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/slab.h>
11 #include <linux/vmalloc.h>
12 #include <linux/time.h>
14 #include <linux/math64.h>
15 #include <linux/sched/signal.h>
16 #include <sound/core.h>
17 #include <sound/minors.h>
18 #include <sound/info.h>
19 #include <sound/control.h>
21 /* max number of user-defined controls */
22 #define MAX_USER_CONTROLS 32
23 #define MAX_CONTROL_COUNT 1028
25 struct snd_kctl_ioctl {
26 struct list_head list; /* list of all ioctls */
27 snd_kctl_ioctl_func_t fioctl;
30 static DECLARE_RWSEM(snd_ioctl_rwsem);
31 static LIST_HEAD(snd_control_ioctls);
33 static LIST_HEAD(snd_control_compat_ioctls);
36 static int snd_ctl_open(struct inode *inode, struct file *file)
39 struct snd_card *card;
40 struct snd_ctl_file *ctl;
43 err = stream_open(inode, file);
47 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
52 err = snd_card_file_add(card, file);
57 if (!try_module_get(card->module)) {
61 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
66 INIT_LIST_HEAD(&ctl->events);
67 init_waitqueue_head(&ctl->change_sleep);
68 spin_lock_init(&ctl->read_lock);
70 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
71 ctl->preferred_subdevice[i] = -1;
72 ctl->pid = get_pid(task_pid(current));
73 file->private_data = ctl;
74 write_lock_irqsave(&card->ctl_files_rwlock, flags);
75 list_add_tail(&ctl->list, &card->ctl_files);
76 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
81 module_put(card->module);
83 snd_card_file_remove(card, file);
90 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
93 struct snd_kctl_event *cread;
95 spin_lock_irqsave(&ctl->read_lock, flags);
96 while (!list_empty(&ctl->events)) {
97 cread = snd_kctl_event(ctl->events.next);
98 list_del(&cread->list);
101 spin_unlock_irqrestore(&ctl->read_lock, flags);
104 static int snd_ctl_release(struct inode *inode, struct file *file)
107 struct snd_card *card;
108 struct snd_ctl_file *ctl;
109 struct snd_kcontrol *control;
112 ctl = file->private_data;
113 file->private_data = NULL;
115 write_lock_irqsave(&card->ctl_files_rwlock, flags);
116 list_del(&ctl->list);
117 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
118 down_write(&card->controls_rwsem);
119 list_for_each_entry(control, &card->controls, list)
120 for (idx = 0; idx < control->count; idx++)
121 if (control->vd[idx].owner == ctl)
122 control->vd[idx].owner = NULL;
123 up_write(&card->controls_rwsem);
124 snd_ctl_empty_read_queue(ctl);
127 module_put(card->module);
128 snd_card_file_remove(card, file);
133 * snd_ctl_notify - Send notification to user-space for a control change
134 * @card: the card to send notification
135 * @mask: the event mask, SNDRV_CTL_EVENT_*
136 * @id: the ctl element id to send notification
138 * This function adds an event record with the given id and mask, appends
139 * to the list and wakes up the user-space for notification. This can be
140 * called in the atomic context.
142 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
143 struct snd_ctl_elem_id *id)
146 struct snd_ctl_file *ctl;
147 struct snd_kctl_event *ev;
149 if (snd_BUG_ON(!card || !id))
153 read_lock_irqsave(&card->ctl_files_rwlock, flags);
154 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
155 card->mixer_oss_change_count++;
157 list_for_each_entry(ctl, &card->ctl_files, list) {
158 if (!ctl->subscribed)
160 spin_lock(&ctl->read_lock);
161 list_for_each_entry(ev, &ctl->events, list) {
162 if (ev->id.numid == id->numid) {
167 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
171 list_add_tail(&ev->list, &ctl->events);
173 dev_err(card->dev, "No memory available to allocate event\n");
176 wake_up(&ctl->change_sleep);
177 spin_unlock(&ctl->read_lock);
178 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
180 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
182 EXPORT_SYMBOL(snd_ctl_notify);
185 * snd_ctl_new - create a new control instance with some elements
186 * @kctl: the pointer to store new control instance
187 * @count: the number of elements in this control
188 * @access: the default access flags for elements in this control
189 * @file: given when locking these elements
191 * Allocates a memory object for a new control instance. The instance has
192 * elements as many as the given number (@count). Each element has given
193 * access permissions (@access). Each element is locked when @file is given.
195 * Return: 0 on success, error code on failure
197 static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
198 unsigned int access, struct snd_ctl_file *file)
202 if (count == 0 || count > MAX_CONTROL_COUNT)
205 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
209 for (idx = 0; idx < count; idx++) {
210 (*kctl)->vd[idx].access = access;
211 (*kctl)->vd[idx].owner = file;
213 (*kctl)->count = count;
219 * snd_ctl_new1 - create a control instance from the template
220 * @ncontrol: the initialization record
221 * @private_data: the private data to set
223 * Allocates a new struct snd_kcontrol instance and initialize from the given
224 * template. When the access field of ncontrol is 0, it's assumed as
225 * READWRITE access. When the count field is 0, it's assumes as one.
227 * Return: The pointer of the newly generated instance, or %NULL on failure.
