sound/core/timer.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Timers abstract layer
   4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5  */
   6
   7 #include <linux/delay.h>
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/time.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/module.h>
  14 #include <linux/string.h>
  15 #include <linux/sched/signal.h>
  16 #include <sound/core.h>
  17 #include <sound/timer.h>
  18 #include <sound/control.h>
  19 #include <sound/info.h>
  20 #include <sound/minors.h>
  21 #include <sound/initval.h>
  22 #include <linux/kmod.h>
  23
  24 /* internal flags */
  25 #define SNDRV_TIMER_IFLG_PAUSED         0x00010000
  26 #define SNDRV_TIMER_IFLG_DEAD           0x00020000
  27
  28 #if IS_ENABLED(CONFIG_SND_HRTIMER)
  29 #define DEFAULT_TIMER_LIMIT 4
  30 #else
  31 #define DEFAULT_TIMER_LIMIT 1
  32 #endif
  33
  34 static int timer_limit = DEFAULT_TIMER_LIMIT;
  35 static int timer_tstamp_monotonic = 1;
  36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
  37 MODULE_DESCRIPTION("ALSA timer interface");
  38 MODULE_LICENSE("GPL");
  39 module_param(timer_limit, int, 0444);
  40 MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  41 module_param(timer_tstamp_monotonic, int, 0444);
  42 MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  43
  44 MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
  45 MODULE_ALIAS("devname:snd/timer");
  46
  47 enum timer_tread_format {
  48         TREAD_FORMAT_NONE = 0,
  49         TREAD_FORMAT_TIME64,
  50         TREAD_FORMAT_TIME32,
  51 };
  52
  53 struct snd_timer_tread32 {
  54         int event;
  55         s32 tstamp_sec;
  56         s32 tstamp_nsec;
  57         unsigned int val;
  58 };
  59
  60 struct snd_timer_tread64 {
  61         int event;
  62         u8 pad1[4];
  63         s64 tstamp_sec;
  64         s64 tstamp_nsec;
  65         unsigned int val;
  66         u8 pad2[4];
  67 };
  68
  69 struct snd_timer_user {
  70         struct snd_timer_instance *timeri;
  71         int tread;              /* enhanced read with timestamps and events */
  72         unsigned long ticks;
  73         unsigned long overrun;
  74         int qhead;
  75         int qtail;
  76         int qused;
  77         int queue_size;
  78         bool disconnected;
  79         struct snd_timer_read *queue;
  80         struct snd_timer_tread64 *tqueue;
  81         spinlock_t qlock;
  82         unsigned long last_resolution;
  83         unsigned int filter;
  84         struct timespec64 tstamp;               /* trigger tstamp */
  85         wait_queue_head_t qchange_sleep;
  86         struct fasync_struct *fasync;
  87         struct mutex ioctl_lock;
  88 };
  89
  90 struct snd_timer_status32 {
  91         s32 tstamp_sec;                 /* Timestamp - last update */
  92         s32 tstamp_nsec;
  93         unsigned int resolution;        /* current period resolution in ns */
  94         unsigned int lost;              /* counter of master tick lost */
  95         unsigned int overrun;           /* count of read queue overruns */
  96         unsigned int queue;             /* used queue size */
  97         unsigned char reserved[64];     /* reserved */
  98 };
  99
 100 #define SNDRV_TIMER_IOCTL_STATUS32      _IOR('T', 0x14, struct snd_timer_status32)
 101
 102 struct snd_timer_status64 {
 103         s64 tstamp_sec;                 /* Timestamp - last update */
 104         s64 tstamp_nsec;
 105         unsigned int resolution;        /* current period resolution in ns */
 106         unsigned int lost;              /* counter of master tick lost */
 107         unsigned int overrun;           /* count of read queue overruns */
 108         unsigned int queue;             /* used queue size */
 109         unsigned char reserved[64];     /* reserved */
 110 };
 111
 112 #define SNDRV_TIMER_IOCTL_STATUS64      _IOR('T', 0x14, struct snd_timer_status64)
 113
 114 /* list of timers */
 115 static LIST_HEAD(snd_timer_list);
 116
 117 /* list of slave instances */
 118 static LIST_HEAD(snd_timer_slave_list);
 119
 120 /* lock for slave active lists */
 121 static DEFINE_SPINLOCK(slave_active_lock);
 122
 123 #define MAX_SLAVE_INSTANCES     1000
 124 static int num_slaves;
 125
 126 static DEFINE_MUTEX(register_mutex);
 127
 128 static int snd_timer_free(struct snd_timer *timer);
 129 static int snd_timer_dev_free(struct snd_device *device);
 130 static int snd_timer_dev_register(struct snd_device *device);
 131 static int snd_timer_dev_disconnect(struct snd_device *device);
 132
 133 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left);
 134
 135 /*
 136  * create a timer instance with the given owner string.
 137  */
 138 struct snd_timer_instance *snd_timer_instance_new(const char *owner)
 139 {
 140         struct snd_timer_instance *timeri;
 141
 142         timeri = kzalloc(sizeof(*timeri), GFP_KERNEL);
 143         if (timeri == NULL)
 144                 return NULL;
 145         timeri->owner = kstrdup(owner, GFP_KERNEL);
 146         if (! timeri->owner) {
 147                 kfree(timeri);
 148                 return NULL;
 149         }
 150         INIT_LIST_HEAD(&timeri->open_list);
 151         INIT_LIST_HEAD(&timeri->active_list);
 152         INIT_LIST_HEAD(&timeri->ack_list);
 153         INIT_LIST_HEAD(&timeri->slave_list_head);
 154         INIT_LIST_HEAD(&timeri->slave_active_head);
 155
 156         return timeri;
 157 }
 158 EXPORT_SYMBOL(snd_timer_instance_new);
 159
 160 void snd_timer_instance_free(struct snd_timer_instance *timeri)
 161 {
 162         if (timeri) {
 163                 if (timeri->private_free)
 164                         timeri->private_free(timeri);
 165                 kfree(timeri->owner);
 166                 kfree(timeri);
 167         }
 168 }
 169 EXPORT_SYMBOL(snd_timer_instance_free);
 170
 171 /*
 172  * find a timer instance from the given timer id
 173  */
 174 static struct snd_timer *snd_timer_find(struct snd_timer_id *tid)
 175 {
 176         struct snd_timer *timer;
 177
 178         list_for_each_entry(timer, &snd_timer_list, device_list) {
 179                 if (timer->tmr_class != tid->dev_class)
 180                         continue;
 181                 if ((timer->tmr_class == SNDRV_TIMER_CLASS_CARD ||
 182                      timer->tmr_class == SNDRV_TIMER_CLASS_PCM) &&
 183                     (timer->card == NULL ||
 184                      timer->card->number != tid->card))
 185                         continue;
 186                 if (timer->tmr_device != tid->device)
 187                         continue;
 188                 if (timer->tmr_subdevice != tid->subdevice)
 189                         continue;
 190                 return timer;
 191         }
 192         return NULL;
 193 }
 194
 195 #ifdef CONFIG_MODULES
 196
 197 static void snd_timer_request(struct snd_timer_id *tid)
 198 {
 199         switch (tid->dev_class) {
 200         case SNDRV_TIMER_CLASS_GLOBAL:
 201                 if (tid->device < timer_limit)
 202                         request_module("snd-timer-%i", tid->device);
 203                 break;
 204         case SNDRV_TIMER_CLASS_CARD:
 205         case SNDRV_TIMER_CLASS_PCM:
 206                 if (tid->card < snd_ecards_limit)
 207                         request_module("snd-card-%i", tid->card);
 208                 break;
 209         default:
 210                 break;
 211         }
 212 }
 213
 214 #endif
 215
 216 /* move the slave if it belongs to the master; return 1 if match */
 217 static int check_matching_master_slave(struct snd_timer_instance *master,
 218                                        struct snd_timer_instance *slave)
 219 {
 220         if (slave->slave_class != master->slave_class ||
 221             slave->slave_id != master->slave_id)
 222                 return 0;
 223         if (master->timer->num_instances >= master->timer->max_instances)
 224                 return -EBUSY;
 225         list_move_tail(&slave->open_list, &master->slave_list_head);
 226         master->timer->num_instances++;
 227         spin_lock_irq(&slave_active_lock);
 228         spin_lock(&master->timer->lock);
 229         slave->master = master;
 230         slave->timer = master->timer;
 231         if (slave->flags & SNDRV_TIMER_IFLG_RUNNING)
 232                 list_add_tail(&slave->active_list, &master->slave_active_head);
 233         spin_unlock(&master->timer->lock);
 234         spin_unlock_irq(&slave_active_lock);
 235         return 1;
 236 }
 237
 238 /*
 239  * look for a master instance matching with the slave id of the given slave.
 240  * when found, relink the open_link of the slave.
 241  *
 242  * call this with register_mutex down.
 243  */
 244 static int snd_timer_check_slave(struct snd_timer_instance *slave)
 245 {
 246         struct snd_timer *timer;
 247         struct snd_timer_instance *master;
 248         int err = 0;
 249
 250         /* FIXME: it's really dumb to look up all entries.. */
 251         list_for_each_entry(timer, &snd_timer_list, device_list) {
 252                 list_for_each_entry(master, &timer->open_list_head, open_list) {
 253                         err = check_matching_master_slave(master, slave);
 254                         if (err != 0) /* match found or error */
 255                                 goto out;
 256                 }
 257         }
 258  out:
 259         return err < 0 ? err : 0;
 260 }
 261
 262 /*
 263  * look for slave instances matching with the slave id of the given master.
 264  * when found, relink the open_link of slaves.
 265  *
 266  * call this with register_mutex down.
