2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/threads.h>
23 #include <linux/interrupt.h>
24 #include <linux/module.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/time.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <sound/control.h>
33 /* max number of user-defined controls */
34 #define MAX_USER_CONTROLS 32
35 #define MAX_CONTROL_COUNT 1028
37 struct snd_kctl_ioctl
{
38 struct list_head list
; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl
;
42 static DECLARE_RWSEM(snd_ioctl_rwsem
);
43 static LIST_HEAD(snd_control_ioctls
);
45 static LIST_HEAD(snd_control_compat_ioctls
);
48 static int snd_ctl_open(struct inode
*inode
, struct file
*file
)
51 struct snd_card
*card
;
52 struct snd_ctl_file
*ctl
;
55 err
= nonseekable_open(inode
, file
);
59 card
= snd_lookup_minor_data(iminor(inode
), SNDRV_DEVICE_TYPE_CONTROL
);
64 err
= snd_card_file_add(card
, file
);
69 if (!try_module_get(card
->module
)) {
73 ctl
= kzalloc(sizeof(*ctl
), GFP_KERNEL
);
78 INIT_LIST_HEAD(&ctl
->events
);
79 init_waitqueue_head(&ctl
->change_sleep
);
80 spin_lock_init(&ctl
->read_lock
);
82 for (i
= 0; i
< SND_CTL_SUBDEV_ITEMS
; i
++)
83 ctl
->preferred_subdevice
[i
] = -1;
84 ctl
->pid
= get_pid(task_pid(current
));
85 file
->private_data
= ctl
;
86 write_lock_irqsave(&card
->ctl_files_rwlock
, flags
);
87 list_add_tail(&ctl
->list
, &card
->ctl_files
);
88 write_unlock_irqrestore(&card
->ctl_files_rwlock
, flags
);
93 module_put(card
->module
);
95 snd_card_file_remove(card
, file
);
102 static void snd_ctl_empty_read_queue(struct snd_ctl_file
* ctl
)
105 struct snd_kctl_event
*cread
;
107 spin_lock_irqsave(&ctl
->read_lock
, flags
);
108 while (!list_empty(&ctl
->events
)) {
109 cread
= snd_kctl_event(ctl
->events
.next
);
110 list_del(&cread
->list
);
113 spin_unlock_irqrestore(&ctl
->read_lock
, flags
);
116 static int snd_ctl_release(struct inode
*inode
, struct file
*file
)
119 struct snd_card
*card
;
120 struct snd_ctl_file
*ctl
;
121 struct snd_kcontrol
*control
;
124 ctl
= file
->private_data
;
125 file
->private_data
= NULL
;
127 write_lock_irqsave(&card
->ctl_files_rwlock
, flags
);
128 list_del(&ctl
->list
);
129 write_unlock_irqrestore(&card
->ctl_files_rwlock
, flags
);
130 down_write(&card
->controls_rwsem
);
131 list_for_each_entry(control
, &card
->controls
, list
)
132 for (idx
= 0; idx
< control
->count
; idx
++)
133 if (control
->vd
[idx
].owner
== ctl
)
134 control
->vd
[idx
].owner
= NULL
;
135 up_write(&card
->controls_rwsem
);
136 snd_ctl_empty_read_queue(ctl
);
139 module_put(card
->module
);
140 snd_card_file_remove(card
, file
);
145 * snd_ctl_notify - Send notification to user-space for a control change
146 * @card: the card to send notification
147 * @mask: the event mask, SNDRV_CTL_EVENT_*
148 * @id: the ctl element id to send notification
150 * This function adds an event record with the given id and mask, appends
151 * to the list and wakes up the user-space for notification. This can be
152 * called in the atomic context.
154 void snd_ctl_notify(struct snd_card
*card
, unsigned int mask
,
155 struct snd_ctl_elem_id
*id
)
158 struct snd_ctl_file
*ctl
;
159 struct snd_kctl_event
*ev
;
161 if (snd_BUG_ON(!card
|| !id
))
165 read_lock(&card
->ctl_files_rwlock
);
166 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
167 card
->mixer_oss_change_count
++;
169 list_for_each_entry(ctl
, &card
->ctl_files
, list
) {
170 if (!ctl
->subscribed
)
172 spin_lock_irqsave(&ctl
->read_lock
, flags
);
173 list_for_each_entry(ev
, &ctl
->events
, list
) {
174 if (ev
->id
.numid
== id
->numid
) {
179 ev
= kzalloc(sizeof(*ev
), GFP_ATOMIC
);
183 list_add_tail(&ev
->list
, &ctl
->events
);
185 dev_err(card
->dev
, "No memory available to allocate event\n");
188 wake_up(&ctl
->change_sleep
);
189 spin_unlock_irqrestore(&ctl
->read_lock
, flags
);
190 kill_fasync(&ctl
->fasync
, SIGIO
, POLL_IN
);
192 read_unlock(&card
->ctl_files_rwlock
);
194 EXPORT_SYMBOL(snd_ctl_notify
);
197 * snd_ctl_new - create a new control instance with some elements
198 * @kctl: the pointer to store new control instance
199 * @count: the number of elements in this control
200 * @access: the default access flags for elements in this control
201 * @file: given when locking these elements
203 * Allocates a memory object for a new control instance. The instance has
204 * elements as many as the given number (@count). Each element has given
205 * access permissions (@access). Each element is locked when @file is given.
207 * Return: 0 on success, error code on failure
209 static int snd_ctl_new(struct snd_kcontrol
**kctl
, unsigned int count
,
210 unsigned int access
, struct snd_ctl_file
*file
)
215 if (count
== 0 || count
> MAX_CONTROL_COUNT
)
218 size
= sizeof(struct snd_kcontrol
);
219 size
+= sizeof(struct snd_kcontrol_volatile
) * count
;
221 *kctl
= kzalloc(size
, GFP_KERNEL
);
225 for (idx
= 0; idx
< count
; idx
++) {
226 (*kctl
)->vd
[idx
].access
= access
;
227 (*kctl
)->vd
[idx
].owner
= file
;
229 (*kctl
)->count
= count
;
235 * snd_ctl_new1 - create a control instance from the template
236 * @ncontrol: the initialization record
237 * @private_data: the private data to set
239 * Allocates a new struct snd_kcontrol instance and initialize from the given
240 * template. When the access field of ncontrol is 0, it's assumed as
241 * READWRITE access. When the count field is 0, it's assumes as one.
243 * Return: The pointer of the newly generated instance, or %NULL on failure.
