control.c 44.8 KB
Newer Older
L
Linus Torvalds 已提交
1 2
/*
 *  Routines for driver control interface
3
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
L
Linus Torvalds 已提交
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/threads.h>
#include <linux/interrupt.h>
24
#include <linux/module.h>
L
Linus Torvalds 已提交
25 26 27 28 29 30 31 32 33 34
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>

/* max number of user-defined controls */
#define MAX_USER_CONTROLS	32
35
#define MAX_CONTROL_COUNT	1028
L
Linus Torvalds 已提交
36

37
struct snd_kctl_ioctl {
L
Linus Torvalds 已提交
38 39
	struct list_head list;		/* list of all ioctls */
	snd_kctl_ioctl_func_t fioctl;
40
};
L
Linus Torvalds 已提交
41 42 43 44 45 46 47 48 49 50

static DECLARE_RWSEM(snd_ioctl_rwsem);
static LIST_HEAD(snd_control_ioctls);
#ifdef CONFIG_COMPAT
static LIST_HEAD(snd_control_compat_ioctls);
#endif

static int snd_ctl_open(struct inode *inode, struct file *file)
{
	unsigned long flags;
51 52
	struct snd_card *card;
	struct snd_ctl_file *ctl;
L
Linus Torvalds 已提交
53 54
	int err;

T
Takashi Iwai 已提交
55 56 57 58
	err = nonseekable_open(inode, file);
	if (err < 0)
		return err;

59
	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
L
Linus Torvalds 已提交
60 61 62 63 64 65 66 67 68 69 70 71 72
	if (!card) {
		err = -ENODEV;
		goto __error1;
	}
	err = snd_card_file_add(card, file);
	if (err < 0) {
		err = -ENODEV;
		goto __error1;
	}
	if (!try_module_get(card->module)) {
		err = -EFAULT;
		goto __error2;
	}
73
	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
L
Linus Torvalds 已提交
74 75 76 77 78 79 80 81
	if (ctl == NULL) {
		err = -ENOMEM;
		goto __error;
	}
	INIT_LIST_HEAD(&ctl->events);
	init_waitqueue_head(&ctl->change_sleep);
	spin_lock_init(&ctl->read_lock);
	ctl->card = card;
82 83
	ctl->prefer_pcm_subdevice = -1;
	ctl->prefer_rawmidi_subdevice = -1;
84
	ctl->pid = get_pid(task_pid(current));
L
Linus Torvalds 已提交
85 86 87 88
	file->private_data = ctl;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_add_tail(&ctl->list, &card->ctl_files);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
89
	snd_card_unref(card);
L
Linus Torvalds 已提交
90 91 92 93 94 95 96
	return 0;

      __error:
	module_put(card->module);
      __error2:
	snd_card_file_remove(card, file);
      __error1:
97 98
	if (card)
		snd_card_unref(card);
L
Linus Torvalds 已提交
99 100 101
      	return err;
}

102
static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
L
Linus Torvalds 已提交
103
{
104
	unsigned long flags;
105
	struct snd_kctl_event *cread;
L
Linus Torvalds 已提交
106
	
107
	spin_lock_irqsave(&ctl->read_lock, flags);
L
Linus Torvalds 已提交
108 109 110 111 112
	while (!list_empty(&ctl->events)) {
		cread = snd_kctl_event(ctl->events.next);
		list_del(&cread->list);
		kfree(cread);
	}
113
	spin_unlock_irqrestore(&ctl->read_lock, flags);
L
Linus Torvalds 已提交
114 115 116 117 118
}

static int snd_ctl_release(struct inode *inode, struct file *file)
{
	unsigned long flags;
119 120 121
	struct snd_card *card;
	struct snd_ctl_file *ctl;
	struct snd_kcontrol *control;
L
Linus Torvalds 已提交
122 123 124 125 126 127 128 129 130
	unsigned int idx;

	ctl = file->private_data;
	file->private_data = NULL;
	card = ctl->card;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_del(&ctl->list);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
	down_write(&card->controls_rwsem);
131
	list_for_each_entry(control, &card->controls, list)
L
Linus Torvalds 已提交
132 133 134 135 136
		for (idx = 0; idx < control->count; idx++)
			if (control->vd[idx].owner == ctl)
				control->vd[idx].owner = NULL;
	up_write(&card->controls_rwsem);
	snd_ctl_empty_read_queue(ctl);
137
	put_pid(ctl->pid);
L
Linus Torvalds 已提交
138 139 140 141 142 143
	kfree(ctl);
	module_put(card->module);
	snd_card_file_remove(card, file);
	return 0;
}

144 145
void snd_ctl_notify(struct snd_card *card, unsigned int mask,
		    struct snd_ctl_elem_id *id)
L
Linus Torvalds 已提交
146 147
{
	unsigned long flags;
148 149
	struct snd_ctl_file *ctl;
	struct snd_kctl_event *ev;
L
Linus Torvalds 已提交
150
	
151 152
	if (snd_BUG_ON(!card || !id))
		return;
L
Linus Torvalds 已提交
153
	read_lock(&card->ctl_files_rwlock);
T
Takashi Iwai 已提交
154
#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
L
Linus Torvalds 已提交
155 156
	card->mixer_oss_change_count++;
#endif
157
	list_for_each_entry(ctl, &card->ctl_files, list) {
L
Linus Torvalds 已提交
158 159 160
		if (!ctl->subscribed)
			continue;
		spin_lock_irqsave(&ctl->read_lock, flags);
161
		list_for_each_entry(ev, &ctl->events, list) {
L
Linus Torvalds 已提交
162 163 164 165 166
			if (ev->id.numid == id->numid) {
				ev->mask |= mask;
				goto _found;
			}
		}
167
		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
L
Linus Torvalds 已提交
168 169 170 171 172
		if (ev) {
			ev->id = *id;
			ev->mask = mask;
			list_add_tail(&ev->list, &ctl->events);
		} else {
173
			dev_err(card->dev, "No memory available to allocate event\n");
L
Linus Torvalds 已提交
174 175 176 177 178 179 180 181 182
		}
	_found:
		wake_up(&ctl->change_sleep);
		spin_unlock_irqrestore(&ctl->read_lock, flags);
		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
	}
	read_unlock(&card->ctl_files_rwlock);
}

183 184
EXPORT_SYMBOL(snd_ctl_notify);

L
Linus Torvalds 已提交
185 186 187 188 189
/**
 * snd_ctl_new - create a control instance from the template
 * @control: the control template
 * @access: the default control access
 *
190
 * Allocates a new struct snd_kcontrol instance and copies the given template 
L
Linus Torvalds 已提交
191 192
 * to the new instance. It does not copy volatile data (access).
 *
193
 * Return: The pointer of the new instance, or %NULL on failure.
L
Linus Torvalds 已提交
194
 */
195 196
static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
					unsigned int access)
L
Linus Torvalds 已提交
197
{
198
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
199 200
	unsigned int idx;
	
