sound/core/timer.c

   1 /*
   2  *  Timers abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/string.h>
  29 #include <sound/core.h>
  30 #include <sound/timer.h>
  31 #include <sound/control.h>
  32 #include <sound/info.h>
  33 #include <sound/minors.h>
  34 #include <sound/initval.h>
  35 #include <linux/kmod.h>
  36
  37 #if defined(CONFIG_SND_HRTIMER) || defined(CONFIG_SND_HRTIMER_MODULE)
  38 #define DEFAULT_TIMER_LIMIT 4
  39 #elif defined(CONFIG_SND_RTCTIMER) || defined(CONFIG_SND_RTCTIMER_MODULE)
  40 #define DEFAULT_TIMER_LIMIT 2
  41 #else
  42 #define DEFAULT_TIMER_LIMIT 1
  43 #endif
  44
  45 static int timer_limit = DEFAULT_TIMER_LIMIT;
  46 static int timer_tstamp_monotonic = 1;
  47 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
  48 MODULE_DESCRIPTION("ALSA timer interface");
  49 MODULE_LICENSE("GPL");
  50 module_param(timer_limit, int, 0444);
  51 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  52 module_param(timer_tstamp_monotonic, int, 0444);
  53 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  54
  55 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
  56 MODULE_ALIAS("devname:snd/timer");
  57
  58 struct snd_timer_user {
  59         struct snd_timer_instance *timeri;
  60         int tread;              /* enhanced read with timestamps and events */
  61         unsigned long ticks;
  62         unsigned long overrun;
  63         int qhead;
  64         int qtail;
  65         int qused;
  66         int queue_size;
  67         struct snd_timer_read *queue;
  68         struct snd_timer_tread *tqueue;
  69         spinlock_t qlock;
  70         unsigned long last_resolution;
  71         unsigned int filter;
  72         struct timespec tstamp;         /* trigger tstamp */
  73         wait_queue_head_t qchange_sleep;
  74         struct fasync_struct *fasync;
  75         struct mutex tread_sem;
  76 };
  77
  78 /* list of timers */
  79 static LIST_HEAD(snd_timer_list);
  80
  81 /* list of slave instances */
  82 static LIST_HEAD(snd_timer_slave_list);
  83
  84 /* lock for slave active lists */
  85 static DEFINE_SPINLOCK(slave_active_lock);
  86
  87 static DEFINE_MUTEX(register_mutex);
  88
  89 static int snd_timer_free(struct snd_timer *timer);
  90 static int snd_timer_dev_free(struct snd_device *device);
  91 static int snd_timer_dev_register(struct snd_device *device);
  92 static int snd_timer_dev_disconnect(struct snd_device *device);
  93
  94 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
  95
  96 /*
  97  * create a timer instance with the given owner string.
  98  * when timer is not NULL, increments the module counter
  99  */
 100 static struct snd_timer_instance *snd_timer_instance_new(char *owner,
 101                                                          struct snd_timer *timer)
 102 {
 103         struct snd_timer_instance *timeri;
 104         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
 105         if (timeri == NULL)
 106                 return NULL;
 107         timeri->owner = kstrdup(owner, GFP_KERNEL);
 108         if (! timeri->owner) {
 109                 kfree(timeri);
 110                 return NULL;
 111         }
 112         INIT_LIST_HEAD(&timeri->open_list);
 113         INIT_LIST_HEAD(&timeri->active_list);
 114         INIT_LIST_HEAD(&timeri->ack_list);
 115         INIT_LIST_HEAD(&timeri->slave_list_head);
 116         INIT_LIST_HEAD(&timeri->slave_active_head);
 117
 118         timeri->timer = timer;
 119         if (timer && !try_module_get(timer->module)) {
 120                 kfree(timeri->owner);
 121                 kfree(timeri);
 122                 return NULL;
 123         }
 124
 125         return timeri;
 126 }
 127
 128 /*
 129  * find a timer instance from the given timer id
 130  */
 131 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
 132 {
 133         struct snd_timer *timer = NULL;
 134
 135         list_for_each_entry(timer, &snd_timer_list, device_list) {
 136                 if (timer->tmr_class != tid->dev_class)
 137                         continue;
 138                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
 139                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
 140                     (timer->card == NULL ||
 141                      timer->card->number != tid->card))
 142                         continue;
 143                 if (timer->tmr_device != tid->device)
 144                         continue;
 145                 if (timer->tmr_subdevice != tid->subdevice)
 146                         continue;
 147                 return timer;
 148         }
 149         return NULL;
 150 }
 151
 152 #ifdef CONFIG_MODULES
 153
 154 static void snd_timer_request(struct snd_timer_id *tid)
 155 {
 156         switch (tid->dev_class) {
 157         case SNDRV_TIMER_CLASS_GLOBAL:
 158                 if (tid->device < timer_limit)
 159                         request_module("snd-timer-%i", tid->device);
 160                 break;
 161         case SNDRV_TIMER_CLASS_CARD:
 162         case SNDRV_TIMER_CLASS_PCM:
 163                 if (tid->card < snd_ecards_limit)
 164                         request_module("snd-card-%i", tid->card);
 165                 break;
 166         default:
 167                 break;
 168         }
 169 }
 170
 171 #endif
 172
 173 /*
 174  * look for a master instance matching with the slave id of the given slave.
 175  * when found, relink the open_link of the slave.
 176  *
 177  * call this with register_mutex down.
 178  */
 179 static void snd_timer_check_slave(struct snd_timer_instance *slave)
 180 {
 181         struct snd_timer *timer;
 182         struct snd_timer_instance *master;
 183
 184         /* FIXME: it's really dumb to look up all entries.. */
 185         list_for_each_entry(timer, &snd_timer_list, device_list) {
 186                 list_for_each_entry(master, &timer->open_list_head, open_list) {
 187                         if (slave->slave_class == master->slave_class &&
 188                             slave->slave_id == master->slave_id) {
 189                                 list_move_tail(&slave->open_list,
 190                                                &master->slave_list_head);
 191                                 spin_lock_irq(&slave_active_lock);
 192                                 slave->master = master;
 193                                 slave->timer = master->timer;
 194                                 spin_unlock_irq(&slave_active_lock);
 195                                 return;
 196                         }
 197                 }
 198         }
 199 }
 200
 201 /*
 202  * look for slave instances matching with the slave id of the given master.
 203  * when found, relink the open_link of slaves.
 204  *
 205  * call this with register_mutex down.
 206  */
 207 static void snd_timer_check_master(struct snd_timer_instance *master)
 208 {
 209         struct snd_timer_instance *slave, *tmp;
 210
 211         /* check all pending slaves */
 212         list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 213                 if (slave->slave_class == master->slave_class &&
 214                     slave->slave_id == master->slave_id) {
 215                         list_move_tail(&slave->open_list, &master->slave_list_head);
 216                         spin_lock_irq(&slave_active_lock);
 217                         slave->master = master;
 218                         slave->timer = master->timer;
 219                         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 220                                 list_add_tail(&slave->active_list,
 221                                               &master->slave_active_head);
 222                         spin_unlock_irq(&slave_active_lock);
 223                 }
 224         }
 225 }
 226
 227 /*
 228  * open a timer instance
 229  * when opening a master, the slave id must be here given.
