1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Routines for driver control interface
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
7 #include <linux/threads.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/moduleparam.h>
11 #include <linux/slab.h>
12 #include <linux/vmalloc.h>
13 #include <linux/time.h>
15 #include <linux/math64.h>
16 #include <linux/sched/signal.h>
17 #include <sound/core.h>
18 #include <sound/minors.h>
19 #include <sound/info.h>
20 #include <sound/control.h>
22 // Max allocation size for user controls.
23 static int max_user_ctl_alloc_size = 8 * 1024 * 1024;
24 module_param_named(max_user_ctl_alloc_size, max_user_ctl_alloc_size, int, 0444);
25 MODULE_PARM_DESC(max_user_ctl_alloc_size, "Max allocation size for user controls");
27 #define MAX_CONTROL_COUNT 1028
29 struct snd_kctl_ioctl {
30 struct list_head list; /* list of all ioctls */
31 snd_kctl_ioctl_func_t fioctl;
34 static DECLARE_RWSEM(snd_ioctl_rwsem);
35 static DECLARE_RWSEM(snd_ctl_layer_rwsem);
36 static LIST_HEAD(snd_control_ioctls);
38 static LIST_HEAD(snd_control_compat_ioctls);
40 static struct snd_ctl_layer_ops *snd_ctl_layer;
42 static int snd_ctl_open(struct inode *inode, struct file *file)
45 struct snd_card *card;
46 struct snd_ctl_file *ctl;
49 err = stream_open(inode, file);
53 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
58 err = snd_card_file_add(card, file);
63 if (!try_module_get(card->module)) {
67 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
72 INIT_LIST_HEAD(&ctl->events);
73 init_waitqueue_head(&ctl->change_sleep);
74 spin_lock_init(&ctl->read_lock);
76 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
77 ctl->preferred_subdevice[i] = -1;
78 ctl->pid = get_pid(task_pid(current));
79 file->private_data = ctl;
80 write_lock_irqsave(&card->ctl_files_rwlock, flags);
81 list_add_tail(&ctl->list, &card->ctl_files);
82 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
87 module_put(card->module);
89 snd_card_file_remove(card, file);
96 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
99 struct snd_kctl_event *cread;
101 spin_lock_irqsave(&ctl->read_lock, flags);
102 while (!list_empty(&ctl->events)) {
103 cread = snd_kctl_event(ctl->events.next);
104 list_del(&cread->list);
107 spin_unlock_irqrestore(&ctl->read_lock, flags);
110 static int snd_ctl_release(struct inode *inode, struct file *file)
113 struct snd_card *card;
114 struct snd_ctl_file *ctl;
115 struct snd_kcontrol *control;
118 ctl = file->private_data;
119 file->private_data = NULL;
121 write_lock_irqsave(&card->ctl_files_rwlock, flags);
122 list_del(&ctl->list);
123 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
124 down_write(&card->controls_rwsem);
125 list_for_each_entry(control, &card->controls, list)
126 for (idx = 0; idx < control->count; idx++)
127 if (control->vd[idx].owner == ctl)
128 control->vd[idx].owner = NULL;
129 up_write(&card->controls_rwsem);
130 snd_ctl_empty_read_queue(ctl);
133 module_put(card->module);
134 snd_card_file_remove(card, file);
139 * snd_ctl_notify - Send notification to user-space for a control change
140 * @card: the card to send notification
141 * @mask: the event mask, SNDRV_CTL_EVENT_*
142 * @id: the ctl element id to send notification
144 * This function adds an event record with the given id and mask, appends
145 * to the list and wakes up the user-space for notification. This can be
146 * called in the atomic context.
148 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
149 struct snd_ctl_elem_id *id)
152 struct snd_ctl_file *ctl;
153 struct snd_kctl_event *ev;
155 if (snd_BUG_ON(!card || !id))
159 read_lock_irqsave(&card->ctl_files_rwlock, flags);
160 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
161 card->mixer_oss_change_count++;
163 list_for_each_entry(ctl, &card->ctl_files, list) {
164 if (!ctl->subscribed)
166 spin_lock(&ctl->read_lock);
167 list_for_each_entry(ev, &ctl->events, list) {
168 if (ev->id.numid == id->numid) {
173 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
177 list_add_tail(&ev->list, &ctl->events);
179 dev_err(card->dev, "No memory available to allocate event\n");
182 wake_up(&ctl->change_sleep);
183 spin_unlock(&ctl->read_lock);
184 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
186 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
188 EXPORT_SYMBOL(snd_ctl_notify);
191 * snd_ctl_notify_one - Send notification to user-space for a control change
192 * @card: the card to send notification
193 * @mask: the event mask, SNDRV_CTL_EVENT_*
194 * @kctl: the pointer with the control instance
195 * @ioff: the additional offset to the control index
197 * This function calls snd_ctl_notify() and does additional jobs
198 * like LED state changes.
200 void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
201 struct snd_kcontrol *kctl, unsigned int ioff)
203 struct snd_ctl_elem_id id = kctl->id;
204 struct snd_ctl_layer_ops *lops;
208 snd_ctl_notify(card, mask, &id);
209 down_read(&snd_ctl_layer_rwsem);
210 for (lops = snd_ctl_layer; lops; lops = lops->next)
211 lops->lnotify(card, mask, kctl, ioff);
212 up_read(&snd_ctl_layer_rwsem);
214 EXPORT_SYMBOL(snd_ctl_notify_one);
217 * snd_ctl_new - create a new control instance with some elements
218 * @kctl: the pointer to store new control instance
219 * @count: the number of elements in this control
220 * @access: the default access flags for elements in this control
221 * @file: given when locking these elements
223 * Allocates a memory object for a new control instance. The instance has
224 * elements as many as the given number (@count). Each element has given
225 * access permissions (@access). Each element is locked when @file is given.
