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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];
21 dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst);
22 }
23}
24
Henrik Rydberg47c78e82010-11-27 09:16:48 +010025/**
Henrik Rydberg8cde8102010-11-27 10:50:54 +010026 * input_mt_init_slots() - initialize MT input slots
Henrik Rydberg47c78e82010-11-27 09:16:48 +010027 * @dev: input device supporting MT events and finger tracking
28 * @num_slots: number of slots used by the device
29 *
Henrik Rydberg8cde8102010-11-27 10:50:54 +010030 * This function allocates all necessary memory for MT slot handling
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010031 * in the input device, prepares the ABS_MT_SLOT and
32 * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
33 * May be called repeatedly. Returns -EINVAL if attempting to
34 * reinitialize with a different number of slots.
Henrik Rydberg47c78e82010-11-27 09:16:48 +010035 */
Henrik Rydbergb4adbbe2012-08-11 22:07:55 +020036int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
37 unsigned int flags)
Henrik Rydberg47c78e82010-11-27 09:16:48 +010038{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020039 struct input_mt *mt = dev->mt;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010040 int i;
41
42 if (!num_slots)
43 return 0;
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020044 if (mt)
45 return mt->num_slots != num_slots ? -EINVAL : 0;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010046
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020047 mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL);
48 if (!mt)
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020049 goto err_mem;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010050
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020051 mt->num_slots = num_slots;
Henrik Rydbergb4adbbe2012-08-11 22:07:55 +020052 mt->flags = flags;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010053 input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +010054 input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
Henrik Rydberg47c78e82010-11-27 09:16:48 +010055
Henrik Rydberg55e49082012-08-22 20:43:22 +020056 if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) {
57 __set_bit(EV_KEY, dev->evbit);
58 __set_bit(BTN_TOUCH, dev->keybit);
59
60 copy_abs(dev, ABS_X, ABS_MT_POSITION_X);
61 copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y);
62 copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE);
63 }
64 if (flags & INPUT_MT_POINTER) {
65 __set_bit(BTN_TOOL_FINGER, dev->keybit);
66 __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
67 if (num_slots >= 3)
68 __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
69 if (num_slots >= 4)
70 __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
71 if (num_slots >= 5)
72 __set_bit(BTN_TOOL_QUINTTAP, dev->keybit);
73 __set_bit(INPUT_PROP_POINTER, dev->propbit);
74 }
75 if (flags & INPUT_MT_DIRECT)
76 __set_bit(INPUT_PROP_DIRECT, dev->propbit);
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020077 if (flags & INPUT_MT_TRACK) {
78 unsigned int n2 = num_slots * num_slots;
79 mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL);
80 if (!mt->red)
81 goto err_mem;
82 }
Henrik Rydberg55e49082012-08-22 20:43:22 +020083
Henrik Rydberg47c78e82010-11-27 09:16:48 +010084 /* Mark slots as 'unused' */
85 for (i = 0; i < num_slots; i++)
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020086 input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
Henrik Rydberg47c78e82010-11-27 09:16:48 +010087
Henrik Rydberg8d18fba2012-09-15 15:15:58 +020088 dev->mt = mt;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010089 return 0;
Henrik Rydberg7c1a8782012-08-12 20:47:05 +020090err_mem:
91 kfree(mt);
92 return -ENOMEM;
Henrik Rydberg47c78e82010-11-27 09:16:48 +010093}
Henrik Rydberg8cde8102010-11-27 10:50:54 +010094EXPORT_SYMBOL(input_mt_init_slots);
Henrik Rydberg47c78e82010-11-27 09:16:48 +010095
96/**
97 * input_mt_destroy_slots() - frees the MT slots of the input device
98 * @dev: input device with allocated MT slots
99 *
100 * This function is only needed in error path as the input core will
101 * automatically free the MT slots when the device is destroyed.
102 */
103void input_mt_destroy_slots(struct input_dev *dev)
104{
Henrik Rydberg7c1a8782012-08-12 20:47:05 +0200105 if (dev->mt) {
106 kfree(dev->mt->red);
107 kfree(dev->mt);
108 }
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100109 dev->mt = NULL;
Henrik Rydberg47c78e82010-11-27 09:16:48 +0100110}
111EXPORT_SYMBOL(input_mt_destroy_slots);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100112
113/**
114 * input_mt_report_slot_state() - report contact state
115 * @dev: input device with allocated MT slots
116 * @tool_type: the tool type to use in this slot
117 * @active: true if contact is active, false otherwise
118 *
119 * Reports a contact via ABS_MT_TRACKING_ID, and optionally
120 * ABS_MT_TOOL_TYPE. If active is true and the slot is currently
121 * inactive, or if the tool type is changed, a new tracking id is
122 * assigned to the slot. The tool type is only reported if the
123 * corresponding absbit field is set.
