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");
350 * snd_ctl_add - add the control instance to the card
351 * @card: the card instance
352 * @kcontrol: the control instance to add
354 * Adds the control instance created via snd_ctl_new() or
355 * snd_ctl_new1() to the given card. Assigns also an unique
356 * numid used for fast search.
358 * It frees automatically the control which cannot be added.
360 * Return: Zero if successful, or a negative error code on failure.
363 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
365 struct snd_ctl_elem_id id;
372 if (snd_BUG_ON(!card || !kcontrol->info))
375 if (id.index > UINT_MAX - kcontrol->count)
378 down_write(&card->controls_rwsem);
379 if (snd_ctl_find_id(card, &id)) {
380 up_write(&card->controls_rwsem);
381 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
390 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
391 up_write(&card->controls_rwsem);
395 list_add_tail(&kcontrol->list, &card->controls);
396 card->controls_count += kcontrol->count;
397 kcontrol->id.numid = card->last_numid + 1;
398 card->last_numid += kcontrol->count;
400 count = kcontrol->count;
401 up_write(&card->controls_rwsem);
402 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
403 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
407 snd_ctl_free_one(kcontrol);
410 EXPORT_SYMBOL(snd_ctl_add);
413 * snd_ctl_replace - replace the control instance of the card
414 * @card: the card instance
415 * @kcontrol: the control instance to replace
416 * @add_on_replace: add the control if not already added
418 * Replaces the given control. If the given control does not exist
419 * and the add_on_replace flag is set, the control is added. If the
420 * control exists, it is destroyed first.
422 * It frees automatically the control which cannot be added or replaced.
424 * Return: Zero if successful, or a negative error code on failure.
426 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
429 struct snd_ctl_elem_id id;
432 struct snd_kcontrol *old;
437 if (snd_BUG_ON(!card || !kcontrol->info)) {
442 down_write(&card->controls_rwsem);
443 old = snd_ctl_find_id(card, &id);
447 up_write(&card->controls_rwsem);
451 ret = snd_ctl_remove(card, old);
453 up_write(&card->controls_rwsem);
457 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
458 up_write(&card->controls_rwsem);
462 list_add_tail(&kcontrol->list, &card->controls);
463 card->controls_count += kcontrol->count;
464 kcontrol->id.numid = card->last_numid + 1;
465 card->last_numid += kcontrol->count;
467 count = kcontrol->count;
468 up_write(&card->controls_rwsem);
469 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
470 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
474 snd_ctl_free_one(kcontrol);
477 EXPORT_SYMBOL(snd_ctl_replace);
480 * snd_ctl_remove - remove the control from the card and release it
481 * @card: the card instance
482 * @kcontrol: the control instance to remove
484 * Removes the control from the card and then releases the instance.
485 * You don't need to call snd_ctl_free_one(). You must be in
486 * the write lock - down_write(&card->controls_rwsem).
488 * Return: 0 if successful, or a negative error code on failure.
490 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
492 struct snd_ctl_elem_id id;
495 if (snd_BUG_ON(!card || !kcontrol))
497 list_del(&kcontrol->list);
498 card->controls_count -= kcontrol->count;
500 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
501 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
502 snd_ctl_free_one(kcontrol);
505 EXPORT_SYMBOL(snd_ctl_remove);
508 * snd_ctl_remove_id - remove the control of the given id and release it
509 * @card: the card instance
510 * @id: the control id to remove
512 * Finds the control instance with the given id, removes it from the
513 * card list and releases it.
515 * Return: 0 if successful, or a negative error code on failure.
517 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
519 struct snd_kcontrol *kctl;
522 down_write(&card->controls_rwsem);
523 kctl = snd_ctl_find_id(card, id);
525 up_write(&card->controls_rwsem);
528 ret = snd_ctl_remove(card, kctl);
529 up_write(&card->controls_rwsem);
532 EXPORT_SYMBOL(snd_ctl_remove_id);
535 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
536 * @file: active control handle
537 * @id: the control id to remove
539 * Finds the control instance with the given id, removes it from the
540 * card list and releases it.
542 * Return: 0 if successful, or a negative error code on failure.
