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1 | /* |
2 | * Force feedback support for memoryless devices |
3 | * |
4 | * Copyright (c) 2006 Anssi Hannula <anssi.hannula@gmail.com> |
5 | * Copyright (c) 2006 Dmitry Torokhov <dtor@mail.ru> |
6 | */ |
7 | |
8 | /* |
9 | * This program is free software; you can redistribute it and/or modify |
10 | * it under the terms of the GNU General Public License as published by |
11 | * the Free Software Foundation; either version 2 of the License, or |
12 | * (at your option) any later version. |
13 | * |
14 | * This program is distributed in the hope that it will be useful, |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
17 | * GNU General Public License for more details. |
18 | * |
19 | * You should have received a copy of the GNU General Public License |
20 | * along with this program; if not, write to the Free Software |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
22 | */ |
23 | |
24 | /* #define DEBUG */ |
25 | |
26 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
27 | |
28 | #include <linux/slab.h> |
29 | #include <linux/input.h> |
30 | #include <linux/module.h> |
31 | #include <linux/mutex.h> |
32 | #include <linux/spinlock.h> |
33 | #include <linux/jiffies.h> |
34 | |
35 | #include "fixp-arith.h" |
36 | |
37 | MODULE_LICENSE("GPL"); |
38 | MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>"); |
39 | MODULE_DESCRIPTION("Force feedback support for memoryless devices"); |
40 | |
41 | /* Number of effects handled with memoryless devices */ |
42 | #define FF_MEMLESS_EFFECTS 16 |
43 | |
44 | /* Envelope update interval in ms */ |
45 | #define FF_ENVELOPE_INTERVAL 50 |
46 | |
47 | #define FF_EFFECT_STARTED 0 |
48 | #define FF_EFFECT_PLAYING 1 |
49 | #define FF_EFFECT_ABORTING 2 |
50 | |
51 | struct ml_effect_state { |
52 | struct ff_effect *effect; |
53 | unsigned long flags; /* effect state (STARTED, PLAYING, etc) */ |
54 | int count; /* loop count of the effect */ |
55 | unsigned long play_at; /* start time */ |
56 | unsigned long stop_at; /* stop time */ |
57 | unsigned long adj_at; /* last time the effect was sent */ |
58 | }; |
59 | |
60 | struct ml_device { |
61 | void *private; |
62 | struct ml_effect_state states[FF_MEMLESS_EFFECTS]; |
63 | int gain; |
64 | struct timer_list timer; |
65 | struct input_dev *dev; |
66 | |
67 | int (*play_effect)(struct input_dev *dev, void *data, |
68 | struct ff_effect *effect); |
69 | }; |
70 | |
71 | static const struct ff_envelope *get_envelope(const struct ff_effect *effect) |
72 | { |
73 | static const struct ff_envelope empty_envelope; |
74 | |
75 | switch (effect->type) { |
76 | case FF_PERIODIC: |
77 | return &effect->u.periodic.envelope; |
78 | case FF_CONSTANT: |
79 | return &effect->u.constant.envelope; |
80 | default: |
81 | return &empty_envelope; |
82 | } |
83 | } |
84 | |
85 | /* |
86 | * Check for the next time envelope requires an update on memoryless devices |
87 | */ |
88 | static unsigned long calculate_next_time(struct ml_effect_state *state) |
89 | { |
90 | const struct ff_envelope *envelope = get_envelope(state->effect); |
91 | unsigned long attack_stop, fade_start, next_fade; |
92 | |
93 | if (envelope->attack_length) { |
94 | attack_stop = state->play_at + |
95 | msecs_to_jiffies(envelope->attack_length); |
96 | if (time_before(state->adj_at, attack_stop)) |
97 | return state->adj_at + |
98 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); |
99 | } |
100 | |
101 | if (state->effect->replay.length) { |
102 | if (envelope->fade_length) { |
103 | /* check when fading should start */ |