 230  */
 231 int snd_timer_open(struct snd_timer_instance **ti,
 232                    char *owner, struct snd_timer_id *tid,
 233                    unsigned int slave_id)
 234 {
 235         struct snd_timer *timer;
 236         struct snd_timer_instance *timeri = NULL;
 237
 238         if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 239                 /* open a slave instance */
 240                 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 241                     tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 242                         snd_printd("invalid slave class %i\n", tid->dev_sclass);
 243                         return -EINVAL;
 244                 }
 245                 mutex_lock(&register_mutex);
 246                 timeri = snd_timer_instance_new(owner, NULL);
 247                 if (!timeri) {
 248                         mutex_unlock(&register_mutex);
 249                         return -ENOMEM;
 250                 }
 251                 timeri->slave_class = tid->dev_sclass;
 252                 timeri->slave_id = tid->device;
 253                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 254                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 255                 snd_timer_check_slave(timeri);
 256                 mutex_unlock(&register_mutex);
 257                 *ti = timeri;
 258                 return 0;
 259         }
 260
 261         /* open a master instance */
 262         mutex_lock(&register_mutex);
 263         timer = snd_timer_find(tid);
 264 #ifdef CONFIG_MODULES
 265         if (!timer) {
 266                 mutex_unlock(&register_mutex);
 267                 snd_timer_request(tid);
 268                 mutex_lock(&register_mutex);
 269                 timer = snd_timer_find(tid);
 270         }
 271 #endif
 272         if (!timer) {
 273                 mutex_unlock(&register_mutex);
 274                 return -ENODEV;
 275         }
 276         if (!list_empty(&timer->open_list_head)) {
 277                 timeri = list_entry(timer->open_list_head.next,
 278                                     struct snd_timer_instance, open_list);
 279                 if (timeri->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 280                         mutex_unlock(&register_mutex);
 281                         return -EBUSY;
 282                 }
 283         }
 284         timeri = snd_timer_instance_new(owner, timer);
 285         if (!timeri) {
 286                 mutex_unlock(&register_mutex);
 287                 return -ENOMEM;
 288         }
 289         timeri->slave_class = tid->dev_sclass;
 290         timeri->slave_id = slave_id;
 291         if (list_empty(&timer->open_list_head) && timer->hw.open)
 292                 timer->hw.open(timer);
 293         list_add_tail(&timeri->open_list, &timer->open_list_head);
 294         snd_timer_check_master(timeri);
 295         mutex_unlock(&register_mutex);
 296         *ti = timeri;
 297         return 0;
 298 }
 299
 300 static int _snd_timer_stop(struct snd_timer_instance *timeri,
 301                            int keep_flag, int event);
 302
 303 /*
 304  * close a timer instance
 305  */
 306 int snd_timer_close(struct snd_timer_instance *timeri)
 307 {
 308         struct snd_timer *timer = NULL;
 309         struct snd_timer_instance *slave, *tmp;
 310
 311         if (snd_BUG_ON(!timeri))
 312                 return -ENXIO;
 313
 314         /* force to stop the timer */
 315         snd_timer_stop(timeri);
 316
 317         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 318                 /* wait, until the active callback is finished */
 319                 spin_lock_irq(&slave_active_lock);
 320                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 321                         spin_unlock_irq(&slave_active_lock);
 322                         udelay(10);
 323                         spin_lock_irq(&slave_active_lock);
 324                 }
 325                 spin_unlock_irq(&slave_active_lock);
 326                 mutex_lock(&register_mutex);
 327                 list_del(&timeri->open_list);
 328                 mutex_unlock(&register_mutex);
 329         } else {
 330                 timer = timeri->timer;
 331                 if (snd_BUG_ON(!timer))
 332                         goto out;
 333                 /* wait, until the active callback is finished */
 334                 spin_lock_irq(&timer->lock);
 335                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 336                         spin_unlock_irq(&timer->lock);
 337                         udelay(10);
 338                         spin_lock_irq(&timer->lock);
 339                 }
 340                 spin_unlock_irq(&timer->lock);
 341                 mutex_lock(&register_mutex);
 342                 list_del(&timeri->open_list);
 343                 if (timer && list_empty(&timer->open_list_head) &&
 344                     timer->hw.close)
 345                         timer->hw.close(timer);
 346                 /* remove slave links */
 347                 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 348                                          open_list) {
 349                         spin_lock_irq(&slave_active_lock);
 350                         _snd_timer_stop(slave, 1, SNDRV_TIMER_EVENT_RESOLUTION);
 351                         list_move_tail(&slave->open_list, &snd_timer_slave_list);
 352                         slave->master = NULL;
 353                         slave->timer = NULL;
 354                         spin_unlock_irq(&slave_active_lock);
 355                 }
 356                 mutex_unlock(&register_mutex);
 357         }
 358  out:
 359         if (timeri->private_free)
 360                 timeri->private_free(timeri);
 361         kfree(timeri->owner);
 362         kfree(timeri);
 363         if (timer)
 364                 module_put(timer->module);
 365         return 0;
 366 }
 367
 368 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 369 {
 370         struct snd_timer * timer;
 371
 372         if (timeri == NULL)
 373                 return 0;
 374         if ((timer = timeri->timer) != NULL) {
 375                 if (timer->hw.c_resolution)
 376                         return timer->hw.c_resolution(timer);
 377                 return timer->hw.resolution;
 378         }
 379         return 0;
 380 }
 381
 382 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 383 {
 384         struct snd_timer *timer;
 385         unsigned long flags;
 386         unsigned long resolution = 0;
 387         struct snd_timer_instance *ts;
 388         struct timespec tstamp;
 389
 390         if (timer_tstamp_monotonic)
 391                 do_posix_clock_monotonic_gettime(&tstamp);
 392         else
 393                 getnstimeofday(&tstamp);
 394         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 395                        event > SNDRV_TIMER_EVENT_PAUSE))
 396                 return;
 397         if (event == SNDRV_TIMER_EVENT_START ||
 398             event == SNDRV_TIMER_EVENT_CONTINUE)
 399                 resolution = snd_timer_resolution(ti);
 400         if (ti->ccallback)
 401                 ti->ccallback(ti, event, &tstamp, resolution);
 402         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 403                 return;
 404         timer = ti->timer;
 405         if (timer == NULL)
 406                 return;
 407         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 408                 return;
 409         spin_lock_irqsave(&timer->lock, flags);
 410         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 411                 if (ts->ccallback)
 412                         ts->ccallback(ti, event + 100, &tstamp, resolution);
 413         spin_unlock_irqrestore(&timer->lock, flags);
 414 }
 415
 416 static int snd_timer_start1(struct snd_timer *timer, struct snd_timer_instance *timeri,
 417                             unsigned long sticks)
 418 {
 419         list_move_tail(&timeri->active_list, &timer->active_list_head);
 420         if (timer->running) {
 421                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 422                         goto __start_now;
 423                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 424                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 425                 return 1;       /* delayed start */
 426         } else {
 427                 timer->sticks = sticks;
 428                 timer->hw.start(timer);
 429               __start_now:
 430                 timer->running++;
 431                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 432                 return 0;
 433         }
 434 }
 435
 436 static int snd_timer_start_slave(struct snd_timer_instance *timeri)
 437 {
 438         unsigned long flags;
