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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 | ||
26 | #define debug(format, arg...) pr_debug("ff-memless: " format "\n", ## arg) | |
27 | ||
28 | #include <linux/input.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/mutex.h> | |
31 | #include <linux/spinlock.h> | |
cd354f1a | 32 | #include <linux/jiffies.h> |
7d928a2b AH |
33 | |
34 | #include "fixp-arith.h" | |
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; | |
64 | spinlock_t timer_lock; | |
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 | debug("calculating next timer"); | |
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 | debug("no actions"); | |
153 | del_timer(&ml->timer); | |
154 | } else { | |
155 | debug("timer set"); | |
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 | debug("value = 0x%x, attack_level = 0x%x", value, | |
177 | 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 | debug("difference = %d", difference); | |
195 | debug("time_from_level = 0x%x", time_from_level); | |
196 | debug("time_of_envelope = 0x%x", time_of_envelope); | |
197 | ||
198 | difference = difference * time_from_level / time_of_envelope; | |
199 | ||
200 | debug("difference = %d", 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 | printk(KERN_ERR | |
219 | "ff-memless: invalid type in get_compatible_type()\n"); | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | /* | |
225 | * Combine two effects and apply gain. | |
226 | */ | |
227 | static void ml_combine_effects(struct ff_effect *effect, | |
228 | struct ml_effect_state *state, | |
229 | int gain) | |
230 | { | |
231 | struct ff_effect *new = state->effect; | |
232 | unsigned int strong, weak, i; | |
233 | int x, y; | |
234 | fixp_t level; | |
235 | ||
236 | switch (new->type) { | |
237 | case FF_CONSTANT: | |
238 | i = new->direction * 360 / 0xffff; | |
239 | level = fixp_new16(apply_envelope(state, | |
240 | new->u.constant.level, | |
241 | &new->u.constant.envelope)); | |
242 | x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; | |
243 | y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; | |
244 | /* | |
245 | * here we abuse ff_ramp to hold x and y of constant force | |
246 | * If in future any driver wants something else than x and y | |
247 | * in s8, this should be changed to something more generic | |
248 | */ | |
249 | effect->u.ramp.start_level = | |
92310474 | 250 | clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); |
7d928a2b | 251 | effect->u.ramp.end_level = |
92310474 | 252 | clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); |
7d928a2b AH |
253 | break; |
254 | ||
255 | case FF_RUMBLE: | |
256 | strong = new->u.rumble.strong_magnitude * gain / 0xffff; | |
257 | weak = new->u.rumble.weak_magnitude * gain / 0xffff; | |
258 | effect->u.rumble.strong_magnitude = | |
259 | min(strong + effect->u.rumble.strong_magnitude, | |
260 | 0xffffU); | |
261 | effect->u.rumble.weak_magnitude = | |
262 | min(weak + effect->u.rumble.weak_magnitude, 0xffffU); | |
263 | break; | |
264 | ||
265 | case FF_PERIODIC: | |
266 | i = apply_envelope(state, abs(new->u.periodic.magnitude), | |
267 | &new->u.periodic.envelope); | |
268 | ||
269 | /* here we also scale it 0x7fff => 0xffff */ | |
270 | i = i * gain / 0x7fff; | |
271 | ||
272 | effect->u.rumble.strong_magnitude = | |
273 | min(i + effect->u.rumble.strong_magnitude, 0xffffU); | |
274 | effect->u.rumble.weak_magnitude = | |
275 | min(i + effect->u.rumble.weak_magnitude, 0xffffU); | |
276 | break; | |
277 | ||
278 | default: | |
279 | printk(KERN_ERR "ff-memless: invalid type in ml_combine_effects()\n"); | |
280 | break; | |
281 | } | |
282 | ||
283 | } | |
284 | ||
285 | ||
286 | /* | |
