sound: snd_ctl_remove_unlocked_id: simplify user control counting
[linux-2.6.git] / sound / core / control.c
1 /*
2  *  Routines for driver control interface
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <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>
31
32 /* max number of user-defined controls */
33 #define MAX_USER_CONTROLS       32
34
35 struct snd_kctl_ioctl {
36         struct list_head list;          /* list of all ioctls */
37         snd_kctl_ioctl_func_t fioctl;
38 };
39
40 static DECLARE_RWSEM(snd_ioctl_rwsem);
41 static LIST_HEAD(snd_control_ioctls);
42 #ifdef CONFIG_COMPAT
43 static LIST_HEAD(snd_control_compat_ioctls);
44 #endif
45
46 static int snd_ctl_open(struct inode *inode, struct file *file)
47 {
48         unsigned long flags;
49         struct snd_card *card;
50         struct snd_ctl_file *ctl;
51         int err;
52
53         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
54         if (!card) {
55                 err = -ENODEV;
56                 goto __error1;
57         }
58         err = snd_card_file_add(card, file);
59         if (err < 0) {
60                 err = -ENODEV;
61                 goto __error1;
62         }
63         if (!try_module_get(card->module)) {
64                 err = -EFAULT;
65                 goto __error2;
66         }
67         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
68         if (ctl == NULL) {
69                 err = -ENOMEM;
70                 goto __error;
71         }
72         INIT_LIST_HEAD(&ctl->events);
73         init_waitqueue_head(&ctl->change_sleep);
74         spin_lock_init(&ctl->read_lock);
75         ctl->card = card;
76         ctl->prefer_pcm_subdevice = -1;
77         ctl->prefer_rawmidi_subdevice = -1;
78         ctl->pid = current->pid;
79         file->private_data = ctl;
80         write_lock_irqsave(&card->ctl_files_rwlock, flags);
81         list_add_tail(&ctl->list, &card->ctl_files);
82         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
83         return 0;
84
85       __error:
86         module_put(card->module);
87       __error2:
88         snd_card_file_remove(card, file);
89       __error1:
90         return err;
91 }
92
93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
94 {
95         unsigned long flags;
96         struct snd_kctl_event *cread;
97         
98         spin_lock_irqsave(&ctl->read_lock, flags);
99         while (!list_empty(&ctl->events)) {
100                 cread = snd_kctl_event(ctl->events.next);
101                 list_del(&cread->list);
102                 kfree(cread);
103         }
104         spin_unlock_irqrestore(&ctl->read_lock, flags);
105 }
106
107 static int snd_ctl_release(struct inode *inode, struct file *file)
108 {
109         unsigned long flags;
110         struct snd_card *card;
111         struct snd_ctl_file *ctl;
112         struct snd_kcontrol *control;
113         unsigned int idx;
114
115         ctl = file->private_data;
116         file->private_data = NULL;
117         card = ctl->card;
118         write_lock_irqsave(&card->ctl_files_rwlock, flags);
119         list_del(&ctl->list);
120         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
121         down_write(&card->controls_rwsem);
122         list_for_each_entry(control, &card->controls, list)
123                 for (idx = 0; idx < control->count; idx++)
124                         if (control->vd[idx].owner == ctl)
125                                 control->vd[idx].owner = NULL;
126         up_write(&card->controls_rwsem);
127         snd_ctl_empty_read_queue(ctl);
128         kfree(ctl);
129         module_put(card->module);
130         snd_card_file_remove(card, file);
131         return 0;
132 }
133
134 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
135                     struct snd_ctl_elem_id *id)
136 {
137         unsigned long flags;
138         struct snd_ctl_file *ctl;
139         struct snd_kctl_event *ev;
140         
141         if (snd_BUG_ON(!card || !id))
142                 return;
143         read_lock(&card->ctl_files_rwlock);
144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
145         card->mixer_oss_change_count++;
146 #endif
147         list_for_each_entry(ctl, &card->ctl_files, list) {
148                 if (!ctl->subscribed)
149                         continue;
150                 spin_lock_irqsave(&ctl->read_lock, flags);
151                 list_for_each_entry(ev, &ctl->events, list) {
152                         if (ev->id.numid == id->numid) {
153                                 ev->mask |= mask;
154                                 goto _found;
155                         }
156                 }
157                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
158                 if (ev) {
159                         ev->id = *id;
160                         ev->mask = mask;
161                         list_add_tail(&ev->list, &ctl->events);
162                 } else {
163                         snd_printk(KERN_ERR "No memory available to allocate event\n");
164                 }
165         _found:
166                 wake_up(&ctl->change_sleep);
167                 spin_unlock_irqrestore(&ctl->read_lock, flags);
168                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
169         }
170         read_unlock(&card->ctl_files_rwlock);
171 }
172
173 EXPORT_SYMBOL(snd_ctl_notify);
174
175 /**
176  * snd_ctl_new - create a control instance from the template
177  * @control: the control template
178  * @access: the default control access
179  *
180  * Allocates a new struct snd_kcontrol instance and copies the given template 
181  * to the new instance. It does not copy volatile data (access).
182  *
183  * Returns the pointer of the new instance, or NULL on failure.
184  */
185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
186                                         unsigned int access)
187 {
188         struct snd_kcontrol *kctl;
189         unsigned int idx;
190         
191         if (snd_BUG_ON(!control || !control->count))
192                 return NULL;
193         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
194         if (kctl == NULL) {
195                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
196                 return NULL;
197         }
198         *kctl = *control;
199         for (idx = 0; idx < kctl->count; idx++)
200                 kctl->vd[idx].access = access;
201         return kctl;
202 }
203
204 /**
205  * snd_ctl_new1 - create a control instance from the template
206  * @ncontrol: the initialization record
207  * @private_data: the private data to set
208  *
209  * Allocates a new struct snd_kcontrol instance and initialize from the given 
210  * template.  When the access field of ncontrol is 0, it's assumed as
211  * READWRITE access. When the count field is 0, it's assumes as one.
