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   1/*
   2 *  Routines for driver control interface
   3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4 *
   5 *
   6 *   This program is free software; you can redistribute it and/or modify
   7 *   it under the terms of the GNU General Public License as published by
   8 *   the Free Software Foundation; either version 2 of the License, or
   9 *   (at your option) any later version.
  10 *
  11 *   This program is distributed in the hope that it will be useful,
  12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *   GNU General Public License for more details.
  15 *
  16 *   You should have received a copy of the GNU General Public License
  17 *   along with this program; if not, write to the Free Software
  18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19 *
  20 */
  21
  22#include <linux/threads.h>
  23#include <linux/interrupt.h>
  24#include <linux/module.h>
  25#include <linux/slab.h>
  26#include <linux/vmalloc.h>
  27#include <linux/time.h>
  28#include <sound/core.h>
  29#include <sound/minors.h>
  30#include <sound/info.h>
  31#include <sound/control.h>
  32
  33/* max number of user-defined controls */
  34#define MAX_USER_CONTROLS	32
  35#define MAX_CONTROL_COUNT	1028
  36
  37struct snd_kctl_ioctl {
  38	struct list_head list;		/* list of all ioctls */
  39	snd_kctl_ioctl_func_t fioctl;
  40};
  41
  42static DECLARE_RWSEM(snd_ioctl_rwsem);
  43static LIST_HEAD(snd_control_ioctls);
  44#ifdef CONFIG_COMPAT
  45static LIST_HEAD(snd_control_compat_ioctls);
  46#endif
  47
  48static int snd_ctl_open(struct inode *inode, struct file *file)
  49{
  50	unsigned long flags;
  51	struct snd_card *card;
  52	struct snd_ctl_file *ctl;
  53	int err;
  54
  55	err = nonseekable_open(inode, file);
  56	if (err < 0)
  57		return err;
  58
  59	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
  60	if (!card) {
  61		err = -ENODEV;
  62		goto __error1;
  63	}
  64	err = snd_card_file_add(card, file);
  65	if (err < 0) {
  66		err = -ENODEV;
  67		goto __error1;
  68	}
  69	if (!try_module_get(card->module)) {
  70		err = -EFAULT;
  71		goto __error2;
  72	}
  73	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
  74	if (ctl == NULL) {
  75		err = -ENOMEM;
  76		goto __error;
  77	}
  78	INIT_LIST_HEAD(&ctl->events);
  79	init_waitqueue_head(&ctl->change_sleep);
  80	spin_lock_init(&ctl->read_lock);
  81	ctl->card = card;
  82	ctl->prefer_pcm_subdevice = -1;
  83	ctl->prefer_rawmidi_subdevice = -1;
  84	ctl->pid = get_pid(task_pid(current));
  85	file->private_data = ctl;
  86	write_lock_irqsave(&card->ctl_files_rwlock, flags);
  87	list_add_tail(&ctl->list, &card->ctl_files);
  88	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
  89	return 0;
  90
  91      __error:
  92	module_put(card->module);
  93      __error2:
  94	snd_card_file_remove(card, file);
  95      __error1:
  96      	return err;
  97}
  98
  99static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
 100{
 101	unsigned long flags;
 102	struct snd_kctl_event *cread;
 103	
 104	spin_lock_irqsave(&ctl->read_lock, flags);
 105	while (!list_empty(&ctl->events)) {
 106		cread = snd_kctl_event(ctl->events.next);
 107		list_del(&cread->list);
 108		kfree(cread);
 109	}
 110	spin_unlock_irqrestore(&ctl->read_lock, flags);
 111}
 112
 113static int snd_ctl_release(struct inode *inode, struct file *file)
 114{
 115	unsigned long flags;
 116	struct snd_card *card;
 117	struct snd_ctl_file *ctl;
 118	struct snd_kcontrol *control;
 119	unsigned int idx;
 120
 121	ctl = file->private_data;
 122	file->private_data = NULL;
 123	card = ctl->card;
 124	write_lock_irqsave(&card->ctl_files_rwlock, flags);
 125	list_del(&ctl->list);
 126	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
 127	down_write(&card->controls_rwsem);
 128	list_for_each_entry(control, &card->controls, list)
 129		for (idx = 0; idx < control->count; idx++)
 130			if (control->vd[idx].owner == ctl)
 131				control->vd[idx].owner = NULL;
 132	up_write(&card->controls_rwsem);
 133	snd_ctl_empty_read_queue(ctl);
 134	put_pid(ctl->pid);
 135	kfree(ctl);
 136	module_put(card->module);
 137	snd_card_file_remove(card, file);
 138	return 0;
 139}
 140
 141void snd_ctl_notify(struct snd_card *card, unsigned int mask,
 142		    struct snd_ctl_elem_id *id)
 143{
 144	unsigned long flags;
 145	struct snd_ctl_file *ctl;
 146	struct snd_kctl_event *ev;
 147	
 148	if (snd_BUG_ON(!card || !id))
 149		return;
 150	read_lock(&card->ctl_files_rwlock);
 151#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 152	card->mixer_oss_change_count++;
 153#endif
 154	list_for_each_entry(ctl, &card->ctl_files, list) {
 155		if (!ctl->subscribed)
 156			continue;
 157		spin_lock_irqsave(&ctl->read_lock, flags);
 158		list_for_each_entry(ev, &ctl->events, list) {
 159			if (ev->id.numid == id->numid) {
 160				ev->mask |= mask;
 161				goto _found;
 162			}
 163		}
 164		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
 165		if (ev) {
 166			ev->id = *id;
 167			ev->mask = mask;
 168			list_add_tail(&ev->list, &ctl->events);
 169		} else {
 170			snd_printk(KERN_ERR "No memory available to allocate event\n");
 171		}
 172	_found:
 173		wake_up(&ctl->change_sleep);
 174		spin_unlock_irqrestore(&ctl->read_lock, flags);
 175		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
 176	}
 177	read_unlock(&card->ctl_files_rwlock);
 178}
 179
 180EXPORT_SYMBOL(snd_ctl_notify);
 181
 182/**
 183 * snd_ctl_new - create a control instance from the template
 184 * @control: the control template
 185 * @access: the default control access
 186 *
 187 * Allocates a new struct snd_kcontrol instance and copies the given template 
 188 * to the new instance. It does not copy volatile data (access).
 189 *
 190 * Returns the pointer of the new instance, or NULL on failure.
