1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ALSA sequencer Timer 4 * Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl> 5 * Jaroslav Kysela <perex@perex.cz> 6 */ 7 8 #include <sound/core.h> 9 #include <linux/slab.h> 10 #include "seq_timer.h" 11 #include "seq_queue.h" 12 #include "seq_info.h" 13 14 /* allowed sequencer timer frequencies, in Hz */ 15 #define MIN_FREQUENCY 10 16 #define MAX_FREQUENCY 6250 17 #define DEFAULT_FREQUENCY 1000 18 19 #define SKEW_BASE 0x10000 /* 16bit shift */ 20 21 static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr) 22 { 23 if (tmr->tempo < 1000000) 24 tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq; 25 else { 26 /* might overflow.. */ 27 unsigned int s; 28 s = tmr->tempo % tmr->ppq; 29 s = (s * 1000) / tmr->ppq; 30 tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000; 31 tmr->tick.resolution += s; 32 } 33 if (tmr->tick.resolution <= 0) 34 tmr->tick.resolution = 1; 35 snd_seq_timer_update_tick(&tmr->tick, 0); 36 } 37 38 /* create new timer (constructor) */ 39 struct snd_seq_timer *snd_seq_timer_new(void) 40 { 41 struct snd_seq_timer *tmr; 42 43 tmr = kzalloc(sizeof(*tmr), GFP_KERNEL); 44 if (!tmr) 45 return NULL; 46 spin_lock_init(&tmr->lock); 47 48 /* reset setup to defaults */ 49 snd_seq_timer_defaults(tmr); 50 51 /* reset time */ 52 snd_seq_timer_reset(tmr); 53 54 return tmr; 55 } 56 57 /* delete timer (destructor) */ 58 void snd_seq_timer_delete(struct snd_seq_timer **tmr) 59 { 60 struct snd_seq_timer *t = *tmr; 61 *tmr = NULL; 62 63 if (t == NULL) { 64 pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n"); 65 return; 66 } 67 t->running = 0; 68 69 /* reset time */ 70 snd_seq_timer_stop(t); 71 snd_seq_timer_reset(t); 72 73 kfree(t); 74 } 75 76 void snd_seq_timer_defaults(struct snd_seq_timer * tmr) 77 { 78 unsigned long flags; 79 80 spin_lock_irqsave(&tmr->lock, flags); 81 /* setup defaults */ 82 tmr->ppq = 96; /* 96 PPQ */ 83 tmr->tempo = 500000; /* 120 BPM */ 84 snd_seq_timer_set_tick_resolution(tmr); 85 tmr->running = 0; 86 87 tmr->type = SNDRV_SEQ_TIMER_ALSA; 88 tmr->alsa_id.dev_class = seq_default_timer_class; 89 tmr->alsa_id.dev_sclass = seq_default_timer_sclass; 90 tmr->alsa_id.card = seq_default_timer_card; 91 tmr->alsa_id.device = seq_default_timer_device; 92 tmr->alsa_id.subdevice = seq_default_timer_subdevice; 93 tmr->preferred_resolution = seq_default_timer_resolution; 94 95 tmr->skew = tmr->skew_base = SKEW_BASE; 96 spin_unlock_irqrestore(&tmr->lock, flags); 97 } 98 99 static void seq_timer_reset(struct snd_seq_timer *tmr) 100 { 101 /* reset time & songposition */ 102 tmr->cur_time.tv_sec = 0; 103 tmr->cur_time.tv_nsec = 0; 104 105 tmr->tick.cur_tick = 0; 106 tmr->tick.fraction = 0; 107 } 108 109 void snd_seq_timer_reset(struct snd_seq_timer *tmr) 110 { 111 unsigned long flags; 112 113 spin_lock_irqsave(&tmr->lock, flags); 114 seq_timer_reset(tmr); 115 spin_unlock_irqrestore(&tmr->lock, flags); 116 } 117 118 119 /* called by timer interrupt routine. the period time since previous invocation is passed */ 120 static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri, 121 unsigned long resolution, 122 unsigned long ticks) 123 { 124 unsigned long flags; 125 struct snd_seq_queue *q = timeri->callback_data; 126 struct snd_seq_timer *tmr; 127 128 