vmap: flush vmap aliases when mapping fails
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / sound / core / control.c
blob9ce00ed20fba3d9141cb13dd045230412ee86e4c
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
34 #define MAX_CONTROL_COUNT 1028
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 err = nonseekable_open(inode, file);
55 if (err < 0)
56 return err;
58 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
59 if (!card) {
60 err = -ENODEV;
61 goto __error1;
63 err = snd_card_file_add(card, file);
64 if (err < 0) {
65 err = -ENODEV;
66 goto __error1;
68 if (!try_module_get(card->module)) {
69 err = -EFAULT;
70 goto __error2;
72 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
73 if (ctl == NULL) {
74 err = -ENOMEM;
75 goto __error;
77 INIT_LIST_HEAD(&ctl->events);
78 init_waitqueue_head(&ctl->change_sleep);
79 spin_lock_init(&ctl->read_lock);
80 ctl->card = card;
81 ctl->prefer_pcm_subdevice = -1;
82 ctl->prefer_rawmidi_subdevice = -1;
83 ctl->pid = get_pid(task_pid(current));
84 file->private_data = ctl;
85 write_lock_irqsave(&card->ctl_files_rwlock, flags);
86 list_add_tail(&ctl->list, &card->ctl_files);
87 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
88 return 0;
90 __error:
91 module_put(card->module);
92 __error2:
93 snd_card_file_remove(card, file);
94 __error1:
95 return err;
98 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
100 unsigned long flags;
101 struct snd_kctl_event *cread;
103 spin_lock_irqsave(&ctl->read_lock, flags);
104 while (!list_empty(&ctl->events)) {
105 cread = snd_kctl_event(ctl->events.next);
106 list_del(&cread->list);
107 kfree(cread);
109 spin_unlock_irqrestore(&ctl->read_lock, flags);
112 static int snd_ctl_release(struct inode *inode, struct file *file)
114 unsigned long flags;
115 struct snd_card *card;
116 struct snd_ctl_file *ctl;
117 struct snd_kcontrol *control;
118 unsigned int idx;
120 ctl = file->private_data;
121 file->private_data = NULL;
122 card = ctl->card;
123 write_lock_irqsave(&card->ctl_files_rwlock, flags);
124 list_del(&ctl->list);
125 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
126 down_write(&card->controls_rwsem);
127 list_for_each_entry(control, &card->controls, list)
128 for (idx = 0; idx < control->count; idx++)
129 if (control->vd[idx].owner == ctl)
130 control->vd[idx].owner = NULL;
131 up_write(&card->controls_rwsem);
132 snd_ctl_empty_read_queue(ctl);
133 put_pid(ctl->pid);
134 kfree(ctl);
135 module_put(card->module);
136 snd_card_file_remove(card, file);
137 return 0;
140 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
141 struct snd_ctl_elem_id *id)
143 unsigned long flags;
144 struct snd_ctl_file *ctl;
145 struct snd_kctl_event *ev;
147 if (snd_BUG_ON(!card || !id))
148 return;
149 read_lock(&card->ctl_files_rwlock);
150 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
151 card->mixer_oss_change_count++;
152 #endif
153 list_for_each_entry(ctl, &card->ctl_files, list) {
154 if (!ctl->subscribed)
155 continue;
156 spin_lock_irqsave(&ctl->read_lock, flags);
157 list_for_each_entry(ev, &ctl->events, list) {
158 if (ev->id.numid == id->numid) {
159 ev->mask |= mask;
160 goto _found;
163 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
164 if (ev) {
165 ev->id = *id;
166 ev->mask = mask;
167 list_add_tail(&ev->list, &ctl->events);
168 } else {
169 snd_printk(KERN_ERR "No memory available to allocate event\n");
171 _found:
172 wake_up(&ctl->change_sleep);
173 spin_unlock_irqrestore(&ctl->read_lock, flags);
174 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
176 read_unlock(&card->ctl_files_rwlock);
179 EXPORT_SYMBOL(snd_ctl_notify);
182 * snd_ctl_new - create a control instance from the template
183 * @control: the control template
184 * @access: the default control access
186 * Allocates a new struct snd_kcontrol instance and copies the given template
187 * to the new instance. It does not copy volatile data (access).
