[ALSA] Add Analog Devices vendor name
[linux-2.6.git] / sound / core / control.c
1 /*
2  *  Routines for driver control interface
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
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.
10  *
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.
15  *
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
19  *
20  */
21
22 #include <sound/driver.h>
23 #include <linux/threads.h>
24 #include <linux/interrupt.h>
25 #include <linux/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/time.h>
29 #include <sound/core.h>
30 #include <sound/minors.h>
31 #include <sound/info.h>
32 #include <sound/control.h>
33
34 /* max number of user-defined controls */
35 #define MAX_USER_CONTROLS       32
36
37 typedef struct _snd_kctl_ioctl {
38         struct list_head list;          /* list of all ioctls */
39         snd_kctl_ioctl_func_t fioctl;
40 } snd_kctl_ioctl_t;
41
42 #define snd_kctl_ioctl(n) list_entry(n, snd_kctl_ioctl_t, list)
43
44 static DECLARE_RWSEM(snd_ioctl_rwsem);
45 static LIST_HEAD(snd_control_ioctls);
46 #ifdef CONFIG_COMPAT
47 static LIST_HEAD(snd_control_compat_ioctls);
48 #endif
49
50 static int snd_ctl_open(struct inode *inode, struct file *file)
51 {
52         int cardnum = SNDRV_MINOR_CARD(iminor(inode));
53         unsigned long flags;
54         snd_card_t *card;
55         snd_ctl_file_t *ctl;
56         int err;
57
58         card = snd_cards[cardnum];
59         if (!card) {
60                 err = -ENODEV;
61                 goto __error1;
62         }
63         err = snd_card_file_add(card, file);
64         if (err < 0) {
65                 err = -ENODEV;
66                 goto __error1;
67         }
68         if (!try_module_get(card->module)) {
69                 err = -EFAULT;
70                 goto __error2;
71         }
72         ctl = kcalloc(1, sizeof(*ctl), GFP_KERNEL);
73         if (ctl == NULL) {
74                 err = -ENOMEM;
75                 goto __error;
76         }
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->pid = current->pid;
82         file->private_data = ctl;
83         write_lock_irqsave(&card->ctl_files_rwlock, flags);
84         list_add_tail(&ctl->list, &card->ctl_files);
85         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
86         return 0;
87
88       __error:
89         module_put(card->module);
90       __error2:
91         snd_card_file_remove(card, file);
92       __error1:
93         return err;
94 }
95
96 static void snd_ctl_empty_read_queue(snd_ctl_file_t * ctl)
97 {
98         snd_kctl_event_t *cread;
99         
100         spin_lock(&ctl->read_lock);
101         while (!list_empty(&ctl->events)) {
102                 cread = snd_kctl_event(ctl->events.next);
103                 list_del(&cread->list);
104                 kfree(cread);
105         }
106         spin_unlock(&ctl->read_lock);
107 }
108
109 static int snd_ctl_release(struct inode *inode, struct file *file)
110 {
111         unsigned long flags;
112         struct list_head *list;
113         snd_card_t *card;
114         snd_ctl_file_t *ctl;
115         snd_kcontrol_t *control;
116         unsigned int idx;
117
118         ctl = file->private_data;
119         fasync_helper(-1, file, 0, &ctl->fasync);
120         file->private_data = NULL;
121         card = ctl->card;
122         write_lock_irqsave(&card->ctl_files_rwlock, flags);
123         list_del(&ctl->list);
124         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
125         down_write(&card->controls_rwsem);
126         list_for_each(list, &card->controls) {
127                 control = snd_kcontrol(list);
128                 for (idx = 0; idx < control->count; idx++)
129                         if (control->vd[idx].owner == ctl)
130                                 control->vd[idx].owner = NULL;
131         }
132         up_write(&card->controls_rwsem);
133         snd_ctl_empty_read_queue(ctl);
134         kfree(ctl);
135         module_put(card->module);
136         snd_card_file_remove(card, file);
137         return 0;
138 }
139
140 void snd_ctl_notify(snd_card_t *card, unsigned int mask, snd_ctl_elem_id_t *id)
141 {
142         unsigned long flags;
143         struct list_head *flist;
144         snd_ctl_file_t *ctl;
145         snd_kctl_event_t *ev;
146         
147         snd_runtime_check(card != NULL && id != NULL, return);
148         read_lock(&card->ctl_files_rwlock);
149 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
150         card->mixer_oss_change_count++;
151 #endif
152         list_for_each(flist, &card->ctl_files) {
153                 struct list_head *elist;
154                 ctl = snd_ctl_file(flist);
155                 if (!ctl->subscribed)
156                         continue;
157                 spin_lock_irqsave(&ctl->read_lock, flags);
158                 list_for_each(elist, &ctl->events) {
159                         ev = snd_kctl_event(elist);
160                         if (ev->id.numid == id->numid) {
161                                 ev->mask |= mask;
162                                 goto _found;
163                         }
164                 }
165                 ev = kcalloc(1, sizeof(*ev), GFP_ATOMIC);
166                 if (ev) {
167                         ev->id = *id;
168                         ev->mask = mask;
169                         list_add_tail(&ev->list, &ctl->events);
170                 } else {
171                         snd_printk(KERN_ERR "No memory available to allocate event\n");
172                 }
173         _found:
174                 wake_up(&ctl->change_sleep);
175                 spin_unlock_irqrestore(&ctl->read_lock, flags);
176                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
177         }
178         read_unlock(&card->ctl_files_rwlock);
179 }
180
181 /**
182  * snd_ctl_new - create a control instance from the template
183  * @control: the control template
184  * @access: the default control access
185  *
186  * Allocates a new snd_kcontrol_t instance and copies the given template 
187  * to the new instance. It does not copy volatile data (access).
