]>
Commit | Line | Data |
---|---|---|
7d928a2b AH |
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 | ||
da0c4901 | 26 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7d928a2b | 27 | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
7d928a2b AH |
29 | #include <linux/input.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/spinlock.h> | |
cd354f1a | 33 | #include <linux/jiffies.h> |
c8e1fb4a | 34 | #include <linux/fixp-arith.h> |
7d928a2b AH |
35 | |
36 | MODULE_LICENSE("GPL"); | |
37 | MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>"); | |
38 | MODULE_DESCRIPTION("Force feedback support for memoryless devices"); | |
39 | ||
40 | /* Number of effects handled with memoryless devices */ | |
41 | #define FF_MEMLESS_EFFECTS 16 | |
42 | ||
43 | /* Envelope update interval in ms */ | |
44 | #define FF_ENVELOPE_INTERVAL 50 | |
45 | ||
46 | #define FF_EFFECT_STARTED 0 | |
47 | #define FF_EFFECT_PLAYING 1 | |
48 | #define FF_EFFECT_ABORTING 2 | |
49 | ||
50 | struct ml_effect_state { | |
51 | struct ff_effect *effect; | |
52 | unsigned long flags; /* effect state (STARTED, PLAYING, etc) */ | |
53 | int count; /* loop count of the effect */ | |
54 | unsigned long play_at; /* start time */ | |
55 | unsigned long stop_at; /* stop time */ | |
56 | unsigned long adj_at; /* last time the effect was sent */ | |
57 | }; | |
58 | ||
59 | struct ml_device { | |
60 | void *private; | |
61 | struct ml_effect_state states[FF_MEMLESS_EFFECTS]; | |
62 | int gain; | |
63 | struct timer_list timer; | |
7d928a2b AH |
64 | struct input_dev *dev; |
65 | ||
66 | int (*play_effect)(struct input_dev *dev, void *data, | |
67 | struct ff_effect *effect); | |
68 | }; | |
69 | ||
70 | static const struct ff_envelope *get_envelope(const struct ff_effect *effect) | |
71 | { | |
72 | static const struct ff_envelope empty_envelope; | |
73 | ||
74 | switch (effect->type) { | |
75 | case FF_PERIODIC: | |
76 | return &effect->u.periodic.envelope; | |
77 | case FF_CONSTANT: | |
78 | return &effect->u.constant.envelope; | |
79 | default: | |
80 | return &empty_envelope; | |
81 | } | |
82 | } | |
83 | ||
84 | /* | |
85 | * Check for the next time envelope requires an update on memoryless devices | |
86 | */ | |
87 | static unsigned long calculate_next_time(struct ml_effect_state *state) | |
88 | { | |
89 | const struct ff_envelope *envelope = get_envelope(state->effect); | |
90 | unsigned long attack_stop, fade_start, next_fade; | |
91 | ||
92 | if (envelope->attack_length) { | |
93 | attack_stop = state->play_at + | |
94 | msecs_to_jiffies(envelope->attack_length); | |
95 | if (time_before(state->adj_at, attack_stop)) | |
96 | return state->adj_at + | |
97 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); | |
98 | } | |
99 | ||
100 | if (state->effect->replay.length) { | |
101 | if (envelope->fade_length) { | |
102 | /* check when fading should start */ | |
103 | fade_start = state->stop_at - | |
104 | msecs_to_jiffies(envelope->fade_length); | |
105 | ||
106 | if (time_before(state->adj_at, fade_start)) | |
107 | return fade_start; | |
108 | ||
109 | /* already fading, advance to next checkpoint */ | |
110 | next_fade = state->adj_at + | |
111 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); | |
112 | if (time_before(next_fade, state->stop_at)) | |
113 | return next_fade; | |
114 | } | |
115 | ||
116 | return state->stop_at; | |
117 | } | |
118 | ||
119 | return state->play_at; | |
120 | } | |
121 | ||
122 | static void ml_schedule_timer(struct ml_device *ml) | |
123 | { | |
124 | struct ml_effect_state *state; | |
125 | unsigned long now = jiffies; | |
126 | unsigned long earliest = 0; | |
127 | unsigned long next_at; | |
128 | int events = 0; | |
129 | int i; | |
130 | ||
