sctp: Correctly start rtx timer on new packet transmissions.
[linux-2.6/next.git] / sound / core / control.c
blob636b3b52ef8bdd56cc2f7eaccf6a779ca8c9c841
1 /*
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/slab.h>
25 #include <linux/vmalloc.h>
26 #include <linux/time.h>
27 #include <sound/core.h>
28 #include <sound/minors.h>
29 #include <sound/info.h>
30 #include <sound/control.h>
32 /* max number of user-defined controls */
33 #define MAX_USER_CONTROLS 32
35 struct snd_kctl_ioctl {
36 struct list_head list; /* list of all ioctls */
37 snd_kctl_ioctl_func_t fioctl;
40 static DECLARE_RWSEM(snd_ioctl_rwsem);
41 static LIST_HEAD(snd_control_ioctls);
42 #ifdef CONFIG_COMPAT
43 static LIST_HEAD(snd_control_compat_ioctls);
44 #endif
46 static int snd_ctl_open(struct inode *inode, struct file *file)
48 unsigned long flags;
49 struct snd_card *card;
50 struct snd_ctl_file *ctl;
51 int err;
53 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
54 if (!card) {
55 err = -ENODEV;
56 goto __error1;
58 err = snd_card_file_add(card, file);
59 if (err < 0) {
60 err = -ENODEV;
61 goto __error1;
63 if (!try_module_get(card->module)) {
64 err = -EFAULT;
65 goto __error2;
67 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
68 if (ctl == NULL) {
69 err = -ENOMEM;
70 goto __error;
72 INIT_LIST_HEAD(&ctl->events);
73 init_waitqueue_head(&ctl->change_sleep);
74 spin_lock_init(&ctl->read_lock);
75 ctl->card = card;
76 ctl->prefer_pcm_subdevice = -1;
77 ctl->prefer_rawmidi_subdevice = -1;
78 ctl->pid = current->pid;
79 file->private_data = ctl;
80 write_lock_irqsave(&card->ctl_files_rwlock, flags);
81 list_add_tail(&ctl->list, &card->ctl_files);
82 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
83 return 0;
85 __error:
86 module_put(card->module);
87 __error2:
88 snd_card_file_remove(card, file);
89 __error1:
90 return err;
93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
95 unsigned long flags;
96 struct snd_kctl_event *cread;
98 spin_lock_irqsave(&ctl->read_lock, flags);
99 while (!list_empty(&ctl->events)) {
100 cread = snd_kctl_event(ctl->events.next);
101 list_del(&cread->list);
102 kfree(cread);
104 spin_unlock_irqrestore(&ctl->read_lock, flags);
107 static int snd_ctl_release(struct inode *inode, struct file *file)
109 unsigned long flags;
110 struct snd_card *card;
111 struct snd_ctl_file *ctl;
112 struct snd_kcontrol *control;
113 unsigned int idx;
115 ctl = file->private_data;
116 file->private_data = NULL;
117 card = ctl->card;
118 write_lock_irqsave(&card->ctl_files_rwlock, flags);
119 list_del(&ctl->list);
120 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
121 down_write(&card->controls_rwsem);
122 list_for_each_entry(control, &card->controls, list)
123 for (idx = 0; idx < control->count; idx++)
124 if (control->vd[idx].owner == ctl)
125 control->vd[idx].owner = NULL;
126 up_write(&card->controls_rwsem);
127 snd_ctl_empty_read_queue(ctl);
128 kfree(ctl);
129 module_put(card->module);
130 snd_card_file_remove(card, file);
131 return 0;
134 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
135 struct snd_ctl_elem_id *id)
137 unsigned long flags;
138 struct snd_ctl_file *ctl;
139 struct snd_kctl_event *ev;
141 if (snd_BUG_ON(!card || !id))
142 return;
143 read_lock(&card->ctl_files_rwlock);
144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
145 card->mixer_oss_change_count++;
146 #endif
147 list_for_each_entry(ctl, &card->ctl_files, list) {
148 if (!ctl->subscribed)
149 continue;
150 spin_lock_irqsave(&ctl->read_lock, flags);
151 list_for_each_entry(ev, &ctl->events, list) {
152 if (ev->id.numid == id->numid) {
153 ev->mask |= mask;
154 goto _found;
157 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
158 if (ev) {
159 ev->id = *id;
160 ev->mask = mask;
161 list_add_tail(&ev->list, &ctl->events);
162 } else {
163 snd_printk(KERN_ERR "No memory available to allocate event\n");
165 _found:
166 wake_up(&ctl->change_sleep);
167 spin_unlock_irqrestore(&ctl->read_lock, flags);
168 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
170 read_unlock(&card->ctl_files_rwlock);
173 EXPORT_SYMBOL(snd_ctl_notify);
176 * snd_ctl_new - create a control instance from the template
177 * @control: the control template
178 * @access: the default control access
180 * Allocates a new struct snd_kcontrol instance and copies the given template
181 * to the new instance. It does not copy volatile data (access).
183 * Returns the pointer of the new instance, or NULL on failure.
