fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / sound / core / control.c
blob4c3aa8e10378bd306763dba42f16b6b9a564ebd5
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 <sound/driver.h>
23 #include <linux/threads.h>
24 #include <linux/interrupt.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
36 struct snd_kctl_ioctl {
37 struct list_head list; /* list of all ioctls */
38 snd_kctl_ioctl_func_t fioctl;
41 static DECLARE_RWSEM(snd_ioctl_rwsem);
42 static LIST_HEAD(snd_control_ioctls);
43 #ifdef CONFIG_COMPAT
44 static LIST_HEAD(snd_control_compat_ioctls);
45 #endif
47 static int snd_ctl_open(struct inode *inode, struct file *file)
49 unsigned long flags;
50 struct snd_card *card;
51 struct snd_ctl_file *ctl;
52 int err;
54 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
55 if (!card) {
56 err = -ENODEV;
57 goto __error1;
59 err = snd_card_file_add(card, file);
60 if (err < 0) {
61 err = -ENODEV;
62 goto __error1;
64 if (!try_module_get(card->module)) {
65 err = -EFAULT;
66 goto __error2;
68 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
69 if (ctl == NULL) {
70 err = -ENOMEM;
71 goto __error;
73 INIT_LIST_HEAD(&ctl->events);
74 init_waitqueue_head(&ctl->change_sleep);
75 spin_lock_init(&ctl->read_lock);
76 ctl->card = card;
77 ctl->prefer_pcm_subdevice = -1;
78 ctl->prefer_rawmidi_subdevice = -1;
79 ctl->pid = current->pid;
80 file->private_data = ctl;
81 write_lock_irqsave(&card->ctl_files_rwlock, flags);
82 list_add_tail(&ctl->list, &card->ctl_files);
83 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
84 return 0;
86 __error:
87 module_put(card->module);
88 __error2:
89 snd_card_file_remove(card, file);
90 __error1:
91 return err;
94 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
96 struct snd_kctl_event *cread;
98 spin_lock(&ctl->read_lock);
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(&ctl->read_lock);
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 fasync_helper(-1, file, 0, &ctl->fasync);
117 file->private_data = NULL;
118 card = ctl->card;
119 write_lock_irqsave(&card->ctl_files_rwlock, flags);
120 list_del(&ctl->list);
121 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
122 down_write(&card->controls_rwsem);
123 list_for_each_entry(control, &card->controls, list)
124 for (idx = 0; idx < control->count; idx++)
125 if (control->vd[idx].owner == ctl)
126 control->vd[idx].owner = NULL;
127 up_write(&card->controls_rwsem);
128 snd_ctl_empty_read_queue(ctl);
129 kfree(ctl);
130 module_put(card->module);
131 snd_card_file_remove(card, file);
132 return 0;
135 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
136 struct snd_ctl_elem_id *id)
138 unsigned long flags;
139 struct snd_ctl_file *ctl;
140 struct snd_kctl_event *ev;
142 snd_assert(card != NULL && id != NULL, 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 snd_assert(control != NULL, return NULL);
192 snd_assert(control->count > 0, 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 snd_assert(ncontrol != NULL, return NULL);
222 snd_assert(ncontrol->info != NULL, 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 kctl.id.index = ncontrol->index;
230 kctl.count = ncontrol->count ? ncontrol->count : 1;
231 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
232 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
233 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
234 SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
235 SNDRV_CTL_ELEM_ACCESS_INDIRECT|
236 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
237 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
238 kctl.info = ncontrol->info;
239 kctl.get = ncontrol->get;
240 kctl.put = ncontrol->put;
241 kctl.tlv.p = ncontrol->tlv.p;
242 kctl.private_value = ncontrol->private_value;
243 kctl.private_data = private_data;
244 return snd_ctl_new(&kctl, access);
247 EXPORT_SYMBOL(snd_ctl_new1);
250 * snd_ctl_free_one - release the control instance
251 * @kcontrol: the control instance
253 * Releases the control instance created via snd_ctl_new()
254 * or snd_ctl_new1().
255 * Don't call this after the control was added to the card.
