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");
351 /* add a new kcontrol object; call with card->controls_rwsem locked */
352 static int __snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
354 struct snd_ctl_elem_id id;
359 if (id.index > UINT_MAX - kcontrol->count)
362 if (snd_ctl_find_id(card, &id)) {
364 "control %i:%i:%i:%s:%i is already present\n",
365 id.iface, id.device, id.subdevice, id.name, id.index);
369 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
372 list_add_tail(&kcontrol->list, &card->controls);
373 card->controls_count += kcontrol->count;
374 kcontrol->id.numid = card->last_numid + 1;
375 card->last_numid += kcontrol->count;
378 count = kcontrol->count;
379 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
380 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
386 * snd_ctl_add - add the control instance to the card
387 * @card: the card instance
388 * @kcontrol: the control instance to add
390 * Adds the control instance created via snd_ctl_new() or
391 * snd_ctl_new1() to the given card. Assigns also an unique
392 * numid used for fast search.
394 * It frees automatically the control which cannot be added.
396 * Return: Zero if successful, or a negative error code on failure.
399 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
405 if (snd_BUG_ON(!card || !kcontrol->info))
408 down_write(&card->controls_rwsem);
409 err = __snd_ctl_add(card, kcontrol);
410 up_write(&card->controls_rwsem);
416 snd_ctl_free_one(kcontrol);
419 EXPORT_SYMBOL(snd_ctl_add);
422 * snd_ctl_replace - replace the control instance of the card
423 * @card: the card instance
424 * @kcontrol: the control instance to replace
425 * @add_on_replace: add the control if not already added
427 * Replaces the given control. If the given control does not exist
428 * and the add_on_replace flag is set, the control is added. If the
429 * control exists, it is destroyed first.
431 * It frees automatically the control which cannot be added or replaced.
433 * Return: Zero if successful, or a negative error code on failure.
435 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
438 struct snd_ctl_elem_id id;
441 struct snd_kcontrol *old;
446 if (snd_BUG_ON(!card || !kcontrol->info)) {
451 down_write(&card->controls_rwsem);
452 old = snd_ctl_find_id(card, &id);
456 up_write(&card->controls_rwsem);
460 ret = snd_ctl_remove(card, old);
462 up_write(&card->controls_rwsem);
466 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
467 up_write(&card->controls_rwsem);
471 list_add_tail(&kcontrol->list, &card->controls);
472 card->controls_count += kcontrol->count;
473 kcontrol->id.numid = card->last_numid + 1;
474 card->last_numid += kcontrol->count;
476 count = kcontrol->count;
477 up_write(&card->controls_rwsem);
478 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
479 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
483 snd_ctl_free_one(kcontrol);
486 EXPORT_SYMBOL(snd_ctl_replace);
489 * snd_ctl_remove - remove the control from the card and release it
490 * @card: the card instance
491 * @kcontrol: the control instance to remove
493 * Removes the control from the card and then releases the instance.
494 * You don't need to call snd_ctl_free_one(). You must be in
495 * the write lock - down_write(&card->controls_rwsem).
497 * Return: 0 if successful, or a negative error code on failure.
499 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
501 struct snd_ctl_elem_id id;
504 if (snd_BUG_ON(!card || !kcontrol))
506 list_del(&kcontrol->list);
507 card->controls_count -= kcontrol->count;
509 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
510 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
511 snd_ctl_free_one(kcontrol);
514 EXPORT_SYMBOL(snd_ctl_remove);
517 * snd_ctl_remove_id - remove the control of the given id and release it
518 * @card: the card instance
519 * @id: the control id to remove
521 * Finds the control instance with the given id, removes it from the
522 * card list and releases it.
524 * Return: 0 if successful, or a negative error code on failure.
526 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
528 struct snd_kcontrol *kctl;
531 down_write(&card->controls_rwsem);
532 kctl = snd_ctl_find_id(card, id);
534 up_write(&card->controls_rwsem);
537 ret = snd_ctl_remove(card, kctl);
538 up_write(&card->controls_rwsem);
541 EXPORT_SYMBOL(snd_ctl_remove_id);
544 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
545 * @file: active control handle
546 * @id: the control id to remove
548 * Finds the control instance with the given id, removes it from the
549 * card list and releases it.
551 * Return: 0 if successful, or a negative error code on failure.