185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
186 unsigned int access)
188 struct snd_kcontrol *kctl;
189 unsigned int idx;
191 if (snd_BUG_ON(!control || !control->count))
192 return NULL;
193 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
194 if (kctl == NULL) {
195 snd_printk(KERN_ERR "Cannot allocate control instance\n");
196 return NULL;
198 *kctl = *control;
199 for (idx = 0; idx < kctl->count; idx++)
200 kctl->vd[idx].access = access;
201 return kctl;
205 * snd_ctl_new1 - create a control instance from the template
206 * @ncontrol: the initialization record
207 * @private_data: the private data to set
209 * Allocates a new struct snd_kcontrol instance and initialize from the given
210 * template. When the access field of ncontrol is 0, it's assumed as
211 * READWRITE access. When the count field is 0, it's assumes as one.
213 * Returns the pointer of the newly generated instance, or NULL on failure.
215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
216 void *private_data)
218 struct snd_kcontrol kctl;
219 unsigned int access;
221 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
222 return NULL;
223 memset(&kctl, 0, sizeof(kctl));
224 kctl.id.iface = ncontrol->iface;
225 kctl.id.device = ncontrol->device;
226 kctl.id.subdevice = ncontrol->subdevice;
227 if (ncontrol->name) {
228 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
229 if (strcmp(ncontrol->name, kctl.id.name) != 0)
230 snd_printk(KERN_WARNING
231 "Control name '%s' truncated to '%s'\n",
232 ncontrol->name, kctl.id.name);
234 kctl.id.index = ncontrol->index;
235 kctl.count = ncontrol->count ? ncontrol->count : 1;
236 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
237 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
238 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
239 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
240 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
241 kctl.info = ncontrol->info;
242 kctl.get = ncontrol->get;
243 kctl.put = ncontrol->put;
244 kctl.tlv.p = ncontrol->tlv.p;
245 kctl.private_value = ncontrol->private_value;
246 kctl.private_data = private_data;
247 return snd_ctl_new(&kctl, access);
250 EXPORT_SYMBOL(snd_ctl_new1);
253 * snd_ctl_free_one - release the control instance
254 * @kcontrol: the control instance
256 * Releases the control instance created via snd_ctl_new()
257 * or snd_ctl_new1().
258 * Don't call this after the control was added to the card.
260 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
262 if (kcontrol) {
263 if (kcontrol->private_free)
264 kcontrol->private_free(kcontrol);
265 kfree(kcontrol);
269 EXPORT_SYMBOL(snd_ctl_free_one);
271 static unsigned int snd_ctl_hole_check(struct snd_card *card,
272 unsigned int count)
274 struct snd_kcontrol *kctl;
276 list_for_each_entry(kctl, &card->controls, list) {
277 if ((kctl->id.numid <= card->last_numid &&
278 kctl->id.numid + kctl->count > card->last_numid) ||
279 (kctl->id.numid <= card->last_numid + count - 1 &&
280 kctl->id.numid + kctl->count > card->last_numid + count - 1))
281 return card->last_numid = kctl->id.numid + kctl->count - 1;
283 return card->last_numid;
286 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
288 unsigned int last_numid, iter = 100000;
290 last_numid = card->last_numid;
291 while (last_numid != snd_ctl_hole_check(card, count)) {
292 if (--iter == 0) {
293 /* this situation is very unlikely */
294 snd_printk(KERN_ERR "unable to allocate new control numid\n");
295 return -ENOMEM;
297 last_numid = card->last_numid;
299 return 0;
303 * snd_ctl_add - add the control instance to the card
304 * @card: the card instance
305 * @kcontrol: the control instance to add
307 * Adds the control instance created via snd_ctl_new() or
308 * snd_ctl_new1() to the given card. Assigns also an unique
309 * numid used for fast search.
311 * Returns zero if successful, or a negative error code on failure.
313 * It frees automatically the control which cannot be added.
315 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
317 struct snd_ctl_elem_id id;
318 unsigned int idx;
319 int err = -EINVAL;
321 if (! kcontrol)
322 return err;
323 if (snd_BUG_ON(!card || !kcontrol->info))
324 goto error;
325 id = kcontrol->id;
326 down_write(&card->controls_rwsem);
327 if (snd_ctl_find_id(card, &id)) {
328 up_write(&card->controls_rwsem);
329 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
330 id.iface,
331 id.device,
332 id.subdevice,
333 id.name,
334 id.index);
335 err = -EBUSY;
336 goto error;
338 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
339 up_write(&card->controls_rwsem);
340 err = -ENOMEM;
341 goto error;
343 list_add_tail(&kcontrol->list, &card->controls);
344 card->controls_count += kcontrol->count;
345 kcontrol->id.numid = card->last_numid + 1;
346 card->last_numid += kcontrol->count;
347 up_write(&card->controls_rwsem);
348 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
349 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
350 return 0;
352 error:
353 snd_ctl_free_one(kcontrol);
354 return err;
357 EXPORT_SYMBOL(snd_ctl_add);
360 * snd_ctl_remove - remove the control from the card and release it
361 * @card: the card instance
362 * @kcontrol: the control instance to remove
364 * Removes the control from the card and then releases the instance.
365 * You don't need to call snd_ctl_free_one(). You must be in
366 * the write lock - down_write(&card->controls_rwsem).
368 * Returns 0 if successful, or a negative error code on failure.
