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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_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 'inactive' */ | |
92 | for (i = 0; i < num_slots; i++) | |
93 | input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); | |
94 | ||
95 | /* Mark slots as 'unused' */ | |
96 | mt->frame = 1; | |
97 | ||
98 | dev->mt = mt; | |
99 | return 0; | |
100 | err_mem: | |
101 | kfree(mt); | |
102 | return -ENOMEM; | |
103 | } | |
104 | EXPORT_SYMBOL(input_mt_init_slots); | |
105 | ||
106 | /** | |
107 | * input_mt_destroy_slots() - frees the MT slots of the input device | |
108 | * @dev: input device with allocated MT slots | |
109 | * | |
110 | * This function is only needed in error path as the input core will | |
111 | * automatically free the MT slots when the device is destroyed. | |
112 | */ | |
113 | void input_mt_destroy_slots(struct input_dev *dev) | |
114 | { | |
115 | if (dev->mt) { | |
116 | kfree(dev->mt->red); | |
117 | kfree(dev->mt); | |
118 | } | |
119 | dev->mt = NULL; | |
120 | } | |
121 | EXPORT_SYMBOL(input_mt_destroy_slots); | |
122 | ||
123 | /** | |
124 | * input_mt_report_slot_state() - report contact state | |
125 | * @dev: input device with allocated MT slots | |
126 | * @tool_type: the tool type to use in this slot | |
127 | * @active: true if contact is active, false otherwise | |
128 | * | |
129 | * Reports a contact via ABS_MT_TRACKING_ID, and optionally | |
130 | * ABS_MT_TOOL_TYPE. If active is true and the slot is currently | |
131 | * inactive, or if the tool type is changed, a new tracking id is | |
132 | * assigned to the slot. The tool type is only reported if the | |
133 | * corresponding absbit field is set. | |
134 | */ | |
135 | void input_mt_report_slot_state(struct input_dev *dev, | |
136 | unsigned int tool_type, bool active) | |
137 | { | |
138 | struct input_mt *mt = dev->mt; | |
139 | struct input_mt_slot *slot; | |
140 | int id; | |
141 | ||
142 | if (!mt) | |
143 | return; | |
144 | ||
145 | slot = &mt->slots[mt->slot]; | |
146 | slot->frame = mt->frame; | |
147 | ||
148 | if (!active) { | |
149 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); | |
150 | return; | |
151 | } | |
152 | ||
153 | id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); | |
154 | if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type) | |
155 | id = input_mt_new_trkid(mt); | |
156 | ||
157 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); | |
158 | input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); | |
159 | } | |
160 | EXPORT_SYMBOL(input_mt_report_slot_state); | |
161 | ||
162 | /** | |
163 | * input_mt_report_finger_count() - report contact count | |
164 | * @dev: input device with allocated MT slots | |
165 | * @count: the number of contacts | |
166 | * | |
167 | * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, | |
168 | * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. | |
169 | * | |
170 | * The input core ensures only the KEY events already setup for | |
171 | * this device will produce output. | |
172 | */ | |
173 | void input_mt_report_finger_count(struct input_dev *dev, int count) | |
174 | { | |
175 | input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); | |
176 | input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); | |
177 | input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); | |
178 | input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); | |
179 | input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); | |
180 | } | |
181 | EXPORT_SYMBOL(input_mt_report_finger_count); | |
182 | ||
183 | /** | |
184 | * input_mt_report_pointer_emulation() - common pointer emulation | |
185 | * @dev: input device with allocated MT slots | |
186 | * @use_count: report number of active contacts as finger count | |
187 | * | |
188 | * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and | |
189 | * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. | |
190 | * | |
191 | * The input core ensures only the KEY and ABS axes already setup for | |
192 | * this device will produce output. | |
193 | */ | |
194 | void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) | |
195 | { | |
196 | struct input_mt *mt = dev->mt; | |
197 | struct input_mt_slot *oldest; | |
198 | int oldid, count, i; | |
199 | ||
200 | if (!mt) | |
201 | return; | |
202 | ||
203 | oldest = NULL; | |
204 | oldid = mt->trkid; | |
205 | count = 0; | |
206 | ||
207 | for (i = 0; i < mt->num_slots; ++i) { | |
208 | struct input_mt_slot *ps = &mt->slots[i]; | |