257 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
259 if (kcontrol) {
260 if (kcontrol->private_free)
261 kcontrol->private_free(kcontrol);
262 kfree(kcontrol);
266 EXPORT_SYMBOL(snd_ctl_free_one);
268 static unsigned int snd_ctl_hole_check(struct snd_card *card,
269 unsigned int count)
271 struct snd_kcontrol *kctl;
273 list_for_each_entry(kctl, &card->controls, list) {
274 if ((kctl->id.numid <= card->last_numid &&
275 kctl->id.numid + kctl->count > card->last_numid) ||
276 (kctl->id.numid <= card->last_numid + count - 1 &&
277 kctl->id.numid + kctl->count > card->last_numid + count - 1))
278 return card->last_numid = kctl->id.numid + kctl->count - 1;
280 return card->last_numid;
283 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
285 unsigned int last_numid, iter = 100000;
287 last_numid = card->last_numid;
288 while (last_numid != snd_ctl_hole_check(card, count)) {
289 if (--iter == 0) {
290 /* this situation is very unlikely */
291 snd_printk(KERN_ERR "unable to allocate new control numid\n");
292 return -ENOMEM;
294 last_numid = card->last_numid;
296 return 0;
300 * snd_ctl_add - add the control instance to the card
301 * @card: the card instance
302 * @kcontrol: the control instance to add
304 * Adds the control instance created via snd_ctl_new() or
305 * snd_ctl_new1() to the given card. Assigns also an unique
306 * numid used for fast search.
308 * Returns zero if successful, or a negative error code on failure.
310 * It frees automatically the control which cannot be added.
312 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
314 struct snd_ctl_elem_id id;
315 unsigned int idx;
316 int err = -EINVAL;
318 if (! kcontrol)
319 return err;
320 snd_assert(card != NULL, goto error);
321 snd_assert(kcontrol->info != NULL, goto error);
322 id = kcontrol->id;
323 down_write(&card->controls_rwsem);
324 if (snd_ctl_find_id(card, &id)) {
325 up_write(&card->controls_rwsem);
326 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
327 id.iface,
328 id.device,
329 id.subdevice,
330 id.name,
331 id.index);
332 err = -EBUSY;
333 goto error;
335 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
336 up_write(&card->controls_rwsem);
337 err = -ENOMEM;
338 goto error;
340 list_add_tail(&kcontrol->list, &card->controls);
341 card->controls_count += kcontrol->count;
342 kcontrol->id.numid = card->last_numid + 1;
343 card->last_numid += kcontrol->count;
344 up_write(&card->controls_rwsem);
345 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
346 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
347 return 0;
349 error:
350 snd_ctl_free_one(kcontrol);
351 return err;
354 EXPORT_SYMBOL(snd_ctl_add);
357 * snd_ctl_remove - remove the control from the card and release it
358 * @card: the card instance
359 * @kcontrol: the control instance to remove
361 * Removes the control from the card and then releases the instance.
362 * You don't need to call snd_ctl_free_one(). You must be in
363 * the write lock - down_write(&card->controls_rwsem).
365 * Returns 0 if successful, or a negative error code on failure.
367 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
369 struct snd_ctl_elem_id id;
370 unsigned int idx;
372 snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
373 list_del(&kcontrol->list);
374 card->controls_count -= kcontrol->count;
375 id = kcontrol->id;
376 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
377 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
378 snd_ctl_free_one(kcontrol);
379 return 0;
382 EXPORT_SYMBOL(snd_ctl_remove);
385 * snd_ctl_remove_id - remove the control of the given id and release it
386 * @card: the card instance
387 * @id: the control id to remove
389 * Finds the control instance with the given id, removes it from the
390 * card list and releases it.
392 * Returns 0 if successful, or a negative error code on failure.
394 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
396 struct snd_kcontrol *kctl;
397 int ret;
399 down_write(&card->controls_rwsem);
400 kctl = snd_ctl_find_id(card, id);
401 if (kctl == NULL) {
402 up_write(&card->controls_rwsem);
403 return -ENOENT;
405 ret = snd_ctl_remove(card, kctl);
406 up_write(&card->controls_rwsem);
407 return ret;
410 EXPORT_SYMBOL(snd_ctl_remove_id);
413 * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
414 * @file: active control handle
415 * @id: the control id to remove
417 * Finds the control instance with the given id, removes it from the
418 * card list and releases it.
420 * Returns 0 if successful, or a negative error code on failure.
422 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
423 struct snd_ctl_elem_id *id)
425 struct snd_card *card = file->card;
426 struct snd_kcontrol *kctl;
427 int idx, ret;
429 down_write(&card->controls_rwsem);
430 kctl = snd_ctl_find_id(card, id);
431 if (kctl == NULL) {
432 up_write(&card->controls_rwsem);
433 return -ENOENT;
435 for (idx = 0; idx < kctl->count; idx++)
436 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
437 up_write(&card->controls_rwsem);
438 return -EBUSY;
440 ret = snd_ctl_remove(card, kctl);
441 up_write(&card->controls_rwsem);
442 return ret;
446 * snd_ctl_rename_id - replace the id of a control on the card
447 * @card: the card instance
448 * @src_id: the old id
449 * @dst_id: the new id
451 * Finds the control with the old id from the card, and replaces the
452 * id with the new one.