189 * Returns the pointer of the new instance, or NULL on failure.
191 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
192 unsigned int access)
194 struct snd_kcontrol *kctl;
195 unsigned int idx;
197 if (snd_BUG_ON(!control || !control->count))
198 return NULL;
200 if (control->count > MAX_CONTROL_COUNT)
201 return NULL;
203 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
204 if (kctl == NULL) {
205 snd_printk(KERN_ERR "Cannot allocate control instance\n");
206 return NULL;
208 *kctl = *control;
209 for (idx = 0; idx < kctl->count; idx++)
210 kctl->vd[idx].access = access;
211 return kctl;
215 * snd_ctl_new1 - create a control instance from the template
216 * @ncontrol: the initialization record
217 * @private_data: the private data to set
219 * Allocates a new struct snd_kcontrol instance and initialize from the given
220 * template. When the access field of ncontrol is 0, it's assumed as
221 * READWRITE access. When the count field is 0, it's assumes as one.
223 * Returns the pointer of the newly generated instance, or NULL on failure.
225 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
226 void *private_data)
228 struct snd_kcontrol kctl;
229 unsigned int access;
231 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
232 return NULL;
233 memset(&kctl, 0, sizeof(kctl));
234 kctl.id.iface = ncontrol->iface;
235 kctl.id.device = ncontrol->device;
236 kctl.id.subdevice = ncontrol->subdevice;
237 if (ncontrol->name) {
238 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
239 if (strcmp(ncontrol->name, kctl.id.name) != 0)
240 snd_printk(KERN_WARNING
241 "Control name '%s' truncated to '%s'\n",
242 ncontrol->name, kctl.id.name);
244 kctl.id.index = ncontrol->index;
245 kctl.count = ncontrol->count ? ncontrol->count : 1;
246 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
247 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
248 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
249 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
250 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
251 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
252 kctl.info = ncontrol->info;
253 kctl.get = ncontrol->get;
254 kctl.put = ncontrol->put;
255 kctl.tlv.p = ncontrol->tlv.p;
256 kctl.private_value = ncontrol->private_value;
257 kctl.private_data = private_data;
258 return snd_ctl_new(&kctl, access);
261 EXPORT_SYMBOL(snd_ctl_new1);
264 * snd_ctl_free_one - release the control instance
265 * @kcontrol: the control instance
267 * Releases the control instance created via snd_ctl_new()
268 * or snd_ctl_new1().
269 * Don't call this after the control was added to the card.
271 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
273 if (kcontrol) {
274 if (kcontrol->private_free)
275 kcontrol->private_free(kcontrol);
276 kfree(kcontrol);
280 EXPORT_SYMBOL(snd_ctl_free_one);
282 static unsigned int snd_ctl_hole_check(struct snd_card *card,
283 unsigned int count)
285 struct snd_kcontrol *kctl;
287 list_for_each_entry(kctl, &card->controls, list) {
288 if ((kctl->id.numid <= card->last_numid &&
289 kctl->id.numid + kctl->count > card->last_numid) ||
290 (kctl->id.numid <= card->last_numid + count - 1 &&
291 kctl->id.numid + kctl->count > card->last_numid + count - 1))
292 return card->last_numid = kctl->id.numid + kctl->count - 1;
294 return card->last_numid;
297 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
299 unsigned int last_numid, iter = 100000;
301 last_numid = card->last_numid;
302 while (last_numid != snd_ctl_hole_check(card, count)) {
303 if (--iter == 0) {
304 /* this situation is very unlikely */
305 snd_printk(KERN_ERR "unable to allocate new control numid\n");
306 return -ENOMEM;
308 last_numid = card->last_numid;
310 return 0;
314 * snd_ctl_add - add the control instance to the card
315 * @card: the card instance
316 * @kcontrol: the control instance to add
318 * Adds the control instance created via snd_ctl_new() or
319 * snd_ctl_new1() to the given card. Assigns also an unique
320 * numid used for fast search.
322 * Returns zero if successful, or a negative error code on failure.
324 * It frees automatically the control which cannot be added.
