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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/slab.h>
25#include <linux/vmalloc.h>
26#include <linux/time.h>
27#include <sound/core.h>
28#include <sound/minors.h>
29#include <sound/info.h>
30#include <sound/control.h>
31
32/* max number of user-defined controls */
33#define MAX_USER_CONTROLS 32
34#define MAX_CONTROL_COUNT 1028
35
36struct snd_kctl_ioctl {
37 struct list_head list; /* list of all ioctls */
38 snd_kctl_ioctl_func_t fioctl;
39};
40
41static DECLARE_RWSEM(snd_ioctl_rwsem);
42static LIST_HEAD(snd_control_ioctls);
43#ifdef CONFIG_COMPAT
44static LIST_HEAD(snd_control_compat_ioctls);
45#endif
46
47static int snd_ctl_open(struct inode *inode, struct file *file)
48{
49 unsigned long flags;
50 struct snd_card *card;
51 struct snd_ctl_file *ctl;
52 int err;
53
54 err = nonseekable_open(inode, file);
55 if (err < 0)
56 return err;
57
58 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
59 if (!card) {
60 err = -ENODEV;
61 goto __error1;
62 }
63 err = snd_card_file_add(card, file);
64 if (err < 0) {
65 err = -ENODEV;
66 goto __error1;
67 }
68 if (!try_module_get(card->module)) {
69 err = -EFAULT;
70 goto __error2;
71 }
72 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
73 if (ctl == NULL) {
74 err = -ENOMEM;
75 goto __error;
76 }
77 INIT_LIST_HEAD(&ctl->events);
78 init_waitqueue_head(&ctl->change_sleep);
79 spin_lock_init(&ctl->read_lock);
80 ctl->card = card;
81 ctl->prefer_pcm_subdevice = -1;
82 ctl->prefer_rawmidi_subdevice = -1;
83 ctl->pid = get_pid(task_pid(current));
84 file->private_data = ctl;
85 write_lock_irqsave(&card->ctl_files_rwlock, flags);
86 list_add_tail(&ctl->list, &card->ctl_files);
87 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
88 return 0;
89
90 __error:
91 module_put(card->module);
92 __error2:
93 snd_card_file_remove(card, file);
94 __error1:
95 return err;
96}
97
98static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
99{
100 unsigned long flags;
101 struct snd_kctl_event *cread;
102
103 spin_lock_irqsave(&ctl->read_lock, flags);
104 while (!list_empty(&ctl->events)) {
105 cread = snd_kctl_event(ctl->events.next);
106 list_del(&cread->list);
107 kfree(cread);
108 }
109 spin_unlock_irqrestore(&ctl->read_lock, flags);
110}
111
112static int snd_ctl_release(struct inode *inode, struct file *file)
113{
114 unsigned long flags;
115 struct snd_card *card;
116 struct snd_ctl_file *ctl;
117 struct snd_kcontrol *control;
118 unsigned int idx;
119
120 ctl = file->private_data;
121 file->private_data = NULL;
122 card = ctl->card;
123 write_lock_irqsave(&card->ctl_files_rwlock, flags);
124 list_del(&ctl->list);
125 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
126 down_write(&card->controls_rwsem);
127 list_for_each_entry(control, &card->controls, list)
128 for (idx = 0; idx < control->count; idx++)
129 if (control->vd[idx].owner == ctl)
130 control->vd[idx].owner = NULL;
131 up_write(&card->controls_rwsem);
132 snd_ctl_empty_read_queue(ctl);
133 put_pid(ctl->pid);
134 kfree(ctl);
135 module_put(card->module);
136 snd_card_file_remove(card, file);
137 return 0;
138}
139
140void snd_ctl_notify(struct snd_card *card, unsigned int mask,
141 struct snd_ctl_elem_id *id)
142{
143 unsigned long flags;
144 struct snd_ctl_file *ctl;
145 struct snd_kctl_event *ev;
146
147 if (snd_BUG_ON(!card || !id))
148 return;
149 read_lock(&card->ctl_files_rwlock);
150#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
151 card->mixer_oss_change_count++;
152#endif
153 list_for_each_entry(ctl, &card->ctl_files, list) {
154 if (!ctl->subscribed)
155 continue;
156 spin_lock_irqsave(&ctl->read_lock, flags);
157 list_for_each_entry(ev, &ctl->events, list) {
158 if (ev->id.numid == id->numid) {
159 ev->mask |= mask;
160 goto _found;
161 }
162 }
163 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
164 if (ev) {
165 ev->id = *id;
166 ev->mask = mask;
167 list_add_tail(&ev->list, &ctl->events);
168 } else {
169 snd_printk(KERN_ERR "No memory available to allocate event\n");
170 }
171 _found:
172 wake_up(&ctl->change_sleep);
173 spin_unlock_irqrestore(&ctl->read_lock, flags);
174 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
175 }
176 read_unlock(&card->ctl_files_rwlock);
177}
178
179EXPORT_SYMBOL(snd_ctl_notify);
180
181/**
182 * snd_ctl_new - create a control instance from the template
183 * @control: the control template
184 * @access: the default control access
185 *
186 * Allocates a new struct snd_kcontrol instance and copies the given template
187 * to the new instance. It does not copy volatile data (access).
188 *
189 * Returns the pointer of the new instance, or NULL on failure.
190 */
191static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
192 unsigned int access)
193{
194 struct snd_kcontrol *kctl;
195 unsigned int idx;
196
197 if (snd_BUG_ON(!control || !control->count))
198 return NULL;
199
200 if (control->count > MAX_CONTROL_COUNT)
201 return NULL;
202
203 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
204 if (kctl == NULL) {
205 snd_printk(KERN_ERR "Cannot allocate control instance\n");
206 return NULL;
207 }
208 *kctl = *control;
209 for (idx = 0; idx < kctl->count; idx++)
210 kctl->vd[idx].access = access;
211 return kctl;
212}
213
214/**
215 * snd_ctl_new1 - create a control instance from the template
216 * @ncontrol: the initialization record
217 * @private_data: the private data to set
218 *
219 * Allocates a new struct snd_kcontrol instance and initialize from the given
220 * template. When the access field of ncontrol is 0, it's assumed as
221 * READWRITE access. When the count field is 0, it's assumes as one.
222 *
223 * Returns the pointer of the newly generated instance, or NULL on failure.
224 */
225struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
226 void *private_data)
227{
228 struct snd_kcontrol kctl;
229 unsigned int access;
230
231 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
232 return NULL;
233 memset(&kctl, 0, sizeof(kctl));
234 kctl.id.iface = ncontrol->iface;
235 kctl.id.device = ncontrol->device;
236 kctl.id.subdevice = ncontrol->subdevice;
237 if (ncontrol->name) {
238 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
239 if (strcmp(ncontrol->name, kctl.id.name) != 0)
240 snd_printk(KERN_WARNING
241 "Control name '%s' truncated to '%s'\n",
242 ncontrol->name, kctl.id.name);
243 }
244 kctl.id.index = ncontrol->index;
245 kctl.count = ncontrol->count ? ncontrol->count : 1;
246 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
247 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
248 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
249 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
250 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
251 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
252 kctl.info = ncontrol->info;
253 kctl.get = ncontrol->get;
254 kctl.put = ncontrol->put;
255 kctl.tlv.p = ncontrol->tlv.p;
256 kctl.private_value = ncontrol->private_value;
257 kctl.private_data = private_data;
258 return snd_ctl_new(&kctl, access);
259}
260
261EXPORT_SYMBOL(snd_ctl_new1);
262
263/**
264 * snd_ctl_free_one - release the control instance
265 * @kcontrol: the control instance
266 *
267 * Releases the control instance created via snd_ctl_new()
268 * or snd_ctl_new1().
269 * Don't call this after the control was added to the card.
270 */
271void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
272{
273 if (kcontrol) {
274 if (kcontrol->private_free)
275 kcontrol->private_free(kcontrol);
276 kfree(kcontrol);
277 }
278}
279
280EXPORT_SYMBOL(snd_ctl_free_one);
281
282static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
283 unsigned int count)
284{
285 struct snd_kcontrol *kctl;
286
287 list_for_each_entry(kctl, &card->controls, list) {
288 if (kctl->id.numid < card->last_numid + 1 + count &&
289 kctl->id.numid + kctl->count > card->last_numid + 1) {
290 card->last_numid = kctl->id.numid + kctl->count - 1;
291 return true;
292 }
293 }
294 return false;
295}
296
297static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
298{
299 unsigned int iter = 100000;
300
301 while (snd_ctl_remove_numid_conflict(card, count)) {
302 if (--iter == 0) {
303 /* this situation is very unlikely */
304 snd_printk(KERN_ERR "unable to allocate new control numid\n");
305 return -ENOMEM;
306 }
307 }
308 return 0;
309}
310
311/**
312 * snd_ctl_add - add the control instance to the card
313 * @card: the card instance
314 * @kcontrol: the control instance to add
315 *
316 * Adds the control instance created via snd_ctl_new() or
317 * snd_ctl_new1() to the given card. Assigns also an unique
318 * numid used for fast search.
319 *
320 * Returns zero if successful, or a negative error code on failure.
321 *
322 * It frees automatically the control which cannot be added.
323 */
324int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
325{
326 struct snd_ctl_elem_id id;
327 unsigned int idx;
328 int err = -EINVAL;
329
330 if (! kcontrol)
331 return err;
332 if (snd_BUG_ON(!card || !kcontrol->info))
333 goto error;
334 id = kcontrol->id;
335 down_write(&card->controls_rwsem);
336 if (snd_ctl_find_id(card, &id)) {
337 up_write(&card->controls_rwsem);
338 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
339 id.iface,
340 id.device,
341 id.subdevice,
342 id.name,
343 id.index);
344 err = -EBUSY;
345 goto error;
346 }
347 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
348 up_write(&card->controls_rwsem);
349 err = -ENOMEM;
350 goto error;
351 }
352 list_add_tail(&kcontrol->list, &card->controls);
353 card->controls_count += kcontrol->count;
354 kcontrol->id.numid = card->last_numid + 1;
355 card->last_numid += kcontrol->count;
356 up_write(&card->controls_rwsem);
357 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
358 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
359 return 0;
360
361 error:
362 snd_ctl_free_one(kcontrol);
363 return err;
364}
365
366EXPORT_SYMBOL(snd_ctl_add);
367
368/**
369 * snd_ctl_replace - replace the control instance of the card
370 * @card: the card instance
371 * @kcontrol: the control instance to replace
372 * @add_on_replace: add the control if not already added
373 *
374 * Replaces the given control. If the given control does not exist
375 * and the add_on_replace flag is set, the control is added. If the
376 * control exists, it is destroyed first.
377 *
378 * Returns zero if successful, or a negative error code on failure.
379 *
380 * It frees automatically the control which cannot be added or replaced.
381 */
382int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
383 bool add_on_replace)
384{
385 struct snd_ctl_elem_id id;
386 unsigned int idx;
387 struct snd_kcontrol *old;
388 int ret;
389
390 if (!kcontrol)
391 return -EINVAL;
392 if (snd_BUG_ON(!card || !kcontrol->info)) {
393 ret = -EINVAL;
394 goto error;
395 }
396 id = kcontrol->id;
397 down_write(&card->controls_rwsem);
398 old = snd_ctl_find_id(card, &id);
399 if (!old) {
400 if (add_on_replace)
401 goto add;
402 up_write(&card->controls_rwsem);
403 ret = -EINVAL;
404 goto error;
405 }
406 ret = snd_ctl_remove(card, old);
407 if (ret < 0) {
408 up_write(&card->controls_rwsem);
409 goto error;
410 }
411add:
412 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
413 up_write(&card->controls_rwsem);
414 ret = -ENOMEM;
415 goto error;
416 }
417 list_add_tail(&kcontrol->list, &card->controls);
418 card->controls_count += kcontrol->count;
419 kcontrol->id.numid = card->last_numid + 1;
420 card->last_numid += kcontrol->count;
421 up_write(&card->controls_rwsem);
422 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
423 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
424 return 0;
425
426error:
427 snd_ctl_free_one(kcontrol);
428 return ret;
429}
430EXPORT_SYMBOL(snd_ctl_replace);
431
432/**
433 * snd_ctl_remove - remove the control from the card and release it
434 * @card: the card instance
435 * @kcontrol: the control instance to remove
436 *
437 * Removes the control from the card and then releases the instance.