454 * Returns zero if successful, or a negative error code on failure.
456 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
457 struct snd_ctl_elem_id *dst_id)
459 struct snd_kcontrol *kctl;
461 down_write(&card->controls_rwsem);
462 kctl = snd_ctl_find_id(card, src_id);
463 if (kctl == NULL) {
464 up_write(&card->controls_rwsem);
465 return -ENOENT;
467 kctl->id = *dst_id;
468 kctl->id.numid = card->last_numid + 1;
469 card->last_numid += kctl->count;
470 up_write(&card->controls_rwsem);
471 return 0;
474 EXPORT_SYMBOL(snd_ctl_rename_id);
477 * snd_ctl_find_numid - find the control instance with the given number-id
478 * @card: the card instance
479 * @numid: the number-id to search
481 * Finds the control instance with the given number-id from the card.
483 * Returns the pointer of the instance if found, or NULL if not.
485 * The caller must down card->controls_rwsem before calling this function
486 * (if the race condition can happen).
488 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
490 struct snd_kcontrol *kctl;
492 snd_assert(card != NULL && numid != 0, return NULL);
493 list_for_each_entry(kctl, &card->controls, list) {
494 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
495 return kctl;
497 return NULL;
500 EXPORT_SYMBOL(snd_ctl_find_numid);
503 * snd_ctl_find_id - find the control instance with the given id
504 * @card: the card instance
505 * @id: the id to search
507 * Finds the control instance with the given id from the card.
509 * Returns the pointer of the instance if found, or NULL if not.
511 * The caller must down card->controls_rwsem before calling this function
512 * (if the race condition can happen).
514 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
515 struct snd_ctl_elem_id *id)
517 struct snd_kcontrol *kctl;
519 snd_assert(card != NULL && id != NULL, return NULL);
520 if (id->numid != 0)
521 return snd_ctl_find_numid(card, id->numid);
522 list_for_each_entry(kctl, &card->controls, list) {
523 if (kctl->id.iface != id->iface)
524 continue;
525 if (kctl->id.device != id->device)
526 continue;
527 if (kctl->id.subdevice != id->subdevice)
528 continue;
529 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
530 continue;
531 if (kctl->id.index > id->index)
532 continue;
533 if (kctl->id.index + kctl->count <= id->index)
534 continue;
535 return kctl;
537 return NULL;
540 EXPORT_SYMBOL(snd_ctl_find_id);
542 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
543 unsigned int cmd, void __user *arg)
545 struct snd_ctl_card_info *info;
547 info = kzalloc(sizeof(*info), GFP_KERNEL);
548 if (! info)
549 return -ENOMEM;
550 down_read(&snd_ioctl_rwsem);
551 info->card = card->number;
552 strlcpy(info->id, card->id, sizeof(info->id));
553 strlcpy(info->driver, card->driver, sizeof(info->driver));
554 strlcpy(info->name, card->shortname, sizeof(info->name));
555 strlcpy(info->longname, card->longname, sizeof(info->longname));
556 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
557 strlcpy(info->components, card->components, sizeof(info->components));
558 up_read(&snd_ioctl_rwsem);
559 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
560 kfree(info);
561 return -EFAULT;
563 kfree(info);
564 return 0;
567 static int snd_ctl_elem_list(struct snd_card *card,
568 struct snd_ctl_elem_list __user *_list)
570 struct list_head *plist;
571 struct snd_ctl_elem_list list;
572 struct snd_kcontrol *kctl;
573 struct snd_ctl_elem_id *dst, *id;
574 unsigned int offset, space, first, jidx;
576 if (copy_from_user(&list, _list, sizeof(list)))
577 return -EFAULT;
578 offset = list.offset;
579 space = list.space;
580 first = 0;
581 /* try limit maximum space */
582 if (space > 16384)
583 return -ENOMEM;
584 if (space > 0) {
585 /* allocate temporary buffer for atomic operation */
586 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
587 if (dst == NULL)
588 return -ENOMEM;
589 down_read(&card->controls_rwsem);
590 list.count = card->controls_count;
591 plist = card->controls.next;
592 while (plist != &card->controls) {
593 if (offset == 0)
594 break;
595 kctl = snd_kcontrol(plist);
596 if (offset < kctl->count)
597 break;
598 offset -= kctl->count;
599 plist = plist->next;
601 list.used = 0;
602 id = dst;
603 while (space > 0 && plist != &card->controls) {
604 kctl = snd_kcontrol(plist);
