2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
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>
33 /* max number of user-defined controls */
34 #define MAX_USER_CONTROLS 32
35 #define MAX_CONTROL_COUNT 1028
37 struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
42 static DECLARE_RWSEM(snd_ioctl_rwsem);
43 static LIST_HEAD(snd_control_ioctls);
45 static LIST_HEAD(snd_control_compat_ioctls);
48 static int snd_ctl_open(struct inode *inode, struct file *file)
51 struct snd_card *card;
52 struct snd_ctl_file *ctl;
55 err = nonseekable_open(inode, file);
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
64 err = snd_card_file_add(card, file);
69 if (!try_module_get(card->module)) {
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
78 INIT_LIST_HEAD(&ctl->events);
79 init_waitqueue_head(&ctl->change_sleep);
80 spin_lock_init(&ctl->read_lock);
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);
92 module_put(card->module);
94 snd_card_file_remove(card, file);
99 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
102 struct snd_kctl_event *cread;
104 spin_lock_irqsave(&ctl->read_lock, flags);
105 while (!list_empty(&ctl->events)) {
106 cread = snd_kctl_event(ctl->events.next);
107 list_del(&cread->list);
110 spin_unlock_irqrestore(&ctl->read_lock, flags);
113 static int snd_ctl_release(struct inode *inode, struct file *file)
116 struct snd_card *card;
117 struct snd_ctl_file *ctl;
118 struct snd_kcontrol *control;
121 ctl = file->private_data;
122 file->private_data = NULL;
124 write_lock_irqsave(&card->ctl_files_rwlock, flags);
125 list_del(&ctl->list);
126 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
127 down_write(&card->controls_rwsem);
128 list_for_each_entry(control, &card->controls, list)
129 for (idx = 0; idx < control->count; idx++)
130 if (control->vd[idx].owner == ctl)
131 control->vd[idx].owner = NULL;
132 up_write(&card->controls_rwsem);
133 snd_ctl_empty_read_queue(ctl);
136 module_put(card->module);
137 snd_card_file_remove(card, file);
141 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
142 struct snd_ctl_elem_id *id)
145 struct snd_ctl_file *ctl;
146 struct snd_kctl_event *ev;
148 if (snd_BUG_ON(!card || !id))
150 read_lock(&card->ctl_files_rwlock);
151 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
152 card->mixer_oss_change_count++;
154 list_for_each_entry(ctl, &card->ctl_files, list) {
155 if (!ctl->subscribed)
157 spin_lock_irqsave(&ctl->read_lock, flags);
158 list_for_each_entry(ev, &ctl->events, list) {
159 if (ev->id.numid == id->numid) {
164 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
168 list_add_tail(&ev->list, &ctl->events);
170 snd_printk(KERN_ERR "No memory available to allocate event\n");
173 wake_up(&ctl->change_sleep);
174 spin_unlock_irqrestore(&ctl->read_lock, flags);
175 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
177 read_unlock(&card->ctl_files_rwlock);
180 EXPORT_SYMBOL(snd_ctl_notify);
183 * snd_ctl_new - create a control instance from the template
184 * @control: the control template
185 * @access: the default control access
187 * Allocates a new struct snd_kcontrol instance and copies the given template
188 * to the new instance. It does not copy volatile data (access).
190 * Returns the pointer of the new instance, or NULL on failure.
192 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
195 struct snd_kcontrol *kctl;
198 if (snd_BUG_ON(!control || !control->count))
201 if (control->count > MAX_CONTROL_COUNT)
204 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
206 snd_printk(KERN_ERR "Cannot allocate control instance\n");
210 for (idx = 0; idx < kctl->count; idx++)
211 kctl->vd[idx].access = access;
216 * snd_ctl_new1 - create a control instance from the template
217 * @ncontrol: the initialization record
218 * @private_data: the private data to set
220 * Allocates a new struct snd_kcontrol instance and initialize from the given
221 * template. When the access field of ncontrol is 0, it's assumed as
222 * READWRITE access. When the count field is 0, it's assumes as one.
224 * Returns the pointer of the newly generated instance, or NULL on failure.