229 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
232 struct snd_kcontrol *kctl;
237 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
240 count = ncontrol->count;
244 access = ncontrol->access;
246 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
247 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
248 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
249 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
250 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
251 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
252 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK |
253 SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
255 err = snd_ctl_new(&kctl, count, access, NULL);
259 /* The 'numid' member is decided when calling snd_ctl_add(). */
260 kctl->id.iface = ncontrol->iface;
261 kctl->id.device = ncontrol->device;
262 kctl->id.subdevice = ncontrol->subdevice;
263 if (ncontrol->name) {
264 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
265 if (strcmp(ncontrol->name, kctl->id.name) != 0)
266 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
267 ncontrol->name, kctl->id.name);
269 kctl->id.index = ncontrol->index;
271 kctl->info = ncontrol->info;
272 kctl->get = ncontrol->get;
273 kctl->put = ncontrol->put;
274 kctl->tlv.p = ncontrol->tlv.p;
276 kctl->private_value = ncontrol->private_value;
277 kctl->private_data = private_data;
281 EXPORT_SYMBOL(snd_ctl_new1);
284 * snd_ctl_free_one - release the control instance
285 * @kcontrol: the control instance
287 * Releases the control instance created via snd_ctl_new()
289 * Don't call this after the control was added to the card.
291 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
294 if (kcontrol->private_free)
295 kcontrol->private_free(kcontrol);
299 EXPORT_SYMBOL(snd_ctl_free_one);
301 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
304 struct snd_kcontrol *kctl;
306 /* Make sure that the ids assigned to the control do not wrap around */
307 if (card->last_numid >= UINT_MAX - count)
308 card->last_numid = 0;
310 list_for_each_entry(kctl, &card->controls, list) {
311 if (kctl->id.numid < card->last_numid + 1 + count &&
312 kctl->id.numid + kctl->count > card->last_numid + 1) {
313 card->last_numid = kctl->id.numid + kctl->count - 1;
320 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
322 unsigned int iter = 100000;
324 while (snd_ctl_remove_numid_conflict(card, count)) {
326 /* this situation is very unlikely */
327 dev_err(card->dev, "unable to allocate new control numid\n");
334 enum snd_ctl_add_mode {
335 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
338 /* add/replace a new kcontrol object; call with card->controls_rwsem locked */
339 static int __snd_ctl_add_replace(struct snd_card *card,
340 struct snd_kcontrol *kcontrol,
341 enum snd_ctl_add_mode mode)
343 struct snd_ctl_elem_id id;
346 struct snd_kcontrol *old;
350 if (id.index > UINT_MAX - kcontrol->count)
353 old = snd_ctl_find_id(card, &id);
355 if (mode == CTL_REPLACE)
358 if (mode == CTL_ADD_EXCLUSIVE) {
360 "control %i:%i:%i:%s:%i is already present\n",
361 id.iface, id.device, id.subdevice, id.name,
366 err = snd_ctl_remove(card, old);
371 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
374 list_add_tail(&kcontrol->list, &card->controls);
375 card->controls_count += kcontrol->count;
376 kcontrol->id.numid = card->last_numid + 1;
377 card->last_numid += kcontrol->count;
380 count = kcontrol->count;
381 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
382 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
387 static int snd_ctl_add_replace(struct snd_card *card,
388 struct snd_kcontrol *kcontrol,
389 enum snd_ctl_add_mode mode)
395 if (snd_BUG_ON(!card || !kcontrol->info))
398 down_write(&card->controls_rwsem);
399 err = __snd_ctl_add_replace(card, kcontrol, mode);
400 up_write(&card->controls_rwsem);
406 snd_ctl_free_one(kcontrol);
411 * snd_ctl_add - add the control instance to the card
412 * @card: the card instance
413 * @kcontrol: the control instance to add
415 * Adds the control instance created via snd_ctl_new() or
416 * snd_ctl_new1() to the given card. Assigns also an unique
417 * numid used for fast search.
419 * It frees automatically the control which cannot be added.
421 * Return: Zero if successful, or a negative error code on failure.
424 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
426 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
428 EXPORT_SYMBOL(snd_ctl_add);
431 * snd_ctl_replace - replace the control instance of the card
432 * @card: the card instance
433 * @kcontrol: the control instance to replace
434 * @add_on_replace: add the control if not already added
436 * Replaces the given control. If the given control does not exist
437 * and the add_on_replace flag is set, the control is added. If the
438 * control exists, it is destroyed first.
440 * It frees automatically the control which cannot be added or replaced.
442 * Return: Zero if successful, or a negative error code on failure.
444 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
447 return snd_ctl_add_replace(card, kcontrol,
448 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
450 EXPORT_SYMBOL(snd_ctl_replace);
453 * snd_ctl_remove - remove the control from the card and release it
454 * @card: the card instance
455 * @kcontrol: the control instance to remove
457 * Removes the control from the card and then releases the instance.
458 * You don't need to call snd_ctl_free_one(). You must be in
459 * the write lock - down_write(&card->controls_rwsem).
461 * Return: 0 if successful, or a negative error code on failure.
463 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
465 struct snd_ctl_elem_id id;
468 if (snd_BUG_ON(!card || !kcontrol))
470 list_del(&kcontrol->list);
471 card->controls_count -= kcontrol->count;
473 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
474 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
475 snd_ctl_free_one(kcontrol);
478 EXPORT_SYMBOL(snd_ctl_remove);
481 * snd_ctl_remove_id - remove the control of the given id and release it
482 * @card: the card instance
483 * @id: the control id to remove
485 * Finds the control instance with the given id, removes it from the
486 * card list and releases it.
488 * Return: 0 if successful, or a negative error code on failure.
490 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
492 struct snd_kcontrol *kctl;
495 down_write(&card->controls_rwsem);
496 kctl = snd_ctl_find_id(card, id);
498 up_write(&card->controls_rwsem);
501 ret = snd_ctl_remove(card, kctl);
502 up_write(&card->controls_rwsem);
505 EXPORT_SYMBOL(snd_ctl_remove_id);
508 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
509 * @file: active control handle
510 * @id: the control id to remove
512 * Finds the control instance with the given id, removes it from the
513 * card list and releases it.
515 * Return: 0 if successful, or a negative error code on failure.
