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Henrik Rydberg47c78e82010-11-27 09:16:48 +01001/*
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>
Paul Gortmaker15d05802011-10-25 14:51:47 -040012#include <linux/export.h>
Henrik Rydberg47c78e82010-11-27 09:16:48 +010013#include <linux/slab.h>
14
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010015#define TRKID_SGN ((TRKID_MAX + 1) >> 1)
16
Henrik Rydberg55e49082012-08-22 20:43:22 +020017static 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];
Henrik Rydberg352ce2b2013-02-15 17:03:57 -080021 dev->absinfo[dst].fuzz = 0;
Henrik Rydberg55e49082012-08-22 20:43:22 +020022 dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst);
23 }
24}
25
Henrik Rydberg47c78e82010-11-27 09:16:48 +010026/**
Henrik Rydberg8cde8102010-11-27 10:50:54 +010027 * input_mt_init_slots() - initialize MT input slots
Henrik Rydberg47c78e82010-11-27 09:16:48 +010028 * @dev: input device supporting MT events and finger tracking
29 * @num_slots: number of slots used by the device
Henrik Rydberg40a81202012-11-08 09:03:47 -080030 * @flags: mt tasks to handle in core
Henrik Rydberg47c78e82010-11-27 09:16:48 +010031 *
Henrik Rydberg8cde8102010-11-27 10:50:54 +010032 * This function allocates all necessary memory for MT slot handling
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010033 * in the input device, prepares the ABS_MT_SLOT and
34 * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
Henrik Rydberg40a81202012-11-08 09:03:47 -080035 * Depending on the flags set, it also performs pointer emulation and
36 * frame synchronization.
37 *
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010038 * May be called repeatedly. Returns -EINVAL if attempting to
39 * reinitialize with a different number of slots.
Henrik Rydberg47c78e82010-11-27 09:16:48 +010040 */
Henrik Rydbergb4adbbe2012-08-11 22:07:55 +020041int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
42 unsigned int flags)
Henrik Rydberg47c78e82010-11-27 09:16:48 +010043{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020044 struct input_mt *mt = dev->mt;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010045 int i;
46
47 if (!num_slots)
48 return 0;
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020049 if (mt)
50 return mt->num_slots != num_slots ? -EINVAL : 0;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010051
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020052 mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL);
53 if (!mt)
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020054 goto err_mem;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010055
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020056 mt->num_slots = num_slots;
Henrik Rydbergb4adbbe2012-08-11 22:07:55 +020057 mt->flags = flags;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010058 input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010059 input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
Henrik Rydberg47c78e82010-11-27 09:16:48 +010060
Henrik Rydberg55e49082012-08-22 20:43:22 +020061 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);
Henrik Rydberga0ef6a32013-04-07 20:52:22 -070082 if (flags & INPUT_MT_SEMI_MT)
83 __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020084 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 }
Henrik Rydberg55e49082012-08-22 20:43:22 +020090
Henrik Rydberg47c78e82010-11-27 09:16:48 +010091 /* Mark slots as 'unused' */
92 for (i = 0; i < num_slots; i++)
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020093 input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
Henrik Rydberg47c78e82010-11-27 09:16:48 +010094
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020095 dev->mt = mt;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010096 return 0;
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020097err_mem:
98 kfree(mt);
99 return -ENOMEM;
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100100}
Henrik Rydberg8cde8102010-11-27 10:50:54 +0100101EXPORT_SYMBOL(input_mt_init_slots);
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100102
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{
