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 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
83 ctl->preferred_subdevice[i] = -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);
93 module_put(card->module);
95 snd_card_file_remove(card, file);
102 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
105 struct snd_kctl_event *cread;
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);
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
116 static int snd_ctl_release(struct inode *inode, struct file *file)
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
124 ctl = file->private_data;
125 file->private_data = NULL;
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);
139 module_put(card->module);
140 snd_card_file_remove(card, file);
145 * snd_ctl_notify - Send notification to user-space for a control change
146 * @card: the card to send notification
147 * @mask: the event mask, SNDRV_CTL_EVENT_*
148 * @id: the ctl element id to send notification
150 * This function adds an event record with the given id and mask, appends
151 * to the list and wakes up the user-space for notification. This can be
152 * called in the atomic context.
154 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
155 struct snd_ctl_elem_id *id)
158 struct snd_ctl_file *ctl;
159 struct snd_kctl_event *ev;
161 if (snd_BUG_ON(!card || !id))
165 read_lock(&card->ctl_files_rwlock);
166 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
167 card->mixer_oss_change_count++;
169 list_for_each_entry(ctl, &card->ctl_files, list) {
170 if (!ctl->subscribed)
172 spin_lock_irqsave(&ctl->read_lock, flags);
173 list_for_each_entry(ev, &ctl->events, list) {
174 if (ev->id.numid == id->numid) {
179 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
183 list_add_tail(&ev->list, &ctl->events);
185 dev_err(card->dev, "No memory available to allocate event\n");
188 wake_up(&ctl->change_sleep);
189 spin_unlock_irqrestore(&ctl->read_lock, flags);
190 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
192 read_unlock(&card->ctl_files_rwlock);
194 EXPORT_SYMBOL(snd_ctl_notify);
197 * snd_ctl_new - create a new control instance with some elements
198 * @kctl: the pointer to store new control instance
199 * @count: the number of elements in this control
200 * @access: the default access flags for elements in this control
201 * @file: given when locking these elements
203 * Allocates a memory object for a new control instance. The instance has
204 * elements as many as the given number (@count). Each element has given
205 * access permissions (@access). Each element is locked when @file is given.
207 * Return: 0 on success, error code on failure
209 static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
210 unsigned int access, struct snd_ctl_file *file)
215 if (count == 0 || count > MAX_CONTROL_COUNT)
218 size = sizeof(struct snd_kcontrol);
219 size += sizeof(struct snd_kcontrol_volatile) * count;
221 *kctl = kzalloc(size, GFP_KERNEL);
225 for (idx = 0; idx < count; idx++) {
226 (*kctl)->vd[idx].access = access;
227 (*kctl)->vd[idx].owner = file;
229 (*kctl)->count = count;
235 * snd_ctl_new1 - create a control instance from the template
236 * @ncontrol: the initialization record
237 * @private_data: the private data to set
239 * Allocates a new struct snd_kcontrol instance and initialize from the given
240 * template. When the access field of ncontrol is 0, it's assumed as
241 * READWRITE access. When the count field is 0, it's assumes as one.
243 * Return: The pointer of the newly generated instance, or %NULL on failure.
245 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
248 struct snd_kcontrol *kctl;
253 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
256 count = ncontrol->count;
260 access = ncontrol->access;
262 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
263 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
264 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
265 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
266 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
267 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
268 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
270 err = snd_ctl_new(&kctl, count, access, NULL);
274 /* The 'numid' member is decided when calling snd_ctl_add(). */
275 kctl->id.iface = ncontrol->iface;
276 kctl->id.device = ncontrol->device;
277 kctl->id.subdevice = ncontrol->subdevice;
278 if (ncontrol->name) {
279 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
280 if (strcmp(ncontrol->name, kctl->id.name) != 0)
281 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
282 ncontrol->name, kctl->id.name);
284 kctl->id.index = ncontrol->index;
286 kctl->info = ncontrol->info;
287 kctl->get = ncontrol->get;
288 kctl->put = ncontrol->put;
289 kctl->tlv.p = ncontrol->tlv.p;
291 kctl->private_value = ncontrol->private_value;
292 kctl->private_data = private_data;
296 EXPORT_SYMBOL(snd_ctl_new1);
299 * snd_ctl_free_one - release the control instance
300 * @kcontrol: the control instance
302 * Releases the control instance created via snd_ctl_new()
304 * Don't call this after the control was added to the card.