 267  */
 268 static int snd_timer_check_master(struct snd_timer_instance *master)
 269 {
 270         struct snd_timer_instance *slave, *tmp;
 271         int err = 0;
 272
 273         /* check all pending slaves */
 274         list_for_each_entry_safe(slave, tmp, &snd_timer_slave_list, open_list) {
 275                 err = check_matching_master_slave(master, slave);
 276                 if (err < 0)
 277                         break;
 278         }
 279         return err < 0 ? err : 0;
 280 }
 281
 282 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 283                                    struct device **card_devp_to_put);
 284
 285 /*
 286  * open a timer instance
 287  * when opening a master, the slave id must be here given.
 288  */
 289 int snd_timer_open(struct snd_timer_instance *timeri,
 290                    struct snd_timer_id *tid,
 291                    unsigned int slave_id)
 292 {
 293         struct snd_timer *timer;
 294         struct device *card_dev_to_put = NULL;
 295         int err;
 296
 297         mutex_lock(&register_mutex);
 298         if (tid->dev_class == SNDRV_TIMER_CLASS_SLAVE) {
 299                 /* open a slave instance */
 300                 if (tid->dev_sclass <= SNDRV_TIMER_SCLASS_NONE ||
 301                     tid->dev_sclass > SNDRV_TIMER_SCLASS_OSS_SEQUENCER) {
 302                         pr_debug("ALSA: timer: invalid slave class %i\n",
 303                                  tid->dev_sclass);
 304                         err = -EINVAL;
 305                         goto unlock;
 306                 }
 307                 if (num_slaves >= MAX_SLAVE_INSTANCES) {
 308                         err = -EBUSY;
 309                         goto unlock;
 310                 }
 311                 timeri->slave_class = tid->dev_sclass;
 312                 timeri->slave_id = tid->device;
 313                 timeri->flags |= SNDRV_TIMER_IFLG_SLAVE;
 314                 list_add_tail(&timeri->open_list, &snd_timer_slave_list);
 315                 num_slaves++;
 316                 err = snd_timer_check_slave(timeri);
 317                 goto list_added;
 318         }
 319
 320         /* open a master instance */
 321         timer = snd_timer_find(tid);
 322 #ifdef CONFIG_MODULES
 323         if (!timer) {
 324                 mutex_unlock(&register_mutex);
 325                 snd_timer_request(tid);
 326                 mutex_lock(&register_mutex);
 327                 timer = snd_timer_find(tid);
 328         }
 329 #endif
 330         if (!timer) {
 331                 err = -ENODEV;
 332                 goto unlock;
 333         }
 334         if (!list_empty(&timer->open_list_head)) {
 335                 struct snd_timer_instance *t =
 336                         list_entry(timer->open_list_head.next,
 337                                     struct snd_timer_instance, open_list);
 338                 if (t->flags & SNDRV_TIMER_IFLG_EXCLUSIVE) {
 339                         err = -EBUSY;
 340                         goto unlock;
 341                 }
 342         }
 343         if (timer->num_instances >= timer->max_instances) {
 344                 err = -EBUSY;
 345                 goto unlock;
 346         }
 347         if (!try_module_get(timer->module)) {
 348                 err = -EBUSY;
 349                 goto unlock;
 350         }
 351         /* take a card refcount for safe disconnection */
 352         if (timer->card) {
 353                 get_device(&timer->card->card_dev);
 354                 card_dev_to_put = &timer->card->card_dev;
 355         }
 356
 357         if (list_empty(&timer->open_list_head) && timer->hw.open) {
 358                 err = timer->hw.open(timer);
 359                 if (err) {
 360                         module_put(timer->module);
 361                         goto unlock;
 362                 }
 363         }
 364
 365         timeri->timer = timer;
 366         timeri->slave_class = tid->dev_sclass;
 367         timeri->slave_id = slave_id;
 368
 369         list_add_tail(&timeri->open_list, &timer->open_list_head);
 370         timer->num_instances++;
 371         err = snd_timer_check_master(timeri);
 372 list_added:
 373         if (err < 0)
 374                 snd_timer_close_locked(timeri, &card_dev_to_put);
 375
 376  unlock:
 377         mutex_unlock(&register_mutex);
 378         /* put_device() is called after unlock for avoiding deadlock */
 379         if (err < 0 && card_dev_to_put)
 380                 put_device(card_dev_to_put);
 381         return err;
 382 }
 383 EXPORT_SYMBOL(snd_timer_open);
 384
 385 /*
 386  * close a timer instance
 387  * call this with register_mutex down.
 388  */
 389 static void snd_timer_close_locked(struct snd_timer_instance *timeri,
 390                                    struct device **card_devp_to_put)
 391 {
 392         struct snd_timer *timer = timeri->timer;
 393         struct snd_timer_instance *slave, *tmp;
 394
 395         if (timer) {
 396                 spin_lock_irq(&timer->lock);
 397                 timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
 398                 spin_unlock_irq(&timer->lock);
 399         }
 400
 401         if (!list_empty(&timeri->open_list)) {
 402                 list_del_init(&timeri->open_list);
 403                 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 404                         num_slaves--;
 405         }
 406
 407         /* force to stop the timer */
 408         snd_timer_stop(timeri);
 409
 410         if (timer) {
 411                 timer->num_instances--;
 412                 /* wait, until the active callback is finished */
 413                 spin_lock_irq(&timer->lock);
 414                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
 415                         spin_unlock_irq(&timer->lock);
 416                         udelay(10);
 417                         spin_lock_irq(&timer->lock);
 418                 }
 419                 spin_unlock_irq(&timer->lock);
 420
 421                 /* remove slave links */
 422                 spin_lock_irq(&slave_active_lock);
 423                 spin_lock(&timer->lock);
 424                 timeri->timer = NULL;
 425                 list_for_each_entry_safe(slave, tmp, &timeri->slave_list_head,
 426                                          open_list) {
 427                         list_move_tail(&slave->open_list, &snd_timer_slave_list);
 428                         timer->num_instances--;
 429                         slave->master = NULL;
 430                         slave->timer = NULL;
 431                         list_del_init(&slave->ack_list);
 432                         list_del_init(&slave->active_list);
 433                 }
 434                 spin_unlock(&timer->lock);
 435                 spin_unlock_irq(&slave_active_lock);
 436
 437                 /* slave doesn't need to release timer resources below */
 438                 if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 439                         timer = NULL;
 440         }
 441
 442         if (timer) {
 443                 if (list_empty(&timer->open_list_head) && timer->hw.close)
 444                         timer->hw.close(timer);
 445                 /* release a card refcount for safe disconnection */
 446                 if (timer->card)
 447                         *card_devp_to_put = &timer->card->card_dev;
 448                 module_put(timer->module);
 449         }
 450 }
 451
 452 /*
 453  * close a timer instance
 454  */
 455 void snd_timer_close(struct snd_timer_instance *timeri)
 456 {
 457         struct device *card_dev_to_put = NULL;
 458
 459         if (snd_BUG_ON(!timeri))
 460                 return;
 461
 462         mutex_lock(&register_mutex);
 463         snd_timer_close_locked(timeri, &card_dev_to_put);
 464         mutex_unlock(&register_mutex);
 465         /* put_device() is called after unlock for avoiding deadlock */
 466         if (card_dev_to_put)
 467                 put_device(card_dev_to_put);
 468 }
 469 EXPORT_SYMBOL(snd_timer_close);
 470
 471 static unsigned long snd_timer_hw_resolution(struct snd_timer *timer)
 472 {
 473         if (timer->hw.c_resolution)
 474                 return timer->hw.c_resolution(timer);
 475         else
 476                 return timer->hw.resolution;
 477 }
 478
 479 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri)
 480 {
 481         struct snd_timer * timer;
 482         unsigned long ret = 0;
 483         unsigned long flags;
 484
 485         if (timeri == NULL)
 486                 return 0;
 487         timer = timeri->timer;
 488         if (timer) {
 489                 spin_lock_irqsave(&timer->lock, flags);
 490                 ret = snd_timer_hw_resolution(timer);
 491                 spin_unlock_irqrestore(&timer->lock, flags);
 492         }
 493         return ret;
 494 }
 495 EXPORT_SYMBOL(snd_timer_resolution);
 496
 497 static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 498 {
 499         struct snd_timer *timer = ti->timer;
 500         unsigned long resolution = 0;
 501         struct snd_timer_instance *ts;
 502         struct timespec64 tstamp;
 503
 504         if (timer_tstamp_monotonic)
 505                 ktime_get_ts64(&tstamp);
 506         else
 507                 ktime_get_real_ts64(&tstamp);
 508         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_START ||
 509                        event > SNDRV_TIMER_EVENT_PAUSE))
 510                 return;
 511         if (timer &&
 512             (event == SNDRV_TIMER_EVENT_START ||
 513              event == SNDRV_TIMER_EVENT_CONTINUE))
 514                 resolution = snd_timer_hw_resolution(timer);
 515         if (ti->ccallback)
 516                 ti->ccallback(ti, event, &tstamp, resolution);
 517         if (ti->flags & SNDRV_TIMER_IFLG_SLAVE)
 518                 return;
 519         if (timer == NULL)
 520                 return;
 521         if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 522                 return;
 523         event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
 524         list_for_each_entry(ts, &ti->slave_active_head, active_list)
 525                 if (ts->ccallback)
 526                         ts->ccallback(ts, event, &tstamp, resolution);
 527 }
 528
 529 /* start/continue a master timer */
 530 static int snd_timer_start1(struct snd_timer_instance *timeri,
 531                             bool start, unsigned long ticks)
 532 {
 533         struct snd_timer *timer;
 534         int result;
 535         unsigned long flags;
 536
 537         timer = timeri->timer;
 538         if (!timer)
 539                 return -EINVAL;
 540
 541         spin_lock_irqsave(&timer->lock, flags);
 542         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
 543                 result = -EINVAL;
 544                 goto unlock;
 545         }
 546         if (timer->card && timer->card->shutdown) {
 547                 result = -ENODEV;
 548                 goto unlock;
 549         }
 550         if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 551                              SNDRV_TIMER_IFLG_START)) {
 552                 result = -EBUSY;
 553                 goto unlock;
 554         }
 555
 556         if (start)
 557                 timeri->ticks = timeri->cticks = ticks;
 558         else if (!timeri->cticks)
 559                 timeri->cticks = 1;
 560         timeri->pticks = 0;
 561
 562         list_move_tail(&timeri->active_list, &timer->active_list_head);
 563         if (timer->running) {