201 202
	if (snd_BUG_ON(!control || !control->count))
		return NULL;
203 204 205 206

	if (control->count > MAX_CONTROL_COUNT)
		return NULL;

207
	kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
T
Takashi Iwai 已提交
208
	if (kctl == NULL) {
209
		pr_err("ALSA: Cannot allocate control instance\n");
L
Linus Torvalds 已提交
210
		return NULL;
T
Takashi Iwai 已提交
211
	}
L
Linus Torvalds 已提交
212 213 214 215 216 217 218 219 220 221 222
	*kctl = *control;
	for (idx = 0; idx < kctl->count; idx++)
		kctl->vd[idx].access = access;
	return kctl;
}

/**
 * snd_ctl_new1 - create a control instance from the template
 * @ncontrol: the initialization record
 * @private_data: the private data to set
 *
223
 * Allocates a new struct snd_kcontrol instance and initialize from the given 
L
Linus Torvalds 已提交
224 225 226
 * template.  When the access field of ncontrol is 0, it's assumed as
 * READWRITE access. When the count field is 0, it's assumes as one.
 *
227
 * Return: The pointer of the newly generated instance, or %NULL on failure.
L
Linus Torvalds 已提交
228
 */
229 230
struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
				  void *private_data)
L
Linus Torvalds 已提交
231
{
232
	struct snd_kcontrol kctl;
L
Linus Torvalds 已提交
233 234
	unsigned int access;
	
235 236
	if (snd_BUG_ON(!ncontrol || !ncontrol->info))
		return NULL;
L
Linus Torvalds 已提交
237 238 239 240
	memset(&kctl, 0, sizeof(kctl));
	kctl.id.iface = ncontrol->iface;
	kctl.id.device = ncontrol->device;
	kctl.id.subdevice = ncontrol->subdevice;
241
	if (ncontrol->name) {
L
Linus Torvalds 已提交
242
		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
243
		if (strcmp(ncontrol->name, kctl.id.name) != 0)
244 245
			pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
				ncontrol->name, kctl.id.name);
246
	}
L
Linus Torvalds 已提交
247 248 249
	kctl.id.index = ncontrol->index;
	kctl.count = ncontrol->count ? ncontrol->count : 1;
	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
250
		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
251
				      SNDRV_CTL_ELEM_ACCESS_VOLATILE|
252
				      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
253 254 255
				      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
				      SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
				      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
L
Linus Torvalds 已提交
256 257 258
	kctl.info = ncontrol->info;
	kctl.get = ncontrol->get;
	kctl.put = ncontrol->put;
259
	kctl.tlv.p = ncontrol->tlv.p;
L
Linus Torvalds 已提交
260 261 262 263 264
	kctl.private_value = ncontrol->private_value;
	kctl.private_data = private_data;
	return snd_ctl_new(&kctl, access);
}

265 266
EXPORT_SYMBOL(snd_ctl_new1);

L
Linus Torvalds 已提交
267 268 269 270 271 272 273 274
/**
 * snd_ctl_free_one - release the control instance
 * @kcontrol: the control instance
 *
 * Releases the control instance created via snd_ctl_new()
 * or snd_ctl_new1().
 * Don't call this after the control was added to the card.
 */
275
void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
L
Linus Torvalds 已提交
276 277 278 279 280 281 282 283
{
	if (kcontrol) {
		if (kcontrol->private_free)
			kcontrol->private_free(kcontrol);
		kfree(kcontrol);
	}
}

284 285
EXPORT_SYMBOL(snd_ctl_free_one);

286 287
static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
					  unsigned int count)
L
Linus Torvalds 已提交
288
{
289
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
290

291 292 293 294
	/* Make sure that the ids assigned to the control do not wrap around */
	if (card->last_numid >= UINT_MAX - count)
		card->last_numid = 0;

295
	list_for_each_entry(kctl, &card->controls, list) {
296
		if (kctl->id.numid < card->last_numid + 1 + count &&
297 298 299 300
		    kctl->id.numid + kctl->count > card->last_numid + 1) {
		    	card->last_numid = kctl->id.numid + kctl->count - 1;
			return true;
		}
L
Linus Torvalds 已提交
301
	}
302
	return false;
L
Linus Torvalds 已提交
303 304
}

305
static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
L
Linus Torvalds 已提交
306
{
307
	unsigned int iter = 100000;
L
Linus Torvalds 已提交
308

309
	while (snd_ctl_remove_numid_conflict(card, count)) {
L
Linus Torvalds 已提交
310 311
		if (--iter == 0) {
			/* this situation is very unlikely */
312
			dev_err(card->dev, "unable to allocate new control numid\n");
L
Linus Torvalds 已提交
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328
			return -ENOMEM;
		}
	}
	return 0;
}

/**
 * snd_ctl_add - add the control instance to the card
 * @card: the card instance
 * @kcontrol: the control instance to add
 *
 * Adds the control instance created via snd_ctl_new() or
 * snd_ctl_new1() to the given card. Assigns also an unique
 * numid used for fast search.
 *
 * It frees automatically the control which cannot be added.
329 330 331
 *
 * Return: Zero if successful, or a negative error code on failure.
 *
L
Linus Torvalds 已提交
332
 */
333
int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
L
Linus Torvalds 已提交
334
{
335
	struct snd_ctl_elem_id id;
L
Linus Torvalds 已提交
336
	unsigned int idx;
337
	unsigned int count;
338
	int err = -EINVAL;
L
Linus Torvalds 已提交
339

T
Takashi Iwai 已提交
340
	if (! kcontrol)
341
		return err;
342 343
	if (snd_BUG_ON(!card || !kcontrol->info))
		goto error;
L
Linus Torvalds 已提交
344
	id = kcontrol->id;
345 346 347
	if (id.index > UINT_MAX - kcontrol->count)
		goto error;

L
Linus Torvalds 已提交
348 349 350
	down_write(&card->controls_rwsem);
	if (snd_ctl_find_id(card, &id)) {
		up_write(&card->controls_rwsem);
351
		dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
L
Linus Torvalds 已提交
352 353 354 355 356
					id.iface,
					id.device,
					id.subdevice,
					id.name,
					id.index);
357 358
		err = -EBUSY;
		goto error;
L
Linus Torvalds 已提交
359 360 361
	}
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
362 363
		err = -ENOMEM;
		goto error;
L
Linus Torvalds 已提交
364 365 366 367 368
	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
369
	count = kcontrol->count;
L
Linus Torvalds 已提交
370
	up_write(&card->controls_rwsem);
371
	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
L
Linus Torvalds 已提交
372 373
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;
374 375 376 377

 error:
	snd_ctl_free_one(kcontrol);
	return err;
L
Linus Torvalds 已提交
378 379
}

380 381
EXPORT_SYMBOL(snd_ctl_add);

