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         list_del_init(&timeri->ack_list);
 628         list_del_init(&timeri->active_list);
 629         if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
 630                                SNDRV_TIMER_IFLG_START))) {
 631                 result = -EBUSY;
 632                 goto unlock;
 633         }
 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         bool running;
 669
 670         spin_lock_irqsave(&slave_active_lock, flags);
 671         running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING;
 672         timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 673         if (timeri->timer) {
 674                 spin_lock(&timeri->timer->lock);
 675                 list_del_init(&timeri->ack_list);
 676                 list_del_init(&timeri->active_list);
 677                 if (running)
 678                         snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP :
 679                                           SNDRV_TIMER_EVENT_PAUSE);
 680                 spin_unlock(&timeri->timer->lock);
 681         }
 682         spin_unlock_irqrestore(&slave_active_lock, flags);
 683         return running ? 0 : -EBUSY;
 684 }
 685
 686 /*
 687  *  start the timer instance
 688  */
 689 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
 690 {
 691         if (timeri == NULL || ticks < 1)
 692                 return -EINVAL;
 693         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 694                 return snd_timer_start_slave(timeri, true);
 695         else
 696                 return snd_timer_start1(timeri, true, ticks);
 697 }
 698 EXPORT_SYMBOL(snd_timer_start);
 699
 700 /*
 701  * stop the timer instance.
 702  *
 703  * do not call this from the timer callback!
 704  */
 705 int snd_timer_stop(struct snd_timer_instance *timeri)
 706 {
 707         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 708                 return snd_timer_stop_slave(timeri, true);
 709         else
 710                 return snd_timer_stop1(timeri, true);
 711 }
 712 EXPORT_SYMBOL(snd_timer_stop);
 713
 714 /*
 715  * start again..  the tick is kept.
 716  */
 717 int snd_timer_continue(struct snd_timer_instance *timeri)
 718 {
 719         /* timer can continue only after pause */
 720         if (!(timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
 721                 return -EINVAL;
 722
 723         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 724                 return snd_timer_start_slave(timeri, false);
 725         else
 726                 return snd_timer_start1(timeri, false, 0);
 727 }
 728 EXPORT_SYMBOL(snd_timer_continue);
 729
 730 /*
 731  * pause.. remember the ticks left
 732  */
 733 int snd_timer_pause(struct snd_timer_instance * timeri)
 734 {
 735         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE)
 736                 return snd_timer_stop_slave(timeri, false);
 737         else
 738                 return snd_timer_stop1(timeri, false);
 739 }
 740 EXPORT_SYMBOL(snd_timer_pause);
 741
 742 /*
 743  * reschedule the timer
 744  *
 745  * start pending instances and check the scheduling ticks.
 746  * when the scheduling ticks is changed set CHANGE flag to reprogram the timer.
 747  */
 748 static void snd_timer_reschedule(struct snd_timer * timer, unsigned long ticks_left)
 749 {
 750         struct snd_timer_instance *ti;
 751         unsigned long ticks = ~0UL;
 752
 753         list_for_each_entry(ti, &timer->active_list_head, active_list) {
 754                 if (ti->flags & SNDRV_TIMER_IFLG_START) {
 755                         ti->flags &= ~SNDRV_TIMER_IFLG_START;
 756                         ti->flags |= SNDRV_TIMER_IFLG_RUNNING;
 757                         timer->running++;
 758                 }
 759                 if (ti->flags & SNDRV_TIMER_IFLG_RUNNING) {
 760                         if (ticks > ti->cticks)
 761                                 ticks = ti->cticks;
 762                 }
 763         }
 764         if (ticks == ~0UL) {
 765                 timer->flags &= ~SNDRV_TIMER_FLG_RESCHED;
 766                 return;
 767         }
 768         if (ticks > timer->hw.ticks)
 769                 ticks = timer->hw.ticks;
 770         if (ticks_left != ticks)
 771                 timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 772         timer->sticks = ticks;
 773 }
 774
 775 /* call callbacks in timer ack list */
 776 static void snd_timer_process_callbacks(struct snd_timer *timer,
 777                                         struct list_head *head)
 778 {
 779         struct snd_timer_instance *ti;
 780         unsigned long resolution, ticks;
 781
 782         while (!list_empty(head)) {
 783                 ti = list_first_entry(head, struct snd_timer_instance,
 784                                       ack_list);
 785
 786                 /* remove from ack_list and make empty */
 787                 list_del_init(&ti->ack_list);
 788
 789                 if (!(ti->flags & SNDRV_TIMER_IFLG_DEAD)) {
 790                         ticks = ti->pticks;
 791                         ti->pticks = 0;
 792                         resolution = ti->resolution;
 793                         ti->flags |= SNDRV_TIMER_IFLG_CALLBACK;
 794                         spin_unlock(&timer->lock);
 795                         if (ti->callback)
 796                                 ti->callback(ti, resolution, ticks);
 797                         spin_lock(&timer->lock);
 798                         ti->flags &= ~SNDRV_TIMER_IFLG_CALLBACK;
 799                 }
 800         }
 801 }
 802
 803 /* clear pending instances from ack list */
 804 static void snd_timer_clear_callbacks(struct snd_timer *timer,
 805                                       struct list_head *head)
 806 {
 807         unsigned long flags;
 808
 809         spin_lock_irqsave(&timer->lock, flags);
 810         while (!list_empty(head))
 811                 list_del_init(head->next);
 812         spin_unlock_irqrestore(&timer->lock, flags);
 813 }
 814
 815 /*
 816  * timer work
 817  *
 818  */
 819 static void snd_timer_work(struct work_struct *work)
 820 {
 821         struct snd_timer *timer = container_of(work, struct snd_timer, task_work);
 822         unsigned long flags;
 823
 824         if (timer->card && timer->card->shutdown) {
 825                 snd_timer_clear_callbacks(timer, &timer->sack_list_head);
 826                 return;
 827         }
 828
 829         spin_lock_irqsave(&timer->lock, flags);
 830         snd_timer_process_callbacks(timer, &timer->sack_list_head);
 831         spin_unlock_irqrestore(&timer->lock, flags);
 832 }
 833
 834 /*
 835  * timer interrupt
 836  *
 837  * ticks_left is usually equal to timer->sticks.
 838  *
 839  */
 840 void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
 841 {
 842         struct snd_timer_instance *ti, *ts, *tmp;
 843         unsigned long resolution;
 844         struct list_head *ack_list_head;
 845         unsigned long flags;
 846         bool use_work = false;
 847
 848         if (timer == NULL)
 849                 return;
 850
 851         if (timer->card && timer->card->shutdown) {
 852                 snd_timer_clear_callbacks(timer, &timer->ack_list_head);
 853                 return;
 854         }
 855
 856         spin_lock_irqsave(&timer->lock, flags);
 857
 858         /* remember the current resolution */
 859         resolution = snd_timer_hw_resolution(timer);
 860
 861         /* loop for all active instances
 862          * Here we cannot use list_for_each_entry because the active_list of a
 863          * processed instance is relinked to done_list_head before the callback
 864          * is called.