 564                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 565                         goto __start_now;
 566                 timer->flags |= SNDRV_TIMER_FLG_RESCHED;
 567                 timeri->flags |= SNDRV_TIMER_IFLG_START;
 568                 result = 1; /* delayed start */
 569         } else {
 570                 if (start)
 571                         timer->sticks = ticks;
 572                 timer->hw.start(timer);
 573               __start_now:
 574                 timer->running++;
 575                 timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 576                 result = 0;
 577         }
 578         snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 579                           SNDRV_TIMER_EVENT_CONTINUE);
 580  unlock:
 581         spin_unlock_irqrestore(&timer->lock, flags);
 582         return result;
 583 }
 584
 585 /* start/continue a slave timer */
 586 static int snd_timer_start_slave(struct snd_timer_instance *timeri,
 587                                  bool start)
 588 {
 589         unsigned long flags;
 590         int err;
 591
 592         spin_lock_irqsave(&slave_active_lock, flags);
 593         if (timeri->flags & SNDRV_TIMER_IFLG_DEAD) {
 594                 err = -EINVAL;
 595                 goto unlock;
 596         }
 597         if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
 598                 err = -EBUSY;
 599                 goto unlock;
 600         }
 601         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
 602         if (timeri->master && timeri->timer) {
 603                 spin_lock(&timeri->timer->lock);
 604                 list_add_tail(&timeri->active_list,
 605                               &timeri->master->slave_active_head);
 606                 snd_timer_notify1(timeri, start ? SNDRV_TIMER_EVENT_START :
 607                                   SNDRV_TIMER_EVENT_CONTINUE);
 608                 spin_unlock(&timeri->timer->lock);
 609         }
 610         err = 1; /* delayed start */
 611  unlock:
 612         spin_unlock_irqrestore(&slave_active_lock, flags);
 613         return err;
 614 }
 615
 616 /* stop/pause a master timer */
 617 static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop)
 618 {
 619         struct snd_timer *timer;
 620         int result = 0;
 621         unsigned long flags;
 622
 623         timer = timeri->timer;
 624         if (!timer)
 625                 return -EINVAL;
 626         spin_lock_irqsave(&timer->lock, flags);
 627         if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 628                                SNDRV_TIMER_IFLG_START))) {
 629                 result = -EBUSY;
 630                 goto unlock;
 631         }
 632         list_del_init(&timeri->ack_list);
 633         list_del_init(&timeri->active_list);
 634         if (timer->card && timer->card->shutdown)
 635                 goto unlock;
 636         if (stop) {
 637                 timeri->cticks = timeri->ticks;
 638                 timeri->pticks = 0;
 639         }
 640         if ((timeri->flags & SNDRV_TIMER_IFLG_RUNNING) &&
 641             !(--timer->running)) {
 642                 timer->hw.stop(timer);
 643                 if (timer->flags & SNDRV_TIMER_FLG_RESCHED) {
 644                         timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 645                         snd_timer_reschedule(timer, 0);
 646                         if (timer->flags & SNDRV_TIMER_FLG_CHANGE) {
 647                                 timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 648                                 timer->hw.start(timer);
 649                         }
 650                 }
 651         }
 652         timeri->flags &= ~(SNDRV_TIMER_IFLG_RUNNING | SNDRV_TIMER_IFLG_START);
 653         if (stop)
 654                 timeri->flags &= ~SNDRV_TIMER_IFLG_PAUSED;
 655         else
 656                 timeri->flags |= SNDRV_TIMER_IFLG_PAUSED;
 657         snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 658                           SNDRV_TIMER_EVENT_PAUSE);
 659  unlock:
 660         spin_unlock_irqrestore(&timer->lock, flags);
 661         return result;
 662 }
 663
 664 /* stop/pause a slave timer */
 665 static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop)
 666 {
 667         unsigned long flags;
 668
 669         spin_lock_irqsave(&slave_active_lock, flags);
 670         if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
 671                 spin_unlock_irqrestore(&slave_active_lock, flags);
 672                 return -EBUSY;
 673         }
 674         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 675         if (timeri->timer) {
 676                 spin_lock(&timeri->timer->lock);
 677                 list_del_init(&timeri->ack_list);
 678                 list_del_init(&timeri->active_list);
 679                 snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 680                                   SNDRV_TIMER_EVENT_PAUSE);
 681                 spin_unlock(&timeri->timer->lock);
 682         }
 683         spin_unlock_irqrestore(&slave_active_lock, flags);
 684         return 0;
 685 }
 686
 687 /*
 688  *  start the timer instance
 689  */
 690 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 691 {
 692         if (timeri == NULL || ticks < 1)
 693                 return -EINVAL;
 694         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 695                 return snd_timer_start_slave(timeri, true);
 696         else
 697                 return snd_timer_start1(timeri, true, ticks);
 698 }
 699 EXPORT_SYMBOL(snd_timer_start);
 700
 701 /*
 702  * stop the timer instance.
 703  *
 704  * do not call this from the timer callback!
 705  */
 706 int snd_timer_stop(struct snd_timer_instance *timeri)
 707 {
 708         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 709                 return snd_timer_stop_slave(timeri, true);
 710         else
 711                 return snd_timer_stop1(timeri, true);
 712 }
 713 EXPORT_SYMBOL(snd_timer_stop);
 714
 715 /*
 716  * start again..  the tick is kept.
 717  */
 718 int snd_timer_continue(struct snd_timer_instance *timeri)
 719 {
 720         /* timer can continue only after pause */
 721         if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
 722                 return -EINVAL;
 723
 724         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 725                 return snd_timer_start_slave(timeri, false);
 726         else
 727                 return snd_timer_start1(timeri, false, 0);
 728 }
 729 EXPORT_SYMBOL(snd_timer_continue);
 730
 731 /*
 732  * pause.. remember the ticks left
 733  */
 734 int snd_timer_pause(struct snd_timer_instance * timeri)
 735 {
 736         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 737                 return snd_timer_stop_slave(timeri, false);
 738         else
 739                 return snd_timer_stop1(timeri, false);
 740 }
 741 EXPORT_SYMBOL(snd_timer_pause);
 742
 743 /*
 744  * reschedule the timer
 745  *
 746  * start pending instances and check the scheduling ticks.
 747  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 748  */
 749 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 750 {
 751         struct snd_timer_instance *ti;
 752         unsigned long ticks = ~0UL;
 753
 754         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 755                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 756                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 757                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 758                         timer->running++;
 759                 }
 760                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 761                         if (ticks > ti->cticks)
 762                                 ticks = ti->cticks;
 763                 }
 764         }
 765         if (ticks == ~0UL) {
 766                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 767                 return;
 768         }
 769         if (ticks > timer->hw.ticks)
 770                 ticks = timer->hw.ticks;
 771         if (ticks_left != ticks)
 772                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 773         timer->sticks = ticks;
 774 }
 775
 776 /* call callbacks in timer ack list */
 777 static void snd_timer_process_callbacks(struct snd_timer *timer,
 778                                         struct list_head *head)
 779 {
 780         struct snd_timer_instance *ti;
 781         unsigned long resolution, ticks;
 782
 783         while (!list_empty(head)) {
 784                 ti = list_first_entry(head, struct snd_timer_instance,
 785                                       ack_list);
 786
 787                 /* remove from ack_list and make empty */
 788                 list_del_init(&ti->ack_list);
 789
 790                 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
 791                         ticks = ti->pticks;
 792                         ti->pticks = 0;
 793                         resolution = ti->resolution;
 794                         ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 795                         spin_unlock(&timer->lock);
 796                         if (ti->callback)
 797                                 ti->callback(ti, resolution, ticks);
 798                         spin_lock(&timer->lock);
 799                         ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 800                 }
 801         }
 802 }
 803
 804 /* clear pending instances from ack list */
 805 static void snd_timer_clear_callbacks(struct snd_timer *timer,
 806                                       struct list_head *head)
 807 {
 808         unsigned long flags;
 809
 810         spin_lock_irqsave(&timer->lock, flags);
 811         while (!list_empty(head))
 812                 list_del_init(head->next);
 813         spin_unlock_irqrestore(&timer->lock, flags);
 814 }
 815
 816 /*
 817  * timer work
 818  *
 819  */
 820 static void snd_timer_work(struct work_struct *work)
 821 {
 822         struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
 823         unsigned long flags;
 824
 825         if (timer->card && timer->card->shutdown) {
 826                 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
 827                 return;
 828         }
 829
 830         spin_lock_irqsave(&timer->lock, flags);
 831         snd_timer_process_callbacks(timer, &timer->sack_list_head);
 832         spin_unlock_irqrestore(&timer->lock, flags);
 833 }
 834
 835 /*
 836  * timer interrupt
 837  *
 838  * ticks_left is usually equal to timer->sticks.
 839  *
 840  */
 841 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 842 {
 843         struct snd_timer_instance *ti, *ts, *tmp;
 844         unsigned long resolution;
 845         struct list_head *ack_list_head;
 846         unsigned long flags;
 847         bool use_work = false;
 848
 849         if (timer == NULL)
 850                 return;
 851
 852         if (timer->card && timer->card->shutdown) {
 853                 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
 854                 return;
 855         }
 856
 857         spin_lock_irqsave(&timer->lock, flags);
 858
 859         /* remember the current resolution */
 860         resolution = snd_timer_hw_resolution(timer);
 861
 862         /* loop for all active instances
 863          * Here we cannot use list_for_each_entry because the active_list of a
 864          * processed instance is relinked to done_list_head before the callback
 865          * is called.