382 383 384 385 386 387 388 389 390 391 392
/**
 * snd_ctl_replace - replace the control instance of the card
 * @card: the card instance
 * @kcontrol: the control instance to replace
 * @add_on_replace: add the control if not already added
 *
 * Replaces the given control.  If the given control does not exist
 * and the add_on_replace flag is set, the control is added.  If the
 * control exists, it is destroyed first.
 *
 * It frees automatically the control which cannot be added or replaced.
393 394
 *
 * Return: Zero if successful, or a negative error code on failure.
395 396 397 398 399
 */
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
		    bool add_on_replace)
{
	struct snd_ctl_elem_id id;
400
	unsigned int count;
401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435
	unsigned int idx;
	struct snd_kcontrol *old;
	int ret;

	if (!kcontrol)
		return -EINVAL;
	if (snd_BUG_ON(!card || !kcontrol->info)) {
		ret = -EINVAL;
		goto error;
	}
	id = kcontrol->id;
	down_write(&card->controls_rwsem);
	old = snd_ctl_find_id(card, &id);
	if (!old) {
		if (add_on_replace)
			goto add;
		up_write(&card->controls_rwsem);
		ret = -EINVAL;
		goto error;
	}
	ret = snd_ctl_remove(card, old);
	if (ret < 0) {
		up_write(&card->controls_rwsem);
		goto error;
	}
add:
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
		ret = -ENOMEM;
		goto error;
	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
436
	count = kcontrol->count;
437
	up_write(&card->controls_rwsem);
438
	for (idx = 0; idx < count; idx++, id.index++, id.numid++)
439 440 441 442 443 444 445 446 447
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;

error:
	snd_ctl_free_one(kcontrol);
	return ret;
}
EXPORT_SYMBOL(snd_ctl_replace);

L
Linus Torvalds 已提交
448 449 450 451 452 453 454 455
/**
 * snd_ctl_remove - remove the control from the card and release it
 * @card: the card instance
 * @kcontrol: the control instance to remove
 *
 * Removes the control from the card and then releases the instance.
 * You don't need to call snd_ctl_free_one(). You must be in
 * the write lock - down_write(&card->controls_rwsem).
456 457
 *
 * Return: 0 if successful, or a negative error code on failure.
L
Linus Torvalds 已提交
458
 */
459
int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
L
Linus Torvalds 已提交
460
{
461
	struct snd_ctl_elem_id id;
L
Linus Torvalds 已提交
462 463
	unsigned int idx;

464 465
	if (snd_BUG_ON(!card || !kcontrol))
		return -EINVAL;
L
Linus Torvalds 已提交
466 467 468 469 470 471 472 473 474
	list_del(&kcontrol->list);
	card->controls_count -= kcontrol->count;
	id = kcontrol->id;
	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
	snd_ctl_free_one(kcontrol);
	return 0;
}

475 476
EXPORT_SYMBOL(snd_ctl_remove);

L
Linus Torvalds 已提交
477 478 479 480 481 482 483
/**
 * snd_ctl_remove_id - remove the control of the given id and release it
 * @card: the card instance
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
484 485
 *
 * Return: 0 if successful, or a negative error code on failure.
L
Linus Torvalds 已提交
486
 */
487
int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
L
Linus Torvalds 已提交
488
{
489
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
490 491 492 493 494 495 496 497 498 499 500 501 502
	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	ret = snd_ctl_remove(card, kctl);
	up_write(&card->controls_rwsem);
	return ret;
}

503 504
EXPORT_SYMBOL(snd_ctl_remove_id);

L
Linus Torvalds 已提交
505
/**
506
 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
L
Linus Torvalds 已提交
507 508 509 510 511
 * @file: active control handle
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
512 513
 *
 * Return: 0 if successful, or a negative error code on failure.
L
Linus Torvalds 已提交
514
 */
515 516
static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
				   struct snd_ctl_elem_id *id)
L
Linus Torvalds 已提交
517
{
518 519
	struct snd_card *card = file->card;
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
520 521 522 523 524
	int idx, ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
525 526
		ret = -ENOENT;
		goto error;
L
Linus Torvalds 已提交
527
	}
528 529 530 531
	if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
		ret = -EINVAL;
		goto error;
	}
L
Linus Torvalds 已提交
532 533
	for (idx = 0; idx < kctl->count; idx++)
		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
534 535
			ret = -EBUSY;
			goto error;
L
Linus Torvalds 已提交
536 537
		}
	ret = snd_ctl_remove(card, kctl);
538 539 540
	if (ret < 0)
		goto error;
	card->user_ctl_count--;
541
error:
L
Linus Torvalds 已提交
542 543 544 545
	up_write(&card->controls_rwsem);
	return ret;
}

T
Takashi Iwai 已提交
546 547 548 549 550 551 552 553 554
/**
 * snd_ctl_activate_id - activate/inactivate the control of the given id
 * @card: the card instance
 * @id: the control id to activate/inactivate
 * @active: non-zero to activate
 *
 * Finds the control instance with the given id, and activate or
 * inactivate the control together with notification, if changed.
 *
555
 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
T
Takashi Iwai 已提交
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591
 */
int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
			int active)
{
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		ret = -ENOENT;
		goto unlock;
	}
	index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
	vd = &kctl->vd[index_offset];
	ret = 0;
	if (active) {
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
			goto unlock;
		vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	} else {
		if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
			goto unlock;
		vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
	}
	ret = 1;
 unlock:
	up_write(&card->controls_rwsem);
	if (ret > 0)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
	return ret;
}
EXPORT_SYMBOL_GPL(snd_ctl_activate_id);

L
Linus Torvalds 已提交
592 593 594 595 596 597 598 599 600
/**
 * snd_ctl_rename_id - replace the id of a control on the card
 * @card: the card instance
 * @src_id: the old id
 * @dst_id: the new id
 *
 * Finds the control with the old id from the card, and replaces the
 * id with the new one.
 *
601
 * Return: Zero if successful, or a negative error code on failure.
L
Linus Torvalds 已提交
602
 */
603 604
int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
		      struct snd_ctl_elem_id *dst_id)
L
Linus Torvalds 已提交
605
{
606
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
607 608 609 610 611 612 613 614 615 616 617 618 619 620