605 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
606 snd_ctl_build_ioff(id, kctl, jidx);
607 id++;
608 space--;
609 list.used++;
611 plist = plist->next;
612 offset = 0;
614 up_read(&card->controls_rwsem);
615 if (list.used > 0 &&
616 copy_to_user(list.pids, dst,
617 list.used * sizeof(struct snd_ctl_elem_id))) {
618 vfree(dst);
619 return -EFAULT;
621 vfree(dst);
622 } else {
623 down_read(&card->controls_rwsem);
624 list.count = card->controls_count;
625 up_read(&card->controls_rwsem);
627 if (copy_to_user(_list, &list, sizeof(list)))
628 return -EFAULT;
629 return 0;
632 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
633 struct snd_ctl_elem_info *info)
635 struct snd_card *card = ctl->card;
636 struct snd_kcontrol *kctl;
637 struct snd_kcontrol_volatile *vd;
638 unsigned int index_offset;
639 int result;
641 down_read(&card->controls_rwsem);
642 kctl = snd_ctl_find_id(card, &info->id);
643 if (kctl == NULL) {
644 up_read(&card->controls_rwsem);
645 return -ENOENT;
647 #ifdef CONFIG_SND_DEBUG
648 info->access = 0;
649 #endif
650 result = kctl->info(kctl, info);
651 if (result >= 0) {
652 snd_assert(info->access == 0, );
653 index_offset = snd_ctl_get_ioff(kctl, &info->id);
654 vd = &kctl->vd[index_offset];
655 snd_ctl_build_ioff(&info->id, kctl, index_offset);
656 info->access = vd->access;
657 if (vd->owner) {
658 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
659 if (vd->owner == ctl)
660 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
661 info->owner = vd->owner_pid;
662 } else {
663 info->owner = -1;
666 up_read(&card->controls_rwsem);
667 return result;
670 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
671 struct snd_ctl_elem_info __user *_info)
673 struct snd_ctl_elem_info info;
674 int result;
676 if (copy_from_user(&info, _info, sizeof(info)))
677 return -EFAULT;
678 snd_power_lock(ctl->card);
679 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
680 if (result >= 0)
681 result = snd_ctl_elem_info(ctl, &info);
682 snd_power_unlock(ctl->card);
683 if (result >= 0)
684 if (copy_to_user(_info, &info, sizeof(info)))
685 return -EFAULT;
686 return result;
689 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
691 struct snd_kcontrol *kctl;
692 struct snd_kcontrol_volatile *vd;
693 unsigned int index_offset;
694 int result, indirect;
696 down_read(&card->controls_rwsem);
697 kctl = snd_ctl_find_id(card, &control->id);
698 if (kctl == NULL) {
699 result = -ENOENT;
700 } else {
701 index_offset = snd_ctl_get_ioff(kctl, &control->id);
702 vd = &kctl->vd[index_offset];
703 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
704 if (control->indirect != indirect) {
705 result = -EACCES;
706 } else {
707 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
708 snd_ctl_build_ioff(&control->id, kctl, index_offset);
709 result = kctl->get(kctl, control);
710 } else {
711 result = -EPERM;
715 up_read(&card->controls_rwsem);
716 return result;
719 static int snd_ctl_elem_read_user(struct snd_card *card,
720 struct snd_ctl_elem_value __user *_control)
722 struct snd_ctl_elem_value *control;
723 int result;
725 control = kmalloc(sizeof(*control), GFP_KERNEL);
726 if (control == NULL)
727 return -ENOMEM;
728 if (copy_from_user(control, _control, sizeof(*control))) {
729 kfree(control);
730 return -EFAULT;
732 snd_power_lock(card);
733 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
734 if (result >= 0)
735 result = snd_ctl_elem_read(card, control);
736 snd_power_unlock(card);
737 if (result >= 0)
738 if (copy_to_user(_control, control, sizeof(*control)))
739 result = -EFAULT;
740 kfree(control);
741 return result;
744 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
745 struct snd_ctl_elem_value *control)
747 struct snd_kcontrol *kctl;
748 struct snd_kcontrol_volatile *vd;
749 unsigned int index_offset;
750 int result, indirect;
752 down_read(&card->controls_rwsem);
753 kctl = snd_ctl_find_id(card, &control->id);
754 if (kctl == NULL) {
755 result = -ENOENT;
756 } else {
757 index_offset = snd_ctl_get_ioff(kctl, &control->id);
758 vd = &kctl->vd[index_offset];
759 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
760 if (control->indirect != indirect) {
761 result = -EACCES;
762 } else {
763 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
764 kctl->put == NULL ||
765 (file && vd->owner != NULL && vd->owner != file)) {
