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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; | |
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 | ||
131 | debug("calculating next timer"); | |
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) { | |
151 | debug("no actions"); | |
152 | del_timer(&ml->timer); | |
153 | } else { | |
154 | debug("timer set"); | |
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))) { | |
175 | debug("value = 0x%x, attack_level = 0x%x", value, | |
176 | envelope->attack_level); | |
177 | time_from_level = jiffies_to_msecs(now - state->play_at); | |
178 | time_of_envelope = envelope->attack_length; | |
179 | envelope_level = min_t(__s16, envelope->attack_level, 0x7fff); | |
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; | |
187 | envelope_level = min_t(__s16, envelope->fade_level, 0x7fff); | |
188 | } else | |
189 | return value; | |
190 | ||
191 | difference = abs(value) - envelope_level; | |
192 | ||
193 | debug("difference = %d", difference); | |
194 | debug("time_from_level = 0x%x", time_from_level); | |
195 | debug("time_of_envelope = 0x%x", time_of_envelope); | |
196 | ||
197 | difference = difference * time_from_level / time_of_envelope; | |
198 | ||
199 | debug("difference = %d", difference); | |
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 | ||
217 | printk(KERN_ERR | |
218 | "ff-memless: invalid type in get_compatible_type()\n"); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | /* | |
224 | * Combine two effects and apply gain. | |
225 | */ | |
226 | static void ml_combine_effects(struct ff_effect *effect, | |
227 | struct ml_effect_state *state, | |
1b11c88d | 228 | int gain) |
7d928a2b AH |
229 | { |
230 | struct ff_effect *new = state->effect; | |
231 | unsigned int strong, weak, i; | |
232 | int x, y; | |
233 | fixp_t level; | |
234 | ||
235 | switch (new->type) { | |
236 | case FF_CONSTANT: | |
237 | i = new->direction * 360 / 0xffff; | |
238 | level = fixp_new16(apply_envelope(state, | |
239 | new->u.constant.level, | |
240 | &new->u.constant.envelope)); | |
241 | x = fixp_mult(fixp_sin(i), level) * gain / 0xffff; | |
242 | y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff; | |
243 | /* | |
244 | * here we abuse ff_ramp to hold x and y of constant force | |
245 | * If in future any driver wants something else than x and y | |
246 | * in s8, this should be changed to something more generic | |
247 | */ | |
248 | effect->u.ramp.start_level = | |
92310474 | 249 | clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f); |
7d928a2b | 250 | effect->u.ramp.end_level = |
92310474 | 251 | clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f); |
7d928a2b AH |
252 | break; |
253 | ||
254 | case FF_RUMBLE: | |
1b11c88d DT |
255 | strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff; |
256 | weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff; | |
7d928a2b AH |
257 | effect->u.rumble.strong_magnitude = |
258 | min(strong + effect->u.rumble.strong_magnitude, | |
259 | 0xffffU); | |
260 | effect->u.rumble.weak_magnitude = | |
261 | min(weak + effect->u.rumble.weak_magnitude, 0xffffU); | |
262 | break; | |
263 | ||
264 | case FF_PERIODIC: | |
265 | i = apply_envelope(state, abs(new->u.periodic.magnitude), | |
266 | &new->u.periodic.envelope); | |
267 | ||
268 | /* here we also scale it 0x7fff => 0xffff */ | |
269 | i = i * gain / 0x7fff; | |
270 | ||
271 | effect->u.rumble.strong_magnitude = | |
272 | min(i + effect->u.rumble.strong_magnitude, 0xffffU); | |
273 | effect->u.rumble.weak_magnitude = | |
274 | min(i + effect->u.rumble.weak_magnitude, 0xffffU); | |
275 | break; | |
276 | ||
277 | default: | |
278 | printk(KERN_ERR "ff-memless: invalid type in ml_combine_effects()\n"); | |
279 | break; | |
280 | } | |
281 | ||
282 | } | |
283 | ||
284 | ||
285 | /* | |
286 | * Because memoryless devices have only one effect per effect type active | |