 439
 440         spin_lock_irqsave(&slave_active_lock, flags);
 441         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 442         if (timeri->master)
 443                 list_add_tail(&timeri->active_list,
 444                               &timeri->master->slave_active_head);
 445         spin_unlock_irqrestore(&slave_active_lock, flags);
 446         return 1; /* delayed start */
 447 }
 448
 449 /*
 450  *  start the timer instance
 451  */
 452 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 453 {
 454         struct snd_timer *timer;
 455         int result = -EINVAL;
 456         unsigned long flags;
 457
 458         if (timeri == NULL || ticks < 1)
 459                 return -EINVAL;
 460         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 461                 result = snd_timer_start_slave(timeri);
 462                 snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 463                 return result;
 464         }
 465         timer = timeri->timer;
 466         if (timer == NULL)
 467                 return -EINVAL;
 468         spin_lock_irqsave(&timer->lock, flags);
 469         timeri->ticks = timeri->cticks = ticks;
 470         timeri->pticks = 0;
 471         result = snd_timer_start1(timer, timeri, ticks);
 472         spin_unlock_irqrestore(&timer->lock, flags);
 473         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
 474         return result;
 475 }
 476
 477 static int _snd_timer_stop(struct snd_timer_instance * timeri,
 478                            int keep_flag, int event)
 479 {
 480         struct snd_timer *timer;
 481         unsigned long flags;
 482
 483         if (snd_BUG_ON(!timeri))
 484                 return -ENXIO;
 485
 486         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
 487                 if (!keep_flag) {
 488                         spin_lock_irqsave(&slave_active_lock, flags);
 489                         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 490                         spin_unlock_irqrestore(&slave_active_lock, flags);
 491                 }
 492                 goto __end;
 493         }
 494         timer = timeri->timer;
 495         if (!timer)
 496                 return -EINVAL;
 497         spin_lock_irqsave(&timer->lock, flags);
 498         list_del_init(&timeri->ack_list);
 499         list_del_init(&timeri->active_list);
 500         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 501             !(--timer->running)) {
 502                 timer->hw.stop(timer);
 503                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 504                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 505                         snd_timer_reschedule(timer, 0);
 506                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 507                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 508                                 timer->hw.start(timer);
 509                         }
 510                 }
 511         }
 512         if (!keep_flag)
 513                 timeri->flags &=
 514                         ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 515         spin_unlock_irqrestore(&timer->lock, flags);
 516       __end:
 517         if (event != SNDRV_TIMER_EVENT_RESOLUTION)
 518                 snd_timer_notify1(timeri, event);
 519         return 0;
 520 }
 521
 522 /*
 523  * stop the timer instance.
 524  *
 525  * do not call this from the timer callback!
 526  */
 527 int snd_timer_stop(struct snd_timer_instance *timeri)
 528 {
 529         struct snd_timer *timer;
 530         unsigned long flags;
 531         int err;
 532
 533         err = _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_STOP);
 534         if (err < 0)
 535                 return err;
 536         timer = timeri->timer;
 537         if (!timer)
 538                 return -EINVAL;
 539         spin_lock_irqsave(&timer->lock, flags);
 540         timeri->cticks = timeri->ticks;
 541         timeri->pticks = 0;
 542         spin_unlock_irqrestore(&timer->lock, flags);
 543         return 0;
 544 }
 545
 546 /*
 547  * start again..  the tick is kept.
 548  */
 549 int snd_timer_continue(struct snd_timer_instance *timeri)
 550 {
 551         struct snd_timer *timer;
 552         int result = -EINVAL;
 553         unsigned long flags;
 554
 555         if (timeri == NULL)
 556                 return result;
 557         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 558                 return snd_timer_start_slave(timeri);
 559         timer = timeri->timer;
 560         if (! timer)
 561                 return -EINVAL;
 562         spin_lock_irqsave(&timer->lock, flags);
 563         if (!timeri->cticks)
 564                 timeri->cticks = 1;
 565         timeri->pticks = 0;
 566         result = snd_timer_start1(timer, timeri, timer->sticks);
 567         spin_unlock_irqrestore(&timer->lock, flags);
 568         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
 569         return result;
 570 }
 571
 572 /*
 573  * pause.. remember the ticks left
 574  */
 575 int snd_timer_pause(struct snd_timer_instance * timeri)
 576 {
 577         return _snd_timer_stop(timeri, 0, SNDRV_TIMER_EVENT_PAUSE);
 578 }
 579
 580 /*
 581  * reschedule the timer
 582  *
 583  * start pending instances and check the scheduling ticks.
 584  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 585  */
 586 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 587 {
 588         struct snd_timer_instance *ti;
 589         unsigned long ticks = ~0UL;
 590
 591         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 592                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 593                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 594                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 595                         timer->running++;
 596                 }
 597                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 598                         if (ticks > ti->cticks)
 599                                 ticks = ti->cticks;
 600                 }
 601         }
 602         if (ticks == ~0UL) {
 603                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 604                 return;
 605         }
 606         if (ticks > timer->hw.ticks)
 607                 ticks = timer->hw.ticks;
 608         if (ticks_left != ticks)
 609                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 610         timer->sticks = ticks;
 611 }
 612
 613 /*
 614  * timer tasklet
 615  *
 616  */
 617 static void snd_timer_tasklet(unsigned long arg)
 618 {
 619         struct snd_timer *timer = (struct snd_timer *) arg;
 620         struct snd_timer_instance *ti;
 621         struct list_head *p;
 622         unsigned long resolution, ticks;
 623         unsigned long flags;
 624
 625         spin_lock_irqsave(&timer->lock, flags);
 626         /* now process all callbacks */
 627         while (!list_empty(&timer->sack_list_head)) {
 628                 p = timer->sack_list_head.next;         /* get first item */
 629                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 630
 631                 /* remove from ack_list and make empty */
 632                 list_del_init(p);
 633
 634                 ticks = ti->pticks;
 635                 ti->pticks = 0;
 636                 resolution = ti->resolution;
 637
 638                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 639                 spin_unlock(&timer->lock);
 640                 if (ti->callback)
 641                         ti->callback(ti, resolution, ticks);
 642                 spin_lock(&timer->lock);
 643                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 644         }
 645         spin_unlock_irqrestore(&timer->lock, flags);
 646 }
 647
 648 /*
 649  * timer interrupt
 650  *
 651  * ticks_left is usually equal to timer->sticks.
 652  *
 653  */
 654 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 655 {
 656         struct snd_timer_instance *ti, *ts, *tmp;
 657         unsigned long resolution, ticks;
 658         struct list_head *p, *ack_list_head;
 659         unsigned long flags;
 660         int use_tasklet = 0;
 661
 662         if (timer == NULL)
 663                 return;
 664
 665         spin_lock_irqsave(&timer->lock, flags);
 666
 667         /* remember the current resolution */
 668         if (timer->hw.c_resolution)
 669                 resolution = timer->hw.c_resolution(timer);
 670         else
 671                 resolution = timer->hw.resolution;
 672
 673         /* loop for all active instances
 674          * Here we cannot use list_for_each_entry because the active_list of a
 675          * processed instance is relinked to done_list_head before the callback
 676          * is called.
