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 IS_ENABLED(CONFIG_SND_HRTIMER)
  39 #define DEFAULT_TIMER_LIMIT 4
  40 #elif IS_ENABLED(CONFIG_SND_RTCTIMER)
  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                         pr_debug("ALSA: timer: invalid slave class %i\n",
 244                                  tid->dev_sclass);
 245                         return -EINVAL;
 246                 }
 247                 mutex_lock(&register_mutex);
 248                 timeri = snd_timer_instance_new(owner, NULL);
 249                 if (!timeri) {
 250                         mutex_unlock(&register_mutex);
 251                         return -ENOMEM;
 252                 }
 253                 timeri->slave_class = tid->dev_sclass;
 254                 timeri->slave_id = tid->device;
 255                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 256                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 257                 snd_timer_check_slave(timeri);
 258                 mutex_unlock(&register_mutex);
 259                 *ti = timeri;
 260                 return 0;
 261         }
 262
 263         /* open a master instance */
 264         mutex_lock(&register_mutex);
 265         timer = snd_timer_find(tid);
 266 #ifdef CONFIG_MODULES
 267         if (!timer) {
 268                 mutex_unlock(&register_mutex);
 269                 snd_timer_request(tid);
 270                 mutex_lock(&register_mutex);
 271                 timer = snd_timer_find(tid);
 272         }
 273 #endif
 274         if (!timer) {
 275                 mutex_unlock(&register_mutex);
 276                 return -ENODEV;
 277         }
 278         if (!list_empty(&timer->open_list_head)) {
 279                 timeri = list_entry(timer->open_list_head.next,
 280                                     struct snd_timer_instance, open_list);
 281                 if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 282                         mutex_unlock(&register_mutex);
 283                         return -EBUSY;
 284                 }
 285         }
 286         timeri = snd_timer_instance_new(owner, timer);
 287         if (!timeri) {
 288                 mutex_unlock(&register_mutex);
 289                 return -ENOMEM;
 290         }
 291         timeri->slave_class = tid->dev_sclass;
 292         timeri->slave_id = slave_id;
 293         if (list_empty(&timer->open_list_head) && timer->hw.open)
 294                 timer->hw.open(timer);
 295         list_add_tail(&timeri->open_list, &timer->open_list_head);
 296         snd_timer_check_master(timeri);
 297         mutex_unlock(&register_mutex);
 298         *ti = timeri;
 299         return 0;
 300 }
 301
 302 static int _snd_timer_stop(struct snd_timer_instance *timeri,
 303                            int keep_flag, int event);
 304
 305 /*
 306  * close a timer instance
 307  */
 308 int snd_timer_close(struct snd_timer_instance *timeri)
 309 {
 310         struct snd_timer *timer = NULL;
 311         struct snd_timer_instance *slave, *tmp;
 312
 313         if (snd_BUG_ON(!timeri))
 314                 return -ENXIO;
 315
 316         /* force to stop the timer */
 317         snd_timer_stop(timeri);
 318
 319         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 320                 /* wait, until the active callback is finished */
 321                 spin_lock_irq(&slave_active_lock);
 322                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 323                         spin_unlock_irq(&slave_active_lock);
 324                         udelay(10);
 325                         spin_lock_irq(&slave_active_lock);
 326                 }
 327                 spin_unlock_irq(&slave_active_lock);
 328                 mutex_lock(&register_mutex);
 329                 list_del(&timeri->open_list);
 330                 mutex_unlock(&register_mutex);
 331         } else {
 332                 timer = timeri->timer;
 333                 if (snd_BUG_ON(!timer))
 334                         goto out;
 335                 /* wait, until the active callback is finished */
 336                 spin_lock_irq(&timer->lock);
 337                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 338                         spin_unlock_irq(&timer->lock);
 339                         udelay(10);
 340                         spin_lock_irq(&timer->lock);
 341                 }
 342                 spin_unlock_irq(&timer->lock);
 343                 mutex_lock(&register_mutex);
 344                 list_del(&timeri->open_list);
 345                 if (timer && list_empty(&timer->open_list_head) &&
 346                     timer->hw.close)
 347                         timer->hw.close(timer);
 348                 /* remove slave links */
 349                 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 350                                          open_list) {
 351                         spin_lock_irq(&slave_active_lock);
 352                         _snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
 353                         list_move_tail(&slave->open_list, &snd_timer_slave_list);
 354                         slave->master = NULL;
 355                         slave->timer = NULL;
 356                         spin_unlock_irq(&slave_active_lock);
 357                 }
 358                 mutex_unlock(&register_mutex);
 359         }
 360  out:
 361         if (timeri->private_free)
 362                 timeri->private_free(timeri);
 363         kfree(timeri->owner);
 364         kfree(timeri);
 365         if (timer)
 366                 module_put(timer->module);
 367         return 0;
 368 }
 369
 370 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 371 {
 372         struct snd_timer * timer;
 373
 374         if (timeri == NULL)
 375                 return 0;
 376         if ((timer = timeri->timer) != NULL) {
 377                 if (timer->hw.c_resolution)
 378                         return timer->hw.c_resolution(timer);
 379                 return timer->hw.resolution;
 380         }
 381         return 0;
 382 }
 383
 384 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 385 {
 386         struct snd_timer *timer;
 387         unsigned long flags;
 388         unsigned long resolution = 0;
 389         struct snd_timer_instance *ts;
 390         struct timespec tstamp;
 391
 392         if (timer_tstamp_monotonic)
 393                 ktime_get_ts(&tstamp);
 394         else
 395                 getnstimeofday(&tstamp);
 396         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 397                        event > SNDRV_TIMER_EVENT_PAUSE))
 398                 return;
 399         if (event == SNDRV_TIMER_EVENT_START ||
 400             event == SNDRV_TIMER_EVENT_CONTINUE)
 401                 resolution = snd_timer_resolution(ti);
 402         if (ti->ccallback)
 403                 ti->ccallback(ti, event, &tstamp, resolution);
 404         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 405                 return;
 406         timer = ti->timer;
 407         if (timer == NULL)
 408                 return;
 409         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 410                 return;
 411         spin_lock_irqsave(&timer->lock, flags);
 412         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 413                 if (ts->ccallback)
 414                         ts->ccallback(ti, event + 100, &tstamp, resolution);
 415         spin_unlock_irqrestore(&timer->lock, flags);
 416 }
 417
 418 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
 419                             unsigned long sticks)
 420 {
 421         list_move_tail(&timeri->active_list, &timer->active_list_head);
 422         if (timer->running) {
 423                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 424                         goto __start_now;
 425                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 426                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 427                 return 1;       /* delayed start */
 428         } else {
 429                 timer->sticks = sticks;
 430                 timer->hw.start(timer);
 431               __start_now:
 432                 timer->running++;
 433                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 434                 return 0;
 435         }
 436 }
 437
 438 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
 439 {
 440         unsigned long flags;
 441
 442         spin_lock_irqsave(&slave_active_lock, flags);
 443         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 444         if (timeri->master)