306 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
309 if (kcontrol->private_free)
310 kcontrol->private_free(kcontrol);
314 EXPORT_SYMBOL(snd_ctl_free_one);
316 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
319 struct snd_kcontrol *kctl;
321 /* Make sure that the ids assigned to the control do not wrap around */
322 if (card->last_numid >= UINT_MAX - count)
323 card->last_numid = 0;
325 list_for_each_entry(kctl, &card->controls, list) {
326 if (kctl->id.numid < card->last_numid + 1 + count &&
327 kctl->id.numid + kctl->count > card->last_numid + 1) {
328 card->last_numid = kctl->id.numid + kctl->count - 1;
335 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
337 unsigned int iter = 100000;
339 while (snd_ctl_remove_numid_conflict(card, count)) {
341 /* this situation is very unlikely */
342 dev_err(card->dev, "unable to allocate new control numid\n");
349 /* add a new kcontrol object; call with card->controls_rwsem locked */
350 static int __snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
352 struct snd_ctl_elem_id id;
357 if (id.index > UINT_MAX - kcontrol->count)
360 if (snd_ctl_find_id(card, &id)) {
362 "control %i:%i:%i:%s:%i is already present\n",
363 id.iface, id.device, id.subdevice, id.name, id.index);
367 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
370 list_add_tail(&kcontrol->list, &card->controls);
371 card->controls_count += kcontrol->count;
372 kcontrol->id.numid = card->last_numid + 1;
373 card->last_numid += kcontrol->count;
376 count = kcontrol->count;
377 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
378 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
384 * snd_ctl_add - add the control instance to the card
385 * @card: the card instance
386 * @kcontrol: the control instance to add
388 * Adds the control instance created via snd_ctl_new() or
389 * snd_ctl_new1() to the given card. Assigns also an unique
390 * numid used for fast search.
392 * It frees automatically the control which cannot be added.
394 * Return: Zero if successful, or a negative error code on failure.
397 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
403 if (snd_BUG_ON(!card || !kcontrol->info))
406 down_write(&card->controls_rwsem);
407 err = __snd_ctl_add(card, kcontrol);
408 up_write(&card->controls_rwsem);
414 snd_ctl_free_one(kcontrol);
417 EXPORT_SYMBOL(snd_ctl_add);
420 * snd_ctl_replace - replace the control instance of the card
421 * @card: the card instance
422 * @kcontrol: the control instance to replace
423 * @add_on_replace: add the control if not already added
425 * Replaces the given control. If the given control does not exist
426 * and the add_on_replace flag is set, the control is added. If the
427 * control exists, it is destroyed first.
429 * It frees automatically the control which cannot be added or replaced.
431 * Return: Zero if successful, or a negative error code on failure.
433 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
436 struct snd_ctl_elem_id id;
439 struct snd_kcontrol *old;
444 if (snd_BUG_ON(!card || !kcontrol->info)) {
449 down_write(&card->controls_rwsem);
450 old = snd_ctl_find_id(card, &id);
454 up_write(&card->controls_rwsem);
458 ret = snd_ctl_remove(card, old);
460 up_write(&card->controls_rwsem);
464 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
465 up_write(&card->controls_rwsem);
469 list_add_tail(&kcontrol->list, &card->controls);
470 card->controls_count += kcontrol->count;
471 kcontrol->id.numid = card->last_numid + 1;
472 card->last_numid += kcontrol->count;
474 count = kcontrol->count;
475 up_write(&card->controls_rwsem);
476 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
477 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
481 snd_ctl_free_one(kcontrol);
484 EXPORT_SYMBOL(snd_ctl_replace);
487 * snd_ctl_remove - remove the control from the card and release it
488 * @card: the card instance
489 * @kcontrol: the control instance to remove
491 * Removes the control from the card and then releases the instance.
492 * You don't need to call snd_ctl_free_one(). You must be in
493 * the write lock - down_write(&card->controls_rwsem).
495 * Return: 0 if successful, or a negative error code on failure.
497 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
499 struct snd_ctl_elem_id id;
502 if (snd_BUG_ON(!card || !kcontrol))
504 list_del(&kcontrol->list);
505 card->controls_count -= kcontrol->count;
507 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
508 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
509 snd_ctl_free_one(kcontrol);
512 EXPORT_SYMBOL(snd_ctl_remove);
515 * snd_ctl_remove_id - remove the control of the given id and release it
516 * @card: the card instance
517 * @id: the control id to remove
519 * Finds the control instance with the given id, removes it from the
520 * card list and releases it.
522 * Return: 0 if successful, or a negative error code on failure.
524 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
526 struct snd_kcontrol *kctl;
529 down_write(&card->controls_rwsem);
530 kctl = snd_ctl_find_id(card, id);
532 up_write(&card->controls_rwsem);
535 ret = snd_ctl_remove(card, kctl);
536 up_write(&card->controls_rwsem);
539 EXPORT_SYMBOL(snd_ctl_remove_id);
542 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
543 * @file: active control handle
544 * @id: the control id to remove
546 * Finds the control instance with the given id, removes it from the
547 * card list and releases it.
549 * Return: 0 if successful, or a negative error code on failure.
551 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
552 struct snd_ctl_elem_id *id)
554 struct snd_card *card = file->card;
555 struct snd_kcontrol *kctl;
558 down_write(&card->controls_rwsem);
559 kctl = snd_ctl_find_id(card, id);
564 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
568 for (idx = 0; idx < kctl->count; idx++)
569 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
573 ret = snd_ctl_remove(card, kctl);
576 card->user_ctl_count--;
578 up_write(&card->controls_rwsem);
583 * snd_ctl_activate_id - activate/inactivate the control of the given id
584 * @card: the card instance
585 * @id: the control id to activate/inactivate
586 * @active: non-zero to activate
588 * Finds the control instance with the given id, and activate or
589 * inactivate the control together with notification, if changed.