287 | * Because memoryless devices have only one effect per effect type active | |
288 | * at one time we have to combine multiple effects into one | |
289 | */ | |
290 | static int ml_get_combo_effect(struct ml_device *ml, | |
291 | unsigned long *effect_handled, | |
292 | struct ff_effect *combo_effect) | |
293 | { | |
294 | struct ff_effect *effect; | |
295 | struct ml_effect_state *state; | |
296 | int effect_type; | |
297 | int i; | |
298 | ||
299 | memset(combo_effect, 0, sizeof(struct ff_effect)); | |
300 | ||
301 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
302 | if (__test_and_set_bit(i, effect_handled)) | |
303 | continue; | |
304 | ||
305 | state = &ml->states[i]; | |
306 | effect = state->effect; | |
307 | ||
308 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
309 | continue; | |
310 | ||
311 | if (time_before(jiffies, state->play_at)) | |
312 | continue; | |
313 | ||
314 | /* | |
315 | * here we have started effects that are either | |
316 | * currently playing (and may need be aborted) | |
317 | * or need to start playing. | |
318 | */ | |
319 | effect_type = get_compatible_type(ml->dev->ff, effect->type); | |
320 | if (combo_effect->type != effect_type) { | |
321 | if (combo_effect->type != 0) { | |
322 | __clear_bit(i, effect_handled); | |
323 | continue; | |
324 | } | |
325 | combo_effect->type = effect_type; | |
326 | } | |
327 | ||
328 | if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { | |
329 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
330 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
331 | } else if (effect->replay.length && | |
332 | time_after_eq(jiffies, state->stop_at)) { | |
333 | ||
334 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
335 | ||
336 | if (--state->count <= 0) { | |
337 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
338 | } else { | |
339 | state->play_at = jiffies + | |
340 | msecs_to_jiffies(effect->replay.delay); | |
341 | state->stop_at = state->play_at + | |
342 | msecs_to_jiffies(effect->replay.length); | |
343 | } | |
344 | } else { | |
345 | __set_bit(FF_EFFECT_PLAYING, &state->flags); | |
346 | state->adj_at = jiffies; | |
347 | ml_combine_effects(combo_effect, state, ml->gain); | |
348 | } | |
349 | } | |
350 | ||
351 | return combo_effect->type != 0; | |
352 | } | |
353 | ||
354 | static void ml_play_effects(struct ml_device *ml) | |
355 | { | |
356 | struct ff_effect effect; | |
357 | DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); | |
358 | ||
359 | memset(handled_bm, 0, sizeof(handled_bm)); | |
360 | ||
361 | while (ml_get_combo_effect(ml, handled_bm, &effect)) | |
362 | ml->play_effect(ml->dev, ml->private, &effect); | |
363 | ||
364 | ml_schedule_timer(ml); | |
365 | } | |
366 | ||
367 | static void ml_effect_timer(unsigned long timer_data) | |
368 | { | |
369 | struct input_dev *dev = (struct input_dev *)timer_data; | |
370 | struct ml_device *ml = dev->ff->private; | |
371 | ||
372 | debug("timer: updating effects"); | |
373 | ||
374 | spin_lock(&ml->timer_lock); | |
375 | ml_play_effects(ml); | |
376 | spin_unlock(&ml->timer_lock); | |
377 | } | |
378 | ||
379 | static void ml_ff_set_gain(struct input_dev *dev, u16 gain) | |
380 | { | |
381 | struct ml_device *ml = dev->ff->private; | |
382 | int i; | |
383 | ||
384 | spin_lock_bh(&ml->timer_lock); | |
385 | ||
386 | ml->gain = gain; | |
387 | ||
388 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
389 | __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); | |
390 | ||
391 | ml_play_effects(ml); | |
392 | ||
393 | spin_unlock_bh(&ml->timer_lock); | |
394 | } | |
395 | ||
396 | static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) | |
397 | { | |
398 | struct ml_device *ml = dev->ff->private; | |