326 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
328 struct snd_ctl_elem_id id;
329 unsigned int idx;
330 int err = -EINVAL;
332 if (! kcontrol)
333 return err;
334 if (snd_BUG_ON(!card || !kcontrol->info))
335 goto error;
336 id = kcontrol->id;
337 down_write(&card->controls_rwsem);
338 if (snd_ctl_find_id(card, &id)) {
339 up_write(&card->controls_rwsem);
340 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
341 id.iface,
342 id.device,
343 id.subdevice,
344 id.name,
345 id.index);
346 err = -EBUSY;
347 goto error;
349 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
350 up_write(&card->controls_rwsem);
351 err = -ENOMEM;
352 goto error;
354 list_add_tail(&kcontrol->list, &card->controls);
355 card->controls_count += kcontrol->count;
356 kcontrol->id.numid = card->last_numid + 1;
357 card->last_numid += kcontrol->count;
358 up_write(&card->controls_rwsem);
359 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
360 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
361 return 0;
363 error:
364 snd_ctl_free_one(kcontrol);
365 return err;
368 EXPORT_SYMBOL(snd_ctl_add);
371 * snd_ctl_remove - remove the control from the card and release it
372 * @card: the card instance
373 * @kcontrol: the control instance to remove
375 * Removes the control from the card and then releases the instance.
376 * You don't need to call snd_ctl_free_one(). You must be in
377 * the write lock - down_write(&card->controls_rwsem).
379 * Returns 0 if successful, or a negative error code on failure.
381 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
383 struct snd_ctl_elem_id id;
384 unsigned int idx;
386 if (snd_BUG_ON(!card || !kcontrol))
387 return -EINVAL;
388 list_del(&kcontrol->list);
389 card->controls_count -= kcontrol->count;
390 id = kcontrol->id;
391 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
392 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
393 snd_ctl_free_one(kcontrol);
394 return 0;
397 EXPORT_SYMBOL(snd_ctl_remove);
400 * snd_ctl_remove_id - remove the control of the given id and release it
401 * @card: the card instance
402 * @id: the control id to remove
404 * Finds the control instance with the given id, removes it from the
405 * card list and releases it.
407 * Returns 0 if successful, or a negative error code on failure.
409 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
411 struct snd_kcontrol *kctl;
412 int ret;
414 down_write(&card->controls_rwsem);
415 kctl = snd_ctl_find_id(card, id);
416 if (kctl == NULL) {
417 up_write(&card->controls_rwsem);
418 return -ENOENT;
420 ret = snd_ctl_remove(card, kctl);
421 up_write(&card->controls_rwsem);
422 return ret;
425 EXPORT_SYMBOL(snd_ctl_remove_id);
428 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
429 * @file: active control handle
430 * @id: the control id to remove
432 * Finds the control instance with the given id, removes it from the
433 * card list and releases it.
435 * Returns 0 if successful, or a negative error code on failure.
437 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
438 struct snd_ctl_elem_id *id)
440 struct snd_card *card = file->card;
441 struct snd_kcontrol *kctl;
442 int idx, ret;
444 down_write(&card->controls_rwsem);
445 kctl = snd_ctl_find_id(card, id);
446 if (kctl == NULL) {
447 ret = -ENOENT;
448 goto error;
450 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
451 ret = -EINVAL;
452 goto error;
454 for (idx = 0; idx < kctl->count; idx++)
455 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
456 ret = -EBUSY;
457 goto error;
459 ret = snd_ctl_remove(card, kctl);
460 if (ret < 0)
461 goto error;
462 card->user_ctl_count--;
463 error:
464 up_write(&card->controls_rwsem);
465 return ret;
469 * snd_ctl_rename_id - replace the id of a control on the card
470 * @card: the card instance
471 * @src_id: the old id
472 * @dst_id: the new id
474 * Finds the control with the old id from the card, and replaces the
475 * id with the new one.
477 * Returns zero if successful, or a negative error code on failure.
479 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
480 struct snd_ctl_elem_id *dst_id)
482 struct snd_kcontrol *kctl;
484 down_write(&card->controls_rwsem);
485 kctl = snd_ctl_find_id(card, src_id);
486 if (kctl == NULL) {
487 up_write(&card->controls_rwsem);
488 return -ENOENT;
490 kctl->id = *dst_id;
491 kctl->id.numid = card->last_numid + 1;
492 card->last_numid += kctl->count;
493 up_write(&card->controls_rwsem);
494 return 0;
497 EXPORT_SYMBOL(snd_ctl_rename_id);
500 * snd_ctl_find_numid - find the control instance with the given number-id
501 * @card: the card instance
502 * @numid: the number-id to search
504 * Finds the control instance with the given number-id from the card.