544 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
545 struct snd_ctl_elem_id *id)
547 struct snd_card *card = file->card;
548 struct snd_kcontrol *kctl;
551 down_write(&card->controls_rwsem);
552 kctl = snd_ctl_find_id(card, id);
557 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
561 for (idx = 0; idx < kctl->count; idx++)
562 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
566 ret = snd_ctl_remove(card, kctl);
569 card->user_ctl_count--;
571 up_write(&card->controls_rwsem);
576 * snd_ctl_activate_id - activate/inactivate the control of the given id
577 * @card: the card instance
578 * @id: the control id to activate/inactivate
579 * @active: non-zero to activate
581 * Finds the control instance with the given id, and activate or
582 * inactivate the control together with notification, if changed.
583 * The given ID data is filled with full information.
585 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
587 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
590 struct snd_kcontrol *kctl;
591 struct snd_kcontrol_volatile *vd;
592 unsigned int index_offset;
595 down_write(&card->controls_rwsem);
596 kctl = snd_ctl_find_id(card, id);
601 index_offset = snd_ctl_get_ioff(kctl, id);
602 vd = &kctl->vd[index_offset];
605 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
607 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
609 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
611 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
613 snd_ctl_build_ioff(id, kctl, index_offset);
616 up_write(&card->controls_rwsem);
618 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
621 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
624 * snd_ctl_rename_id - replace the id of a control on the card
625 * @card: the card instance
626 * @src_id: the old id
627 * @dst_id: the new id
629 * Finds the control with the old id from the card, and replaces the
630 * id with the new one.
632 * Return: Zero if successful, or a negative error code on failure.
634 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
635 struct snd_ctl_elem_id *dst_id)
637 struct snd_kcontrol *kctl;
639 down_write(&card->controls_rwsem);
640 kctl = snd_ctl_find_id(card, src_id);
642 up_write(&card->controls_rwsem);
646 kctl->id.numid = card->last_numid + 1;
647 card->last_numid += kctl->count;
648 up_write(&card->controls_rwsem);
651 EXPORT_SYMBOL(snd_ctl_rename_id);
654 * snd_ctl_find_numid - find the control instance with the given number-id
655 * @card: the card instance
656 * @numid: the number-id to search
658 * Finds the control instance with the given number-id from the card.
660 * The caller must down card->controls_rwsem before calling this function
661 * (if the race condition can happen).
663 * Return: The pointer of the instance if found, or %NULL if not.
666 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
668 struct snd_kcontrol *kctl;
670 if (snd_BUG_ON(!card || !numid))
672 list_for_each_entry(kctl, &card->controls, list) {
673 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
678 EXPORT_SYMBOL(snd_ctl_find_numid);
681 * snd_ctl_find_id - find the control instance with the given id
682 * @card: the card instance
683 * @id: the id to search
685 * Finds the control instance with the given id from the card.
687 * The caller must down card->controls_rwsem before calling this function
688 * (if the race condition can happen).
690 * Return: The pointer of the instance if found, or %NULL if not.
693 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
694 struct snd_ctl_elem_id *id)
696 struct snd_kcontrol *kctl;
698 if (snd_BUG_ON(!card || !id))
701 return snd_ctl_find_numid(card, id->numid);
702 list_for_each_entry(kctl, &card->controls, list) {
703 if (kctl->id.iface != id->iface)
705 if (kctl->id.device != id->device)
707 if (kctl->id.subdevice != id->subdevice)
709 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
711 if (kctl->id.index > id->index)
713 if (kctl->id.index + kctl->count <= id->index)
719 EXPORT_SYMBOL(snd_ctl_find_id);
721 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
722 unsigned int cmd, void __user *arg)
724 struct snd_ctl_card_info *info;
726 info = kzalloc(sizeof(*info), GFP_KERNEL);
729 down_read(&snd_ioctl_rwsem);
730 info->card = card->number;
731 strlcpy(info->id, card->id, sizeof(info->id));
732 strlcpy(info->driver, card->driver, sizeof(info->driver));
733 strlcpy(info->name, card->shortname, sizeof(info->name));
734 strlcpy(info->longname, card->longname, sizeof(info->longname));
735 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
736 strlcpy(info->components, card->components, sizeof(info->components));