590 * The given ID data is filled with full information.
592 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
594 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
597 struct snd_kcontrol *kctl;
598 struct snd_kcontrol_volatile *vd;
599 unsigned int index_offset;
602 down_write(&card->controls_rwsem);
603 kctl = snd_ctl_find_id(card, id);
608 index_offset = snd_ctl_get_ioff(kctl, id);
609 vd = &kctl->vd[index_offset];
612 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
614 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
616 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
618 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
620 snd_ctl_build_ioff(id, kctl, index_offset);
623 up_write(&card->controls_rwsem);
625 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
628 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
631 * snd_ctl_rename_id - replace the id of a control on the card
632 * @card: the card instance
633 * @src_id: the old id
634 * @dst_id: the new id
636 * Finds the control with the old id from the card, and replaces the
637 * id with the new one.
639 * Return: Zero if successful, or a negative error code on failure.
641 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
642 struct snd_ctl_elem_id *dst_id)
644 struct snd_kcontrol *kctl;
646 down_write(&card->controls_rwsem);
647 kctl = snd_ctl_find_id(card, src_id);
649 up_write(&card->controls_rwsem);
653 kctl->id.numid = card->last_numid + 1;
654 card->last_numid += kctl->count;
655 up_write(&card->controls_rwsem);
658 EXPORT_SYMBOL(snd_ctl_rename_id);
661 * snd_ctl_find_numid - find the control instance with the given number-id
662 * @card: the card instance
663 * @numid: the number-id to search
665 * Finds the control instance with the given number-id from the card.
667 * The caller must down card->controls_rwsem before calling this function
668 * (if the race condition can happen).
670 * Return: The pointer of the instance if found, or %NULL if not.
673 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
675 struct snd_kcontrol *kctl;
677 if (snd_BUG_ON(!card || !numid))
679 list_for_each_entry(kctl, &card->controls, list) {
680 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
685 EXPORT_SYMBOL(snd_ctl_find_numid);
688 * snd_ctl_find_id - find the control instance with the given id
689 * @card: the card instance
690 * @id: the id to search
692 * Finds the control instance with the given id from the card.
694 * The caller must down card->controls_rwsem before calling this function
695 * (if the race condition can happen).
697 * Return: The pointer of the instance if found, or %NULL if not.
700 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
701 struct snd_ctl_elem_id *id)
703 struct snd_kcontrol *kctl;
705 if (snd_BUG_ON(!card || !id))
708 return snd_ctl_find_numid(card, id->numid);
709 list_for_each_entry(kctl, &card->controls, list) {
710 if (kctl->id.iface != id->iface)
712 if (kctl->id.device != id->device)
714 if (kctl->id.subdevice != id->subdevice)
716 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
718 if (kctl->id.index > id->index)
720 if (kctl->id.index + kctl->count <= id->index)
726 EXPORT_SYMBOL(snd_ctl_find_id);
728 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
729 unsigned int cmd, void __user *arg)
731 struct snd_ctl_card_info *info;
733 info = kzalloc(sizeof(*info), GFP_KERNEL);
736 down_read(&snd_ioctl_rwsem);
737 info->card = card->number;
738 strlcpy(info->id, card->id, sizeof(info->id));
739 strlcpy(info->driver, card->driver, sizeof(info->driver));
740 strlcpy(info->name, card->shortname, sizeof(info->name));
741 strlcpy(info->longname, card->longname, sizeof(info->longname));
742 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
743 strlcpy(info->components, card->components, sizeof(info->components));
744 up_read(&snd_ioctl_rwsem);
745 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
753 static int snd_ctl_elem_list(struct snd_card *card,
754 struct snd_ctl_elem_list __user *_list)
756 struct list_head *plist;
757 struct snd_ctl_elem_list list;
758 struct snd_kcontrol *kctl;
759 struct snd_ctl_elem_id *dst, *id;
760 unsigned int offset, space, jidx;
762 if (copy_from_user(&list, _list, sizeof(list)))
764 offset = list.offset;
766 /* try limit maximum space */
770 /* allocate temporary buffer for atomic operation */
771 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
774 down_read(&card->controls_rwsem);
775 list.count = card->controls_count;
776 plist = card->controls.next;
777 while (plist != &card->controls) {
780 kctl = snd_kcontrol(plist);
781 if (offset < kctl->count)
783 offset -= kctl->count;
788 while (space > 0 && plist != &card->controls) {
789 kctl = snd_kcontrol(plist);
790 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
791 snd_ctl_build_ioff(id, kctl, jidx);
799 up_read(&card->controls_rwsem);
801 copy_to_user(list.pids, dst,
802 list.used * sizeof(struct snd_ctl_elem_id))) {
808 down_read(&card->controls_rwsem);
809 list.count = card->controls_count;
810 up_read(&card->controls_rwsem);
812 if (copy_to_user(_list, &list, sizeof(list)))
817 static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
819 unsigned int members;
822 if (info->dimen.d[0] == 0)
826 for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
827 if (info->dimen.d[i] == 0)
829 members *= info->dimen.d[i];
832 * info->count should be validated in advance, to guarantee
833 * calculation soundness.