212  *
213  * Returns the pointer of the newly generated instance, or NULL on failure.
214  */
215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
216                                   void *private_data)
217 {
218         struct snd_kcontrol kctl;
219         unsigned int access;
220         
221         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
222                 return NULL;
223         memset(&kctl, 0, sizeof(kctl));
224         kctl.id.iface = ncontrol->iface;
225         kctl.id.device = ncontrol->device;
226         kctl.id.subdevice = ncontrol->subdevice;
227         if (ncontrol->name) {
228                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
229                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
230                         snd_printk(KERN_WARNING
231                                    "Control name '%s' truncated to '%s'\n",
232                                    ncontrol->name, kctl.id.name);
233         }
234         kctl.id.index = ncontrol->index;
235         kctl.count = ncontrol->count ? ncontrol->count : 1;
236         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
237                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
238                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
239                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
240                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
241         kctl.info = ncontrol->info;
242         kctl.get = ncontrol->get;
243         kctl.put = ncontrol->put;
244         kctl.tlv.p = ncontrol->tlv.p;
245         kctl.private_value = ncontrol->private_value;
246         kctl.private_data = private_data;
247         return snd_ctl_new(&kctl, access);
248 }
249
250 EXPORT_SYMBOL(snd_ctl_new1);
251
252 /**
253  * snd_ctl_free_one - release the control instance
254  * @kcontrol: the control instance
255  *
256  * Releases the control instance created via snd_ctl_new()
257  * or snd_ctl_new1().
258  * Don't call this after the control was added to the card.
259  */
260 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
261 {
262         if (kcontrol) {
263                 if (kcontrol->private_free)
264                         kcontrol->private_free(kcontrol);
265                 kfree(kcontrol);
266         }
267 }
268
269 EXPORT_SYMBOL(snd_ctl_free_one);
270
271 static unsigned int snd_ctl_hole_check(struct snd_card *card,
272                                        unsigned int count)
273 {
274         struct snd_kcontrol *kctl;
275
276         list_for_each_entry(kctl, &card->controls, list) {
277                 if ((kctl->id.numid <= card->last_numid &&
278                      kctl->id.numid + kctl->count > card->last_numid) ||
279                     (kctl->id.numid <= card->last_numid + count - 1 &&
280                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
281                         return card->last_numid = kctl->id.numid + kctl->count - 1;
282         }
283         return card->last_numid;
284 }
285
286 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
287 {
288         unsigned int last_numid, iter = 100000;
289
290         last_numid = card->last_numid;
291         while (last_numid != snd_ctl_hole_check(card, count)) {
292                 if (--iter == 0) {
293                         /* this situation is very unlikely */
294                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
295                         return -ENOMEM;
296                 }
297                 last_numid = card->last_numid;
298         }
299         return 0;
300 }
301
302 /**
303  * snd_ctl_add - add the control instance to the card
304  * @card: the card instance
305  * @kcontrol: the control instance to add
306  *
307  * Adds the control instance created via snd_ctl_new() or
308  * snd_ctl_new1() to the given card. Assigns also an unique
309  * numid used for fast search.
310  *
311  * Returns zero if successful, or a negative error code on failure.
312  *
313  * It frees automatically the control which cannot be added.
314  */
315 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
316 {
317         struct snd_ctl_elem_id id;
318         unsigned int idx;
319         int err = -EINVAL;
320
321         if (! kcontrol)
322                 return err;
323         if (snd_BUG_ON(!card || !kcontrol->info))
324                 goto error;
325         id = kcontrol->id;
326         down_write(&card->controls_rwsem);
327         if (snd_ctl_find_id(card, &id)) {
328                 up_write(&card->controls_rwsem);
329                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
330                                         id.iface,
331                                         id.device,
332                                         id.subdevice,
333                                         id.name,
334                                         id.index);
335                 err = -EBUSY;
336                 goto error;
337         }
338         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
339                 up_write(&card->controls_rwsem);
340                 err = -ENOMEM;
341                 goto error;
342         }
343         list_add_tail(&kcontrol->list, &card->controls);
344         card->controls_count += kcontrol->count;
345         kcontrol->id.numid = card->last_numid + 1;
346         card->last_numid += kcontrol->count;
347         up_write(&card->controls_rwsem);
348         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
349                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
350         return 0;
351
352  error:
353         snd_ctl_free_one(kcontrol);
354         return err;
355 }
356
357 EXPORT_SYMBOL(snd_ctl_add);
358
359 /**
360  * snd_ctl_remove - remove the control from the card and release it
361  * @card: the card instance
362  * @kcontrol: the control instance to remove
363  *
364  * Removes the control from the card and then releases the instance.
365  * You don't need to call snd_ctl_free_one(). You must be in
366  * the write lock - down_write(&card->controls_rwsem).
367  * 
368  * Returns 0 if successful, or a negative error code on failure.
369  */
370 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
371 {
372         struct snd_ctl_elem_id id;
373         unsigned int idx;
374
375         if (snd_BUG_ON(!card || !kcontrol))
376                 return -EINVAL;
377         list_del(&kcontrol->list);
378         card->controls_count -= kcontrol->count;
379         id = kcontrol->id;
380         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
381                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
382         snd_ctl_free_one(kcontrol);
383         return 0;
384 }
385
386 EXPORT_SYMBOL(snd_ctl_remove);
387
388 /**
389  * snd_ctl_remove_id - remove the control of the given id and release it
390  * @card: the card instance
391  * @id: the control id to remove
392  *
393  * Finds the control instance with the given id, removes it from the
394  * card list and releases it.
