git.oblomov.eu Git - linux-2.6/blob - sound/core/timer.c

   1 /*
   2  *  Timers abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/string.h>
  29 #include <sound/core.h>
  30 #include <sound/timer.h>
  31 #include <sound/control.h>
  32 #include <sound/info.h>
  33 #include <sound/minors.h>
  34 #include <sound/initval.h>
  35 #include <linux/kmod.h>
  36
  37 #if defined(CONFIG_SND_HPET) || defined(CONFIG_SND_HPET_MODULE)
  38 #define DEFAULT_TIMER_LIMIT 3
  39 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
  40 #define DEFAULT_TIMER_LIMIT 2
  41 #else
  42 #define DEFAULT_TIMER_LIMIT 1
  43 #endif
  44
  45 static int timer_limit = DEFAULT_TIMER_LIMIT;
  46 static int timer_tstamp_monotonic = 1;
  47 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
  48 MODULE_DESCRIPTION("ALSA timer interface");
  49 MODULE_LICENSE("GPL");
  50 module_param(timer_limit, int, 0444);
  51 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  52 module_param(timer_tstamp_monotonic, int, 0444);
  53 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  54
  55 struct snd_timer_user {
  56         struct snd_timer_instance *timeri;
  57         int tread;              /* enhanced read with timestamps and events */
  58         unsigned long ticks;
  59         unsigned long overrun;
  60         int qhead;
  61         int qtail;
  62         int qused;
  63         int queue_size;
  64         struct snd_timer_read *queue;
  65         struct snd_timer_tread *tqueue;
  66         spinlock_t qlock;
  67         unsigned long last_resolution;
  68         unsigned int filter;
  69         struct timespec tstamp;         /* trigger tstamp */
  70         wait_queue_head_t qchange_sleep;
  71         struct fasync_struct *fasync;
  72         struct mutex tread_sem;
  73 };
  74
  75 /* list of timers */
  76 static LIST_HEAD(snd_timer_list);
  77
  78 /* list of slave instances */
  79 static LIST_HEAD(snd_timer_slave_list);
  80
  81 /* lock for slave active lists */
  82 static DEFINE_SPINLOCK(slave_active_lock);
  83
  84 static DEFINE_MUTEX(register_mutex);
  85
  86 static int snd_timer_free(struct snd_timer *timer);
  87 static int snd_timer_dev_free(struct snd_device *device);
  88 static int snd_timer_dev_register(struct snd_device *device);
  89 static int snd_timer_dev_disconnect(struct snd_device *device);
  90
  91 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
  92
  93 /*
  94  * create a timer instance with the given owner string.
  95  * when timer is not NULL, increments the module counter
  96  */
  97 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
  98                                                          struct snd_timer *timer)
  99 {
 100         struct snd_timer_instance *timeri;
 101         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
 102         if (timeri == NULL)
 103                 return NULL;
 104         timeri->owner = kstrdup(owner, GFP_KERNEL);
 105         if (! timeri->owner) {
 106                 kfree(timeri);
 107                 return NULL;
 108         }
 109         INIT_LIST_HEAD(&timeri->open_list);
 110         INIT_LIST_HEAD(&timeri->active_list);
 111         INIT_LIST_HEAD(&timeri->ack_list);
 112         INIT_LIST_HEAD(&timeri->slave_list_head);
 113         INIT_LIST_HEAD(&timeri->slave_active_head);
 114
 115         timeri->timer = timer;
 116         if (timer && !try_module_get(timer->module)) {
 117                 kfree(timeri->owner);
 118                 kfree(timeri);
 119                 return NULL;
 120         }
 121
 122         return timeri;
 123 }
 124
 125 /*
 126  * find a timer instance from the given timer id
 127  */
 128 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
 129 {
 130         struct snd_timer *timer = NULL;
 131
 132         list_for_each_entry(timer, &snd_timer_list, device_list) {
 133                 if (timer->tmr_class != tid->dev_class)
 134                         continue;
 135                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
 136                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
 137                     (timer->card == NULL ||
 138                      timer->card->number != tid->card))
 139                         continue;
 140                 if (timer->tmr_device != tid->device)
 141                         continue;
 142                 if (timer->tmr_subdevice != tid->subdevice)
 143                         continue;
 144                 return timer;
 145         }
 146         return NULL;
 147 }
 148
 149 #ifdef CONFIG_MODULES
 150
 151 static void snd_timer_request(struct snd_timer_id *tid)
 152 {
 153         switch (tid->dev_class) {
 154         case SNDRV_TIMER_CLASS_GLOBAL:
 155                 if (tid->device < timer_limit)
 156                         request_module("snd-timer-%i", tid->device);
 157                 break;
 158         case SNDRV_TIMER_CLASS_CARD:
 159         case SNDRV_TIMER_CLASS_PCM:
 160                 if (tid->card < snd_ecards_limit)
 161                         request_module("snd-card-%i", tid->card);
 162                 break;
 163         default:
 164                 break;
 165         }
 166 }
 167
 168 #endif
 169
 170 /*
 171  * look for a master instance matching with the slave id of the given slave.
 172  * when found, relink the open_link of the slave.
 173  *
 174  * call this with register_mutex down.
 175  */
 176 static void snd_timer_check_slave(struct snd_timer_instance *slave)
 177 {
 178         struct snd_timer *timer;
 179         struct snd_timer_instance *master;
 180
 181         /* FIXME: it's really dumb to look up all entries.. */
 182         list_for_each_entry(timer, &snd_timer_list, device_list) {
 183                 list_for_each_entry(master, &timer->open_list_head, open_list) {
 184                         if (slave->slave_class == master->slave_class &&
 185                             slave->slave_id == master->slave_id) {
 186                                 list_del(&slave->open_list);
 187                                 list_add_tail(&slave->open_list,
 188                                               &master->slave_list_head);
 189                                 spin_lock_irq(&slave_active_lock);
 190                                 slave->master = master;
 191                                 slave->timer = master->timer;
 192                                 spin_unlock_irq(&slave_active_lock);
 193                                 return;
 194                         }
 195                 }
 196         }
 197 }
 198
 199 /*
 200  * look for slave instances matching with the slave id of the given master.
 201  * when found, relink the open_link of slaves.
 202  *
 203  * call this with register_mutex down.
 204  */
 205 static void snd_timer_check_master(struct snd_timer_instance *master)
 206 {
 207         struct snd_timer_instance *slave, *tmp;
 208
 209         /* check all pending slaves */
 210         list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 211                 if (slave->slave_class == master->slave_class &&
 212                     slave->slave_id == master->slave_id) {
 213                         list_move_tail(&slave->open_list, &master->slave_list_head);
 214                         spin_lock_irq(&slave_active_lock);
 215                         slave->master = master;
 216                         slave->timer = master->timer;
 217                         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 218                                 list_add_tail(&slave->active_list,
 219                                               &master->slave_active_head);
 220                         spin_unlock_irq(&slave_active_lock);
 221                 }
 222         }
 223 }
 224
 225 /*
 226  * open a timer instance
 227  * when opening a master, the slave id must be here given.