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, src_id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	kctl->id = *dst_id;
	kctl->id.numid = card->last_numid + 1;
	card->last_numid += kctl->count;
	up_write(&card->controls_rwsem);
	return 0;
}

621 622
EXPORT_SYMBOL(snd_ctl_rename_id);

L
Linus Torvalds 已提交
623 624 625 626 627 628 629 630 631
/**
 * snd_ctl_find_numid - find the control instance with the given number-id
 * @card: the card instance
 * @numid: the number-id to search
 *
 * Finds the control instance with the given number-id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
632 633 634
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
L
Linus Torvalds 已提交
635
 */
636
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
L
Linus Torvalds 已提交
637
{
638
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
639

640 641
	if (snd_BUG_ON(!card || !numid))
		return NULL;
642
	list_for_each_entry(kctl, &card->controls, list) {
L
Linus Torvalds 已提交
643 644 645 646 647 648
		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
			return kctl;
	}
	return NULL;
}

649 650
EXPORT_SYMBOL(snd_ctl_find_numid);

L
Linus Torvalds 已提交
651 652 653 654 655 656 657 658 659
/**
 * snd_ctl_find_id - find the control instance with the given id
 * @card: the card instance
 * @id: the id to search
 *
 * Finds the control instance with the given id from the card.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
660 661 662
 *
 * Return: The pointer of the instance if found, or %NULL if not.
 *
L
Linus Torvalds 已提交
663
 */
664 665
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
L
Linus Torvalds 已提交
666
{
667
	struct snd_kcontrol *kctl;
L
Linus Torvalds 已提交
668

669 670
	if (snd_BUG_ON(!card || !id))
		return NULL;
L
Linus Torvalds 已提交
671 672
	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
673
	list_for_each_entry(kctl, &card->controls, list) {
L
Linus Torvalds 已提交
674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
		if (kctl->id.iface != id->iface)
			continue;
		if (kctl->id.device != id->device)
			continue;
		if (kctl->id.subdevice != id->subdevice)
			continue;
		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
			continue;
		if (kctl->id.index > id->index)
			continue;
		if (kctl->id.index + kctl->count <= id->index)
			continue;
		return kctl;
	}
	return NULL;
}

691 692
EXPORT_SYMBOL(snd_ctl_find_id);

693
static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
L
Linus Torvalds 已提交
694 695
			     unsigned int cmd, void __user *arg)
{
696
	struct snd_ctl_card_info *info;
L
Linus Torvalds 已提交
697

698
	info = kzalloc(sizeof(*info), GFP_KERNEL);
L
Linus Torvalds 已提交
699 700 701 702 703 704 705 706 707 708 709
	if (! info)
		return -ENOMEM;
	down_read(&snd_ioctl_rwsem);
	info->card = card->number;
	strlcpy(info->id, card->id, sizeof(info->id));
	strlcpy(info->driver, card->driver, sizeof(info->driver));
	strlcpy(info->name, card->shortname, sizeof(info->name));
	strlcpy(info->longname, card->longname, sizeof(info->longname));
	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
	strlcpy(info->components, card->components, sizeof(info->components));
	up_read(&snd_ioctl_rwsem);
710
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
L
Linus Torvalds 已提交
711 712 713 714 715 716 717
		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

718 719
static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
L
Linus Torvalds 已提交
720 721
{
	struct list_head *plist;
722 723 724
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
	struct snd_ctl_elem_id *dst, *id;
725
	unsigned int offset, space, jidx;
L
Linus Torvalds 已提交
726 727 728 729 730 731 732 733 734 735
	
	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
	/* try limit maximum space */
	if (space > 16384)
		return -ENOMEM;
	if (space > 0) {
		/* allocate temporary buffer for atomic operation */
736
		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
L
Linus Torvalds 已提交
737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764
		if (dst == NULL)
			return -ENOMEM;
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		plist = card->controls.next;
		while (plist != &card->controls) {
			if (offset == 0)
				break;
			kctl = snd_kcontrol(plist);
			if (offset < kctl->count)
				break;
			offset -= kctl->count;
			plist = plist->next;
		}
		list.used = 0;
		id = dst;
		while (space > 0 && plist != &card->controls) {
			kctl = snd_kcontrol(plist);
			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(id, kctl, jidx);
				id++;
				space--;
				list.used++;
			}
			plist = plist->next;
			offset = 0;
		}
		up_read(&card->controls_rwsem);
765 766 767
		if (list.used > 0 &&
		    copy_to_user(list.pids, dst,
				 list.used * sizeof(struct snd_ctl_elem_id))) {
L
Linus Torvalds 已提交
768 769 770 771 772 773 774 775 776 777 778 779 780 781
			vfree(dst);
			return -EFAULT;
		}
		vfree(dst);
	} else {
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		up_read(&card->controls_rwsem);
	}
	if (copy_to_user(_list, &list, sizeof(list)))
		return -EFAULT;
	return 0;
}

782 783
static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
L
Linus Torvalds 已提交
784
{
785 786 787
	struct snd_card *card = ctl->card;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
L
Linus Torvalds 已提交
788 789 790 791 792 793 794 795 796 797 798 799 800 801
	unsigned int index_offset;
	int result;
	
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &info->id);
	if (kctl == NULL) {
		up_read(&card->controls_rwsem);
		return -ENOENT;
	}
#ifdef CONFIG_SND_DEBUG
	info->access = 0;
#endif
	result = kctl->info(kctl, info);
	if (result >= 0) {
802
		snd_BUG_ON(info->access);
L
Linus Torvalds 已提交
803 804 805 806 807 808 809 810
		index_offset = snd_ctl_get_ioff(kctl, &info->id);
		vd = &kctl->vd[index_offset];
		snd_ctl_build_ioff(&info->id, kctl, index_offset);
		info->access = vd->access;
		if (vd->owner) {
			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
			if (vd->owner == ctl)
				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
811
			info->owner = pid_vnr(vd->owner->pid);
L
Linus Torvalds 已提交
812 813 814 815 816 817 818 819
		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

820 821
static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
L
Linus Torvalds 已提交
822
{
823
	struct snd_ctl_elem_info info;
L
Linus Torvalds 已提交
824 825 826 827
	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
828
	snd_power_lock(ctl->card);
829
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
830 831 832
	if (result >= 0)
		result = snd_ctl_elem_info(ctl, &info);
	snd_power_unlock(ctl->card);
L
Linus Torvalds 已提交
833 834 835 836 837 838
	if (result >= 0)
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
	return result;
}

839 840
static int snd_ctl_elem_read(struct snd_card *card,
			     struct snd_ctl_elem_value *control)
L
Linus Torvalds 已提交
841
{
842 843
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
L
Linus Torvalds 已提交
844
	unsigned int index_offset;
845
	int result;
L
Linus Torvalds 已提交
846 847 848 849 850 851 852 853

