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