517 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
518 struct snd_ctl_elem_id *id)
520 struct snd_card *card = file->card;
521 struct snd_kcontrol *kctl;
524 down_write(&card->controls_rwsem);
525 kctl = snd_ctl_find_id(card, id);
530 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
534 for (idx = 0; idx < kctl->count; idx++)
535 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
539 ret = snd_ctl_remove(card, kctl);
542 card->user_ctl_count--;
544 up_write(&card->controls_rwsem);
549 * snd_ctl_activate_id - activate/inactivate the control of the given id
550 * @card: the card instance
551 * @id: the control id to activate/inactivate
552 * @active: non-zero to activate
554 * Finds the control instance with the given id, and activate or
555 * inactivate the control together with notification, if changed.
556 * The given ID data is filled with full information.
558 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
560 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
563 struct snd_kcontrol *kctl;
564 struct snd_kcontrol_volatile *vd;
565 unsigned int index_offset;
568 down_write(&card->controls_rwsem);
569 kctl = snd_ctl_find_id(card, id);
574 index_offset = snd_ctl_get_ioff(kctl, id);
575 vd = &kctl->vd[index_offset];
578 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
580 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
582 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
584 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
586 snd_ctl_build_ioff(id, kctl, index_offset);
589 up_write(&card->controls_rwsem);
591 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
594 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
597 * snd_ctl_rename_id - replace the id of a control on the card
598 * @card: the card instance
599 * @src_id: the old id
600 * @dst_id: the new id
602 * Finds the control with the old id from the card, and replaces the
603 * id with the new one.
605 * Return: Zero if successful, or a negative error code on failure.
607 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
608 struct snd_ctl_elem_id *dst_id)
610 struct snd_kcontrol *kctl;
612 down_write(&card->controls_rwsem);
613 kctl = snd_ctl_find_id(card, src_id);
615 up_write(&card->controls_rwsem);
619 kctl->id.numid = card->last_numid + 1;
620 card->last_numid += kctl->count;
621 up_write(&card->controls_rwsem);
624 EXPORT_SYMBOL(snd_ctl_rename_id);
627 * snd_ctl_find_numid - find the control instance with the given number-id
628 * @card: the card instance
629 * @numid: the number-id to search
631 * Finds the control instance with the given number-id from the card.
633 * The caller must down card->controls_rwsem before calling this function
634 * (if the race condition can happen).
636 * Return: The pointer of the instance if found, or %NULL if not.
639 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
641 struct snd_kcontrol *kctl;
643 if (snd_BUG_ON(!card || !numid))
645 list_for_each_entry(kctl, &card->controls, list) {
646 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
651 EXPORT_SYMBOL(snd_ctl_find_numid);
654 * snd_ctl_find_id - find the control instance with the given id
655 * @card: the card instance
656 * @id: the id to search
658 * Finds the control instance with the given 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_id(struct snd_card *card,
667 struct snd_ctl_elem_id *id)
669 struct snd_kcontrol *kctl;
671 if (snd_BUG_ON(!card || !id))
674 return snd_ctl_find_numid(card, id->numid);
675 list_for_each_entry(kctl, &card->controls, list) {
676 if (kctl->id.iface != id->iface)
678 if (kctl->id.device != id->device)
680 if (kctl->id.subdevice != id->subdevice)
682 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
684 if (kctl->id.index > id->index)
686 if (kctl->id.index + kctl->count <= id->index)
692 EXPORT_SYMBOL(snd_ctl_find_id);
694 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
695 unsigned int cmd, void __user *arg)
697 struct snd_ctl_card_info *info;
699 info = kzalloc(sizeof(*info), GFP_KERNEL);
702 down_read(&snd_ioctl_rwsem);
703 info->card = card->number;
704 strlcpy(info->id, card->id, sizeof(info->id));
705 strlcpy(info->driver, card->driver, sizeof(info->driver));
706 strlcpy(info->name, card->shortname, sizeof(info->name));
707 strlcpy(info->longname, card->longname, sizeof(info->longname));
708 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
709 strlcpy(info->components, card->components, sizeof(info->components));
710 up_read(&snd_ioctl_rwsem);
711 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
719 static int snd_ctl_elem_list(struct snd_card *card,
720 struct snd_ctl_elem_list *list)
722 struct snd_kcontrol *kctl;
723 struct snd_ctl_elem_id id;
724 unsigned int offset, space, jidx;
727 offset = list->offset;
730 down_read(&card->controls_rwsem);
731 list->count = card->controls_count;
734 list_for_each_entry(kctl, &card->controls, list) {
735 if (offset >= kctl->count) {
736 offset -= kctl->count;
739 for (jidx = offset; jidx < kctl->count; jidx++) {
740 snd_ctl_build_ioff(&id, kctl, jidx);
741 if (copy_to_user(list->pids + list->used, &id,
754 up_read(&card->controls_rwsem);
758 static int snd_ctl_elem_list_user(struct snd_card *card,
759 struct snd_ctl_elem_list __user *_list)
761 struct snd_ctl_elem_list list;
764 if (copy_from_user(&list, _list, sizeof(list)))
766 err = snd_ctl_elem_list(card, &list);
769 if (copy_to_user(_list, &list, sizeof(list)))
775 /* Check whether the given kctl info is valid */
776 static int snd_ctl_check_elem_info(struct snd_card *card,
777 const struct snd_ctl_elem_info *info)
779 static const unsigned int max_value_counts[] = {
780 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
781 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
782 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
783 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
784 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
785 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
788 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
789 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
792 "control %i:%i:%i:%s:%i: invalid type %d\n",
793 info->id.iface, info->id.device,
794 info->id.subdevice, info->id.name,
795 info->id.index, info->type);
798 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
799 info->value.enumerated.items == 0) {
802 "control %i:%i:%i:%s:%i: zero enum items\n",
803 info->id.iface, info->id.device,
804 info->id.subdevice, info->id.name,
808 if (info->count > max_value_counts[info->type]) {
811 "control %i:%i:%i:%s:%i: invalid count %d\n",
812 info->id.iface, info->id.device,
813 info->id.subdevice, info->id.name,
814 info->id.index, info->count);
821 /* The capacity of struct snd_ctl_elem_value.value.*/
822 static const unsigned int value_sizes[] = {