 866          */
 867         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 868                                  active_list) {
 869                 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
 870                         continue;
 871                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 872                         continue;
 873                 ti->pticks += ticks_left;
 874                 ti->resolution = resolution;
 875                 if (ti->cticks < ticks_left)
 876                         ti->cticks = 0;
 877                 else
 878                         ti->cticks -= ticks_left;
 879                 if (ti->cticks) /* not expired */
 880                         continue;
 881                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 882                         ti->cticks = ti->ticks;
 883                 } else {
 884                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 885                         --timer->running;
 886                         list_del_init(&ti->active_list);
 887                 }
 888                 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
 889                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 890                         ack_list_head = &timer->ack_list_head;
 891                 else
 892                         ack_list_head = &timer->sack_list_head;
 893                 if (list_empty(&ti->ack_list))
 894                         list_add_tail(&ti->ack_list, ack_list_head);
 895                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 896                         ts->pticks = ti->pticks;
 897                         ts->resolution = resolution;
 898                         if (list_empty(&ts->ack_list))
 899                                 list_add_tail(&ts->ack_list, ack_list_head);
 900                 }
 901         }
 902         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 903                 snd_timer_reschedule(timer, timer->sticks);
 904         if (timer->running) {
 905                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 906                         timer->hw.stop(timer);
 907                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 908                 }
 909                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 910                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 911                         /* restart timer */
 912                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 913                         timer->hw.start(timer);
 914                 }
 915         } else {
 916                 timer->hw.stop(timer);
 917         }
 918
 919         /* now process all fast callbacks */
 920         snd_timer_process_callbacks(timer, &timer->ack_list_head);
 921
 922         /* do we have any slow callbacks? */
 923         use_work = !list_empty(&timer->sack_list_head);
 924         spin_unlock_irqrestore(&timer->lock, flags);
 925
 926         if (use_work)
 927                 queue_work(system_highpri_wq, &timer->task_work);
 928 }
 929 EXPORT_SYMBOL(snd_timer_interrupt);
 930
 931 /*
 932
 933  */
 934
 935 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 936                   struct snd_timer **rtimer)
 937 {
 938         struct snd_timer *timer;
 939         int err;
 940         static const struct snd_device_ops ops = {
 941                 .dev_free = snd_timer_dev_free,
 942                 .dev_register = snd_timer_dev_register,
 943                 .dev_disconnect = snd_timer_dev_disconnect,
 944         };
 945
 946         if (snd_BUG_ON(!tid))
 947                 return -EINVAL;
 948         if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
 949             tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
 950                 if (WARN_ON(!card))
 951                         return -EINVAL;
 952         }
 953         if (rtimer)
 954                 *rtimer = NULL;
 955         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 956         if (!timer)
 957                 return -ENOMEM;
 958         timer->tmr_class = tid->dev_class;
 959         timer->card = card;
 960         timer->tmr_device = tid->device;
 961         timer->tmr_subdevice = tid->subdevice;
 962         if (id)
 963                 strscpy(timer->id, id, sizeof(timer->id));
 964         timer->sticks = 1;
 965         INIT_LIST_HEAD(&timer->device_list);
 966         INIT_LIST_HEAD(&timer->open_list_head);
 967         INIT_LIST_HEAD(&timer->active_list_head);
 968         INIT_LIST_HEAD(&timer->ack_list_head);
 969         INIT_LIST_HEAD(&timer->sack_list_head);
 970         spin_lock_init(&timer->lock);
 971         INIT_WORK(&timer->task_work, snd_timer_work);
 972         timer->max_instances = 1000; /* default limit per timer */
 973         if (card != NULL) {
 974                 timer->module = card->module;
 975                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 976                 if (err < 0) {
 977                         snd_timer_free(timer);
 978                         return err;
 979                 }
 980         }
 981         if (rtimer)
 982                 *rtimer = timer;
 983         return 0;
 984 }
 985 EXPORT_SYMBOL(snd_timer_new);
 986
 987 static int snd_timer_free(struct snd_timer *timer)
 988 {
 989         if (!timer)
 990                 return 0;
 991
 992         mutex_lock(&register_mutex);
 993         if (! list_empty(&timer->open_list_head)) {
 994                 struct list_head *p, *n;
 995                 struct snd_timer_instance *ti;
 996                 pr_warn("ALSA: timer %p is busy?\n", timer);
 997                 list_for_each_safe(p, n, &timer->open_list_head) {
 998                         list_del_init(p);
 999                         ti = list_entry(p, struct snd_timer_instance, open_list);
1000                         ti->timer = NULL;
1001                 }
1002         }
1003         list_del(&timer->device_list);
1004         mutex_unlock(&register_mutex);
1005
1006         if (timer->private_free)
1007                 timer->private_free(timer);
1008         kfree(timer);
1009         return 0;
1010 }
1011
1012 static int snd_timer_dev_free(struct snd_device *device)
1013 {
1014         struct snd_timer *timer = device->device_data;
1015         return snd_timer_free(timer);
1016 }
1017
1018 static int snd_timer_dev_register(struct snd_device *dev)
1019 {
1020         struct snd_timer *timer = dev->device_data;
1021         struct snd_timer *timer1;
1022
1023         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1024                 return -ENXIO;
1025         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1026             !timer->hw.resolution && timer->hw.c_resolution == NULL)
1027                 return -EINVAL;
1028
1029         mutex_lock(&register_mutex);
1030         list_for_each_entry(timer1, &snd_timer_list, device_list) {
1031                 if (timer1->tmr_class > timer->tmr_class)
1032                         break;
1033                 if (timer1->tmr_class < timer->tmr_class)
1034                         continue;
1035                 if (timer1->card && timer->card) {
1036                         if (timer1->card->number > timer->card->number)
1037                                 break;
1038                         if (timer1->card->number < timer->card->number)
1039                                 continue;
1040                 }
1041                 if (timer1->tmr_device > timer->tmr_device)
1042                         break;
1043                 if (timer1->tmr_device < timer->tmr_device)
1044                         continue;
1045                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1046                         break;
1047                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1048                         continue;
1049                 /* conflicts.. */
1050                 mutex_unlock(&register_mutex);
1051                 return -EBUSY;
1052         }
1053         list_add_tail(&timer->device_list, &timer1->device_list);
1054         mutex_unlock(&register_mutex);
1055         return 0;
1056 }
1057
1058 static int snd_timer_dev_disconnect(struct snd_device *device)
1059 {
1060         struct snd_timer *timer = device->device_data;
1061         struct snd_timer_instance *ti;
1062
1063         mutex_lock(&register_mutex);
1064         list_del_init(&timer->device_list);
1065         /* wake up pending sleepers */
1066         list_for_each_entry(ti, &timer->open_list_head, open_list) {
1067                 if (ti->disconnect)
1068                         ti->disconnect(ti);
1069         }
1070         mutex_unlock(&register_mutex);
1071         return 0;
1072 }
1073
1074 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1075 {
1076         unsigned long flags;
1077         unsigned long resolution = 0;
1078         struct snd_timer_instance *ti, *ts;
1079
1080         if (timer->card && timer->card->shutdown)
1081                 return;
1082         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1083                 return;
1084         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1085                        event > SNDRV_TIMER_EVENT_MRESUME))
1086                 return;
1087         spin_lock_irqsave(&timer->lock, flags);
1088         if (event == SNDRV_TIMER_EVENT_MSTART ||
1089             event == SNDRV_TIMER_EVENT_MCONTINUE ||
1090             event == SNDRV_TIMER_EVENT_MRESUME)
1091                 resolution = snd_timer_hw_resolution(timer);
1092         list_for_each_entry(ti, &timer->active_list_head, active_list) {
1093                 if (ti->ccallback)
1094                         ti->ccallback(ti, event, tstamp, resolution);
1095                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1096                         if (ts->ccallback)
1097                                 ts->ccallback(ts, event, tstamp, resolution);
1098         }
1099         spin_unlock_irqrestore(&timer->lock, flags);
1100 }
1101 EXPORT_SYMBOL(snd_timer_notify);
1102
1103 /*
1104  * exported functions for global timers
1105  */
1106 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1107 {
1108         struct snd_timer_id tid;
1109
1110         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1111         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1112         tid.card = -1;
1113         tid.device = device;
1114         tid.subdevice = 0;
1115         return snd_timer_new(NULL, id, &tid, rtimer);
1116 }
1117 EXPORT_SYMBOL(snd_timer_global_new);
1118
1119 int snd_timer_global_free(struct snd_timer *timer)
1120 {
1121         return snd_timer_free(timer);
1122 }
1123 EXPORT_SYMBOL(snd_timer_global_free);
1124
1125 int snd_timer_global_register(struct snd_timer *timer)
1126 {
1127         struct snd_device dev;
1128
1129         memset(&dev, 0, sizeof(dev));
1130         dev.device_data = timer;
1131         return snd_timer_dev_register(&dev);
1132 }
1133 EXPORT_SYMBOL(snd_timer_global_register);
1134
1135 /*
1136  *  System timer
1137  */
1138
1139 struct snd_timer_system_private {
1140         struct timer_list tlist;
1141         struct snd_timer *snd_timer;
1142         unsigned long last_expires;
1143         unsigned long last_jiffies;
1144         unsigned long correction;
1145 };
1146
1147 static void snd_timer_s_function(struct timer_list *t)
1148 {
1149         struct snd_timer_system_private *priv = from_timer(priv, t,
1150                                                                 tlist);
1151         struct snd_timer *timer = priv->snd_timer;
1152         unsigned long jiff = jiffies;
1153         if (time_after(jiff, priv->last_expires))