226 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
229 struct snd_kcontrol kctl;
232 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
234 memset(&kctl, 0, sizeof(kctl));
235 kctl.id.iface = ncontrol->iface;
236 kctl.id.device = ncontrol->device;
237 kctl.id.subdevice = ncontrol->subdevice;
238 if (ncontrol->name) {
239 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
240 if (strcmp(ncontrol->name, kctl.id.name) != 0)
241 snd_printk(KERN_WARNING
242 "Control name '%s' truncated to '%s'\n",
243 ncontrol->name, kctl.id.name);
245 kctl.id.index = ncontrol->index;
246 kctl.count = ncontrol->count ? ncontrol->count : 1;
247 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
248 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
249 SNDRV_CTL_ELEM_ACCESS_VOLATILE|
250 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
251 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
252 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
253 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
254 kctl.info = ncontrol->info;
255 kctl.get = ncontrol->get;
256 kctl.put = ncontrol->put;
257 kctl.tlv.p = ncontrol->tlv.p;
258 kctl.private_value = ncontrol->private_value;
259 kctl.private_data = private_data;
260 return snd_ctl_new(&kctl, access);
263 EXPORT_SYMBOL(snd_ctl_new1);
266 * snd_ctl_free_one - release the control instance
267 * @kcontrol: the control instance
269 * Releases the control instance created via snd_ctl_new()
271 * Don't call this after the control was added to the card.
273 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
276 if (kcontrol->private_free)
277 kcontrol->private_free(kcontrol);
282 EXPORT_SYMBOL(snd_ctl_free_one);
284 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
287 struct snd_kcontrol *kctl;
289 list_for_each_entry(kctl, &card->controls, list) {
290 if (kctl->id.numid < card->last_numid + 1 + count &&
291 kctl->id.numid + kctl->count > card->last_numid + 1) {
292 card->last_numid = kctl->id.numid + kctl->count - 1;
299 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
301 unsigned int iter = 100000;
303 while (snd_ctl_remove_numid_conflict(card, count)) {
305 /* this situation is very unlikely */
306 snd_printk(KERN_ERR "unable to allocate new control numid\n");
314 * snd_ctl_add - add the control instance to the card
315 * @card: the card instance
316 * @kcontrol: the control instance to add
318 * Adds the control instance created via snd_ctl_new() or
319 * snd_ctl_new1() to the given card. Assigns also an unique
320 * numid used for fast search.
322 * Returns zero if successful, or a negative error code on failure.
324 * It frees automatically the control which cannot be added.
326 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
328 struct snd_ctl_elem_id id;
334 if (snd_BUG_ON(!card || !kcontrol->info))
337 down_write(&card->controls_rwsem);
338 if (snd_ctl_find_id(card, &id)) {
339 up_write(&card->controls_rwsem);
340 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
349 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
350 up_write(&card->controls_rwsem);
354 list_add_tail(&kcontrol->list, &card->controls);
355 card->controls_count += kcontrol->count;
356 kcontrol->id.numid = card->last_numid + 1;
357 card->last_numid += kcontrol->count;
358 up_write(&card->controls_rwsem);
359 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
360 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
364 snd_ctl_free_one(kcontrol);
368 EXPORT_SYMBOL(snd_ctl_add);
371 * snd_ctl_replace - replace the control instance of the card
372 * @card: the card instance
373 * @kcontrol: the control instance to replace
374 * @add_on_replace: add the control if not already added
376 * Replaces the given control. If the given control does not exist
377 * and the add_on_replace flag is set, the control is added. If the
378 * control exists, it is destroyed first.
380 * Returns zero if successful, or a negative error code on failure.
382 * It frees automatically the control which cannot be added or replaced.
384 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
387 struct snd_ctl_elem_id id;
389 struct snd_kcontrol *old;
394 if (snd_BUG_ON(!card || !kcontrol->info)) {
399 down_write(&card->controls_rwsem);
400 old = snd_ctl_find_id(card, &id);
404 up_write(&card->controls_rwsem);
408 ret = snd_ctl_remove(card, old);
410 up_write(&card->controls_rwsem);
414 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
415 up_write(&card->controls_rwsem);
419 list_add_tail(&kcontrol->list, &card->controls);
420 card->controls_count += kcontrol->count;
421 kcontrol->id.numid = card->last_numid + 1;
422 card->last_numid += kcontrol->count;
423 up_write(&card->controls_rwsem);
424 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
425 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
429 snd_ctl_free_one(kcontrol);
432 EXPORT_SYMBOL(snd_ctl_replace);
435 * snd_ctl_remove - remove the control from the card and release it
436 * @card: the card instance
437 * @kcontrol: the control instance to remove
439 * Removes the control from the card and then releases the instance.
440 * You don't need to call snd_ctl_free_one(). You must be in
441 * the write lock - down_write(&card->controls_rwsem).
443 * Returns 0 if successful, or a negative error code on failure.