823 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
824 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
825 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
826 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
827 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
828 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
831 #ifdef CONFIG_SND_CTL_VALIDATION
832 /* fill the remaining snd_ctl_elem_value data with the given pattern */
833 static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
834 struct snd_ctl_elem_info *info,
837 size_t offset = value_sizes[info->type] * info->count;
839 offset = (offset + sizeof(u32) - 1) / sizeof(u32);
840 memset32((u32 *)control->value.bytes.data + offset, pattern,
841 sizeof(control->value) / sizeof(u32) - offset);
844 /* check whether the given integer ctl value is valid */
845 static int sanity_check_int_value(struct snd_card *card,
846 const struct snd_ctl_elem_value *control,
847 const struct snd_ctl_elem_info *info,
850 long long lval, lmin, lmax, lstep;
853 switch (info->type) {
855 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
856 lval = control->value.integer.value[i];
861 case SNDRV_CTL_ELEM_TYPE_INTEGER:
862 lval = control->value.integer.value[i];
863 lmin = info->value.integer.min;
864 lmax = info->value.integer.max;
865 lstep = info->value.integer.step;
867 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
868 lval = control->value.integer64.value[i];
869 lmin = info->value.integer64.min;
870 lmax = info->value.integer64.max;
871 lstep = info->value.integer64.step;
873 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
874 lval = control->value.enumerated.item[i];
876 lmax = info->value.enumerated.items - 1;
881 if (lval < lmin || lval > lmax) {
883 "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
884 control->id.iface, control->id.device,
885 control->id.subdevice, control->id.name,
886 control->id.index, lval, lmin, lmax, i);
890 div64_u64_rem(lval, lstep, &rem);
893 "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
894 control->id.iface, control->id.device,
895 control->id.subdevice, control->id.name,
896 control->id.index, lval, lstep, i);
904 /* perform sanity checks to the given snd_ctl_elem_value object */
905 static int sanity_check_elem_value(struct snd_card *card,
906 const struct snd_ctl_elem_value *control,
907 const struct snd_ctl_elem_info *info,
914 switch (info->type) {
915 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
916 case SNDRV_CTL_ELEM_TYPE_INTEGER:
917 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
918 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
919 for (i = 0; i < info->count; i++) {
920 ret = sanity_check_int_value(card, control, info, i);
929 /* check whether the remaining area kept untouched */
930 offset = value_sizes[info->type] * info->count;
931 offset = (offset + sizeof(u32) - 1) / sizeof(u32);
932 p = (u32 *)control->value.bytes.data + offset;
933 for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
938 *p = 0; /* clear the checked area */
944 static inline void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
945 struct snd_ctl_elem_info *info,
950 static inline int sanity_check_elem_value(struct snd_card *card,
951 struct snd_ctl_elem_value *control,
952 struct snd_ctl_elem_info *info,
959 static int __snd_ctl_elem_info(struct snd_card *card,
960 struct snd_kcontrol *kctl,
961 struct snd_ctl_elem_info *info,
962 struct snd_ctl_file *ctl)
964 struct snd_kcontrol_volatile *vd;
965 unsigned int index_offset;
968 #ifdef CONFIG_SND_DEBUG
971 result = kctl->info(kctl, info);
973 snd_BUG_ON(info->access);
974 index_offset = snd_ctl_get_ioff(kctl, &info->id);
975 vd = &kctl->vd[index_offset];
976 snd_ctl_build_ioff(&info->id, kctl, index_offset);
977 info->access = vd->access;
979 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
980 if (vd->owner == ctl)
981 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
982 info->owner = pid_vnr(vd->owner->pid);
986 if (!snd_ctl_skip_validation(info) &&
987 snd_ctl_check_elem_info(card, info) < 0)
993 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
994 struct snd_ctl_elem_info *info)
996 struct snd_card *card = ctl->card;
997 struct snd_kcontrol *kctl;
1000 down_read(&card->controls_rwsem);
1001 kctl = snd_ctl_find_id(card, &info->id);
1005 result = __snd_ctl_elem_info(card, kctl, info, ctl);
1006 up_read(&card->controls_rwsem);
1010 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
1011 struct snd_ctl_elem_info __user *_info)
1013 struct snd_ctl_elem_info info;
1016 if (copy_from_user(&info, _info, sizeof(info)))
1018 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
1021 result = snd_ctl_elem_info(ctl, &info);
1024 /* drop internal access flags */
1025 info.access &= ~SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK;
1026 if (copy_to_user(_info, &info, sizeof(info)))
1031 static int snd_ctl_elem_read(struct snd_card *card,
1032 struct snd_ctl_elem_value *control)
1034 struct snd_kcontrol *kctl;
1035 struct snd_kcontrol_volatile *vd;
1036 unsigned int index_offset;
1037 struct snd_ctl_elem_info info;
1038 const u32 pattern = 0xdeadbeef;
1041 kctl = snd_ctl_find_id(card, &control->id);
1045 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1046 vd = &kctl->vd[index_offset];
1047 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
1050 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1052 #ifdef CONFIG_SND_CTL_VALIDATION
1053 /* info is needed only for validation */
1054 memset(&info, 0, sizeof(info));
1055 info.id = control->id;
1056 ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
1061 if (!snd_ctl_skip_validation(&info))
1062 fill_remaining_elem_value(control, &info, pattern);
1063 ret = kctl->get(kctl, control);
1066 if (!snd_ctl_skip_validation(&info) &&
1067 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1069 "control %i:%i:%i:%s:%i: access overflow\n",
1070 control->id.iface, control->id.device,
1071 control->id.subdevice, control->id.name,
1078 static int snd_ctl_elem_read_user(struct snd_card *card,
1079 struct snd_ctl_elem_value __user *_control)
1081 struct snd_ctl_elem_value *control;
1084 control = memdup_user(_control, sizeof(*control));
1085 if (IS_ERR(control))
1086 return PTR_ERR(control);
1088 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1092 down_read(&card->controls_rwsem);
1093 result = snd_ctl_elem_read(card, control);
1094 up_read(&card->controls_rwsem);
1098 if (copy_to_user(_control, control, sizeof(*control)))
1105 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1106 struct snd_ctl_elem_value *control)
1108 struct snd_kcontrol *kctl;
1109 struct snd_kcontrol_volatile *vd;
1110 unsigned int index_offset;
1113 kctl = snd_ctl_find_id(card, &control->id);