370 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
372 struct snd_ctl_elem_id id;
373 unsigned int idx;
375 if (snd_BUG_ON(!card || !kcontrol))
376 return -EINVAL;
377 list_del(&kcontrol->list);
378 card->controls_count -= kcontrol->count;
379 id = kcontrol->id;
380 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
381 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
382 snd_ctl_free_one(kcontrol);
383 return 0;
386 EXPORT_SYMBOL(snd_ctl_remove);
389 * snd_ctl_remove_id - remove the control of the given id and release it
390 * @card: the card instance
391 * @id: the control id to remove
393 * Finds the control instance with the given id, removes it from the
394 * card list and releases it.
396 * Returns 0 if successful, or a negative error code on failure.
398 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
400 struct snd_kcontrol *kctl;
401 int ret;
403 down_write(&card->controls_rwsem);
404 kctl = snd_ctl_find_id(card, id);
405 if (kctl == NULL) {
406 up_write(&card->controls_rwsem);
407 return -ENOENT;
409 ret = snd_ctl_remove(card, kctl);
410 up_write(&card->controls_rwsem);
411 return ret;
414 EXPORT_SYMBOL(snd_ctl_remove_id);
417 * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
418 * @file: active control handle
419 * @id: the control id to remove
421 * Finds the control instance with the given id, removes it from the
422 * card list and releases it.
424 * Returns 0 if successful, or a negative error code on failure.
426 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
427 struct snd_ctl_elem_id *id)
429 struct snd_card *card = file->card;
430 struct snd_kcontrol *kctl;
431 int idx, ret;
433 down_write(&card->controls_rwsem);
434 kctl = snd_ctl_find_id(card, id);
435 if (kctl == NULL) {
436 up_write(&card->controls_rwsem);
437 return -ENOENT;
439 for (idx = 0; idx < kctl->count; idx++)
440 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
441 up_write(&card->controls_rwsem);
442 return -EBUSY;
444 ret = snd_ctl_remove(card, kctl);
445 up_write(&card->controls_rwsem);
446 return ret;
450 * snd_ctl_rename_id - replace the id of a control on the card
451 * @card: the card instance
452 * @src_id: the old id
453 * @dst_id: the new id
455 * Finds the control with the old id from the card, and replaces the
456 * id with the new one.
458 * Returns zero if successful, or a negative error code on failure.
460 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
461 struct snd_ctl_elem_id *dst_id)
463 struct snd_kcontrol *kctl;
465 down_write(&card->controls_rwsem);
466 kctl = snd_ctl_find_id(card, src_id);
467 if (kctl == NULL) {
468 up_write(&card->controls_rwsem);
469 return -ENOENT;
471 kctl->id = *dst_id;
472 kctl->id.numid = card->last_numid + 1;
473 card->last_numid += kctl->count;
474 up_write(&card->controls_rwsem);
475 return 0;
478 EXPORT_SYMBOL(snd_ctl_rename_id);
481 * snd_ctl_find_numid - find the control instance with the given number-id
482 * @card: the card instance
483 * @numid: the number-id to search
485 * Finds the control instance with the given number-id from the card.
487 * Returns the pointer of the instance if found, or NULL if not.
489 * The caller must down card->controls_rwsem before calling this function
490 * (if the race condition can happen).
492 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
494 struct snd_kcontrol *kctl;
496 if (snd_BUG_ON(!card || !numid))
497 return NULL;
498 list_for_each_entry(kctl, &card->controls, list) {
499 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
500 return kctl;
502 return NULL;
505 EXPORT_SYMBOL(snd_ctl_find_numid);
508 * snd_ctl_find_id - find the control instance with the given id
509 * @card: the card instance
510 * @id: the id to search
512 * Finds the control instance with the given id from the card.
514 * Returns the pointer of the instance if found, or NULL if not.
516 * The caller must down card->controls_rwsem before calling this function
517 * (if the race condition can happen).
519 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
520 struct snd_ctl_elem_id *id)
522 struct snd_kcontrol *kctl;
524 if (snd_BUG_ON(!card || !id))
525 return NULL;
526 if (id->numid != 0)
527 return snd_ctl_find_numid(card, id->numid);
528 list_for_each_entry(kctl, &card->controls, list) {
529 if (kctl->id.iface != id->iface)
530 continue;
531 if (kctl->id.device != id->device)
532 continue;
533 if (kctl->id.subdevice != id->subdevice)
534 continue;
535 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
536 continue;
537 if (kctl->id.index > id->index)
538 continue;
539 if (kctl->id.index + kctl->count <= id->index)
540 continue;
541 return kctl;
543 return NULL;
546 EXPORT_SYMBOL(snd_ctl_find_id);
548 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
549 unsigned int cmd, void __user *arg)
551 struct snd_ctl_card_info *info;
553 info = kzalloc(sizeof(*info), GFP_KERNEL);
554 if (! info)
555 return -ENOMEM;
556 down_read(&snd_ioctl_rwsem);
557 info->card = card->number;
558 strlcpy(info->id, card->id, sizeof(info->id));
559 strlcpy(info->driver, card->driver, sizeof(info->driver));
560 strlcpy(info->name, card->shortname, sizeof(info->name));
