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) { | |
41091ad0 BC |
75 | case FF_PERIODIC: |
76 | return &effect->u.periodic.envelope; | |
77 | ||
78 | case FF_CONSTANT: | |
79 | return &effect->u.constant.envelope; | |
80 | ||
81 | default: | |
82 | return &empty_envelope; | |
7d928a2b AH |
83 | } |
84 | } | |
85 | ||
86 | /* | |
87 | * Check for the next time envelope requires an update on memoryless devices | |
88 | */ | |
89 | static unsigned long calculate_next_time(struct ml_effect_state *state) | |
90 | { | |
91 | const struct ff_envelope *envelope = get_envelope(state->effect); | |
92 | unsigned long attack_stop, fade_start, next_fade; | |
93 | ||
94 | if (envelope->attack_length) { | |
95 | attack_stop = state->play_at + | |
96 | msecs_to_jiffies(envelope->attack_length); | |
97 | if (time_before(state->adj_at, attack_stop)) | |
98 | return state->adj_at + | |
99 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); | |
100 | } | |
101 | ||
102 | if (state->effect->replay.length) { | |
103 | if (envelope->fade_length) { | |
104 | /* check when fading should start */ | |
105 | fade_start = state->stop_at - | |
106 | msecs_to_jiffies(envelope->fade_length); | |
107 | ||
108 | if (time_before(state->adj_at, fade_start)) | |
109 | return fade_start; | |
110 | ||
111 | /* already fading, advance to next checkpoint */ | |
112 | next_fade = state->adj_at + | |
113 | msecs_to_jiffies(FF_ENVELOPE_INTERVAL); | |
114 | if (time_before(next_fade, state->stop_at)) | |
115 | return next_fade; | |
116 | } | |
117 | ||
118 | return state->stop_at; | |
119 | } | |
120 | ||
121 | return state->play_at; | |
122 | } | |
123 | ||
124 | static void ml_schedule_timer(struct ml_device *ml) | |
125 | { | |
126 | struct ml_effect_state *state; | |
127 | unsigned long now = jiffies; | |
128 | unsigned long earliest = 0; | |
129 | unsigned long next_at; | |
130 | int events = 0; | |
131 | int i; | |
132 | ||
da0c4901 | 133 | pr_debug("calculating next timer\n"); |
7d928a2b AH |
134 | |
135 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
136 | ||
137 | state = &ml->states[i]; | |
138 | ||
139 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
140 | continue; | |
141 | ||
142 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
143 | next_at = calculate_next_time(state); | |
144 | else | |
145 | next_at = state->play_at; | |
146 | ||
147 | if (time_before_eq(now, next_at) && | |
148 | (++events == 1 || time_before(next_at, earliest))) | |
149 | earliest = next_at; | |
150 | } | |
151 | ||
152 | if (!events) { | |
da0c4901 | 153 | pr_debug("no actions\n"); |
7d928a2b AH |
154 | del_timer(&ml->timer); |
155 | } else { | |
da0c4901 | 156 | pr_debug("timer set\n"); |
7d928a2b AH |
157 | mod_timer(&ml->timer, earliest); |
158 | } | |
159 | } | |
160 | ||
161 | /* | |
162 | * Apply an envelope to a value | |
163 | */ | |
164 | static int apply_envelope(struct ml_effect_state *state, int value, | |
165 | struct ff_envelope *envelope) | |
166 | { | |
167 | struct ff_effect *effect = state->effect; | |
168 | unsigned long now = jiffies; | |
169 | int time_from_level; | |
170 | int time_of_envelope; | |
171 | int envelope_level; | |
172 | int difference; | |
173 | ||
174 | if (envelope->attack_length && | |
175 | time_before(now, | |
176 | state->play_at + msecs_to_jiffies(envelope->attack_length))) { | |
da0c4901 JP |