227 * Return: 0 on success, error code on failure
229 static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
230 unsigned int access, struct snd_ctl_file *file)
234 if (count == 0 || count > MAX_CONTROL_COUNT)
237 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
241 for (idx = 0; idx < count; idx++) {
242 (*kctl)->vd[idx].access = access;
243 (*kctl)->vd[idx].owner = file;
245 (*kctl)->count = count;
251 * snd_ctl_new1 - create a control instance from the template
252 * @ncontrol: the initialization record
253 * @private_data: the private data to set
255 * Allocates a new struct snd_kcontrol instance and initialize from the given
256 * template. When the access field of ncontrol is 0, it's assumed as
257 * READWRITE access. When the count field is 0, it's assumes as one.
259 * Return: The pointer of the newly generated instance, or %NULL on failure.
261 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
264 struct snd_kcontrol *kctl;
269 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
272 count = ncontrol->count;
276 access = ncontrol->access;
278 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
279 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
280 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
281 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
282 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
283 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
284 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
285 SNDRV_CTL_ELEM_ACCESS_LED_MASK |
286 SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
288 err = snd_ctl_new(&kctl, count, access, NULL);
292 /* The 'numid' member is decided when calling snd_ctl_add(). */
293 kctl->id.iface = ncontrol->iface;
294 kctl->id.device = ncontrol->device;
295 kctl->id.subdevice = ncontrol->subdevice;
296 if (ncontrol->name) {
297 strscpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
298 if (strcmp(ncontrol->name, kctl->id.name) != 0)
299 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
300 ncontrol->name, kctl->id.name);
302 kctl->id.index = ncontrol->index;
304 kctl->info = ncontrol->info;
305 kctl->get = ncontrol->get;
306 kctl->put = ncontrol->put;
307 kctl->tlv.p = ncontrol->tlv.p;
309 kctl->private_value = ncontrol->private_value;
310 kctl->private_data = private_data;
314 EXPORT_SYMBOL(snd_ctl_new1);
317 * snd_ctl_free_one - release the control instance
318 * @kcontrol: the control instance
320 * Releases the control instance created via snd_ctl_new()
322 * Don't call this after the control was added to the card.
324 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
327 if (kcontrol->private_free)
328 kcontrol->private_free(kcontrol);
332 EXPORT_SYMBOL(snd_ctl_free_one);
334 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
337 struct snd_kcontrol *kctl;
339 /* Make sure that the ids assigned to the control do not wrap around */
340 if (card->last_numid >= UINT_MAX - count)
341 card->last_numid = 0;
343 list_for_each_entry(kctl, &card->controls, list) {
344 if (kctl->id.numid < card->last_numid + 1 + count &&
345 kctl->id.numid + kctl->count > card->last_numid + 1) {
346 card->last_numid = kctl->id.numid + kctl->count - 1;
353 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
355 unsigned int iter = 100000;
357 while (snd_ctl_remove_numid_conflict(card, count)) {
359 /* this situation is very unlikely */
360 dev_err(card->dev, "unable to allocate new control numid\n");
367 enum snd_ctl_add_mode {
368 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
371 /* add/replace a new kcontrol object; call with card->controls_rwsem locked */
372 static int __snd_ctl_add_replace(struct snd_card *card,
373 struct snd_kcontrol *kcontrol,
374 enum snd_ctl_add_mode mode)
376 struct snd_ctl_elem_id id;
378 struct snd_kcontrol *old;
382 if (id.index > UINT_MAX - kcontrol->count)
385 old = snd_ctl_find_id(card, &id);
387 if (mode == CTL_REPLACE)
390 if (mode == CTL_ADD_EXCLUSIVE) {
392 "control %i:%i:%i:%s:%i is already present\n",
393 id.iface, id.device, id.subdevice, id.name,
398 err = snd_ctl_remove(card, old);
403 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
406 list_add_tail(&kcontrol->list, &card->controls);
407 card->controls_count += kcontrol->count;
408 kcontrol->id.numid = card->last_numid + 1;
409 card->last_numid += kcontrol->count;
411 for (idx = 0; idx < kcontrol->count; idx++)
412 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
417 static int snd_ctl_add_replace(struct snd_card *card,
418 struct snd_kcontrol *kcontrol,
419 enum snd_ctl_add_mode mode)
425 if (snd_BUG_ON(!card || !kcontrol->info))
428 down_write(&card->controls_rwsem);
429 err = __snd_ctl_add_replace(card, kcontrol, mode);
430 up_write(&card->controls_rwsem);
436 snd_ctl_free_one(kcontrol);
441 * snd_ctl_add - add the control instance to the card
442 * @card: the card instance
443 * @kcontrol: the control instance to add
445 * Adds the control instance created via snd_ctl_new() or
446 * snd_ctl_new1() to the given card. Assigns also an unique
447 * numid used for fast search.
449 * It frees automatically the control which cannot be added.
451 * Return: Zero if successful, or a negative error code on failure.
454 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
456 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
458 EXPORT_SYMBOL(snd_ctl_add);
461 * snd_ctl_replace - replace the control instance of the card
462 * @card: the card instance
463 * @kcontrol: the control instance to replace
464 * @add_on_replace: add the control if not already added
466 * Replaces the given control. If the given control does not exist
467 * and the add_on_replace flag is set, the control is added. If the
468 * control exists, it is destroyed first.
470 * It frees automatically the control which cannot be added or replaced.
472 * Return: Zero if successful, or a negative error code on failure.
474 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
477 return snd_ctl_add_replace(card, kcontrol,
478 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
480 EXPORT_SYMBOL(snd_ctl_replace);
483 * snd_ctl_remove - remove the control from the card and release it
484 * @card: the card instance
485 * @kcontrol: the control instance to remove
487 * Removes the control from the card and then releases the instance.
488 * You don't need to call snd_ctl_free_one(). You must be in
489 * the write lock - down_write(&card->controls_rwsem).
491 * Return: 0 if successful, or a negative error code on failure.
493 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
497 if (snd_BUG_ON(!card || !kcontrol))
499 list_del(&kcontrol->list);
500 card->controls_count -= kcontrol->count;
501 for (idx = 0; idx < kcontrol->count; idx++)
502 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
503 snd_ctl_free_one(kcontrol);
506 EXPORT_SYMBOL(snd_ctl_remove);
509 * snd_ctl_remove_id - remove the control of the given id and release it
510 * @card: the card instance
511 * @id: the control id to remove
513 * Finds the control instance with the given id, removes it from the
514 * card list and releases it.
