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
  34static int timer_limit = DEFAULT_TIMER_LIMIT;
  35static int timer_tstamp_monotonic = 1;
  36MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
  37MODULE_DESCRIPTION("ALSA timer interface");
  38MODULE_LICENSE("GPL");
  39module_param(timer_limit, int, 0444);
  40MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
  41module_param(timer_tstamp_monotonic, int, 0444);
  42MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
  43
  44MODULE_ALIAS_CHARDEV(CONFIG_SND_MAJOR, SNDRV_MINOR_TIMER);
  45MODULE_ALIAS("devname:snd/timer");
  46
  47enum timer_tread_format {
  48	TREAD_FORMAT_NONE = 0,
  49	TREAD_FORMAT_TIME64,
  50	TREAD_FORMAT_TIME32,
  51};
  52
  53struct snd_timer_tread32 {
  54	int event;
  55	s32 tstamp_sec;
  56	s32 tstamp_nsec;
  57	unsigned int val;
  58};
  59
  60struct 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
  69struct 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 snd_fasync *fasync;
  87	struct mutex ioctl_lock;
  88};
  89
  90struct 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
 102struct 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 */
 115static LIST_HEAD(snd_timer_list);
 116
 117/* list of slave instances */
 118static LIST_HEAD(snd_timer_slave_list);
 119
 120/* lock for slave active lists */
 121static DEFINE_SPINLOCK(slave_active_lock);
 122
 123#define MAX_SLAVE_INSTANCES	1000
 124static int num_slaves;
 125
 126static DEFINE_MUTEX(register_mutex);
 127
 128static int snd_timer_free(struct snd_timer *timer);
 129static int snd_timer_dev_free(struct snd_device *device);
 130static int snd_timer_dev_register(struct snd_device *device);
 131static int snd_timer_dev_disconnect(struct snd_device *device);
 132
 133static 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 */
 138struct 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}
 158EXPORT_SYMBOL(snd_timer_instance_new);
 159
 160void 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}
 169EXPORT_SYMBOL(snd_timer_instance_free);
 170
 171/*
 172 * find a timer instance from the given timer id
 173 */
 174static 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
 197static 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 */
 217static 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 */
 244static 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 */
 268static 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
 282static 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 */
 289int 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);
 372list_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}
 383EXPORT_SYMBOL(snd_timer_open);
 384
 385/*
 386 * close a timer instance
 387 * call this with register_mutex down.
 388 */
 389static 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 */
 455void 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}
 469EXPORT_SYMBOL(snd_timer_close);
 470
 471static 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
 479unsigned 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}
 495EXPORT_SYMBOL(snd_timer_resolution);
 496
 497static 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 */
 530static 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 */
 586static 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 */
 617static 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 */
 665static 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 */
 689int 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}
 698EXPORT_SYMBOL(snd_timer_start);
 699
 700/*
 701 * stop the timer instance.
 702 *
 703 * do not call this from the timer callback!
 704 */
 705int 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}
 712EXPORT_SYMBOL(snd_timer_stop);
 713
 714/*
 715 * start again..  the tick is kept.
 716 */
 717int 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}
 728EXPORT_SYMBOL(snd_timer_continue);
 729
 730/*
 731 * pause.. remember the ticks left
 732 */
 733int 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}
 740EXPORT_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 */
 748static 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 */
 776static 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 */
 804static 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 */
 819static 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 */
 840void 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}
 928EXPORT_SYMBOL(snd_timer_interrupt);
 929
 930/*
 931
 932 */
 933
 934int 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}
 984EXPORT_SYMBOL(snd_timer_new);
 985