 677          */
 678         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 679                                  active_list) {
 680                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 681                         continue;
 682                 ti->pticks += ticks_left;
 683                 ti->resolution = resolution;
 684                 if (ti->cticks < ticks_left)
 685                         ti->cticks = 0;
 686                 else
 687                         ti->cticks -= ticks_left;
 688                 if (ti->cticks) /* not expired */
 689                         continue;
 690                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 691                         ti->cticks = ti->ticks;
 692                 } else {
 693                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 694                         if (--timer->running)
 695                                 list_del(&ti->active_list);
 696                 }
 697                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
 698                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 699                         ack_list_head = &timer->ack_list_head;
 700                 else
 701                         ack_list_head = &timer->sack_list_head;
 702                 if (list_empty(&ti->ack_list))
 703                         list_add_tail(&ti->ack_list, ack_list_head);
 704                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 705                         ts->pticks = ti->pticks;
 706                         ts->resolution = resolution;
 707                         if (list_empty(&ts->ack_list))
 708                                 list_add_tail(&ts->ack_list, ack_list_head);
 709                 }
 710         }
 711         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 712                 snd_timer_reschedule(timer, timer->sticks);
 713         if (timer->running) {
 714                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 715                         timer->hw.stop(timer);
 716                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 717                 }
 718                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 719                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 720                         /* restart timer */
 721                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 722                         timer->hw.start(timer);
 723                 }
 724         } else {
 725                 timer->hw.stop(timer);
 726         }
 727
 728         /* now process all fast callbacks */
 729         while (!list_empty(&timer->ack_list_head)) {
 730                 p = timer->ack_list_head.next;          /* get first item */
 731                 ti = list_entry(p, struct snd_timer_instance, ack_list);
 732
 733                 /* remove from ack_list and make empty */
 734                 list_del_init(p);
 735
 736                 ticks = ti->pticks;
 737                 ti->pticks = 0;
 738
 739                 ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 740                 spin_unlock(&timer->lock);
 741                 if (ti->callback)
 742                         ti->callback(ti, resolution, ticks);
 743                 spin_lock(&timer->lock);
 744                 ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 745         }
 746
 747         /* do we have any slow callbacks? */
 748         use_tasklet = !list_empty(&timer->sack_list_head);
 749         spin_unlock_irqrestore(&timer->lock, flags);
 750
 751         if (use_tasklet)
 752                 tasklet_schedule(&timer->task_queue);
 753 }
 754
 755 /*
 756
 757  */
 758
 759 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 760                   struct snd_timer **rtimer)
 761 {
 762         struct snd_timer *timer;
 763         int err;
 764         static struct snd_device_ops ops = {
 765                 .dev_free = snd_timer_dev_free,
 766                 .dev_register = snd_timer_dev_register,
 767                 .dev_disconnect = snd_timer_dev_disconnect,
 768         };
 769
 770         if (snd_BUG_ON(!tid))
 771                 return -EINVAL;
 772         if (rtimer)
 773                 *rtimer = NULL;
 774         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 775         if (timer == NULL) {
 776                 snd_printk(KERN_ERR "timer: cannot allocate\n");
 777                 return -ENOMEM;
 778         }
 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                 snd_printk(KERN_WARNING "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         init_timer(&priv->tlist);
1032         priv->tlist.function = snd_timer_s_function;
1033         priv->tlist.data = (unsigned long) timer;
1034         timer->private_data = priv;
1035         timer->private_free = snd_timer_free_system;
1036         return snd_timer_global_register(timer);
1037 }
1038
1039 #ifdef CONFIG_PROC_FS
1040 /*
1041  *  Info interface
1042  */
1043
1044 static void snd_timer_proc_read(struct snd_info_entry *entry,
1045                                 struct snd_info_buffer *buffer)
1046 {
1047         struct snd_timer *timer;
1048         struct snd_timer_instance *ti;
1049
1050         mutex_lock(&register_mutex);
1051         list_for_each_entry(timer, &snd_timer_list, device_list) {
1052                 switch (timer->tmr_class) {
1053                 case SNDRV_TIMER_CLASS_GLOBAL:
1054                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1055                         break;
1056                 case SNDRV_TIMER_CLASS_CARD:
1057                         snd_iprintf(buffer, "C%i-%i: ",
1058                                     timer->card->number, timer->tmr_device);
1059                         break;
1060                 case SNDRV_TIMER_CLASS_PCM:
1061                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1062                                     timer->tmr_device, timer->tmr_subdevice);
1063                         break;
1064                 default:
1065                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1066                                     timer->card ? timer->card->number : -1,
1067                                     timer->tmr_device, timer->tmr_subdevice);
1068                 }
1069                 snd_iprintf(buffer, "%s :", timer->name);
1070                 if (timer->hw.resolution)
1071                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1072                                     timer->hw.resolution / 1000,
1073                                     timer->hw.resolution % 1000,
1074                                     timer->hw.ticks);
1075                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1076                         snd_iprintf(buffer, " SLAVE");
1077                 snd_iprintf(buffer, "\n");
1078                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1079                         snd_iprintf(buffer, "  Client %s : %s\n",
1080                                     ti->owner ? ti->owner : "unknown",
1081                                     ti->flags & (SNDRV_TIMER_IFLG_START |
1082                                                  SNDRV_TIMER_IFLG_RUNNING)
1083                                     ? "running" : "stopped");
1084         }
1085         mutex_unlock(&register_mutex);
1086 }
1087
1088 static struct snd_info_entry *snd_timer_proc_entry;
1089
1090 static void __init snd_timer_proc_init(void)
1091 {
1092         struct snd_info_entry *entry;
1093
1094         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1095         if (entry != NULL) {
1096                 entry->c.text.read = snd_timer_proc_read;
1097                 if (snd_info_register(entry) < 0) {
1098                         snd_info_free_entry(entry);
1099                         entry = NULL;
1100                 }
1101         }
1102         snd_timer_proc_entry = entry;
1103 }
1104
1105 static void __exit snd_timer_proc_done(void)
1106 {
1107         snd_info_free_entry(snd_timer_proc_entry);
1108 }
1109 #else /* !CONFIG_PROC_FS */
1110 #define snd_timer_proc_init()
1111 #define snd_timer_proc_done()
1112 #endif
1113
1114 /*
1115  *  USER SPACE interface
1116  */
1117
1118 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1119                                      unsigned long resolution,
1120                                      unsigned long ticks)
1121 {
1122         struct snd_timer_user *tu = timeri->callback_data;
1123         struct snd_timer_read *r;
1124         int prev;
1125
1126         spin_lock(&tu->qlock);
1127         if (tu->qused > 0) {
1128                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1129                 r = &tu->queue[prev];
1130                 if (r->resolution == resolution) {