da0c4901 | 131 | pr_debug("calculating next timer\n"); |
7d928a2b AH |
132 | |
133 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
134 | ||
135 | state = &ml->states[i]; | |
136 | ||
137 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
138 | continue; | |
139 | ||
140 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
141 | next_at = calculate_next_time(state); | |
142 | else | |
143 | next_at = state->play_at; | |
144 | ||
145 | if (time_before_eq(now, next_at) && | |
146 | (++events == 1 || time_before(next_at, earliest))) | |
147 | earliest = next_at; | |
148 | } | |
149 | ||
150 | if (!events) { | |
da0c4901 | 151 | pr_debug("no actions\n"); |
7d928a2b AH |
152 | del_timer(&ml->timer); |
153 | } else { | |
da0c4901 | 154 | pr_debug("timer set\n"); |
7d928a2b AH |
155 | mod_timer(&ml->timer, earliest); |
156 | } | |
157 | } | |
158 | ||
159 | /* | |
160 | * Apply an envelope to a value | |
161 | */ | |
162 | static int apply_envelope(struct ml_effect_state *state, int value, | |
163 | struct ff_envelope *envelope) | |
164 | { | |
165 | struct ff_effect *effect = state->effect; | |
166 | unsigned long now = jiffies; | |
167 | int time_from_level; | |
168 | int time_of_envelope; | |
169 | int envelope_level; | |
170 | int difference; | |
171 | ||
172 | if (envelope->attack_length && | |
173 | time_before(now, | |
174 | state->play_at + msecs_to_jiffies(envelope->attack_length))) { | |
da0c4901 JP |
175 | pr_debug("value = 0x%x, attack_level = 0x%x\n", |
176 | value, envelope->attack_level); | |
7d928a2b AH |
177 | time_from_level = jiffies_to_msecs(now - state->play_at); |
178 | time_of_envelope = envelope->attack_length; | |
9a932145 | 179 | envelope_level = min_t(u16, envelope->attack_level, 0x7fff); |
7d928a2b AH |
180 | |
181 | } else if (envelope->fade_length && effect->replay.length && | |
182 | time_after(now, | |
183 | state->stop_at - msecs_to_jiffies(envelope->fade_length)) && | |
184 | time_before(now, state->stop_at)) { | |
185 | time_from_level = jiffies_to_msecs(state->stop_at - now); | |
186 | time_of_envelope = envelope->fade_length; | |
9a932145 | 187 | envelope_level = min_t(u16, envelope->fade_level, 0x7fff); |
7d928a2b AH |
188 | } else |
189 | return value; | |
190 | ||
191 | difference = abs(value) - envelope_level; | |
192 | ||
da0c4901 JP |
193 | pr_debug("difference = %d\n", difference); |
194 | pr_debug("time_from_level = 0x%x\n", time_from_level); | |
195 | pr_debug("time_of_envelope = 0x%x\n", time_of_envelope); | |
7d928a2b AH |
196 | |
197 | difference = difference * time_from_level / time_of_envelope; | |
198 | ||
da0c4901 | 199 | pr_debug("difference = %d\n", difference); |
7d928a2b AH |
200 | |
201 | return value < 0 ? | |
202 | -(difference + envelope_level) : (difference + envelope_level); | |
203 | } | |
204 | ||
205 | /* | |
206 | * Return the type the effect has to be converted into (memless devices) | |
207 | */ | |
208 | static int get_compatible_type(struct ff_device *ff, int effect_type) | |
209 | { | |
210 | ||
211 | if (test_bit(effect_type, ff->ffbit)) | |
212 | return effect_type; | |
213 | ||
214 | if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit)) | |
215 | return FF_RUMBLE; | |
216 | ||
da0c4901 | 217 | pr_err("invalid type in get_compatible_type()\n"); |
7d928a2b AH |
218 | |
219 | return 0; | |
220 | } | |
221 | ||
94ec26c8 JV |
222 | /* |
223 | * Only left/right direction should be used (under/over 0x8000) for | |
224 | * forward/reverse motor direction (to keep calculation fast & simple). | |
225 | */ | |
226 | static u16 ml_calculate_direction(u16 direction, u16 force, | |
227 | u16 new_direction, u16 new_force) | |
228 | { | |
229 | if (!force) | |
230 | return new_direction; | |
231 | if (!new_force) | |