 191 */
 192static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
 193					unsigned int access)
 194{
 195	struct snd_kcontrol *kctl;
 196	unsigned int idx;
 197	
 198	if (snd_BUG_ON(!control || !control->count))
 199		return NULL;
 200
 201	if (control->count > MAX_CONTROL_COUNT)
 202		return NULL;
 203
 204	kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
 205	if (kctl == NULL) {
 206		snd_printk(KERN_ERR "Cannot allocate control instance\n");
 207		return NULL;
 208	}
 209	*kctl = *control;
 210	for (idx = 0; idx < kctl->count; idx++)
 211		kctl->vd[idx].access = access;
 212	return kctl;
 213}
 214
 215/**
 216 * snd_ctl_new1 - create a control instance from the template
 217 * @ncontrol: the initialization record
 218 * @private_data: the private data to set
 219 *
 220 * Allocates a new struct snd_kcontrol instance and initialize from the given 
 221 * template.  When the access field of ncontrol is 0, it's assumed as
 222 * READWRITE access. When the count field is 0, it's assumes as one.
 223 *
 224 * Returns the pointer of the newly generated instance, or NULL on failure.
 225 */
 226struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
 227				  void *private_data)
 228{
 229	struct snd_kcontrol kctl;
 230	unsigned int access;
 231	
 232	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
 233		return NULL;
 234	memset(&kctl, 0, sizeof(kctl));
 235	kctl.id.iface = ncontrol->iface;
 236	kctl.id.device = ncontrol->device;
 237	kctl.id.subdevice = ncontrol->subdevice;
 238	if (ncontrol->name) {
 239		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
 240		if (strcmp(ncontrol->name, kctl.id.name) != 0)
 241			snd_printk(KERN_WARNING
 242				   "Control name '%s' truncated to '%s'\n",
 243				   ncontrol->name, kctl.id.name);
 244	}
 245	kctl.id.index = ncontrol->index;
 246	kctl.count = ncontrol->count ? ncontrol->count : 1;
 247	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
 248		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
 249				      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
 250				      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
 251				      SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
 252				      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
 253	kctl.info = ncontrol->info;
 254	kctl.get = ncontrol->get;
 255	kctl.put = ncontrol->put;
 256	kctl.tlv.p = ncontrol->tlv.p;
 257	kctl.private_value = ncontrol->private_value;
 258	kctl.private_data = private_data;
 259	return snd_ctl_new(&kctl, access);
 260}
 261
 262EXPORT_SYMBOL(snd_ctl_new1);
 263
 264/**
 265 * snd_ctl_free_one - release the control instance
 266 * @kcontrol: the control instance
 267 *
 268 * Releases the control instance created via snd_ctl_new()
 269 * or snd_ctl_new1().
 270 * Don't call this after the control was added to the card.
 271 */
 272void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
 273{
 274	if (kcontrol) {
 275		if (kcontrol->private_free)
 276			kcontrol->private_free(kcontrol);
 277		kfree(kcontrol);
 278	}
 279}
 280
 281EXPORT_SYMBOL(snd_ctl_free_one);
 282
 283static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
 284					  unsigned int count)
 285{
 286	struct snd_kcontrol *kctl;
 287
 288	list_for_each_entry(kctl, &card->controls, list) {
 289		if (kctl->id.numid < card->last_numid + 1 + count &&
 290		    kctl->id.numid + kctl->count > card->last_numid + 1) {
 291		    	card->last_numid = kctl->id.numid + kctl->count - 1;
 292			return true;
 293		}
 294	}
 295	return false;
 296}
 297
 298static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
 299{
 300	unsigned int iter = 100000;
 301
 302	while (snd_ctl_remove_numid_conflict(card, count)) {
 303		if (--iter == 0) {
 304			/* this situation is very unlikely */
 305			snd_printk(KERN_ERR "unable to allocate new control numid\n");
 306			return -ENOMEM;
 307		}
 308	}
 309	return 0;
 310}
 311
 312/**
 313 * snd_ctl_add - add the control instance to the card
 314 * @card: the card instance
 315 * @kcontrol: the control instance to add
 316 *
 317 * Adds the control instance created via snd_ctl_new() or
 318 * snd_ctl_new1() to the given card. Assigns also an unique
 319 * numid used for fast search.
 320 *
 321 * Returns zero if successful, or a negative error code on failure.
 322 *
 323 * It frees automatically the control which cannot be added.
 324 */
 325int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
 326{
 327	struct snd_ctl_elem_id id;
 328	unsigned int idx;
 329	int err = -EINVAL;
 330
 331	if (! kcontrol)
 332		return err;
 333	if (snd_BUG_ON(!card || !kcontrol->info))
 334		goto error;
 335	id = kcontrol->id;
 336	down_write(&card->controls_rwsem);
 337	if (snd_ctl_find_id(card, &id)) {
 338		up_write(&card->controls_rwsem);
 339		snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
 340					id.iface,
 341					id.device,
 342					id.subdevice,
 343					id.name,
 344					id.index);
 345		err = -EBUSY;
 346		goto error;
 347	}
 348	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 349		up_write(&card->controls_rwsem);
 350		err = -ENOMEM;
 351		goto error;
 352	}
 353	list_add_tail(&kcontrol->list, &card->controls);
 354	card->controls_count += kcontrol->count;
 355	kcontrol->id.numid = card->last_numid + 1;
 356	card->last_numid += kcontrol->count;
 357	up_write(&card->controls_rwsem);
 358	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 359		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 360	return 0;
 361
 362 error:
 363	snd_ctl_free_one(kcontrol);
 364	return err;
 365}
 366
 367EXPORT_SYMBOL(snd_ctl_add);
 368
 369/**
 370 * snd_ctl_replace - replace the control instance of the card
 371 * @card: the card instance
 372 * @kcontrol: the control instance to replace
 373 * @add_on_replace: add the control if not already added
 374 *
 375 * Replaces the given control.  If the given control does not exist
 376 * and the add_on_replace flag is set, the control is added.  If the
 377 * control exists, it is destroyed first.
 378 *
 379 * Returns zero if successful, or a negative error code on failure.
 380 *
 381 * It frees automatically the control which cannot be added or replaced.
 382 */
 383int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
 384		    bool add_on_replace)
 385{
 386	struct snd_ctl_elem_id id;
 387	unsigned int idx;
 388	struct snd_kcontrol *old;
 389	int ret;
 390
 391	if (!kcontrol)
 392		return -EINVAL;
 393	if (snd_BUG_ON(!card || !kcontrol->info)) {
 394		ret = -EINVAL;
 395		goto error;
 396	}
 397	id = kcontrol->id;
 398	down_write(&card->controls_rwsem);
 399	old = snd_ctl_find_id(card, &id);
 400	if (!old) {
 401		if (add_on_replace)
 402			goto add;
 403		up_write(&card->controls_rwsem);
 404		ret = -EINVAL;
 405		goto error;
 406	}
 407	ret = snd_ctl_remove(card, old);
 408	if (ret < 0) {
 409		up_write(&card->controls_rwsem);
 410		goto error;
 411	}
 412add:
 413	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
 414		up_write(&card->controls_rwsem);
 415		ret = -ENOMEM;
 416		goto error;
 417	}
 418	list_add_tail(&kcontrol->list, &card->controls);
 419	card->controls_count += kcontrol->count;
 420	kcontrol->id.numid = card->last_numid + 1;
 421	card->last_numid += kcontrol->count;
 422	up_write(&card->controls_rwsem);
 423	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 424		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
 425	return 0;
 426
 427error:
 428	snd_ctl_free_one(kcontrol);
 429	return ret;
 430}
 431EXPORT_SYMBOL(snd_ctl_replace);
 432
 433/**
 434 * snd_ctl_remove - remove the control from the card and release it
 435 * @card: the card instance
 436 * @kcontrol: the control instance to remove
 437 *
 438 * Removes the control from the card and then releases the instance.