1117 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1118 vd = &kctl->vd[index_offset];
1119 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1120 (file && vd->owner && vd->owner != file)) {
1124 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1125 result = kctl->put(kctl, control);
1130 struct snd_ctl_elem_id id = control->id;
1131 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
1137 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1138 struct snd_ctl_elem_value __user *_control)
1140 struct snd_ctl_elem_value *control;
1141 struct snd_card *card;
1144 control = memdup_user(_control, sizeof(*control));
1145 if (IS_ERR(control))
1146 return PTR_ERR(control);
1149 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1153 down_write(&card->controls_rwsem);
1154 result = snd_ctl_elem_write(card, file, control);
1155 up_write(&card->controls_rwsem);
1159 if (copy_to_user(_control, control, sizeof(*control)))
1166 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1167 struct snd_ctl_elem_id __user *_id)
1169 struct snd_card *card = file->card;
1170 struct snd_ctl_elem_id id;
1171 struct snd_kcontrol *kctl;
1172 struct snd_kcontrol_volatile *vd;
1175 if (copy_from_user(&id, _id, sizeof(id)))
1177 down_write(&card->controls_rwsem);
1178 kctl = snd_ctl_find_id(card, &id);
1182 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1183 if (vd->owner != NULL)
1190 up_write(&card->controls_rwsem);
1194 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1195 struct snd_ctl_elem_id __user *_id)
1197 struct snd_card *card = file->card;
1198 struct snd_ctl_elem_id id;
1199 struct snd_kcontrol *kctl;
1200 struct snd_kcontrol_volatile *vd;
1203 if (copy_from_user(&id, _id, sizeof(id)))
1205 down_write(&card->controls_rwsem);
1206 kctl = snd_ctl_find_id(card, &id);
1210 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1211 if (vd->owner == NULL)
1213 else if (vd->owner != file)
1220 up_write(&card->controls_rwsem);
1224 struct user_element {
1225 struct snd_ctl_elem_info info;
1226 struct snd_card *card;
1227 char *elem_data; /* element data */
1228 unsigned long elem_data_size; /* size of element data in bytes */
1229 void *tlv_data; /* TLV data */
1230 unsigned long tlv_data_size; /* TLV data size */
1231 void *priv_data; /* private data (like strings for enumerated type) */
1234 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1235 struct snd_ctl_elem_info *uinfo)
1237 struct user_element *ue = kcontrol->private_data;
1238 unsigned int offset;
1240 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1242 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1247 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1248 struct snd_ctl_elem_info *uinfo)
1250 struct user_element *ue = kcontrol->private_data;
1253 unsigned int offset;
1255 item = uinfo->value.enumerated.item;
1257 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1259 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1261 item = min(item, uinfo->value.enumerated.items - 1);
1262 uinfo->value.enumerated.item = item;
1264 names = ue->priv_data;
1265 for (; item > 0; --item)
1266 names += strlen(names) + 1;
1267 strcpy(uinfo->value.enumerated.name, names);
1272 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1273 struct snd_ctl_elem_value *ucontrol)
1275 struct user_element *ue = kcontrol->private_data;
1276 unsigned int size = ue->elem_data_size;
1277 char *src = ue->elem_data +
1278 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1280 memcpy(&ucontrol->value, src, size);
1284 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1285 struct snd_ctl_elem_value *ucontrol)
1288 struct user_element *ue = kcontrol->private_data;
1289 unsigned int size = ue->elem_data_size;
1290 char *dst = ue->elem_data +
1291 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1293 change = memcmp(&ucontrol->value, dst, size) != 0;
1295 memcpy(dst, &ucontrol->value, size);
1299 static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1302 struct user_element *ue = kctl->private_data;
1303 unsigned int *container;
1304 struct snd_ctl_elem_id id;
1305 unsigned int mask = 0;
1309 if (size > 1024 * 128) /* sane value */
1312 container = vmemdup_user(buf, size);
1313 if (IS_ERR(container))
1314 return PTR_ERR(container);
1316 change = ue->tlv_data_size != size;
1318 change = memcmp(ue->tlv_data, container, size) != 0;
1324 if (ue->tlv_data == NULL) {
1325 /* Now TLV data is available. */
1326 for (i = 0; i < kctl->count; ++i)
1327 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1328 mask = SNDRV_CTL_EVENT_MASK_INFO;
1331 kvfree(ue->tlv_data);
1332 ue->tlv_data = container;
1333 ue->tlv_data_size = size;
1335 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1336 for (i = 0; i < kctl->count; ++i) {
1337 snd_ctl_build_ioff(&id, kctl, i);
1338 snd_ctl_notify(ue->card, mask, &id);
1344 static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1347 struct user_element *ue = kctl->private_data;
1349 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1352 if (size < ue->tlv_data_size)
1355 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1361 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1362 unsigned int size, unsigned int __user *buf)
1364 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1365 return replace_user_tlv(kctl, buf, size);
1367 return read_user_tlv(kctl, buf, size);
1370 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1373 size_t buf_len, name_len;
1375 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1377 if (ue->info.value.enumerated.names_length > 64 * 1024)
1380 names = vmemdup_user((const void __user *)user_ptrval,
1381 ue->info.value.enumerated.names_length);
1383 return PTR_ERR(names);
1385 /* check that there are enough valid names */
1386 buf_len = ue->info.value.enumerated.names_length;
1388 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1389 name_len = strnlen(p, buf_len);
1390 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1395 buf_len -= name_len + 1;
1398 ue->priv_data = names;
1399 ue->info.value.enumerated.names_ptr = 0;
1404 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1406 struct user_element *ue = kcontrol->private_data;
1408 kvfree(ue->tlv_data);
1409 kvfree(ue->priv_data);
1413 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1414 struct snd_ctl_elem_info *info, int replace)
1416 struct snd_card *card = file->card;
1417 struct snd_kcontrol *kctl;
1419 unsigned int access;
1421 struct user_element *ue;
1422 unsigned int offset;
1425 if (!*info->id.name)
1427 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1430 /* Delete a control to replace them if needed. */
1433 err = snd_ctl_remove_user_ctl(file, &info->id);
1439 * The number of userspace controls are counted control by control,
1440 * not element by element.