766 result = -EPERM;
767 } else {
768 snd_ctl_build_ioff(&control->id, kctl, index_offset);
769 result = kctl->put(kctl, control);
771 if (result > 0) {
772 up_read(&card->controls_rwsem);
773 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
774 return 0;
778 up_read(&card->controls_rwsem);
779 return result;
782 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
783 struct snd_ctl_elem_value __user *_control)
785 struct snd_ctl_elem_value *control;
786 struct snd_card *card;
787 int result;
789 control = kmalloc(sizeof(*control), GFP_KERNEL);
790 if (control == NULL)
791 return -ENOMEM;
792 if (copy_from_user(control, _control, sizeof(*control))) {
793 kfree(control);
794 return -EFAULT;
796 card = file->card;
797 snd_power_lock(card);
798 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
799 if (result >= 0)
800 result = snd_ctl_elem_write(card, file, control);
801 snd_power_unlock(card);
802 if (result >= 0)
803 if (copy_to_user(_control, control, sizeof(*control)))
804 result = -EFAULT;
805 kfree(control);
806 return result;
809 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
810 struct snd_ctl_elem_id __user *_id)
812 struct snd_card *card = file->card;
813 struct snd_ctl_elem_id id;
814 struct snd_kcontrol *kctl;
815 struct snd_kcontrol_volatile *vd;
816 int result;
818 if (copy_from_user(&id, _id, sizeof(id)))
819 return -EFAULT;
820 down_write(&card->controls_rwsem);
821 kctl = snd_ctl_find_id(card, &id);
822 if (kctl == NULL) {
823 result = -ENOENT;
824 } else {
825 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
826 if (vd->owner != NULL)
827 result = -EBUSY;
828 else {
829 vd->owner = file;
830 vd->owner_pid = current->pid;
831 result = 0;
834 up_write(&card->controls_rwsem);
835 return result;
838 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
839 struct snd_ctl_elem_id __user *_id)
841 struct snd_card *card = file->card;
842 struct snd_ctl_elem_id id;
843 struct snd_kcontrol *kctl;
844 struct snd_kcontrol_volatile *vd;
845 int result;
847 if (copy_from_user(&id, _id, sizeof(id)))
848 return -EFAULT;
849 down_write(&card->controls_rwsem);
850 kctl = snd_ctl_find_id(card, &id);
851 if (kctl == NULL) {
852 result = -ENOENT;
853 } else {
854 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
855 if (vd->owner == NULL)
856 result = -EINVAL;
857 else if (vd->owner != file)
858 result = -EPERM;
859 else {
860 vd->owner = NULL;
861 vd->owner_pid = 0;
862 result = 0;
865 up_write(&card->controls_rwsem);
866 return result;
869 struct user_element {
870 struct snd_ctl_elem_info info;
871 void *elem_data; /* element data */
872 unsigned long elem_data_size; /* size of element data in bytes */
873 void *tlv_data; /* TLV data */
874 unsigned long tlv_data_size; /* TLV data size */
875 void *priv_data; /* private data (like strings for enumerated type) */
876 unsigned long priv_data_size; /* size of private data in bytes */
879 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
880 struct snd_ctl_elem_info *uinfo)
882 struct user_element *ue = kcontrol->private_data;
884 *uinfo = ue->info;
885 return 0;
888 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
889 struct snd_ctl_elem_value *ucontrol)
891 struct user_element *ue = kcontrol->private_data;
893 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
894 return 0;
897 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
898 struct snd_ctl_elem_value *ucontrol)
900 int change;
901 struct user_element *ue = kcontrol->private_data;
903 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
904 if (change)
905 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
906 return change;
909 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
910 int op_flag,
911 unsigned int size,
912 unsigned int __user *tlv)
914 struct user_element *ue = kcontrol->private_data;
915 int change = 0;
916 void *new_data;
918 if (op_flag > 0) {
919 if (size > 1024 * 128) /* sane value */
920 return -EINVAL;
921 new_data = kmalloc(size, GFP_KERNEL);
922 if (new_data == NULL)
923 return -ENOMEM;
924 if (copy_from_user(new_data, tlv, size)) {
925 kfree(new_data);
926 return -EFAULT;
928 change = ue->tlv_data_size != size;
929 if (!change)
930 change = memcmp(ue->tlv_data, new_data, size);
931 kfree(ue->tlv_data);
932 ue->tlv_data = new_data;