506 * Returns the pointer of the instance if found, or NULL if not.
508 * The caller must down card->controls_rwsem before calling this function
509 * (if the race condition can happen).
511 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
513 struct snd_kcontrol *kctl;
515 if (snd_BUG_ON(!card || !numid))
516 return NULL;
517 list_for_each_entry(kctl, &card->controls, list) {
518 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
519 return kctl;
521 return NULL;
524 EXPORT_SYMBOL(snd_ctl_find_numid);
527 * snd_ctl_find_id - find the control instance with the given id
528 * @card: the card instance
529 * @id: the id to search
531 * Finds the control instance with the given id from the card.
533 * Returns the pointer of the instance if found, or NULL if not.
535 * The caller must down card->controls_rwsem before calling this function
536 * (if the race condition can happen).
538 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
539 struct snd_ctl_elem_id *id)
541 struct snd_kcontrol *kctl;
543 if (snd_BUG_ON(!card || !id))
544 return NULL;
545 if (id->numid != 0)
546 return snd_ctl_find_numid(card, id->numid);
547 list_for_each_entry(kctl, &card->controls, list) {
548 if (kctl->id.iface != id->iface)
549 continue;
550 if (kctl->id.device != id->device)
551 continue;
552 if (kctl->id.subdevice != id->subdevice)
553 continue;
554 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
555 continue;
556 if (kctl->id.index > id->index)
557 continue;
558 if (kctl->id.index + kctl->count <= id->index)
559 continue;
560 return kctl;
562 return NULL;
565 EXPORT_SYMBOL(snd_ctl_find_id);
567 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
568 unsigned int cmd, void __user *arg)
570 struct snd_ctl_card_info *info;
572 info = kzalloc(sizeof(*info), GFP_KERNEL);
573 if (! info)
574 return -ENOMEM;
575 down_read(&snd_ioctl_rwsem);
576 info->card = card->number;
577 strlcpy(info->id, card->id, sizeof(info->id));
578 strlcpy(info->driver, card->driver, sizeof(info->driver));
579 strlcpy(info->name, card->shortname, sizeof(info->name));
580 strlcpy(info->longname, card->longname, sizeof(info->longname));
581 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
582 strlcpy(info->components, card->components, sizeof(info->components));
583 up_read(&snd_ioctl_rwsem);
584 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
585 kfree(info);
586 return -EFAULT;
588 kfree(info);
589 return 0;
592 static int snd_ctl_elem_list(struct snd_card *card,
593 struct snd_ctl_elem_list __user *_list)
595 struct list_head *plist;
596 struct snd_ctl_elem_list list;
597 struct snd_kcontrol *kctl;
598 struct snd_ctl_elem_id *dst, *id;
599 unsigned int offset, space, first, jidx;
601 if (copy_from_user(&list, _list, sizeof(list)))
602 return -EFAULT;
603 offset = list.offset;
604 space = list.space;
605 first = 0;
606 /* try limit maximum space */
607 if (space > 16384)
608 return -ENOMEM;
609 if (space > 0) {
610 /* allocate temporary buffer for atomic operation */
611 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
612 if (dst == NULL)
613 return -ENOMEM;
614 down_read(&card->controls_rwsem);
615 list.count = card->controls_count;
616 plist = card->controls.next;
617 while (plist != &card->controls) {
618 if (offset == 0)
619 break;
620 kctl = snd_kcontrol(plist);
621 if (offset < kctl->count)
622 break;
623 offset -= kctl->count;
624 plist = plist->next;
626 list.used = 0;
627 id = dst;
628 while (space > 0 && plist != &card->controls) {
629 kctl = snd_kcontrol(plist);
630 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
631 snd_ctl_build_ioff(id, kctl, jidx);
632 id++;
633 space--;
634 list.used++;
636 plist = plist->next;
637 offset = 0;
639 up_read(&card->controls_rwsem);
640 if (list.used > 0 &&
641 copy_to_user(list.pids, dst,
642 list.used * sizeof(struct snd_ctl_elem_id))) {
643 vfree(dst);
644 return -EFAULT;
646 vfree(dst);
647 } else {
648 down_read(&card->controls_rwsem);
649 list.count = card->controls_count;
650 up_read(&card->controls_rwsem);