516 * Return: 0 if successful, or a negative error code on failure.
518 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
520 struct snd_kcontrol *kctl;
523 down_write(&card->controls_rwsem);
524 kctl = snd_ctl_find_id(card, id);
526 up_write(&card->controls_rwsem);
529 ret = snd_ctl_remove(card, kctl);
530 up_write(&card->controls_rwsem);
533 EXPORT_SYMBOL(snd_ctl_remove_id);
536 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
537 * @file: active control handle
538 * @id: the control id to remove
540 * Finds the control instance with the given id, removes it from the
541 * card list and releases it.
543 * Return: 0 if successful, or a negative error code on failure.
545 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
546 struct snd_ctl_elem_id *id)
548 struct snd_card *card = file->card;
549 struct snd_kcontrol *kctl;
552 down_write(&card->controls_rwsem);
553 kctl = snd_ctl_find_id(card, id);
558 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
562 for (idx = 0; idx < kctl->count; idx++)
563 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
567 ret = snd_ctl_remove(card, kctl);
569 up_write(&card->controls_rwsem);
574 * snd_ctl_activate_id - activate/inactivate the control of the given id
575 * @card: the card instance
576 * @id: the control id to activate/inactivate
577 * @active: non-zero to activate
579 * Finds the control instance with the given id, and activate or
580 * inactivate the control together with notification, if changed.
581 * The given ID data is filled with full information.
583 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
585 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
588 struct snd_kcontrol *kctl;
589 struct snd_kcontrol_volatile *vd;
590 unsigned int index_offset;
593 down_write(&card->controls_rwsem);
594 kctl = snd_ctl_find_id(card, id);
599 index_offset = snd_ctl_get_ioff(kctl, id);
600 vd = &kctl->vd[index_offset];
603 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
605 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
607 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
609 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
611 snd_ctl_build_ioff(id, kctl, index_offset);
612 downgrade_write(&card->controls_rwsem);
613 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
614 up_read(&card->controls_rwsem);
618 up_write(&card->controls_rwsem);
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 strscpy(info->id, card->id, sizeof(info->id));
732 strscpy(info->driver, card->driver, sizeof(info->driver));
733 strscpy(info->name, card->shortname, sizeof(info->name));
734 strscpy(info->longname, card->longname, sizeof(info->longname));
735 strscpy(info->mixername, card->mixername, sizeof(info->mixername));
736 strscpy(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 *list)
749 struct snd_kcontrol *kctl;
750 struct snd_ctl_elem_id id;
751 unsigned int offset, space, jidx;
754 offset = list->offset;
757 down_read(&card->controls_rwsem);
758 list->count = card->controls_count;
761 list_for_each_entry(kctl, &card->controls, list) {
762 if (offset >= kctl->count) {
763 offset -= kctl->count;
766 for (jidx = offset; jidx < kctl->count; jidx++) {
767 snd_ctl_build_ioff(&id, kctl, jidx);
768 if (copy_to_user(list->pids + list->used, &id,
781 up_read(&card->controls_rwsem);
785 static int snd_ctl_elem_list_user(struct snd_card *card,
786 struct snd_ctl_elem_list __user *_list)
788 struct snd_ctl_elem_list list;
791 if (copy_from_user(&list, _list, sizeof(list)))
793 err = snd_ctl_elem_list(card, &list);
796 if (copy_to_user(_list, &list, sizeof(list)))
802 /* Check whether the given kctl info is valid */
803 static int snd_ctl_check_elem_info(struct snd_card *card,
804 const struct snd_ctl_elem_info *info)
806 static const unsigned int max_value_counts[] = {
807 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
808 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
809 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
810 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
811 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
812 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
815 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
816 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
819 "control %i:%i:%i:%s:%i: invalid type %d\n",
820 info->id.iface, info->id.device,
821 info->id.subdevice, info->id.name,
822 info->id.index, info->type);
825 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
826 info->value.enumerated.items == 0) {
829 "control %i:%i:%i:%s:%i: zero enum items\n",
830 info->id.iface, info->id.device,
831 info->id.subdevice, info->id.name,
835 if (info->count > max_value_counts[info->type]) {
838 "control %i:%i:%i:%s:%i: invalid count %d\n",
839 info->id.iface, info->id.device,
840 info->id.subdevice, info->id.name,
841 info->id.index, info->count);
848 /* The capacity of struct snd_ctl_elem_value.value.*/
849 static const unsigned int value_sizes[] = {
850 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
851 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
852 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
853 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
854 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
855 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
858 #ifdef CONFIG_SND_CTL_VALIDATION
859 /* fill the remaining snd_ctl_elem_value data with the given pattern */
860 static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
861 struct snd_ctl_elem_info *info,
864 size_t offset = value_sizes[info->type] * info->count;
866 offset = DIV_ROUND_UP(offset, sizeof(u32));
867 memset32((u32 *)control->value.bytes.data + offset, pattern,
868 sizeof(control->value) / sizeof(u32) - offset);
871 /* check whether the given integer ctl value is valid */
872 static int sanity_check_int_value(struct snd_card *card,
873 const struct snd_ctl_elem_value *control,
874 const struct snd_ctl_elem_info *info,
877 long long lval, lmin, lmax, lstep;
880 switch (info->type) {
882 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
883 lval = control->value.integer.value[i];
888 case SNDRV_CTL_ELEM_TYPE_INTEGER:
889 lval = control->value.integer.value[i];
890 lmin = info->value.integer.min;
891 lmax = info->value.integer.max;
892 lstep = info->value.integer.step;
894 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
895 lval = control->value.integer64.value[i];
896 lmin = info->value.integer64.min;
897 lmax = info->value.integer64.max;
898 lstep = info->value.integer64.step;
900 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
901 lval = control->value.enumerated.item[i];
903 lmax = info->value.enumerated.items - 1;
908 if (lval < lmin || lval > lmax) {
910 "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
911 control->id.iface, control->id.device,
912 control->id.subdevice, control->id.name,
913 control->id.index, lval, lmin, lmax, i);
917 div64_u64_rem(lval, lstep, &rem);
920 "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
921 control->id.iface, control->id.device,
922 control->id.subdevice, control->id.name,
923 control->id.index, lval, lstep, i);
