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47c78e89 HR |
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> | |
15d0580f | 12 | #include <linux/export.h> |
47c78e89 HR |
13 | #include <linux/slab.h> |
14 | ||
c5f4dec1 HR |
15 | #define TRKID_SGN ((TRKID_MAX + 1) >> 1) |
16 | ||
55e49089 HR |
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]; | |
352ce2b0 | 21 | dev->absinfo[dst].fuzz = 0; |
55e49089 HR |
22 | dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst); |
23 | } | |
24 | } | |
25 | ||
47c78e89 | 26 | /** |
8cde8100 | 27 | * input_mt_init_slots() - initialize MT input slots |
47c78e89 HR |
28 | * @dev: input device supporting MT events and finger tracking |
29 | * @num_slots: number of slots used by the device | |
40a81204 | 30 | * @flags: mt tasks to handle in core |
47c78e89 | 31 | * |
8cde8100 | 32 | * This function allocates all necessary memory for MT slot handling |
c5f4dec1 HR |
33 | * in the input device, prepares the ABS_MT_SLOT and |
34 | * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers. | |
40a81204 HR |
35 | * Depending on the flags set, it also performs pointer emulation and |
36 | * frame synchronization. | |
37 | * | |
c5f4dec1 HR |
38 | * May be called repeatedly. Returns -EINVAL if attempting to |
39 | * reinitialize with a different number of slots. | |
47c78e89 | 40 | */ |
b4adbbef HR |
41 | int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, |
42 | unsigned int flags) | |
47c78e89 | 43 | { |
8d18fba2 | 44 | struct input_mt *mt = dev->mt; |
47c78e89 HR |
45 | int i; |
46 | ||
47 | if (!num_slots) | |
48 | return 0; | |
8d18fba2 HR |
49 | if (mt) |
50 | return mt->num_slots != num_slots ? -EINVAL : 0; | |
47c78e89 | 51 | |
acafe7e3 | 52 | mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL); |
8d18fba2 | 53 | if (!mt) |
7c1a8789 | 54 | goto err_mem; |
47c78e89 | 55 | |
8d18fba2 | 56 | mt->num_slots = num_slots; |
b4adbbef | 57 | mt->flags = flags; |
47c78e89 | 58 | input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0); |
c5f4dec1 | 59 | input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0); |
47c78e89 | 60 | |
55e49089 HR |
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); | |
a0ef6a34 HR |
82 | if (flags & INPUT_MT_SEMI_MT) |
83 | __set_bit(INPUT_PROP_SEMI_MT, dev->propbit); | |
7c1a8789 HR |
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 | } | |
55e49089 | 90 | |
c6275892 | 91 | /* Mark slots as 'inactive' */ |
47c78e89 | 92 | for (i = 0; i < num_slots; i++) |
8d18fba2 | 93 | input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); |
47c78e89 | 94 | |
c6275892 BT |
95 | /* Mark slots as 'unused' */ |
96 | mt->frame = 1; | |
97 | ||
8d18fba2 | 98 | dev->mt = mt; |
47c78e89 | 99 | return 0; |
7c1a8789 HR |
100 | err_mem: |
101 | kfree(mt); | |
102 | return -ENOMEM; | |
47c78e89 | 103 | } |
8cde8100 | 104 | EXPORT_SYMBOL(input_mt_init_slots); |
47c78e89 HR |
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 | { | |
7c1a8789 HR |
115 | if (dev->mt) { |
116 | kfree(dev->mt->red); | |
117 | kfree(dev->mt); | |
118 | } | |
47c78e89 | 119 | dev->mt = NULL; |
47c78e89 HR |
120 | } |
121 | EXPORT_SYMBOL(input_mt_destroy_slots); | |
c5f4dec1 HR |
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. | |
bf6247a7 DT |
134 | * |
135 | * Returns true if contact is active. | |
c5f4dec1 | 136 | */ |
bf6247a7 | 137 | bool input_mt_report_slot_state(struct input_dev *dev, |
c5f4dec1 HR |
138 | unsigned int tool_type, bool active) |
139 | { | |
8d18fba2 HR |
140 | struct input_mt *mt = dev->mt; |
141 | struct input_mt_slot *slot; | |
c5f4dec1 HR |
142 | int id; |
143 | ||
55e49089 | 144 | if (!mt) |
bf6247a7 | 145 | return false; |
55e49089 HR |
146 | |
147 | slot = &mt->slots[mt->slot]; | |
148 | slot->frame = mt->frame; | |
149 | ||
150 | if (!active) { | |
c5f4dec1 | 151 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); |
bf6247a7 | 152 | return false; |
c5f4dec1 HR |
153 | } |
154 | ||
8d18fba2 | 155 | id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); |
c258e84b | 156 | if (id < 0) |