835 if (members > info->count)
839 for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
840 if (info->dimen.d[i] > 0)
844 return members == info->count;
847 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
848 struct snd_ctl_elem_info *info)
850 struct snd_card *card = ctl->card;
851 struct snd_kcontrol *kctl;
852 struct snd_kcontrol_volatile *vd;
853 unsigned int index_offset;
856 down_read(&card->controls_rwsem);
857 kctl = snd_ctl_find_id(card, &info->id);
859 up_read(&card->controls_rwsem);
862 #ifdef CONFIG_SND_DEBUG
865 result = kctl->info(kctl, info);
867 snd_BUG_ON(info->access);
868 index_offset = snd_ctl_get_ioff(kctl, &info->id);
869 vd = &kctl->vd[index_offset];
870 snd_ctl_build_ioff(&info->id, kctl, index_offset);
871 info->access = vd->access;
873 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
874 if (vd->owner == ctl)
875 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
876 info->owner = pid_vnr(vd->owner->pid);
881 up_read(&card->controls_rwsem);
885 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
886 struct snd_ctl_elem_info __user *_info)
888 struct snd_ctl_elem_info info;
891 if (copy_from_user(&info, _info, sizeof(info)))
893 snd_power_lock(ctl->card);
894 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
896 result = snd_ctl_elem_info(ctl, &info);
897 snd_power_unlock(ctl->card);
899 if (copy_to_user(_info, &info, sizeof(info)))
904 static int snd_ctl_elem_read(struct snd_card *card,
905 struct snd_ctl_elem_value *control)
907 struct snd_kcontrol *kctl;
908 struct snd_kcontrol_volatile *vd;
909 unsigned int index_offset;
912 down_read(&card->controls_rwsem);
913 kctl = snd_ctl_find_id(card, &control->id);
917 index_offset = snd_ctl_get_ioff(kctl, &control->id);
918 vd = &kctl->vd[index_offset];
919 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
921 snd_ctl_build_ioff(&control->id, kctl, index_offset);
922 result = kctl->get(kctl, control);
926 up_read(&card->controls_rwsem);
930 static int snd_ctl_elem_read_user(struct snd_card *card,
931 struct snd_ctl_elem_value __user *_control)
933 struct snd_ctl_elem_value *control;
936 control = memdup_user(_control, sizeof(*control));
938 return PTR_ERR(control);
940 snd_power_lock(card);
941 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
943 result = snd_ctl_elem_read(card, control);
944 snd_power_unlock(card);
946 if (copy_to_user(_control, control, sizeof(*control)))
952 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
953 struct snd_ctl_elem_value *control)
955 struct snd_kcontrol *kctl;
956 struct snd_kcontrol_volatile *vd;
957 unsigned int index_offset;
960 down_read(&card->controls_rwsem);
961 kctl = snd_ctl_find_id(card, &control->id);
965 index_offset = snd_ctl_get_ioff(kctl, &control->id);
966 vd = &kctl->vd[index_offset];
967 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
969 (file && vd->owner && vd->owner != file)) {
972 snd_ctl_build_ioff(&control->id, kctl, index_offset);
973 result = kctl->put(kctl, control);
976 struct snd_ctl_elem_id id = control->id;
977 up_read(&card->controls_rwsem);
978 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
982 up_read(&card->controls_rwsem);
986 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
987 struct snd_ctl_elem_value __user *_control)
989 struct snd_ctl_elem_value *control;
990 struct snd_card *card;
993 control = memdup_user(_control, sizeof(*control));
995 return PTR_ERR(control);
998 snd_power_lock(card);
999 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1001 result = snd_ctl_elem_write(card, file, control);
1002 snd_power_unlock(card);
1004 if (copy_to_user(_control, control, sizeof(*control)))
1010 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1011 struct snd_ctl_elem_id __user *_id)
1013 struct snd_card *card = file->card;
1014 struct snd_ctl_elem_id id;
1015 struct snd_kcontrol *kctl;
1016 struct snd_kcontrol_volatile *vd;
1019 if (copy_from_user(&id, _id, sizeof(id)))
1021 down_write(&card->controls_rwsem);
1022 kctl = snd_ctl_find_id(card, &id);
1026 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1027 if (vd->owner != NULL)
1034 up_write(&card->controls_rwsem);
1038 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1039 struct snd_ctl_elem_id __user *_id)
1041 struct snd_card *card = file->card;
1042 struct snd_ctl_elem_id id;
1043 struct snd_kcontrol *kctl;
1044 struct snd_kcontrol_volatile *vd;
1047 if (copy_from_user(&id, _id, sizeof(id)))
1049 down_write(&card->controls_rwsem);
1050 kctl = snd_ctl_find_id(card, &id);
1054 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1055 if (vd->owner == NULL)
1057 else if (vd->owner != file)
1064 up_write(&card->controls_rwsem);
1068 struct user_element {
1069 struct snd_ctl_elem_info info;
1070 struct snd_card *card;
1071 char *elem_data; /* element data */
1072 unsigned long elem_data_size; /* size of element data in bytes */
1073 void *tlv_data; /* TLV data */
1074 unsigned long tlv_data_size; /* TLV data size */