395  * 
396  * Returns 0 if successful, or a negative error code on failure.
397  */
398 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
399 {
400         struct snd_kcontrol *kctl;
401         int ret;
402
403         down_write(&card->controls_rwsem);
404         kctl = snd_ctl_find_id(card, id);
405         if (kctl == NULL) {
406                 up_write(&card->controls_rwsem);
407                 return -ENOENT;
408         }
409         ret = snd_ctl_remove(card, kctl);
410         up_write(&card->controls_rwsem);
411         return ret;
412 }
413
414 EXPORT_SYMBOL(snd_ctl_remove_id);
415
416 /**
417  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
418  * @file: active control handle
419  * @id: the control id to remove
420  *
421  * Finds the control instance with the given id, removes it from the
422  * card list and releases it.
423  * 
424  * Returns 0 if successful, or a negative error code on failure.
425  */
426 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
427                                    struct snd_ctl_elem_id *id)
428 {
429         struct snd_card *card = file->card;
430         struct snd_kcontrol *kctl;
431         int idx, ret;
432
433         down_write(&card->controls_rwsem);
434         kctl = snd_ctl_find_id(card, id);
435         if (kctl == NULL) {
436                 ret = -ENOENT;
437                 goto error;
438         }
439         for (idx = 0; idx < kctl->count; idx++)
440                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
441                         ret = -EBUSY;
442                         goto error;
443                 }
444         ret = snd_ctl_remove(card, kctl);
445         if (ret < 0)
446                 goto error;
447         card->user_ctl_count--;
448 error:
449         up_write(&card->controls_rwsem);
450         return ret;
451 }
452
453 /**
454  * snd_ctl_rename_id - replace the id of a control on the card
455  * @card: the card instance
456  * @src_id: the old id
457  * @dst_id: the new id
458  *
459  * Finds the control with the old id from the card, and replaces the
460  * id with the new one.
461  *
462  * Returns zero if successful, or a negative error code on failure.
463  */
464 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
465                       struct snd_ctl_elem_id *dst_id)
466 {
467         struct snd_kcontrol *kctl;
468
469         down_write(&card->controls_rwsem);
470         kctl = snd_ctl_find_id(card, src_id);
471         if (kctl == NULL) {
472                 up_write(&card->controls_rwsem);
473                 return -ENOENT;
474         }
475         kctl->id = *dst_id;
476         kctl->id.numid = card->last_numid + 1;
477         card->last_numid += kctl->count;
478         up_write(&card->controls_rwsem);
479         return 0;
480 }
481
482 EXPORT_SYMBOL(snd_ctl_rename_id);
483
484 /**
485  * snd_ctl_find_numid - find the control instance with the given number-id
486  * @card: the card instance
487  * @numid: the number-id to search
488  *
489  * Finds the control instance with the given number-id from the card.
490  *
491  * Returns the pointer of the instance if found, or NULL if not.
492  *
493  * The caller must down card->controls_rwsem before calling this function
494  * (if the race condition can happen).
495  */
496 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
497 {
498         struct snd_kcontrol *kctl;
499
500         if (snd_BUG_ON(!card || !numid))
501                 return NULL;
502         list_for_each_entry(kctl, &card->controls, list) {
503                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
504                         return kctl;
505         }
506         return NULL;
507 }
508
509 EXPORT_SYMBOL(snd_ctl_find_numid);
510
511 /**
512  * snd_ctl_find_id - find the control instance with the given id
513  * @card: the card instance
514  * @id: the id to search
515  *
516  * Finds the control instance with the given id from the card.
517  *
518  * Returns the pointer of the instance if found, or NULL if not.
519  *
520  * The caller must down card->controls_rwsem before calling this function
521  * (if the race condition can happen).
522  */
523 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
524                                      struct snd_ctl_elem_id *id)
525 {
526         struct snd_kcontrol *kctl;
527
528         if (snd_BUG_ON(!card || !id))
529                 return NULL;
530         if (id->numid != 0)
531                 return snd_ctl_find_numid(card, id->numid);
532         list_for_each_entry(kctl, &card->controls, list) {
533                 if (kctl->id.iface != id->iface)
534                         continue;
535                 if (kctl->id.device != id->device)
536                         continue;
537                 if (kctl->id.subdevice != id->subdevice)
538                         continue;
539                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
540                         continue;
541                 if (kctl->id.index > id->index)
542                         continue;
543                 if (kctl->id.index + kctl->count <= id->index)
544                         continue;
545                 return kctl;
546         }
547         return NULL;
548 }
549
550 EXPORT_SYMBOL(snd_ctl_find_id);
551
552 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
553                              unsigned int cmd, void __user *arg)
554 {
555         struct snd_ctl_card_info *info;
556
557         info = kzalloc(sizeof(*info), GFP_KERNEL);
558         if (! info)
559                 return -ENOMEM;
560         down_read(&snd_ioctl_rwsem);
561         info->card = card->number;
562         strlcpy(info->id, card->id, sizeof(info->id));
563         strlcpy(info->driver, card->driver, sizeof(info->driver));
564         strlcpy(info->name, card->shortname, sizeof(info->name));
565         strlcpy(info->longname, card->longname, sizeof(info->longname));
566         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
567         strlcpy(info->components, card->components, sizeof(info->components));
568         up_read(&snd_ioctl_rwsem);
569         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
570                 kfree(info);
571                 return -EFAULT;
572         }
573         kfree(info);
574         return 0;
575 }
576
577 static int snd_ctl_elem_list(struct snd_card *card,
578                              struct snd_ctl_elem_list __user *_list)
579 {
580         struct list_head *plist;
581         struct snd_ctl_elem_list list;
582         struct snd_kcontrol *kctl;
583         struct snd_ctl_elem_id *dst, *id;
584         unsigned int offset, space, first, jidx;
585         
586         if (copy_from_user(&list, _list, sizeof(list)))
587                 return -EFAULT;
588         offset = list.offset;
589         space = list.space;
590         first = 0;
591         /* try limit maximum space */
592         if (space > 16384)
593                 return -ENOMEM;