8d18fba2 | 157 | id = input_mt_new_trkid(mt); |
c5f4dec1 HR |
158 | |
159 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); | |
160 | input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); | |
bf6247a7 DT |
161 | |
162 | return true; | |
c5f4dec1 HR |
163 | } |
164 | EXPORT_SYMBOL(input_mt_report_slot_state); | |
165 | ||
166 | /** | |
167 | * input_mt_report_finger_count() - report contact count | |
168 | * @dev: input device with allocated MT slots | |
169 | * @count: the number of contacts | |
170 | * | |
171 | * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, | |
172 | * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. | |
173 | * | |
174 | * The input core ensures only the KEY events already setup for | |
175 | * this device will produce output. | |
176 | */ | |
177 | void input_mt_report_finger_count(struct input_dev *dev, int count) | |
178 | { | |
179 | input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); | |
180 | input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); | |
181 | input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); | |
182 | input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); | |
d5051272 | 183 | input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); |
c5f4dec1 HR |
184 | } |
185 | EXPORT_SYMBOL(input_mt_report_finger_count); | |
186 | ||
187 | /** | |
188 | * input_mt_report_pointer_emulation() - common pointer emulation | |
189 | * @dev: input device with allocated MT slots | |
190 | * @use_count: report number of active contacts as finger count | |
191 | * | |
192 | * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and | |
193 | * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. | |
194 | * | |
195 | * The input core ensures only the KEY and ABS axes already setup for | |
196 | * this device will produce output. | |
197 | */ | |
198 | void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) | |
199 | { | |
8d18fba2 HR |
200 | struct input_mt *mt = dev->mt; |
201 | struct input_mt_slot *oldest; | |
202 | int oldid, count, i; | |
203 | ||
204 | if (!mt) | |
205 | return; | |
206 | ||
5161870f | 207 | oldest = NULL; |
8d18fba2 HR |
208 | oldid = mt->trkid; |
209 | count = 0; | |
c5f4dec1 | 210 | |
8d18fba2 HR |
211 | for (i = 0; i < mt->num_slots; ++i) { |
212 | struct input_mt_slot *ps = &mt->slots[i]; | |
c5f4dec1 HR |
213 | int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); |
214 | ||
215 | if (id < 0) | |
216 | continue; | |
217 | if ((id - oldid) & TRKID_SGN) { | |
218 | oldest = ps; | |
219 | oldid = id; | |
220 | } | |
221 | count++; | |
222 | } | |
223 | ||
224 | input_event(dev, EV_KEY, BTN_TOUCH, count > 0); | |
0fd80a77 KL |
225 | |
226 | if (use_count) { | |
227 | if (count == 0 && | |
228 | !test_bit(ABS_MT_DISTANCE, dev->absbit) && | |
229 | test_bit(ABS_DISTANCE, dev->absbit) && | |
230 | input_abs_get_val(dev, ABS_DISTANCE) != 0) { | |
231 | /* | |
232 | * Force reporting BTN_TOOL_FINGER for devices that | |
233 | * only report general hover (and not per-contact | |
234 | * distance) when contact is in proximity but not | |
235 | * on the surface. | |
236 | */ | |
237 | count = 1; | |
238 | } | |
239 | ||
c5f4dec1 | 240 | input_mt_report_finger_count(dev, count); |
0fd80a77 | 241 | } |
c5f4dec1 HR |
242 | |
243 | if (oldest) { | |
244 | int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); | |
245 | int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); | |
c5f4dec1 HR |
246 | |
247 | input_event(dev, EV_ABS, ABS_X, x); | |
248 | input_event(dev, EV_ABS, ABS_Y, y); | |
22739293 HR |
249 | |
250 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { | |
251 | int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); | |
252 | input_event(dev, EV_ABS, ABS_PRESSURE, p); | |
253 | } | |
c5f4dec1 | 254 | } else { |
22739293 HR |
255 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) |
256 | input_event(dev, EV_ABS, ABS_PRESSURE, 0); | |
c5f4dec1 HR |
257 | } |
258 | } | |
259 | EXPORT_SYMBOL(input_mt_report_pointer_emulation); | |