445 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
447 struct snd_ctl_elem_id id;
450 if (snd_BUG_ON(!card || !kcontrol))
452 list_del(&kcontrol->list);
453 card->controls_count -= kcontrol->count;
455 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
456 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
457 snd_ctl_free_one(kcontrol);
461 EXPORT_SYMBOL(snd_ctl_remove);
464 * snd_ctl_remove_id - remove the control of the given id and release it
465 * @card: the card instance
466 * @id: the control id to remove
468 * Finds the control instance with the given id, removes it from the
469 * card list and releases it.
471 * Returns 0 if successful, or a negative error code on failure.
473 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
475 struct snd_kcontrol *kctl;
478 down_write(&card->controls_rwsem);
479 kctl = snd_ctl_find_id(card, id);
481 up_write(&card->controls_rwsem);
484 ret = snd_ctl_remove(card, kctl);
485 up_write(&card->controls_rwsem);
489 EXPORT_SYMBOL(snd_ctl_remove_id);
492 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
493 * @file: active control handle
494 * @id: the control id to remove
496 * Finds the control instance with the given id, removes it from the
497 * card list and releases it.
499 * Returns 0 if successful, or a negative error code on failure.
501 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
502 struct snd_ctl_elem_id *id)
504 struct snd_card *card = file->card;
505 struct snd_kcontrol *kctl;
508 down_write(&card->controls_rwsem);
509 kctl = snd_ctl_find_id(card, id);
514 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
518 for (idx = 0; idx < kctl->count; idx++)
519 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
523 ret = snd_ctl_remove(card, kctl);
526 card->user_ctl_count--;
528 up_write(&card->controls_rwsem);
533 * snd_ctl_activate_id - activate/inactivate the control of the given id
534 * @card: the card instance
535 * @id: the control id to activate/inactivate
536 * @active: non-zero to activate
538 * Finds the control instance with the given id, and activate or
539 * inactivate the control together with notification, if changed.
541 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
543 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
546 struct snd_kcontrol *kctl;
547 struct snd_kcontrol_volatile *vd;
548 unsigned int index_offset;
551 down_write(&card->controls_rwsem);
552 kctl = snd_ctl_find_id(card, id);
557 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
558 vd = &kctl->vd[index_offset];
561 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
563 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
565 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
567 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
571 up_write(&card->controls_rwsem);
573 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
576 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
579 * snd_ctl_rename_id - replace the id of a control on the card
580 * @card: the card instance
581 * @src_id: the old id
582 * @dst_id: the new id
584 * Finds the control with the old id from the card, and replaces the
585 * id with the new one.
587 * Returns zero if successful, or a negative error code on failure.
589 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
590 struct snd_ctl_elem_id *dst_id)
592 struct snd_kcontrol *kctl;
594 down_write(&card->controls_rwsem);
595 kctl = snd_ctl_find_id(card, src_id);
597 up_write(&card->controls_rwsem);
601 kctl->id.numid = card->last_numid + 1;
602 card->last_numid += kctl->count;
603 up_write(&card->controls_rwsem);
607 EXPORT_SYMBOL(snd_ctl_rename_id);
610 * snd_ctl_find_numid - find the control instance with the given number-id
611 * @card: the card instance
612 * @numid: the number-id to search
614 * Finds the control instance with the given number-id from the card.
616 * Returns the pointer of the instance if found, or NULL if not.
618 * The caller must down card->controls_rwsem before calling this function
619 * (if the race condition can happen).
621 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
623 struct snd_kcontrol *kctl;
625 if (snd_BUG_ON(!card || !numid))
627 list_for_each_entry(kctl, &card->controls, list) {
628 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
634 EXPORT_SYMBOL(snd_ctl_find_numid);
637 * snd_ctl_find_id - find the control instance with the given id
638 * @card: the card instance
639 * @id: the id to search
641 * Finds the control instance with the given id from the card.
643 * Returns the pointer of the instance if found, or NULL if not.
645 * The caller must down card->controls_rwsem before calling this function
646 * (if the race condition can happen).