 439 * You don't need to call snd_ctl_free_one(). You must be in
 440 * the write lock - down_write(&card->controls_rwsem).
 441 * 
 442 * Returns 0 if successful, or a negative error code on failure.
 443 */
 444int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
 445{
 446	struct snd_ctl_elem_id id;
 447	unsigned int idx;
 448
 449	if (snd_BUG_ON(!card || !kcontrol))
 450		return -EINVAL;
 451	list_del(&kcontrol->list);
 452	card->controls_count -= kcontrol->count;
 453	id = kcontrol->id;
 454	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
 455		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
 456	snd_ctl_free_one(kcontrol);
 457	return 0;
 458}
 459
 460EXPORT_SYMBOL(snd_ctl_remove);
 461
 462/**
 463 * snd_ctl_remove_id - remove the control of the given id and release it
 464 * @card: the card instance
 465 * @id: the control id to remove
 466 *
 467 * Finds the control instance with the given id, removes it from the
 468 * card list and releases it.
 469 * 
 470 * Returns 0 if successful, or a negative error code on failure.
 471 */
 472int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
 473{
 474	struct snd_kcontrol *kctl;
 475	int ret;
 476
 477	down_write(&card->controls_rwsem);
 478	kctl = snd_ctl_find_id(card, id);
 479	if (kctl == NULL) {
 480		up_write(&card->controls_rwsem);
 481		return -ENOENT;
 482	}
 483	ret = snd_ctl_remove(card, kctl);
 484	up_write(&card->controls_rwsem);
 485	return ret;
 486}
 487
 488EXPORT_SYMBOL(snd_ctl_remove_id);
 489
 490/**
 491 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
 492 * @file: active control handle
 493 * @id: the control id to remove
 494 *
 495 * Finds the control instance with the given id, removes it from the
 496 * card list and releases it.
 497 * 
 498 * Returns 0 if successful, or a negative error code on failure.
 499 */
 500static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
 501				   struct snd_ctl_elem_id *id)
 502{
 503	struct snd_card *card = file->card;
 504	struct snd_kcontrol *kctl;
 505	int idx, ret;
 506
 507	down_write(&card->controls_rwsem);
 508	kctl = snd_ctl_find_id(card, id);
 509	if (kctl == NULL) {
 510		ret = -ENOENT;
 511		goto error;
 512	}
 513	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
 514		ret = -EINVAL;
 515		goto error;
 516	}
 517	for (idx = 0; idx < kctl->count; idx++)
 518		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
 519			ret = -EBUSY;
 520			goto error;
 521		}
 522	ret = snd_ctl_remove(card, kctl);
 523	if (ret < 0)
 524		goto error;
 525	card->user_ctl_count--;
 526error:
 527	up_write(&card->controls_rwsem);
 528	return ret;
 529}
 530
 531/**
 532 * snd_ctl_activate_id - activate/inactivate the control of the given id
 533 * @card: the card instance
 534 * @id: the control id to activate/inactivate
 535 * @active: non-zero to activate
 536 *
 537 * Finds the control instance with the given id, and activate or
 538 * inactivate the control together with notification, if changed.
 539 *
 540 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
 541 */
 542int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 543			int active)
 544{
 545	struct snd_kcontrol *kctl;
 546	struct snd_kcontrol_volatile *vd;
 547	unsigned int index_offset;
 548	int ret;
 549
 550	down_write(&card->controls_rwsem);
 551	kctl = snd_ctl_find_id(card, id);
 552	if (kctl == NULL) {
 553		ret = -ENOENT;
 554		goto unlock;
 555	}
 556	index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
 557	vd = &kctl->vd[index_offset];
 558	ret = 0;
 559	if (active) {
 560		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
 561			goto unlock;
 562		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 563	} else {
 564		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
 565			goto unlock;
 566		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
 567	}
 568	ret = 1;
 569 unlock:
 570	up_write(&card->controls_rwsem);
 571	if (ret > 0)
 572		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
 573	return ret;
 574}
 575EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
 576
 577/**
 578 * snd_ctl_rename_id - replace the id of a control on the card
 579 * @card: the card instance
 580 * @src_id: the old id
 581 * @dst_id: the new id
 582 *
 583 * Finds the control with the old id from the card, and replaces the
 584 * id with the new one.
 585 *
 586 * Returns zero if successful, or a negative error code on failure.
 587 */
 588int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
 589		      struct snd_ctl_elem_id *dst_id)
 590{
 591	struct snd_kcontrol *kctl;
 592
 593	down_write(&card->controls_rwsem);
 594	kctl = snd_ctl_find_id(card, src_id);
 595	if (kctl == NULL) {
 596		up_write(&card->controls_rwsem);
 597		return -ENOENT;
 598	}
 599	kctl->id = *dst_id;
 600	kctl->id.numid = card->last_numid + 1;
 601	card->last_numid += kctl->count;
 602	up_write(&card->controls_rwsem);
 603	return 0;
 604}
 605
 606EXPORT_SYMBOL(snd_ctl_rename_id);
 607
 608/**
 609 * snd_ctl_find_numid - find the control instance with the given number-id
 610 * @card: the card instance
 611 * @numid: the number-id to search
 612 *
 613 * Finds the control instance with the given number-id from the card.
 614 *
 615 * Returns the pointer of the instance if found, or NULL if not.
 616 *
 617 * The caller must down card->controls_rwsem before calling this function
 618 * (if the race condition can happen).
 619 */
 620struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
 621{
 622	struct snd_kcontrol *kctl;
 623
 624	if (snd_BUG_ON(!card || !numid))
 625		return NULL;
 626	list_for_each_entry(kctl, &card->controls, list) {
 627		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
 628			return kctl;
 629	}
 630	return NULL;
 631}
 632
 633EXPORT_SYMBOL(snd_ctl_find_numid);
 634
 635/**
 636 * snd_ctl_find_id - find the control instance with the given id
 637 * @card: the card instance
 638 * @id: the id to search
 639 *
 640 * Finds the control instance with the given id from the card.
 641 *
 642 * Returns the pointer of the instance if found, or NULL if not.
 643 *
 644 * The caller must down card->controls_rwsem before calling this function
 645 * (if the race condition can happen).