245 struct snd_kcontrol
*snd_ctl_new1(const struct snd_kcontrol_new
*ncontrol
,
248 struct snd_kcontrol
*kctl
;
253 if (snd_BUG_ON(!ncontrol
|| !ncontrol
->info
))
256 count
= ncontrol
->count
;
260 access
= ncontrol
->access
;
262 access
= SNDRV_CTL_ELEM_ACCESS_READWRITE
;
263 access
&= (SNDRV_CTL_ELEM_ACCESS_READWRITE
|
264 SNDRV_CTL_ELEM_ACCESS_VOLATILE
|
265 SNDRV_CTL_ELEM_ACCESS_INACTIVE
|
266 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE
|
267 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND
|
268 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK
);
270 err
= snd_ctl_new(&kctl
, count
, access
, NULL
);
274 /* The 'numid' member is decided when calling snd_ctl_add(). */
275 kctl
->id
.iface
= ncontrol
->iface
;
276 kctl
->id
.device
= ncontrol
->device
;
277 kctl
->id
.subdevice
= ncontrol
->subdevice
;
278 if (ncontrol
->name
) {
279 strlcpy(kctl
->id
.name
, ncontrol
->name
, sizeof(kctl
->id
.name
));
280 if (strcmp(ncontrol
->name
, kctl
->id
.name
) != 0)
281 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
282 ncontrol
->name
, kctl
->id
.name
);
284 kctl
->id
.index
= ncontrol
->index
;
286 kctl
->info
= ncontrol
->info
;
287 kctl
->get
= ncontrol
->get
;
288 kctl
->put
= ncontrol
->put
;
289 kctl
->tlv
.p
= ncontrol
->tlv
.p
;
291 kctl
->private_value
= ncontrol
->private_value
;
292 kctl
->private_data
= private_data
;
296 EXPORT_SYMBOL(snd_ctl_new1
);
299 * snd_ctl_free_one - release the control instance
300 * @kcontrol: the control instance
302 * Releases the control instance created via snd_ctl_new()
304 * Don't call this after the control was added to the card.
306 void snd_ctl_free_one(struct snd_kcontrol
*kcontrol
)
309 if (kcontrol
->private_free
)
310 kcontrol
->private_free(kcontrol
);
314 EXPORT_SYMBOL(snd_ctl_free_one
);
316 static bool snd_ctl_remove_numid_conflict(struct snd_card
*card
,
319 struct snd_kcontrol
*kctl
;
321 /* Make sure that the ids assigned to the control do not wrap around */
322 if (card
->last_numid
>= UINT_MAX
- count
)
323 card
->last_numid
= 0;
325 list_for_each_entry(kctl
, &card
->controls
, list
) {
326 if (kctl
->id
.numid
< card
->last_numid
+ 1 + count
&&
327 kctl
->id
.numid
+ kctl
->count
> card
->last_numid
+ 1) {
328 card
->last_numid
= kctl
->id
.numid
+ kctl
->count
- 1;
335 static int snd_ctl_find_hole(struct snd_card
*card
, unsigned int count
)
337 unsigned int iter
= 100000;
339 while (snd_ctl_remove_numid_conflict(card
, count
)) {
341 /* this situation is very unlikely */
342 dev_err(card
->dev
, "unable to allocate new control numid\n");
350 * snd_ctl_add - add the control instance to the card
351 * @card: the card instance
352 * @kcontrol: the control instance to add
354 * Adds the control instance created via snd_ctl_new() or
355 * snd_ctl_new1() to the given card. Assigns also an unique
356 * numid used for fast search.
358 * It frees automatically the control which cannot be added.
360 * Return: Zero if successful, or a negative error code on failure.
363 int snd_ctl_add(struct snd_card
*card
, struct snd_kcontrol
*kcontrol
)
365 struct snd_ctl_elem_id id
;
372 if (snd_BUG_ON(!card
|| !kcontrol
->info
))
375 if (id
.index
> UINT_MAX
- kcontrol
->count
)
378 down_write(&card
->controls_rwsem
);
379 if (snd_ctl_find_id(card
, &id
)) {
380 up_write(&card
->controls_rwsem
);
381 dev_err(card
->dev
, "control %i:%i:%i:%s:%i is already present\n",
390 if (snd_ctl_find_hole(card
, kcontrol
->count
) < 0) {
391 up_write(&card
->controls_rwsem
);
395 list_add_tail(&kcontrol
->list
, &card
->controls
);
396 card
->controls_count
+= kcontrol
->count
;
397 kcontrol
->id
.numid
= card
->last_numid
+ 1;
398 card
->last_numid
+= kcontrol
->count
;
400 count
= kcontrol
->count
;
401 up_write(&card
->controls_rwsem
);
402 for (idx
= 0; idx
< count
; idx
++, id
.index
++, id
.numid
++)
403 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_ADD
, &id
);
407 snd_ctl_free_one(kcontrol
);
410 EXPORT_SYMBOL(snd_ctl_add
);
413 * snd_ctl_replace - replace the control instance of the card
414 * @card: the card instance
415 * @kcontrol: the control instance to replace
416 * @add_on_replace: add the control if not already added
418 * Replaces the given control. If the given control does not exist
419 * and the add_on_replace flag is set, the control is added. If the
420 * control exists, it is destroyed first.
422 * It frees automatically the control which cannot be added or replaced.
424 * Return: Zero if successful, or a negative error code on failure.
426 int snd_ctl_replace(struct snd_card
*card
, struct snd_kcontrol
*kcontrol
,
429 struct snd_ctl_elem_id id
;
432 struct snd_kcontrol
*old
;
437 if (snd_BUG_ON(!card
|| !kcontrol
->info
)) {
442 down_write(&card
->controls_rwsem
);
443 old
= snd_ctl_find_id(card
, &id
);
447 up_write(&card
->controls_rwsem
);
451 ret
= snd_ctl_remove(card
, old
);
453 up_write(&card
->controls_rwsem
);
457 if (snd_ctl_find_hole(card
, kcontrol
->count
) < 0) {
458 up_write(&card
->controls_rwsem
);
462 list_add_tail(&kcontrol
->list
, &card
->controls
);
463 card
->controls_count
+= kcontrol
->count
;
464 kcontrol
->id
.numid
= card
->last_numid
+ 1;
465 card
->last_numid
+= kcontrol
->count
;
467 count
= kcontrol
->count
;
468 up_write(&card
->controls_rwsem
);
469 for (idx
= 0; idx
< count
; idx
++, id
.index
++, id
.numid
++)
470 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_ADD
, &id
);
474 snd_ctl_free_one(kcontrol
);
477 EXPORT_SYMBOL(snd_ctl_replace
);
480 * snd_ctl_remove - remove the control from the card and release it
481 * @card: the card instance
482 * @kcontrol: the control instance to remove
484 * Removes the control from the card and then releases the instance.
485 * You don't need to call snd_ctl_free_one(). You must be in
486 * the write lock - down_write(&card->controls_rwsem).
488 * Return: 0 if successful, or a negative error code on failure.
490 int snd_ctl_remove(struct snd_card
*card
, struct snd_kcontrol
*kcontrol
)
492 struct snd_ctl_elem_id id
;
495 if (snd_BUG_ON(!card
|| !kcontrol
))
497 list_del(&kcontrol
->list
);
498 card
->controls_count
-= kcontrol
->count
;
500 for (idx
= 0; idx
< kcontrol
->count
; idx
++, id
.index
++, id
.numid
++)
501 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_REMOVE
, &id
);
502 snd_ctl_free_one(kcontrol
);
505 EXPORT_SYMBOL(snd_ctl_remove
);
508 * snd_ctl_remove_id - remove the control of the given id and release it
509 * @card: the card instance
510 * @id: the control id to remove
512 * Finds the control instance with the given id, removes it from the
513 * card list and releases it.
515 * Return: 0 if successful, or a negative error code on failure.
517 int snd_ctl_remove_id(struct snd_card
*card
, struct snd_ctl_elem_id
*id
)
519 struct snd_kcontrol
*kctl
;
522 down_write(&card
->controls_rwsem
);
523 kctl
= snd_ctl_find_id(card
, id
);
525 up_write(&card
->controls_rwsem
);
528 ret
= snd_ctl_remove(card
, kctl
);
529 up_write(&card
->controls_rwsem
);
532 EXPORT_SYMBOL(snd_ctl_remove_id
);
535 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
536 * @file: active control handle
537 * @id: the control id to remove
539 * Finds the control instance with the given id, removes it from the
540 * card list and releases it.