648 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
649 struct snd_ctl_elem_id *id)
651 struct snd_kcontrol *kctl;
653 if (snd_BUG_ON(!card || !id))
656 return snd_ctl_find_numid(card, id->numid);
657 list_for_each_entry(kctl, &card->controls, list) {
658 if (kctl->id.iface != id->iface)
660 if (kctl->id.device != id->device)
662 if (kctl->id.subdevice != id->subdevice)
664 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
666 if (kctl->id.index > id->index)
668 if (kctl->id.index + kctl->count <= id->index)
675 EXPORT_SYMBOL(snd_ctl_find_id);
677 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
678 unsigned int cmd, void __user *arg)
680 struct snd_ctl_card_info *info;
682 info = kzalloc(sizeof(*info), GFP_KERNEL);
685 down_read(&snd_ioctl_rwsem);
686 info->card = card->number;
687 strlcpy(info->id, card->id, sizeof(info->id));
688 strlcpy(info->driver, card->driver, sizeof(info->driver));
689 strlcpy(info->name, card->shortname, sizeof(info->name));
690 strlcpy(info->longname, card->longname, sizeof(info->longname));
691 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
692 strlcpy(info->components, card->components, sizeof(info->components));
693 up_read(&snd_ioctl_rwsem);
694 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
702 static int snd_ctl_elem_list(struct snd_card *card,
703 struct snd_ctl_elem_list __user *_list)
705 struct list_head *plist;
706 struct snd_ctl_elem_list list;
707 struct snd_kcontrol *kctl;
708 struct snd_ctl_elem_id *dst, *id;
709 unsigned int offset, space, jidx;
711 if (copy_from_user(&list, _list, sizeof(list)))
713 offset = list.offset;
715 /* try limit maximum space */
719 /* allocate temporary buffer for atomic operation */
720 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
723 down_read(&card->controls_rwsem);
724 list.count = card->controls_count;
725 plist = card->controls.next;
726 while (plist != &card->controls) {
729 kctl = snd_kcontrol(plist);
730 if (offset < kctl->count)
732 offset -= kctl->count;
737 while (space > 0 && plist != &card->controls) {
738 kctl = snd_kcontrol(plist);
739 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
740 snd_ctl_build_ioff(id, kctl, jidx);
748 up_read(&card->controls_rwsem);
750 copy_to_user(list.pids, dst,
751 list.used * sizeof(struct snd_ctl_elem_id))) {
757 down_read(&card->controls_rwsem);
758 list.count = card->controls_count;
759 up_read(&card->controls_rwsem);
761 if (copy_to_user(_list, &list, sizeof(list)))
766 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
767 struct snd_ctl_elem_info *info)
769 struct snd_card *card = ctl->card;
770 struct snd_kcontrol *kctl;
771 struct snd_kcontrol_volatile *vd;
772 unsigned int index_offset;
775 down_read(&card->controls_rwsem);
776 kctl = snd_ctl_find_id(card, &info->id);
778 up_read(&card->controls_rwsem);
781 #ifdef CONFIG_SND_DEBUG
784 result = kctl->info(kctl, info);
786 snd_BUG_ON(info->access);
787 index_offset = snd_ctl_get_ioff(kctl, &info->id);
788 vd = &kctl->vd[index_offset];
789 snd_ctl_build_ioff(&info->id, kctl, index_offset);
790 info->access = vd->access;
792 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
793 if (vd->owner == ctl)
794 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
795 info->owner = pid_vnr(vd->owner->pid);
800 up_read(&card->controls_rwsem);
804 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
805 struct snd_ctl_elem_info __user *_info)
807 struct snd_ctl_elem_info info;
810 if (copy_from_user(&info, _info, sizeof(info)))
812 snd_power_lock(ctl->card);
813 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
815 result = snd_ctl_elem_info(ctl, &info);
816 snd_power_unlock(ctl->card);
818 if (copy_to_user(_info, &info, sizeof(info)))
823 static int snd_ctl_elem_read(struct snd_card *card,
824 struct snd_ctl_elem_value *control)
826 struct snd_kcontrol *kctl;
827 struct snd_kcontrol_volatile *vd;
828 unsigned int index_offset;
831 down_read(&card->controls_rwsem);
832 kctl = snd_ctl_find_id(card, &control->id);
836 index_offset = snd_ctl_get_ioff(kctl, &control->id);
837 vd = &kctl->vd[index_offset];
838 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
840 snd_ctl_build_ioff(&control->id, kctl, index_offset);
841 result = kctl->get(kctl, control);
845 up_read(&card->controls_rwsem);
849 static int snd_ctl_elem_read_user(struct snd_card *card,
850 struct snd_ctl_elem_value __user *_control)
852 struct snd_ctl_elem_value *control;
855 control = memdup_user(_control, sizeof(*control));
857 return PTR_ERR(control);
859 snd_power_lock(card);
860 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
862 result = snd_ctl_elem_read(card, control);
863 snd_power_unlock(card);
865 if (copy_to_user(_control, control, sizeof(*control)))
871 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
