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 = snd_power_ref_and_wait(card);
1000 result = kctl->info(kctl, info);
1001 snd_power_unref(card);
1003 snd_BUG_ON(info->access);
1004 index_offset = snd_ctl_get_ioff(kctl, &info->id);
1005 vd = &kctl->vd[index_offset];
1006 snd_ctl_build_ioff(&info->id, kctl, index_offset);
1007 info->access = vd->access;
1009 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
1010 if (vd->owner == ctl)
1011 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
1012 info->owner = pid_vnr(vd->owner->pid);
1016 if (!snd_ctl_skip_validation(info) &&
1017 snd_ctl_check_elem_info(card, info) < 0)
1023 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
1024 struct snd_ctl_elem_info *info)
1026 struct snd_card *card = ctl->card;
1027 struct snd_kcontrol *kctl;
1030 down_read(&card->controls_rwsem);
1031 kctl = snd_ctl_find_id(card, &info->id);
1035 result = __snd_ctl_elem_info(card, kctl, info, ctl);
1036 up_read(&card->controls_rwsem);
1040 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1041 struct snd_ctl_elem_info __user *_info)
1043 struct snd_ctl_elem_info info;
1046 if (copy_from_user(&info, _info, sizeof(info)))
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 = snd_power_ref_and_wait(card);
1093 ret = kctl->get(kctl, control);
1094 snd_power_unref(card);
1097 if (!snd_ctl_skip_validation(&info) &&
1098 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1100 "control %i:%i:%i:%s:%i: access overflow\n",
1101 control->id.iface, control->id.device,
1102 control->id.subdevice, control->id.name,
1109 static int snd_ctl_elem_read_user(struct snd_card *card,
1110 struct snd_ctl_elem_value __user *_control)
1112 struct snd_ctl_elem_value *control;
1115 control = memdup_user(_control, sizeof(*control));
1116 if (IS_ERR(control))
1117 return PTR_ERR(control);
1119 down_read(&card->controls_rwsem);
1120 result = snd_ctl_elem_read(card, control);
1121 up_read(&card->controls_rwsem);
1125 if (copy_to_user(_control, control, sizeof(*control)))
1132 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1133 struct snd_ctl_elem_value *control)
1135 struct snd_kcontrol *kctl;
1136 struct snd_kcontrol_volatile *vd;
1137 unsigned int index_offset;
1140 down_write(&card->controls_rwsem);
1141 kctl = snd_ctl_find_id(card, &control->id);
1143 up_write(&card->controls_rwsem);
1147 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1148 vd = &kctl->vd[index_offset];
1149 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1150 (file && vd->owner && vd->owner != file)) {
1151 up_write(&card->controls_rwsem);
1155 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1156 result = snd_power_ref_and_wait(card);
1158 result = kctl->put(kctl, control);
1159 snd_power_unref(card);
1161 up_write(&card->controls_rwsem);
1166 downgrade_write(&card->controls_rwsem);
1167 snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
1168 up_read(&card->controls_rwsem);
1170 up_write(&card->controls_rwsem);
1176 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1177 struct snd_ctl_elem_value __user *_control)
1179 struct snd_ctl_elem_value *control;
1180 struct snd_card *card;
1183 control = memdup_user(_control, sizeof(*control));
1184 if (IS_ERR(control))
1185 return PTR_ERR(control);
1188 result = snd_ctl_elem_write(card, file, control);
1192 if (copy_to_user(_control, control, sizeof(*control)))
1199 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1200 struct snd_ctl_elem_id __user *_id)
1202 struct snd_card *card = file->card;
1203 struct snd_ctl_elem_id id;
1204 struct snd_kcontrol *kctl;
1205 struct snd_kcontrol_volatile *vd;
1208 if (copy_from_user(&id, _id, sizeof(id)))
1210 down_write(&card->controls_rwsem);
1211 kctl = snd_ctl_find_id(card, &id);
1215 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1216 if (vd->owner != NULL)
1223 up_write(&card->controls_rwsem);
1227 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1228 struct snd_ctl_elem_id __user *_id)
1230 struct snd_card *card = file->card;
1231 struct snd_ctl_elem_id id;
1232 struct snd_kcontrol *kctl;
1233 struct snd_kcontrol_volatile *vd;
1236 if (copy_from_user(&id, _id, sizeof(id)))
1238 down_write(&card->controls_rwsem);
1239 kctl = snd_ctl_find_id(card, &id);
1243 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1244 if (vd->owner == NULL)
1246 else if (vd->owner != file)
1253 up_write(&card->controls_rwsem);
1257 struct user_element {
1258 struct snd_ctl_elem_info info;
1259 struct snd_card *card;
1260 char *elem_data; /* element data */
1261 unsigned long elem_data_size; /* size of element data in bytes */
1262 void *tlv_data; /* TLV data */
1263 unsigned long tlv_data_size; /* TLV data size */
1264 void *priv_data; /* private data (like strings for enumerated type) */
1267 // check whether the addition (in bytes) of user ctl element may overflow the limit.
