sound: snd_ctl_elem_add: fix value count check
[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_unlocked_id - remove the unlocked control of the given id and release it
418  * @file: active control handle
419  * @id: the control id to remove
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_unlocked_id(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                 up_write(&card->controls_rwsem);
437                 return -ENOENT;
438         }
439         for (idx = 0; idx < kctl->count; idx++)
440                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
441                         up_write(&card->controls_rwsem);
442                         return -EBUSY;
443                 }
444         ret = snd_ctl_remove(card, kctl);
445         up_write(&card->controls_rwsem);
446         return ret;
447 }
448
449 /**
450  * snd_ctl_rename_id - replace the id of a control on the card
451  * @card: the card instance
452  * @src_id: the old id
453  * @dst_id: the new id
454  *
455  * Finds the control with the old id from the card, and replaces the
456  * id with the new one.
457  *
458  * Returns zero if successful, or a negative error code on failure.
459  */
460 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
461                       struct snd_ctl_elem_id *dst_id)
462 {
463         struct snd_kcontrol *kctl;
464
465         down_write(&card->controls_rwsem);
466         kctl = snd_ctl_find_id(card, src_id);
467         if (kctl == NULL) {
468                 up_write(&card->controls_rwsem);
469                 return -ENOENT;
470         }
471         kctl->id = *dst_id;
472         kctl->id.numid = card->last_numid + 1;
473         card->last_numid += kctl->count;
474         up_write(&card->controls_rwsem);
475         return 0;
476 }
477
478 EXPORT_SYMBOL(snd_ctl_rename_id);
479
480 /**
481  * snd_ctl_find_numid - find the control instance with the given number-id
482  * @card: the card instance
483  * @numid: the number-id to search
484  *
485  * Finds the control instance with the given number-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 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
493 {
494         struct snd_kcontrol *kctl;
495
496         if (snd_BUG_ON(!card || !numid))
497                 return NULL;
498         list_for_each_entry(kctl, &card->controls, list) {
499                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
500                         return kctl;
501         }
502         return NULL;
503 }
504
505 EXPORT_SYMBOL(snd_ctl_find_numid);
506
507 /**
508  * snd_ctl_find_id - find the control instance with the given id
509  * @card: the card instance
510  * @id: the id to search
511  *
512  * Finds the control instance with the given id from the card.
513  *
514  * Returns the pointer of the instance if found, or NULL if not.
515  *
516  * The caller must down card->controls_rwsem before calling this function
517  * (if the race condition can happen).
518  */
519 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
520                                      struct snd_ctl_elem_id *id)
521 {
522         struct snd_kcontrol *kctl;
523
524         if (snd_BUG_ON(!card || !id))
525                 return NULL;
526         if (id->numid != 0)
527                 return snd_ctl_find_numid(card, id->numid);
528         list_for_each_entry(kctl, &card->controls, list) {
529                 if (kctl->id.iface != id->iface)
530                         continue;
531                 if (kctl->id.device != id->device)
532                         continue;
533                 if (kctl->id.subdevice != id->subdevice)
534                         continue;
535                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
536                         continue;
537                 if (kctl->id.index > id->index)
538                         continue;
539                 if (kctl->id.index + kctl->count <= id->index)
540                         continue;
541                 return kctl;
542         }
543         return NULL;
544 }
545
546 EXPORT_SYMBOL(snd_ctl_find_id);
547
548 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
549                              unsigned int cmd, void __user *arg)
550 {
551         struct snd_ctl_card_info *info;
552
553         info = kzalloc(sizeof(*info), GFP_KERNEL);
554         if (! info)
555                 return -ENOMEM;
556         down_read(&snd_ioctl_rwsem);
557         info->card = card->number;
558         strlcpy(info->id, card->id, sizeof(info->id));
559         strlcpy(info->driver, card->driver, sizeof(info->driver));
560         strlcpy(info->name, card->shortname, sizeof(info->name));
561         strlcpy(info->longname, card->longname, sizeof(info->longname));
562         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
563         strlcpy(info->components, card->components, sizeof(info->components));
564         up_read(&snd_ioctl_rwsem);
565         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
566                 kfree(info);
567                 return -EFAULT;
568         }
569         kfree(info);
570         return 0;
571 }
572
573 static int snd_ctl_elem_list(struct snd_card *card,
574                              struct snd_ctl_elem_list __user *_list)
575 {
576         struct list_head *plist;
577         struct snd_ctl_elem_list list;
578         struct snd_kcontrol *kctl;
579         struct snd_ctl_elem_id *dst, *id;
580         unsigned int offset, space, first, jidx;
581         
582         if (copy_from_user(&list, _list, sizeof(list)))
583                 return -EFAULT;
584         offset = list.offset;
585         space = list.space;
586         first = 0;
587         /* try limit maximum space */
588         if (space > 16384)
589                 return -ENOMEM;
590         if (space > 0) {
591                 /* allocate temporary buffer for atomic operation */
592                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
593                 if (dst == NULL)
594                         return -ENOMEM;
595                 down_read(&card->controls_rwsem);
596                 list.count = card->controls_count;