652 if (copy_to_user(_list, &list, sizeof(list)))
653 return -EFAULT;
654 return 0;
657 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
658 struct snd_ctl_elem_info *info)
660 struct snd_card *card = ctl->card;
661 struct snd_kcontrol *kctl;
662 struct snd_kcontrol_volatile *vd;
663 unsigned int index_offset;
664 int result;
666 down_read(&card->controls_rwsem);
667 kctl = snd_ctl_find_id(card, &info->id);
668 if (kctl == NULL) {
669 up_read(&card->controls_rwsem);
670 return -ENOENT;
672 #ifdef CONFIG_SND_DEBUG
673 info->access = 0;
674 #endif
675 result = kctl->info(kctl, info);
676 if (result >= 0) {
677 snd_BUG_ON(info->access);
678 index_offset = snd_ctl_get_ioff(kctl, &info->id);
679 vd = &kctl->vd[index_offset];
680 snd_ctl_build_ioff(&info->id, kctl, index_offset);
681 info->access = vd->access;
682 if (vd->owner) {
683 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
684 if (vd->owner == ctl)
685 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
686 info->owner = pid_vnr(vd->owner->pid);
687 } else {
688 info->owner = -1;
691 up_read(&card->controls_rwsem);
692 return result;
695 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
696 struct snd_ctl_elem_info __user *_info)
698 struct snd_ctl_elem_info info;
699 int result;
701 if (copy_from_user(&info, _info, sizeof(info)))
702 return -EFAULT;
703 snd_power_lock(ctl->card);
704 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
705 if (result >= 0)
706 result = snd_ctl_elem_info(ctl, &info);
707 snd_power_unlock(ctl->card);
708 if (result >= 0)
709 if (copy_to_user(_info, &info, sizeof(info)))
710 return -EFAULT;
711 return result;
714 static int snd_ctl_elem_read(struct snd_card *card,
715 struct snd_ctl_elem_value *control)
717 struct snd_kcontrol *kctl;
718 struct snd_kcontrol_volatile *vd;
719 unsigned int index_offset;
720 int result;
722 down_read(&card->controls_rwsem);
723 kctl = snd_ctl_find_id(card, &control->id);
724 if (kctl == NULL) {
725 result = -ENOENT;
726 } else {
727 index_offset = snd_ctl_get_ioff(kctl, &control->id);
728 vd = &kctl->vd[index_offset];
729 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
730 kctl->get != NULL) {
731 snd_ctl_build_ioff(&control->id, kctl, index_offset);
732 result = kctl->get(kctl, control);
733 } else
734 result = -EPERM;
736 up_read(&card->controls_rwsem);
737 return result;
740 static int snd_ctl_elem_read_user(struct snd_card *card,
741 struct snd_ctl_elem_value __user *_control)
743 struct snd_ctl_elem_value *control;
744 int result;
746 control = memdup_user(_control, sizeof(*control));
747 if (IS_ERR(control))
748 return PTR_ERR(control);
750 snd_power_lock(card);
751 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
752 if (result >= 0)
753 result = snd_ctl_elem_read(card, control);
754 snd_power_unlock(card);
755 if (result >= 0)
756 if (copy_to_user(_control, control, sizeof(*control)))
757 result = -EFAULT;
758 kfree(control);
759 return result;
762 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
763 struct snd_ctl_elem_value *control)
765 struct snd_kcontrol *kctl;
766 struct snd_kcontrol_volatile *vd;
767 unsigned int index_offset;
768 int result;
770 down_read(&card->controls_rwsem);
771 kctl = snd_ctl_find_id(card, &control->id);
772 if (kctl == NULL) {
773 result = -ENOENT;
774 } else {
775 index_offset = snd_ctl_get_ioff(kctl, &control->id);
776 vd = &kctl->vd[index_offset];
777 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
778 kctl->put == NULL ||
779 (file && vd->owner && vd->owner != file)) {
780 result = -EPERM;
781 } else {
782 snd_ctl_build_ioff(&control->id, kctl, index_offset);
783 result = kctl->put(kctl, control);
785 if (result > 0) {
786 up_read(&card->controls_rwsem);
787 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
788 &control->id);
789 return 0;
792 up_read(&card->controls_rwsem);
793 return result;
796 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
797 struct snd_ctl_elem_value __user *_control)
799 struct snd_ctl_elem_value *control;