 865          */
 866         list_for_each_entry_safe(ti, tmp, &timer->active_list_head,
 867                                  active_list) {
 868                 if (ti->flags & SNDRV_TIMER_IFLG_DEAD)
 869                         continue;
 870                 if (!(ti->flags & SNDRV_TIMER_IFLG_RUNNING))
 871                         continue;
 872                 ti->pticks += ticks_left;
 873                 ti->resolution = resolution;
 874                 if (ti->cticks < ticks_left)
 875                         ti->cticks = 0;
 876                 else
 877                         ti->cticks -= ticks_left;
 878                 if (ti->cticks) /* not expired */
 879                         continue;
 880                 if (ti->flags & SNDRV_TIMER_IFLG_AUTO) {
 881                         ti->cticks = ti->ticks;
 882                 } else {
 883                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
 884                         --timer->running;
 885                         list_del_init(&ti->active_list);
 886                 }
 887                 if ((timer->hw.flags & SNDRV_TIMER_HW_WORK) ||
 888                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
 889                         ack_list_head = &timer->ack_list_head;
 890                 else
 891                         ack_list_head = &timer->sack_list_head;
 892                 if (list_empty(&ti->ack_list))
 893                         list_add_tail(&ti->ack_list, ack_list_head);
 894                 list_for_each_entry(ts, &ti->slave_active_head, active_list) {
 895                         ts->pticks = ti->pticks;
 896                         ts->resolution = resolution;
 897                         if (list_empty(&ts->ack_list))
 898                                 list_add_tail(&ts->ack_list, ack_list_head);
 899                 }
 900         }
 901         if (timer->flags & SNDRV_TIMER_FLG_RESCHED)
 902                 snd_timer_reschedule(timer, timer->sticks);
 903         if (timer->running) {
 904                 if (timer->hw.flags & SNDRV_TIMER_HW_STOP) {
 905                         timer->hw.stop(timer);
 906                         timer->flags |= SNDRV_TIMER_FLG_CHANGE;
 907                 }
 908                 if (!(timer->hw.flags & SNDRV_TIMER_HW_AUTO) ||
 909                     (timer->flags & SNDRV_TIMER_FLG_CHANGE)) {
 910                         /* restart timer */
 911                         timer->flags &= ~SNDRV_TIMER_FLG_CHANGE;
 912                         timer->hw.start(timer);
 913                 }
 914         } else {
 915                 timer->hw.stop(timer);
 916         }
 917
 918         /* now process all fast callbacks */
 919         snd_timer_process_callbacks(timer, &timer->ack_list_head);
 920
 921         /* do we have any slow callbacks? */
 922         use_work = !list_empty(&timer->sack_list_head);
 923         spin_unlock_irqrestore(&timer->lock, flags);
 924
 925         if (use_work)
 926                 queue_work(system_highpri_wq, &timer->task_work);
 927 }
 928 EXPORT_SYMBOL(snd_timer_interrupt);
 929
 930 /*
 931
 932  */
 933
 934 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid,
 935                   struct snd_timer **rtimer)
 936 {
 937         struct snd_timer *timer;
 938         int err;
 939         static const struct snd_device_ops ops = {
 940                 .dev_free = snd_timer_dev_free,
 941                 .dev_register = snd_timer_dev_register,
 942                 .dev_disconnect = snd_timer_dev_disconnect,
 943         };
 944
 945         if (snd_BUG_ON(!tid))
 946                 return -EINVAL;
 947         if (tid->dev_class == SNDRV_TIMER_CLASS_CARD ||
 948             tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
 949                 if (WARN_ON(!card))
 950                         return -EINVAL;
 951         }
 952         if (rtimer)
 953                 *rtimer = NULL;
 954         timer = kzalloc(sizeof(*timer), GFP_KERNEL);
 955         if (!timer)
 956                 return -ENOMEM;
 957         timer->tmr_class = tid->dev_class;
 958         timer->card = card;
 959         timer->tmr_device = tid->device;
 960         timer->tmr_subdevice = tid->subdevice;
 961         if (id)
 962                 strscpy(timer->id, id, sizeof(timer->id));
 963         timer->sticks = 1;
 964         INIT_LIST_HEAD(&timer->device_list);
 965         INIT_LIST_HEAD(&timer->open_list_head);
 966         INIT_LIST_HEAD(&timer->active_list_head);
 967         INIT_LIST_HEAD(&timer->ack_list_head);
 968         INIT_LIST_HEAD(&timer->sack_list_head);
 969         spin_lock_init(&timer->lock);
 970         INIT_WORK(&timer->task_work, snd_timer_work);
 971         timer->max_instances = 1000; /* default limit per timer */
 972         if (card != NULL) {
 973                 timer->module = card->module;
 974                 err = snd_device_new(card, SNDRV_DEV_TIMER, timer, &ops);
 975                 if (err < 0) {
 976                         snd_timer_free(timer);
 977                         return err;
 978                 }
 979         }
 980         if (rtimer)
 981                 *rtimer = timer;
 982         return 0;
 983 }
 984 EXPORT_SYMBOL(snd_timer_new);
 985
 986 static int snd_timer_free(struct snd_timer *timer)
 987 {
 988         if (!timer)
 989                 return 0;
 990
 991         mutex_lock(&register_mutex);
 992         if (! list_empty(&timer->open_list_head)) {
 993                 struct list_head *p, *n;
 994                 struct snd_timer_instance *ti;
 995                 pr_warn("ALSA: timer %p is busy?\n", timer);
 996                 list_for_each_safe(p, n, &timer->open_list_head) {
 997                         list_del_init(p);
 998                         ti = list_entry(p, struct snd_timer_instance, open_list);
 999                         ti->timer = NULL;
1000                 }
1001         }
1002         list_del(&timer->device_list);
1003         mutex_unlock(&register_mutex);
1004
1005         if (timer->private_free)
1006                 timer->private_free(timer);
1007         kfree(timer);
1008         return 0;
1009 }
1010
1011 static int snd_timer_dev_free(struct snd_device *device)
1012 {
1013         struct snd_timer *timer = device->device_data;
1014         return snd_timer_free(timer);
1015 }
1016
1017 static int snd_timer_dev_register(struct snd_device *dev)
1018 {
1019         struct snd_timer *timer = dev->device_data;
1020         struct snd_timer *timer1;
1021
1022         if (snd_BUG_ON(!timer || !timer->hw.start || !timer->hw.stop))
1023                 return -ENXIO;
1024         if (!(timer->hw.flags & SNDRV_TIMER_HW_SLAVE) &&
1025             !timer->hw.resolution && timer->hw.c_resolution == NULL)
1026                 return -EINVAL;
1027
1028         mutex_lock(&register_mutex);
1029         list_for_each_entry(timer1, &snd_timer_list, device_list) {
1030                 if (timer1->tmr_class > timer->tmr_class)
1031                         break;
1032                 if (timer1->tmr_class < timer->tmr_class)
1033                         continue;
1034                 if (timer1->card && timer->card) {
1035                         if (timer1->card->number > timer->card->number)
1036                                 break;
1037                         if (timer1->card->number < timer->card->number)
1038                                 continue;
1039                 }
1040                 if (timer1->tmr_device > timer->tmr_device)
1041                         break;
1042                 if (timer1->tmr_device < timer->tmr_device)
1043                         continue;
1044                 if (timer1->tmr_subdevice > timer->tmr_subdevice)
1045                         break;
1046                 if (timer1->tmr_subdevice < timer->tmr_subdevice)
1047                         continue;
1048                 /* conflicts.. */
1049                 mutex_unlock(&register_mutex);
1050                 return -EBUSY;
1051         }
1052         list_add_tail(&timer->device_list, &timer1->device_list);
1053         mutex_unlock(&register_mutex);
1054         return 0;
1055 }
1056
1057 static int snd_timer_dev_disconnect(struct snd_device *device)
1058 {
1059         struct snd_timer *timer = device->device_data;
1060         struct snd_timer_instance *ti;
1061
1062         mutex_lock(&register_mutex);
1063         list_del_init(&timer->device_list);