1154                 priv->correction += (long)jiff - (long)priv->last_expires;
1155         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1156 }
1157
1158 static int snd_timer_s_start(struct snd_timer * timer)
1159 {
1160         struct snd_timer_system_private *priv;
1161         unsigned long njiff;
1162
1163         priv = (struct snd_timer_system_private *) timer->private_data;
1164         njiff = (priv->last_jiffies = jiffies);
1165         if (priv->correction > timer->sticks - 1) {
1166                 priv->correction -= timer->sticks - 1;
1167                 njiff++;
1168         } else {
1169                 njiff += timer->sticks - priv->correction;
1170                 priv->correction = 0;
1171         }
1172         priv->last_expires = njiff;
1173         mod_timer(&priv->tlist, njiff);
1174         return 0;
1175 }
1176
1177 static int snd_timer_s_stop(struct snd_timer * timer)
1178 {
1179         struct snd_timer_system_private *priv;
1180         unsigned long jiff;
1181
1182         priv = (struct snd_timer_system_private *) timer->private_data;
1183         del_timer(&priv->tlist);
1184         jiff = jiffies;
1185         if (time_before(jiff, priv->last_expires))
1186                 timer->sticks = priv->last_expires - jiff;
1187         else
1188                 timer->sticks = 1;
1189         priv->correction = 0;
1190         return 0;
1191 }
1192
1193 static int snd_timer_s_close(struct snd_timer *timer)
1194 {
1195         struct snd_timer_system_private *priv;
1196
1197         priv = (struct snd_timer_system_private *)timer->private_data;
1198         del_timer_sync(&priv->tlist);
1199         return 0;
1200 }
1201
1202 static const struct snd_timer_hardware snd_timer_system =
1203 {
1204         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1205         .resolution =   1000000000L / HZ,
1206         .ticks =        10000000L,
1207         .close =        snd_timer_s_close,
1208         .start =        snd_timer_s_start,
1209         .stop =         snd_timer_s_stop
1210 };
1211
1212 static void snd_timer_free_system(struct snd_timer *timer)
1213 {
1214         kfree(timer->private_data);
1215 }
1216
1217 static int snd_timer_register_system(void)
1218 {
1219         struct snd_timer *timer;
1220         struct snd_timer_system_private *priv;
1221         int err;
1222
1223         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1224         if (err < 0)
1225                 return err;
1226         strcpy(timer->name, "system timer");
1227         timer->hw = snd_timer_system;
1228         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1229         if (priv == NULL) {
1230                 snd_timer_free(timer);
1231                 return -ENOMEM;
1232         }
1233         priv->snd_timer = timer;
1234         timer_setup(&priv->tlist, snd_timer_s_function, 0);
1235         timer->private_data = priv;
1236         timer->private_free = snd_timer_free_system;
1237         return snd_timer_global_register(timer);
1238 }
1239
1240 #ifdef CONFIG_SND_PROC_FS
1241 /*
1242  *  Info interface
1243  */
1244
1245 static void snd_timer_proc_read(struct snd_info_entry *entry,
1246                                 struct snd_info_buffer *buffer)
1247 {
1248         struct snd_timer *timer;
1249         struct snd_timer_instance *ti;
1250
1251         mutex_lock(&register_mutex);
1252         list_for_each_entry(timer, &snd_timer_list, device_list) {
1253                 if (timer->card && timer->card->shutdown)
1254                         continue;
1255                 switch (timer->tmr_class) {
1256                 case SNDRV_TIMER_CLASS_GLOBAL:
1257                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1258                         break;
1259                 case SNDRV_TIMER_CLASS_CARD:
1260                         snd_iprintf(buffer, "C%i-%i: ",
1261                                     timer->card->number, timer->tmr_device);
1262                         break;
1263                 case SNDRV_TIMER_CLASS_PCM:
1264                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1265                                     timer->tmr_device, timer->tmr_subdevice);
1266                         break;
1267                 default:
1268                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1269                                     timer->card ? timer->card->number : -1,
1270                                     timer->tmr_device, timer->tmr_subdevice);
1271                 }
1272                 snd_iprintf(buffer, "%s :", timer->name);
1273                 if (timer->hw.resolution)
1274                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1275                                     timer->hw.resolution / 1000,
1276                                     timer->hw.resolution % 1000,
1277                                     timer->hw.ticks);
1278                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1279                         snd_iprintf(buffer, " SLAVE");
1280                 snd_iprintf(buffer, "\n");
1281                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1282                         snd_iprintf(buffer, "  Client %s : %s\n",
1283                                     ti->owner ? ti->owner : "unknown",
1284                                     (ti->flags & (SNDRV_TIMER_IFLG_START |
1285                                                   SNDRV_TIMER_IFLG_RUNNING))
1286                                     ? "running" : "stopped");
1287         }
1288         mutex_unlock(&register_mutex);
1289 }
1290
1291 static struct snd_info_entry *snd_timer_proc_entry;
1292
1293 static void __init snd_timer_proc_init(void)
1294 {
1295         struct snd_info_entry *entry;
1296
1297         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1298         if (entry != NULL) {
1299                 entry->c.text.read = snd_timer_proc_read;
1300                 if (snd_info_register(entry) < 0) {
1301                         snd_info_free_entry(entry);
1302                         entry = NULL;
1303                 }
1304         }
1305         snd_timer_proc_entry = entry;
1306 }
1307
1308 static void __exit snd_timer_proc_done(void)
1309 {
1310         snd_info_free_entry(snd_timer_proc_entry);
1311 }
1312 #else /* !CONFIG_SND_PROC_FS */
1313 #define snd_timer_proc_init()
1314 #define snd_timer_proc_done()
1315 #endif
1316
1317 /*
1318  *  USER SPACE interface
1319  */
1320
1321 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1322                                      unsigned long resolution,
1323                                      unsigned long ticks)
1324 {
1325         struct snd_timer_user *tu = timeri->callback_data;
1326         struct snd_timer_read *r;
1327         int prev;
1328
1329         spin_lock(&tu->qlock);
1330         if (tu->qused > 0) {
1331                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1332                 r = &tu->queue[prev];
1333                 if (r->resolution == resolution) {
1334                         r->ticks += ticks;
1335                         goto __wake;
1336                 }
1337         }
1338         if (tu->qused >= tu->queue_size) {
1339                 tu->overrun++;
1340         } else {
1341                 r = &tu->queue[tu->qtail++];
1342                 tu->qtail %= tu->queue_size;
1343                 r->resolution = resolution;
1344                 r->ticks = ticks;
1345                 tu->qused++;
1346         }
1347       __wake:
1348         spin_unlock(&tu->qlock);
1349         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1350         wake_up(&tu->qchange_sleep);
1351 }
1352
1353 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1354                                             struct snd_timer_tread64 *tread)
1355 {
1356         if (tu->qused >= tu->queue_size) {
1357                 tu->overrun++;
1358         } else {
1359                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1360                 tu->qtail %= tu->queue_size;
1361                 tu->qused++;
1362         }
1363 }
1364
1365 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1366                                      int event,
1367                                      struct timespec64 *tstamp,
1368                                      unsigned long resolution)
1369 {
1370         struct snd_timer_user *tu = timeri->callback_data;
1371         struct snd_timer_tread64 r1;
1372         unsigned long flags;
1373
1374         if (event >= SNDRV_TIMER_EVENT_START &&
1375             event <= SNDRV_TIMER_EVENT_PAUSE)
1376                 tu->tstamp = *tstamp;
1377         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1378                 return;
1379         memset(&r1, 0, sizeof(r1));
1380         r1.event = event;
1381         r1.tstamp_sec = tstamp->tv_sec;
1382         r1.tstamp_nsec = tstamp->tv_nsec;
1383         r1.val = resolution;
1384         spin_lock_irqsave(&tu->qlock, flags);
1385         snd_timer_user_append_to_tqueue(tu, &r1);
1386         spin_unlock_irqrestore(&tu->qlock, flags);
1387         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1388         wake_up(&tu->qchange_sleep);
1389 }
1390
1391 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1392 {
1393         struct snd_timer_user *tu = timeri->callback_data;
1394
1395         tu->disconnected = true;
1396         wake_up(&tu->qchange_sleep);
1397 }
1398
1399 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1400                                       unsigned long resolution,
1401                                       unsigned long ticks)
1402 {
1403         struct snd_timer_user *tu = timeri->callback_data;
1404         struct snd_timer_tread64 *r, r1;
1405         struct timespec64 tstamp;
1406         int prev, append = 0;
1407
1408         memset(&r1, 0, sizeof(r1));
1409         memset(&tstamp, 0, sizeof(tstamp));
1410         spin_lock(&tu->qlock);
1411         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1412                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1413                 spin_unlock(&tu->qlock);
1414                 return;
1415         }
1416         if (tu->last_resolution != resolution || ticks > 0) {
1417                 if (timer_tstamp_monotonic)
1418                         ktime_get_ts64(&tstamp);
1419                 else
1420                         ktime_get_real_ts64(&tstamp);
1421         }
1422         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1423             tu->last_resolution != resolution) {
1424                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1425                 r1.tstamp_sec = tstamp.tv_sec;
1426                 r1.tstamp_nsec = tstamp.tv_nsec;
1427                 r1.val = resolution;
1428                 snd_timer_user_append_to_tqueue(tu, &r1);
1429                 tu->last_resolution = resolution;
1430                 append++;
1431         }
1432         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1433                 goto __wake;
1434         if (ticks == 0)
1435                 goto __wake;
1436         if (tu->qused > 0) {
1437                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1438                 r = &tu->tqueue[prev];
1439                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1440                         r->tstamp_sec = tstamp.tv_sec;
1441                         r->tstamp_nsec = tstamp.tv_nsec;
1442                         r->val += ticks;
1443                         append++;
1444                         goto __wake;
1445                 }
1446         }
1447         r1.event = SNDRV_TIMER_EVENT_TICK;
1448         r1.tstamp_sec = tstamp.tv_sec;
1449         r1.tstamp_nsec = tstamp.tv_nsec;