438 * You don't need to call snd_ctl_free_one(). You must be in
439 * the write lock - down_write(&card->controls_rwsem).
440 *
441 * Returns 0 if successful, or a negative error code on failure.
442 */
443int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
444{
445 struct snd_ctl_elem_id id;
446 unsigned int idx;
447
448 if (snd_BUG_ON(!card || !kcontrol))
449 return -EINVAL;
450 list_del(&kcontrol->list);
451 card->controls_count -= kcontrol->count;
452 id = kcontrol->id;
453 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
454 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
455 snd_ctl_free_one(kcontrol);
456 return 0;
457}
458
459EXPORT_SYMBOL(snd_ctl_remove);
460
461/**
462 * snd_ctl_remove_id - remove the control of the given id and release it
463 * @card: the card instance
464 * @id: the control id to remove
465 *
466 * Finds the control instance with the given id, removes it from the
467 * card list and releases it.
468 *
469 * Returns 0 if successful, or a negative error code on failure.
470 */
471int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
472{
473 struct snd_kcontrol *kctl;
474 int ret;
475
476 down_write(&card->controls_rwsem);
477 kctl = snd_ctl_find_id(card, id);
478 if (kctl == NULL) {
479 up_write(&card->controls_rwsem);
480 return -ENOENT;
481 }
482 ret = snd_ctl_remove(card, kctl);
483 up_write(&card->controls_rwsem);
484 return ret;
485}
486
487EXPORT_SYMBOL(snd_ctl_remove_id);
488
489/**
490 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
491 * @file: active control handle
492 * @id: the control id to remove
493 *
494 * Finds the control instance with the given id, removes it from the
495 * card list and releases it.
496 *
497 * Returns 0 if successful, or a negative error code on failure.
498 */
499static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
500 struct snd_ctl_elem_id *id)
501{
502 struct snd_card *card = file->card;
503 struct snd_kcontrol *kctl;
504 int idx, ret;
505
506 down_write(&card->controls_rwsem);
507 kctl = snd_ctl_find_id(card, id);
508 if (kctl == NULL) {
509 ret = -ENOENT;
510 goto error;
511 }
512 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
513 ret = -EINVAL;
514 goto error;
515 }
516 for (idx = 0; idx < kctl->count; idx++)
517 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
518 ret = -EBUSY;
519 goto error;
520 }
521 ret = snd_ctl_remove(card, kctl);
522 if (ret < 0)
523 goto error;
524 card->user_ctl_count--;
525error:
526 up_write(&card->controls_rwsem);
527 return ret;
528}
529
530/**
531 * snd_ctl_activate_id - activate/inactivate the control of the given id
532 * @card: the card instance
533 * @id: the control id to activate/inactivate
534 * @active: non-zero to activate
535 *
536 * Finds the control instance with the given id, and activate or
537 * inactivate the control together with notification, if changed.
538 *
539 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
540 */
541int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
542 int active)
543{
544 struct snd_kcontrol *kctl;
545 struct snd_kcontrol_volatile *vd;
546 unsigned int index_offset;
547 int ret;
548
549 down_write(&card->controls_rwsem);
550 kctl = snd_ctl_find_id(card, id);
551 if (kctl == NULL) {
552 ret = -ENOENT;
553 goto unlock;
554 }
555 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
556 vd = &kctl->vd[index_offset];
557 ret = 0;
558 if (active) {
559 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
560 goto unlock;
561 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
562 } else {
563 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
564 goto unlock;
565 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
566 }
567 ret = 1;
568 unlock:
569 up_write(&card->controls_rwsem);
570 if (ret > 0)
571 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
572 return ret;
573}
574EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
575
576/**
577 * snd_ctl_rename_id - replace the id of a control on the card
578 * @card: the card instance
579 * @src_id: the old id
580 * @dst_id: the new id
581 *
582 * Finds the control with the old id from the card, and replaces the
583 * id with the new one.
584 *
585 * Returns zero if successful, or a negative error code on failure.
586 */
587int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
588 struct snd_ctl_elem_id *dst_id)
589{
590 struct snd_kcontrol *kctl;
591
592 down_write(&card->controls_rwsem);
593 kctl = snd_ctl_find_id(card, src_id);
594 if (kctl == NULL) {
595 up_write(&card->controls_rwsem);
596 return -ENOENT;
597 }
598 kctl->id = *dst_id;
599 kctl->id.numid = card->last_numid + 1;
600 card->last_numid += kctl->count;
601 up_write(&card->controls_rwsem);
602 return 0;
603}
604
605EXPORT_SYMBOL(snd_ctl_rename_id);
606
607/**
608 * snd_ctl_find_numid - find the control instance with the given number-id
609 * @card: the card instance
610 * @numid: the number-id to search
611 *
612 * Finds the control instance with the given number-id from the card.
613 *
614 * Returns the pointer of the instance if found, or NULL if not.
615 *
616 * The caller must down card->controls_rwsem before calling this function
617 * (if the race condition can happen).
618 */
619struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
620{
621 struct snd_kcontrol *kctl;
622
623 if (snd_BUG_ON(!card || !numid))
624 return NULL;
625 list_for_each_entry(kctl, &card->controls, list) {
626 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
627 return kctl;
628 }
629 return NULL;
630}
631
632EXPORT_SYMBOL(snd_ctl_find_numid);
633
634/**
635 * snd_ctl_find_id - find the control instance with the given id
636 * @card: the card instance
637 * @id: the id to search
638 *
639 * Finds the control instance with the given id from the card.
640 *
641 * Returns the pointer of the instance if found, or NULL if not.
642 *
643 * The caller must down card->controls_rwsem before calling this function
644 * (if the race condition can happen).
645 */
646struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
647 struct snd_ctl_elem_id *id)
648{
649 struct snd_kcontrol *kctl;
650
651 if (snd_BUG_ON(!card || !id))
652 return NULL;
653 if (id->numid != 0)
654 return snd_ctl_find_numid(card, id->numid);
655 list_for_each_entry(kctl, &card->controls, list) {
656 if (kctl->id.iface != id->iface)
657 continue;
658 if (kctl->id.device != id->device)
659 continue;
660 if (kctl->id.subdevice != id->subdevice)
661 continue;
662 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
663 continue;
664 if (kctl->id.index > id->index)
665 continue;
666 if (kctl->id.index + kctl->count <= id->index)
667 continue;
668 return kctl;
669 }
670 return NULL;
671}
672
673EXPORT_SYMBOL(snd_ctl_find_id);
674
675static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
676 unsigned int cmd, void __user *arg)
677{
678 struct snd_ctl_card_info *info;
679
680 info = kzalloc(sizeof(*info), GFP_KERNEL);
681 if (! info)
682 return -ENOMEM;
683 down_read(&snd_ioctl_rwsem);
684 info->card = card->number;
685 strlcpy(info->id, card->id, sizeof(info->id));
686 strlcpy(info->driver, card->driver, sizeof(info->driver));
687 strlcpy(info->name, card->shortname, sizeof(info->name));
688 strlcpy(info->longname, card->longname, sizeof(info->longname));
689 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
690 strlcpy(info->components, card->components, sizeof(info->components));
691 up_read(&snd_ioctl_rwsem);
692 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
693 kfree(info);
694 return -EFAULT;
695 }
696 kfree(info);
697 return 0;
698}
699
700static int snd_ctl_elem_list(struct snd_card *card,
701 struct snd_ctl_elem_list __user *_list)
702{
703 struct list_head *plist;
704 struct snd_ctl_elem_list list;
705 struct snd_kcontrol *kctl;
706 struct snd_ctl_elem_id *dst, *id;
707 unsigned int offset, space, jidx;
708
709 if (copy_from_user(&list, _list, sizeof(list)))
710 return -EFAULT;
711 offset = list.offset;
712 space = list.space;
713 /* try limit maximum space */
714 if (space > 16384)
715 return -ENOMEM;
716 if (space > 0) {
717 /* allocate temporary buffer for atomic operation */
718 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
719 if (dst == NULL)
720 return -ENOMEM;
721 down_read(&card->controls_rwsem);
722 list.count = card->controls_count;
723 plist = card->controls.next;
724 while (plist != &card->controls) {
725 if (offset == 0)
726 break;
727 kctl = snd_kcontrol(plist);
728 if (offset < kctl->count)
729 break;
730 offset -= kctl->count;
731 plist = plist->next;
732 }
733 list.used = 0;
734 id = dst;
735 while (space > 0 && plist != &card->controls) {
736 kctl = snd_kcontrol(plist);
737 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
738 snd_ctl_build_ioff(id, kctl, jidx);
739 id++;
740 space--;
741 list.used++;
742 }
743 plist = plist->next;
744 offset = 0;
745 }
746 up_read(&card->controls_rwsem);
747 if (list.used > 0 &&
748 copy_to_user(list.pids, dst,
749 list.used * sizeof(struct snd_ctl_elem_id))) {
750 vfree(dst);
751 return -EFAULT;
752 }
753 vfree(dst);
754 } else {
755 down_read(&card->controls_rwsem);
756 list.count = card->controls_count;
757 up_read(&card->controls_rwsem);
758 }
759 if (copy_to_user(_list, &list, sizeof(list)))
760 return -EFAULT;
761 return 0;
762}
763
764static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
765 struct snd_ctl_elem_info *info)
766{
767 struct snd_card *card = ctl->card;
768 struct snd_kcontrol *kctl;
769 struct snd_kcontrol_volatile *vd;
770 unsigned int index_offset;
771 int result;
772
773 down_read(&card->controls_rwsem);
774 kctl = snd_ctl_find_id(card, &info->id);
775 if (kctl == NULL) {
776 up_read(&card->controls_rwsem);
777 return -ENOENT;
778 }
779#ifdef CONFIG_SND_DEBUG
780 info->access = 0;
781#endif
782 result = kctl->info(kctl, info);
783 if (result >= 0) {
784 snd_BUG_ON(info->access);
785 index_offset = snd_ctl_get_ioff(kctl, &info->id);
786 vd = &kctl->vd[index_offset];
787 snd_ctl_build_ioff(&info->id, kctl, index_offset);
788 info->access = vd->access;
789 if (vd->owner) {
790 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
791 if (vd->owner == ctl)
792 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
793 info->owner = pid_vnr(vd->owner->pid);
794 } else {
795 info->owner = -1;
796 }
797 }
798 up_read(&card->controls_rwsem);
799 return result;
800}
801
802static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
803 struct snd_ctl_elem_info __user *_info)
804{
805 struct snd_ctl_elem_info info;
806 int result;
807
808 if (copy_from_user(&info, _info, sizeof(info)))
809 return -EFAULT;
810 snd_power_lock(ctl->card);
811 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
812 if (result >= 0)
813 result = snd_ctl_elem_info(ctl, &info);
814 snd_power_unlock(ctl->card);
815 if (result >= 0)
816 if (copy_to_user(_info, &info, sizeof(info)))
817 return -EFAULT;
818 return result;
819}
820
821static int snd_ctl_elem_read(struct snd_card *card,
822 struct snd_ctl_elem_value *control)
823{
824 struct snd_kcontrol *kctl;
825 struct snd_kcontrol_volatile *vd;
826 unsigned int index_offset;
827 int result;
828
829 down_read(&card->controls_rwsem);
830 kctl = snd_ctl_find_id(card, &control->id);
831 if (kctl == NULL) {
832 result = -ENOENT;
833 } else {
834 index_offset = snd_ctl_get_ioff(kctl, &control->id);