if (q == NULL) 129 return; 130 tmr = q->timer; 131 if (tmr == NULL) 132 return; 133 spin_lock_irqsave(&tmr->lock, flags); 134 if (!tmr->running) { 135 spin_unlock_irqrestore(&tmr->lock, flags); 136 return; 137 } 138 139 resolution *= ticks; 140 if (tmr->skew != tmr->skew_base) { 141 /* FIXME: assuming skew_base = 0x10000 */ 142 resolution = (resolution >> 16) * tmr->skew + 143 (((resolution & 0xffff) * tmr->skew) >> 16); 144 } 145 146 /* update timer */ 147 snd_seq_inc_time_nsec(&tmr->cur_time, resolution); 148 149 /* calculate current tick */ 150 snd_seq_timer_update_tick(&tmr->tick, resolution); 151 152 /* register actual time of this timer update */ 153 ktime_get_ts64(&tmr->last_update); 154 155 spin_unlock_irqrestore(&tmr->lock, flags); 156 157 /* check queues and dispatch events */ 158 snd_seq_check_queue(q, 1, 0); 159 } 160 161 /* set current tempo */ 162 int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo) 163 { 164 unsigned long flags; 165 166 if (snd_BUG_ON(!tmr)) 167 return -EINVAL; 168 if (tempo <= 0) 169 return -EINVAL; 170 spin_lock_irqsave(&tmr->lock, flags); 171 if ((unsigned int)tempo != tmr->tempo) { 172 tmr->tempo = tempo; 173 snd_seq_timer_set_tick_resolution(tmr); 174 } 175 spin_unlock_irqrestore(&tmr->lock, flags); 176 return 0; 177 } 178 179 /* set current tempo and ppq in a shot */ 180 int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq) 181 { 182 int changed; 183 unsigned long flags; 184 185 if (snd_BUG_ON(!tmr)) 186 return -EINVAL; 187 if (tempo <= 0 || ppq <= 0) 188 return -EINVAL; 189 spin_lock_irqsave(&tmr->lock, flags); 190 if (tmr->running && (ppq != tmr->ppq)) { 191 /* refuse to change ppq on running timers */ 192 /* because it will upset the song position (ticks) */ 193 spin_unlock_irqrestore(&tmr->lock, flags); 194 pr_debug("ALSA: seq: cannot change ppq of a running timer\n"); 195 return -EBUSY; 196 } 197 changed = (tempo != tmr->tempo) || (ppq != tmr->ppq); 198 tmr->tempo = tempo; 199 tmr->ppq = ppq; 200 if (changed) 201 snd_seq_timer_set_tick_resolution(tmr); 202 spin_unlock_irqrestore(&tmr->lock, flags); 203 return 0; 204 } 205 206 /* set current tick position */ 207 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, 208 snd_seq_tick_time_t position) 209 { 210 unsigned long flags; 211 212 if (snd_BUG_ON(!tmr)) 213 return -EINVAL; 214 215 spin_lock_irqsave(&tmr->lock, flags); 216 tmr->tick.cur_tick = position; 217 tmr->tick.fraction = 0; 218 spin_unlock_irqrestore(&tmr->lock, flags); 219 return 0; 220 } 221 222 /* set current real-time position */ 223 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, 224 snd_seq_real_time_t position) 225 { 226 unsigned long flags; 227 228 if (snd_BUG_ON(!tmr)) 229 return -EINVAL; 230 231 snd_seq_sanity_real_time(&position); 232 spin_lock_irqsave(&tmr->lock, flags); 233 tmr->cur_time = position; 234 spin_unlock_irqrestore(&tmr->lock, flags); 235 return 0; 236 } 237 238 /* set timer skew */ 239 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, 240 unsigned int base) 241 { 242 unsigned long flags; 243 244 if (snd_BUG_ON(!tmr)) 245 return -EINVAL; 246 247 /* FIXME */ 248 if (base != SKEW_BASE) { 249 pr_debug("ALSA: seq: invalid skew base 0x%x\n", base); 250 return -EINVAL; 251 } 252 spin_lock_irqsave(&tmr->lock, flags); 253 tmr->skew = skew; 254 spin_unlock_irqrestore(&tmr->lock, flags); 255 return 0; 256 } 257 258 int snd_seq_timer_open(struct snd_seq_queue *q) 259 { 260 struct snd_timer_instance *t; 261 struct snd_seq_timer *tmr; 262 char str[32]; 263 int err; 264 265 tmr = q->timer; 266 if (snd_BUG_ON(!tmr)) 267 return -EINVAL; 268 if (tmr->timeri) 269 return -EBUSY; 270 sprintf(str, "sequencer queue %i", q->queue); 271 if (tmr->type != SNDRV_SEQ_TIMER_ALSA) /* standard ALSA timer */ 272 return -EINVAL; 273 if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) 274 tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER; 275 t = snd_timer_instance_new(str); 276 if (!t) 277 return -ENOMEM; 278 t->callback = snd_seq_timer_interrupt; 279 t->callback_data = q; 280 t->flags |= SNDRV_TIMER_IFLG_AUTO; 281 err = snd_timer_open(t, &tmr->alsa_id, q->queue); 282 if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) { 283 if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL || 284 tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) { 285 struct snd_timer_id tid; 286 memset(&tid, 0, sizeof(tid)); 287 tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL; 288 tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER; 289 tid.card = -1; 290 tid.device = SNDRV_TIMER_GLOBAL_SYSTEM; 291 err = snd_timer_open(t, &tid, q->queue); 292 } 293 } 294 if (err < 0) { 295 pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err); 296 snd_timer_instance_free(t); 297 return err; 298 } 299 spin_lock_irq(&tmr->lock); 300 if (tmr->timeri) 301 err = -EBUSY; 302 else 303 tmr->timeri = t; 304 spin_unlock_irq(&tmr->lock); 305 if (err < 0) { 306 snd_timer_close(t); 307 snd_timer_instance_free(t); 308 return err; 309 } 310 return 0; 311 } 312 313 int snd_seq_timer_close(struct snd_seq_queue *q) 314 { 315 struct snd_seq_timer *tmr; 316 struct snd_timer_instance *t; 317 318 tmr = q->timer; 319 if (snd_BUG_ON(!tmr)) 320 return -EINVAL; 321 spin_lock_irq(&tmr->lock); 322 t = tmr->timeri; 323 tmr->timeri = NULL; 324 spin_unlock_irq(&tmr->lock); 325 if (t) { 326 snd_timer_close(t); 327 snd_timer_instance_free(t); 328 } 329 return 0; 330 } 331 332 static int seq_timer_stop(struct snd_seq_timer *tmr) 333 { 334 if (! tmr->timeri) 335 return -EINVAL; 336 if (!tmr->running) 337 return 0; 338 tmr->running = 0; 339 snd_timer_pause(tmr->timeri); 340 return 0; 341 } 342 343 int snd_seq_timer_stop(struct snd_seq_timer *tmr) 344 { 345 unsigned long flags; 346 int err; 347 348 spin_lock_irqsave(&tmr->lock, flags); 349 err = seq_timer_stop(tmr); 350 spin_unlock_irqrestore(&tmr->lock, flags); 351 return err; 352 } 353 354 static int initialize_timer(struct snd_seq_timer *tmr) 355 { 356 struct snd_timer *t; 357 unsigned long freq; 358 359 t = tmr->timeri->timer; 360 if (!t) 361 return -EINVAL; 362 363 freq = tmr->preferred_resolution; 364 if (!freq) 365 freq = DEFAULT_FREQUENCY; 366 else if (freq < MIN_FREQUENCY) 367 freq = MIN_FREQUENCY; 368 else if (freq > MAX_FREQUENCY) 369 freq = MAX_FREQUENCY; 370 371 tmr->ticks = 1; 372 if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) { 373 unsigned long r = snd_timer_resolution(tmr->timeri); 374 if (r) { 375 tmr->ticks = (unsigned int)(1000000000uL / (r * freq)); 376 if (! tmr->ticks) 377 tmr->ticks = 1; 378 } 379 } 380 tmr->initialized = 1; 381 