177 | pr_debug("value = 0x%x, attack_level = 0x%x\n", |
178 | value, envelope->attack_level); | |
7d928a2b AH |
179 | time_from_level = jiffies_to_msecs(now - state->play_at); |
180 | time_of_envelope = envelope->attack_length; | |
9a932145 | 181 | envelope_level = min_t(u16, envelope->attack_level, 0x7fff); |
7d928a2b AH |
182 | |
183 | } else if (envelope->fade_length && effect->replay.length && | |
184 | time_after(now, | |
185 | state->stop_at - msecs_to_jiffies(envelope->fade_length)) && | |
186 | time_before(now, state->stop_at)) { | |
187 | time_from_level = jiffies_to_msecs(state->stop_at - now); | |
188 | time_of_envelope = envelope->fade_length; | |
9a932145 | 189 | envelope_level = min_t(u16, envelope->fade_level, 0x7fff); |
7d928a2b AH |
190 | } else |
191 | return value; | |
192 | ||
193 | difference = abs(value) - envelope_level; | |
194 | ||
da0c4901 JP |
195 | pr_debug("difference = %d\n", difference); |
196 | pr_debug("time_from_level = 0x%x\n", time_from_level); | |
197 | pr_debug("time_of_envelope = 0x%x\n", time_of_envelope); | |
7d928a2b AH |
198 | |
199 | difference = difference * time_from_level / time_of_envelope; | |
200 | ||
da0c4901 | 201 | pr_debug("difference = %d\n", difference); |
7d928a2b AH |
202 | |
203 | return value < 0 ? | |
204 | -(difference + envelope_level) : (difference + envelope_level); | |
205 | } | |
206 | ||
207 | /* | |
208 | * Return the type the effect has to be converted into (memless devices) | |
209 | */ | |
210 | static int get_compatible_type(struct ff_device *ff, int effect_type) | |
211 | { | |
212 | ||
213 | if (test_bit(effect_type, ff->ffbit)) | |
214 | return effect_type; | |
215 | ||
216 | if (effect_type == FF_PERIODIC && test_bit(FF_RUMBLE, ff->ffbit)) | |
217 | return FF_RUMBLE; | |
218 | ||
da0c4901 | 219 | pr_err("invalid type in get_compatible_type()\n"); |
7d928a2b AH |
220 | |
221 | return 0; | |
222 | } | |
223 | ||
94ec26c8 JV |
224 | /* |
225 | * Only left/right direction should be used (under/over 0x8000) for | |
226 | * forward/reverse motor direction (to keep calculation fast & simple). | |
227 | */ | |
228 | static u16 ml_calculate_direction(u16 direction, u16 force, | |
229 | u16 new_direction, u16 new_force) | |
230 | { | |
231 | if (!force) | |
232 | return new_direction; | |
233 | if (!new_force) | |
234 | return direction; | |
235 | return (((u32)(direction >> 1) * force + | |
236 | (new_direction >> 1) * new_force) / | |
237 | (force + new_force)) << 1; | |
238 | } | |
239 | ||
7d928a2b AH |
240 | /* |
241 | * Combine two effects and apply gain. | |
242 | */ | |
243 | static void ml_combine_effects(struct ff_effect *effect, | |
244 | struct ml_effect_state *state, | |
1b11c88d | 245 | int gain) |
7d928a2b AH |
246 | { |
247 | struct ff_effect *new = state->effect; | |
248 | unsigned int strong, weak, i; | |
249 | int x, y; | |
250 | fixp_t level; | |
251 | ||
252 | switch (new->type) { | |
253 | case FF_CONSTANT: | |
254 | i = new->direction * 360 / 0xffff; | |
255 | level = fixp_new16(apply_envelope(state, | |
256 | new->u.constant.level, | |
257 | &new->u.constant.envelope)); | |
258 | x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; | |
259 | y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; | |
260 | /* | |
261 | * here we abuse ff_ramp to hold x and y of constant force | |
262 | * If in future any driver wants something else than x and y | |
