cpupower: Rename package from cpupowerutils to cpupower
[linux-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
35 #include "fixp-arith.h"
36
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>");
39 MODULE_DESCRIPTION("Force feedback support for memoryless devices");
40
41 /* Number of effects handled with memoryless devices */
42 #define FF_MEMLESS_EFFECTS      16
43
44 /* Envelope update interval in ms */
45 #define FF_ENVELOPE_INTERVAL    50
46
47 #define FF_EFFECT_STARTED       0
48 #define FF_EFFECT_PLAYING       1
49 #define FF_EFFECT_ABORTING      2
50
51 struct ml_effect_state {
52         struct ff_effect *effect;
53         unsigned long flags;    /* effect state (STARTED, PLAYING, etc) */
54         int count;              /* loop count of the effect */
55         unsigned long play_at;  /* start time */
56         unsigned long stop_at;  /* stop time */
57         unsigned long adj_at;   /* last time the effect was sent */
58 };
59
60 struct ml_device {
61         void *private;
62         struct ml_effect_state states[FF_MEMLESS_EFFECTS];
63         int gain;
64         struct timer_list timer;
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         pr_debug("calculating next timer\n");
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                 pr_debug("no actions\n");
153                 del_timer(&ml->timer);
154         } else {
155                 pr_debug("timer set\n");
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                 pr_debug("value = 0x%x, attack_level = 0x%x\n",
177                          value, 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         pr_debug("difference = %d\n", difference);
195         pr_debug("time_from_level = 0x%x\n", time_from_level);
196         pr_debug("time_of_envelope = 0x%x\n", time_of_envelope);
197
198         difference = difference * time_from_level / time_of_envelope;
199
200         pr_debug("difference = %d\n", 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         pr_err("invalid type in get_compatible_type()\n");
219
220         return 0;
221 }
222
223 /*
224  * Only left/right direction should be used (under/over 0x8000) for
225  * forward/reverse motor direction (to keep calculation fast & simple).
226  */
227 static u16 ml_calculate_direction(u16 direction, u16 force,
228                                   u16 new_direction, u16 new_force)
229 {
230         if (!force)
231                 return new_direction;
232         if (!new_force)
233                 return direction;
234         return (((u32)(direction >> 1) * force +
235                  (new_direction >> 1) * new_force) /
236                 (force + new_force)) << 1;
237 }
238
239 /*
240  * Combine two effects and apply gain.
241  */
242 static void ml_combine_effects(struct ff_effect *effect,
243                                struct ml_effect_state *state,
244                                int gain)
245 {
246         struct ff_effect *new = state->effect;
247         unsigned int strong, weak, i;
248         int x, y;
249         fixp_t level;
250
251         switch (new->type) {
252         case FF_CONSTANT:
253                 i = new->direction * 360 / 0xffff;
254                 level = fixp_new16(apply_envelope(state,
255                                         new->u.constant.level,
256                                         &new->u.constant.envelope));
257                 x = fixp_mult(fixp_sin(i), level) * gain / 0xffff;
258                 y = fixp_mult(-fixp_cos(i), level) * gain / 0xffff;
259                 /*
260                  * here we abuse ff_ramp to hold x and y of constant force
261                  * If in future any driver wants something else than x and y
262                  * in s8, this should be changed to something more generic
263                  */
264                 effect->u.ramp.start_level =
265                         clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
266                 effect->u.ramp.end_level =
267                         clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
268                 break;
269
270         case FF_RUMBLE:
271                 strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
272                 weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
273
274                 if (effect->u.rumble.strong_magnitude + strong)
275                         effect->direction = ml_calculate_direction(
276                                 effect->direction,
277                                 effect->u.rumble.strong_magnitude,
278                                 new->direction, strong);
279                 else if (effect->u.rumble.weak_magnitude + weak)
280                         effect->direction = ml_calculate_direction(
281                                 effect->direction,
282                                 effect->u.rumble.weak_magnitude,
283                                 new->direction, weak);
284                 else
285                         effect->direction = 0;
286                 effect->u.rumble.strong_magnitude =
287                         min(strong + effect->u.rumble.strong_magnitude,
288                             0xffffU);