835 vd = &kctl->vd[index_offset];
836 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
837 kctl->get != NULL) {
838 snd_ctl_build_ioff(&control->id, kctl, index_offset);
839 result = kctl->get(kctl, control);
840 } else
841 result = -EPERM;
842 }
843 up_read(&card->controls_rwsem);
844 return result;
845}
846
847static int snd_ctl_elem_read_user(struct snd_card *card,
848 struct snd_ctl_elem_value __user *_control)
849{
850 struct snd_ctl_elem_value *control;
851 int result;
852
853 control = memdup_user(_control, sizeof(*control));
854 if (IS_ERR(control))
855 return PTR_ERR(control);
856
857 snd_power_lock(card);
858 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
859 if (result >= 0)
860 result = snd_ctl_elem_read(card, control);
861 snd_power_unlock(card);
862 if (result >= 0)
863 if (copy_to_user(_control, control, sizeof(*control)))
864 result = -EFAULT;
865 kfree(control);
866 return result;
867}
868
869static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
870 struct snd_ctl_elem_value *control)
871{
872 struct snd_kcontrol *kctl;
873 struct snd_kcontrol_volatile *vd;
874 unsigned int index_offset;
875 int result;
876
877 down_read(&card->controls_rwsem);
878 kctl = snd_ctl_find_id(card, &control->id);
879 if (kctl == NULL) {
880 result = -ENOENT;
881 } else {
882 index_offset = snd_ctl_get_ioff(kctl, &control->id);
883 vd = &kctl->vd[index_offset];
884 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
885 kctl->put == NULL ||
886 (file && vd->owner && vd->owner != file)) {
887 result = -EPERM;
888 } else {
889 snd_ctl_build_ioff(&control->id, kctl, index_offset);
890 result = kctl->put(kctl, control);
891 }
892 if (result > 0) {
893 up_read(&card->controls_rwsem);
894 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
895 &control->id);
896 return 0;
897 }
898 }
899 up_read(&card->controls_rwsem);
900 return result;
901}
902
903static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
904 struct snd_ctl_elem_value __user *_control)
905{
906 struct snd_ctl_elem_value *control;
907 struct snd_card *card;
908 int result;
909
910 control = memdup_user(_control, sizeof(*control));
911 if (IS_ERR(control))
912 return PTR_ERR(control);
913
914 card = file->card;
915 snd_power_lock(card);
916 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
917 if (result >= 0)
918 result = snd_ctl_elem_write(card, file, control);
919 snd_power_unlock(card);
920 if (result >= 0)
921 if (copy_to_user(_control, control, sizeof(*control)))
922 result = -EFAULT;
923 kfree(control);
924 return result;
925}
926
927static int snd_ctl_elem_lock(struct snd_ctl_file *file,
928 struct snd_ctl_elem_id __user *_id)
929{
930 struct snd_card *card = file->card;
931 struct snd_ctl_elem_id id;
932 struct snd_kcontrol *kctl;
933 struct snd_kcontrol_volatile *vd;
934 int result;
935
936 if (copy_from_user(&id, _id, sizeof(id)))
937 return -EFAULT;
938 down_write(&card->controls_rwsem);
939 kctl = snd_ctl_find_id(card, &id);
940 if (kctl == NULL) {
941 result = -ENOENT;
942 } else {
943 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
944 if (vd->owner != NULL)
945 result = -EBUSY;
946 else {
947 vd->owner = file;
948 result = 0;
949 }
950 }
951 up_write(&card->controls_rwsem);
952 return result;
953}
954
955static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
956 struct snd_ctl_elem_id __user *_id)
957{
958 struct snd_card *card = file->card;
959 struct snd_ctl_elem_id id;
960 struct snd_kcontrol *kctl;
961 struct snd_kcontrol_volatile *vd;
962 int result;
963
964 if (copy_from_user(&id, _id, sizeof(id)))
965 return -EFAULT;
966 down_write(&card->controls_rwsem);
967 kctl = snd_ctl_find_id(card, &id);
968 if (kctl == NULL) {
969 result = -ENOENT;
970 } else {
971 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
972 if (vd->owner == NULL)
973 result = -EINVAL;
974 else if (vd->owner != file)
975 result = -EPERM;
976 else {
977 vd->owner = NULL;
978 result = 0;
979 }
980 }
981 up_write(&card->controls_rwsem);
982 return result;
983}
984
985struct user_element {
986 struct snd_ctl_elem_info info;
987 void *elem_data; /* element data */
988 unsigned long elem_data_size; /* size of element data in bytes */
989 void *tlv_data; /* TLV data */
990 unsigned long tlv_data_size; /* TLV data size */
991 void *priv_data; /* private data (like strings for enumerated type) */
992 unsigned long priv_data_size; /* size of private data in bytes */
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_get(struct snd_kcontrol *kcontrol,
1005 struct snd_ctl_elem_value *ucontrol)
1006{
1007 struct user_element *ue = kcontrol->private_data;
1008
1009 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1010 return 0;
1011}
1012
1013static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1014 struct snd_ctl_elem_value *ucontrol)
1015{
1016 int change;
1017 struct user_element *ue = kcontrol->private_data;
1018
1019 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1020 if (change)
1021 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1022 return change;
1023}
1024
1025static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1026 int op_flag,
1027 unsigned int size,
1028 unsigned int __user *tlv)
1029{
1030 struct user_element *ue = kcontrol->private_data;
1031 int change = 0;
1032 void *new_data;
1033
1034 if (op_flag > 0) {
1035 if (size > 1024 * 128) /* sane value */
1036 return -EINVAL;
1037
1038 new_data = memdup_user(tlv, size);
1039 if (IS_ERR(new_data))
1040 return PTR_ERR(new_data);
1041 change = ue->tlv_data_size != size;
1042 if (!change)
1043 change = memcmp(ue->tlv_data, new_data, size);
1044 kfree(ue->tlv_data);
1045 ue->tlv_data = new_data;
1046 ue->tlv_data_size = size;
1047 } else {
1048 if (! ue->tlv_data_size || ! ue->tlv_data)
1049 return -ENXIO;
1050 if (size < ue->tlv_data_size)
1051 return -ENOSPC;
1052 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1053 return -EFAULT;
1054 }
1055 return change;
1056}
1057
1058static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1059{
1060 struct user_element *ue = kcontrol->private_data;
1061 if (ue->tlv_data)
1062 kfree(ue->tlv_data);
1063 kfree(ue);
1064}
1065
1066static int snd_ctl_elem_add(struct snd_ctl_file *file,
1067 struct snd_ctl_elem_info *info, int replace)
1068{
1069 struct snd_card *card = file->card;
1070 struct snd_kcontrol kctl, *_kctl;
1071 unsigned int access;
1072 long private_size;
1073 struct user_element *ue;
1074 int idx, err;
1075
1076 if (card->user_ctl_count >= MAX_USER_CONTROLS)
1077 return -ENOMEM;
1078 if (info->count < 1)
1079 return -EINVAL;
1080 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1081 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1082 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1083 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1084 info->id.numid = 0;
1085 memset(&kctl, 0, sizeof(kctl));
1086 down_write(&card->controls_rwsem);
1087 _kctl = snd_ctl_find_id(card, &info->id);
1088 err = 0;
1089 if (_kctl) {
1090 if (replace)
1091 err = snd_ctl_remove(card, _kctl);
1092 else
1093 err = -EBUSY;
1094 } else {
1095 if (replace)
1096 err = -ENOENT;
1097 }
1098 up_write(&card->controls_rwsem);
1099 if (err < 0)
1100 return err;
1101 memcpy(&kctl.id, &info->id, sizeof(info->id));
1102 kctl.count = info->owner ? info->owner : 1;
1103 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1104 kctl.info = snd_ctl_elem_user_info;
1105 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1106 kctl.get = snd_ctl_elem_user_get;
1107 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1108 kctl.put = snd_ctl_elem_user_put;
1109 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1110 kctl.tlv.c = snd_ctl_elem_user_tlv;
1111 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1112 }
1113 switch (info->type) {
1114 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1115 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1116 private_size = sizeof(long);
1117 if (info->count > 128)
1118 return -EINVAL;
1119 break;
1120 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1121 private_size = sizeof(long long);
1122 if (info->count > 64)
1123 return -EINVAL;
1124 break;
1125 case SNDRV_CTL_ELEM_TYPE_BYTES:
1126 private_size = sizeof(unsigned char);
1127 if (info->count > 512)
1128 return -EINVAL;
1129 break;
1130 case SNDRV_CTL_ELEM_TYPE_IEC958:
1131 private_size = sizeof(struct snd_aes_iec958);
1132 if (info->count != 1)
1133 return -EINVAL;
1134 break;
1135 default:
1136 return -EINVAL;
1137 }
1138 private_size *= info->count;
1139 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1140 if (ue == NULL)
1141 return -ENOMEM;
1142 ue->info = *info;
1143 ue->info.access = 0;
1144 ue->elem_data = (char *)ue + sizeof(*ue);
1145 ue->elem_data_size = private_size;
1146 kctl.private_free = snd_ctl_elem_user_free;
1147 _kctl = snd_ctl_new(&kctl, access);
1148 if (_kctl == NULL) {
1149 kfree(ue);
1150 return -ENOMEM;
1151 }
1152 _kctl->private_data = ue;
1153 for (idx = 0; idx < _kctl->count; idx++)
1154 _kctl->vd[idx].owner = file;
1155 err = snd_ctl_add(card, _kctl);
1156 if (err < 0)
1157 return err;
1158
1159 down_write(&card->controls_rwsem);
1160 card->user_ctl_count++;
1161 up_write(&card->controls_rwsem);
1162
1163 return 0;
1164}
1165
1166static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1167 struct snd_ctl_elem_info __user *_info, int replace)
1168{
1169 struct snd_ctl_elem_info info;
1170 if (copy_from_user(&info, _info, sizeof(info)))
1171 return -EFAULT;
1172 return snd_ctl_elem_add(file, &info, replace);
1173}
1174
1175static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1176 struct snd_ctl_elem_id __user *_id)
1177{
1178 struct snd_ctl_elem_id id;
1179
1180 if (copy_from_user(&id, _id, sizeof(id)))
1181 return -EFAULT;
1182 return snd_ctl_remove_user_ctl(file, &id);
1183}
1184
1185static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1186{
1187 int subscribe;
1188 if (get_user(subscribe, ptr))
1189 return -EFAULT;
1190 if (subscribe < 0) {
1191 subscribe = file->subscribed;
1192 if (put_user(subscribe, ptr))
1193 return -EFAULT;
1194 return 0;
1195 }
1196 if (subscribe) {
1197 file->subscribed = 1;
1198 return 0;
1199 } else if (file->subscribed) {
1200 snd_ctl_empty_read_queue(file);
1201 file->subscribed = 0;
1202 }
1203 return 0;
1204}
1205
1206static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1207 struct snd_ctl_tlv __user *_tlv,
1208 int op_flag)
1209{
1210 struct snd_card *card = file->card;
1211 struct snd_ctl_tlv tlv;
1212 struct snd_kcontrol *kctl;
1213 struct snd_kcontrol_volatile *vd;
1214 unsigned int len;
1215 int err = 0;
1216
1217 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1218 return -EFAULT;
1219 if (tlv.length < sizeof(unsigned int) * 2)
1220 return -EINVAL;
1221 down_read(&card->controls_rwsem);
1222 kctl = snd_ctl_find_numid(card, tlv.numid);
1223 if (kctl == NULL) {
1224 err = -ENOENT;
1225 goto __kctl_end;
1226 }
1227 if (kctl->tlv.p == NULL) {
1228 err = -ENXIO;
1229 goto __kctl_end;
1230 }
1231 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1232 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1233 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1234 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1235 err = -ENXIO;
1236 goto __kctl_end;
1237 }