 646 */
 647struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
 648				     struct snd_ctl_elem_id *id)
 649{
 650	struct snd_kcontrol *kctl;
 651
 652	if (snd_BUG_ON(!card || !id))
 653		return NULL;
 654	if (id->numid != 0)
 655		return snd_ctl_find_numid(card, id->numid);
 656	list_for_each_entry(kctl, &card->controls, list) {
 657		if (kctl->id.iface != id->iface)
 658			continue;
 659		if (kctl->id.device != id->device)
 660			continue;
 661		if (kctl->id.subdevice != id->subdevice)
 662			continue;
 663		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
 664			continue;
 665		if (kctl->id.index > id->index)
 666			continue;
 667		if (kctl->id.index + kctl->count <= id->index)
 668			continue;
 669		return kctl;
 670	}
 671	return NULL;
 672}
 673
 674EXPORT_SYMBOL(snd_ctl_find_id);
 675
 676static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
 677			     unsigned int cmd, void __user *arg)
 678{
 679	struct snd_ctl_card_info *info;
 680
 681	info = kzalloc(sizeof(*info), GFP_KERNEL);
 682	if (! info)
 683		return -ENOMEM;
 684	down_read(&snd_ioctl_rwsem);
 685	info->card = card->number;
 686	strlcpy(info->id, card->id, sizeof(info->id));
 687	strlcpy(info->driver, card->driver, sizeof(info->driver));
 688	strlcpy(info->name, card->shortname, sizeof(info->name));
 689	strlcpy(info->longname, card->longname, sizeof(info->longname));
 690	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
 691	strlcpy(info->components, card->components, sizeof(info->components));
 692	up_read(&snd_ioctl_rwsem);
 693	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
 694		kfree(info);
 695		return -EFAULT;
 696	}
 697	kfree(info);
 698	return 0;
 699}
 700
 701static int snd_ctl_elem_list(struct snd_card *card,
 702			     struct snd_ctl_elem_list __user *_list)
 703{
 704	struct list_head *plist;
 705	struct snd_ctl_elem_list list;
 706	struct snd_kcontrol *kctl;
 707	struct snd_ctl_elem_id *dst, *id;
 708	unsigned int offset, space, jidx;
 709	
 710	if (copy_from_user(&list, _list, sizeof(list)))
 711		return -EFAULT;
 712	offset = list.offset;
 713	space = list.space;
 714	/* try limit maximum space */
 715	if (space > 16384)
 716		return -ENOMEM;
 717	if (space > 0) {
 718		/* allocate temporary buffer for atomic operation */
 719		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
 720		if (dst == NULL)
 721			return -ENOMEM;
 722		down_read(&card->controls_rwsem);
 723		list.count = card->controls_count;
 724		plist = card->controls.next;
 725		while (plist != &card->controls) {
 726			if (offset == 0)
 727				break;
 728			kctl = snd_kcontrol(plist);
 729			if (offset < kctl->count)
 730				break;
 731			offset -= kctl->count;
 732			plist = plist->next;
 733		}
 734		list.used = 0;
 735		id = dst;
 736		while (space > 0 && plist != &card->controls) {
 737			kctl = snd_kcontrol(plist);
 738			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
 739				snd_ctl_build_ioff(id, kctl, jidx);
 740				id++;
 741				space--;
 742				list.used++;
 743			}
 744			plist = plist->next;
 745			offset = 0;
 746		}
 747		up_read(&card->controls_rwsem);
 748		if (list.used > 0 &&
 749		    copy_to_user(list.pids, dst,
 750				 list.used * sizeof(struct snd_ctl_elem_id))) {
 751			vfree(dst);
 752			return -EFAULT;
 753		}
 754		vfree(dst);
 755	} else {
 756		down_read(&card->controls_rwsem);
 757		list.count = card->controls_count;
 758		up_read(&card->controls_rwsem);
 759	}
 760	if (copy_to_user(_list, &list, sizeof(list)))
 761		return -EFAULT;
 762	return 0;
 763}
 764
 765static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
 766			     struct snd_ctl_elem_info *info)
 767{
 768	struct snd_card *card = ctl->card;
 769	struct snd_kcontrol *kctl;
 770	struct snd_kcontrol_volatile *vd;
 771	unsigned int index_offset;
 772	int result;
 773	
 774	down_read(&card->controls_rwsem);
 775	kctl = snd_ctl_find_id(card, &info->id);
 776	if (kctl == NULL) {
 777		up_read(&card->controls_rwsem);
 778		return -ENOENT;
 779	}
 780#ifdef CONFIG_SND_DEBUG
 781	info->access = 0;
 782#endif
 783	result = kctl->info(kctl, info);
 784	if (result >= 0) {
 785		snd_BUG_ON(info->access);
 786		index_offset = snd_ctl_get_ioff(kctl, &info->id);
 787		vd = &kctl->vd[index_offset];
 788		snd_ctl_build_ioff(&info->id, kctl, index_offset);
 789		info->access = vd->access;
 790		if (vd->owner) {
 791			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
 792			if (vd->owner == ctl)
 793				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
 794			info->owner = pid_vnr(vd->owner->pid);
 795		} else {
 796			info->owner = -1;
 797		}
 798	}
 799	up_read(&card->controls_rwsem);
 800	return result;
 801}
 802
 803static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
 804				  struct snd_ctl_elem_info __user *_info)
 805{
 806	struct snd_ctl_elem_info info;
 807	int result;
 808
 809	if (copy_from_user(&info, _info, sizeof(info)))
 810		return -EFAULT;
 811	snd_power_lock(ctl->card);
 812	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
 813	if (result >= 0)
 814		result = snd_ctl_elem_info(ctl, &info);
 815	snd_power_unlock(ctl->card);
 816	if (result >= 0)
 817		if (copy_to_user(_info, &info, sizeof(info)))
 818			return -EFAULT;
 819	return result;
 820}
 821
 822static int snd_ctl_elem_read(struct snd_card *card,
 823			     struct snd_ctl_elem_value *control)
 824{
 825	struct snd_kcontrol *kctl;
 826	struct snd_kcontrol_volatile *vd;
 827	unsigned int index_offset;
 828	int result;
 829
 830	down_read(&card->controls_rwsem);
 831	kctl = snd_ctl_find_id(card, &control->id);
 832	if (kctl == NULL) {
 833		result = -ENOENT;
 834	} else {
 835		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 836		vd = &kctl->vd[index_offset];
 837		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
 838		    kctl->get != NULL) {
 839			snd_ctl_build_ioff(&control->id, kctl, index_offset);
 840			result = kctl->get(kctl, control);
 841		} else
 842			result = -EPERM;
 843	}
 844	up_read(&card->controls_rwsem);
 845	return result;
 846}
 847
 848static int snd_ctl_elem_read_user(struct snd_card *card,
 849				  struct snd_ctl_elem_value __user *_control)
 850{
 851	struct snd_ctl_elem_value *control;
 852	int result;
 853