209 | int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); | |
210 | ||
211 | if (id < 0) | |
212 | continue; | |
213 | if ((id - oldid) & TRKID_SGN) { | |
214 | oldest = ps; | |
215 | oldid = id; | |
216 | } | |
217 | count++; | |
218 | } | |
219 | ||
220 | input_event(dev, EV_KEY, BTN_TOUCH, count > 0); | |
221 | ||
222 | if (use_count) { | |
223 | if (count == 0 && | |
224 | !test_bit(ABS_MT_DISTANCE, dev->absbit) && | |
225 | test_bit(ABS_DISTANCE, dev->absbit) && | |
226 | input_abs_get_val(dev, ABS_DISTANCE) != 0) { | |
227 | /* | |
228 | * Force reporting BTN_TOOL_FINGER for devices that | |
229 | * only report general hover (and not per-contact | |
230 | * distance) when contact is in proximity but not | |
231 | * on the surface. | |
232 | */ | |
233 | count = 1; | |
234 | } | |
235 | ||
236 | input_mt_report_finger_count(dev, count); | |
237 | } | |
238 | ||
239 | if (oldest) { | |
240 | int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); | |
241 | int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); | |
242 | ||
243 | input_event(dev, EV_ABS, ABS_X, x); | |
244 | input_event(dev, EV_ABS, ABS_Y, y); | |
245 | ||
246 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { | |
247 | int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); | |
248 | input_event(dev, EV_ABS, ABS_PRESSURE, p); | |
249 | } | |
250 | } else { | |
251 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) | |
252 | input_event(dev, EV_ABS, ABS_PRESSURE, 0); | |
253 | } | |
254 | } | |
255 | EXPORT_SYMBOL(input_mt_report_pointer_emulation); | |
256 | ||
257 | static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) | |
258 | { | |
259 | int i; | |
260 | ||
261 | for (i = 0; i < mt->num_slots; i++) { | |
262 | if (!input_mt_is_used(mt, &mt->slots[i])) { | |
263 | input_mt_slot(dev, i); | |
264 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); | |
265 | } | |
266 | } | |
267 | } | |
268 | ||
269 | /** | |
270 | * input_mt_drop_unused() - Inactivate slots not seen in this frame | |
271 | * @dev: input device with allocated MT slots | |
272 | * | |
273 | * Lift all slots not seen since the last call to this function. | |
274 | */ | |
275 | void input_mt_drop_unused(struct input_dev *dev) | |
276 | { | |
277 | struct input_mt *mt = dev->mt; | |
278 | ||
279 | if (mt) { | |
280 | __input_mt_drop_unused(dev, mt); | |
281 | mt->frame++; | |
282 | } | |
283 | } | |
284 | EXPORT_SYMBOL(input_mt_drop_unused); | |
285 | ||
286 | /** | |
287 | * input_mt_sync_frame() - synchronize mt frame | |
288 | * @dev: input device with allocated MT slots | |
289 | * | |
290 | * Close the frame and prepare the internal state for a new one. | |
291 | * Depending on the flags, marks unused slots as inactive and performs | |
292 | * pointer emulation. | |
293 | */ | |
294 | void input_mt_sync_frame(struct input_dev *dev) | |
295 | { | |
296 | struct input_mt *mt = dev->mt; | |
297 | bool use_count = false; | |
298 | ||
299 | if (!mt) | |
300 | return; | |
301 | ||
302 | if (mt->flags & INPUT_MT_DROP_UNUSED) | |
303 | __input_mt_drop_unused(dev, mt); | |
304 | ||
305 | if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT)) | |
306 | use_count = true; | |
307 | ||
308 | input_mt_report_pointer_emulation(dev, use_count); | |
309 | ||
310 | mt->frame++; | |
311 | } | |
312 | EXPORT_SYMBOL(input_mt_sync_frame); | |
313 | ||
314 | static int adjust_dual(int *begin, int step, int *end, int eq, int mu) | |
315 | { | |
316 | int f, *p, s, c; | |
317 | ||
318 | if (begin == end) | |
319 | return 0; | |
320 | ||
321 | f = *begin; | |
322 | p = begin + step; | |
323 | s = p == end ? f + 1 : *p; | |
324 | ||
325 | for (; p != end; p += step) | |
326 | if (*p < f) | |
327 | s = f, f = *p; | |
328 | else if (*p < s) | |
329 | s = *p; | |
330 | ||
331 | c = (f + s + 1) / 2; | |
332 | if (c == 0 || (c > mu && (!eq || mu > 0))) | |
333 | return 0; | |
334 | /* Improve convergence for positive matrices by penalizing overcovers */ | |
335 | if (s < 0 && mu <= 0) | |
336 | c *= 2; | |
337 | ||
338 | for (p = begin; p != end; p += step) | |
339 | *p -= c; | |
340 | ||
341 | return (c < s && s <= 0) || (f >= 0 && f < c); | |
342 | } | |
343 | ||
344 | static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) | |
345 | { | |
346 | int i, k, sum; | |
347 | ||
348 | for (k = 0; k < nrc; k++) { | |
349 | for (i = 0; i < nr; i++) | |
350 | adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu); | |
351 | sum = 0; | |
352 | for (i = 0; i < nrc; i += nr) | |