931 /* perform sanity checks to the given snd_ctl_elem_value object */
932 static int sanity_check_elem_value(struct snd_card *card,
933 const struct snd_ctl_elem_value *control,
934 const struct snd_ctl_elem_info *info,
941 switch (info->type) {
942 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
943 case SNDRV_CTL_ELEM_TYPE_INTEGER:
944 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
945 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
946 for (i = 0; i < info->count; i++) {
947 ret = sanity_check_int_value(card, control, info, i);
956 /* check whether the remaining area kept untouched */
957 offset = value_sizes[info->type] * info->count;
958 offset = DIV_ROUND_UP(offset, sizeof(u32));
959 p = (u32 *)control->value.bytes.data + offset;
960 for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
965 *p = 0; /* clear the checked area */
971 static inline void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
972 struct snd_ctl_elem_info *info,
977 static inline int sanity_check_elem_value(struct snd_card *card,
978 struct snd_ctl_elem_value *control,
979 struct snd_ctl_elem_info *info,
986 static int __snd_ctl_elem_info(struct snd_card *card,
987 struct snd_kcontrol *kctl,
988 struct snd_ctl_elem_info *info,
989 struct snd_ctl_file *ctl)
991 struct snd_kcontrol_volatile *vd;
992 unsigned int index_offset;
995 #ifdef CONFIG_SND_DEBUG
998 result = kctl->info(kctl, info);
1000 snd_BUG_ON(info->access);
1001 index_offset = snd_ctl_get_ioff(kctl, &info->id);
1002 vd = &kctl->vd[index_offset];
1003 snd_ctl_build_ioff(&info->id, kctl, index_offset);
1004 info->access = vd->access;
1006 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
1007 if (vd->owner == ctl)
1008 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
1009 info->owner = pid_vnr(vd->owner->pid);
1013 if (!snd_ctl_skip_validation(info) &&
1014 snd_ctl_check_elem_info(card, info) < 0)
1020 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
1021 struct snd_ctl_elem_info *info)
1023 struct snd_card *card = ctl->card;
1024 struct snd_kcontrol *kctl;
1027 down_read(&card->controls_rwsem);
1028 kctl = snd_ctl_find_id(card, &info->id);
1032 result = __snd_ctl_elem_info(card, kctl, info, ctl);
1033 up_read(&card->controls_rwsem);
1037 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1038 struct snd_ctl_elem_info __user *_info)
1040 struct snd_ctl_elem_info info;
1043 if (copy_from_user(&info, _info, sizeof(info)))
1045 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
1048 result = snd_ctl_elem_info(ctl, &info);
1051 /* drop internal access flags */
1052 info.access &= ~(SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK|
1053 SNDRV_CTL_ELEM_ACCESS_LED_MASK);
1054 if (copy_to_user(_info, &info, sizeof(info)))
1059 static int snd_ctl_elem_read(struct snd_card *card,
1060 struct snd_ctl_elem_value *control)
1062 struct snd_kcontrol *kctl;
1063 struct snd_kcontrol_volatile *vd;
1064 unsigned int index_offset;
1065 struct snd_ctl_elem_info info;
1066 const u32 pattern = 0xdeadbeef;
1069 kctl = snd_ctl_find_id(card, &control->id);
1073 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1074 vd = &kctl->vd[index_offset];
1075 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
1078 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1080 #ifdef CONFIG_SND_CTL_VALIDATION
1081 /* info is needed only for validation */
1082 memset(&info, 0, sizeof(info));
1083 info.id = control->id;
1084 ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
1089 if (!snd_ctl_skip_validation(&info))
1090 fill_remaining_elem_value(control, &info, pattern);
1091 ret = kctl->get(kctl, control);
1094 if (!snd_ctl_skip_validation(&info) &&
1095 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1097 "control %i:%i:%i:%s:%i: access overflow\n",
1098 control->id.iface, control->id.device,
1099 control->id.subdevice, control->id.name,
1106 static int snd_ctl_elem_read_user(struct snd_card *card,
1107 struct snd_ctl_elem_value __user *_control)
1109 struct snd_ctl_elem_value *control;
1112 control = memdup_user(_control, sizeof(*control));
1113 if (IS_ERR(control))
1114 return PTR_ERR(control);
1116 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1120 down_read(&card->controls_rwsem);
1121 result = snd_ctl_elem_read(card, control);
1122 up_read(&card->controls_rwsem);
1126 if (copy_to_user(_control, control, sizeof(*control)))
1133 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1134 struct snd_ctl_elem_value *control)
1136 struct snd_kcontrol *kctl;
1137 struct snd_kcontrol_volatile *vd;
1138 unsigned int index_offset;
1141 down_write(&card->controls_rwsem);
1142 kctl = snd_ctl_find_id(card, &control->id);
1144 up_write(&card->controls_rwsem);
1148 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1149 vd = &kctl->vd[index_offset];
1150 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1151 (file && vd->owner && vd->owner != file)) {
1152 up_write(&card->controls_rwsem);
1156 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1157 result = kctl->put(kctl, control);
1159 up_write(&card->controls_rwsem);
1164 downgrade_write(&card->controls_rwsem);
1165 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
1166 up_read(&card->controls_rwsem);
1168 up_write(&card->controls_rwsem);
1174 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1175 struct snd_ctl_elem_value __user *_control)
1177 struct snd_ctl_elem_value *control;
1178 struct snd_card *card;
1181 control = memdup_user(_control, sizeof(*control));
1182 if (IS_ERR(control))
1183 return PTR_ERR(control);
1186 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1190 result = snd_ctl_elem_write(card, file, control);
1194 if (copy_to_user(_control, control, sizeof(*control)))
1201 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1202 struct snd_ctl_elem_id __user *_id)
1204 struct snd_card *card = file->card;
1205 struct snd_ctl_elem_id id;
1206 struct snd_kcontrol *kctl;
1207 struct snd_kcontrol_volatile *vd;
1210 if (copy_from_user(&id, _id, sizeof(id)))
1212 down_write(&card->controls_rwsem);
1213 kctl = snd_ctl_find_id(card, &id);
1217 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1218 if (vd->owner != NULL)
1225 up_write(&card->controls_rwsem);
1229 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1230 struct snd_ctl_elem_id __user *_id)
1232 struct snd_card *card = file->card;
1233 struct snd_ctl_elem_id id;
1234 struct snd_kcontrol *kctl;
1235 struct snd_kcontrol_volatile *vd;
1238 if (copy_from_user(&id, _id, sizeof(id)))
1240 down_write(&card->controls_rwsem);
1241 kctl = snd_ctl_find_id(card, &id);
1245 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1246 if (vd->owner == NULL)
1248 else if (vd->owner != file)
1255 up_write(&card->controls_rwsem);
1259 struct user_element {
1260 struct snd_ctl_elem_info info;
1261 struct snd_card *card;
1262 char *elem_data; /* element data */
1263 unsigned long elem_data_size; /* size of element data in bytes */
1264 void *tlv_data; /* TLV data */
1265 unsigned long tlv_data_size; /* TLV data size */
1266 void *priv_data; /* private data (like strings for enumerated type) */
1269 // check whether the addition (in bytes) of user ctl element may overflow the limit.