188  *
189  * Returns the pointer of the new instance, or NULL on failure.
190  */
191 snd_kcontrol_t *snd_ctl_new(snd_kcontrol_t * control, unsigned int access)
192 {
193         snd_kcontrol_t *kctl;
194         unsigned int idx;
195         
196         snd_runtime_check(control != NULL, return NULL);
197         snd_runtime_check(control->count > 0, return NULL);
198         kctl = kcalloc(1, sizeof(*kctl) + sizeof(snd_kcontrol_volatile_t) * control->count, GFP_KERNEL);
199         if (kctl == NULL)
200                 return NULL;
201         *kctl = *control;
202         for (idx = 0; idx < kctl->count; idx++)
203                 kctl->vd[idx].access = access;
204         return kctl;
205 }
206
207 /**
208  * snd_ctl_new1 - create a control instance from the template
209  * @ncontrol: the initialization record
210  * @private_data: the private data to set
211  *
212  * Allocates a new snd_kcontrol_t instance and initialize from the given 
213  * template.  When the access field of ncontrol is 0, it's assumed as
214  * READWRITE access. When the count field is 0, it's assumes as one.
215  *
216  * Returns the pointer of the newly generated instance, or NULL on failure.
217  */
218 snd_kcontrol_t *snd_ctl_new1(snd_kcontrol_new_t * ncontrol, void *private_data)
219 {
220         snd_kcontrol_t kctl;
221         unsigned int access;
222         
223         snd_runtime_check(ncontrol != NULL, return NULL);
224         snd_assert(ncontrol->info != NULL, return NULL);
225         memset(&kctl, 0, sizeof(kctl));
226         kctl.id.iface = ncontrol->iface;
227         kctl.id.device = ncontrol->device;
228         kctl.id.subdevice = ncontrol->subdevice;
229         if (ncontrol->name)
230                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
231         kctl.id.index = ncontrol->index;
232         kctl.count = ncontrol->count ? ncontrol->count : 1;
233         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
234                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
235                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
236         kctl.info = ncontrol->info;
237         kctl.get = ncontrol->get;
238         kctl.put = ncontrol->put;
239         kctl.private_value = ncontrol->private_value;
240         kctl.private_data = private_data;
241         return snd_ctl_new(&kctl, access);
242 }
243
244 /**
245  * snd_ctl_free_one - release the control instance
246  * @kcontrol: the control instance
247  *
248  * Releases the control instance created via snd_ctl_new()
249  * or snd_ctl_new1().
250  * Don't call this after the control was added to the card.
251  */
252 void snd_ctl_free_one(snd_kcontrol_t * kcontrol)
253 {
254         if (kcontrol) {
255                 if (kcontrol->private_free)
256                         kcontrol->private_free(kcontrol);
257                 kfree(kcontrol);
258         }
259 }
260
261 static unsigned int snd_ctl_hole_check(snd_card_t * card,
262                                        unsigned int count)
263 {
264         struct list_head *list;
265         snd_kcontrol_t *kctl;
266
267         list_for_each(list, &card->controls) {
268                 kctl = snd_kcontrol(list);
269                 if ((kctl->id.numid <= card->last_numid &&
270                      kctl->id.numid + kctl->count > card->last_numid) ||
271                     (kctl->id.numid <= card->last_numid + count - 1 &&
272                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
273                         return card->last_numid = kctl->id.numid + kctl->count - 1;
274         }
275         return card->last_numid;
276 }
277
278 static int snd_ctl_find_hole(snd_card_t * card, unsigned int count)
279 {
280         unsigned int last_numid, iter = 100000;
281
282         last_numid = card->last_numid;
283         while (last_numid != snd_ctl_hole_check(card, count)) {
284                 if (--iter == 0) {
285                         /* this situation is very unlikely */
286                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
287                         return -ENOMEM;
288                 }
289                 last_numid = card->last_numid;
290         }
291         return 0;
292 }
293
294 /**
295  * snd_ctl_add - add the control instance to the card
296  * @card: the card instance
297  * @kcontrol: the control instance to add
298  *
299  * Adds the control instance created via snd_ctl_new() or
300  * snd_ctl_new1() to the given card. Assigns also an unique
301  * numid used for fast search.
302  *
303  * Returns zero if successful, or a negative error code on failure.
304  *
305  * It frees automatically the control which cannot be added.
306  */
307 int snd_ctl_add(snd_card_t * card, snd_kcontrol_t * kcontrol)
308 {
309         snd_ctl_elem_id_t id;
310         unsigned int idx;
311
312         snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
313         snd_assert(kcontrol->info != NULL, return -EINVAL);
314         id = kcontrol->id;
315         down_write(&card->controls_rwsem);
316         if (snd_ctl_find_id(card, &id)) {
317                 up_write(&card->controls_rwsem);
318                 snd_ctl_free_one(kcontrol);
319                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
320                                         id.iface,
321                                         id.device,
322                                         id.subdevice,
323                                         id.name,
324                                         id.index);
325                 return -EBUSY;
326         }
327         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
328                 up_write(&card->controls_rwsem);
329                 snd_ctl_free_one(kcontrol);
330                 return -ENOMEM;
331         }
332         list_add_tail(&kcontrol->list, &card->controls);
333         card->controls_count += kcontrol->count;
334         kcontrol->id.numid = card->last_numid + 1;
335         card->last_numid += kcontrol->count;
336         up_write(&card->controls_rwsem);
337         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
338                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
339         return 0;
340 }
341
342 /**
343  * snd_ctl_remove - remove the control from the card and release it
344  * @card: the card instance
345  * @kcontrol: the control instance to remove
346  *
347  * Removes the control from the card and then releases the instance.
348  * You don't need to call snd_ctl_free_one(). You must be in
349  * the write lock - down_write(&card->controls_rwsem).