104 | fade_start = state->stop_at - |
105 | msecs_to_jiffies(envelope->fade_length); |
106 | |
107 | if (time_before(state->adj_at, fade_start)) |
108 | return fade_start; |
109 | |
110 | /* already fading, advance to next checkpoint */ |
111 | next_fade = state->adj_at + |
112 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); |
113 | if (time_before(next_fade, state->stop_at)) |
114 | return next_fade; |
115 | } |
116 | |
117 | return state->stop_at; |
118 | } |
119 | |
120 | return state->play_at; |
121 | } |
122 | |
123 | static void ml_schedule_timer(struct ml_device *ml) |
124 | { |
125 | struct ml_effect_state *state; |
126 | unsigned long now = jiffies; |
127 | unsigned long earliest = 0; |
128 | unsigned long next_at; |
129 | int events = 0; |
130 | int i; |
131 | |
132 | pr_debug("calculating next timer\n"); |
133 | |
134 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { |
135 | |
136 | state = &ml->states[i]; |
137 | |
138 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) |
139 | continue; |
140 | |
141 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) |
142 | next_at = calculate_next_time(state); |
143 | else |
144 | next_at = state->play_at; |
145 | |
146 | if (time_before_eq(now, next_at) && |
147 | (++events == 1 || time_before(next_at, earliest))) |
148 | earliest = next_at; |
149 | } |
150 | |
151 | if (!events) { |
152 | pr_debug("no actions\n"); |
153 | del_timer(&ml->timer); |
154 | } else { |
155 | pr_debug("timer set\n"); |
156 | mod_timer(&ml->timer, earliest); |
157 | } |
158 | } |
159 | |
160 | /* |
161 | * Apply an envelope to a value |
162 | */ |
163 | static int apply_envelope(struct ml_effect_state *state, int value, |
164 | struct ff_envelope *envelope) |
165 | { |
166 | struct ff_effect *effect = state->effect; |
167 | unsigned long now = jiffies; |
168 | int time_from_level; |
169 | int time_of_envelope; |
170 | int envelope_level; |
171 | int difference; |
172 | |
173 | if (envelope->attack_length && |
174 | time_before(now, |
175 | state->play_at + msecs_to_jiffies(envelope->attack_length))) { |
176 | pr_debug("value = 0x%x, attack_level = 0x%x\n", |
177 | value, envelope->attack_level); |
178 | time_from_level = jiffies_to_msecs(now - state->play_at); |
179 | time_of_envelope = envelope->attack_length; |
180 | envelope_level = min_t(__s16, envelope->attack_level, 0x7fff); |
181 | |
182 | } else if (envelope->fade_length && effect->replay.length && |
183 | time_after(now, |
184 | state->stop_at - msecs_to_jiffies(envelope->fade_length)) && |
185 | time_before(now, state->stop_at)) { |
186 | time_from_level = jiffies_to_msecs(state->stop_at - now); |
187 | time_of_envelope = envelope->fade_length; |
188 | envelope_level = min_t(__s16, envelope->fade_level, 0x7fff); |
189 | } else |
190 | return value; |
191 | |
192 | difference = abs(value) - envelope_level; |
193 | |
194 | pr_debug("difference = %d\n", difference); |
195 | pr_debug("time_from_level = 0x%x\n", time_from_level); |
196 | pr_debug("time_of_envelope = 0x%x\n", time_of_envelope); |
197 | |
198 | difference = difference * time_from_level / time_of_envelope; |
199 | |
200 | pr_debug("difference = %d\n", difference); |
201 | |
202 | return value < 0 ? |
203 | -(difference + envelope_level) : (difference + envelope_level); |
204 | } |
205 | |
206 | /* |
207 | * Return the type the effect has to be converted into (memless devices) |
208 | */ |
209 | static int get_compatible_type(struct ff_device *ff, int effect_type) |
210 | { |
211 | |
212 | if (test_bit(effect_type, ff->ffbit)) |
213 | return effect_type; |
214 | |
215 | if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit)) |