1238 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1239 if (vd->owner != NULL && vd->owner != file) {
1240 err = -EPERM;
1241 goto __kctl_end;
1242 }
1243 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1244 if (err > 0) {
1245 up_read(&card->controls_rwsem);
1246 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1247 return 0;
1248 }
1249 } else {
1250 if (op_flag) {
1251 err = -ENXIO;
1252 goto __kctl_end;
1253 }
1254 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1255 if (tlv.length < len) {
1256 err = -ENOMEM;
1257 goto __kctl_end;
1258 }
1259 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1260 err = -EFAULT;
1261 }
1262 __kctl_end:
1263 up_read(&card->controls_rwsem);
1264 return err;
1265}
1266
1267static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1268{
1269 struct snd_ctl_file *ctl;
1270 struct snd_card *card;
1271 struct snd_kctl_ioctl *p;
1272 void __user *argp = (void __user *)arg;
1273 int __user *ip = argp;
1274 int err;
1275
1276 ctl = file->private_data;
1277 card = ctl->card;
1278 if (snd_BUG_ON(!card))
1279 return -ENXIO;
1280 switch (cmd) {
1281 case SNDRV_CTL_IOCTL_PVERSION:
1282 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1283 case SNDRV_CTL_IOCTL_CARD_INFO:
1284 return snd_ctl_card_info(card, ctl, cmd, argp);
1285 case SNDRV_CTL_IOCTL_ELEM_LIST:
1286 return snd_ctl_elem_list(card, argp);
1287 case SNDRV_CTL_IOCTL_ELEM_INFO:
1288 return snd_ctl_elem_info_user(ctl, argp);
1289 case SNDRV_CTL_IOCTL_ELEM_READ:
1290 return snd_ctl_elem_read_user(card, argp);
1291 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1292 return snd_ctl_elem_write_user(ctl, argp);
1293 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1294 return snd_ctl_elem_lock(ctl, argp);
1295 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1296 return snd_ctl_elem_unlock(ctl, argp);
1297 case SNDRV_CTL_IOCTL_ELEM_ADD:
1298 return snd_ctl_elem_add_user(ctl, argp, 0);
1299 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1300 return snd_ctl_elem_add_user(ctl, argp, 1);
1301 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1302 return snd_ctl_elem_remove(ctl, argp);
1303 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1304 return snd_ctl_subscribe_events(ctl, ip);
1305 case SNDRV_CTL_IOCTL_TLV_READ:
1306 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1307 case SNDRV_CTL_IOCTL_TLV_WRITE:
1308 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1309 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1310 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1311 case SNDRV_CTL_IOCTL_POWER:
1312 return -ENOPROTOOPT;
1313 case SNDRV_CTL_IOCTL_POWER_STATE:
1314#ifdef CONFIG_PM
1315 return put_user(card->power_state, ip) ? -EFAULT : 0;
1316#else
1317 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1318#endif
1319 }
1320 down_read(&snd_ioctl_rwsem);
1321 list_for_each_entry(p, &snd_control_ioctls, list) {
1322 err = p->fioctl(card, ctl, cmd, arg);
1323 if (err != -ENOIOCTLCMD) {
1324 up_read(&snd_ioctl_rwsem);
1325 return err;
1326 }
1327 }
1328 up_read(&snd_ioctl_rwsem);
1329 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1330 return -ENOTTY;
1331}
1332
1333static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1334 size_t count, loff_t * offset)
1335{
1336 struct snd_ctl_file *ctl;
1337 int err = 0;
1338 ssize_t result = 0;
1339
1340 ctl = file->private_data;
1341 if (snd_BUG_ON(!ctl || !ctl->card))
1342 return -ENXIO;
1343 if (!ctl->subscribed)
1344 return -EBADFD;
1345 if (count < sizeof(struct snd_ctl_event))
1346 return -EINVAL;
1347 spin_lock_irq(&ctl->read_lock);
1348 while (count >= sizeof(struct snd_ctl_event)) {
1349 struct snd_ctl_event ev;
1350 struct snd_kctl_event *kev;
1351 while (list_empty(&ctl->events)) {
1352 wait_queue_t wait;
1353 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1354 err = -EAGAIN;
1355 goto __end_lock;
1356 }
1357 init_waitqueue_entry(&wait, current);
1358 add_wait_queue(&ctl->change_sleep, &wait);
1359 set_current_state(TASK_INTERRUPTIBLE);
1360 spin_unlock_irq(&ctl->read_lock);
1361 schedule();
1362 remove_wait_queue(&ctl->change_sleep, &wait);
1363 if (signal_pending(current))
1364 return -ERESTARTSYS;
1365 spin_lock_irq(&ctl->read_lock);
1366 }
1367 kev = snd_kctl_event(ctl->events.next);
1368 ev.type = SNDRV_CTL_EVENT_ELEM;
1369 ev.data.elem.mask = kev->mask;
1370 ev.data.elem.id = kev->id;
1371 list_del(&kev->list);
1372 spin_unlock_irq(&ctl->read_lock);
1373 kfree(kev);
1374 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1375 err = -EFAULT;
1376 goto __end;
1377 }
1378 spin_lock_irq(&ctl->read_lock);
1379 buffer += sizeof(struct snd_ctl_event);
1380 count -= sizeof(struct snd_ctl_event);
1381 result += sizeof(struct snd_ctl_event);
1382 }
1383 __end_lock:
1384 spin_unlock_irq(&ctl->read_lock);
1385 __end:
1386 return result > 0 ? result : err;
1387}
1388
1389static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1390{
1391 unsigned int mask;
1392 struct snd_ctl_file *ctl;
1393
1394 ctl = file->private_data;
1395 if (!ctl->subscribed)
1396 return 0;
1397 poll_wait(file, &ctl->change_sleep, wait);
1398
1399 mask = 0;
1400 if (!list_empty(&ctl->events))
1401 mask |= POLLIN | POLLRDNORM;
1402
1403 return mask;
1404}
1405
1406/*
1407 * register the device-specific control-ioctls.
1408 * called from each device manager like pcm.c, hwdep.c, etc.
1409 */
1410static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1411{
1412 struct snd_kctl_ioctl *pn;
1413
1414 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1415 if (pn == NULL)
1416 return -ENOMEM;
1417 pn->fioctl = fcn;
1418 down_write(&snd_ioctl_rwsem);
1419 list_add_tail(&pn->list, lists);
1420 up_write(&snd_ioctl_rwsem);
1421 return 0;
1422}
1423
1424int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1425{
1426 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1427}
1428
1429EXPORT_SYMBOL(snd_ctl_register_ioctl);
1430
1431#ifdef CONFIG_COMPAT
1432int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1433{
1434 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1435}
1436
1437EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1438#endif
1439
1440/*
1441 * de-register the device-specific control-ioctls.
1442 */
1443static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1444 struct list_head *lists)
1445{
1446 struct snd_kctl_ioctl *p;
1447
1448 if (snd_BUG_ON(!fcn))
1449 return -EINVAL;
1450 down_write(&snd_ioctl_rwsem);
1451 list_for_each_entry(p, lists, list) {
1452 if (p->fioctl == fcn) {
1453 list_del(&p->list);
1454 up_write(&snd_ioctl_rwsem);
1455 kfree(p);
1456 return 0;
1457 }
1458 }
1459 up_write(&snd_ioctl_rwsem);
1460 snd_BUG();
1461 return -EINVAL;
1462}
1463
1464int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1465{
1466 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1467}
1468
1469EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1470
1471#ifdef CONFIG_COMPAT
1472int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1473{
1474 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1475}
1476
1477EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1478#endif
1479
1480static int snd_ctl_fasync(int fd, struct file * file, int on)
1481{
1482 struct snd_ctl_file *ctl;
1483
1484 ctl = file->private_data;
1485 return fasync_helper(fd, file, on, &ctl->fasync);
1486}
1487
1488/*
1489 * ioctl32 compat
1490 */
1491#ifdef CONFIG_COMPAT
1492#include "control_compat.c"
1493#else
1494#define snd_ctl_ioctl_compat NULL
1495#endif
1496
1497/*
1498 * INIT PART
1499 */
1500
1501static const struct file_operations snd_ctl_f_ops =
1502{
1503 .owner = THIS_MODULE,
1504 .read = snd_ctl_read,
1505 .open = snd_ctl_open,
1506 .release = snd_ctl_release,
1507 .llseek = no_llseek,
1508 .poll = snd_ctl_poll,
1509 .unlocked_ioctl = snd_ctl_ioctl,
1510 .compat_ioctl = snd_ctl_ioctl_compat,
1511 .fasync = snd_ctl_fasync,
1512};
1513
1514/*
1515 * registration of the control device
1516 */
1517static int snd_ctl_dev_register(struct snd_device *device)
1518{
1519 struct snd_card *card = device->device_data;
1520 int err, cardnum;
1521 char name[16];
1522
1523 if (snd_BUG_ON(!card))
1524 return -ENXIO;
1525 cardnum = card->number;
1526 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1527 return -ENXIO;
1528 sprintf(name, "controlC%i", cardnum);
1529 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1530 &snd_ctl_f_ops, card, name)) < 0)
1531 return err;
1532 return 0;
1533}
1534
1535/*
1536 * disconnection of the control device
1537 */
1538static int snd_ctl_dev_disconnect(struct snd_device *device)
1539{
1540 struct snd_card *card = device->device_data;
1541 struct snd_ctl_file *ctl;
1542 int err, cardnum;
1543
1544 if (snd_BUG_ON(!card))
1545 return -ENXIO;
1546 cardnum = card->number;
1547 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1548 return -ENXIO;
1549
1550 read_lock(&card->ctl_files_rwlock);
1551 list_for_each_entry(ctl, &card->ctl_files, list) {
1552 wake_up(&ctl->change_sleep);
1553 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1554 }
1555 read_unlock(&card->ctl_files_rwlock);
1556
1557 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1558 card, -1)) < 0)
1559 return err;
1560 return 0;
1561}
1562
1563/*
1564 * free all controls
1565 */
1566static int snd_ctl_dev_free(struct snd_device *device)
1567{
1568 struct snd_card *card = device->device_data;
1569 struct snd_kcontrol *control;
1570
1571 down_write(&card->controls_rwsem);
1572 while (!list_empty(&card->controls)) {
1573 control = snd_kcontrol(card->controls.next);
1574 snd_ctl_remove(card, control);
1575 }
1576 up_write(&card->controls_rwsem);
1577 return 0;
1578}
1579
1580/*
1581 * create control core:
1582 * called from init.c
1583 */
1584int snd_ctl_create(struct snd_card *card)
1585{
1586 static struct snd_device_ops ops = {
1587 .dev_free = snd_ctl_dev_free,
1588 .dev_register = snd_ctl_dev_register,
1589 .dev_disconnect = snd_ctl_dev_disconnect,
1590 };
1591
1592 if (snd_BUG_ON(!card))
1593 return -ENXIO;
1594 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1595}
1596
1597/*
1598 * Frequently used control callbacks/helpers
1599 */
1600int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1601 struct snd_ctl_elem_info *uinfo)
1602{
1603 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1604 uinfo->count = 1;
1605 uinfo->value.integer.min = 0;
1606 uinfo->value.integer.max = 1;
1607 return 0;
1608}
1609
1610EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1611
1612int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1613 struct snd_ctl_elem_info *uinfo)
1614{
1615 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1616 uinfo->count = 2;
1617 uinfo->value.integer.min = 0;
1618 uinfo->value.integer.max = 1;
1619 return 0;
1620}
1621
1622EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1623
1624/**
1625 * snd_ctl_enum_info - fills the info structure for an enumerated control
1626 * @info: the structure to be filled
1627 * @channels: the number of the control's channels; often one
1628 * @items: the number of control values; also the size of @names
1629 * @names: an array containing the names of all control values
1630 *
1631 * Sets all required fields in @info to their appropriate values.
1632 * If the control's accessibility is not the default (readable and writable),
1633 * the caller has to fill @info->access.
