1/* 2 * Input Multitouch Library 3 * 4 * Copyright (c) 2008-2010 Henrik Rydberg 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 */ 10 11#include <linux/input/mt.h> 12#include <linux/export.h> 13#include <linux/slab.h> 14 15#define TRKID_SGN ((TRKID_MAX + 1) >> 1) 16 17static void copy_abs(struct input_dev *dev, unsigned int dst, unsigned int src) 18{ 19 if (dev->absinfo && test_bit(src, dev->absbit)) { 20 dev->absinfo[dst] = dev->absinfo[src]; 21 dev->absinfo[dst].fuzz = 0; 22 dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst); 23 } 24} 25 26/** 27 * input_mt_init_slots() - initialize MT input slots 28 * @dev: input device supporting MT events and finger tracking 29 * @num_slots: number of slots used by the device 30 * @flags: mt tasks to handle in core 31 * 32 * This function allocates all necessary memory for MT slot handling 33 * in the input device, prepares the ABS_MT_SLOT and 34 * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers. 35 * Depending on the flags set, it also performs pointer emulation and 36 * frame synchronization. 37 * 38 * May be called repeatedly. Returns -EINVAL if attempting to 39 * reinitialize with a different number of slots. 40 */ 41int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, 42 unsigned int flags) 43{ 44 struct input_mt *mt = dev->mt; 45 int i; 46 47 if (!num_slots) 48 return 0; 49 if (mt) 50 return mt->num_slots != num_slots ? -EINVAL : 0; 51 52 mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL); 53 if (!mt) 54 goto err_mem; 55 56 mt->num_slots = num_slots; 57 mt->flags = flags; 58 input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0); 59 input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0); 60 61 if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) { 62 __set_bit(EV_KEY, dev->evbit); 63 __set_bit(BTN_TOUCH, dev->keybit); 64 65 copy_abs(dev, ABS_X, ABS_MT_POSITION_X); 66 copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y); 67 copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE); 68 } 69 if (flags & INPUT_MT_POINTER) { 70 __set_bit(BTN_TOOL_FINGER, dev->keybit); 71 __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit); 72 if (num_slots >= 3) 73 __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit); 74 if (num_slots >= 4) 75 __set_bit(BTN_TOOL_QUADTAP, dev->keybit); 76 if (num_slots >= 5) 77 __set_bit(BTN_TOOL_QUINTTAP, dev->keybit); 78 __set_bit(INPUT_PROP_POINTER, dev->propbit); 79 } 80 if (flags & INPUT_MT_DIRECT) 81 __set_bit(INPUT_PROP_DIRECT, dev->propbit); 82 if (flags & INPUT_MT_SEMI_MT) 83 __set_bit(INPUT_PROP_SEMI_MT, dev->propbit); 84 if (flags & INPUT_MT_TRACK) { 85 unsigned int n2 = num_slots * num_slots; 86 mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); 87 if (!mt->red) 88 goto err_mem; 89 } 90 91 /* Mark slots as 'unused' */ 92 for (i = 0; i < num_slots; i++) 93 input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); 94 95 dev->mt = mt; 96 return 0; 97err_mem: 98 kfree(mt); 99 return -ENOMEM; 100} 101EXPORT_SYMBOL(input_mt_init_slots); 102 103/** 104 * input_mt_destroy_slots() - frees the MT slots of the input device 105 * @dev: input device with allocated MT slots 106 * 107 * This function is only needed in error path as the input core will 108 * automatically free the MT slots when the device is destroyed. 109 */ 110void input_mt_destroy_slots(struct input_dev *dev) 111{ 112 if (dev->mt) { 113 kfree(dev->mt->red); 114 kfree(dev->mt); 115 } 116 dev->mt = NULL; 117} 118EXPORT_SYMBOL(input_mt_destroy_slots); 119 120/** 121 * input_mt_report_slot_state() - report contact state 122 * @dev: input device with allocated MT slots 123 * @tool_type: the tool type to use in this slot 124 * @active: true if contact is active, false otherwise 125 * 126 * Reports a contact via ABS_MT_TRACKING_ID, and optionally 127 * ABS_MT_TOOL_TYPE. If active is true and the slot is currently 128 * inactive, or if the tool type is changed, a new tracking id is 129 * assigned to the slot. The tool type is only reported if the 130 * corresponding absbit field is set. 131 */ 132void input_mt_report_slot_state(struct input_dev *dev, 133 unsigned int tool_type, bool active) 134{ 135 struct input_mt *mt = dev->mt; 136 struct input_mt_slot *slot; 137 int id; 138 139 if (!mt) 