594         if (space > 0) {
595                 /* allocate temporary buffer for atomic operation */
596                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
597                 if (dst == NULL)
598                         return -ENOMEM;
599                 down_read(&card->controls_rwsem);
600                 list.count = card->controls_count;
601                 plist = card->controls.next;
602                 while (plist != &card->controls) {
603                         if (offset == 0)
604                                 break;
605                         kctl = snd_kcontrol(plist);
606                         if (offset < kctl->count)
607                                 break;
608                         offset -= kctl->count;
609                         plist = plist->next;
610                 }
611                 list.used = 0;
612                 id = dst;
613                 while (space > 0 && plist != &card->controls) {
614                         kctl = snd_kcontrol(plist);
615                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
616                                 snd_ctl_build_ioff(id, kctl, jidx);
617                                 id++;
618                                 space--;
619                                 list.used++;
620                         }
621                         plist = plist->next;
622                         offset = 0;
623                 }
624                 up_read(&card->controls_rwsem);
625                 if (list.used > 0 &&
626                     copy_to_user(list.pids, dst,
627                                  list.used * sizeof(struct snd_ctl_elem_id))) {
628                         vfree(dst);
629                         return -EFAULT;
630                 }
631                 vfree(dst);
632         } else {
633                 down_read(&card->controls_rwsem);
634                 list.count = card->controls_count;
635                 up_read(&card->controls_rwsem);
636         }
637         if (copy_to_user(_list, &list, sizeof(list)))
638                 return -EFAULT;
639         return 0;
640 }
641
642 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
643                              struct snd_ctl_elem_info *info)
644 {
645         struct snd_card *card = ctl->card;
646         struct snd_kcontrol *kctl;
647         struct snd_kcontrol_volatile *vd;
648         unsigned int index_offset;
649         int result;
650         
651         down_read(&card->controls_rwsem);
652         kctl = snd_ctl_find_id(card, &info->id);
653         if (kctl == NULL) {
654                 up_read(&card->controls_rwsem);
655                 return -ENOENT;
656         }
657 #ifdef CONFIG_SND_DEBUG
658         info->access = 0;
659 #endif
660         result = kctl->info(kctl, info);
661         if (result >= 0) {
662                 snd_BUG_ON(info->access);
663                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
664                 vd = &kctl->vd[index_offset];
665                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
666                 info->access = vd->access;
667                 if (vd->owner) {
668                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
669                         if (vd->owner == ctl)
670                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
671                         info->owner = vd->owner_pid;
672                 } else {
673                         info->owner = -1;
674                 }
675         }
676         up_read(&card->controls_rwsem);
677         return result;
678 }
679
680 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
681                                   struct snd_ctl_elem_info __user *_info)
682 {
683         struct snd_ctl_elem_info info;
684         int result;
685
686         if (copy_from_user(&info, _info, sizeof(info)))
687                 return -EFAULT;
688         snd_power_lock(ctl->card);
689         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
690         if (result >= 0)
691                 result = snd_ctl_elem_info(ctl, &info);
692         snd_power_unlock(ctl->card);
693         if (result >= 0)
694                 if (copy_to_user(_info, &info, sizeof(info)))
695                         return -EFAULT;
696         return result;
697 }
698
699 static int snd_ctl_elem_read(struct snd_card *card,
700                              struct snd_ctl_elem_value *control)
701 {
702         struct snd_kcontrol *kctl;
703         struct snd_kcontrol_volatile *vd;
704         unsigned int index_offset;
705         int result;
706
707         down_read(&card->controls_rwsem);
708         kctl = snd_ctl_find_id(card, &control->id);
709         if (kctl == NULL) {
710                 result = -ENOENT;
711         } else {
712                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
713                 vd = &kctl->vd[index_offset];
714                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
715                     kctl->get != NULL) {
716                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
717                         result = kctl->get(kctl, control);
718                 } else
719                         result = -EPERM;
720         }
721         up_read(&card->controls_rwsem);
722         return result;
723 }
724
725 static int snd_ctl_elem_read_user(struct snd_card *card,
726                                   struct snd_ctl_elem_value __user *_control)
727 {
728         struct snd_ctl_elem_value *control;
729         int result;
730
731         control = memdup_user(_control, sizeof(*control));
732         if (IS_ERR(control))
733                 return PTR_ERR(control);
734
735         snd_power_lock(card);
736         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
737         if (result >= 0)
738                 result = snd_ctl_elem_read(card, control);
739         snd_power_unlock(card);
740         if (result >= 0)
741                 if (copy_to_user(_control, control, sizeof(*control)))
742                         result = -EFAULT;
743         kfree(control);
744         return result;
745 }
746
747 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
748                               struct snd_ctl_elem_value *control)
749 {
750         struct snd_kcontrol *kctl;
751         struct snd_kcontrol_volatile *vd;
752         unsigned int index_offset;
753         int result;
754
755         down_read(&card->controls_rwsem);
756         kctl = snd_ctl_find_id(card, &control->id);
757         if (kctl == NULL) {
758                 result = -ENOENT;
759         } else {
760                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
761                 vd = &kctl->vd[index_offset];
762                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
763                     kctl->put == NULL ||
764                     (file && vd->owner && vd->owner != file)) {
765                         result = -EPERM;
766                 } else {
