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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]; | |
21 | dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst); | |
22 | } | |
23 | } | |
24 | ||
47c78e89 | 25 | /** |
8cde8100 | 26 | * input_mt_init_slots() - initialize MT input slots |
47c78e89 HR |
27 | * @dev: input device supporting MT events and finger tracking |
28 | * @num_slots: number of slots used by the device | |
40a81204 | 29 | * @flags: mt tasks to handle in core |
47c78e89 | 30 | * |
8cde8100 | 31 | * This function allocates all necessary memory for MT slot handling |
c5f4dec1 HR |
32 | * in the input device, prepares the ABS_MT_SLOT and |
33 | * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers. | |
40a81204 HR |
34 | * Depending on the flags set, it also performs pointer emulation and |
35 | * frame synchronization. | |
36 | * | |
c5f4dec1 HR |
37 | * May be called repeatedly. Returns -EINVAL if attempting to |
38 | * reinitialize with a different number of slots. | |
47c78e89 | 39 | */ |
b4adbbef HR |
40 | int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, |
41 | unsigned int flags) | |
47c78e89 | 42 | { |
8d18fba2 | 43 | struct input_mt *mt = dev->mt; |
47c78e89 HR |
44 | int i; |
45 | ||
46 | if (!num_slots) | |
47 | return 0; | |
8d18fba2 HR |
48 | if (mt) |
49 | return mt->num_slots != num_slots ? -EINVAL : 0; | |
47c78e89 | 50 | |
8d18fba2 HR |
51 | mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL); |
52 | if (!mt) | |
7c1a8789 | 53 | goto err_mem; |
47c78e89 | 54 | |
8d18fba2 | 55 | mt->num_slots = num_slots; |
b4adbbef | 56 | mt->flags = flags; |
47c78e89 | 57 | input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0); |
c5f4dec1 | 58 | input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0); |
47c78e89 | 59 | |
55e49089 HR |
60 | if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) { |
61 | __set_bit(EV_KEY, dev->evbit); | |
62 | __set_bit(BTN_TOUCH, dev->keybit); | |
63 | ||
64 | copy_abs(dev, ABS_X, ABS_MT_POSITION_X); | |
65 | copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y); | |
66 | copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE); | |
67 | } | |
68 | if (flags & INPUT_MT_POINTER) { | |
69 | __set_bit(BTN_TOOL_FINGER, dev->keybit); | |
70 | __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit); | |
71 | if (num_slots >= 3) | |
72 | __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit); | |
73 | if (num_slots >= 4) | |
74 | __set_bit(BTN_TOOL_QUADTAP, dev->keybit); | |
75 | if (num_slots >= 5) | |
76 | __set_bit(BTN_TOOL_QUINTTAP, dev->keybit); | |
77 | __set_bit(INPUT_PROP_POINTER, dev->propbit); | |
78 | } | |
79 | if (flags & INPUT_MT_DIRECT) | |
80 | __set_bit(INPUT_PROP_DIRECT, dev->propbit); | |
7c1a8789 HR |
81 | if (flags & INPUT_MT_TRACK) { |
82 | unsigned int n2 = num_slots * num_slots; | |
83 | mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); | |
84 | if (!mt->red) | |
85 | goto err_mem; | |
86 | } | |
55e49089 | 87 | |
47c78e89 HR |
88 | /* Mark slots as 'unused' */ |
89 | for (i = 0; i < num_slots; i++) | |
8d18fba2 | 90 | input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); |
47c78e89 | 91 | |
8d18fba2 | 92 | dev->mt = mt; |
47c78e89 | 93 | return 0; |
7c1a8789 HR |
94 | err_mem: |
95 | kfree(mt); | |
96 | return -ENOMEM; | |
47c78e89 | 97 | } |
8cde8100 | 98 | EXPORT_SYMBOL(input_mt_init_slots); |
47c78e89 HR |
99 | |
100 | /** | |
101 | * input_mt_destroy_slots() - frees the MT slots of the input device | |
102 | * @dev: input device with allocated MT slots | |
103 | * | |
104 | * This function is only needed in error path as the input core will | |
105 | * automatically free the MT slots when the device is destroyed. | |