1064         /* wake up pending sleepers */
1065         list_for_each_entry(ti, &timer->open_list_head, open_list) {
1066                 if (ti->disconnect)
1067                         ti->disconnect(ti);
1068         }
1069         mutex_unlock(&register_mutex);
1070         return 0;
1071 }
1072
1073 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp)
1074 {
1075         unsigned long flags;
1076         unsigned long resolution = 0;
1077         struct snd_timer_instance *ti, *ts;
1078
1079         if (timer->card && timer->card->shutdown)
1080                 return;
1081         if (! (timer->hw.flags & SNDRV_TIMER_HW_SLAVE))
1082                 return;
1083         if (snd_BUG_ON(event < SNDRV_TIMER_EVENT_MSTART ||
1084                        event > SNDRV_TIMER_EVENT_MRESUME))
1085                 return;
1086         spin_lock_irqsave(&timer->lock, flags);
1087         if (event == SNDRV_TIMER_EVENT_MSTART ||
1088             event == SNDRV_TIMER_EVENT_MCONTINUE ||
1089             event == SNDRV_TIMER_EVENT_MRESUME)
1090                 resolution = snd_timer_hw_resolution(timer);
1091         list_for_each_entry(ti, &timer->active_list_head, active_list) {
1092                 if (ti->ccallback)
1093                         ti->ccallback(ti, event, tstamp, resolution);
1094                 list_for_each_entry(ts, &ti->slave_active_head, active_list)
1095                         if (ts->ccallback)
1096                                 ts->ccallback(ts, event, tstamp, resolution);
1097         }
1098         spin_unlock_irqrestore(&timer->lock, flags);
1099 }
1100 EXPORT_SYMBOL(snd_timer_notify);
1101
1102 /*
1103  * exported functions for global timers
1104  */
1105 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer)
1106 {
1107         struct snd_timer_id tid;
1108
1109         tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
1110         tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1111         tid.card = -1;
1112         tid.device = device;
1113         tid.subdevice = 0;
1114         return snd_timer_new(NULL, id, &tid, rtimer);
1115 }
1116 EXPORT_SYMBOL(snd_timer_global_new);
1117
1118 int snd_timer_global_free(struct snd_timer *timer)
1119 {
1120         return snd_timer_free(timer);
1121 }
1122 EXPORT_SYMBOL(snd_timer_global_free);
1123
1124 int snd_timer_global_register(struct snd_timer *timer)
1125 {
1126         struct snd_device dev;
1127
1128         memset(&dev, 0, sizeof(dev));
1129         dev.device_data = timer;
1130         return snd_timer_dev_register(&dev);
1131 }
1132 EXPORT_SYMBOL(snd_timer_global_register);
1133
1134 /*
1135  *  System timer
1136  */
1137
1138 struct snd_timer_system_private {
1139         struct timer_list tlist;
1140         struct snd_timer *snd_timer;
1141         unsigned long last_expires;
1142         unsigned long last_jiffies;
1143         unsigned long correction;
1144 };
1145
1146 static void snd_timer_s_function(struct timer_list *t)
1147 {
1148         struct snd_timer_system_private *priv = from_timer(priv, t,
1149                                                                 tlist);
1150         struct snd_timer *timer = priv->snd_timer;
1151         unsigned long jiff = jiffies;
1152         if (time_after(jiff, priv->last_expires))
1153                 priv->correction += (long)jiff - (long)priv->last_expires;
1154         snd_timer_interrupt(timer, (long)jiff - (long)priv->last_jiffies);
1155 }
1156
1157 static int snd_timer_s_start(struct snd_timer * timer)
1158 {
1159         struct snd_timer_system_private *priv;
1160         unsigned long njiff;
1161
1162         priv = (struct snd_timer_system_private *) timer->private_data;
1163         njiff = (priv->last_jiffies = jiffies);
1164         if (priv->correction > timer->sticks - 1) {
1165                 priv->correction -= timer->sticks - 1;
1166                 njiff++;
1167         } else {
1168                 njiff += timer->sticks - priv->correction;
1169                 priv->correction = 0;
1170         }
1171         priv->last_expires = njiff;
1172         mod_timer(&priv->tlist, njiff);
1173         return 0;
1174 }
1175
1176 static int snd_timer_s_stop(struct snd_timer * timer)
1177 {
1178         struct snd_timer_system_private *priv;
1179         unsigned long jiff;
1180
1181         priv = (struct snd_timer_system_private *) timer->private_data;
1182         del_timer(&priv->tlist);
1183         jiff = jiffies;
1184         if (time_before(jiff, priv->last_expires))
1185                 timer->sticks = priv->last_expires - jiff;
1186         else
1187                 timer->sticks = 1;
1188         priv->correction = 0;
1189         return 0;
1190 }
1191
1192 static int snd_timer_s_close(struct snd_timer *timer)
1193 {
1194         struct snd_timer_system_private *priv;
1195
1196         priv = (struct snd_timer_system_private *)timer->private_data;
1197         del_timer_sync(&priv->tlist);
1198         return 0;
1199 }
1200
1201 static const struct snd_timer_hardware snd_timer_system =
1202 {
1203         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_WORK,
1204         .resolution =   1000000000L / HZ,
1205         .ticks =        10000000L,
1206         .close =        snd_timer_s_close,
1207         .start =        snd_timer_s_start,
1208         .stop =         snd_timer_s_stop
1209 };
1210
1211 static void snd_timer_free_system(struct snd_timer *timer)
1212 {
1213         kfree(timer->private_data);
1214 }
1215
1216 static int snd_timer_register_system(void)
1217 {
1218         struct snd_timer *timer;
1219         struct snd_timer_system_private *priv;
1220         int err;
1221
1222         err = snd_timer_global_new("system", SNDRV_TIMER_GLOBAL_SYSTEM, &timer);
1223         if (err < 0)
1224                 return err;
1225         strcpy(timer->name, "system timer");
1226         timer->hw = snd_timer_system;
1227         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1228         if (priv == NULL) {
1229                 snd_timer_free(timer);
1230                 return -ENOMEM;
1231         }
1232         priv->snd_timer = timer;
1233         timer_setup(&priv->tlist, snd_timer_s_function, 0);
1234         timer->private_data = priv;
1235         timer->private_free = snd_timer_free_system;
1236         return snd_timer_global_register(timer);
1237 }
1238
1239 #ifdef CONFIG_SND_PROC_FS
1240 /*
1241  *  Info interface
1242  */
1243
1244 static void snd_timer_proc_read(struct snd_info_entry *entry,
1245                                 struct snd_info_buffer *buffer)
1246 {
1247         struct snd_timer *timer;
1248         struct snd_timer_instance *ti;
1249
1250         mutex_lock(&register_mutex);
1251         list_for_each_entry(timer, &snd_timer_list, device_list) {
1252                 if (timer->card && timer->card->shutdown)
1253                         continue;
1254                 switch (timer->tmr_class) {
1255                 case SNDRV_TIMER_CLASS_GLOBAL:
1256                         snd_iprintf(buffer, "G%i: ", timer->tmr_device);
1257                         break;
1258                 case SNDRV_TIMER_CLASS_CARD:
1259                         snd_iprintf(buffer, "C%i-%i: ",
1260                                     timer->card->number, timer->tmr_device);
1261                         break;
1262                 case SNDRV_TIMER_CLASS_PCM:
1263                         snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
1264                                     timer->tmr_device, timer->tmr_subdevice);
1265                         break;
1266                 default:
1267                         snd_iprintf(buffer, "?%i-%i-%i-%i: ", timer->tmr_class,
1268                                     timer->card ? timer->card->number : -1,
1269                                     timer->tmr_device, timer->tmr_subdevice);
1270                 }
1271                 snd_iprintf(buffer, "%s :", timer->name);
1272                 if (timer->hw.resolution)
1273                         snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1274                                     timer->hw.resolution / 1000,
1275                                     timer->hw.resolution % 1000,
1276                                     timer->hw.ticks);
1277                 if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1278                         snd_iprintf(buffer, " SLAVE");
1279                 snd_iprintf(buffer, "\n");