216 | return FF_RUMBLE; |
217 | |
218 | pr_err("invalid type in get_compatible_type()\n"); |
219 | |
220 | return 0; |
221 | } |
222 | |
223 | /* |
224 | * Only left/right direction should be used (under/over 0x8000) for |
225 | * forward/reverse motor direction (to keep calculation fast & simple). |
226 | */ |
227 | static u16 ml_calculate_direction(u16 direction, u16 force, |
228 | u16 new_direction, u16 new_force) |
229 | { |
230 | if (!force) |
231 | return new_direction; |
232 | if (!new_force) |
233 | return direction; |
234 | return (((u32)(direction >> 1) * force + |
235 | (new_direction >> 1) * new_force) / |
236 | (force + new_force)) << 1; |
237 | } |
238 | |
239 | /* |
240 | * Combine two effects and apply gain. |
241 | */ |
242 | static void ml_combine_effects(struct ff_effect *effect, |
243 | struct ml_effect_state *state, |
244 | int gain) |
245 | { |
246 | struct ff_effect *new = state->effect; |
247 | unsigned int strong, weak, i; |
248 | int x, y; |
249 | fixp_t level; |
250 | |
251 | switch (new->type) { |
252 | case FF_CONSTANT: |
253 | i = new->direction * 360 / 0xffff; |
254 | level = fixp_new16(apply_envelope(state, |
255 | new->u.constant.level, |
256 | &new->u.constant.envelope)); |
257 | x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; |
258 | y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; |
259 | /* |
260 | * here we abuse ff_ramp to hold x and y of constant force |
261 | * If in future any driver wants something else than x and y |
262 | * in s8, this should be changed to something more generic |
263 | */ |
264 | effect->u.ramp.start_level = |
265 | clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); |
266 | effect->u.ramp.end_level = |
267 | clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); |
268 | break; |
269 | |
270 | case FF_RUMBLE: |
271 | strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff; |
272 | weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff; |
273 | |
274 | if (effect->u.rumble.strong_magnitude + strong) |
275 | effect->direction = ml_calculate_direction( |
276 | effect->direction, |
277 | effect->u.rumble.strong_magnitude, |
278 | new->direction, strong); |
279 | else if (effect->u.rumble.weak_magnitude + weak) |
280 | effect->direction = ml_calculate_direction( |
281 | effect->direction, |
282 | effect->u.rumble.weak_magnitude, |
283 | new->direction, weak); |
284 | else |
285 | effect->direction = 0; |
286 | effect->u.rumble.strong_magnitude = |
287 | min(strong + effect->u.rumble.strong_magnitude, |
288 | 0xffffU); |
289 | effect->u.rumble.weak_magnitude = |
290 | min(weak + effect->u.rumble.weak_magnitude, 0xffffU); |
291 | break; |
292 | |
293 | case FF_PERIODIC: |
294 | i = apply_envelope(state, abs(new->u.periodic.magnitude), |
295 | &new->u.periodic.envelope); |
296 | |
297 | /* here we also scale it 0x7fff => 0xffff */ |
298 | i = i * gain / 0x7fff; |
299 | |
300 | if (effect->u.rumble.strong_magnitude + i) |
301 | effect->direction = ml_calculate_direction( |
302 | effect->direction, |
303 | effect->u.rumble.strong_magnitude, |
304 | new->direction, i); |
305 | else |
306 | effect->direction = 0; |
307 | effect->u.rumble.strong_magnitude = |
308 | min(i + effect->u.rumble.strong_magnitude, 0xffffU); |
309 | effect->u.rumble.weak_magnitude = |
310 | min(i + effect->u.rumble.weak_magnitude, 0xffffU); |
311 | break; |
312 | |
313 | default: |
314 | pr_err("invalid type in ml_combine_effects()\n"); |
315 | break; |
316 | } |
317 | |
318 | } |
319 | |
320 | |
321 | /* |
322 | * Because memoryless devices have only one effect per effect type active |