140 return; 141 142 slot = &mt->slots[mt->slot]; 143 slot->frame = mt->frame; 144 145 if (!active) { 146 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); 147 return; 148 } 149 150 id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); 151 if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type) 152 id = input_mt_new_trkid(mt); 153 154 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); 155 input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); 156} 157EXPORT_SYMBOL(input_mt_report_slot_state); 158 159/** 160 * input_mt_report_finger_count() - report contact count 161 * @dev: input device with allocated MT slots 162 * @count: the number of contacts 163 * 164 * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, 165 * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. 166 * 167 * The input core ensures only the KEY events already setup for 168 * this device will produce output. 169 */ 170void input_mt_report_finger_count(struct input_dev *dev, int count) 171{ 172 input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); 173 input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); 174 input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); 175 input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); 176 input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); 177} 178EXPORT_SYMBOL(input_mt_report_finger_count); 179 180/** 181 * input_mt_report_pointer_emulation() - common pointer emulation 182 * @dev: input device with allocated MT slots 183 * @use_count: report number of active contacts as finger count 184 * 185 * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and 186 * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. 187 * 188 * The input core ensures only the KEY and ABS axes already setup for 189 * this device will produce output. 190 */ 191void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) 192{ 193 struct input_mt *mt = dev->mt; 194 struct input_mt_slot *oldest; 195 int oldid, count, i; 196 197 if (!mt) 198 return; 199 200 oldest = NULL; 201 oldid = mt->trkid; 202 count = 0; 203 204 for (i = 0; i < mt->num_slots; ++i) { 205 struct input_mt_slot *ps = &mt->slots[i]; 206 int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); 207 208 if (id < 0) 209 continue; 210 if ((id - oldid) & TRKID_SGN) { 211 oldest = ps; 212 oldid = id; 213 } 214 count++; 215 } 216 217 input_event(dev, EV_KEY, BTN_TOUCH, count > 0); 218 if (use_count) 219 input_mt_report_finger_count(dev, count); 220 221 if (oldest) { 222 int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); 223 int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); 224 225 input_event(dev, EV_ABS, ABS_X, x); 226 input_event(dev, EV_ABS, ABS_Y, y); 227 228 if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { 229 int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); 230 input_event(dev, EV_ABS, ABS_PRESSURE, p); 231 } 232 } else { 233 if (test_bit(ABS_MT_PRESSURE, dev->absbit)) 234 input_event(dev, EV_ABS, ABS_PRESSURE, 0); 235 } 236} 237EXPORT_SYMBOL(input_mt_report_pointer_emulation); 238 239static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) 240{ 241 int i; 242 243 for (i = 0; i < mt->num_slots; i++) { 244 if (!input_mt_is_used(mt, &mt->slots[i])) { 245 input_mt_slot(dev, i); 246 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); 247 } 248 } 249} 250 251/** 252 * input_mt_drop_unused() - Inactivate slots not seen in this frame 253 * @dev: input device with allocated MT slots 254 * 255 * Lift all slots not seen since the last call to this function. 256 */ 257void input_mt_drop_unused(struct input_dev *dev) 258{ 259 struct input_mt *mt = dev->mt; 260 261 if (mt) { 262 __input_mt_drop_unused(dev, mt); 263 mt->frame++; 264 } 265} 266EXPORT_SYMBOL(input_mt_drop_unused); 267 268/** 269 * input_mt_sync_frame() - synchronize mt frame 270 * @dev: input device with allocated MT slots 271 * 272 * Close the frame and prepare the internal state for a new one. 273 * Depending on the flags, marks unused slots as inactive and performs 274 * pointer emulation. 