561 strlcpy(info->longname, card->longname, sizeof(info->longname));
562 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
563 strlcpy(info->components, card->components, sizeof(info->components));
564 up_read(&snd_ioctl_rwsem);
565 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
566 kfree(info);
567 return -EFAULT;
569 kfree(info);
570 return 0;
573 static int snd_ctl_elem_list(struct snd_card *card,
574 struct snd_ctl_elem_list __user *_list)
576 struct list_head *plist;
577 struct snd_ctl_elem_list list;
578 struct snd_kcontrol *kctl;
579 struct snd_ctl_elem_id *dst, *id;
580 unsigned int offset, space, first, jidx;
582 if (copy_from_user(&list, _list, sizeof(list)))
583 return -EFAULT;
584 offset = list.offset;
585 space = list.space;
586 first = 0;
587 /* try limit maximum space */
588 if (space > 16384)
589 return -ENOMEM;
590 if (space > 0) {
591 /* allocate temporary buffer for atomic operation */
592 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
593 if (dst == NULL)
594 return -ENOMEM;
595 down_read(&card->controls_rwsem);
596 list.count = card->controls_count;
597 plist = card->controls.next;
598 while (plist != &card->controls) {
599 if (offset == 0)
600 break;
601 kctl = snd_kcontrol(plist);
602 if (offset < kctl->count)
603 break;
604 offset -= kctl->count;
605 plist = plist->next;
607 list.used = 0;
608 id = dst;
609 while (space > 0 && plist != &card->controls) {
610 kctl = snd_kcontrol(plist);
611 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
612 snd_ctl_build_ioff(id, kctl, jidx);
613 id++;
614 space--;
615 list.used++;
617 plist = plist->next;
618 offset = 0;
620 up_read(&card->controls_rwsem);
621 if (list.used > 0 &&
622 copy_to_user(list.pids, dst,
623 list.used * sizeof(struct snd_ctl_elem_id))) {
624 vfree(dst);
625 return -EFAULT;
627 vfree(dst);
628 } else {
629 down_read(&card->controls_rwsem);
630 list.count = card->controls_count;
631 up_read(&card->controls_rwsem);
633 if (copy_to_user(_list, &list, sizeof(list)))
634 return -EFAULT;
635 return 0;
638 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
639 struct snd_ctl_elem_info *info)
641 struct snd_card *card = ctl->card;
642 struct snd_kcontrol *kctl;
643 struct snd_kcontrol_volatile *vd;
644 unsigned int index_offset;
645 int result;
647 down_read(&card->controls_rwsem);
648 kctl = snd_ctl_find_id(card, &info->id);
649 if (kctl == NULL) {
650 up_read(&card->controls_rwsem);
651 return -ENOENT;
653 #ifdef CONFIG_SND_DEBUG
654 info->access = 0;
655 #endif
656 result = kctl->info(kctl, info);
657 if (result >= 0) {
658 snd_BUG_ON(info->access);
659 index_offset = snd_ctl_get_ioff(kctl, &info->id);
660 vd = &kctl->vd[index_offset];
661 snd_ctl_build_ioff(&info->id, kctl, index_offset);
662 info->access = vd->access;
663 if (vd->owner) {
664 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
665 if (vd->owner == ctl)
666 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
667 info->owner = vd->owner_pid;
668 } else {
669 info->owner = -1;
672 up_read(&card->controls_rwsem);
673 return result;
676 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
677 struct snd_ctl_elem_info __user *_info)
679 struct snd_ctl_elem_info info;
680 int result;
682 if (copy_from_user(&info, _info, sizeof(info)))
683 return -EFAULT;
684 snd_power_lock(ctl->card);
685 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
686 if (result >= 0)
687 result = snd_ctl_elem_info(ctl, &info);
688 snd_power_unlock(ctl->card);
689 if (result >= 0)
690 if (copy_to_user(_info, &info, sizeof(info)))
691 return -EFAULT;
692 return result;
695 static int snd_ctl_elem_read(struct snd_card *card,
696 struct snd_ctl_elem_value *control)
698 struct snd_kcontrol *kctl;
699 struct snd_kcontrol_volatile *vd;
700 unsigned int index_offset;
701 int result;
703 down_read(&card->controls_rwsem);
704 kctl = snd_ctl_find_id(card, &control->id);
705 if (kctl == NULL) {
706 result = -ENOENT;
707 } else {
708 index_offset = snd_ctl_get_ioff(kctl, &control->id);
709 vd = &kctl->vd[index_offset];
710 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
711 kctl->get != NULL) {
712 snd_ctl_build_ioff(&control->id, kctl, index_offset);
713 result = kctl->get(kctl, control);
714 } else
715 result = -EPERM;
717 up_read(&card->controls_rwsem);
718 return result;
721 static int snd_ctl_elem_read_user(struct snd_card *card,
722 struct snd_ctl_elem_value __user *_control)
724 struct snd_ctl_elem_value *control;
725 int result;
727 control = kmalloc(sizeof(*control), GFP_KERNEL);
728 if (control == NULL)
729 return -ENOMEM;
730 if (copy_from_user(control, _control, sizeof(*control))) {
731 kfree(control);
732 return -EFAULT;
734 snd_power_lock(card);
735 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
736 if (result >= 0)
737 result = snd_ctl_elem_read(card, control);
738 snd_power_unlock(card);
739 if (result >= 0)
740 if (copy_to_user(_control, control, sizeof(*control)))
741 result = -EFAULT;
742 kfree(control);
743 return result;
746 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
747 struct snd_ctl_elem_value *control)
749 struct snd_kcontrol *kctl;