106 | */ | |
107 | void input_mt_destroy_slots(struct input_dev *dev) | |
108 | { | |
7c1a8789 HR |
109 | if (dev->mt) { |
110 | kfree(dev->mt->red); | |
111 | kfree(dev->mt); | |
112 | } | |
47c78e89 | 113 | dev->mt = NULL; |
47c78e89 HR |
114 | } |
115 | EXPORT_SYMBOL(input_mt_destroy_slots); | |
c5f4dec1 HR |
116 | |
117 | /** | |
118 | * input_mt_report_slot_state() - report contact state | |
119 | * @dev: input device with allocated MT slots | |
120 | * @tool_type: the tool type to use in this slot | |
121 | * @active: true if contact is active, false otherwise | |
122 | * | |
123 | * Reports a contact via ABS_MT_TRACKING_ID, and optionally | |
124 | * ABS_MT_TOOL_TYPE. If active is true and the slot is currently | |
125 | * inactive, or if the tool type is changed, a new tracking id is | |
126 | * assigned to the slot. The tool type is only reported if the | |
127 | * corresponding absbit field is set. | |
128 | */ | |
129 | void input_mt_report_slot_state(struct input_dev *dev, | |
130 | unsigned int tool_type, bool active) | |
131 | { | |
8d18fba2 HR |
132 | struct input_mt *mt = dev->mt; |
133 | struct input_mt_slot *slot; | |
c5f4dec1 HR |
134 | int id; |
135 | ||
55e49089 HR |
136 | if (!mt) |
137 | return; | |
138 | ||
139 | slot = &mt->slots[mt->slot]; | |
140 | slot->frame = mt->frame; | |
141 | ||
142 | if (!active) { | |
c5f4dec1 HR |
143 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); |
144 | return; | |
145 | } | |
146 | ||
8d18fba2 HR |
147 | id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); |
148 | if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type) | |
149 | id = input_mt_new_trkid(mt); | |
c5f4dec1 HR |
150 | |
151 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id); | |
152 | input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type); | |
153 | } | |
154 | EXPORT_SYMBOL(input_mt_report_slot_state); | |
155 | ||
156 | /** | |
157 | * input_mt_report_finger_count() - report contact count | |
158 | * @dev: input device with allocated MT slots | |
159 | * @count: the number of contacts | |
160 | * | |
161 | * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, | |
162 | * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. | |
163 | * | |
164 | * The input core ensures only the KEY events already setup for | |
165 | * this device will produce output. | |
166 | */ | |
167 | void input_mt_report_finger_count(struct input_dev *dev, int count) | |
168 | { | |
169 | input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1); | |
170 | input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2); | |
171 | input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3); | |
172 | input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4); | |
d5051272 | 173 | input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); |
c5f4dec1 HR |
174 | } |
175 | EXPORT_SYMBOL(input_mt_report_finger_count); | |
176 | ||
177 | /** | |
178 | * input_mt_report_pointer_emulation() - common pointer emulation | |
179 | * @dev: input device with allocated MT slots | |
180 | * @use_count: report number of active contacts as finger count | |
181 | * | |
182 | * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and | |
183 | * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. | |
184 | * | |
185 | * The input core ensures only the KEY and ABS axes already setup for | |
186 | * this device will produce output. | |
187 | */ | |
188 | void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) | |
189 | { | |
8d18fba2 HR |
190 | struct input_mt *mt = dev->mt; |
191 | struct input_mt_slot *oldest; | |
192 | int oldid, count, i; | |
193 | ||
194 | if (!mt) | |
195 | return; | |