350  * 
351  * Returns 0 if successful, or a negative error code on failure.
352  */
353 int snd_ctl_remove(snd_card_t * card, snd_kcontrol_t * kcontrol)
354 {
355         snd_ctl_elem_id_t id;
356         unsigned int idx;
357
358         snd_runtime_check(card != NULL && kcontrol != NULL, return -EINVAL);
359         list_del(&kcontrol->list);
360         card->controls_count -= kcontrol->count;
361         id = kcontrol->id;
362         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
363                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
364         snd_ctl_free_one(kcontrol);
365         return 0;
366 }
367
368 /**
369  * snd_ctl_remove_id - remove the control of the given id and release it
370  * @card: the card instance
371  * @id: the control id to remove
372  *
373  * Finds the control instance with the given id, removes it from the
374  * card list and releases it.
375  * 
376  * Returns 0 if successful, or a negative error code on failure.
377  */
378 int snd_ctl_remove_id(snd_card_t * card, snd_ctl_elem_id_t *id)
379 {
380         snd_kcontrol_t *kctl;
381         int ret;
382
383         down_write(&card->controls_rwsem);
384         kctl = snd_ctl_find_id(card, id);
385         if (kctl == NULL) {
386                 up_write(&card->controls_rwsem);
387                 return -ENOENT;
388         }
389         ret = snd_ctl_remove(card, kctl);
390         up_write(&card->controls_rwsem);
391         return ret;
392 }
393
394 /**
395  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
396  * @file: active control handle
397  * @id: the control id to remove
398  *
399  * Finds the control instance with the given id, removes it from the
400  * card list and releases it.
401  * 
402  * Returns 0 if successful, or a negative error code on failure.
403  */
404 static int snd_ctl_remove_unlocked_id(snd_ctl_file_t * file, snd_ctl_elem_id_t *id)
405 {
406         snd_card_t *card = file->card;
407         snd_kcontrol_t *kctl;
408         int idx, ret;
409
410         down_write(&card->controls_rwsem);
411         kctl = snd_ctl_find_id(card, id);
412         if (kctl == NULL) {
413                 up_write(&card->controls_rwsem);
414                 return -ENOENT;
415         }
416         for (idx = 0; idx < kctl->count; idx++)
417                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
418                         up_write(&card->controls_rwsem);
419                         return -EBUSY;
420                 }
421         ret = snd_ctl_remove(card, kctl);
422         up_write(&card->controls_rwsem);
423         return ret;
424 }
425
426 /**
427  * snd_ctl_rename_id - replace the id of a control on the card
428  * @card: the card instance
429  * @src_id: the old id
430  * @dst_id: the new id
431  *
432  * Finds the control with the old id from the card, and replaces the
433  * id with the new one.
434  *
435  * Returns zero if successful, or a negative error code on failure.
436  */
437 int snd_ctl_rename_id(snd_card_t * card, snd_ctl_elem_id_t *src_id, snd_ctl_elem_id_t *dst_id)
438 {
439         snd_kcontrol_t *kctl;
440
441         down_write(&card->controls_rwsem);
442         kctl = snd_ctl_find_id(card, src_id);
443         if (kctl == NULL) {
444                 up_write(&card->controls_rwsem);
445                 return -ENOENT;
446         }
447         kctl->id = *dst_id;
448         kctl->id.numid = card->last_numid + 1;
449         card->last_numid += kctl->count;
450         up_write(&card->controls_rwsem);
451         return 0;
452 }
453
454 /**
455  * snd_ctl_find_numid - find the control instance with the given number-id
456  * @card: the card instance
457  * @numid: the number-id to search
458  *
459  * Finds the control instance with the given number-id from the card.
460  *
461  * Returns the pointer of the instance if found, or NULL if not.
462  *
463  * The caller must down card->controls_rwsem before calling this function
464  * (if the race condition can happen).
465  */
466 snd_kcontrol_t *snd_ctl_find_numid(snd_card_t * card, unsigned int numid)
467 {
468         struct list_head *list;
469         snd_kcontrol_t *kctl;
470
471         snd_runtime_check(card != NULL && numid != 0, return NULL);
472         list_for_each(list, &card->controls) {
473                 kctl = snd_kcontrol(list);
474                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
475                         return kctl;
476         }
477         return NULL;
478 }
479
480 /**
481  * snd_ctl_find_id - find the control instance with the given id
482  * @card: the card instance
483  * @id: the id to search
484  *
485  * Finds the control instance with the given id from the card.
486  *
487  * Returns the pointer of the instance if found, or NULL if not.
488  *
489  * The caller must down card->controls_rwsem before calling this function
490  * (if the race condition can happen).
