Pepper: Spotfix for write silence
[linux-3.10.git] / drivers / input / ff-memless.c
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 #include <linux/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         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
78         case FF_CONSTANT:
79                 return &effect->u.constant.envelope;
80
81         default:
82                 return &empty_envelope;
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
133         pr_debug("calculating next timer\n");
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) {
153                 pr_debug("no actions\n");
154                 del_timer(&ml->timer);
155         } else {
156                 pr_debug("timer set\n");
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))) {
177                 pr_debug("value = 0x%x, attack_level = 0x%x\n",
178                          value, envelope->attack_level);
179                 time_from_level = jiffies_to_msecs(now - state->play_at);
180                 time_of_envelope = envelope->attack_length;
181                 envelope_level = min_t(u16, envelope->attack_level, 0x7fff);
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;
189                 envelope_level = min_t(u16, envelope->fade_level, 0x7fff);
190         } else
191                 return value;
192
193         difference = abs(value) - envelope_level;
194
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);
198
199         difference = difference * time_from_level / time_of_envelope;
200
201         pr_debug("difference = %d\n", difference);
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
219         pr_err("invalid type in get_compatible_type()\n");
220
221         return 0;
222 }
223
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
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,
245                                int gain)
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 =
266                         clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
267                 effect->u.ramp.end_level =
268                         clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
269                 break;
270
271         case FF_RUMBLE:
272                 strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
273                 weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
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;
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
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;
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:
315                 pr_err("invalid type in ml_combine_effects()\n");
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;
407         unsigned long flags;
408
409         pr_debug("timer: updating effects\n");
410
411         spin_lock_irqsave(&dev->event_lock, flags);
412         ml_play_effects(ml);
413         spin_unlock_irqrestore(&dev->event_lock, flags);
414 }
415
416 /*
417  * Sets requested gain for FF effects. Called with dev->event_lock held.
418  */
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
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);
430 }
431
432 /*
433  * Start/stop specified FF effect. Called with dev->event_lock held.
434  */
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];
439
440         if (value > 0) {
441                 pr_debug("initiated play\n");
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
451         } else {
452                 pr_debug("initiated stop\n");
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);
458         }
459
460         ml_play_effects(ml);
461
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
471         spin_lock_irq(&dev->event_lock);
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
483         spin_unlock_irq(&dev->event_lock);
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 /**
496  * input_ff_create_memless() - create memoryless force-feedback device
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;
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);