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(struct_size(mt, slots, num_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 | * Returns true if contact is active. |
136 | */ |
137 | bool input_mt_report_slot_state(struct input_dev *dev, |
138 | unsigned int tool_type, bool active) |
139 | { |
140 | struct input_mt *mt = dev->mt; |
141 | struct input_mt_slot *slot; |
142 | int id; |
143 | |
144 | if (!mt) |
145 | return false; |
146 | |
147 | slot = &mt->slots[mt->slot]; |
148 | slot->frame = mt->frame; |
149 | |
150 | if (!active) { |
151 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); |
152 | return false; |
153 | } |
154 | |
155 | id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); |
156 | if (id < 0) |
157 | id = input_mt_new_trkid(mt); |
158 | |
159 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); |
160 | input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); |
161 | |
162 | return true; |
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); |
183 | input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); |
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 | { |
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 | |
207 | oldest = NULL; |
208 | oldid = mt->trkid; |
209 | count = 0; |
210 | |
211 | for (i = 0; i < mt->num_slots; ++i) { |
212 | struct input_mt_slot *ps = &mt->slots[i]; |
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); |
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 | |
240 | input_mt_report_finger_count(dev, count); |
241 | } |
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); |
246 | |
247 | input_event(dev, EV_ABS, ABS_X, x); |
248 | input_event(dev, EV_ABS, ABS_Y, y); |
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 | } |
254 | } else { |
255 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) |
256 | input_event(dev, EV_ABS, ABS_PRESSURE, 0); |
257 | } |
258 | } |
259 | EXPORT_SYMBOL(input_mt_report_pointer_emulation); |
260 | |
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 | |
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; |
282 | |
283 | if (mt) { |
284 | __input_mt_drop_unused(dev, mt); |
285 | mt->frame++; |
286 | } |
287 | } |
288 | EXPORT_SYMBOL(input_mt_drop_unused); |
289 | |
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; |
301 | bool use_count = false; |
302 | |
303 | if (!mt) |
304 | return; |
305 | |
306 | if (mt->flags & INPUT_MT_DROP_UNUSED) |
307 | __input_mt_drop_unused(dev, mt); |
308 | |
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); |
313 | |
314 | mt->frame++; |
315 | } |
316 | EXPORT_SYMBOL(input_mt_sync_frame); |
317 | |
318 | static int adjust_dual(int *begin, int step, int *end, int eq, int mu) |
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; |
336 | if (c == 0 || (c > mu && (!eq || mu > 0))) |
337 | return 0; |
338 | /* Improve convergence for positive matrices by penalizing overcovers */ |
339 | if (s < 0 && mu <= 0) |
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 | |
348 | static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) |
349 | { |
350 | int i, k, sum; |
351 | |
352 | for (k = 0; k < nrc; k++) { |
353 | for (i = 0; i < nr; i++) |
354 | adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu); |
355 | sum = 0; |
356 | for (i = 0; i < nrc; i += nr) |
357 | sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu); |
358 | if (!sum) |
359 | break; |
360 | } |
361 | } |
362 | |
363 | static int input_mt_set_matrix(struct input_mt *mt, |
364 | const struct input_mt_pos *pos, int num_pos, |
365 | int mu) |
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; |
379 | *w++ = dx * dx + dy * dy - mu; |
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; |
390 | int *w = mt->red, j; |
391 | |
392 | for (j = 0; j != num_pos; j++) |
393 | slots[j] = -1; |
394 | |
395 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { |
396 | if (!input_mt_is_active(s)) |
397 | continue; |
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; |
407 | } |
408 | |
409 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { |
410 | if (input_mt_is_active(s)) |
411 | continue; |
412 | |
413 | for (j = 0; j != num_pos; j++) { |
414 | if (slots[j] < 0) { |
415 | slots[j] = s - mt->slots; |
416 | break; |
417 | } |
418 | } |
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 |
428 | * @dmax: maximum ABS_MT_POSITION displacement (zero for infinite) |
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 | * |
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 | * |
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, |
441 | const struct input_mt_pos *pos, int num_pos, |
442 | int dmax) |
443 | { |
444 | struct input_mt *mt = dev->mt; |
445 | int mu = 2 * dmax * dmax; |
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 | |
455 | nrc = input_mt_set_matrix(mt, pos, num_pos, mu); |
456 | find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu); |
457 | input_mt_set_slots(mt, slots, num_pos); |
458 | |
459 | return 0; |
460 | } |
461 | EXPORT_SYMBOL(input_mt_assign_slots); |
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. |
472 | * Note that for this function to work properly, input_mt_sync_frame() has |
473 | * to be called at each frame. |
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++) |
488 | if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) { |
489 | s->key = key; |
490 | return s - mt->slots; |
491 | } |
492 | |
493 | return -1; |
494 | } |
495 | EXPORT_SYMBOL(input_mt_get_slot_by_key); |
496 | |