491  */
492 snd_kcontrol_t *snd_ctl_find_id(snd_card_t * card, snd_ctl_elem_id_t *id)
493 {
494         struct list_head *list;
495         snd_kcontrol_t *kctl;
496
497         snd_runtime_check(card != NULL && id != NULL, return NULL);
498         if (id->numid != 0)
499                 return snd_ctl_find_numid(card, id->numid);
500         list_for_each(list, &card->controls) {
501                 kctl = snd_kcontrol(list);
502                 if (kctl->id.iface != id->iface)
503                         continue;
504                 if (kctl->id.device != id->device)
505                         continue;
506                 if (kctl->id.subdevice != id->subdevice)
507                         continue;
508                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
509                         continue;
510                 if (kctl->id.index > id->index)
511                         continue;
512                 if (kctl->id.index + kctl->count <= id->index)
513                         continue;
514                 return kctl;
515         }
516         return NULL;
517 }
518
519 static int snd_ctl_card_info(snd_card_t * card, snd_ctl_file_t * ctl,
520                              unsigned int cmd, void __user *arg)
521 {
522         snd_ctl_card_info_t *info;
523
524         info = kcalloc(1, sizeof(*info), GFP_KERNEL);
525         if (! info)
526                 return -ENOMEM;
527         down_read(&snd_ioctl_rwsem);
528         info->card = card->number;
529         strlcpy(info->id, card->id, sizeof(info->id));
530         strlcpy(info->driver, card->driver, sizeof(info->driver));
531         strlcpy(info->name, card->shortname, sizeof(info->name));
532         strlcpy(info->longname, card->longname, sizeof(info->longname));
533         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
534         strlcpy(info->components, card->components, sizeof(info->components));
535         up_read(&snd_ioctl_rwsem);
536         if (copy_to_user(arg, info, sizeof(snd_ctl_card_info_t))) {
537                 kfree(info);
538                 return -EFAULT;
539         }
540         kfree(info);
541         return 0;
542 }
543
544 static int snd_ctl_elem_list(snd_card_t *card, snd_ctl_elem_list_t __user *_list)
545 {
546         struct list_head *plist;
547         snd_ctl_elem_list_t list;
548         snd_kcontrol_t *kctl;
549         snd_ctl_elem_id_t *dst, *id;
550         unsigned int offset, space, first, jidx;
551         
552         if (copy_from_user(&list, _list, sizeof(list)))
553                 return -EFAULT;
554         offset = list.offset;
555         space = list.space;
556         first = 0;
557         /* try limit maximum space */
558         if (space > 16384)
559                 return -ENOMEM;
560         if (space > 0) {
561                 /* allocate temporary buffer for atomic operation */
562                 dst = vmalloc(space * sizeof(snd_ctl_elem_id_t));
563                 if (dst == NULL)
564                         return -ENOMEM;
565                 down_read(&card->controls_rwsem);
566                 list.count = card->controls_count;
567                 plist = card->controls.next;
568                 while (plist != &card->controls) {
569                         if (offset == 0)
570                                 break;
571                         kctl = snd_kcontrol(plist);
572                         if (offset < kctl->count)
573                                 break;
574                         offset -= kctl->count;
575                         plist = plist->next;
576                 }
577                 list.used = 0;
578                 id = dst;
579                 while (space > 0 && plist != &card->controls) {
580                         kctl = snd_kcontrol(plist);
581                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
582                                 snd_ctl_build_ioff(id, kctl, jidx);
583                                 id++;
584                                 space--;
585                                 list.used++;
586                         }
587                         plist = plist->next;
588                         offset = 0;
589                 }
590                 up_read(&card->controls_rwsem);
591                 if (list.used > 0 && copy_to_user(list.pids, dst, list.used * sizeof(snd_ctl_elem_id_t))) {
592                         vfree(dst);
593                         return -EFAULT;
594                 }
595                 vfree(dst);
596         } else {
597                 down_read(&card->controls_rwsem);
598                 list.count = card->controls_count;
599                 up_read(&card->controls_rwsem);
600         }
601         if (copy_to_user(_list, &list, sizeof(list)))
602                 return -EFAULT;
603         return 0;
604 }
605
606 static int snd_ctl_elem_info(snd_ctl_file_t *ctl, snd_ctl_elem_info_t *info)
607 {
608         snd_card_t *card = ctl->card;
609         snd_kcontrol_t *kctl;
610         snd_kcontrol_volatile_t *vd;
611         unsigned int index_offset;
612         int result;
613         
614         down_read(&card->controls_rwsem);
615         kctl = snd_ctl_find_id(card, &info->id);
616         if (kctl == NULL) {
617                 up_read(&card->controls_rwsem);
618                 return -ENOENT;
619         }
620 #ifdef CONFIG_SND_DEBUG
621         info->access = 0;
622 #endif
623         result = kctl->info(kctl, info);
624         if (result >= 0) {
625                 snd_assert(info->access == 0, );
626                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
627                 vd = &kctl->vd[index_offset];
628                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
629                 info->access = vd->access;
630                 if (vd->owner) {
631                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
632                         if (vd->owner == ctl)
633                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
634                         info->owner = vd->owner_pid;
635                 } else {
636                         info->owner = -1;
637                 }
638         }
639         up_read(&card->controls_rwsem);
640         return result;
641 }
642
643 static int snd_ctl_elem_info_user(snd_ctl_file_t *ctl, snd_ctl_elem_info_t __user *_info)
644 {
645         snd_ctl_elem_info_t info;
646         int result;
647
648         if (copy_from_user(&info, _info, sizeof(info)))
649                 return -EFAULT;
650         result = snd_ctl_elem_info(ctl, &info);
651         if (result >= 0)
652                 if (copy_to_user(_info, &info, sizeof(info)))
653                         return -EFAULT;
654         return result;
655 }
656
657 int snd_ctl_elem_read(snd_card_t *card, snd_ctl_elem_value_t *control)
658 {
659         snd_kcontrol_t *kctl;
