Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[sfrench/cifs-2.6.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                 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         pr_debug("calculating next timer\n");
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                 pr_debug("no actions\n");
152                 del_timer(&ml->timer);
153         } else {
154                 pr_debug("timer set\n");
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                 pr_debug("value = 0x%x, attack_level = 0x%x\n",
176                          value, 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         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);
196
197         difference = difference * time_from_level / time_of_envelope;
198
199         pr_debug("difference = %d\n", 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         pr_err("invalid type in get_compatible_type()\n");
218
219         return 0;
220 }
221
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
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,
243                                int gain)
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 =
264                         clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
265                 effect->u.ramp.end_level =
266                         clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
267                 break;
268
269         case FF_RUMBLE:
270                 strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
271                 weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
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;
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
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;
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:
313                 pr_err("invalid type in ml_combine_effects()\n");
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;
405         unsigned long flags;
406
407         pr_debug("timer: updating effects\n");
408
409         spin_lock_irqsave(&dev->event_lock, flags);
410         ml_play_effects(ml);
411         spin_unlock_irqrestore(&dev->event_lock, flags);
412 }
413
414 /*
415  * Sets requested gain for FF effects. Called with dev->event_lock held.
416  */
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
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);
428 }
429
430 /*
431  * Start/stop specified FF effect. Called with dev->event_lock held.
432  */
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];
437
438         if (value > 0) {
439                 pr_debug("initiated play\n");
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
449         } else {
450                 pr_debug("initiated stop\n");
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);
456         }
457
458         ml_play_effects(ml);
459
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
469         spin_lock_irq(&dev->event_lock);
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
481         spin_unlock_irq(&dev->event_lock);
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 /**
494  * input_ff_create_memless() - create memoryless force-feedback device
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;
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);