542 * Return: 0 if successful, or a negative error code on failure.
544 static int snd_ctl_remove_user_ctl(struct snd_ctl_file
* file
,
545 struct snd_ctl_elem_id
*id
)
547 struct snd_card
*card
= file
->card
;
548 struct snd_kcontrol
*kctl
;
551 down_write(&card
->controls_rwsem
);
552 kctl
= snd_ctl_find_id(card
, id
);
557 if (!(kctl
->vd
[0].access
& SNDRV_CTL_ELEM_ACCESS_USER
)) {
561 for (idx
= 0; idx
< kctl
->count
; idx
++)
562 if (kctl
->vd
[idx
].owner
!= NULL
&& kctl
->vd
[idx
].owner
!= file
) {
566 ret
= snd_ctl_remove(card
, kctl
);
569 card
->user_ctl_count
--;
571 up_write(&card
->controls_rwsem
);
576 * snd_ctl_activate_id - activate/inactivate the control of the given id
577 * @card: the card instance
578 * @id: the control id to activate/inactivate
579 * @active: non-zero to activate
581 * Finds the control instance with the given id, and activate or
582 * inactivate the control together with notification, if changed.
583 * The given ID data is filled with full information.
585 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
587 int snd_ctl_activate_id(struct snd_card
*card
, struct snd_ctl_elem_id
*id
,
590 struct snd_kcontrol
*kctl
;
591 struct snd_kcontrol_volatile
*vd
;
592 unsigned int index_offset
;
595 down_write(&card
->controls_rwsem
);
596 kctl
= snd_ctl_find_id(card
, id
);
601 index_offset
= snd_ctl_get_ioff(kctl
, id
);
602 vd
= &kctl
->vd
[index_offset
];
605 if (!(vd
->access
& SNDRV_CTL_ELEM_ACCESS_INACTIVE
))
607 vd
->access
&= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE
;
609 if (vd
->access
& SNDRV_CTL_ELEM_ACCESS_INACTIVE
)
611 vd
->access
|= SNDRV_CTL_ELEM_ACCESS_INACTIVE
;
613 snd_ctl_build_ioff(id
, kctl
, index_offset
);
616 up_write(&card
->controls_rwsem
);
618 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_INFO
, id
);
621 EXPORT_SYMBOL_GPL(snd_ctl_activate_id
);
624 * snd_ctl_rename_id - replace the id of a control on the card
625 * @card: the card instance
626 * @src_id: the old id
627 * @dst_id: the new id
629 * Finds the control with the old id from the card, and replaces the
630 * id with the new one.
632 * Return: Zero if successful, or a negative error code on failure.
634 int snd_ctl_rename_id(struct snd_card
*card
, struct snd_ctl_elem_id
*src_id
,
635 struct snd_ctl_elem_id
*dst_id
)
637 struct snd_kcontrol
*kctl
;
639 down_write(&card
->controls_rwsem
);
640 kctl
= snd_ctl_find_id(card
, src_id
);
642 up_write(&card
->controls_rwsem
);
646 kctl
->id
.numid
= card
->last_numid
+ 1;
647 card
->last_numid
+= kctl
->count
;
648 up_write(&card
->controls_rwsem
);
651 EXPORT_SYMBOL(snd_ctl_rename_id
);
654 * snd_ctl_find_numid - find the control instance with the given number-id
655 * @card: the card instance
656 * @numid: the number-id to search
658 * Finds the control instance with the given number-id from the card.
660 * The caller must down card->controls_rwsem before calling this function
661 * (if the race condition can happen).
663 * Return: The pointer of the instance if found, or %NULL if not.
666 struct snd_kcontrol
*snd_ctl_find_numid(struct snd_card
*card
, unsigned int numid
)
668 struct snd_kcontrol
*kctl
;
670 if (snd_BUG_ON(!card
|| !numid
))
672 list_for_each_entry(kctl
, &card
->controls
, list
) {
673 if (kctl
->id
.numid
<= numid
&& kctl
->id
.numid
+ kctl
->count
> numid
)
678 EXPORT_SYMBOL(snd_ctl_find_numid
);
681 * snd_ctl_find_id - find the control instance with the given id
682 * @card: the card instance
683 * @id: the id to search
685 * Finds the control instance with the given id from the card.
687 * The caller must down card->controls_rwsem before calling this function
688 * (if the race condition can happen).
690 * Return: The pointer of the instance if found, or %NULL if not.
693 struct snd_kcontrol
*snd_ctl_find_id(struct snd_card
*card
,
694 struct snd_ctl_elem_id
*id
)
696 struct snd_kcontrol
*kctl
;
698 if (snd_BUG_ON(!card
|| !id
))
701 return snd_ctl_find_numid(card
, id
->numid
);
702 list_for_each_entry(kctl
, &card
->controls
, list
) {
703 if (kctl
->id
.iface
!= id
->iface
)
705 if (kctl
->id
.device
!= id
->device
)
707 if (kctl
->id
.subdevice
!= id
->subdevice
)
709 if (strncmp(kctl
->id
.name
, id
->name
, sizeof(kctl
->id
.name
)))
711 if (kctl
->id
.index
> id
->index
)
713 if (kctl
->id
.index
+ kctl
->count
<= id
->index
)
719 EXPORT_SYMBOL(snd_ctl_find_id
);
721 static int snd_ctl_card_info(struct snd_card
*card
, struct snd_ctl_file
* ctl
,
722 unsigned int cmd
, void __user
*arg
)
724 struct snd_ctl_card_info
*info
;
726 info
= kzalloc(sizeof(*info
), GFP_KERNEL
);
729 down_read(&snd_ioctl_rwsem
);
730 info
->card
= card
->number
;
731 strlcpy(info
->id
, card
->id
, sizeof(info
->id
));
732 strlcpy(info
->driver
, card
->driver
, sizeof(info
->driver
));
733 strlcpy(info
->name
, card
->shortname
, sizeof(info
->name
));
734 strlcpy(info
->longname
, card
->longname
, sizeof(info
->longname
));
735 strlcpy(info
->mixername
, card
->mixername
, sizeof(info
->mixername
));
736 strlcpy(info
->components
, card
->components
, sizeof(info
->components
));
737 up_read(&snd_ioctl_rwsem
);
738 if (copy_to_user(arg
, info
, sizeof(struct snd_ctl_card_info
))) {
746 static int snd_ctl_elem_list(struct snd_card
*card
,
747 struct snd_ctl_elem_list __user
*_list
)
749 struct list_head
*plist
;
750 struct snd_ctl_elem_list list
;
751 struct snd_kcontrol
*kctl
;
752 struct snd_ctl_elem_id
*dst
, *id
;
753 unsigned int offset
, space
, jidx
;
755 if (copy_from_user(&list
, _list
, sizeof(list
)))
757 offset
= list
.offset
;
759 /* try limit maximum space */
