sound/core/timer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Timers abstract layer
   4  *  Copyright (c) by Jaroslav Kysela <[email protected]>
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/time.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/module.h>
  14 #include <linux/string.h>
  15 #include <linux/sched/signal.h>
  16 #include <sound/core.h>
  17 #include <sound/timer.h>
  18 #include <sound/control.h>
  19 #include <sound/info.h>
  20 #include <sound/minors.h>
  21 #include <sound/initval.h>
  22 #include <linux/kmod.h>
  23
  24 /* internal flags */
  25 #define SNDRV_TIMER_IFLG_PAUSED         0x00010000
  26 #define SNDRV_TIMER_IFLG_DEAD           0x00020000
  27
  28 #if IS_ENABLED(CONFIG_SND_HRTIMER)
  29 #define DEFAULT_TIMER_LIMIT 4
  30 #else
  31 #define DEFAULT_TIMER_LIMIT 1
  32 #endif
  33
  34 static int timer_limit = DEFAULT_TIMER_LIMIT;
  35 static int timer_tstamp_monotonic = 1;
  36 MODULE_AUTHOR("Jaroslav Kysela <[email protected]>, Takashi Iwai <[email protected]>");
  37 MODULE_DESCRIPTION("ALSA timer interface");
  38 MODULE_LICENSE("GPL");
  39 module_param(timer_limit, int, 0444);
  40 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  41 module_param(timer_tstamp_monotonic, int, 0444);
  42 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  43
  44 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
  45 MODULE_ALIAS("devname:snd/timer");
  46
  47 struct snd_timer_user {
  48         struct snd_timer_instance *timeri;
  49         int tread;              /* enhanced read with timestamps and events */
  50         unsigned long ticks;
  51         unsigned long overrun;
  52         int qhead;
  53         int qtail;
  54         int qused;
  55         int queue_size;
  56         bool disconnected;
  57         struct snd_timer_read *queue;
  58         struct snd_timer_tread *tqueue;
  59         spinlock_t qlock;
  60         unsigned long last_resolution;
  61         unsigned int filter;
  62         struct timespec tstamp;         /* trigger tstamp */
  63         wait_queue_head_t qchange_sleep;
  64         struct fasync_struct *fasync;
  65         struct mutex ioctl_lock;
  66 };
  67
  68 /* list of timers */
  69 static LIST_HEAD(snd_timer_list);
  70
  71 /* list of slave instances */
  72 static LIST_HEAD(snd_timer_slave_list);
  73
  74 /* lock for slave active lists */
  75 static DEFINE_SPINLOCK(slave_active_lock);
  76
  77 static DEFINE_MUTEX(register_mutex);
  78
  79 static int snd_timer_free(struct snd_timer *timer);
  80 static int snd_timer_dev_free(struct snd_device *device);
  81 static int snd_timer_dev_register(struct snd_device *device);
  82 static int snd_timer_dev_disconnect(struct snd_device *device);
  83
  84 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
  85
  86 /*
  87  * create a timer instance with the given owner string.
  88  * when timer is not NULL, increments the module counter
  89  */
  90 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
  91                                                          struct snd_timer *timer)
  92 {
  93         struct snd_timer_instance *timeri;
  94         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
  95         if (timeri == NULL)
  96                 return NULL;
  97         timeri->owner = kstrdup(owner, GFP_KERNEL);
  98         if (! timeri->owner) {
  99                 kfree(timeri);
 100                 return NULL;
 101         }
 102         INIT_LIST_HEAD(&timeri->open_list);
 103         INIT_LIST_HEAD(&timeri->active_list);
 104         INIT_LIST_HEAD(&timeri->ack_list);
 105         INIT_LIST_HEAD(&timeri->slave_list_head);
 106         INIT_LIST_HEAD(&timeri->slave_active_head);
 107
 108         timeri->timer = timer;
 109         if (timer && !try_module_get(timer->module)) {
 110                 kfree(timeri->owner);
 111                 kfree(timeri);
 112                 return NULL;
 113         }
 114
 115         return timeri;
 116 }
 117
 118 /*
 119  * find a timer instance from the given timer id
 120  */
 121 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
 122 {
 123         struct snd_timer *timer = NULL;
 124
 125         list_for_each_entry(timer, &snd_timer_list, device_list) {
 126                 if (timer->tmr_class != tid->dev_class)
 127                         continue;
 128                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
 129                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
 130                     (timer->card == NULL ||
 131                      timer->card->number != tid->card))
 132                         continue;
 133                 if (timer->tmr_device != tid->device)
 134                         continue;
 135                 if (timer->tmr_subdevice != tid->subdevice)
 136                         continue;
 137                 return timer;
 138         }
 139         return NULL;
 140 }
 141
 142 #ifdef CONFIG_MODULES
 143
 144 static void snd_timer_request(struct snd_timer_id *tid)
 145 {
 146         switch (tid->dev_class) {
 147         case SNDRV_TIMER_CLASS_GLOBAL:
 148                 if (tid->device < timer_limit)
 149                         request_module("snd-timer-%i", tid->device);
 150                 break;
 151         case SNDRV_TIMER_CLASS_CARD:
 152         case SNDRV_TIMER_CLASS_PCM:
 153                 if (tid->card < snd_ecards_limit)
 154                         request_module("snd-card-%i", tid->card);
 155                 break;
 156         default:
 157                 break;
 158         }
 159 }
 160
 161 #endif
 162
 163 /*
 164  * look for a master instance matching with the slave id of the given slave.
 165  * when found, relink the open_link of the slave.
 166  *
 167  * call this with register_mutex down.
 168  */
 169 static int snd_timer_check_slave(struct snd_timer_instance *slave)
 170 {
 171         struct snd_timer *timer;
 172         struct snd_timer_instance *master;
 173
 174         /* FIXME: it's really dumb to look up all entries.. */
 175         list_for_each_entry(timer, &snd_timer_list, device_list) {
 176                 list_for_each_entry(master, &timer->open_list_head, open_list) {
 177                         if (slave->slave_class == master->slave_class &&
 178                             slave->slave_id == master->slave_id) {
 179                                 if (master->timer->num_instances >=
 180                                     master->timer->max_instances)
 181                                         return -EBUSY;
 182                                 list_move_tail(&slave->open_list,
 183                                                &master->slave_list_head);
 184                                 master->timer->num_instances++;
 185                                 spin_lock_irq(&slave_active_lock);
 186                                 slave->master = master;
 187                                 slave->timer = master->timer;
 188                                 spin_unlock_irq(&slave_active_lock);
 189                                 return 0;
 190                         }
 191                 }
 192         }
 193         return 0;
 194 }
 195
 196 /*
 197  * look for slave instances matching with the slave id of the given master.
 198  * when found, relink the open_link of slaves.
 199  *
 200  * call this with register_mutex down.
 201  */
 202 static int snd_timer_check_master(struct snd_timer_instance *master)
 203 {
 204         struct snd_timer_instance *slave, *tmp;
 205
 206         /* check all pending slaves */
 207         list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 208                 if (slave->slave_class == master->slave_class &&
 209                     slave->slave_id == master->slave_id) {
 210                         if (master->timer->num_instances >=
 211                             master->timer->max_instances)
 212                                 return -EBUSY;
 213                         list_move_tail(&slave->open_list, &master->slave_list_head);
 214                         master->timer->num_instances++;
 215                         spin_lock_irq(&slave_active_lock);
 216                         spin_lock(&master->timer->lock);
 217                         slave->master = master;
 218                         slave->timer = master->timer;
 219                         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 220                                 list_add_tail(&slave->active_list,
 221                                               &master->slave_active_head);
 222                         spin_unlock(&master->timer->lock);
 223                         spin_unlock_irq(&slave_active_lock);
 224                 }
 225         }
 226         return 0;
 227 }
 228
 229 static int snd_timer_close_locked(struct snd_timer_instance *timeri);
 230
 231 /*
 232  * open a timer instance
 233  * when opening a master, the slave id must be here given.