232 | return direction; | |
233 | return (((u32)(direction >> 1) * force + | |
234 | (new_direction >> 1) * new_force) / | |
235 | (force + new_force)) << 1; | |
236 | } | |
237 | ||
7d928a2b AH |
238 | /* |
239 | * Combine two effects and apply gain. | |
240 | */ | |
241 | static void ml_combine_effects(struct ff_effect *effect, | |
242 | struct ml_effect_state *state, | |
1b11c88d | 243 | int gain) |
7d928a2b AH |
244 | { |
245 | struct ff_effect *new = state->effect; | |
246 | unsigned int strong, weak, i; | |
247 | int x, y; | |
248 | fixp_t level; | |
249 | ||
250 | switch (new->type) { | |
251 | case FF_CONSTANT: | |
252 | i = new->direction * 360 / 0xffff; | |
253 | level = fixp_new16(apply_envelope(state, | |
254 | new->u.constant.level, | |
255 | &new->u.constant.envelope)); | |
256 | x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; | |
257 | y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; | |
258 | /* | |
259 | * here we abuse ff_ramp to hold x and y of constant force | |
260 | * If in future any driver wants something else than x and y | |
261 | * in s8, this should be changed to something more generic | |
262 | */ | |
263 | effect->u.ramp.start_level = | |
92310474 | 264 | clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); |
7d928a2b | 265 | effect->u.ramp.end_level = |
92310474 | 266 | clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); |
7d928a2b AH |
267 | break; |
268 | ||
269 | case FF_RUMBLE: | |
1b11c88d DT |
270 | strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff; |
271 | weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff; | |
94ec26c8 JV |
272 | |
273 | if (effect->u.rumble.strong_magnitude + strong) | |
274 | effect->direction = ml_calculate_direction( | |
275 | effect->direction, | |
276 | effect->u.rumble.strong_magnitude, | |
277 | new->direction, strong); | |
278 | else if (effect->u.rumble.weak_magnitude + weak) | |
279 | effect->direction = ml_calculate_direction( | |
280 | effect->direction, | |
281 | effect->u.rumble.weak_magnitude, | |
282 | new->direction, weak); | |
283 | else | |
284 | effect->direction = 0; | |
7d928a2b AH |
285 | effect->u.rumble.strong_magnitude = |
286 | min(strong + effect->u.rumble.strong_magnitude, | |
287 | 0xffffU); | |
288 | effect->u.rumble.weak_magnitude = | |
289 | min(weak + effect->u.rumble.weak_magnitude, 0xffffU); | |
290 | break; | |
291 | ||
292 | case FF_PERIODIC: | |
293 | i = apply_envelope(state, abs(new->u.periodic.magnitude), | |
294 | &new->u.periodic.envelope); | |
295 | ||
296 | /* here we also scale it 0x7fff => 0xffff */ | |
297 | i = i * gain / 0x7fff; | |
298 | ||
94ec26c8 JV |
299 | if (effect->u.rumble.strong_magnitude + i) |
300 | effect->direction = ml_calculate_direction( | |
301 | effect->direction, | |
302 | effect->u.rumble.strong_magnitude, | |
303 | new->direction, i); | |
304 | else | |
305 | effect->direction = 0; | |
7d928a2b AH |
306 | effect->u.rumble.strong_magnitude = |
307 | min(i + effect->u.rumble.strong_magnitude, 0xffffU); | |
308 | effect->u.rumble.weak_magnitude = | |
309 | min(i + effect->u.rumble.weak_magnitude, 0xffffU); | |
310 | break; | |
311 | ||
312 | default: | |
da0c4901 | 313 | pr_err("invalid type in ml_combine_effects()\n"); |
7d928a2b AH |
314 | break; |
315 | } | |
316 | ||
317 | } | |
318 | ||
319 | ||
320 | /* | |
321 | * Because memoryless devices have only one effect per effect type active | |
322 | * at one time we have to combine multiple effects into one | |
323 | */ | |
324 | static int ml_get_combo_effect(struct ml_device *ml, | |
325 | unsigned long *effect_handled, | |
326 | struct ff_effect *combo_effect) | |
327 | { | |
328 | struct ff_effect *effect; | |
329 | struct ml_effect_state *state; | |
330 | int effect_type; | |