1634 */
1635int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1636 unsigned int items, const char *const names[])
1637{
1638 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1639 info->count = channels;
1640 info->value.enumerated.items = items;
1641 if (info->value.enumerated.item >= items)
1642 info->value.enumerated.item = items - 1;
1643 strlcpy(info->value.enumerated.name,
1644 names[info->value.enumerated.item],
1645 sizeof(info->value.enumerated.name));
1646 return 0;
1647}
1648EXPORT_SYMBOL(snd_ctl_enum_info);
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 snd_card_unref(card);
90 return 0;
91
92 __error:
93 module_put(card->module);
94 __error2:
95 snd_card_file_remove(card, file);
96 __error1:
97 if (card)
98 snd_card_unref(card);
99 return err;
100}
101
102static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
103{
104 unsigned long flags;
105 struct snd_kctl_event *cread;
106
107 spin_lock_irqsave(&ctl->read_lock, flags);
108 while (!list_empty(&ctl->events)) {
109 cread = snd_kctl_event(ctl->events.next);
110 list_del(&cread->list);
111 kfree(cread);
112 }
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
114}
115
116static int snd_ctl_release(struct inode *inode, struct file *file)
117{
118 unsigned long flags;
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
122 unsigned int idx;
123
124 ctl = file->private_data;
125 file->private_data = NULL;
126 card = ctl->card;
127 write_lock_irqsave(&card->ctl_files_rwlock, flags);
128 list_del(&ctl->list);
129 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
130 down_write(&card->controls_rwsem);
131 list_for_each_entry(control, &card->controls, list)
132 for (idx = 0; idx < control->count; idx++)
133 if (control->vd[idx].owner == ctl)
134 control->vd[idx].owner = NULL;
135 up_write(&card->controls_rwsem);
136 snd_ctl_empty_read_queue(ctl);
137 put_pid(ctl->pid);
138 kfree(ctl);
139 module_put(card->module);
140 snd_card_file_remove(card, file);
141 return 0;
142}
143
144void snd_ctl_notify(struct snd_card *card, unsigned int mask,
145 struct snd_ctl_elem_id *id)
146{
147 unsigned long flags;
148 struct snd_ctl_file *ctl;
149 struct snd_kctl_event *ev;
150
151 if (snd_BUG_ON(!card || !id))
152 return;
153 read_lock(&card->ctl_files_rwlock);
154#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
155 card->mixer_oss_change_count++;
156#endif
157 list_for_each_entry(ctl, &card->ctl_files, list) {
158 if (!ctl->subscribed)
159 continue;
160 spin_lock_irqsave(&ctl->read_lock, flags);
161 list_for_each_entry(ev, &ctl->events, list) {
162 if (ev->id.numid == id->numid) {
163 ev->mask |= mask;
164 goto _found;
165 }
166 }
167 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
168 if (ev) {
169 ev->id = *id;
170 ev->mask = mask;
171 list_add_tail(&ev->list, &ctl->events);
172 } else {
173 dev_err(card->dev, "No memory available to allocate event\n");
174 }
175 _found:
176 wake_up(&ctl->change_sleep);
177 spin_unlock_irqrestore(&ctl->read_lock, flags);
178 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
179 }
180 read_unlock(&card->ctl_files_rwlock);
181}
182
183EXPORT_SYMBOL(snd_ctl_notify);
184
185/**
186 * snd_ctl_new - create a control instance from the template
187 * @control: the control template
188 * @access: the default control access
189 *
190 * Allocates a new struct snd_kcontrol instance and copies the given template
191 * to the new instance. It does not copy volatile data (access).
192 *
193 * Return: The pointer of the new instance, or %NULL on failure.
194 */
195static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
196 unsigned int access)
197{
198 struct snd_kcontrol *kctl;
199 unsigned int idx;
200
201 if (snd_BUG_ON(!control || !control->count))
202 return NULL;
203
204 if (control->count > MAX_CONTROL_COUNT)
205 return NULL;
206
207 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
208 if (kctl == NULL) {
209 pr_err("ALSA: Cannot allocate control instance\n");
210 return NULL;
211 }
212 *kctl = *control;
213 for (idx = 0; idx < kctl->count; idx++)
214 kctl->vd[idx].access = access;
215 return kctl;
216}
217
218/**
219 * snd_ctl_new1 - create a control instance from the template
220 * @ncontrol: the initialization record
221 * @private_data: the private data to set
222 *
223 * Allocates a new struct snd_kcontrol instance and initialize from the given
224 * template. When the access field of ncontrol is 0, it's assumed as
225 * READWRITE access. When the count field is 0, it's assumes as one.
226 *
227 * Return: The pointer of the newly generated instance, or %NULL on failure.
228 */
229struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
230 void *private_data)
231{
232 struct snd_kcontrol kctl;
233 unsigned int access;
234
235 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
236 return NULL;
237 memset(&kctl, 0, sizeof(kctl));
238 kctl.id.iface = ncontrol->iface;
239 kctl.id.device = ncontrol->device;
240 kctl.id.subdevice = ncontrol->subdevice;
241 if (ncontrol->name) {
242 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
243 if (strcmp(ncontrol->name, kctl.id.name) != 0)
244 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
245 ncontrol->name, kctl.id.name);
246 }
247 kctl.id.index = ncontrol->index;
248 kctl.count = ncontrol->count ? ncontrol->count : 1;
249 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 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
254 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
255 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
256 kctl.info = ncontrol->info;
257 kctl.get = ncontrol->get;
258 kctl.put = ncontrol->put;
259 kctl.tlv.p = ncontrol->tlv.p;
260 kctl.private_value = ncontrol->private_value;
261 kctl.private_data = private_data;
262 return snd_ctl_new(&kctl, access);
263}
264
265EXPORT_SYMBOL(snd_ctl_new1);
266
267/**
268 * snd_ctl_free_one - release the control instance
269 * @kcontrol: the control instance
270 *
271 * Releases the control instance created via snd_ctl_new()
272 * or snd_ctl_new1().
273 * Don't call this after the control was added to the card.
274 */
275void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
276{
277 if (kcontrol) {
278 if (kcontrol->private_free)
279 kcontrol->private_free(kcontrol);
280 kfree(kcontrol);
281 }
282}
283
284EXPORT_SYMBOL(snd_ctl_free_one);
285
286static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
287 unsigned int count)
288{
289 struct snd_kcontrol *kctl;
290
291 list_for_each_entry(kctl, &card->controls, list) {
292 if (kctl->id.numid < card->last_numid + 1 + count &&
293 kctl->id.numid + kctl->count > card->last_numid + 1) {
294 card->last_numid = kctl->id.numid + kctl->count - 1;
295 return true;
296 }
297 }
298 return false;
299}
300
301static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
302{
303 unsigned int iter = 100000;
304
305 while (snd_ctl_remove_numid_conflict(card, count)) {
306 if (--iter == 0) {
307 /* this situation is very unlikely */
308 dev_err(card->dev, "unable to allocate new control numid\n");
309 return -ENOMEM;
310 }
311 }
312 return 0;
313}
314
315/**
316 * snd_ctl_add - add the control instance to the card
317 * @card: the card instance
318 * @kcontrol: the control instance to add
319 *
320 * Adds the control instance created via snd_ctl_new() or
321 * snd_ctl_new1() to the given card. Assigns also an unique
322 * numid used for fast search.
323 *
324 * It frees automatically the control which cannot be added.
325 *
326 * Return: Zero if successful, or a negative error code on failure.
327 *
328 */
329int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
330{
331 struct snd_ctl_elem_id id;
332 unsigned int idx;
333 int err = -EINVAL;
334
335 if (! kcontrol)
336 return err;
337 if (snd_BUG_ON(!card || !kcontrol->info))
338 goto error;
339 id = kcontrol->id;
340 down_write(&card->controls_rwsem);
341 if (snd_ctl_find_id(card, &id)) {
342 up_write(&card->controls_rwsem);
343 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
344 id.iface,
345 id.device,
346 id.subdevice,
347 id.name,
348 id.index);
349 err = -EBUSY;
350 goto error;
351 }
352 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
353 up_write(&card->controls_rwsem);
354 err = -ENOMEM;
355 goto error;
356 }
357 list_add_tail(&kcontrol->list, &card->controls);
358 card->controls_count += kcontrol->count;
359 kcontrol->id.numid = card->last_numid + 1;
360 card->last_numid += kcontrol->count;
361 up_write(&card->controls_rwsem);
362 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
363 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
364 return 0;
365
366 error:
367 snd_ctl_free_one(kcontrol);
368 return err;
369}
370
371EXPORT_SYMBOL(snd_ctl_add);
372
373/**
374 * snd_ctl_replace - replace the control instance of the card
375 * @card: the card instance
376 * @kcontrol: the control instance to replace
377 * @add_on_replace: add the control if not already added
378 *
379 * Replaces the given control. If the given control does not exist
380 * and the add_on_replace flag is set, the control is added. If the
381 * control exists, it is destroyed first.
382 *
383 * It frees automatically the control which cannot be added or replaced.
384 *
385 * Return: Zero if successful, or a negative error code on failure.
386 */
387int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
388 bool add_on_replace)
389{
390 struct snd_ctl_elem_id id;
391 unsigned int idx;
392 struct snd_kcontrol *old;
393 int ret;
394
395 if (!kcontrol)
396 return -EINVAL;
397 if (snd_BUG_ON(!card || !kcontrol->info)) {
398 ret = -EINVAL;
399 goto error;
400 }
401 id = kcontrol->id;
402 down_write(&card->controls_rwsem);
403 old = snd_ctl_find_id(card, &id);
404 if (!old) {
405 if (add_on_replace)
406 goto add;
407 up_write(&card->controls_rwsem);
408 ret = -EINVAL;
409 goto error;
410 }
411 ret = snd_ctl_remove(card, old);
412 if (ret < 0) {
413 up_write(&card->controls_rwsem);
414 goto error;
415 }
416add:
417 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
418 up_write(&card->controls_rwsem);
419 ret = -ENOMEM;
420 goto error;
421 }
422 list_add_tail(&kcontrol->list, &card->controls);
423 card->controls_count += kcontrol->count;
424 kcontrol->id.numid = card->last_numid + 1;
425 card->last_numid += kcontrol->count;
426 up_write(&card->controls_rwsem);
427 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
428 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
429 return 0;
430
431error:
432 snd_ctl_free_one(kcontrol);
433 return ret;
434}
435EXPORT_SYMBOL(snd_ctl_replace);
436
437/**
438 * snd_ctl_remove - remove the control from the card and release it
439 * @card: the card instance
440 * @kcontrol: the control instance to remove
441 *
442 * Removes the control from the card and then releases the instance.
443 * You don't need to call snd_ctl_free_one(). You must be in
444 * the write lock - down_write(&card->controls_rwsem).
445 *
446 * Return: 0 if successful, or a negative error code on failure.
447 */
448int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
449{
450 struct snd_ctl_elem_id id;
451 unsigned int idx;
452
453 if (snd_BUG_ON(!card || !kcontrol))
454 return -EINVAL;
455 list_del(&kcontrol->list);
456 card->controls_count -= kcontrol->count;
457 id = kcontrol->id;
458 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
459 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
460 snd_ctl_free_one(kcontrol);
461 return 0;
462}
463
464EXPORT_SYMBOL(snd_ctl_remove);
465
466/**
467 * snd_ctl_remove_id - remove the control of the given id and release it
468 * @card: the card instance
469 * @id: the control id to remove
470 *
471 * Finds the control instance with the given id, removes it from the
472 * card list and releases it.
473 *
474 * Return: 0 if successful, or a negative error code on failure.
475 */
476int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
477{
478 struct snd_kcontrol *kctl;
479 int ret;
480
481 down_write(&card->controls_rwsem);
482 kctl = snd_ctl_find_id(card, id);
483 if (kctl == NULL) {
484 up_write(&card->controls_rwsem);
485 return -ENOENT;
486 }
487 ret = snd_ctl_remove(card, kctl);
488 up_write(&card->controls_rwsem);
489 return ret;
490}
491
492EXPORT_SYMBOL(snd_ctl_remove_id);
493
494/**
495 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
496 * @file: active control handle
497 * @id: the control id to remove
498 *
499 * Finds the control instance with the given id, removes it from the
500 * card list and releases it.
501 *
502 * Return: 0 if successful, or a negative error code on failure.