553 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
554 struct snd_ctl_elem_id *id)
556 struct snd_card *card = file->card;
557 struct snd_kcontrol *kctl;
560 down_write(&card->controls_rwsem);
561 kctl = snd_ctl_find_id(card, id);
566 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
570 for (idx = 0; idx < kctl->count; idx++)
571 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
575 ret = snd_ctl_remove(card, kctl);
578 card->user_ctl_count--;
580 up_write(&card->controls_rwsem);
585 * snd_ctl_activate_id - activate/inactivate the control of the given id
586 * @card: the card instance
587 * @id: the control id to activate/inactivate
588 * @active: non-zero to activate
590 * Finds the control instance with the given id, and activate or
591 * inactivate the control together with notification, if changed.
592 * The given ID data is filled with full information.
594 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
596 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
599 struct snd_kcontrol *kctl;
600 struct snd_kcontrol_volatile *vd;
601 unsigned int index_offset;
604 down_write(&card->controls_rwsem);
605 kctl = snd_ctl_find_id(card, id);
610 index_offset = snd_ctl_get_ioff(kctl, id);
611 vd = &kctl->vd[index_offset];
614 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
616 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
618 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
620 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
622 snd_ctl_build_ioff(id, kctl, index_offset);
625 up_write(&card->controls_rwsem);
627 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
630 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
633 * snd_ctl_rename_id - replace the id of a control on the card
634 * @card: the card instance
635 * @src_id: the old id
636 * @dst_id: the new id
638 * Finds the control with the old id from the card, and replaces the
639 * id with the new one.
641 * Return: Zero if successful, or a negative error code on failure.
643 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
644 struct snd_ctl_elem_id *dst_id)
646 struct snd_kcontrol *kctl;
648 down_write(&card->controls_rwsem);
649 kctl = snd_ctl_find_id(card, src_id);
651 up_write(&card->controls_rwsem);
655 kctl->id.numid = card->last_numid + 1;
656 card->last_numid += kctl->count;
657 up_write(&card->controls_rwsem);
660 EXPORT_SYMBOL(snd_ctl_rename_id);
663 * snd_ctl_find_numid - find the control instance with the given number-id
664 * @card: the card instance
665 * @numid: the number-id to search
667 * Finds the control instance with the given number-id from the card.
669 * The caller must down card->controls_rwsem before calling this function
670 * (if the race condition can happen).
672 * Return: The pointer of the instance if found, or %NULL if not.
675 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
677 struct snd_kcontrol *kctl;
679 if (snd_BUG_ON(!card || !numid))
681 list_for_each_entry(kctl, &card->controls, list) {
682 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
687 EXPORT_SYMBOL(snd_ctl_find_numid);
690 * snd_ctl_find_id - find the control instance with the given id
691 * @card: the card instance
692 * @id: the id to search
694 * Finds the control instance with the given id from the card.
696 * The caller must down card->controls_rwsem before calling this function
697 * (if the race condition can happen).
699 * Return: The pointer of the instance if found, or %NULL if not.
702 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
703 struct snd_ctl_elem_id *id)
705 struct snd_kcontrol *kctl;
707 if (snd_BUG_ON(!card || !id))
710 return snd_ctl_find_numid(card, id->numid);
711 list_for_each_entry(kctl, &card->controls, list) {
712 if (kctl->id.iface != id->iface)
714 if (kctl->id.device != id->device)
716 if (kctl->id.subdevice != id->subdevice)
718 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
720 if (kctl->id.index > id->index)
722 if (kctl->id.index + kctl->count <= id->index)
728 EXPORT_SYMBOL(snd_ctl_find_id);
730 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
731 unsigned int cmd, void __user *arg)
733 struct snd_ctl_card_info *info;
735 info = kzalloc(sizeof(*info), GFP_KERNEL);
738 down_read(&snd_ioctl_rwsem);
739 info->card = card->number;
740 strlcpy(info->id, card->id, sizeof(info->id));
741 strlcpy(info->driver, card->driver, sizeof(info->driver));
742 strlcpy(info->name, card->shortname, sizeof(info->name));
743 strlcpy(info->longname, card->longname, sizeof(info->longname));
744 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
745 strlcpy(info->components, card->components, sizeof(info->components));
746 up_read(&snd_ioctl_rwsem);
747 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
755 static int snd_ctl_elem_list(struct snd_card *card,
756 struct snd_ctl_elem_list __user *_list)
758 struct snd_ctl_elem_list list;
759 struct snd_kcontrol *kctl;
760 struct snd_ctl_elem_id id;
761 unsigned int offset, space, jidx;
764 if (copy_from_user(&list, _list, sizeof(list)))
766 offset = list.offset;
769 down_read(&card->controls_rwsem);
770 list.count = card->controls_count;
773 list_for_each_entry(kctl, &card->controls, list) {
774 if (offset >= kctl->count) {
775 offset -= kctl->count;
778 for (jidx = offset; jidx < kctl->count; jidx++) {
779 snd_ctl_build_ioff(&id, kctl, jidx);
780 if (copy_to_user(list.pids + list.used, &id,
793 up_read(&card->controls_rwsem);
794 if (!err && copy_to_user(_list, &list, sizeof(list)))
799 static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
801 unsigned int members;
804 if (info->dimen.d[0] == 0)
808 for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
809 if (info->dimen.d[i] == 0)
811 members *= info->dimen.d[i];
814 * info->count should be validated in advance, to guarantee
815 * calculation soundness.