872 struct snd_ctl_elem_value *control)
874 struct snd_kcontrol *kctl;
875 struct snd_kcontrol_volatile *vd;
876 unsigned int index_offset;
879 down_read(&card->controls_rwsem);
880 kctl = snd_ctl_find_id(card, &control->id);
884 index_offset = snd_ctl_get_ioff(kctl, &control->id);
885 vd = &kctl->vd[index_offset];
886 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
888 (file && vd->owner && vd->owner != file)) {
891 snd_ctl_build_ioff(&control->id, kctl, index_offset);
892 result = kctl->put(kctl, control);
895 up_read(&card->controls_rwsem);
896 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
901 up_read(&card->controls_rwsem);
905 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
906 struct snd_ctl_elem_value __user *_control)
908 struct snd_ctl_elem_value *control;
909 struct snd_card *card;
912 control = memdup_user(_control, sizeof(*control));
914 return PTR_ERR(control);
917 snd_power_lock(card);
918 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
920 result = snd_ctl_elem_write(card, file, control);
921 snd_power_unlock(card);
923 if (copy_to_user(_control, control, sizeof(*control)))
929 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
930 struct snd_ctl_elem_id __user *_id)
932 struct snd_card *card = file->card;
933 struct snd_ctl_elem_id id;
934 struct snd_kcontrol *kctl;
935 struct snd_kcontrol_volatile *vd;
938 if (copy_from_user(&id, _id, sizeof(id)))
940 down_write(&card->controls_rwsem);
941 kctl = snd_ctl_find_id(card, &id);
945 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
946 if (vd->owner != NULL)
953 up_write(&card->controls_rwsem);
957 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
958 struct snd_ctl_elem_id __user *_id)
960 struct snd_card *card = file->card;
961 struct snd_ctl_elem_id id;
962 struct snd_kcontrol *kctl;
963 struct snd_kcontrol_volatile *vd;
966 if (copy_from_user(&id, _id, sizeof(id)))
968 down_write(&card->controls_rwsem);
969 kctl = snd_ctl_find_id(card, &id);
973 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
974 if (vd->owner == NULL)
976 else if (vd->owner != file)
983 up_write(&card->controls_rwsem);
987 struct user_element {
988 struct snd_ctl_elem_info info;
989 void *elem_data; /* element data */
990 unsigned long elem_data_size; /* size of element data in bytes */
991 void *tlv_data; /* TLV data */
992 unsigned long tlv_data_size; /* TLV data size */
993 void *priv_data; /* private data (like strings for enumerated type) */
996 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
997 struct snd_ctl_elem_info *uinfo)
999 struct user_element *ue = kcontrol->private_data;
1005 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1006 struct snd_ctl_elem_info *uinfo)
1008 struct user_element *ue = kcontrol->private_data;
1012 item = uinfo->value.enumerated.item;
1016 item = min(item, uinfo->value.enumerated.items - 1);
1017 uinfo->value.enumerated.item = item;
1019 names = ue->priv_data;
1020 for (; item > 0; --item)
1021 names += strlen(names) + 1;
1022 strcpy(uinfo->value.enumerated.name, names);
1027 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1028 struct snd_ctl_elem_value *ucontrol)
1030 struct user_element *ue = kcontrol->private_data;
1032 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1036 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1037 struct snd_ctl_elem_value *ucontrol)
1040 struct user_element *ue = kcontrol->private_data;
1042 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1044 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1048 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1051 unsigned int __user *tlv)
1053 struct user_element *ue = kcontrol->private_data;
1058 if (size > 1024 * 128) /* sane value */
1061 new_data = memdup_user(tlv, size);
1062 if (IS_ERR(new_data))
1063 return PTR_ERR(new_data);
1064 change = ue->tlv_data_size != size;
1066 change = memcmp(ue->tlv_data, new_data, size);
1067 kfree(ue->tlv_data);
1068 ue->tlv_data = new_data;
1069 ue->tlv_data_size = size;
1071 if (! ue->tlv_data_size || ! ue->tlv_data)
1073 if (size < ue->tlv_data_size)
1075 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1081 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1084 size_t buf_len, name_len;
1086 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1088 if (ue->info.value.enumerated.names_length > 64 * 1024)
1091 names = memdup_user((const void __user *)user_ptrval,
1092 ue->info.value.enumerated.names_length);
1094 return PTR_ERR(names);
1096 /* check that there are enough valid names */
1097 buf_len = ue->info.value.enumerated.names_length;
1099 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1100 name_len = strnlen(p, buf_len);
1101 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1106 buf_len -= name_len + 1;
1109 ue->priv_data = names;
1110 ue->info.value.enumerated.names_ptr = 0;