263 | * in s8, this should be changed to something more generic | |
264 | */ | |
265 | effect->u.ramp.start_level = | |
92310474 | 266 | clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); |
7d928a2b | 267 | effect->u.ramp.end_level = |
92310474 | 268 | clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); |
7d928a2b AH |
269 | break; |
270 | ||
271 | case FF_RUMBLE: | |
1b11c88d DT |
272 | strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff; |
273 | weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff; | |
94ec26c8 JV |
274 | |
275 | if (effect->u.rumble.strong_magnitude + strong) | |
276 | effect->direction = ml_calculate_direction( | |
277 | effect->direction, | |
278 | effect->u.rumble.strong_magnitude, | |
279 | new->direction, strong); | |
280 | else if (effect->u.rumble.weak_magnitude + weak) | |
281 | effect->direction = ml_calculate_direction( | |
282 | effect->direction, | |
283 | effect->u.rumble.weak_magnitude, | |
284 | new->direction, weak); | |
285 | else | |
286 | effect->direction = 0; | |
7d928a2b AH |
287 | effect->u.rumble.strong_magnitude = |
288 | min(strong + effect->u.rumble.strong_magnitude, | |
289 | 0xffffU); | |
290 | effect->u.rumble.weak_magnitude = | |
291 | min(weak + effect->u.rumble.weak_magnitude, 0xffffU); | |
292 | break; | |
293 | ||
294 | case FF_PERIODIC: | |
295 | i = apply_envelope(state, abs(new->u.periodic.magnitude), | |
296 | &new->u.periodic.envelope); | |
297 | ||
298 | /* here we also scale it 0x7fff => 0xffff */ | |
299 | i = i * gain / 0x7fff; | |
300 | ||
94ec26c8 JV |
301 | if (effect->u.rumble.strong_magnitude + i) |
302 | effect->direction = ml_calculate_direction( | |
303 | effect->direction, | |
304 | effect->u.rumble.strong_magnitude, | |
305 | new->direction, i); | |
306 | else | |
307 | effect->direction = 0; | |
7d928a2b AH |
308 | effect->u.rumble.strong_magnitude = |
309 | min(i + effect->u.rumble.strong_magnitude, 0xffffU); | |
310 | effect->u.rumble.weak_magnitude = | |
311 | min(i + effect->u.rumble.weak_magnitude, 0xffffU); | |
312 | break; | |
313 | ||
314 | default: | |
da0c4901 | 315 | pr_err("invalid type in ml_combine_effects()\n"); |
7d928a2b AH |
316 | break; |
317 | } | |
318 | ||
319 | } | |
320 | ||
321 | ||
322 | /* | |
323 | * Because memoryless devices have only one effect per effect type active | |
324 | * at one time we have to combine multiple effects into one | |
325 | */ | |
326 | static int ml_get_combo_effect(struct ml_device *ml, | |
327 | unsigned long *effect_handled, | |
328 | struct ff_effect *combo_effect) | |
329 | { | |
330 | struct ff_effect *effect; | |
331 | struct ml_effect_state *state; | |
332 | int effect_type; | |
333 | int i; | |
334 | ||
335 | memset(combo_effect, 0, sizeof(struct ff_effect)); | |
336 | ||
337 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
338 | if (__test_and_set_bit(i, effect_handled)) | |
339 | continue; | |
340 | ||
341 | state = &ml->states[i]; | |
342 | effect = state->effect; | |
343 | ||
344 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
345 | continue; | |
346 | ||
347 | if (time_before(jiffies, state->play_at)) | |
348 | continue; | |
349 | ||
350 | /* | |
351 | * here we have started effects that are either | |
352 | * currently playing (and may need be aborted) | |
353 | * or need to start playing. | |
354 | */ | |
355 | effect_type = get_compatible_type(ml->dev->ff, effect->type); | |