275 */ 276void input_mt_sync_frame(struct input_dev *dev) 277{ 278 struct input_mt *mt = dev->mt; 279 bool use_count = false; 280 281 if (!mt) 282 return; 283 284 if (mt->flags & INPUT_MT_DROP_UNUSED) 285 __input_mt_drop_unused(dev, mt); 286 287 if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT)) 288 use_count = true; 289 290 input_mt_report_pointer_emulation(dev, use_count); 291 292 mt->frame++; 293} 294EXPORT_SYMBOL(input_mt_sync_frame); 295 296static int adjust_dual(int *begin, int step, int *end, int eq) 297{ 298 int f, *p, s, c; 299 300 if (begin == end) 301 return 0; 302 303 f = *begin; 304 p = begin + step; 305 s = p == end ? f + 1 : *p; 306 307 for (; p != end; p += step) 308 if (*p < f) 309 s = f, f = *p; 310 else if (*p < s) 311 s = *p; 312 313 c = (f + s + 1) / 2; 314 if (c == 0 || (c > 0 && !eq)) 315 return 0; 316 if (s < 0) 317 c *= 2; 318 319 for (p = begin; p != end; p += step) 320 *p -= c; 321 322 return (c < s && s <= 0) || (f >= 0 && f < c); 323} 324 325static void find_reduced_matrix(int *w, int nr, int nc, int nrc) 326{ 327 int i, k, sum; 328 329 for (k = 0; k < nrc; k++) { 330 for (i = 0; i < nr; i++) 331 adjust_dual(w + i, nr, w + i + nrc, nr <= nc); 332 sum = 0; 333 for (i = 0; i < nrc; i += nr) 334 sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr); 335 if (!sum) 336 break; 337 } 338} 339 340static int input_mt_set_matrix(struct input_mt *mt, 341 const struct input_mt_pos *pos, int num_pos) 342{ 343 const struct input_mt_pos *p; 344 struct input_mt_slot *s; 345 int *w = mt->red; 346 int x, y; 347 348 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 349 if (!input_mt_is_active(s)) 350 continue; 351 x = input_mt_get_value(s, ABS_MT_POSITION_X); 352 y = input_mt_get_value(s, ABS_MT_POSITION_Y); 353 for (p = pos; p != pos + num_pos; p++) { 354 int dx = x - p->x, dy = y - p->y; 355 *w++ = dx * dx + dy * dy; 356 } 357 } 358 359 return w - mt->red; 360} 361 362static void input_mt_set_slots(struct input_mt *mt, 363 int *slots, int num_pos) 364{ 365 struct input_mt_slot *s; 366 int *w = mt->red, *p; 367 368 for (p = slots; p != slots + num_pos; p++) 369 *p = -1; 370 371 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 372 if (!input_mt_is_active(s)) 373 continue; 374 for (p = slots; p != slots + num_pos; p++) 375 if (*w++ < 0) 376 *p = s - mt->slots; 377 } 378 379 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 380 if (input_mt_is_active(s)) 381 continue; 382 for (p = slots; p != slots + num_pos; p++) 383 if (*p < 0) { 384 *p = s - mt->slots; 385 break; 386 } 387 } 388} 389 390/** 391 * input_mt_assign_slots() - perform a best-match assignment 392 * @dev: input device with allocated MT slots 393 * @slots: the slot assignment to be filled 394 * @pos: the position array to match 395 * @num_pos: number of positions 396 * 397 * Performs a best match against the current contacts and returns 398 * the slot assignment list. New contacts are assigned to unused 399 * slots. 400 * 401 * Returns zero on success, or negative error in case of failure. 402 */ 403int input_mt_assign_slots(struct input_dev *dev, int *slots, 404 const struct input_mt_pos *pos, int num_pos) 405{ 406 struct input_mt *mt = dev->mt; 407 int nrc; 408 409 if (!mt || !mt->red) 410 return -ENXIO; 411 if (num_pos > mt->num_slots) 412 return -EINVAL; 413 if (num_pos < 1) 414 return 0; 415 416 nrc = input_mt_set_matrix(mt, pos, num_pos); 417 find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc); 418 input_mt_set_slots(mt, slots, num_pos); 419 420 return 0; 421} 422EXPORT_SYMBOL(input_mt_assign_slots); 423 424/** 425 * input_mt_get_slot_by_key() - return slot matching key 426 * @dev: input device with allocated MT slots 427 * @key: the key of the sought slot 428 * 429 * Returns the slot of the given key, if it exists, otherwise 430 * set the key on the first unused slot and return. 431 * 432 * If no available slot can be found, -1 is returned. 433 */ 434int input_mt_get_slot_by_key(struct input_dev *dev, int key) 435{ 436 struct input_mt *mt = dev->mt; 437 struct input_mt_slot *s; 438 439 if (!mt) 440 return -1; 441 442 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) 443 if (input_mt_is_active(s) && s->key == key) 444 return s - mt->slots; 445 446 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) 447 if (!input_mt_is_active(s)) { 448 s->key = key; 449 return s - mt->slots; 450 } 451 452 return -1; 453} 454EXPORT_SYMBOL(input_mt_get_slot_by_key); 455