817 if (members > info->count)
821 for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
822 if (info->dimen.d[i] > 0)
826 return members == info->count;
829 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
830 struct snd_ctl_elem_info *info)
832 struct snd_card *card = ctl->card;
833 struct snd_kcontrol *kctl;
834 struct snd_kcontrol_volatile *vd;
835 unsigned int index_offset;
838 down_read(&card->controls_rwsem);
839 kctl = snd_ctl_find_id(card, &info->id);
841 up_read(&card->controls_rwsem);
844 #ifdef CONFIG_SND_DEBUG
847 result = kctl->info(kctl, info);
849 snd_BUG_ON(info->access);
850 index_offset = snd_ctl_get_ioff(kctl, &info->id);
851 vd = &kctl->vd[index_offset];
852 snd_ctl_build_ioff(&info->id, kctl, index_offset);
853 info->access = vd->access;
855 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
856 if (vd->owner == ctl)
857 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
858 info->owner = pid_vnr(vd->owner->pid);
863 up_read(&card->controls_rwsem);
867 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
868 struct snd_ctl_elem_info __user *_info)
870 struct snd_ctl_elem_info info;
873 if (copy_from_user(&info, _info, sizeof(info)))
875 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
878 result = snd_ctl_elem_info(ctl, &info);
881 if (copy_to_user(_info, &info, sizeof(info)))
886 static int snd_ctl_elem_read(struct snd_card *card,
887 struct snd_ctl_elem_value *control)
889 struct snd_kcontrol *kctl;
890 struct snd_kcontrol_volatile *vd;
891 unsigned int index_offset;
893 kctl = snd_ctl_find_id(card, &control->id);
897 index_offset = snd_ctl_get_ioff(kctl, &control->id);
898 vd = &kctl->vd[index_offset];
899 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
902 snd_ctl_build_ioff(&control->id, kctl, index_offset);
903 return kctl->get(kctl, control);
906 static int snd_ctl_elem_read_user(struct snd_card *card,
907 struct snd_ctl_elem_value __user *_control)
909 struct snd_ctl_elem_value *control;
912 control = memdup_user(_control, sizeof(*control));
914 return PTR_ERR(control);
916 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
920 down_read(&card->controls_rwsem);
921 result = snd_ctl_elem_read(card, control);
922 up_read(&card->controls_rwsem);
926 if (copy_to_user(_control, control, sizeof(*control)))
933 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
934 struct snd_ctl_elem_value *control)
936 struct snd_kcontrol *kctl;
937 struct snd_kcontrol_volatile *vd;
938 unsigned int index_offset;
941 kctl = snd_ctl_find_id(card, &control->id);
945 index_offset = snd_ctl_get_ioff(kctl, &control->id);
946 vd = &kctl->vd[index_offset];
947 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
948 (file && vd->owner && vd->owner != file)) {
952 snd_ctl_build_ioff(&control->id, kctl, index_offset);
953 result = kctl->put(kctl, control);
958 struct snd_ctl_elem_id id = control->id;
959 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
965 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
966 struct snd_ctl_elem_value __user *_control)
968 struct snd_ctl_elem_value *control;
969 struct snd_card *card;
972 control = memdup_user(_control, sizeof(*control));
974 return PTR_ERR(control);
977 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
981 down_write(&card->controls_rwsem);
982 result = snd_ctl_elem_write(card, file, control);
983 up_write(&card->controls_rwsem);
987 if (copy_to_user(_control, control, sizeof(*control)))
994 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
995 struct snd_ctl_elem_id __user *_id)
997 struct snd_card *card = file->card;
998 struct snd_ctl_elem_id id;
999 struct snd_kcontrol *kctl;
1000 struct snd_kcontrol_volatile *vd;
1003 if (copy_from_user(&id, _id, sizeof(id)))
1005 down_write(&card->controls_rwsem);
1006 kctl = snd_ctl_find_id(card, &id);
1010 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1011 if (vd->owner != NULL)
1018 up_write(&card->controls_rwsem);
1022 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1023 struct snd_ctl_elem_id __user *_id)
1025 struct snd_card *card = file->card;
1026 struct snd_ctl_elem_id id;
1027 struct snd_kcontrol *kctl;
1028 struct snd_kcontrol_volatile *vd;
1031 if (copy_from_user(&id, _id, sizeof(id)))
1033 down_write(&card->controls_rwsem);
1034 kctl = snd_ctl_find_id(card, &id);
1038 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1039 if (vd->owner == NULL)
1041 else if (vd->owner != file)