 228  */
 229 int snd_timer_open(struct snd_timer_instance **ti,
 230                    char *owner, struct snd_timer_id *tid,
 231                    unsigned int slave_id)
 232 {
 233         struct snd_timer *timer;
 234         struct snd_timer_instance *timeri = NULL;
 235
 236         if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 237                 /* open a slave instance */
 238                 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 239                     tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 240                         snd_printd("invalid slave class %i\n", tid->dev_sclass);
 241                         return -EINVAL;
 242                 }
 243                 mutex_lock(&register_mutex);
 244                 timeri = snd_timer_instance_new(owner, NULL);
 245                 if (!timeri) {
 246                         mutex_unlock(&register_mutex);
 247                         return -ENOMEM;
 248                 }
 249                 timeri->slave_class = tid->dev_sclass;
 250                 timeri->slave_id = tid->device;
 251                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 252                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 253                 snd_timer_check_slave(timeri);
 254                 mutex_unlock(&register_mutex);
 255                 *ti = timeri;
 256                 return 0;
 257         }
 258
 259         /* open a master instance */
 260         mutex_lock(&register_mutex);
 261         timer = snd_timer_find(tid);
 262 #ifdef CONFIG_MODULES
 263         if (!timer) {
 264                 mutex_unlock(&register_mutex);
 265                 snd_timer_request(tid);
 266                 mutex_lock(&register_mutex);
 267                 timer = snd_timer_find(tid);
 268         }
 269 #endif
 270         if (!timer) {
 271                 mutex_unlock(&register_mutex);
 272                 return -ENODEV;
 273         }
 274         if (!list_empty(&timer->open_list_head)) {
 275                 timeri = list_entry(timer->open_list_head.next,
 276                                     struct snd_timer_instance, open_list);
 277                 if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 278                         mutex_unlock(&register_mutex);
 279                         return -EBUSY;
 280                 }
 281         }
 282         timeri = snd_timer_instance_new(owner, timer);
 283         if (!timeri) {
 284                 mutex_unlock(&register_mutex);
 285                 return -ENOMEM;
 286         }
 287         timeri->slave_class = tid->dev_sclass;
 288         timeri->slave_id = slave_id;
 289         if (list_empty(&timer->open_list_head) && timer->hw.open)
 290                 timer->hw.open(timer);
 291         list_add_tail(&timeri->open_list, &timer->open_list_head);
 292         snd_timer_check_master(timeri);
 293         mutex_unlock(&register_mutex);
 294         *ti = timeri;
 295         return 0;
 296 }
 297
 298 static int _snd_timer_stop(struct snd_timer_instance *timeri,
 299                            int keep_flag, int event);
 300
 301 /*
 302  * close a timer instance
 303  */
 304 int snd_timer_close(struct snd_timer_instance *timeri)
 305 {
 306         struct snd_timer *timer = NULL;
 307         struct snd_timer_instance *slave, *tmp;
 308
 309         if (snd_BUG_ON(!timeri))
 310                 return -ENXIO;
 311
 312         /* force to stop the timer */
 313         snd_timer_stop(timeri);
 314
 315         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 316                 /* wait, until the active callback is finished */
 317                 spin_lock_irq(&slave_active_lock);
 318                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 319                         spin_unlock_irq(&slave_active_lock);
 320                         udelay(10);
 321                         spin_lock_irq(&slave_active_lock);
 322                 }
 323                 spin_unlock_irq(&slave_active_lock);
 324                 mutex_lock(&register_mutex);
 325                 list_del(&timeri->open_list);
 326                 mutex_unlock(&register_mutex);
 327         } else {
 328                 timer = timeri->timer;
 329                 /* wait, until the active callback is finished */
 330                 spin_lock_irq(&timer->lock);
 331                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 332                         spin_unlock_irq(&timer->lock);
 333                         udelay(10);
 334                         spin_lock_irq(&timer->lock);
 335                 }
 336                 spin_unlock_irq(&timer->lock);
 337                 mutex_lock(&register_mutex);
 338                 list_del(&timeri->open_list);
 339                 if (timer && list_empty(&timer->open_list_head) &&
 340                     timer->hw.close)
 341                         timer->hw.close(timer);
 342                 /* remove slave links */
 343                 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 344                                          open_list) {
 345                         spin_lock_irq(&slave_active_lock);
 346                         _snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
 347                         list_move_tail(&slave->open_list, &snd_timer_slave_list);
 348                         slave->master = NULL;
 349                         slave->timer = NULL;
 350                         spin_unlock_irq(&slave_active_lock);
 351                 }
 352                 mutex_unlock(&register_mutex);
 353         }
 354         if (timeri->private_free)
 355                 timeri->private_free(timeri);
 356         kfree(timeri->owner);
 357         kfree(timeri);
 358         if (timer)
 359                 module_put(timer->module);
 360         return 0;
 361 }
 362
 363 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 364 {
 365         struct snd_timer * timer;
 366
 367         if (timeri == NULL)
 368                 return 0;
 369         if ((timer = timeri->timer) != NULL) {
 370                 if (timer->hw.c_resolution)
 371                         return timer->hw.c_resolution(timer);
 372                 return timer->hw.resolution;
 373         }
 374         return 0;
 375 }
 376
 377 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 378 {
 379         struct snd_timer *timer;
 380         unsigned long flags;
 381         unsigned long resolution = 0;
 382         struct snd_timer_instance *ts;
 383         struct timespec tstamp;
 384
 385         if (timer_tstamp_monotonic)
 386                 do_posix_clock_monotonic_gettime(&tstamp);
 387         else
 388                 getnstimeofday(&tstamp);
 389         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 390                        event > SNDRV_TIMER_EVENT_PAUSE))
 391                 return;
 392         if (event == SNDRV_TIMER_EVENT_START ||
 393             event == SNDRV_TIMER_EVENT_CONTINUE)
 394                 resolution = snd_timer_resolution(ti);
 395         if (ti->ccallback)
 396                 ti->ccallback(ti, SNDRV_TIMER_EVENT_START, &tstamp, resolution);
 397         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 398                 return;
 399         timer = ti->timer;
 400         if (timer == NULL)
 401                 return;
 402         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 403                 return;
 404         spin_lock_irqsave(&timer->lock, flags);
 405         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 406                 if (ts->ccallback)
 407                         ts->ccallback(ti, event + 100, &tstamp, resolution);
 408         spin_unlock_irqrestore(&timer->lock, flags);
 409 }
 410
 411 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
 412                             unsigned long sticks)
 413 {
 414         list_del(&timeri->active_list);
 415         list_add_tail(&timeri->active_list, &timer->active_list_head);
 416         if (timer->running) {
 417                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 418                         goto __start_now;
 419                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 420                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 421                 return 1;       /* delayed start */
 422         } else {
 423                 timer->sticks = sticks;
 424                 timer->hw.start(timer);
 425               __start_now:
 426                 timer->running++;
 427                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 428                 return 0;
 429         }
 430 }
 431
 432 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
 433 {
 434         unsigned long flags;
 435
 436         spin_lock_irqsave(&slave_active_lock, flags);
 437         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 438         if (timeri->master)
 439                 list_add_tail(&timeri->active_list,
 440                               &timeri->master->slave_active_head);
 441         spin_unlock_irqrestore(&slave_active_lock, flags);
 442         return 1; /* delayed start */
 443 }
 444
 445 /*
 446  *  start the timer instance
 447  */
 448 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 449 {
 450         struct snd_timer *timer;
 451         int result = -EINVAL;
 452         unsigned long flags;
 453
 454         if (timeri == NULL || ticks < 1)
 455                 return -EINVAL;
 456         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 457                 result = snd_timer_start_slave(timeri);
 458                 snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 459                 return result;
 460         }
 461         timer = timeri->timer;
 462         if (timer == NULL)
 463                 return -EINVAL;
 464         spin_lock_irqsave(&timer->lock, flags);
 465         timeri->ticks = timeri->cticks = ticks;
 466         timeri->pticks = 0;
 467         result = snd_timer_start1(timer, timeri, ticks);
 468         spin_unlock_irqrestore(&timer->lock, flags);
 469         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 470         return result;
 471 }
 472
 473 static int _snd_timer_stop(struct snd_timer_instance * timeri,
 474                            int keep_flag, int event)
 475 {
 476         struct snd_timer *timer;
 477         unsigned long flags;
 478
 479         if (snd_BUG_ON(!timeri))
 480                 return -ENXIO;
 481
 482         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 483                 if (!keep_flag) {
 484                         spin_lock_irqsave(&slave_active_lock, flags);
 485                         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 486                         spin_unlock_irqrestore(&slave_active_lock, flags);
 487                 }
 488                 goto __end;
 489         }
 490         timer = timeri->timer;
 491         if (!timer)
 492                 return -EINVAL;
 493         spin_lock_irqsave(&timer->lock, flags);
 494         list_del_init(&timeri->ack_list);
 495         list_del_init(&timeri->active_list);
 496         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 497             !(--timer->running)) {
 498                 timer->hw.stop(timer);
 499                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 500                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 501                         snd_timer_reschedule(timer, 0);
 502                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 503                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 504                                 timer->hw.start(timer);
 505                         }
 506                 }
 507         }
 508         if (!keep_flag)
 509                 timeri->flags &=
 510                         ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 511         spin_unlock_irqrestore(&timer->lock, flags);
 512       __end:
 513         if (event != SNDRV_TIMER_EVENT_RESOLUTION)
 514                 snd_timer_notify1(timeri, event);
 515         return 0;
 516 }
 517
 518 /*
 519  * stop the timer instance.