 234  */
 235 int snd_timer_open(struct snd_timer_instance **ti,
 236                    char *owner, struct snd_timer_id *tid,
 237                    unsigned int slave_id)
 238 {
 239         struct snd_timer *timer;
 240         struct snd_timer_instance *timeri = NULL;
 241         int err;
 242
 243         mutex_lock(&register_mutex);
 244         if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 245                 /* open a slave instance */
 246                 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 247                     tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 248                         pr_debug("ALSA: timer: invalid slave class %i\n",
 249                                  tid->dev_sclass);
 250                         err = -EINVAL;
 251                         goto unlock;
 252                 }
 253                 timeri = snd_timer_instance_new(owner, NULL);
 254                 if (!timeri) {
 255                         err = -ENOMEM;
 256                         goto unlock;
 257                 }
 258                 timeri->slave_class = tid->dev_sclass;
 259                 timeri->slave_id = tid->device;
 260                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 261                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 262                 err = snd_timer_check_slave(timeri);
 263                 if (err < 0) {
 264                         snd_timer_close_locked(timeri);
 265                         timeri = NULL;
 266                 }
 267                 goto unlock;
 268         }
 269
 270         /* open a master instance */
 271         timer = snd_timer_find(tid);
 272 #ifdef CONFIG_MODULES
 273         if (!timer) {
 274                 mutex_unlock(&register_mutex);
 275                 snd_timer_request(tid);
 276                 mutex_lock(&register_mutex);
 277                 timer = snd_timer_find(tid);
 278         }
 279 #endif
 280         if (!timer) {
 281                 err = -ENODEV;
 282                 goto unlock;
 283         }
 284         if (!list_empty(&timer->open_list_head)) {
 285                 timeri = list_entry(timer->open_list_head.next,
 286                                     struct snd_timer_instance, open_list);
 287                 if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 288                         err = -EBUSY;
 289                         timeri = NULL;
 290                         goto unlock;
 291                 }
 292         }
 293         if (timer->num_instances >= timer->max_instances) {
 294                 err = -EBUSY;
 295                 goto unlock;
 296         }
 297         timeri = snd_timer_instance_new(owner, timer);
 298         if (!timeri) {
 299                 err = -ENOMEM;
 300                 goto unlock;
 301         }
 302         /* take a card refcount for safe disconnection */
 303         if (timer->card)
 304                 get_device(&timer->card->card_dev);
 305         timeri->slave_class = tid->dev_sclass;
 306         timeri->slave_id = slave_id;
 307
 308         if (list_empty(&timer->open_list_head) && timer->hw.open) {
 309                 err = timer->hw.open(timer);
 310                 if (err) {
 311                         kfree(timeri->owner);
 312                         kfree(timeri);
 313                         timeri = NULL;
 314
 315                         if (timer->card)
 316                                 put_device(&timer->card->card_dev);
 317                         module_put(timer->module);
 318                         goto unlock;
 319                 }
 320         }
 321
 322         list_add_tail(&timeri->open_list, &timer->open_list_head);
 323         timer->num_instances++;
 324         err = snd_timer_check_master(timeri);
 325         if (err < 0) {
 326                 snd_timer_close_locked(timeri);
 327                 timeri = NULL;
 328         }
 329
 330  unlock:
 331         mutex_unlock(&register_mutex);
 332         *ti = timeri;
 333         return err;
 334 }
 335 EXPORT_SYMBOL(snd_timer_open);
 336
 337 /*
 338  * close a timer instance
 339  * call this with register_mutex down.
 340  */
 341 static int snd_timer_close_locked(struct snd_timer_instance *timeri)
 342 {
 343         struct snd_timer *timer = timeri->timer;
 344         struct snd_timer_instance *slave, *tmp;
 345
 346         if (timer) {
 347                 spin_lock_irq(&timer->lock);
 348                 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
 349                 spin_unlock_irq(&timer->lock);
 350         }
 351
 352         list_del(&timeri->open_list);
 353
 354         /* force to stop the timer */
 355         snd_timer_stop(timeri);
 356
 357         if (timer) {
 358                 timer->num_instances--;
 359                 /* wait, until the active callback is finished */
 360                 spin_lock_irq(&timer->lock);
 361                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 362                         spin_unlock_irq(&timer->lock);
 363                         udelay(10);
 364                         spin_lock_irq(&timer->lock);
 365                 }
 366                 spin_unlock_irq(&timer->lock);
 367
 368                 /* remove slave links */
 369                 spin_lock_irq(&slave_active_lock);
 370                 spin_lock(&timer->lock);
 371                 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 372                                          open_list) {
 373                         list_move_tail(&slave->open_list, &snd_timer_slave_list);
 374                         timer->num_instances--;
 375                         slave->master = NULL;
 376                         slave->timer = NULL;
 377                         list_del_init(&slave->ack_list);
 378                         list_del_init(&slave->active_list);
 379                 }
 380                 spin_unlock(&timer->lock);
 381                 spin_unlock_irq(&slave_active_lock);
 382
 383                 /* slave doesn't need to release timer resources below */
 384                 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 385                         timer = NULL;
 386         }
 387
 388         if (timeri->private_free)
 389                 timeri->private_free(timeri);
 390         kfree(timeri->owner);
 391         kfree(timeri);
 392
 393         if (timer) {
 394                 if (list_empty(&timer->open_list_head) && timer->hw.close)
 395                         timer->hw.close(timer);
 396                 /* release a card refcount for safe disconnection */
 397                 if (timer->card)
 398                         put_device(&timer->card->card_dev);
 399                 module_put(timer->module);
 400         }
 401
 402         return 0;
 403 }
 404
 405 /*
 406  * close a timer instance
 407  */
 408 int snd_timer_close(struct snd_timer_instance *timeri)
 409 {
 410         int err;
 411
 412         if (snd_BUG_ON(!timeri))
 413                 return -ENXIO;
 414
 415         mutex_lock(&register_mutex);
 416         err = snd_timer_close_locked(timeri);
 417         mutex_unlock(&register_mutex);
 418         return err;
 419 }
 420 EXPORT_SYMBOL(snd_timer_close);
 421
 422 static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
 423 {
 424         if (timer->hw.c_resolution)
 425                 return timer->hw.c_resolution(timer);
 426         else
 427                 return timer->hw.resolution;
 428 }
 429
 430 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 431 {
 432         struct snd_timer * timer;
 433         unsigned long ret = 0;
 434         unsigned long flags;
 435
 436         if (timeri == NULL)
 437                 return 0;
 438         timer = timeri->timer;
 439         if (timer) {
 440                 spin_lock_irqsave(&timer->lock, flags);
 441                 ret = snd_timer_hw_resolution(timer);
 442                 spin_unlock_irqrestore(&timer->lock, flags);
 443         }
 444         return ret;
 445 }
 446 EXPORT_SYMBOL(snd_timer_resolution);
 447
 448 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 449 {
 450         struct snd_timer *timer = ti->timer;
 451         unsigned long resolution = 0;
 452         struct snd_timer_instance *ts;
 453         struct timespec tstamp;
 454
 455         if (timer_tstamp_monotonic)
 456                 ktime_get_ts(&tstamp);
 457         else
 458                 getnstimeofday(&tstamp);
 459         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 460                        event > SNDRV_TIMER_EVENT_PAUSE))
 461                 return;
 462         if (timer &&
 463             (event == SNDRV_TIMER_EVENT_START ||
 464              event == SNDRV_TIMER_EVENT_CONTINUE))
 465                 resolution = snd_timer_hw_resolution(timer);
 466         if (ti->ccallback)
 467                 ti->ccallback(ti, event, &tstamp, resolution);
 468         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 469                 return;
 470         if (timer == NULL)
 471                 return;
 472         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 473                 return;
 474         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 475                 if (ts->ccallback)
 476                         ts->ccallback(ts, event + 100, &tstamp, resolution);
 477 }
 478
 479 /* start/continue a master timer */
 480 static int snd_timer_start1(struct snd_timer_instance *timeri,
 481                             bool start, unsigned long ticks)
 482 {
 483         struct snd_timer *timer;
 484         int result;
 485         unsigned long flags;
 486
 487         timer = timeri->timer;
 488         if (!timer)
 489                 return -EINVAL;
 490
 491         spin_lock_irqsave(&timer->lock, flags);
 492         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
 493                 result = -EINVAL;
 494                 goto unlock;
 495         }
 496         if (timer->card && timer->card->shutdown) {
 497                 result = -ENODEV;
 498                 goto unlock;
 499         }
 500         if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 501                              SNDRV_TIMER_IFLG_START)) {
 502                 result = -EBUSY;
 503                 goto unlock;
 504         }
 505
 506         if (start)
 507                 timeri->ticks = timeri->cticks = ticks;
 508         else if (!timeri->cticks)
 509                 timeri->cticks = 1;
 510         timeri->pticks = 0;
 511
 512         list_move_tail(&timeri->active_list, &timer->active_list_head);
 513         if (timer->running) {
 514                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 515                         goto __start_now;
 516                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 517                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 518                 result = 1; /* delayed start */
 519         } else {
 520                 if (start)
 521                         timer->sticks = ticks;
 522                 timer->hw.start(timer);
