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>
29 #include <linux/sched/signal.h>
30 #include <sound/core.h>
31 #include <sound/minors.h>
32 #include <sound/info.h>
33 #include <sound/control.h>
35 /* max number of user-defined controls */
36 #define MAX_USER_CONTROLS 32
37 #define MAX_CONTROL_COUNT 1028
39 struct snd_kctl_ioctl {
40 struct list_head list; /* list of all ioctls */
41 snd_kctl_ioctl_func_t fioctl;
44 static DECLARE_RWSEM(snd_ioctl_rwsem);
45 static LIST_HEAD(snd_control_ioctls);
47 static LIST_HEAD(snd_control_compat_ioctls);
50 static int snd_ctl_open(struct inode *inode, struct file *file)
53 struct snd_card *card;
54 struct snd_ctl_file *ctl;
57 err = nonseekable_open(inode, file);
61 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
66 err = snd_card_file_add(card, file);
71 if (!try_module_get(card->module)) {
75 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
80 INIT_LIST_HEAD(&ctl->events);
81 init_waitqueue_head(&ctl->change_sleep);
82 spin_lock_init(&ctl->read_lock);
84 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
85 ctl->preferred_subdevice[i] = -1;
86 ctl->pid = get_pid(task_pid(current));
87 file->private_data = ctl;
88 write_lock_irqsave(&card->ctl_files_rwlock, flags);
89 list_add_tail(&ctl->list, &card->ctl_files);
90 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
95 module_put(card->module);
97 snd_card_file_remove(card, file);
100 snd_card_unref(card);
104 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
107 struct snd_kctl_event *cread;
109 spin_lock_irqsave(&ctl->read_lock, flags);
110 while (!list_empty(&ctl->events)) {
111 cread = snd_kctl_event(ctl->events.next);
112 list_del(&cread->list);
115 spin_unlock_irqrestore(&ctl->read_lock, flags);
118 static int snd_ctl_release(struct inode *inode, struct file *file)
121 struct snd_card *card;
122 struct snd_ctl_file *ctl;
123 struct snd_kcontrol *control;
126 ctl = file->private_data;
127 file->private_data = NULL;
129 write_lock_irqsave(&card->ctl_files_rwlock, flags);
130 list_del(&ctl->list);
131 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
132 down_write(&card->controls_rwsem);
133 list_for_each_entry(control, &card->controls, list)
134 for (idx = 0; idx < control->count; idx++)
135 if (control->vd[idx].owner == ctl)
136 control->vd[idx].owner = NULL;
137 up_write(&card->controls_rwsem);
138 snd_ctl_empty_read_queue(ctl);
141 module_put(card->module);
142 snd_card_file_remove(card, file);
147 * snd_ctl_notify - Send notification to user-space for a control change
148 * @card: the card to send notification
149 * @mask: the event mask, SNDRV_CTL_EVENT_*
150 * @id: the ctl element id to send notification
152 * This function adds an event record with the given id and mask, appends
153 * to the list and wakes up the user-space for notification. This can be
154 * called in the atomic context.
156 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
157 struct snd_ctl_elem_id *id)
160 struct snd_ctl_file *ctl;
161 struct snd_kctl_event *ev;
163 if (snd_BUG_ON(!card || !id))
167 read_lock(&card->ctl_files_rwlock);
168 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
169 card->mixer_oss_change_count++;
171 list_for_each_entry(ctl, &card->ctl_files, list) {
172 if (!ctl->subscribed)
174 spin_lock_irqsave(&ctl->read_lock, flags);
175 list_for_each_entry(ev, &ctl->events, list) {
176 if (ev->id.numid == id->numid) {
181 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
185 list_add_tail(&ev->list, &ctl->events);
187 dev_err(card->dev, "No memory available to allocate event\n");
190 wake_up(&ctl->change_sleep);
191 spin_unlock_irqrestore(&ctl->read_lock, flags);
192 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
194 read_unlock(&card->ctl_files_rwlock);
196 EXPORT_SYMBOL(snd_ctl_notify);
199 * snd_ctl_new - create a new control instance with some elements
200 * @kctl: the pointer to store new control instance
201 * @count: the number of elements in this control
202 * @access: the default access flags for elements in this control
203 * @file: given when locking these elements
205 * Allocates a memory object for a new control instance. The instance has
206 * elements as many as the given number (@count). Each element has given
207 * access permissions (@access). Each element is locked when @file is given.
209 * Return: 0 on success, error code on failure
211 static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
212 unsigned int access, struct snd_ctl_file *file)
217 if (count == 0 || count > MAX_CONTROL_COUNT)
220 size = sizeof(struct snd_kcontrol);
221 size += sizeof(struct snd_kcontrol_volatile) * count;
223 *kctl = kzalloc(size, GFP_KERNEL);
227 for (idx = 0; idx < count; idx++) {
228 (*kctl)->vd[idx].access = access;
229 (*kctl)->vd[idx].owner = file;
231 (*kctl)->count = count;
237 * snd_ctl_new1 - create a control instance from the template
238 * @ncontrol: the initialization record
239 * @private_data: the private data to set
241 * Allocates a new struct snd_kcontrol instance and initialize from the given
242 * template. When the access field of ncontrol is 0, it's assumed as
243 * READWRITE access. When the count field is 0, it's assumes as one.