1131                         r->ticks += ticks;
1132                         goto __wake;
1133                 }
1134         }
1135         if (tu->qused >= tu->queue_size) {
1136                 tu->overrun++;
1137         } else {
1138                 r = &tu->queue[tu->qtail++];
1139                 tu->qtail %= tu->queue_size;
1140                 r->resolution = resolution;
1141                 r->ticks = ticks;
1142                 tu->qused++;
1143         }
1144       __wake:
1145         spin_unlock(&tu->qlock);
1146         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1147         wake_up(&tu->qchange_sleep);
1148 }
1149
1150 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1151                                             struct snd_timer_tread *tread)
1152 {
1153         if (tu->qused >= tu->queue_size) {
1154                 tu->overrun++;
1155         } else {
1156                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1157                 tu->qtail %= tu->queue_size;
1158                 tu->qused++;
1159         }
1160 }
1161
1162 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1163                                      int event,
1164                                      struct timespec *tstamp,
1165                                      unsigned long resolution)
1166 {
1167         struct snd_timer_user *tu = timeri->callback_data;
1168         struct snd_timer_tread r1;
1169         unsigned long flags;
1170
1171         if (event >= SNDRV_TIMER_EVENT_START &&
1172             event <= SNDRV_TIMER_EVENT_PAUSE)
1173                 tu->tstamp = *tstamp;
1174         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1175                 return;
1176         r1.event = event;
1177         r1.tstamp = *tstamp;
1178         r1.val = resolution;
1179         spin_lock_irqsave(&tu->qlock, flags);
1180         snd_timer_user_append_to_tqueue(tu, &r1);
1181         spin_unlock_irqrestore(&tu->qlock, flags);
1182         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1183         wake_up(&tu->qchange_sleep);
1184 }
1185
1186 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1187                                       unsigned long resolution,
1188                                       unsigned long ticks)
1189 {
1190         struct snd_timer_user *tu = timeri->callback_data;
1191         struct snd_timer_tread *r, r1;
1192         struct timespec tstamp;
1193         int prev, append = 0;
1194
1195         memset(&tstamp, 0, sizeof(tstamp));
1196         spin_lock(&tu->qlock);
1197         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1198                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1199                 spin_unlock(&tu->qlock);
1200                 return;
1201         }
1202         if (tu->last_resolution != resolution || ticks > 0) {
1203                 if (timer_tstamp_monotonic)
1204                         do_posix_clock_monotonic_gettime(&tstamp);
1205                 else
1206                         getnstimeofday(&tstamp);
1207         }
1208         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1209             tu->last_resolution != resolution) {
1210                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1211                 r1.tstamp = tstamp;
1212                 r1.val = resolution;
1213                 snd_timer_user_append_to_tqueue(tu, &r1);
1214                 tu->last_resolution = resolution;
1215                 append++;
1216         }
1217         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1218                 goto __wake;
1219         if (ticks == 0)
1220                 goto __wake;
1221         if (tu->qused > 0) {
1222                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1223                 r = &tu->tqueue[prev];
1224                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1225                         r->tstamp = tstamp;
1226                         r->val += ticks;
1227                         append++;
1228                         goto __wake;
1229                 }
1230         }
1231         r1.event = SNDRV_TIMER_EVENT_TICK;
1232         r1.tstamp = tstamp;
1233         r1.val = ticks;
1234         snd_timer_user_append_to_tqueue(tu, &r1);
1235         append++;
1236       __wake:
1237         spin_unlock(&tu->qlock);
1238         if (append == 0)
1239                 return;
1240         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1241         wake_up(&tu->qchange_sleep);
1242 }
1243
1244 static int snd_timer_user_open(struct inode *inode, struct file *file)
1245 {
1246         struct snd_timer_user *tu;
1247         int err;
1248
1249         err = nonseekable_open(inode, file);
1250         if (err < 0)
1251                 return err;
1252
1253         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1254         if (tu == NULL)
1255                 return -ENOMEM;
1256         spin_lock_init(&tu->qlock);
1257         init_waitqueue_head(&tu->qchange_sleep);
1258         mutex_init(&tu->tread_sem);
1259         tu->ticks = 1;
1260         tu->queue_size = 128;
1261         tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1262                             GFP_KERNEL);
1263         if (tu->queue == NULL) {
1264                 kfree(tu);
1265                 return -ENOMEM;
1266         }
1267         file->private_data = tu;
1268         return 0;
1269 }
1270
1271 static int snd_timer_user_release(struct inode *inode, struct file *file)
1272 {
1273         struct snd_timer_user *tu;
1274
1275         if (file->private_data) {
1276                 tu = file->private_data;
1277                 file->private_data = NULL;
1278                 if (tu->timeri)
1279                         snd_timer_close(tu->timeri);
1280                 kfree(tu->queue);
1281                 kfree(tu->tqueue);
1282                 kfree(tu);
1283         }
1284         return 0;
1285 }
1286
1287 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1288 {
1289         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1290         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1291         id->card = -1;
1292         id->device = -1;
1293         id->subdevice = -1;
1294 }
1295
1296 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1297 {
1298         id->dev_class = timer->tmr_class;
1299         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1300         id->card = timer->card ? timer->card->number : -1;
1301         id->device = timer->tmr_device;
1302         id->subdevice = timer->tmr_subdevice;
1303 }
1304
1305 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1306 {
1307         struct snd_timer_id id;
1308         struct snd_timer *timer;
1309         struct list_head *p;
1310
1311         if (copy_from_user(&id, _tid, sizeof(id)))
1312                 return -EFAULT;
1313         mutex_lock(&register_mutex);
1314         if (id.dev_class < 0) {         /* first item */
1315                 if (list_empty(&snd_timer_list))
1316                         snd_timer_user_zero_id(&id);
1317                 else {
1318                         timer = list_entry(snd_timer_list.next,
1319                                            struct snd_timer, device_list);
1320                         snd_timer_user_copy_id(&id, timer);
1321                 }
1322         } else {
1323                 switch (id.dev_class) {
1324                 case SNDRV_TIMER_CLASS_GLOBAL:
1325                         id.device = id.device < 0 ? 0 : id.device + 1;
1326                         list_for_each(p, &snd_timer_list) {
1327                                 timer = list_entry(p, struct snd_timer, device_list);
1328                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1329                                         snd_timer_user_copy_id(&id, timer);
1330                                         break;
1331                                 }
1332                                 if (timer->tmr_device >= id.device) {
1333                                         snd_timer_user_copy_id(&id, timer);
1334                                         break;
1335                                 }
1336                         }
1337                         if (p == &snd_timer_list)
1338                                 snd_timer_user_zero_id(&id);
1339                         break;
1340                 case SNDRV_TIMER_CLASS_CARD:
1341                 case SNDRV_TIMER_CLASS_PCM:
1342                         if (id.card < 0) {
1343                                 id.card = 0;
1344                         } else {
1345                                 if (id.card < 0) {
1346                                         id.card = 0;
1347                                 } else {
1348                                         if (id.device < 0) {