1268 static bool check_user_elem_overflow(struct snd_card *card, ssize_t add)
1270 return (ssize_t)card->user_ctl_alloc_size + add > max_user_ctl_alloc_size;
1273 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1274 struct snd_ctl_elem_info *uinfo)
1276 struct user_element *ue = kcontrol->private_data;
1277 unsigned int offset;
1279 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1281 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1286 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1287 struct snd_ctl_elem_info *uinfo)
1289 struct user_element *ue = kcontrol->private_data;
1292 unsigned int offset;
1294 item = uinfo->value.enumerated.item;
1296 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1298 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1300 item = min(item, uinfo->value.enumerated.items - 1);
1301 uinfo->value.enumerated.item = item;
1303 names = ue->priv_data;
1304 for (; item > 0; --item)
1305 names += strlen(names) + 1;
1306 strcpy(uinfo->value.enumerated.name, names);
1311 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1312 struct snd_ctl_elem_value *ucontrol)
1314 struct user_element *ue = kcontrol->private_data;
1315 unsigned int size = ue->elem_data_size;
1316 char *src = ue->elem_data +
1317 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1319 memcpy(&ucontrol->value, src, size);
1323 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1324 struct snd_ctl_elem_value *ucontrol)
1327 struct user_element *ue = kcontrol->private_data;
1328 unsigned int size = ue->elem_data_size;
1329 char *dst = ue->elem_data +
1330 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1332 change = memcmp(&ucontrol->value, dst, size) != 0;
1334 memcpy(dst, &ucontrol->value, size);
1338 /* called in controls_rwsem write lock */
1339 static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1342 struct user_element *ue = kctl->private_data;
1343 unsigned int *container;
1344 unsigned int mask = 0;
1348 if (size > 1024 * 128) /* sane value */
1351 // does the TLV size change cause overflow?
1352 if (check_user_elem_overflow(ue->card, (ssize_t)(size - ue->tlv_data_size)))
1355 container = vmemdup_user(buf, size);
1356 if (IS_ERR(container))
1357 return PTR_ERR(container);
1359 change = ue->tlv_data_size != size;
1361 change = memcmp(ue->tlv_data, container, size) != 0;
1367 if (ue->tlv_data == NULL) {
1368 /* Now TLV data is available. */
1369 for (i = 0; i < kctl->count; ++i)
1370 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1371 mask = SNDRV_CTL_EVENT_MASK_INFO;
1373 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1374 ue->tlv_data_size = 0;
1375 kvfree(ue->tlv_data);
1378 ue->tlv_data = container;
1379 ue->tlv_data_size = size;
1380 // decremented at private_free.
1381 ue->card->user_ctl_alloc_size += size;
1383 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1384 for (i = 0; i < kctl->count; ++i)
1385 snd_ctl_notify_one(ue->card, mask, kctl, i);
1390 static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1393 struct user_element *ue = kctl->private_data;
1395 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1398 if (size < ue->tlv_data_size)
1401 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1407 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1408 unsigned int size, unsigned int __user *buf)
1410 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1411 return replace_user_tlv(kctl, buf, size);
1413 return read_user_tlv(kctl, buf, size);
1416 /* called in controls_rwsem write lock */
1417 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1420 size_t buf_len, name_len;
1422 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1424 buf_len = ue->info.value.enumerated.names_length;
1425 if (buf_len > 64 * 1024)
1428 if (check_user_elem_overflow(ue->card, buf_len))
1430 names = vmemdup_user((const void __user *)user_ptrval, buf_len);
1432 return PTR_ERR(names);
1434 /* check that there are enough valid names */
1436 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1437 name_len = strnlen(p, buf_len);
1438 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1443 buf_len -= name_len + 1;
1446 ue->priv_data = names;
1447 ue->info.value.enumerated.names_ptr = 0;
1448 // increment the allocation size; decremented again at private_free.