1115 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1117 struct user_element *ue = kcontrol->private_data;
1119 kfree(ue->tlv_data);
1120 kfree(ue->priv_data);
1124 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1125 struct snd_ctl_elem_info *info, int replace)
1127 struct snd_card *card = file->card;
1128 struct snd_kcontrol kctl, *_kctl;
1129 unsigned int access;
1131 struct user_element *ue;
1134 if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1136 if (info->count < 1)
1138 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1139 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1140 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1141 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1143 memset(&kctl, 0, sizeof(kctl));
1144 down_write(&card->controls_rwsem);
1145 _kctl = snd_ctl_find_id(card, &info->id);
1149 err = snd_ctl_remove(card, _kctl);
1156 up_write(&card->controls_rwsem);
1159 memcpy(&kctl.id, &info->id, sizeof(info->id));
1160 kctl.count = info->owner ? info->owner : 1;
1161 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1162 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1163 kctl.info = snd_ctl_elem_user_enum_info;
1165 kctl.info = snd_ctl_elem_user_info;
1166 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1167 kctl.get = snd_ctl_elem_user_get;
1168 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1169 kctl.put = snd_ctl_elem_user_put;
1170 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1171 kctl.tlv.c = snd_ctl_elem_user_tlv;
1172 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1174 switch (info->type) {
1175 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1176 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1177 private_size = sizeof(long);
1178 if (info->count > 128)
1181 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1182 private_size = sizeof(long long);
1183 if (info->count > 64)
1186 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1187 private_size = sizeof(unsigned int);
1188 if (info->count > 128 || info->value.enumerated.items == 0)
1191 case SNDRV_CTL_ELEM_TYPE_BYTES:
1192 private_size = sizeof(unsigned char);
1193 if (info->count > 512)
1196 case SNDRV_CTL_ELEM_TYPE_IEC958:
1197 private_size = sizeof(struct snd_aes_iec958);
1198 if (info->count != 1)
1204 private_size *= info->count;
1205 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1209 ue->info.access = 0;
1210 ue->elem_data = (char *)ue + sizeof(*ue);
1211 ue->elem_data_size = private_size;
1212 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1213 err = snd_ctl_elem_init_enum_names(ue);
1219 kctl.private_free = snd_ctl_elem_user_free;
1220 _kctl = snd_ctl_new(&kctl, access);
1221 if (_kctl == NULL) {
1222 kfree(ue->priv_data);
1226 _kctl->private_data = ue;
1227 for (idx = 0; idx < _kctl->count; idx++)
1228 _kctl->vd[idx].owner = file;
1229 err = snd_ctl_add(card, _kctl);
1233 down_write(&card->controls_rwsem);
1234 card->user_ctl_count++;
1235 up_write(&card->controls_rwsem);
1240 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1241 struct snd_ctl_elem_info __user *_info, int replace)
1243 struct snd_ctl_elem_info info;
1244 if (copy_from_user(&info, _info, sizeof(info)))
1246 return snd_ctl_elem_add(file, &info, replace);
1249 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1250 struct snd_ctl_elem_id __user *_id)
1252 struct snd_ctl_elem_id id;
1254 if (copy_from_user(&id, _id, sizeof(id)))
1256 return snd_ctl_remove_user_ctl(file, &id);
1259 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1262 if (get_user(subscribe, ptr))
1264 if (subscribe < 0) {
1265 subscribe = file->subscribed;
1266 if (put_user(subscribe, ptr))
1271 file->subscribed = 1;
1273 } else if (file->subscribed) {
1274 snd_ctl_empty_read_queue(file);
1275 file->subscribed = 0;
1280 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1281 struct snd_ctl_tlv __user *_tlv,
1284 struct snd_card *card = file->card;
1285 struct snd_ctl_tlv tlv;
1286 struct snd_kcontrol *kctl;
1287 struct snd_kcontrol_volatile *vd;
1291 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1293 if (tlv.length < sizeof(unsigned int) * 2)
1295 down_read(&card->controls_rwsem);
1296 kctl = snd_ctl_find_numid(card, tlv.numid);
1301 if (kctl->tlv.p == NULL) {
1305 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1306 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1307 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1308 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1312 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1313 if (vd->owner != NULL && vd->owner != file) {
1317 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1319 up_read(&card->controls_rwsem);
1320 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1328 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1329 if (tlv.length < len) {