 445                 list_add_tail(&timeri->active_list,
 446                               &timeri->master->slave_active_head);
 447         spin_unlock_irqrestore(&slave_active_lock, flags);
 448         return 1; /* delayed start */
 449 }
 450
 451 /*
 452  *  start the timer instance
 453  */
 454 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 455 {
 456         struct snd_timer *timer;
 457         int result = -EINVAL;
 458         unsigned long flags;
 459
 460         if (timeri == NULL || ticks < 1)
 461                 return -EINVAL;
 462         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 463                 result = snd_timer_start_slave(timeri);
 464                 snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 465                 return result;
 466         }
 467         timer = timeri->timer;
 468         if (timer == NULL)
 469                 return -EINVAL;
 470         spin_lock_irqsave(&timer->lock, flags);
 471         timeri->ticks = timeri->cticks = ticks;
 472         timeri->pticks = 0;
 473         result = snd_timer_start1(timer, timeri, ticks);
 474         spin_unlock_irqrestore(&timer->lock, flags);
 475         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 476         return result;
 477 }
 478
 479 static int _snd_timer_stop(struct snd_timer_instance * timeri,
 480                            int keep_flag, int event)
 481 {
 482         struct snd_timer *timer;
 483         unsigned long flags;
 484
 485         if (snd_BUG_ON(!timeri))
 486                 return -ENXIO;
 487
 488         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 489                 if (!keep_flag) {
 490                         spin_lock_irqsave(&slave_active_lock, flags);
 491                         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 492                         spin_unlock_irqrestore(&slave_active_lock, flags);
 493                 }
 494                 goto __end;
 495         }
 496         timer = timeri->timer;
 497         if (!timer)
 498                 return -EINVAL;
 499         spin_lock_irqsave(&timer->lock, flags);
 500         list_del_init(&timeri->ack_list);
 501         list_del_init(&timeri->active_list);
 502         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 503             !(--timer->running)) {
 504                 timer->hw.stop(timer);
 505                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 506                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 507                         snd_timer_reschedule(timer, 0);
 508                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 509                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 510                                 timer->hw.start(timer);
 511                         }
 512                 }
 513         }
 514         if (!keep_flag)
 515                 timeri->flags &=
 516                         ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 517         spin_unlock_irqrestore(&timer->lock, flags);
 518       __end:
 519         if (event != SNDRV_TIMER_EVENT_RESOLUTION)
 520                 snd_timer_notify1(timeri, event);
 521         return 0;
 522 }
 523
 524 /*
 525  * stop the timer instance.
 526  *
 527  * do not call this from the timer callback!
 528  */
 529 int snd_timer_stop(struct snd_timer_instance *timeri)
 530 {
 531         struct snd_timer *timer;
 532         unsigned long flags;
 533         int err;
 534
 535         err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
 536         if (err < 0)
 537                 return err;
 538         timer = timeri->timer;
 539         if (!timer)
 540                 return -EINVAL;
 541         spin_lock_irqsave(&timer->lock, flags);
 542         timeri->cticks = timeri->ticks;
 543         timeri->pticks = 0;
 544         spin_unlock_irqrestore(&timer->lock, flags);
 545         return 0;
 546 }
 547
 548 /*
 549  * start again..  the tick is kept.
 550  */
 551 int snd_timer_continue(struct snd_timer_instance *timeri)
 552 {
 553         struct snd_timer *timer;
 554         int result = -EINVAL;
 555         unsigned long flags;
 556
 557         if (timeri == NULL)
 558                 return result;
 559         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 560                 return snd_timer_start_slave(timeri);
 561         timer = timeri->timer;
 562         if (! timer)
 563                 return -EINVAL;
 564         spin_lock_irqsave(&timer->lock, flags);
 565         if (!timeri->cticks)
 566                 timeri->cticks = 1;
 567         timeri->pticks = 0;
 568         result = snd_timer_start1(timer, timeri, timer->sticks);
 569         spin_unlock_irqrestore(&timer->lock, flags);
 570         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
 571         return result;
 572 }
 573
 574 /*
 575  * pause.. remember the ticks left
 576  */
 577 int snd_timer_pause(struct snd_timer_instance * timeri)
 578 {
 579         return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
 580 }
 581
 582 /*
 583  * reschedule the timer
 584  *
 585  * start pending instances and check the scheduling ticks.
 586  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 587  */
 588 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 589 {
 590         struct snd_timer_instance *ti;
 591         unsigned long ticks = ~0UL;
 592
 593         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 594                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 595                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 596                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 597                         timer->running++;
 598                 }
 599                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 600                         if (ticks > ti->cticks)
 601                                 ticks = ti->cticks;
 602                 }
 603         }
 604         if (ticks == ~0UL) {
 605                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 606                 return;
 607         }
 608         if (ticks > timer->hw.ticks)
 609                 ticks = timer->hw.ticks;
 610         if (ticks_left != ticks)
 611                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 612         timer->sticks = ticks;
 613 }
 614
 615 /*
 616  * timer tasklet
 617  *
 618  */
 619 static void snd_timer_tasklet(unsigned long arg)
 620 {
 621         struct snd_timer *timer = (struct snd_timer *) arg;
 622         struct snd_timer_instance *ti;
 623         struct list_head *p;
 624         unsigned long resolution, ticks;
 625         unsigned long flags;
 626
 627         spin_lock_irqsave(&timer->lock, flags);
 628         /* now process all callbacks */
 629         while (!list_empty(&timer->sack_list_head)) {
 630                 p = timer->sack_list_head.next;         /* get first item */
 631                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 632
 633                 /* remove from ack_list and make empty */
 634                 list_del_init(p);
 635
 636                 ticks = ti->pticks;
 637                 ti->pticks = 0;
 638                 resolution = ti->resolution;
 639
 640                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 641                 spin_unlock(&timer->lock);
 642                 if (ti->callback)
 643                         ti->callback(ti, resolution, ticks);
 644                 spin_lock(&timer->lock);
 645                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 646         }
 647         spin_unlock_irqrestore(&timer->lock, flags);
 648 }
 649
 650 /*
 651  * timer interrupt
 652  *
 653  * ticks_left is usually equal to timer->sticks.
 654  *
 655  */
 656 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 657 {
 658         struct snd_timer_instance *ti, *ts, *tmp;
 659         unsigned long resolution, ticks;
 660         struct list_head *p, *ack_list_head;
 661         unsigned long flags;
 662         int use_tasklet = 0;
 663
 664         if (timer == NULL)
 665                 return;
 666
 667         spin_lock_irqsave(&timer->lock, flags);
 668
 669         /* remember the current resolution */
 670         if (timer->hw.c_resolution)
 671                 resolution = timer->hw.c_resolution(timer);
 672         else
 673                 resolution = timer->hw.resolution;
 674
 675         /* loop for all active instances
 676          * Here we cannot use list_for_each_entry because the active_list of a
 677          * processed instance is relinked to done_list_head before the callback
 678          * is called.