933 ue->tlv_data_size = size;
934 } else {
935 if (! ue->tlv_data_size || ! ue->tlv_data)
936 return -ENXIO;
937 if (size < ue->tlv_data_size)
938 return -ENOSPC;
939 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
940 return -EFAULT;
942 return change;
945 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
947 struct user_element *ue = kcontrol->private_data;
948 if (ue->tlv_data)
949 kfree(ue->tlv_data);
950 kfree(ue);
953 static int snd_ctl_elem_add(struct snd_ctl_file *file,
954 struct snd_ctl_elem_info *info, int replace)
956 struct snd_card *card = file->card;
957 struct snd_kcontrol kctl, *_kctl;
958 unsigned int access;
959 long private_size;
960 struct user_element *ue;
961 int idx, err;
963 if (card->user_ctl_count >= MAX_USER_CONTROLS)
964 return -ENOMEM;
965 if (info->count > 1024)
966 return -EINVAL;
967 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
968 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
969 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
970 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
971 info->id.numid = 0;
972 memset(&kctl, 0, sizeof(kctl));
973 down_write(&card->controls_rwsem);
974 _kctl = snd_ctl_find_id(card, &info->id);
975 err = 0;
976 if (_kctl) {
977 if (replace)
978 err = snd_ctl_remove(card, _kctl);
979 else
980 err = -EBUSY;
981 } else {
982 if (replace)
983 err = -ENOENT;
985 up_write(&card->controls_rwsem);
986 if (err < 0)
987 return err;
988 memcpy(&kctl.id, &info->id, sizeof(info->id));
989 kctl.count = info->owner ? info->owner : 1;
990 access |= SNDRV_CTL_ELEM_ACCESS_USER;
991 kctl.info = snd_ctl_elem_user_info;
992 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
993 kctl.get = snd_ctl_elem_user_get;
994 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
995 kctl.put = snd_ctl_elem_user_put;
996 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
997 kctl.tlv.c = snd_ctl_elem_user_tlv;
998 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1000 switch (info->type) {
1001 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1002 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1003 private_size = sizeof(long);
1004 if (info->count > 128)
1005 return -EINVAL;
1006 break;
1007 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1008 private_size = sizeof(long long);
1009 if (info->count > 64)
1010 return -EINVAL;
1011 break;
1012 case SNDRV_CTL_ELEM_TYPE_BYTES:
1013 private_size = sizeof(unsigned char);
1014 if (info->count > 512)
1015 return -EINVAL;
1016 break;
1017 case SNDRV_CTL_ELEM_TYPE_IEC958:
1018 private_size = sizeof(struct snd_aes_iec958);
1019 if (info->count != 1)
1020 return -EINVAL;
1021 break;
1022 default:
1023 return -EINVAL;
1025 private_size *= info->count;
1026 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1027 if (ue == NULL)
1028 return -ENOMEM;
1029 ue->info = *info;
1030 ue->info.access = 0;
1031 ue->elem_data = (char *)ue + sizeof(*ue);
1032 ue->elem_data_size = private_size;
1033 kctl.private_free = snd_ctl_elem_user_free;
1034 _kctl = snd_ctl_new(&kctl, access);
1035 if (_kctl == NULL) {
1036 kfree(ue);
1037 return -ENOMEM;
1039 _kctl->private_data = ue;
1040 for (idx = 0; idx < _kctl->count; idx++)
1041 _kctl->vd[idx].owner = file;
1042 err = snd_ctl_add(card, _kctl);
1043 if (err < 0)
1044 return err;
1046 down_write(&card->controls_rwsem);
1047 card->user_ctl_count++;
1048 up_write(&card->controls_rwsem);
1050 return 0;
1053 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1054 struct snd_ctl_elem_info __user *_info, int replace)
1056 struct snd_ctl_elem_info info;
1057 if (copy_from_user(&info, _info, sizeof(info)))
1058 return -EFAULT;
1059 return snd_ctl_elem_add(file, &info, replace);
1062 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1063 struct snd_ctl_elem_id __user *_id)
1065 struct snd_ctl_elem_id id;
1066 int err;
1068 if (copy_from_user(&id, _id, sizeof(id)))
1069 return -EFAULT;
1070 err = snd_ctl_remove_unlocked_id(file, &id);
1071 if (! err) {
1072 struct snd_card *card = file->card;
1073 down_write(&card->controls_rwsem);
1074 card->user_ctl_count--;
1075 up_write(&card->controls_rwsem);
1077 return err;
1080 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1082 int subscribe;
1083 if (get_user(subscribe, ptr))
1084 return -EFAULT;
1085 if (subscribe < 0) {
1086 subscribe = file->subscribed;