750 struct snd_kcontrol_volatile *vd;
751 unsigned int index_offset;
752 int result;
754 down_read(&card->controls_rwsem);
755 kctl = snd_ctl_find_id(card, &control->id);
756 if (kctl == NULL) {
757 result = -ENOENT;
758 } else {
759 index_offset = snd_ctl_get_ioff(kctl, &control->id);
760 vd = &kctl->vd[index_offset];
761 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
762 kctl->put == NULL ||
763 (file && vd->owner && vd->owner != file)) {
764 result = -EPERM;
765 } else {
766 snd_ctl_build_ioff(&control->id, kctl, index_offset);
767 result = kctl->put(kctl, control);
769 if (result > 0) {
770 up_read(&card->controls_rwsem);
771 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
772 &control->id);
773 return 0;
776 up_read(&card->controls_rwsem);
777 return result;
780 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
781 struct snd_ctl_elem_value __user *_control)
783 struct snd_ctl_elem_value *control;
784 struct snd_card *card;
785 int result;
787 control = kmalloc(sizeof(*control), GFP_KERNEL);
788 if (control == NULL)
789 return -ENOMEM;
790 if (copy_from_user(control, _control, sizeof(*control))) {
791 kfree(control);
792 return -EFAULT;
794 card = file->card;
795 snd_power_lock(card);
796 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
797 if (result >= 0)
798 result = snd_ctl_elem_write(card, file, control);
799 snd_power_unlock(card);
800 if (result >= 0)
801 if (copy_to_user(_control, control, sizeof(*control)))
802 result = -EFAULT;
803 kfree(control);
804 return result;
807 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
808 struct snd_ctl_elem_id __user *_id)
810 struct snd_card *card = file->card;
811 struct snd_ctl_elem_id id;
812 struct snd_kcontrol *kctl;
813 struct snd_kcontrol_volatile *vd;
814 int result;
816 if (copy_from_user(&id, _id, sizeof(id)))
817 return -EFAULT;
818 down_write(&card->controls_rwsem);
819 kctl = snd_ctl_find_id(card, &id);
820 if (kctl == NULL) {
821 result = -ENOENT;
822 } else {
823 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
824 if (vd->owner != NULL)
825 result = -EBUSY;
826 else {
827 vd->owner = file;
828 vd->owner_pid = current->pid;
829 result = 0;
832 up_write(&card->controls_rwsem);
833 return result;
836 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
837 struct snd_ctl_elem_id __user *_id)
839 struct snd_card *card = file->card;
840 struct snd_ctl_elem_id id;
841 struct snd_kcontrol *kctl;
842 struct snd_kcontrol_volatile *vd;
843 int result;
845 if (copy_from_user(&id, _id, sizeof(id)))
846 return -EFAULT;
847 down_write(&card->controls_rwsem);
848 kctl = snd_ctl_find_id(card, &id);
849 if (kctl == NULL) {
850 result = -ENOENT;
851 } else {
852 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
853 if (vd->owner == NULL)
854 result = -EINVAL;
855 else if (vd->owner != file)
856 result = -EPERM;
857 else {
858 vd->owner = NULL;
859 vd->owner_pid = 0;
860 result = 0;
863 up_write(&card->controls_rwsem);
864 return result;
867 struct user_element {
868 struct snd_ctl_elem_info info;
869 void *elem_data; /* element data */
870 unsigned long elem_data_size; /* size of element data in bytes */
871 void *tlv_data; /* TLV data */
872 unsigned long tlv_data_size; /* TLV data size */
873 void *priv_data; /* private data (like strings for enumerated type) */
874 unsigned long priv_data_size; /* size of private data in bytes */
877 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
878 struct snd_ctl_elem_info *uinfo)
880 struct user_element *ue = kcontrol->private_data;
882 *uinfo = ue->info;
883 return 0;
886 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
887 struct snd_ctl_elem_value *ucontrol)
889 struct user_element *ue = kcontrol->private_data;
891 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
892 return 0;
895 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
896 struct snd_ctl_elem_value *ucontrol)
898 int change;
899 struct user_element *ue = kcontrol->private_data;
901 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
902 if (change)
903 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
904 return change;
907 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
908 int op_flag,
909 unsigned int size,
910 unsigned int __user *tlv)
912 struct user_element *ue = kcontrol->private_data;
913 int change = 0;
914 void *new_data;
916 if (op_flag > 0) {
917 if (size > 1024 * 128) /* sane value */
918 return -EINVAL;
919 new_data = kmalloc(size, GFP_KERNEL);
920 if (new_data == NULL)
921 return -ENOMEM;
922 if (copy_from_user(new_data, tlv, size)) {
923 kfree(new_data);
924 return -EFAULT;
926 change = ue->tlv_data_size != size;
927 if (!change)
928 change = memcmp(ue->tlv_data, new_data, size);
929 kfree(ue->tlv_data);
930 ue->tlv_data = new_data;
931 ue->tlv_data_size = size;
932 } else {
933 if (! ue->tlv_data_size || ! ue->tlv_data)
934 return -ENXIO;
935 if (size < ue->tlv_data_size)
936 return -ENOSPC;
937 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
938 return -EFAULT;
940 return change;
943 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
945 struct user_element *ue = kcontrol->private_data;