399 | struct ml_effect_state *state = &ml->states[effect_id]; | |
211f05a0 | 400 | unsigned long flags; |
7d928a2b | 401 | |
211f05a0 | 402 | spin_lock_irqsave(&ml->timer_lock, flags); |
7d928a2b AH |
403 | |
404 | if (value > 0) { | |
405 | debug("initiated play"); | |
406 | ||
407 | __set_bit(FF_EFFECT_STARTED, &state->flags); | |
408 | state->count = value; | |
409 | state->play_at = jiffies + | |
410 | msecs_to_jiffies(state->effect->replay.delay); | |
411 | state->stop_at = state->play_at + | |
412 | msecs_to_jiffies(state->effect->replay.length); | |
413 | state->adj_at = state->play_at; | |
414 | ||
415 | ml_schedule_timer(ml); | |
416 | ||
417 | } else { | |
418 | debug("initiated stop"); | |
419 | ||
420 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
421 | __set_bit(FF_EFFECT_ABORTING, &state->flags); | |
422 | else | |
423 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
424 | ||
425 | ml_play_effects(ml); | |
426 | } | |
427 | ||
211f05a0 | 428 | spin_unlock_irqrestore(&ml->timer_lock, flags); |
7d928a2b AH |
429 | |
430 | return 0; | |
431 | } | |
432 | ||
433 | static int ml_ff_upload(struct input_dev *dev, | |
434 | struct ff_effect *effect, struct ff_effect *old) | |
435 | { | |
436 | struct ml_device *ml = dev->ff->private; | |
437 | struct ml_effect_state *state = &ml->states[effect->id]; | |
438 | ||
439 | spin_lock_bh(&ml->timer_lock); | |
440 | ||
441 | if (test_bit(FF_EFFECT_STARTED, &state->flags)) { | |
442 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
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 | ml_schedule_timer(ml); | |
449 | } | |
450 | ||
451 | spin_unlock_bh(&ml->timer_lock); | |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | static void ml_ff_destroy(struct ff_device *ff) | |
457 | { | |
458 | struct ml_device *ml = ff->private; | |
459 | ||
460 | kfree(ml->private); | |
461 | } | |
462 | ||
463 | /** | |
e4477d2d | 464 | * input_ff_create_memless() - create memoryless force-feedback device |
7d928a2b AH |
465 | * @dev: input device supporting force-feedback |
466 | * @data: driver-specific data to be passed into @play_effect | |
467 | * @play_effect: driver-specific method for playing FF effect | |
468 | */ | |
469 | int input_ff_create_memless(struct input_dev *dev, void *data, | |
470 | int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) | |
471 | { | |
472 | struct ml_device *ml; | |
473 | struct ff_device *ff; | |
474 | int error; | |
475 | int i; | |
476 | ||
477 | ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); | |
478 | if (!ml) | |
479 | return -ENOMEM; | |
480 | ||
481 | ml->dev = dev; | |
482 | ml->private = data; | |
483 | ml->play_effect = play_effect; | |
484 | ml->gain = 0xffff; | |
485 | spin_lock_init(&ml->timer_lock); | |
486 | setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); | |
487 | ||
488 | set_bit(FF_GAIN, dev->ffbit); | |
489 | ||
490 | error = input_ff_create(dev, FF_MEMLESS_EFFECTS); | |
491 | if (error) { | |
492 | kfree(ml); | |
493 | return error; | |
494 | } | |
495 | ||
496 | ff = dev->ff; | |
497 | ff->private = ml; | |
498 | ff->upload = ml_ff_upload; | |
499 | ff->playback = ml_ff_playback; | |
500 | ff->set_gain = ml_ff_set_gain; | |
501 | ff->destroy = ml_ff_destroy; | |
502 | ||
503 | /* we can emulate periodic effects with RUMBLE */ | |
504 | if (test_bit(FF_RUMBLE, ff->ffbit)) { | |
505 | set_bit(FF_PERIODIC, dev->ffbit); | |
506 | set_bit(FF_SINE, dev->ffbit); | |
507 | set_bit(FF_TRIANGLE, dev->ffbit); | |
508 | set_bit(FF_SQUARE, dev->ffbit); | |
509 | } | |
510 | ||
511 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
512 | ml->states[i].effect = &ff->effects[i]; | |
513 | ||
514 | return 0; | |
515 | } | |
516 | EXPORT_SYMBOL_GPL(input_ff_create_memless); |