 986static 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
1011static 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
1017static 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
1057static 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
1073void 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}
1100EXPORT_SYMBOL(snd_timer_notify);
1101
1102/*
1103 * exported functions for global timers
1104 */
1105int 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}
1116EXPORT_SYMBOL(snd_timer_global_new);
1117
1118int snd_timer_global_free(struct snd_timer *timer)
1119{
1120	return snd_timer_free(timer);
1121}
1122EXPORT_SYMBOL(snd_timer_global_free);
1123
1124int 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}
1132EXPORT_SYMBOL(snd_timer_global_register);
1133
1134/*
1135 *  System timer
1136 */
1137
1138struct 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
1146static 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
1157static 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
1176static 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
1192static 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
1201static 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
1211static void snd_timer_free_system(struct snd_timer *timer)
1212{
1213	kfree(timer->private_data);
1214}
1215
1216static 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
1244static 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	unsigned long resolution;
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		spin_lock_irq(&timer->lock);
1274		resolution = snd_timer_hw_resolution(timer);
1275		spin_unlock_irq(&timer->lock);
1276		if (resolution)
1277			snd_iprintf(buffer, " %lu.%03luus (%lu ticks)",
1278				    resolution / 1000,
1279				    resolution % 1000,
1280				    timer->hw.ticks);
1281		if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
1282			snd_iprintf(buffer, " SLAVE");
1283		snd_iprintf(buffer, "\n");
1284		list_for_each_entry(ti, &timer->open_list_head, open_list)
1285			snd_iprintf(buffer, "  Client %s : %s\n",
1286				    ti->owner ? ti->owner : "unknown",
1287				    (ti->flags & (SNDRV_TIMER_IFLG_START |
1288						  SNDRV_TIMER_IFLG_RUNNING))
1289				    ? "running" : "stopped");
1290	}
1291	mutex_unlock(&register_mutex);
1292}
1293
1294static struct snd_info_entry *snd_timer_proc_entry;
1295
1296static void __init snd_timer_proc_init(void)
1297{
1298	struct snd_info_entry *entry;
1299
1300	entry = snd_info_create_module_entry(THIS_MODULE, "timers", NULL);
1301	if (entry != NULL) {
1302		entry->c.text.read = snd_timer_proc_read;
1303		if (snd_info_register(entry) < 0) {
1304			snd_info_free_entry(entry);
1305			entry = NULL;
1306		}
1307	}
1308	snd_timer_proc_entry = entry;
1309}
1310
1311static void __exit snd_timer_proc_done(void)
1312{
1313	snd_info_free_entry(snd_timer_proc_entry);
1314}
1315#else /* !CONFIG_SND_PROC_FS */
1316#define snd_timer_proc_init()
1317#define snd_timer_proc_done()
1318#endif
1319
1320/*
1321 *  USER SPACE interface
1322 */
1323
1324static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
1325				     unsigned long resolution,
1326				     unsigned long ticks)
1327{
1328	struct snd_timer_user *tu = timeri->callback_data;
1329	struct snd_timer_read *r;
1330	int prev;
1331
1332	spin_lock(&tu->qlock);
1333	if (tu->qused > 0) {
1334		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1335		r = &tu->queue[prev];
1336		if (r->resolution == resolution) {
1337			r->ticks += ticks;
1338			goto __wake;
1339		}
1340	}
1341	if (tu->qused >= tu->queue_size) {
1342		tu->overrun++;
1343	} else {
1344		r = &tu->queue[tu->qtail++];
1345		tu->qtail %= tu->queue_size;
1346		r->resolution = resolution;
1347		r->ticks = ticks;
1348		tu->qused++;
1349	}
1350      __wake:
1351	spin_unlock(&tu->qlock);
1352	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1353	wake_up(&tu->qchange_sleep);
1354}
1355
1356static void snd_timer_user_append_to_tqueue(struct snd_timer_user *tu,
1357					    struct snd_timer_tread64 *tread)
1358{
1359	if (tu->qused >= tu->queue_size) {
1360		tu->overrun++;
1361	} else {
1362		memcpy(&tu->tqueue[tu->qtail++], tread, sizeof(*tread));
1363		tu->qtail %= tu->queue_size;
1364		tu->qused++;
1365	}
1366}
1367
1368static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
1369				     int event,
1370				     struct timespec64 *tstamp,
1371				     unsigned long resolution)
1372{
1373	struct snd_timer_user *tu = timeri->callback_data;
1374	struct snd_timer_tread64 r1;
1375	unsigned long flags;
1376
1377	if (event >= SNDRV_TIMER_EVENT_START &&
1378	    event <= SNDRV_TIMER_EVENT_PAUSE)
1379		tu->tstamp = *tstamp;
1380	if ((tu->filter & (1 << event)) == 0 || !tu->tread)