 523               __start_now:
 524                 timer->running++;
 525                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 526                 result = 0;
 527         }
 528         snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 529                           SNDRV_TIMER_EVENT_CONTINUE);
 530  unlock:
 531         spin_unlock_irqrestore(&timer->lock, flags);
 532         return result;
 533 }
 534
 535 /* start/continue a slave timer */
 536 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
 537                                  bool start)
 538 {
 539         unsigned long flags;
 540         int err;
 541
 542         spin_lock_irqsave(&slave_active_lock, flags);
 543         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
 544                 err = -EINVAL;
 545                 goto unlock;
 546         }
 547         if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
 548                 err = -EBUSY;
 549                 goto unlock;
 550         }
 551         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 552         if (timeri->master && timeri->timer) {
 553                 spin_lock(&timeri->timer->lock);
 554                 list_add_tail(&timeri->active_list,
 555                               &timeri->master->slave_active_head);
 556                 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 557                                   SNDRV_TIMER_EVENT_CONTINUE);
 558                 spin_unlock(&timeri->timer->lock);
 559         }
 560         err = 1; /* delayed start */
 561  unlock:
 562         spin_unlock_irqrestore(&slave_active_lock, flags);
 563         return err;
 564 }
 565
 566 /* stop/pause a master timer */
 567 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
 568 {
 569         struct snd_timer *timer;
 570         int result = 0;
 571         unsigned long flags;
 572
 573         timer = timeri->timer;
 574         if (!timer)
 575                 return -EINVAL;
 576         spin_lock_irqsave(&timer->lock, flags);
 577         if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 578                                SNDRV_TIMER_IFLG_START))) {
 579                 result = -EBUSY;
 580                 goto unlock;
 581         }
 582         list_del_init(&timeri->ack_list);
 583         list_del_init(&timeri->active_list);
 584         if (timer->card && timer->card->shutdown)
 585                 goto unlock;
 586         if (stop) {
 587                 timeri->cticks = timeri->ticks;
 588                 timeri->pticks = 0;
 589         }
 590         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 591             !(--timer->running)) {
 592                 timer->hw.stop(timer);
 593                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 594                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 595                         snd_timer_reschedule(timer, 0);
 596                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 597                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 598                                 timer->hw.start(timer);
 599                         }
 600                 }
 601         }
 602         timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 603         if (stop)
 604                 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
 605         else
 606                 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
 607         snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 608                           SNDRV_TIMER_EVENT_PAUSE);
 609  unlock:
 610         spin_unlock_irqrestore(&timer->lock, flags);
 611         return result;
 612 }
 613
 614 /* stop/pause a slave timer */
 615 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
 616 {
 617         unsigned long flags;
 618
 619         spin_lock_irqsave(&slave_active_lock, flags);
 620         if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
 621                 spin_unlock_irqrestore(&slave_active_lock, flags);
 622                 return -EBUSY;
 623         }
 624         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 625         if (timeri->timer) {
 626                 spin_lock(&timeri->timer->lock);
 627                 list_del_init(&timeri->ack_list);
 628                 list_del_init(&timeri->active_list);
 629                 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 630                                   SNDRV_TIMER_EVENT_PAUSE);
 631                 spin_unlock(&timeri->timer->lock);
 632         }
 633         spin_unlock_irqrestore(&slave_active_lock, flags);
 634         return 0;
 635 }
 636
 637 /*
 638  *  start the timer instance
 639  */
 640 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 641 {
 642         if (timeri == NULL || ticks < 1)
 643                 return -EINVAL;
 644         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 645                 return snd_timer_start_slave(timeri, true);
 646         else
 647                 return snd_timer_start1(timeri, true, ticks);
 648 }
 649 EXPORT_SYMBOL(snd_timer_start);
 650
 651 /*
 652  * stop the timer instance.
 653  *
 654  * do not call this from the timer callback!
 655  */
 656 int snd_timer_stop(struct snd_timer_instance *timeri)
 657 {
 658         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 659                 return snd_timer_stop_slave(timeri, true);
 660         else
 661                 return snd_timer_stop1(timeri, true);
 662 }
 663 EXPORT_SYMBOL(snd_timer_stop);
 664
 665 /*
 666  * start again..  the tick is kept.
 667  */
 668 int snd_timer_continue(struct snd_timer_instance *timeri)
 669 {
 670         /* timer can continue only after pause */
 671         if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
 672                 return -EINVAL;
 673
 674         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 675                 return snd_timer_start_slave(timeri, false);
 676         else
 677                 return snd_timer_start1(timeri, false, 0);
 678 }
 679 EXPORT_SYMBOL(snd_timer_continue);
 680
 681 /*
 682  * pause.. remember the ticks left
 683  */
 684 int snd_timer_pause(struct snd_timer_instance * timeri)
 685 {
 686         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 687                 return snd_timer_stop_slave(timeri, false);
 688         else
 689                 return snd_timer_stop1(timeri, false);
 690 }
 691 EXPORT_SYMBOL(snd_timer_pause);
 692
 693 /*
 694  * reschedule the timer
 695  *
 696  * start pending instances and check the scheduling ticks.
 697  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 698  */
 699 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 700 {
 701         struct snd_timer_instance *ti;
 702         unsigned long ticks = ~0UL;
 703
 704         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 705                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 706                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 707                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 708                         timer->running++;
 709                 }
 710                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 711                         if (ticks > ti->cticks)
 712                                 ticks = ti->cticks;
 713                 }
 714         }
 715         if (ticks == ~0UL) {
 716                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 717                 return;
 718         }
 719         if (ticks > timer->hw.ticks)
 720                 ticks = timer->hw.ticks;
 721         if (ticks_left != ticks)
 722                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 723         timer->sticks = ticks;
 724 }
 725
 726 /* call callbacks in timer ack list */
 727 static void snd_timer_process_callbacks(struct snd_timer *timer,
 728                                         struct list_head *head)
 729 {
 730         struct snd_timer_instance *ti;
 731         unsigned long resolution, ticks;
 732
 733         while (!list_empty(head)) {
 734                 ti = list_first_entry(head, struct snd_timer_instance,
 735                                       ack_list);
 736
 737                 /* remove from ack_list and make empty */
 738                 list_del_init(&ti->ack_list);
 739
 740                 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
 741                         ticks = ti->pticks;
 742                         ti->pticks = 0;
 743                         resolution = ti->resolution;
 744                         ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 745                         spin_unlock(&timer->lock);
 746                         if (ti->callback)
 747                                 ti->callback(ti, resolution, ticks);
 748                         spin_lock(&timer->lock);
 749                         ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 750                 }
 751         }
 752 }
 753
 754 /* clear pending instances from ack list */
 755 static void snd_timer_clear_callbacks(struct snd_timer *timer,
 756                                       struct list_head *head)
 757 {
 758         unsigned long flags;
 759
 760         spin_lock_irqsave(&timer->lock, flags);
 761         while (!list_empty(head))
 762                 list_del_init(head->next);
 763         spin_unlock_irqrestore(&timer->lock, flags);
 764 }
 765
 766 /*
 767  * timer tasklet
 768  *
 769  */
 770 static void snd_timer_tasklet(unsigned long arg)
 771 {
 772         struct snd_timer *timer = (struct snd_timer *) arg;
 773         unsigned long flags;
 774
 775         if (timer->card && timer->card->shutdown) {
 776                 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
 777                 return;
 778         }
 779
 780         spin_lock_irqsave(&timer->lock, flags);
 781         snd_timer_process_callbacks(timer, &timer->sack_list_head);
 782         spin_unlock_irqrestore(&timer->lock, flags);
 783 }
 784
 785 /*
 786  * timer interrupt
 787  *
 788  * ticks_left is usually equal to timer->sticks.
 789  *
 790  */
 791 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 792 {
 793         struct snd_timer_instance *ti, *ts, *tmp;
 794         unsigned long resolution;
 795         struct list_head *ack_list_head;
 796         unsigned long flags;
 797         int use_tasklet = 0;
 798
 799         if (timer == NULL)
 800                 return;
 801
 802         if (timer->card && timer->card->shutdown) {
 803                 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
 804                 return;
 805         }
 806
 807         spin_lock_irqsave(&timer->lock, flags);
 808
 809         /* remember the current resolution */
 810         resolution = snd_timer_hw_resolution(timer);
 811
 812         /* loop for all active instances
 813          * Here we cannot use list_for_each_entry because the active_list of a
 814          * processed instance is relinked to done_list_head before the callback
 815          * is called.