1048 up_write(&card->controls_rwsem);
1052 struct user_element {
1053 struct snd_ctl_elem_info info;
1054 struct snd_card *card;
1055 char *elem_data; /* element data */
1056 unsigned long elem_data_size; /* size of element data in bytes */
1057 void *tlv_data; /* TLV data */
1058 unsigned long tlv_data_size; /* TLV data size */
1059 void *priv_data; /* private data (like strings for enumerated type) */
1062 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1063 struct snd_ctl_elem_info *uinfo)
1065 struct user_element *ue = kcontrol->private_data;
1066 unsigned int offset;
1068 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1070 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1075 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1076 struct snd_ctl_elem_info *uinfo)
1078 struct user_element *ue = kcontrol->private_data;
1081 unsigned int offset;
1083 item = uinfo->value.enumerated.item;
1085 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1087 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1089 item = min(item, uinfo->value.enumerated.items - 1);
1090 uinfo->value.enumerated.item = item;
1092 names = ue->priv_data;
1093 for (; item > 0; --item)
1094 names += strlen(names) + 1;
1095 strcpy(uinfo->value.enumerated.name, names);
1100 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1101 struct snd_ctl_elem_value *ucontrol)
1103 struct user_element *ue = kcontrol->private_data;
1104 unsigned int size = ue->elem_data_size;
1105 char *src = ue->elem_data +
1106 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1108 memcpy(&ucontrol->value, src, size);
1112 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1113 struct snd_ctl_elem_value *ucontrol)
1116 struct user_element *ue = kcontrol->private_data;
1117 unsigned int size = ue->elem_data_size;
1118 char *dst = ue->elem_data +
1119 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1121 change = memcmp(&ucontrol->value, dst, size) != 0;
1123 memcpy(dst, &ucontrol->value, size);
1127 static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1130 struct user_element *ue = kctl->private_data;
1131 unsigned int *container;
1132 struct snd_ctl_elem_id id;
1133 unsigned int mask = 0;
1137 if (size > 1024 * 128) /* sane value */
1140 container = vmemdup_user(buf, size);
1141 if (IS_ERR(container))
1142 return PTR_ERR(container);
1144 change = ue->tlv_data_size != size;
1146 change = memcmp(ue->tlv_data, container, size) != 0;
1152 if (ue->tlv_data == NULL) {
1153 /* Now TLV data is available. */
1154 for (i = 0; i < kctl->count; ++i)
1155 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1156 mask = SNDRV_CTL_EVENT_MASK_INFO;
1159 kvfree(ue->tlv_data);
1160 ue->tlv_data = container;
1161 ue->tlv_data_size = size;
1163 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1164 for (i = 0; i < kctl->count; ++i) {
1165 snd_ctl_build_ioff(&id, kctl, i);
1166 snd_ctl_notify(ue->card, mask, &id);
1172 static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1175 struct user_element *ue = kctl->private_data;
1177 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1180 if (size < ue->tlv_data_size)
1183 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1189 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1190 unsigned int size, unsigned int __user *buf)
1192 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1193 return replace_user_tlv(kctl, buf, size);
1195 return read_user_tlv(kctl, buf, size);
1198 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1201 size_t buf_len, name_len;
1203 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1205 if (ue->info.value.enumerated.names_length > 64 * 1024)
1208 names = vmemdup_user((const void __user *)user_ptrval,
1209 ue->info.value.enumerated.names_length);
1211 return PTR_ERR(names);
1213 /* check that there are enough valid names */
1214 buf_len = ue->info.value.enumerated.names_length;
1216 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1217 name_len = strnlen(p, buf_len);
1218 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1223 buf_len -= name_len + 1;
1226 ue->priv_data = names;
1227 ue->info.value.enumerated.names_ptr = 0;
1232 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1234 struct user_element *ue = kcontrol->private_data;
1236 kvfree(ue->tlv_data);
1237 kvfree(ue->priv_data);
1241 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1242 struct snd_ctl_elem_info *info, int replace)