1280                 list_for_each_entry(ti, &timer->open_list_head, open_list)
1281                         snd_iprintf(buffer, "  Client %s : %s\n",
1282                                     ti->owner ? ti->owner : "unknown",
1283                                     (ti->flags & (SNDRV_TIMER_IFLG_START |
1284                                                   SNDRV_TIMER_IFLG_RUNNING))
1285                                     ? "running" : "stopped");
1286         }
1287         mutex_unlock(&register_mutex);
1288 }
1289
1290 static struct snd_info_entry *snd_timer_proc_entry;
1291
1292 static void __init snd_timer_proc_init(void)
1293 {
1294         struct snd_info_entry *entry;
1295
1296         entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1297         if (entry != NULL) {
1298                 entry->c.text.read = snd_timer_proc_read;
1299                 if (snd_info_register(entry) < 0) {
1300                         snd_info_free_entry(entry);
1301                         entry = NULL;
1302                 }
1303         }
1304         snd_timer_proc_entry = entry;
1305 }
1306
1307 static void __exit snd_timer_proc_done(void)
1308 {
1309         snd_info_free_entry(snd_timer_proc_entry);
1310 }
1311 #else /* !CONFIG_SND_PROC_FS */
1312 #define snd_timer_proc_init()
1313 #define snd_timer_proc_done()
1314 #endif
1315
1316 /*
1317  *  USER SPACE interface
1318  */
1319
1320 static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1321                                      unsigned long resolution,
1322                                      unsigned long ticks)
1323 {
1324         struct snd_timer_user *tu = timeri->callback_data;
1325         struct snd_timer_read *r;
1326         int prev;
1327
1328         spin_lock(&tu->qlock);
1329         if (tu->qused > 0) {
1330                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1331                 r = &tu->queue[prev];
1332                 if (r->resolution == resolution) {
1333                         r->ticks += ticks;
1334                         goto __wake;
1335                 }
1336         }
1337         if (tu->qused >= tu->queue_size) {
1338                 tu->overrun++;
1339         } else {
1340                 r = &tu->queue[tu->qtail++];
1341                 tu->qtail %= tu->queue_size;
1342                 r->resolution = resolution;
1343                 r->ticks = ticks;
1344                 tu->qused++;
1345         }
1346       __wake:
1347         spin_unlock(&tu->qlock);
1348         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1349         wake_up(&tu->qchange_sleep);
1350 }
1351
1352 static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1353                                             struct snd_timer_tread64 *tread)
1354 {
1355         if (tu->qused >= tu->queue_size) {
1356                 tu->overrun++;
1357         } else {
1358                 memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1359                 tu->qtail %= tu->queue_size;
1360                 tu->qused++;
1361         }
1362 }
1363
1364 static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1365                                      int event,
1366                                      struct timespec64 *tstamp,
1367                                      unsigned long resolution)
1368 {
1369         struct snd_timer_user *tu = timeri->callback_data;
1370         struct snd_timer_tread64 r1;
1371         unsigned long flags;
1372
1373         if (event >= SNDRV_TIMER_EVENT_START &&
1374             event <= SNDRV_TIMER_EVENT_PAUSE)
1375                 tu->tstamp = *tstamp;
1376         if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1377                 return;
1378         memset(&r1, 0, sizeof(r1));
1379         r1.event = event;
1380         r1.tstamp_sec = tstamp->tv_sec;
1381         r1.tstamp_nsec = tstamp->tv_nsec;
1382         r1.val = resolution;
1383         spin_lock_irqsave(&tu->qlock, flags);
1384         snd_timer_user_append_to_tqueue(tu, &r1);
1385         spin_unlock_irqrestore(&tu->qlock, flags);
1386         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1387         wake_up(&tu->qchange_sleep);
1388 }
1389
1390 static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1391 {
1392         struct snd_timer_user *tu = timeri->callback_data;
1393
1394         tu->disconnected = true;
1395         wake_up(&tu->qchange_sleep);
1396 }
1397
1398 static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1399                                       unsigned long resolution,
1400                                       unsigned long ticks)
1401 {
1402         struct snd_timer_user *tu = timeri->callback_data;
1403         struct snd_timer_tread64 *r, r1;
1404         struct timespec64 tstamp;
1405         int prev, append = 0;
1406
1407         memset(&r1, 0, sizeof(r1));
1408         memset(&tstamp, 0, sizeof(tstamp));
1409         spin_lock(&tu->qlock);
1410         if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1411                            (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1412                 spin_unlock(&tu->qlock);
1413                 return;
1414         }
1415         if (tu->last_resolution != resolution || ticks > 0) {
1416                 if (timer_tstamp_monotonic)
1417                         ktime_get_ts64(&tstamp);
1418                 else
1419                         ktime_get_real_ts64(&tstamp);
1420         }
1421         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1422             tu->last_resolution != resolution) {
1423                 r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1424                 r1.tstamp_sec = tstamp.tv_sec;
1425                 r1.tstamp_nsec = tstamp.tv_nsec;
1426                 r1.val = resolution;
1427                 snd_timer_user_append_to_tqueue(tu, &r1);
1428                 tu->last_resolution = resolution;
1429                 append++;
1430         }
1431         if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1432                 goto __wake;
1433         if (ticks == 0)
1434                 goto __wake;
1435         if (tu->qused > 0) {
1436                 prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1437                 r = &tu->tqueue[prev];
1438                 if (r->event == SNDRV_TIMER_EVENT_TICK) {
1439                         r->tstamp_sec = tstamp.tv_sec;
1440                         r->tstamp_nsec = tstamp.tv_nsec;
1441                         r->val += ticks;
1442                         append++;
1443                         goto __wake;
1444                 }
1445         }
1446         r1.event = SNDRV_TIMER_EVENT_TICK;
1447         r1.tstamp_sec = tstamp.tv_sec;
1448         r1.tstamp_nsec = tstamp.tv_nsec;
1449         r1.val = ticks;
1450         snd_timer_user_append_to_tqueue(tu, &r1);
1451         append++;
1452       __wake:
1453         spin_unlock(&tu->qlock);
1454         if (append == 0)
1455                 return;
1456         kill_fasync(&tu->fasync, SIGIO, POLL_IN);
1457         wake_up(&tu->qchange_sleep);
1458 }
1459
1460 static int realloc_user_queue(struct snd_timer_user *tu, int size)
1461 {
1462         struct snd_timer_read *queue = NULL;
1463         struct snd_timer_tread64 *tqueue = NULL;
1464
1465         if (tu->tread) {
1466                 tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1467                 if (!tqueue)
1468                         return -ENOMEM;
1469         } else {
1470                 queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1471                 if (!queue)
1472                         return -ENOMEM;
1473         }
1474
1475         spin_lock_irq(&tu->qlock);
1476         kfree(tu->queue);
1477         kfree(tu->tqueue);
1478         tu->queue_size = size;
1479         tu->queue = queue;
1480         tu->tqueue = tqueue;
1481         tu->qhead = tu->qtail = tu->qused = 0;
1482         spin_unlock_irq(&tu->qlock);
1483
1484         return 0;
1485 }
1486
1487 static int snd_timer_user_open(struct inode *inode, struct file *file)
1488 {
1489         struct snd_timer_user *tu;
1490         int err;
1491
1492         err = stream_open(inode, file);
1493         if (err < 0)
1494                 return err;
1495
1496         tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1497         if (tu == NULL)
1498                 return -ENOMEM;
1499         spin_lock_init(&tu->qlock);
1500         init_waitqueue_head(&tu->qchange_sleep);