1449 ue->card->user_ctl_alloc_size += ue->info.value.enumerated.names_length;
1454 static size_t compute_user_elem_size(size_t size, unsigned int count)
1456 return sizeof(struct user_element) + size * count;
1459 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1461 struct user_element *ue = kcontrol->private_data;
1463 // decrement the allocation size.
1464 ue->card->user_ctl_alloc_size -= compute_user_elem_size(ue->elem_data_size, kcontrol->count);
1465 ue->card->user_ctl_alloc_size -= ue->tlv_data_size;
1467 ue->card->user_ctl_alloc_size -= ue->info.value.enumerated.names_length;
1469 kvfree(ue->tlv_data);
1470 kvfree(ue->priv_data);
1474 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1475 struct snd_ctl_elem_info *info, int replace)
1477 struct snd_card *card = file->card;
1478 struct snd_kcontrol *kctl;
1480 unsigned int access;
1483 struct user_element *ue;
1484 unsigned int offset;
1487 if (!*info->id.name)
1489 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1492 /* Delete a control to replace them if needed. */
1495 err = snd_ctl_remove_user_ctl(file, &info->id);
1500 /* Check the number of elements for this userspace control. */
1501 count = info->owner;
1505 /* Arrange access permissions if needed. */
1506 access = info->access;
1508 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1509 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1510 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1511 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1513 /* In initial state, nothing is available as TLV container. */
1514 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1515 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1516 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1519 * Check information and calculate the size of data specific to
1520 * this userspace control.
1522 /* pass NULL to card for suppressing error messages */
1523 err = snd_ctl_check_elem_info(NULL, info);
1526 /* user-space control doesn't allow zero-size data */
1527 if (info->count < 1)
1529 private_size = value_sizes[info->type] * info->count;
1530 alloc_size = compute_user_elem_size(private_size, count);
1532 down_write(&card->controls_rwsem);
1533 if (check_user_elem_overflow(card, alloc_size)) {
1539 * Keep memory object for this userspace control. After passing this
1540 * code block, the instance should be freed by snd_ctl_free_one().
1542 * Note that these elements in this control are locked.
1544 err = snd_ctl_new(&kctl, count, access, file);
1547 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1548 ue = kzalloc(alloc_size, GFP_KERNEL);
1554 kctl->private_data = ue;
1555 kctl->private_free = snd_ctl_elem_user_free;
1557 // increment the allocated size; decremented again at private_free.
1558 card->user_ctl_alloc_size += alloc_size;
1560 /* Set private data for this userspace control. */
1563 ue->info.access = 0;
1564 ue->elem_data = (char *)ue + sizeof(*ue);
1565 ue->elem_data_size = private_size;
1566 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1567 err = snd_ctl_elem_init_enum_names(ue);
1569 snd_ctl_free_one(kctl);
1574 /* Set callback functions. */
1575 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1576 kctl->info = snd_ctl_elem_user_enum_info;
1578 kctl->info = snd_ctl_elem_user_info;
1579 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1580 kctl->get = snd_ctl_elem_user_get;
1581 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1582 kctl->put = snd_ctl_elem_user_put;
1583 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1584 kctl->tlv.c = snd_ctl_elem_user_tlv;
1586 /* This function manage to free the instance on failure. */
1587 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1589 snd_ctl_free_one(kctl);
1592 offset = snd_ctl_get_ioff(kctl, &info->id);
1593 snd_ctl_build_ioff(&info->id, kctl, offset);
1595 * Here we cannot fill any field for the number of elements added by
1596 * this operation because there're no specific fields. The usage of
1597 * 'owner' field for this purpose may cause any bugs to userspace
1598 * applications because the field originally means PID of a process
1599 * which locks the element.