 679          */
 680         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 681                                  active_list) {
 682                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 683                         continue;
 684                 ti->pticks += ticks_left;
 685                 ti->resolution = resolution;
 686                 if (ti->cticks < ticks_left)
 687                         ti->cticks = 0;
 688                 else
 689                         ti->cticks -= ticks_left;
 690                 if (ti->cticks) /* not expired */
 691                         continue;
 692                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 693                         ti->cticks = ti->ticks;
 694                 } else {
 695                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 696                         if (--timer->running)
 697                                 list_del(&ti->active_list);
 698                 }
 699                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
 700                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 701                         ack_list_head = &timer->ack_list_head;
 702                 else
 703                         ack_list_head = &timer->sack_list_head;
 704                 if (list_empty(&ti->ack_list))
 705                         list_add_tail(&ti->ack_list, ack_list_head);
 706                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 707                         ts->pticks = ti->pticks;
 708                         ts->resolution = resolution;
 709                         if (list_empty(&ts->ack_list))
 710                                 list_add_tail(&ts->ack_list, ack_list_head);
 711                 }
 712         }
 713         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 714                 snd_timer_reschedule(timer, timer->sticks);
 715         if (timer->running) {
 716                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 717                         timer->hw.stop(timer);
 718                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 719                 }
 720                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 721                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 722                         /* restart timer */
 723                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 724                         timer->hw.start(timer);
 725                 }
 726         } else {
 727                 timer->hw.stop(timer);
 728         }
 729
 730         /* now process all fast callbacks */
 731         while (!list_empty(&timer->ack_list_head)) {
 732                 p = timer->ack_list_head.next;          /* get first item */
 733                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 734
 735                 /* remove from ack_list and make empty */
 736                 list_del_init(p);
 737
 738                 ticks = ti->pticks;
 739                 ti->pticks = 0;
 740
 741                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 742                 spin_unlock(&timer->lock);
 743                 if (ti->callback)
 744                         ti->callback(ti, resolution, ticks);
 745                 spin_lock(&timer->lock);
 746                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 747         }
 748
 749         /* do we have any slow callbacks? */
 750         use_tasklet = !list_empty(&timer->sack_list_head);
 751         spin_unlock_irqrestore(&timer->lock, flags);
 752
 753         if (use_tasklet)
 754                 tasklet_schedule(&timer->task_queue);
 755 }
 756
 757 /*
 758
 759  */
 760
 761 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 762                   struct snd_timer **rtimer)
 763 {
 764         struct snd_timer *timer;
 765         int err;
 766         static struct snd_device_ops ops = {
 767                 .dev_free = snd_timer_dev_free,
 768                 .dev_register = snd_timer_dev_register,
 769                 .dev_disconnect = snd_timer_dev_disconnect,
 770         };
 771
 772         if (snd_BUG_ON(!tid))
 773                 return -EINVAL;
 774         if (rtimer)
 775                 *rtimer = NULL;
 776         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 777         if (!timer)
 778                 return -ENOMEM;
 779         timer->tmr_class = tid->dev_class;
 780         timer->card = card;
 781         timer->tmr_device = tid->device;
 782         timer->tmr_subdevice = tid->subdevice;
 783         if (id)
 784                 strlcpy(timer->id, id, sizeof(timer->id));
 785         INIT_LIST_HEAD(&timer->device_list);
 786         INIT_LIST_HEAD(&timer->open_list_head);
 787         INIT_LIST_HEAD(&timer->active_list_head);
 788         INIT_LIST_HEAD(&timer->ack_list_head);
 789         INIT_LIST_HEAD(&timer->sack_list_head);
 790         spin_lock_init(&timer->lock);
 791         tasklet_init(&timer->task_queue, snd_timer_tasklet,
 792                      (unsigned long)timer);
 793         if (card != NULL) {
 794                 timer->module = card->module;
 795                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 796                 if (err < 0) {
 797                         snd_timer_free(timer);
 798                         return err;
 799                 }
 800         }
 801         if (rtimer)
 802                 *rtimer = timer;
 803         return 0;
 804 }
 805
 806 static int snd_timer_free(struct snd_timer *timer)
 807 {
 808         if (!timer)
 809                 return 0;
 810
 811         mutex_lock(&register_mutex);
 812         if (! list_empty(&timer->open_list_head)) {
 813                 struct list_head *p, *n;
 814                 struct snd_timer_instance *ti;
 815                 pr_warn("ALSA: timer %p is busy?\n", timer);
 816                 list_for_each_safe(p, n, &timer->open_list_head) {
 817                         list_del_init(p);
 818                         ti = list_entry(p, struct snd_timer_instance, open_list);
 819                         ti->timer = NULL;
 820                 }
 821         }
 822         list_del(&timer->device_list);
 823         mutex_unlock(&register_mutex);
 824
 825         if (timer->private_free)
 826                 timer->private_free(timer);
 827         kfree(timer);
 828         return 0;
 829 }
 830
 831 static int snd_timer_dev_free(struct snd_device *device)
 832 {
 833         struct snd_timer *timer = device->device_data;
 834         return snd_timer_free(timer);
 835 }
 836
 837 static int snd_timer_dev_register(struct snd_device *dev)
 838 {
 839         struct snd_timer *timer = dev->device_data;
 840         struct snd_timer *timer1;
 841
 842         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
 843                 return -ENXIO;
 844         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
 845             !timer->hw.resolution && timer->hw.c_resolution == NULL)
 846                 return -EINVAL;
 847
 848         mutex_lock(&register_mutex);
 849         list_for_each_entry(timer1, &snd_timer_list, device_list) {
 850                 if (timer1->tmr_class > timer->tmr_class)
 851                         break;
 852                 if (timer1->tmr_class < timer->tmr_class)
 853                         continue;
 854                 if (timer1->card && timer->card) {
 855                         if (timer1->card->number > timer->card->number)
 856                                 break;
 857                         if (timer1->card->number < timer->card->number)
 858                                 continue;
 859                 }
 860                 if (timer1->tmr_device > timer->tmr_device)
 861                         break;
 862                 if (timer1->tmr_device < timer->tmr_device)
 863                         continue;
 864                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
 865                         break;
 866                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
 867                         continue;
 868                 /* conflicts.. */
 869                 mutex_unlock(&register_mutex);
 870                 return -EBUSY;
 871         }
 872         list_add_tail(&timer->device_list, &timer1->device_list);
 873         mutex_unlock(&register_mutex);
 874         return 0;
 875 }
 876
 877 static int snd_timer_dev_disconnect(struct snd_device *device)
 878 {
 879         struct snd_timer *timer = device->device_data;
 880         mutex_lock(&register_mutex);
 881         list_del_init(&timer->device_list);
 882         mutex_unlock(&register_mutex);
 883         return 0;
 884 }
 885
 886 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp)
 887 {
 888         unsigned long flags;
 889         unsigned long resolution = 0;
 890         struct snd_timer_instance *ti, *ts;
 891
