projects/linux·blob v3.8 · refs

425 lines · 10.9 KiB

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
17static 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
25/**
26 * input_mt_init_slots() - initialize MT input slots
27 * @dev: input device supporting MT events and finger tracking
28 * @num_slots: number of slots used by the device
29 * @flags: mt tasks to handle in core
30 *
31 * This function allocates all necessary memory for MT slot handling
32 * in the input device, prepares the ABS_MT_SLOT and
33 * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
34 * Depending on the flags set, it also performs pointer emulation and
35 * frame synchronization.
36 *
37 * May be called repeatedly. Returns -EINVAL if attempting to
38 * reinitialize with a different number of slots.
39 */
40int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
41 unsigned int flags)
42{
43 struct input_mt *mt = dev->mt;
44 int i;
45
46 if (!num_slots)
47 return 0;
48 if (mt)
49 return mt->num_slots != num_slots ? -EINVAL : 0;
50
51 mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL);
52 if (!mt)
53 goto err_mem;
54
55 mt->num_slots = num_slots;
56 mt->flags = flags;
57 input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
58 input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
59
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);
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 }
87
88 /* Mark slots as 'unused' */
89 for (i = 0; i < num_slots; i++)
90 input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1);
91
92 dev->mt = mt;
93 return 0;
94err_mem:
95 kfree(mt);
96 return -ENOMEM;
97}
98EXPORT_SYMBOL(input_mt_init_slots);
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 */
107void input_mt_destroy_slots(struct input_dev *dev)
108{
109 if (dev->mt) {
110 kfree(dev->mt->red);
111 kfree(dev->mt);
112 }
113 dev->mt = NULL;
114}
115EXPORT_SYMBOL(input_mt_destroy_slots);
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 */
129void input_mt_report_slot_state(struct input_dev *dev,
130 unsigned int tool_type, bool active)
131{
132 struct input_mt *mt = dev->mt;
133 struct input_mt_slot *slot;
134 int id;
135
136 if (!mt)
137 return;
138
139 slot = &mt->slots[mt->slot];
140 slot->frame = mt->frame;
141
142 if (!active) {
143 input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
144 return;
145 }
146
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);
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}
154EXPORT_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 */
167void 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);
173 input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5);
174}
175EXPORT_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 */
188void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
189{
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
197 oldest = NULL;
198 oldid = mt->trkid;
199 count = 0;
200
201 for (i = 0; i < mt->num_slots; ++i) {
202 struct input_mt_slot *ps = &mt->slots[i];
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);
221
222 input_event(dev, EV_ABS, ABS_X, x);
223 input_event(dev, EV_ABS, ABS_Y, y);
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 }
229 } else {
230 if (test_bit(ABS_MT_PRESSURE, dev->absbit))
231 input_event(dev, EV_ABS, ABS_PRESSURE, 0);
232 }
233}
234EXPORT_SYMBOL(input_mt_report_pointer_emulation);
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 */
244void 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 (input_mt_is_used(mt, s))
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}
265EXPORT_SYMBOL(input_mt_sync_frame);
266
267static 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
296static 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
311static 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
333static 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 */
374int 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}
393EXPORT_SYMBOL(input_mt_assign_slots);
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 */
405int 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}
425EXPORT_SYMBOL(input_mt_get_slot_by_key);