 816          */
 817         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 818                                  active_list) {
 819                 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
 820                         continue;
 821                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 822                         continue;
 823                 ti->pticks += ticks_left;
 824                 ti->resolution = resolution;
 825                 if (ti->cticks < ticks_left)
 826                         ti->cticks = 0;
 827                 else
 828                         ti->cticks -= ticks_left;
 829                 if (ti->cticks) /* not expired */
 830                         continue;
 831                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 832                         ti->cticks = ti->ticks;
 833                 } else {
 834                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 835                         --timer->running;
 836                         list_del_init(&ti->active_list);
 837                 }
 838                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
 839                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 840                         ack_list_head = &timer->ack_list_head;
 841                 else
 842                         ack_list_head = &timer->sack_list_head;
 843                 if (list_empty(&ti->ack_list))
 844                         list_add_tail(&ti->ack_list, ack_list_head);
 845                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 846                         ts->pticks = ti->pticks;
 847                         ts->resolution = resolution;
 848                         if (list_empty(&ts->ack_list))
 849                                 list_add_tail(&ts->ack_list, ack_list_head);
 850                 }
 851         }
 852         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 853                 snd_timer_reschedule(timer, timer->sticks);
 854         if (timer->running) {
 855                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 856                         timer->hw.stop(timer);
 857                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 858                 }
 859                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 860                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 861                         /* restart timer */
 862                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 863                         timer->hw.start(timer);
 864                 }
 865         } else {
 866                 timer->hw.stop(timer);
 867         }
 868
 869         /* now process all fast callbacks */
 870         snd_timer_process_callbacks(timer, &timer->ack_list_head);
 871
 872         /* do we have any slow callbacks? */
 873         use_tasklet = !list_empty(&timer->sack_list_head);
 874         spin_unlock_irqrestore(&timer->lock, flags);
 875
 876         if (use_tasklet)
 877                 tasklet_schedule(&timer->task_queue);
 878 }
 879 EXPORT_SYMBOL(snd_timer_interrupt);
 880
 881 /*
 882
 883  */
 884
 885 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 886                   struct snd_timer **rtimer)
 887 {
 888         struct snd_timer *timer;
 889         int err;
 890         static struct snd_device_ops ops = {
 891                 .dev_free = snd_timer_dev_free,
 892                 .dev_register = snd_timer_dev_register,
 893                 .dev_disconnect = snd_timer_dev_disconnect,
 894         };
 895
 896         if (snd_BUG_ON(!tid))
 897                 return -EINVAL;
 898         if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
 899             tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
 900                 if (WARN_ON(!card))
 901                         return -EINVAL;
 902         }
 903         if (rtimer)
 904                 *rtimer = NULL;
 905         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 906         if (!timer)
 907                 return -ENOMEM;
 908         timer->tmr_class = tid->dev_class;
 909         timer->card = card;
 910         timer->tmr_device = tid->device;
 911         timer->tmr_subdevice = tid->subdevice;
 912         if (id)
 913                 strlcpy(timer->id, id, sizeof(timer->id));
 914         timer->sticks = 1;
 915         INIT_LIST_HEAD(&timer->device_list);
 916         INIT_LIST_HEAD(&timer->open_list_head);
 917         INIT_LIST_HEAD(&timer->active_list_head);
 918         INIT_LIST_HEAD(&timer->ack_list_head);
 919         INIT_LIST_HEAD(&timer->sack_list_head);
 920         spin_lock_init(&timer->lock);
 921         tasklet_init(&timer->task_queue, snd_timer_tasklet,
 922                      (unsigned long)timer);
 923         timer->max_instances = 1000; /* default limit per timer */
 924         if (card != NULL) {
 925                 timer->module = card->module;
 926                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 927                 if (err < 0) {
 928                         snd_timer_free(timer);
 929                         return err;
 930                 }
 931         }
 932         if (rtimer)
 933                 *rtimer = timer;
 934         return 0;
 935 }
 936 EXPORT_SYMBOL(snd_timer_new);
 937
 938 static int snd_timer_free(struct snd_timer *timer)
 939 {
 940         if (!timer)
 941                 return 0;
 942
 943         mutex_lock(&register_mutex);
 944         if (! list_empty(&timer->open_list_head)) {
 945                 struct list_head *p, *n;
 946                 struct snd_timer_instance *ti;
 947                 pr_warn("ALSA: timer %p is busy?\n", timer);
 948                 list_for_each_safe(p, n, &timer->open_list_head) {
 949                         list_del_init(p);
 950                         ti = list_entry(p, struct snd_timer_instance, open_list);
 951                         ti->timer = NULL;
 952                 }
 953         }
 954         list_del(&timer->device_list);
 955         mutex_unlock(&register_mutex);
 956
 957         if (timer->private_free)
 958                 timer->private_free(timer);
 959         kfree(timer);
 960         return 0;
 961 }
 962
 963 static int snd_timer_dev_free(struct snd_device *device)
 964 {
 965         struct snd_timer *timer = device->device_data;
 966         return snd_timer_free(timer);
 967 }
 968
 969 static int snd_timer_dev_register(struct snd_device *dev)
 970 {
 971         struct snd_timer *timer = dev->device_data;
 972         struct snd_timer *timer1;
 973
 974         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
 975                 return -ENXIO;
 976         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
 977             !timer->hw.resolution && timer->hw.c_resolution == NULL)
 978                 return -EINVAL;
 979
 980         mutex_lock(&register_mutex);
 981         list_for_each_entry(timer1, &snd_timer_list, device_list) {
 982                 if (timer1->tmr_class > timer->tmr_class)
 983                         break;
 984                 if (timer1->tmr_class < timer->tmr_class)
 985                         continue;
 986                 if (timer1->card && timer->card) {
 987                         if (timer1->card->number > timer->card->number)
 988                                 break;
 989                         if (timer1->card->number < timer->card->number)
 990                                 continue;
 991                 }
 992                 if (timer1->tmr_device > timer->tmr_device)
 993                         break;
 994                 if (timer1->tmr_device < timer->tmr_device)
 995                         continue;
 996                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
 997                         break;
 998                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
 999                         continue;
1000                 /* conflicts.. */
1001                 mutex_unlock(&register_mutex);
1002                 return -EBUSY;
1003         }
1004         list_add_tail(&timer->device_list, &timer1->device_list);
1005         mutex_unlock(&register_mutex);
1006         return 0;
1007 }
1008
1009 static int snd_timer_dev_disconnect(struct snd_device *device)
1010 {
1011         struct snd_timer *timer = device->device_data;
1012         struct snd_timer_instance *ti;
1013
1014         mutex_lock(&register_mutex);
1015         list_del_init(&timer->device_list);
1016         /* wake up pending sleepers */
1017         list_for_each_entry(ti, &timer->open_list_head, open_list) {
1018                 if (ti->disconnect)
1019                         ti->disconnect(ti);
1020         }
1021         mutex_unlock(&register_mutex);
1022         return 0;
1023 }
1024
1025 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
1026 {
1027         unsigned long flags;
1028         unsigned long resolution = 0;
1029         struct snd_timer_instance *ti, *ts;
1030
1031         if (timer->card && timer->card->shutdown)
1032                 return;
1033         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1034                 return;
1035         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1036                        event > SNDRV_TIMER_EVENT_MRESUME))
1037                 return;
1038         spin_lock_irqsave(&timer->lock, flags);
1039         if (event == SNDRV_TIMER_EVENT_MSTART ||
1040             event == SNDRV_TIMER_EVENT_MCONTINUE ||
1041             event == SNDRV_TIMER_EVENT_MRESUME)
1042                 resolution = snd_timer_hw_resolution(timer);
1043         list_for_each_entry(ti, &timer->active_list_head, active_list) {
1044                 if (ti->ccallback)
1045                         ti->ccallback(ti, event, tstamp, resolution);
1046                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1047                         if (ts->ccallback)
1048                                 ts->ccallback(ts, event, tstamp, resolution);
1049         }
1050         spin_unlock_irqrestore(&timer->lock, flags);
1051 }
1052 EXPORT_SYMBOL(snd_timer_notify);
1053
1054 /*
1055  * exported functions for global timers
1056  */
1057 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1058 {
1059         struct snd_timer_id tid;
1060
1061         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1062         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1063         tid.card = -1;
1064         tid.device = device;
1065         tid.subdevice = 0;
1066         return snd_timer_new(NULL, id, &tid, rtimer);
1067 }
1068 EXPORT_SYMBOL(snd_timer_global_new);
1069
1070 int snd_timer_global_free(struct snd_timer *timer)
1071 {
1072         return snd_timer_free(timer);
1073 }
1074 EXPORT_SYMBOL(snd_timer_global_free);
1075
1076 int snd_timer_global_register(struct snd_timer *timer)
1077 {
1078         struct snd_device dev;
1079
1080         memset(&dev, 0, sizeof(dev));
1081         dev.device_data = timer;