1075 void *priv_data; /* private data (like strings for enumerated type) */
1078 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1079 struct snd_ctl_elem_info *uinfo)
1081 struct user_element *ue = kcontrol->private_data;
1082 unsigned int offset;
1084 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1086 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1091 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1092 struct snd_ctl_elem_info *uinfo)
1094 struct user_element *ue = kcontrol->private_data;
1097 unsigned int offset;
1099 item = uinfo->value.enumerated.item;
1101 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1103 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1105 item = min(item, uinfo->value.enumerated.items - 1);
1106 uinfo->value.enumerated.item = item;
1108 names = ue->priv_data;
1109 for (; item > 0; --item)
1110 names += strlen(names) + 1;
1111 strcpy(uinfo->value.enumerated.name, names);
1116 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1117 struct snd_ctl_elem_value *ucontrol)
1119 struct user_element *ue = kcontrol->private_data;
1120 unsigned int size = ue->elem_data_size;
1121 char *src = ue->elem_data +
1122 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1124 mutex_lock(&ue->card->user_ctl_lock);
1125 memcpy(&ucontrol->value, src, size);
1126 mutex_unlock(&ue->card->user_ctl_lock);
1130 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1131 struct snd_ctl_elem_value *ucontrol)
1134 struct user_element *ue = kcontrol->private_data;
1135 unsigned int size = ue->elem_data_size;
1136 char *dst = ue->elem_data +
1137 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1139 mutex_lock(&ue->card->user_ctl_lock);
1140 change = memcmp(&ucontrol->value, dst, size) != 0;
1142 memcpy(dst, &ucontrol->value, size);
1143 mutex_unlock(&ue->card->user_ctl_lock);
1147 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1150 unsigned int __user *tlv)
1152 struct user_element *ue = kcontrol->private_data;
1156 if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1157 if (size > 1024 * 128) /* sane value */
1160 new_data = memdup_user(tlv, size);
1161 if (IS_ERR(new_data))
1162 return PTR_ERR(new_data);
1163 mutex_lock(&ue->card->user_ctl_lock);
1164 change = ue->tlv_data_size != size;
1166 change = memcmp(ue->tlv_data, new_data, size) != 0;
1167 kfree(ue->tlv_data);
1168 ue->tlv_data = new_data;
1169 ue->tlv_data_size = size;
1170 mutex_unlock(&ue->card->user_ctl_lock);
1174 mutex_lock(&ue->card->user_ctl_lock);
1175 if (!ue->tlv_data_size || !ue->tlv_data) {
1179 if (size < ue->tlv_data_size) {
1183 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1186 mutex_unlock(&ue->card->user_ctl_lock);
1193 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1196 size_t buf_len, name_len;
1198 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1200 if (ue->info.value.enumerated.names_length > 64 * 1024)
1203 names = memdup_user((const void __user *)user_ptrval,
1204 ue->info.value.enumerated.names_length);
1206 return PTR_ERR(names);
1208 /* check that there are enough valid names */
1209 buf_len = ue->info.value.enumerated.names_length;
1211 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1212 name_len = strnlen(p, buf_len);
1213 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1218 buf_len -= name_len + 1;
1221 ue->priv_data = names;
1222 ue->info.value.enumerated.names_ptr = 0;
1227 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1229 struct user_element *ue = kcontrol->private_data;
1231 kfree(ue->tlv_data);
1232 kfree(ue->priv_data);
1236 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1237 struct snd_ctl_elem_info *info, int replace)
1239 /* The capacity of struct snd_ctl_elem_value.value.*/
1240 static const unsigned int value_sizes[] = {
1241 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1242 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1243 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1244 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1245 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1246 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1248 static const unsigned int max_value_counts[] = {
1249 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1250 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1251 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1252 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1253 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1254 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1256 struct snd_card *card = file->card;
1257 struct snd_kcontrol *kctl;
1259 unsigned int access;
1261 struct user_element *ue;
1262 unsigned int offset;
1265 if (!*info->id.name)
1267 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1270 /* Delete a control to replace them if needed. */
1273 err = snd_ctl_remove_user_ctl(file, &info->id);
1279 * The number of userspace controls are counted control by control,
1280 * not element by element.