245 * Return: The pointer of the newly generated instance, or %NULL on failure.
247 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
250 struct snd_kcontrol *kctl;
255 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
258 count = ncontrol->count;
262 access = ncontrol->access;
264 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
265 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
266 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
267 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
268 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
269 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
270 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
272 err = snd_ctl_new(&kctl, count, access, NULL);
276 /* The 'numid' member is decided when calling snd_ctl_add(). */
277 kctl->id.iface = ncontrol->iface;
278 kctl->id.device = ncontrol->device;
279 kctl->id.subdevice = ncontrol->subdevice;
280 if (ncontrol->name) {
281 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
282 if (strcmp(ncontrol->name, kctl->id.name) != 0)
283 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
284 ncontrol->name, kctl->id.name);
286 kctl->id.index = ncontrol->index;
288 kctl->info = ncontrol->info;
289 kctl->get = ncontrol->get;
290 kctl->put = ncontrol->put;
291 kctl->tlv.p = ncontrol->tlv.p;
293 kctl->private_value = ncontrol->private_value;
294 kctl->private_data = private_data;
298 EXPORT_SYMBOL(snd_ctl_new1);
301 * snd_ctl_free_one - release the control instance
302 * @kcontrol: the control instance
304 * Releases the control instance created via snd_ctl_new()
306 * Don't call this after the control was added to the card.
308 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
311 if (kcontrol->private_free)
312 kcontrol->private_free(kcontrol);
316 EXPORT_SYMBOL(snd_ctl_free_one);
318 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
321 struct snd_kcontrol *kctl;
323 /* Make sure that the ids assigned to the control do not wrap around */
324 if (card->last_numid >= UINT_MAX - count)
325 card->last_numid = 0;
327 list_for_each_entry(kctl, &card->controls, list) {
328 if (kctl->id.numid < card->last_numid + 1 + count &&
329 kctl->id.numid + kctl->count > card->last_numid + 1) {
330 card->last_numid = kctl->id.numid + kctl->count - 1;
337 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
339 unsigned int iter = 100000;
341 while (snd_ctl_remove_numid_conflict(card, count)) {
343 /* this situation is very unlikely */
344 dev_err(card->dev, "unable to allocate new control numid\n");
352 * snd_ctl_add - add the control instance to the card
353 * @card: the card instance
354 * @kcontrol: the control instance to add
356 * Adds the control instance created via snd_ctl_new() or
357 * snd_ctl_new1() to the given card. Assigns also an unique
358 * numid used for fast search.
360 * It frees automatically the control which cannot be added.
362 * Return: Zero if successful, or a negative error code on failure.
365 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
367 struct snd_ctl_elem_id id;
374 if (snd_BUG_ON(!card || !kcontrol->info))
377 if (id.index > UINT_MAX - kcontrol->count)
380 down_write(&card->controls_rwsem);
381 if (snd_ctl_find_id(card, &id)) {
382 up_write(&card->controls_rwsem);
383 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
392 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
393 up_write(&card->controls_rwsem);
397 list_add_tail(&kcontrol->list, &card->controls);
398 card->controls_count += kcontrol->count;
399 kcontrol->id.numid = card->last_numid + 1;
400 card->last_numid += kcontrol->count;
402 count = kcontrol->count;
403 up_write(&card->controls_rwsem);
404 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
405 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
409 snd_ctl_free_one(kcontrol);
412 EXPORT_SYMBOL(snd_ctl_add);
415 * snd_ctl_replace - replace the control instance of the card
416 * @card: the card instance
417 * @kcontrol: the control instance to replace
418 * @add_on_replace: add the control if not already added
420 * Replaces the given control. If the given control does not exist
421 * and the add_on_replace flag is set, the control is added. If the
422 * control exists, it is destroyed first.
424 * It frees automatically the control which cannot be added or replaced.
426 * Return: Zero if successful, or a negative error code on failure.
428 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
431 struct snd_ctl_elem_id id;
434 struct snd_kcontrol *old;
439 if (snd_BUG_ON(!card || !kcontrol->info)) {
444 down_write(&card->controls_rwsem);
445 old = snd_ctl_find_id(card, &id);
449 up_write(&card->controls_rwsem);
453 ret = snd_ctl_remove(card, old);
455 up_write(&card->controls_rwsem);
459 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
460 up_write(&card->controls_rwsem);
464 list_add_tail(&kcontrol->list, &card->controls);
465 card->controls_count += kcontrol->count;
466 kcontrol->id.numid = card->last_numid + 1;
467 card->last_numid += kcontrol->count;
469 count = kcontrol->count;
470 up_write(&card->controls_rwsem);
471 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
472 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
476 snd_ctl_free_one(kcontrol);
479 EXPORT_SYMBOL(snd_ctl_replace);
482 * snd_ctl_remove - remove the control from the card and release it
483 * @card: the card instance
484 * @kcontrol: the control instance to remove
486 * Removes the control from the card and then releases the instance.