	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
854 855 856 857 858 859
		if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
		    kctl->get != NULL) {
			snd_ctl_build_ioff(&control->id, kctl, index_offset);
			result = kctl->get(kctl, control);
		} else
			result = -EPERM;
L
Linus Torvalds 已提交
860 861 862 863 864
	}
	up_read(&card->controls_rwsem);
	return result;
}

865 866
static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
L
Linus Torvalds 已提交
867
{
868
	struct snd_ctl_elem_value *control;
L
Linus Torvalds 已提交
869
	int result;
L
Li Zefan 已提交
870 871 872 873 874

	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

875
	snd_power_lock(card);
876
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
877 878 879
	if (result >= 0)
		result = snd_ctl_elem_read(card, control);
	snd_power_unlock(card);
L
Linus Torvalds 已提交
880 881 882 883 884 885 886
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

887 888
static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
			      struct snd_ctl_elem_value *control)
L
Linus Torvalds 已提交
889
{
890 891
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
L
Linus Torvalds 已提交
892
	unsigned int index_offset;
893
	int result;
L
Linus Torvalds 已提交
894 895 896 897 898 899 900 901

	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
902 903 904 905
		if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
		    kctl->put == NULL ||
		    (file && vd->owner && vd->owner != file)) {
			result = -EPERM;
L
Linus Torvalds 已提交
906
		} else {
907 908 909 910
			snd_ctl_build_ioff(&control->id, kctl, index_offset);
			result = kctl->put(kctl, control);
		}
		if (result > 0) {
911
			struct snd_ctl_elem_id id = control->id;
912
			up_read(&card->controls_rwsem);
913
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
914
			return 0;
L
Linus Torvalds 已提交
915 916 917 918 919 920
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

921 922
static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
L
Linus Torvalds 已提交
923
{
924
	struct snd_ctl_elem_value *control;
925
	struct snd_card *card;
L
Linus Torvalds 已提交
926 927
	int result;

L
Li Zefan 已提交
928 929 930 931
	control = memdup_user(_control, sizeof(*control));
	if (IS_ERR(control))
		return PTR_ERR(control);

932 933
	card = file->card;
	snd_power_lock(card);
934
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
935 936 937
	if (result >= 0)
		result = snd_ctl_elem_write(card, file, control);
	snd_power_unlock(card);
L
Linus Torvalds 已提交
938 939 940 941 942 943 944
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

945 946
static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
L
Linus Torvalds 已提交
947
{
948 949 950 951
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
L
Linus Torvalds 已提交
952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972
	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner != NULL)
			result = -EBUSY;
		else {
			vd->owner = file;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

973 974
static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
L
Linus Torvalds 已提交
975
{
976 977 978 979
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
L
Linus Torvalds 已提交
980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner == NULL)
			result = -EINVAL;
		else if (vd->owner != file)
			result = -EPERM;
		else {
			vd->owner = NULL;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

struct user_element {
1004
	struct snd_ctl_elem_info info;
1005
	struct snd_card *card;
L
Linus Torvalds 已提交
1006 1007
	void *elem_data;		/* element data */
	unsigned long elem_data_size;	/* size of element data in bytes */
1008 1009
	void *tlv_data;			/* TLV data */
	unsigned long tlv_data_size;	/* TLV data size */
L
Linus Torvalds 已提交
1010 1011 1012
	void *priv_data;		/* private data (like strings for enumerated type) */
};

1013 1014
static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_info *uinfo)
L
Linus Torvalds 已提交
1015 1016 1017 1018 1019 1020 1021
{
	struct user_element *ue = kcontrol->private_data;

	*uinfo = ue->info;
	return 0;
}

1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
				       struct snd_ctl_elem_info *uinfo)
{
	struct user_element *ue = kcontrol->private_data;
	const char *names;
	unsigned int item;

	item = uinfo->value.enumerated.item;

	*uinfo = ue->info;

	item = min(item, uinfo->value.enumerated.items - 1);
	uinfo->value.enumerated.item = item;

	names = ue->priv_data;
	for (; item > 0; --item)
		names += strlen(names) + 1;
	strcpy(uinfo->value.enumerated.name, names);

	return 0;
}

1044 1045
static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
L
Linus Torvalds 已提交
1046 1047 1048
{
	struct user_element *ue = kcontrol->private_data;

1049
	mutex_lock(&ue->card->user_ctl_lock);
L
Linus Torvalds 已提交
1050
	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1051
	mutex_unlock(&ue->card->user_ctl_lock);
L
Linus Torvalds 已提交
1052 1053 1054
	return 0;
}

1055 1056
static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
L
Linus Torvalds 已提交
1057 1058 1059
{
	int change;
	struct user_element *ue = kcontrol->private_data;
1060 1061

	mutex_lock(&ue->card->user_ctl_lock);
L
Linus Torvalds 已提交
1062 1063 1064
	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
	if (change)
		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1065
	mutex_unlock(&ue->card->user_ctl_lock);
L
Linus Torvalds 已提交
1066 1067 1068
	return change;
}

1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080
static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
				 int op_flag,
				 unsigned int size,
				 unsigned int __user *tlv)
{
	struct user_element *ue = kcontrol->private_data;
	int change = 0;
	void *new_data;

	if (op_flag > 0) {
		if (size > 1024 * 128)	/* sane value */
			return -EINVAL;
L
Li Zefan 已提交
1081 1082 1083 1084

		new_data = memdup_user(tlv, size);
		if (IS_ERR(new_data))
			return PTR_ERR(new_data);
1085
		mutex_lock(&ue->card->user_ctl_lock);
1086 1087 1088 1089 1090 1091
		change = ue->tlv_data_size != size;
		if (!change)
			change = memcmp(ue->tlv_data, new_data, size);
		kfree(ue->tlv_data);
		ue->tlv_data = new_data;
		ue->tlv_data_size = size;
1092
		mutex_unlock(&ue->card->user_ctl_lock);
1093
	} else {
1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104
		int ret = 0;

		mutex_lock(&ue->card->user_ctl_lock);
		if (!ue->tlv_data_size || !ue->tlv_data) {
			ret = -ENXIO;
			goto err_unlock;
		}
		if (size < ue->tlv_data_size) {
			ret = -ENOSPC;
			goto err_unlock;
		}
1105
		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1106 1107 1108 1109 1110
			ret = -EFAULT;
err_unlock:
		mutex_unlock(&ue->card->user_ctl_lock);
		if (ret)
			return ret;
1111 1112 1113 1114
	}
	return change;
}