1282 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1285 /* Check the number of elements for this userspace control. */
1286 count = info->owner;
1290 /* Arrange access permissions if needed. */
1291 access = info->access;
1293 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1294 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1295 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1296 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
1297 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1298 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1299 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1302 * Check information and calculate the size of data specific to
1303 * this userspace control.
1305 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1306 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1308 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1309 info->value.enumerated.items == 0)
1311 if (info->count < 1 ||
1312 info->count > max_value_counts[info->type])
1314 if (!validate_element_member_dimension(info))
1316 private_size = value_sizes[info->type] * info->count;
1319 * Keep memory object for this userspace control. After passing this
1320 * code block, the instance should be freed by snd_ctl_free_one().
1322 * Note that these elements in this control are locked.
1324 err = snd_ctl_new(&kctl, count, access, file);
1327 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1328 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1330 if (kctl->private_data == NULL) {
1334 kctl->private_free = snd_ctl_elem_user_free;
1336 /* Set private data for this userspace control. */
1337 ue = (struct user_element *)kctl->private_data;
1340 ue->info.access = 0;
1341 ue->elem_data = (char *)ue + sizeof(*ue);
1342 ue->elem_data_size = private_size;
1343 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1344 err = snd_ctl_elem_init_enum_names(ue);
1346 snd_ctl_free_one(kctl);
1351 /* Set callback functions. */
1352 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1353 kctl->info = snd_ctl_elem_user_enum_info;
1355 kctl->info = snd_ctl_elem_user_info;
1356 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1357 kctl->get = snd_ctl_elem_user_get;
1358 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1359 kctl->put = snd_ctl_elem_user_put;
1360 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1361 kctl->tlv.c = snd_ctl_elem_user_tlv;
1363 /* This function manage to free the instance on failure. */
1364 down_write(&card->controls_rwsem);
1365 err = __snd_ctl_add(card, kctl);
1367 snd_ctl_free_one(kctl);
1370 offset = snd_ctl_get_ioff(kctl, &info->id);
1371 snd_ctl_build_ioff(&info->id, kctl, offset);
1373 * Here we cannot fill any field for the number of elements added by
1374 * this operation because there're no specific fields. The usage of
1375 * 'owner' field for this purpose may cause any bugs to userspace
1376 * applications because the field originally means PID of a process
1377 * which locks the element.
1380 card->user_ctl_count++;
1383 up_write(&card->controls_rwsem);
1387 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1388 struct snd_ctl_elem_info __user *_info, int replace)
1390 struct snd_ctl_elem_info info;
1393 if (copy_from_user(&info, _info, sizeof(info)))
1395 err = snd_ctl_elem_add(file, &info, replace);
1398 if (copy_to_user(_info, &info, sizeof(info))) {
1399 snd_ctl_remove_user_ctl(file, &info.id);
1406 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1407 struct snd_ctl_elem_id __user *_id)
1409 struct snd_ctl_elem_id id;
1411 if (copy_from_user(&id, _id, sizeof(id)))
1413 return snd_ctl_remove_user_ctl(file, &id);
1416 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1419 if (get_user(subscribe, ptr))
1421 if (subscribe < 0) {
1422 subscribe = file->subscribed;
1423 if (put_user(subscribe, ptr))
1428 file->subscribed = 1;
1430 } else if (file->subscribed) {
1431 snd_ctl_empty_read_queue(file);
1432 file->subscribed = 0;
1437 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1438 struct snd_ctl_tlv __user *_tlv,
1441 struct snd_card *card = file->card;
1442 struct snd_ctl_tlv tlv;
1443 struct snd_kcontrol *kctl;
1444 struct snd_kcontrol_volatile *vd;
1448 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1450 if (tlv.length < sizeof(unsigned int) * 2)
1454 down_read(&card->controls_rwsem);
1455 kctl = snd_ctl_find_numid(card, tlv.numid);
1460 if (kctl->tlv.p == NULL) {
1464 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1465 if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
1466 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1467 (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
1468 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1469 (op_flag == SNDRV_CTL_TLV_OP_CMD &&
1470 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1474 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1475 if (vd->owner != NULL && vd->owner != file) {
1479 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1481 struct snd_ctl_elem_id id = kctl->id;
1482 up_read(&card->controls_rwsem);