Henrik Rydberg7c1a8782012-08-12 20:47:05 +0200112 if (dev->mt) {
113 kfree(dev->mt->red);
114 kfree(dev->mt);
115 }
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100116 dev->mt = NULL;
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100117}
118EXPORT_SYMBOL(input_mt_destroy_slots);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100119
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{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200135 struct input_mt *mt = dev->mt;
136 struct input_mt_slot *slot;
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100137 int id;
138
Henrik Rydberg55e49082012-08-22 20:43:22 +0200139 if (!mt)
140 return;
141
142 slot = &mt->slots[mt->slot];
143 slot->frame = mt->frame;
144
145 if (!active) {
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100146 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
147 return;
148 }
149
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200150 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);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100153
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);
Daniel Kurtzd5051272011-08-23 23:02:48 -0700176 input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100177}
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{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200193 struct input_mt *mt = dev->mt;
194 struct input_mt_slot *oldest;
195 int oldid, count, i;
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100196
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200197 if (!mt)
198 return;
199
Dmitry Torokhov51618702012-10-24 23:53:01 -0700200 oldest = NULL;
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200201 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];
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100206 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);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100224
225 input_event(dev, EV_ABS, ABS_X, x);
226 input_event(dev, EV_ABS, ABS_Y, y);
Henrik Rydberg22739292012-09-15 08:57:18 +0200227
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 }
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100232 } else {
Henrik Rydberg22739292012-09-15 08:57:18 +0200233 if (test_bit(ABS_MT_PRESSURE, dev->absbit))
234 input_event(dev, EV_ABS, ABS_PRESSURE, 0);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100235 }
236}
237EXPORT_SYMBOL(input_mt_report_pointer_emulation);
Henrik Rydberg55e49082012-08-22 20:43:22 +0200238
239/**
Henrik Rydbergf8ec8942014-07-25 17:16:42 -0700240 * input_mt_drop_unused() - Inactivate slots not seen in this frame
241 * @dev: input device with allocated MT slots
242 *
243 * Lift all slots not seen since the last call to this function.
244 */
245void input_mt_drop_unused(struct input_dev *dev)
246{
247 struct input_mt *mt = dev->mt;
248 int i;
249
250 if (!mt)
251 return;
252
253 for (i = 0; i < mt->num_slots; i++) {
254 if (!input_mt_is_used(mt, &mt->slots[i])) {
255 input_mt_slot(dev, i);
256 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
257 }
258 }
259
260 mt->frame++;
261}
262EXPORT_SYMBOL(input_mt_drop_unused);
263
264/**
Henrik Rydberg55e49082012-08-22 20:43:22 +0200265 * input_mt_sync_frame() - synchronize mt frame
266 * @dev: input device with allocated MT slots
267 *
268 * Close the frame and prepare the internal state for a new one.
269 * Depending on the flags, marks unused slots as inactive and performs
270 * pointer emulation.
271 */
272void input_mt_sync_frame(struct input_dev *dev)
273{
274 struct input_mt *mt = dev->mt;
Henrik Rydberga0ef6a32013-04-07 20:52:22 -0700275 bool use_count = false;
Henrik Rydberg55e49082012-08-22 20:43:22 +0200276
277 if (!mt)
278 return;
279
Henrik Rydbergf8ec8942014-07-25 17:16:42 -0700280 if (mt->flags & INPUT_MT_DROP_UNUSED)
281 input_mt_drop_unused(dev);
Henrik Rydberg55e49082012-08-22 20:43:22 +0200282
Henrik Rydberga0ef6a32013-04-07 20:52:22 -0700283 if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT))
284 use_count = true;
285
286 input_mt_report_pointer_emulation(dev, use_count);
Henrik Rydberg55e49082012-08-22 20:43:22 +0200287}