 892         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
 893                 return;
 894         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
 895                        event > SNDRV_TIMER_EVENT_MRESUME))
 896                 return;
 897         spin_lock_irqsave(&timer->lock, flags);
 898         if (event == SNDRV_TIMER_EVENT_MSTART ||
 899             event == SNDRV_TIMER_EVENT_MCONTINUE ||
 900             event == SNDRV_TIMER_EVENT_MRESUME) {
 901                 if (timer->hw.c_resolution)
 902                         resolution = timer->hw.c_resolution(timer);
 903                 else
 904                         resolution = timer->hw.resolution;
 905         }
 906         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 907                 if (ti->ccallback)
 908                         ti->ccallback(ti, event, tstamp, resolution);
 909                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
 910                         if (ts->ccallback)
 911                                 ts->ccallback(ts, event, tstamp, resolution);
 912         }
 913         spin_unlock_irqrestore(&timer->lock, flags);
 914 }
 915
 916 /*
 917  * exported functions for global timers
 918  */
 919 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
 920 {
 921         struct snd_timer_id tid;
 922
 923         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
 924         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
 925         tid.card = -1;
 926         tid.device = device;
 927         tid.subdevice = 0;
 928         return snd_timer_new(NULL, id, &tid, rtimer);
 929 }
 930
 931 int snd_timer_global_free(struct snd_timer *timer)
 932 {
 933         return snd_timer_free(timer);
 934 }
 935
 936 int snd_timer_global_register(struct snd_timer *timer)
 937 {
 938         struct snd_device dev;
 939
 940         memset(&dev, 0, sizeof(dev));
 941         dev.device_data = timer;
 942         return snd_timer_dev_register(&dev);
 943 }
 944
 945 /*
 946  *  System timer
 947  */
 948
 949 struct snd_timer_system_private {
 950         struct timer_list tlist;
 951         unsigned long last_expires;
 952         unsigned long last_jiffies;
 953         unsigned long correction;
 954 };
 955
 956 static void snd_timer_s_function(unsigned long data)
 957 {
 958         struct snd_timer *timer = (struct snd_timer *)data;
 959         struct snd_timer_system_private *priv = timer->private_data;
 960         unsigned long jiff = jiffies;
 961         if (time_after(jiff, priv->last_expires))
 962                 priv->correction += (long)jiff - (long)priv->last_expires;
 963         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
 964 }
 965
 966 static int snd_timer_s_start(struct snd_timer * timer)
 967 {
 968         struct snd_timer_system_private *priv;
 969         unsigned long njiff;
 970
 971         priv = (struct snd_timer_system_private *) timer->private_data;
 972         njiff = (priv->last_jiffies = jiffies);
 973         if (priv->correction > timer->sticks - 1) {
 974                 priv->correction -= timer->sticks - 1;
 975                 njiff++;
 976         } else {
 977                 njiff += timer->sticks - priv->correction;
 978                 priv->correction = 0;
 979         }
 980         priv->last_expires = priv->tlist.expires = njiff;
 981         add_timer(&priv->tlist);
 982         return 0;
 983 }
 984
 985 static int snd_timer_s_stop(struct snd_timer * timer)
 986 {
 987         struct snd_timer_system_private *priv;
 988         unsigned long jiff;
 989
 990         priv = (struct snd_timer_system_private *) timer->private_data;
 991         del_timer(&priv->tlist);
 992         jiff = jiffies;
 993         if (time_before(jiff, priv->last_expires))
 994                 timer->sticks = priv->last_expires - jiff;
 995         else
 996                 timer->sticks = 1;
 997         priv->correction = 0;
 998         return 0;
 999 }
1000
1001 static struct snd_timer_hardware snd_timer_system =
1002 {
1003         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
1004         .resolution =   1000000000L / HZ,
1005         .ticks =        10000000L,
1006         .start =        snd_timer_s_start,
1007         .stop =         snd_timer_s_stop
1008 };
1009
1010 static void snd_timer_free_system(struct snd_timer *timer)
1011 {
1012         kfree(timer->private_data);
1013 }
1014
1015 static int snd_timer_register_system(void)
1016 {
1017         struct snd_timer *timer;
1018         struct snd_timer_system_private *priv;
1019         int err;
1020
1021         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1022         if (err < 0)
1023                 return err;
1024         strcpy(timer->name, "system timer");
1025         timer->hw = snd_timer_system;
1026         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1027         if (priv == NULL) {
1028                 snd_timer_free(timer);
1029                 return -ENOMEM;
1030         }
1031         setup_timer(&priv->tlist, snd_timer_s_function, (unsigned long) timer);
1032         timer->private_data = priv;
1033         timer->private_free = snd_timer_free_system;
1034         return snd_timer_global_register(timer);
1035 }
1036
1037 #ifdef CONFIG_SND_PROC_FS
1038 /*
1039  *  Info interface
1040  */
1041
1042 static void snd_timer_proc_read(struct snd_info_entry *entry,
1043                                 struct snd_info_buffer *buffer)
1044 {
1045         struct snd_timer *timer;
1046         struct snd_timer_instance *ti;
1047
1048         mutex_lock(&register_mutex);
1049         list_for_each_entry(timer, &snd_timer_list, device_list) {
1050                 switch (timer->tmr_class) {
1051                 case SNDRV_TIMER_CLASS_GLOBAL:
1052                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1053                         break;
1054                 case SNDRV_TIMER_CLASS_CARD:
1055                         snd_iprintf(buffer, "C%i-%i: ",
1056                                     timer->card->number, timer->tmr_device);
1057                         break;
1058                 case SNDRV_TIMER_CLASS_PCM:
1059                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1060                                     timer->tmr_device, timer->tmr_subdevice);
1061                         break;
1062                 default:
1063                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1064                                     timer->card ? timer->card->number : -1,
1065                                     timer->tmr_device, timer->tmr_subdevice);
1066                 }
1067                 snd_iprintf(buffer, "%s :", timer->name);
1068                 if (timer->hw.resolution)
1069                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1070                                     timer->hw.resolution / 1000,
1071                                     timer->hw.resolution % 1000,
1072                                     timer->hw.ticks);
1073                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1074                         snd_iprintf(buffer, " SLAVE");
1075                 snd_iprintf(buffer, "\n");
1076                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1077                         snd_iprintf(buffer, "  Client %s : %s\n",
1078                                     ti->owner ? ti->owner : "unknown",
1079                                     ti->flags & (SNDRV_TIMER_IFLG_START |
1080                                                  SNDRV_TIMER_IFLG_RUNNING)
1081                                     ? "running" : "stopped");
1082         }
1083         mutex_unlock(&register_mutex);
1084 }
1085
1086 static struct snd_info_entry *snd_timer_proc_entry;
1087
1088 static void __init snd_timer_proc_init(void)
1089 {
1090         struct snd_info_entry *entry;
1091
1092         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1093         if (entry != NULL) {
1094                 entry->c.text.read = snd_timer_proc_read;
1095                 if (snd_info_register(entry) < 0) {
1096                         snd_info_free_entry(entry);
1097                         entry = NULL;
1098                 }
1099         }
1100         snd_timer_proc_entry = entry;
1101 }
1102
1103 static void __exit snd_timer_proc_done(void)
1104 {
1105         snd_info_free_entry(snd_timer_proc_entry);
1106 }
1107 #else /* !CONFIG_SND_PROC_FS */
1108 #define snd_timer_proc_init()
1109 #define snd_timer_proc_done()
1110 #endif
1111
1112 /*
1113  *  USER SPACE interface
1114  */
1115
1116 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1117                                      unsigned long resolution,
1118                                      unsigned long ticks)
1119 {
1120         struct snd_timer_user *tu = timeri->callback_data;
1121         struct snd_timer_read *r;
1122         int prev;
1123
1124         spin_lock(&tu->qlock);