356 | if (combo_effect->type != effect_type) { | |
357 | if (combo_effect->type != 0) { | |
358 | __clear_bit(i, effect_handled); | |
359 | continue; | |
360 | } | |
361 | combo_effect->type = effect_type; | |
362 | } | |
363 | ||
364 | if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { | |
365 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
366 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
367 | } else if (effect->replay.length && | |
368 | time_after_eq(jiffies, state->stop_at)) { | |
369 | ||
370 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
371 | ||
372 | if (--state->count <= 0) { | |
373 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
374 | } else { | |
375 | state->play_at = jiffies + | |
376 | msecs_to_jiffies(effect->replay.delay); | |
377 | state->stop_at = state->play_at + | |
378 | msecs_to_jiffies(effect->replay.length); | |
379 | } | |
380 | } else { | |
381 | __set_bit(FF_EFFECT_PLAYING, &state->flags); | |
382 | state->adj_at = jiffies; | |
383 | ml_combine_effects(combo_effect, state, ml->gain); | |
384 | } | |
385 | } | |
386 | ||
387 | return combo_effect->type != 0; | |
388 | } | |
389 | ||
390 | static void ml_play_effects(struct ml_device *ml) | |
391 | { | |
392 | struct ff_effect effect; | |
393 | DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); | |
394 | ||
395 | memset(handled_bm, 0, sizeof(handled_bm)); | |
396 | ||
397 | while (ml_get_combo_effect(ml, handled_bm, &effect)) | |
398 | ml->play_effect(ml->dev, ml->private, &effect); | |
399 | ||
400 | ml_schedule_timer(ml); | |
401 | } | |
402 | ||
403 | static void ml_effect_timer(unsigned long timer_data) | |
404 | { | |
405 | struct input_dev *dev = (struct input_dev *)timer_data; | |
406 | struct ml_device *ml = dev->ff->private; | |
bf3204cb | 407 | unsigned long flags; |
7d928a2b | 408 | |
da0c4901 | 409 | pr_debug("timer: updating effects\n"); |
7d928a2b | 410 | |
bf3204cb | 411 | spin_lock_irqsave(&dev->event_lock, flags); |
7d928a2b | 412 | ml_play_effects(ml); |
bf3204cb | 413 | spin_unlock_irqrestore(&dev->event_lock, flags); |
7d928a2b AH |
414 | } |
415 | ||
bf3204cb DT |
416 | /* |
417 | * Sets requested gain for FF effects. Called with dev->event_lock held. | |
418 | */ | |
7d928a2b AH |
419 | static void ml_ff_set_gain(struct input_dev *dev, u16 gain) |
420 | { | |
421 | struct ml_device *ml = dev->ff->private; | |
422 | int i; | |
423 | ||
7d928a2b AH |
424 | ml->gain = gain; |
425 | ||
426 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
427 | __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); | |
428 | ||
429 | ml_play_effects(ml); | |
7d928a2b AH |
430 | } |
431 | ||
bf3204cb DT |
432 | /* |
433 | * Start/stop specified FF effect. Called with dev->event_lock held. | |
434 | */ | |
7d928a2b AH |
435 | static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) |
436 | { | |
437 | struct ml_device *ml = dev->ff->private; | |
438 | struct ml_effect_state *state = &ml->states[effect_id]; | |
7d928a2b AH |
439 | |
440 | if (value > 0) { | |
da0c4901 | 441 | pr_debug("initiated play\n"); |
7d928a2b AH |
442 | |
443 | __set_bit(FF_EFFECT_STARTED, &state->flags); | |
444 | state->count = value; | |
445 | state->play_at = jiffies + | |
446 | msecs_to_jiffies(state->effect->replay.delay); | |
447 | state->stop_at = state->play_at + | |
448 | msecs_to_jiffies(state->effect->replay.length); | |