1087 if (put_user(subscribe, ptr))
1088 return -EFAULT;
1089 return 0;
1091 if (subscribe) {
1092 file->subscribed = 1;
1093 return 0;
1094 } else if (file->subscribed) {
1095 snd_ctl_empty_read_queue(file);
1096 file->subscribed = 0;
1098 return 0;
1101 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1102 struct snd_ctl_tlv __user *_tlv,
1103 int op_flag)
1105 struct snd_card *card = file->card;
1106 struct snd_ctl_tlv tlv;
1107 struct snd_kcontrol *kctl;
1108 struct snd_kcontrol_volatile *vd;
1109 unsigned int len;
1110 int err = 0;
1112 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1113 return -EFAULT;
1114 if (tlv.length < sizeof(unsigned int) * 3)
1115 return -EINVAL;
1116 down_read(&card->controls_rwsem);
1117 kctl = snd_ctl_find_numid(card, tlv.numid);
1118 if (kctl == NULL) {
1119 err = -ENOENT;
1120 goto __kctl_end;
1122 if (kctl->tlv.p == NULL) {
1123 err = -ENXIO;
1124 goto __kctl_end;
1126 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1127 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1128 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1129 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1130 err = -ENXIO;
1131 goto __kctl_end;
1133 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1134 if (file && vd->owner != NULL && vd->owner != file) {
1135 err = -EPERM;
1136 goto __kctl_end;
1138 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1139 if (err > 0) {
1140 up_read(&card->controls_rwsem);
1141 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1142 return 0;
1144 } else {
1145 if (op_flag) {
1146 err = -ENXIO;
1147 goto __kctl_end;
1149 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1150 if (tlv.length < len) {
1151 err = -ENOMEM;
1152 goto __kctl_end;
1154 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1155 err = -EFAULT;
1157 __kctl_end:
1158 up_read(&card->controls_rwsem);
1159 return err;
1162 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1164 struct snd_ctl_file *ctl;
1165 struct snd_card *card;
1166 struct snd_kctl_ioctl *p;
1167 void __user *argp = (void __user *)arg;
1168 int __user *ip = argp;
1169 int err;
1171 ctl = file->private_data;
1172 card = ctl->card;
1173 snd_assert(card != NULL, return -ENXIO);
1174 switch (cmd) {
1175 case SNDRV_CTL_IOCTL_PVERSION:
1176 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1177 case SNDRV_CTL_IOCTL_CARD_INFO:
1178 return snd_ctl_card_info(card, ctl, cmd, argp);
1179 case SNDRV_CTL_IOCTL_ELEM_LIST:
1180 return snd_ctl_elem_list(card, argp);
1181 case SNDRV_CTL_IOCTL_ELEM_INFO:
1182 return snd_ctl_elem_info_user(ctl, argp);
1183 case SNDRV_CTL_IOCTL_ELEM_READ:
1184 return snd_ctl_elem_read_user(card, argp);
1185 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1186 return snd_ctl_elem_write_user(ctl, argp);
1187 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1188 return snd_ctl_elem_lock(ctl, argp);
1189 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1190 return snd_ctl_elem_unlock(ctl, argp);
1191 case SNDRV_CTL_IOCTL_ELEM_ADD:
1192 return snd_ctl_elem_add_user(ctl, argp, 0);
1193 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1194 return snd_ctl_elem_add_user(ctl, argp, 1);
1195 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1196 return snd_ctl_elem_remove(ctl, argp);
1197 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1198 return snd_ctl_subscribe_events(ctl, ip);
1199 case SNDRV_CTL_IOCTL_TLV_READ:
1200 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1201 case SNDRV_CTL_IOCTL_TLV_WRITE:
1202 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1203 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1204 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1205 case SNDRV_CTL_IOCTL_POWER:
1206 return -ENOPROTOOPT;
1207 case SNDRV_CTL_IOCTL_POWER_STATE:
1208 #ifdef CONFIG_PM
1209 return put_user(card->power_state, ip) ? -EFAULT : 0;
1210 #else
1211 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1212 #endif
1214 down_read(&snd_ioctl_rwsem);
1215 list_for_each_entry(p, &snd_control_ioctls, list) {
1216 err = p->fioctl(card, ctl, cmd, arg);
1217 if (err != -ENOIOCTLCMD) {
1218 up_read(&snd_ioctl_rwsem);
1219 return err;
1222 up_read(&snd_ioctl_rwsem);
1223 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1224 return -ENOTTY;