1450         r1.val = ticks;
1451         snd_timer_user_append_to_tqueue(tu, &r1);
1452         append++;
1453       __wake:
1454         spin_unlock(&tu->qlock);
1455         if (append == 0)
1456                 return;
1457         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1458         wake_up(&tu->qchange_sleep);
1459 }
1460
1461 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1462 {
1463         struct snd_timer_read *queue = NULL;
1464         struct snd_timer_tread64 *tqueue = NULL;
1465
1466         if (tu->tread) {
1467                 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1468                 if (!tqueue)
1469                         return -ENOMEM;
1470         } else {
1471                 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1472                 if (!queue)
1473                         return -ENOMEM;
1474         }
1475
1476         spin_lock_irq(&tu->qlock);
1477         kfree(tu->queue);
1478         kfree(tu->tqueue);
1479         tu->queue_size = size;
1480         tu->queue = queue;
1481         tu->tqueue = tqueue;
1482         tu->qhead = tu->qtail = tu->qused = 0;
1483         spin_unlock_irq(&tu->qlock);
1484
1485         return 0;
1486 }
1487
1488 static int snd_timer_user_open(struct inode *inode, struct file *file)
1489 {
1490         struct snd_timer_user *tu;
1491         int err;
1492
1493         err = stream_open(inode, file);
1494         if (err < 0)
1495                 return err;
1496
1497         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1498         if (tu == NULL)
1499                 return -ENOMEM;
1500         spin_lock_init(&tu->qlock);
1501         init_waitqueue_head(&tu->qchange_sleep);
1502         mutex_init(&tu->ioctl_lock);
1503         tu->ticks = 1;
1504         if (realloc_user_queue(tu, 128) < 0) {
1505                 kfree(tu);
1506                 return -ENOMEM;
1507         }
1508         file->private_data = tu;
1509         return 0;
1510 }
1511
1512 static int snd_timer_user_release(struct inode *inode, struct file *file)
1513 {
1514         struct snd_timer_user *tu;
1515
1516         if (file->private_data) {
1517                 tu = file->private_data;
1518                 file->private_data = NULL;
1519                 mutex_lock(&tu->ioctl_lock);
1520                 if (tu->timeri) {
1521                         snd_timer_close(tu->timeri);
1522                         snd_timer_instance_free(tu->timeri);
1523                 }
1524                 mutex_unlock(&tu->ioctl_lock);
1525                 kfree(tu->queue);
1526                 kfree(tu->tqueue);
1527                 kfree(tu);
1528         }
1529         return 0;
1530 }
1531
1532 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1533 {
1534         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1535         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1536         id->card = -1;
1537         id->device = -1;
1538         id->subdevice = -1;
1539 }
1540
1541 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1542 {
1543         id->dev_class = timer->tmr_class;
1544         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1545         id->card = timer->card ? timer->card->number : -1;
1546         id->device = timer->tmr_device;
1547         id->subdevice = timer->tmr_subdevice;
1548 }
1549
1550 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1551 {
1552         struct snd_timer_id id;
1553         struct snd_timer *timer;
1554         struct list_head *p;
1555
1556         if (copy_from_user(&id, _tid, sizeof(id)))
1557                 return -EFAULT;
1558         mutex_lock(&register_mutex);
1559         if (id.dev_class < 0) {         /* first item */
1560                 if (list_empty(&snd_timer_list))
1561                         snd_timer_user_zero_id(&id);
1562                 else {
1563                         timer = list_entry(snd_timer_list.next,
1564                                            struct snd_timer, device_list);
1565                         snd_timer_user_copy_id(&id, timer);
1566                 }
1567         } else {
1568                 switch (id.dev_class) {
1569                 case SNDRV_TIMER_CLASS_GLOBAL:
1570                         id.device = id.device < 0 ? 0 : id.device + 1;
1571                         list_for_each(p, &snd_timer_list) {
1572                                 timer = list_entry(p, struct snd_timer, device_list);
1573                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1574                                         snd_timer_user_copy_id(&id, timer);
1575                                         break;
1576                                 }
1577                                 if (timer->tmr_device >= id.device) {
1578                                         snd_timer_user_copy_id(&id, timer);
1579                                         break;
1580                                 }
1581                         }
1582                         if (p == &snd_timer_list)
1583                                 snd_timer_user_zero_id(&id);
1584                         break;
1585                 case SNDRV_TIMER_CLASS_CARD:
1586                 case SNDRV_TIMER_CLASS_PCM:
1587                         if (id.card < 0) {
1588                                 id.card = 0;
1589                         } else {
1590                                 if (id.device < 0) {
1591                                         id.device = 0;
1592                                 } else {
1593                                         if (id.subdevice < 0)
1594                                                 id.subdevice = 0;
1595                                         else if (id.subdevice < INT_MAX)
1596                                                 id.subdevice++;
1597                                 }
1598                         }
1599                         list_for_each(p, &snd_timer_list) {
1600                                 timer = list_entry(p, struct snd_timer, device_list);
1601                                 if (timer->tmr_class > id.dev_class) {
1602                                         snd_timer_user_copy_id(&id, timer);
1603                                         break;
1604                                 }
1605                                 if (timer->tmr_class < id.dev_class)
1606                                         continue;
1607                                 if (timer->card->number > id.card) {
1608                                         snd_timer_user_copy_id(&id, timer);
1609                                         break;
1610                                 }
1611                                 if (timer->card->number < id.card)
1612                                         continue;
1613                                 if (timer->tmr_device > id.device) {
1614                                         snd_timer_user_copy_id(&id, timer);
1615                                         break;
1616                                 }
1617                                 if (timer->tmr_device < id.device)
1618                                         continue;
1619                                 if (timer->tmr_subdevice > id.subdevice) {
1620                                         snd_timer_user_copy_id(&id, timer);
1621                                         break;
1622                                 }
1623                                 if (timer->tmr_subdevice < id.subdevice)
1624                                         continue;
1625                                 snd_timer_user_copy_id(&id, timer);
1626                                 break;
1627                         }
1628                         if (p == &snd_timer_list)
1629                                 snd_timer_user_zero_id(&id);
1630                         break;
1631                 default:
1632                         snd_timer_user_zero_id(&id);
1633                 }
1634         }
1635         mutex_unlock(&register_mutex);
1636         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1637                 return -EFAULT;
1638         return 0;
1639 }
1640
1641 static int snd_timer_user_ginfo(struct file *file,
1642                                 struct snd_timer_ginfo __user *_ginfo)
1643 {
1644         struct snd_timer_ginfo *ginfo;
1645         struct snd_timer_id tid;
1646         struct snd_timer *t;
1647         struct list_head *p;
1648         int err = 0;
1649
1650         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1651         if (IS_ERR(ginfo))
1652                 return PTR_ERR(ginfo);
1653
1654         tid = ginfo->tid;
1655         memset(ginfo, 0, sizeof(*ginfo));
1656         ginfo->tid = tid;
1657         mutex_lock(&register_mutex);
1658         t = snd_timer_find(&tid);
1659         if (t != NULL) {
1660                 ginfo->card = t->card ? t->card->number : -1;
1661                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1662                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1663                 strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1664                 strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1665                 ginfo->resolution = t->hw.resolution;
1666                 if (t->hw.resolution_min > 0) {
1667                         ginfo->resolution_min = t->hw.resolution_min;
1668                         ginfo->resolution_max = t->hw.resolution_max;
1669                 }
1670                 list_for_each(p, &t->open_list_head) {
1671                         ginfo->clients++;
1672                 }
1673         } else {
1674                 err = -ENODEV;
1675         }
1676         mutex_unlock(&register_mutex);
1677         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1678                 err = -EFAULT;
1679         kfree(ginfo);
1680         return err;
1681 }
1682
1683 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1684 {
1685         struct snd_timer *t;
1686         int err;
1687
1688         mutex_lock(&register_mutex);
1689         t = snd_timer_find(&gparams->tid);
1690         if (!t) {
1691                 err = -ENODEV;
1692                 goto _error;
1693         }
1694         if (!list_empty(&t->open_list_head)) {
1695                 err = -EBUSY;
1696                 goto _error;
1697         }
1698         if (!t->hw.set_period) {
1699                 err = -ENOSYS;
1700                 goto _error;
1701         }
1702         err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1703 _error:
1704         mutex_unlock(&register_mutex);
1705         return err;
1706 }
1707
1708 static int snd_timer_user_gparams(struct file *file,
1709                                   struct snd_timer_gparams __user *_gparams)
1710 {
1711         struct snd_timer_gparams gparams;
1712
1713         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1714                 return -EFAULT;
1715         return timer_set_gparams(&gparams);
1716 }
1717
1718 static int snd_timer_user_gstatus(struct file *file,
1719                                   struct snd_timer_gstatus __user *_gstatus)
1720 {
1721         struct snd_timer_gstatus gstatus;
1722         struct snd_timer_id tid;
1723         struct snd_timer *t;
1724         int err = 0;
1725
1726         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1727                 return -EFAULT;
1728         tid = gstatus.tid;
1729         memset(&gstatus, 0, sizeof(gstatus));
1730         gstatus.tid = tid;
1731         mutex_lock(&register_mutex);
1732         t = snd_timer_find(&tid);
1733         if (t != NULL) {
1734                 spin_lock_irq(&t->lock);
1735                 gstatus.resolution = snd_timer_hw_resolution(t);