287 | * at one time we have to combine multiple effects into one | |
288 | */ | |
289 | static int ml_get_combo_effect(struct ml_device *ml, | |
290 | unsigned long *effect_handled, | |
291 | struct ff_effect *combo_effect) | |
292 | { | |
293 | struct ff_effect *effect; | |
294 | struct ml_effect_state *state; | |
295 | int effect_type; | |
296 | int i; | |
297 | ||
298 | memset(combo_effect, 0, sizeof(struct ff_effect)); | |
299 | ||
300 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) { | |
301 | if (__test_and_set_bit(i, effect_handled)) | |
302 | continue; | |
303 | ||
304 | state = &ml->states[i]; | |
305 | effect = state->effect; | |
306 | ||
307 | if (!test_bit(FF_EFFECT_STARTED, &state->flags)) | |
308 | continue; | |
309 | ||
310 | if (time_before(jiffies, state->play_at)) | |
311 | continue; | |
312 | ||
313 | /* | |
314 | * here we have started effects that are either | |
315 | * currently playing (and may need be aborted) | |
316 | * or need to start playing. | |
317 | */ | |
318 | effect_type = get_compatible_type(ml->dev->ff, effect->type); | |
319 | if (combo_effect->type != effect_type) { | |
320 | if (combo_effect->type != 0) { | |
321 | __clear_bit(i, effect_handled); | |
322 | continue; | |
323 | } | |
324 | combo_effect->type = effect_type; | |
325 | } | |
326 | ||
327 | if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) { | |
328 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
329 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
330 | } else if (effect->replay.length && | |
331 | time_after_eq(jiffies, state->stop_at)) { | |
332 | ||
333 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
334 | ||
335 | if (--state->count <= 0) { | |
336 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
337 | } else { | |
338 | state->play_at = jiffies + | |
339 | msecs_to_jiffies(effect->replay.delay); | |
340 | state->stop_at = state->play_at + | |
341 | msecs_to_jiffies(effect->replay.length); | |
342 | } | |
343 | } else { | |
344 | __set_bit(FF_EFFECT_PLAYING, &state->flags); | |
345 | state->adj_at = jiffies; | |
346 | ml_combine_effects(combo_effect, state, ml->gain); | |
347 | } | |
348 | } | |
349 | ||
350 | return combo_effect->type != 0; | |
351 | } | |
352 | ||
353 | static void ml_play_effects(struct ml_device *ml) | |
354 | { | |
355 | struct ff_effect effect; | |
356 | DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS); | |
357 | ||
358 | memset(handled_bm, 0, sizeof(handled_bm)); | |
359 | ||
360 | while (ml_get_combo_effect(ml, handled_bm, &effect)) | |
361 | ml->play_effect(ml->dev, ml->private, &effect); | |
362 | ||
363 | ml_schedule_timer(ml); | |
364 | } | |
365 | ||
366 | static void ml_effect_timer(unsigned long timer_data) | |
367 | { | |
368 | struct input_dev *dev = (struct input_dev *)timer_data; | |
369 | struct ml_device *ml = dev->ff->private; | |
bf3204cb | 370 | unsigned long flags; |
7d928a2b AH |
371 | |
372 | debug("timer: updating effects"); | |
373 | ||
bf3204cb | 374 | spin_lock_irqsave(&dev->event_lock, flags); |
7d928a2b | 375 | ml_play_effects(ml); |
bf3204cb | 376 | spin_unlock_irqrestore(&dev->event_lock, flags); |
7d928a2b AH |
377 | } |
378 | ||
bf3204cb DT |
379 | /* |
380 | * Sets requested gain for FF effects. Called with dev->event_lock held. | |
381 | */ | |
7d928a2b AH |
382 | static void ml_ff_set_gain(struct input_dev *dev, u16 gain) |
383 | { | |
384 | struct ml_device *ml = dev->ff->private; | |
385 | int i; | |
386 | ||
7d928a2b AH |
387 | ml->gain = gain; |
388 | ||
389 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
390 | __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags); | |
391 | ||
392 | ml_play_effects(ml); | |
7d928a2b AH |
393 | } |
394 | ||
bf3204cb DT |
395 | /* |
396 | * Start/stop specified FF effect. Called with dev->event_lock held. | |
397 | */ | |
7d928a2b AH |