1244 /* The capacity of struct snd_ctl_elem_value.value.*/
1245 static const unsigned int value_sizes[] = {
1246 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1247 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1248 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1249 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1250 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1251 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1253 static const unsigned int max_value_counts[] = {
1254 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1255 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1256 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1257 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1258 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1259 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1261 struct snd_card *card = file->card;
1262 struct snd_kcontrol *kctl;
1264 unsigned int access;
1266 struct user_element *ue;
1267 unsigned int offset;
1270 if (!*info->id.name)
1272 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1275 /* Delete a control to replace them if needed. */
1278 err = snd_ctl_remove_user_ctl(file, &info->id);
1284 * The number of userspace controls are counted control by control,
1285 * not element by element.
1287 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1290 /* Check the number of elements for this userspace control. */
1291 count = info->owner;
1295 /* Arrange access permissions if needed. */
1296 access = info->access;
1298 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1299 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1300 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1301 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1303 /* In initial state, nothing is available as TLV container. */
1304 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1305 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1306 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1309 * Check information and calculate the size of data specific to
1310 * this userspace control.
1312 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1313 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1315 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1316 info->value.enumerated.items == 0)
1318 if (info->count < 1 ||
1319 info->count > max_value_counts[info->type])
1321 if (!validate_element_member_dimension(info))
1323 private_size = value_sizes[info->type] * info->count;
1326 * Keep memory object for this userspace control. After passing this
1327 * code block, the instance should be freed by snd_ctl_free_one().
1329 * Note that these elements in this control are locked.
1331 err = snd_ctl_new(&kctl, count, access, file);
1334 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1335 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1337 if (kctl->private_data == NULL) {
1341 kctl->private_free = snd_ctl_elem_user_free;
1343 /* Set private data for this userspace control. */
1344 ue = (struct user_element *)kctl->private_data;
1347 ue->info.access = 0;
1348 ue->elem_data = (char *)ue + sizeof(*ue);
1349 ue->elem_data_size = private_size;
1350 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1351 err = snd_ctl_elem_init_enum_names(ue);
1353 snd_ctl_free_one(kctl);
1358 /* Set callback functions. */
1359 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1360 kctl->info = snd_ctl_elem_user_enum_info;
1362 kctl->info = snd_ctl_elem_user_info;
1363 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1364 kctl->get = snd_ctl_elem_user_get;
1365 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1366 kctl->put = snd_ctl_elem_user_put;
1367 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1368 kctl->tlv.c = snd_ctl_elem_user_tlv;
1370 /* This function manage to free the instance on failure. */
1371 down_write(&card->controls_rwsem);
1372 err = __snd_ctl_add(card, kctl);
1374 snd_ctl_free_one(kctl);
1377 offset = snd_ctl_get_ioff(kctl, &info->id);
1378 snd_ctl_build_ioff(&info->id, kctl, offset);
1380 * Here we cannot fill any field for the number of elements added by
1381 * this operation because there're no specific fields. The usage of
1382 * 'owner' field for this purpose may cause any bugs to userspace
1383 * applications because the field originally means PID of a process
1384 * which locks the element.