1736                 if (t->hw.precise_resolution) {
1737                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1738                                                  &gstatus.resolution_den);
1739                 } else {
1740                         gstatus.resolution_num = gstatus.resolution;
1741                         gstatus.resolution_den = 1000000000uL;
1742                 }
1743                 spin_unlock_irq(&t->lock);
1744         } else {
1745                 err = -ENODEV;
1746         }
1747         mutex_unlock(&register_mutex);
1748         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1749                 err = -EFAULT;
1750         return err;
1751 }
1752
1753 static int snd_timer_user_tselect(struct file *file,
1754                                   struct snd_timer_select __user *_tselect)
1755 {
1756         struct snd_timer_user *tu;
1757         struct snd_timer_select tselect;
1758         char str[32];
1759         int err = 0;
1760
1761         tu = file->private_data;
1762         if (tu->timeri) {
1763                 snd_timer_close(tu->timeri);
1764                 snd_timer_instance_free(tu->timeri);
1765                 tu->timeri = NULL;
1766         }
1767         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1768                 err = -EFAULT;
1769                 goto __err;
1770         }
1771         sprintf(str, "application %i", current->pid);
1772         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1773                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1774         tu->timeri = snd_timer_instance_new(str);
1775         if (!tu->timeri) {
1776                 err = -ENOMEM;
1777                 goto __err;
1778         }
1779
1780         tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1781         tu->timeri->callback = tu->tread
1782                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1783         tu->timeri->ccallback = snd_timer_user_ccallback;
1784         tu->timeri->callback_data = (void *)tu;
1785         tu->timeri->disconnect = snd_timer_user_disconnect;
1786
1787         err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1788         if (err < 0) {
1789                 snd_timer_instance_free(tu->timeri);
1790                 tu->timeri = NULL;
1791         }
1792
1793       __err:
1794         return err;
1795 }
1796
1797 static int snd_timer_user_info(struct file *file,
1798                                struct snd_timer_info __user *_info)
1799 {
1800         struct snd_timer_user *tu;
1801         struct snd_timer_info *info;
1802         struct snd_timer *t;
1803         int err = 0;
1804
1805         tu = file->private_data;
1806         if (!tu->timeri)
1807                 return -EBADFD;
1808         t = tu->timeri->timer;
1809         if (!t)
1810                 return -EBADFD;
1811
1812         info = kzalloc(sizeof(*info), GFP_KERNEL);
1813         if (! info)
1814                 return -ENOMEM;
1815         info->card = t->card ? t->card->number : -1;
1816         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1817                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1818         strscpy(info->id, t->id, sizeof(info->id));
1819         strscpy(info->name, t->name, sizeof(info->name));
1820         info->resolution = t->hw.resolution;
1821         if (copy_to_user(_info, info, sizeof(*_info)))
1822                 err = -EFAULT;
1823         kfree(info);
1824         return err;
1825 }
1826
1827 static int snd_timer_user_params(struct file *file,
1828                                  struct snd_timer_params __user *_params)
1829 {
1830         struct snd_timer_user *tu;
1831         struct snd_timer_params params;
1832         struct snd_timer *t;
1833         int err;
1834
1835         tu = file->private_data;
1836         if (!tu->timeri)
1837                 return -EBADFD;
1838         t = tu->timeri->timer;
1839         if (!t)
1840                 return -EBADFD;
1841         if (copy_from_user(&params, _params, sizeof(params)))
1842                 return -EFAULT;
1843         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1844                 u64 resolution;
1845
1846                 if (params.ticks < 1) {
1847                         err = -EINVAL;
1848                         goto _end;
1849                 }
1850
1851                 /* Don't allow resolution less than 1ms */
1852                 resolution = snd_timer_resolution(tu->timeri);
1853                 resolution *= params.ticks;
1854                 if (resolution < 1000000) {
1855                         err = -EINVAL;
1856                         goto _end;
1857                 }
1858         }
1859         if (params.queue_size > 0 &&
1860             (params.queue_size < 32 || params.queue_size > 1024)) {
1861                 err = -EINVAL;
1862                 goto _end;
1863         }
1864         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1865                               (1<<SNDRV_TIMER_EVENT_TICK)|
1866                               (1<<SNDRV_TIMER_EVENT_START)|
1867                               (1<<SNDRV_TIMER_EVENT_STOP)|
1868                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1869                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1870                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1871                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1872                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1873                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1874                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1875                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1876                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1877                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1878                 err = -EINVAL;
1879                 goto _end;
1880         }
1881         snd_timer_stop(tu->timeri);
1882         spin_lock_irq(&t->lock);
1883         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1884                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1885                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1886         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1887                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1888         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1889                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1890         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1891                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1892         spin_unlock_irq(&t->lock);
1893         if (params.queue_size > 0 &&
1894             (unsigned int)tu->queue_size != params.queue_size) {
1895                 err = realloc_user_queue(tu, params.queue_size);
1896                 if (err < 0)
1897                         goto _end;
1898         }
1899         spin_lock_irq(&tu->qlock);
1900         tu->qhead = tu->qtail = tu->qused = 0;
1901         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1902                 if (tu->tread) {
1903                         struct snd_timer_tread64 tread;
1904                         memset(&tread, 0, sizeof(tread));
1905                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1906                         tread.tstamp_sec = 0;
1907                         tread.tstamp_nsec = 0;
1908                         tread.val = 0;
1909                         snd_timer_user_append_to_tqueue(tu, &tread);
1910                 } else {
1911                         struct snd_timer_read *r = &tu->queue[0];
1912                         r->resolution = 0;
1913                         r->ticks = 0;
1914                         tu->qused++;
1915                         tu->qtail++;
1916                 }
1917         }
1918         tu->filter = params.filter;
1919         tu->ticks = params.ticks;
1920         spin_unlock_irq(&tu->qlock);
1921         err = 0;
1922  _end:
1923         if (copy_to_user(_params, &params, sizeof(params)))
1924                 return -EFAULT;
1925         return err;
1926 }
1927
1928 static int snd_timer_user_status32(struct file *file,
1929                                    struct snd_timer_status32 __user *_status)
1930  {
1931         struct snd_timer_user *tu;
1932         struct snd_timer_status32 status;
1933
1934         tu = file->private_data;
1935         if (!tu->timeri)
1936                 return -EBADFD;
1937         memset(&status, 0, sizeof(status));
1938         status.tstamp_sec = tu->tstamp.tv_sec;
1939         status.tstamp_nsec = tu->tstamp.tv_nsec;
1940         status.resolution = snd_timer_resolution(tu->timeri);
1941         status.lost = tu->timeri->lost;
1942         status.overrun = tu->overrun;
1943         spin_lock_irq(&tu->qlock);
1944         status.queue = tu->qused;
1945         spin_unlock_irq(&tu->qlock);
1946         if (copy_to_user(_status, &status, sizeof(status)))
1947                 return -EFAULT;
1948         return 0;
1949 }
1950
1951 static int snd_timer_user_status64(struct file *file,
1952                                    struct snd_timer_status64 __user *_status)
1953 {
1954         struct snd_timer_user *tu;
1955         struct snd_timer_status64 status;
1956
1957         tu = file->private_data;
1958         if (!tu->timeri)
1959                 return -EBADFD;
1960         memset(&status, 0, sizeof(status));
1961         status.tstamp_sec = tu->tstamp.tv_sec;
1962         status.tstamp_nsec = tu->tstamp.tv_nsec;
1963         status.resolution = snd_timer_resolution(tu->timeri);
1964         status.lost = tu->timeri->lost;
1965         status.overrun = tu->overrun;
1966         spin_lock_irq(&tu->qlock);
1967         status.queue = tu->qused;
1968         spin_unlock_irq(&tu->qlock);
1969         if (copy_to_user(_status, &status, sizeof(status)))
1970                 return -EFAULT;
1971         return 0;
1972 }
1973
1974 static int snd_timer_user_start(struct file *file)
1975 {
1976         int err;
1977         struct snd_timer_user *tu;
1978
1979         tu = file->private_data;
1980         if (!tu->timeri)
1981                 return -EBADFD;
1982         snd_timer_stop(tu->timeri);
1983         tu->timeri->lost = 0;
1984         tu->last_resolution = 0;
1985         err = snd_timer_start(tu->timeri, tu->ticks);
1986         if (err < 0)
1987                 return err;
1988         return 0;
1989 }
1990
1991 static int snd_timer_user_stop(struct file *file)
1992 {
1993         int err;
1994         struct snd_timer_user *tu;
1995
1996         tu = file->private_data;
1997         if (!tu->timeri)
1998                 return -EBADFD;
1999         err = snd_timer_stop(tu->timeri);
2000         if (err < 0)
2001                 return err;
2002         return 0;
2003 }
2004
2005 static int snd_timer_user_continue(struct file *file)
2006 {
2007         int err;
2008         struct snd_timer_user *tu;
2009
2010         tu = file->private_data;
2011         if (!tu->timeri)
2012                 return -EBADFD;
2013         /* start timer instead of continue if it's not used before */
2014         if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2015                 return snd_timer_user_start(file);
2016         tu->timeri->lost = 0;
2017         err = snd_timer_continue(tu->timeri);
2018         if (err < 0)
2019                 return err;
2020         return 0;
2021 }
2022
2023 static int snd_timer_user_pause(struct file *file)
2024 {
2025         int err;
2026         struct snd_timer_user *tu;
2027
2028         tu = file->private_data;
2029         if (!tu->timeri)
2030                 return -EBADFD;