737 up_read(&snd_ioctl_rwsem);
738 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
746 static int snd_ctl_elem_list(struct snd_card *card,
747 struct snd_ctl_elem_list __user *_list)
749 struct list_head *plist;
750 struct snd_ctl_elem_list list;
751 struct snd_kcontrol *kctl;
752 struct snd_ctl_elem_id *dst, *id;
753 unsigned int offset, space, jidx;
755 if (copy_from_user(&list, _list, sizeof(list)))
757 offset = list.offset;
759 /* try limit maximum space */
763 /* allocate temporary buffer for atomic operation */
764 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
767 down_read(&card->controls_rwsem);
768 list.count = card->controls_count;
769 plist = card->controls.next;
770 while (plist != &card->controls) {
773 kctl = snd_kcontrol(plist);
774 if (offset < kctl->count)
776 offset -= kctl->count;
781 while (space > 0 && plist != &card->controls) {
782 kctl = snd_kcontrol(plist);
783 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
784 snd_ctl_build_ioff(id, kctl, jidx);
792 up_read(&card->controls_rwsem);
794 copy_to_user(list.pids, dst,
795 list.used * sizeof(struct snd_ctl_elem_id))) {
801 down_read(&card->controls_rwsem);
802 list.count = card->controls_count;
803 up_read(&card->controls_rwsem);
805 if (copy_to_user(_list, &list, sizeof(list)))
810 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
811 struct snd_ctl_elem_info *info)
813 struct snd_card *card = ctl->card;
814 struct snd_kcontrol *kctl;
815 struct snd_kcontrol_volatile *vd;
816 unsigned int index_offset;
819 down_read(&card->controls_rwsem);
820 kctl = snd_ctl_find_id(card, &info->id);
822 up_read(&card->controls_rwsem);
825 #ifdef CONFIG_SND_DEBUG
828 result = kctl->info(kctl, info);
830 snd_BUG_ON(info->access);
831 index_offset = snd_ctl_get_ioff(kctl, &info->id);
832 vd = &kctl->vd[index_offset];
833 snd_ctl_build_ioff(&info->id, kctl, index_offset);
834 info->access = vd->access;
836 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
837 if (vd->owner == ctl)
838 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
839 info->owner = pid_vnr(vd->owner->pid);
844 up_read(&card->controls_rwsem);
848 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
849 struct snd_ctl_elem_info __user *_info)
851 struct snd_ctl_elem_info info;
854 if (copy_from_user(&info, _info, sizeof(info)))
856 snd_power_lock(ctl->card);
857 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
859 result = snd_ctl_elem_info(ctl, &info);
860 snd_power_unlock(ctl->card);
862 if (copy_to_user(_info, &info, sizeof(info)))
867 static int snd_ctl_elem_read(struct snd_card *card,
868 struct snd_ctl_elem_value *control)
870 struct snd_kcontrol *kctl;
871 struct snd_kcontrol_volatile *vd;
872 unsigned int index_offset;
875 down_read(&card->controls_rwsem);
876 kctl = snd_ctl_find_id(card, &control->id);
880 index_offset = snd_ctl_get_ioff(kctl, &control->id);
881 vd = &kctl->vd[index_offset];
882 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
884 snd_ctl_build_ioff(&control->id, kctl, index_offset);
885 result = kctl->get(kctl, control);
889 up_read(&card->controls_rwsem);
893 static int snd_ctl_elem_read_user(struct snd_card *card,
894 struct snd_ctl_elem_value __user *_control)
896 struct snd_ctl_elem_value *control;
899 control = memdup_user(_control, sizeof(*control));
901 return PTR_ERR(control);
903 snd_power_lock(card);
904 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
906 result = snd_ctl_elem_read(card, control);
907 snd_power_unlock(card);
909 if (copy_to_user(_control, control, sizeof(*control)))
915 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
916 struct snd_ctl_elem_value *control)
918 struct snd_kcontrol *kctl;
919 struct snd_kcontrol_volatile *vd;
920 unsigned int index_offset;
923 down_read(&card->controls_rwsem);
924 kctl = snd_ctl_find_id(card, &control->id);
928 index_offset = snd_ctl_get_ioff(kctl, &control->id);
929 vd = &kctl->vd[index_offset];
930 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
932 (file && vd->owner && vd->owner != file)) {
935 snd_ctl_build_ioff(&control->id, kctl, index_offset);
936 result = kctl->put(kctl, control);
939 struct snd_ctl_elem_id id = control->id;
940 up_read(&card->controls_rwsem);
941 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
945 up_read(&card->controls_rwsem);
949 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
950 struct snd_ctl_elem_value __user *_control)
952 struct snd_ctl_elem_value *control;
953 struct snd_card *card;
956 control = memdup_user(_control, sizeof(*control));
958 return PTR_ERR(control);
961 snd_power_lock(card);
962 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