1115 1116 1117 1118 1119
static int snd_ctl_elem_init_enum_names(struct user_element *ue)
{
	char *names, *p;
	size_t buf_len, name_len;
	unsigned int i;
1120
	const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1121 1122 1123 1124

	if (ue->info.value.enumerated.names_length > 64 * 1024)
		return -EINVAL;

1125
	names = memdup_user((const void __user *)user_ptrval,
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148
		ue->info.value.enumerated.names_length);
	if (IS_ERR(names))
		return PTR_ERR(names);

	/* check that there are enough valid names */
	buf_len = ue->info.value.enumerated.names_length;
	p = names;
	for (i = 0; i < ue->info.value.enumerated.items; ++i) {
		name_len = strnlen(p, buf_len);
		if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
			kfree(names);
			return -EINVAL;
		}
		p += name_len + 1;
		buf_len -= name_len + 1;
	}

	ue->priv_data = names;
	ue->info.value.enumerated.names_ptr = 0;

	return 0;
}

1149
static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
L
Linus Torvalds 已提交
1150
{
1151
	struct user_element *ue = kcontrol->private_data;
1152 1153 1154

	kfree(ue->tlv_data);
	kfree(ue->priv_data);
1155
	kfree(ue);
L
Linus Torvalds 已提交
1156 1157
}

1158 1159
static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
L
Linus Torvalds 已提交
1160
{
1161 1162
	struct snd_card *card = file->card;
	struct snd_kcontrol kctl, *_kctl;
L
Linus Torvalds 已提交
1163 1164 1165 1166
	unsigned int access;
	long private_size;
	struct user_element *ue;
	int idx, err;
L
Lu Guanqun 已提交
1167

1168
	if (info->count < 1)
L
Linus Torvalds 已提交
1169 1170
		return -EINVAL;
	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1171
		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1172 1173
				 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
				 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
L
Linus Torvalds 已提交
1174 1175
	info->id.numid = 0;
	memset(&kctl, 0, sizeof(kctl));
1176 1177 1178 1179 1180

	if (replace) {
		err = snd_ctl_remove_user_ctl(file, &info->id);
		if (err)
			return err;
L
Linus Torvalds 已提交
1181
	}
1182 1183 1184 1185

	if (card->user_ctl_count >= MAX_USER_CONTROLS)
		return -ENOMEM;

L
Linus Torvalds 已提交
1186 1187 1188
	memcpy(&kctl.id, &info->id, sizeof(info->id));
	kctl.count = info->owner ? info->owner : 1;
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
1189 1190 1191 1192
	if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
		kctl.info = snd_ctl_elem_user_enum_info;
	else
		kctl.info = snd_ctl_elem_user_info;
L
Linus Torvalds 已提交
1193 1194 1195 1196
	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
		kctl.get = snd_ctl_elem_user_get;
	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
		kctl.put = snd_ctl_elem_user_put;
1197 1198 1199 1200
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
		kctl.tlv.c = snd_ctl_elem_user_tlv;
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
	}
L
Linus Torvalds 已提交
1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
	switch (info->type) {
	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
	case SNDRV_CTL_ELEM_TYPE_INTEGER:
		private_size = sizeof(long);
		if (info->count > 128)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
		private_size = sizeof(long long);
		if (info->count > 64)
			return -EINVAL;
		break;
1213 1214 1215 1216 1217
	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
		private_size = sizeof(unsigned int);
		if (info->count > 128 || info->value.enumerated.items == 0)
			return -EINVAL;
		break;
L
Linus Torvalds 已提交
1218 1219 1220 1221 1222 1223
	case SNDRV_CTL_ELEM_TYPE_BYTES:
		private_size = sizeof(unsigned char);
		if (info->count > 512)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_IEC958:
1224
		private_size = sizeof(struct snd_aes_iec958);
L
Linus Torvalds 已提交
1225 1226 1227 1228 1229 1230 1231
		if (info->count != 1)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}
	private_size *= info->count;
1232
	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
L
Linus Torvalds 已提交
1233 1234
	if (ue == NULL)
		return -ENOMEM;
1235
	ue->card = card;
L
Linus Torvalds 已提交
1236
	ue->info = *info;
1237
	ue->info.access = 0;
L
Linus Torvalds 已提交
1238 1239
	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
1240 1241 1242 1243 1244 1245 1246
	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
		err = snd_ctl_elem_init_enum_names(ue);
		if (err < 0) {
			kfree(ue);
			return err;
		}
	}
L
Linus Torvalds 已提交
1247 1248 1249
	kctl.private_free = snd_ctl_elem_user_free;
	_kctl = snd_ctl_new(&kctl, access);
	if (_kctl == NULL) {
1250
		kfree(ue->priv_data);
1251
		kfree(ue);
L
Linus Torvalds 已提交
1252 1253 1254 1255 1256 1257
		return -ENOMEM;
	}
	_kctl->private_data = ue;
	for (idx = 0; idx < _kctl->count; idx++)
		_kctl->vd[idx].owner = file;
	err = snd_ctl_add(card, _kctl);
1258
	if (err < 0)
L
Linus Torvalds 已提交
1259 1260 1261 1262 1263 1264 1265 1266 1267
		return err;

	down_write(&card->controls_rwsem);
	card->user_ctl_count++;
	up_write(&card->controls_rwsem);

	return 0;
}

1268 1269
static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
				 struct snd_ctl_elem_info __user *_info, int replace)
L
Linus Torvalds 已提交
1270
{
1271
	struct snd_ctl_elem_info info;
L
Linus Torvalds 已提交
1272 1273 1274 1275 1276
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
	return snd_ctl_elem_add(file, &info, replace);
}

1277 1278
static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
L
Linus Torvalds 已提交
1279
{
1280
	struct snd_ctl_elem_id id;
L
Linus Torvalds 已提交
1281 1282 1283

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
1284
	return snd_ctl_remove_user_ctl(file, &id);
L
Linus Torvalds 已提交
1285 1286
}

1287
static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
L
Linus Torvalds 已提交
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
{
	int subscribe;
	if (get_user(subscribe, ptr))
		return -EFAULT;
	if (subscribe < 0) {
		subscribe = file->subscribed;
		if (put_user(subscribe, ptr))
			return -EFAULT;
		return 0;
	}
	if (subscribe) {
		file->subscribed = 1;
		return 0;
	} else if (file->subscribed) {
		snd_ctl_empty_read_queue(file);
		file->subscribed = 0;
	}
	return 0;
}

1308 1309 1310
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
                             struct snd_ctl_tlv __user *_tlv,
                             int op_flag)
1311
{
1312
	struct snd_card *card = file->card;
1313 1314
	struct snd_ctl_tlv tlv;
	struct snd_kcontrol *kctl;
1315
	struct snd_kcontrol_volatile *vd;
1316 1317 1318 1319 1320
	unsigned int len;
	int err = 0;