1387 card->user_ctl_count++;
1390 up_write(&card->controls_rwsem);
1394 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1395 struct snd_ctl_elem_info __user *_info, int replace)
1397 struct snd_ctl_elem_info info;
1400 if (copy_from_user(&info, _info, sizeof(info)))
1402 err = snd_ctl_elem_add(file, &info, replace);
1405 if (copy_to_user(_info, &info, sizeof(info))) {
1406 snd_ctl_remove_user_ctl(file, &info.id);
1413 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1414 struct snd_ctl_elem_id __user *_id)
1416 struct snd_ctl_elem_id id;
1418 if (copy_from_user(&id, _id, sizeof(id)))
1420 return snd_ctl_remove_user_ctl(file, &id);
1423 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1426 if (get_user(subscribe, ptr))
1428 if (subscribe < 0) {
1429 subscribe = file->subscribed;
1430 if (put_user(subscribe, ptr))
1435 file->subscribed = 1;
1437 } else if (file->subscribed) {
1438 snd_ctl_empty_read_queue(file);
1439 file->subscribed = 0;
1444 static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1445 struct snd_kcontrol *kctl,
1446 struct snd_ctl_elem_id *id,
1447 unsigned int __user *buf, unsigned int size)
1449 static const struct {
1453 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1454 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1455 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1457 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1460 /* Check support of the request for this element. */
1461 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1462 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1465 if (i == ARRAY_SIZE(pairs))
1468 if (kctl->tlv.c == NULL)
1471 /* Write and command operations are not allowed for locked element. */
1472 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1473 vd->owner != NULL && vd->owner != file)
1476 return kctl->tlv.c(kctl, op_flag, size, buf);
1479 static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1480 unsigned int __user *buf, unsigned int size)
1482 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1485 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1488 if (kctl->tlv.p == NULL)
1491 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1495 if (copy_to_user(buf, kctl->tlv.p, len))
1501 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1502 struct snd_ctl_tlv __user *buf,
1505 struct snd_ctl_tlv header;
1506 unsigned int __user *container;
1507 unsigned int container_size;
1508 struct snd_kcontrol *kctl;
1509 struct snd_ctl_elem_id id;
1510 struct snd_kcontrol_volatile *vd;
1512 if (copy_from_user(&header, buf, sizeof(header)))
1515 /* In design of control core, numerical ID starts at 1. */
1516 if (header.numid == 0)
1519 /* At least, container should include type and length fields. */
1520 if (header.length < sizeof(unsigned int) * 2)
1522 container_size = header.length;
1523 container = buf->tlv;
1525 kctl = snd_ctl_find_numid(file->card, header.numid);
1529 /* Calculate index of the element in this set. */
1531 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1532 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1534 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1535 return call_tlv_handler(file, op_flag, kctl, &id, container,
1538 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1539 return read_tlv_buf(kctl, &id, container,
1544 /* Not supported. */
1548 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1550 struct snd_ctl_file *ctl;
1551 struct snd_card *card;
1552 struct snd_kctl_ioctl *p;
1553 void __user *argp = (void __user *)arg;
1554 int __user *ip = argp;
1557 ctl = file->private_data;
1559 if (snd_BUG_ON(!card))
1562 case SNDRV_CTL_IOCTL_PVERSION:
1563 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1564 case SNDRV_CTL_IOCTL_CARD_INFO:
1565 return snd_ctl_card_info(card, ctl, cmd, argp);
1566 case SNDRV_CTL_IOCTL_ELEM_LIST:
1567 return snd_ctl_elem_list(card, argp);
1568 case SNDRV_CTL_IOCTL_ELEM_INFO:
1569 return snd_ctl_elem_info_user(ctl, argp);
1570 case SNDRV_CTL_IOCTL_ELEM_READ:
1571 return snd_ctl_elem_read_user(card, argp);
1572 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1573 return snd_ctl_elem_write_user(ctl, argp);
1574 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1575 return snd_ctl_elem_lock(ctl, argp);