800 struct snd_card *card;
801 int result;
803 control = memdup_user(_control, sizeof(*control));
804 if (IS_ERR(control))
805 return PTR_ERR(control);
807 card = file->card;
808 snd_power_lock(card);
809 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
810 if (result >= 0)
811 result = snd_ctl_elem_write(card, file, control);
812 snd_power_unlock(card);
813 if (result >= 0)
814 if (copy_to_user(_control, control, sizeof(*control)))
815 result = -EFAULT;
816 kfree(control);
817 return result;
820 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
821 struct snd_ctl_elem_id __user *_id)
823 struct snd_card *card = file->card;
824 struct snd_ctl_elem_id id;
825 struct snd_kcontrol *kctl;
826 struct snd_kcontrol_volatile *vd;
827 int result;
829 if (copy_from_user(&id, _id, sizeof(id)))
830 return -EFAULT;
831 down_write(&card->controls_rwsem);
832 kctl = snd_ctl_find_id(card, &id);
833 if (kctl == NULL) {
834 result = -ENOENT;
835 } else {
836 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
837 if (vd->owner != NULL)
838 result = -EBUSY;
839 else {
840 vd->owner = file;
841 result = 0;
844 up_write(&card->controls_rwsem);
845 return result;
848 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
849 struct snd_ctl_elem_id __user *_id)
851 struct snd_card *card = file->card;
852 struct snd_ctl_elem_id id;
853 struct snd_kcontrol *kctl;
854 struct snd_kcontrol_volatile *vd;
855 int result;
857 if (copy_from_user(&id, _id, sizeof(id)))
858 return -EFAULT;
859 down_write(&card->controls_rwsem);
860 kctl = snd_ctl_find_id(card, &id);
861 if (kctl == NULL) {
862 result = -ENOENT;
863 } else {
864 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
865 if (vd->owner == NULL)
866 result = -EINVAL;
867 else if (vd->owner != file)
868 result = -EPERM;
869 else {
870 vd->owner = NULL;
871 result = 0;
874 up_write(&card->controls_rwsem);
875 return result;
878 struct user_element {
879 struct snd_ctl_elem_info info;
880 void *elem_data; /* element data */
881 unsigned long elem_data_size; /* size of element data in bytes */
882 void *tlv_data; /* TLV data */
883 unsigned long tlv_data_size; /* TLV data size */
884 void *priv_data; /* private data (like strings for enumerated type) */
885 unsigned long priv_data_size; /* size of private data in bytes */
888 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
889 struct snd_ctl_elem_info *uinfo)
891 struct user_element *ue = kcontrol->private_data;
893 *uinfo = ue->info;
894 return 0;
897 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
898 struct snd_ctl_elem_value *ucontrol)
900 struct user_element *ue = kcontrol->private_data;
902 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
903 return 0;
906 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
907 struct snd_ctl_elem_value *ucontrol)
909 int change;
910 struct user_element *ue = kcontrol->private_data;
912 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
913 if (change)
914 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
915 return change;
918 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
919 int op_flag,
920 unsigned int size,
921 unsigned int __user *tlv)
923 struct user_element *ue = kcontrol->private_data;
924 int change = 0;
925 void *new_data;
927 if (op_flag > 0) {
928 if (size > 1024 * 128) /* sane value */
929 return -EINVAL;
931 new_data = memdup_user(tlv, size);
932 if (IS_ERR(new_data))
933 return PTR_ERR(new_data);
934 change = ue->tlv_data_size != size;
935 if (!change)
936 change = memcmp(ue->tlv_data, new_data, size);
937 kfree(ue->tlv_data);
938 ue->tlv_data = new_data;
939 ue->tlv_data_size = size;
940 } else {
941 if (! ue->tlv_data_size || ! ue->tlv_data)
942 return -ENXIO;
943 if (size < ue->tlv_data_size)
944 return -ENOSPC;
945 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
946 return -EFAULT;
948 return change;
951 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
953 struct user_element *ue = kcontrol->private_data;
954 if (ue->tlv_data)