1483 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1487 if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1491 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1492 if (tlv.length < len) {
1496 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1500 up_read(&card->controls_rwsem);
1504 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1506 struct snd_ctl_file *ctl;
1507 struct snd_card *card;
1508 struct snd_kctl_ioctl *p;
1509 void __user *argp = (void __user *)arg;
1510 int __user *ip = argp;
1513 ctl = file->private_data;
1515 if (snd_BUG_ON(!card))
1518 case SNDRV_CTL_IOCTL_PVERSION:
1519 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1520 case SNDRV_CTL_IOCTL_CARD_INFO:
1521 return snd_ctl_card_info(card, ctl, cmd, argp);
1522 case SNDRV_CTL_IOCTL_ELEM_LIST:
1523 return snd_ctl_elem_list(card, argp);
1524 case SNDRV_CTL_IOCTL_ELEM_INFO:
1525 return snd_ctl_elem_info_user(ctl, argp);
1526 case SNDRV_CTL_IOCTL_ELEM_READ:
1527 return snd_ctl_elem_read_user(card, argp);
1528 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1529 return snd_ctl_elem_write_user(ctl, argp);
1530 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1531 return snd_ctl_elem_lock(ctl, argp);
1532 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1533 return snd_ctl_elem_unlock(ctl, argp);
1534 case SNDRV_CTL_IOCTL_ELEM_ADD:
1535 return snd_ctl_elem_add_user(ctl, argp, 0);
1536 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1537 return snd_ctl_elem_add_user(ctl, argp, 1);
1538 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1539 return snd_ctl_elem_remove(ctl, argp);
1540 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1541 return snd_ctl_subscribe_events(ctl, ip);
1542 case SNDRV_CTL_IOCTL_TLV_READ:
1543 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1544 case SNDRV_CTL_IOCTL_TLV_WRITE:
1545 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1546 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1547 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1548 case SNDRV_CTL_IOCTL_POWER:
1549 return -ENOPROTOOPT;
1550 case SNDRV_CTL_IOCTL_POWER_STATE:
1552 return put_user(card->power_state, ip) ? -EFAULT : 0;
1554 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1557 down_read(&snd_ioctl_rwsem);
1558 list_for_each_entry(p, &snd_control_ioctls, list) {
1559 err = p->fioctl(card, ctl, cmd, arg);
1560 if (err != -ENOIOCTLCMD) {
1561 up_read(&snd_ioctl_rwsem);
1565 up_read(&snd_ioctl_rwsem);
1566 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1570 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1571 size_t count, loff_t * offset)
1573 struct snd_ctl_file *ctl;
1577 ctl = file->private_data;
1578 if (snd_BUG_ON(!ctl || !ctl->card))
1580 if (!ctl->subscribed)
1582 if (count < sizeof(struct snd_ctl_event))
1584 spin_lock_irq(&ctl->read_lock);
1585 while (count >= sizeof(struct snd_ctl_event)) {
1586 struct snd_ctl_event ev;
1587 struct snd_kctl_event *kev;
1588 while (list_empty(&ctl->events)) {
1590 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1594 init_waitqueue_entry(&wait, current);
1595 add_wait_queue(&ctl->change_sleep, &wait);
1596 set_current_state(TASK_INTERRUPTIBLE);
1597 spin_unlock_irq(&ctl->read_lock);
1599 remove_wait_queue(&ctl->change_sleep, &wait);
1600 if (ctl->card->shutdown)
1602 if (signal_pending(current))
1603 return -ERESTARTSYS;
1604 spin_lock_irq(&ctl->read_lock);
1606 kev = snd_kctl_event(ctl->events.next);
1607 ev.type = SNDRV_CTL_EVENT_ELEM;
1608 ev.data.elem.mask = kev->mask;
1609 ev.data.elem.id = kev->id;
1610 list_del(&kev->list);
1611 spin_unlock_irq(&ctl->read_lock);
1613 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1617 spin_lock_irq(&ctl->read_lock);
1618 buffer += sizeof(struct snd_ctl_event);
1619 count -= sizeof(struct snd_ctl_event);
1620 result += sizeof(struct snd_ctl_event);
1623 spin_unlock_irq(&ctl->read_lock);
1625 return result > 0 ? result : err;
1628 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1631 struct snd_ctl_file *ctl;
1633 ctl = file->private_data;
1634 if (!ctl->subscribed)
1636 poll_wait(file, &ctl->change_sleep, wait);
1639 if (!list_empty(&ctl->events))
1640 mask |= POLLIN | POLLRDNORM;
1646 * register the device-specific control-ioctls.
1647 * called from each device manager like pcm.c, hwdep.c, etc.
1649 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1651 struct snd_kctl_ioctl *pn;
1653 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1657 down_write(&snd_ioctl_rwsem);
1658 list_add_tail(&pn->list, lists);
1659 up_write(&snd_ioctl_rwsem);
1664 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1665 * @fcn: ioctl callback function
1667 * called from each device manager like pcm.c, hwdep.c, etc.
1669 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1671 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1673 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1675 #ifdef CONFIG_COMPAT
1677 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1679 * @fcn: ioctl callback function
1681 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1683 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1685 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1689 * de-register the device-specific control-ioctls.