1270 static bool check_user_elem_overflow(struct snd_card *card, ssize_t add)
1272 return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size;
1275 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1276 struct snd_ctl_elem_info *uinfo)
1278 struct user_element *ue = kcontrol->private_data;
1279 unsigned int offset;
1281 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1283 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1288 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1289 struct snd_ctl_elem_info *uinfo)
1291 struct user_element *ue = kcontrol->private_data;
1294 unsigned int offset;
1296 item = uinfo->value.enumerated.item;
1298 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1300 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1302 item = min(item, uinfo->value.enumerated.items - 1);
1303 uinfo->value.enumerated.item = item;
1305 names = ue->priv_data;
1306 for (; item > 0; --item)
1307 names += strlen(names) + 1;
1308 strcpy(uinfo->value.enumerated.name, names);
1313 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1314 struct snd_ctl_elem_value *ucontrol)
1316 struct user_element *ue = kcontrol->private_data;
1317 unsigned int size = ue->elem_data_size;
1318 char *src = ue->elem_data +
1319 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1321 memcpy(&ucontrol->value, src, size);
1325 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1326 struct snd_ctl_elem_value *ucontrol)
1329 struct user_element *ue = kcontrol->private_data;
1330 unsigned int size = ue->elem_data_size;
1331 char *dst = ue->elem_data +
1332 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1334 change = memcmp(&ucontrol->value, dst, size) != 0;
1336 memcpy(dst, &ucontrol->value, size);
1340 /* called in controls_rwsem write lock */
1341 static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1344 struct user_element *ue = kctl->private_data;
1345 unsigned int *container;
1346 unsigned int mask = 0;
1350 if (size > 1024 * 128) /* sane value */
1353 // does the TLV size change cause overflow?
1354 if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size)))
1357 container = vmemdup_user(buf, size);
1358 if (IS_ERR(container))
1359 return PTR_ERR(container);
1361 change = ue->tlv_data_size != size;
1363 change = memcmp(ue->tlv_data, container, size) != 0;
1369 if (ue->tlv_data == NULL) {
1370 /* Now TLV data is available. */
1371 for (i = 0; i < kctl->count; ++i)
1372 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1373 mask = SNDRV_CTL_EVENT_MASK_INFO;
1375 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1376 ue->tlv_data_size = 0;
1377 kvfree(ue->tlv_data);
1380 ue->tlv_data = container;
1381 ue->tlv_data_size = size;
1382 // decremented at private_free.
1383 ue->card->user_ctl_alloc_size += size;
1385 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1386 for (i = 0; i < kctl->count; ++i)
1387 snd_ctl_notify_one(ue->card, mask, kctl, i);
1392 static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1395 struct user_element *ue = kctl->private_data;
1397 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1400 if (size < ue->tlv_data_size)
1403 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1409 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1410 unsigned int size, unsigned int __user *buf)
1412 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1413 return replace_user_tlv(kctl, buf, size);
1415 return read_user_tlv(kctl, buf, size);
1418 /* called in controls_rwsem write lock */
1419 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1422 size_t buf_len, name_len;
1424 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1426 buf_len = ue->info.value.enumerated.names_length;
1427 if (buf_len > 64 * 1024)
1430 if (check_user_elem_overflow(ue->card, buf_len))
1432 names = vmemdup_user((const void __user *)user_ptrval, buf_len);
1434 return PTR_ERR(names);
1436 /* check that there are enough valid names */
1438 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1439 name_len = strnlen(p, buf_len);
1440 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1445 buf_len -= name_len + 1;
1448 ue->priv_data = names;
1449 ue->info.value.enumerated.names_ptr = 0;
1450 // increment the allocation size; decremented again at private_free.
1451 ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length;
1456 static size_t compute_user_elem_size(size_t size, unsigned int count)
1458 return sizeof(struct user_element) + size * count;
1461 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1463 struct user_element *ue = kcontrol->private_data;
1465 // decrement the allocation size.
1466 ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count);
1467 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1469 ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length;
1471 kvfree(ue->tlv_data);
1472 kvfree(ue->priv_data);
1476 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1477 struct snd_ctl_elem_info *info, int replace)
1479 struct snd_card *card = file->card;
1480 struct snd_kcontrol *kctl;
1482 unsigned int access;
1485 struct user_element *ue;
1486 unsigned int offset;
1489 if (!*info->id.name)
1491 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1494 /* Delete a control to replace them if needed. */
1497 err = snd_ctl_remove_user_ctl(file, &info->id);
1502 /* Check the number of elements for this userspace control. */
1503 count = info->owner;
1507 /* Arrange access permissions if needed. */
1508 access = info->access;
1510 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1511 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1512 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1513 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1515 /* In initial state, nothing is available as TLV container. */
1516 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1517 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1518 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1521 * Check information and calculate the size of data specific to
1522 * this userspace control.