487 * You don't need to call snd_ctl_free_one(). You must be in
488 * the write lock - down_write(&card->controls_rwsem).
490 * Return: 0 if successful, or a negative error code on failure.
492 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
494 struct snd_ctl_elem_id id;
497 if (snd_BUG_ON(!card || !kcontrol))
499 list_del(&kcontrol->list);
500 card->controls_count -= kcontrol->count;
502 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
503 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
504 snd_ctl_free_one(kcontrol);
507 EXPORT_SYMBOL(snd_ctl_remove);
510 * snd_ctl_remove_id - remove the control of the given id and release it
511 * @card: the card instance
512 * @id: the control id to remove
514 * Finds the control instance with the given id, removes it from the
515 * card list and releases it.
517 * Return: 0 if successful, or a negative error code on failure.
519 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
521 struct snd_kcontrol *kctl;
524 down_write(&card->controls_rwsem);
525 kctl = snd_ctl_find_id(card, id);
527 up_write(&card->controls_rwsem);
530 ret = snd_ctl_remove(card, kctl);
531 up_write(&card->controls_rwsem);
534 EXPORT_SYMBOL(snd_ctl_remove_id);
537 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
538 * @file: active control handle
539 * @id: the control id to remove
541 * Finds the control instance with the given id, removes it from the
542 * card list and releases it.
544 * Return: 0 if successful, or a negative error code on failure.
546 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
547 struct snd_ctl_elem_id *id)
549 struct snd_card *card = file->card;
550 struct snd_kcontrol *kctl;
553 down_write(&card->controls_rwsem);
554 kctl = snd_ctl_find_id(card, id);
559 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
563 for (idx = 0; idx < kctl->count; idx++)
564 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
568 ret = snd_ctl_remove(card, kctl);
571 card->user_ctl_count--;
573 up_write(&card->controls_rwsem);
578 * snd_ctl_activate_id - activate/inactivate the control of the given id
579 * @card: the card instance
580 * @id: the control id to activate/inactivate
581 * @active: non-zero to activate
583 * Finds the control instance with the given id, and activate or
584 * inactivate the control together with notification, if changed.
585 * The given ID data is filled with full information.
587 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
589 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
592 struct snd_kcontrol *kctl;
593 struct snd_kcontrol_volatile *vd;
594 unsigned int index_offset;
597 down_write(&card->controls_rwsem);
598 kctl = snd_ctl_find_id(card, id);
603 index_offset = snd_ctl_get_ioff(kctl, id);
604 vd = &kctl->vd[index_offset];
607 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
609 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
611 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
613 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
615 snd_ctl_build_ioff(id, kctl, index_offset);
618 up_write(&card->controls_rwsem);
620 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
623 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
626 * snd_ctl_rename_id - replace the id of a control on the card
627 * @card: the card instance
628 * @src_id: the old id
629 * @dst_id: the new id
631 * Finds the control with the old id from the card, and replaces the
632 * id with the new one.
634 * Return: Zero if successful, or a negative error code on failure.
636 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
637 struct snd_ctl_elem_id *dst_id)
639 struct snd_kcontrol *kctl;
641 down_write(&card->controls_rwsem);
642 kctl = snd_ctl_find_id(card, src_id);
644 up_write(&card->controls_rwsem);
648 kctl->id.numid = card->last_numid + 1;
649 card->last_numid += kctl->count;
650 up_write(&card->controls_rwsem);
653 EXPORT_SYMBOL(snd_ctl_rename_id);
656 * snd_ctl_find_numid - find the control instance with the given number-id
657 * @card: the card instance
658 * @numid: the number-id to search
660 * Finds the control instance with the given number-id from the card.
662 * The caller must down card->controls_rwsem before calling this function
663 * (if the race condition can happen).
665 * Return: The pointer of the instance if found, or %NULL if not.
668 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
670 struct snd_kcontrol *kctl;
672 if (snd_BUG_ON(!card || !numid))
674 list_for_each_entry(kctl, &card->controls, list) {
675 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
680 EXPORT_SYMBOL(snd_ctl_find_numid);
683 * snd_ctl_find_id - find the control instance with the given id
684 * @card: the card instance
685 * @id: the id to search
687 * Finds the control instance with the given id from the card.
689 * The caller must down card->controls_rwsem before calling this function
690 * (if the race condition can happen).
692 * Return: The pointer of the instance if found, or %NULL if not.