763 /* allocate temporary buffer for atomic operation */
764 dst
= vmalloc(space
* sizeof(struct snd_ctl_elem_id
));
767 down_read(&card
->controls_rwsem
);
768 list
.count
= card
->controls_count
;
769 plist
= card
->controls
.next
;
770 while (plist
!= &card
->controls
) {
773 kctl
= snd_kcontrol(plist
);
774 if (offset
< kctl
->count
)
776 offset
-= kctl
->count
;
781 while (space
> 0 && plist
!= &card
->controls
) {
782 kctl
= snd_kcontrol(plist
);
783 for (jidx
= offset
; space
> 0 && jidx
< kctl
->count
; jidx
++) {
784 snd_ctl_build_ioff(id
, kctl
, jidx
);
792 up_read(&card
->controls_rwsem
);
794 copy_to_user(list
.pids
, dst
,
795 list
.used
* sizeof(struct snd_ctl_elem_id
))) {
801 down_read(&card
->controls_rwsem
);
802 list
.count
= card
->controls_count
;
803 up_read(&card
->controls_rwsem
);
805 if (copy_to_user(_list
, &list
, sizeof(list
)))
810 static int snd_ctl_elem_info(struct snd_ctl_file
*ctl
,
811 struct snd_ctl_elem_info
*info
)
813 struct snd_card
*card
= ctl
->card
;
814 struct snd_kcontrol
*kctl
;
815 struct snd_kcontrol_volatile
*vd
;
816 unsigned int index_offset
;
819 down_read(&card
->controls_rwsem
);
820 kctl
= snd_ctl_find_id(card
, &info
->id
);
822 up_read(&card
->controls_rwsem
);
825 #ifdef CONFIG_SND_DEBUG
828 result
= kctl
->info(kctl
, info
);
830 snd_BUG_ON(info
->access
);
831 index_offset
= snd_ctl_get_ioff(kctl
, &info
->id
);
832 vd
= &kctl
->vd
[index_offset
];
833 snd_ctl_build_ioff(&info
->id
, kctl
, index_offset
);
834 info
->access
= vd
->access
;
836 info
->access
|= SNDRV_CTL_ELEM_ACCESS_LOCK
;
837 if (vd
->owner
== ctl
)
838 info
->access
|= SNDRV_CTL_ELEM_ACCESS_OWNER
;
839 info
->owner
= pid_vnr(vd
->owner
->pid
);
844 up_read(&card
->controls_rwsem
);
848 static int snd_ctl_elem_info_user(struct snd_ctl_file
*ctl
,
849 struct snd_ctl_elem_info __user
*_info
)
851 struct snd_ctl_elem_info info
;
854 if (copy_from_user(&info
, _info
, sizeof(info
)))
856 snd_power_lock(ctl
->card
);
857 result
= snd_power_wait(ctl
->card
, SNDRV_CTL_POWER_D0
);
859 result
= snd_ctl_elem_info(ctl
, &info
);
860 snd_power_unlock(ctl
->card
);
862 if (copy_to_user(_info
, &info
, sizeof(info
)))
867 static int snd_ctl_elem_read(struct snd_card
*card
,
868 struct snd_ctl_elem_value
*control
)
870 struct snd_kcontrol
*kctl
;
871 struct snd_kcontrol_volatile
*vd
;
872 unsigned int index_offset
;
875 down_read(&card
->controls_rwsem
);
876 kctl
= snd_ctl_find_id(card
, &control
->id
);
880 index_offset
= snd_ctl_get_ioff(kctl
, &control
->id
);
881 vd
= &kctl
->vd
[index_offset
];
882 if ((vd
->access
& SNDRV_CTL_ELEM_ACCESS_READ
) &&
884 snd_ctl_build_ioff(&control
->id
, kctl
, index_offset
);
885 result
= kctl
->get(kctl
, control
);
889 up_read(&card
->controls_rwsem
);
893 static int snd_ctl_elem_read_user(struct snd_card
*card
,
894 struct snd_ctl_elem_value __user
*_control
)
896 struct snd_ctl_elem_value
*control
;
899 control
= memdup_user(_control
, sizeof(*control
));
901 return PTR_ERR(control
);
903 snd_power_lock(card
);
904 result
= snd_power_wait(card
, SNDRV_CTL_POWER_D0
);
906 result
= snd_ctl_elem_read(card
, control
);
907 snd_power_unlock(card
);
909 if (copy_to_user(_control
, control
, sizeof(*control
)))
915 static int snd_ctl_elem_write(struct snd_card
*card
, struct snd_ctl_file
*file
,
916 struct snd_ctl_elem_value
*control
)
918 struct snd_kcontrol
*kctl
;
919 struct snd_kcontrol_volatile
*vd
;
920 unsigned int index_offset
;
923 down_read(&card
->controls_rwsem
);
924 kctl
= snd_ctl_find_id(card
, &control
->id
);
928 index_offset
= snd_ctl_get_ioff(kctl
, &control
->id
);
929 vd
= &kctl
->vd
[index_offset
];
930 if (!(vd
->access
& SNDRV_CTL_ELEM_ACCESS_WRITE
) ||
932 (file
&& vd
->owner
&& vd
->owner
!= file
)) {
935 snd_ctl_build_ioff(&control
->id
, kctl
, index_offset
);
936 result
= kctl
->put(kctl
, control
);
939 struct snd_ctl_elem_id id
= control
->id
;
940 up_read(&card
->controls_rwsem
);
941 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_VALUE
, &id
);
945 up_read(&card
->controls_rwsem
);
949 static int snd_ctl_elem_write_user(struct snd_ctl_file
*file
,
950 struct snd_ctl_elem_value __user
*_control
)
952 struct snd_ctl_elem_value
*control
;
953 struct snd_card
*card
;
956 control
= memdup_user(_control
, sizeof(*control
));
958 return PTR_ERR(control
);
961 snd_power_lock(card
);
962 result
= snd_power_wait(card
, SNDRV_CTL_POWER_D0
);
964 result
= snd_ctl_elem_write(card
, file
, control
);
965 snd_power_unlock(card
);
967 if (copy_to_user(_control
, control
, sizeof(*control
)))
973 static int snd_ctl_elem_lock(struct snd_ctl_file
*file
,
974 struct snd_ctl_elem_id __user
*_id
)
976 struct snd_card
*card
= file
->card
;
977 struct snd_ctl_elem_id id
;
978 struct snd_kcontrol
*kctl
;
979 struct snd_kcontrol_volatile
*vd
;
982 if (copy_from_user(&id
, _id
, sizeof(id
)))
984 down_write(&card
->controls_rwsem
);
985 kctl
= snd_ctl_find_id(card
, &id
);
989 vd
= &kctl
->vd
[snd_ctl_get_ioff(kctl
, &id
)];
990 if (vd
->owner
!= NULL
)
997 up_write(&card
->controls_rwsem
);
1001 static int snd_ctl_elem_unlock(struct snd_ctl_file
*file
,
1002 struct snd_ctl_elem_id __user
*_id
)
1004 struct snd_card
*card
= file
->card
;
1005 struct snd_ctl_elem_id id
;
1006 struct snd_kcontrol
*kctl
;
1007 struct snd_kcontrol_volatile
*vd
;
1010 if (copy_from_user(&id
, _id
, sizeof(id
)))
1012 down_write(&card
->controls_rwsem
);
1013 kctl
= snd_ctl_find_id(card
, &id
);
1017 vd
= &kctl
->vd
[snd_ctl_get_ioff(kctl
, &id
)];
1018 if (vd
->owner
== NULL
)
1020 else if (vd