55e49089 | 260 | |
8ff21f44 DT |
261 | static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) |
262 | { | |
263 | int i; | |
264 | ||
265 | for (i = 0; i < mt->num_slots; i++) { | |
266 | if (!input_mt_is_used(mt, &mt->slots[i])) { | |
267 | input_mt_slot(dev, i); | |
268 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); | |
269 | } | |
270 | } | |
271 | } | |
272 | ||
f8ec8949 HR |
273 | /** |
274 | * input_mt_drop_unused() - Inactivate slots not seen in this frame | |
275 | * @dev: input device with allocated MT slots | |
276 | * | |
277 | * Lift all slots not seen since the last call to this function. | |
278 | */ | |
279 | void input_mt_drop_unused(struct input_dev *dev) | |
280 | { | |
281 | struct input_mt *mt = dev->mt; | |
f8ec8949 | 282 | |
8ff21f44 DT |
283 | if (mt) { |
284 | __input_mt_drop_unused(dev, mt); | |
285 | mt->frame++; | |
f8ec8949 | 286 | } |
f8ec8949 HR |
287 | } |
288 | EXPORT_SYMBOL(input_mt_drop_unused); | |
289 | ||
55e49089 HR |
290 | /** |
291 | * input_mt_sync_frame() - synchronize mt frame | |
292 | * @dev: input device with allocated MT slots | |
293 | * | |
294 | * Close the frame and prepare the internal state for a new one. | |
295 | * Depending on the flags, marks unused slots as inactive and performs | |
296 | * pointer emulation. | |
297 | */ | |
298 | void input_mt_sync_frame(struct input_dev *dev) | |
299 | { | |
300 | struct input_mt *mt = dev->mt; | |
a0ef6a34 | 301 | bool use_count = false; |
55e49089 HR |
302 | |
303 | if (!mt) | |
304 | return; | |
305 | ||
f8ec8949 | 306 | if (mt->flags & INPUT_MT_DROP_UNUSED) |
8ff21f44 | 307 | __input_mt_drop_unused(dev, mt); |
55e49089 | 308 | |
a0ef6a34 HR |
309 | if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT)) |
310 | use_count = true; | |
311 | ||
312 | input_mt_report_pointer_emulation(dev, use_count); | |
8ff21f44 DT |
313 | |
314 | mt->frame++; | |
55e49089 HR |
315 | } |
316 | EXPORT_SYMBOL(input_mt_sync_frame); | |
7c1a8789 | 317 | |
448c7f38 | 318 | static int adjust_dual(int *begin, int step, int *end, int eq, int mu) |
7c1a8789 HR |
319 | { |
320 | int f, *p, s, c; | |
321 | ||
322 | if (begin == end) | |
323 | return 0; | |
324 | ||
325 | f = *begin; | |
326 | p = begin + step; | |
327 | s = p == end ? f + 1 : *p; | |
328 | ||
329 | for (; p != end; p += step) | |
330 | if (*p < f) | |
331 | s = f, f = *p; | |
332 | else if (*p < s) | |
333 | s = *p; | |
334 | ||
335 | c = (f + s + 1) / 2; | |
448c7f38 | 336 | if (c == 0 || (c > mu && (!eq || mu > 0))) |
7c1a8789 | 337 | return 0; |
448c7f38 HR |
338 | /* Improve convergence for positive matrices by penalizing overcovers */ |
339 | if (s < 0 && mu <= 0) | |
7c1a8789 HR |
340 | c *= 2; |
341 | ||
342 | for (p = begin; p != end; p += step) | |
343 | *p -= c; | |
344 | ||
345 | return (c < s && s <= 0) || (f >= 0 && f < c); | |
346 | } | |
347 | ||
448c7f38 | 348 | static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) |
7c1a8789 HR |
349 | { |
350 | int i, k, sum; | |
351 | ||
352 | for (k = 0; k < nrc; k++) { | |
353 | for (i = 0; i < nr; i++) | |
448c7f38 | 354 | adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu); |
7c1a8789 HR |
355 | sum = 0; |
356 | for (i = 0; i < nrc; i += nr) | |
448c7f38 | 357 | sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu); |
7c1a8789 HR |
358 | if (!sum) |
359 | break; | |
360 | } | |
361 | } | |
362 | ||
363 | static int input_mt_set_matrix(struct input_mt *mt, | |
448c7f38 HR |
364 | const struct input_mt_pos *pos, int num_pos, |
365 | int mu) | |
7c1a8789 HR |
366 | { |
367 | const struct input_mt_pos *p; | |
368 | struct input_mt_slot *s; | |
369 | int *w = mt->red; | |
370 | int x, y; | |
371 | ||
372 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
373 | if (!input_mt_is_active(s)) | |
374 | continue; | |
375 | x = input_mt_get_value(s, ABS_MT_POSITION_X); | |
376 | y = input_mt_get_value(s, ABS_MT_POSITION_Y); | |
377 | for (p = pos; p != pos + num_pos; p++) { | |
378 | int dx = x - p->x, dy = y - p->y; | |
448c7f38 | 379 | *w++ = dx * dx + dy * dy - mu; |