1125         if (tu->qused > 0) {
1126                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1127                 r = &tu->queue[prev];
1128                 if (r->resolution == resolution) {
1129                         r->ticks += ticks;
1130                         goto __wake;
1131                 }
1132         }
1133         if (tu->qused >= tu->queue_size) {
1134                 tu->overrun++;
1135         } else {
1136                 r = &tu->queue[tu->qtail++];
1137                 tu->qtail %= tu->queue_size;
1138                 r->resolution = resolution;
1139                 r->ticks = ticks;
1140                 tu->qused++;
1141         }
1142       __wake:
1143         spin_unlock(&tu->qlock);
1144         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1145         wake_up(&tu->qchange_sleep);
1146 }
1147
1148 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1149                                             struct snd_timer_tread *tread)
1150 {
1151         if (tu->qused >= tu->queue_size) {
1152                 tu->overrun++;
1153         } else {
1154                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1155                 tu->qtail %= tu->queue_size;
1156                 tu->qused++;
1157         }
1158 }
1159
1160 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1161                                      int event,
1162                                      struct timespec *tstamp,
1163                                      unsigned long resolution)
1164 {
1165         struct snd_timer_user *tu = timeri->callback_data;
1166         struct snd_timer_tread r1;
1167         unsigned long flags;
1168
1169         if (event >= SNDRV_TIMER_EVENT_START &&
1170             event <= SNDRV_TIMER_EVENT_PAUSE)
1171                 tu->tstamp = *tstamp;
1172         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1173                 return;
1174         r1.event = event;
1175         r1.tstamp = *tstamp;
1176         r1.val = resolution;
1177         spin_lock_irqsave(&tu->qlock, flags);
1178         snd_timer_user_append_to_tqueue(tu, &r1);
1179         spin_unlock_irqrestore(&tu->qlock, flags);
1180         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1181         wake_up(&tu->qchange_sleep);
1182 }
1183
1184 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1185                                       unsigned long resolution,
1186                                       unsigned long ticks)
1187 {
1188         struct snd_timer_user *tu = timeri->callback_data;
1189         struct snd_timer_tread *r, r1;
1190         struct timespec tstamp;
1191         int prev, append = 0;
1192
1193         memset(&tstamp, 0, sizeof(tstamp));
1194         spin_lock(&tu->qlock);
1195         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1196                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1197                 spin_unlock(&tu->qlock);
1198                 return;
1199         }
1200         if (tu->last_resolution != resolution || ticks > 0) {
1201                 if (timer_tstamp_monotonic)
1202                         ktime_get_ts(&tstamp);
1203                 else
1204                         getnstimeofday(&tstamp);
1205         }
1206         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1207             tu->last_resolution != resolution) {
1208                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1209                 r1.tstamp = tstamp;
1210                 r1.val = resolution;
1211                 snd_timer_user_append_to_tqueue(tu, &r1);
1212                 tu->last_resolution = resolution;
1213                 append++;
1214         }
1215         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1216                 goto __wake;
1217         if (ticks == 0)
1218                 goto __wake;
1219         if (tu->qused > 0) {
1220                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1221                 r = &tu->tqueue[prev];
1222                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1223                         r->tstamp = tstamp;
1224                         r->val += ticks;
1225                         append++;
1226                         goto __wake;
1227                 }
1228         }
1229         r1.event = SNDRV_TIMER_EVENT_TICK;
1230         r1.tstamp = tstamp;
1231         r1.val = ticks;
1232         snd_timer_user_append_to_tqueue(tu, &r1);
1233         append++;
1234       __wake:
1235         spin_unlock(&tu->qlock);
1236         if (append == 0)
1237                 return;
1238         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1239         wake_up(&tu->qchange_sleep);
1240 }
1241
1242 static int snd_timer_user_open(struct inode *inode, struct file *file)
1243 {
1244         struct snd_timer_user *tu;
1245         int err;
1246
1247         err = nonseekable_open(inode, file);
1248         if (err < 0)
1249                 return err;
1250
1251         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1252         if (tu == NULL)
1253                 return -ENOMEM;
1254         spin_lock_init(&tu->qlock);
1255         init_waitqueue_head(&tu->qchange_sleep);
1256         mutex_init(&tu->tread_sem);
1257         tu->ticks = 1;
1258         tu->queue_size = 128;
1259         tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1260                             GFP_KERNEL);
1261         if (tu->queue == NULL) {
1262                 kfree(tu);
1263                 return -ENOMEM;
1264         }
1265         file->private_data = tu;
1266         return 0;
1267 }
1268
1269 static int snd_timer_user_release(struct inode *inode, struct file *file)
1270 {
1271         struct snd_timer_user *tu;
1272
1273         if (file->private_data) {
1274                 tu = file->private_data;
1275                 file->private_data = NULL;
1276                 if (tu->timeri)
1277                         snd_timer_close(tu->timeri);
1278                 kfree(tu->queue);
1279                 kfree(tu->tqueue);
1280                 kfree(tu);
1281         }
1282         return 0;
1283 }
1284
1285 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1286 {
1287         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1288         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1289         id->card = -1;
1290         id->device = -1;
1291         id->subdevice = -1;
1292 }
1293
1294 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1295 {
1296         id->dev_class = timer->tmr_class;
1297         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1298         id->card = timer->card ? timer->card->number : -1;
1299         id->device = timer->tmr_device;
1300         id->subdevice = timer->tmr_subdevice;
1301 }
1302
1303 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1304 {
1305         struct snd_timer_id id;
1306         struct snd_timer *timer;
1307         struct list_head *p;
1308
1309         if (copy_from_user(&id, _tid, sizeof(id)))
1310                 return -EFAULT;
1311         mutex_lock(&register_mutex);
1312         if (id.dev_class < 0) {         /* first item */
1313                 if (list_empty(&snd_timer_list))
1314                         snd_timer_user_zero_id(&id);
1315                 else {
1316                         timer = list_entry(snd_timer_list.next,
1317                                            struct snd_timer, device_list);
1318                         snd_timer_user_copy_id(&id, timer);
1319                 }
1320         } else {
1321                 switch (id.dev_class) {
1322                 case SNDRV_TIMER_CLASS_GLOBAL:
1323                         id.device = id.device < 0 ? 0 : id.device + 1;
1324                         list_for_each(p, &snd_timer_list) {
1325                                 timer = list_entry(p, struct snd_timer, device_list);
1326                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1327                                         snd_timer_user_copy_id(&id, timer);
1328                                         break;
1329                                 }
1330                                 if (timer->tmr_device >= id.device) {
1331                                         snd_timer_user_copy_id(&id, timer);
1332                                         break;
1333                                 }
1334                         }
1335                         if (p == &snd_timer_list)
1336                                 snd_timer_user_zero_id(&id);
1337                         break;
1338                 case SNDRV_TIMER_CLASS_CARD:
1339                 case SNDRV_TIMER_CLASS_PCM:
1340                         if (id.card < 0) {
1341                                 id.card = 0;
1342                         } else {
1343                                 if (id.card < 0) {
1344                                         id.card = 0;