1602 up_write(&card->controls_rwsem);
1606 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1607 struct snd_ctl_elem_info __user *_info, int replace)
1609 struct snd_ctl_elem_info info;
1612 if (copy_from_user(&info, _info, sizeof(info)))
1614 err = snd_ctl_elem_add(file, &info, replace);
1617 if (copy_to_user(_info, &info, sizeof(info))) {
1618 snd_ctl_remove_user_ctl(file, &info.id);
1625 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1626 struct snd_ctl_elem_id __user *_id)
1628 struct snd_ctl_elem_id id;
1630 if (copy_from_user(&id, _id, sizeof(id)))
1632 return snd_ctl_remove_user_ctl(file, &id);
1635 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1638 if (get_user(subscribe, ptr))
1640 if (subscribe < 0) {
1641 subscribe = file->subscribed;
1642 if (put_user(subscribe, ptr))
1647 file->subscribed = 1;
1649 } else if (file->subscribed) {
1650 snd_ctl_empty_read_queue(file);
1651 file->subscribed = 0;
1656 static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1657 struct snd_kcontrol *kctl,
1658 struct snd_ctl_elem_id *id,
1659 unsigned int __user *buf, unsigned int size)
1661 static const struct {
1665 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1666 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1667 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1669 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1672 /* Check support of the request for this element. */
1673 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1674 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1677 if (i == ARRAY_SIZE(pairs))
1680 if (kctl->tlv.c == NULL)
1683 /* Write and command operations are not allowed for locked element. */
1684 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1685 vd->owner != NULL && vd->owner != file)
1688 ret = snd_power_ref_and_wait(file->card);
1690 ret = kctl->tlv.c(kctl, op_flag, size, buf);
1691 snd_power_unref(file->card);
1695 static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1696 unsigned int __user *buf, unsigned int size)
1698 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1701 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1704 if (kctl->tlv.p == NULL)
1707 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1711 if (copy_to_user(buf, kctl->tlv.p, len))
1717 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1718 struct snd_ctl_tlv __user *buf,
1721 struct snd_ctl_tlv header;
1722 unsigned int __user *container;
1723 unsigned int container_size;
1724 struct snd_kcontrol *kctl;
1725 struct snd_ctl_elem_id id;
1726 struct snd_kcontrol_volatile *vd;
1728 if (copy_from_user(&header, buf, sizeof(header)))
1731 /* In design of control core, numerical ID starts at 1. */
1732 if (header.numid == 0)
1735 /* At least, container should include type and length fields. */
1736 if (header.length < sizeof(unsigned int) * 2)
1738 container_size = header.length;
1739 container = buf->tlv;
1741 kctl = snd_ctl_find_numid(file->card, header.numid);
1745 /* Calculate index of the element in this set. */
1747 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1748 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1750 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1751 return call_tlv_handler(file, op_flag, kctl, &id, container,
1754 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1755 return read_tlv_buf(kctl, &id, container,
1760 /* Not supported. */
1764 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1766 struct snd_ctl_file *ctl;
1767 struct snd_card *card;
1768 struct snd_kctl_ioctl *p;
1769 void __user *argp = (void __user *)arg;
1770 int __user *ip = argp;
1773 ctl = file->private_data;
1775 if (snd_BUG_ON(!card))
1778 case SNDRV_CTL_IOCTL_PVERSION:
1779 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1780 case SNDRV_CTL_IOCTL_CARD_INFO:
1781 return snd_ctl_card_info(card, ctl, cmd, argp);
1782 case SNDRV_CTL_IOCTL_ELEM_LIST:
1783 return snd_ctl_elem_list_user(card, argp);
1784 case SNDRV_CTL_IOCTL_ELEM_INFO:
1785 return snd_ctl_elem_info_user(ctl, argp);
1786 case SNDRV_CTL_IOCTL_ELEM_READ:
1787 return snd_ctl_elem_read_user(card, argp);
1788 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1789 return snd_ctl_elem_write_user(ctl, argp);
1790 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1791 return snd_ctl_elem_lock(ctl, argp);