1381		return;
1382	memset(&r1, 0, sizeof(r1));
1383	r1.event = event;
1384	r1.tstamp_sec = tstamp->tv_sec;
1385	r1.tstamp_nsec = tstamp->tv_nsec;
1386	r1.val = resolution;
1387	spin_lock_irqsave(&tu->qlock, flags);
1388	snd_timer_user_append_to_tqueue(tu, &r1);
1389	spin_unlock_irqrestore(&tu->qlock, flags);
1390	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1391	wake_up(&tu->qchange_sleep);
1392}
1393
1394static void snd_timer_user_disconnect(struct snd_timer_instance *timeri)
1395{
1396	struct snd_timer_user *tu = timeri->callback_data;
1397
1398	tu->disconnected = true;
1399	wake_up(&tu->qchange_sleep);
1400}
1401
1402static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
1403				      unsigned long resolution,
1404				      unsigned long ticks)
1405{
1406	struct snd_timer_user *tu = timeri->callback_data;
1407	struct snd_timer_tread64 *r, r1;
1408	struct timespec64 tstamp;
1409	int prev, append = 0;
1410
1411	memset(&r1, 0, sizeof(r1));
1412	memset(&tstamp, 0, sizeof(tstamp));
1413	spin_lock(&tu->qlock);
1414	if ((tu->filter & ((1 << SNDRV_TIMER_EVENT_RESOLUTION) |
1415			   (1 << SNDRV_TIMER_EVENT_TICK))) == 0) {
1416		spin_unlock(&tu->qlock);
1417		return;
1418	}
1419	if (tu->last_resolution != resolution || ticks > 0) {
1420		if (timer_tstamp_monotonic)
1421			ktime_get_ts64(&tstamp);
1422		else
1423			ktime_get_real_ts64(&tstamp);
1424	}
1425	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
1426	    tu->last_resolution != resolution) {
1427		r1.event = SNDRV_TIMER_EVENT_RESOLUTION;
1428		r1.tstamp_sec = tstamp.tv_sec;
1429		r1.tstamp_nsec = tstamp.tv_nsec;
1430		r1.val = resolution;
1431		snd_timer_user_append_to_tqueue(tu, &r1);
1432		tu->last_resolution = resolution;
1433		append++;
1434	}
1435	if ((tu->filter & (1 << SNDRV_TIMER_EVENT_TICK)) == 0)
1436		goto __wake;
1437	if (ticks == 0)
1438		goto __wake;
1439	if (tu->qused > 0) {
1440		prev = tu->qtail == 0 ? tu->queue_size - 1 : tu->qtail - 1;
1441		r = &tu->tqueue[prev];
1442		if (r->event == SNDRV_TIMER_EVENT_TICK) {
1443			r->tstamp_sec = tstamp.tv_sec;
1444			r->tstamp_nsec = tstamp.tv_nsec;
1445			r->val += ticks;
1446			append++;
1447			goto __wake;
1448		}
1449	}
1450	r1.event = SNDRV_TIMER_EVENT_TICK;
1451	r1.tstamp_sec = tstamp.tv_sec;
1452	r1.tstamp_nsec = tstamp.tv_nsec;
1453	r1.val = ticks;
1454	snd_timer_user_append_to_tqueue(tu, &r1);
1455	append++;
1456      __wake:
1457	spin_unlock(&tu->qlock);
1458	if (append == 0)
1459		return;
1460	snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
1461	wake_up(&tu->qchange_sleep);
1462}
1463
1464static int realloc_user_queue(struct snd_timer_user *tu, int size)
1465{
1466	struct snd_timer_read *queue = NULL;
1467	struct snd_timer_tread64 *tqueue = NULL;
1468
1469	if (tu->tread) {
1470		tqueue = kcalloc(size, sizeof(*tqueue), GFP_KERNEL);
1471		if (!tqueue)
1472			return -ENOMEM;
1473	} else {
1474		queue = kcalloc(size, sizeof(*queue), GFP_KERNEL);
1475		if (!queue)
1476			return -ENOMEM;
1477	}
1478
1479	spin_lock_irq(&tu->qlock);
1480	kfree(tu->queue);
1481	kfree(tu->tqueue);
1482	tu->queue_size = size;
1483	tu->queue = queue;
1484	tu->tqueue = tqueue;
1485	tu->qhead = tu->qtail = tu->qused = 0;
1486	spin_unlock_irq(&tu->qlock);
1487
1488	return 0;
1489}
1490
1491static int snd_timer_user_open(struct inode *inode, struct file *file)
1492{
1493	struct snd_timer_user *tu;
1494	int err;
1495
1496	err = stream_open(inode, file);
1497	if (err < 0)
1498		return err;
1499
1500	tu = kzalloc(sizeof(*tu), GFP_KERNEL);
1501	if (tu == NULL)
1502		return -ENOMEM;
1503	spin_lock_init(&tu->qlock);
1504	init_waitqueue_head(&tu->qchange_sleep);
1505	mutex_init(&tu->ioctl_lock);
1506	tu->ticks = 1;
1507	if (realloc_user_queue(tu, 128) < 0) {
1508		kfree(tu);
1509		return -ENOMEM;
1510	}
1511	file->private_data = tu;
1512	return 0;
1513}
1514
1515static int snd_timer_user_release(struct inode *inode, struct file *file)
1516{
1517	struct snd_timer_user *tu;
1518
1519	if (file->private_data) {
1520		tu = file->private_data;
1521		file->private_data = NULL;
1522		mutex_lock(&tu->ioctl_lock);
1523		if (tu->timeri) {
1524			snd_timer_close(tu->timeri);
1525			snd_timer_instance_free(tu->timeri);
1526		}
1527		mutex_unlock(&tu->ioctl_lock);
1528		snd_fasync_free(tu->fasync);
1529		kfree(tu->queue);
1530		kfree(tu->tqueue);
1531		kfree(tu);
1532	}
1533	return 0;
1534}
1535
1536static void snd_timer_user_zero_id(struct snd_timer_id *id)
1537{
1538	id->dev_class = SNDRV_TIMER_CLASS_NONE;
1539	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1540	id->card = -1;
1541	id->device = -1;
1542	id->subdevice = -1;
1543}
1544