1082         return snd_timer_dev_register(&dev);
1083 }
1084 EXPORT_SYMBOL(snd_timer_global_register);
1085
1086 /*
1087  *  System timer
1088  */
1089
1090 struct snd_timer_system_private {
1091         struct timer_list tlist;
1092         struct snd_timer *snd_timer;
1093         unsigned long last_expires;
1094         unsigned long last_jiffies;
1095         unsigned long correction;
1096 };
1097
1098 static void snd_timer_s_function(struct timer_list *t)
1099 {
1100         struct snd_timer_system_private *priv = from_timer(priv, t,
1101                                                                 tlist);
1102         struct snd_timer *timer = priv->snd_timer;
1103         unsigned long jiff = jiffies;
1104         if (time_after(jiff, priv->last_expires))
1105                 priv->correction += (long)jiff - (long)priv->last_expires;
1106         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1107 }
1108
1109 static int snd_timer_s_start(struct snd_timer * timer)
1110 {
1111         struct snd_timer_system_private *priv;
1112         unsigned long njiff;
1113
1114         priv = (struct snd_timer_system_private *) timer->private_data;
1115         njiff = (priv->last_jiffies = jiffies);
1116         if (priv->correction > timer->sticks - 1) {
1117                 priv->correction -= timer->sticks - 1;
1118                 njiff++;
1119         } else {
1120                 njiff += timer->sticks - priv->correction;
1121                 priv->correction = 0;
1122         }
1123         priv->last_expires = njiff;
1124         mod_timer(&priv->tlist, njiff);
1125         return 0;
1126 }
1127
1128 static int snd_timer_s_stop(struct snd_timer * timer)
1129 {
1130         struct snd_timer_system_private *priv;
1131         unsigned long jiff;
1132
1133         priv = (struct snd_timer_system_private *) timer->private_data;
1134         del_timer(&priv->tlist);
1135         jiff = jiffies;
1136         if (time_before(jiff, priv->last_expires))
1137                 timer->sticks = priv->last_expires - jiff;
1138         else
1139                 timer->sticks = 1;
1140         priv->correction = 0;
1141         return 0;
1142 }
1143
1144 static int snd_timer_s_close(struct snd_timer *timer)
1145 {
1146         struct snd_timer_system_private *priv;
1147
1148         priv = (struct snd_timer_system_private *)timer->private_data;
1149         del_timer_sync(&priv->tlist);
1150         return 0;
1151 }
1152
1153 static struct snd_timer_hardware snd_timer_system =
1154 {
1155         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1156         .resolution =   1000000000L / HZ,
1157         .ticks =        10000000L,
1158         .close =        snd_timer_s_close,
1159         .start =        snd_timer_s_start,
1160         .stop =         snd_timer_s_stop
1161 };
1162
1163 static void snd_timer_free_system(struct snd_timer *timer)
1164 {
1165         kfree(timer->private_data);
1166 }
1167
1168 static int snd_timer_register_system(void)
1169 {
1170         struct snd_timer *timer;
1171         struct snd_timer_system_private *priv;
1172         int err;
1173
1174         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1175         if (err < 0)
1176                 return err;
1177         strcpy(timer->name, "system timer");
1178         timer->hw = snd_timer_system;
1179         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1180         if (priv == NULL) {
1181                 snd_timer_free(timer);
1182                 return -ENOMEM;
1183         }
1184         priv->snd_timer = timer;
1185         timer_setup(&priv->tlist, snd_timer_s_function, 0);
1186         timer->private_data = priv;
1187         timer->private_free = snd_timer_free_system;
1188         return snd_timer_global_register(timer);
1189 }
1190
1191 #ifdef CONFIG_SND_PROC_FS
1192 /*
1193  *  Info interface
1194  */
1195
1196 static void snd_timer_proc_read(struct snd_info_entry *entry,
1197                                 struct snd_info_buffer *buffer)
1198 {
1199         struct snd_timer *timer;
1200         struct snd_timer_instance *ti;
1201
1202         mutex_lock(&register_mutex);
1203         list_for_each_entry(timer, &snd_timer_list, device_list) {
1204                 if (timer->card && timer->card->shutdown)
1205                         continue;
1206                 switch (timer->tmr_class) {
1207                 case SNDRV_TIMER_CLASS_GLOBAL:
1208                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1209                         break;
1210                 case SNDRV_TIMER_CLASS_CARD:
1211                         snd_iprintf(buffer, "C%i-%i: ",
1212                                     timer->card->number, timer->tmr_device);
1213                         break;
1214                 case SNDRV_TIMER_CLASS_PCM:
1215                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1216                                     timer->tmr_device, timer->tmr_subdevice);
1217                         break;
1218                 default:
1219                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1220                                     timer->card ? timer->card->number : -1,
1221                                     timer->tmr_device, timer->tmr_subdevice);
1222                 }
1223                 snd_iprintf(buffer, "%s :", timer->name);
1224                 if (timer->hw.resolution)
1225                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1226                                     timer->hw.resolution / 1000,
1227                                     timer->hw.resolution % 1000,
1228                                     timer->hw.ticks);
1229                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1230                         snd_iprintf(buffer, " SLAVE");
1231                 snd_iprintf(buffer, "\n");
1232                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1233                         snd_iprintf(buffer, "  Client %s : %s\n",
1234                                     ti->owner ? ti->owner : "unknown",
1235                                     ti->flags & (SNDRV_TIMER_IFLG_START |
1236                                                  SNDRV_TIMER_IFLG_RUNNING)
1237                                     ? "running" : "stopped");
1238         }
1239         mutex_unlock(&register_mutex);
1240 }
1241
1242 static struct snd_info_entry *snd_timer_proc_entry;
1243
1244 static void __init snd_timer_proc_init(void)
1245 {
1246         struct snd_info_entry *entry;
1247
1248         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1249         if (entry != NULL) {
1250                 entry->c.text.read = snd_timer_proc_read;
1251                 if (snd_info_register(entry) < 0) {
1252                         snd_info_free_entry(entry);
1253                         entry = NULL;
1254                 }
1255         }
1256         snd_timer_proc_entry = entry;
1257 }
1258
1259 static void __exit snd_timer_proc_done(void)
1260 {
1261         snd_info_free_entry(snd_timer_proc_entry);
1262 }
1263 #else /* !CONFIG_SND_PROC_FS */
1264 #define snd_timer_proc_init()
1265 #define snd_timer_proc_done()
1266 #endif
1267
1268 /*
1269  *  USER SPACE interface
1270  */
1271
1272 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1273                                      unsigned long resolution,
1274                                      unsigned long ticks)
1275 {
1276         struct snd_timer_user *tu = timeri->callback_data;
1277         struct snd_timer_read *r;
1278         int prev;
1279
1280         spin_lock(&tu->qlock);
1281         if (tu->qused > 0) {
1282                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1283                 r = &tu->queue[prev];
1284                 if (r->resolution == resolution) {
1285                         r->ticks += ticks;
1286                         goto __wake;
1287                 }
1288         }
1289         if (tu->qused >= tu->queue_size) {
1290                 tu->overrun++;
1291         } else {
1292                 r = &tu->queue[tu->qtail++];
1293                 tu->qtail %= tu->queue_size;
1294                 r->resolution = resolution;
1295                 r->ticks = ticks;
1296                 tu->qused++;
1297         }
1298       __wake:
1299         spin_unlock(&tu->qlock);
1300         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1301         wake_up(&tu->qchange_sleep);
1302 }
1303
1304 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1305                                             struct snd_timer_tread *tread)
1306 {
1307         if (tu->qused >= tu->queue_size) {
1308                 tu->overrun++;
1309         } else {
1310                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1311                 tu->qtail %= tu->queue_size;
1312                 tu->qused++;
1313         }
1314 }
1315
1316 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1317                                      int event,
1318                                      struct timespec *tstamp,
1319                                      unsigned long resolution)
1320 {
1321         struct snd_timer_user *tu = timeri->callback_data;
1322         struct snd_timer_tread r1;
1323         unsigned long flags;
1324
1325         if (event >= SNDRV_TIMER_EVENT_START &&
1326             event <= SNDRV_TIMER_EVENT_PAUSE)
1327                 tu->tstamp = *tstamp;
1328         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1329                 return;
1330         memset(&r1, 0, sizeof(r1));
1331         r1.event = event;
1332         r1.tstamp = *tstamp;
1333         r1.val = resolution;
1334         spin_lock_irqsave(&tu->qlock, flags);
1335         snd_timer_user_append_to_tqueue(tu, &r1);
1336         spin_unlock_irqrestore(&tu->qlock, flags);
1337         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1338         wake_up(&tu->qchange_sleep);
1339 }
1340
1341 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1342 {
1343         struct snd_timer_user *tu = timeri->callback_data;
1344
1345         tu->disconnected = true;
1346         wake_up(&tu->qchange_sleep);
1347 }
1348
1349 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1350                                       unsigned long resolution,
1351                                       unsigned long ticks)
1352 {
1353         struct snd_timer_user *tu = timeri->callback_data;
1354         struct snd_timer_tread *r, r1;
1355         struct timespec tstamp;
1356         int prev, append = 0;
1357
1358         memset(&r1, 0, sizeof(r1));
1359         memset(&tstamp, 0, sizeof(tstamp));
1360         spin_lock(&tu->qlock);
1361         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1362                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1363                 spin_unlock(&tu->qlock);
1364                 return;
1365         }
1366         if (tu->last_resolution != resolution || ticks > 0) {
1367                 if (timer_tstamp_monotonic)