1349                                                 id.device = 0;
1350                                         } else {
1351                                                 if (id.subdevice < 0) {
1352                                                         id.subdevice = 0;
1353                                                 } else {
1354                                                         id.subdevice++;
1355                                                 }
1356                                         }
1357                                 }
1358                         }
1359                         list_for_each(p, &snd_timer_list) {
1360                                 timer = list_entry(p, struct snd_timer, device_list);
1361                                 if (timer->tmr_class > id.dev_class) {
1362                                         snd_timer_user_copy_id(&id, timer);
1363                                         break;
1364                                 }
1365                                 if (timer->tmr_class < id.dev_class)
1366                                         continue;
1367                                 if (timer->card->number > id.card) {
1368                                         snd_timer_user_copy_id(&id, timer);
1369                                         break;
1370                                 }
1371                                 if (timer->card->number < id.card)
1372                                         continue;
1373                                 if (timer->tmr_device > id.device) {
1374                                         snd_timer_user_copy_id(&id, timer);
1375                                         break;
1376                                 }
1377                                 if (timer->tmr_device < id.device)
1378                                         continue;
1379                                 if (timer->tmr_subdevice > id.subdevice) {
1380                                         snd_timer_user_copy_id(&id, timer);
1381                                         break;
1382                                 }
1383                                 if (timer->tmr_subdevice < id.subdevice)
1384                                         continue;
1385                                 snd_timer_user_copy_id(&id, timer);
1386                                 break;
1387                         }
1388                         if (p == &snd_timer_list)
1389                                 snd_timer_user_zero_id(&id);
1390                         break;
1391                 default:
1392                         snd_timer_user_zero_id(&id);
1393                 }
1394         }
1395         mutex_unlock(&register_mutex);
1396         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1397                 return -EFAULT;
1398         return 0;
1399 }
1400
1401 static int snd_timer_user_ginfo(struct file *file,
1402                                 struct snd_timer_ginfo __user *_ginfo)
1403 {
1404         struct snd_timer_ginfo *ginfo;
1405         struct snd_timer_id tid;
1406         struct snd_timer *t;
1407         struct list_head *p;
1408         int err = 0;
1409
1410         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1411         if (IS_ERR(ginfo))
1412                 return PTR_ERR(ginfo);
1413
1414         tid = ginfo->tid;
1415         memset(ginfo, 0, sizeof(*ginfo));
1416         ginfo->tid = tid;
1417         mutex_lock(&register_mutex);
1418         t = snd_timer_find(&tid);
1419         if (t != NULL) {
1420                 ginfo->card = t->card ? t->card->number : -1;
1421                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1422                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1423                 strlcpy(ginfo->id, t->id, sizeof(ginfo->id));
1424                 strlcpy(ginfo->name, t->name, sizeof(ginfo->name));
1425                 ginfo->resolution = t->hw.resolution;
1426                 if (t->hw.resolution_min > 0) {
1427                         ginfo->resolution_min = t->hw.resolution_min;
1428                         ginfo->resolution_max = t->hw.resolution_max;
1429                 }
1430                 list_for_each(p, &t->open_list_head) {
1431                         ginfo->clients++;
1432                 }
1433         } else {
1434                 err = -ENODEV;
1435         }
1436         mutex_unlock(&register_mutex);
1437         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1438                 err = -EFAULT;
1439         kfree(ginfo);
1440         return err;
1441 }
1442
1443 static int snd_timer_user_gparams(struct file *file,
1444                                   struct snd_timer_gparams __user *_gparams)
1445 {
1446         struct snd_timer_gparams gparams;
1447         struct snd_timer *t;
1448         int err;
1449
1450         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1451                 return -EFAULT;
1452         mutex_lock(&register_mutex);
1453         t = snd_timer_find(&gparams.tid);
1454         if (!t) {
1455                 err = -ENODEV;
1456                 goto _error;
1457         }
1458         if (!list_empty(&t->open_list_head)) {
1459                 err = -EBUSY;
1460                 goto _error;
1461         }
1462         if (!t->hw.set_period) {
1463                 err = -ENOSYS;
1464                 goto _error;
1465         }
1466         err = t->hw.set_period(t, gparams.period_num, gparams.period_den);
1467 _error:
1468         mutex_unlock(&register_mutex);
1469         return err;
1470 }
1471
1472 static int snd_timer_user_gstatus(struct file *file,
1473                                   struct snd_timer_gstatus __user *_gstatus)
1474 {
1475         struct snd_timer_gstatus gstatus;
1476         struct snd_timer_id tid;
1477         struct snd_timer *t;
1478         int err = 0;
1479
1480         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1481                 return -EFAULT;
1482         tid = gstatus.tid;
1483         memset(&gstatus, 0, sizeof(gstatus));
1484         gstatus.tid = tid;
1485         mutex_lock(&register_mutex);
1486         t = snd_timer_find(&tid);
1487         if (t != NULL) {
1488                 if (t->hw.c_resolution)
1489                         gstatus.resolution = t->hw.c_resolution(t);
1490                 else
1491                         gstatus.resolution = t->hw.resolution;
1492                 if (t->hw.precise_resolution) {
1493                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1494                                                  &gstatus.resolution_den);
1495                 } else {
1496                         gstatus.resolution_num = gstatus.resolution;
1497                         gstatus.resolution_den = 1000000000uL;
1498                 }
1499         } else {
1500                 err = -ENODEV;
1501         }
1502         mutex_unlock(&register_mutex);
1503         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1504                 err = -EFAULT;
1505         return err;
1506 }
1507
1508 static int snd_timer_user_tselect(struct file *file,
1509                                   struct snd_timer_select __user *_tselect)
1510 {
1511         struct snd_timer_user *tu;
1512         struct snd_timer_select tselect;
1513         char str[32];
1514         int err = 0;
1515
1516         tu = file->private_data;
1517         mutex_lock(&tu->tread_sem);
1518         if (tu->timeri) {
1519                 snd_timer_close(tu->timeri);
1520                 tu->timeri = NULL;
1521         }
1522         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1523                 err = -EFAULT;
1524                 goto __err;
1525         }
1526         sprintf(str, "application %i", current->pid);
1527         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1528                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1529         err = snd_timer_open(&tu->timeri, str, &tselect.id, current->pid);
1530         if (err < 0)
1531                 goto __err;
1532
1533         kfree(tu->queue);
1534         tu->queue = NULL;
1535         kfree(tu->tqueue);
1536         tu->tqueue = NULL;
1537         if (tu->tread) {
1538                 tu->tqueue = kmalloc(tu->queue_size * sizeof(struct snd_timer_tread),
1539                                      GFP_KERNEL);
1540                 if (tu->tqueue == NULL)
1541                         err = -ENOMEM;
1542         } else {
1543                 tu->queue = kmalloc(tu->queue_size * sizeof(struct snd_timer_read),
1544                                     GFP_KERNEL);
1545                 if (tu->queue == NULL)
1546                         err = -ENOMEM;
1547         }
1548
1549         if (err < 0) {
1550                 snd_timer_close(tu->timeri);
1551                 tu->timeri = NULL;