1545static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *timer)
1546{
1547	id->dev_class = timer->tmr_class;
1548	id->dev_sclass = SNDRV_TIMER_SCLASS_NONE;
1549	id->card = timer->card ? timer->card->number : -1;
1550	id->device = timer->tmr_device;
1551	id->subdevice = timer->tmr_subdevice;
1552}
1553
1554static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
1555{
1556	struct snd_timer_id id;
1557	struct snd_timer *timer;
1558	struct list_head *p;
1559
1560	if (copy_from_user(&id, _tid, sizeof(id)))
1561		return -EFAULT;
1562	mutex_lock(&register_mutex);
1563	if (id.dev_class < 0) {		/* first item */
1564		if (list_empty(&snd_timer_list))
1565			snd_timer_user_zero_id(&id);
1566		else {
1567			timer = list_entry(snd_timer_list.next,
1568					   struct snd_timer, device_list);
1569			snd_timer_user_copy_id(&id, timer);
1570		}
1571	} else {
1572		switch (id.dev_class) {
1573		case SNDRV_TIMER_CLASS_GLOBAL:
1574			id.device = id.device < 0 ? 0 : id.device + 1;
1575			list_for_each(p, &snd_timer_list) {
1576				timer = list_entry(p, struct snd_timer, device_list);
1577				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
1578					snd_timer_user_copy_id(&id, timer);
1579					break;
1580				}
1581				if (timer->tmr_device >= id.device) {
1582					snd_timer_user_copy_id(&id, timer);
1583					break;
1584				}
1585			}
1586			if (p == &snd_timer_list)
1587				snd_timer_user_zero_id(&id);
1588			break;
1589		case SNDRV_TIMER_CLASS_CARD:
1590		case SNDRV_TIMER_CLASS_PCM:
1591			if (id.card < 0) {
1592				id.card = 0;
1593			} else {
1594				if (id.device < 0) {
1595					id.device = 0;
1596				} else {
1597					if (id.subdevice < 0)
1598						id.subdevice = 0;
1599					else if (id.subdevice < INT_MAX)
1600						id.subdevice++;
1601				}
1602			}
1603			list_for_each(p, &snd_timer_list) {
1604				timer = list_entry(p, struct snd_timer, device_list);
1605				if (timer->tmr_class > id.dev_class) {
1606					snd_timer_user_copy_id(&id, timer);
1607					break;
1608				}
1609				if (timer->tmr_class < id.dev_class)
1610					continue;
1611				if (timer->card->number > id.card) {
1612					snd_timer_user_copy_id(&id, timer);
1613					break;
1614				}
1615				if (timer->card->number < id.card)
1616					continue;
1617				if (timer->tmr_device > id.device) {
1618					snd_timer_user_copy_id(&id, timer);
1619					break;
1620				}
1621				if (timer->tmr_device < id.device)
1622					continue;
1623				if (timer->tmr_subdevice > id.subdevice) {
1624					snd_timer_user_copy_id(&id, timer);
1625					break;
1626				}
1627				if (timer->tmr_subdevice < id.subdevice)
1628					continue;
1629				snd_timer_user_copy_id(&id, timer);
1630				break;
1631			}
1632			if (p == &snd_timer_list)
1633				snd_timer_user_zero_id(&id);
1634			break;
1635		default:
1636			snd_timer_user_zero_id(&id);
1637		}
1638	}
1639	mutex_unlock(&register_mutex);
1640	if (copy_to_user(_tid, &id, sizeof(*_tid)))
1641		return -EFAULT;
1642	return 0;
1643}
1644
1645static int snd_timer_user_ginfo(struct file *file,
1646				struct snd_timer_ginfo __user *_ginfo)
1647{
1648	struct snd_timer_ginfo *ginfo;
1649	struct snd_timer_id tid;
1650	struct snd_timer *t;
1651	struct list_head *p;
1652	int err = 0;
1653
1654	ginfo = memdup_user(_ginfo, sizeof(*ginfo));
1655	if (IS_ERR(ginfo))
1656		return PTR_ERR(ginfo);
1657
1658	tid = ginfo->tid;
1659	memset(ginfo, 0, sizeof(*ginfo));
1660	ginfo->tid = tid;
1661	mutex_lock(&register_mutex);
1662	t = snd_timer_find(&tid);
1663	if (t != NULL) {
1664		ginfo->card = t->card ? t->card->number : -1;
1665		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1666			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
1667		strscpy(ginfo->id, t->id, sizeof(ginfo->id));
1668		strscpy(ginfo->name, t->name, sizeof(ginfo->name));
1669		spin_lock_irq(&t->lock);
1670		ginfo->resolution = snd_timer_hw_resolution(t);
1671		spin_unlock_irq(&t->lock);
1672		if (t->hw.resolution_min > 0) {
1673			ginfo->resolution_min = t->hw.resolution_min;
1674			ginfo->resolution_max = t->hw.resolution_max;
1675		}
1676		list_for_each(p, &t->open_list_head) {
1677			ginfo->clients++;
1678		}
1679	} else {
1680		err = -ENODEV;
1681	}
1682	mutex_unlock(&register_mutex);
1683	if (err >= 0 && copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
1684		err = -EFAULT;
1685	kfree(ginfo);
1686	return err;
1687}
1688
1689static int timer_set_gparams(struct snd_timer_gparams *gparams)
1690{
1691	struct snd_timer *t;
1692	int err;
1693
1694	mutex_lock(&register_mutex);
1695	t = snd_timer_find(&gparams->tid);
1696	if (!t) {
1697		err = -ENODEV;
1698		goto _error;
1699	}
1700	if (!list_empty(&t->open_list_head)) {
1701		err = -EBUSY;
1702		goto _error;
1703	}
1704	if (!t->hw.set_period) {