695 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
696 struct snd_ctl_elem_id *id)
698 struct snd_kcontrol *kctl;
700 if (snd_BUG_ON(!card || !id))
703 return snd_ctl_find_numid(card, id->numid);
704 list_for_each_entry(kctl, &card->controls, list) {
705 if (kctl->id.iface != id->iface)
707 if (kctl->id.device != id->device)
709 if (kctl->id.subdevice != id->subdevice)
711 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
713 if (kctl->id.index > id->index)
715 if (kctl->id.index + kctl->count <= id->index)
721 EXPORT_SYMBOL(snd_ctl_find_id);
723 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
724 unsigned int cmd, void __user *arg)
726 struct snd_ctl_card_info *info;
728 info = kzalloc(sizeof(*info), GFP_KERNEL);
731 down_read(&snd_ioctl_rwsem);
732 info->card = card->number;
733 strlcpy(info->id, card->id, sizeof(info->id));
734 strlcpy(info->driver, card->driver, sizeof(info->driver));
735 strlcpy(info->name, card->shortname, sizeof(info->name));
736 strlcpy(info->longname, card->longname, sizeof(info->longname));
737 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
738 strlcpy(info->components, card->components, sizeof(info->components));
739 up_read(&snd_ioctl_rwsem);
740 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
748 static int snd_ctl_elem_list(struct snd_card *card,
749 struct snd_ctl_elem_list __user *_list)
751 struct snd_ctl_elem_list list;
752 struct snd_kcontrol *kctl;
753 struct snd_ctl_elem_id id;
754 unsigned int offset, space, jidx;
757 if (copy_from_user(&list, _list, sizeof(list)))
759 offset = list.offset;
762 down_read(&card->controls_rwsem);
763 list.count = card->controls_count;
766 list_for_each_entry(kctl, &card->controls, list) {
767 if (offset >= kctl->count) {
768 offset -= kctl->count;
771 for (jidx = offset; jidx < kctl->count; jidx++) {
772 snd_ctl_build_ioff(&id, kctl, jidx);
773 if (copy_to_user(list.pids + list.used, &id,
786 up_read(&card->controls_rwsem);
787 if (!err && copy_to_user(_list, &list, sizeof(list)))
792 static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
794 unsigned int members;
797 if (info->dimen.d[0] == 0)
801 for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
802 if (info->dimen.d[i] == 0)
804 members *= info->dimen.d[i];
807 * info->count should be validated in advance, to guarantee
808 * calculation soundness.
810 if (members > info->count)
814 for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
815 if (info->dimen.d[i] > 0)
819 return members == info->count;
822 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
823 struct snd_ctl_elem_info *info)
825 struct snd_card *card = ctl->card;
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, &info->id);
834 up_read(&card->controls_rwsem);
837 #ifdef CONFIG_SND_DEBUG
840 result = kctl->info(kctl, info);
842 snd_BUG_ON(info->access);
843 index_offset = snd_ctl_get_ioff(kctl, &info->id);
844 vd = &kctl->vd[index_offset];
845 snd_ctl_build_ioff(&info->id, kctl, index_offset);
846 info->access = vd->access;
848 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
849 if (vd->owner == ctl)
850 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
851 info->owner = pid_vnr(vd->owner->pid);
856 up_read(&card->controls_rwsem);
860 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
861 struct snd_ctl_elem_info __user *_info)
863 struct snd_ctl_elem_info info;
866 if (copy_from_user(&info, _info, sizeof(info)))
868 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
871 result = snd_ctl_elem_info(ctl, &info);
874 if (copy_to_user(_info, &info, sizeof(info)))
879 static int snd_ctl_elem_read(struct snd_card *card,
880 struct snd_ctl_elem_value *control)
882 struct snd_kcontrol *kctl;
883 struct snd_kcontrol_volatile *vd;
884 unsigned int index_offset;
886 kctl = snd_ctl_find_id(card, &control->id);
890 index_offset = snd_ctl_get_ioff(kctl, &control->id);
891 vd = &kctl->vd[index_offset];
892 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get == NULL)
895 snd_ctl_build_ioff(&control->id, kctl, index_offset);
896 return kctl->get(kctl, control);
899 static int snd_ctl_elem_read_user(struct snd_card *card,
900 struct snd_ctl_elem_value __user *_control)
902 struct snd_ctl_elem_value *control;
905 control = memdup_user(_control, sizeof(*control));
907 return PTR_ERR(control);
909 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
913 down_read(&card->controls_rwsem);
914 result = snd_ctl_elem_read(card, control);
915 up_read(&card->controls_rwsem);
919 if (copy_to_user(_control, control, sizeof(*control)))
926 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
927 struct snd_ctl_elem_value *control)
929 struct snd_kcontrol *kctl;
930 struct snd_kcontrol_volatile *vd;
931 unsigned int index_offset;
934 kctl = snd_ctl_find_id(card, &control->id);
938 index_offset = snd_ctl_get_ioff(kctl, &control->id);
939 vd = &kctl->vd[index_offset];
940 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
941 (file && vd->owner && vd->owner != file)) {
945 snd_ctl_build_ioff(&control->id, kctl, index_offset);
946 result = kctl->put(kctl, control);
951 struct snd_ctl_elem_id id = control->id;
952 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
958 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
959 struct snd_ctl_elem_value __user *_control)
961 struct snd_ctl_elem_value *control;
962 struct snd_card *card;
965 control = memdup_user(_control, sizeof(*control));
967 return PTR_ERR(control);
970 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
974 down_write(&card->controls_rwsem);
975 result = snd_ctl_elem_write(card, file, control);
976 up_write(&card->controls_rwsem);
980 if (copy_to_user(_control, control, sizeof(*control)))
987 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
988 struct snd_ctl_elem_id __user *_id)
990 struct snd_card *card = file->card;
991 struct snd_ctl_elem_id id;
992 struct snd_kcontrol *kctl;
993 struct snd_kcontrol_volatile *vd;
996 if (copy_from_user(&id, _id, sizeof(id)))
998 down_write(&card->controls_rwsem);
999 kctl = snd_ctl_find_id(card, &id);
1003 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1004 if (vd->owner != NULL)
1011 up_write(&card->controls_rwsem);