1333 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1337 up_read(&card->controls_rwsem);
1341 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1343 struct snd_ctl_file *ctl;
1344 struct snd_card *card;
1345 struct snd_kctl_ioctl *p;
1346 void __user *argp = (void __user *)arg;
1347 int __user *ip = argp;
1350 ctl = file->private_data;
1352 if (snd_BUG_ON(!card))
1355 case SNDRV_CTL_IOCTL_PVERSION:
1356 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1357 case SNDRV_CTL_IOCTL_CARD_INFO:
1358 return snd_ctl_card_info(card, ctl, cmd, argp);
1359 case SNDRV_CTL_IOCTL_ELEM_LIST:
1360 return snd_ctl_elem_list(card, argp);
1361 case SNDRV_CTL_IOCTL_ELEM_INFO:
1362 return snd_ctl_elem_info_user(ctl, argp);
1363 case SNDRV_CTL_IOCTL_ELEM_READ:
1364 return snd_ctl_elem_read_user(card, argp);
1365 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1366 return snd_ctl_elem_write_user(ctl, argp);
1367 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1368 return snd_ctl_elem_lock(ctl, argp);
1369 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1370 return snd_ctl_elem_unlock(ctl, argp);
1371 case SNDRV_CTL_IOCTL_ELEM_ADD:
1372 return snd_ctl_elem_add_user(ctl, argp, 0);
1373 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1374 return snd_ctl_elem_add_user(ctl, argp, 1);
1375 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1376 return snd_ctl_elem_remove(ctl, argp);
1377 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1378 return snd_ctl_subscribe_events(ctl, ip);
1379 case SNDRV_CTL_IOCTL_TLV_READ:
1380 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1381 case SNDRV_CTL_IOCTL_TLV_WRITE:
1382 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1383 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1384 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1385 case SNDRV_CTL_IOCTL_POWER:
1386 return -ENOPROTOOPT;
1387 case SNDRV_CTL_IOCTL_POWER_STATE:
1389 return put_user(card->power_state, ip) ? -EFAULT : 0;
1391 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1394 down_read(&snd_ioctl_rwsem);
1395 list_for_each_entry(p, &snd_control_ioctls, list) {
1396 err = p->fioctl(card, ctl, cmd, arg);
1397 if (err != -ENOIOCTLCMD) {
1398 up_read(&snd_ioctl_rwsem);
1402 up_read(&snd_ioctl_rwsem);
1403 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1407 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1408 size_t count, loff_t * offset)
1410 struct snd_ctl_file *ctl;
1414 ctl = file->private_data;
1415 if (snd_BUG_ON(!ctl || !ctl->card))
1417 if (!ctl->subscribed)
1419 if (count < sizeof(struct snd_ctl_event))
1421 spin_lock_irq(&ctl->read_lock);
1422 while (count >= sizeof(struct snd_ctl_event)) {
1423 struct snd_ctl_event ev;
1424 struct snd_kctl_event *kev;
1425 while (list_empty(&ctl->events)) {
1427 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1431 init_waitqueue_entry(&wait, current);
1432 add_wait_queue(&ctl->change_sleep, &wait);
1433 set_current_state(TASK_INTERRUPTIBLE);
1434 spin_unlock_irq(&ctl->read_lock);
1436 remove_wait_queue(&ctl->change_sleep, &wait);
1437 if (signal_pending(current))
1438 return -ERESTARTSYS;
1439 spin_lock_irq(&ctl->read_lock);
1441 kev = snd_kctl_event(ctl->events.next);
1442 ev.type = SNDRV_CTL_EVENT_ELEM;
1443 ev.data.elem.mask = kev->mask;
1444 ev.data.elem.id = kev->id;
1445 list_del(&kev->list);
1446 spin_unlock_irq(&ctl->read_lock);
1448 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1452 spin_lock_irq(&ctl->read_lock);
1453 buffer += sizeof(struct snd_ctl_event);
1454 count -= sizeof(struct snd_ctl_event);
1455 result += sizeof(struct snd_ctl_event);
1458 spin_unlock_irq(&ctl->read_lock);
1460 return result > 0 ? result : err;
1463 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1466 struct snd_ctl_file *ctl;
1468 ctl = file->private_data;
1469 if (!ctl->subscribed)
1471 poll_wait(file, &ctl->change_sleep, wait);
1474 if (!list_empty(&ctl->events))
1475 mask |= POLLIN | POLLRDNORM;
1481 * register the device-specific control-ioctls.
1482 * called from each device manager like pcm.c, hwdep.c, etc.
1484 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1486 struct snd_kctl_ioctl *pn;
1488 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1492 down_write(&snd_ioctl_rwsem);
1493 list_add_tail(&pn->list, lists);
1494 up_write(&snd_ioctl_rwsem);
1498 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1500 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1503 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1505 #ifdef CONFIG_COMPAT
1506 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1508 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1511 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1515 * de-register the device-specific control-ioctls.