946 if (ue->tlv_data)
947 kfree(ue->tlv_data);
948 kfree(ue);
951 static int snd_ctl_elem_add(struct snd_ctl_file *file,
952 struct snd_ctl_elem_info *info, int replace)
954 struct snd_card *card = file->card;
955 struct snd_kcontrol kctl, *_kctl;
956 unsigned int access;
957 long private_size;
958 struct user_element *ue;
959 int idx, err;
961 if (card->user_ctl_count >= MAX_USER_CONTROLS)
962 return -ENOMEM;
963 if (info->count > 1024)
964 return -EINVAL;
965 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
966 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
967 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
968 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
969 info->id.numid = 0;
970 memset(&kctl, 0, sizeof(kctl));
971 down_write(&card->controls_rwsem);
972 _kctl = snd_ctl_find_id(card, &info->id);
973 err = 0;
974 if (_kctl) {
975 if (replace)
976 err = snd_ctl_remove(card, _kctl);
977 else
978 err = -EBUSY;
979 } else {
980 if (replace)
981 err = -ENOENT;
983 up_write(&card->controls_rwsem);
984 if (err < 0)
985 return err;
986 memcpy(&kctl.id, &info->id, sizeof(info->id));
987 kctl.count = info->owner ? info->owner : 1;
988 access |= SNDRV_CTL_ELEM_ACCESS_USER;
989 kctl.info = snd_ctl_elem_user_info;
990 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
991 kctl.get = snd_ctl_elem_user_get;
992 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
993 kctl.put = snd_ctl_elem_user_put;
994 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
995 kctl.tlv.c = snd_ctl_elem_user_tlv;
996 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
998 switch (info->type) {
999 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1000 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1001 private_size = sizeof(long);
1002 if (info->count > 128)
1003 return -EINVAL;
1004 break;
1005 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1006 private_size = sizeof(long long);
1007 if (info->count > 64)
1008 return -EINVAL;
1009 break;
1010 case SNDRV_CTL_ELEM_TYPE_BYTES:
1011 private_size = sizeof(unsigned char);
1012 if (info->count > 512)
1013 return -EINVAL;
1014 break;
1015 case SNDRV_CTL_ELEM_TYPE_IEC958:
1016 private_size = sizeof(struct snd_aes_iec958);
1017 if (info->count != 1)
1018 return -EINVAL;
1019 break;
1020 default:
1021 return -EINVAL;
1023 private_size *= info->count;
1024 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1025 if (ue == NULL)
1026 return -ENOMEM;
1027 ue->info = *info;
1028 ue->info.access = 0;
1029 ue->elem_data = (char *)ue + sizeof(*ue);
1030 ue->elem_data_size = private_size;
1031 kctl.private_free = snd_ctl_elem_user_free;
1032 _kctl = snd_ctl_new(&kctl, access);
1033 if (_kctl == NULL) {
1034 kfree(ue);
1035 return -ENOMEM;
1037 _kctl->private_data = ue;
1038 for (idx = 0; idx < _kctl->count; idx++)
1039 _kctl->vd[idx].owner = file;
1040 err = snd_ctl_add(card, _kctl);
1041 if (err < 0)
1042 return err;
1044 down_write(&card->controls_rwsem);
1045 card->user_ctl_count++;
1046 up_write(&card->controls_rwsem);
1048 return 0;
1051 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1052 struct snd_ctl_elem_info __user *_info, int replace)
1054 struct snd_ctl_elem_info info;
1055 if (copy_from_user(&info, _info, sizeof(info)))
1056 return -EFAULT;
1057 return snd_ctl_elem_add(file, &info, replace);
1060 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1061 struct snd_ctl_elem_id __user *_id)
1063 struct snd_ctl_elem_id id;
1064 int err;
1066 if (copy_from_user(&id, _id, sizeof(id)))
1067 return -EFAULT;
1068 err = snd_ctl_remove_unlocked_id(file, &id);
1069 if (! err) {
1070 struct snd_card *card = file->card;
1071 down_write(&card->controls_rwsem);
1072 card->user_ctl_count--;
1073 up_write(&card->controls_rwsem);
1075 return err;
1078 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1080 int subscribe;
1081 if (get_user(subscribe, ptr))
1082 return -EFAULT;
1083 if (subscribe < 0) {
1084 subscribe = file->subscribed;
1085 if (put_user(subscribe, ptr))
1086 return -EFAULT;
1087 return 0;
1089 if (subscribe) {
1090 file->subscribed = 1;
1091 return 0;
1092 } else if (file->subscribed) {
1093 snd_ctl_empty_read_queue(file);
1094 file->subscribed = 0;
1096 return 0;
1099 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1100 struct snd_ctl_tlv __user *_tlv,
1101 int op_flag)
1103 struct snd_card *card = file->card;
1104 struct snd_ctl_tlv tlv;
1105 struct snd_kcontrol *kctl;
1106 struct snd_kcontrol_volatile *vd;
1107 unsigned int len;
1108 int err = 0;
1110 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1111 return -EFAULT;
1112 if (tlv.length < sizeof(unsigned int) * 3)
1113 return -EINVAL;
1114 down_read(&card->controls_rwsem);
1115 kctl = snd_ctl_find_numid(card, tlv.numid);
1116 if (kctl == NULL) {
1117 err = -ENOENT;
1118 goto __kctl_end;
1120 if (kctl->tlv.p == NULL) {
1121 err = -ENXIO;
1122 goto __kctl_end;
1124 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1125 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1126 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1127 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1128 err = -ENXIO;