1501         mutex_init(&tu->ioctl_lock);
1502         tu->ticks = 1;
1503         if (realloc_user_queue(tu, 128) < 0) {
1504                 kfree(tu);
1505                 return -ENOMEM;
1506         }
1507         file->private_data = tu;
1508         return 0;
1509 }
1510
1511 static int snd_timer_user_release(struct inode *inode, struct file *file)
1512 {
1513         struct snd_timer_user *tu;
1514
1515         if (file->private_data) {
1516                 tu = file->private_data;
1517                 file->private_data = NULL;
1518                 mutex_lock(&tu->ioctl_lock);
1519                 if (tu->timeri) {
1520                         snd_timer_close(tu->timeri);
1521                         snd_timer_instance_free(tu->timeri);
1522                 }
1523                 mutex_unlock(&tu->ioctl_lock);
1524                 kfree(tu->queue);
1525                 kfree(tu->tqueue);
1526                 kfree(tu);
1527         }
1528         return 0;
1529 }
1530
1531 static void snd_timer_user_zero_id(struct snd_timer_id *id)
1532 {
1533         id->dev_class = SNDRV_TIMER_CLASS_NONE;
1534         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1535         id->card = -1;
1536         id->device = -1;
1537         id->subdevice = -1;
1538 }
1539
1540 static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1541 {
1542         id->dev_class = timer->tmr_class;
1543         id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1544         id->card = timer->card ? timer->card->number : -1;
1545         id->device = timer->tmr_device;
1546         id->subdevice = timer->tmr_subdevice;
1547 }
1548
1549 static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1550 {
1551         struct snd_timer_id id;
1552         struct snd_timer *timer;
1553         struct list_head *p;
1554
1555         if (copy_from_user(&id, _tid, sizeof(id)))
1556                 return -EFAULT;
1557         mutex_lock(&register_mutex);
1558         if (id.dev_class < 0) {         /* first item */
1559                 if (list_empty(&snd_timer_list))
1560                         snd_timer_user_zero_id(&id);
1561                 else {
1562                         timer = list_entry(snd_timer_list.next,
1563                                            struct snd_timer, device_list);
1564                         snd_timer_user_copy_id(&id, timer);
1565                 }
1566         } else {
1567                 switch (id.dev_class) {
1568                 case SNDRV_TIMER_CLASS_GLOBAL:
1569                         id.device = id.device < 0 ? 0 : id.device + 1;
1570                         list_for_each(p, &snd_timer_list) {
1571                                 timer = list_entry(p, struct snd_timer, device_list);
1572                                 if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1573                                         snd_timer_user_copy_id(&id, timer);
1574                                         break;
1575                                 }
1576                                 if (timer->tmr_device >= id.device) {
1577                                         snd_timer_user_copy_id(&id, timer);
1578                                         break;
1579                                 }
1580                         }
1581                         if (p == &snd_timer_list)
1582                                 snd_timer_user_zero_id(&id);
1583                         break;
1584                 case SNDRV_TIMER_CLASS_CARD:
1585                 case SNDRV_TIMER_CLASS_PCM:
1586                         if (id.card < 0) {
1587                                 id.card = 0;
1588                         } else {
1589                                 if (id.device < 0) {
1590                                         id.device = 0;
1591                                 } else {
1592                                         if (id.subdevice < 0)
1593                                                 id.subdevice = 0;
1594                                         else if (id.subdevice < INT_MAX)
1595                                                 id.subdevice++;
1596                                 }
1597                         }
1598                         list_for_each(p, &snd_timer_list) {
1599                                 timer = list_entry(p, struct snd_timer, device_list);
1600                                 if (timer->tmr_class > id.dev_class) {
1601                                         snd_timer_user_copy_id(&id, timer);
1602                                         break;
1603                                 }
1604                                 if (timer->tmr_class < id.dev_class)
1605                                         continue;
1606                                 if (timer->card->number > id.card) {
1607                                         snd_timer_user_copy_id(&id, timer);
1608                                         break;
1609                                 }
1610                                 if (timer->card->number < id.card)
1611                                         continue;
1612                                 if (timer->tmr_device > id.device) {
1613                                         snd_timer_user_copy_id(&id, timer);
1614                                         break;
1615                                 }
1616                                 if (timer->tmr_device < id.device)
1617                                         continue;
1618                                 if (timer->tmr_subdevice > id.subdevice) {
1619                                         snd_timer_user_copy_id(&id, timer);
1620                                         break;
1621                                 }
1622                                 if (timer->tmr_subdevice < id.subdevice)
1623                                         continue;
1624                                 snd_timer_user_copy_id(&id, timer);
1625                                 break;
1626                         }
1627                         if (p == &snd_timer_list)
1628                                 snd_timer_user_zero_id(&id);
1629                         break;
1630                 default:
1631                         snd_timer_user_zero_id(&id);
1632                 }
1633         }
1634         mutex_unlock(&register_mutex);
1635         if (copy_to_user(_tid, &id, sizeof(*_tid)))
1636                 return -EFAULT;
1637         return 0;
1638 }
1639
1640 static int snd_timer_user_ginfo(struct file *file,
1641                                 struct snd_timer_ginfo __user *_ginfo)
1642 {
1643         struct snd_timer_ginfo *ginfo;
1644         struct snd_timer_id tid;
1645         struct snd_timer *t;
1646         struct list_head *p;
1647         int err = 0;
1648
1649         ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1650         if (IS_ERR(ginfo))
1651                 return PTR_ERR(ginfo);
1652
1653         tid = ginfo->tid;
1654         memset(ginfo, 0, sizeof(*ginfo));
1655         ginfo->tid = tid;
1656         mutex_lock(&register_mutex);
1657         t = snd_timer_find(&tid);
1658         if (t != NULL) {
1659                 ginfo->card = t->card ? t->card->number : -1;
1660                 if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1661                         ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1662                 strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1663                 strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1664                 ginfo->resolution = t->hw.resolution;
1665                 if (t->hw.resolution_min > 0) {
1666                         ginfo->resolution_min = t->hw.resolution_min;
1667                         ginfo->resolution_max = t->hw.resolution_max;
1668                 }
1669                 list_for_each(p, &t->open_list_head) {
1670                         ginfo->clients++;
1671                 }
1672         } else {
1673                 err = -ENODEV;
1674         }
1675         mutex_unlock(&register_mutex);
1676         if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1677                 err = -EFAULT;
1678         kfree(ginfo);
1679         return err;
1680 }
1681
1682 static int timer_set_gparams(struct snd_timer_gparams *gparams)
1683 {
1684         struct snd_timer *t;
1685         int err;
1686
1687         mutex_lock(&register_mutex);