2031         err = snd_timer_pause(tu->timeri);
2032         if (err < 0)
2033                 return err;
2034         return 0;
2035 }
2036
2037 static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2038                                 unsigned int cmd, bool compat)
2039 {
2040         int __user *p = argp;
2041         int xarg, old_tread;
2042
2043         if (tu->timeri) /* too late */
2044                 return -EBUSY;
2045         if (get_user(xarg, p))
2046                 return -EFAULT;
2047
2048         old_tread = tu->tread;
2049
2050         if (!xarg)
2051                 tu->tread = TREAD_FORMAT_NONE;
2052         else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2053                  (IS_ENABLED(CONFIG_64BIT) && !compat))
2054                 tu->tread = TREAD_FORMAT_TIME64;
2055         else
2056                 tu->tread = TREAD_FORMAT_TIME32;
2057
2058         if (tu->tread != old_tread &&
2059             realloc_user_queue(tu, tu->queue_size) < 0) {
2060                 tu->tread = old_tread;
2061                 return -ENOMEM;
2062         }
2063
2064         return 0;
2065 }
2066
2067 enum {
2068         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2069         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2070         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2071         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2072 };
2073
2074 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2075                                  unsigned long arg, bool compat)
2076 {
2077         struct snd_timer_user *tu;
2078         void __user *argp = (void __user *)arg;
2079         int __user *p = argp;
2080
2081         tu = file->private_data;
2082         switch (cmd) {
2083         case SNDRV_TIMER_IOCTL_PVERSION:
2084                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2085         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2086                 return snd_timer_user_next_device(argp);
2087         case SNDRV_TIMER_IOCTL_TREAD_OLD:
2088         case SNDRV_TIMER_IOCTL_TREAD64:
2089                 return snd_timer_user_tread(argp, tu, cmd, compat);
2090         case SNDRV_TIMER_IOCTL_GINFO:
2091                 return snd_timer_user_ginfo(file, argp);
2092         case SNDRV_TIMER_IOCTL_GPARAMS:
2093                 return snd_timer_user_gparams(file, argp);
2094         case SNDRV_TIMER_IOCTL_GSTATUS:
2095                 return snd_timer_user_gstatus(file, argp);
2096         case SNDRV_TIMER_IOCTL_SELECT:
2097                 return snd_timer_user_tselect(file, argp);
2098         case SNDRV_TIMER_IOCTL_INFO:
2099                 return snd_timer_user_info(file, argp);
2100         case SNDRV_TIMER_IOCTL_PARAMS:
2101                 return snd_timer_user_params(file, argp);
2102         case SNDRV_TIMER_IOCTL_STATUS32:
2103                 return snd_timer_user_status32(file, argp);
2104         case SNDRV_TIMER_IOCTL_STATUS64:
2105                 return snd_timer_user_status64(file, argp);
2106         case SNDRV_TIMER_IOCTL_START:
2107         case SNDRV_TIMER_IOCTL_START_OLD:
2108                 return snd_timer_user_start(file);
2109         case SNDRV_TIMER_IOCTL_STOP:
2110         case SNDRV_TIMER_IOCTL_STOP_OLD:
2111                 return snd_timer_user_stop(file);
2112         case SNDRV_TIMER_IOCTL_CONTINUE:
2113         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2114                 return snd_timer_user_continue(file);
2115         case SNDRV_TIMER_IOCTL_PAUSE:
2116         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2117                 return snd_timer_user_pause(file);
2118         }
2119         return -ENOTTY;
2120 }
2121
2122 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2123                                  unsigned long arg)
2124 {
2125         struct snd_timer_user *tu = file->private_data;
2126         long ret;
2127
2128         mutex_lock(&tu->ioctl_lock);
2129         ret = __snd_timer_user_ioctl(file, cmd, arg, false);
2130         mutex_unlock(&tu->ioctl_lock);
2131         return ret;
2132 }
2133
2134 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2135 {
2136         struct snd_timer_user *tu;
2137
2138         tu = file->private_data;
2139         return fasync_helper(fd, file, on, &tu->fasync);
2140 }
2141
2142 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2143                                    size_t count, loff_t *offset)
2144 {
2145         struct snd_timer_tread64 *tread;
2146         struct snd_timer_tread32 tread32;
2147         struct snd_timer_user *tu;
2148         long result = 0, unit;
2149         int qhead;
2150         int err = 0;
2151
2152         tu = file->private_data;
2153         switch (tu->tread) {
2154         case TREAD_FORMAT_TIME64:
2155                 unit = sizeof(struct snd_timer_tread64);
2156                 break;
2157         case TREAD_FORMAT_TIME32:
2158                 unit = sizeof(struct snd_timer_tread32);
2159                 break;
2160         case TREAD_FORMAT_NONE:
2161                 unit = sizeof(struct snd_timer_read);
2162                 break;
2163         default:
2164                 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2165                 return -ENOTSUPP;
2166         }
2167
2168         mutex_lock(&tu->ioctl_lock);
2169         spin_lock_irq(&tu->qlock);
2170         while ((long)count - result >= unit) {
2171                 while (!tu->qused) {
2172                         wait_queue_entry_t wait;
2173
2174                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2175                                 err = -EAGAIN;
2176                                 goto _error;
2177                         }
2178
2179                         set_current_state(TASK_INTERRUPTIBLE);
2180                         init_waitqueue_entry(&wait, current);
2181                         add_wait_queue(&tu->qchange_sleep, &wait);
2182
2183                         spin_unlock_irq(&tu->qlock);
2184                         mutex_unlock(&tu->ioctl_lock);
2185                         schedule();
2186                         mutex_lock(&tu->ioctl_lock);
2187                         spin_lock_irq(&tu->qlock);
2188
2189                         remove_wait_queue(&tu->qchange_sleep, &wait);
2190
2191                         if (tu->disconnected) {
2192                                 err = -ENODEV;
2193                                 goto _error;
2194                         }
2195                         if (signal_pending(current)) {
2196                                 err = -ERESTARTSYS;
2197                                 goto _error;
2198                         }
2199                 }
2200
2201                 qhead = tu->qhead++;
2202                 tu->qhead %= tu->queue_size;
2203                 tu->qused--;
2204                 spin_unlock_irq(&tu->qlock);
2205
2206                 tread = &tu->tqueue[qhead];
2207
2208                 switch (tu->tread) {
2209                 case TREAD_FORMAT_TIME64:
2210                         if (copy_to_user(buffer, tread,
2211                                          sizeof(struct snd_timer_tread64)))
2212                                 err = -EFAULT;
2213                         break;
2214                 case TREAD_FORMAT_TIME32:
2215                         memset(&tread32, 0, sizeof(tread32));
2216                         tread32 = (struct snd_timer_tread32) {
2217                                 .event = tread->event,
2218                                 .tstamp_sec = tread->tstamp_sec,
2219                                 .tstamp_nsec = tread->tstamp_nsec,
2220                                 .val = tread->val,
2221                         };
2222
2223                         if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2224                                 err = -EFAULT;
2225                         break;
2226                 case TREAD_FORMAT_NONE:
2227                         if (copy_to_user(buffer, &tu->queue[qhead],
2228                                          sizeof(struct snd_timer_read)))
2229                                 err = -EFAULT;
2230                         break;
2231                 default:
2232                         err = -ENOTSUPP;
2233                         break;
2234                 }
2235
2236                 spin_lock_irq(&tu->qlock);
2237                 if (err < 0)
2238                         goto _error;
2239                 result += unit;
2240                 buffer += unit;
2241         }
2242  _error:
2243         spin_unlock_irq(&tu->qlock);
2244         mutex_unlock(&tu->ioctl_lock);
2245         return result > 0 ? result : err;
2246 }
2247
2248 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2249 {
2250         __poll_t mask;
2251         struct snd_timer_user *tu;
2252
2253         tu = file->private_data;
2254
2255         poll_wait(file, &tu->qchange_sleep, wait);
2256
2257         mask = 0;
2258         spin_lock_irq(&tu->qlock);
2259         if (tu->qused)
2260                 mask |= EPOLLIN | EPOLLRDNORM;
2261         if (tu->disconnected)
2262                 mask |= EPOLLERR;
2263         spin_unlock_irq(&tu->qlock);
2264
2265         return mask;
2266 }
2267
2268 #ifdef CONFIG_COMPAT
2269 #include "timer_compat.c"
2270 #else
2271 #define snd_timer_user_ioctl_compat     NULL
2272 #endif
2273
2274 static const struct file_operations snd_timer_f_ops =
2275 {
2276         .owner =        THIS_MODULE,
2277         .read =         snd_timer_user_read,
2278         .open =         snd_timer_user_open,
2279         .release =      snd_timer_user_release,
2280         .llseek =       no_llseek,
2281         .poll =         snd_timer_user_poll,
2282         .unlocked_ioctl =       snd_timer_user_ioctl,
2283         .compat_ioctl = snd_timer_user_ioctl_compat,
2284         .fasync =       snd_timer_user_fasync,
2285 };
2286
2287 /* unregister the system timer */
2288 static void snd_timer_free_all(void)
2289 {
2290         struct snd_timer *timer, *n;
2291
2292         list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2293                 snd_timer_free(timer);
2294 }
2295
2296 static struct device timer_dev;
2297
2298 /*
2299  *  ENTRY functions
2300  */
2301
2302 static int __init alsa_timer_init(void)
2303 {
2304         int err;
2305
2306         snd_device_initialize(&timer_dev, NULL);
2307         dev_set_name(&timer_dev, "timer");
2308
2309 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2310         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2311                               "system timer");
2312 #endif
2313
2314         err = snd_timer_register_system();
2315         if (err < 0) {
2316                 pr_err("ALSA: unable to register system timer (%i)\n", err);
2317                 goto put_timer;
2318         }
2319
2320         err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2321                                   &snd_timer_f_ops, NULL, &timer_dev);
2322         if (err < 0) {
2323                 pr_err("ALSA: unable to register timer device (%i)\n", err);
2324                 snd_timer_free_all();
2325                 goto put_timer;
2326         }
2327
2328         snd_timer_proc_init();
2329         return 0;
2330
2331 put_timer:
2332         put_device(&timer_dev);
2333         return err;
2334 }
2335
2336 static void __exit alsa_timer_exit(void)
2337 {
2338         snd_unregister_device(&timer_dev);
2339         snd_timer_free_all();
2340         put_device(&timer_dev);
2341         snd_timer_proc_done();
2342 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2343         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2344 #endif
2345 }
2346
2347 module_init(alsa_timer_init)
2348 module_exit(alsa_timer_exit)