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 17 static 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 */ 41 int 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_TRACK) { 83 unsigned int n2 = num_slots * num_slots; 84 mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); 85 if (!mt->red) 86 goto err_mem; 87 } 88 89 /* Mark slots as 'unused' */ 90 for (i = 0; i < num_slots; i++) 91 input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); 92 93 dev->mt = mt; 94 return 0; 95 err_mem: 96 kfree(mt); 97 return -ENOMEM; 98 } 99 EXPORT_SYMBOL(input_mt_init_slots); 100 101 /** 102 * input_mt_destroy_slots() - frees the MT slots of the input device 103 * @dev: input device with allocated MT slots 104 * 105 * This function is only needed in error path as the input core will 106 * automatically free the MT slots when the device is destroyed. 107 */ 108 void input_mt_destroy_slots(struct input_dev *dev) 109 { 110 if (dev->mt) { 111 kfree(dev->mt->red); 112 kfree(dev->mt); 113 } 114 dev->mt = NULL; 115 } 116 EXPORT_SYMBOL(input_mt_destroy_slots); 117 118 /** 119 * input_mt_report_slot_state() - report contact state 120 * @dev: input device with allocated MT slots 121 * @tool_type: the tool type to use in this slot 122 * @active: true if contact is active, false otherwise 123 * 124 * Reports a contact via ABS_MT_TRACKING_ID, and optionally 125 * ABS_MT_TOOL_TYPE. If active is true and the slot is currently 126 * inactive, or if the tool type is changed, a new tracking id is 127 * assigned to the slot. The tool type is only reported if the 128 * corresponding absbit field is set. 129 */ 130 void input_mt_report_slot_state(struct input_dev *dev, 131 unsigned int tool_type, bool active) 132 { 133 struct input_mt *mt = dev->mt; 134 struct input_mt_slot *slot; 135 int id; 136 137 if (!mt) 138 return; 139 140 slot = &mt->slots[mt->slot]; 141 slot->frame = mt->frame; 142 143 if (!active) { 144 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); 145 return; 146 } 147 148 id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); 149 if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type) 150 id = input_mt_new_trkid(mt); 151 152 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); 153 input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); 154 } 155 EXPORT_SYMBOL(input_mt_report_slot_state); 156 157 /** 158 * input_mt_report_finger_count() - report contact count 159 * @dev: input device with allocated MT slots 160 * @count: the number of contacts 161 * 162 * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, 163 * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. 164 * 165 * The input core ensures only the KEY events already setup for 166 * this device will produce output. 167 */ 168 void input_mt_report_finger_count(struct input_dev *dev, int count) 169 { 170 input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); 171 input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); 172 input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); 173 input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); 174 input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); 175 } 176 EXPORT_SYMBOL(input_mt_report_finger_count); 177 178 /** 179 * input_mt_report_pointer_emulation() - common pointer emulation 180 * @dev: input device with allocated MT slots 181 * @use_count: report number of active contacts as finger count 182 * 183 * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and 184 * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. 185 * 186 * The input core ensures only the KEY and ABS axes already setup for 187 * this device will produce output. 188 */ 189 void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) 190 { 191 struct input_mt *mt = dev->mt; 192 struct input_mt_slot *oldest; 193 int oldid, count, i; 194 195 if (!mt) 196 return; 197 198 oldest = NULL; 199 oldid = mt->trkid; 200 count = 0; 201 202 for (i = 0; i < mt->num_slots; ++i) { 203 struct input_mt_slot *ps = &mt->slots[i]; 204 int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); 205 206 if (id < 0) 207 continue; 208 if ((id - oldid) & TRKID_SGN) { 209 oldest = ps; 210 oldid = id; 211 } 212 count++; 213 } 214 215 input_event(dev, EV_KEY, BTN_TOUCH, count > 0); 216 if (use_count) 217 input_mt_report_finger_count(dev, count); 218 219 if (oldest) { 220 int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); 221 int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); 222 223 input_event(dev, EV_ABS, ABS_X, x); 224 input_event(dev, EV_ABS, ABS_Y, y); 225 226 if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { 227 int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); 228 input_event(dev, EV_ABS, ABS_PRESSURE, p); 229 } 230 } else { 231 if (test_bit(ABS_MT_PRESSURE, dev->absbit)) 232 input_event(dev, EV_ABS, ABS_PRESSURE, 0); 233 } 234 } 235 EXPORT_SYMBOL(input_mt_report_pointer_emulation); 236 237 /** 238 * input_mt_sync_frame() - synchronize mt frame 239 * @dev: input device with allocated MT slots 240 * 241 * Close the frame and prepare the internal state for a new one. 242 * Depending on the flags, marks unused slots as inactive and performs 243 * pointer emulation. 