1345                                 } else {
1346                                         if (id.device < 0) {
1347                                                 id.device = 0;
1348                                         } else {
1349                                                 if (id.subdevice < 0) {
1350                                                         id.subdevice = 0;
1351                                                 } else {
1352                                                         id.subdevice++;
1353                                                 }
1354                                         }
1355                                 }
1356                         }
1357                         list_for_each(p, &snd_timer_list) {
1358                                 timer = list_entry(p, struct snd_timer, device_list);
1359                                 if (timer->tmr_class > id.dev_class) {
1360                                         snd_timer_user_copy_id(&id, timer);
1361                                         break;
1362                                 }
1363                                 if (timer->tmr_class < id.dev_class)
1364                                         continue;
1365                                 if (timer->card->number > id.card) {
1366                                         snd_timer_user_copy_id(&id, timer);
1367                                         break;
1368                                 }
1369                                 if (timer->card->number < id.card)
1370                                         continue;
1371                                 if (timer->tmr_device > id.device) {
1372                                         snd_timer_user_copy_id(&id, timer);
1373                                         break;
1374                                 }
1375                                 if (timer->tmr_device < id.device)
1376                                         continue;
1377                                 if (timer->tmr_subdevice > id.subdevice) {
1378                                         snd_timer_user_copy_id(&id, timer);
1379                                         break;
1380                                 }
1381                                 if (timer->tmr_subdevice < id.subdevice)
1382                                         continue;
1383                                 snd_timer_user_copy_id(&id, timer);
1384                                 break;
1385                         }
1386                         if (p == &snd_timer_list)
1387                                 snd_timer_user_zero_id(&id);
1388                         break;
1389                 default:
1390                         snd_timer_user_zero_id(&id);
1391                 }
1392         }
1393         mutex_unlock(&register_mutex);
1394         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1395                 return -EFAULT;
1396         return 0;
1397 }
1398
1399 static int snd_timer_user_ginfo(struct file *file,
1400                                 struct snd_timer_ginfo __user *_ginfo)
1401 {
1402         struct snd_timer_ginfo *ginfo;
1403         struct snd_timer_id tid;
1404         struct snd_timer *t;
1405         struct list_head *p;
1406         int err = 0;
1407
1408         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1409         if (IS_ERR(ginfo))
1410                 return PTR_ERR(ginfo);
1411
1412         tid = ginfo->tid;
1413         memset(ginfo, 0, sizeof(*ginfo));
1414         ginfo->tid = tid;
1415         mutex_lock(&register_mutex);
1416         t = snd_timer_find(&tid);
1417         if (t != NULL) {
1418                 ginfo->card = t->card ? t->card->number : -1;
1419                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1420                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1421                 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1422                 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1423                 ginfo->resolution = t->hw.resolution;
1424                 if (t->hw.resolution_min > 0) {
1425                         ginfo->resolution_min = t->hw.resolution_min;
1426                         ginfo->resolution_max = t->hw.resolution_max;
1427                 }
1428                 list_for_each(p, &t->open_list_head) {
1429                         ginfo->clients++;
1430                 }
1431         } else {
1432                 err = -ENODEV;
1433         }
1434         mutex_unlock(&register_mutex);
1435         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1436                 err = -EFAULT;
1437         kfree(ginfo);
1438         return err;
1439 }
1440
1441 static int snd_timer_user_gparams(struct file *file,
1442                                   struct snd_timer_gparams __user *_gparams)
1443 {
1444         struct snd_timer_gparams gparams;
1445         struct snd_timer *t;
1446         int err;
1447
1448         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1449                 return -EFAULT;
1450         mutex_lock(&register_mutex);
1451         t = snd_timer_find(&gparams.tid);
1452         if (!t) {
1453                 err = -ENODEV;
1454                 goto _error;
1455         }
1456         if (!list_empty(&t->open_list_head)) {
1457                 err = -EBUSY;
1458                 goto _error;
1459         }
1460         if (!t->hw.set_period) {
1461                 err = -ENOSYS;
1462                 goto _error;
1463         }
1464         err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1465 _error:
1466         mutex_unlock(&register_mutex);
1467         return err;
1468 }
1469
1470 static int snd_timer_user_gstatus(struct file *file,
1471                                   struct snd_timer_gstatus __user *_gstatus)
1472 {
1473         struct snd_timer_gstatus gstatus;
1474         struct snd_timer_id tid;
1475         struct snd_timer *t;
1476         int err = 0;
1477
1478         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1479                 return -EFAULT;
1480         tid = gstatus.tid;
1481         memset(&gstatus, 0, sizeof(gstatus));
1482         gstatus.tid = tid;
1483         mutex_lock(&register_mutex);
1484         t = snd_timer_find(&tid);
1485         if (t != NULL) {
1486                 if (t->hw.c_resolution)
1487                         gstatus.resolution = t->hw.c_resolution(t);
1488                 else
1489                         gstatus.resolution = t->hw.resolution;
1490                 if (t->hw.precise_resolution) {
1491                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1492                                                  &gstatus.resolution_den);
1493                 } else {
1494                         gstatus.resolution_num = gstatus.resolution;
1495                         gstatus.resolution_den = 1000000000uL;
1496                 }
1497         } else {
1498                 err = -ENODEV;
1499         }
1500         mutex_unlock(&register_mutex);
1501         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1502                 err = -EFAULT;
1503         return err;
1504 }
1505
1506 static int snd_timer_user_tselect(struct file *file,
1507                                   struct snd_timer_select __user *_tselect)
1508 {
1509         struct snd_timer_user *tu;
1510         struct snd_timer_select tselect;
1511         char str[32];
1512         int err = 0;
1513
1514         tu = file->private_data;
1515         mutex_lock(&tu->tread_sem);
1516         if (tu->timeri) {
1517                 snd_timer_close(tu->timeri);
1518                 tu->timeri = NULL;
1519         }
1520         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1521                 err = -EFAULT;
1522                 goto __err;
1523         }
1524         sprintf(str, "application %i", current->pid);
1525         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1526                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1527         err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1528         if (err < 0)
1529                 goto __err;
1530
1531         kfree(tu->queue);
1532         tu->queue = NULL;
1533         kfree(tu->tqueue);
1534         tu->tqueue = NULL;
1535         if (tu->tread) {
1536                 tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1537                                      GFP_KERNEL);
1538                 if (tu->tqueue == NULL)
1539                         err = -ENOMEM;
1540         } else {
1541                 tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1542                                     GFP_KERNEL);
1543                 if (tu->queue == NULL)
1544                         err = -ENOMEM;
1545         }
1546
1547         if (err < 0) {
1548                 snd_timer_close(tu->timeri);
1549                 tu->timeri = NULL;
1550         } else {