1792 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1793 return snd_ctl_elem_unlock(ctl, argp);
1794 case SNDRV_CTL_IOCTL_ELEM_ADD:
1795 return snd_ctl_elem_add_user(ctl, argp, 0);
1796 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1797 return snd_ctl_elem_add_user(ctl, argp, 1);
1798 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1799 return snd_ctl_elem_remove(ctl, argp);
1800 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1801 return snd_ctl_subscribe_events(ctl, ip);
1802 case SNDRV_CTL_IOCTL_TLV_READ:
1803 down_read(&ctl->card->controls_rwsem);
1804 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1805 up_read(&ctl->card->controls_rwsem);
1807 case SNDRV_CTL_IOCTL_TLV_WRITE:
1808 down_write(&ctl->card->controls_rwsem);
1809 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1810 up_write(&ctl->card->controls_rwsem);
1812 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1813 down_write(&ctl->card->controls_rwsem);
1814 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1815 up_write(&ctl->card->controls_rwsem);
1817 case SNDRV_CTL_IOCTL_POWER:
1818 return -ENOPROTOOPT;
1819 case SNDRV_CTL_IOCTL_POWER_STATE:
1820 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1822 down_read(&snd_ioctl_rwsem);
1823 list_for_each_entry(p, &snd_control_ioctls, list) {
1824 err = p->fioctl(card, ctl, cmd, arg);
1825 if (err != -ENOIOCTLCMD) {
1826 up_read(&snd_ioctl_rwsem);
1830 up_read(&snd_ioctl_rwsem);
1831 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1835 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1836 size_t count, loff_t * offset)
1838 struct snd_ctl_file *ctl;
1842 ctl = file->private_data;
1843 if (snd_BUG_ON(!ctl || !ctl->card))
1845 if (!ctl->subscribed)
1847 if (count < sizeof(struct snd_ctl_event))
1849 spin_lock_irq(&ctl->read_lock);
1850 while (count >= sizeof(struct snd_ctl_event)) {
1851 struct snd_ctl_event ev;
1852 struct snd_kctl_event *kev;
1853 while (list_empty(&ctl->events)) {
1854 wait_queue_entry_t wait;
1855 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1859 init_waitqueue_entry(&wait, current);
1860 add_wait_queue(&ctl->change_sleep, &wait);
1861 set_current_state(TASK_INTERRUPTIBLE);
1862 spin_unlock_irq(&ctl->read_lock);
1864 remove_wait_queue(&ctl->change_sleep, &wait);
1865 if (ctl->card->shutdown)
1867 if (signal_pending(current))
1868 return -ERESTARTSYS;
1869 spin_lock_irq(&ctl->read_lock);
1871 kev = snd_kctl_event(ctl->events.next);
1872 ev.type = SNDRV_CTL_EVENT_ELEM;
1873 ev.data.elem.mask = kev->mask;
1874 ev.data.elem.id = kev->id;
1875 list_del(&kev->list);
1876 spin_unlock_irq(&ctl->read_lock);
1878 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1882 spin_lock_irq(&ctl->read_lock);
1883 buffer += sizeof(struct snd_ctl_event);
1884 count -= sizeof(struct snd_ctl_event);
1885 result += sizeof(struct snd_ctl_event);
1888 spin_unlock_irq(&ctl->read_lock);
1890 return result > 0 ? result : err;
1893 static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1896 struct snd_ctl_file *ctl;
1898 ctl = file->private_data;
1899 if (!ctl->subscribed)
1901 poll_wait(file, &ctl->change_sleep, wait);
1904 if (!list_empty(&ctl->events))
1905 mask |= EPOLLIN | EPOLLRDNORM;
1911 * register the device-specific control-ioctls.
1912 * called from each device manager like pcm.c, hwdep.c, etc.
1914 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1916 struct snd_kctl_ioctl *pn;
1918 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1922 down_write(&snd_ioctl_rwsem);
1923 list_add_tail(&pn->list, lists);
1924 up_write(&snd_ioctl_rwsem);
1929 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1930 * @fcn: ioctl callback function
1932 * called from each device manager like pcm.c, hwdep.c, etc.
1934 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1936 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1938 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1940 #ifdef CONFIG_COMPAT
1942 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1944 * @fcn: ioctl callback function
1946 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1948 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1950 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1954 * de-register the device-specific control-ioctls.