244 */ 245 void input_mt_sync_frame(struct input_dev *dev) 246 { 247 struct input_mt *mt = dev->mt; 248 struct input_mt_slot *s; 249 250 if (!mt) 251 return; 252 253 if (mt->flags & INPUT_MT_DROP_UNUSED) { 254 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 255 if (input_mt_is_used(mt, s)) 256 continue; 257 input_mt_slot(dev, s - mt->slots); 258 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); 259 } 260 } 261 262 input_mt_report_pointer_emulation(dev, (mt->flags & INPUT_MT_POINTER)); 263 264 mt->frame++; 265 } 266 EXPORT_SYMBOL(input_mt_sync_frame); 267 268 static int adjust_dual(int *begin, int step, int *end, int eq) 269 { 270 int f, *p, s, c; 271 272 if (begin == end) 273 return 0; 274 275 f = *begin; 276 p = begin + step; 277 s = p == end ? f + 1 : *p; 278 279 for (; p != end; p += step) 280 if (*p < f) 281 s = f, f = *p; 282 else if (*p < s) 283 s = *p; 284 285 c = (f + s + 1) / 2; 286 if (c == 0 || (c > 0 && !eq)) 287 return 0; 288 if (s < 0) 289 c *= 2; 290 291 for (p = begin; p != end; p += step) 292 *p -= c; 293 294 return (c < s && s <= 0) || (f >= 0 && f < c); 295 } 296 297 static void find_reduced_matrix(int *w, int nr, int nc, int nrc) 298 { 299 int i, k, sum; 300 301 for (k = 0; k < nrc; k++) { 302 for (i = 0; i < nr; i++) 303 adjust_dual(w + i, nr, w + i + nrc, nr <= nc); 304 sum = 0; 305 for (i = 0; i < nrc; i += nr) 306 sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr); 307 if (!sum) 308 break; 309 } 310 } 311 312 static int input_mt_set_matrix(struct input_mt *mt, 313 const struct input_mt_pos *pos, int num_pos) 314 { 315 const struct input_mt_pos *p; 316 struct input_mt_slot *s; 317 int *w = mt->red; 318 int x, y; 319 320 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 321 if (!input_mt_is_active(s)) 322 continue; 323 x = input_mt_get_value(s, ABS_MT_POSITION_X); 324 y = input_mt_get_value(s, ABS_MT_POSITION_Y); 325 for (p = pos; p != pos + num_pos; p++) { 326 int dx = x - p->x, dy = y - p->y; 327 *w++ = dx * dx + dy * dy; 328 } 329 } 330 331 return w - mt->red; 332 } 333 334 static void input_mt_set_slots(struct input_mt *mt, 335 int *slots, int num_pos) 336 { 337 struct input_mt_slot *s; 338 int *w = mt->red, *p; 339 340 for (p = slots; p != slots + num_pos; p++) 341 *p = -1; 342 343 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 344 if (!input_mt_is_active(s)) 345 continue; 346 for (p = slots; p != slots + num_pos; p++) 347 if (*w++ < 0) 348 *p = s - mt->slots; 349 } 350 351 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { 352 if (input_mt_is_active(s)) 353 continue; 354 for (p = slots; p != slots + num_pos; p++) 355 if (*p < 0) { 356 *p = s - mt->slots; 357 break; 358 } 359 } 360 } 361 362 /** 363 * input_mt_assign_slots() - perform a best-match assignment 364 * @dev: input device with allocated MT slots 365 * @slots: the slot assignment to be filled 366 * @pos: the position array to match 367 * @num_pos: number of positions 368 * 369 * Performs a best match against the current contacts and returns 370 * the slot assignment list. New contacts are assigned to unused 371 * slots. 372 * 373 * Returns zero on success, or negative error in case of failure. 374 */ 375 int input_mt_assign_slots(struct input_dev *dev, int *slots, 376 const struct input_mt_pos *pos, int num_pos) 377 { 378 struct input_mt *mt = dev->mt; 379 int nrc; 380 381 if (!mt || !mt->red) 382 return -ENXIO; 383 if (num_pos > mt->num_slots) 384 return -EINVAL; 385 if (num_pos < 1) 386 return 0; 387 388 nrc = input_mt_set_matrix(mt, pos, num_pos); 389 find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc); 390 input_mt_set_slots(mt, slots, num_pos); 391 392 return 0; 393 } 394 EXPORT_SYMBOL(input_mt_assign_slots); 395 396 /** 397 * input_mt_get_slot_by_key() - return slot matching key 398 * @dev: input device with allocated MT slots 399 * @key: the key of the sought slot 400 * 401 * Returns the slot of the given key, if it exists, otherwise 402 * set the key on the first unused slot and return. 403 * 404 * If no available slot can be found, -1 is returned. 405 */ 406 int input_mt_get_slot_by_key(struct input_dev *dev, int key) 407 { 408 struct input_mt *mt = dev->mt; 409 struct input_mt_slot *s; 410 411 if (!mt) 412 return -1; 413 414 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) 415 if (input_mt_is_active(s) && s->key == key) 416 return s - mt->slots; 417 418 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) 419 if (!input_mt_is_active(s)) { 420 s->key = key; 421 return s - mt->slots; 422 } 423 424 return -1; 425 } 426 EXPORT_SYMBOL(input_mt_get_slot_by_key); 427