196 | ||
5161870f | 197 | oldest = NULL; |
8d18fba2 HR |
198 | oldid = mt->trkid; |
199 | count = 0; | |
c5f4dec1 | 200 | |
8d18fba2 HR |
201 | for (i = 0; i < mt->num_slots; ++i) { |
202 | struct input_mt_slot *ps = &mt->slots[i]; | |
c5f4dec1 HR |
203 | int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); |
204 | ||
205 | if (id < 0) | |
206 | continue; | |
207 | if ((id - oldid) & TRKID_SGN) { | |
208 | oldest = ps; | |
209 | oldid = id; | |
210 | } | |
211 | count++; | |
212 | } | |
213 | ||
214 | input_event(dev, EV_KEY, BTN_TOUCH, count > 0); | |
215 | if (use_count) | |
216 | input_mt_report_finger_count(dev, count); | |
217 | ||
218 | if (oldest) { | |
219 | int x = input_mt_get_value(oldest, ABS_MT_POSITION_X); | |
220 | int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y); | |
c5f4dec1 HR |
221 | |
222 | input_event(dev, EV_ABS, ABS_X, x); | |
223 | input_event(dev, EV_ABS, ABS_Y, y); | |
22739293 HR |
224 | |
225 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { | |
226 | int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); | |
227 | input_event(dev, EV_ABS, ABS_PRESSURE, p); | |
228 | } | |
c5f4dec1 | 229 | } else { |
22739293 HR |
230 | if (test_bit(ABS_MT_PRESSURE, dev->absbit)) |
231 | input_event(dev, EV_ABS, ABS_PRESSURE, 0); | |
c5f4dec1 HR |
232 | } |
233 | } | |
234 | EXPORT_SYMBOL(input_mt_report_pointer_emulation); | |
55e49089 HR |
235 | |
236 | /** | |
237 | * input_mt_sync_frame() - synchronize mt frame | |
238 | * @dev: input device with allocated MT slots | |
239 | * | |
240 | * Close the frame and prepare the internal state for a new one. | |
241 | * Depending on the flags, marks unused slots as inactive and performs | |
242 | * pointer emulation. | |
243 | */ | |
244 | void input_mt_sync_frame(struct input_dev *dev) | |
245 | { | |
246 | struct input_mt *mt = dev->mt; | |
247 | struct input_mt_slot *s; | |
248 | ||
249 | if (!mt) | |
250 | return; | |
251 | ||
252 | if (mt->flags & INPUT_MT_DROP_UNUSED) { | |
253 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
254 | if (s->frame == mt->frame) | |
255 | continue; | |
256 | input_mt_slot(dev, s - mt->slots); | |
257 | input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); | |
258 | } | |
259 | } | |
260 | ||
261 | input_mt_report_pointer_emulation(dev, (mt->flags & INPUT_MT_POINTER)); | |
262 | ||
263 | mt->frame++; | |
264 | } | |
265 | EXPORT_SYMBOL(input_mt_sync_frame); | |
7c1a8789 HR |
266 | |
267 | static int adjust_dual(int *begin, int step, int *end, int eq) | |
268 | { | |
269 | int f, *p, s, c; | |
270 | ||
271 | if (begin == end) | |
272 | return 0; | |
273 | ||
274 | f = *begin; | |
275 | p = begin + step; | |
276 | s = p == end ? f + 1 : *p; | |
277 | ||
278 | for (; p != end; p += step) | |
279 | if (*p < f) | |
280 | s = f, f = *p; | |
281 | else if (*p < s) | |
282 | s = *p; | |
283 | ||
284 | c = (f + s + 1) / 2; | |
285 | if (c == 0 || (c > 0 && !eq)) | |
286 | return 0; | |
287 | if (s < 0) | |
288 | c *= 2; | |
289 | ||
290 | for (p = begin; p != end; p += step) | |
291 | *p -= c; | |
292 | ||
293 | return (c < s && s <= 0) || (f >= 0 && f < c); | |
294 | } | |
295 | ||
296 | static void find_reduced_matrix(int *w, int nr, int nc, int nrc) | |
297 | { | |
298 | int i, k, sum; | |
299 | ||
300 | for (k = 0; k < nrc; k++) { | |
301 | for (i = 0; i < nr; i++) | |
302 | adjust_dual(w + i, nr, w + i + nrc, nr <= nc); | |
303 | sum = 0; | |
304 | for (i = 0; i < nrc; i += nr) | |
305 | sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr); | |
306 | if (!sum) | |
307 | break; | |
308 | } | |
309 | } | |
310 | ||
311 | static int input_mt_set_matrix(struct input_mt *mt, | |