return 0; 382 } 383 384 static int seq_timer_start(struct snd_seq_timer *tmr) 385 { 386 if (! tmr->timeri) 387 return -EINVAL; 388 if (tmr->running) 389 seq_timer_stop(tmr); 390 seq_timer_reset(tmr); 391 if (initialize_timer(tmr) < 0) 392 return -EINVAL; 393 snd_timer_start(tmr->timeri, tmr->ticks); 394 tmr->running = 1; 395 ktime_get_ts64(&tmr->last_update); 396 return 0; 397 } 398 399 int snd_seq_timer_start(struct snd_seq_timer *tmr) 400 { 401 unsigned long flags; 402 int err; 403 404 spin_lock_irqsave(&tmr->lock, flags); 405 err = seq_timer_start(tmr); 406 spin_unlock_irqrestore(&tmr->lock, flags); 407 return err; 408 } 409 410 static int seq_timer_continue(struct snd_seq_timer *tmr) 411 { 412 if (! tmr->timeri) 413 return -EINVAL; 414 if (tmr->running) 415 return -EBUSY; 416 if (! tmr->initialized) { 417 seq_timer_reset(tmr); 418 if (initialize_timer(tmr) < 0) 419 return -EINVAL; 420 } 421 snd_timer_start(tmr->timeri, tmr->ticks); 422 tmr->running = 1; 423 ktime_get_ts64(&tmr->last_update); 424 return 0; 425 } 426 427 int snd_seq_timer_continue(struct snd_seq_timer *tmr) 428 { 429 unsigned long flags; 430 int err; 431 432 spin_lock_irqsave(&tmr->lock, flags); 433 err = seq_timer_continue(tmr); 434 spin_unlock_irqrestore(&tmr->lock, flags); 435 return err; 436 } 437 438 /* return current 'real' time. use timeofday() to get better granularity. */ 439 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr, 440 bool adjust_ktime) 441 { 442 snd_seq_real_time_t cur_time; 443 unsigned long flags; 444 445 spin_lock_irqsave(&tmr->lock, flags); 446 cur_time = tmr->cur_time; 447 if (adjust_ktime && tmr->running) { 448 struct timespec64 tm; 449 450 ktime_get_ts64(&tm); 451 tm = timespec64_sub(tm, tmr->last_update); 452 cur_time.tv_nsec += tm.tv_nsec; 453 cur_time.tv_sec += tm.tv_sec; 454 snd_seq_sanity_real_time(&cur_time); 455 } 456 spin_unlock_irqrestore(&tmr->lock, flags); 457 return cur_time; 458 } 459 460 /* TODO: use interpolation on tick queue (will only be useful for very 461 high PPQ values) */ 462 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr) 463 { 464 snd_seq_tick_time_t cur_tick; 465 unsigned long flags; 466 467 spin_lock_irqsave(&tmr->lock, flags); 468 cur_tick = tmr->tick.cur_tick; 469 spin_unlock_irqrestore(&tmr->lock, flags); 470 return cur_tick; 471 } 472 473 474 #ifdef CONFIG_SND_PROC_FS 475 /* exported to seq_info.c */ 476 void snd_seq_info_timer_read(struct snd_info_entry *entry, 477 struct snd_info_buffer *buffer) 478 { 479 int idx; 480 struct snd_seq_queue *q; 481 struct snd_seq_timer *tmr; 482 struct snd_timer_instance *ti; 483 unsigned long resolution; 484 485 for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) { 486 q = queueptr(idx); 487 if (q == NULL) 488 continue; 489 mutex_lock(&q->timer_mutex); 490 tmr = q->timer; 491 if (!tmr) 492 goto unlock; 493 ti = tmr->timeri; 494 if (!ti) 495 goto unlock; 496 snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name); 497 resolution = snd_timer_resolution(ti) * tmr->ticks; 498 snd_iprintf(buffer, " Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000); 499 snd_iprintf(buffer, " Skew : %u / %u\n", tmr->skew, tmr->skew_base); 500 unlock: 501 mutex_unlock(&q->timer_mutex); 502 queuefree(q); 503 } 504 } 505 #endif /* CONFIG_SND_PROC_FS */ 506 507