,
 562             uint32_t time)
 563 {
 564         switch (e->code) {
 565         case BTN_TOUCH:
 566                 if (!touchpad->has_pressure) {
 567                         if (e->value && !(touchpad->state & TOUCHPAD_STATE_TOUCH))
 568                                 on_touch(touchpad);
 569                         else if (!e->value)
 570                                 on_release(touchpad);
 571                 }
 572                 break;
 573         case BTN_LEFT:
 574         case BTN_RIGHT:
 575         case BTN_MIDDLE:
 576         case BTN_SIDE:
 577         case BTN_EXTRA:
 578         case BTN_FORWARD:
 579         case BTN_BACK:
 580         case BTN_TASK:
 581                 notify_button(device->seat,
 582                               time, e->code,
 583                               e->value ? WL_POINTER_BUTTON_STATE_PRESSED :
 584                                          WL_POINTER_BUTTON_STATE_RELEASED);
 585                 break;
 586         case BTN_TOOL_PEN:
 587         case BTN_TOOL_RUBBER:
 588         case BTN_TOOL_BRUSH:
 589         case BTN_TOOL_PENCIL:
 590         case BTN_TOOL_AIRBRUSH:
 591         case BTN_TOOL_MOUSE:
 592         case BTN_TOOL_LENS:
 593                 touchpad->reset = 1;
 594                 break;
 595         case BTN_TOOL_FINGER:
 596                 if (e->value)
 597                         touchpad->finger_state |= TOUCHPAD_FINGERS_ONE;
 598                 else
 599                         touchpad->finger_state &= ~TOUCHPAD_FINGERS_ONE;
 600                 break;
 601         case BTN_TOOL_DOUBLETAP:
 602                 if (e->value)
 603                         touchpad->finger_state |= TOUCHPAD_FINGERS_TWO;
 604                 else
 605                         touchpad->finger_state &= ~TOUCHPAD_FINGERS_TWO;
 606                 break;
 607         case BTN_TOOL_TRIPLETAP:
 608                 if (e->value)
 609                         touchpad->finger_state |= TOUCHPAD_FINGERS_THREE;
 610                 else
 611                         touchpad->finger_state &= ~TOUCHPAD_FINGERS_THREE;
 612                 break;
 613         }
 614 }
 615
 616 static void
 617 touchpad_process(struct evdev_dispatch *dispatch,
 618                  struct evdev_device *device,
 619                  struct input_event *e,
 620                  uint32_t time)
 621 {
 622         struct touchpad_dispatch *touchpad =
 623                 (struct touchpad_dispatch *) dispatch;
 624
 625         switch (e->type) {
 626         case EV_SYN:
 627                 if (e->code == SYN_REPORT)
 628                         touchpad->event_mask |= TOUCHPAD_EVENT_REPORT;
 629                 break;
 630         case EV_ABS:
 631                 process_absolute(touchpad, device, e);
 632                 break;
 633         case EV_KEY:
 634                 process_key(touchpad, device, e, time);
 635                 break;
 636         }
 637
 638         touchpad_update_state(touchpad, time);
 639 }
 640
 641 static void
 642 touchpad_destroy(struct evdev_dispatch *dispatch)
 643 {
 644         struct touchpad_dispatch *touchpad =
 645                 (struct touchpad_dispatch *) dispatch;
 646
 647         touchpad->filter->interface->destroy(touchpad->filter);
 648         wl_event_source_remove(touchpad->fsm.timer_source);
 649         free(dispatch);
 650 }
 651
 652 struct evdev_dispatch_interface touchpad_interface = {
 653         touchpad_process,
 654         touchpad_destroy
 655 };
 656
 657 static int
 658 touchpad_init(struct touchpad_dispatch *touchpad,
 659               struct evdev_device *device)
 660 {
 661         struct weston_motion_filter *accel;
 662         struct wl_event_loop *loop;
 663
 664         struct input_absinfo absinfo;
 665         unsigned long abs_bits[NBITS(ABS_MAX)];
 666
 667         double width;
 668         double height;
 669         double diagonal;
 670
 671         touchpad->base.interface = &touchpad_interface;
 672         touchpad->device = device;
 673
 674         /* Detect model */
 675         touchpad->model = get_touchpad_model(device);
 676
 677         /* Configure pressure */
 678         ioctl(device->fd, EVIOCGBIT(EV_ABS, sizeof(abs_bits)), abs_bits);
 679         if (TEST_BIT(abs_bits, ABS_PRESSURE)) {
 680                 ioctl(device->fd, EVIOCGABS(ABS_PRESSURE), &absinfo);
 681                 configure_touchpad_pressure(touchpad,
 682                                             absinfo.minimum,
 683                                             absinfo.maximum);
 684         }
 685
 686         /* Configure acceleration factor */
 687         width = abs(device->abs.max_x - device->abs.min_x);
 688         height = abs(device->abs.max_y - device->abs.min_y);
 689         diagonal = sqrt(width*width + height*height);
 690
 691         touchpad->constant_accel_factor =
 692                 DEFAULT_CONSTANT_ACCEL_NUMERATOR / diagonal;
 693
 694         touchpad->min_accel_factor = DEFAULT_MIN_ACCEL_FACTOR;
 695         touchpad->max_accel_factor = DEFAULT_MAX_ACCEL_FACTOR;
 696
 697         touchpad->hysteresis.margin_x =
 698                 diagonal / DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR;
 699         touchpad->hysteresis.margin_y =
 700                 diagonal / DEFAULT_HYSTERESIS_MARGIN_DENOMINATOR;
 701         touchpad->hysteresis.center_x = 0;
 702         touchpad->hysteresis.center_y = 0;
 703
 704         /* Configure acceleration profile */
 705         accel = create_pointer_accelator_filter(touchpad_profile);
 706         if (accel == NULL)
 707                 return -1;
 708         touchpad->filter = accel;
 709
 710         /* Setup initial state */
 711         touchpad->reset = 1;
 712
 713         memset(touchpad->motion_history, 0, sizeof touchpad->motion_history);
 714         touchpad->motion_index = 0;
 715         touchpad->motion_count = 0;
 716
 717         touchpad->state = TOUCHPAD_STATE_NONE;
 718         touchpad->last_finger_state = 0;
 719         touchpad->finger_state = 0;
 720
 721         wl_array_init(&touchpad->fsm.events);
 722         touchpad->fsm.state = FSM_IDLE;
 723
 724         loop = wl_display_get_event_loop(device->seat->compositor->wl_display);
 725         touchpad->fsm.timer_source =
 726                 wl_event_loop_add_timer(loop, fsm_timout_handler, touchpad);
 727         if (touchpad->fsm.timer_source == NULL) {
 728                 accel->interface->destroy(accel);
 729                 return -1;
 730         }
 731
 732         return 0;
 733 }
 734
 735 struct evdev_dispatch *
 736 evdev_touchpad_create(struct evdev_device *device)
 737 {
 738         struct touchpad_dispatch *touchpad;
 739
 740         touchpad = malloc(sizeof *touchpad);
 741         if (touchpad == NULL)
 742                 return NULL;
 743
 744         if (touchpad_init(touchpad, device) != 0) {
 745                 free(touchpad);
 746                 return NULL;
 747         }
 748
 749         return &touchpad->base;
 750 }