1552         } else {
1553                 tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1554                 tu->timeri->callback = tu->tread
1555                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1556                 tu->timeri->ccallback = snd_timer_user_ccallback;
1557                 tu->timeri->callback_data = (void *)tu;
1558         }
1559
1560       __err:
1561         mutex_unlock(&tu->tread_sem);
1562         return err;
1563 }
1564
1565 static int snd_timer_user_info(struct file *file,
1566                                struct snd_timer_info __user *_info)
1567 {
1568         struct snd_timer_user *tu;
1569         struct snd_timer_info *info;
1570         struct snd_timer *t;
1571         int err = 0;
1572
1573         tu = file->private_data;
1574         if (!tu->timeri)
1575                 return -EBADFD;
1576         t = tu->timeri->timer;
1577         if (!t)
1578                 return -EBADFD;
1579
1580         info = kzalloc(sizeof(*info), GFP_KERNEL);
1581         if (! info)
1582                 return -ENOMEM;
1583         info->card = t->card ? t->card->number : -1;
1584         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1585                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1586         strlcpy(info->id, t->id, sizeof(info->id));
1587         strlcpy(info->name, t->name, sizeof(info->name));
1588         info->resolution = t->hw.resolution;
1589         if (copy_to_user(_info, info, sizeof(*_info)))
1590                 err = -EFAULT;
1591         kfree(info);
1592         return err;
1593 }
1594
1595 static int snd_timer_user_params(struct file *file,
1596                                  struct snd_timer_params __user *_params)
1597 {
1598         struct snd_timer_user *tu;
1599         struct snd_timer_params params;
1600         struct snd_timer *t;
1601         struct snd_timer_read *tr;
1602         struct snd_timer_tread *ttr;
1603         int err;
1604
1605         tu = file->private_data;
1606         if (!tu->timeri)
1607                 return -EBADFD;
1608         t = tu->timeri->timer;
1609         if (!t)
1610                 return -EBADFD;
1611         if (copy_from_user(&params, _params, sizeof(params)))
1612                 return -EFAULT;
1613         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE) && params.ticks < 1) {
1614                 err = -EINVAL;
1615                 goto _end;
1616         }
1617         if (params.queue_size > 0 &&
1618             (params.queue_size < 32 || params.queue_size > 1024)) {
1619                 err = -EINVAL;
1620                 goto _end;
1621         }
1622         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1623                               (1<<SNDRV_TIMER_EVENT_TICK)|
1624                               (1<<SNDRV_TIMER_EVENT_START)|
1625                               (1<<SNDRV_TIMER_EVENT_STOP)|
1626                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1627                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1628                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1629                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1630                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1631                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1632                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1633                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1634                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1635                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1636                 err = -EINVAL;
1637                 goto _end;
1638         }
1639         snd_timer_stop(tu->timeri);
1640         spin_lock_irq(&t->lock);
1641         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1642                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1643                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1644         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1645                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1646         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1647                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1648         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1649                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1650         spin_unlock_irq(&t->lock);
1651         if (params.queue_size > 0 &&
1652             (unsigned int)tu->queue_size != params.queue_size) {
1653                 if (tu->tread) {
1654                         ttr = kmalloc(params.queue_size * sizeof(*ttr),
1655                                       GFP_KERNEL);
1656                         if (ttr) {
1657                                 kfree(tu->tqueue);
1658                                 tu->queue_size = params.queue_size;
1659                                 tu->tqueue = ttr;
1660                         }
1661                 } else {
1662                         tr = kmalloc(params.queue_size * sizeof(*tr),
1663                                      GFP_KERNEL);
1664                         if (tr) {
1665                                 kfree(tu->queue);
1666                                 tu->queue_size = params.queue_size;
1667                                 tu->queue = tr;
1668                         }
1669                 }
1670         }
1671         tu->qhead = tu->qtail = tu->qused = 0;
1672         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1673                 if (tu->tread) {
1674                         struct snd_timer_tread tread;
1675                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1676                         tread.tstamp.tv_sec = 0;
1677                         tread.tstamp.tv_nsec = 0;
1678                         tread.val = 0;
1679                         snd_timer_user_append_to_tqueue(tu, &tread);
1680                 } else {
1681                         struct snd_timer_read *r = &tu->queue[0];
1682                         r->resolution = 0;
1683                         r->ticks = 0;
1684                         tu->qused++;
1685                         tu->qtail++;
1686                 }
1687         }
1688         tu->filter = params.filter;
1689         tu->ticks = params.ticks;
1690         err = 0;
1691  _end:
1692         if (copy_to_user(_params, &params, sizeof(params)))
1693                 return -EFAULT;
1694         return err;
1695 }
1696
1697 static int snd_timer_user_status(struct file *file,
1698                                  struct snd_timer_status __user *_status)
1699 {
1700         struct snd_timer_user *tu;
1701         struct snd_timer_status status;
1702
1703         tu = file->private_data;
1704         if (!tu->timeri)
1705                 return -EBADFD;
1706         memset(&status, 0, sizeof(status));
1707         status.tstamp = tu->tstamp;
1708         status.resolution = snd_timer_resolution(tu->timeri);
1709         status.lost = tu->timeri->lost;
1710         status.overrun = tu->overrun;
1711         spin_lock_irq(&tu->qlock);
1712         status.queue = tu->qused;
1713         spin_unlock_irq(&tu->qlock);
1714         if (copy_to_user(_status, &status, sizeof(status)))
1715                 return -EFAULT;
1716         return 0;
1717 }
1718
1719 static int snd_timer_user_start(struct file *file)
1720 {
1721         int err;
1722         struct snd_timer_user *tu;
1723
1724         tu = file->private_data;
1725         if (!tu->timeri)
1726                 return -EBADFD;
1727         snd_timer_stop(tu->timeri);
1728         tu->timeri->lost = 0;
1729         tu->last_resolution = 0;
1730         return (err = snd_timer_start(tu->timeri, tu->ticks)) < 0 ? err : 0;
1731 }
1732
1733 static int snd_timer_user_stop(struct file *file)
1734 {
1735         int err;
1736         struct snd_timer_user *tu;
1737
1738         tu = file->private_data;
1739         if (!tu->timeri)
1740                 return -EBADFD;
1741         return (err = snd_timer_stop(tu->timeri)) < 0 ? err : 0;
1742 }
1743
1744 static int snd_timer_user_continue(struct file *file)
1745 {
1746         int err;
1747         struct snd_timer_user *tu;
1748
1749         tu = file->private_data;
1750         if (!tu->timeri)
1751                 return -EBADFD;
1752         tu->timeri->lost = 0;
1753         return (err = snd_timer_continue(tu->timeri)) < 0 ? err : 0;
1754 }
1755
1756 static int snd_timer_user_pause(struct file *file)
1757 {
1758         int err;
1759         struct snd_timer_user *tu;
1760
1761         tu = file->private_data;
1762         if (!tu->timeri)
1763                 return -EBADFD;
1764         return (err = snd_timer_pause(tu->timeri)) < 0 ? err : 0;
1765 }
1766
1767 enum {