7c1a8789 HR |
380 | } |
381 | } | |
382 | ||
383 | return w - mt->red; | |
384 | } | |
385 | ||
386 | static void input_mt_set_slots(struct input_mt *mt, | |
387 | int *slots, int num_pos) | |
388 | { | |
389 | struct input_mt_slot *s; | |
73e8a8e7 | 390 | int *w = mt->red, j; |
7c1a8789 | 391 | |
73e8a8e7 BT |
392 | for (j = 0; j != num_pos; j++) |
393 | slots[j] = -1; | |
7c1a8789 HR |
394 | |
395 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
396 | if (!input_mt_is_active(s)) | |
397 | continue; | |
73e8a8e7 BT |
398 | |
399 | for (j = 0; j != num_pos; j++) { | |
400 | if (w[j] < 0) { | |
401 | slots[j] = s - mt->slots; | |
402 | break; | |
403 | } | |
404 | } | |
405 | ||
406 | w += num_pos; | |
7c1a8789 HR |
407 | } |
408 | ||
409 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
410 | if (input_mt_is_active(s)) | |
411 | continue; | |
73e8a8e7 BT |
412 | |
413 | for (j = 0; j != num_pos; j++) { | |
414 | if (slots[j] < 0) { | |
415 | slots[j] = s - mt->slots; | |
7c1a8789 HR |
416 | break; |
417 | } | |
73e8a8e7 | 418 | } |
7c1a8789 HR |
419 | } |
420 | } | |
421 | ||
422 | /** | |
423 | * input_mt_assign_slots() - perform a best-match assignment | |
424 | * @dev: input device with allocated MT slots | |
425 | * @slots: the slot assignment to be filled | |
426 | * @pos: the position array to match | |
427 | * @num_pos: number of positions | |
448c7f38 | 428 | * @dmax: maximum ABS_MT_POSITION displacement (zero for infinite) |
7c1a8789 HR |
429 | * |
430 | * Performs a best match against the current contacts and returns | |
431 | * the slot assignment list. New contacts are assigned to unused | |
432 | * slots. | |
433 | * | |
448c7f38 HR |
434 | * The assignments are balanced so that all coordinate displacements are |
435 | * below the euclidian distance dmax. If no such assignment can be found, | |
436 | * some contacts are assigned to unused slots. | |
437 | * | |
7c1a8789 HR |
438 | * Returns zero on success, or negative error in case of failure. |
439 | */ | |
440 | int input_mt_assign_slots(struct input_dev *dev, int *slots, | |
448c7f38 HR |
441 | const struct input_mt_pos *pos, int num_pos, |
442 | int dmax) | |
7c1a8789 HR |
443 | { |
444 | struct input_mt *mt = dev->mt; | |
448c7f38 | 445 | int mu = 2 * dmax * dmax; |
7c1a8789 HR |
446 | int nrc; |
447 | ||
448 | if (!mt || !mt->red) | |
449 | return -ENXIO; | |
450 | if (num_pos > mt->num_slots) | |
451 | return -EINVAL; | |
452 | if (num_pos < 1) | |
453 | return 0; | |
454 | ||
448c7f38 HR |
455 | nrc = input_mt_set_matrix(mt, pos, num_pos, mu); |
456 | find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu); | |
7c1a8789 HR |
457 | input_mt_set_slots(mt, slots, num_pos); |
458 | ||
459 | return 0; | |
460 | } | |
461 | EXPORT_SYMBOL(input_mt_assign_slots); | |
17a465a7 HR |
462 | |
463 | /** | |
464 | * input_mt_get_slot_by_key() - return slot matching key | |
465 | * @dev: input device with allocated MT slots | |
466 | * @key: the key of the sought slot | |
467 | * | |
468 | * Returns the slot of the given key, if it exists, otherwise | |
469 | * set the key on the first unused slot and return. | |
470 | * | |
471 | * If no available slot can be found, -1 is returned. | |
c6275892 BT |
472 | * Note that for this function to work properly, input_mt_sync_frame() has |
473 | * to be called at each frame. | |
17a465a7 HR |
474 | */ |
475 | int input_mt_get_slot_by_key(struct input_dev *dev, int key) | |
476 | { | |
477 | struct input_mt *mt = dev->mt; | |
478 | struct input_mt_slot *s; | |
479 | ||
480 | if (!mt) | |
481 | return -1; | |
482 | ||
483 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
484 | if (input_mt_is_active(s) && s->key == key) | |
485 | return s - mt->slots; | |
486 | ||
487 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
c6275892 | 488 | if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) { |
17a465a7 HR |
489 | s->key = key; |
490 | return s - mt->slots; | |
491 | } | |
492 | ||
493 | return -1; | |
494 | } | |
495 | EXPORT_SYMBOL(input_mt_get_slot_by_key); |