503 */
504static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
505 struct snd_ctl_elem_id *id)
506{
507 struct snd_card *card = file->card;
508 struct snd_kcontrol *kctl;
509 int idx, ret;
510
511 down_write(&card->controls_rwsem);
512 kctl = snd_ctl_find_id(card, id);
513 if (kctl == NULL) {
514 ret = -ENOENT;
515 goto error;
516 }
517 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
518 ret = -EINVAL;
519 goto error;
520 }
521 for (idx = 0; idx < kctl->count; idx++)
522 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
523 ret = -EBUSY;
524 goto error;
525 }
526 ret = snd_ctl_remove(card, kctl);
527 if (ret < 0)
528 goto error;
529 card->user_ctl_count--;
530error:
531 up_write(&card->controls_rwsem);
532 return ret;
533}
534
535/**
536 * snd_ctl_activate_id - activate/inactivate the control of the given id
537 * @card: the card instance
538 * @id: the control id to activate/inactivate
539 * @active: non-zero to activate
540 *
541 * Finds the control instance with the given id, and activate or
542 * inactivate the control together with notification, if changed.
543 *
544 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
545 */
546int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
547 int active)
548{
549 struct snd_kcontrol *kctl;
550 struct snd_kcontrol_volatile *vd;
551 unsigned int index_offset;
552 int ret;
553
554 down_write(&card->controls_rwsem);
555 kctl = snd_ctl_find_id(card, id);
556 if (kctl == NULL) {
557 ret = -ENOENT;
558 goto unlock;
559 }
560 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
561 vd = &kctl->vd[index_offset];
562 ret = 0;
563 if (active) {
564 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
565 goto unlock;
566 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
567 } else {
568 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
569 goto unlock;
570 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
571 }
572 ret = 1;
573 unlock:
574 up_write(&card->controls_rwsem);
575 if (ret > 0)
576 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
577 return ret;
578}
579EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
580
581/**
582 * snd_ctl_rename_id - replace the id of a control on the card
583 * @card: the card instance
584 * @src_id: the old id
585 * @dst_id: the new id
586 *
587 * Finds the control with the old id from the card, and replaces the
588 * id with the new one.
589 *
590 * Return: Zero if successful, or a negative error code on failure.
591 */
592int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
593 struct snd_ctl_elem_id *dst_id)
594{
595 struct snd_kcontrol *kctl;
596
597 down_write(&card->controls_rwsem);
598 kctl = snd_ctl_find_id(card, src_id);
599 if (kctl == NULL) {
600 up_write(&card->controls_rwsem);
601 return -ENOENT;
602 }
603 kctl->id = *dst_id;
604 kctl->id.numid = card->last_numid + 1;
605 card->last_numid += kctl->count;
606 up_write(&card->controls_rwsem);
607 return 0;
608}
609
610EXPORT_SYMBOL(snd_ctl_rename_id);
611
612/**
613 * snd_ctl_find_numid - find the control instance with the given number-id
614 * @card: the card instance
615 * @numid: the number-id to search
616 *
617 * Finds the control instance with the given number-id from the card.
618 *
619 * The caller must down card->controls_rwsem before calling this function
620 * (if the race condition can happen).
621 *
622 * Return: The pointer of the instance if found, or %NULL if not.
623 *
624 */
625struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
626{
627 struct snd_kcontrol *kctl;
628
629 if (snd_BUG_ON(!card || !numid))
630 return NULL;
631 list_for_each_entry(kctl, &card->controls, list) {
632 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
633 return kctl;
634 }
635 return NULL;
636}
637
638EXPORT_SYMBOL(snd_ctl_find_numid);
639
640/**
641 * snd_ctl_find_id - find the control instance with the given id
642 * @card: the card instance
643 * @id: the id to search
644 *
645 * Finds the control instance with the given id from the card.
646 *
647 * The caller must down card->controls_rwsem before calling this function
648 * (if the race condition can happen).
649 *
650 * Return: The pointer of the instance if found, or %NULL if not.
651 *
652 */
653struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
654 struct snd_ctl_elem_id *id)
655{
656 struct snd_kcontrol *kctl;
657
658 if (snd_BUG_ON(!card || !id))
659 return NULL;
660 if (id->numid != 0)
661 return snd_ctl_find_numid(card, id->numid);
662 list_for_each_entry(kctl, &card->controls, list) {
663 if (kctl->id.iface != id->iface)
664 continue;
665 if (kctl->id.device != id->device)
666 continue;
667 if (kctl->id.subdevice != id->subdevice)
668 continue;
669 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
670 continue;
671 if (kctl->id.index > id->index)
672 continue;
673 if (kctl->id.index + kctl->count <= id->index)
674 continue;
675 return kctl;
676 }
677 return NULL;
678}
679
680EXPORT_SYMBOL(snd_ctl_find_id);
681
682static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
683 unsigned int cmd, void __user *arg)
684{
685 struct snd_ctl_card_info *info;
686
687 info = kzalloc(sizeof(*info), GFP_KERNEL);
688 if (! info)
689 return -ENOMEM;
690 down_read(&snd_ioctl_rwsem);
691 info->card = card->number;
692 strlcpy(info->id, card->id, sizeof(info->id));
693 strlcpy(info->driver, card->driver, sizeof(info->driver));
694 strlcpy(info->name, card->shortname, sizeof(info->name));
695 strlcpy(info->longname, card->longname, sizeof(info->longname));
696 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
697 strlcpy(info->components, card->components, sizeof(info->components));
698 up_read(&snd_ioctl_rwsem);
699 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
700 kfree(info);
701 return -EFAULT;
702 }
703 kfree(info);
704 return 0;
705}
706
707static int snd_ctl_elem_list(struct snd_card *card,
708 struct snd_ctl_elem_list __user *_list)
709{
710 struct list_head *plist;
711 struct snd_ctl_elem_list list;
712 struct snd_kcontrol *kctl;
713 struct snd_ctl_elem_id *dst, *id;
714 unsigned int offset, space, jidx;
715
716 if (copy_from_user(&list, _list, sizeof(list)))
717 return -EFAULT;
718 offset = list.offset;
719 space = list.space;
720 /* try limit maximum space */
721 if (space > 16384)
722 return -ENOMEM;
723 if (space > 0) {
724 /* allocate temporary buffer for atomic operation */
725 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
726 if (dst == NULL)
727 return -ENOMEM;
728 down_read(&card->controls_rwsem);
729 list.count = card->controls_count;
730 plist = card->controls.next;
731 while (plist != &card->controls) {
732 if (offset == 0)
733 break;
734 kctl = snd_kcontrol(plist);
735 if (offset < kctl->count)
736 break;
737 offset -= kctl->count;
738 plist = plist->next;
739 }
740 list.used = 0;
741 id = dst;
742 while (space > 0 && plist != &card->controls) {
743 kctl = snd_kcontrol(plist);
744 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
745 snd_ctl_build_ioff(id, kctl, jidx);
746 id++;
747 space--;
748 list.used++;
749 }
750 plist = plist->next;
751 offset = 0;
752 }
753 up_read(&card->controls_rwsem);
754 if (list.used > 0 &&
755 copy_to_user(list.pids, dst,
756 list.used * sizeof(struct snd_ctl_elem_id))) {
757 vfree(dst);
758 return -EFAULT;
759 }
760 vfree(dst);
761 } else {
762 down_read(&card->controls_rwsem);
763 list.count = card->controls_count;
764 up_read(&card->controls_rwsem);
765 }
766 if (copy_to_user(_list, &list, sizeof(list)))
767 return -EFAULT;
768 return 0;
769}
770
771static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
772 struct snd_ctl_elem_info *info)
773{
774 struct snd_card *card = ctl->card;
775 struct snd_kcontrol *kctl;
776 struct snd_kcontrol_volatile *vd;
777 unsigned int index_offset;
778 int result;
779
780 down_read(&card->controls_rwsem);
781 kctl = snd_ctl_find_id(card, &info->id);
782 if (kctl == NULL) {
783 up_read(&card->controls_rwsem);
784 return -ENOENT;
785 }
786#ifdef CONFIG_SND_DEBUG
787 info->access = 0;
788#endif
789 result = kctl->info(kctl, info);
790 if (result >= 0) {
791 snd_BUG_ON(info->access);
792 index_offset = snd_ctl_get_ioff(kctl, &info->id);
793 vd = &kctl->vd[index_offset];
794 snd_ctl_build_ioff(&info->id, kctl, index_offset);
795 info->access = vd->access;
796 if (vd->owner) {
797 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
798 if (vd->owner == ctl)
799 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
800 info->owner = pid_vnr(vd->owner->pid);
801 } else {
802 info->owner = -1;
803 }
804 }
805 up_read(&card->controls_rwsem);
806 return result;
807}
808
809static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
810 struct snd_ctl_elem_info __user *_info)
811{
812 struct snd_ctl_elem_info info;
813 int result;
814
815 if (copy_from_user(&info, _info, sizeof(info)))
816 return -EFAULT;
817 snd_power_lock(ctl->card);
818 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
819 if (result >= 0)
820 result = snd_ctl_elem_info(ctl, &info);
821 snd_power_unlock(ctl->card);
822 if (result >= 0)
823 if (copy_to_user(_info, &info, sizeof(info)))
824 return -EFAULT;
825 return result;
826}
827
828static int snd_ctl_elem_read(struct snd_card *card,
829 struct snd_ctl_elem_value *control)
830{
831 struct snd_kcontrol *kctl;
832 struct snd_kcontrol_volatile *vd;
833 unsigned int index_offset;
834 int result;
835
836 down_read(&card->controls_rwsem);
837 kctl = snd_ctl_find_id(card, &control->id);
838 if (kctl == NULL) {
839 result = -ENOENT;
840 } else {
841 index_offset = snd_ctl_get_ioff(kctl, &control->id);
842 vd = &kctl->vd[index_offset];
843 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
844 kctl->get != NULL) {
845 snd_ctl_build_ioff(&control->id, kctl, index_offset);
846 result = kctl->get(kctl, control);
847 } else
848 result = -EPERM;
849 }
850 up_read(&card->controls_rwsem);
851 return result;
852}
853
854static int snd_ctl_elem_read_user(struct snd_card *card,
855 struct snd_ctl_elem_value __user *_control)
856{
857 struct snd_ctl_elem_value *control;
858 int result;
859
860 control = memdup_user(_control, sizeof(*control));
861 if (IS_ERR(control))
862 return PTR_ERR(control);
863
864 snd_power_lock(card);
865 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
866 if (result >= 0)
867 result = snd_ctl_elem_read(card, control);
868 snd_power_unlock(card);
869 if (result >= 0)
870 if (copy_to_user(_control, control, sizeof(*control)))
871 result = -EFAULT;
872 kfree(control);
873 return result;
874}
875
876static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
877 struct snd_ctl_elem_value *control)
878{
879 struct snd_kcontrol *kctl;
880 struct snd_kcontrol_volatile *vd;
881 unsigned int index_offset;
882 int result;
883
884 down_read(&card->controls_rwsem);
885 kctl = snd_ctl_find_id(card, &control->id);
886 if (kctl == NULL) {
887 result = -ENOENT;
888 } else {
889 index_offset = snd_ctl_get_ioff(kctl, &control->id);
890 vd = &kctl->vd[index_offset];
891 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
892 kctl->put == NULL ||
893 (file && vd->owner && vd->owner != file)) {
894 result = -EPERM;
895 } else {
896 snd_ctl_build_ioff(&control->id, kctl, index_offset);
897 result = kctl->put(kctl, control);
898 }
899 if (result > 0) {
900 up_read(&card->controls_rwsem);
901 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
902 &control->id);
903 return 0;
904 }
905 }
906 up_read(&card->controls_rwsem);
907 return result;
908}
909
910static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
911 struct snd_ctl_elem_value __user *_control)
912{
913 struct snd_ctl_elem_value *control;
914 struct snd_card *card;
915 int result;
916
