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Anssi Hannula7d928a22006-07-19 01:40:30 -04001/*
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
Joe Perchesda0c4902010-11-29 23:33:07 -080026#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Anssi Hannula7d928a22006-07-19 01:40:30 -040027
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Anssi Hannula7d928a22006-07-19 01:40:30 -040029#include <linux/input.h>
30#include <linux/module.h>
31#include <linux/mutex.h>
32#include <linux/spinlock.h>
Tim Schmielaucd354f12007-02-14 00:33:14 -080033#include <linux/jiffies.h>
Anssi Hannula7d928a22006-07-19 01:40:30 -040034
35#include "fixp-arith.h"
36
37MODULE_LICENSE("GPL");
38MODULE_AUTHOR("Anssi Hannula <anssi.hannula@gmail.com>");
39MODULE_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
51struct 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
60struct ml_device {
61 void *private;
62 struct ml_effect_state states[FF_MEMLESS_EFFECTS];
63 int gain;
64 struct timer_list timer;
Anssi Hannula7d928a22006-07-19 01:40:30 -040065 struct input_dev *dev;
66
67 int (*play_effect)(struct input_dev *dev, void *data,
68 struct ff_effect *effect);
69};
70
71static 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 */
88static 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
123static 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
Joe Perchesda0c4902010-11-29 23:33:07 -0800132 pr_debug("calculating next timer\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400133
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) {
Joe Perchesda0c4902010-11-29 23:33:07 -0800152 pr_debug("no actions\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400153 del_timer(&ml->timer);
154 } else {
Joe Perchesda0c4902010-11-29 23:33:07 -0800155 pr_debug("timer set\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400156 mod_timer(&ml->timer, earliest);
157 }
158}
159
160/*
161 * Apply an envelope to a value
162 */
163static 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))) {
Joe Perchesda0c4902010-11-29 23:33:07 -0800176 pr_debug("value = 0x%x, attack_level = 0x%x\n",
177 value, envelope->attack_level);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400178 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
Joe Perchesda0c4902010-11-29 23:33:07 -0800194 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);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400197
198 difference = difference * time_from_level / time_of_envelope;
199
Joe Perchesda0c4902010-11-29 23:33:07 -0800200 pr_debug("difference = %d\n", difference);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400201
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 */
209static 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
Joe Perchesda0c4902010-11-29 23:33:07 -0800218 pr_err("invalid type in get_compatible_type()\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400219
220 return 0;
221}
222
223/*
Jari Vanhala94ec26c2009-12-24 21:52:20 -0800224 * Only left/right direction should be used (under/over 0x8000) for
225 * forward/reverse motor direction (to keep calculation fast & simple).
226 */
227static 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/*
Anssi Hannula7d928a22006-07-19 01:40:30 -0400240 * Combine two effects and apply gain.
241 */
242static void ml_combine_effects(struct ff_effect *effect,
243 struct ml_effect_state *state,
Dmitry Torokhov1b11c882009-12-24 21:44:19 -0800244 int gain)
Anssi Hannula7d928a22006-07-19 01:40:30 -0400245{
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 =
Harvey Harrison92310472008-05-05 11:50:59 -0400265 clamp_val(effect->u.ramp.start_level + x, -0x80, 0x7f);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400266 effect->u.ramp.end_level =
Harvey Harrison92310472008-05-05 11:50:59 -0400267 clamp_val(effect->u.ramp.end_level + y, -0x80, 0x7f);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400268 break;
269
270 case FF_RUMBLE:
Dmitry Torokhov1b11c882009-12-24 21:44:19 -0800271 strong = (u32)new->u.rumble.strong_magnitude * gain / 0xffff;
272 weak = (u32)new->u.rumble.weak_magnitude * gain / 0xffff;
Jari Vanhala94ec26c2009-12-24 21:52:20 -0800273
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;
Anssi Hannula7d928a22006-07-19 01:40:30 -0400286 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
Jari Vanhala94ec26c2009-12-24 21:52:20 -0800300 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;
Anssi Hannula7d928a22006-07-19 01:40:30 -0400307 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:
Joe Perchesda0c4902010-11-29 23:33:07 -0800314 pr_err("invalid type in ml_combine_effects()\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400315 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 */
325static 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
389static 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
402static 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;
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800406 unsigned long flags;
Anssi Hannula7d928a22006-07-19 01:40:30 -0400407
Joe Perchesda0c4902010-11-29 23:33:07 -0800408 pr_debug("timer: updating effects\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400409
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800410 spin_lock_irqsave(&dev->event_lock, flags);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400411 ml_play_effects(ml);
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800412 spin_unlock_irqrestore(&dev->event_lock, flags);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400413}
414
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800415/*
416 * Sets requested gain for FF effects. Called with dev->event_lock held.
417 */
Anssi Hannula7d928a22006-07-19 01:40:30 -0400418static void ml_ff_set_gain(struct input_dev *dev, u16 gain)
419{
420 struct ml_device *ml = dev->ff->private;
421 int i;
422
Anssi Hannula7d928a22006-07-19 01:40:30 -0400423 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);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400429}
430
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800431/*
432 * Start/stop specified FF effect. Called with dev->event_lock held.
433 */
Anssi Hannula7d928a22006-07-19 01:40:30 -0400434static 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];
Anssi Hannula7d928a22006-07-19 01:40:30 -0400438
439 if (value > 0) {
Joe Perchesda0c4902010-11-29 23:33:07 -0800440 pr_debug("initiated play\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400441
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
Anssi Hannula7d928a22006-07-19 01:40:30 -0400450 } else {
Joe Perchesda0c4902010-11-29 23:33:07 -0800451 pr_debug("initiated stop\n");
Anssi Hannula7d928a22006-07-19 01:40:30 -0400452
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);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400457 }
458
Jari Vanhala25ae0832009-12-24 21:52:19 -0800459 ml_play_effects(ml);
460
Anssi Hannula7d928a22006-07-19 01:40:30 -0400461 return 0;
462}
463
464static 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
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800470 spin_lock_irq(&dev->event_lock);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400471
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
Dmitry Torokhovbf3204c2009-11-06 21:39:07 -0800482 spin_unlock_irq(&dev->event_lock);
Anssi Hannula7d928a22006-07-19 01:40:30 -0400483
484 return 0;
485}
486
487static void ml_ff_destroy(struct ff_device *ff)
488{
489 struct ml_device *ml = ff->private;
490
491 kfree(ml->private);
492}
493
494/**
Randy Dunlape4477d22006-11-24 00:43:09 -0500495 * input_ff_create_memless() - create memoryless force-feedback device
Anssi Hannula7d928a22006-07-19 01:40:30 -0400496 * @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 */
500int 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;
Anssi Hannula7d928a22006-07-19 01:40:30 -0400516 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}
546EXPORT_SYMBOL_GPL(input_ff_create_memless);