964 result = snd_ctl_elem_write(card, file, control);
965 snd_power_unlock(card);
967 if (copy_to_user(_control, control, sizeof(*control)))
973 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
974 struct snd_ctl_elem_id __user *_id)
976 struct snd_card *card = file->card;
977 struct snd_ctl_elem_id id;
978 struct snd_kcontrol *kctl;
979 struct snd_kcontrol_volatile *vd;
982 if (copy_from_user(&id, _id, sizeof(id)))
984 down_write(&card->controls_rwsem);
985 kctl = snd_ctl_find_id(card, &id);
989 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
990 if (vd->owner != NULL)
997 up_write(&card->controls_rwsem);
1001 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1002 struct snd_ctl_elem_id __user *_id)
1004 struct snd_card *card = file->card;
1005 struct snd_ctl_elem_id id;
1006 struct snd_kcontrol *kctl;
1007 struct snd_kcontrol_volatile *vd;
1010 if (copy_from_user(&id, _id, sizeof(id)))
1012 down_write(&card->controls_rwsem);
1013 kctl = snd_ctl_find_id(card, &id);
1017 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1018 if (vd->owner == NULL)
1020 else if (vd->owner != file)
1027 up_write(&card->controls_rwsem);
1031 struct user_element {
1032 struct snd_ctl_elem_info info;
1033 struct snd_card *card;
1034 char *elem_data; /* element data */
1035 unsigned long elem_data_size; /* size of element data in bytes */
1036 void *tlv_data; /* TLV data */
1037 unsigned long tlv_data_size; /* TLV data size */
1038 void *priv_data; /* private data (like strings for enumerated type) */
1041 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1042 struct snd_ctl_elem_info *uinfo)
1044 struct user_element *ue = kcontrol->private_data;
1045 unsigned int offset;
1047 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1049 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1054 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1055 struct snd_ctl_elem_info *uinfo)
1057 struct user_element *ue = kcontrol->private_data;
1060 unsigned int offset;
1062 item = uinfo->value.enumerated.item;
1064 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1066 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1068 item = min(item, uinfo->value.enumerated.items - 1);
1069 uinfo->value.enumerated.item = item;
1071 names = ue->priv_data;
1072 for (; item > 0; --item)
1073 names += strlen(names) + 1;
1074 strcpy(uinfo->value.enumerated.name, names);
1079 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1080 struct snd_ctl_elem_value *ucontrol)
1082 struct user_element *ue = kcontrol->private_data;
1083 unsigned int size = ue->elem_data_size;
1084 char *src = ue->elem_data +
1085 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1087 mutex_lock(&ue->card->user_ctl_lock);
1088 memcpy(&ucontrol->value, src, size);
1089 mutex_unlock(&ue->card->user_ctl_lock);
1093 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1094 struct snd_ctl_elem_value *ucontrol)
1097 struct user_element *ue = kcontrol->private_data;
1098 unsigned int size = ue->elem_data_size;
1099 char *dst = ue->elem_data +
1100 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1102 mutex_lock(&ue->card->user_ctl_lock);
1103 change = memcmp(&ucontrol->value, dst, size) != 0;
1105 memcpy(dst, &ucontrol->value, size);
1106 mutex_unlock(&ue->card->user_ctl_lock);
1110 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1113 unsigned int __user *tlv)
1115 struct user_element *ue = kcontrol->private_data;
1119 if (op_flag == SNDRV_CTL_TLV_OP_WRITE) {
1120 if (size > 1024 * 128) /* sane value */
1123 new_data = memdup_user(tlv, size);
1124 if (IS_ERR(new_data))
1125 return PTR_ERR(new_data);
1126 mutex_lock(&ue->card->user_ctl_lock);
1127 change = ue->tlv_data_size != size;
1129 change = memcmp(ue->tlv_data, new_data, size);
1130 kfree(ue->tlv_data);
1131 ue->tlv_data = new_data;
1132 ue->tlv_data_size = size;
1133 mutex_unlock(&ue->card->user_ctl_lock);
1137 mutex_lock(&ue->card->user_ctl_lock);
1138 if (!ue->tlv_data_size || !ue->tlv_data) {
1142 if (size < ue->tlv_data_size) {
1146 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1149 mutex_unlock(&ue->card->user_ctl_lock);
1156 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1159 size_t buf_len, name_len;
1161 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1163 if (ue->info.value.enumerated.names_length > 64 * 1024)
1166 names = memdup_user((const void __user *)user_ptrval,
1167 ue->info.value.enumerated.names_length);
1169 return PTR_ERR(names);
1171 /* check that there are enough valid names */
1172 buf_len = ue->info.value.enumerated.names_length;
1174 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1175 name_len = strnlen(p, buf_len);