124 */
125void input_mt_report_slot_state(struct input_dev *dev,
126 unsigned int tool_type, bool active)
127{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200128 struct input_mt *mt = dev->mt;
129 struct input_mt_slot *slot;
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100130 int id;
131
Henrik Rydberg55e49082012-08-22 20:43:22 +0200132 if (!mt)
133 return;
134
135 slot = &mt->slots[mt->slot];
136 slot->frame = mt->frame;
137
138 if (!active) {
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100139 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
140 return;
141 }
142
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200143 id = input_mt_get_value(slot, ABS_MT_TRACKING_ID);
144 if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type)
145 id = input_mt_new_trkid(mt);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100146
147 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
148 input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
149}
150EXPORT_SYMBOL(input_mt_report_slot_state);
151
152/**
153 * input_mt_report_finger_count() - report contact count
154 * @dev: input device with allocated MT slots
155 * @count: the number of contacts
156 *
157 * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP,
158 * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP.
159 *
160 * The input core ensures only the KEY events already setup for
161 * this device will produce output.
162 */
163void input_mt_report_finger_count(struct input_dev *dev, int count)
164{
165 input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
166 input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
167 input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
168 input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4);
Daniel Kurtzd5051272011-08-23 23:02:48 -0700169 input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100170}
171EXPORT_SYMBOL(input_mt_report_finger_count);
172
173/**
174 * input_mt_report_pointer_emulation() - common pointer emulation
175 * @dev: input device with allocated MT slots
176 * @use_count: report number of active contacts as finger count
177 *
178 * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
179 * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true.
180 *
181 * The input core ensures only the KEY and ABS axes already setup for
182 * this device will produce output.
183 */
184void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
185{
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200186 struct input_mt *mt = dev->mt;
187 struct input_mt_slot *oldest;
188 int oldid, count, i;
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100189
Henrik Rydberg8d18fba2012-09-15 15:15:58 +0200190 if (!mt)
191 return;
192
193 oldest = 0;
194 oldid = mt->trkid;
195 count = 0;
196
197 for (i = 0; i < mt->num_slots; ++i) {
198 struct input_mt_slot *ps = &mt->slots[i];
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100199 int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
200
201 if (id < 0)
202 continue;
203 if ((id - oldid) & TRKID_SGN) {
204 oldest = ps;
205 oldid = id;
206 }
207 count++;
208 }
209
210 input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
211 if (use_count)
212 input_mt_report_finger_count(dev, count);
213
214 if (oldest) {
215 int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
216 int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100217
218 input_event(dev, EV_ABS, ABS_X, x);
219 input_event(dev, EV_ABS, ABS_Y, y);
Henrik Rydberg22739292012-09-15 08:57:18 +0200220
221 if (test_bit(ABS_MT_PRESSURE, dev->absbit)) {
222 int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);
223 input_event(dev, EV_ABS, ABS_PRESSURE, p);
224 }
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100225 } else {
Henrik Rydberg22739292012-09-15 08:57:18 +0200226 if (test_bit(ABS_MT_PRESSURE, dev->absbit))
227 input_event(dev, EV_ABS, ABS_PRESSURE, 0);
Henrik Rydbergc5f4dec2010-12-15 13:50:34 +0100228 }
229}
230EXPORT_SYMBOL(input_mt_report_pointer_emulation);
Henrik Rydberg55e49082012-08-22 20:43:22 +0200231
232/**
233 * input_mt_sync_frame() - synchronize mt frame
234 * @dev: input device with allocated MT slots
235 *
236 * Close the frame and prepare the internal state for a new one.
237 * Depending on the flags, marks unused slots as inactive and performs
238 * pointer emulation.