1524 /* pass NULL to card for suppressing error messages */
1525 err = snd_ctl_check_elem_info(NULL, info);
1528 /* user-space control doesn't allow zero-size data */
1529 if (info->count < 1)
1531 private_size = value_sizes[info->type] * info->count;
1532 alloc_size = compute_user_elem_size(private_size, count);
1534 down_write(&card->controls_rwsem);
1535 if (check_user_elem_overflow(card, alloc_size)) {
1541 * Keep memory object for this userspace control. After passing this
1542 * code block, the instance should be freed by snd_ctl_free_one().
1544 * Note that these elements in this control are locked.
1546 err = snd_ctl_new(&kctl, count, access, file);
1549 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1550 ue = kzalloc(alloc_size, GFP_KERNEL);
1556 kctl->private_data = ue;
1557 kctl->private_free = snd_ctl_elem_user_free;
1559 // increment the allocated size; decremented again at private_free.
1560 card->user_ctl_alloc_size += alloc_size;
1562 /* Set private data for this userspace control. */
1565 ue->info.access = 0;
1566 ue->elem_data = (char *)ue + sizeof(*ue);
1567 ue->elem_data_size = private_size;
1568 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1569 err = snd_ctl_elem_init_enum_names(ue);
1571 snd_ctl_free_one(kctl);
1576 /* Set callback functions. */
1577 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1578 kctl->info = snd_ctl_elem_user_enum_info;
1580 kctl->info = snd_ctl_elem_user_info;
1581 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1582 kctl->get = snd_ctl_elem_user_get;
1583 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1584 kctl->put = snd_ctl_elem_user_put;
1585 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1586 kctl->tlv.c = snd_ctl_elem_user_tlv;
1588 /* This function manage to free the instance on failure. */
1589 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1591 snd_ctl_free_one(kctl);
1594 offset = snd_ctl_get_ioff(kctl, &info->id);
1595 snd_ctl_build_ioff(&info->id, kctl, offset);
1597 * Here we cannot fill any field for the number of elements added by
1598 * this operation because there're no specific fields. The usage of
1599 * 'owner' field for this purpose may cause any bugs to userspace
1600 * applications because the field originally means PID of a process
1601 * which locks the element.
1604 up_write(&card->controls_rwsem);
1608 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1609 struct snd_ctl_elem_info __user *_info, int replace)
1611 struct snd_ctl_elem_info info;
1614 if (copy_from_user(&info, _info, sizeof(info)))
1616 err = snd_ctl_elem_add(file, &info, replace);
1619 if (copy_to_user(_info, &info, sizeof(info))) {
1620 snd_ctl_remove_user_ctl(file, &info.id);
1627 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1628 struct snd_ctl_elem_id __user *_id)
1630 struct snd_ctl_elem_id id;
1632 if (copy_from_user(&id, _id, sizeof(id)))
1634 return snd_ctl_remove_user_ctl(file, &id);
1637 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1640 if (get_user(subscribe, ptr))
1642 if (subscribe < 0) {
1643 subscribe = file->subscribed;
1644 if (put_user(subscribe, ptr))
1649 file->subscribed = 1;
1651 } else if (file->subscribed) {
1652 snd_ctl_empty_read_queue(file);
1653 file->subscribed = 0;
1658 static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1659 struct snd_kcontrol *kctl,
1660 struct snd_ctl_elem_id *id,
1661 unsigned int __user *buf, unsigned int size)
1663 static const struct {
1667 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1668 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1669 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1671 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1674 /* Check support of the request for this element. */
1675 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1676 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1679 if (i == ARRAY_SIZE(pairs))
1682 if (kctl->tlv.c == NULL)
1685 /* Write and command operations are not allowed for locked element. */
1686 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1687 vd->owner != NULL && vd->owner != file)
1690 return kctl->tlv.c(kctl, op_flag, size, buf);
1693 static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1694 unsigned int __user *buf, unsigned int size)
1696 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1699 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1702 if (kctl->tlv.p == NULL)
1705 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1709 if (copy_to_user(buf, kctl->tlv.p, len))
1715 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1716 struct snd_ctl_tlv __user *buf,
1719 struct snd_ctl_tlv header;
1720 unsigned int __user *container;
1721 unsigned int container_size;
1722 struct snd_kcontrol *kctl;
1723 struct snd_ctl_elem_id id;
1724 struct snd_kcontrol_volatile *vd;
1726 if (copy_from_user(&header, buf, sizeof(header)))
1729 /* In design of control core, numerical ID starts at 1. */
1730 if (header.numid == 0)
1733 /* At least, container should include type and length fields. */
1734 if (header.length < sizeof(unsigned int) * 2)
1736 container_size = header.length;
1737 container = buf->tlv;
1739 kctl = snd_ctl_find_numid(file->card, header.numid);
1743 /* Calculate index of the element in this set. */
1745 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1746 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1748 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1749 return call_tlv_handler(file, op_flag, kctl, &id, container,
1752 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1753 return read_tlv_buf(kctl, &id, container,
1758 /* Not supported. */
1762 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1764 struct snd_ctl_file *ctl;
1765 struct snd_card *card;
1766 struct snd_kctl_ioctl *p;
1767 void __user *argp = (void __user *)arg;
1768 int __user *ip = argp;
1771 ctl = file->private_data;
1773 if (snd_BUG_ON(!card))
1776 case SNDRV_CTL_IOCTL_PVERSION:
1777 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1778 case SNDRV_CTL_IOCTL_CARD_INFO:
1779 return snd_ctl_card_info(card, ctl, cmd, argp);
1780 case SNDRV_CTL_IOCTL_ELEM_LIST:
1781 return snd_ctl_elem_list_user(card, argp);
1782 case SNDRV_CTL_IOCTL_ELEM_INFO:
1783 return snd_ctl_elem_info_user(ctl, argp);
1784 case SNDRV_CTL_IOCTL_ELEM_READ:
1785 return snd_ctl_elem_read_user(card, argp);
1786 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1787 return snd_ctl_elem_write_user(ctl, argp);