767                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
768                         result = kctl->put(kctl, control);
769                 }
770                 if (result > 0) {
771                         up_read(&card->controls_rwsem);
772                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
773                                        &control->id);
774                         return 0;
775                 }
776         }
777         up_read(&card->controls_rwsem);
778         return result;
779 }
780
781 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
782                                    struct snd_ctl_elem_value __user *_control)
783 {
784         struct snd_ctl_elem_value *control;
785         struct snd_card *card;
786         int result;
787
788         control = memdup_user(_control, sizeof(*control));
789         if (IS_ERR(control))
790                 return PTR_ERR(control);
791
792         card = file->card;
793         snd_power_lock(card);
794         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
795         if (result >= 0)
796                 result = snd_ctl_elem_write(card, file, control);
797         snd_power_unlock(card);
798         if (result >= 0)
799                 if (copy_to_user(_control, control, sizeof(*control)))
800                         result = -EFAULT;
801         kfree(control);
802         return result;
803 }
804
805 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
806                              struct snd_ctl_elem_id __user *_id)
807 {
808         struct snd_card *card = file->card;
809         struct snd_ctl_elem_id id;
810         struct snd_kcontrol *kctl;
811         struct snd_kcontrol_volatile *vd;
812         int result;
813         
814         if (copy_from_user(&id, _id, sizeof(id)))
815                 return -EFAULT;
816         down_write(&card->controls_rwsem);
817         kctl = snd_ctl_find_id(card, &id);
818         if (kctl == NULL) {
819                 result = -ENOENT;
820         } else {
821                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
822                 if (vd->owner != NULL)
823                         result = -EBUSY;
824                 else {
825                         vd->owner = file;
826                         vd->owner_pid = current->pid;
827                         result = 0;
828                 }
829         }
830         up_write(&card->controls_rwsem);
831         return result;
832 }
833
834 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
835                                struct snd_ctl_elem_id __user *_id)
836 {
837         struct snd_card *card = file->card;
838         struct snd_ctl_elem_id id;
839         struct snd_kcontrol *kctl;
840         struct snd_kcontrol_volatile *vd;
841         int result;
842         
843         if (copy_from_user(&id, _id, sizeof(id)))
844                 return -EFAULT;
845         down_write(&card->controls_rwsem);
846         kctl = snd_ctl_find_id(card, &id);
847         if (kctl == NULL) {
848                 result = -ENOENT;
849         } else {
850                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
851                 if (vd->owner == NULL)
852                         result = -EINVAL;
853                 else if (vd->owner != file)
854                         result = -EPERM;
855                 else {
856                         vd->owner = NULL;
857                         vd->owner_pid = 0;
858                         result = 0;
859                 }
860         }
861         up_write(&card->controls_rwsem);
862         return result;
863 }
864
865 struct user_element {
866         struct snd_ctl_elem_info info;
867         void *elem_data;                /* element data */
868         unsigned long elem_data_size;   /* size of element data in bytes */
869         void *tlv_data;                 /* TLV data */
870         unsigned long tlv_data_size;    /* TLV data size */
871         void *priv_data;                /* private data (like strings for enumerated type) */
872         unsigned long priv_data_size;   /* size of private data in bytes */
873 };
874
875 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
876                                   struct snd_ctl_elem_info *uinfo)
877 {
878         struct user_element *ue = kcontrol->private_data;
879
880         *uinfo = ue->info;
881         return 0;
882 }
883
884 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
885                                  struct snd_ctl_elem_value *ucontrol)
886 {
887         struct user_element *ue = kcontrol->private_data;
888
889         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
890         return 0;
891 }
892
893 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
894                                  struct snd_ctl_elem_value *ucontrol)
895 {
896         int change;
897         struct user_element *ue = kcontrol->private_data;
898         
899         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
900         if (change)
901                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
902         return change;
903 }
904
905 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
906                                  int op_flag,
907                                  unsigned int size,
908                                  unsigned int __user *tlv)
909 {
910         struct user_element *ue = kcontrol->private_data;
911         int change = 0;
912         void *new_data;
913
914         if (op_flag > 0) {
915                 if (size > 1024 * 128)  /* sane value */
916                         return -EINVAL;
917
918                 new_data = memdup_user(tlv, size);
919                 if (IS_ERR(new_data))
920                         return PTR_ERR(new_data);
921                 change = ue->tlv_data_size != size;
922                 if (!change)
923                         change = memcmp(ue->tlv_data, new_data, size);
924                 kfree(ue->tlv_data);
925                 ue->tlv_data = new_data;
926                 ue->tlv_data_size = size;
927         } else {
928                 if (! ue->tlv_data_size || ! ue->tlv_data)
929                         return -ENXIO;
930                 if (size < ue->tlv_data_size)
931                         return -ENOSPC;
932                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
933                         return -EFAULT;
934         }
935         return change;
936 }
937
938 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
939 {
940         struct user_element *ue = kcontrol->private_data;
941         if (ue->tlv_data)
942                 kfree(ue->tlv_data);
943         kfree(ue);
944 }
945
946 static int snd_ctl_elem_add(struct snd_ctl_file *file,
947                             struct snd_ctl_elem_info *info, int replace)
948 {
949         struct snd_card *card = file->card;
950         struct snd_kcontrol kctl, *_kctl;
951         unsigned int access;