 520  *
 521  * do not call this from the timer callback!
 522  */
 523 int snd_timer_stop(struct snd_timer_instance *timeri)
 524 {
 525         struct snd_timer *timer;
 526         unsigned long flags;
 527         int err;
 528
 529         err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
 530         if (err < 0)
 531                 return err;
 532         timer = timeri->timer;
 533         spin_lock_irqsave(&timer->lock, flags);
 534         timeri->cticks = timeri->ticks;
 535         timeri->pticks = 0;
 536         spin_unlock_irqrestore(&timer->lock, flags);
 537         return 0;
 538 }
 539
 540 /*
 541  * start again..  the tick is kept.
 542  */
 543 int snd_timer_continue(struct snd_timer_instance *timeri)
 544 {
 545         struct snd_timer *timer;
 546         int result = -EINVAL;
 547         unsigned long flags;
 548
 549         if (timeri == NULL)
 550                 return result;
 551         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 552                 return snd_timer_start_slave(timeri);
 553         timer = timeri->timer;
 554         if (! timer)
 555                 return -EINVAL;
 556         spin_lock_irqsave(&timer->lock, flags);
 557         if (!timeri->cticks)
 558                 timeri->cticks = 1;
 559         timeri->pticks = 0;
 560         result = snd_timer_start1(timer, timeri, timer->sticks);
 561         spin_unlock_irqrestore(&timer->lock, flags);
 562         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
 563         return result;
 564 }
 565
 566 /*
 567  * pause.. remember the ticks left
 568  */
 569 int snd_timer_pause(struct snd_timer_instance * timeri)
 570 {
 571         return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
 572 }
 573
 574 /*
 575  * reschedule the timer
 576  *
 577  * start pending instances and check the scheduling ticks.
 578  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 579  */
 580 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 581 {
 582         struct snd_timer_instance *ti;
 583         unsigned long ticks = ~0UL;
 584
 585         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 586                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 587                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 588                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 589                         timer->running++;
 590                 }
 591                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 592                         if (ticks > ti->cticks)
 593                                 ticks = ti->cticks;
 594                 }
 595         }
 596         if (ticks == ~0UL) {
 597                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 598                 return;
 599         }
 600         if (ticks > timer->hw.ticks)
 601                 ticks = timer->hw.ticks;
 602         if (ticks_left != ticks)
 603                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 604         timer->sticks = ticks;
 605 }
 606
 607 /*
 608  * timer tasklet
 609  *
 610  */
 611 static void snd_timer_tasklet(unsigned long arg)
 612 {
 613         struct snd_timer *timer = (struct snd_timer *) arg;
 614         struct snd_timer_instance *ti;
 615         struct list_head *p;
 616         unsigned long resolution, ticks;
 617         unsigned long flags;
 618
 619         spin_lock_irqsave(&timer->lock, flags);
 620         /* now process all callbacks */
 621         while (!list_empty(&timer->sack_list_head)) {
 622                 p = timer->sack_list_head.next;         /* get first item */
 623                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 624
 625                 /* remove from ack_list and make empty */
 626                 list_del_init(p);
 627
 628                 ticks = ti->pticks;
 629                 ti->pticks = 0;
 630                 resolution = ti->resolution;
 631
 632                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 633                 spin_unlock(&timer->lock);
 634                 if (ti->callback)
 635                         ti->callback(ti, resolution, ticks);
 636                 spin_lock(&timer->lock);
 637                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 638         }
 639         spin_unlock_irqrestore(&timer->lock, flags);
 640 }
 641
 642 /*
 643  * timer interrupt
 644  *
 645  * ticks_left is usually equal to timer->sticks.
 646  *
 647  */
 648 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 649 {
 650         struct snd_timer_instance *ti, *ts, *tmp;
 651         unsigned long resolution, ticks;
 652         struct list_head *p, *ack_list_head;
 653         unsigned long flags;
 654         int use_tasklet = 0;
 655
 656         if (timer == NULL)
 657                 return;
 658
 659         spin_lock_irqsave(&timer->lock, flags);
 660
 661         /* remember the current resolution */
 662         if (timer->hw.c_resolution)
 663                 resolution = timer->hw.c_resolution(timer);
 664         else
 665                 resolution = timer->hw.resolution;
 666
 667         /* loop for all active instances
 668          * Here we cannot use list_for_each_entry because the active_list of a
 669          * processed instance is relinked to done_list_head before the callback
 670          * is called.
 671          */
 672         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 673                                  active_list) {
 674                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 675                         continue;
 676                 ti->pticks += ticks_left;
 677                 ti->resolution = resolution;
 678                 if (ti->cticks < ticks_left)
 679                         ti->cticks = 0;
 680                 else
 681                         ti->cticks -= ticks_left;
 682                 if (ti->cticks) /* not expired */
 683                         continue;
 684                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 685                         ti->cticks = ti->ticks;
 686                 } else {
 687                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 688                         if (--timer->running)
 689                                 list_del(&ti->active_list);
 690                 }
 691                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
 692                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 693                         ack_list_head = &timer->ack_list_head;
 694                 else
 695                         ack_list_head = &timer->sack_list_head;
 696                 if (list_empty(&ti->ack_list))
 697                         list_add_tail(&ti->ack_list, ack_list_head);
 698                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 699                         ts->pticks = ti->pticks;
 700                         ts->resolution = resolution;
 701                         if (list_empty(&ts->ack_list))
 702                                 list_add_tail(&ts->ack_list, ack_list_head);
 703                 }
 704         }
 705         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 706                 snd_timer_reschedule(timer, timer->sticks);
 707         if (timer->running) {
 708                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 709                         timer->hw.stop(timer);
 710                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 711                 }
 712                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 713                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 714                         /* restart timer */
 715                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 716                         timer->hw.start(timer);
 717                 }
 718         } else {
 719                 timer->hw.stop(timer);
 720         }
 721
 722         /* now process all fast callbacks */
 723         while (!list_empty(&timer->ack_list_head)) {
 724                 p = timer->ack_list_head.next;          /* get first item */
 725                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 726
 727                 /* remove from ack_list and make empty */
 728                 list_del_init(p);
 729
 730                 ticks = ti->pticks;
 731                 ti->pticks = 0;
 732
 733                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 734                 spin_unlock(&timer->lock);
 735                 if (ti->callback)
 736                         ti->callback(ti, resolution, ticks);
 737                 spin_lock(&timer->lock);
 738                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 739         }
 740
 741         /* do we have any slow callbacks? */
 742         use_tasklet = !list_empty(&timer->sack_list_head);
 743         spin_unlock_irqrestore(&timer->lock, flags);
 744
 745         if (use_tasklet)
 746                 tasklet_schedule(&timer->task_queue);
 747 }
 748
 749 /*
 750
 751  */
 752
 753 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 754                   struct snd_timer **rtimer)
 755 {
 756         struct snd_timer *timer;
 757         int err;
 758         static struct snd_device_ops ops = {
 759                 .dev_free = snd_timer_dev_free,
 760                 .dev_register = snd_timer_dev_register,
 761                 .dev_disconnect = snd_timer_dev_disconnect,
 762         };
 763
 764         if (snd_BUG_ON(!tid))
 765                 return -EINVAL;
 766         if (rtimer)
 767                 *rtimer = NULL;
 768         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 769         if (timer == NULL) {
 770                 snd_printk(KERN_ERR "timer: cannot allocate\n");