 854	control = memdup_user(_control, sizeof(*control));
 855	if (IS_ERR(control))
 856		return PTR_ERR(control);
 857
 858	snd_power_lock(card);
 859	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 860	if (result >= 0)
 861		result = snd_ctl_elem_read(card, control);
 862	snd_power_unlock(card);
 863	if (result >= 0)
 864		if (copy_to_user(_control, control, sizeof(*control)))
 865			result = -EFAULT;
 866	kfree(control);
 867	return result;
 868}
 869
 870static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
 871			      struct snd_ctl_elem_value *control)
 872{
 873	struct snd_kcontrol *kctl;
 874	struct snd_kcontrol_volatile *vd;
 875	unsigned int index_offset;
 876	int result;
 877
 878	down_read(&card->controls_rwsem);
 879	kctl = snd_ctl_find_id(card, &control->id);
 880	if (kctl == NULL) {
 881		result = -ENOENT;
 882	} else {
 883		index_offset = snd_ctl_get_ioff(kctl, &control->id);
 884		vd = &kctl->vd[index_offset];
 885		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
 886		    kctl->put == NULL ||
 887		    (file && vd->owner && vd->owner != file)) {
 888			result = -EPERM;
 889		} else {
 890			snd_ctl_build_ioff(&control->id, kctl, index_offset);
 891			result = kctl->put(kctl, control);
 892		}
 893		if (result > 0) {
 894			up_read(&card->controls_rwsem);
 895			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 896				       &control->id);
 897			return 0;
 898		}
 899	}
 900	up_read(&card->controls_rwsem);
 901	return result;
 902}
 903
 904static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
 905				   struct snd_ctl_elem_value __user *_control)
 906{
 907	struct snd_ctl_elem_value *control;
 908	struct snd_card *card;
 909	int result;
 910
 911	control = memdup_user(_control, sizeof(*control));
 912	if (IS_ERR(control))
 913		return PTR_ERR(control);
 914
 915	card = file->card;
 916	snd_power_lock(card);
 917	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
 918	if (result >= 0)
 919		result = snd_ctl_elem_write(card, file, control);
 920	snd_power_unlock(card);
 921	if (result >= 0)
 922		if (copy_to_user(_control, control, sizeof(*control)))
 923			result = -EFAULT;
 924	kfree(control);
 925	return result;
 926}
 927
 928static int snd_ctl_elem_lock(struct snd_ctl_file *file,
 929			     struct snd_ctl_elem_id __user *_id)
 930{
 931	struct snd_card *card = file->card;
 932	struct snd_ctl_elem_id id;
 933	struct snd_kcontrol *kctl;
 934	struct snd_kcontrol_volatile *vd;
 935	int result;
 936	
 937	if (copy_from_user(&id, _id, sizeof(id)))
 938		return -EFAULT;
 939	down_write(&card->controls_rwsem);
 940	kctl = snd_ctl_find_id(card, &id);
 941	if (kctl == NULL) {
 942		result = -ENOENT;
 943	} else {
 944		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 945		if (vd->owner != NULL)
 946			result = -EBUSY;
 947		else {
 948			vd->owner = file;
 949			result = 0;
 950		}
 951	}
 952	up_write(&card->controls_rwsem);
 953	return result;
 954}
 955
 956static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
 957			       struct snd_ctl_elem_id __user *_id)
 958{
 959	struct snd_card *card = file->card;
 960	struct snd_ctl_elem_id id;
 961	struct snd_kcontrol *kctl;
 962	struct snd_kcontrol_volatile *vd;
 963	int result;
 964	
 965	if (copy_from_user(&id, _id, sizeof(id)))
 966		return -EFAULT;
 967	down_write(&card->controls_rwsem);
 968	kctl = snd_ctl_find_id(card, &id);
 969	if (kctl == NULL) {
 970		result = -ENOENT;
 971	} else {
 972		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
 973		if (vd->owner == NULL)
 974			result = -EINVAL;
 975		else if (vd->owner != file)
 976			result = -EPERM;
 977		else {
 978			vd->owner = NULL;
 979			result = 0;
 980		}
 981	}
 982	up_write(&card->controls_rwsem);
 983	return result;
 984}
 985
 986struct user_element {
 987	struct snd_ctl_elem_info info;
 988	void *elem_data;		/* element data */
 989	unsigned long elem_data_size;	/* size of element data in bytes */
 990	void *tlv_data;			/* TLV data */
 991	unsigned long tlv_data_size;	/* TLV data size */
 992	void *priv_data;		/* private data (like strings for enumerated type) */
 993};
 994
 995static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
 996				  struct snd_ctl_elem_info *uinfo)
 997{
 998	struct user_element *ue = kcontrol->private_data;
 999
1000	*uinfo = ue->info;
1001	return 0;
1002}
1003
1004static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1005				       struct snd_ctl_elem_info *uinfo)
1006{
1007	struct user_element *ue = kcontrol->private_data;
1008	const char *names;
1009	unsigned int item;
1010
1011	item = uinfo->value.enumerated.item;
1012
1013	*uinfo = ue->info;
1014
1015	item = min(item, uinfo->value.enumerated.items - 1);
1016	uinfo->value.enumerated.item = item;
1017
1018	names = ue->priv_data;
1019	for (; item > 0; --item)
1020		names += strlen(names) + 1;
1021	strcpy(uinfo->value.enumerated.name, names);
1022
1023	return 0;
1024}
1025
1026static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1027				 struct snd_ctl_elem_value *ucontrol)
1028{
1029	struct user_element *ue = kcontrol->private_data;
1030
1031	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1032	return 0;
1033}
1034
1035static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1036				 struct snd_ctl_elem_value *ucontrol)
1037{
1038	int change;
1039	struct user_element *ue = kcontrol->private_data;
1040	
1041	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1042	if (change)
1043		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1044	return change;
1045}
1046
1047static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1048				 int op_flag,
1049				 unsigned int size,
1050				 unsigned int __user *tlv)
1051{
1052	struct user_element *ue = kcontrol->private_data;
1053	int change = 0;
1054	void *new_data;
1055
1056	if (op_flag > 0) {
1057		if (size > 1024 * 128)	/* sane value */
1058			return -EINVAL;
1059
1060		new_data = memdup_user(tlv, size);
1061		if (IS_ERR(new_data))
1062			return PTR_ERR(new_data);
1063		change = ue->tlv_data_size != size;
1064		if (!change)
1065			change = memcmp(ue->tlv_data, new_data, size);
1066		kfree(ue->tlv_data);
1067		ue->tlv_data = new_data;
1068		ue->tlv_data_size = size;
1069	} else {
1070		if (! ue->tlv_data_size || ! ue->tlv_data)