1368                         ktime_get_ts(&tstamp);
1369                 else
1370                         getnstimeofday(&tstamp);
1371         }
1372         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1373             tu->last_resolution != resolution) {
1374                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1375                 r1.tstamp = tstamp;
1376                 r1.val = resolution;
1377                 snd_timer_user_append_to_tqueue(tu, &r1);
1378                 tu->last_resolution = resolution;
1379                 append++;
1380         }
1381         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1382                 goto __wake;
1383         if (ticks == 0)
1384                 goto __wake;
1385         if (tu->qused > 0) {
1386                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1387                 r = &tu->tqueue[prev];
1388                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1389                         r->tstamp = tstamp;
1390                         r->val += ticks;
1391                         append++;
1392                         goto __wake;
1393                 }
1394         }
1395         r1.event = SNDRV_TIMER_EVENT_TICK;
1396         r1.tstamp = tstamp;
1397         r1.val = ticks;
1398         snd_timer_user_append_to_tqueue(tu, &r1);
1399         append++;
1400       __wake:
1401         spin_unlock(&tu->qlock);
1402         if (append == 0)
1403                 return;
1404         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1405         wake_up(&tu->qchange_sleep);
1406 }
1407
1408 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1409 {
1410         struct snd_timer_read *queue = NULL;
1411         struct snd_timer_tread *tqueue = NULL;
1412
1413         if (tu->tread) {
1414                 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1415                 if (!tqueue)
1416                         return -ENOMEM;
1417         } else {
1418                 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1419                 if (!queue)
1420                         return -ENOMEM;
1421         }
1422
1423         spin_lock_irq(&tu->qlock);
1424         kfree(tu->queue);
1425         kfree(tu->tqueue);
1426         tu->queue_size = size;
1427         tu->queue = queue;
1428         tu->tqueue = tqueue;
1429         tu->qhead = tu->qtail = tu->qused = 0;
1430         spin_unlock_irq(&tu->qlock);
1431
1432         return 0;
1433 }
1434
1435 static int snd_timer_user_open(struct inode *inode, struct file *file)
1436 {
1437         struct snd_timer_user *tu;
1438         int err;
1439
1440         err = stream_open(inode, file);
1441         if (err < 0)
1442                 return err;
1443
1444         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1445         if (tu == NULL)
1446                 return -ENOMEM;
1447         spin_lock_init(&tu->qlock);
1448         init_waitqueue_head(&tu->qchange_sleep);
1449         mutex_init(&tu->ioctl_lock);
1450         tu->ticks = 1;
1451         if (realloc_user_queue(tu, 128) < 0) {
1452                 kfree(tu);
1453                 return -ENOMEM;
1454         }
1455         file->private_data = tu;
1456         return 0;
1457 }
1458
1459 static int snd_timer_user_release(struct inode *inode, struct file *file)
1460 {
1461         struct snd_timer_user *tu;
1462
1463         if (file->private_data) {
1464                 tu = file->private_data;
1465                 file->private_data = NULL;
1466                 mutex_lock(&tu->ioctl_lock);
1467                 if (tu->timeri)
1468                         snd_timer_close(tu->timeri);
1469                 mutex_unlock(&tu->ioctl_lock);
1470                 kfree(tu->queue);
1471                 kfree(tu->tqueue);
1472                 kfree(tu);
1473         }
1474         return 0;
1475 }
1476
1477 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1478 {
1479         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1480         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1481         id->card = -1;
1482         id->device = -1;
1483         id->subdevice = -1;
1484 }
1485
1486 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1487 {
1488         id->dev_class = timer->tmr_class;
1489         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1490         id->card = timer->card ? timer->card->number : -1;
1491         id->device = timer->tmr_device;
1492         id->subdevice = timer->tmr_subdevice;
1493 }
1494
1495 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1496 {
1497         struct snd_timer_id id;
1498         struct snd_timer *timer;
1499         struct list_head *p;
1500
1501         if (copy_from_user(&id, _tid, sizeof(id)))
1502                 return -EFAULT;
1503         mutex_lock(&register_mutex);
1504         if (id.dev_class < 0) {         /* first item */
1505                 if (list_empty(&snd_timer_list))
1506                         snd_timer_user_zero_id(&id);
1507                 else {
1508                         timer = list_entry(snd_timer_list.next,
1509                                            struct snd_timer, device_list);
1510                         snd_timer_user_copy_id(&id, timer);
1511                 }
1512         } else {
1513                 switch (id.dev_class) {
1514                 case SNDRV_TIMER_CLASS_GLOBAL:
1515                         id.device = id.device < 0 ? 0 : id.device + 1;
1516                         list_for_each(p, &snd_timer_list) {
1517                                 timer = list_entry(p, struct snd_timer, device_list);
1518                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1519                                         snd_timer_user_copy_id(&id, timer);
1520                                         break;
1521                                 }
1522                                 if (timer->tmr_device >= id.device) {
1523                                         snd_timer_user_copy_id(&id, timer);
1524                                         break;
1525                                 }
1526                         }
1527                         if (p == &snd_timer_list)
1528                                 snd_timer_user_zero_id(&id);
1529                         break;
1530                 case SNDRV_TIMER_CLASS_CARD:
1531                 case SNDRV_TIMER_CLASS_PCM:
1532                         if (id.card < 0) {
1533                                 id.card = 0;
1534                         } else {
1535                                 if (id.device < 0) {
1536                                         id.device = 0;
1537                                 } else {
1538                                         if (id.subdevice < 0)
1539                                                 id.subdevice = 0;
1540                                         else if (id.subdevice < INT_MAX)
1541                                                 id.subdevice++;
1542                                 }
1543                         }
1544                         list_for_each(p, &snd_timer_list) {
1545                                 timer = list_entry(p, struct snd_timer, device_list);
1546                                 if (timer->tmr_class > id.dev_class) {
1547                                         snd_timer_user_copy_id(&id, timer);
1548                                         break;
1549                                 }
1550                                 if (timer->tmr_class < id.dev_class)
1551                                         continue;
1552                                 if (timer->card->number > id.card) {
1553                                         snd_timer_user_copy_id(&id, timer);
1554                                         break;
1555                                 }
1556                                 if (timer->card->number < id.card)
1557                                         continue;
1558                                 if (timer->tmr_device > id.device) {
1559                                         snd_timer_user_copy_id(&id, timer);
1560                                         break;
1561                                 }
1562                                 if (timer->tmr_device < id.device)
1563                                         continue;
1564                                 if (timer->tmr_subdevice > id.subdevice) {
1565                                         snd_timer_user_copy_id(&id, timer);
1566                                         break;
1567                                 }
1568                                 if (timer->tmr_subdevice < id.subdevice)
1569                                         continue;
1570                                 snd_timer_user_copy_id(&id, timer);
1571                                 break;
1572                         }
1573                         if (p == &snd_timer_list)
1574                                 snd_timer_user_zero_id(&id);
1575                         break;
1576                 default:
1577                         snd_timer_user_zero_id(&id);
1578                 }
1579         }
1580         mutex_unlock(&register_mutex);
1581         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1582                 return -EFAULT;
1583         return 0;
1584 }
1585
1586 static int snd_timer_user_ginfo(struct file *file,
1587                                 struct snd_timer_ginfo __user *_ginfo)
1588 {
1589         struct snd_timer_ginfo *ginfo;
1590         struct snd_timer_id tid;
1591         struct snd_timer *t;
1592         struct list_head *p;
1593         int err = 0;
1594
1595         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1596         if (IS_ERR(ginfo))
1597                 return PTR_ERR(ginfo);
1598
1599         tid = ginfo->tid;
1600         memset(ginfo, 0, sizeof(*ginfo));
1601         ginfo->tid = tid;
1602         mutex_lock(&register_mutex);
1603         t = snd_timer_find(&tid);
1604         if (t != NULL) {
1605                 ginfo->card = t->card ? t->card->number : -1;
1606                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1607                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1608                 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1609                 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1610                 ginfo->resolution = t->hw.resolution;
1611                 if (t->hw.resolution_min > 0) {
1612                         ginfo->resolution_min = t->hw.resolution_min;
1613                         ginfo->resolution_max = t->hw.resolution_max;
1614                 }
1615                 list_for_each(p, &t->open_list_head) {
1616                         ginfo->clients++;
1617                 }
1618         } else {
1619                 err = -ENODEV;
1620         }
1621         mutex_unlock(&register_mutex);
1622         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1623                 err = -EFAULT;