1705		err = -ENOSYS;
1706		goto _error;
1707	}
1708	err = t->hw.set_period(t, gparams->period_num, gparams->period_den);
1709_error:
1710	mutex_unlock(&register_mutex);
1711	return err;
1712}
1713
1714static int snd_timer_user_gparams(struct file *file,
1715				  struct snd_timer_gparams __user *_gparams)
1716{
1717	struct snd_timer_gparams gparams;
1718
1719	if (copy_from_user(&gparams, _gparams, sizeof(gparams)))
1720		return -EFAULT;
1721	return timer_set_gparams(&gparams);
1722}
1723
1724static int snd_timer_user_gstatus(struct file *file,
1725				  struct snd_timer_gstatus __user *_gstatus)
1726{
1727	struct snd_timer_gstatus gstatus;
1728	struct snd_timer_id tid;
1729	struct snd_timer *t;
1730	int err = 0;
1731
1732	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
1733		return -EFAULT;
1734	tid = gstatus.tid;
1735	memset(&gstatus, 0, sizeof(gstatus));
1736	gstatus.tid = tid;
1737	mutex_lock(&register_mutex);
1738	t = snd_timer_find(&tid);
1739	if (t != NULL) {
1740		spin_lock_irq(&t->lock);
1741		gstatus.resolution = snd_timer_hw_resolution(t);
1742		if (t->hw.precise_resolution) {
1743			t->hw.precise_resolution(t, &gstatus.resolution_num,
1744						 &gstatus.resolution_den);
1745		} else {
1746			gstatus.resolution_num = gstatus.resolution;
1747			gstatus.resolution_den = 1000000000uL;
1748		}
1749		spin_unlock_irq(&t->lock);
1750	} else {
1751		err = -ENODEV;
1752	}
1753	mutex_unlock(&register_mutex);
1754	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
1755		err = -EFAULT;
1756	return err;
1757}
1758
1759static int snd_timer_user_tselect(struct file *file,
1760				  struct snd_timer_select __user *_tselect)
1761{
1762	struct snd_timer_user *tu;
1763	struct snd_timer_select tselect;
1764	char str[32];
1765	int err = 0;
1766
1767	tu = file->private_data;
1768	if (tu->timeri) {
1769		snd_timer_close(tu->timeri);
1770		snd_timer_instance_free(tu->timeri);
1771		tu->timeri = NULL;
1772	}
1773	if (copy_from_user(&tselect, _tselect, sizeof(tselect))) {
1774		err = -EFAULT;
1775		goto __err;
1776	}
1777	sprintf(str, "application %i", current->pid);
1778	if (tselect.id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
1779		tselect.id.dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION;
1780	tu->timeri = snd_timer_instance_new(str);
1781	if (!tu->timeri) {
1782		err = -ENOMEM;
1783		goto __err;
1784	}
1785
1786	tu->timeri->flags |= SNDRV_TIMER_IFLG_FAST;
1787	tu->timeri->callback = tu->tread
1788			? snd_timer_user_tinterrupt : snd_timer_user_interrupt;
1789	tu->timeri->ccallback = snd_timer_user_ccallback;
1790	tu->timeri->callback_data = (void *)tu;
1791	tu->timeri->disconnect = snd_timer_user_disconnect;
1792
1793	err = snd_timer_open(tu->timeri, &tselect.id, current->pid);
1794	if (err < 0) {
1795		snd_timer_instance_free(tu->timeri);
1796		tu->timeri = NULL;
1797	}
1798
1799      __err:
1800	return err;
1801}
1802
1803static int snd_timer_user_info(struct file *file,
1804			       struct snd_timer_info __user *_info)
1805{
1806	struct snd_timer_user *tu;
1807	struct snd_timer_info *info;
1808	struct snd_timer *t;
1809	int err = 0;
1810
1811	tu = file->private_data;
1812	if (!tu->timeri)
1813		return -EBADFD;
1814	t = tu->timeri->timer;
1815	if (!t)
1816		return -EBADFD;
1817
1818	info = kzalloc(sizeof(*info), GFP_KERNEL);
1819	if (! info)
1820		return -ENOMEM;
1821	info->card = t->card ? t->card->number : -1;
1822	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
1823		info->flags |= SNDRV_TIMER_FLG_SLAVE;
1824	strscpy(info->id, t->id, sizeof(info->id));
1825	strscpy(info->name, t->name, sizeof(info->name));
1826	spin_lock_irq(&t->lock);
1827	info->resolution = snd_timer_hw_resolution(t);
1828	spin_unlock_irq(&t->lock);
1829	if (copy_to_user(_info, info, sizeof(*_info)))
1830		err = -EFAULT;
1831	kfree(info);
1832	return err;
1833}
1834
1835static int snd_timer_user_params(struct file *file,
1836				 struct snd_timer_params __user *_params)
1837{
1838	struct snd_timer_user *tu;
1839	struct snd_timer_params params;
1840	struct snd_timer *t;
1841	int err;
1842
1843	tu = file->private_data;
1844	if (!tu->timeri)
1845		return -EBADFD;
1846	t = tu->timeri->timer;
1847	if (!t)
1848		return -EBADFD;
1849	if (copy_from_user(&params, _params, sizeof(params)))
1850		return -EFAULT;
1851	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
1852		u64 resolution;
1853
1854		if (params.ticks < 1) {
1855			err = -EINVAL;
1856			goto _end;
1857		}
1858
1859		/* Don't allow resolution less than 1ms */
1860		resolution = snd_timer_resolution(tu->timeri);
1861		resolution *= params.ticks;
1862		if (resolution < 1000000) {
1863			err = -EINVAL;
1864			goto _end;