1576 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1577 return snd_ctl_elem_unlock(ctl, argp);
1578 case SNDRV_CTL_IOCTL_ELEM_ADD:
1579 return snd_ctl_elem_add_user(ctl, argp, 0);
1580 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1581 return snd_ctl_elem_add_user(ctl, argp, 1);
1582 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1583 return snd_ctl_elem_remove(ctl, argp);
1584 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1585 return snd_ctl_subscribe_events(ctl, ip);
1586 case SNDRV_CTL_IOCTL_TLV_READ:
1587 down_read(&ctl->card->controls_rwsem);
1588 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1589 up_read(&ctl->card->controls_rwsem);
1591 case SNDRV_CTL_IOCTL_TLV_WRITE:
1592 down_write(&ctl->card->controls_rwsem);
1593 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1594 up_write(&ctl->card->controls_rwsem);
1596 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1597 down_write(&ctl->card->controls_rwsem);
1598 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1599 up_write(&ctl->card->controls_rwsem);
1601 case SNDRV_CTL_IOCTL_POWER:
1602 return -ENOPROTOOPT;
1603 case SNDRV_CTL_IOCTL_POWER_STATE:
1605 return put_user(card->power_state, ip) ? -EFAULT : 0;
1607 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1610 down_read(&snd_ioctl_rwsem);
1611 list_for_each_entry(p, &snd_control_ioctls, list) {
1612 err = p->fioctl(card, ctl, cmd, arg);
1613 if (err != -ENOIOCTLCMD) {
1614 up_read(&snd_ioctl_rwsem);
1618 up_read(&snd_ioctl_rwsem);
1619 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1623 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1624 size_t count, loff_t * offset)
1626 struct snd_ctl_file *ctl;
1630 ctl = file->private_data;
1631 if (snd_BUG_ON(!ctl || !ctl->card))
1633 if (!ctl->subscribed)
1635 if (count < sizeof(struct snd_ctl_event))
1637 spin_lock_irq(&ctl->read_lock);
1638 while (count >= sizeof(struct snd_ctl_event)) {
1639 struct snd_ctl_event ev;
1640 struct snd_kctl_event *kev;
1641 while (list_empty(&ctl->events)) {
1642 wait_queue_entry_t wait;
1643 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1647 init_waitqueue_entry(&wait, current);
1648 add_wait_queue(&ctl->change_sleep, &wait);
1649 set_current_state(TASK_INTERRUPTIBLE);
1650 spin_unlock_irq(&ctl->read_lock);
1652 remove_wait_queue(&ctl->change_sleep, &wait);
1653 if (ctl->card->shutdown)
1655 if (signal_pending(current))
1656 return -ERESTARTSYS;
1657 spin_lock_irq(&ctl->read_lock);
1659 kev = snd_kctl_event(ctl->events.next);
1660 ev.type = SNDRV_CTL_EVENT_ELEM;
1661 ev.data.elem.mask = kev->mask;
1662 ev.data.elem.id = kev->id;
1663 list_del(&kev->list);
1664 spin_unlock_irq(&ctl->read_lock);
1666 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1670 spin_lock_irq(&ctl->read_lock);
1671 buffer += sizeof(struct snd_ctl_event);
1672 count -= sizeof(struct snd_ctl_event);
1673 result += sizeof(struct snd_ctl_event);
1676 spin_unlock_irq(&ctl->read_lock);
1678 return result > 0 ? result : err;
1681 static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1684 struct snd_ctl_file *ctl;
1686 ctl = file->private_data;
1687 if (!ctl->subscribed)
1689 poll_wait(file, &ctl->change_sleep, wait);
1692 if (!list_empty(&ctl->events))
1693 mask |= EPOLLIN | EPOLLRDNORM;
1699 * register the device-specific control-ioctls.
1700 * called from each device manager like pcm.c, hwdep.c, etc.
1702 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1704 struct snd_kctl_ioctl *pn;
1706 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1710 down_write(&snd_ioctl_rwsem);
1711 list_add_tail(&pn->list, lists);
1712 up_write(&snd_ioctl_rwsem);
1717 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1718 * @fcn: ioctl callback function
1720 * called from each device manager like pcm.c, hwdep.c, etc.
1722 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1724 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1726 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1728 #ifdef CONFIG_COMPAT
1730 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1732 * @fcn: ioctl callback function
1734 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1736 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1738 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1742 * de-register the device-specific control-ioctls.