1015 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1016 struct snd_ctl_elem_id __user *_id)
1018 struct snd_card *card = file->card;
1019 struct snd_ctl_elem_id id;
1020 struct snd_kcontrol *kctl;
1021 struct snd_kcontrol_volatile *vd;
1024 if (copy_from_user(&id, _id, sizeof(id)))
1026 down_write(&card->controls_rwsem);
1027 kctl = snd_ctl_find_id(card, &id);
1031 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1032 if (vd->owner == NULL)
1034 else if (vd->owner != file)
1041 up_write(&card->controls_rwsem);
1045 struct user_element {
1046 struct snd_ctl_elem_info info;
1047 struct snd_card *card;
1048 char *elem_data; /* element data */
1049 unsigned long elem_data_size; /* size of element data in bytes */
1050 void *tlv_data; /* TLV data */
1051 unsigned long tlv_data_size; /* TLV data size */
1052 void *priv_data; /* private data (like strings for enumerated type) */
1055 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1056 struct snd_ctl_elem_info *uinfo)
1058 struct user_element *ue = kcontrol->private_data;
1059 unsigned int offset;
1061 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1063 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1068 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1069 struct snd_ctl_elem_info *uinfo)
1071 struct user_element *ue = kcontrol->private_data;
1074 unsigned int offset;
1076 item = uinfo->value.enumerated.item;
1078 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1080 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1082 item = min(item, uinfo->value.enumerated.items - 1);
1083 uinfo->value.enumerated.item = item;
1085 names = ue->priv_data;
1086 for (; item > 0; --item)
1087 names += strlen(names) + 1;
1088 strcpy(uinfo->value.enumerated.name, names);
1093 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1094 struct snd_ctl_elem_value *ucontrol)
1096 struct user_element *ue = kcontrol->private_data;
1097 unsigned int size = ue->elem_data_size;
1098 char *src = ue->elem_data +
1099 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1101 memcpy(&ucontrol->value, src, size);
1105 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1106 struct snd_ctl_elem_value *ucontrol)
1109 struct user_element *ue = kcontrol->private_data;
1110 unsigned int size = ue->elem_data_size;
1111 char *dst = ue->elem_data +
1112 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1114 change = memcmp(&ucontrol->value, dst, size) != 0;
1116 memcpy(dst, &ucontrol->value, size);
1120 static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1123 struct user_element *ue = kctl->private_data;
1124 unsigned int *container;
1125 struct snd_ctl_elem_id id;
1126 unsigned int mask = 0;
1130 if (size > 1024 * 128) /* sane value */
1133 container = vmemdup_user(buf, size);
1134 if (IS_ERR(container))
1135 return PTR_ERR(container);
1137 change = ue->tlv_data_size != size;
1139 change = memcmp(ue->tlv_data, container, size) != 0;
1145 if (ue->tlv_data == NULL) {
1146 /* Now TLV data is available. */
1147 for (i = 0; i < kctl->count; ++i)
1148 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1149 mask = SNDRV_CTL_EVENT_MASK_INFO;
1152 kvfree(ue->tlv_data);
1153 ue->tlv_data = container;
1154 ue->tlv_data_size = size;
1156 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1157 for (i = 0; i < kctl->count; ++i) {
1158 snd_ctl_build_ioff(&id, kctl, i);
1159 snd_ctl_notify(ue->card, mask, &id);
1165 static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1168 struct user_element *ue = kctl->private_data;
1170 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1173 if (size < ue->tlv_data_size)
1176 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1182 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1183 unsigned int size, unsigned int __user *buf)
1185 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1186 return replace_user_tlv(kctl, buf, size);
1188 return read_user_tlv(kctl, buf, size);
1191 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1194 size_t buf_len, name_len;
1196 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1198 if (ue->info.value.enumerated.names_length > 64 * 1024)
1201 names = vmemdup_user((const void __user *)user_ptrval,
1202 ue->info.value.enumerated.names_length);
1204 return PTR_ERR(names);
1206 /* check that there are enough valid names */
1207 buf_len = ue->info.value.enumerated.names_length;
1209 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1210 name_len = strnlen(p, buf_len);
1211 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1216 buf_len -= name_len + 1;
1219 ue->priv_data = names;
1220 ue->info.value.enumerated.names_ptr = 0;
1225 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1227 struct user_element *ue = kcontrol->private_data;
1229 kvfree(ue->tlv_data);
1230 kvfree(ue->priv_data);
1234 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1235 struct snd_ctl_elem_info *info, int replace)
1237 /* The capacity of struct snd_ctl_elem_value.value.*/
1238 static const unsigned int value_sizes[] = {
1239 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1240 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1241 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1242 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1243 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1244 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1246 static const unsigned int max_value_counts[] = {
1247 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1248 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1249 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1250 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1251 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1252 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1254 struct snd_card *card = file->card;
1255 struct snd_kcontrol *kctl;
1257 unsigned int access;
1259 struct user_element *ue;
1260 unsigned int offset;
1263 if (!*info->id.name)
1265 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1268 /* Delete a control to replace them if needed. */
1271 err = snd_ctl_remove_user_ctl(file, &info->id);
1277 * The number of userspace controls are counted control by control,
1278 * not element by element.