1788 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1789 return snd_ctl_elem_lock(ctl, argp);
1790 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1791 return snd_ctl_elem_unlock(ctl, argp);
1792 case SNDRV_CTL_IOCTL_ELEM_ADD:
1793 return snd_ctl_elem_add_user(ctl, argp, 0);
1794 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1795 return snd_ctl_elem_add_user(ctl, argp, 1);
1796 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1797 return snd_ctl_elem_remove(ctl, argp);
1798 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1799 return snd_ctl_subscribe_events(ctl, ip);
1800 case SNDRV_CTL_IOCTL_TLV_READ:
1801 down_read(&ctl->card->controls_rwsem);
1802 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1803 up_read(&ctl->card->controls_rwsem);
1805 case SNDRV_CTL_IOCTL_TLV_WRITE:
1806 down_write(&ctl->card->controls_rwsem);
1807 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1808 up_write(&ctl->card->controls_rwsem);
1810 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1811 down_write(&ctl->card->controls_rwsem);
1812 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1813 up_write(&ctl->card->controls_rwsem);
1815 case SNDRV_CTL_IOCTL_POWER:
1816 return -ENOPROTOOPT;
1817 case SNDRV_CTL_IOCTL_POWER_STATE:
1819 return put_user(card->power_state, ip) ? -EFAULT : 0;
1821 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1824 down_read(&snd_ioctl_rwsem);
1825 list_for_each_entry(p, &snd_control_ioctls, list) {
1826 err = p->fioctl(card, ctl, cmd, arg);
1827 if (err != -ENOIOCTLCMD) {
1828 up_read(&snd_ioctl_rwsem);
1832 up_read(&snd_ioctl_rwsem);
1833 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1837 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1838 size_t count, loff_t * offset)
1840 struct snd_ctl_file *ctl;
1844 ctl = file->private_data;
1845 if (snd_BUG_ON(!ctl || !ctl->card))
1847 if (!ctl->subscribed)
1849 if (count < sizeof(struct snd_ctl_event))
1851 spin_lock_irq(&ctl->read_lock);
1852 while (count >= sizeof(struct snd_ctl_event)) {
1853 struct snd_ctl_event ev;
1854 struct snd_kctl_event *kev;
1855 while (list_empty(&ctl->events)) {
1856 wait_queue_entry_t wait;
1857 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1861 init_waitqueue_entry(&wait, current);
1862 add_wait_queue(&ctl->change_sleep, &wait);
1863 set_current_state(TASK_INTERRUPTIBLE);
1864 spin_unlock_irq(&ctl->read_lock);
1866 remove_wait_queue(&ctl->change_sleep, &wait);
1867 if (ctl->card->shutdown)
1869 if (signal_pending(current))
1870 return -ERESTARTSYS;
1871 spin_lock_irq(&ctl->read_lock);
1873 kev = snd_kctl_event(ctl->events.next);
1874 ev.type = SNDRV_CTL_EVENT_ELEM;
1875 ev.data.elem.mask = kev->mask;
1876 ev.data.elem.id = kev->id;
1877 list_del(&kev->list);
1878 spin_unlock_irq(&ctl->read_lock);
1880 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1884 spin_lock_irq(&ctl->read_lock);
1885 buffer += sizeof(struct snd_ctl_event);
1886 count -= sizeof(struct snd_ctl_event);
1887 result += sizeof(struct snd_ctl_event);
1890 spin_unlock_irq(&ctl->read_lock);
1892 return result > 0 ? result : err;
1895 static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1898 struct snd_ctl_file *ctl;
1900 ctl = file->private_data;
1901 if (!ctl->subscribed)
1903 poll_wait(file, &ctl->change_sleep, wait);
1906 if (!list_empty(&ctl->events))
1907 mask |= EPOLLIN | EPOLLRDNORM;
1913 * register the device-specific control-ioctls.
1914 * called from each device manager like pcm.c, hwdep.c, etc.
1916 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1918 struct snd_kctl_ioctl *pn;
1920 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1924 down_write(&snd_ioctl_rwsem);
1925 list_add_tail(&pn->list, lists);
1926 up_write(&snd_ioctl_rwsem);
1931 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1932 * @fcn: ioctl callback function
1934 * called from each device manager like pcm.c, hwdep.c, etc.
1936 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1938 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1940 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1942 #ifdef CONFIG_COMPAT
1944 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1946 * @fcn: ioctl callback function
1948 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1950 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1952 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1956 * de-register the device-specific control-ioctls.
1958 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1959 struct list_head *lists)
1961 struct snd_kctl_ioctl *p;
1963 if (snd_BUG_ON(!fcn))
1965 down_write(&snd_ioctl_rwsem);
1966 list_for_each_entry(p, lists, list) {
1967 if (p->fioctl == fcn) {
1969 up_write(&snd_ioctl_rwsem);
1974 up_write(&snd_ioctl_rwsem);
1980 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1981 * @fcn: ioctl callback function to unregister
1983 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1985 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1987 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1989 #ifdef CONFIG_COMPAT
1991 * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat
1992 * 32bit control-ioctls
1993 * @fcn: ioctl callback function to unregister
1995 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1997 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1999 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
2002 static int snd_ctl_fasync(int fd, struct file * file, int on)
2004 struct snd_ctl_file *ctl;
2006 ctl = file->private_data;
2007 return fasync_helper(fd, file, on, &ctl->fasync);
2010 /* return the preferred subdevice number if already assigned;
2011 * otherwise return -1
2013 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
2015 struct snd_ctl_file *kctl;
2017 unsigned long flags;
2019 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2020 list_for_each_entry(kctl, &card->ctl_files, list) {
2021 if (kctl->pid == task_pid(current)) {
2022 subdevice = kctl->preferred_subdevice[type];
2023 if (subdevice != -1)
2027 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2030 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
2035 #ifdef CONFIG_COMPAT
2036 #include "control_compat.c"
2038 #define snd_ctl_ioctl_compat NULL
2042 * control layers (audio LED etc.)
2046 * snd_ctl_request_layer - request to use the layer
2047 * @module_name: Name of the kernel module (NULL == build-in)
2049 * Return an error code when the module cannot be loaded.