1227 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1228 size_t count, loff_t * offset)
1230 struct snd_ctl_file *ctl;
1231 int err = 0;
1232 ssize_t result = 0;
1234 ctl = file->private_data;
1235 snd_assert(ctl != NULL && ctl->card != NULL, 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 snd_assert(fcn != NULL, return -EINVAL);
1342 down_write(&snd_ioctl_rwsem);
1343 list_for_each_entry(p, lists, list) {
1344 if (p->fioctl == fcn) {
1345 list_del(&p->list);
1346 up_write(&snd_ioctl_rwsem);
1347 kfree(p);
1348 return 0;
1351 up_write(&snd_ioctl_rwsem);
1352 snd_BUG();
1353 return -EINVAL;
1356 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1358 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1361 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1363 #ifdef CONFIG_COMPAT
1364 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1366 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1369 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1370 #endif
1372 static int snd_ctl_fasync(int fd, struct file * file, int on)
1374 struct snd_ctl_file *ctl;
1375 int err;
1376 ctl = file->private_data;
1377 err = fasync_helper(fd, file, on, &ctl->fasync);
1378 if (err < 0)
1379 return err;
1380 return 0;
1384 * ioctl32 compat
1386 #ifdef CONFIG_COMPAT
1387 #include "control_compat.c"
1388 #else
1389 #define snd_ctl_ioctl_compat NULL
1390 #endif
1393 * INIT PART
1396 static const struct file_operations snd_ctl_f_ops =
1398 .owner = THIS_MODULE,
1399 .read = snd_ctl_read,
1400 .open = snd_ctl_open,
1401 .release = snd_ctl_release,
1402 .poll = snd_ctl_poll,
1403 .unlocked_ioctl = snd_ctl_ioctl,
1404 .compat_ioctl = snd_ctl_ioctl_compat,
1405 .fasync = snd_ctl_fasync,
1409 * registration of the control device
1411 static int snd_ctl_dev_register(struct snd_device *device)
1413 struct snd_card *card = device->device_data;
1414 int err, cardnum;
1415 char name[16];
1417 snd_assert(card != NULL, return -ENXIO);
1418 cardnum = card->number;
1419 snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1420 sprintf(name, "controlC%i", cardnum);
1421 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1422 &snd_ctl_f_ops, card, name)) < 0)
1423 return err;
1424 return 0;
1428 * disconnection of the control device
1430 static int snd_ctl_dev_disconnect(struct snd_device *device)
1432 struct snd_card *card = device->device_data;
1433 struct snd_ctl_file *ctl;
1434 int err, cardnum;
1436 snd_assert(card != NULL, return -ENXIO);
1437 cardnum = card->number;
1438 snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1440 down_read(&card->controls_rwsem);
1441 list_for_each_entry(ctl, &card->ctl_files, list) {
1442 wake_up(&ctl->change_sleep);
1443 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1445 up_read(&card->controls_rwsem);
1447 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1448 card, -1)) < 0)
1449 return err;
1450 return 0;
1454 * free all controls
1456 static int snd_ctl_dev_free(struct snd_device *device)
1458 struct snd_card *card = device->device_data;
1459 struct snd_kcontrol *control;
1461 down_write(&card->controls_rwsem);
1462 while (!list_empty(&card->controls)) {
1463 control = snd_kcontrol(card->controls.next);
1464 snd_ctl_remove(card, control);
1466 up_write(&card->controls_rwsem);
1467 return 0;
1471 * create control core:
1472 * called from init.c
1474 int snd_ctl_create(struct snd_card *card)
1476 static struct snd_device_ops ops = {
1477 .dev_free = snd_ctl_dev_free,
1478 .dev_register = snd_ctl_dev_register,
1479 .dev_disconnect = snd_ctl_dev_disconnect,
1482 snd_assert(card != NULL, return -ENXIO);
1483 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1487 * Frequently used control callbacks
1489 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1490 struct snd_ctl_elem_info *uinfo)
1492 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1493 uinfo->count = 1;
1494 uinfo->value.integer.min = 0;
1495 uinfo->value.integer.max = 1;
1496 return 0;
1499 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1501 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1502 struct snd_ctl_elem_info *uinfo)
1504 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1505 uinfo->count = 2;
1506 uinfo->value.integer.min = 0;
1507 uinfo->value.integer.max = 1;
1508 return 0;
1511 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);