917 control = memdup_user(_control, sizeof(*control));
918 if (IS_ERR(control))
919 return PTR_ERR(control);
920
921 card = file->card;
922 snd_power_lock(card);
923 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
924 if (result >= 0)
925 result = snd_ctl_elem_write(card, file, control);
926 snd_power_unlock(card);
927 if (result >= 0)
928 if (copy_to_user(_control, control, sizeof(*control)))
929 result = -EFAULT;
930 kfree(control);
931 return result;
932}
933
934static int snd_ctl_elem_lock(struct snd_ctl_file *file,
935 struct snd_ctl_elem_id __user *_id)
936{
937 struct snd_card *card = file->card;
938 struct snd_ctl_elem_id id;
939 struct snd_kcontrol *kctl;
940 struct snd_kcontrol_volatile *vd;
941 int result;
942
943 if (copy_from_user(&id, _id, sizeof(id)))
944 return -EFAULT;
945 down_write(&card->controls_rwsem);
946 kctl = snd_ctl_find_id(card, &id);
947 if (kctl == NULL) {
948 result = -ENOENT;
949 } else {
950 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
951 if (vd->owner != NULL)
952 result = -EBUSY;
953 else {
954 vd->owner = file;
955 result = 0;
956 }
957 }
958 up_write(&card->controls_rwsem);
959 return result;
960}
961
962static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
963 struct snd_ctl_elem_id __user *_id)
964{
965 struct snd_card *card = file->card;
966 struct snd_ctl_elem_id id;
967 struct snd_kcontrol *kctl;
968 struct snd_kcontrol_volatile *vd;
969 int result;
970
971 if (copy_from_user(&id, _id, sizeof(id)))
972 return -EFAULT;
973 down_write(&card->controls_rwsem);
974 kctl = snd_ctl_find_id(card, &id);
975 if (kctl == NULL) {
976 result = -ENOENT;
977 } else {
978 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
979 if (vd->owner == NULL)
980 result = -EINVAL;
981 else if (vd->owner != file)
982 result = -EPERM;
983 else {
984 vd->owner = NULL;
985 result = 0;
986 }
987 }
988 up_write(&card->controls_rwsem);
989 return result;
990}
991
992struct user_element {
993 struct snd_ctl_elem_info info;
994 void *elem_data; /* element data */
995 unsigned long elem_data_size; /* size of element data in bytes */
996 void *tlv_data; /* TLV data */
997 unsigned long tlv_data_size; /* TLV data size */
998 void *priv_data; /* private data (like strings for enumerated type) */
999};
1000
1001static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1002 struct snd_ctl_elem_info *uinfo)
1003{
1004 struct user_element *ue = kcontrol->private_data;
1005
1006 *uinfo = ue->info;
1007 return 0;
1008}
1009
1010static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1011 struct snd_ctl_elem_info *uinfo)
1012{
1013 struct user_element *ue = kcontrol->private_data;
1014 const char *names;
1015 unsigned int item;
1016
1017 item = uinfo->value.enumerated.item;
1018
1019 *uinfo = ue->info;
1020
1021 item = min(item, uinfo->value.enumerated.items - 1);
1022 uinfo->value.enumerated.item = item;
1023
1024 names = ue->priv_data;
1025 for (; item > 0; --item)
1026 names += strlen(names) + 1;
1027 strcpy(uinfo->value.enumerated.name, names);
1028
1029 return 0;
1030}
1031
1032static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1033 struct snd_ctl_elem_value *ucontrol)
1034{
1035 struct user_element *ue = kcontrol->private_data;
1036
1037 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1038 return 0;
1039}
1040
1041static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1042 struct snd_ctl_elem_value *ucontrol)
1043{
1044 int change;
1045 struct user_element *ue = kcontrol->private_data;
1046
1047 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1048 if (change)
1049 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1050 return change;
1051}
1052
1053static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1054 int op_flag,
1055 unsigned int size,
1056 unsigned int __user *tlv)
1057{
1058 struct user_element *ue = kcontrol->private_data;
1059 int change = 0;
1060 void *new_data;
1061
1062 if (op_flag > 0) {
1063 if (size > 1024 * 128) /* sane value */
1064 return -EINVAL;
1065
1066 new_data = memdup_user(tlv, size);
1067 if (IS_ERR(new_data))
1068 return PTR_ERR(new_data);
1069 change = ue->tlv_data_size != size;
1070 if (!change)
1071 change = memcmp(ue->tlv_data, new_data, size);
1072 kfree(ue->tlv_data);
1073 ue->tlv_data = new_data;
1074 ue->tlv_data_size = size;
1075 } else {
1076 if (! ue->tlv_data_size || ! ue->tlv_data)
1077 return -ENXIO;
1078 if (size < ue->tlv_data_size)
1079 return -ENOSPC;
1080 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1081 return -EFAULT;
1082 }
1083 return change;
1084}
1085
1086static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1087{
1088 char *names, *p;
1089 size_t buf_len, name_len;
1090 unsigned int i;
1091 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1092
1093 if (ue->info.value.enumerated.names_length > 64 * 1024)
1094 return -EINVAL;
1095
1096 names = memdup_user((const void __user *)user_ptrval,
1097 ue->info.value.enumerated.names_length);
1098 if (IS_ERR(names))
1099 return PTR_ERR(names);
1100
1101 /* check that there are enough valid names */
1102 buf_len = ue->info.value.enumerated.names_length;
1103 p = names;
1104 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1105 name_len = strnlen(p, buf_len);
1106 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1107 kfree(names);
1108 return -EINVAL;
1109 }
1110 p += name_len + 1;
1111 buf_len -= name_len + 1;
1112 }
1113
1114 ue->priv_data = names;
1115 ue->info.value.enumerated.names_ptr = 0;
1116
1117 return 0;
1118}
1119
1120static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1121{
1122 struct user_element *ue = kcontrol->private_data;
1123
1124 kfree(ue->tlv_data);
1125 kfree(ue->priv_data);
1126 kfree(ue);
1127}
1128
1129static int snd_ctl_elem_add(struct snd_ctl_file *file,
1130 struct snd_ctl_elem_info *info, int replace)
1131{
1132 struct snd_card *card = file->card;
1133 struct snd_kcontrol kctl, *_kctl;
1134 unsigned int access;
1135 long private_size;
1136 struct user_element *ue;
1137 int idx, err;
1138
1139 if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1140 return -ENOMEM;
1141 if (info->count < 1)
1142 return -EINVAL;
1143 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1144 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1145 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1146 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1147 info->id.numid = 0;
1148 memset(&kctl, 0, sizeof(kctl));
1149 down_write(&card->controls_rwsem);
1150 _kctl = snd_ctl_find_id(card, &info->id);
1151 err = 0;
1152 if (_kctl) {
1153 if (replace)
1154 err = snd_ctl_remove(card, _kctl);
1155 else
1156 err = -EBUSY;
1157 } else {
1158 if (replace)
1159 err = -ENOENT;
1160 }
1161 up_write(&card->controls_rwsem);
1162 if (err < 0)
1163 return err;
1164 memcpy(&kctl.id, &info->id, sizeof(info->id));
1165 kctl.count = info->owner ? info->owner : 1;
1166 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1167 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1168 kctl.info = snd_ctl_elem_user_enum_info;
1169 else
1170 kctl.info = snd_ctl_elem_user_info;
1171 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1172 kctl.get = snd_ctl_elem_user_get;
1173 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1174 kctl.put = snd_ctl_elem_user_put;
1175 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1176 kctl.tlv.c = snd_ctl_elem_user_tlv;
1177 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1178 }
1179 switch (info->type) {
1180 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1181 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1182 private_size = sizeof(long);
1183 if (info->count > 128)
1184 return -EINVAL;
1185 break;
1186 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1187 private_size = sizeof(long long);
1188 if (info->count > 64)
1189 return -EINVAL;
1190 break;
1191 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1192 private_size = sizeof(unsigned int);
1193 if (info->count > 128 || info->value.enumerated.items == 0)
1194 return -EINVAL;
1195 break;
1196 case SNDRV_CTL_ELEM_TYPE_BYTES:
1197 private_size = sizeof(unsigned char);
1198 if (info->count > 512)
1199 return -EINVAL;
1200 break;
1201 case SNDRV_CTL_ELEM_TYPE_IEC958:
1202 private_size = sizeof(struct snd_aes_iec958);
1203 if (info->count != 1)
1204 return -EINVAL;
1205 break;
1206 default:
1207 return -EINVAL;
1208 }
1209 private_size *= info->count;
1210 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1211 if (ue == NULL)
1212 return -ENOMEM;
1213 ue->info = *info;
1214 ue->info.access = 0;
1215 ue->elem_data = (char *)ue + sizeof(*ue);
1216 ue->elem_data_size = private_size;
1217 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1218 err = snd_ctl_elem_init_enum_names(ue);
1219 if (err < 0) {
1220 kfree(ue);
1221 return err;
1222 }
1223 }
1224 kctl.private_free = snd_ctl_elem_user_free;
1225 _kctl = snd_ctl_new(&kctl, access);
1226 if (_kctl == NULL) {
1227 kfree(ue->priv_data);
1228 kfree(ue);
1229 return -ENOMEM;
1230 }
1231 _kctl->private_data = ue;
1232 for (idx = 0; idx < _kctl->count; idx++)
1233 _kctl->vd[idx].owner = file;
1234 err = snd_ctl_add(card, _kctl);
1235 if (err < 0)
1236 return err;
1237
1238 down_write(&card->controls_rwsem);
1239 card->user_ctl_count++;
1240 up_write(&card->controls_rwsem);
1241
1242 return 0;
1243}
1244
1245static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1246 struct snd_ctl_elem_info __user *_info, int replace)
1247{
1248 struct snd_ctl_elem_info info;
1249 if (copy_from_user(&info, _info, sizeof(info)))
1250 return -EFAULT;
1251 return snd_ctl_elem_add(file, &info, replace);
1252}
1253
1254static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1255 struct snd_ctl_elem_id __user *_id)
1256{
1257 struct snd_ctl_elem_id id;
1258
1259 if (copy_from_user(&id, _id, sizeof(id)))
1260 return -EFAULT;
1261 return snd_ctl_remove_user_ctl(file, &id);
1262}
1263
1264static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1265{
1266 int subscribe;
1267 if (get_user(subscribe, ptr))
1268 return -EFAULT;
1269 if (subscribe < 0) {
1270 subscribe = file->subscribed;
1271 if (put_user(subscribe, ptr))
1272 return -EFAULT;
1273 return 0;
1274 }
1275 if (subscribe) {
1276 file->subscribed = 1;
1277 return 0;
1278 } else if (file->subscribed) {
1279 snd_ctl_empty_read_queue(file);
1280 file->subscribed = 0;
1281 }
1282 return 0;
1283}
1284
1285static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1286 struct snd_ctl_tlv __user *_tlv,
1287 int op_flag)
1288{
1289 struct snd_card *card = file->card;
1290 struct snd_ctl_tlv tlv;
1291 struct snd_kcontrol *kctl;
1292 struct snd_kcontrol_volatile *vd;
1293 unsigned int len;
1294 int err = 0;
1295
1296 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1297 return -EFAULT;
1298 if (tlv.length < sizeof(unsigned int) * 2)
1299 return -EINVAL;
1300 down_read(&card->controls_rwsem);
1301 kctl = snd_ctl_find_numid(card, tlv.numid);
1302 if (kctl == NULL) {
1303 err = -ENOENT;
1304 goto __kctl_end;
1305 }
1306 if (kctl->tlv.p == NULL) {
1307 err = -ENXIO;
1308 goto __kctl_end;
1309 }
1310 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1311 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1312 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1313 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1314 err = -ENXIO;
1315 goto __kctl_end;
1316 }
1317 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1318 if (vd->owner != NULL && vd->owner != file) {
1319 err = -EPERM;
1320 goto __kctl_end;
1321 }
1322 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1323 if (err > 0) {
1324 up_read(&card->controls_rwsem);