312 | const struct input_mt_pos *pos, int num_pos) | |
313 | { | |
314 | const struct input_mt_pos *p; | |
315 | struct input_mt_slot *s; | |
316 | int *w = mt->red; | |
317 | int x, y; | |
318 | ||
319 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
320 | if (!input_mt_is_active(s)) | |
321 | continue; | |
322 | x = input_mt_get_value(s, ABS_MT_POSITION_X); | |
323 | y = input_mt_get_value(s, ABS_MT_POSITION_Y); | |
324 | for (p = pos; p != pos + num_pos; p++) { | |
325 | int dx = x - p->x, dy = y - p->y; | |
326 | *w++ = dx * dx + dy * dy; | |
327 | } | |
328 | } | |
329 | ||
330 | return w - mt->red; | |
331 | } | |
332 | ||
333 | static void input_mt_set_slots(struct input_mt *mt, | |
334 | int *slots, int num_pos) | |
335 | { | |
336 | struct input_mt_slot *s; | |
337 | int *w = mt->red, *p; | |
338 | ||
339 | for (p = slots; p != slots + num_pos; p++) | |
340 | *p = -1; | |
341 | ||
342 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
343 | if (!input_mt_is_active(s)) | |
344 | continue; | |
345 | for (p = slots; p != slots + num_pos; p++) | |
346 | if (*w++ < 0) | |
347 | *p = s - mt->slots; | |
348 | } | |
349 | ||
350 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { | |
351 | if (input_mt_is_active(s)) | |
352 | continue; | |
353 | for (p = slots; p != slots + num_pos; p++) | |
354 | if (*p < 0) { | |
355 | *p = s - mt->slots; | |
356 | break; | |
357 | } | |
358 | } | |
359 | } | |
360 | ||
361 | /** | |
362 | * input_mt_assign_slots() - perform a best-match assignment | |
363 | * @dev: input device with allocated MT slots | |
364 | * @slots: the slot assignment to be filled | |
365 | * @pos: the position array to match | |
366 | * @num_pos: number of positions | |
367 | * | |
368 | * Performs a best match against the current contacts and returns | |
369 | * the slot assignment list. New contacts are assigned to unused | |
370 | * slots. | |
371 | * | |
372 | * Returns zero on success, or negative error in case of failure. | |
373 | */ | |
374 | int input_mt_assign_slots(struct input_dev *dev, int *slots, | |
375 | const struct input_mt_pos *pos, int num_pos) | |
376 | { | |
377 | struct input_mt *mt = dev->mt; | |
378 | int nrc; | |
379 | ||
380 | if (!mt || !mt->red) | |
381 | return -ENXIO; | |
382 | if (num_pos > mt->num_slots) | |
383 | return -EINVAL; | |
384 | if (num_pos < 1) | |
385 | return 0; | |
386 | ||
387 | nrc = input_mt_set_matrix(mt, pos, num_pos); | |
388 | find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc); | |
389 | input_mt_set_slots(mt, slots, num_pos); | |
390 | ||
391 | return 0; | |
392 | } | |
393 | EXPORT_SYMBOL(input_mt_assign_slots); | |
17a465a7 HR |
394 | |
395 | /** | |
396 | * input_mt_get_slot_by_key() - return slot matching key | |
397 | * @dev: input device with allocated MT slots | |
398 | * @key: the key of the sought slot | |
399 | * | |
400 | * Returns the slot of the given key, if it exists, otherwise | |
401 | * set the key on the first unused slot and return. | |
402 | * | |
403 | * If no available slot can be found, -1 is returned. | |
404 | */ | |
405 | int input_mt_get_slot_by_key(struct input_dev *dev, int key) | |
406 | { | |
407 | struct input_mt *mt = dev->mt; | |
408 | struct input_mt_slot *s; | |
409 | ||
410 | if (!mt) | |
411 | return -1; | |
412 | ||
413 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
414 | if (input_mt_is_active(s) && s->key == key) | |
415 | return s - mt->slots; | |
416 | ||
417 | for (s = mt->slots; s != mt->slots + mt->num_slots; s++) | |
418 | if (!input_mt_is_active(s)) { | |
419 | s->key = key; | |
420 | return s - mt->slots; | |
421 | } | |
422 | ||
423 | return -1; | |
424 | } | |
425 | EXPORT_SYMBOL(input_mt_get_slot_by_key); |