955 kfree(ue->tlv_data);
956 kfree(ue);
959 static int snd_ctl_elem_add(struct snd_ctl_file *file,
960 struct snd_ctl_elem_info *info, int replace)
962 struct snd_card *card = file->card;
963 struct snd_kcontrol kctl, *_kctl;
964 unsigned int access;
965 long private_size;
966 struct user_element *ue;
967 int idx, err;
969 if (card->user_ctl_count >= MAX_USER_CONTROLS)
970 return -ENOMEM;
971 if (info->count < 1)
972 return -EINVAL;
973 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
974 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
975 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
976 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
977 info->id.numid = 0;
978 memset(&kctl, 0, sizeof(kctl));
979 down_write(&card->controls_rwsem);
980 _kctl = snd_ctl_find_id(card, &info->id);
981 err = 0;
982 if (_kctl) {
983 if (replace)
984 err = snd_ctl_remove(card, _kctl);
985 else
986 err = -EBUSY;
987 } else {
988 if (replace)
989 err = -ENOENT;
991 up_write(&card->controls_rwsem);
992 if (err < 0)
993 return err;
994 memcpy(&kctl.id, &info->id, sizeof(info->id));
995 kctl.count = info->owner ? info->owner : 1;
996 access |= SNDRV_CTL_ELEM_ACCESS_USER;
997 kctl.info = snd_ctl_elem_user_info;
998 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
999 kctl.get = snd_ctl_elem_user_get;
1000 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1001 kctl.put = snd_ctl_elem_user_put;
1002 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1003 kctl.tlv.c = snd_ctl_elem_user_tlv;
1004 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1006 switch (info->type) {
1007 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1008 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1009 private_size = sizeof(long);
1010 if (info->count > 128)
1011 return -EINVAL;
1012 break;
1013 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1014 private_size = sizeof(long long);
1015 if (info->count > 64)
1016 return -EINVAL;
1017 break;
1018 case SNDRV_CTL_ELEM_TYPE_BYTES:
1019 private_size = sizeof(unsigned char);
1020 if (info->count > 512)
1021 return -EINVAL;
1022 break;
1023 case SNDRV_CTL_ELEM_TYPE_IEC958:
1024 private_size = sizeof(struct snd_aes_iec958);
1025 if (info->count != 1)
1026 return -EINVAL;
1027 break;
1028 default:
1029 return -EINVAL;
1031 private_size *= info->count;
1032 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1033 if (ue == NULL)
1034 return -ENOMEM;
1035 ue->info = *info;
1036 ue->info.access = 0;
1037 ue->elem_data = (char *)ue + sizeof(*ue);
1038 ue->elem_data_size = private_size;
1039 kctl.private_free = snd_ctl_elem_user_free;
1040 _kctl = snd_ctl_new(&kctl, access);
1041 if (_kctl == NULL) {
1042 kfree(ue);
1043 return -ENOMEM;
1045 _kctl->private_data = ue;
1046 for (idx = 0; idx < _kctl->count; idx++)
1047 _kctl->vd[idx].owner = file;
1048 err = snd_ctl_add(card, _kctl);
1049 if (err < 0)
1050 return err;
1052 down_write(&card->controls_rwsem);
1053 card->user_ctl_count++;
1054 up_write(&card->controls_rwsem);
1056 return 0;
1059 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1060 struct snd_ctl_elem_info __user *_info, int replace)
1062 struct snd_ctl_elem_info info;
1063 if (copy_from_user(&info, _info, sizeof(info)))
1064 return -EFAULT;
1065 return snd_ctl_elem_add(file, &info, replace);
1068 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1069 struct snd_ctl_elem_id __user *_id)
1071 struct snd_ctl_elem_id id;
1073 if (copy_from_user(&id, _id, sizeof(id)))
1074 return -EFAULT;
1075 return snd_ctl_remove_user_ctl(file, &id);
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) * 2)
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 (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;
1377 ctl = file->private_data;
1378 return fasync_helper(fd, file, on, &ctl->fasync);
1382 * ioctl32 compat
1384 #ifdef CONFIG_COMPAT
1385 #include "control_compat.c"
1386 #else
1387 #define snd_ctl_ioctl_compat NULL
1388 #endif
1391 * INIT PART
1394 static const struct file_operations snd_ctl_f_ops =