1517 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1518 struct list_head *lists)
1520 struct snd_kctl_ioctl *p;
1522 if (snd_BUG_ON(!fcn))
1524 down_write(&snd_ioctl_rwsem);
1525 list_for_each_entry(p, lists, list) {
1526 if (p->fioctl == fcn) {
1528 up_write(&snd_ioctl_rwsem);
1533 up_write(&snd_ioctl_rwsem);
1538 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1540 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1543 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1545 #ifdef CONFIG_COMPAT
1546 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1548 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1551 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1554 static int snd_ctl_fasync(int fd, struct file * file, int on)
1556 struct snd_ctl_file *ctl;
1558 ctl = file->private_data;
1559 return fasync_helper(fd, file, on, &ctl->fasync);
1565 #ifdef CONFIG_COMPAT
1566 #include "control_compat.c"
1568 #define snd_ctl_ioctl_compat NULL
1575 static const struct file_operations snd_ctl_f_ops =
1577 .owner = THIS_MODULE,
1578 .read = snd_ctl_read,
1579 .open = snd_ctl_open,
1580 .release = snd_ctl_release,
1581 .llseek = no_llseek,
1582 .poll = snd_ctl_poll,
1583 .unlocked_ioctl = snd_ctl_ioctl,
1584 .compat_ioctl = snd_ctl_ioctl_compat,
1585 .fasync = snd_ctl_fasync,
1589 * registration of the control device
1591 static int snd_ctl_dev_register(struct snd_device *device)
1593 struct snd_card *card = device->device_data;
1597 if (snd_BUG_ON(!card))
1599 cardnum = card->number;
1600 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1602 sprintf(name, "controlC%i", cardnum);
1603 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1604 &snd_ctl_f_ops, card, name)) < 0)
1610 * disconnection of the control device
1612 static int snd_ctl_dev_disconnect(struct snd_device *device)
1614 struct snd_card *card = device->device_data;
1615 struct snd_ctl_file *ctl;
1618 if (snd_BUG_ON(!card))
1620 cardnum = card->number;
1621 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1624 read_lock(&card->ctl_files_rwlock);
1625 list_for_each_entry(ctl, &card->ctl_files, list) {
1626 wake_up(&ctl->change_sleep);
1627 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1629 read_unlock(&card->ctl_files_rwlock);
1631 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1640 static int snd_ctl_dev_free(struct snd_device *device)
1642 struct snd_card *card = device->device_data;
1643 struct snd_kcontrol *control;
1645 down_write(&card->controls_rwsem);
1646 while (!list_empty(&card->controls)) {
1647 control = snd_kcontrol(card->controls.next);
1648 snd_ctl_remove(card, control);
1650 up_write(&card->controls_rwsem);
1655 * create control core:
1656 * called from init.c
1658 int snd_ctl_create(struct snd_card *card)
1660 static struct snd_device_ops ops = {
1661 .dev_free = snd_ctl_dev_free,
1662 .dev_register = snd_ctl_dev_register,
1663 .dev_disconnect = snd_ctl_dev_disconnect,
1666 if (snd_BUG_ON(!card))
1668 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1672 * Frequently used control callbacks/helpers
1674 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1675 struct snd_ctl_elem_info *uinfo)
1677 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1679 uinfo->value.integer.min = 0;
1680 uinfo->value.integer.max = 1;
1684 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1686 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1687 struct snd_ctl_elem_info *uinfo)
1689 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1691 uinfo->value.integer.min = 0;
1692 uinfo->value.integer.max = 1;
1696 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1699 * snd_ctl_enum_info - fills the info structure for an enumerated control
1700 * @info: the structure to be filled
1701 * @channels: the number of the control's channels; often one
1702 * @items: the number of control values; also the size of @names
1703 * @names: an array containing the names of all control values
1705 * Sets all required fields in @info to their appropriate values.
1706 * If the control's accessibility is not the default (readable and writable),
1707 * the caller has to fill @info->access.
1709 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1710 unsigned int items, const char *const names[])
1712 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1713 info->count = channels;
1714 info->value.enumerated.items = items;
1715 if (info->value.enumerated.item >= items)
1716 info->value.enumerated.item = items - 1;
1717 strlcpy(info->value.enumerated.name,
1718 names[info->value.enumerated.item],
1719 sizeof(info->value.enumerated.name));
1722 EXPORT_SYMBOL(snd_ctl_enum_info);