1688         t = snd_timer_find(&gparams->tid);
1689         if (!t) {
1690                 err = -ENODEV;
1691                 goto _error;
1692         }
1693         if (!list_empty(&t->open_list_head)) {
1694                 err = -EBUSY;
1695                 goto _error;
1696         }
1697         if (!t->hw.set_period) {
1698                 err = -ENOSYS;
1699                 goto _error;
1700         }
1701         err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1702 _error:
1703         mutex_unlock(&register_mutex);
1704         return err;
1705 }
1706
1707 static int snd_timer_user_gparams(struct file *file,
1708                                   struct snd_timer_gparams __user *_gparams)
1709 {
1710         struct snd_timer_gparams gparams;
1711
1712         if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1713                 return -EFAULT;
1714         return timer_set_gparams(&gparams);
1715 }
1716
1717 static int snd_timer_user_gstatus(struct file *file,
1718                                   struct snd_timer_gstatus __user *_gstatus)
1719 {
1720         struct snd_timer_gstatus gstatus;
1721         struct snd_timer_id tid;
1722         struct snd_timer *t;
1723         int err = 0;
1724
1725         if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1726                 return -EFAULT;
1727         tid = gstatus.tid;
1728         memset(&gstatus, 0, sizeof(gstatus));
1729         gstatus.tid = tid;
1730         mutex_lock(&register_mutex);
1731         t = snd_timer_find(&tid);
1732         if (t != NULL) {
1733                 spin_lock_irq(&t->lock);
1734                 gstatus.resolution = snd_timer_hw_resolution(t);
1735                 if (t->hw.precise_resolution) {
1736                         t->hw.precise_resolution(t, &gstatus.resolution_num,
1737                                                  &gstatus.resolution_den);
1738                 } else {
1739                         gstatus.resolution_num = gstatus.resolution;
1740                         gstatus.resolution_den = 1000000000uL;
1741                 }
1742                 spin_unlock_irq(&t->lock);
1743         } else {
1744                 err = -ENODEV;
1745         }
1746         mutex_unlock(&register_mutex);
1747         if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1748                 err = -EFAULT;
1749         return err;
1750 }
1751
1752 static int snd_timer_user_tselect(struct file *file,
1753                                   struct snd_timer_select __user *_tselect)
1754 {
1755         struct snd_timer_user *tu;
1756         struct snd_timer_select tselect;
1757         char str[32];
1758         int err = 0;
1759
1760         tu = file->private_data;
1761         if (tu->timeri) {
1762                 snd_timer_close(tu->timeri);
1763                 snd_timer_instance_free(tu->timeri);
1764                 tu->timeri = NULL;
1765         }
1766         if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1767                 err = -EFAULT;
1768                 goto __err;
1769         }
1770         sprintf(str, "application %i", current->pid);
1771         if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1772                 tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1773         tu->timeri = snd_timer_instance_new(str);
1774         if (!tu->timeri) {
1775                 err = -ENOMEM;
1776                 goto __err;
1777         }
1778
1779         tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1780         tu->timeri->callback = tu->tread
1781                         ? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1782         tu->timeri->ccallback = snd_timer_user_ccallback;
1783         tu->timeri->callback_data = (void *)tu;
1784         tu->timeri->disconnect = snd_timer_user_disconnect;
1785
1786         err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1787         if (err < 0) {
1788                 snd_timer_instance_free(tu->timeri);
1789                 tu->timeri = NULL;
1790         }
1791
1792       __err:
1793         return err;
1794 }
1795
1796 static int snd_timer_user_info(struct file *file,
1797                                struct snd_timer_info __user *_info)
1798 {
1799         struct snd_timer_user *tu;
1800         struct snd_timer_info *info;
1801         struct snd_timer *t;
1802         int err = 0;
1803
1804         tu = file->private_data;
1805         if (!tu->timeri)
1806                 return -EBADFD;
1807         t = tu->timeri->timer;
1808         if (!t)
1809                 return -EBADFD;
1810
1811         info = kzalloc(sizeof(*info), GFP_KERNEL);
1812         if (! info)
1813                 return -ENOMEM;
1814         info->card = t->card ? t->card->number : -1;
1815         if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1816                 info->flags |= SNDRV_TIMER_FLG_SLAVE;
1817         strscpy(info->id, t->id, sizeof(info->id));
1818         strscpy(info->name, t->name, sizeof(info->name));
1819         info->resolution = t->hw.resolution;
1820         if (copy_to_user(_info, info, sizeof(*_info)))
1821                 err = -EFAULT;
1822         kfree(info);
1823         return err;
1824 }
1825
1826 static int snd_timer_user_params(struct file *file,
1827                                  struct snd_timer_params __user *_params)
1828 {
1829         struct snd_timer_user *tu;
1830         struct snd_timer_params params;
1831         struct snd_timer *t;
1832         int err;
1833
1834         tu = file->private_data;
1835         if (!tu->timeri)
1836                 return -EBADFD;
1837         t = tu->timeri->timer;
1838         if (!t)
1839                 return -EBADFD;
1840         if (copy_from_user(&params, _params, sizeof(params)))
1841                 return -EFAULT;
1842         if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1843                 u64 resolution;
1844
1845                 if (params.ticks < 1) {
1846                         err = -EINVAL;
1847                         goto _end;
1848                 }
1849
1850                 /* Don't allow resolution less than 1ms */
1851                 resolution = snd_timer_resolution(tu->timeri);
1852                 resolution *= params.ticks;
1853                 if (resolution < 1000000) {
1854                         err = -EINVAL;
1855                         goto _end;
1856                 }
1857         }
1858         if (params.queue_size > 0 &&
1859             (params.queue_size < 32 || params.queue_size > 1024)) {
1860                 err = -EINVAL;
1861                 goto _end;
1862         }
1863         if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1864                               (1<<SNDRV_TIMER_EVENT_TICK)|
1865                               (1<<SNDRV_TIMER_EVENT_START)|
1866                               (1<<SNDRV_TIMER_EVENT_STOP)|
1867                               (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1868                               (1<<SNDRV_TIMER_EVENT_PAUSE)|
1869                               (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1870                               (1<<SNDRV_TIMER_EVENT_RESUME)|
1871                               (1<<SNDRV_TIMER_EVENT_MSTART)|
1872                               (1<<SNDRV_TIMER_EVENT_MSTOP)|
1873                               (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1874                               (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1875                               (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1876                               (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1877                 err = -EINVAL;
1878                 goto _end;
1879         }
1880         snd_timer_stop(tu->timeri);
1881         spin_lock_irq(&t->lock);
1882         tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1883                                SNDRV_TIMER_IFLG_EXCLUSIVE|
1884                                SNDRV_TIMER_IFLG_EARLY_EVENT);
1885         if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1886                 tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1887         if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1888                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1889         if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1890                 tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1891         spin_unlock_irq(&t->lock);