289                 effect->u.rumble.weak_magnitude =
290                         min(weak + effect->u.rumble.weak_magnitude, 0xffffU);
291                 break;
292
293         case FF_PERIODIC:
294                 i = apply_envelope(state, abs(new->u.periodic.magnitude),
295                                    &new->u.periodic.envelope);
296
297                 /* here we also scale it 0x7fff => 0xffff */
298                 i = i * gain / 0x7fff;
299
300                 if (effect->u.rumble.strong_magnitude + i)
301                         effect->direction = ml_calculate_direction(
302                                 effect->direction,
303                                 effect->u.rumble.strong_magnitude,
304                                 new->direction, i);
305                 else
306                         effect->direction = 0;
307                 effect->u.rumble.strong_magnitude =
308                         min(i + effect->u.rumble.strong_magnitude, 0xffffU);
309                 effect->u.rumble.weak_magnitude =
310                         min(i + effect->u.rumble.weak_magnitude, 0xffffU);
311                 break;
312
313         default:
314                 pr_err("invalid type in ml_combine_effects()\n");
315                 break;
316         }
317
318 }
319
320
321 /*
322  * Because memoryless devices have only one effect per effect type active
323  * at one time we have to combine multiple effects into one
324  */
325 static int ml_get_combo_effect(struct ml_device *ml,
326                                unsigned long *effect_handled,
327                                struct ff_effect *combo_effect)
328 {
329         struct ff_effect *effect;
330         struct ml_effect_state *state;
331         int effect_type;
332         int i;
333
334         memset(combo_effect, 0, sizeof(struct ff_effect));
335
336         for (i = 0; i < FF_MEMLESS_EFFECTS; i++) {
337                 if (__test_and_set_bit(i, effect_handled))
338                         continue;
339
340                 state = &ml->states[i];
341                 effect = state->effect;
342
343                 if (!test_bit(FF_EFFECT_STARTED, &state->flags))
344                         continue;
345
346                 if (time_before(jiffies, state->play_at))
347                         continue;
348
349                 /*
350                  * here we have started effects that are either
351                  * currently playing (and may need be aborted)
352                  * or need to start playing.
353                  */
354                 effect_type = get_compatible_type(ml->dev->ff, effect->type);
355                 if (combo_effect->type != effect_type) {
356                         if (combo_effect->type != 0) {
357                                 __clear_bit(i, effect_handled);
358                                 continue;
359                         }
360                         combo_effect->type = effect_type;
361                 }
362
363                 if (__test_and_clear_bit(FF_EFFECT_ABORTING, &state->flags)) {
364                         __clear_bit(FF_EFFECT_PLAYING, &state->flags);
365                         __clear_bit(FF_EFFECT_STARTED, &state->flags);
366                 } else if (effect->replay.length &&
367                            time_after_eq(jiffies, state->stop_at)) {
368
369                         __clear_bit(FF_EFFECT_PLAYING, &state->flags);
370
371                         if (--state->count <= 0) {
372                                 __clear_bit(FF_EFFECT_STARTED, &state->flags);
373                         } else {
374                                 state->play_at = jiffies +
375                                         msecs_to_jiffies(effect->replay.delay);
376                                 state->stop_at = state->play_at +
377                                         msecs_to_jiffies(effect->replay.length);
378                         }
379                 } else {
380                         __set_bit(FF_EFFECT_PLAYING, &state->flags);
381                         state->adj_at = jiffies;
382                         ml_combine_effects(combo_effect, state, ml->gain);
383                 }
384         }
385
386         return combo_effect->type != 0;
387 }
388
389 static void ml_play_effects(struct ml_device *ml)
390 {
391         struct ff_effect effect;
392         DECLARE_BITMAP(handled_bm, FF_MEMLESS_EFFECTS);
393
394         memset(handled_bm, 0, sizeof(handled_bm));
395
396         while (ml_get_combo_effect(ml, handled_bm, &effect))
397                 ml->play_effect(ml->dev, ml->private, &effect);
398
399         ml_schedule_timer(ml);
400 }
401
402 static void ml_effect_timer(unsigned long timer_data)
403 {
404         struct input_dev *dev = (struct input_dev *)timer_data;
405         struct ml_device *ml = dev->ff->private;
406         unsigned long flags;
407
408         pr_debug("timer: updating effects\n");
409
410         spin_lock_irqsave(&dev->event_lock, flags);
411         ml_play_effects(ml);
412         spin_unlock_irqrestore(&dev->event_lock, flags);
413 }
414
415 /*
416  * Sets requested gain for FF effects. Called with dev->event_lock held.
