Input: matrix-keypad - switch to using dev_pm_ops
[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 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>
32 #include <linux/jiffies.h>
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         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,
228                                unsigned int gain)
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 =
249                         clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
250                 effect->u.ramp.end_level =
251                         clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
252                 break;
253
254         case FF_RUMBLE:
255                 strong = new->u.rumble.strong_magnitude * gain / 0xffff;
256                 weak = new->u.rumble.weak_magnitude * gain / 0xffff;
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;
370         unsigned long flags;
371
372         debug("timer: updating effects");
373
374         spin_lock_irqsave(&dev->event_lock, flags);
375         ml_play_effects(ml);
376         spin_unlock_irqrestore(&dev->event_lock, flags);
377 }
378
379 /*
380  * Sets requested gain for FF effects. Called with dev->event_lock held.
381  */
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
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);
393 }
394
395 /*
396  * Start/stop specified FF effect. Called with dev->event_lock held.
397  */
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];
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
414                 ml_schedule_timer(ml);
415
416         } else {
417                 debug("initiated stop");
418
419                 if (test_bit(FF_EFFECT_PLAYING, &state->flags))
420                         __set_bit(FF_EFFECT_ABORTING, &state->flags);
421                 else
422                         __clear_bit(FF_EFFECT_STARTED, &state->flags);
423
424                 ml_play_effects(ml);
425         }
426
427         return 0;
428 }
429
430 static int ml_ff_upload(struct input_dev *dev,
431                         struct ff_effect *effect, struct ff_effect *old)
432 {
433         struct ml_device *ml = dev->ff->private;
434         struct ml_effect_state *state = &ml->states[effect->id];
435
436         spin_lock_irq(&dev->event_lock);
437
438         if (test_bit(FF_EFFECT_STARTED, &state->flags)) {
439                 __clear_bit(FF_EFFECT_PLAYING, &state->flags);
440                 state->play_at = jiffies +
441                                  msecs_to_jiffies(state->effect->replay.delay);
442                 state->stop_at = state->play_at +
443                                  msecs_to_jiffies(state->effect->replay.length);
444                 state->adj_at = state->play_at;
445                 ml_schedule_timer(ml);
446         }
447
448         spin_unlock_irq(&dev->event_lock);
449
450         return 0;
451 }
452
453 static void ml_ff_destroy(struct ff_device *ff)
454 {
455         struct ml_device *ml = ff->private;
456
457         kfree(ml->private);
458 }
459
460 /**
461  * input_ff_create_memless() - create memoryless force-feedback device
462  * @dev: input device supporting force-feedback
463  * @data: driver-specific data to be passed into @play_effect
464  * @play_effect: driver-specific method for playing FF effect
465  */
466 int input_ff_create_memless(struct input_dev *dev, void *data,
467                 int (*play_effect)(struct input_dev *, void *, struct ff_effect *))
468 {
469         struct ml_device *ml;
470         struct ff_device *ff;
471         int error;
472         int i;
473
474         ml = kzalloc(sizeof(struct ml_device), GFP_KERNEL);
475         if (!ml)
476                 return -ENOMEM;
477
478         ml->dev = dev;
479         ml->private = data;
480         ml->play_effect = play_effect;
481         ml->gain = 0xffff;
482         setup_timer(&ml->timer, ml_effect_timer, (unsigned long)dev);
483
484         set_bit(FF_GAIN, dev->ffbit);
485
486         error = input_ff_create(dev, FF_MEMLESS_EFFECTS);
487         if (error) {
488                 kfree(ml);
489                 return error;
490         }
491
492         ff = dev->ff;
493         ff->private = ml;
494         ff->upload = ml_ff_upload;
495         ff->playback = ml_ff_playback;
496         ff->set_gain = ml_ff_set_gain;
497         ff->destroy = ml_ff_destroy;
498
499         /* we can emulate periodic effects with RUMBLE */
500         if (test_bit(FF_RUMBLE, ff->ffbit)) {
501                 set_bit(FF_PERIODIC, dev->ffbit);
502                 set_bit(FF_SINE, dev->ffbit);
503                 set_bit(FF_TRIANGLE, dev->ffbit);
504                 set_bit(FF_SQUARE, dev->ffbit);
505         }
506
507         for (i = 0; i < FF_MEMLESS_EFFECTS; i++)
508                 ml->states[i].effect = &ff->effects[i];
509
510         return 0;
511 }
512 EXPORT_SYMBOL_GPL(input_ff_create_memless);