1624         kfree(ginfo);
1625         return err;
1626 }
1627
1628 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1629 {
1630         struct snd_timer *t;
1631         int err;
1632
1633         mutex_lock(&register_mutex);
1634         t = snd_timer_find(&gparams->tid);
1635         if (!t) {
1636                 err = -ENODEV;
1637                 goto _error;
1638         }
1639         if (!list_empty(&t->open_list_head)) {
1640                 err = -EBUSY;
1641                 goto _error;
1642         }
1643         if (!t->hw.set_period) {
1644                 err = -ENOSYS;
1645                 goto _error;
1646         }
1647         err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1648 _error:
1649         mutex_unlock(&register_mutex);
1650         return err;
1651 }
1652
1653 static int snd_timer_user_gparams(struct file *file,
1654                                   struct snd_timer_gparams __user *_gparams)
1655 {
1656         struct snd_timer_gparams gparams;
1657
1658         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1659                 return -EFAULT;
1660         return timer_set_gparams(&gparams);
1661 }
1662
1663 static int snd_timer_user_gstatus(struct file *file,
1664                                   struct snd_timer_gstatus __user *_gstatus)
1665 {
1666         struct snd_timer_gstatus gstatus;
1667         struct snd_timer_id tid;
1668         struct snd_timer *t;
1669         int err = 0;
1670
1671         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1672                 return -EFAULT;
1673         tid = gstatus.tid;
1674         memset(&gstatus, 0, sizeof(gstatus));
1675         gstatus.tid = tid;
1676         mutex_lock(&register_mutex);
1677         t = snd_timer_find(&tid);
1678         if (t != NULL) {
1679                 spin_lock_irq(&t->lock);
1680                 gstatus.resolution = snd_timer_hw_resolution(t);
1681                 if (t->hw.precise_resolution) {
1682                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1683                                                  &gstatus.resolution_den);
1684                 } else {
1685                         gstatus.resolution_num = gstatus.resolution;
1686                         gstatus.resolution_den = 1000000000uL;
1687                 }
1688                 spin_unlock_irq(&t->lock);
1689         } else {
1690                 err = -ENODEV;
1691         }
1692         mutex_unlock(&register_mutex);
1693         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1694                 err = -EFAULT;
1695         return err;
1696 }
1697
1698 static int snd_timer_user_tselect(struct file *file,
1699                                   struct snd_timer_select __user *_tselect)
1700 {
1701         struct snd_timer_user *tu;
1702         struct snd_timer_select tselect;
1703         char str[32];
1704         int err = 0;
1705
1706         tu = file->private_data;
1707         if (tu->timeri) {
1708                 snd_timer_close(tu->timeri);
1709                 tu->timeri = NULL;
1710         }
1711         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1712                 err = -EFAULT;
1713                 goto __err;
1714         }
1715         sprintf(str, "application %i", current->pid);
1716         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1717                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1718         err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1719         if (err < 0)
1720                 goto __err;
1721
1722         tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1723         tu->timeri->callback = tu->tread
1724                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1725         tu->timeri->ccallback = snd_timer_user_ccallback;
1726         tu->timeri->callback_data = (void *)tu;
1727         tu->timeri->disconnect = snd_timer_user_disconnect;
1728
1729       __err:
1730         return err;
1731 }
1732
1733 static int snd_timer_user_info(struct file *file,
1734                                struct snd_timer_info __user *_info)
1735 {
1736         struct snd_timer_user *tu;
1737         struct snd_timer_info *info;
1738         struct snd_timer *t;
1739         int err = 0;
1740
1741         tu = file->private_data;
1742         if (!tu->timeri)
1743                 return -EBADFD;
1744         t = tu->timeri->timer;
1745         if (!t)
1746                 return -EBADFD;
1747
1748         info = kzalloc(sizeof(*info), GFP_KERNEL);
1749         if (! info)
1750                 return -ENOMEM;
1751         info->card = t->card ? t->card->number : -1;
1752         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1753                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1754         strlcpy(info->id, t->id, sizeof(info->id));
1755         strlcpy(info->name, t->name, sizeof(info->name));
1756         info->resolution = t->hw.resolution;
1757         if (copy_to_user(_info, info, sizeof(*_info)))
1758                 err = -EFAULT;
1759         kfree(info);
1760         return err;
1761 }
1762
1763 static int snd_timer_user_params(struct file *file,
1764                                  struct snd_timer_params __user *_params)
1765 {
1766         struct snd_timer_user *tu;
1767         struct snd_timer_params params;
1768         struct snd_timer *t;
1769         int err;
1770
1771         tu = file->private_data;
1772         if (!tu->timeri)
1773                 return -EBADFD;
1774         t = tu->timeri->timer;
1775         if (!t)
1776                 return -EBADFD;
1777         if (copy_from_user(&params, _params, sizeof(params)))
1778                 return -EFAULT;
1779         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1780                 u64 resolution;
1781
1782                 if (params.ticks < 1) {
1783                         err = -EINVAL;
1784                         goto _end;
1785                 }
1786
1787                 /* Don't allow resolution less than 1ms */
1788                 resolution = snd_timer_resolution(tu->timeri);
1789                 resolution *= params.ticks;
1790                 if (resolution < 1000000) {
1791                         err = -EINVAL;
1792                         goto _end;
1793                 }
1794         }
1795         if (params.queue_size > 0 &&
1796             (params.queue_size < 32 || params.queue_size > 1024)) {
1797                 err = -EINVAL;
1798                 goto _end;
1799         }
1800         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1801                               (1<<SNDRV_TIMER_EVENT_TICK)|
1802                               (1<<SNDRV_TIMER_EVENT_START)|
1803                               (1<<SNDRV_TIMER_EVENT_STOP)|
1804                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1805                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1806                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1807                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1808                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1809                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1810                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1811                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1812                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1813                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1814                 err = -EINVAL;
1815                 goto _end;
1816         }
1817         snd_timer_stop(tu->timeri);
1818         spin_lock_irq(&t->lock);
1819         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1820                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1821                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1822         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1823                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1824         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1825                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1826         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1827                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1828         spin_unlock_irq(&t->lock);
1829         if (params.queue_size > 0 &&
1830             (unsigned int)tu->queue_size != params.queue_size) {
1831                 err = realloc_user_queue(tu, params.queue_size);
1832                 if (err < 0)
1833                         goto _end;
1834         }
1835         spin_lock_irq(&tu->qlock);
1836         tu->qhead = tu->qtail = tu->qused = 0;
1837         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1838                 if (tu->tread) {
1839                         struct snd_timer_tread tread;
1840                         memset(&tread, 0, sizeof(tread));
1841                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1842                         tread.tstamp.tv_sec = 0;
1843                         tread.tstamp.tv_nsec = 0;
1844                         tread.val = 0;
1845                         snd_timer_user_append_to_tqueue(tu, &tread);
1846                 } else {
1847                         struct snd_timer_read *r = &tu->queue[0];
1848                         r->resolution = 0;
1849                         r->ticks = 0;
1850                         tu->qused++;
1851                         tu->qtail++;
1852                 }
1853         }
1854         tu->filter = params.filter;
1855         tu->ticks = params.ticks;
1856         spin_unlock_irq(&tu->qlock);
1857         err = 0;
1858  _end:
1859         if (copy_to_user(_params, &params, sizeof(params)))
1860                 return -EFAULT;
1861         return err;
1862 }
1863
1864 static int snd_timer_user_status(struct file *file,
1865                                  struct snd_timer_status __user *_status)
1866 {
1867         struct snd_timer_user *tu;
1868         struct snd_timer_status status;
1869
1870         tu = file->private_data;
1871         if (!tu->timeri)
1872                 return -EBADFD;
1873         memset(&status, 0, sizeof(status));
1874         status.tstamp = tu->tstamp;
1875         status.resolution = snd_timer_resolution(tu->timeri);
1876         status.lost = tu->timeri->lost;
1877         status.overrun = tu->overrun;
1878         spin_lock_irq(&tu->qlock);
1879         status.queue = tu->qused;
1880         spin_unlock_irq(&tu->qlock);
1881         if (copy_to_user(_status, &status, sizeof(status)))
1882                 return -EFAULT;
1883         return 0;
1884 }
1885
1886 static int snd_timer_user_start(struct file *file)
1887 {
1888         int err;
1889         struct snd_timer_user *tu;
1890
1891         tu = file->private_data;
1892         if (!tu->timeri)
1893                 return -EBADFD;
1894         snd_timer_stop(tu->timeri);
1895         tu->timeri->lost = 0;
1896         tu->last_resolution = 0;