417  */
418 static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
419 {
420         struct ml_device *ml = dev->ff->private;
421         int i;
422
423         ml->gain = gain;
424
425         for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
426                 __clear_bit(FF_EFFECT_PLAYING, &ml->states[i].flags);
427
428         ml_play_effects(ml);
429 }
430
431 /*
432  * Start/stop specified FF effect. Called with dev->event_lock held.
433  */
434 static int ml_ff_playback(struct input_dev *dev, int effect_id, int value)
435 {
436         struct ml_device *ml = dev->ff->private;
437         struct ml_effect_state *state = &ml->states[effect_id];
438
439         if (value > 0) {
440                 pr_debug("initiated play\n");
441
442                 __set_bit(FF_EFFECT_STARTED, &state->flags);
443                 state->count = value;
444                 state->play_at = jiffies +
445                                  msecs_to_jiffies(state->effect->replay.delay);
446                 state->stop_at = state->play_at +
447                                  msecs_to_jiffies(state->effect->replay.length);
448                 state->adj_at = state->play_at;
449
450         } else {
451                 pr_debug("initiated stop\n");
452
453                 if (test_bit(FF_EFFECT_PLAYING, &state->flags))
454                         __set_bit(FF_EFFECT_ABORTING, &state->flags);
455                 else
456                         __clear_bit(FF_EFFECT_STARTED, &state->flags);
457         }
458
459         ml_play_effects(ml);
460
461         return 0;
462 }
463
464 static int ml_ff_upload(struct input_dev *dev,
465                         struct ff_effect *effect, struct ff_effect *old)
466 {
467         struct ml_device *ml = dev->ff->private;
468         struct ml_effect_state *state = &ml->states[effect->id];
469
470         spin_lock_irq(&dev->event_lock);
471
472         if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
473                 __clear_bit(FF_EFFECT_PLAYING, &state->flags);
474                 state->play_at = jiffies +
475                                  msecs_to_jiffies(state->effect->replay.delay);
476                 state->stop_at = state->play_at +
477                                  msecs_to_jiffies(state->effect->replay.length);
478                 state->adj_at = state->play_at;
479                 ml_schedule_timer(ml);
480         }
481
482         spin_unlock_irq(&dev->event_lock);
483
484         return 0;
485 }
486
487 static void ml_ff_destroy(struct ff_device *ff)
488 {
489         struct ml_device *ml = ff->private;
490
491         kfree(ml->private);
492 }
493
494 /**
495  * input_ff_create_memless() - create memoryless force-feedback device
496  * @dev: input device supporting force-feedback
497  * @data: driver-specific data to be passed into @play_effect
498  * @play_effect: driver-specific method for playing FF effect
499  */
500 int input_ff_create_memless(struct input_dev *dev, void *data,
501                 int (*play_effect)(struct input_dev *, void *, struct ff_effect *))
502 {
503         struct ml_device *ml;
504         struct ff_device *ff;
505         int error;
506         int i;
507
508         ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL);
509         if (!ml)
510                 return -ENOMEM;
511
512         ml->dev = dev;
513         ml->private = data;
514         ml->play_effect = play_effect;
515         ml->gain = 0xffff;
516         setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev);
517
518         set_bit(FF_GAIN, dev->ffbit);
519
520         error = input_ff_create(dev, FF_MEMLESS_EFFECTS);
521         if (error) {
522                 kfree(ml);
523                 return error;
524         }
525
526         ff = dev->ff;
527         ff->private = ml;
528         ff->upload = ml_ff_upload;
529         ff->playback = ml_ff_playback;
530         ff->set_gain = ml_ff_set_gain;
531         ff->destroy = ml_ff_destroy;
532
533         /* we can emulate periodic effects with RUMBLE */
534         if (test_bit(FF_RUMBLE, ff->ffbit)) {
535                 set_bit(FF_PERIODIC, dev->ffbit);
536                 set_bit(FF_SINE, dev->ffbit);
537                 set_bit(FF_TRIANGLE, dev->ffbit);
538                 set_bit(FF_SQUARE, dev->ffbit);
539         }
540
541         for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
542                 ml->states[i].effect = &ff->effects[i];
543
544         return 0;
545 }
546 EXPORT_SYMBOL_GPL(input_ff_create_memless);