331 | int i; | |
332 | ||
333 | memset(combo_effect, 0, sizeof(struct ff_effect)); | |
334 | ||
335 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
336 | if (__test_and_set_bit(i, effect_handled)) | |
337 | continue; | |
338 | ||
339 | state = &ml->states[i]; | |
340 | effect = state->effect; | |
341 | ||
342 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
343 | continue; | |
344 | ||
345 | if (time_before(jiffies, state->play_at)) | |
346 | continue; | |
347 | ||
348 | /* | |
349 | * here we have started effects that are either | |
350 | * currently playing (and may need be aborted) | |
351 | * or need to start playing. | |
352 | */ | |
353 | effect_type = get_compatible_type(ml->dev->ff, effect->type); | |
354 | if (combo_effect->type != effect_type) { | |
355 | if (combo_effect->type != 0) { | |
356 | __clear_bit(i, effect_handled); | |
357 | continue; | |
358 | } | |
359 | combo_effect->type = effect_type; | |
360 | } | |
361 | ||
362 | if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { | |
363 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
364 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
365 | } else if (effect->replay.length && | |
366 | time_after_eq(jiffies, state->stop_at)) { | |
367 | ||
368 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
369 | ||
370 | if (--state->count <= 0) { | |
371 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
372 | } else { | |
373 | state->play_at = jiffies + | |
374 | msecs_to_jiffies(effect->replay.delay); | |
375 | state->stop_at = state->play_at + | |
376 | msecs_to_jiffies(effect->replay.length); | |
377 | } | |
378 | } else { | |
379 | __set_bit(FF_EFFECT_PLAYING, &state->flags); | |
380 | state->adj_at = jiffies; | |
381 | ml_combine_effects(combo_effect, state, ml->gain); | |
382 | } | |
383 | } | |
384 | ||
385 | return combo_effect->type != 0; | |
386 | } | |
387 | ||
388 | static void ml_play_effects(struct ml_device *ml) | |
389 | { | |
390 | struct ff_effect effect; | |
391 | DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); | |
392 | ||
393 | memset(handled_bm, 0, sizeof(handled_bm)); | |
394 | ||
395 | while (ml_get_combo_effect(ml, handled_bm, &effect)) | |
396 | ml->play_effect(ml->dev, ml->private, &effect); | |
397 | ||
398 | ml_schedule_timer(ml); | |
399 | } | |
400 | ||
401 | static void ml_effect_timer(unsigned long timer_data) | |
402 | { | |
403 | struct input_dev *dev = (struct input_dev *)timer_data; | |
404 | struct ml_device *ml = dev->ff->private; | |
bf3204cb | 405 | unsigned long flags; |
7d928a2b | 406 | |
da0c4901 | 407 | pr_debug("timer: updating effects\n"); |
7d928a2b | 408 | |
bf3204cb | 409 | spin_lock_irqsave(&dev->event_lock, flags); |
7d928a2b | 410 | ml_play_effects(ml); |
bf3204cb | 411 | spin_unlock_irqrestore(&dev->event_lock, flags); |
7d928a2b AH |
412 | } |
413 | ||
bf3204cb DT |
414 | /* |
415 | * Sets requested gain for FF effects. Called with dev->event_lock held. | |
416 | */ | |
7d928a2b AH |
417 | static void ml_ff_set_gain(struct input_dev *dev, u16 gain) |
418 | { | |
419 | struct ml_device *ml = dev->ff->private; | |
420 | int i; | |
421 | ||
7d928a2b AH |
422 | ml->gain = gain; |
423 | ||
424 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
425 | __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); | |
426 | ||
427 | ml_play_effects(ml); | |
7d928a2b AH |
428 | } |
429 | ||
bf3204cb DT |
430 | /* |
431 | * Start/stop specified FF effect. Called with dev->event_lock held. | |
432 | */ | |
7d928a2b AH |
433 | static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) |
434 | { | |
435 | struct ml_device *ml = dev->ff->private; | |
436 | struct ml_effect_state *state = &ml->states[effect_id]; | |
7d928a2b AH |
437 | |