1744 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1745 struct list_head *lists)
1747 struct snd_kctl_ioctl *p;
1749 if (snd_BUG_ON(!fcn))
1751 down_write(&snd_ioctl_rwsem);
1752 list_for_each_entry(p, lists, list) {
1753 if (p->fioctl == fcn) {
1755 up_write(&snd_ioctl_rwsem);
1760 up_write(&snd_ioctl_rwsem);
1766 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1767 * @fcn: ioctl callback function to unregister
1769 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1771 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1773 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1775 #ifdef CONFIG_COMPAT
1777 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1779 * @fcn: ioctl callback function to unregister
1781 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1783 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1785 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1788 static int snd_ctl_fasync(int fd, struct file * file, int on)
1790 struct snd_ctl_file *ctl;
1792 ctl = file->private_data;
1793 return fasync_helper(fd, file, on, &ctl->fasync);
1796 /* return the preferred subdevice number if already assigned;
1797 * otherwise return -1
1799 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1801 struct snd_ctl_file *kctl;
1804 read_lock(&card->ctl_files_rwlock);
1805 list_for_each_entry(kctl, &card->ctl_files, list) {
1806 if (kctl->pid == task_pid(current)) {
1807 subdevice = kctl->preferred_subdevice[type];
1808 if (subdevice != -1)
1812 read_unlock(&card->ctl_files_rwlock);
1815 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1820 #ifdef CONFIG_COMPAT
1821 #include "control_compat.c"
1823 #define snd_ctl_ioctl_compat NULL
1830 static const struct file_operations snd_ctl_f_ops =
1832 .owner = THIS_MODULE,
1833 .read = snd_ctl_read,
1834 .open = snd_ctl_open,
1835 .release = snd_ctl_release,
1836 .llseek = no_llseek,
1837 .poll = snd_ctl_poll,
1838 .unlocked_ioctl = snd_ctl_ioctl,
1839 .compat_ioctl = snd_ctl_ioctl_compat,
1840 .fasync = snd_ctl_fasync,
1844 * registration of the control device
1846 static int snd_ctl_dev_register(struct snd_device *device)
1848 struct snd_card *card = device->device_data;
1850 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1851 &snd_ctl_f_ops, card, &card->ctl_dev);
1855 * disconnection of the control device
1857 static int snd_ctl_dev_disconnect(struct snd_device *device)
1859 struct snd_card *card = device->device_data;
1860 struct snd_ctl_file *ctl;
1862 read_lock(&card->ctl_files_rwlock);
1863 list_for_each_entry(ctl, &card->ctl_files, list) {
1864 wake_up(&ctl->change_sleep);
1865 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1867 read_unlock(&card->ctl_files_rwlock);
1869 return snd_unregister_device(&card->ctl_dev);
1875 static int snd_ctl_dev_free(struct snd_device *device)
1877 struct snd_card *card = device->device_data;
1878 struct snd_kcontrol *control;
1880 down_write(&card->controls_rwsem);
1881 while (!list_empty(&card->controls)) {
1882 control = snd_kcontrol(card->controls.next);
1883 snd_ctl_remove(card, control);
1885 up_write(&card->controls_rwsem);
1886 put_device(&card->ctl_dev);
1891 * create control core:
1892 * called from init.c
1894 int snd_ctl_create(struct snd_card *card)
1896 static struct snd_device_ops ops = {
1897 .dev_free = snd_ctl_dev_free,
1898 .dev_register = snd_ctl_dev_register,
1899 .dev_disconnect = snd_ctl_dev_disconnect,
1903 if (snd_BUG_ON(!card))
1905 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1908 snd_device_initialize(&card->ctl_dev, card);
1909 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1911 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1913 put_device(&card->ctl_dev);
1918 * Frequently used control callbacks/helpers
1922 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1923 * callback with a mono channel
1924 * @kcontrol: the kcontrol instance
1925 * @uinfo: info to store
1927 * This is a function that can be used as info callback for a standard
1928 * boolean control with a single mono channel.
1930 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1931 struct snd_ctl_elem_info *uinfo)
1933 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1935 uinfo->value.integer.min = 0;
1936 uinfo->value.integer.max = 1;
1939 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1942 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1943 * callback with stereo two channels
1944 * @kcontrol: the kcontrol instance
1945 * @uinfo: info to store
1947 * This is a function that can be used as info callback for a standard
1948 * boolean control with stereo two channels.
1950 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1951 struct snd_ctl_elem_info *uinfo)
1953 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1955 uinfo->value.integer.min = 0;
1956 uinfo->value.integer.max = 1;
1959 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1962 * snd_ctl_enum_info - fills the info structure for an enumerated control
1963 * @info: the structure to be filled
1964 * @channels: the number of the control's channels; often one
1965 * @items: the number of control values; also the size of @names
1966 * @names: an array containing the names of all control values
1968 * Sets all required fields in @info to their appropriate values.
1969 * If the control's accessibility is not the default (readable and writable),
1970 * the caller has to fill @info->access.
1974 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1975 unsigned int items, const char *const names[])
1977 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1978 info->count = channels;
1979 info->value.enumerated.items = items;
1982 if (info->value.enumerated.item >= items)
1983 info->value.enumerated.item = items - 1;
1984 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1985 "ALSA: too long item name '%s'\n",
1986 names[info->value.enumerated.item]);
1987 strlcpy(info->value.enumerated.name,
1988 names[info->value.enumerated.item],
1989 sizeof(info->value.enumerated.name));
1992 EXPORT_SYMBOL(snd_ctl_enum_info);