1442 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1445 /* Check the number of elements for this userspace control. */
1446 count = info->owner;
1450 /* Arrange access permissions if needed. */
1451 access = info->access;
1453 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1454 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1455 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1456 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1458 /* In initial state, nothing is available as TLV container. */
1459 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1460 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1461 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1464 * Check information and calculate the size of data specific to
1465 * this userspace control.
1467 /* pass NULL to card for suppressing error messages */
1468 err = snd_ctl_check_elem_info(NULL, info);
1471 /* user-space control doesn't allow zero-size data */
1472 if (info->count < 1)
1474 private_size = value_sizes[info->type] * info->count;
1477 * Keep memory object for this userspace control. After passing this
1478 * code block, the instance should be freed by snd_ctl_free_one().
1480 * Note that these elements in this control are locked.
1482 err = snd_ctl_new(&kctl, count, access, file);
1485 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1486 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1488 if (kctl->private_data == NULL) {
1492 kctl->private_free = snd_ctl_elem_user_free;
1494 /* Set private data for this userspace control. */
1495 ue = (struct user_element *)kctl->private_data;
1498 ue->info.access = 0;
1499 ue->elem_data = (char *)ue + sizeof(*ue);
1500 ue->elem_data_size = private_size;
1501 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1502 err = snd_ctl_elem_init_enum_names(ue);
1504 snd_ctl_free_one(kctl);
1509 /* Set callback functions. */
1510 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1511 kctl->info = snd_ctl_elem_user_enum_info;
1513 kctl->info = snd_ctl_elem_user_info;
1514 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1515 kctl->get = snd_ctl_elem_user_get;
1516 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1517 kctl->put = snd_ctl_elem_user_put;
1518 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1519 kctl->tlv.c = snd_ctl_elem_user_tlv;
1521 /* This function manage to free the instance on failure. */
1522 down_write(&card->controls_rwsem);
1523 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1525 snd_ctl_free_one(kctl);
1528 offset = snd_ctl_get_ioff(kctl, &info->id);
1529 snd_ctl_build_ioff(&info->id, kctl, offset);
1531 * Here we cannot fill any field for the number of elements added by
1532 * this operation because there're no specific fields. The usage of
1533 * 'owner' field for this purpose may cause any bugs to userspace
1534 * applications because the field originally means PID of a process
1535 * which locks the element.
1538 card->user_ctl_count++;
1541 up_write(&card->controls_rwsem);
1545 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1546 struct snd_ctl_elem_info __user *_info, int replace)
1548 struct snd_ctl_elem_info info;
1551 if (copy_from_user(&info, _info, sizeof(info)))
1553 err = snd_ctl_elem_add(file, &info, replace);
1556 if (copy_to_user(_info, &info, sizeof(info))) {
1557 snd_ctl_remove_user_ctl(file, &info.id);
1564 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1565 struct snd_ctl_elem_id __user *_id)
1567 struct snd_ctl_elem_id id;
1569 if (copy_from_user(&id, _id, sizeof(id)))
1571 return snd_ctl_remove_user_ctl(file, &id);
1574 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1577 if (get_user(subscribe, ptr))
1579 if (subscribe < 0) {
1580 subscribe = file->subscribed;
1581 if (put_user(subscribe, ptr))
1586 file->subscribed = 1;
1588 } else if (file->subscribed) {
1589 snd_ctl_empty_read_queue(file);
1590 file->subscribed = 0;
1595 static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1596 struct snd_kcontrol *kctl,
1597 struct snd_ctl_elem_id *id,
1598 unsigned int __user *buf, unsigned int size)
1600 static const struct {
1604 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1605 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1606 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1608 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1611 /* Check support of the request for this element. */
1612 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1613 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1616 if (i == ARRAY_SIZE(pairs))
1619 if (kctl->tlv.c == NULL)
1622 /* Write and command operations are not allowed for locked element. */
1623 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1624 vd->owner != NULL && vd->owner != file)
1627 return kctl->tlv.c(kctl, op_flag, size, buf);
1630 static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1631 unsigned int __user *buf, unsigned int size)
1633 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1636 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1639 if (kctl->tlv.p == NULL)
1642 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1646 if (copy_to_user(buf, kctl->tlv.p, len))
1652 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1653 struct snd_ctl_tlv __user *buf,
1656 struct snd_ctl_tlv header;
1657 unsigned int __user *container;
1658 unsigned int container_size;
1659 struct snd_kcontrol *kctl;
1660 struct snd_ctl_elem_id id;
1661 struct snd_kcontrol_volatile *vd;