438 | if (value > 0) { | |
da0c4901 | 439 | pr_debug("initiated play\n"); |
7d928a2b AH |
440 | |
441 | __set_bit(FF_EFFECT_STARTED, &state->flags); | |
442 | state->count = value; | |
443 | state->play_at = jiffies + | |
444 | msecs_to_jiffies(state->effect->replay.delay); | |
445 | state->stop_at = state->play_at + | |
446 | msecs_to_jiffies(state->effect->replay.length); | |
447 | state->adj_at = state->play_at; | |
448 | ||
7d928a2b | 449 | } else { |
da0c4901 | 450 | pr_debug("initiated stop\n"); |
7d928a2b AH |
451 | |
452 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
453 | __set_bit(FF_EFFECT_ABORTING, &state->flags); | |
454 | else | |
455 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
7d928a2b AH |
456 | } |
457 | ||
25ae0831 JV |
458 | ml_play_effects(ml); |
459 | ||
7d928a2b AH |
460 | return 0; |
461 | } | |
462 | ||
463 | static int ml_ff_upload(struct input_dev *dev, | |
464 | struct ff_effect *effect, struct ff_effect *old) | |
465 | { | |
466 | struct ml_device *ml = dev->ff->private; | |
467 | struct ml_effect_state *state = &ml->states[effect->id]; | |
468 | ||
bf3204cb | 469 | spin_lock_irq(&dev->event_lock); |
7d928a2b AH |
470 | |
471 | if (test_bit(FF_EFFECT_STARTED, &state->flags)) { | |
472 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
473 | state->play_at = jiffies + | |
474 | msecs_to_jiffies(state->effect->replay.delay); | |
475 | state->stop_at = state->play_at + | |
476 | msecs_to_jiffies(state->effect->replay.length); | |
477 | state->adj_at = state->play_at; | |
478 | ml_schedule_timer(ml); | |
479 | } | |
480 | ||
bf3204cb | 481 | spin_unlock_irq(&dev->event_lock); |
7d928a2b AH |
482 | |
483 | return 0; | |
484 | } | |
485 | ||
486 | static void ml_ff_destroy(struct ff_device *ff) | |
487 | { | |
488 | struct ml_device *ml = ff->private; | |
489 | ||
490 | kfree(ml->private); | |
491 | } | |
492 | ||
493 | /** | |
e4477d2d | 494 | * input_ff_create_memless() - create memoryless force-feedback device |
7d928a2b AH |
495 | * @dev: input device supporting force-feedback |
496 | * @data: driver-specific data to be passed into @play_effect | |
497 | * @play_effect: driver-specific method for playing FF effect | |
498 | */ | |
499 | int input_ff_create_memless(struct input_dev *dev, void *data, | |
500 | int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) | |
501 | { | |
502 | struct ml_device *ml; | |
503 | struct ff_device *ff; | |
504 | int error; | |
505 | int i; | |
506 | ||
507 | ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); | |
508 | if (!ml) | |
509 | return -ENOMEM; | |
510 | ||
511 | ml->dev = dev; | |
512 | ml->private = data; | |
513 | ml->play_effect = play_effect; | |
514 | ml->gain = 0xffff; | |
7d928a2b AH |
515 | setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); |
516 | ||
517 | set_bit(FF_GAIN, dev->ffbit); | |
518 | ||
519 | error = input_ff_create(dev, FF_MEMLESS_EFFECTS); | |
520 | if (error) { | |
521 | kfree(ml); | |
522 | return error; | |
523 | } | |
524 | ||
525 | ff = dev->ff; | |
526 | ff->private = ml; | |
527 | ff->upload = ml_ff_upload; | |
528 | ff->playback = ml_ff_playback; | |
529 | ff->set_gain = ml_ff_set_gain; | |
530 | ff->destroy = ml_ff_destroy; | |
531 | ||
532 | /* we can emulate periodic effects with RUMBLE */ | |
533 | if (test_bit(FF_RUMBLE, ff->ffbit)) { | |
534 | set_bit(FF_PERIODIC, dev->ffbit); | |
535 | set_bit(FF_SINE, dev->ffbit); | |
536 | set_bit(FF_TRIANGLE, dev->ffbit); | |
537 | set_bit(FF_SQUARE, dev->ffbit); | |
538 | } | |
539 | ||
540 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
541 | ml->states[i].effect = &ff->effects[i]; | |
542 | ||
543 | return 0; | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(input_ff_create_memless); |