1071			return -ENXIO;
1072		if (size < ue->tlv_data_size)
1073			return -ENOSPC;
1074		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1075			return -EFAULT;
1076	}
1077	return change;
1078}
1079
1080static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1081{
1082	char *names, *p;
1083	size_t buf_len, name_len;
1084	unsigned int i;
1085	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1086
1087	if (ue->info.value.enumerated.names_length > 64 * 1024)
1088		return -EINVAL;
1089
1090	names = memdup_user((const void __user *)user_ptrval,
1091		ue->info.value.enumerated.names_length);
1092	if (IS_ERR(names))
1093		return PTR_ERR(names);
1094
1095	/* check that there are enough valid names */
1096	buf_len = ue->info.value.enumerated.names_length;
1097	p = names;
1098	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1099		name_len = strnlen(p, buf_len);
1100		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1101			kfree(names);
1102			return -EINVAL;
1103		}
1104		p += name_len + 1;
1105		buf_len -= name_len + 1;
1106	}
1107
1108	ue->priv_data = names;
1109	ue->info.value.enumerated.names_ptr = 0;
1110
1111	return 0;
1112}
1113
1114static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1115{
1116	struct user_element *ue = kcontrol->private_data;
1117
1118	kfree(ue->tlv_data);
1119	kfree(ue->priv_data);
1120	kfree(ue);
1121}
1122
1123static int snd_ctl_elem_add(struct snd_ctl_file *file,
1124			    struct snd_ctl_elem_info *info, int replace)
1125{
1126	struct snd_card *card = file->card;
1127	struct snd_kcontrol kctl, *_kctl;
1128	unsigned int access;
1129	long private_size;
1130	struct user_element *ue;
1131	int idx, err;
1132
1133	if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1134		return -ENOMEM;
1135	if (info->count < 1)
1136		return -EINVAL;
1137	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1138		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1139				 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1140				 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1141	info->id.numid = 0;
1142	memset(&kctl, 0, sizeof(kctl));
1143	down_write(&card->controls_rwsem);
1144	_kctl = snd_ctl_find_id(card, &info->id);
1145	err = 0;
1146	if (_kctl) {
1147		if (replace)
1148			err = snd_ctl_remove(card, _kctl);
1149		else
1150			err = -EBUSY;
1151	} else {
1152		if (replace)
1153			err = -ENOENT;
1154	}
1155	up_write(&card->controls_rwsem);
1156	if (err < 0)
1157		return err;
1158	memcpy(&kctl.id, &info->id, sizeof(info->id));
1159	kctl.count = info->owner ? info->owner : 1;
1160	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1161	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1162		kctl.info = snd_ctl_elem_user_enum_info;
1163	else
1164		kctl.info = snd_ctl_elem_user_info;
1165	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1166		kctl.get = snd_ctl_elem_user_get;
1167	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1168		kctl.put = snd_ctl_elem_user_put;
1169	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1170		kctl.tlv.c = snd_ctl_elem_user_tlv;
1171		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1172	}
1173	switch (info->type) {
1174	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1175	case SNDRV_CTL_ELEM_TYPE_INTEGER:
1176		private_size = sizeof(long);
1177		if (info->count > 128)
1178			return -EINVAL;
1179		break;
1180	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1181		private_size = sizeof(long long);
1182		if (info->count > 64)
1183			return -EINVAL;
1184		break;
1185	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1186		private_size = sizeof(unsigned int);
1187		if (info->count > 128 || info->value.enumerated.items == 0)
1188			return -EINVAL;
1189		break;
1190	case SNDRV_CTL_ELEM_TYPE_BYTES:
1191		private_size = sizeof(unsigned char);
1192		if (info->count > 512)
1193			return -EINVAL;
1194		break;
1195	case SNDRV_CTL_ELEM_TYPE_IEC958:
1196		private_size = sizeof(struct snd_aes_iec958);
1197		if (info->count != 1)
1198			return -EINVAL;
1199		break;
1200	default:
1201		return -EINVAL;
1202	}
1203	private_size *= info->count;
1204	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1205	if (ue == NULL)
1206		return -ENOMEM;
1207	ue->info = *info;
1208	ue->info.access = 0;
1209	ue->elem_data = (char *)ue + sizeof(*ue);
1210	ue->elem_data_size = private_size;
1211	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1212		err = snd_ctl_elem_init_enum_names(ue);
1213		if (err < 0) {
1214			kfree(ue);
1215			return err;
1216		}
1217	}
1218	kctl.private_free = snd_ctl_elem_user_free;
1219	_kctl = snd_ctl_new(&kctl, access);
1220	if (_kctl == NULL) {
1221		kfree(ue->priv_data);
1222		kfree(ue);
1223		return -ENOMEM;
1224	}
1225	_kctl->private_data = ue;
1226	for (idx = 0; idx < _kctl->count; idx++)
1227		_kctl->vd[idx].owner = file;
1228	err = snd_ctl_add(card, _kctl);
1229	if (err < 0)
1230		return err;
1231
1232	down_write(&card->controls_rwsem);
1233	card->user_ctl_count++;
1234	up_write(&card->controls_rwsem);
1235
1236	return 0;
1237}
1238
1239static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1240				 struct snd_ctl_elem_info __user *_info, int replace)
1241{
1242	struct snd_ctl_elem_info info;
1243	if (copy_from_user(&info, _info, sizeof(info)))
1244		return -EFAULT;
1245	return snd_ctl_elem_add(file, &info, replace);
1246}
1247
1248static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1249			       struct snd_ctl_elem_id __user *_id)
1250{
1251	struct snd_ctl_elem_id id;
1252
1253	if (copy_from_user(&id, _id, sizeof(id)))
1254		return -EFAULT;
1255	return snd_ctl_remove_user_ctl(file, &id);
1256}
1257
1258static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1259{
1260	int subscribe;
1261	if (get_user(subscribe, ptr))
1262		return -EFAULT;
1263	if (subscribe < 0) {
1264		subscribe = file->subscribed;
1265		if (put_user(subscribe, ptr))
1266			return -EFAULT;
1267		return 0;
1268	}
1269	if (subscribe) {
1270		file->subscribed = 1;
1271		return 0;
1272	} else if (file->subscribed) {
1273		snd_ctl_empty_read_queue(file);
1274		file->subscribed = 0;
1275	}
1276	return 0;
1277}
1278
1279static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1280                             struct snd_ctl_tlv __user *_tlv,