660         snd_kcontrol_volatile_t *vd;
661         unsigned int index_offset;
662         int result, indirect;
663
664         down_read(&card->controls_rwsem);
665         kctl = snd_ctl_find_id(card, &control->id);
666         if (kctl == NULL) {
667                 result = -ENOENT;
668         } else {
669                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
670                 vd = &kctl->vd[index_offset];
671                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
672                 if (control->indirect != indirect) {
673                         result = -EACCES;
674                 } else {
675                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
676                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
677                                 result = kctl->get(kctl, control);
678                         } else {
679                                 result = -EPERM;
680                         }
681                 }
682         }
683         up_read(&card->controls_rwsem);
684         return result;
685 }
686
687 static int snd_ctl_elem_read_user(snd_card_t *card, snd_ctl_elem_value_t __user *_control)
688 {
689         snd_ctl_elem_value_t *control;
690         int result;
691         
692         control = kmalloc(sizeof(*control), GFP_KERNEL);
693         if (control == NULL)
694                 return -ENOMEM; 
695         if (copy_from_user(control, _control, sizeof(*control))) {
696                 kfree(control);
697                 return -EFAULT;
698         }
699         result = snd_ctl_elem_read(card, control);
700         if (result >= 0)
701                 if (copy_to_user(_control, control, sizeof(*control)))
702                         result = -EFAULT;
703         kfree(control);
704         return result;
705 }
706
707 int snd_ctl_elem_write(snd_card_t *card, snd_ctl_file_t *file, snd_ctl_elem_value_t *control)
708 {
709         snd_kcontrol_t *kctl;
710         snd_kcontrol_volatile_t *vd;
711         unsigned int index_offset;
712         int result, indirect;
713
714         down_read(&card->controls_rwsem);
715         kctl = snd_ctl_find_id(card, &control->id);
716         if (kctl == NULL) {
717                 result = -ENOENT;
718         } else {
719                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
720                 vd = &kctl->vd[index_offset];
721                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
722                 if (control->indirect != indirect) {
723                         result = -EACCES;
724                 } else {
725                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
726                             kctl->put == NULL ||
727                             (file && vd->owner != NULL && vd->owner != file)) {
728                                 result = -EPERM;
729                         } else {
730                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
731                                 result = kctl->put(kctl, control);
732                         }
733                         if (result > 0) {
734                                 up_read(&card->controls_rwsem);
735                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
736                                 return 0;
737                         }
738                 }
739         }
740         up_read(&card->controls_rwsem);
741         return result;
742 }
743
744 static int snd_ctl_elem_write_user(snd_ctl_file_t *file, snd_ctl_elem_value_t __user *_control)
745 {
746         snd_ctl_elem_value_t *control;
747         int result;
748
749         control = kmalloc(sizeof(*control), GFP_KERNEL);
750         if (control == NULL)
751                 return -ENOMEM; 
752         if (copy_from_user(control, _control, sizeof(*control))) {
753                 kfree(control);
754                 return -EFAULT;
755         }
756         result = snd_ctl_elem_write(file->card, file, control);
757         if (result >= 0)
758                 if (copy_to_user(_control, control, sizeof(*control)))
759                         result = -EFAULT;
760         kfree(control);
761         return result;
762 }
763
764 static int snd_ctl_elem_lock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
765 {
766         snd_card_t *card = file->card;
767         snd_ctl_elem_id_t id;
768         snd_kcontrol_t *kctl;
769         snd_kcontrol_volatile_t *vd;
770         int result;
771         
772         if (copy_from_user(&id, _id, sizeof(id)))
773                 return -EFAULT;
774         down_write(&card->controls_rwsem);
775         kctl = snd_ctl_find_id(card, &id);
776         if (kctl == NULL) {
777                 result = -ENOENT;
778         } else {
779                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
780                 if (vd->owner != NULL)
781                         result = -EBUSY;
782                 else {
783                         vd->owner = file;
784                         vd->owner_pid = current->pid;
785                         result = 0;
786                 }
787         }
788         up_write(&card->controls_rwsem);
789         return result;
790 }
791
792 static int snd_ctl_elem_unlock(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
793 {
794         snd_card_t *card = file->card;
795         snd_ctl_elem_id_t id;
796         snd_kcontrol_t *kctl;
797         snd_kcontrol_volatile_t *vd;
798         int result;
799         
800         if (copy_from_user(&id, _id, sizeof(id)))
801                 return -EFAULT;
802         down_write(&card->controls_rwsem);
803         kctl = snd_ctl_find_id(card, &id);
804         if (kctl == NULL) {
805                 result = -ENOENT;
806         } else {
807                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
808                 if (vd->owner == NULL)
809                         result = -EINVAL;
810                 else if (vd->owner != file)
811                         result = -EPERM;
812                 else {
813                         vd->owner = NULL;
814                         vd->owner_pid = 0;
815                         result = 0;
816                 }
817         }
818         up_write(&card->controls_rwsem);
819         return result;
820 }
821
822 struct user_element {
823         snd_ctl_elem_info_t info;
824         void *elem_data;                /* element data */
825         unsigned long elem_data_size;   /* size of element data in bytes */
826         void *priv_data;                /* private data (like strings for enumerated type) */
827         unsigned long priv_data_size;   /* size of private data in bytes */
828 };
829
830 static int snd_ctl_elem_user_info(snd_kcontrol_t *kcontrol, snd_ctl_elem_info_t *uinfo)
831 {
832         struct user_element *ue = kcontrol->private_data;
833