->owner
!= file
)
1027 up_write(&card
->controls_rwsem
);
1031 struct user_element
{
1032 struct snd_ctl_elem_info info
;
1033 struct snd_card
*card
;
1034 char *elem_data
; /* element data */
1035 unsigned long elem_data_size
; /* size of element data in bytes */
1036 void *tlv_data
; /* TLV data */
1037 unsigned long tlv_data_size
; /* TLV data size */
1038 void *priv_data
; /* private data (like strings for enumerated type) */
1041 static int snd_ctl_elem_user_info(struct snd_kcontrol
*kcontrol
,
1042 struct snd_ctl_elem_info
*uinfo
)
1044 struct user_element
*ue
= kcontrol
->private_data
;
1045 unsigned int offset
;
1047 offset
= snd_ctl_get_ioff(kcontrol
, &uinfo
->id
);
1049 snd_ctl_build_ioff(&uinfo
->id
, kcontrol
, offset
);
1054 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol
*kcontrol
,
1055 struct snd_ctl_elem_info
*uinfo
)
1057 struct user_element
*ue
= kcontrol
->private_data
;
1060 unsigned int offset
;
1062 item
= uinfo
->value
.enumerated
.item
;
1064 offset
= snd_ctl_get_ioff(kcontrol
, &uinfo
->id
);
1066 snd_ctl_build_ioff(&uinfo
->id
, kcontrol
, offset
);
1068 item
= min(item
, uinfo
->value
.enumerated
.items
- 1);
1069 uinfo
->value
.enumerated
.item
= item
;
1071 names
= ue
->priv_data
;
1072 for (; item
> 0; --item
)
1073 names
+= strlen(names
) + 1;
1074 strcpy(uinfo
->value
.enumerated
.name
, names
);
1079 static int snd_ctl_elem_user_get(struct snd_kcontrol
*kcontrol
,
1080 struct snd_ctl_elem_value
*ucontrol
)
1082 struct user_element
*ue
= kcontrol
->private_data
;
1083 unsigned int size
= ue
->elem_data_size
;
1084 char *src
= ue
->elem_data
+
1085 snd_ctl_get_ioff(kcontrol
, &ucontrol
->id
) * size
;
1087 mutex_lock(&ue
->card
->user_ctl_lock
);
1088 memcpy(&ucontrol
->value
, src
, size
);
1089 mutex_unlock(&ue
->card
->user_ctl_lock
);
1093 static int snd_ctl_elem_user_put(struct snd_kcontrol
*kcontrol
,
1094 struct snd_ctl_elem_value
*ucontrol
)
1097 struct user_element
*ue
= kcontrol
->private_data
;
1098 unsigned int size
= ue
->elem_data_size
;
1099 char *dst
= ue
->elem_data
+
1100 snd_ctl_get_ioff(kcontrol
, &ucontrol
->id
) * size
;
1102 mutex_lock(&ue
->card
->user_ctl_lock
);
1103 change
= memcmp(&ucontrol
->value
, dst
, size
) != 0;
1105 memcpy(dst
, &ucontrol
->value
, size
);
1106 mutex_unlock(&ue
->card
->user_ctl_lock
);
1110 static int snd_ctl_elem_user_tlv(struct snd_kcontrol
*kcontrol
,
1113 unsigned int __user
*tlv
)
1115 struct user_element
*ue
= kcontrol
->private_data
;
1119 if (op_flag
== SNDRV_CTL_TLV_OP_WRITE
) {
1120 if (size
> 1024 * 128) /* sane value */
1123 new_data
= memdup_user(tlv
, size
);
1124 if (IS_ERR(new_data
))
1125 return PTR_ERR(new_data
);
1126 mutex_lock(&ue
->card
->user_ctl_lock
);
1127 change
= ue
->tlv_data_size
!= size
;
1129 change
= memcmp(ue
->tlv_data
, new_data
, size
);
1130 kfree(ue
->tlv_data
);
1131 ue
->tlv_data
= new_data
;
1132 ue
->tlv_data_size
= size
;
1133 mutex_unlock(&ue
->card
->user_ctl_lock
);
1137 mutex_lock(&ue
->card
->user_ctl_lock
);
1138 if (!ue
->tlv_data_size
|| !ue
->tlv_data
) {
1142 if (size
< ue
->tlv_data_size
) {
1146 if (copy_to_user(tlv
, ue
->tlv_data
, ue
->tlv_data_size
))
1149 mutex_unlock(&ue
->card
->user_ctl_lock
);
1156 static int snd_ctl_elem_init_enum_names(struct user_element
*ue
)
1159 size_t buf_len
, name_len
;
1161 const uintptr_t user_ptrval
= ue
->info
.value
.enumerated
.names_ptr
;
1163 if (ue
->info
.value
.enumerated
.names_length
> 64 * 1024)
1166 names
= memdup_user((const void __user
*)user_ptrval
,
1167 ue
->info
.value
.enumerated
.names_length
);
1169 return PTR_ERR(names
);
1171 /* check that there are enough valid names */
1172 buf_len
= ue
->info
.value
.enumerated
.names_length
;
1174 for (i
= 0; i
< ue
->info
.value
.enumerated
.items
; ++i
) {
1175 name_len
= strnlen(p
, buf_len
);
1176 if (name_len
== 0 || name_len
>= 64 || name_len
== buf_len
) {
1181 buf_len
-= name_len
+ 1;
1184 ue
->priv_data
= names
;
1185 ue
->info
.value
.enumerated
.names_ptr
= 0;
1190 static void snd_ctl_elem_user_free(struct snd_kcontrol
*kcontrol
)
1192 struct user_element
*ue
= kcontrol
->private_data
;
1194 kfree(ue
->tlv_data
);
1195 kfree(ue
->priv_data
);
1199 static int snd_ctl_elem_add(struct snd_ctl_file
*file
,
1200 struct snd_ctl_elem_info
*info
, int replace
)
1202 /* The capacity of struct snd_ctl_elem_value.value.*/
1203 static const unsigned int value_sizes
[] = {
1204 [SNDRV_CTL_ELEM_TYPE_BOOLEAN
] = sizeof(long),
1205 [SNDRV_CTL_ELEM_TYPE_INTEGER
] = sizeof(long),
1206 [SNDRV_CTL_ELEM_TYPE_ENUMERATED
] = sizeof(unsigned int),
1207 [SNDRV_CTL_ELEM_TYPE_BYTES
] = sizeof(unsigned char),
1208 [SNDRV_CTL_ELEM_TYPE_IEC958
] = sizeof(struct snd_aes_iec958
),
1209 [SNDRV_CTL_ELEM_TYPE_INTEGER64
] = sizeof(long long),
1211 static const unsigned int max_value_counts
[] = {
1212 [SNDRV_CTL_ELEM_TYPE_BOOLEAN
] = 128,
1213 [SNDRV_CTL_ELEM_TYPE_INTEGER
] = 128,
1214 [SNDRV_CTL_ELEM_TYPE_ENUMERATED
] = 128,
1215 [SNDRV_CTL_ELEM_TYPE_BYTES
] = 512,
1216 [SNDRV_CTL_ELEM_TYPE_IEC958
] = 1,
1217 [SNDRV_CTL_ELEM_TYPE_INTEGER64
] = 64,
1219 struct snd_card
*card
= file
->card
;
1220 struct snd_kcontrol
*kctl
;
1222 unsigned int access
;
1224 struct user_element
*ue
;
1225 unsigned int offset
;
1228 if (!*info
->id
.name
)
1230 if (strnlen(info
->id
.name
, sizeof(info
->id
.name
)) >= sizeof(info
->id
.name
))
1233 /* Delete a control to replace them if needed. */
1236 err
= snd_ctl_remove_user_ctl(file
, &info
->id
);
1242 * The number of userspace controls are counted control by control,
1243 * not element by element.