1663 if (copy_from_user(&header, buf, sizeof(header)))
1666 /* In design of control core, numerical ID starts at 1. */
1667 if (header.numid == 0)
1670 /* At least, container should include type and length fields. */
1671 if (header.length < sizeof(unsigned int) * 2)
1673 container_size = header.length;
1674 container = buf->tlv;
1676 kctl = snd_ctl_find_numid(file->card, header.numid);
1680 /* Calculate index of the element in this set. */
1682 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1683 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1685 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1686 return call_tlv_handler(file, op_flag, kctl, &id, container,
1689 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1690 return read_tlv_buf(kctl, &id, container,
1695 /* Not supported. */
1699 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1701 struct snd_ctl_file *ctl;
1702 struct snd_card *card;
1703 struct snd_kctl_ioctl *p;
1704 void __user *argp = (void __user *)arg;
1705 int __user *ip = argp;
1708 ctl = file->private_data;
1710 if (snd_BUG_ON(!card))
1713 case SNDRV_CTL_IOCTL_PVERSION:
1714 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1715 case SNDRV_CTL_IOCTL_CARD_INFO:
1716 return snd_ctl_card_info(card, ctl, cmd, argp);
1717 case SNDRV_CTL_IOCTL_ELEM_LIST:
1718 return snd_ctl_elem_list_user(card, argp);
1719 case SNDRV_CTL_IOCTL_ELEM_INFO:
1720 return snd_ctl_elem_info_user(ctl, argp);
1721 case SNDRV_CTL_IOCTL_ELEM_READ:
1722 return snd_ctl_elem_read_user(card, argp);
1723 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1724 return snd_ctl_elem_write_user(ctl, argp);
1725 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1726 return snd_ctl_elem_lock(ctl, argp);
1727 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1728 return snd_ctl_elem_unlock(ctl, argp);
1729 case SNDRV_CTL_IOCTL_ELEM_ADD:
1730 return snd_ctl_elem_add_user(ctl, argp, 0);
1731 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1732 return snd_ctl_elem_add_user(ctl, argp, 1);
1733 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1734 return snd_ctl_elem_remove(ctl, argp);
1735 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1736 return snd_ctl_subscribe_events(ctl, ip);
1737 case SNDRV_CTL_IOCTL_TLV_READ:
1738 down_read(&ctl->card->controls_rwsem);
1739 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1740 up_read(&ctl->card->controls_rwsem);
1742 case SNDRV_CTL_IOCTL_TLV_WRITE:
1743 down_write(&ctl->card->controls_rwsem);
1744 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1745 up_write(&ctl->card->controls_rwsem);
1747 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1748 down_write(&ctl->card->controls_rwsem);
1749 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1750 up_write(&ctl->card->controls_rwsem);
1752 case SNDRV_CTL_IOCTL_POWER:
1753 return -ENOPROTOOPT;
1754 case SNDRV_CTL_IOCTL_POWER_STATE:
1756 return put_user(card->power_state, ip) ? -EFAULT : 0;
1758 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1761 down_read(&snd_ioctl_rwsem);
1762 list_for_each_entry(p, &snd_control_ioctls, list) {
1763 err = p->fioctl(card, ctl, cmd, arg);
1764 if (err != -ENOIOCTLCMD) {
1765 up_read(&snd_ioctl_rwsem);
1769 up_read(&snd_ioctl_rwsem);
1770 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1774 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1775 size_t count, loff_t * offset)
1777 struct snd_ctl_file *ctl;
1781 ctl = file->private_data;
1782 if (snd_BUG_ON(!ctl || !ctl->card))
1784 if (!ctl->subscribed)
1786 if (count < sizeof(struct snd_ctl_event))
1788 spin_lock_irq(&ctl->read_lock);
1789 while (count >= sizeof(struct snd_ctl_event)) {
1790 struct snd_ctl_event ev;
1791 struct snd_kctl_event *kev;
1792 while (list_empty(&ctl->events)) {
1793 wait_queue_entry_t wait;
1794 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1798 init_waitqueue_entry(&wait, current);
1799 add_wait_queue(&ctl->change_sleep, &wait);
1800 set_current_state(TASK_INTERRUPTIBLE);
1801 spin_unlock_irq(&ctl->read_lock);
1803 remove_wait_queue(&ctl->change_sleep, &wait);
1804 if (ctl->card->shutdown)
1806 if (signal_pending(current))
1807 return -ERESTARTSYS;
1808 spin_lock_irq(&ctl->read_lock);
1810 kev = snd_kctl_event(ctl->events.next);
1811 ev.type = SNDRV_CTL_EVENT_ELEM;
1812 ev.data.elem.mask = kev->mask;
1813 ev.data.elem.id = kev->id;
1814 list_del(&kev->list);
1815 spin_unlock_irq(&ctl->read_lock);
1817 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1821 spin_lock_irq(&ctl->read_lock);
1822 buffer += sizeof(struct snd_ctl_event);
1823 count -= sizeof(struct snd_ctl_event);
1824 result += sizeof(struct snd_ctl_event);
1827 spin_unlock_irq(&ctl->read_lock);
1829 return result > 0 ? result : err;
1832 static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1835 struct snd_ctl_file *ctl;
1837 ctl = file->private_data;
1838 if (!ctl->subscribed)
1840 poll_wait(file, &ctl->change_sleep, wait);
1843 if (!list_empty(&ctl->events))
1844 mask |= EPOLLIN | EPOLLRDNORM;
1850 * register the device-specific control-ioctls.
1851 * called from each device manager like pcm.c, hwdep.c, etc.
1853 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1855 struct snd_kctl_ioctl *pn;
1857 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1861 down_write(&snd_ioctl_rwsem);
1862 list_add_tail(&pn->list, lists);
1863 up_write(&snd_ioctl_rwsem);
1868 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1869 * @fcn: ioctl callback function
1871 * called from each device manager like pcm.c, hwdep.c, etc.