1281                             int op_flag)
1282{
1283	struct snd_card *card = file->card;
1284	struct snd_ctl_tlv tlv;
1285	struct snd_kcontrol *kctl;
1286	struct snd_kcontrol_volatile *vd;
1287	unsigned int len;
1288	int err = 0;
1289
1290	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1291		return -EFAULT;
1292	if (tlv.length < sizeof(unsigned int) * 2)
1293		return -EINVAL;
1294	down_read(&card->controls_rwsem);
1295	kctl = snd_ctl_find_numid(card, tlv.numid);
1296	if (kctl == NULL) {
1297		err = -ENOENT;
1298		goto __kctl_end;
1299	}
1300	if (kctl->tlv.p == NULL) {
1301		err = -ENXIO;
1302		goto __kctl_end;
1303	}
1304	vd = &kctl->vd[tlv.numid - kctl->id.numid];
1305	if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1306	    (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1307	    (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1308	    	err = -ENXIO;
1309	    	goto __kctl_end;
1310	}
1311	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1312		if (vd->owner != NULL && vd->owner != file) {
1313			err = -EPERM;
1314			goto __kctl_end;
1315		}
1316		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1317		if (err > 0) {
1318			up_read(&card->controls_rwsem);
1319			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1320			return 0;
1321		}
1322	} else {
1323		if (op_flag) {
1324			err = -ENXIO;
1325			goto __kctl_end;
1326		}
1327		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1328		if (tlv.length < len) {
1329			err = -ENOMEM;
1330			goto __kctl_end;
1331		}
1332		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1333			err = -EFAULT;
1334	}
1335      __kctl_end:
1336	up_read(&card->controls_rwsem);
1337	return err;
1338}
1339
1340static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1341{
1342	struct snd_ctl_file *ctl;
1343	struct snd_card *card;
1344	struct snd_kctl_ioctl *p;
1345	void __user *argp = (void __user *)arg;
1346	int __user *ip = argp;
1347	int err;
1348
1349	ctl = file->private_data;
1350	card = ctl->card;
1351	if (snd_BUG_ON(!card))
1352		return -ENXIO;
1353	switch (cmd) {
1354	case SNDRV_CTL_IOCTL_PVERSION:
1355		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1356	case SNDRV_CTL_IOCTL_CARD_INFO:
1357		return snd_ctl_card_info(card, ctl, cmd, argp);
1358	case SNDRV_CTL_IOCTL_ELEM_LIST:
1359		return snd_ctl_elem_list(card, argp);
1360	case SNDRV_CTL_IOCTL_ELEM_INFO:
1361		return snd_ctl_elem_info_user(ctl, argp);
1362	case SNDRV_CTL_IOCTL_ELEM_READ:
1363		return snd_ctl_elem_read_user(card, argp);
1364	case SNDRV_CTL_IOCTL_ELEM_WRITE:
1365		return snd_ctl_elem_write_user(ctl, argp);
1366	case SNDRV_CTL_IOCTL_ELEM_LOCK:
1367		return snd_ctl_elem_lock(ctl, argp);
1368	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1369		return snd_ctl_elem_unlock(ctl, argp);
1370	case SNDRV_CTL_IOCTL_ELEM_ADD:
1371		return snd_ctl_elem_add_user(ctl, argp, 0);
1372	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1373		return snd_ctl_elem_add_user(ctl, argp, 1);
1374	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1375		return snd_ctl_elem_remove(ctl, argp);
1376	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1377		return snd_ctl_subscribe_events(ctl, ip);
1378	case SNDRV_CTL_IOCTL_TLV_READ:
1379		return snd_ctl_tlv_ioctl(ctl, argp, 0);
1380	case SNDRV_CTL_IOCTL_TLV_WRITE:
1381		return snd_ctl_tlv_ioctl(ctl, argp, 1);
1382	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1383		return snd_ctl_tlv_ioctl(ctl, argp, -1);
1384	case SNDRV_CTL_IOCTL_POWER:
1385		return -ENOPROTOOPT;
1386	case SNDRV_CTL_IOCTL_POWER_STATE:
1387#ifdef CONFIG_PM
1388		return put_user(card->power_state, ip) ? -EFAULT : 0;
1389#else
1390		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1391#endif
1392	}
1393	down_read(&snd_ioctl_rwsem);
1394	list_for_each_entry(p, &snd_control_ioctls, list) {
1395		err = p->fioctl(card, ctl, cmd, arg);
1396		if (err != -ENOIOCTLCMD) {
1397			up_read(&snd_ioctl_rwsem);
1398			return err;
1399		}
1400	}
1401	up_read(&snd_ioctl_rwsem);
1402	snd_printdd("unknown ioctl = 0x%x\n", cmd);
1403	return -ENOTTY;
1404}
1405
1406static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1407			    size_t count, loff_t * offset)
1408{
1409	struct snd_ctl_file *ctl;
1410	int err = 0;
1411	ssize_t result = 0;
1412
1413	ctl = file->private_data;
1414	if (snd_BUG_ON(!ctl || !ctl->card))
1415		return -ENXIO;
1416	if (!ctl->subscribed)
1417		return -EBADFD;
1418	if (count < sizeof(struct snd_ctl_event))
1419		return -EINVAL;
1420	spin_lock_irq(&ctl->read_lock);
1421	while (count >= sizeof(struct snd_ctl_event)) {
1422		struct snd_ctl_event ev;
1423		struct snd_kctl_event *kev;
1424		while (list_empty(&ctl->events)) {
1425			wait_queue_t wait;
1426			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1427				err = -EAGAIN;
1428				goto __end_lock;
1429			}
1430			init_waitqueue_entry(&wait, current);
1431			add_wait_queue(&ctl->change_sleep, &wait);
1432			set_current_state(TASK_INTERRUPTIBLE);
1433			spin_unlock_irq(&ctl->read_lock);
1434			schedule();
1435			remove_wait_queue(&ctl->change_sleep, &wait);
1436			if (signal_pending(current))
1437				return -ERESTARTSYS;
1438			spin_lock_irq(&ctl->read_lock);
1439		}
1440		kev = snd_kctl_event(ctl->events.next);
1441		ev.type = SNDRV_CTL_EVENT_ELEM;
1442		ev.data.elem.mask = kev->mask;
1443		ev.data.elem.id = kev->id;
1444		list_del(&kev->list);
1445		spin_unlock_irq(&ctl->read_lock);
1446		kfree(kev);
1447		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1448			err = -EFAULT;
1449			goto __end;
1450		}
1451		spin_lock_irq(&ctl->read_lock);
1452		buffer += sizeof(struct snd_ctl_event);
1453		count -= sizeof(struct snd_ctl_event);
1454		result += sizeof(struct snd_ctl_event);
1455	}
1456      __end_lock:
1457	spin_unlock_irq(&ctl->read_lock);
1458      __end:
1459      	return result > 0 ? result : err;
1460}
1461
1462static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1463{
1464	unsigned int mask;
1465	struct snd_ctl_file *ctl;
1466
1467	ctl = file->private_data;
1468	if (!ctl->subscribed)
1469		return 0;
1470	poll_wait(file, &ctl->change_sleep, wait);
1471
1472	mask = 0;
1473	if (!list_empty(&ctl->events))
1474		mask |= POLLIN | POLLRDNORM;
1475
1476	return mask;
1477}
1478
1479/*
1480 * register the device-specific control-ioctls.