353 | sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu); | |
354 | if (!sum) | |
355 | break; | |
356 | } | |
357 | } | |
358 | ||
359 | static int input_mt_set_matrix(struct input_mt *mt, | |
360 | const struct input_mt_pos *pos, int num_pos, | |
361 | int mu) | |
362 | { | |
363 | const struct input_mt_pos *p; | |
364 | struct input_mt_slot *s; | |
365 | int *w = mt->red; | |
366 | int x, y; | |
367 | ||
368 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
369 | if (!input_mt_is_active(s)) | |
370 | continue; | |
371 | x = input_mt_get_value(s, ABS_MT_POSITION_X); | |
372 | y = input_mt_get_value(s, ABS_MT_POSITION_Y); | |
373 | for (p = pos; p != pos + num_pos; p++) { | |
374 | int dx = x - p->x, dy = y - p->y; | |
375 | *w++ = dx * dx + dy * dy - mu; | |
376 | } | |
377 | } | |
378 | ||
379 | return w - mt->red; | |
380 | } | |
381 | ||
382 | static void input_mt_set_slots(struct input_mt *mt, | |
383 | int *slots, int num_pos) | |
384 | { | |
385 | struct input_mt_slot *s; | |
386 | int *w = mt->red, j; | |
387 | ||
388 | for (j = 0; j != num_pos; j++) | |
389 | slots[j] = -1; | |
390 | ||
391 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
392 | if (!input_mt_is_active(s)) | |
393 | continue; | |
394 | ||
395 | for (j = 0; j != num_pos; j++) { | |
396 | if (w[j] < 0) { | |
397 | slots[j] = s - mt->slots; | |
398 | break; | |
399 | } | |
400 | } | |
401 | ||
402 | w += num_pos; | |
403 | } | |
404 | ||
405 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
406 | if (input_mt_is_active(s)) | |
407 | continue; | |
408 | ||
409 | for (j = 0; j != num_pos; j++) { | |
410 | if (slots[j] < 0) { | |
411 | slots[j] = s - mt->slots; | |
412 | break; | |
413 | } | |
414 | } | |
415 | } | |
416 | } | |
417 | ||
418 | /** | |
419 | * input_mt_assign_slots() - perform a best-match assignment | |
420 | * @dev: input device with allocated MT slots | |
421 | * @slots: the slot assignment to be filled | |
422 | * @pos: the position array to match | |
423 | * @num_pos: number of positions | |
424 | * @dmax: maximum ABS_MT_POSITION displacement (zero for infinite) | |
425 | * | |
426 | * Performs a best match against the current contacts and returns | |
427 | * the slot assignment list. New contacts are assigned to unused | |
428 | * slots. | |
429 | * | |
430 | * The assignments are balanced so that all coordinate displacements are | |
431 | * below the euclidian distance dmax. If no such assignment can be found, | |
432 | * some contacts are assigned to unused slots. | |
433 | * | |
434 | * Returns zero on success, or negative error in case of failure. | |
435 | */ | |
436 | int input_mt_assign_slots(struct input_dev *dev, int *slots, | |
437 | const struct input_mt_pos *pos, int num_pos, | |
438 | int dmax) | |
439 | { | |
440 | struct input_mt *mt = dev->mt; | |
441 | int mu = 2 * dmax * dmax; | |
442 | int nrc; | |
443 | ||
444 | if (!mt || !mt->red) | |
445 | return -ENXIO; | |
446 | if (num_pos > mt->num_slots) | |
447 | return -EINVAL; | |
448 | if (num_pos < 1) | |
449 | return 0; | |
450 | ||
451 | nrc = input_mt_set_matrix(mt, pos, num_pos, mu); | |
452 | find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu); | |
453 | input_mt_set_slots(mt, slots, num_pos); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | EXPORT_SYMBOL(input_mt_assign_slots); | |
458 | ||
459 | /** | |
460 | * input_mt_get_slot_by_key() - return slot matching key | |
461 | * @dev: input device with allocated MT slots | |
462 | * @key: the key of the sought slot | |
463 | * | |
464 | * Returns the slot of the given key, if it exists, otherwise | |
465 | * set the key on the first unused slot and return. | |
466 | * | |
467 | * If no available slot can be found, -1 is returned. | |
468 | * Note that for this function to work properly, input_mt_sync_frame() has | |
469 | * to be called at each frame. | |
470 | */ | |
471 | int input_mt_get_slot_by_key(struct input_dev *dev, int key) | |
472 | { | |
473 | struct input_mt *mt = dev->mt; | |
474 | struct input_mt_slot *s; | |
475 | ||
476 | if (!mt) | |
477 | return -1; | |
478 | ||
479 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
480 | if (input_mt_is_active(s) && s->key == key) | |
481 | return s - mt->slots; | |
482 | ||
483 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
484 | if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) { | |
485 | s->key = key; | |
486 | return s - mt->slots; | |
487 | } | |
488 | ||
489 | return -1; | |
490 | } | |
491 | EXPORT_SYMBOL(input_mt_get_slot_by_key); |