952         long private_size;
953         struct user_element *ue;
954         int idx, err;
955         
956         if (card->user_ctl_count >= MAX_USER_CONTROLS)
957                 return -ENOMEM;
958         if (info->count < 1)
959                 return -EINVAL;
960         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
961                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
962                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
963                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
964         info->id.numid = 0;
965         memset(&kctl, 0, sizeof(kctl));
966         down_write(&card->controls_rwsem);
967         _kctl = snd_ctl_find_id(card, &info->id);
968         err = 0;
969         if (_kctl) {
970                 if (replace)
971                         err = snd_ctl_remove(card, _kctl);
972                 else
973                         err = -EBUSY;
974         } else {
975                 if (replace)
976                         err = -ENOENT;
977         }
978         up_write(&card->controls_rwsem);
979         if (err < 0)
980                 return err;
981         memcpy(&kctl.id, &info->id, sizeof(info->id));
982         kctl.count = info->owner ? info->owner : 1;
983         access |= SNDRV_CTL_ELEM_ACCESS_USER;
984         kctl.info = snd_ctl_elem_user_info;
985         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
986                 kctl.get = snd_ctl_elem_user_get;
987         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
988                 kctl.put = snd_ctl_elem_user_put;
989         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
990                 kctl.tlv.c = snd_ctl_elem_user_tlv;
991                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
992         }
993         switch (info->type) {
994         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
995         case SNDRV_CTL_ELEM_TYPE_INTEGER:
996                 private_size = sizeof(long);
997                 if (info->count > 128)
998                         return -EINVAL;
999                 break;
1000         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1001                 private_size = sizeof(long long);
1002                 if (info->count > 64)
1003                         return -EINVAL;
1004                 break;
1005         case SNDRV_CTL_ELEM_TYPE_BYTES:
1006                 private_size = sizeof(unsigned char);
1007                 if (info->count > 512)
1008                         return -EINVAL;
1009                 break;
1010         case SNDRV_CTL_ELEM_TYPE_IEC958:
1011                 private_size = sizeof(struct snd_aes_iec958);
1012                 if (info->count != 1)
1013                         return -EINVAL;
1014                 break;
1015         default:
1016                 return -EINVAL;
1017         }
1018         private_size *= info->count;
1019         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1020         if (ue == NULL)
1021                 return -ENOMEM;
1022         ue->info = *info;
1023         ue->info.access = 0;
1024         ue->elem_data = (char *)ue + sizeof(*ue);
1025         ue->elem_data_size = private_size;
1026         kctl.private_free = snd_ctl_elem_user_free;
1027         _kctl = snd_ctl_new(&kctl, access);
1028         if (_kctl == NULL) {
1029                 kfree(ue);
1030                 return -ENOMEM;
1031         }
1032         _kctl->private_data = ue;
1033         for (idx = 0; idx < _kctl->count; idx++)
1034                 _kctl->vd[idx].owner = file;
1035         err = snd_ctl_add(card, _kctl);
1036         if (err < 0)
1037                 return err;
1038
1039         down_write(&card->controls_rwsem);
1040         card->user_ctl_count++;
1041         up_write(&card->controls_rwsem);
1042
1043         return 0;
1044 }
1045
1046 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1047                                  struct snd_ctl_elem_info __user *_info, int replace)
1048 {
1049         struct snd_ctl_elem_info info;
1050         if (copy_from_user(&info, _info, sizeof(info)))
1051                 return -EFAULT;
1052         return snd_ctl_elem_add(file, &info, replace);
1053 }
1054
1055 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1056                                struct snd_ctl_elem_id __user *_id)
1057 {
1058         struct snd_ctl_elem_id id;
1059
1060         if (copy_from_user(&id, _id, sizeof(id)))
1061                 return -EFAULT;
1062         return snd_ctl_remove_user_ctl(file, &id);
1063 }
1064
1065 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1066 {
1067         int subscribe;
1068         if (get_user(subscribe, ptr))
1069                 return -EFAULT;
1070         if (subscribe < 0) {
1071                 subscribe = file->subscribed;
1072                 if (put_user(subscribe, ptr))
1073                         return -EFAULT;
1074                 return 0;
1075         }
1076         if (subscribe) {
1077                 file->subscribed = 1;
1078                 return 0;
1079         } else if (file->subscribed) {
1080                 snd_ctl_empty_read_queue(file);
1081                 file->subscribed = 0;
1082         }
1083         return 0;
1084 }
1085
1086 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1087                              struct snd_ctl_tlv __user *_tlv,
1088                              int op_flag)
1089 {
1090         struct snd_card *card = file->card;
1091         struct snd_ctl_tlv tlv;
1092         struct snd_kcontrol *kctl;
1093         struct snd_kcontrol_volatile *vd;
1094         unsigned int len;
1095         int err = 0;
1096
1097         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1098                 return -EFAULT;
1099         if (tlv.length < sizeof(unsigned int) * 3)
1100                 return -EINVAL;
1101         down_read(&card->controls_rwsem);
1102         kctl = snd_ctl_find_numid(card, tlv.numid);
1103         if (kctl == NULL) {
1104                 err = -ENOENT;
1105                 goto __kctl_end;
1106         }
1107         if (kctl->tlv.p == NULL) {
1108                 err = -ENXIO;
1109                 goto __kctl_end;
1110         }
1111         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1112         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1113             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1114             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1115                 err = -ENXIO;
1116                 goto __kctl_end;
1117         }
1118         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1119                 if (file && vd->owner != NULL && vd->owner != file) {
1120                         err = -EPERM;
1121                         goto __kctl_end;
1122                 }
1123                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1124                 if (err > 0) {
1125                         up_read(&card->controls_rwsem);