239 */
240void input_mt_sync_frame(struct input_dev *dev)
241{
242 struct input_mt *mt = dev->mt;
243 struct input_mt_slot *s;
244
245 if (!mt)
246 return;
247
248 if (mt->flags & INPUT_MT_DROP_UNUSED) {
249 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
250 if (s->frame == mt->frame)
251 continue;
252 input_mt_slot(dev, s - mt->slots);
253 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
254 }
255 }
256
257 input_mt_report_pointer_emulation(dev, (mt->flags & INPUT_MT_POINTER));
258
259 mt->frame++;
260}
261EXPORT_SYMBOL(input_mt_sync_frame);
Henrik Rydberg7c1a8782012-08-12 20:47:05 +0200262
263static int adjust_dual(int *begin, int step, int *end, int eq)
264{
265 int f, *p, s, c;
266
267 if (begin == end)
268 return 0;
269
270 f = *begin;
271 p = begin + step;
272 s = p == end ? f + 1 : *p;
273
274 for (; p != end; p += step)
275 if (*p < f)
276 s = f, f = *p;
277 else if (*p < s)
278 s = *p;
279
280 c = (f + s + 1) / 2;
281 if (c == 0 || (c > 0 && !eq))
282 return 0;
283 if (s < 0)
284 c *= 2;
285
286 for (p = begin; p != end; p += step)
287 *p -= c;
288
289 return (c < s && s <= 0) || (f >= 0 && f < c);
290}
291
292static void find_reduced_matrix(int *w, int nr, int nc, int nrc)
293{
294 int i, k, sum;
295
296 for (k = 0; k < nrc; k++) {
297 for (i = 0; i < nr; i++)
298 adjust_dual(w + i, nr, w + i + nrc, nr <= nc);
299 sum = 0;
300 for (i = 0; i < nrc; i += nr)
301 sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr);
302 if (!sum)
303 break;
304 }
305}
306
307static int input_mt_set_matrix(struct input_mt *mt,
308 const struct input_mt_pos *pos, int num_pos)
309{
310 const struct input_mt_pos *p;
311 struct input_mt_slot *s;
312 int *w = mt->red;
313 int x, y;
314
315 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
316 if (!input_mt_is_active(s))
317 continue;
318 x = input_mt_get_value(s, ABS_MT_POSITION_X);
319 y = input_mt_get_value(s, ABS_MT_POSITION_Y);
320 for (p = pos; p != pos + num_pos; p++) {
321 int dx = x - p->x, dy = y - p->y;
322 *w++ = dx * dx + dy * dy;
323 }
324 }
325
326 return w - mt->red;
327}
328
329static void input_mt_set_slots(struct input_mt *mt,
330 int *slots, int num_pos)
331{
332 struct input_mt_slot *s;
333 int *w = mt->red, *p;
334
335 for (p = slots; p != slots + num_pos; p++)
336 *p = -1;
337
338 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
339 if (!input_mt_is_active(s))
340 continue;
341 for (p = slots; p != slots + num_pos; p++)
342 if (*w++ < 0)
343 *p = s - mt->slots;
344 }
345
346 for (s = mt->slots; s != mt->slots + mt->num_slots; s++) {
347 if (input_mt_is_active(s))
348 continue;
349 for (p = slots; p != slots + num_pos; p++)
350 if (*p < 0) {
351 *p = s - mt->slots;
352 break;
353 }
354 }
355}
356
357/**
358 * input_mt_assign_slots() - perform a best-match assignment
359 * @dev: input device with allocated MT slots
360 * @slots: the slot assignment to be filled
361 * @pos: the position array to match
362 * @num_pos: number of positions
363 *
364 * Performs a best match against the current contacts and returns
365 * the slot assignment list. New contacts are assigned to unused
366 * slots.
367 *
368 * Returns zero on success, or negative error in case of failure.
369 */
370int input_mt_assign_slots(struct input_dev *dev, int *slots,
371 const struct input_mt_pos *pos, int num_pos)
372{
373 struct input_mt *mt = dev->mt;
374 int nrc;
375
376 if (!mt || !mt->red)
377 return -ENXIO;
378 if (num_pos > mt->num_slots)
379 return -EINVAL;
380 if (num_pos < 1)
381 return 0;
382
383 nrc = input_mt_set_matrix(mt, pos, num_pos);
384 find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc);
385 input_mt_set_slots(mt, slots, num_pos);
386
387 return 0;
388}
389EXPORT_SYMBOL(input_mt_assign_slots);
Henrik Rydberg17a465a2012-09-01 09:27:20 +0200390
391/**
392 * input_mt_get_slot_by_key() - return slot matching key
393 * @dev: input device with allocated MT slots
394 * @key: the key of the sought slot
395 *
396 * Returns the slot of the given key, if it exists, otherwise
397 * set the key on the first unused slot and return.
398 *
399 * If no available slot can be found, -1 is returned.
400 */
401int input_mt_get_slot_by_key(struct input_dev *dev, int key)
402{
403 struct input_mt *mt = dev->mt;
404 struct input_mt_slot *s;
405
406 if (!mt)
407 return -1;
408
409 for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
410 if (input_mt_is_active(s) && s->key == key)
411 return s - mt->slots;
412
413 for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
414 if (!input_mt_is_active(s)) {
415 s->key = key;
416 return s - mt->slots;
417 }
418
419 return -1;
420}
421EXPORT_SYMBOL(input_mt_get_slot_by_key);