1176 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1181 buf_len -= name_len + 1;
1184 ue->priv_data = names;
1185 ue->info.value.enumerated.names_ptr = 0;
1190 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1192 struct user_element *ue = kcontrol->private_data;
1194 kfree(ue->tlv_data);
1195 kfree(ue->priv_data);
1199 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1200 struct snd_ctl_elem_info *info, int replace)
1202 /* The capacity of struct snd_ctl_elem_value.value.*/
1203 static const unsigned int value_sizes[] = {
1204 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1205 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1206 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1207 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1208 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1209 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1211 static const unsigned int max_value_counts[] = {
1212 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1213 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1214 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1215 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1216 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1217 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1219 struct snd_card *card = file->card;
1220 struct snd_kcontrol *kctl;
1222 unsigned int access;
1224 struct user_element *ue;
1225 unsigned int offset;
1228 if (!*info->id.name)
1230 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1233 /* Delete a control to replace them if needed. */
1236 err = snd_ctl_remove_user_ctl(file, &info->id);
1242 * The number of userspace controls are counted control by control,
1243 * not element by element.
1245 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1248 /* Check the number of elements for this userspace control. */
1249 count = info->owner;
1253 /* Arrange access permissions if needed. */
1254 access = info->access;
1256 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1257 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1258 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1259 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE);
1260 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1261 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1262 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1265 * Check information and calculate the size of data specific to
1266 * this userspace control.
1268 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1269 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1271 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1272 info->value.enumerated.items == 0)
1274 if (info->count < 1 ||
1275 info->count > max_value_counts[info->type])
1277 private_size = value_sizes[info->type] * info->count;
1280 * Keep memory object for this userspace control. After passing this
1281 * code block, the instance should be freed by snd_ctl_free_one().
1283 * Note that these elements in this control are locked.
1285 err = snd_ctl_new(&kctl, count, access, file);
1288 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1289 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1291 if (kctl->private_data == NULL) {
1295 kctl->private_free = snd_ctl_elem_user_free;
1297 /* Set private data for this userspace control. */
1298 ue = (struct user_element *)kctl->private_data;
1301 ue->info.access = 0;
1302 ue->elem_data = (char *)ue + sizeof(*ue);
1303 ue->elem_data_size = private_size;
1304 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1305 err = snd_ctl_elem_init_enum_names(ue);
1307 snd_ctl_free_one(kctl);
1312 /* Set callback functions. */
1313 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1314 kctl->info = snd_ctl_elem_user_enum_info;
1316 kctl->info = snd_ctl_elem_user_info;
1317 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1318 kctl->get = snd_ctl_elem_user_get;
1319 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1320 kctl->put = snd_ctl_elem_user_put;
1321 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE)
1322 kctl->tlv.c = snd_ctl_elem_user_tlv;
1324 /* This function manage to free the instance on failure. */
1325 err = snd_ctl_add(card, kctl);
1328 offset = snd_ctl_get_ioff(kctl, &info->id);
1329 snd_ctl_build_ioff(&info->id, kctl, offset);
1331 * Here we cannot fill any field for the number of elements added by
1332 * this operation because there're no specific fields. The usage of
1333 * 'owner' field for this purpose may cause any bugs to userspace
1334 * applications because the field originally means PID of a process
1335 * which locks the element.