 771                 return -ENOMEM;
 772         }
 773         timer->tmr_class = tid->dev_class;
 774         timer->card = card;
 775         timer->tmr_device = tid->device;
 776         timer->tmr_subdevice = tid->subdevice;
 777         if (id)
 778                 strlcpy(timer->id, id, sizeof(timer->id));
 779         INIT_LIST_HEAD(&timer->device_list);
 780         INIT_LIST_HEAD(&timer->open_list_head);
 781         INIT_LIST_HEAD(&timer->active_list_head);
 782         INIT_LIST_HEAD(&timer->ack_list_head);
 783         INIT_LIST_HEAD(&timer->sack_list_head);
 784         spin_lock_init(&timer->lock);
 785         tasklet_init(&timer->task_queue, snd_timer_tasklet,
 786                      (unsigned long)timer);
 787         if (card != NULL) {
 788                 timer->module = card->module;
 789                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 790                 if (err < 0) {
 791                         snd_timer_free(timer);
 792                         return err;
 793                 }
 794         }
 795         if (rtimer)
 796                 *rtimer = timer;
 797         return 0;
 798 }
 799
 800 static int snd_timer_free(struct snd_timer *timer)
 801 {
 802         if (!timer)
 803                 return 0;
 804
 805         mutex_lock(&register_mutex);
 806         if (! list_empty(&timer->open_list_head)) {
 807                 struct list_head *p, *n;
 808                 struct snd_timer_instance *ti;
 809                 snd_printk(KERN_WARNING "timer %p is busy?\n", timer);
 810                 list_for_each_safe(p, n, &timer->open_list_head) {
 811                         list_del_init(p);
 812                         ti = list_entry(p, struct snd_timer_instance, open_list);
 813                         ti->timer = NULL;
 814                 }
 815         }
 816         list_del(&timer->device_list);
 817         mutex_unlock(&register_mutex);
 818
 819         if (timer->private_free)
 820                 timer->private_free(timer);
 821         kfree(timer);
 822         return 0;
 823 }
 824
 825 static int snd_timer_dev_free(struct snd_device *device)
 826 {
 827         struct snd_timer *timer = device->device_data;
 828         return snd_timer_free(timer);
 829 }
 830
 831 static int snd_timer_dev_register(struct snd_device *dev)
 832 {
 833         struct snd_timer *timer = dev->device_data;
 834         struct snd_timer *timer1;
 835
 836         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
 837                 return -ENXIO;
 838         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
 839             !timer->hw.resolution && timer->hw.c_resolution == NULL)
 840                 return -EINVAL;
 841
 842         mutex_lock(&register_mutex);
 843         list_for_each_entry(timer1, &snd_timer_list, device_list) {
 844                 if (timer1->tmr_class > timer->tmr_class)
 845                         break;
 846                 if (timer1->tmr_class < timer->tmr_class)
 847                         continue;
 848                 if (timer1->card && timer->card) {
 849                         if (timer1->card->number > timer->card->number)
 850                                 break;
 851                         if (timer1->card->number < timer->card->number)
 852                                 continue;
 853                 }
 854                 if (timer1->tmr_device > timer->tmr_device)
 855                         break;
 856                 if (timer1->tmr_device < timer->tmr_device)
 857                         continue;
 858                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
 859                         break;
 860                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
 861                         continue;
 862                 /* conflicts.. */
 863                 mutex_unlock(&register_mutex);
 864                 return -EBUSY;
 865         }
 866         list_add_tail(&timer->device_list, &timer1->device_list);
 867         mutex_unlock(&register_mutex);
 868         return 0;
 869 }
 870
 871 static int snd_timer_dev_disconnect(struct snd_device *device)
 872 {
 873         struct snd_timer *timer = device->device_data;
 874         mutex_lock(&register_mutex);
 875         list_del_init(&timer->device_list);
 876         mutex_unlock(&register_mutex);
 877         return 0;
 878 }
 879
 880 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
 881 {
 882         unsigned long flags;
 883         unsigned long resolution = 0;
 884         struct snd_timer_instance *ti, *ts;
 885
 886         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
 887                 return;
 888         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
 889                        event > SNDRV_TIMER_EVENT_MRESUME))
 890                 return;
 891         spin_lock_irqsave(&timer->lock, flags);
 892         if (event == SNDRV_TIMER_EVENT_MSTART ||
 893             event == SNDRV_TIMER_EVENT_MCONTINUE ||
 894             event == SNDRV_TIMER_EVENT_MRESUME) {
 895                 if (timer->hw.c_resolution)
 896                         resolution = timer->hw.c_resolution(timer);
 897                 else
 898                         resolution = timer->hw.resolution;
 899         }
 900         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 901                 if (ti->ccallback)
 902                         ti->ccallback(ti, event, tstamp, resolution);
 903                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
 904                         if (ts->ccallback)
 905                                 ts->ccallback(ts, event, tstamp, resolution);
 906         }
 907         spin_unlock_irqrestore(&timer->lock, flags);
 908 }
 909
 910 /*
 911  * exported functions for global timers
 912  */
 913 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
 914 {
 915         struct snd_timer_id tid;
 916
 917         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
 918         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
 919         tid.card = -1;
 920         tid.device = device;
 921         tid.subdevice = 0;
 922         return snd_timer_new(NULL, id, &tid, rtimer);
 923 }
 924
 925 int snd_timer_global_free(struct snd_timer *timer)
 926 {
 927         return snd_timer_free(timer);
 928 }
 929
 930 int snd_timer_global_register(struct snd_timer *timer)
 931 {
 932         struct snd_device dev;
 933
 934         memset(&dev, 0, sizeof(dev));
 935         dev.device_data = timer;
 936         return snd_timer_dev_register(&dev);
 937 }
 938
 939 /*
 940  *  System timer
 941  */
 942
 943 struct snd_timer_system_private {
 944         struct timer_list tlist;
 945         unsigned long last_expires;
 946         unsigned long last_jiffies;
 947         unsigned long correction;
 948 };
 949
 950 static void snd_timer_s_function(unsigned long data)
 951 {
 952         struct snd_timer *timer = (struct snd_timer *)data;
 953         struct snd_timer_system_private *priv = timer->private_data;
 954         unsigned long jiff = jiffies;
 955         if (time_after(jiff, priv->last_expires))
 956                 priv->correction += (long)jiff - (long)priv->last_expires;
 957         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
 958 }
 959
 960 static int snd_timer_s_start(struct snd_timer * timer)
 961 {
 962         struct snd_timer_system_private *priv;
 963         unsigned long njiff;
 964
 965         priv = (struct snd_timer_system_private *) timer->private_data;
 966         njiff = (priv->last_jiffies = jiffies);
 967         if (priv->correction > timer->sticks - 1) {
 968                 priv->correction -= timer->sticks - 1;
 969                 njiff++;
 970         } else {
 971                 njiff += timer->sticks - priv->correction;
 972                 priv->correction = 0;
 973         }
 974         priv->last_expires = priv->tlist.expires = njiff;
 975         add_timer(&priv->tlist);
 976         return 0;
 977 }
 978
 979 static int snd_timer_s_stop(struct snd_timer * timer)
 980 {
 981         struct snd_timer_system_private *priv;
 982         unsigned long jiff;
 983
 984         priv = (struct snd_timer_system_private *) timer->private_data;
 985         del_timer(&priv->tlist);
 986         jiff = jiffies;
 987         if (time_before(jiff, priv->last_expires))
 988                 timer->sticks = priv->last_expires - jiff;
 989         else
 990                 timer->sticks = 1;
 991         priv->correction = 0;
 992         return 0;
 993 }
 994
 995 static struct snd_timer_hardware snd_timer_system =
 996 {
 997         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
 998         .resolution =   1000000000L / HZ,
 999         .ticks =        10000000L,
1000         .start =        snd_timer_s_start,
1001         .stop =         snd_timer_s_stop
1002 };
1003
1004 static void snd_timer_free_system(struct snd_timer *timer)
1005 {
1006         kfree(timer->private_data);
1007 }
1008
1009 static int snd_timer_register_system(void)
1010 {
1011         struct snd_timer *timer;
1012         struct snd_timer_system_private *priv;
1013         int err;
1014
1015         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1016         if (err < 0)
1017                 return err;
1018         strcpy(timer->name, "system timer");
1019         timer->hw = snd_timer_system;
1020         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1021         if (priv == NULL) {
1022                 snd_timer_free(timer);
1023                 return -ENOMEM;
1024         }
1025         init_timer(&priv->tlist);
1026         priv->tlist.function = snd_timer_s_function;
1027         priv->tlist.data = (unsigned long) timer;
1028         timer->private_data = priv;