1126                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1127                         return 0;
1128                 }
1129         } else {
1130                 if (op_flag) {
1131                         err = -ENXIO;
1132                         goto __kctl_end;
1133                 }
1134                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1135                 if (tlv.length < len) {
1136                         err = -ENOMEM;
1137                         goto __kctl_end;
1138                 }
1139                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1140                         err = -EFAULT;
1141         }
1142       __kctl_end:
1143         up_read(&card->controls_rwsem);
1144         return err;
1145 }
1146
1147 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1148 {
1149         struct snd_ctl_file *ctl;
1150         struct snd_card *card;
1151         struct snd_kctl_ioctl *p;
1152         void __user *argp = (void __user *)arg;
1153         int __user *ip = argp;
1154         int err;
1155
1156         ctl = file->private_data;
1157         card = ctl->card;
1158         if (snd_BUG_ON(!card))
1159                 return -ENXIO;
1160         switch (cmd) {
1161         case SNDRV_CTL_IOCTL_PVERSION:
1162                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1163         case SNDRV_CTL_IOCTL_CARD_INFO:
1164                 return snd_ctl_card_info(card, ctl, cmd, argp);
1165         case SNDRV_CTL_IOCTL_ELEM_LIST:
1166                 return snd_ctl_elem_list(card, argp);
1167         case SNDRV_CTL_IOCTL_ELEM_INFO:
1168                 return snd_ctl_elem_info_user(ctl, argp);
1169         case SNDRV_CTL_IOCTL_ELEM_READ:
1170                 return snd_ctl_elem_read_user(card, argp);
1171         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1172                 return snd_ctl_elem_write_user(ctl, argp);
1173         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1174                 return snd_ctl_elem_lock(ctl, argp);
1175         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1176                 return snd_ctl_elem_unlock(ctl, argp);
1177         case SNDRV_CTL_IOCTL_ELEM_ADD:
1178                 return snd_ctl_elem_add_user(ctl, argp, 0);
1179         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1180                 return snd_ctl_elem_add_user(ctl, argp, 1);
1181         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1182                 return snd_ctl_elem_remove(ctl, argp);
1183         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1184                 return snd_ctl_subscribe_events(ctl, ip);
1185         case SNDRV_CTL_IOCTL_TLV_READ:
1186                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1187         case SNDRV_CTL_IOCTL_TLV_WRITE:
1188                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1189         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1190                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1191         case SNDRV_CTL_IOCTL_POWER:
1192                 return -ENOPROTOOPT;
1193         case SNDRV_CTL_IOCTL_POWER_STATE:
1194 #ifdef CONFIG_PM
1195                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1196 #else
1197                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1198 #endif
1199         }
1200         down_read(&snd_ioctl_rwsem);
1201         list_for_each_entry(p, &snd_control_ioctls, list) {
1202                 err = p->fioctl(card, ctl, cmd, arg);
1203                 if (err != -ENOIOCTLCMD) {
1204                         up_read(&snd_ioctl_rwsem);
1205                         return err;
1206                 }
1207         }
1208         up_read(&snd_ioctl_rwsem);
1209         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1210         return -ENOTTY;
1211 }
1212
1213 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1214                             size_t count, loff_t * offset)
1215 {
1216         struct snd_ctl_file *ctl;
1217         int err = 0;
1218         ssize_t result = 0;
1219
1220         ctl = file->private_data;
1221         if (snd_BUG_ON(!ctl || !ctl->card))
1222                 return -ENXIO;
1223         if (!ctl->subscribed)
1224                 return -EBADFD;
1225         if (count < sizeof(struct snd_ctl_event))
1226                 return -EINVAL;
1227         spin_lock_irq(&ctl->read_lock);
1228         while (count >= sizeof(struct snd_ctl_event)) {
1229                 struct snd_ctl_event ev;
1230                 struct snd_kctl_event *kev;
1231                 while (list_empty(&ctl->events)) {
1232                         wait_queue_t wait;
1233                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1234                                 err = -EAGAIN;
1235                                 goto __end_lock;
1236                         }
1237                         init_waitqueue_entry(&wait, current);
1238                         add_wait_queue(&ctl->change_sleep, &wait);
1239                         set_current_state(TASK_INTERRUPTIBLE);
1240                         spin_unlock_irq(&ctl->read_lock);
1241                         schedule();
1242                         remove_wait_queue(&ctl->change_sleep, &wait);
1243                         if (signal_pending(current))
1244                                 return -ERESTARTSYS;
1245                         spin_lock_irq(&ctl->read_lock);
1246                 }
1247                 kev = snd_kctl_event(ctl->events.next);
1248                 ev.type = SNDRV_CTL_EVENT_ELEM;
1249                 ev.data.elem.mask = kev->mask;
1250                 ev.data.elem.id = kev->id;
1251                 list_del(&kev->list);
1252                 spin_unlock_irq(&ctl->read_lock);
1253                 kfree(kev);
1254                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1255                         err = -EFAULT;
1256                         goto __end;
1257                 }
1258                 spin_lock_irq(&ctl->read_lock);
1259                 buffer += sizeof(struct snd_ctl_event);
1260                 count -= sizeof(struct snd_ctl_event);
1261                 result += sizeof(struct snd_ctl_event);
1262         }
1263       __end_lock:
1264         spin_unlock_irq(&ctl->read_lock);
1265       __end:
1266         return result > 0 ? result : err;
1267 }
1268
1269 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1270 {
1271         unsigned int mask;
1272         struct snd_ctl_file *ctl;
1273
1274         ctl = file->private_data;
1275         if (!ctl->subscribed)
1276                 return 0;
1277         poll_wait(file, &ctl->change_sleep, wait);
1278
1279         mask = 0;
1280         if (!list_empty(&ctl->events))
1281                 mask |= POLLIN | POLLRDNORM;
1282
1283         return mask;
1284 }
1285
1286 /*
1287  * register the device-specific control-ioctls.
1288  * called from each device manager like pcm.c, hwdep.c, etc.