1551                 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1552                 tu->timeri->callback = tu->tread
1553                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1554                 tu->timeri->ccallback = snd_timer_user_ccallback;
1555                 tu->timeri->callback_data = (void *)tu;
1556         }
1557
1558       __err:
1559         mutex_unlock(&tu->tread_sem);
1560         return err;
1561 }
1562
1563 static int snd_timer_user_info(struct file *file,
1564                                struct snd_timer_info __user *_info)
1565 {
1566         struct snd_timer_user *tu;
1567         struct snd_timer_info *info;
1568         struct snd_timer *t;
1569         int err = 0;
1570
1571         tu = file->private_data;
1572         if (!tu->timeri)
1573                 return -EBADFD;
1574         t = tu->timeri->timer;
1575         if (!t)
1576                 return -EBADFD;
1577
1578         info = kzalloc(sizeof(*info), GFP_KERNEL);
1579         if (! info)
1580                 return -ENOMEM;
1581         info->card = t->card ? t->card->number : -1;
1582         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1583                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1584         strlcpy(info->id, t->id, sizeof(info->id));
1585         strlcpy(info->name, t->name, sizeof(info->name));
1586         info->resolution = t->hw.resolution;
1587         if (copy_to_user(_info, info, sizeof(*_info)))
1588                 err = -EFAULT;
1589         kfree(info);
1590         return err;
1591 }
1592
1593 static int snd_timer_user_params(struct file *file,
1594                                  struct snd_timer_params __user *_params)
1595 {
1596         struct snd_timer_user *tu;
1597         struct snd_timer_params params;
1598         struct snd_timer *t;
1599         struct snd_timer_read *tr;
1600         struct snd_timer_tread *ttr;
1601         int err;
1602
1603         tu = file->private_data;
1604         if (!tu->timeri)
1605                 return -EBADFD;
1606         t = tu->timeri->timer;
1607         if (!t)
1608                 return -EBADFD;
1609         if (copy_from_user(&params, _params, sizeof(params)))
1610                 return -EFAULT;
1611         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1612                 err = -EINVAL;
1613                 goto _end;
1614         }
1615         if (params.queue_size > 0 &&
1616             (params.queue_size < 32 || params.queue_size > 1024)) {
1617                 err = -EINVAL;
1618                 goto _end;
1619         }
1620         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1621                               (1<<SNDRV_TIMER_EVENT_TICK)|
1622                               (1<<SNDRV_TIMER_EVENT_START)|
1623                               (1<<SNDRV_TIMER_EVENT_STOP)|
1624                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1625                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1626                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1627                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1628                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1629                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1630                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1631                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1632                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1633                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1634                 err = -EINVAL;
1635                 goto _end;
1636         }
1637         snd_timer_stop(tu->timeri);
1638         spin_lock_irq(&t->lock);
1639         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1640                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1641                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1642         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1643                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1644         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1645                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1646         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1647                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1648         spin_unlock_irq(&t->lock);
1649         if (params.queue_size > 0 &&
1650             (unsigned int)tu->queue_size != params.queue_size) {
1651                 if (tu->tread) {
1652                         ttr = kmalloc(params.queue_size * sizeof(*ttr),
1653                                       GFP_KERNEL);
1654                         if (ttr) {
1655                                 kfree(tu->tqueue);
1656                                 tu->queue_size = params.queue_size;
1657                                 tu->tqueue = ttr;
1658                         }
1659                 } else {
1660                         tr = kmalloc(params.queue_size * sizeof(*tr),
1661                                      GFP_KERNEL);
1662                         if (tr) {
1663                                 kfree(tu->queue);
1664                                 tu->queue_size = params.queue_size;
1665                                 tu->queue = tr;
1666                         }
1667                 }
1668         }
1669         tu->qhead = tu->qtail = tu->qused = 0;
1670         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1671                 if (tu->tread) {
1672                         struct snd_timer_tread tread;
1673                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1674                         tread.tstamp.tv_sec = 0;
1675                         tread.tstamp.tv_nsec = 0;
1676                         tread.val = 0;
1677                         snd_timer_user_append_to_tqueue(tu, &tread);
1678                 } else {
1679                         struct snd_timer_read *r = &tu->queue[0];
1680                         r->resolution = 0;
1681                         r->ticks = 0;
1682                         tu->qused++;
1683                         tu->qtail++;
1684                 }
1685         }
1686         tu->filter = params.filter;
1687         tu->ticks = params.ticks;
1688         err = 0;
1689  _end:
1690         if (copy_to_user(_params, &params, sizeof(params)))
1691                 return -EFAULT;
1692         return err;
1693 }
1694
1695 static int snd_timer_user_status(struct file *file,
1696                                  struct snd_timer_status __user *_status)
1697 {
1698         struct snd_timer_user *tu;
1699         struct snd_timer_status status;
1700
1701         tu = file->private_data;
1702         if (!tu->timeri)
1703                 return -EBADFD;
1704         memset(&status, 0, sizeof(status));
1705         status.tstamp = tu->tstamp;
1706         status.resolution = snd_timer_resolution(tu->timeri);
1707         status.lost = tu->timeri->lost;
1708         status.overrun = tu->overrun;
1709         spin_lock_irq(&tu->qlock);
1710         status.queue = tu->qused;
1711         spin_unlock_irq(&tu->qlock);
1712         if (copy_to_user(_status, &status, sizeof(status)))
1713                 return -EFAULT;
1714         return 0;
1715 }
1716
1717 static int snd_timer_user_start(struct file *file)
1718 {
1719         int err;
1720         struct snd_timer_user *tu;
1721
1722         tu = file->private_data;
1723         if (!tu->timeri)
1724                 return -EBADFD;
1725         snd_timer_stop(tu->timeri);
1726         tu->timeri->lost = 0;
1727         tu->last_resolution = 0;
1728         return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1729 }
1730
1731 static int snd_timer_user_stop(struct file *file)
1732 {
1733         int err;
1734         struct snd_timer_user *tu;
1735
1736         tu = file->private_data;
1737         if (!tu->timeri)
1738                 return -EBADFD;
1739         return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1740 }
1741
1742 static int snd_timer_user_continue(struct file *file)
1743 {
1744         int err;
1745         struct snd_timer_user *tu;
1746
1747         tu = file->private_data;
1748         if (!tu->timeri)
1749                 return -EBADFD;
1750         tu->timeri->lost = 0;
1751         return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1752 }
1753
1754 static int snd_timer_user_pause(struct file *file)
1755 {
1756         int err;
1757         struct snd_timer_user *tu;
1758
1759         tu = file->private_data;
1760         if (!tu->timeri)
1761                 return -EBADFD;
1762         return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1763 }
1764
1765 enum {
1766         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1767         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1768         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1769         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1770 };