1029         timer->private_free = snd_timer_free_system;
1030         return snd_timer_global_register(timer);
1031 }
1032
1033 #ifdef CONFIG_PROC_FS
1034 /*
1035  *  Info interface
1036  */
1037
1038 static void snd_timer_proc_read(struct snd_info_entry *entry,
1039                                 struct snd_info_buffer *buffer)
1040 {
1041         struct snd_timer *timer;
1042         struct snd_timer_instance *ti;
1043
1044         mutex_lock(&register_mutex);
1045         list_for_each_entry(timer, &snd_timer_list, device_list) {
1046                 switch (timer->tmr_class) {
1047                 case SNDRV_TIMER_CLASS_GLOBAL:
1048                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1049                         break;
1050                 case SNDRV_TIMER_CLASS_CARD:
1051                         snd_iprintf(buffer, "C%i-%i: ",
1052                                     timer->card->number, timer->tmr_device);
1053                         break;
1054                 case SNDRV_TIMER_CLASS_PCM:
1055                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1056                                     timer->tmr_device, timer->tmr_subdevice);
1057                         break;
1058                 default:
1059                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1060                                     timer->card ? timer->card->number : -1,
1061                                     timer->tmr_device, timer->tmr_subdevice);
1062                 }
1063                 snd_iprintf(buffer, "%s :", timer->name);
1064                 if (timer->hw.resolution)
1065                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1066                                     timer->hw.resolution / 1000,
1067                                     timer->hw.resolution % 1000,
1068                                     timer->hw.ticks);
1069                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1070                         snd_iprintf(buffer, " SLAVE");
1071                 snd_iprintf(buffer, "\n");
1072                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1073                         snd_iprintf(buffer, "  Client %s : %s\n",
1074                                     ti->owner ? ti->owner : "unknown",
1075                                     ti->flags & (SNDRV_TIMER_IFLG_START |
1076                                                  SNDRV_TIMER_IFLG_RUNNING)
1077                                     ? "running" : "stopped");
1078         }
1079         mutex_unlock(&register_mutex);
1080 }
1081
1082 static struct snd_info_entry *snd_timer_proc_entry;
1083
1084 static void __init snd_timer_proc_init(void)
1085 {
1086         struct snd_info_entry *entry;
1087
1088         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1089         if (entry != NULL) {
1090                 entry->c.text.read = snd_timer_proc_read;
1091                 if (snd_info_register(entry) < 0) {
1092                         snd_info_free_entry(entry);
1093                         entry = NULL;
1094                 }
1095         }
1096         snd_timer_proc_entry = entry;
1097 }
1098
1099 static void __exit snd_timer_proc_done(void)
1100 {
1101         snd_info_free_entry(snd_timer_proc_entry);
1102 }
1103 #else /* !CONFIG_PROC_FS */
1104 #define snd_timer_proc_init()
1105 #define snd_timer_proc_done()
1106 #endif
1107
1108 /*
1109  *  USER SPACE interface
1110  */
1111
1112 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1113                                      unsigned long resolution,
1114                                      unsigned long ticks)
1115 {
1116         struct snd_timer_user *tu = timeri->callback_data;
1117         struct snd_timer_read *r;
1118         int prev;
1119
1120         spin_lock(&tu->qlock);
1121         if (tu->qused > 0) {
1122                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1123                 r = &tu->queue[prev];
1124                 if (r->resolution == resolution) {
1125                         r->ticks += ticks;
1126                         goto __wake;
1127                 }
1128         }
1129         if (tu->qused >= tu->queue_size) {
1130                 tu->overrun++;
1131         } else {
1132                 r = &tu->queue[tu->qtail++];
1133                 tu->qtail %= tu->queue_size;
1134                 r->resolution = resolution;
1135                 r->ticks = ticks;
1136                 tu->qused++;
1137         }
1138       __wake:
1139         spin_unlock(&tu->qlock);
1140         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1141         wake_up(&tu->qchange_sleep);
1142 }
1143
1144 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1145                                             struct snd_timer_tread *tread)
1146 {
1147         if (tu->qused >= tu->queue_size) {
1148                 tu->overrun++;
1149         } else {
1150                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1151                 tu->qtail %= tu->queue_size;
1152                 tu->qused++;
1153         }
1154 }
1155
1156 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1157                                      int event,
1158                                      struct timespec *tstamp,
1159                                      unsigned long resolution)
1160 {
1161         struct snd_timer_user *tu = timeri->callback_data;
1162         struct snd_timer_tread r1;
1163
1164         if (event >= SNDRV_TIMER_EVENT_START &&
1165             event <= SNDRV_TIMER_EVENT_PAUSE)
1166                 tu->tstamp = *tstamp;
1167         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1168                 return;
1169         r1.event = event;
1170         r1.tstamp = *tstamp;
1171         r1.val = resolution;
1172         spin_lock(&tu->qlock);
1173         snd_timer_user_append_to_tqueue(tu, &r1);
1174         spin_unlock(&tu->qlock);
1175         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1176         wake_up(&tu->qchange_sleep);
1177 }
1178
1179 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1180                                       unsigned long resolution,
1181                                       unsigned long ticks)
1182 {
1183         struct snd_timer_user *tu = timeri->callback_data;
1184         struct snd_timer_tread *r, r1;
1185         struct timespec tstamp;
1186         int prev, append = 0;
1187
1188         memset(&tstamp, 0, sizeof(tstamp));
1189         spin_lock(&tu->qlock);
1190         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1191                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1192                 spin_unlock(&tu->qlock);
1193                 return;
1194         }
1195         if (tu->last_resolution != resolution || ticks > 0) {
1196                 if (timer_tstamp_monotonic)
1197                         do_posix_clock_monotonic_gettime(&tstamp);
1198                 else
1199                         getnstimeofday(&tstamp);
1200         }
1201         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1202             tu->last_resolution != resolution) {
1203                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1204                 r1.tstamp = tstamp;
1205                 r1.val = resolution;
1206                 snd_timer_user_append_to_tqueue(tu, &r1);
1207                 tu->last_resolution = resolution;
1208                 append++;
1209         }
1210         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1211                 goto __wake;
1212         if (ticks == 0)
1213                 goto __wake;
1214         if (tu->qused > 0) {
1215                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1216                 r = &tu->tqueue[prev];
1217                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1218                         r->tstamp = tstamp;
1219                         r->val += ticks;
1220                         append++;
1221                         goto __wake;
1222                 }
1223         }
1224         r1.event = SNDRV_TIMER_EVENT_TICK;
1225         r1.tstamp = tstamp;
1226         r1.val = ticks;
1227         snd_timer_user_append_to_tqueue(tu, &r1);
1228         append++;
1229       __wake:
1230         spin_unlock(&tu->qlock);
1231         if (append == 0)
1232                 return;
1233         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1234         wake_up(&tu->qchange_sleep);
1235 }
1236
1237 static int snd_timer_user_open(struct inode *inode, struct file *file)
1238 {
1239         struct snd_timer_user *tu;
1240
1241         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1242         if (tu == NULL)
1243                 return -ENOMEM;
1244         spin_lock_init(&tu->qlock);
1245         init_waitqueue_head(&tu->qchange_sleep);
1246         mutex_init(&tu->tread_sem);
1247         tu->ticks = 1;
1248         tu->queue_size = 128;
1249         tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1250                             GFP_KERNEL);
1251         if (tu->queue == NULL) {
1252                 kfree(tu);
1253                 return -ENOMEM;
1254         }
1255         file->private_data = tu;
1256         return 0;
1257 }
1258
1259 static int snd_timer_user_release(struct inode *inode, struct file *file)
1260 {
1261         struct snd_timer_user *tu;
1262
1263         if (file->private_data) {
1264                 tu = file->private_data;
1265                 file->private_data = NULL;
1266                 if (tu->timeri)
1267                         snd_timer_close(tu->timeri);
1268                 kfree(tu->queue);
1269                 kfree(tu->tqueue);
1270                 kfree(tu);
1271         }
1272         return 0;
1273 }
1274