1280 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1283 /* Check the number of elements for this userspace control. */
1284 count = info->owner;
1288 /* Arrange access permissions if needed. */
1289 access = info->access;
1291 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1292 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1293 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1294 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1296 /* In initial state, nothing is available as TLV container. */
1297 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
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_WRITE)
1361 kctl->tlv.c = snd_ctl_elem_user_tlv;
1363 /* This function manage to free the instance on failure. */
1364 err = snd_ctl_add(card, kctl);
1367 offset = snd_ctl_get_ioff(kctl, &info->id);
1368 snd_ctl_build_ioff(&info->id, kctl, offset);
1370 * Here we cannot fill any field for the number of elements added by
1371 * this operation because there're no specific fields. The usage of
1372 * 'owner' field for this purpose may cause any bugs to userspace
1373 * applications because the field originally means PID of a process
1374 * which locks the element.
1377 down_write(&card->controls_rwsem);
1378 card->user_ctl_count++;
1379 up_write(&card->controls_rwsem);
1384 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1385 struct snd_ctl_elem_info __user *_info, int replace)
1387 struct snd_ctl_elem_info info;
1390 if (copy_from_user(&info, _info, sizeof(info)))
1392 err = snd_ctl_elem_add(file, &info, replace);
1395 if (copy_to_user(_info, &info, sizeof(info))) {
1396 snd_ctl_remove_user_ctl(file, &info.id);
1403 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1404 struct snd_ctl_elem_id __user *_id)
1406 struct snd_ctl_elem_id id;
1408 if (copy_from_user(&id, _id, sizeof(id)))
1410 return snd_ctl_remove_user_ctl(file, &id);
1413 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1416 if (get_user(subscribe, ptr))
1418 if (subscribe < 0) {
1419 subscribe = file->subscribed;
1420 if (put_user(subscribe, ptr))
1425 file->subscribed = 1;
1427 } else if (file->subscribed) {
1428 snd_ctl_empty_read_queue(file);
1429 file->subscribed = 0;
1434 static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1435 struct snd_kcontrol *kctl,
1436 struct snd_ctl_elem_id *id,
1437 unsigned int __user *buf, unsigned int size)
1439 static const struct {
1443 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1444 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1445 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1447 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1450 /* Check support of the request for this element. */
1451 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1452 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1455 if (i == ARRAY_SIZE(pairs))
1458 if (kctl->tlv.c == NULL)
1461 /* When locked, this is unavailable. */
1462 if (vd->owner != NULL && vd->owner != file)
1465 return kctl->tlv.c(kctl, op_flag, size, buf);
1468 static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1469 unsigned int __user *buf, unsigned int size)
1471 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1474 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1477 if (kctl->tlv.p == NULL)
1480 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1484 if (copy_to_user(buf, kctl->tlv.p, len))
1490 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1491 struct snd_ctl_tlv __user *buf,
1494 struct snd_ctl_tlv header;
1495 unsigned int *container;
1496 unsigned int container_size;
1497 struct snd_kcontrol *kctl;
1498 struct snd_ctl_elem_id id;
1499 struct snd_kcontrol_volatile *vd;
1501 if (copy_from_user(&header, buf, sizeof(header)))
1504 /* In design of control core, numerical ID starts at 1. */
1505 if (header.numid == 0)
1508 /* At least, container should include type and length fields. */
1509 if (header.length < sizeof(unsigned int) * 2)
1511 container_size = header.length;
1512 container = buf->tlv;
1514 kctl = snd_ctl_find_numid(file->card, header.numid);
1518 /* Calculate index of the element in this set. */
1520 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1521 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1523 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1524 return call_tlv_handler(file, op_flag, kctl, &id, container,
1527 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1528 return read_tlv_buf(kctl, &id, container,
1533 /* Not supported. */
1537 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1539 struct snd_ctl_file *ctl;
1540 struct snd_card *card;
1541 struct snd_kctl_ioctl *p;
1542 void __user *argp = (void __user *)arg;
1543 int __user *ip = argp;
1546 ctl = file->private_data;
1548 if (snd_BUG_ON(!card))
1551 case SNDRV_CTL_IOCTL_PVERSION:
1552 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1553 case SNDRV_CTL_IOCTL_CARD_INFO:
1554 return snd_ctl_card_info(card, ctl, cmd, argp);
1555 case SNDRV_CTL_IOCTL_ELEM_LIST:
1556 return snd_ctl_elem_list(card, argp);
1557 case SNDRV_CTL_IOCTL_ELEM_INFO:
1558 return snd_ctl_elem_info_user(ctl, argp);
1559 case SNDRV_CTL_IOCTL_ELEM_READ:
1560 return snd_ctl_elem_read_user(card, argp);
1561 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1562 return snd_ctl_elem_write_user(ctl, argp);
1563 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1564 return snd_ctl_elem_lock(ctl, argp);
1565 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1566 return snd_ctl_elem_unlock(ctl, argp);
1567 case SNDRV_CTL_IOCTL_ELEM_ADD:
1568 return snd_ctl_elem_add_user(ctl, argp, 0);
1569 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1570 return snd_ctl_elem_add_user(ctl, argp, 1);
1571 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1572 return snd_ctl_elem_remove(ctl, argp);
1573 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1574 return snd_ctl_subscribe_events(ctl, ip);
1575 case SNDRV_CTL_IOCTL_TLV_READ:
1576 down_read(&ctl->card->controls_rwsem);
1577 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1578 up_read(&ctl->card->controls_rwsem);
1580 case SNDRV_CTL_IOCTL_TLV_WRITE:
1581 down_write(&ctl->card->controls_rwsem);
1582 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1583 up_write(&ctl->card->controls_rwsem);
1585 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1586 down_write(&ctl->card->controls_rwsem);
1587 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1588 up_write(&ctl->card->controls_rwsem);
1590 case SNDRV_CTL_IOCTL_POWER:
1591 return -ENOPROTOOPT;
1592 case SNDRV_CTL_IOCTL_POWER_STATE:
1594 return put_user(card->power_state, ip) ? -EFAULT : 0;
1596 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1599 down_read(&snd_ioctl_rwsem);
1600 list_for_each_entry(p, &snd_control_ioctls, list) {
1601 err = p->fioctl(card, ctl, cmd, arg);
1602 if (err != -ENOIOCTLCMD) {
1603 up_read(&snd_ioctl_rwsem);
1607 up_read(&snd_ioctl_rwsem);
1608 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1612 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1613 size_t count, loff_t * offset)
1615 struct snd_ctl_file *ctl;
1619 ctl = file->private_data;
1620 if (snd_BUG_ON(!ctl || !ctl->card))
1622 if (!ctl->subscribed)
1624 if (count < sizeof(struct snd_ctl_event))
1626 spin_lock_irq(&ctl->read_lock);
1627 while (count >= sizeof(struct snd_ctl_event)) {
1628 struct snd_ctl_event ev;
1629 struct snd_kctl_event *kev;
1630 while (list_empty(&ctl->events)) {
1631 wait_queue_entry_t wait;
1632 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1636 init_waitqueue_entry(&wait, current);
1637 add_wait_queue(&ctl->change_sleep, &wait);
1638 set_current_state(TASK_INTERRUPTIBLE);
1639 spin_unlock_irq(&ctl->read_lock);
1641 remove_wait_queue(&ctl->change_sleep, &wait);
1642 if (ctl->card->shutdown)
1644 if (signal_pending(current))
1645 return -ERESTARTSYS;
1646 spin_lock_irq(&ctl->read_lock);
1648 kev = snd_kctl_event(ctl->events.next);
1649 ev.type = SNDRV_CTL_EVENT_ELEM;
1650 ev.data.elem.mask = kev->mask;
1651 ev.data.elem.id = kev->id;
1652 list_del(&kev->list);
1653 spin_unlock_irq(&ctl->read_lock);
1655 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1659 spin_lock_irq(&ctl->read_lock);
1660 buffer += sizeof(struct snd_ctl_event);
1661 count -= sizeof(struct snd_ctl_event);
1662 result += sizeof(struct snd_ctl_event);
1665 spin_unlock_irq(&ctl->read_lock);
1667 return result > 0 ? result : err;
1670 static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1673 struct snd_ctl_file *ctl;
1675 ctl = file->private_data;
1676 if (!ctl->subscribed)
1678 poll_wait(file, &ctl->change_sleep, wait);
1681 if (!list_empty(&ctl->events))
1682 mask |= EPOLLIN | EPOLLRDNORM;
1688 * register the device-specific control-ioctls.
1689 * called from each device manager like pcm.c, hwdep.c, etc.
1691 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1693 struct snd_kctl_ioctl *pn;
1695 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1699 down_write(&snd_ioctl_rwsem);
1700 list_add_tail(&pn->list, lists);
1701 up_write(&snd_ioctl_rwsem);
1706 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1707 * @fcn: ioctl callback function
1709 * called from each device manager like pcm.c, hwdep.c, etc.
1711 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1713 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1715 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1717 #ifdef CONFIG_COMPAT
1719 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1721 * @fcn: ioctl callback function
1723 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1725 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1727 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1731 * de-register the device-specific control-ioctls.