1771
1772 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1773                                  unsigned long arg)
1774 {
1775         struct snd_timer_user *tu;
1776         void __user *argp = (void __user *)arg;
1777         int __user *p = argp;
1778
1779         tu = file->private_data;
1780         switch (cmd) {
1781         case SNDRV_TIMER_IOCTL_PVERSION:
1782                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1783         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1784                 return snd_timer_user_next_device(argp);
1785         case SNDRV_TIMER_IOCTL_TREAD:
1786         {
1787                 int xarg;
1788
1789                 mutex_lock(&tu->tread_sem);
1790                 if (tu->timeri) {       /* too late */
1791                         mutex_unlock(&tu->tread_sem);
1792                         return -EBUSY;
1793                 }
1794                 if (get_user(xarg, p)) {
1795                         mutex_unlock(&tu->tread_sem);
1796                         return -EFAULT;
1797                 }
1798                 tu->tread = xarg ? 1 : 0;
1799                 mutex_unlock(&tu->tread_sem);
1800                 return 0;
1801         }
1802         case SNDRV_TIMER_IOCTL_GINFO:
1803                 return snd_timer_user_ginfo(file, argp);
1804         case SNDRV_TIMER_IOCTL_GPARAMS:
1805                 return snd_timer_user_gparams(file, argp);
1806         case SNDRV_TIMER_IOCTL_GSTATUS:
1807                 return snd_timer_user_gstatus(file, argp);
1808         case SNDRV_TIMER_IOCTL_SELECT:
1809                 return snd_timer_user_tselect(file, argp);
1810         case SNDRV_TIMER_IOCTL_INFO:
1811                 return snd_timer_user_info(file, argp);
1812         case SNDRV_TIMER_IOCTL_PARAMS:
1813                 return snd_timer_user_params(file, argp);
1814         case SNDRV_TIMER_IOCTL_STATUS:
1815                 return snd_timer_user_status(file, argp);
1816         case SNDRV_TIMER_IOCTL_START:
1817         case SNDRV_TIMER_IOCTL_START_OLD:
1818                 return snd_timer_user_start(file);
1819         case SNDRV_TIMER_IOCTL_STOP:
1820         case SNDRV_TIMER_IOCTL_STOP_OLD:
1821                 return snd_timer_user_stop(file);
1822         case SNDRV_TIMER_IOCTL_CONTINUE:
1823         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1824                 return snd_timer_user_continue(file);
1825         case SNDRV_TIMER_IOCTL_PAUSE:
1826         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1827                 return snd_timer_user_pause(file);
1828         }
1829         return -ENOTTY;
1830 }
1831
1832 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1833 {
1834         struct snd_timer_user *tu;
1835
1836         tu = file->private_data;
1837         return fasync_helper(fd, file, on, &tu->fasync);
1838 }
1839
1840 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1841                                    size_t count, loff_t *offset)
1842 {
1843         struct snd_timer_user *tu;
1844         long result = 0, unit;
1845         int err = 0;
1846
1847         tu = file->private_data;
1848         unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1849         spin_lock_irq(&tu->qlock);
1850         while ((long)count - result >= unit) {
1851                 while (!tu->qused) {
1852                         wait_queue_t wait;
1853
1854                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1855                                 err = -EAGAIN;
1856                                 break;
1857                         }
1858
1859                         set_current_state(TASK_INTERRUPTIBLE);
1860                         init_waitqueue_entry(&wait, current);
1861                         add_wait_queue(&tu->qchange_sleep, &wait);
1862
1863                         spin_unlock_irq(&tu->qlock);
1864                         schedule();
1865                         spin_lock_irq(&tu->qlock);
1866
1867                         remove_wait_queue(&tu->qchange_sleep, &wait);
1868
1869                         if (signal_pending(current)) {
1870                                 err = -ERESTARTSYS;
1871                                 break;
1872                         }
1873                 }
1874
1875                 spin_unlock_irq(&tu->qlock);
1876                 if (err < 0)
1877                         goto _error;
1878
1879                 if (tu->tread) {
1880                         if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1881                                          sizeof(struct snd_timer_tread))) {
1882                                 err = -EFAULT;
1883                                 goto _error;
1884                         }
1885                 } else {
1886                         if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1887                                          sizeof(struct snd_timer_read))) {
1888                                 err = -EFAULT;
1889                                 goto _error;
1890                         }
1891                 }
1892
1893                 tu->qhead %= tu->queue_size;
1894
1895                 result += unit;
1896                 buffer += unit;
1897
1898                 spin_lock_irq(&tu->qlock);
1899                 tu->qused--;
1900         }
1901         spin_unlock_irq(&tu->qlock);
1902  _error:
1903         return result > 0 ? result : err;
1904 }
1905
1906 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1907 {
1908         unsigned int mask;
1909         struct snd_timer_user *tu;
1910
1911         tu = file->private_data;
1912
1913         poll_wait(file, &tu->qchange_sleep, wait);
1914
1915         mask = 0;
1916         if (tu->qused)
1917                 mask |= POLLIN | POLLRDNORM;
1918
1919         return mask;
1920 }
1921
1922 #ifdef CONFIG_COMPAT
1923 #include "timer_compat.c"
1924 #else
1925 #define snd_timer_user_ioctl_compat     NULL
1926 #endif
1927
1928 static const struct file_operations snd_timer_f_ops =
1929 {
1930         .owner =        THIS_MODULE,
1931         .read =         snd_timer_user_read,
1932         .open =         snd_timer_user_open,
1933         .release =      snd_timer_user_release,
1934         .llseek =       no_llseek,
1935         .poll =         snd_timer_user_poll,
1936         .unlocked_ioctl =       snd_timer_user_ioctl,
1937         .compat_ioctl = snd_timer_user_ioctl_compat,
1938         .fasync =       snd_timer_user_fasync,
1939 };
1940
1941 /* unregister the system timer */
1942 static void snd_timer_free_all(void)
1943 {
1944         struct snd_timer *timer, *n;
1945
1946         list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
1947                 snd_timer_free(timer);
1948 }
1949
1950 static struct device timer_dev;
1951
1952 /*
1953  *  ENTRY functions
1954  */
1955
1956 static int __init alsa_timer_init(void)
1957 {
1958         int err;
1959
1960         snd_device_initialize(&timer_dev, NULL);
1961         dev_set_name(&timer_dev, "timer");
1962
1963 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1964         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1965                               "system timer");
1966 #endif
1967
1968         err = snd_timer_register_system();
1969         if (err < 0) {
1970                 pr_err("ALSA: unable to register system timer (%i)\n", err);
1971                 put_device(&timer_dev);
1972                 return err;
1973         }
1974
1975         err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1976                                   &snd_timer_f_ops, NULL, &timer_dev);
1977         if (err < 0) {
1978                 pr_err("ALSA: unable to register timer device (%i)\n", err);
1979                 snd_timer_free_all();
1980                 put_device(&timer_dev);
1981                 return err;
1982         }
1983
1984         snd_timer_proc_init();
1985         return 0;
1986 }
1987
1988 static void __exit alsa_timer_exit(void)
1989 {
1990         snd_unregister_device(&timer_dev);
1991         snd_timer_free_all();
1992         put_device(&timer_dev);
1993         snd_timer_proc_done();
1994 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1995         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1996 #endif
1997 }
1998
1999 module_init(alsa_timer_init)
2000 module_exit(alsa_timer_exit)
2001
2002 EXPORT_SYMBOL(snd_timer_open);
2003 EXPORT_SYMBOL(snd_timer_close);
2004 EXPORT_SYMBOL(snd_timer_resolution);
2005 EXPORT_SYMBOL(snd_timer_start);
2006 EXPORT_SYMBOL(snd_timer_stop);
2007 EXPORT_SYMBOL(snd_timer_continue);
2008 EXPORT_SYMBOL(snd_timer_pause);
2009 EXPORT_SYMBOL(snd_timer_new);
2010 EXPORT_SYMBOL(snd_timer_notify);
2011 EXPORT_SYMBOL(snd_timer_global_new);
2012 EXPORT_SYMBOL(snd_timer_global_free);
2013 EXPORT_SYMBOL(snd_timer_global_register);
2014 EXPORT_SYMBOL(snd_timer_interrupt);