1275 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1276 {
1277         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1278         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1279         id->card = -1;
1280         id->device = -1;
1281         id->subdevice = -1;
1282 }
1283
1284 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1285 {
1286         id->dev_class = timer->tmr_class;
1287         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1288         id->card = timer->card ? timer->card->number : -1;
1289         id->device = timer->tmr_device;
1290         id->subdevice = timer->tmr_subdevice;
1291 }
1292
1293 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1294 {
1295         struct snd_timer_id id;
1296         struct snd_timer *timer;
1297         struct list_head *p;
1298
1299         if (copy_from_user(&id, _tid, sizeof(id)))
1300                 return -EFAULT;
1301         mutex_lock(&register_mutex);
1302         if (id.dev_class < 0) {         /* first item */
1303                 if (list_empty(&snd_timer_list))
1304                         snd_timer_user_zero_id(&id);
1305                 else {
1306                         timer = list_entry(snd_timer_list.next,
1307                                            struct snd_timer, device_list);
1308                         snd_timer_user_copy_id(&id, timer);
1309                 }
1310         } else {
1311                 switch (id.dev_class) {
1312                 case SNDRV_TIMER_CLASS_GLOBAL:
1313                         id.device = id.device < 0 ? 0 : id.device + 1;
1314                         list_for_each(p, &snd_timer_list) {
1315                                 timer = list_entry(p, struct snd_timer, device_list);
1316                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1317                                         snd_timer_user_copy_id(&id, timer);
1318                                         break;
1319                                 }
1320                                 if (timer->tmr_device >= id.device) {
1321                                         snd_timer_user_copy_id(&id, timer);
1322                                         break;
1323                                 }
1324                         }
1325                         if (p == &snd_timer_list)
1326                                 snd_timer_user_zero_id(&id);
1327                         break;
1328                 case SNDRV_TIMER_CLASS_CARD:
1329                 case SNDRV_TIMER_CLASS_PCM:
1330                         if (id.card < 0) {
1331                                 id.card = 0;
1332                         } else {
1333                                 if (id.card < 0) {
1334                                         id.card = 0;
1335                                 } else {
1336                                         if (id.device < 0) {
1337                                                 id.device = 0;
1338                                         } else {
1339                                                 if (id.subdevice < 0) {
1340                                                         id.subdevice = 0;
1341                                                 } else {
1342                                                         id.subdevice++;
1343                                                 }
1344                                         }
1345                                 }
1346                         }
1347                         list_for_each(p, &snd_timer_list) {
1348                                 timer = list_entry(p, struct snd_timer, device_list);
1349                                 if (timer->tmr_class > id.dev_class) {
1350                                         snd_timer_user_copy_id(&id, timer);
1351                                         break;
1352                                 }
1353                                 if (timer->tmr_class < id.dev_class)
1354                                         continue;
1355                                 if (timer->card->number > id.card) {
1356                                         snd_timer_user_copy_id(&id, timer);
1357                                         break;
1358                                 }
1359                                 if (timer->card->number < id.card)
1360                                         continue;
1361                                 if (timer->tmr_device > id.device) {
1362                                         snd_timer_user_copy_id(&id, timer);
1363                                         break;
1364                                 }
1365                                 if (timer->tmr_device < id.device)
1366                                         continue;
1367                                 if (timer->tmr_subdevice > id.subdevice) {
1368                                         snd_timer_user_copy_id(&id, timer);
1369                                         break;
1370                                 }
1371                                 if (timer->tmr_subdevice < id.subdevice)
1372                                         continue;
1373                                 snd_timer_user_copy_id(&id, timer);
1374                                 break;
1375                         }
1376                         if (p == &snd_timer_list)
1377                                 snd_timer_user_zero_id(&id);
1378                         break;
1379                 default:
1380                         snd_timer_user_zero_id(&id);
1381                 }
1382         }
1383         mutex_unlock(&register_mutex);
1384         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1385                 return -EFAULT;
1386         return 0;
1387 }
1388
1389 static int snd_timer_user_ginfo(struct file *file,
1390                                 struct snd_timer_ginfo __user *_ginfo)
1391 {
1392         struct snd_timer_ginfo *ginfo;
1393         struct snd_timer_id tid;
1394         struct snd_timer *t;
1395         struct list_head *p;
1396         int err = 0;
1397
1398         ginfo = kmalloc(sizeof(*ginfo), GFP_KERNEL);
1399         if (! ginfo)
1400                 return -ENOMEM;
1401         if (copy_from_user(ginfo, _ginfo, sizeof(*ginfo))) {
1402                 kfree(ginfo);
1403                 return -EFAULT;
1404         }
1405         tid = ginfo->tid;
1406         memset(ginfo, 0, sizeof(*ginfo));
1407         ginfo->tid = tid;
1408         mutex_lock(&register_mutex);
1409         t = snd_timer_find(&tid);
1410         if (t != NULL) {
1411                 ginfo->card = t->card ? t->card->number : -1;
1412                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1413                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1414                 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1415                 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1416                 ginfo->resolution = t->hw.resolution;
1417                 if (t->hw.resolution_min > 0) {
1418                         ginfo->resolution_min = t->hw.resolution_min;
1419                         ginfo->resolution_max = t->hw.resolution_max;
1420                 }
1421                 list_for_each(p, &t->open_list_head) {
1422                         ginfo->clients++;
1423                 }
1424         } else {
1425                 err = -ENODEV;
1426         }
1427         mutex_unlock(&register_mutex);
1428         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1429                 err = -EFAULT;
1430         kfree(ginfo);
1431         return err;
1432 }
1433
1434 static int snd_timer_user_gparams(struct file *file,
1435                                   struct snd_timer_gparams __user *_gparams)
1436 {
1437         struct snd_timer_gparams gparams;
1438         struct snd_timer *t;
1439         int err;
1440
1441         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1442                 return -EFAULT;
1443         mutex_lock(&register_mutex);
1444         t = snd_timer_find(&gparams.tid);
1445         if (!t) {
1446                 err = -ENODEV;
1447                 goto _error;
1448         }
1449         if (!list_empty(&t->open_list_head)) {
1450                 err = -EBUSY;
1451                 goto _error;
1452         }
1453         if (!t->hw.set_period) {
1454                 err = -ENOSYS;
1455                 goto _error;
1456         }
1457         err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1458 _error:
1459         mutex_unlock(&register_mutex);
1460         return err;
1461 }
1462
1463 static int snd_timer_user_gstatus(struct file *file,
1464                                   struct snd_timer_gstatus __user *_gstatus)
1465 {
1466         struct snd_timer_gstatus gstatus;
1467         struct snd_timer_id tid;
1468         struct snd_timer *t;
1469         int err = 0;
1470
1471         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1472                 return -EFAULT;
1473         tid = gstatus.tid;
1474         memset(&gstatus, 0, sizeof(gstatus));
1475         gstatus.tid = tid;
1476         mutex_lock(&register_mutex);
1477         t = snd_timer_find(&tid);
1478         if (t != NULL) {
1479                 if (t->hw.c_resolution)
1480                         gstatus.resolution = t->hw.c_resolution(t);
1481                 else
1482                         gstatus.resolution = t->hw.resolution;
1483                 if (t->hw.precise_resolution) {
1484                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1485                                                  &gstatus.resolution_den);
1486                 } else {
1487                         gstatus.resolution_num = gstatus.resolution;
1488                         gstatus.resolution_den = 1000000000uL;