398 | static int ml_ff_playback(struct input_dev *dev, int effect_id, int value) |
399 | { | |
400 | struct ml_device *ml = dev->ff->private; | |
401 | struct ml_effect_state *state = &ml->states[effect_id]; | |
7d928a2b AH |
402 | |
403 | if (value > 0) { | |
404 | debug("initiated play"); | |
405 | ||
406 | __set_bit(FF_EFFECT_STARTED, &state->flags); | |
407 | state->count = value; | |
408 | state->play_at = jiffies + | |
409 | msecs_to_jiffies(state->effect->replay.delay); | |
410 | state->stop_at = state->play_at + | |
411 | msecs_to_jiffies(state->effect->replay.length); | |
412 | state->adj_at = state->play_at; | |
413 | ||
7d928a2b AH |
414 | } else { |
415 | debug("initiated stop"); | |
416 | ||
417 | if (test_bit(FF_EFFECT_PLAYING, &state->flags)) | |
418 | __set_bit(FF_EFFECT_ABORTING, &state->flags); | |
419 | else | |
420 | __clear_bit(FF_EFFECT_STARTED, &state->flags); | |
7d928a2b AH |
421 | } |
422 | ||
25ae0831 JV |
423 | ml_play_effects(ml); |
424 | ||
7d928a2b AH |
425 | return 0; |
426 | } | |
427 | ||
428 | static int ml_ff_upload(struct input_dev *dev, | |
429 | struct ff_effect *effect, struct ff_effect *old) | |
430 | { | |
431 | struct ml_device *ml = dev->ff->private; | |
432 | struct ml_effect_state *state = &ml->states[effect->id]; | |
433 | ||
bf3204cb | 434 | spin_lock_irq(&dev->event_lock); |
7d928a2b AH |
435 | |
436 | if (test_bit(FF_EFFECT_STARTED, &state->flags)) { | |
437 | __clear_bit(FF_EFFECT_PLAYING, &state->flags); | |
438 | state->play_at = jiffies + | |
439 | msecs_to_jiffies(state->effect->replay.delay); | |
440 | state->stop_at = state->play_at + | |
441 | msecs_to_jiffies(state->effect->replay.length); | |
442 | state->adj_at = state->play_at; | |
443 | ml_schedule_timer(ml); | |
444 | } | |
445 | ||
bf3204cb | 446 | spin_unlock_irq(&dev->event_lock); |
7d928a2b AH |
447 | |
448 | return 0; | |
449 | } | |
450 | ||
451 | static void ml_ff_destroy(struct ff_device *ff) | |
452 | { | |
453 | struct ml_device *ml = ff->private; | |
454 | ||
455 | kfree(ml->private); | |
456 | } | |
457 | ||
458 | /** | |
e4477d2d | 459 | * input_ff_create_memless() - create memoryless force-feedback device |
7d928a2b AH |
460 | * @dev: input device supporting force-feedback |
461 | * @data: driver-specific data to be passed into @play_effect | |
462 | * @play_effect: driver-specific method for playing FF effect | |
463 | */ | |
464 | int input_ff_create_memless(struct input_dev *dev, void *data, | |
465 | int (*play_effect)(struct input_dev *, void *, struct ff_effect *)) | |
466 | { | |
467 | struct ml_device *ml; | |
468 | struct ff_device *ff; | |
469 | int error; | |
470 | int i; | |
471 | ||
472 | ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL); | |
473 | if (!ml) | |
474 | return -ENOMEM; | |
475 | ||
476 | ml->dev = dev; | |
477 | ml->private = data; | |
478 | ml->play_effect = play_effect; | |
479 | ml->gain = 0xffff; | |
7d928a2b AH |
480 | setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev); |
481 | ||
482 | set_bit(FF_GAIN, dev->ffbit); | |
483 | ||
484 | error = input_ff_create(dev, FF_MEMLESS_EFFECTS); | |
485 | if (error) { | |
486 | kfree(ml); | |
487 | return error; | |
488 | } | |
489 | ||
490 | ff = dev->ff; | |
491 | ff->private = ml; | |
492 | ff->upload = ml_ff_upload; | |
493 | ff->playback = ml_ff_playback; | |
494 | ff->set_gain = ml_ff_set_gain; | |
495 | ff->destroy = ml_ff_destroy; | |
496 | ||
497 | /* we can emulate periodic effects with RUMBLE */ | |
498 | if (test_bit(FF_RUMBLE, ff->ffbit)) { | |
499 | set_bit(FF_PERIODIC, dev->ffbit); | |
500 | set_bit(FF_SINE, dev->ffbit); | |
501 | set_bit(FF_TRIANGLE, dev->ffbit); | |
502 | set_bit(FF_SQUARE, dev->ffbit); | |
503 | } | |
504 | ||
505 | for (i = 0; i < FF_MEMLESS_EFFECTS; i++) | |
506 | ml->states[i].effect = &ff->effects[i]; | |
507 | ||
508 | return 0; | |
509 | } | |
510 | EXPORT_SYMBOL_GPL(input_ff_create_memless); |