1892         if (params.queue_size > 0 &&
1893             (unsigned int)tu->queue_size != params.queue_size) {
1894                 err = realloc_user_queue(tu, params.queue_size);
1895                 if (err < 0)
1896                         goto _end;
1897         }
1898         spin_lock_irq(&tu->qlock);
1899         tu->qhead = tu->qtail = tu->qused = 0;
1900         if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1901                 if (tu->tread) {
1902                         struct snd_timer_tread64 tread;
1903                         memset(&tread, 0, sizeof(tread));
1904                         tread.event = SNDRV_TIMER_EVENT_EARLY;
1905                         tread.tstamp_sec = 0;
1906                         tread.tstamp_nsec = 0;
1907                         tread.val = 0;
1908                         snd_timer_user_append_to_tqueue(tu, &tread);
1909                 } else {
1910                         struct snd_timer_read *r = &tu->queue[0];
1911                         r->resolution = 0;
1912                         r->ticks = 0;
1913                         tu->qused++;
1914                         tu->qtail++;
1915                 }
1916         }
1917         tu->filter = params.filter;
1918         tu->ticks = params.ticks;
1919         spin_unlock_irq(&tu->qlock);
1920         err = 0;
1921  _end:
1922         if (copy_to_user(_params, &params, sizeof(params)))
1923                 return -EFAULT;
1924         return err;
1925 }
1926
1927 static int snd_timer_user_status32(struct file *file,
1928                                    struct snd_timer_status32 __user *_status)
1929  {
1930         struct snd_timer_user *tu;
1931         struct snd_timer_status32 status;
1932
1933         tu = file->private_data;
1934         if (!tu->timeri)
1935                 return -EBADFD;
1936         memset(&status, 0, sizeof(status));
1937         status.tstamp_sec = tu->tstamp.tv_sec;
1938         status.tstamp_nsec = tu->tstamp.tv_nsec;
1939         status.resolution = snd_timer_resolution(tu->timeri);
1940         status.lost = tu->timeri->lost;
1941         status.overrun = tu->overrun;
1942         spin_lock_irq(&tu->qlock);
1943         status.queue = tu->qused;
1944         spin_unlock_irq(&tu->qlock);
1945         if (copy_to_user(_status, &status, sizeof(status)))
1946                 return -EFAULT;
1947         return 0;
1948 }
1949
1950 static int snd_timer_user_status64(struct file *file,
1951                                    struct snd_timer_status64 __user *_status)
1952 {
1953         struct snd_timer_user *tu;
1954         struct snd_timer_status64 status;
1955
1956         tu = file->private_data;
1957         if (!tu->timeri)
1958                 return -EBADFD;
1959         memset(&status, 0, sizeof(status));
1960         status.tstamp_sec = tu->tstamp.tv_sec;
1961         status.tstamp_nsec = tu->tstamp.tv_nsec;
1962         status.resolution = snd_timer_resolution(tu->timeri);
1963         status.lost = tu->timeri->lost;
1964         status.overrun = tu->overrun;
1965         spin_lock_irq(&tu->qlock);
1966         status.queue = tu->qused;
1967         spin_unlock_irq(&tu->qlock);
1968         if (copy_to_user(_status, &status, sizeof(status)))
1969                 return -EFAULT;
1970         return 0;
1971 }
1972
1973 static int snd_timer_user_start(struct file *file)
1974 {
1975         int err;
1976         struct snd_timer_user *tu;
1977
1978         tu = file->private_data;
1979         if (!tu->timeri)
1980                 return -EBADFD;
1981         snd_timer_stop(tu->timeri);
1982         tu->timeri->lost = 0;
1983         tu->last_resolution = 0;
1984         err = snd_timer_start(tu->timeri, tu->ticks);
1985         if (err < 0)
1986                 return err;
1987         return 0;
1988 }
1989
1990 static int snd_timer_user_stop(struct file *file)
1991 {
1992         int err;
1993         struct snd_timer_user *tu;
1994
1995         tu = file->private_data;
1996         if (!tu->timeri)
1997                 return -EBADFD;
1998         err = snd_timer_stop(tu->timeri);
1999         if (err < 0)
2000                 return err;
2001         return 0;
2002 }
2003
2004 static int snd_timer_user_continue(struct file *file)
2005 {
2006         int err;
2007         struct snd_timer_user *tu;
2008
2009         tu = file->private_data;
2010         if (!tu->timeri)
2011                 return -EBADFD;
2012         /* start timer instead of continue if it's not used before */
2013         if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2014                 return snd_timer_user_start(file);
2015         tu->timeri->lost = 0;
2016         err = snd_timer_continue(tu->timeri);
2017         if (err < 0)
2018                 return err;
2019         return 0;
2020 }
2021
2022 static int snd_timer_user_pause(struct file *file)
2023 {
2024         int err;
2025         struct snd_timer_user *tu;
2026
2027         tu = file->private_data;
2028         if (!tu->timeri)
2029                 return -EBADFD;
2030         err = snd_timer_pause(tu->timeri);
2031         if (err < 0)
2032                 return err;
2033         return 0;
2034 }
2035
2036 static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2037                                 unsigned int cmd, bool compat)
2038 {
2039         int __user *p = argp;
2040         int xarg, old_tread;
2041
2042         if (tu->timeri) /* too late */
2043                 return -EBUSY;
2044         if (get_user(xarg, p))
2045                 return -EFAULT;
2046
2047         old_tread = tu->tread;
2048
2049         if (!xarg)
2050                 tu->tread = TREAD_FORMAT_NONE;
2051         else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2052                  (IS_ENABLED(CONFIG_64BIT) && !compat))
2053                 tu->tread = TREAD_FORMAT_TIME64;
2054         else
2055                 tu->tread = TREAD_FORMAT_TIME32;
2056
2057         if (tu->tread != old_tread &&
2058             realloc_user_queue(tu, tu->queue_size) < 0) {
2059                 tu->tread = old_tread;
2060                 return -ENOMEM;
2061         }
2062
2063         return 0;
2064 }
2065
2066 enum {
2067         SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2068         SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2069         SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2070         SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2071 };
2072
2073 static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2074                                  unsigned long arg, bool compat)
2075 {
2076         struct snd_timer_user *tu;
2077         void __user *argp = (void __user *)arg;
2078         int __user *p = argp;
2079
2080         tu = file->private_data;
2081         switch (cmd) {
2082         case SNDRV_TIMER_IOCTL_PVERSION:
2083                 return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2084         case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2085                 return snd_timer_user_next_device(argp);
2086         case SNDRV_TIMER_IOCTL_TREAD_OLD:
2087         case SNDRV_TIMER_IOCTL_TREAD64:
2088                 return snd_timer_user_tread(argp, tu, cmd, compat);
2089         case SNDRV_TIMER_IOCTL_GINFO:
2090                 return snd_timer_user_ginfo(file, argp);
2091         case SNDRV_TIMER_IOCTL_GPARAMS:
2092                 return snd_timer_user_gparams(file, argp);
2093         case SNDRV_TIMER_IOCTL_GSTATUS:
2094                 return snd_timer_user_gstatus(file, argp);
2095         case SNDRV_TIMER_IOCTL_SELECT:
2096                 return snd_timer_user_tselect(file, argp);
2097         case SNDRV_TIMER_IOCTL_INFO:
2098                 return snd_timer_user_info(file, argp);
2099         case SNDRV_TIMER_IOCTL_PARAMS:
2100                 return snd_timer_user_params(file, argp);
2101         case SNDRV_TIMER_IOCTL_STATUS32:
2102                 return snd_timer_user_status32(file, argp);
2103         case SNDRV_TIMER_IOCTL_STATUS64:
2104                 return snd_timer_user_status64(file, argp);
2105         case SNDRV_TIMER_IOCTL_START:
2106         case SNDRV_TIMER_IOCTL_START_OLD:
2107                 return snd_timer_user_start(file);
2108         case SNDRV_TIMER_IOCTL_STOP:
2109         case SNDRV_TIMER_IOCTL_STOP_OLD:
2110                 return snd_timer_user_stop(file);
2111         case SNDRV_TIMER_IOCTL_CONTINUE:
2112         case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2113                 return snd_timer_user_continue(file);
2114         case SNDRV_TIMER_IOCTL_PAUSE:
2115         case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2116                 return snd_timer_user_pause(file);
2117         }
2118         return -ENOTTY;
2119 }
2120
2121 static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2122                                  unsigned long arg)
2123 {
2124         struct snd_timer_user *tu = file->private_data;
2125         long ret;
2126
2127         mutex_lock(&tu->ioctl_lock);
2128         ret = __snd_timer_user_ioctl(file, cmd, arg, false);
2129         mutex_unlock(&tu->ioctl_lock);
2130         return ret;
2131 }
2132
2133 static int snd_timer_user_fasync(int fd, struct file * file, int on)
2134 {
2135         struct snd_timer_user *tu;
2136
2137         tu = file->private_data;
2138         return fasync_helper(fd, file, on, &tu->fasync);
2139 }
2140
2141 static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2142                                    size_t count, loff_t *offset)
2143 {
2144         struct snd_timer_tread64 *tread;
2145         struct snd_timer_tread32 tread32;
2146         struct snd_timer_user *tu;
2147         long result = 0, unit;
2148         int qhead;
2149         int err = 0;
2150
2151         tu = file->private_data;
2152         switch (tu->tread) {
2153         case TREAD_FORMAT_TIME64:
2154                 unit = sizeof(struct snd_timer_tread64);
2155                 break;
2156         case TREAD_FORMAT_TIME32:
2157                 unit = sizeof(struct snd_timer_tread32);
2158                 break;
2159         case TREAD_FORMAT_NONE:
2160                 unit = sizeof(struct snd_timer_read);
2161                 break;
2162         default:
2163                 WARN_ONCE(1, "Corrupt snd_timer_user\n");
2164                 return -ENOTSUPP;
2165         }
2166
2167         mutex_lock(&tu->ioctl_lock);
2168         spin_lock_irq(&tu->qlock);
2169         while ((long)count - result >= unit) {
2170                 while (!tu->qused) {
2171                         wait_queue_entry_t wait;
2172
2173                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2174                                 err = -EAGAIN;
2175                                 goto _error;
2176                         }
2177
2178                         set_current_state(TASK_INTERRUPTIBLE);
2179                         init_waitqueue_entry(&wait, current);
2180                         add_wait_queue(&tu->qchange_sleep, &wait);
2181
2182                         spin_unlock_irq(&tu->qlock);
2183                         mutex_unlock(&tu->ioctl_lock);
2184                         schedule();
2185                         mutex_lock(&tu->ioctl_lock);
2186                         spin_lock_irq(&tu->qlock);
2187
2188                         remove_wait_queue(&tu->qchange_sleep, &wait);
2189
2190                         if (tu->disconnected) {
2191                                 err = -ENODEV;
2192                                 goto _error;
2193                         }
2194                         if (signal_pending(current)) {
2195                                 err = -ERESTARTSYS;
2196                                 goto _error;
2197                         }
2198                 }
2199
2200                 qhead = tu->qhead++;
2201                 tu->qhead %= tu->queue_size;
2202                 tu->qused--;
2203                 spin_unlock_irq(&tu->qlock);
2204
2205                 tread = &tu->tqueue[qhead];
2206
2207                 switch (tu->tread) {
2208                 case TREAD_FORMAT_TIME64:
2209                         if (copy_to_user(buffer, tread,
2210                                          sizeof(struct snd_timer_tread64)))
2211                                 err = -EFAULT;
2212                         break;
2213                 case TREAD_FORMAT_TIME32:
2214                         memset(&tread32, 0, sizeof(tread32));
2215                         tread32 = (struct snd_timer_tread32) {
2216                                 .event = tread->event,
2217                                 .tstamp_sec = tread->tstamp_sec,
2218                                 .tstamp_nsec = tread->tstamp_nsec,
2219                                 .val = tread->val,
2220                         };
2221
2222                         if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2223                                 err = -EFAULT;
2224                         break;
2225                 case TREAD_FORMAT_NONE:
2226                         if (copy_to_user(buffer, &tu->queue[qhead],
2227                                          sizeof(struct snd_timer_read)))
2228                                 err = -EFAULT;
2229                         break;
2230                 default:
2231                         err = -ENOTSUPP;
2232                         break;
2233                 }
2234
2235                 spin_lock_irq(&tu->qlock);
2236                 if (err < 0)
2237                         goto _error;
2238                 result += unit;
2239                 buffer += unit;
2240         }
2241  _error:
2242         spin_unlock_irq(&tu->qlock);
2243         mutex_unlock(&tu->ioctl_lock);
2244         return result > 0 ? result : err;
2245 }
2246
2247 static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2248 {
2249         __poll_t mask;
2250         struct snd_timer_user *tu;
2251
2252         tu = file->private_data;
2253
2254         poll_wait(file, &tu->qchange_sleep, wait);
2255
2256         mask = 0;
2257         spin_lock_irq(&tu->qlock);
2258         if (tu->qused)
2259                 mask |= EPOLLIN | EPOLLRDNORM;
2260         if (tu->disconnected)
2261                 mask |= EPOLLERR;
2262         spin_unlock_irq(&tu->qlock);
2263
2264         return mask;
2265 }
2266
2267 #ifdef CONFIG_COMPAT
2268 #include "timer_compat.c"
2269 #else
2270 #define snd_timer_user_ioctl_compat     NULL
2271 #endif
2272
2273 static const struct file_operations snd_timer_f_ops =
2274 {
2275         .owner =        THIS_MODULE,
2276         .read =         snd_timer_user_read,
2277         .open =         snd_timer_user_open,
2278         .release =      snd_timer_user_release,
2279         .llseek =       no_llseek,
2280         .poll =         snd_timer_user_poll,
2281         .unlocked_ioctl =       snd_timer_user_ioctl,
2282         .compat_ioctl = snd_timer_user_ioctl_compat,
2283         .fasync =       snd_timer_user_fasync,
2284 };
2285
2286 /* unregister the system timer */
2287 static void snd_timer_free_all(void)
2288 {
2289         struct snd_timer *timer, *n;
2290
2291         list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2292                 snd_timer_free(timer);
2293 }
2294
2295 static struct device timer_dev;
2296
2297 /*
2298  *  ENTRY functions
2299  */
2300
2301 static int __init alsa_timer_init(void)
2302 {
2303         int err;
2304
2305         snd_device_initialize(&timer_dev, NULL);
2306         dev_set_name(&timer_dev, "timer");
2307
2308 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2309         snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2310                               "system timer");
2311 #endif
2312
2313         err = snd_timer_register_system();
2314         if (err < 0) {
2315                 pr_err("ALSA: unable to register system timer (%i)\n", err);
2316                 goto put_timer;
2317         }
2318
2319         err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2320                                   &snd_timer_f_ops, NULL, &timer_dev);
2321         if (err < 0) {
2322                 pr_err("ALSA: unable to register timer device (%i)\n", err);
2323                 snd_timer_free_all();
2324                 goto put_timer;
2325         }
2326
2327         snd_timer_proc_init();
2328         return 0;
2329
2330 put_timer:
2331         put_device(&timer_dev);
2332         return err;
2333 }
2334
2335 static void __exit alsa_timer_exit(void)
2336 {
2337         snd_unregister_device(&timer_dev);
2338         snd_timer_free_all();
2339         put_device(&timer_dev);
2340         snd_timer_proc_done();
2341 #ifdef SNDRV_OSS_INFO_DEV_TIMERS
2342         snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2343 #endif
2344 }
2345
2346 module_init(alsa_timer_init)
2347 module_exit(alsa_timer_exit)