1873 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1875 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1877 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1879 #ifdef CONFIG_COMPAT
1881 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1883 * @fcn: ioctl callback function
1885 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1887 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1889 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1893 * de-register the device-specific control-ioctls.
1895 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1896 struct list_head *lists)
1898 struct snd_kctl_ioctl *p;
1900 if (snd_BUG_ON(!fcn))
1902 down_write(&snd_ioctl_rwsem);
1903 list_for_each_entry(p, lists, list) {
1904 if (p->fioctl == fcn) {
1906 up_write(&snd_ioctl_rwsem);
1911 up_write(&snd_ioctl_rwsem);
1917 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1918 * @fcn: ioctl callback function to unregister
1920 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1922 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1924 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1926 #ifdef CONFIG_COMPAT
1928 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1930 * @fcn: ioctl callback function to unregister
1932 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1934 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1936 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1939 static int snd_ctl_fasync(int fd, struct file * file, int on)
1941 struct snd_ctl_file *ctl;
1943 ctl = file->private_data;
1944 return fasync_helper(fd, file, on, &ctl->fasync);
1947 /* return the preferred subdevice number if already assigned;
1948 * otherwise return -1
1950 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1952 struct snd_ctl_file *kctl;
1954 unsigned long flags;
1956 read_lock_irqsave(&card->ctl_files_rwlock, flags);
1957 list_for_each_entry(kctl, &card->ctl_files, list) {
1958 if (kctl->pid == task_pid(current)) {
1959 subdevice = kctl->preferred_subdevice[type];
1960 if (subdevice != -1)
1964 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
1967 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1972 #ifdef CONFIG_COMPAT
1973 #include "control_compat.c"
1975 #define snd_ctl_ioctl_compat NULL
1982 static const struct file_operations snd_ctl_f_ops =
1984 .owner = THIS_MODULE,
1985 .read = snd_ctl_read,
1986 .open = snd_ctl_open,
1987 .release = snd_ctl_release,
1988 .llseek = no_llseek,
1989 .poll = snd_ctl_poll,
1990 .unlocked_ioctl = snd_ctl_ioctl,
1991 .compat_ioctl = snd_ctl_ioctl_compat,
1992 .fasync = snd_ctl_fasync,
1996 * registration of the control device
1998 static int snd_ctl_dev_register(struct snd_device *device)
2000 struct snd_card *card = device->device_data;
2002 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
2003 &snd_ctl_f_ops, card, &card->ctl_dev);
2007 * disconnection of the control device
2009 static int snd_ctl_dev_disconnect(struct snd_device *device)
2011 struct snd_card *card = device->device_data;
2012 struct snd_ctl_file *ctl;
2013 unsigned long flags;
2015 read_lock_irqsave(&card->ctl_files_rwlock, flags);
2016 list_for_each_entry(ctl, &card->ctl_files, list) {
2017 wake_up(&ctl->change_sleep);
2018 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
2020 read_unlock_irqrestore(&card->ctl_files_rwlock, flags);
2022 return snd_unregister_device(&card->ctl_dev);
2028 static int snd_ctl_dev_free(struct snd_device *device)
2030 struct snd_card *card = device->device_data;
2031 struct snd_kcontrol *control;
2033 down_write(&card->controls_rwsem);
2034 while (!list_empty(&card->controls)) {
2035 control = snd_kcontrol(card->controls.next);
2036 snd_ctl_remove(card, control);
2038 up_write(&card->controls_rwsem);
2039 put_device(&card->ctl_dev);
2044 * create control core:
2045 * called from init.c
2047 int snd_ctl_create(struct snd_card *card)
2049 static const struct snd_device_ops ops = {
2050 .dev_free = snd_ctl_dev_free,
2051 .dev_register = snd_ctl_dev_register,
2052 .dev_disconnect = snd_ctl_dev_disconnect,
2056 if (snd_BUG_ON(!card))
2058 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2061 snd_device_initialize(&card->ctl_dev, card);
2062 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
2064 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2066 put_device(&card->ctl_dev);
2071 * Frequently used control callbacks/helpers
2075 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2076 * callback with a mono channel
2077 * @kcontrol: the kcontrol instance
2078 * @uinfo: info to store
2080 * This is a function that can be used as info callback for a standard
2081 * boolean control with a single mono channel.
2083 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2084 struct snd_ctl_elem_info *uinfo)
2086 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2088 uinfo->value.integer.min = 0;
2089 uinfo->value.integer.max = 1;
2092 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2095 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2096 * callback with stereo two channels
2097 * @kcontrol: the kcontrol instance
2098 * @uinfo: info to store
2100 * This is a function that can be used as info callback for a standard
2101 * boolean control with stereo two channels.
2103 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2104 struct snd_ctl_elem_info *uinfo)
2106 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2108 uinfo->value.integer.min = 0;
2109 uinfo->value.integer.max = 1;
2112 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2115 * snd_ctl_enum_info - fills the info structure for an enumerated control
2116 * @info: the structure to be filled
2117 * @channels: the number of the control's channels; often one
2118 * @items: the number of control values; also the size of @names
2119 * @names: an array containing the names of all control values
2121 * Sets all required fields in @info to their appropriate values.
2122 * If the control's accessibility is not the default (readable and writable),
2123 * the caller has to fill @info->access.
2127 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2128 unsigned int items, const char *const names[])
2130 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2131 info->count = channels;
2132 info->value.enumerated.items = items;
2135 if (info->value.enumerated.item >= items)
2136 info->value.enumerated.item = items - 1;
2137 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2138 "ALSA: too long item name '%s'\n",
2139 names[info->value.enumerated.item]);
2140 strlcpy(info->value.enumerated.name,
2141 names[info->value.enumerated.item],
2142 sizeof(info->value.enumerated.name));
2145 EXPORT_SYMBOL(snd_ctl_enum_info);