1956 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1957 struct list_head *lists)
1959 struct snd_kctl_ioctl *p;
1961 if (snd_BUG_ON(!fcn))
1963 down_write(&snd_ioctl_rwsem);
1964 list_for_each_entry(p, lists, list) {
1965 if (p->fioctl == fcn) {
1967 up_write(&snd_ioctl_rwsem);
1972 up_write(&snd_ioctl_rwsem);
1978 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1979 * @fcn: ioctl callback function to unregister
1981 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1983 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1985 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1987 #ifdef CONFIG_COMPAT
1989 * snd_ctl_unregister_ioctl_compat - de-register the device-specific compat
1990 * 32bit control-ioctls
1991 * @fcn: ioctl callback function to unregister
1993 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1995 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1997 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
2000 static int snd_ctl_fasync(int fd, struct file * file, int on)
2002 struct snd_ctl_file *ctl;
2004 ctl = file->private_data;
2005 return fasync_helper(fd, file, on, &ctl->fasync);
2008 /* return the preferred subdevice number if already assigned;
2009 * otherwise return -1
2011 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
2013 struct snd_ctl_file *kctl;
2015 unsigned long flags;
2017 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2018 list_for_each_entry(kctl, &card->ctl_files, list) {
2019 if (kctl->pid == task_pid(current)) {
2020 subdevice = kctl->preferred_subdevice[type];
2021 if (subdevice != -1)
2025 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2028 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
2033 #ifdef CONFIG_COMPAT
2034 #include "control_compat.c"
2036 #define snd_ctl_ioctl_compat NULL
2040 * control layers (audio LED etc.)
2044 * snd_ctl_request_layer - request to use the layer
2045 * @module_name: Name of the kernel module (NULL == build-in)
2047 * Return an error code when the module cannot be loaded.
2049 int snd_ctl_request_layer(const char *module_name)
2051 struct snd_ctl_layer_ops *lops;
2053 if (module_name == NULL)
2055 down_read(&snd_ctl_layer_rwsem);
2056 for (lops = snd_ctl_layer; lops; lops = lops->next)
2057 if (strcmp(lops->module_name, module_name) == 0)
2059 up_read(&snd_ctl_layer_rwsem);
2062 return request_module(module_name);
2064 EXPORT_SYMBOL_GPL(snd_ctl_request_layer);
2067 * snd_ctl_register_layer - register new control layer
2068 * @lops: operation structure
2070 * The new layer can track all control elements and do additional
2071 * operations on top (like audio LED handling).
2073 void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops)
2075 struct snd_card *card;
2078 down_write(&snd_ctl_layer_rwsem);
2079 lops->next = snd_ctl_layer;
2080 snd_ctl_layer = lops;
2081 up_write(&snd_ctl_layer_rwsem);
2082 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
2083 card = snd_card_ref(card_number);
2085 down_read(&card->controls_rwsem);
2086 lops->lregister(card);
2087 up_read(&card->controls_rwsem);
2088 snd_card_unref(card);
2092 EXPORT_SYMBOL_GPL(snd_ctl_register_layer);
2095 * snd_ctl_disconnect_layer - disconnect control layer
2096 * @lops: operation structure
2098 * It is expected that the information about tracked cards
2099 * is freed before this call (the disconnect callback is
2102 void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops)
2104 struct snd_ctl_layer_ops *lops2, *prev_lops2;
2106 down_write(&snd_ctl_layer_rwsem);
2107 for (lops2 = snd_ctl_layer, prev_lops2 = NULL; lops2; lops2 = lops2->next) {
2108 if (lops2 == lops) {
2110 snd_ctl_layer = lops->next;
2112 prev_lops2->next = lops->next;
2117 up_write(&snd_ctl_layer_rwsem);
2119 EXPORT_SYMBOL_GPL(snd_ctl_disconnect_layer);
2125 static const struct file_operations snd_ctl_f_ops =
2127 .owner = THIS_MODULE,
2128 .read = snd_ctl_read,
2129 .open = snd_ctl_open,
2130 .release = snd_ctl_release,
2131 .llseek = no_llseek,
2132 .poll = snd_ctl_poll,
2133 .unlocked_ioctl = snd_ctl_ioctl,
2134 .compat_ioctl = snd_ctl_ioctl_compat,
2135 .fasync = snd_ctl_fasync,
2139 * registration of the control device
2141 static int snd_ctl_dev_register(struct snd_device *device)
2143 struct snd_card *card = device->device_data;
2144 struct snd_ctl_layer_ops *lops;
2147 err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