288EXPORT_SYMBOL(input_mt_sync_frame);
Henrik Rydberg7c1a8782012-08-12 20:47:05 +0200289
290static int adjust_dual(int *begin, int step, int *end, int eq)
291{
292 int f, *p, s, c;
293
294 if (begin == end)
295 return 0;
296
297 f = *begin;
298 p = begin + step;
299 s = p == end ? f + 1 : *p;
300
301 for (; p != end; p += step)
302 if (*p < f)
303 s = f, f = *p;
304 else if (*p < s)
305 s = *p;
306
307 c = (f + s + 1) / 2;
308 if (c == 0 || (c > 0 && !eq))
309 return 0;
310 if (s < 0)
311 c *= 2;
312
313 for (p = begin; p != end; p += step)
314 *p -= c;
315
316 return (c < s && s <= 0) || (f >= 0 && f < c);
317}
318
319static void find_reduced_matrix(int *w, int nr, int nc, int nrc)
320{
321 int i, k, sum;
322
323 for (k = 0; k < nrc; k++) {
324 for (i = 0; i < nr; i++)
325 adjust_dual(w + i, nr, w + i + nrc, nr <= nc);
326 sum = 0;
327 for (i = 0; i < nrc; i += nr)
328 sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr);
329 if (!sum)
330 break;
331 }
332}
333
334static int input_mt_set_matrix(struct input_mt *mt,
335 const struct input_mt_pos *pos, int num_pos)
336{
337 const struct input_mt_pos *p;
338 struct input_mt_slot *s;
339 int *w = mt->red;
340 int x, y;
341
342 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
343 if (!input_mt_is_active(s))
344 continue;
345 x = input_mt_get_value(s, ABS_MT_POSITION_X);
346 y = input_mt_get_value(s, ABS_MT_POSITION_Y);
347 for (p = pos; p != pos + num_pos; p++) {
348 int dx = x - p->x, dy = y - p->y;
349 *w++ = dx * dx + dy * dy;
350 }
351 }
352
353 return w - mt->red;
354}
355
356static void input_mt_set_slots(struct input_mt *mt,
357 int *slots, int num_pos)
358{
359 struct input_mt_slot *s;
360 int *w = mt->red, *p;
361
362 for (p = slots; p != slots + num_pos; p++)
363 *p = -1;
364
365 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
366 if (!input_mt_is_active(s))
367 continue;
368 for (p = slots; p != slots + num_pos; p++)
369 if (*w++ < 0)
370 *p = s - mt->slots;
371 }
372
373 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
374 if (input_mt_is_active(s))
375 continue;
376 for (p = slots; p != slots + num_pos; p++)
377 if (*p < 0) {
378 *p = s - mt->slots;
379 break;
380 }
381 }
382}
383
384/**
385 * input_mt_assign_slots() - perform a best-match assignment
386 * @dev: input device with allocated MT slots
387 * @slots: the slot assignment to be filled
388 * @pos: the position array to match
389 * @num_pos: number of positions
390 *
391 * Performs a best match against the current contacts and returns
392 * the slot assignment list. New contacts are assigned to unused
393 * slots.
394 *
395 * Returns zero on success, or negative error in case of failure.
396 */
397int input_mt_assign_slots(struct input_dev *dev, int *slots,
398 const struct input_mt_pos *pos, int num_pos)
399{
400 struct input_mt *mt = dev->mt;
401 int nrc;
402
403 if (!mt || !mt->red)
404 return -ENXIO;
405 if (num_pos > mt->num_slots)
406 return -EINVAL;
407 if (num_pos < 1)
408 return 0;
409
410 nrc = input_mt_set_matrix(mt, pos, num_pos);
411 find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc);
412 input_mt_set_slots(mt, slots, num_pos);
413
414 return 0;
415}
416EXPORT_SYMBOL(input_mt_assign_slots);
Henrik Rydberg17a465a2012-09-01 09:27:20 +0200417
418/**
419 * input_mt_get_slot_by_key() - return slot matching key
420 * @dev: input device with allocated MT slots
421 * @key: the key of the sought slot
422 *
423 * Returns the slot of the given key, if it exists, otherwise
424 * set the key on the first unused slot and return.
425 *
426 * If no available slot can be found, -1 is returned.
427 */
428int input_mt_get_slot_by_key(struct input_dev *dev, int key)
429{
430 struct input_mt *mt = dev->mt;
431 struct input_mt_slot *s;
432
433 if (!mt)
434 return -1;
435
436 for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
437 if (input_mt_is_active(s) && s->key == key)
438 return s - mt->slots;
439
440 for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
441 if (!input_mt_is_active(s)) {
442 s->key = key;
443 return s - mt->slots;
444 }
445
446 return -1;
447}
448EXPORT_SYMBOL(input_mt_get_slot_by_key);