449 | state->adj_at = state->play_at; | |
450 | ||
7d928a2b | 451 | } else { |
da0c4901 | 452 | pr_debug("initiated stop\n"); |
7d928a2b AH |
453 | |
454 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
455 | __set_bit(FF_EFFECT_ABORTING, &state->flags); | |
456 | else | |
457 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
7d928a2b AH |
458 | } |
459 | ||
25ae0831 JV |
460 | ml_play_effects(ml); |
461 | ||
7d928a2b AH |
462 | return 0; |
463 | } | |
464 | ||
465 | static int ml_ff_upload(struct input_dev *dev, | |
466 | struct ff_effect *effect, struct ff_effect *old) | |
467 | { | |
468 | struct ml_device *ml = dev->ff->private; | |
469 | struct ml_effect_state *state = &ml->states[effect->id]; | |
470 | ||
bf3204cb | 471 | spin_lock_irq(&dev->event_lock); |
7d928a2b AH |
472 | |
473 | if (test_bit(FF_EFFECT_STARTED, &state->flags)) { | |
474 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
475 | state->play_at = jiffies + | |
476 | msecs_to_jiffies(state->effect->replay.delay); | |
477 | state->stop_at = state->play_at + | |
478 | msecs_to_jiffies(state->effect->replay.length); | |
479 | state->adj_at = state->play_at; | |
480 | ml_schedule_timer(ml); | |
481 | } | |
482 | ||
bf3204cb | 483 | spin_unlock_irq(&dev->event_lock); |
7d928a2b AH |
484 | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static void ml_ff_destroy(struct ff_device *ff) | |
489 | { | |
490 | struct ml_device *ml = ff->private; | |
491 | ||
492 | kfree(ml->private); | |
493 | } | |
494 | ||
495 | /** | |
e4477d2d | 496 | * input_ff_create_memless() - create memoryless force-feedback device |
7d928a2b AH |
497 | * @dev: input device supporting force-feedback |
498 | * @data: driver-specific data to be passed into @play_effect | |
499 | * @play_effect: driver-specific method for playing FF effect | |
500 | */ | |
501 | int input_ff_create_memless(struct input_dev *dev, void *data, | |
502 | int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) | |
503 | { | |
504 | struct ml_device *ml; | |
505 | struct ff_device *ff; | |
506 | int error; | |
507 | int i; | |
508 | ||
509 | ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); | |
510 | if (!ml) | |
511 | return -ENOMEM; | |
512 | ||
513 | ml->dev = dev; | |
514 | ml->private = data; | |
515 | ml->play_effect = play_effect; | |
516 | ml->gain = 0xffff; | |
7d928a2b AH |
517 | setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); |
518 | ||
519 | set_bit(FF_GAIN, dev->ffbit); | |
520 | ||
521 | error = input_ff_create(dev, FF_MEMLESS_EFFECTS); | |
522 | if (error) { | |
523 | kfree(ml); | |
524 | return error; | |
525 | } | |
526 | ||
527 | ff = dev->ff; | |
528 | ff->private = ml; | |
529 | ff->upload = ml_ff_upload; | |
530 | ff->playback = ml_ff_playback; | |
531 | ff->set_gain = ml_ff_set_gain; | |
532 | ff->destroy = ml_ff_destroy; | |
533 | ||
534 | /* we can emulate periodic effects with RUMBLE */ | |
535 | if (test_bit(FF_RUMBLE, ff->ffbit)) { | |
536 | set_bit(FF_PERIODIC, dev->ffbit); | |
537 | set_bit(FF_SINE, dev->ffbit); | |
538 | set_bit(FF_TRIANGLE, dev->ffbit); | |
539 | set_bit(FF_SQUARE, dev->ffbit); | |
540 | } | |
541 | ||
542 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
543 | ml->states[i].effect = &ff->effects[i]; | |
544 | ||
545 | return 0; | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(input_ff_create_memless); |