2051 int snd_ctl_request_layer(const char *module_name)
2053 struct snd_ctl_layer_ops *lops;
2055 if (module_name == NULL)
2057 down_read(&snd_ctl_layer_rwsem);
2058 for (lops = snd_ctl_layer; lops; lops = lops->next)
2059 if (strcmp(lops->module_name, module_name) == 0)
2061 up_read(&snd_ctl_layer_rwsem);
2064 return request_module(module_name);
2066 EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
2069 * snd_ctl_register_layer - register new control layer
2070 * @lops: operation structure
2072 * The new layer can track all control elements and do additional
2073 * operations on top (like audio LED handling).
2075 void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
2077 struct snd_card *card;
2080 down_write(&snd_ctl_layer_rwsem);
2081 lops->next = snd_ctl_layer;
2082 snd_ctl_layer = lops;
2083 up_write(&snd_ctl_layer_rwsem);
2084 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
2085 card = snd_card_ref(card_number);
2087 down_read(&card->controls_rwsem);
2088 lops->lregister(card);
2089 up_read(&card->controls_rwsem);
2090 snd_card_unref(card);
2094 EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
2097 * snd_ctl_disconnect_layer - disconnect control layer
2098 * @lops: operation structure
2100 * It is expected that the information about tracked cards
2101 * is freed before this call (the disconnect callback is
2104 void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
2106 struct snd_ctl_layer_ops *lops2, *prev_lops2;
2108 down_write(&snd_ctl_layer_rwsem);
2109 for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) {
2110 if (lops2 == lops) {
2112 snd_ctl_layer = lops->next;
2114 prev_lops2->next = lops->next;
2119 up_write(&snd_ctl_layer_rwsem);
2121 EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
2127 static const struct file_operations snd_ctl_f_ops =
2129 .owner = THIS_MODULE,
2130 .read = snd_ctl_read,
2131 .open = snd_ctl_open,
2132 .release = snd_ctl_release,
2133 .llseek = no_llseek,
2134 .poll = snd_ctl_poll,
2135 .unlocked_ioctl = snd_ctl_ioctl,
2136 .compat_ioctl = snd_ctl_ioctl_compat,
2137 .fasync = snd_ctl_fasync,
2141 * registration of the control device
2143 static int snd_ctl_dev_register(struct snd_device *device)
2145 struct snd_card *card = device->device_data;
2146 struct snd_ctl_layer_ops *lops;
2149 err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
2150 &snd_ctl_f_ops, card, &card->ctl_dev);
2153 down_read(&card->controls_rwsem);
2154 down_read(&snd_ctl_layer_rwsem);
2155 for (lops = snd_ctl_layer; lops; lops = lops->next)
2156 lops->lregister(card);
2157 up_read(&snd_ctl_layer_rwsem);
2158 up_read(&card->controls_rwsem);
2163 * disconnection of the control device
2165 static int snd_ctl_dev_disconnect(struct snd_device *device)
2167 struct snd_card *card = device->device_data;
2168 struct snd_ctl_file *ctl;
2169 struct snd_ctl_layer_ops *lops;
2170 unsigned long flags;
2172 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2173 list_for_each_entry(ctl, &card->ctl_files, list) {
2174 wake_up(&ctl->change_sleep);
2175 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
2177 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2179 down_read(&card->controls_rwsem);
2180 down_read(&snd_ctl_layer_rwsem);
2181 for (lops = snd_ctl_layer; lops; lops = lops->next)
2182 lops->ldisconnect(card);
2183 up_read(&snd_ctl_layer_rwsem);
2184 up_read(&card->controls_rwsem);
2186 return snd_unregister_device(&card->ctl_dev);
2192 static int snd_ctl_dev_free(struct snd_device *device)
2194 struct snd_card *card = device->device_data;
2195 struct snd_kcontrol *control;
2197 down_write(&card->controls_rwsem);
2198 while (!list_empty(&card->controls)) {
2199 control = snd_kcontrol(card->controls.next);
2200 snd_ctl_remove(card, control);
2202 up_write(&card->controls_rwsem);
2203 put_device(&card->ctl_dev);
2208 * create control core:
2209 * called from init.c
2211 int snd_ctl_create(struct snd_card *card)
2213 static const struct snd_device_ops ops = {
2214 .dev_free = snd_ctl_dev_free,
2215 .dev_register = snd_ctl_dev_register,
2216 .dev_disconnect = snd_ctl_dev_disconnect,
2220 if (snd_BUG_ON(!card))
2222 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2225 snd_device_initialize(&card->ctl_dev, card);
2226 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
2228 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2230 put_device(&card->ctl_dev);
2235 * Frequently used control callbacks/helpers
2239 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2240 * callback with a mono channel
2241 * @kcontrol: the kcontrol instance
2242 * @uinfo: info to store
2244 * This is a function that can be used as info callback for a standard
2245 * boolean control with a single mono channel.
2247 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2248 struct snd_ctl_elem_info *uinfo)
2250 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2252 uinfo->value.integer.min = 0;
2253 uinfo->value.integer.max = 1;
2256 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2259 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2260 * callback with stereo two channels
2261 * @kcontrol: the kcontrol instance
2262 * @uinfo: info to store
2264 * This is a function that can be used as info callback for a standard
2265 * boolean control with stereo two channels.
2267 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2268 struct snd_ctl_elem_info *uinfo)
2270 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2272 uinfo->value.integer.min = 0;
2273 uinfo->value.integer.max = 1;
2276 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2279 * snd_ctl_enum_info - fills the info structure for an enumerated control
2280 * @info: the structure to be filled
2281 * @channels: the number of the control's channels; often one
2282 * @items: the number of control values; also the size of @names
2283 * @names: an array containing the names of all control values
2285 * Sets all required fields in @info to their appropriate values.
2286 * If the control's accessibility is not the default (readable and writable),
2287 * the caller has to fill @info->access.
2291 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2292 unsigned int items, const char *const names[])
2294 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2295 info->count = channels;
2296 info->value.enumerated.items = items;
2299 if (info->value.enumerated.item >= items)
2300 info->value.enumerated.item = items - 1;
2301 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2302 "ALSA: too long item name '%s'\n",
2303 names[info->value.enumerated.item]);
2304 strscpy(info->value.enumerated.name,
2305 names[info->value.enumerated.item],
2306 sizeof(info->value.enumerated.name));
2309 EXPORT_SYMBOL(snd_ctl_enum_info);