1129 goto __kctl_end;
1131 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1132 if (file && vd->owner != NULL && vd->owner != file) {
1133 err = -EPERM;
1134 goto __kctl_end;
1136 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1137 if (err > 0) {
1138 up_read(&card->controls_rwsem);
1139 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1140 return 0;
1142 } else {
1143 if (op_flag) {
1144 err = -ENXIO;
1145 goto __kctl_end;
1147 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1148 if (tlv.length < len) {
1149 err = -ENOMEM;
1150 goto __kctl_end;
1152 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1153 err = -EFAULT;
1155 __kctl_end:
1156 up_read(&card->controls_rwsem);
1157 return err;
1160 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1162 struct snd_ctl_file *ctl;
1163 struct snd_card *card;
1164 struct snd_kctl_ioctl *p;
1165 void __user *argp = (void __user *)arg;
1166 int __user *ip = argp;
1167 int err;
1169 ctl = file->private_data;
1170 card = ctl->card;
1171 if (snd_BUG_ON(!card))
1172 return -ENXIO;
1173 switch (cmd) {
1174 case SNDRV_CTL_IOCTL_PVERSION:
1175 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1176 case SNDRV_CTL_IOCTL_CARD_INFO:
1177 return snd_ctl_card_info(card, ctl, cmd, argp);
1178 case SNDRV_CTL_IOCTL_ELEM_LIST:
1179 return snd_ctl_elem_list(card, argp);
1180 case SNDRV_CTL_IOCTL_ELEM_INFO:
1181 return snd_ctl_elem_info_user(ctl, argp);
1182 case SNDRV_CTL_IOCTL_ELEM_READ:
1183 return snd_ctl_elem_read_user(card, argp);
1184 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1185 return snd_ctl_elem_write_user(ctl, argp);
1186 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1187 return snd_ctl_elem_lock(ctl, argp);
1188 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1189 return snd_ctl_elem_unlock(ctl, argp);
1190 case SNDRV_CTL_IOCTL_ELEM_ADD:
1191 return snd_ctl_elem_add_user(ctl, argp, 0);
1192 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1193 return snd_ctl_elem_add_user(ctl, argp, 1);
1194 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1195 return snd_ctl_elem_remove(ctl, argp);
1196 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1197 return snd_ctl_subscribe_events(ctl, ip);
1198 case SNDRV_CTL_IOCTL_TLV_READ:
1199 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1200 case SNDRV_CTL_IOCTL_TLV_WRITE:
1201 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1202 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1203 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1204 case SNDRV_CTL_IOCTL_POWER:
1205 return -ENOPROTOOPT;
1206 case SNDRV_CTL_IOCTL_POWER_STATE:
1207 #ifdef CONFIG_PM
1208 return put_user(card->power_state, ip) ? -EFAULT : 0;
1209 #else
1210 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1211 #endif
1213 down_read(&snd_ioctl_rwsem);
1214 list_for_each_entry(p, &snd_control_ioctls, list) {
1215 err = p->fioctl(card, ctl, cmd, arg);
1216 if (err != -ENOIOCTLCMD) {
1217 up_read(&snd_ioctl_rwsem);
1218 return err;
1221 up_read(&snd_ioctl_rwsem);
1222 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1223 return -ENOTTY;
1226 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1227 size_t count, loff_t * offset)
1229 struct snd_ctl_file *ctl;
1230 int err = 0;
1231 ssize_t result = 0;
1233 ctl = file->private_data;
1234 if (snd_BUG_ON(!ctl || !ctl->card))
1235 return -ENXIO;
1236 if (!ctl->subscribed)
1237 return -EBADFD;
1238 if (count < sizeof(struct snd_ctl_event))
1239 return -EINVAL;
1240 spin_lock_irq(&ctl->read_lock);
1241 while (count >= sizeof(struct snd_ctl_event)) {
1242 struct snd_ctl_event ev;
1243 struct snd_kctl_event *kev;
1244 while (list_empty(&ctl->events)) {
1245 wait_queue_t wait;
1246 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1247 err = -EAGAIN;
1248 goto __end_lock;
1250 init_waitqueue_entry(&wait, current);
1251 add_wait_queue(&ctl->change_sleep, &wait);
1252 set_current_state(TASK_INTERRUPTIBLE);
1253 spin_unlock_irq(&ctl->read_lock);
1254 schedule();
1255 remove_wait_queue(&ctl->change_sleep, &wait);
1256 if (signal_pending(current))
1257 return -ERESTARTSYS;
1258 spin_lock_irq(&ctl->read_lock);
1260 kev = snd_kctl_event(ctl->events.next);
1261 ev.type = SNDRV_CTL_EVENT_ELEM;
1262 ev.data.elem.mask = kev->mask;
1263 ev.data.elem.id = kev->id;
1264 list_del(&kev->list);
1265 spin_unlock_irq(&ctl->read_lock);
1266 kfree(kev);
1267 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1268 err = -EFAULT;
1269 goto __end;
1271 spin_lock_irq(&ctl->read_lock);
1272 buffer += sizeof(struct snd_ctl_event);
1273 count -= sizeof(struct snd_ctl_event);
1274 result += sizeof(struct snd_ctl_event);
1276 __end_lock:
1277 spin_unlock_irq(&ctl->read_lock);
1278 __end:
1279 return result > 0 ? result : err;
1282 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1284 unsigned int mask;
1285 struct snd_ctl_file *ctl;
1287 ctl = file->private_data;
1288 if (!ctl->subscribed)
1289 return 0;
1290 poll_wait(file, &ctl->change_sleep, wait);
1292 mask = 0;
1293 if (!list_empty(&ctl->events))
1294 mask |= POLLIN | POLLRDNORM;
1296 return mask;
1300 * register the device-specific control-ioctls.