1865		}
1866	}
1867	if (params.queue_size > 0 &&
1868	    (params.queue_size < 32 || params.queue_size > 1024)) {
1869		err = -EINVAL;
1870		goto _end;
1871	}
1872	if (params.filter & ~((1<<SNDRV_TIMER_EVENT_RESOLUTION)|
1873			      (1<<SNDRV_TIMER_EVENT_TICK)|
1874			      (1<<SNDRV_TIMER_EVENT_START)|
1875			      (1<<SNDRV_TIMER_EVENT_STOP)|
1876			      (1<<SNDRV_TIMER_EVENT_CONTINUE)|
1877			      (1<<SNDRV_TIMER_EVENT_PAUSE)|
1878			      (1<<SNDRV_TIMER_EVENT_SUSPEND)|
1879			      (1<<SNDRV_TIMER_EVENT_RESUME)|
1880			      (1<<SNDRV_TIMER_EVENT_MSTART)|
1881			      (1<<SNDRV_TIMER_EVENT_MSTOP)|
1882			      (1<<SNDRV_TIMER_EVENT_MCONTINUE)|
1883			      (1<<SNDRV_TIMER_EVENT_MPAUSE)|
1884			      (1<<SNDRV_TIMER_EVENT_MSUSPEND)|
1885			      (1<<SNDRV_TIMER_EVENT_MRESUME))) {
1886		err = -EINVAL;
1887		goto _end;
1888	}
1889	snd_timer_stop(tu->timeri);
1890	spin_lock_irq(&t->lock);
1891	tu->timeri->flags &= ~(SNDRV_TIMER_IFLG_AUTO|
1892			       SNDRV_TIMER_IFLG_EXCLUSIVE|
1893			       SNDRV_TIMER_IFLG_EARLY_EVENT);
1894	if (params.flags & SNDRV_TIMER_PSFLG_AUTO)
1895		tu->timeri->flags |= SNDRV_TIMER_IFLG_AUTO;
1896	if (params.flags & SNDRV_TIMER_PSFLG_EXCLUSIVE)
1897		tu->timeri->flags |= SNDRV_TIMER_IFLG_EXCLUSIVE;
1898	if (params.flags & SNDRV_TIMER_PSFLG_EARLY_EVENT)
1899		tu->timeri->flags |= SNDRV_TIMER_IFLG_EARLY_EVENT;
1900	spin_unlock_irq(&t->lock);
1901	if (params.queue_size > 0 &&
1902	    (unsigned int)tu->queue_size != params.queue_size) {
1903		err = realloc_user_queue(tu, params.queue_size);
1904		if (err < 0)
1905			goto _end;
1906	}
1907	spin_lock_irq(&tu->qlock);
1908	tu->qhead = tu->qtail = tu->qused = 0;
1909	if (tu->timeri->flags & SNDRV_TIMER_IFLG_EARLY_EVENT) {
1910		if (tu->tread) {
1911			struct snd_timer_tread64 tread;
1912			memset(&tread, 0, sizeof(tread));
1913			tread.event = SNDRV_TIMER_EVENT_EARLY;
1914			tread.tstamp_sec = 0;
1915			tread.tstamp_nsec = 0;
1916			tread.val = 0;
1917			snd_timer_user_append_to_tqueue(tu, &tread);
1918		} else {
1919			struct snd_timer_read *r = &tu->queue[0];
1920			r->resolution = 0;
1921			r->ticks = 0;
1922			tu->qused++;
1923			tu->qtail++;
1924		}
1925	}
1926	tu->filter = params.filter;
1927	tu->ticks = params.ticks;
1928	spin_unlock_irq(&tu->qlock);
1929	err = 0;
1930 _end:
1931	if (copy_to_user(_params, &params, sizeof(params)))
1932		return -EFAULT;
1933	return err;
1934}
1935
1936static int snd_timer_user_status32(struct file *file,
1937				   struct snd_timer_status32 __user *_status)
1938 {
1939	struct snd_timer_user *tu;
1940	struct snd_timer_status32 status;
1941
1942	tu = file->private_data;
1943	if (!tu->timeri)
1944		return -EBADFD;
1945	memset(&status, 0, sizeof(status));
1946	status.tstamp_sec = tu->tstamp.tv_sec;
1947	status.tstamp_nsec = tu->tstamp.tv_nsec;
1948	status.resolution = snd_timer_resolution(tu->timeri);
1949	status.lost = tu->timeri->lost;
1950	status.overrun = tu->overrun;
1951	spin_lock_irq(&tu->qlock);
1952	status.queue = tu->qused;
1953	spin_unlock_irq(&tu->qlock);
1954	if (copy_to_user(_status, &status, sizeof(status)))
1955		return -EFAULT;
1956	return 0;
1957}
1958
1959static int snd_timer_user_status64(struct file *file,
1960				   struct snd_timer_status64 __user *_status)
1961{
1962	struct snd_timer_user *tu;
1963	struct snd_timer_status64 status;
1964
1965	tu = file->private_data;
1966	if (!tu->timeri)
1967		return -EBADFD;
1968	memset(&status, 0, sizeof(status));
1969	status.tstamp_sec = tu->tstamp.tv_sec;
1970	status.tstamp_nsec = tu->tstamp.tv_nsec;
1971	status.resolution = snd_timer_resolution(tu->timeri);
1972	status.lost = tu->timeri->lost;
1973	status.overrun = tu->overrun;
1974	spin_lock_irq(&tu->qlock);
1975	status.queue = tu->qused;
1976	spin_unlock_irq(&tu->qlock);
1977	if (copy_to_user(_status, &status, sizeof(status)))
1978		return -EFAULT;
1979	return 0;
1980}
1981
1982static int snd_timer_user_start(struct file *file)
1983{
1984	int err;
1985	struct snd_timer_user *tu;
1986
1987	tu = file->private_data;
1988	if (!tu->timeri)
1989		return -EBADFD;
1990	snd_timer_stop(tu->timeri);
1991	tu->timeri->lost = 0;
1992	tu->last_resolution = 0;
1993	err = snd_timer_start(tu->timeri, tu->ticks);
1994	if (err < 0)
1995		return err;
1996	return 0;
1997}
1998
1999static int snd_timer_user_stop(struct file *file)
2000{
2001	int err;
2002	struct snd_timer_user *tu;
2003
2004	tu = file->private_data;
2005	if (!tu->timeri)
2006		return -EBADFD;
2007	err = snd_timer_stop(tu->timeri);
2008	if (err < 0)
2009		return err;
2010	return 0;
2011}
2012
2013static int snd_timer_user_continue(struct file *file)
2014{
2015	int err;
2016	struct snd_timer_user *tu;
2017
2018	tu = file->private_data;