1691 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1692 struct list_head *lists)
1694 struct snd_kctl_ioctl *p;
1696 if (snd_BUG_ON(!fcn))
1698 down_write(&snd_ioctl_rwsem);
1699 list_for_each_entry(p, lists, list) {
1700 if (p->fioctl == fcn) {
1702 up_write(&snd_ioctl_rwsem);
1707 up_write(&snd_ioctl_rwsem);
1713 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1714 * @fcn: ioctl callback function to unregister
1716 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1718 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1720 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1722 #ifdef CONFIG_COMPAT
1724 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1726 * @fcn: ioctl callback function to unregister
1728 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1730 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1732 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1735 static int snd_ctl_fasync(int fd, struct file * file, int on)
1737 struct snd_ctl_file *ctl;
1739 ctl = file->private_data;
1740 return fasync_helper(fd, file, on, &ctl->fasync);
1743 /* return the preferred subdevice number if already assigned;
1744 * otherwise return -1
1746 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1748 struct snd_ctl_file *kctl;
1751 read_lock(&card->ctl_files_rwlock);
1752 list_for_each_entry(kctl, &card->ctl_files, list) {
1753 if (kctl->pid == task_pid(current)) {
1754 subdevice = kctl->preferred_subdevice[type];
1755 if (subdevice != -1)
1759 read_unlock(&card->ctl_files_rwlock);
1762 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1767 #ifdef CONFIG_COMPAT
1768 #include "control_compat.c"
1770 #define snd_ctl_ioctl_compat NULL
1777 static const struct file_operations snd_ctl_f_ops =
1779 .owner = THIS_MODULE,
1780 .read = snd_ctl_read,
1781 .open = snd_ctl_open,
1782 .release = snd_ctl_release,
1783 .llseek = no_llseek,
1784 .poll = snd_ctl_poll,
1785 .unlocked_ioctl = snd_ctl_ioctl,
1786 .compat_ioctl = snd_ctl_ioctl_compat,
1787 .fasync = snd_ctl_fasync,
1791 * registration of the control device
1793 static int snd_ctl_dev_register(struct snd_device *device)
1795 struct snd_card *card = device->device_data;
1797 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1798 &snd_ctl_f_ops, card, &card->ctl_dev);
1802 * disconnection of the control device
1804 static int snd_ctl_dev_disconnect(struct snd_device *device)
1806 struct snd_card *card = device->device_data;
1807 struct snd_ctl_file *ctl;
1809 read_lock(&card->ctl_files_rwlock);
1810 list_for_each_entry(ctl, &card->ctl_files, list) {
1811 wake_up(&ctl->change_sleep);
1812 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1814 read_unlock(&card->ctl_files_rwlock);
1816 return snd_unregister_device(&card->ctl_dev);
1822 static int snd_ctl_dev_free(struct snd_device *device)
1824 struct snd_card *card = device->device_data;
1825 struct snd_kcontrol *control;
1827 down_write(&card->controls_rwsem);
1828 while (!list_empty(&card->controls)) {
1829 control = snd_kcontrol(card->controls.next);
1830 snd_ctl_remove(card, control);
1832 up_write(&card->controls_rwsem);
1833 put_device(&card->ctl_dev);
1838 * create control core:
1839 * called from init.c
1841 int snd_ctl_create(struct snd_card *card)
1843 static struct snd_device_ops ops = {
1844 .dev_free = snd_ctl_dev_free,
1845 .dev_register = snd_ctl_dev_register,
1846 .dev_disconnect = snd_ctl_dev_disconnect,
1850 if (snd_BUG_ON(!card))
1852 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1855 snd_device_initialize(&card->ctl_dev, card);
1856 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1858 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1860 put_device(&card->ctl_dev);
1865 * Frequently used control callbacks/helpers
1869 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1870 * callback with a mono channel
1871 * @kcontrol: the kcontrol instance
1872 * @uinfo: info to store
1874 * This is a function that can be used as info callback for a standard
1875 * boolean control with a single mono channel.
1877 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1878 struct snd_ctl_elem_info *uinfo)
1880 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1882 uinfo->value.integer.min = 0;
1883 uinfo->value.integer.max = 1;
1886 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1889 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1890 * callback with stereo two channels
1891 * @kcontrol: the kcontrol instance
1892 * @uinfo: info to store
1894 * This is a function that can be used as info callback for a standard
1895 * boolean control with stereo two channels.
1897 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1898 struct snd_ctl_elem_info *uinfo)
1900 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1902 uinfo->value.integer.min = 0;
1903 uinfo->value.integer.max = 1;
1906 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1909 * snd_ctl_enum_info - fills the info structure for an enumerated control
1910 * @info: the structure to be filled
1911 * @channels: the number of the control's channels; often one
1912 * @items: the number of control values; also the size of @names
1913 * @names: an array containing the names of all control values
1915 * Sets all required fields in @info to their appropriate values.
1916 * If the control's accessibility is not the default (readable and writable),
1917 * the caller has to fill @info->access.
1921 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1922 unsigned int items, const char *const names[])
1924 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1925 info->count = channels;
1926 info->value.enumerated.items = items;
1929 if (info->value.enumerated.item >= items)
1930 info->value.enumerated.item = items - 1;
1931 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1932 "ALSA: too long item name '%s'\n",
1933 names[info->value.enumerated.item]);
1934 strlcpy(info->value.enumerated.name,
1935 names[info->value.enumerated.item],
1936 sizeof(info->value.enumerated.name));
1939 EXPORT_SYMBOL(snd_ctl_enum_info);