1489                 }
1490         } else {
1491                 err = -ENODEV;
1492         }
1493         mutex_unlock(&register_mutex);
1494         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1495                 err = -EFAULT;
1496         return err;
1497 }
1498
1499 static int snd_timer_user_tselect(struct file *file,
1500                                   struct snd_timer_select __user *_tselect)
1501 {
1502         struct snd_timer_user *tu;
1503         struct snd_timer_select tselect;
1504         char str[32];
1505         int err = 0;
1506
1507         tu = file->private_data;
1508         mutex_lock(&tu->tread_sem);
1509         if (tu->timeri) {
1510                 snd_timer_close(tu->timeri);
1511                 tu->timeri = NULL;
1512         }
1513         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1514                 err = -EFAULT;
1515                 goto __err;
1516         }
1517         sprintf(str, "application %i", current->pid);
1518         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1519                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1520         err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1521         if (err < 0)
1522                 goto __err;
1523
1524         kfree(tu->queue);
1525         tu->queue = NULL;
1526         kfree(tu->tqueue);
1527         tu->tqueue = NULL;
1528         if (tu->tread) {
1529                 tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1530                                      GFP_KERNEL);
1531                 if (tu->tqueue == NULL)
1532                         err = -ENOMEM;
1533         } else {
1534                 tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1535                                     GFP_KERNEL);
1536                 if (tu->queue == NULL)
1537                         err = -ENOMEM;
1538         }
1539
1540         if (err < 0) {
1541                 snd_timer_close(tu->timeri);
1542                 tu->timeri = NULL;
1543         } else {
1544                 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1545                 tu->timeri->callback = tu->tread
1546                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1547                 tu->timeri->ccallback = snd_timer_user_ccallback;
1548                 tu->timeri->callback_data = (void *)tu;
1549         }
1550
1551       __err:
1552         mutex_unlock(&tu->tread_sem);
1553         return err;
1554 }
1555
1556 static int snd_timer_user_info(struct file *file,
1557                                struct snd_timer_info __user *_info)
1558 {
1559         struct snd_timer_user *tu;
1560         struct snd_timer_info *info;
1561         struct snd_timer *t;
1562         int err = 0;
1563
1564         tu = file->private_data;
1565         if (!tu->timeri)
1566                 return -EBADFD;
1567         t = tu->timeri->timer;
1568         if (!t)
1569                 return -EBADFD;
1570
1571         info = kzalloc(sizeof(*info), GFP_KERNEL);
1572         if (! info)
1573                 return -ENOMEM;
1574         info->card = t->card ? t->card->number : -1;
1575         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1576                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1577         strlcpy(info->id, t->id, sizeof(info->id));
1578         strlcpy(info->name, t->name, sizeof(info->name));
1579         info->resolution = t->hw.resolution;
1580         if (copy_to_user(_info, info, sizeof(*_info)))
1581                 err = -EFAULT;
1582         kfree(info);
1583         return err;
1584 }
1585
1586 static int snd_timer_user_params(struct file *file,
1587                                  struct snd_timer_params __user *_params)
1588 {
1589         struct snd_timer_user *tu;
1590         struct snd_timer_params params;
1591         struct snd_timer *t;
1592         struct snd_timer_read *tr;
1593         struct snd_timer_tread *ttr;
1594         int err;
1595
1596         tu = file->private_data;
1597         if (!tu->timeri)
1598                 return -EBADFD;
1599         t = tu->timeri->timer;
1600         if (!t)
1601                 return -EBADFD;
1602         if (copy_from_user(&params, _params, sizeof(params)))
1603                 return -EFAULT;
1604         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1605                 err = -EINVAL;
1606                 goto _end;
1607         }
1608         if (params.queue_size > 0 &&
1609             (params.queue_size < 32 || params.queue_size > 1024)) {
1610                 err = -EINVAL;
1611                 goto _end;
1612         }
1613         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1614                               (1<<SNDRV_TIMER_EVENT_TICK)|
1615                               (1<<SNDRV_TIMER_EVENT_START)|
1616                               (1<<SNDRV_TIMER_EVENT_STOP)|
1617                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1618                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1619                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1620                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1621                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1622                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1623                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1624                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1625                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1626                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1627                 err = -EINVAL;
1628                 goto _end;
1629         }
1630         snd_timer_stop(tu->timeri);
1631         spin_lock_irq(&t->lock);
1632         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1633                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1634                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1635         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1636                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1637         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1638                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1639         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1640                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1641         spin_unlock_irq(&t->lock);
1642         if (params.queue_size > 0 &&
1643             (unsigned int)tu->queue_size != params.queue_size) {
1644                 if (tu->tread) {
1645                         ttr = kmalloc(params.queue_size * sizeof(*ttr),
1646                                       GFP_KERNEL);
1647                         if (ttr) {
1648                                 kfree(tu->tqueue);
1649                                 tu->queue_size = params.queue_size;
1650                                 tu->tqueue = ttr;
1651                         }
1652                 } else {
1653                         tr = kmalloc(params.queue_size * sizeof(*tr),
1654                                      GFP_KERNEL);
1655                         if (tr) {
1656                                 kfree(tu->queue);
1657                                 tu->queue_size = params.queue_size;
1658                                 tu->queue = tr;
1659                         }
1660                 }
1661         }
1662         tu->qhead = tu->qtail = tu->qused = 0;
1663         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1664                 if (tu->tread) {
1665                         struct snd_timer_tread tread;
1666                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1667                         tread.tstamp.tv_sec = 0;
1668                         tread.tstamp.tv_nsec = 0;
1669                         tread.val = 0;
1670                         snd_timer_user_append_to_tqueue(tu, &tread);
1671                 } else {
1672                         struct snd_timer_read *r = &tu->queue[0];
1673                         r->resolution = 0;
1674                         r->ticks = 0;
1675                         tu->qused++;
1676                         tu->qtail++;
1677                 }
1678         }
1679         tu->filter = params.filter;
1680         tu->ticks = params.ticks;
1681         err = 0;
1682  _end:
1683         if (copy_to_user(_params, &params, sizeof(params)))
1684                 return -EFAULT;
1685         return err;
1686 }
1687
1688 static int snd_timer_user_status(struct file *file,
1689                                  struct snd_timer_status __user *_status)
1690 {
1691         struct snd_timer_user *tu;
1692         struct snd_timer_status status;
1693
1694         tu = file->private_data;
1695         if (!tu->timeri)
1696                 return -EBADFD;
1697         memset(&status, 0, sizeof(status));
1698         status.tstamp = tu->tstamp;
1699         status.resolution = snd_timer_resolution(tu->timeri);
1700         status.lost = tu->timeri->lost;
1701         status.overrun = tu->overrun;
1702         spin_lock_irq(&tu->qlock);
1703         status.queue = tu->qused;
1704         spin_unlock_irq(&tu->qlock);
1705         if (copy_to_user(_status, &status, sizeof(status)))
1706                 return -EFAULT;
1707         return 0;
1708 }
1709
1710 static int snd_timer_user_start(struct file *file)
1711 {
1712         int err;
1713         struct snd_timer_user *tu;
1714
1715         tu = file->private_data;
1716         if (!tu->timeri)
1717                 return -EBADFD;
1718         snd_timer_stop(tu->timeri);
1719         tu->timeri->lost = 0;
1720         tu->last_resolution = 0;
1721         return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1722 }
1723