323 | * at one time we have to combine multiple effects into one |
324 | */ |
325 | static int ml_get_combo_effect(struct ml_device *ml, |
326 | unsigned long *effect_handled, |
327 | struct ff_effect *combo_effect) |
328 | { |
329 | struct ff_effect *effect; |
330 | struct ml_effect_state *state; |
331 | int effect_type; |
332 | int i; |
333 | |
334 | memset(combo_effect, 0, sizeof(struct ff_effect)); |
335 | |
336 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { |
337 | if (__test_and_set_bit(i, effect_handled)) |
338 | continue; |
339 | |
340 | state = &ml->states[i]; |
341 | effect = state->effect; |
342 | |
343 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) |
344 | continue; |
345 | |
346 | if (time_before(jiffies, state->play_at)) |
347 | continue; |
348 | |
349 | /* |
350 | * here we have started effects that are either |
351 | * currently playing (and may need be aborted) |
352 | * or need to start playing. |
353 | */ |
354 | effect_type = get_compatible_type(ml->dev->ff, effect->type); |
355 | if (combo_effect->type != effect_type) { |
356 | if (combo_effect->type != 0) { |
357 | __clear_bit(i, effect_handled); |
358 | continue; |
359 | } |
360 | combo_effect->type = effect_type; |
361 | } |
362 | |
363 | if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { |
364 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); |
365 | __clear_bit(FF_EFFECT_STARTED, &state->flags); |
366 | } else if (effect->replay.length && |
367 | time_after_eq(jiffies, state->stop_at)) { |
368 | |
369 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); |
370 | |
371 | if (--state->count <= 0) { |
372 | __clear_bit(FF_EFFECT_STARTED, &state->flags); |
373 | } else { |
374 | state->play_at = jiffies + |
375 | msecs_to_jiffies(effect->replay.delay); |
376 | state->stop_at = state->play_at + |
377 | msecs_to_jiffies(effect->replay.length); |
378 | } |
379 | } else { |
380 | __set_bit(FF_EFFECT_PLAYING, &state->flags); |
381 | state->adj_at = jiffies; |
382 | ml_combine_effects(combo_effect, state, ml->gain); |
383 | } |
384 | } |
385 | |
386 | return combo_effect->type != 0; |
387 | } |
388 | |
389 | static void ml_play_effects(struct ml_device *ml) |
390 | { |
391 | struct ff_effect effect; |
392 | DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); |
393 | |
394 | memset(handled_bm, 0, sizeof(handled_bm)); |
395 | |
396 | while (ml_get_combo_effect(ml, handled_bm, &effect)) |
397 | ml->play_effect(ml->dev, ml->private, &effect); |
398 | |
399 | ml_schedule_timer(ml); |
400 | } |
401 | |
402 | static void ml_effect_timer(unsigned long timer_data) |
403 | { |
404 | struct input_dev *dev = (struct input_dev *)timer_data; |
405 | struct ml_device *ml = dev->ff->private; |
406 | unsigned long flags; |
407 | |
408 | pr_debug("timer: updating effects\n"); |
409 | |
410 | spin_lock_irqsave(&dev->event_lock, flags); |
411 | ml_play_effects(ml); |
412 | spin_unlock_irqrestore(&dev->event_lock, flags); |
413 | } |
414 | |
415 | /* |
416 | * Sets requested gain for FF effects. Called with dev->event_lock held. |
417 | */ |
418 | static void ml_ff_set_gain(struct input_dev *dev, u16 gain) |
419 | { |
420 | struct ml_device *ml = dev->ff->private; |
421 | int i; |
422 | |
423 | ml->gain = gain; |
424 | |
425 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) |
426 | __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); |
427 | |
428 | ml_play_effects(ml); |
429 | } |
430 | |
431 | /* |
432 | * Start/stop specified FF effect. Called with dev->event_lock held. |
433 | */ |
434 | static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) |