	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
		return -EFAULT;
1321
	if (tlv.length < sizeof(unsigned int) * 2)
1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340
		return -EINVAL;
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_numid(card, tlv.numid);
	if (kctl == NULL) {
		err = -ENOENT;
		goto __kctl_end;
	}
	if (kctl->tlv.p == NULL) {
		err = -ENXIO;
		goto __kctl_end;
	}
	vd = &kctl->vd[tlv.numid - kctl->id.numid];
	if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
	    (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
	    (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
	    	err = -ENXIO;
	    	goto __kctl_end;
	}
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1341
		if (vd->owner != NULL && vd->owner != file) {
1342 1343 1344
			err = -EPERM;
			goto __kctl_end;
		}
1345
		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1346
		if (err > 0) {
1347
			struct snd_ctl_elem_id id = kctl->id;
1348
			up_read(&card->controls_rwsem);
1349
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364
			return 0;
		}
	} else {
		if (op_flag) {
			err = -ENXIO;
			goto __kctl_end;
		}
		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
		if (tlv.length < len) {
			err = -ENOMEM;
			goto __kctl_end;
		}
		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
			err = -EFAULT;
	}
1365
      __kctl_end:
1366 1367
	up_read(&card->controls_rwsem);
	return err;
1368 1369
}

L
Linus Torvalds 已提交
1370 1371
static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
1372 1373 1374
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct snd_kctl_ioctl *p;
L
Linus Torvalds 已提交
1375 1376 1377 1378 1379 1380
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
1381 1382
	if (snd_BUG_ON(!card))
		return -ENXIO;
L
Linus Torvalds 已提交
1383 1384 1385 1386 1387 1388
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PVERSION:
		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
	case SNDRV_CTL_IOCTL_CARD_INFO:
		return snd_ctl_card_info(card, ctl, cmd, argp);
	case SNDRV_CTL_IOCTL_ELEM_LIST:
1389
		return snd_ctl_elem_list(card, argp);
L
Linus Torvalds 已提交
1390 1391 1392
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
1393
		return snd_ctl_elem_read_user(card, argp);
L
Linus Torvalds 已提交
1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407
	case SNDRV_CTL_IOCTL_ELEM_WRITE:
		return snd_ctl_elem_write_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_LOCK:
		return snd_ctl_elem_lock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
		return snd_ctl_elem_unlock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_ADD:
		return snd_ctl_elem_add_user(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
		return snd_ctl_elem_add_user(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
		return snd_ctl_elem_remove(ctl, argp);
	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
		return snd_ctl_subscribe_events(ctl, ip);
1408
	case SNDRV_CTL_IOCTL_TLV_READ:
1409
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1410
	case SNDRV_CTL_IOCTL_TLV_WRITE:
1411
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1412
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
1413
		return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
L
Linus Torvalds 已提交
1414
	case SNDRV_CTL_IOCTL_POWER:
T
Takashi Iwai 已提交
1415
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
1416 1417 1418 1419 1420 1421 1422 1423
	case SNDRV_CTL_IOCTL_POWER_STATE:
#ifdef CONFIG_PM
		return put_user(card->power_state, ip) ? -EFAULT : 0;
#else
		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
#endif
	}
	down_read(&snd_ioctl_rwsem);
1424
	list_for_each_entry(p, &snd_control_ioctls, list) {
L
Linus Torvalds 已提交
1425 1426 1427 1428 1429 1430 1431
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
1432
	dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
L
Linus Torvalds 已提交
1433 1434 1435
	return -ENOTTY;
}

1436 1437
static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
L
Linus Torvalds 已提交
1438
{
1439
	struct snd_ctl_file *ctl;
L
Linus Torvalds 已提交
1440 1441 1442 1443
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
1444 1445
	if (snd_BUG_ON(!ctl || !ctl->card))
		return -ENXIO;
L
Linus Torvalds 已提交
1446 1447
	if (!ctl->subscribed)
		return -EBADFD;
1448
	if (count < sizeof(struct snd_ctl_event))
L
Linus Torvalds 已提交
1449 1450
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
1451 1452 1453
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
L
Linus Torvalds 已提交
1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465
		while (list_empty(&ctl->events)) {
			wait_queue_t wait;
			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				goto __end_lock;
			}
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&ctl->change_sleep, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(&ctl->read_lock);
			schedule();
			remove_wait_queue(&ctl->change_sleep, &wait);
1466 1467
			if (ctl->card->shutdown)
				return -ENODEV;
L
Linus Torvalds 已提交
1468
			if (signal_pending(current))
1469
				return -ERESTARTSYS;
L
Linus Torvalds 已提交
1470 1471 1472 1473 1474 1475 1476 1477 1478
			spin_lock_irq(&ctl->read_lock);
		}
		kev = snd_kctl_event(ctl->events.next);
		ev.type = SNDRV_CTL_EVENT_ELEM;
		ev.data.elem.mask = kev->mask;
		ev.data.elem.id = kev->id;
		list_del(&kev->list);
		spin_unlock_irq(&ctl->read_lock);
		kfree(kev);
1479
		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
L
Linus Torvalds 已提交
1480 1481 1482 1483
			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
1484 1485 1486
		buffer += sizeof(struct snd_ctl_event);
		count -= sizeof(struct snd_ctl_event);
		result += sizeof(struct snd_ctl_event);
L
Linus Torvalds 已提交
1487 1488 1489 1490 1491 1492 1493 1494 1495 1496
	}
      __end_lock:
	spin_unlock_irq(&ctl->read_lock);
      __end:
      	return result > 0 ? result : err;
}

static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
{
	unsigned int mask;
1497
	struct snd_ctl_file *ctl;
L
Linus Torvalds 已提交
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516

	ctl = file->private_data;
	if (!ctl->subscribed)
		return 0;
	poll_wait(file, &ctl->change_sleep, wait);

	mask = 0;
	if (!list_empty(&ctl->events))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

/*
 * register the device-specific control-ioctls.
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
{
1517
	struct snd_kctl_ioctl *pn;
L
Linus Torvalds 已提交
1518

1519
	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
L
Linus Torvalds 已提交
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
	if (pn == NULL)
		return -ENOMEM;
	pn->fioctl = fcn;
	down_write(&snd_ioctl_rwsem);
	list_add_tail(&pn->list, lists);
	up_write(&snd_ioctl_rwsem);
	return 0;
}

int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
}

1534 1535
EXPORT_SYMBOL(snd_ctl_register_ioctl);