834         *uinfo = ue->info;
835         return 0;
836 }
837
838 static int snd_ctl_elem_user_get(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
839 {
840         struct user_element *ue = kcontrol->private_data;
841
842         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
843         return 0;
844 }
845
846 static int snd_ctl_elem_user_put(snd_kcontrol_t * kcontrol, snd_ctl_elem_value_t * ucontrol)
847 {
848         int change;
849         struct user_element *ue = kcontrol->private_data;
850         
851         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
852         if (change)
853                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
854         return change;
855 }
856
857 static void snd_ctl_elem_user_free(snd_kcontrol_t * kcontrol)
858 {
859         kfree(kcontrol->private_data);
860 }
861
862 static int snd_ctl_elem_add(snd_ctl_file_t *file, snd_ctl_elem_info_t *info, int replace)
863 {
864         snd_card_t *card = file->card;
865         snd_kcontrol_t kctl, *_kctl;
866         unsigned int access;
867         long private_size;
868         struct user_element *ue;
869         int idx, err;
870         
871         if (card->user_ctl_count >= MAX_USER_CONTROLS)
872                 return -ENOMEM;
873         if (info->count > 1024)
874                 return -EINVAL;
875         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
876                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE));
877         info->id.numid = 0;
878         memset(&kctl, 0, sizeof(kctl));
879         down_write(&card->controls_rwsem);
880         _kctl = snd_ctl_find_id(card, &info->id);
881         err = 0;
882         if (_kctl) {
883                 if (replace)
884                         err = snd_ctl_remove(card, _kctl);
885                 else
886                         err = -EBUSY;
887         } else {
888                 if (replace)
889                         err = -ENOENT;
890         }
891         up_write(&card->controls_rwsem);
892         if (err < 0)
893                 return err;
894         memcpy(&kctl.id, &info->id, sizeof(info->id));
895         kctl.count = info->owner ? info->owner : 1;
896         access |= SNDRV_CTL_ELEM_ACCESS_USER;
897         kctl.info = snd_ctl_elem_user_info;
898         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
899                 kctl.get = snd_ctl_elem_user_get;
900         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
901                 kctl.put = snd_ctl_elem_user_put;
902         switch (info->type) {
903         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
904                 private_size = sizeof(char);
905                 if (info->count > 128)
906                         return -EINVAL;
907                 break;
908         case SNDRV_CTL_ELEM_TYPE_INTEGER:
909                 private_size = sizeof(long);
910                 if (info->count > 128)
911                         return -EINVAL;
912                 break;
913         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
914                 private_size = sizeof(long long);
915                 if (info->count > 64)
916                         return -EINVAL;
917                 break;
918         case SNDRV_CTL_ELEM_TYPE_BYTES:
919                 private_size = sizeof(unsigned char);
920                 if (info->count > 512)
921                         return -EINVAL;
922                 break;
923         case SNDRV_CTL_ELEM_TYPE_IEC958:
924                 private_size = sizeof(struct sndrv_aes_iec958);
925                 if (info->count != 1)
926                         return -EINVAL;
927                 break;
928         default:
929                 return -EINVAL;
930         }
931         private_size *= info->count;
932         ue = kcalloc(1, sizeof(struct user_element) + private_size, GFP_KERNEL);
933         if (ue == NULL)
934                 return -ENOMEM;
935         ue->info = *info;
936         ue->elem_data = (char *)ue + sizeof(*ue);
937         ue->elem_data_size = private_size;
938         kctl.private_free = snd_ctl_elem_user_free;
939         _kctl = snd_ctl_new(&kctl, access);
940         if (_kctl == NULL) {
941                 kfree(_kctl->private_data);
942                 return -ENOMEM;
943         }
944         _kctl->private_data = ue;
945         for (idx = 0; idx < _kctl->count; idx++)
946                 _kctl->vd[idx].owner = file;
947         err = snd_ctl_add(card, _kctl);
948         if (err < 0) {
949                 snd_ctl_free_one(_kctl);
950                 return err;
951         }
952
953         down_write(&card->controls_rwsem);
954         card->user_ctl_count++;
955         up_write(&card->controls_rwsem);
956
957         return 0;
958 }
959
960 static int snd_ctl_elem_add_user(snd_ctl_file_t *file, snd_ctl_elem_info_t __user *_info, int replace)
961 {
962         snd_ctl_elem_info_t info;
963         if (copy_from_user(&info, _info, sizeof(info)))
964                 return -EFAULT;
965         return snd_ctl_elem_add(file, &info, replace);
966 }
967
968 static int snd_ctl_elem_remove(snd_ctl_file_t *file, snd_ctl_elem_id_t __user *_id)
969 {
970         snd_ctl_elem_id_t id;
971         int err;
972
973         if (copy_from_user(&id, _id, sizeof(id)))
974                 return -EFAULT;
975         err = snd_ctl_remove_unlocked_id(file, &id);
976         if (! err) {
977                 snd_card_t *card = file->card;
978                 down_write(&card->controls_rwsem);
979                 card->user_ctl_count--;
980                 up_write(&card->controls_rwsem);
981         }
982         return err;
983 }
984
985 static int snd_ctl_subscribe_events(snd_ctl_file_t *file, int __user *ptr)
986 {
987         int subscribe;
988         if (get_user(subscribe, ptr))
989                 return -EFAULT;
990         if (subscribe < 0) {
991                 subscribe = file->subscribed;
992                 if (put_user(subscribe, ptr))
993                         return -EFAULT;
994                 return 0;
995         }
996         if (subscribe) {
997                 file->subscribed = 1;
998                 return 0;
999         } else if (file->subscribed) {
1000                 snd_ctl_empty_read_queue(file);
1001                 file->subscribed = 0;
1002         }
1003         return 0;
1004 }
1005
1006 #ifdef CONFIG_PM
1007 /*
1008  * change the power state
1009  */
1010 static int snd_ctl_set_power_state(snd_card_t *card, unsigned int power_state)
1011 {
1012         switch (power_state) {
1013         case SNDRV_CTL_POWER_D0:
1014                 if (card->power_state != power_state) {
1015                         card->pm_resume(card);
1016                         snd_power_change_state(card, power_state);
1017                 }
1018                 break;
1019         case SNDRV_CTL_POWER_D3hot:
1020                 if (card->power_state != power_state) {
1021                         card->pm_suspend(card, PMSG_SUSPEND);
1022                         snd_power_change_state(card, power_state);
1023                 }
1024                 break;
1025         case SNDRV_CTL_POWER_D1:
1026         case SNDRV_CTL_POWER_D2:
1027         case SNDRV_CTL_POWER_D3cold:
1028                 /* not supported yet */
1029         default:
1030                 return -EINVAL;
1031         }
1032         return 0;
1033 }
1034 #endif
1035
1036 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1037 {
1038         snd_ctl_file_t *ctl;
1039         snd_card_t *card;
1040         struct list_head *list;
1041         snd_kctl_ioctl_t *p;
1042         void __user *argp = (void __user *)arg;
1043         int __user *ip = argp;
1044         int err;
1045
1046         ctl = file->private_data;
1047         card = ctl->card;
1048         snd_assert(card != NULL, return -ENXIO);
1049         switch (cmd) {
1050         case SNDRV_CTL_IOCTL_PVERSION:
1051                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1052         case SNDRV_CTL_IOCTL_CARD_INFO:
1053                 return snd_ctl_card_info(card, ctl, cmd, argp);
1054         case SNDRV_CTL_IOCTL_ELEM_LIST:
1055                 return snd_ctl_elem_list(ctl->card, argp);
1056         case SNDRV_CTL_IOCTL_ELEM_INFO:
1057                 return snd_ctl_elem_info_user(ctl, argp);
1058         case SNDRV_CTL_IOCTL_ELEM_READ:
1059                 return snd_ctl_elem_read_user(ctl->card, argp);
1060         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1061                 return snd_ctl_elem_write_user(ctl, argp);
1062         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1063                 return snd_ctl_elem_lock(ctl, argp);
1064         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1065                 return snd_ctl_elem_unlock(ctl, argp);
1066         case SNDRV_CTL_IOCTL_ELEM_ADD:
1067                 return snd_ctl_elem_add_user(ctl, argp, 0);
1068         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1069                 return snd_ctl_elem_add_user(ctl, argp, 1);
1070         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1071                 return snd_ctl_elem_remove(ctl, argp);
1072         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1073                 return snd_ctl_subscribe_events(ctl, ip);
1074         case SNDRV_CTL_IOCTL_POWER:
1075                 if (get_user(err, ip))
1076                         return -EFAULT;
1077                 if (!capable(CAP_SYS_ADMIN))
1078                         return -EPERM;
1079 #ifdef CONFIG_PM
1080                 if (card->pm_suspend && card->pm_resume) {
1081                         snd_power_lock(card);
1082                         err = snd_ctl_set_power_state(card, err);
1083                         snd_power_unlock(card);
1084                 } else
1085 #endif
1086                         err = -ENOPROTOOPT;
1087                 return err;
1088         case SNDRV_CTL_IOCTL_POWER_STATE:
1089 #ifdef CONFIG_PM
1090                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1091 #else
1092                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1093 #endif
1094         }
1095         down_read(&snd_ioctl_rwsem);
1096         list_for_each(list, &snd_control_ioctls) {
1097                 p = list_entry(list, snd_kctl_ioctl_t, list);
1098                 err = p->fioctl(card, ctl, cmd, arg);
1099                 if (err != -ENOIOCTLCMD) {
1100                         up_read(&snd_ioctl_rwsem);
1101                         return err;
1102                 }
1103         }
1104         up_read(&snd_ioctl_rwsem);
1105         snd_printd("unknown ioctl = 0x%x\n", cmd);
1106         return -ENOTTY;
1107 }
1108
1109 static ssize_t snd_ctl_read(struct file *file, char __user *buffer, size_t count, loff_t * offset)
1110 {
1111         snd_ctl_file_t *ctl;
1112         int err = 0;
1113         ssize_t result = 0;
1114
1115         ctl = file->private_data;
1116         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1117         if (!ctl->subscribed)
1118                 return -EBADFD;
1119         if (count < sizeof(snd_ctl_event_t))
1120                 return -EINVAL;
1121         spin_lock_irq(&ctl->read_lock);
1122         while (count >= sizeof(snd_ctl_event_t)) {
1123                 snd_ctl_event_t ev;
1124                 snd_kctl_event_t *kev;
1125                 while (list_empty(&ctl->events)) {
1126                         wait_queue_t wait;
1127                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1128                                 err = -EAGAIN;
1129                                 goto __end_lock;
1130                         }
1131                         init_waitqueue_entry(&wait, current);
1132                         add_wait_queue(&ctl->change_sleep, &wait);
1133                         set_current_state(TASK_INTERRUPTIBLE);
1134                         spin_unlock_irq(&ctl->read_lock);
1135                         schedule();
1136                         remove_wait_queue(&ctl->change_sleep, &wait);
1137                         if (signal_pending(current))
1138                                 return result > 0 ? result : -ERESTARTSYS;
1139                         spin_lock_irq(&ctl->read_lock);
1140                 }
1141                 kev = snd_kctl_event(ctl->events.next);
1142                 ev.type = SNDRV_CTL_EVENT_ELEM;
1143                 ev.data.elem.mask = kev->mask;
1144                 ev.data.elem.id = kev->id;
1145                 list_del(&kev->list);
1146                 spin_unlock_irq(&ctl->read_lock);
1147                 kfree(kev);
1148                 if (copy_to_user(buffer, &ev, sizeof(snd_ctl_event_t))) {
1149                         err = -EFAULT;
1150                         goto __end;
1151                 }
1152                 spin_lock_irq(&ctl->read_lock);
1153                 buffer += sizeof(snd_ctl_event_t);
1154                 count -= sizeof(snd_ctl_event_t);
1155                 result += sizeof(snd_ctl_event_t);
1156         }
1157       __end_lock:
1158         spin_unlock_irq(&ctl->read_lock);
1159       __end:
1160         return result > 0 ? result : err;
1161 }
1162
1163 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1164 {
1165         unsigned int mask;
1166         snd_ctl_file_t *ctl;
1167
1168         ctl = file->private_data;
1169         if (!ctl->subscribed)
1170                 return 0;
1171         poll_wait(file, &ctl->change_sleep, wait);
1172
1173         mask = 0;
1174         if (!list_empty(&ctl->events))
1175                 mask |= POLLIN | POLLRDNORM;
1176
1177         return mask;
1178 }
1179
1180 /*
1181  * register the device-specific control-ioctls.