1396 .owner = THIS_MODULE,
1397 .read = snd_ctl_read,
1398 .open = snd_ctl_open,
1399 .release = snd_ctl_release,
1400 .llseek = no_llseek,
1401 .poll = snd_ctl_poll,
1402 .unlocked_ioctl = snd_ctl_ioctl,
1403 .compat_ioctl = snd_ctl_ioctl_compat,
1404 .fasync = snd_ctl_fasync,
1408 * registration of the control device
1410 static int snd_ctl_dev_register(struct snd_device *device)
1412 struct snd_card *card = device->device_data;
1413 int err, cardnum;
1414 char name[16];
1416 if (snd_BUG_ON(!card))
1417 return -ENXIO;
1418 cardnum = card->number;
1419 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1420 return -ENXIO;
1421 sprintf(name, "controlC%i", cardnum);
1422 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1423 &snd_ctl_f_ops, card, name)) < 0)
1424 return err;
1425 return 0;
1429 * disconnection of the control device
1431 static int snd_ctl_dev_disconnect(struct snd_device *device)
1433 struct snd_card *card = device->device_data;
1434 struct snd_ctl_file *ctl;
1435 int err, cardnum;
1437 if (snd_BUG_ON(!card))
1438 return -ENXIO;
1439 cardnum = card->number;
1440 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1441 return -ENXIO;
1443 read_lock(&card->ctl_files_rwlock);
1444 list_for_each_entry(ctl, &card->ctl_files, list) {
1445 wake_up(&ctl->change_sleep);
1446 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1448 read_unlock(&card->ctl_files_rwlock);
1450 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1451 card, -1)) < 0)
1452 return err;
1453 return 0;
1457 * free all controls
1459 static int snd_ctl_dev_free(struct snd_device *device)
1461 struct snd_card *card = device->device_data;
1462 struct snd_kcontrol *control;
1464 down_write(&card->controls_rwsem);
1465 while (!list_empty(&card->controls)) {
1466 control = snd_kcontrol(card->controls.next);
1467 snd_ctl_remove(card, control);
1469 up_write(&card->controls_rwsem);
1470 return 0;
1474 * create control core:
1475 * called from init.c
1477 int snd_ctl_create(struct snd_card *card)
1479 static struct snd_device_ops ops = {
1480 .dev_free = snd_ctl_dev_free,
1481 .dev_register = snd_ctl_dev_register,
1482 .dev_disconnect = snd_ctl_dev_disconnect,
1485 if (snd_BUG_ON(!card))
1486 return -ENXIO;
1487 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1491 * Frequently used control callbacks/helpers
1493 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1494 struct snd_ctl_elem_info *uinfo)
1496 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1497 uinfo->count = 1;
1498 uinfo->value.integer.min = 0;
1499 uinfo->value.integer.max = 1;
1500 return 0;
1503 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1505 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1506 struct snd_ctl_elem_info *uinfo)
1508 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1509 uinfo->count = 2;
1510 uinfo->value.integer.min = 0;
1511 uinfo->value.integer.max = 1;
1512 return 0;
1515 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1518 * snd_ctl_enum_info - fills the info structure for an enumerated control
1519 * @info: the structure to be filled
1520 * @channels: the number of the control's channels; often one
1521 * @items: the number of control values; also the size of @names
1522 * @names: an array containing the names of all control values
1524 * Sets all required fields in @info to their appropriate values.
1525 * If the control's accessibility is not the default (readable and writable),
1526 * the caller has to fill @info->access.
1528 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1529 unsigned int items, const char *const names[])
1531 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1532 info->count = channels;
1533 info->value.enumerated.items = items;
1534 if (info->value.enumerated.item >= items)
1535 info->value.enumerated.item = items - 1;
1536 strlcpy(info->value.enumerated.name,
1537 names[info->value.enumerated.item],
1538 sizeof(info->value.enumerated.name));
1539 return 0;
1541 EXPORT_SYMBOL(snd_ctl_enum_info);