L
Linus Torvalds 已提交
1536 1537 1538 1539 1540
#ifdef CONFIG_COMPAT
int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
}
1541 1542

EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
L
Linus Torvalds 已提交
1543 1544 1545 1546 1547
#endif

/*
 * de-register the device-specific control-ioctls.
 */
1548 1549
static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
				     struct list_head *lists)
L
Linus Torvalds 已提交
1550
{
1551
	struct snd_kctl_ioctl *p;
L
Linus Torvalds 已提交
1552

1553 1554
	if (snd_BUG_ON(!fcn))
		return -EINVAL;
L
Linus Torvalds 已提交
1555
	down_write(&snd_ioctl_rwsem);
1556
	list_for_each_entry(p, lists, list) {
L
Linus Torvalds 已提交
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
		if (p->fioctl == fcn) {
			list_del(&p->list);
			up_write(&snd_ioctl_rwsem);
			kfree(p);
			return 0;
		}
	}
	up_write(&snd_ioctl_rwsem);
	snd_BUG();
	return -EINVAL;
}

int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
}

1574 1575
EXPORT_SYMBOL(snd_ctl_unregister_ioctl);

L
Linus Torvalds 已提交
1576 1577 1578 1579 1580 1581
#ifdef CONFIG_COMPAT
int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
}

1582
EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
L
Linus Torvalds 已提交
1583 1584 1585 1586
#endif

static int snd_ctl_fasync(int fd, struct file * file, int on)
{
1587
	struct snd_ctl_file *ctl;
1588

L
Linus Torvalds 已提交
1589
	ctl = file->private_data;
1590
	return fasync_helper(fd, file, on, &ctl->fasync);
L
Linus Torvalds 已提交
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605
}

/*
 * ioctl32 compat
 */
#ifdef CONFIG_COMPAT
#include "control_compat.c"
#else
#define snd_ctl_ioctl_compat	NULL
#endif

/*
 *  INIT PART
 */

1606
static const struct file_operations snd_ctl_f_ops =
L
Linus Torvalds 已提交
1607 1608 1609 1610 1611
{
	.owner =	THIS_MODULE,
	.read =		snd_ctl_read,
	.open =		snd_ctl_open,
	.release =	snd_ctl_release,
T
Takashi Iwai 已提交
1612
	.llseek =	no_llseek,
L
Linus Torvalds 已提交
1613 1614 1615 1616 1617 1618 1619 1620 1621
	.poll =		snd_ctl_poll,
	.unlocked_ioctl =	snd_ctl_ioctl,
	.compat_ioctl =	snd_ctl_ioctl_compat,
	.fasync =	snd_ctl_fasync,
};

/*
 * registration of the control device
 */
1622
static int snd_ctl_dev_register(struct snd_device *device)
L
Linus Torvalds 已提交
1623
{
1624
	struct snd_card *card = device->device_data;
L
Linus Torvalds 已提交
1625 1626 1627
	int err, cardnum;
	char name[16];

1628 1629
	if (snd_BUG_ON(!card))
		return -ENXIO;
L
Linus Torvalds 已提交
1630
	cardnum = card->number;
1631 1632
	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
		return -ENXIO;
L
Linus Torvalds 已提交
1633
	sprintf(name, "controlC%i", cardnum);
1634 1635
	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
				       &snd_ctl_f_ops, card, name)) < 0)
L
Linus Torvalds 已提交
1636 1637 1638 1639 1640 1641 1642
		return err;
	return 0;
}

/*
 * disconnection of the control device
 */
1643
static int snd_ctl_dev_disconnect(struct snd_device *device)
L
Linus Torvalds 已提交
1644
{
1645 1646
	struct snd_card *card = device->device_data;
	struct snd_ctl_file *ctl;
1647 1648
	int err, cardnum;

1649 1650
	if (snd_BUG_ON(!card))
		return -ENXIO;
1651
	cardnum = card->number;
1652 1653
	if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
		return -ENXIO;
L
Linus Torvalds 已提交
1654

1655
	read_lock(&card->ctl_files_rwlock);
1656
	list_for_each_entry(ctl, &card->ctl_files, list) {
L
Linus Torvalds 已提交
1657 1658 1659
		wake_up(&ctl->change_sleep);
		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
	}
1660
	read_unlock(&card->ctl_files_rwlock);
1661 1662 1663 1664

	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
					 card, -1)) < 0)
		return err;
L
Linus Torvalds 已提交
1665 1666 1667 1668 1669 1670
	return 0;
}

/*
 * free all controls
 */
1671
static int snd_ctl_dev_free(struct snd_device *device)
L
Linus Torvalds 已提交
1672
{
1673 1674
	struct snd_card *card = device->device_data;
	struct snd_kcontrol *control;
L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688

	down_write(&card->controls_rwsem);
	while (!list_empty(&card->controls)) {
		control = snd_kcontrol(card->controls.next);
		snd_ctl_remove(card, control);
	}
	up_write(&card->controls_rwsem);
	return 0;
}

/*
 * create control core:
 * called from init.c
 */
1689
int snd_ctl_create(struct snd_card *card)
L
Linus Torvalds 已提交
1690
{
1691
	static struct snd_device_ops ops = {
L
Linus Torvalds 已提交
1692 1693 1694 1695 1696
		.dev_free = snd_ctl_dev_free,
		.dev_register =	snd_ctl_dev_register,
		.dev_disconnect = snd_ctl_dev_disconnect,
	};

1697 1698
	if (snd_BUG_ON(!card))
		return -ENXIO;
L
Linus Torvalds 已提交
1699 1700
	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
}
1701 1702

/*
1703
 * Frequently used control callbacks/helpers
1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727
 */
int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
			      struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 1;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}

EXPORT_SYMBOL(snd_ctl_boolean_mono_info);

int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
				struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}

EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738

/**
 * snd_ctl_enum_info - fills the info structure for an enumerated control
 * @info: the structure to be filled
 * @channels: the number of the control's channels; often one
 * @items: the number of control values; also the size of @names
 * @names: an array containing the names of all control values
 *
 * Sets all required fields in @info to their appropriate values.
 * If the control's accessibility is not the default (readable and writable),
 * the caller has to fill @info->access.
1739 1740
 *
 * Return: Zero.
1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755
 */
int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
		      unsigned int items, const char *const names[])
{
	info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
	info->count = channels;
	info->value.enumerated.items = items;
	if (info->value.enumerated.item >= items)
		info->value.enumerated.item = items - 1;
	strlcpy(info->value.enumerated.name,
		names[info->value.enumerated.item],
		sizeof(info->value.enumerated.name));
	return 0;
}
EXPORT_SYMBOL(snd_ctl_enum_info);