1733 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1734 struct list_head *lists)
1736 struct snd_kctl_ioctl *p;
1738 if (snd_BUG_ON(!fcn))
1740 down_write(&snd_ioctl_rwsem);
1741 list_for_each_entry(p, lists, list) {
1742 if (p->fioctl == fcn) {
1744 up_write(&snd_ioctl_rwsem);
1749 up_write(&snd_ioctl_rwsem);
1755 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1756 * @fcn: ioctl callback function to unregister
1758 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1760 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1762 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1764 #ifdef CONFIG_COMPAT
1766 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1768 * @fcn: ioctl callback function to unregister
1770 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1772 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1774 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1777 static int snd_ctl_fasync(int fd, struct file * file, int on)
1779 struct snd_ctl_file *ctl;
1781 ctl = file->private_data;
1782 return fasync_helper(fd, file, on, &ctl->fasync);
1785 /* return the preferred subdevice number if already assigned;
1786 * otherwise return -1
1788 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1790 struct snd_ctl_file *kctl;
1793 read_lock(&card->ctl_files_rwlock);
1794 list_for_each_entry(kctl, &card->ctl_files, list) {
1795 if (kctl->pid == task_pid(current)) {
1796 subdevice = kctl->preferred_subdevice[type];
1797 if (subdevice != -1)
1801 read_unlock(&card->ctl_files_rwlock);
1804 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1809 #ifdef CONFIG_COMPAT
1810 #include "control_compat.c"
1812 #define snd_ctl_ioctl_compat NULL
1819 static const struct file_operations snd_ctl_f_ops =
1821 .owner = THIS_MODULE,
1822 .read = snd_ctl_read,
1823 .open = snd_ctl_open,
1824 .release = snd_ctl_release,
1825 .llseek = no_llseek,
1826 .poll = snd_ctl_poll,
1827 .unlocked_ioctl = snd_ctl_ioctl,
1828 .compat_ioctl = snd_ctl_ioctl_compat,
1829 .fasync = snd_ctl_fasync,
1833 * registration of the control device
1835 static int snd_ctl_dev_register(struct snd_device *device)
1837 struct snd_card *card = device->device_data;
1839 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1840 &snd_ctl_f_ops, card, &card->ctl_dev);
1844 * disconnection of the control device
1846 static int snd_ctl_dev_disconnect(struct snd_device *device)
1848 struct snd_card *card = device->device_data;
1849 struct snd_ctl_file *ctl;
1851 read_lock(&card->ctl_files_rwlock);
1852 list_for_each_entry(ctl, &card->ctl_files, list) {
1853 wake_up(&ctl->change_sleep);
1854 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1856 read_unlock(&card->ctl_files_rwlock);
1858 return snd_unregister_device(&card->ctl_dev);
1864 static int snd_ctl_dev_free(struct snd_device *device)
1866 struct snd_card *card = device->device_data;
1867 struct snd_kcontrol *control;
1869 down_write(&card->controls_rwsem);
1870 while (!list_empty(&card->controls)) {
1871 control = snd_kcontrol(card->controls.next);
1872 snd_ctl_remove(card, control);
1874 up_write(&card->controls_rwsem);
1875 put_device(&card->ctl_dev);
1880 * create control core:
1881 * called from init.c
1883 int snd_ctl_create(struct snd_card *card)
1885 static struct snd_device_ops ops = {
1886 .dev_free = snd_ctl_dev_free,
1887 .dev_register = snd_ctl_dev_register,
1888 .dev_disconnect = snd_ctl_dev_disconnect,
1892 if (snd_BUG_ON(!card))
1894 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1897 snd_device_initialize(&card->ctl_dev, card);
1898 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1900 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1902 put_device(&card->ctl_dev);
1907 * Frequently used control callbacks/helpers
1911 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1912 * callback with a mono channel
1913 * @kcontrol: the kcontrol instance
1914 * @uinfo: info to store
1916 * This is a function that can be used as info callback for a standard
1917 * boolean control with a single mono channel.
1919 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1920 struct snd_ctl_elem_info *uinfo)
1922 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1924 uinfo->value.integer.min = 0;
1925 uinfo->value.integer.max = 1;
1928 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1931 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1932 * callback with stereo two channels
1933 * @kcontrol: the kcontrol instance
1934 * @uinfo: info to store
1936 * This is a function that can be used as info callback for a standard
1937 * boolean control with stereo two channels.
1939 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1940 struct snd_ctl_elem_info *uinfo)
1942 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1944 uinfo->value.integer.min = 0;
1945 uinfo->value.integer.max = 1;
1948 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1951 * snd_ctl_enum_info - fills the info structure for an enumerated control
1952 * @info: the structure to be filled
1953 * @channels: the number of the control's channels; often one
1954 * @items: the number of control values; also the size of @names
1955 * @names: an array containing the names of all control values
1957 * Sets all required fields in @info to their appropriate values.
1958 * If the control's accessibility is not the default (readable and writable),
1959 * the caller has to fill @info->access.
1963 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1964 unsigned int items, const char *const names[])
1966 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1967 info->count = channels;
1968 info->value.enumerated.items = items;
1971 if (info->value.enumerated.item >= items)
1972 info->value.enumerated.item = items - 1;
1973 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1974 "ALSA: too long item name '%s'\n",
1975 names[info->value.enumerated.item]);
1976 strlcpy(info->value.enumerated.name,
1977 names[info->value.enumerated.item],
1978 sizeof(info->value.enumerated.name));
1981 EXPORT_SYMBOL(snd_ctl_enum_info);