1724 static int snd_timer_user_stop(struct file *file)
1725 {
1726         int err;
1727         struct snd_timer_user *tu;
1728
1729         tu = file->private_data;
1730         if (!tu->timeri)
1731                 return -EBADFD;
1732         return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1733 }
1734
1735 static int snd_timer_user_continue(struct file *file)
1736 {
1737         int err;
1738         struct snd_timer_user *tu;
1739
1740         tu = file->private_data;
1741         if (!tu->timeri)
1742                 return -EBADFD;
1743         tu->timeri->lost = 0;
1744         return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1745 }
1746
1747 static int snd_timer_user_pause(struct file *file)
1748 {
1749         int err;
1750         struct snd_timer_user *tu;
1751
1752         tu = file->private_data;
1753         if (!tu->timeri)
1754                 return -EBADFD;
1755         return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1756 }
1757
1758 enum {
1759         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1760         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1761         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1762         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1763 };
1764
1765 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1766                                  unsigned long arg)
1767 {
1768         struct snd_timer_user *tu;
1769         void __user *argp = (void __user *)arg;
1770         int __user *p = argp;
1771
1772         tu = file->private_data;
1773         switch (cmd) {
1774         case SNDRV_TIMER_IOCTL_PVERSION:
1775                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1776         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1777                 return snd_timer_user_next_device(argp);
1778         case SNDRV_TIMER_IOCTL_TREAD:
1779         {
1780                 int xarg;
1781
1782                 mutex_lock(&tu->tread_sem);
1783                 if (tu->timeri) {       /* too late */
1784                         mutex_unlock(&tu->tread_sem);
1785                         return -EBUSY;
1786                 }
1787                 if (get_user(xarg, p)) {
1788                         mutex_unlock(&tu->tread_sem);
1789                         return -EFAULT;
1790                 }
1791                 tu->tread = xarg ? 1 : 0;
1792                 mutex_unlock(&tu->tread_sem);
1793                 return 0;
1794         }
1795         case SNDRV_TIMER_IOCTL_GINFO:
1796                 return snd_timer_user_ginfo(file, argp);
1797         case SNDRV_TIMER_IOCTL_GPARAMS:
1798                 return snd_timer_user_gparams(file, argp);
1799         case SNDRV_TIMER_IOCTL_GSTATUS:
1800                 return snd_timer_user_gstatus(file, argp);
1801         case SNDRV_TIMER_IOCTL_SELECT:
1802                 return snd_timer_user_tselect(file, argp);
1803         case SNDRV_TIMER_IOCTL_INFO:
1804                 return snd_timer_user_info(file, argp);
1805         case SNDRV_TIMER_IOCTL_PARAMS:
1806                 return snd_timer_user_params(file, argp);
1807         case SNDRV_TIMER_IOCTL_STATUS:
1808                 return snd_timer_user_status(file, argp);
1809         case SNDRV_TIMER_IOCTL_START:
1810         case SNDRV_TIMER_IOCTL_START_OLD:
1811                 return snd_timer_user_start(file);
1812         case SNDRV_TIMER_IOCTL_STOP:
1813         case SNDRV_TIMER_IOCTL_STOP_OLD:
1814                 return snd_timer_user_stop(file);
1815         case SNDRV_TIMER_IOCTL_CONTINUE:
1816         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1817                 return snd_timer_user_continue(file);
1818         case SNDRV_TIMER_IOCTL_PAUSE:
1819         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1820                 return snd_timer_user_pause(file);
1821         }
1822         return -ENOTTY;
1823 }
1824
1825 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1826 {
1827         struct snd_timer_user *tu;
1828         int err;
1829
1830         tu = file->private_data;
1831         err = fasync_helper(fd, file, on, &tu->fasync);
1832         if (err < 0)
1833                 return err;
1834         return 0;
1835 }
1836
1837 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1838                                    size_t count, loff_t *offset)
1839 {
1840         struct snd_timer_user *tu;
1841         long result = 0, unit;
1842         int err = 0;
1843
1844         tu = file->private_data;
1845         unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1846         spin_lock_irq(&tu->qlock);
1847         while ((long)count - result >= unit) {
1848                 while (!tu->qused) {
1849                         wait_queue_t wait;
1850
1851                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1852                                 err = -EAGAIN;
1853                                 break;
1854                         }
1855
1856                         set_current_state(TASK_INTERRUPTIBLE);
1857                         init_waitqueue_entry(&wait, current);
1858                         add_wait_queue(&tu->qchange_sleep, &wait);
1859
1860                         spin_unlock_irq(&tu->qlock);
1861                         schedule();
1862                         spin_lock_irq(&tu->qlock);
1863
1864                         remove_wait_queue(&tu->qchange_sleep, &wait);
1865
1866                         if (signal_pending(current)) {
1867                                 err = -ERESTARTSYS;
1868                                 break;
1869                         }
1870                 }
1871
1872                 spin_unlock_irq(&tu->qlock);
1873                 if (err < 0)
1874                         goto _error;
1875
1876                 if (tu->tread) {
1877                         if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1878                                          sizeof(struct snd_timer_tread))) {
1879                                 err = -EFAULT;
1880                                 goto _error;
1881                         }
1882                 } else {
1883                         if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1884                                          sizeof(struct snd_timer_read))) {
1885                                 err = -EFAULT;
1886                                 goto _error;
1887                         }
1888                 }
1889
1890                 tu->qhead %= tu->queue_size;
1891
1892                 result += unit;
1893                 buffer += unit;
1894
1895                 spin_lock_irq(&tu->qlock);
1896                 tu->qused--;
1897         }
1898         spin_unlock_irq(&tu->qlock);
1899  _error:
1900         return result > 0 ? result : err;
1901 }
1902
1903 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1904 {
1905         unsigned int mask;
1906         struct snd_timer_user *tu;
1907
1908         tu = file->private_data;
1909
1910         poll_wait(file, &tu->qchange_sleep, wait);
1911
1912         mask = 0;
1913         if (tu->qused)
1914                 mask |= POLLIN | POLLRDNORM;
1915
1916         return mask;
1917 }
1918
1919 #ifdef CONFIG_COMPAT
1920 #include "timer_compat.c"
1921 #else
1922 #define snd_timer_user_ioctl_compat     NULL
1923 #endif
1924
1925 static const struct file_operations snd_timer_f_ops =
1926 {
1927         .owner =        THIS_MODULE,
1928         .read =         snd_timer_user_read,
1929         .open =         snd_timer_user_open,
1930         .release =      snd_timer_user_release,
1931         .poll =         snd_timer_user_poll,
1932         .unlocked_ioctl =       snd_timer_user_ioctl,
1933         .compat_ioctl = snd_timer_user_ioctl_compat,
1934         .fasync =       snd_timer_user_fasync,
1935 };
1936
1937 /*
1938  *  ENTRY functions
1939  */
1940
1941 static int __init alsa_timer_init(void)
1942 {
1943         int err;
1944
1945 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1946         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1947                               "system timer");
1948 #endif
1949
1950         if ((err = snd_timer_register_system()) < 0)
1951                 snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1952                            err);
1953         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1954                                        &snd_timer_f_ops, NULL, "timer")) < 0)
1955                 snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1956                            err);
1957         snd_timer_proc_init();
1958         return 0;
1959 }
1960
1961 static void __exit alsa_timer_exit(void)
1962 {
1963         struct list_head *p, *n;
1964
1965         snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1966         /* unregister the system timer */
1967         list_for_each_safe(p, n, &snd_timer_list) {
1968                 struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1969                 snd_timer_free(timer);
1970         }
1971         snd_timer_proc_done();
1972 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1973         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1974 #endif
1975 }
1976
1977 module_init(alsa_timer_init)
1978 module_exit(alsa_timer_exit)
1979
1980 EXPORT_SYMBOL(snd_timer_open);
1981 EXPORT_SYMBOL(snd_timer_close);
1982 EXPORT_SYMBOL(snd_timer_resolution);
1983 EXPORT_SYMBOL(snd_timer_start);
1984 EXPORT_SYMBOL(snd_timer_stop);
1985 EXPORT_SYMBOL(snd_timer_continue);
1986 EXPORT_SYMBOL(snd_timer_pause);
1987 EXPORT_SYMBOL(snd_timer_new);
1988 EXPORT_SYMBOL(snd_timer_notify);
1989 EXPORT_SYMBOL(snd_timer_global_new);
1990 EXPORT_SYMBOL(snd_timer_global_free);
1991 EXPORT_SYMBOL(snd_timer_global_register);
1992 EXPORT_SYMBOL(snd_timer_interrupt);