1481 * called from each device manager like pcm.c, hwdep.c, etc.
1482 */
1483static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1484{
1485	struct snd_kctl_ioctl *pn;
1486
1487	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1488	if (pn == NULL)
1489		return -ENOMEM;
1490	pn->fioctl = fcn;
1491	down_write(&snd_ioctl_rwsem);
1492	list_add_tail(&pn->list, lists);
1493	up_write(&snd_ioctl_rwsem);
1494	return 0;
1495}
1496
1497int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1498{
1499	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1500}
1501
1502EXPORT_SYMBOL(snd_ctl_register_ioctl);
1503
1504#ifdef CONFIG_COMPAT
1505int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1506{
1507	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1508}
1509
1510EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1511#endif
1512
1513/*
1514 * de-register the device-specific control-ioctls.
1515 */
1516static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1517				     struct list_head *lists)
1518{
1519	struct snd_kctl_ioctl *p;
1520
1521	if (snd_BUG_ON(!fcn))
1522		return -EINVAL;
1523	down_write(&snd_ioctl_rwsem);
1524	list_for_each_entry(p, lists, list) {
1525		if (p->fioctl == fcn) {
1526			list_del(&p->list);
1527			up_write(&snd_ioctl_rwsem);
1528			kfree(p);
1529			return 0;
1530		}
1531	}
1532	up_write(&snd_ioctl_rwsem);
1533	snd_BUG();
1534	return -EINVAL;
1535}
1536
1537int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1538{
1539	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1540}
1541
1542EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1543
1544#ifdef CONFIG_COMPAT
1545int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1546{
1547	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1548}
1549
1550EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1551#endif
1552
1553static int snd_ctl_fasync(int fd, struct file * file, int on)
1554{
1555	struct snd_ctl_file *ctl;
1556
1557	ctl = file->private_data;
1558	return fasync_helper(fd, file, on, &ctl->fasync);
1559}
1560
1561/*
1562 * ioctl32 compat
1563 */
1564#ifdef CONFIG_COMPAT
1565#include "control_compat.c"
1566#else
1567#define snd_ctl_ioctl_compat	NULL
1568#endif
1569
1570/*
1571 *  INIT PART
1572 */
1573
1574static const struct file_operations snd_ctl_f_ops =
1575{
1576	.owner =	THIS_MODULE,
1577	.read =		snd_ctl_read,
1578	.open =		snd_ctl_open,
1579	.release =	snd_ctl_release,
1580	.llseek =	no_llseek,
1581	.poll =		snd_ctl_poll,
1582	.unlocked_ioctl =	snd_ctl_ioctl,
1583	.compat_ioctl =	snd_ctl_ioctl_compat,
1584	.fasync =	snd_ctl_fasync,
1585};
1586
1587/*
1588 * registration of the control device
1589 */
1590static int snd_ctl_dev_register(struct snd_device *device)
1591{
1592	struct snd_card *card = device->device_data;
1593	int err, cardnum;
1594	char name[16];
1595
1596	if (snd_BUG_ON(!card))
1597		return -ENXIO;
1598	cardnum = card->number;
1599	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1600		return -ENXIO;
1601	sprintf(name, "controlC%i", cardnum);
1602	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1603				       &snd_ctl_f_ops, card, name)) < 0)
1604		return err;
1605	return 0;
1606}
1607
1608/*
1609 * disconnection of the control device
1610 */
1611static int snd_ctl_dev_disconnect(struct snd_device *device)
1612{
1613	struct snd_card *card = device->device_data;
1614	struct snd_ctl_file *ctl;
1615	int err, cardnum;
1616
1617	if (snd_BUG_ON(!card))
1618		return -ENXIO;
1619	cardnum = card->number;
1620	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1621		return -ENXIO;
1622
1623	read_lock(&card->ctl_files_rwlock);
1624	list_for_each_entry(ctl, &card->ctl_files, list) {
1625		wake_up(&ctl->change_sleep);
1626		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1627	}
1628	read_unlock(&card->ctl_files_rwlock);
1629
1630	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1631					 card, -1)) < 0)
1632		return err;
1633	return 0;
1634}
1635
1636/*
1637 * free all controls
1638 */
1639static int snd_ctl_dev_free(struct snd_device *device)
1640{
1641	struct snd_card *card = device->device_data;
1642	struct snd_kcontrol *control;
1643
1644	down_write(&card->controls_rwsem);
1645	while (!list_empty(&card->controls)) {
1646		control = snd_kcontrol(card->controls.next);
1647		snd_ctl_remove(card, control);
1648	}
1649	up_write(&card->controls_rwsem);
1650	return 0;
1651}
1652
1653/*
1654 * create control core:
1655 * called from init.c
1656 */
1657int snd_ctl_create(struct snd_card *card)
1658{
1659	static struct snd_device_ops ops = {
1660		.dev_free = snd_ctl_dev_free,
1661		.dev_register =	snd_ctl_dev_register,
1662		.dev_disconnect = snd_ctl_dev_disconnect,
1663	};
1664
1665	if (snd_BUG_ON(!card))
1666		return -ENXIO;
1667	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1668}
1669
1670/*
1671 * Frequently used control callbacks/helpers
1672 */
1673int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1674			      struct snd_ctl_elem_info *uinfo)
1675{
1676	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1677	uinfo->count = 1;
1678	uinfo->value.integer.min = 0;
1679	uinfo->value.integer.max = 1;
1680	return 0;
1681}
1682
1683EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1684
1685int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1686				struct snd_ctl_elem_info *uinfo)
1687{
1688	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1689	uinfo->count = 2;
1690	uinfo->value.integer.min = 0;
1691	uinfo->value.integer.max = 1;
1692	return 0;
1693}
1694
1695EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1696
1697/**
1698 * snd_ctl_enum_info - fills the info structure for an enumerated control
1699 * @info: the structure to be filled
1700 * @channels: the number of the control's channels; often one
1701 * @items: the number of control values; also the size of @names
1702 * @names: an array containing the names of all control values
1703 *
1704 * Sets all required fields in @info to their appropriate values.
1705 * If the control's accessibility is not the default (readable and writable),
1706 * the caller has to fill @info->access.
1707 */
1708int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1709		      unsigned int items, const char *const names[])
1710{
1711	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1712	info->count = channels;
1713	info->value.enumerated.items = items;
1714	if (info->value.enumerated.item >= items)
1715		info->value.enumerated.item = items - 1;
1716	strlcpy(info->value.enumerated.name,
1717		names[info->value.enumerated.item],
1718		sizeof(info->value.enumerated.name));
1719	return 0;
1720}
1721EXPORT_SYMBOL(snd_ctl_enum_info);