1897         err = snd_timer_start(tu->timeri, tu->ticks);
1898         if (err < 0)
1899                 return err;
1900         return 0;
1901 }
1902
1903 static int snd_timer_user_stop(struct file *file)
1904 {
1905         int err;
1906         struct snd_timer_user *tu;
1907
1908         tu = file->private_data;
1909         if (!tu->timeri)
1910                 return -EBADFD;
1911         err = snd_timer_stop(tu->timeri);
1912         if (err < 0)
1913                 return err;
1914         return 0;
1915 }
1916
1917 static int snd_timer_user_continue(struct file *file)
1918 {
1919         int err;
1920         struct snd_timer_user *tu;
1921
1922         tu = file->private_data;
1923         if (!tu->timeri)
1924                 return -EBADFD;
1925         /* start timer instead of continue if it's not used before */
1926         if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
1927                 return snd_timer_user_start(file);
1928         tu->timeri->lost = 0;
1929         err = snd_timer_continue(tu->timeri);
1930         if (err < 0)
1931                 return err;
1932         return 0;
1933 }
1934
1935 static int snd_timer_user_pause(struct file *file)
1936 {
1937         int err;
1938         struct snd_timer_user *tu;
1939
1940         tu = file->private_data;
1941         if (!tu->timeri)
1942                 return -EBADFD;
1943         err = snd_timer_pause(tu->timeri);
1944         if (err < 0)
1945                 return err;
1946         return 0;
1947 }
1948
1949 enum {
1950         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1951         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1952         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1953         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1954 };
1955
1956 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1957                                  unsigned long arg)
1958 {
1959         struct snd_timer_user *tu;
1960         void __user *argp = (void __user *)arg;
1961         int __user *p = argp;
1962
1963         tu = file->private_data;
1964         switch (cmd) {
1965         case SNDRV_TIMER_IOCTL_PVERSION:
1966                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1967         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1968                 return snd_timer_user_next_device(argp);
1969         case SNDRV_TIMER_IOCTL_TREAD:
1970         {
1971                 int xarg, old_tread;
1972
1973                 if (tu->timeri) /* too late */
1974                         return -EBUSY;
1975                 if (get_user(xarg, p))
1976                         return -EFAULT;
1977                 old_tread = tu->tread;
1978                 tu->tread = xarg ? 1 : 0;
1979                 if (tu->tread != old_tread &&
1980                     realloc_user_queue(tu, tu->queue_size) < 0) {
1981                         tu->tread = old_tread;
1982                         return -ENOMEM;
1983                 }
1984                 return 0;
1985         }
1986         case SNDRV_TIMER_IOCTL_GINFO:
1987                 return snd_timer_user_ginfo(file, argp);
1988         case SNDRV_TIMER_IOCTL_GPARAMS:
1989                 return snd_timer_user_gparams(file, argp);
1990         case SNDRV_TIMER_IOCTL_GSTATUS:
1991                 return snd_timer_user_gstatus(file, argp);
1992         case SNDRV_TIMER_IOCTL_SELECT:
1993                 return snd_timer_user_tselect(file, argp);
1994         case SNDRV_TIMER_IOCTL_INFO:
1995                 return snd_timer_user_info(file, argp);
1996         case SNDRV_TIMER_IOCTL_PARAMS:
1997                 return snd_timer_user_params(file, argp);
1998         case SNDRV_TIMER_IOCTL_STATUS:
1999                 return snd_timer_user_status(file, argp);
2000         case SNDRV_TIMER_IOCTL_START:
2001         case SNDRV_TIMER_IOCTL_START_OLD:
2002                 return snd_timer_user_start(file);
2003         case SNDRV_TIMER_IOCTL_STOP:
2004         case SNDRV_TIMER_IOCTL_STOP_OLD:
2005                 return snd_timer_user_stop(file);
2006         case SNDRV_TIMER_IOCTL_CONTINUE:
2007         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2008                 return snd_timer_user_continue(file);
2009         case SNDRV_TIMER_IOCTL_PAUSE:
2010         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2011                 return snd_timer_user_pause(file);
2012         }
2013         return -ENOTTY;
2014 }
2015
2016 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2017                                  unsigned long arg)
2018 {
2019         struct snd_timer_user *tu = file->private_data;
2020         long ret;
2021
2022         mutex_lock(&tu->ioctl_lock);
2023         ret = __snd_timer_user_ioctl(file, cmd, arg);
2024         mutex_unlock(&tu->ioctl_lock);
2025         return ret;
2026 }
2027
2028 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2029 {
2030         struct snd_timer_user *tu;
2031
2032         tu = file->private_data;
2033         return fasync_helper(fd, file, on, &tu->fasync);
2034 }
2035
2036 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2037                                    size_t count, loff_t *offset)
2038 {
2039         struct snd_timer_user *tu;
2040         long result = 0, unit;
2041         int qhead;
2042         int err = 0;
2043
2044         tu = file->private_data;
2045         unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
2046         mutex_lock(&tu->ioctl_lock);
2047         spin_lock_irq(&tu->qlock);
2048         while ((long)count - result >= unit) {
2049                 while (!tu->qused) {
2050                         wait_queue_entry_t wait;
2051
2052                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2053                                 err = -EAGAIN;
2054                                 goto _error;
2055                         }
2056
2057                         set_current_state(TASK_INTERRUPTIBLE);
2058                         init_waitqueue_entry(&wait, current);
2059                         add_wait_queue(&tu->qchange_sleep, &wait);
2060
2061                         spin_unlock_irq(&tu->qlock);
2062                         mutex_unlock(&tu->ioctl_lock);
2063                         schedule();
2064                         mutex_lock(&tu->ioctl_lock);
2065                         spin_lock_irq(&tu->qlock);
2066
2067                         remove_wait_queue(&tu->qchange_sleep, &wait);
2068
2069                         if (tu->disconnected) {
2070                                 err = -ENODEV;
2071                                 goto _error;
2072                         }
2073                         if (signal_pending(current)) {
2074                                 err = -ERESTARTSYS;
2075                                 goto _error;
2076                         }
2077                 }
2078
2079                 qhead = tu->qhead++;
2080                 tu->qhead %= tu->queue_size;
2081                 tu->qused--;
2082                 spin_unlock_irq(&tu->qlock);
2083
2084                 if (tu->tread) {
2085                         if (copy_to_user(buffer, &tu->tqueue[qhead],
2086                                          sizeof(struct snd_timer_tread)))
2087                                 err = -EFAULT;
2088                 } else {
2089                         if (copy_to_user(buffer, &tu->queue[qhead],
2090                                          sizeof(struct snd_timer_read)))
2091                                 err = -EFAULT;
2092                 }
2093
2094                 spin_lock_irq(&tu->qlock);
2095                 if (err < 0)
2096                         goto _error;
2097                 result += unit;
2098                 buffer += unit;
2099         }
2100  _error:
2101         spin_unlock_irq(&tu->qlock);
2102         mutex_unlock(&tu->ioctl_lock);
2103         return result > 0 ? result : err;
2104 }
2105
2106 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2107 {
2108         __poll_t mask;
2109         struct snd_timer_user *tu;
2110
2111         tu = file->private_data;
2112
2113         poll_wait(file, &tu->qchange_sleep, wait);
2114
2115         mask = 0;
2116         spin_lock_irq(&tu->qlock);
2117         if (tu->qused)
2118                 mask |= EPOLLIN | EPOLLRDNORM;
2119         if (tu->disconnected)
2120                 mask |= EPOLLERR;
2121         spin_unlock_irq(&tu->qlock);
2122
2123         return mask;
2124 }
2125
2126 #ifdef CONFIG_COMPAT
2127 #include "timer_compat.c"
2128 #else
2129 #define snd_timer_user_ioctl_compat     NULL
2130 #endif
2131
2132 static const struct file_operations snd_timer_f_ops =
2133 {
2134         .owner =        THIS_MODULE,
2135         .read =         snd_timer_user_read,
2136         .open =         snd_timer_user_open,
2137         .release =      snd_timer_user_release,
2138         .llseek =       no_llseek,
2139         .poll =         snd_timer_user_poll,
2140         .unlocked_ioctl =       snd_timer_user_ioctl,
2141         .compat_ioctl = snd_timer_user_ioctl_compat,
2142         .fasync =       snd_timer_user_fasync,
2143 };
2144
2145 /* unregister the system timer */
2146 static void snd_timer_free_all(void)
2147 {
2148         struct snd_timer *timer, *n;
2149
2150         list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2151                 snd_timer_free(timer);
2152 }
2153
2154 static struct device timer_dev;
2155
2156 /*
2157  *  ENTRY functions
2158  */
2159
2160 static int __init alsa_timer_init(void)
2161 {
2162         int err;
2163
2164         snd_device_initialize(&timer_dev, NULL);
2165         dev_set_name(&timer_dev, "timer");
2166
2167 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2168         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2169                               "system timer");
2170 #endif
2171
2172         err = snd_timer_register_system();
2173         if (err < 0) {
2174                 pr_err("ALSA: unable to register system timer (%i)\n", err);
2175                 goto put_timer;
2176         }
2177
2178         err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2179                                   &snd_timer_f_ops, NULL, &timer_dev);
2180         if (err < 0) {
2181                 pr_err("ALSA: unable to register timer device (%i)\n", err);
2182                 snd_timer_free_all();
2183                 goto put_timer;
2184         }
2185
2186         snd_timer_proc_init();
2187         return 0;
2188
2189 put_timer:
2190         put_device(&timer_dev);
2191         return err;
2192 }
2193
2194 static void __exit alsa_timer_exit(void)
2195 {
2196         snd_unregister_device(&timer_dev);
2197         snd_timer_free_all();
2198         put_device(&timer_dev);
2199         snd_timer_proc_done();
2200 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2201         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2202 #endif
2203 }
2204
2205 module_init(alsa_timer_init)
2206 module_exit(alsa_timer_exit)