1325 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1326 return 0;
1327 }
1328 } else {
1329 if (op_flag) {
1330 err = -ENXIO;
1331 goto __kctl_end;
1332 }
1333 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1334 if (tlv.length < len) {
1335 err = -ENOMEM;
1336 goto __kctl_end;
1337 }
1338 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1339 err = -EFAULT;
1340 }
1341 __kctl_end:
1342 up_read(&card->controls_rwsem);
1343 return err;
1344}
1345
1346static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1347{
1348 struct snd_ctl_file *ctl;
1349 struct snd_card *card;
1350 struct snd_kctl_ioctl *p;
1351 void __user *argp = (void __user *)arg;
1352 int __user *ip = argp;
1353 int err;
1354
1355 ctl = file->private_data;
1356 card = ctl->card;
1357 if (snd_BUG_ON(!card))
1358 return -ENXIO;
1359 switch (cmd) {
1360 case SNDRV_CTL_IOCTL_PVERSION:
1361 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1362 case SNDRV_CTL_IOCTL_CARD_INFO:
1363 return snd_ctl_card_info(card, ctl, cmd, argp);
1364 case SNDRV_CTL_IOCTL_ELEM_LIST:
1365 return snd_ctl_elem_list(card, argp);
1366 case SNDRV_CTL_IOCTL_ELEM_INFO:
1367 return snd_ctl_elem_info_user(ctl, argp);
1368 case SNDRV_CTL_IOCTL_ELEM_READ:
1369 return snd_ctl_elem_read_user(card, argp);
1370 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1371 return snd_ctl_elem_write_user(ctl, argp);
1372 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1373 return snd_ctl_elem_lock(ctl, argp);
1374 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1375 return snd_ctl_elem_unlock(ctl, argp);
1376 case SNDRV_CTL_IOCTL_ELEM_ADD:
1377 return snd_ctl_elem_add_user(ctl, argp, 0);
1378 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1379 return snd_ctl_elem_add_user(ctl, argp, 1);
1380 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1381 return snd_ctl_elem_remove(ctl, argp);
1382 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1383 return snd_ctl_subscribe_events(ctl, ip);
1384 case SNDRV_CTL_IOCTL_TLV_READ:
1385 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1386 case SNDRV_CTL_IOCTL_TLV_WRITE:
1387 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1388 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1389 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1390 case SNDRV_CTL_IOCTL_POWER:
1391 return -ENOPROTOOPT;
1392 case SNDRV_CTL_IOCTL_POWER_STATE:
1393#ifdef CONFIG_PM
1394 return put_user(card->power_state, ip) ? -EFAULT : 0;
1395#else
1396 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1397#endif
1398 }
1399 down_read(&snd_ioctl_rwsem);
1400 list_for_each_entry(p, &snd_control_ioctls, list) {
1401 err = p->fioctl(card, ctl, cmd, arg);
1402 if (err != -ENOIOCTLCMD) {
1403 up_read(&snd_ioctl_rwsem);
1404 return err;
1405 }
1406 }
1407 up_read(&snd_ioctl_rwsem);
1408 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1409 return -ENOTTY;
1410}
1411
1412static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1413 size_t count, loff_t * offset)
1414{
1415 struct snd_ctl_file *ctl;
1416 int err = 0;
1417 ssize_t result = 0;
1418
1419 ctl = file->private_data;
1420 if (snd_BUG_ON(!ctl || !ctl->card))
1421 return -ENXIO;
1422 if (!ctl->subscribed)
1423 return -EBADFD;
1424 if (count < sizeof(struct snd_ctl_event))
1425 return -EINVAL;
1426 spin_lock_irq(&ctl->read_lock);
1427 while (count >= sizeof(struct snd_ctl_event)) {
1428 struct snd_ctl_event ev;
1429 struct snd_kctl_event *kev;
1430 while (list_empty(&ctl->events)) {
1431 wait_queue_t wait;
1432 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1433 err = -EAGAIN;
1434 goto __end_lock;
1435 }
1436 init_waitqueue_entry(&wait, current);
1437 add_wait_queue(&ctl->change_sleep, &wait);
1438 set_current_state(TASK_INTERRUPTIBLE);
1439 spin_unlock_irq(&ctl->read_lock);
1440 schedule();
1441 remove_wait_queue(&ctl->change_sleep, &wait);
1442 if (ctl->card->shutdown)
1443 return -ENODEV;
1444 if (signal_pending(current))
1445 return -ERESTARTSYS;
1446 spin_lock_irq(&ctl->read_lock);
1447 }
1448 kev = snd_kctl_event(ctl->events.next);
1449 ev.type = SNDRV_CTL_EVENT_ELEM;
1450 ev.data.elem.mask = kev->mask;
1451 ev.data.elem.id = kev->id;
1452 list_del(&kev->list);
1453 spin_unlock_irq(&ctl->read_lock);
1454 kfree(kev);
1455 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1456 err = -EFAULT;
1457 goto __end;
1458 }
1459 spin_lock_irq(&ctl->read_lock);
1460 buffer += sizeof(struct snd_ctl_event);
1461 count -= sizeof(struct snd_ctl_event);
1462 result += sizeof(struct snd_ctl_event);
1463 }
1464 __end_lock:
1465 spin_unlock_irq(&ctl->read_lock);
1466 __end:
1467 return result > 0 ? result : err;
1468}
1469
1470static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1471{
1472 unsigned int mask;
1473 struct snd_ctl_file *ctl;
1474
1475 ctl = file->private_data;
1476 if (!ctl->subscribed)
1477 return 0;
1478 poll_wait(file, &ctl->change_sleep, wait);
1479
1480 mask = 0;
1481 if (!list_empty(&ctl->events))
1482 mask |= POLLIN | POLLRDNORM;
1483
1484 return mask;
1485}
1486
1487/*
1488 * register the device-specific control-ioctls.
1489 * called from each device manager like pcm.c, hwdep.c, etc.
1490 */
1491static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1492{
1493 struct snd_kctl_ioctl *pn;
1494
1495 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1496 if (pn == NULL)
1497 return -ENOMEM;
1498 pn->fioctl = fcn;
1499 down_write(&snd_ioctl_rwsem);
1500 list_add_tail(&pn->list, lists);
1501 up_write(&snd_ioctl_rwsem);
1502 return 0;
1503}
1504
1505int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1506{
1507 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1508}
1509
1510EXPORT_SYMBOL(snd_ctl_register_ioctl);
1511
1512#ifdef CONFIG_COMPAT
1513int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1514{
1515 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1516}
1517
1518EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1519#endif
1520
1521/*
1522 * de-register the device-specific control-ioctls.
1523 */
1524static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1525 struct list_head *lists)
1526{
1527 struct snd_kctl_ioctl *p;
1528
1529 if (snd_BUG_ON(!fcn))
1530 return -EINVAL;
1531 down_write(&snd_ioctl_rwsem);
1532 list_for_each_entry(p, lists, list) {
1533 if (p->fioctl == fcn) {
1534 list_del(&p->list);
1535 up_write(&snd_ioctl_rwsem);
1536 kfree(p);
1537 return 0;
1538 }
1539 }
1540 up_write(&snd_ioctl_rwsem);
1541 snd_BUG();
1542 return -EINVAL;
1543}
1544
1545int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1546{
1547 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1548}
1549
1550EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1551
1552#ifdef CONFIG_COMPAT
1553int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1554{
1555 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1556}
1557
1558EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1559#endif
1560
1561static int snd_ctl_fasync(int fd, struct file * file, int on)
1562{
1563 struct snd_ctl_file *ctl;
1564
1565 ctl = file->private_data;
1566 return fasync_helper(fd, file, on, &ctl->fasync);
1567}
1568
1569/*
1570 * ioctl32 compat
1571 */
1572#ifdef CONFIG_COMPAT
1573#include "control_compat.c"
1574#else
1575#define snd_ctl_ioctl_compat NULL
1576#endif
1577
1578/*
1579 * INIT PART
1580 */
1581
1582static const struct file_operations snd_ctl_f_ops =
1583{
1584 .owner = THIS_MODULE,
1585 .read = snd_ctl_read,
1586 .open = snd_ctl_open,
1587 .release = snd_ctl_release,
1588 .llseek = no_llseek,
1589 .poll = snd_ctl_poll,
1590 .unlocked_ioctl = snd_ctl_ioctl,
1591 .compat_ioctl = snd_ctl_ioctl_compat,
1592 .fasync = snd_ctl_fasync,
1593};
1594
1595/*
1596 * registration of the control device
1597 */
1598static int snd_ctl_dev_register(struct snd_device *device)
1599{
1600 struct snd_card *card = device->device_data;
1601 int err, cardnum;
1602 char name[16];
1603
1604 if (snd_BUG_ON(!card))
1605 return -ENXIO;
1606 cardnum = card->number;
1607 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1608 return -ENXIO;
1609 sprintf(name, "controlC%i", cardnum);
1610 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1611 &snd_ctl_f_ops, card, name)) < 0)
1612 return err;
1613 return 0;
1614}
1615
1616/*
1617 * disconnection of the control device
1618 */
1619static int snd_ctl_dev_disconnect(struct snd_device *device)
1620{
1621 struct snd_card *card = device->device_data;
1622 struct snd_ctl_file *ctl;
1623 int err, cardnum;
1624
1625 if (snd_BUG_ON(!card))
1626 return -ENXIO;
1627 cardnum = card->number;
1628 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1629 return -ENXIO;
1630
1631 read_lock(&card->ctl_files_rwlock);
1632 list_for_each_entry(ctl, &card->ctl_files, list) {
1633 wake_up(&ctl->change_sleep);
1634 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1635 }
1636 read_unlock(&card->ctl_files_rwlock);
1637
1638 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1639 card, -1)) < 0)
1640 return err;
1641 return 0;
1642}
1643
1644/*
1645 * free all controls
1646 */
1647static int snd_ctl_dev_free(struct snd_device *device)
1648{
1649 struct snd_card *card = device->device_data;
1650 struct snd_kcontrol *control;
1651
1652 down_write(&card->controls_rwsem);
1653 while (!list_empty(&card->controls)) {
1654 control = snd_kcontrol(card->controls.next);
1655 snd_ctl_remove(card, control);
1656 }
1657 up_write(&card->controls_rwsem);
1658 return 0;
1659}
1660
1661/*
1662 * create control core:
1663 * called from init.c
1664 */
1665int snd_ctl_create(struct snd_card *card)
1666{
1667 static struct snd_device_ops ops = {
1668 .dev_free = snd_ctl_dev_free,
1669 .dev_register = snd_ctl_dev_register,
1670 .dev_disconnect = snd_ctl_dev_disconnect,
1671 };
1672
1673 if (snd_BUG_ON(!card))
1674 return -ENXIO;
1675 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1676}
1677
1678/*
1679 * Frequently used control callbacks/helpers
1680 */
1681int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1682 struct snd_ctl_elem_info *uinfo)
1683{
1684 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1685 uinfo->count = 1;
1686 uinfo->value.integer.min = 0;
1687 uinfo->value.integer.max = 1;
1688 return 0;
1689}
1690
1691EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1692
1693int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1694 struct snd_ctl_elem_info *uinfo)
1695{
1696 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1697 uinfo->count = 2;
1698 uinfo->value.integer.min = 0;
1699 uinfo->value.integer.max = 1;
1700 return 0;
1701}
1702
1703EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1704
1705/**
1706 * snd_ctl_enum_info - fills the info structure for an enumerated control
1707 * @info: the structure to be filled
1708 * @channels: the number of the control's channels; often one
1709 * @items: the number of control values; also the size of @names
1710 * @names: an array containing the names of all control values
1711 *
1712 * Sets all required fields in @info to their appropriate values.
1713 * If the control's accessibility is not the default (readable and writable),
1714 * the caller has to fill @info->access.
1715 *
1716 * Return: Zero.
1717 */
1718int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1719 unsigned int items, const char *const names[])
1720{
1721 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1722 info->count = channels;
1723 info->value.enumerated.items = items;
1724 if (info->value.enumerated.item >= items)
1725 info->value.enumerated.item = items - 1;
1726 strlcpy(info->value.enumerated.name,
1727 names[info->value.enumerated.item],
1728 sizeof(info->value.enumerated.name));
1729 return 0;
1730}
1731EXPORT_SYMBOL(snd_ctl_enum_info);