1245 if (card
->user_ctl_count
+ 1 > MAX_USER_CONTROLS
)
1248 /* Check the number of elements for this userspace control. */
1249 count
= info
->owner
;
1253 /* Arrange access permissions if needed. */
1254 access
= info
->access
;
1256 access
= SNDRV_CTL_ELEM_ACCESS_READWRITE
;
1257 access
&= (SNDRV_CTL_ELEM_ACCESS_READWRITE
|
1258 SNDRV_CTL_ELEM_ACCESS_INACTIVE
|
1259 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE
);
1260 if (access
& SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE
)
1261 access
|= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK
;
1262 access
|= SNDRV_CTL_ELEM_ACCESS_USER
;
1265 * Check information and calculate the size of data specific to
1266 * this userspace control.
1268 if (info
->type
< SNDRV_CTL_ELEM_TYPE_BOOLEAN
||
1269 info
->type
> SNDRV_CTL_ELEM_TYPE_INTEGER64
)
1271 if (info
->type
== SNDRV_CTL_ELEM_TYPE_ENUMERATED
&&
1272 info
->value
.enumerated
.items
== 0)
1274 if (info
->count
< 1 ||
1275 info
->count
> max_value_counts
[info
->type
])
1277 private_size
= value_sizes
[info
->type
] * info
->count
;
1280 * Keep memory object for this userspace control. After passing this
1281 * code block, the instance should be freed by snd_ctl_free_one().
1283 * Note that these elements in this control are locked.
1285 err
= snd_ctl_new(&kctl
, count
, access
, file
);
1288 memcpy(&kctl
->id
, &info
->id
, sizeof(kctl
->id
));
1289 kctl
->private_data
= kzalloc(sizeof(struct user_element
) + private_size
* count
,
1291 if (kctl
->private_data
== NULL
) {
1295 kctl
->private_free
= snd_ctl_elem_user_free
;
1297 /* Set private data for this userspace control. */
1298 ue
= (struct user_element
*)kctl
->private_data
;
1301 ue
->info
.access
= 0;
1302 ue
->elem_data
= (char *)ue
+ sizeof(*ue
);
1303 ue
->elem_data_size
= private_size
;
1304 if (ue
->info
.type
== SNDRV_CTL_ELEM_TYPE_ENUMERATED
) {
1305 err
= snd_ctl_elem_init_enum_names(ue
);
1307 snd_ctl_free_one(kctl
);
1312 /* Set callback functions. */
1313 if (info
->type
== SNDRV_CTL_ELEM_TYPE_ENUMERATED
)
1314 kctl
->info
= snd_ctl_elem_user_enum_info
;
1316 kctl
->info
= snd_ctl_elem_user_info
;
1317 if (access
& SNDRV_CTL_ELEM_ACCESS_READ
)
1318 kctl
->get
= snd_ctl_elem_user_get
;
1319 if (access
& SNDRV_CTL_ELEM_ACCESS_WRITE
)
1320 kctl
->put
= snd_ctl_elem_user_put
;
1321 if (access
& SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE
)
1322 kctl
->tlv
.c
= snd_ctl_elem_user_tlv
;
1324 /* This function manage to free the instance on failure. */
1325 err
= snd_ctl_add(card
, kctl
);
1328 offset
= snd_ctl_get_ioff(kctl
, &info
->id
);
1329 snd_ctl_build_ioff(&info
->id
, kctl
, offset
);
1331 * Here we cannot fill any field for the number of elements added by
1332 * this operation because there're no specific fields. The usage of
1333 * 'owner' field for this purpose may cause any bugs to userspace
1334 * applications because the field originally means PID of a process
1335 * which locks the element.
1338 down_write(&card
->controls_rwsem
);
1339 card
->user_ctl_count
++;
1340 up_write(&card
->controls_rwsem
);
1345 static int snd_ctl_elem_add_user(struct snd_ctl_file
*file
,
1346 struct snd_ctl_elem_info __user
*_info
, int replace
)
1348 struct snd_ctl_elem_info info
;
1351 if (copy_from_user(&info
, _info
, sizeof(info
)))
1353 err
= snd_ctl_elem_add(file
, &info
, replace
);
1356 if (copy_to_user(_info
, &info
, sizeof(info
))) {
1357 snd_ctl_remove_user_ctl(file
, &info
.id
);
1364 static int snd_ctl_elem_remove(struct snd_ctl_file
*file
,
1365 struct snd_ctl_elem_id __user
*_id
)
1367 struct snd_ctl_elem_id id
;
1369 if (copy_from_user(&id
, _id
, sizeof(id
)))
1371 return snd_ctl_remove_user_ctl(file
, &id
);
1374 static int snd_ctl_subscribe_events(struct snd_ctl_file
*file
, int __user
*ptr
)
1377 if (get_user(subscribe
, ptr
))
1379 if (subscribe
< 0) {
1380 subscribe
= file
->subscribed
;
1381 if (put_user(subscribe
, ptr
))
1386 file
->subscribed
= 1;
1388 } else if (file
->subscribed
) {
1389 snd_ctl_empty_read_queue(file
);
1390 file
->subscribed
= 0;
1395 static int snd_ctl_tlv_ioctl(struct snd_ctl_file
*file
,
1396 struct snd_ctl_tlv __user
*_tlv
,
1399 struct snd_card
*card
= file
->card
;
1400 struct snd_ctl_tlv tlv
;
1401 struct snd_kcontrol
*kctl
;
1402 struct snd_kcontrol_volatile
*vd
;
1406 if (copy_from_user(&tlv
, _tlv
, sizeof(tlv
)))
1408 if (tlv
.length
< sizeof(unsigned int) * 2)
1412 down_read(&card
->controls_rwsem
);
1413 kctl
= snd_ctl_find_numid(card
, tlv
.numid
);
1418 if (kctl
->tlv
.p
== NULL
) {
1422 vd
= &kctl
->vd
[tlv
.numid
- kctl
->id
.numid
];
1423 if ((op_flag
== SNDRV_CTL_TLV_OP_READ
&&
1424 (vd
->access
& SNDRV_CTL_ELEM_ACCESS_TLV_READ
) == 0) ||
1425 (op_flag
== SNDRV_CTL_TLV_OP_WRITE
&&
1426 (vd
->access
& SNDRV_CTL_ELEM_ACCESS_TLV_WRITE
) == 0) ||
1427 (op_flag
== SNDRV_CTL_TLV_OP_CMD
&&
1428 (vd
->access
& SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND
) == 0)) {
1432 if (vd
->access
& SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK
) {
1433 if (vd
->owner
!= NULL
&& vd
->owner
!= file
) {
1437 err
= kctl
->tlv
.c(kctl
, op_flag
, tlv
.length
, _tlv
->tlv
);
1439 struct snd_ctl_elem_id id
= kctl
->id
;
1440 up_read(&card
->controls_rwsem
);
1441 snd_ctl_notify(card
, SNDRV_CTL_EVENT_MASK_TLV
, &id
);
1445 if (op_flag
!= SNDRV_CTL_TLV_OP_READ
) {
1449 len