2019	if (!tu->timeri)
2020		return -EBADFD;
2021	/* start timer instead of continue if it's not used before */
2022	if (!(tu->timeri->flags & SNDRV_TIMER_IFLG_PAUSED))
2023		return snd_timer_user_start(file);
2024	tu->timeri->lost = 0;
2025	err = snd_timer_continue(tu->timeri);
2026	if (err < 0)
2027		return err;
2028	return 0;
2029}
2030
2031static int snd_timer_user_pause(struct file *file)
2032{
2033	int err;
2034	struct snd_timer_user *tu;
2035
2036	tu = file->private_data;
2037	if (!tu->timeri)
2038		return -EBADFD;
2039	err = snd_timer_pause(tu->timeri);
2040	if (err < 0)
2041		return err;
2042	return 0;
2043}
2044
2045static int snd_timer_user_tread(void __user *argp, struct snd_timer_user *tu,
2046				unsigned int cmd, bool compat)
2047{
2048	int __user *p = argp;
2049	int xarg, old_tread;
2050
2051	if (tu->timeri)	/* too late */
2052		return -EBUSY;
2053	if (get_user(xarg, p))
2054		return -EFAULT;
2055
2056	old_tread = tu->tread;
2057
2058	if (!xarg)
2059		tu->tread = TREAD_FORMAT_NONE;
2060	else if (cmd == SNDRV_TIMER_IOCTL_TREAD64 ||
2061		 (IS_ENABLED(CONFIG_64BIT) && !compat))
2062		tu->tread = TREAD_FORMAT_TIME64;
2063	else
2064		tu->tread = TREAD_FORMAT_TIME32;
2065
2066	if (tu->tread != old_tread &&
2067	    realloc_user_queue(tu, tu->queue_size) < 0) {
2068		tu->tread = old_tread;
2069		return -ENOMEM;
2070	}
2071
2072	return 0;
2073}
2074
2075enum {
2076	SNDRV_TIMER_IOCTL_START_OLD = _IO('T', 0x20),
2077	SNDRV_TIMER_IOCTL_STOP_OLD = _IO('T', 0x21),
2078	SNDRV_TIMER_IOCTL_CONTINUE_OLD = _IO('T', 0x22),
2079	SNDRV_TIMER_IOCTL_PAUSE_OLD = _IO('T', 0x23),
2080};
2081
2082static long __snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2083				 unsigned long arg, bool compat)
2084{
2085	struct snd_timer_user *tu;
2086	void __user *argp = (void __user *)arg;
2087	int __user *p = argp;
2088
2089	tu = file->private_data;
2090	switch (cmd) {
2091	case SNDRV_TIMER_IOCTL_PVERSION:
2092		return put_user(SNDRV_TIMER_VERSION, p) ? -EFAULT : 0;
2093	case SNDRV_TIMER_IOCTL_NEXT_DEVICE:
2094		return snd_timer_user_next_device(argp);
2095	case SNDRV_TIMER_IOCTL_TREAD_OLD:
2096	case SNDRV_TIMER_IOCTL_TREAD64:
2097		return snd_timer_user_tread(argp, tu, cmd, compat);
2098	case SNDRV_TIMER_IOCTL_GINFO:
2099		return snd_timer_user_ginfo(file, argp);
2100	case SNDRV_TIMER_IOCTL_GPARAMS:
2101		return snd_timer_user_gparams(file, argp);
2102	case SNDRV_TIMER_IOCTL_GSTATUS:
2103		return snd_timer_user_gstatus(file, argp);
2104	case SNDRV_TIMER_IOCTL_SELECT:
2105		return snd_timer_user_tselect(file, argp);
2106	case SNDRV_TIMER_IOCTL_INFO:
2107		return snd_timer_user_info(file, argp);
2108	case SNDRV_TIMER_IOCTL_PARAMS:
2109		return snd_timer_user_params(file, argp);
2110	case SNDRV_TIMER_IOCTL_STATUS32:
2111		return snd_timer_user_status32(file, argp);
2112	case SNDRV_TIMER_IOCTL_STATUS64:
2113		return snd_timer_user_status64(file, argp);
2114	case SNDRV_TIMER_IOCTL_START:
2115	case SNDRV_TIMER_IOCTL_START_OLD:
2116		return snd_timer_user_start(file);
2117	case SNDRV_TIMER_IOCTL_STOP:
2118	case SNDRV_TIMER_IOCTL_STOP_OLD:
2119		return snd_timer_user_stop(file);
2120	case SNDRV_TIMER_IOCTL_CONTINUE:
2121	case SNDRV_TIMER_IOCTL_CONTINUE_OLD:
2122		return snd_timer_user_continue(file);
2123	case SNDRV_TIMER_IOCTL_PAUSE:
2124	case SNDRV_TIMER_IOCTL_PAUSE_OLD:
2125		return snd_timer_user_pause(file);
2126	}
2127	return -ENOTTY;
2128}
2129
2130static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
2131				 unsigned long arg)
2132{
2133	struct snd_timer_user *tu = file->private_data;
2134	long ret;
2135
2136	mutex_lock(&tu->ioctl_lock);
2137	ret = __snd_timer_user_ioctl(file, cmd, arg, false);
2138	mutex_unlock(&tu->ioctl_lock);
2139	return ret;
2140}
2141
2142static int snd_timer_user_fasync(int fd, struct file * file, int on)
2143{
2144	struct snd_timer_user *tu;
2145
2146	tu = file->private_data;
2147	return snd_fasync_helper(fd, file, on, &tu->fasync);
2148}
2149
2150static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
2151				   size_t count, loff_t *offset)
2152{
2153	struct snd_timer_tread64 *tread;
2154	struct snd_timer_tread32 tread32;
2155	struct snd_timer_user *tu;
2156	long result = 0, unit;
2157	int qhead;
2158	int err = 0;
2159
2160	tu = file->private_data;
2161	switch (tu->tread) {
2162	case TREAD_FORMAT_TIME64:
2163		unit = sizeof(struct snd_timer_tread64);
2164		break;
2165	case TREAD_FORMAT_TIME32:
2166		unit = sizeof(struct snd_timer_tread32);
2167		break;
2168	case TREAD_FORMAT_NONE:
2169		unit = sizeof(struct snd_timer_read);
2170		break;
2171	default:
2172		WARN_ONCE(1, "Corrupt snd_timer_user\n");
2173		return -ENOTSUPP;
2174	}
2175
2176	mutex_lock(&tu->ioctl_lock);