2148 &snd_ctl_f_ops, card, &card->ctl_dev);
2151 down_read(&card->controls_rwsem);
2152 down_read(&snd_ctl_layer_rwsem);
2153 for (lops = snd_ctl_layer; lops; lops = lops->next)
2154 lops->lregister(card);
2155 up_read(&snd_ctl_layer_rwsem);
2156 up_read(&card->controls_rwsem);
2161 * disconnection of the control device
2163 static int snd_ctl_dev_disconnect(struct snd_device *device)
2165 struct snd_card *card = device->device_data;
2166 struct snd_ctl_file *ctl;
2167 struct snd_ctl_layer_ops *lops;
2168 unsigned long flags;
2170 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2171 list_for_each_entry(ctl, &card->ctl_files, list) {
2172 wake_up(&ctl->change_sleep);
2173 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
2175 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2177 down_read(&card->controls_rwsem);
2178 down_read(&snd_ctl_layer_rwsem);
2179 for (lops = snd_ctl_layer; lops; lops = lops->next)
2180 lops->ldisconnect(card);
2181 up_read(&snd_ctl_layer_rwsem);
2182 up_read(&card->controls_rwsem);
2184 return snd_unregister_device(&card->ctl_dev);
2190 static int snd_ctl_dev_free(struct snd_device *device)
2192 struct snd_card *card = device->device_data;
2193 struct snd_kcontrol *control;
2195 down_write(&card->controls_rwsem);
2196 while (!list_empty(&card->controls)) {
2197 control = snd_kcontrol(card->controls.next);
2198 snd_ctl_remove(card, control);
2200 up_write(&card->controls_rwsem);
2201 put_device(&card->ctl_dev);
2206 * create control core:
2207 * called from init.c
2209 int snd_ctl_create(struct snd_card *card)
2211 static const struct snd_device_ops ops = {
2212 .dev_free = snd_ctl_dev_free,
2213 .dev_register = snd_ctl_dev_register,
2214 .dev_disconnect = snd_ctl_dev_disconnect,
2218 if (snd_BUG_ON(!card))
2220 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2223 snd_device_initialize(&card->ctl_dev, card);
2224 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
2226 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2228 put_device(&card->ctl_dev);
2233 * Frequently used control callbacks/helpers
2237 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2238 * callback with a mono channel
2239 * @kcontrol: the kcontrol instance
2240 * @uinfo: info to store
2242 * This is a function that can be used as info callback for a standard
2243 * boolean control with a single mono channel.
2245 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2246 struct snd_ctl_elem_info *uinfo)
2248 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2250 uinfo->value.integer.min = 0;
2251 uinfo->value.integer.max = 1;
2254 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2257 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2258 * callback with stereo two channels
2259 * @kcontrol: the kcontrol instance
2260 * @uinfo: info to store
2262 * This is a function that can be used as info callback for a standard
2263 * boolean control with stereo two channels.
2265 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2266 struct snd_ctl_elem_info *uinfo)
2268 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2270 uinfo->value.integer.min = 0;
2271 uinfo->value.integer.max = 1;
2274 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2277 * snd_ctl_enum_info - fills the info structure for an enumerated control
2278 * @info: the structure to be filled
2279 * @channels: the number of the control's channels; often one
2280 * @items: the number of control values; also the size of @names
2281 * @names: an array containing the names of all control values
2283 * Sets all required fields in @info to their appropriate values.
2284 * If the control's accessibility is not the default (readable and writable),
2285 * the caller has to fill @info->access.
2289 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2290 unsigned int items, const char *const names[])
2292 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2293 info->count = channels;
2294 info->value.enumerated.items = items;
2297 if (info->value.enumerated.item >= items)
2298 info->value.enumerated.item = items - 1;
2299 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2300 "ALSA: too long item name '%s'\n",
2301 names[info->value.enumerated.item]);
2302 strscpy(info->value.enumerated.name,
2303 names[info->value.enumerated.item],
2304 sizeof(info->value.enumerated.name));
2307 EXPORT_SYMBOL(snd_ctl_enum_info);