= kctl
->tlv
.p
[1] + 2 * sizeof(unsigned int);
1450 if (tlv
.length
< len
) {
1454 if (copy_to_user(_tlv
->tlv
, kctl
->tlv
.p
, len
))
1458 up_read(&card
->controls_rwsem
);
1462 static long snd_ctl_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
1464 struct snd_ctl_file
*ctl
;
1465 struct snd_card
*card
;
1466 struct snd_kctl_ioctl
*p
;
1467 void __user
*argp
= (void __user
*)arg
;
1468 int __user
*ip
= argp
;
1471 ctl
= file
->private_data
;
1473 if (snd_BUG_ON(!card
))
1476 case SNDRV_CTL_IOCTL_PVERSION
:
1477 return put_user(SNDRV_CTL_VERSION
, ip
) ? -EFAULT
: 0;
1478 case SNDRV_CTL_IOCTL_CARD_INFO
:
1479 return snd_ctl_card_info(card
, ctl
, cmd
, argp
);
1480 case SNDRV_CTL_IOCTL_ELEM_LIST
:
1481 return snd_ctl_elem_list(card
, argp
);
1482 case SNDRV_CTL_IOCTL_ELEM_INFO
:
1483 return snd_ctl_elem_info_user(ctl
, argp
);
1484 case SNDRV_CTL_IOCTL_ELEM_READ
:
1485 return snd_ctl_elem_read_user(card
, argp
);
1486 case SNDRV_CTL_IOCTL_ELEM_WRITE
:
1487 return snd_ctl_elem_write_user(ctl
, argp
);
1488 case SNDRV_CTL_IOCTL_ELEM_LOCK
:
1489 return snd_ctl_elem_lock(ctl
, argp
);
1490 case SNDRV_CTL_IOCTL_ELEM_UNLOCK
:
1491 return snd_ctl_elem_unlock(ctl
, argp
);
1492 case SNDRV_CTL_IOCTL_ELEM_ADD
:
1493 return snd_ctl_elem_add_user(ctl
, argp
, 0);
1494 case SNDRV_CTL_IOCTL_ELEM_REPLACE
:
1495 return snd_ctl_elem_add_user(ctl
, argp
, 1);
1496 case SNDRV_CTL_IOCTL_ELEM_REMOVE
:
1497 return snd_ctl_elem_remove(ctl
, argp
);
1498 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS
:
1499 return snd_ctl_subscribe_events(ctl
, ip
);
1500 case SNDRV_CTL_IOCTL_TLV_READ
:
1501 return snd_ctl_tlv_ioctl(ctl
, argp
, SNDRV_CTL_TLV_OP_READ
);
1502 case SNDRV_CTL_IOCTL_TLV_WRITE
:
1503 return snd_ctl_tlv_ioctl(ctl
, argp
, SNDRV_CTL_TLV_OP_WRITE
);
1504 case SNDRV_CTL_IOCTL_TLV_COMMAND
:
1505 return snd_ctl_tlv_ioctl(ctl
, argp
, SNDRV_CTL_TLV_OP_CMD
);
1506 case SNDRV_CTL_IOCTL_POWER
:
1507 return -ENOPROTOOPT
;
1508 case SNDRV_CTL_IOCTL_POWER_STATE
:
1510 return put_user(card
->power_state
, ip
) ? -EFAULT
: 0;
1512 return put_user(SNDRV_CTL_POWER_D0
, ip
) ? -EFAULT
: 0;
1515 down_read(&snd_ioctl_rwsem
);
1516 list_for_each_entry(p
, &snd_control_ioctls
, list
) {
1517 err
= p
->fioctl(card
, ctl
, cmd
, arg
);
1518 if (err
!= -ENOIOCTLCMD
) {
1519 up_read(&snd_ioctl_rwsem
);
1523 up_read(&snd_ioctl_rwsem
);
1524 dev_dbg(card
->dev
, "unknown ioctl = 0x%x\n", cmd
);
1528 static ssize_t
snd_ctl_read(struct file
*file
, char __user
*buffer
,
1529 size_t count
, loff_t
* offset
)
1531 struct snd_ctl_file
*ctl
;
1535 ctl
= file
->private_data
;
1536 if (snd_BUG_ON(!ctl
|| !ctl
->card
))
1538 if (!ctl
->subscribed
)
1540 if (count
< sizeof(struct snd_ctl_event
))
1542 spin_lock_irq(&ctl
->read_lock
);
1543 while (count
>= sizeof(struct snd_ctl_event
)) {
1544 struct snd_ctl_event ev
;
1545 struct snd_kctl_event
*kev
;
1546 while (list_empty(&ctl
->events
)) {
1548 if ((file
->f_flags
& O_NONBLOCK
) != 0 || result
> 0) {
1552 init_waitqueue_entry(&wait
, current
);
1553 add_wait_queue(&ctl
->change_sleep
, &wait
);
1554 set_current_state(TASK_INTERRUPTIBLE
);
1555 spin_unlock_irq(&ctl
->read_lock
);
1557 remove_wait_queue(&ctl
->change_sleep
, &wait
);
1558 if (ctl
->card
->shutdown
)
1560 if (signal_pending(current
))
1561 return -ERESTARTSYS
;
1562 spin_lock_irq(&ctl
->read_lock
);
1564 kev
= snd_kctl_event(ctl
->events
.next
);
1565 ev
.type
= SNDRV_CTL_EVENT_ELEM
;
1566 ev
.data
.elem
.mask
= kev
->mask
;
1567 ev
.data
.elem
.id
= kev
->id
;
1568 list_del(&kev
->list
);
1569 spin_unlock_irq(&ctl
->read_lock
);
1571 if (copy_to_user(buffer
, &ev
, sizeof(struct snd_ctl_event
))) {
1575 spin_lock_irq(&ctl
->read_lock
);
1576 buffer
+= sizeof(struct snd_ctl_event
);
1577 count
-= sizeof(struct snd_ctl_event
);
1578 result
+= sizeof(struct snd_ctl_event
);
1581 spin_unlock_irq(&ctl
->read_lock
);
1583 return result
> 0 ? result
: err
;
1586 static unsigned int snd_ctl_poll(struct file
*file
, poll_table
* wait
)
1589 struct snd_ctl_file
*ctl
;
1591 ctl
= file
->private_data
;
1592 if (!ctl
->subscribed
)
1594 poll_wait(file
, &ctl
->change_sleep
, wait
);
1597 if (!list_empty(&ctl
->events
))
1598 mask
|= POLLIN
| POLLRDNORM
;
1604 * register the device-specific control-ioctls.
1605 * called from each device manager like pcm.c, hwdep.c, etc.
1607 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn
, struct list_head
*lists
)
1609 struct snd_kctl_ioctl
*pn
;
1611 pn
= kzalloc(sizeof(struct snd_kctl_ioctl
), GFP_KERNEL
);
1615 down_write(&snd_ioctl_rwsem
);
1616 list_add_tail(&pn
->list
, lists
);
1617 up_write(&snd_ioctl_rwsem
);
1622 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1623 * @fcn: ioctl callback function
1625 * called from each device manager like pcm.c, hwdep.c, etc.
1627 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn
)
1629 return _snd_ctl_register_ioctl(fcn
, &snd_control_ioctls
);
1631 EXPORT_SYMBOL(snd_ctl_register_ioctl
);
1633 #ifdef CONFIG_COMPAT
1635 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1637 * @fcn: ioctl callback function
1639 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn
)
1641 return _snd_ctl_register_ioctl(fcn
, &snd_control_compat_ioctls
);
1643 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat
);
1647 * de-register the device-specific control-ioctls.