1338 down_write(&card->controls_rwsem);
1339 card->user_ctl_count++;
1340 up_write(&card->controls_rwsem);
1345 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1346 struct snd_ctl_elem_info __user *_info, int replace)
1348 struct snd_ctl_elem_info info;
1351 if (copy_from_user(&info, _info, sizeof(info)))
1353 err = snd_ctl_elem_add(file, &info, replace);
1356 if (copy_to_user(_info, &info, sizeof(info))) {
1357 snd_ctl_remove_user_ctl(file, &info.id);
1364 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1365 struct snd_ctl_elem_id __user *_id)
1367 struct snd_ctl_elem_id id;
1369 if (copy_from_user(&id, _id, sizeof(id)))
1371 return snd_ctl_remove_user_ctl(file, &id);
1374 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1377 if (get_user(subscribe, ptr))
1379 if (subscribe < 0) {
1380 subscribe = file->subscribed;
1381 if (put_user(subscribe, ptr))
1386 file->subscribed = 1;
1388 } else if (file->subscribed) {
1389 snd_ctl_empty_read_queue(file);
1390 file->subscribed = 0;
1395 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1396 struct snd_ctl_tlv __user *_tlv,
1399 struct snd_card *card = file->card;
1400 struct snd_ctl_tlv tlv;
1401 struct snd_kcontrol *kctl;
1402 struct snd_kcontrol_volatile *vd;
1406 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1408 if (tlv.length < sizeof(unsigned int) * 2)
1412 down_read(&card->controls_rwsem);
1413 kctl = snd_ctl_find_numid(card, tlv.numid);
1418 if (kctl->tlv.p == NULL) {
1422 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1423 if ((op_flag == SNDRV_CTL_TLV_OP_READ &&
1424 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1425 (op_flag == SNDRV_CTL_TLV_OP_WRITE &&
1426 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1427 (op_flag == SNDRV_CTL_TLV_OP_CMD &&
1428 (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1432 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1433 if (vd->owner != NULL && vd->owner != file) {
1437 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1439 struct snd_ctl_elem_id id = kctl->id;
1440 up_read(&card->controls_rwsem);
1441 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &id);
1445 if (op_flag != SNDRV_CTL_TLV_OP_READ) {
1449 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1450 if (tlv.length < len) {
1454 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1458 up_read(&card->controls_rwsem);
1462 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1464 struct snd_ctl_file *ctl;
1465 struct snd_card *card;
1466 struct snd_kctl_ioctl *p;
1467 void __user *argp = (void __user *)arg;
1468 int __user *ip = argp;
1471 ctl = file->private_data;
1473 if (snd_BUG_ON(!card))
1476 case SNDRV_CTL_IOCTL_PVERSION:
1477 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1478 case SNDRV_CTL_IOCTL_CARD_INFO:
1479 return snd_ctl_card_info(card, ctl, cmd, argp);
1480 case SNDRV_CTL_IOCTL_ELEM_LIST:
1481 return snd_ctl_elem_list(card, argp);
1482 case SNDRV_CTL_IOCTL_ELEM_INFO:
1483 return snd_ctl_elem_info_user(ctl, argp);
1484 case SNDRV_CTL_IOCTL_ELEM_READ:
1485 return snd_ctl_elem_read_user(card, argp);
1486 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1487 return snd_ctl_elem_write_user(ctl, argp);
1488 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1489 return snd_ctl_elem_lock(ctl, argp);
1490 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1491 return snd_ctl_elem_unlock(ctl, argp);
1492 case SNDRV_CTL_IOCTL_ELEM_ADD:
1493 return snd_ctl_elem_add_user(ctl, argp, 0);
1494 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1495 return snd_ctl_elem_add_user(ctl, argp, 1);
1496 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1497 return snd_ctl_elem_remove(ctl, argp);
1498 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1499 return snd_ctl_subscribe_events(ctl, ip);
1500 case SNDRV_CTL_IOCTL_TLV_READ:
1501 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1502 case SNDRV_CTL_IOCTL_TLV_WRITE:
1503 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1504 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1505 return snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1506 case SNDRV_CTL_IOCTL_POWER:
1507 return -ENOPROTOOPT;
1508 case SNDRV_CTL_IOCTL_POWER_STATE:
1510 return put_user(card->power_state, ip) ? -EFAULT : 0;
1512 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1515 down_read(&snd_ioctl_rwsem);
1516 list_for_each_entry(p, &snd_control_ioctls, list) {
1517 err = p->fioctl(card, ctl, cmd, arg);