1768         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
1769         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
1770         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
1771         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
1772 };
1773
1774 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
1775                                  unsigned long arg)
1776 {
1777         struct snd_timer_user *tu;
1778         void __user *argp = (void __user *)arg;
1779         int __user *p = argp;
1780
1781         tu = file->private_data;
1782         switch (cmd) {
1783         case SNDRV_TIMER_IOCTL_PVERSION:
1784                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
1785         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
1786                 return snd_timer_user_next_device(argp);
1787         case SNDRV_TIMER_IOCTL_TREAD:
1788         {
1789                 int xarg;
1790
1791                 mutex_lock(&tu->tread_sem);
1792                 if (tu->timeri) {       /* too late */
1793                         mutex_unlock(&tu->tread_sem);
1794                         return -EBUSY;
1795                 }
1796                 if (get_user(xarg, p)) {
1797                         mutex_unlock(&tu->tread_sem);
1798                         return -EFAULT;
1799                 }
1800                 tu->tread = xarg ? 1 : 0;
1801                 mutex_unlock(&tu->tread_sem);
1802                 return 0;
1803         }
1804         case SNDRV_TIMER_IOCTL_GINFO:
1805                 return snd_timer_user_ginfo(file, argp);
1806         case SNDRV_TIMER_IOCTL_GPARAMS:
1807                 return snd_timer_user_gparams(file, argp);
1808         case SNDRV_TIMER_IOCTL_GSTATUS:
1809                 return snd_timer_user_gstatus(file, argp);
1810         case SNDRV_TIMER_IOCTL_SELECT:
1811                 return snd_timer_user_tselect(file, argp);
1812         case SNDRV_TIMER_IOCTL_INFO:
1813                 return snd_timer_user_info(file, argp);
1814         case SNDRV_TIMER_IOCTL_PARAMS:
1815                 return snd_timer_user_params(file, argp);
1816         case SNDRV_TIMER_IOCTL_STATUS:
1817                 return snd_timer_user_status(file, argp);
1818         case SNDRV_TIMER_IOCTL_START:
1819         case SNDRV_TIMER_IOCTL_START_OLD:
1820                 return snd_timer_user_start(file);
1821         case SNDRV_TIMER_IOCTL_STOP:
1822         case SNDRV_TIMER_IOCTL_STOP_OLD:
1823                 return snd_timer_user_stop(file);
1824         case SNDRV_TIMER_IOCTL_CONTINUE:
1825         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
1826                 return snd_timer_user_continue(file);
1827         case SNDRV_TIMER_IOCTL_PAUSE:
1828         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
1829                 return snd_timer_user_pause(file);
1830         }
1831         return -ENOTTY;
1832 }
1833
1834 static int snd_timer_user_fasync(int fd, struct file * file, int on)
1835 {
1836         struct snd_timer_user *tu;
1837
1838         tu = file->private_data;
1839         return fasync_helper(fd, file, on, &tu->fasync);
1840 }
1841
1842 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
1843                                    size_t count, loff_t *offset)
1844 {
1845         struct snd_timer_user *tu;
1846         long result = 0, unit;
1847         int err = 0;
1848
1849         tu = file->private_data;
1850         unit = tu->tread ? sizeof(struct snd_timer_tread) : sizeof(struct snd_timer_read);
1851         spin_lock_irq(&tu->qlock);
1852         while ((long)count - result >= unit) {
1853                 while (!tu->qused) {
1854                         wait_queue_t wait;
1855
1856                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1857                                 err = -EAGAIN;
1858                                 break;
1859                         }
1860
1861                         set_current_state(TASK_INTERRUPTIBLE);
1862                         init_waitqueue_entry(&wait, current);
1863                         add_wait_queue(&tu->qchange_sleep, &wait);
1864
1865                         spin_unlock_irq(&tu->qlock);
1866                         schedule();
1867                         spin_lock_irq(&tu->qlock);
1868
1869                         remove_wait_queue(&tu->qchange_sleep, &wait);
1870
1871                         if (signal_pending(current)) {
1872                                 err = -ERESTARTSYS;
1873                                 break;
1874                         }
1875                 }
1876
1877                 spin_unlock_irq(&tu->qlock);
1878                 if (err < 0)
1879                         goto _error;
1880
1881                 if (tu->tread) {
1882                         if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
1883                                          sizeof(struct snd_timer_tread))) {
1884                                 err = -EFAULT;
1885                                 goto _error;
1886                         }
1887                 } else {
1888                         if (copy_to_user(buffer, &tu->queue[tu->qhead++],
1889                                          sizeof(struct snd_timer_read))) {
1890                                 err = -EFAULT;
1891                                 goto _error;
1892                         }
1893                 }
1894
1895                 tu->qhead %= tu->queue_size;
1896
1897                 result += unit;
1898                 buffer += unit;
1899
1900                 spin_lock_irq(&tu->qlock);
1901                 tu->qused--;
1902         }
1903         spin_unlock_irq(&tu->qlock);
1904  _error:
1905         return result > 0 ? result : err;
1906 }
1907
1908 static unsigned int snd_timer_user_poll(struct file *file, poll_table * wait)
1909 {
1910         unsigned int mask;
1911         struct snd_timer_user *tu;
1912
1913         tu = file->private_data;
1914
1915         poll_wait(file, &tu->qchange_sleep, wait);
1916
1917         mask = 0;
1918         if (tu->qused)
1919                 mask |= POLLIN | POLLRDNORM;
1920
1921         return mask;
1922 }
1923
1924 #ifdef CONFIG_COMPAT
1925 #include "timer_compat.c"
1926 #else
1927 #define snd_timer_user_ioctl_compat     NULL
1928 #endif
1929
1930 static const struct file_operations snd_timer_f_ops =
1931 {
1932         .owner =        THIS_MODULE,
1933         .read =         snd_timer_user_read,
1934         .open =         snd_timer_user_open,
1935         .release =      snd_timer_user_release,
1936         .llseek =       no_llseek,
1937         .poll =         snd_timer_user_poll,
1938         .unlocked_ioctl =       snd_timer_user_ioctl,
1939         .compat_ioctl = snd_timer_user_ioctl_compat,
1940         .fasync =       snd_timer_user_fasync,
1941 };
1942
1943 /*
1944  *  ENTRY functions
1945  */
1946
1947 static int __init alsa_timer_init(void)
1948 {
1949         int err;
1950
1951 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1952         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
1953                               "system timer");
1954 #endif
1955
1956         if ((err = snd_timer_register_system()) < 0)
1957                 snd_printk(KERN_ERR "unable to register system timer (%i)\n",
1958                            err);
1959         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
1960                                        &snd_timer_f_ops, NULL, "timer")) < 0)
1961                 snd_printk(KERN_ERR "unable to register timer device (%i)\n",
1962                            err);
1963         snd_timer_proc_init();
1964         return 0;
1965 }
1966
1967 static void __exit alsa_timer_exit(void)
1968 {
1969         struct list_head *p, *n;
1970
1971         snd_unregister_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0);
1972         /* unregister the system timer */
1973         list_for_each_safe(p, n, &snd_timer_list) {
1974                 struct snd_timer *timer = list_entry(p, struct snd_timer, device_list);
1975                 snd_timer_free(timer);
1976         }
1977         snd_timer_proc_done();
1978 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
1979         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
1980 #endif
1981 }
1982
1983 module_init(alsa_timer_init)
1984 module_exit(alsa_timer_exit)
1985
1986 EXPORT_SYMBOL(snd_timer_open);
1987 EXPORT_SYMBOL(snd_timer_close);
1988 EXPORT_SYMBOL(snd_timer_resolution);
1989 EXPORT_SYMBOL(snd_timer_start);
1990 EXPORT_SYMBOL(snd_timer_stop);
1991 EXPORT_SYMBOL(snd_timer_continue);
1992 EXPORT_SYMBOL(snd_timer_pause);
1993 EXPORT_SYMBOL(snd_timer_new);
1994 EXPORT_SYMBOL(snd_timer_notify);
1995 EXPORT_SYMBOL(snd_timer_global_new);
1996 EXPORT_SYMBOL(snd_timer_global_free);
1997 EXPORT_SYMBOL(snd_timer_global_register);
1998 EXPORT_SYMBOL(snd_timer_interrupt);