1301 * called from each device manager like pcm.c, hwdep.c, etc.
1303 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1305 struct snd_kctl_ioctl *pn;
1307 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1308 if (pn == NULL)
1309 return -ENOMEM;
1310 pn->fioctl = fcn;
1311 down_write(&snd_ioctl_rwsem);
1312 list_add_tail(&pn->list, lists);
1313 up_write(&snd_ioctl_rwsem);
1314 return 0;
1317 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1319 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1322 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1324 #ifdef CONFIG_COMPAT
1325 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1327 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1330 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1331 #endif
1334 * de-register the device-specific control-ioctls.
1336 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1337 struct list_head *lists)
1339 struct snd_kctl_ioctl *p;
1341 if (snd_BUG_ON(!fcn))
1342 return -EINVAL;
1343 down_write(&snd_ioctl_rwsem);
1344 list_for_each_entry(p, lists, list) {
1345 if (p->fioctl == fcn) {
1346 list_del(&p->list);
1347 up_write(&snd_ioctl_rwsem);
1348 kfree(p);
1349 return 0;
1352 up_write(&snd_ioctl_rwsem);
1353 snd_BUG();
1354 return -EINVAL;
1357 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1359 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1362 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1364 #ifdef CONFIG_COMPAT
1365 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1367 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1370 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1371 #endif
1373 static int snd_ctl_fasync(int fd, struct file * file, int on)
1375 struct snd_ctl_file *ctl;
1376 int err;
1377 ctl = file->private_data;
1378 err = fasync_helper(fd, file, on, &ctl->fasync);
1379 if (err < 0)
1380 return err;
1381 return 0;
1385 * ioctl32 compat
1387 #ifdef CONFIG_COMPAT
1388 #include "control_compat.c"
1389 #else
1390 #define snd_ctl_ioctl_compat NULL
1391 #endif
1394 * INIT PART
1397 static const struct file_operations snd_ctl_f_ops =
1399 .owner = THIS_MODULE,
1400 .read = snd_ctl_read,
1401 .open = snd_ctl_open,
1402 .release = snd_ctl_release,
1403 .poll = snd_ctl_poll,
1404 .unlocked_ioctl = snd_ctl_ioctl,
1405 .compat_ioctl = snd_ctl_ioctl_compat,
1406 .fasync = snd_ctl_fasync,
1410 * registration of the control device
1412 static int snd_ctl_dev_register(struct snd_device *device)
1414 struct snd_card *card = device->device_data;
1415 int err, cardnum;
1416 char name[16];
1418 if (snd_BUG_ON(!card))
1419 return -ENXIO;
1420 cardnum = card->number;
1421 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1422 return -ENXIO;
1423 sprintf(name, "controlC%i", cardnum);
1424 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1425 &snd_ctl_f_ops, card, name)) < 0)
1426 return err;
1427 return 0;
1431 * disconnection of the control device
1433 static int snd_ctl_dev_disconnect(struct snd_device *device)
1435 struct snd_card *card = device->device_data;
1436 struct snd_ctl_file *ctl;
1437 int err, cardnum;
1439 if (snd_BUG_ON(!card))
1440 return -ENXIO;
1441 cardnum = card->number;
1442 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1443 return -ENXIO;
1445 read_lock(&card->ctl_files_rwlock);
1446 list_for_each_entry(ctl, &card->ctl_files, list) {
1447 wake_up(&ctl->change_sleep);
1448 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1450 read_unlock(&card->ctl_files_rwlock);
1452 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1453 card, -1)) < 0)
1454 return err;
1455 return 0;
1459 * free all controls
1461 static int snd_ctl_dev_free(struct snd_device *device)
1463 struct snd_card *card = device->device_data;
1464 struct snd_kcontrol *control;
1466 down_write(&card->controls_rwsem);
1467 while (!list_empty(&card->controls)) {
1468 control = snd_kcontrol(card->controls.next);
1469 snd_ctl_remove(card, control);
1471 up_write(&card->controls_rwsem);
1472 return 0;
1476 * create control core:
1477 * called from init.c
1479 int snd_ctl_create(struct snd_card *card)
1481 static struct snd_device_ops ops = {
1482 .dev_free = snd_ctl_dev_free,
1483 .dev_register = snd_ctl_dev_register,
1484 .dev_disconnect = snd_ctl_dev_disconnect,
1487 if (snd_BUG_ON(!card))
1488 return -ENXIO;
1489 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1493 * Frequently used control callbacks
1495 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1496 struct snd_ctl_elem_info *uinfo)
1498 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1499 uinfo->count = 1;
1500 uinfo->value.integer.min = 0;
1501 uinfo->value.integer.max = 1;
1502 return 0;
1505 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1507 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1508 struct snd_ctl_elem_info *uinfo)
1510 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1511 uinfo->count = 2;
1512 uinfo->value.integer.min = 0;
1513 uinfo->value.integer.max = 1;
1514 return 0;
1517 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);