2177	spin_lock_irq(&tu->qlock);
2178	while ((long)count - result >= unit) {
2179		while (!tu->qused) {
2180			wait_queue_entry_t wait;
2181
2182			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
2183				err = -EAGAIN;
2184				goto _error;
2185			}
2186
2187			set_current_state(TASK_INTERRUPTIBLE);
2188			init_waitqueue_entry(&wait, current);
2189			add_wait_queue(&tu->qchange_sleep, &wait);
2190
2191			spin_unlock_irq(&tu->qlock);
2192			mutex_unlock(&tu->ioctl_lock);
2193			schedule();
2194			mutex_lock(&tu->ioctl_lock);
2195			spin_lock_irq(&tu->qlock);
2196
2197			remove_wait_queue(&tu->qchange_sleep, &wait);
2198
2199			if (tu->disconnected) {
2200				err = -ENODEV;
2201				goto _error;
2202			}
2203			if (signal_pending(current)) {
2204				err = -ERESTARTSYS;
2205				goto _error;
2206			}
2207		}
2208
2209		qhead = tu->qhead++;
2210		tu->qhead %= tu->queue_size;
2211		tu->qused--;
2212		spin_unlock_irq(&tu->qlock);
2213
2214		tread = &tu->tqueue[qhead];
2215
2216		switch (tu->tread) {
2217		case TREAD_FORMAT_TIME64:
2218			if (copy_to_user(buffer, tread,
2219					 sizeof(struct snd_timer_tread64)))
2220				err = -EFAULT;
2221			break;
2222		case TREAD_FORMAT_TIME32:
2223			memset(&tread32, 0, sizeof(tread32));
2224			tread32 = (struct snd_timer_tread32) {
2225				.event = tread->event,
2226				.tstamp_sec = tread->tstamp_sec,
2227				.tstamp_nsec = tread->tstamp_nsec,
2228				.val = tread->val,
2229			};
2230
2231			if (copy_to_user(buffer, &tread32, sizeof(tread32)))
2232				err = -EFAULT;
2233			break;
2234		case TREAD_FORMAT_NONE:
2235			if (copy_to_user(buffer, &tu->queue[qhead],
2236					 sizeof(struct snd_timer_read)))
2237				err = -EFAULT;
2238			break;
2239		default:
2240			err = -ENOTSUPP;
2241			break;
2242		}
2243
2244		spin_lock_irq(&tu->qlock);
2245		if (err < 0)
2246			goto _error;
2247		result += unit;
2248		buffer += unit;
2249	}
2250 _error:
2251	spin_unlock_irq(&tu->qlock);
2252	mutex_unlock(&tu->ioctl_lock);
2253	return result > 0 ? result : err;
2254}
2255
2256static __poll_t snd_timer_user_poll(struct file *file, poll_table * wait)
2257{
2258        __poll_t mask;
2259        struct snd_timer_user *tu;
2260
2261        tu = file->private_data;
2262
2263        poll_wait(file, &tu->qchange_sleep, wait);
2264
2265	mask = 0;
2266	spin_lock_irq(&tu->qlock);
2267	if (tu->qused)
2268		mask |= EPOLLIN | EPOLLRDNORM;
2269	if (tu->disconnected)
2270		mask |= EPOLLERR;
2271	spin_unlock_irq(&tu->qlock);
2272
2273	return mask;
2274}
2275
2276#ifdef CONFIG_COMPAT
2277#include "timer_compat.c"
2278#else
2279#define snd_timer_user_ioctl_compat	NULL
2280#endif
2281
2282static const struct file_operations snd_timer_f_ops =
2283{
2284	.owner =	THIS_MODULE,
2285	.read =		snd_timer_user_read,
2286	.open =		snd_timer_user_open,
2287	.release =	snd_timer_user_release,
2288	.llseek =	no_llseek,
2289	.poll =		snd_timer_user_poll,
2290	.unlocked_ioctl =	snd_timer_user_ioctl,
2291	.compat_ioctl =	snd_timer_user_ioctl_compat,
2292	.fasync = 	snd_timer_user_fasync,
2293};
2294
2295/* unregister the system timer */
2296static void snd_timer_free_all(void)
2297{
2298	struct snd_timer *timer, *n;
2299
2300	list_for_each_entry_safe(timer, n, &snd_timer_list, device_list)
2301		snd_timer_free(timer);
2302}
2303
2304static struct device *timer_dev;
2305
2306/*
2307 *  ENTRY functions
2308 */
2309
2310static int __init alsa_timer_init(void)
2311{
2312	int err;
2313
2314	err = snd_device_alloc(&timer_dev, NULL);
2315	if (err < 0)
2316		return err;
2317	dev_set_name(timer_dev, "timer");
2318
2319#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2320	snd_oss_info_register(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1,
2321			      "system timer");
2322#endif
2323
2324	err = snd_timer_register_system();
2325	if (err < 0) {
2326		pr_err("ALSA: unable to register system timer (%i)\n", err);
2327		goto put_timer;
2328	}
2329
2330	err = snd_register_device(SNDRV_DEVICE_TYPE_TIMER, NULL, 0,
2331				  &snd_timer_f_ops, NULL, timer_dev);
2332	if (err < 0) {
2333		pr_err("ALSA: unable to register timer device (%i)\n", err);
2334		snd_timer_free_all();
2335		goto put_timer;
2336	}
2337
2338	snd_timer_proc_init();
2339	return 0;
2340
2341put_timer:
2342	put_device(timer_dev);
2343	return err;
2344}
2345
2346static void __exit alsa_timer_exit(void)
2347{
2348	snd_unregister_device(timer_dev);
2349	snd_timer_free_all();
2350	put_device(timer_dev);
2351	snd_timer_proc_done();
2352#ifdef SNDRV_OSS_INFO_DEV_TIMERS
2353	snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_TIMERS, SNDRV_CARDS - 1);
2354#endif
2355}
2356
2357module_init(alsa_timer_init)
2358module_exit(alsa_timer_exit)