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