435 | { |
436 | struct ml_device *ml = dev->ff->private; |
437 | struct ml_effect_state *state = &ml->states[effect_id]; |
438 | |
439 | if (value > 0) { |
440 | pr_debug("initiated play\n"); |
441 | |
442 | __set_bit(FF_EFFECT_STARTED, &state->flags); |
443 | state->count = value; |
444 | state->play_at = jiffies + |
445 | msecs_to_jiffies(state->effect->replay.delay); |
446 | state->stop_at = state->play_at + |
447 | msecs_to_jiffies(state->effect->replay.length); |
448 | state->adj_at = state->play_at; |
449 | |
450 | } else { |
451 | pr_debug("initiated stop\n"); |
452 | |
453 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) |
454 | __set_bit(FF_EFFECT_ABORTING, &state->flags); |
455 | else |
456 | __clear_bit(FF_EFFECT_STARTED, &state->flags); |
457 | } |
458 | |
459 | ml_play_effects(ml); |
460 | |
461 | return 0; |
462 | } |
463 | |
464 | static int ml_ff_upload(struct input_dev *dev, |
465 | struct ff_effect *effect, struct ff_effect *old) |
466 | { |
467 | struct ml_device *ml = dev->ff->private; |
468 | struct ml_effect_state *state = &ml->states[effect->id]; |
469 | |
470 | spin_lock_irq(&dev->event_lock); |
471 | |
472 | if (test_bit(FF_EFFECT_STARTED, &state->flags)) { |
473 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); |
474 | state->play_at = jiffies + |
475 | msecs_to_jiffies(state->effect->replay.delay); |
476 | state->stop_at = state->play_at + |
477 | msecs_to_jiffies(state->effect->replay.length); |
478 | state->adj_at = state->play_at; |
479 | ml_schedule_timer(ml); |
480 | } |
481 | |
482 | spin_unlock_irq(&dev->event_lock); |
483 | |
484 | return 0; |
485 | } |
486 | |
487 | static void ml_ff_destroy(struct ff_device *ff) |
488 | { |
489 | struct ml_device *ml = ff->private; |
490 | |
491 | kfree(ml->private); |
492 | } |
493 | |
494 | /** |
495 | * input_ff_create_memless() - create memoryless force-feedback device |
496 | * @dev: input device supporting force-feedback |
497 | * @data: driver-specific data to be passed into @play_effect |
498 | * @play_effect: driver-specific method for playing FF effect |
499 | */ |
500 | int input_ff_create_memless(struct input_dev *dev, void *data, |
501 | int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) |
502 | { |
503 | struct ml_device *ml; |
504 | struct ff_device *ff; |
505 | int error; |
506 | int i; |
507 | |
508 | ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); |
509 | if (!ml) |
510 | return -ENOMEM; |
511 | |
512 | ml->dev = dev; |
513 | ml->private = data; |
514 | ml->play_effect = play_effect; |
515 | ml->gain = 0xffff; |
516 | setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); |
517 | |
518 | set_bit(FF_GAIN, dev->ffbit); |
519 | |
520 | error = input_ff_create(dev, FF_MEMLESS_EFFECTS); |
521 | if (error) { |
522 | kfree(ml); |
523 | return error; |
524 | } |
525 | |
526 | ff = dev->ff; |
527 | ff->private = ml; |
528 | ff->upload = ml_ff_upload; |
529 | ff->playback = ml_ff_playback; |
530 | ff->set_gain = ml_ff_set_gain; |
531 | ff->destroy = ml_ff_destroy; |
532 | |
533 | /* we can emulate periodic effects with RUMBLE */ |
534 | if (test_bit(FF_RUMBLE, ff->ffbit)) { |
535 | set_bit(FF_PERIODIC, dev->ffbit); |
536 | set_bit(FF_SINE, dev->ffbit); |
537 | set_bit(FF_TRIANGLE, dev->ffbit); |
538 | set_bit(FF_SQUARE, dev->ffbit); |
539 | } |
540 | |
541 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) |
542 | ml->states[i].effect = &ff->effects[i]; |
543 | |
544 | return 0; |
545 | } |
546 | EXPORT_SYMBOL_GPL(input_ff_create_memless); |
547 |
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