1518 if (err != -ENOIOCTLCMD) {
1519 up_read(&snd_ioctl_rwsem);
1523 up_read(&snd_ioctl_rwsem);
1524 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1528 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1529 size_t count, loff_t * offset)
1531 struct snd_ctl_file *ctl;
1535 ctl = file->private_data;
1536 if (snd_BUG_ON(!ctl || !ctl->card))
1538 if (!ctl->subscribed)
1540 if (count < sizeof(struct snd_ctl_event))
1542 spin_lock_irq(&ctl->read_lock);
1543 while (count >= sizeof(struct snd_ctl_event)) {
1544 struct snd_ctl_event ev;
1545 struct snd_kctl_event *kev;
1546 while (list_empty(&ctl->events)) {
1548 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1552 init_waitqueue_entry(&wait, current);
1553 add_wait_queue(&ctl->change_sleep, &wait);
1554 set_current_state(TASK_INTERRUPTIBLE);
1555 spin_unlock_irq(&ctl->read_lock);
1557 remove_wait_queue(&ctl->change_sleep, &wait);
1558 if (ctl->card->shutdown)
1560 if (signal_pending(current))
1561 return -ERESTARTSYS;
1562 spin_lock_irq(&ctl->read_lock);
1564 kev = snd_kctl_event(ctl->events.next);
1565 ev.type = SNDRV_CTL_EVENT_ELEM;
1566 ev.data.elem.mask = kev->mask;
1567 ev.data.elem.id = kev->id;
1568 list_del(&kev->list);
1569 spin_unlock_irq(&ctl->read_lock);
1571 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1575 spin_lock_irq(&ctl->read_lock);
1576 buffer += sizeof(struct snd_ctl_event);
1577 count -= sizeof(struct snd_ctl_event);
1578 result += sizeof(struct snd_ctl_event);
1581 spin_unlock_irq(&ctl->read_lock);
1583 return result > 0 ? result : err;
1586 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1589 struct snd_ctl_file *ctl;
1591 ctl = file->private_data;
1592 if (!ctl->subscribed)
1594 poll_wait(file, &ctl->change_sleep, wait);
1597 if (!list_empty(&ctl->events))
1598 mask |= POLLIN | POLLRDNORM;
1604 * register the device-specific control-ioctls.
1605 * called from each device manager like pcm.c, hwdep.c, etc.
1607 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1609 struct snd_kctl_ioctl *pn;
1611 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1615 down_write(&snd_ioctl_rwsem);
1616 list_add_tail(&pn->list, lists);
1617 up_write(&snd_ioctl_rwsem);
1622 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1623 * @fcn: ioctl callback function
1625 * called from each device manager like pcm.c, hwdep.c, etc.
1627 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1629 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1631 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1633 #ifdef CONFIG_COMPAT
1635 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1637 * @fcn: ioctl callback function
1639 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1641 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1643 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1647 * de-register the device-specific control-ioctls.
1649 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1650 struct list_head *lists)
1652 struct snd_kctl_ioctl *p;
1654 if (snd_BUG_ON(!fcn))
1656 down_write(&snd_ioctl_rwsem);
1657 list_for_each_entry(p, lists, list) {
1658 if (p->fioctl == fcn) {
1660 up_write(&snd_ioctl_rwsem);
1665 up_write(&snd_ioctl_rwsem);
1671 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1672 * @fcn: ioctl callback function to unregister
1674 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1676 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1678 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1680 #ifdef CONFIG_COMPAT
1682 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1684 * @fcn: ioctl callback function to unregister
1686 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1688 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1690 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1693 static int snd_ctl_fasync(int fd, struct file * file, int on)
1695 struct snd_ctl_file *ctl;
1697 ctl = file->private_data;
1698 return fasync_helper(fd, file, on, &ctl->fasync);
1701 /* return the preferred subdevice number if already assigned;
1702 * otherwise return -1
1704 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1706 struct snd_ctl_file *kctl;
1709 read_lock(&card->ctl_files_rwlock);
1710 list_for_each_entry(kctl, &card->ctl_files, list) {
1711 if (kctl->pid == task_pid(current)) {
1712 subdevice = kctl->preferred_subdevice[type];
1713 if (subdevice != -1)
1717 read_unlock(&card->ctl_files_rwlock);
1720 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1725 #ifdef CONFIG_COMPAT