1289  */
1290 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1291 {
1292         struct snd_kctl_ioctl *pn;
1293
1294         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1295         if (pn == NULL)
1296                 return -ENOMEM;
1297         pn->fioctl = fcn;
1298         down_write(&snd_ioctl_rwsem);
1299         list_add_tail(&pn->list, lists);
1300         up_write(&snd_ioctl_rwsem);
1301         return 0;
1302 }
1303
1304 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1305 {
1306         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1307 }
1308
1309 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1310
1311 #ifdef CONFIG_COMPAT
1312 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1313 {
1314         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1315 }
1316
1317 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1318 #endif
1319
1320 /*
1321  * de-register the device-specific control-ioctls.
1322  */
1323 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1324                                      struct list_head *lists)
1325 {
1326         struct snd_kctl_ioctl *p;
1327
1328         if (snd_BUG_ON(!fcn))
1329                 return -EINVAL;
1330         down_write(&snd_ioctl_rwsem);
1331         list_for_each_entry(p, lists, list) {
1332                 if (p->fioctl == fcn) {
1333                         list_del(&p->list);
1334                         up_write(&snd_ioctl_rwsem);
1335                         kfree(p);
1336                         return 0;
1337                 }
1338         }
1339         up_write(&snd_ioctl_rwsem);
1340         snd_BUG();
1341         return -EINVAL;
1342 }
1343
1344 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1345 {
1346         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1347 }
1348
1349 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1350
1351 #ifdef CONFIG_COMPAT
1352 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1353 {
1354         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1355 }
1356
1357 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1358 #endif
1359
1360 static int snd_ctl_fasync(int fd, struct file * file, int on)
1361 {
1362         struct snd_ctl_file *ctl;
1363
1364         ctl = file->private_data;
1365         return fasync_helper(fd, file, on, &ctl->fasync);
1366 }
1367
1368 /*
1369  * ioctl32 compat
1370  */
1371 #ifdef CONFIG_COMPAT
1372 #include "control_compat.c"
1373 #else
1374 #define snd_ctl_ioctl_compat    NULL
1375 #endif
1376
1377 /*
1378  *  INIT PART
1379  */
1380
1381 static const struct file_operations snd_ctl_f_ops =
1382 {
1383         .owner =        THIS_MODULE,
1384         .read =         snd_ctl_read,
1385         .open =         snd_ctl_open,
1386         .release =      snd_ctl_release,
1387         .poll =         snd_ctl_poll,
1388         .unlocked_ioctl =       snd_ctl_ioctl,
1389         .compat_ioctl = snd_ctl_ioctl_compat,
1390         .fasync =       snd_ctl_fasync,
1391 };
1392
1393 /*
1394  * registration of the control device
1395  */
1396 static int snd_ctl_dev_register(struct snd_device *device)
1397 {
1398         struct snd_card *card = device->device_data;
1399         int err, cardnum;
1400         char name[16];
1401
1402         if (snd_BUG_ON(!card))
1403                 return -ENXIO;
1404         cardnum = card->number;
1405         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1406                 return -ENXIO;
1407         sprintf(name, "controlC%i", cardnum);
1408         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1409                                        &snd_ctl_f_ops, card, name)) < 0)
1410                 return err;
1411         return 0;
1412 }
1413
1414 /*
1415  * disconnection of the control device
1416  */
1417 static int snd_ctl_dev_disconnect(struct snd_device *device)
1418 {
1419         struct snd_card *card = device->device_data;
1420         struct snd_ctl_file *ctl;
1421         int err, cardnum;
1422
1423         if (snd_BUG_ON(!card))
1424                 return -ENXIO;
1425         cardnum = card->number;
1426         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1427                 return -ENXIO;
1428
1429         read_lock(&card->ctl_files_rwlock);
1430         list_for_each_entry(ctl, &card->ctl_files, list) {
1431                 wake_up(&ctl->change_sleep);
1432                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1433         }
1434         read_unlock(&card->ctl_files_rwlock);
1435
1436         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1437                                          card, -1)) < 0)
1438                 return err;
1439         return 0;
1440 }
1441
1442 /*
1443  * free all controls
1444  */
1445 static int snd_ctl_dev_free(struct snd_device *device)
1446 {
1447         struct snd_card *card = device->device_data;
1448         struct snd_kcontrol *control;
1449
1450         down_write(&card->controls_rwsem);
1451         while (!list_empty(&card->controls)) {
1452                 control = snd_kcontrol(card->controls.next);
1453                 snd_ctl_remove(card, control);
1454         }
1455         up_write(&card->controls_rwsem);
1456         return 0;
1457 }
1458
1459 /*
1460  * create control core:
1461  * called from init.c
1462  */
1463 int snd_ctl_create(struct snd_card *card)
1464 {
1465         static struct snd_device_ops ops = {
1466                 .dev_free = snd_ctl_dev_free,
1467                 .dev_register = snd_ctl_dev_register,
1468                 .dev_disconnect = snd_ctl_dev_disconnect,
1469         };
1470
1471         if (snd_BUG_ON(!card))
1472                 return -ENXIO;
1473         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1474 }
1475
1476 /*
1477  * Frequently used control callbacks
1478  */
1479 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1480                               struct snd_ctl_elem_info *uinfo)
1481 {
1482         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1483         uinfo->count = 1;
1484         uinfo->value.integer.min = 0;
1485         uinfo->value.integer.max = 1;
1486         return 0;
1487 }
1488
1489 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1490
1491 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1492                                 struct snd_ctl_elem_info *uinfo)
1493 {
1494         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1495         uinfo->count = 2;
1496         uinfo->value.integer.min = 0;
1497         uinfo->value.integer.max = 1;
1498         return 0;
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);