1182  * called from each device manager like pcm.c, hwdep.c, etc.
1183  */
1184 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1185 {
1186         snd_kctl_ioctl_t *pn;
1187
1188         pn = kcalloc(1, sizeof(snd_kctl_ioctl_t), GFP_KERNEL);
1189         if (pn == NULL)
1190                 return -ENOMEM;
1191         pn->fioctl = fcn;
1192         down_write(&snd_ioctl_rwsem);
1193         list_add_tail(&pn->list, lists);
1194         up_write(&snd_ioctl_rwsem);
1195         return 0;
1196 }
1197
1198 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1199 {
1200         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1201 }
1202
1203 #ifdef CONFIG_COMPAT
1204 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1205 {
1206         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1207 }
1208 #endif
1209
1210 /*
1211  * de-register the device-specific control-ioctls.
1212  */
1213 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1214 {
1215         struct list_head *list;
1216         snd_kctl_ioctl_t *p;
1217
1218         snd_runtime_check(fcn != NULL, return -EINVAL);
1219         down_write(&snd_ioctl_rwsem);
1220         list_for_each(list, lists) {
1221                 p = list_entry(list, snd_kctl_ioctl_t, list);
1222                 if (p->fioctl == fcn) {
1223                         list_del(&p->list);
1224                         up_write(&snd_ioctl_rwsem);
1225                         kfree(p);
1226                         return 0;
1227                 }
1228         }
1229         up_write(&snd_ioctl_rwsem);
1230         snd_BUG();
1231         return -EINVAL;
1232 }
1233
1234 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1235 {
1236         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1237 }
1238
1239 #ifdef CONFIG_COMPAT
1240 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1241 {
1242         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1243 }
1244
1245 #endif
1246
1247 static int snd_ctl_fasync(int fd, struct file * file, int on)
1248 {
1249         snd_ctl_file_t *ctl;
1250         int err;
1251         ctl = file->private_data;
1252         err = fasync_helper(fd, file, on, &ctl->fasync);
1253         if (err < 0)
1254                 return err;
1255         return 0;
1256 }
1257
1258 /*
1259  * ioctl32 compat
1260  */
1261 #ifdef CONFIG_COMPAT
1262 #include "control_compat.c"
1263 #else
1264 #define snd_ctl_ioctl_compat    NULL
1265 #endif
1266
1267 /*
1268  *  INIT PART
1269  */
1270
1271 static struct file_operations snd_ctl_f_ops =
1272 {
1273         .owner =        THIS_MODULE,
1274         .read =         snd_ctl_read,
1275         .open =         snd_ctl_open,
1276         .release =      snd_ctl_release,
1277         .poll =         snd_ctl_poll,
1278         .unlocked_ioctl =       snd_ctl_ioctl,
1279         .compat_ioctl = snd_ctl_ioctl_compat,
1280         .fasync =       snd_ctl_fasync,
1281 };
1282
1283 static snd_minor_t snd_ctl_reg =
1284 {
1285         .comment =      "ctl",
1286         .f_ops =        &snd_ctl_f_ops,
1287 };
1288
1289 /*
1290  * registration of the control device
1291  */
1292 static int snd_ctl_dev_register(snd_device_t *device)
1293 {
1294         snd_card_t *card = device->device_data;
1295         int err, cardnum;
1296         char name[16];
1297
1298         snd_assert(card != NULL, return -ENXIO);
1299         cardnum = card->number;
1300         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1301         sprintf(name, "controlC%i", cardnum);
1302         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL,
1303                                         card, 0, &snd_ctl_reg, name)) < 0)
1304                 return err;
1305         return 0;
1306 }
1307
1308 /*
1309  * disconnection of the control device
1310  */
1311 static int snd_ctl_dev_disconnect(snd_device_t *device)
1312 {
1313         snd_card_t *card = device->device_data;
1314         struct list_head *flist;
1315         snd_ctl_file_t *ctl;
1316
1317         down_read(&card->controls_rwsem);
1318         list_for_each(flist, &card->ctl_files) {
1319                 ctl = snd_ctl_file(flist);
1320                 wake_up(&ctl->change_sleep);
1321                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1322         }
1323         up_read(&card->controls_rwsem);
1324         return 0;
1325 }
1326
1327 /*
1328  * free all controls
1329  */
1330 static int snd_ctl_dev_free(snd_device_t *device)
1331 {
1332         snd_card_t *card = device->device_data;
1333         snd_kcontrol_t *control;
1334
1335         down_write(&card->controls_rwsem);
1336         while (!list_empty(&card->controls)) {
1337                 control = snd_kcontrol(card->controls.next);
1338                 snd_ctl_remove(card, control);
1339         }
1340         up_write(&card->controls_rwsem);
1341         return 0;
1342 }
1343
1344 /*
1345  * de-registration of the control device
1346  */
1347 static int snd_ctl_dev_unregister(snd_device_t *device)
1348 {
1349         snd_card_t *card = device->device_data;
1350         int err, cardnum;
1351
1352         snd_assert(card != NULL, return -ENXIO);
1353         cardnum = card->number;
1354         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1355         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL, card, 0)) < 0)
1356                 return err;
1357         return snd_ctl_dev_free(device);
1358 }
1359
1360 /*
1361  * create control core:
1362  * called from init.c
1363  */
1364 int snd_ctl_create(snd_card_t *card)
1365 {
1366         static snd_device_ops_t ops = {
1367                 .dev_free = snd_ctl_dev_free,
1368                 .dev_register = snd_ctl_dev_register,
1369                 .dev_disconnect = snd_ctl_dev_disconnect,
1370                 .dev_unregister = snd_ctl_dev_unregister
1371         };
1372
1373         snd_assert(card != NULL, return -ENXIO);
1374         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1375 }