1726 #include "control_compat.c"
1728 #define snd_ctl_ioctl_compat NULL
1735 static const struct file_operations snd_ctl_f_ops =
1737 .owner = THIS_MODULE,
1738 .read = snd_ctl_read,
1739 .open = snd_ctl_open,
1740 .release = snd_ctl_release,
1741 .llseek = no_llseek,
1742 .poll = snd_ctl_poll,
1743 .unlocked_ioctl = snd_ctl_ioctl,
1744 .compat_ioctl = snd_ctl_ioctl_compat,
1745 .fasync = snd_ctl_fasync,
1749 * registration of the control device
1751 static int snd_ctl_dev_register(struct snd_device *device)
1753 struct snd_card *card = device->device_data;
1755 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1756 &snd_ctl_f_ops, card, &card->ctl_dev);
1760 * disconnection of the control device
1762 static int snd_ctl_dev_disconnect(struct snd_device *device)
1764 struct snd_card *card = device->device_data;
1765 struct snd_ctl_file *ctl;
1767 read_lock(&card->ctl_files_rwlock);
1768 list_for_each_entry(ctl, &card->ctl_files, list) {
1769 wake_up(&ctl->change_sleep);
1770 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1772 read_unlock(&card->ctl_files_rwlock);
1774 return snd_unregister_device(&card->ctl_dev);
1780 static int snd_ctl_dev_free(struct snd_device *device)
1782 struct snd_card *card = device->device_data;
1783 struct snd_kcontrol *control;
1785 down_write(&card->controls_rwsem);
1786 while (!list_empty(&card->controls)) {
1787 control = snd_kcontrol(card->controls.next);
1788 snd_ctl_remove(card, control);
1790 up_write(&card->controls_rwsem);
1791 put_device(&card->ctl_dev);
1796 * create control core:
1797 * called from init.c
1799 int snd_ctl_create(struct snd_card *card)
1801 static struct snd_device_ops ops = {
1802 .dev_free = snd_ctl_dev_free,
1803 .dev_register = snd_ctl_dev_register,
1804 .dev_disconnect = snd_ctl_dev_disconnect,
1808 if (snd_BUG_ON(!card))
1810 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1813 snd_device_initialize(&card->ctl_dev, card);
1814 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1816 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1818 put_device(&card->ctl_dev);
1823 * Frequently used control callbacks/helpers
1827 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1828 * callback with a mono channel
1829 * @kcontrol: the kcontrol instance
1830 * @uinfo: info to store
1832 * This is a function that can be used as info callback for a standard
1833 * boolean control with a single mono channel.
1835 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1836 struct snd_ctl_elem_info *uinfo)
1838 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1840 uinfo->value.integer.min = 0;
1841 uinfo->value.integer.max = 1;
1844 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1847 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1848 * callback with stereo two channels
1849 * @kcontrol: the kcontrol instance
1850 * @uinfo: info to store
1852 * This is a function that can be used as info callback for a standard
1853 * boolean control with stereo two channels.
1855 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1856 struct snd_ctl_elem_info *uinfo)
1858 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1860 uinfo->value.integer.min = 0;
1861 uinfo->value.integer.max = 1;
1864 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1867 * snd_ctl_enum_info - fills the info structure for an enumerated control
1868 * @info: the structure to be filled
1869 * @channels: the number of the control's channels; often one
1870 * @items: the number of control values; also the size of @names
1871 * @names: an array containing the names of all control values
1873 * Sets all required fields in @info to their appropriate values.
1874 * If the control's accessibility is not the default (readable and writable),
1875 * the caller has to fill @info->access.
1879 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1880 unsigned int items, const char *const names[])
1882 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1883 info->count = channels;
1884 info->value.enumerated.items = items;
1887 if (info->value.enumerated.item >= items)
1888 info->value.enumerated.item = items - 1;
1889 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1890 "ALSA: too long item name '%s'\n",
1891 names[info->value.enumerated.item]);
1892 strlcpy(info->value.enumerated.name,
1893 names[info->value.enumerated.item],
1894 sizeof(info->value.enumerated.name));
1897 EXPORT_SYMBOL(snd_ctl_enum_info);