1649 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn
,
1650 struct list_head
*lists
)
1652 struct snd_kctl_ioctl
*p
;
1654 if (snd_BUG_ON(!fcn
))
1656 down_write(&snd_ioctl_rwsem
);
1657 list_for_each_entry(p
, lists
, list
) {
1658 if (p
->fioctl
== fcn
) {
1660 up_write(&snd_ioctl_rwsem
);
1665 up_write(&snd_ioctl_rwsem
);
1671 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1672 * @fcn: ioctl callback function to unregister
1674 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn
)
1676 return _snd_ctl_unregister_ioctl(fcn
, &snd_control_ioctls
);
1678 EXPORT_SYMBOL(snd_ctl_unregister_ioctl
);
1680 #ifdef CONFIG_COMPAT
1682 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1684 * @fcn: ioctl callback function to unregister
1686 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn
)
1688 return _snd_ctl_unregister_ioctl(fcn
, &snd_control_compat_ioctls
);
1690 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat
);
1693 static int snd_ctl_fasync(int fd
, struct file
* file
, int on
)
1695 struct snd_ctl_file
*ctl
;
1697 ctl
= file
->private_data
;
1698 return fasync_helper(fd
, file
, on
, &ctl
->fasync
);
1701 /* return the preferred subdevice number if already assigned;
1702 * otherwise return -1
1704 int snd_ctl_get_preferred_subdevice(struct snd_card
*card
, int type
)
1706 struct snd_ctl_file
*kctl
;
1709 read_lock(&card
->ctl_files_rwlock
);
1710 list_for_each_entry(kctl
, &card
->ctl_files
, list
) {
1711 if (kctl
->pid
== task_pid(current
)) {
1712 subdevice
= kctl
->preferred_subdevice
[type
];
1713 if (subdevice
!= -1)
1717 read_unlock(&card
->ctl_files_rwlock
);
1720 EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice
);
1725 #ifdef CONFIG_COMPAT
1726 #include "control_compat.c"
1728 #define snd_ctl_ioctl_compat NULL
1735 static const struct file_operations snd_ctl_f_ops
=
1737 .owner
= THIS_MODULE
,
1738 .read
= snd_ctl_read
,
1739 .open
= snd_ctl_open
,
1740 .release
= snd_ctl_release
,
1741 .llseek
= no_llseek
,
1742 .poll
= snd_ctl_poll
,
1743 .unlocked_ioctl
= snd_ctl_ioctl
,
1744 .compat_ioctl
= snd_ctl_ioctl_compat
,
1745 .fasync
= snd_ctl_fasync
,
1749 * registration of the control device
1751 static int snd_ctl_dev_register(struct snd_device
*device
)
1753 struct snd_card
*card
= device
->device_data
;
1755 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL
, card
, -1,
1756 &snd_ctl_f_ops
, card
, &card
->ctl_dev
);
1760 * disconnection of the control device
1762 static int snd_ctl_dev_disconnect(struct snd_device
*device
)
1764 struct snd_card
*card
= device
->device_data
;
1765 struct snd_ctl_file
*ctl
;
1767 read_lock(&card
->ctl_files_rwlock
);
1768 list_for_each_entry(ctl
, &card
->ctl_files
, list
) {
1769 wake_up(&ctl
->change_sleep
);
1770 kill_fasync(&ctl
->fasync
, SIGIO
, POLL_ERR
);
1772 read_unlock(&card
->ctl_files_rwlock
);
1774 return snd_unregister_device(&card
->ctl_dev
);
1780 static int snd_ctl_dev_free(struct snd_device
*device
)
1782 struct snd_card
*card
= device
->device_data
;
1783 struct snd_kcontrol
*control
;
1785 down_write(&card
->controls_rwsem
);
1786 while (!list_empty(&card
->controls
)) {
1787 control
= snd_kcontrol(card
->controls
.next
);
1788 snd_ctl_remove(card
, control
);
1790 up_write(&card
->controls_rwsem
);
1791 put_device(&card
->ctl_dev
);
1796 * create control core:
1797 * called from init.c
1799 int snd_ctl_create(struct snd_card
*card
)
1801 static struct snd_device_ops ops
= {
1802 .dev_free
= snd_ctl_dev_free
,
1803 .dev_register
= snd_ctl_dev_register
,
1804 .dev_disconnect
= snd_ctl_dev_disconnect
,
1808 if (snd_BUG_ON(!card
))
1810 if (snd_BUG_ON(card
->number
< 0 || card
->number
>= SNDRV_CARDS
))
1813 snd_device_initialize(&card
->ctl_dev
, card
);
1814 dev_set_name(&card
->ctl_dev
, "controlC%d", card
->number
);
1816 err
= snd_device_new(card
, SNDRV_DEV_CONTROL
, card
, &ops
);
1818 put_device(&card
->ctl_dev
);
1823 * Frequently used control callbacks/helpers
1827 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1828 * callback with a mono channel
1829 * @kcontrol: the kcontrol instance
1830 * @uinfo: info to store
1832 * This is a function that can be used as info callback for a standard
1833 * boolean control with a single mono channel.
1835 int snd_ctl_boolean_mono_info(struct snd_kcontrol
*kcontrol
,
1836 struct snd_ctl_elem_info
*uinfo
)
1838 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_BOOLEAN
;
1840 uinfo
->value
.integer
.min
= 0;
1841 uinfo
->value
.integer
.max
= 1;
1844 EXPORT_SYMBOL(snd_ctl_boolean_mono_info
);
1847 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1848 * callback with stereo two channels
1849 * @kcontrol: the kcontrol instance
1850 * @uinfo: info to store
1852 * This is a function that can be used as info callback for a standard
1853 * boolean control with stereo two channels.
1855 int snd_ctl_boolean_stereo_info(struct snd_kcontrol
*kcontrol
,
1856 struct snd_ctl_elem_info
*uinfo
)
1858 uinfo
->type
= SNDRV_CTL_ELEM_TYPE_BOOLEAN
;
1860 uinfo
->value
.integer
.min
= 0;
1861 uinfo
->value
.integer
.max
= 1;
1864 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info
);
1867 * snd_ctl_enum_info - fills the info structure for an enumerated control
1868 * @info: the structure to be filled
1869 * @channels: the number of the control's channels; often one
1870 * @items: the number of control values; also the size of @names
1871 * @names: an array containing the names of all control values
1873 * Sets all required fields in @info to their appropriate values.
1874 * If the control's accessibility is not the default (readable and writable),
1875 * the caller has to fill @info->access.
1879 int snd_ctl_enum_info(struct snd_ctl_elem_info
*info
, unsigned int channels
,
1880 unsigned int items
, const char *const names
[])
1882 info
->type
= SNDRV_CTL_ELEM_TYPE_ENUMERATED
;
1883 info
->count
= channels
;
1884 info
->value
.enumerated
.items
= items
;
1887 if (info
->value
.enumerated
.item
>= items
)
1888 info
->value
.enumerated
.item
= items
- 1;
1889 WARN(strlen(names
[info
->value
.enumerated
.item
]) >= sizeof(info
->value
.enumerated
.name
),
1890 "ALSA: too long item name '%s'\n",
1891 names
[info
->value
.enumerated
.item
]);
1892 strlcpy(info
->value
.enumerated
.name
,
1893 names
[info
->value
.enumerated
.item
],
1894 sizeof(info
->value
.enumerated
.name
));
1897 EXPORT_SYMBOL(snd_ctl_enum_info
);