597                 plist = card->controls.next;
598                 while (plist != &card->controls) {
599                         if (offset == 0)
600                                 break;
601                         kctl = snd_kcontrol(plist);
602                         if (offset < kctl->count)
603                                 break;
604                         offset -= kctl->count;
605                         plist = plist->next;
606                 }
607                 list.used = 0;
608                 id = dst;
609                 while (space > 0 && plist != &card->controls) {
610                         kctl = snd_kcontrol(plist);
611                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
612                                 snd_ctl_build_ioff(id, kctl, jidx);
613                                 id++;
614                                 space--;
615                                 list.used++;
616                         }
617                         plist = plist->next;
618                         offset = 0;
619                 }
620                 up_read(&card->controls_rwsem);
621                 if (list.used > 0 &&
622                     copy_to_user(list.pids, dst,
623                                  list.used * sizeof(struct snd_ctl_elem_id))) {
624                         vfree(dst);
625                         return -EFAULT;
626                 }
627                 vfree(dst);
628         } else {
629                 down_read(&card->controls_rwsem);
630                 list.count = card->controls_count;
631                 up_read(&card->controls_rwsem);
632         }
633         if (copy_to_user(_list, &list, sizeof(list)))
634                 return -EFAULT;
635         return 0;
636 }
637
638 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
639                              struct snd_ctl_elem_info *info)
640 {
641         struct snd_card *card = ctl->card;
642         struct snd_kcontrol *kctl;
643         struct snd_kcontrol_volatile *vd;
644         unsigned int index_offset;
645         int result;
646         
647         down_read(&card->controls_rwsem);
648         kctl = snd_ctl_find_id(card, &info->id);
649         if (kctl == NULL) {
650                 up_read(&card->controls_rwsem);
651                 return -ENOENT;
652         }
653 #ifdef CONFIG_SND_DEBUG
654         info->access = 0;
655 #endif
656         result = kctl->info(kctl, info);
657         if (result >= 0) {
658                 snd_BUG_ON(info->access);
659                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
660                 vd = &kctl->vd[index_offset];
661                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
662                 info->access = vd->access;
663                 if (vd->owner) {
664                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
665                         if (vd->owner == ctl)
666                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
667                         info->owner = vd->owner_pid;
668                 } else {
669                         info->owner = -1;
670                 }
671         }
672         up_read(&card->controls_rwsem);
673         return result;
674 }
675
676 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
677                                   struct snd_ctl_elem_info __user *_info)
678 {
679         struct snd_ctl_elem_info info;
680         int result;
681
682         if (copy_from_user(&info, _info, sizeof(info)))
683                 return -EFAULT;
684         snd_power_lock(ctl->card);
685         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
686         if (result >= 0)
687                 result = snd_ctl_elem_info(ctl, &info);
688         snd_power_unlock(ctl->card);
689         if (result >= 0)
690                 if (copy_to_user(_info, &info, sizeof(info)))
691                         return -EFAULT;
692         return result;
693 }
694
695 static int snd_ctl_elem_read(struct snd_card *card,
696                              struct snd_ctl_elem_value *control)
697 {
698         struct snd_kcontrol *kctl;
699         struct snd_kcontrol_volatile *vd;
700         unsigned int index_offset;
701         int result;
702
703         down_read(&card->controls_rwsem);
704         kctl = snd_ctl_find_id(card, &control->id);
705         if (kctl == NULL) {
706                 result = -ENOENT;
707         } else {
708                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
709                 vd = &kctl->vd[index_offset];
710                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
711                     kctl->get != NULL) {
712                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
713                         result = kctl->get(kctl, control);
714                 } else
715                         result = -EPERM;
716         }
717         up_read(&card->controls_rwsem);
718         return result;
719 }
720
721 static int snd_ctl_elem_read_user(struct snd_card *card,
722                                   struct snd_ctl_elem_value __user *_control)
723 {
724         struct snd_ctl_elem_value *control;
725         int result;
726
727         control = memdup_user(_control, sizeof(*control));
728         if (IS_ERR(control))
729                 return PTR_ERR(control);
730
731         snd_power_lock(card);
732         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
733         if (result >= 0)
734                 result = snd_ctl_elem_read(card, control);
735         snd_power_unlock(card);
736         if (result >= 0)
737                 if (copy_to_user(_control, control, sizeof(*control)))
738                         result = -EFAULT;
739         kfree(control);
740         return result;
741 }
742
743 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
744                               struct snd_ctl_elem_value *control)
745 {
746         struct snd_kcontrol *kctl;
747         struct snd_kcontrol_volatile *vd;
748         unsigned int index_offset;
749         int result;
750
751         down_read(&card->controls_rwsem);
752         kctl = snd_ctl_find_id(card, &control->id);
753         if (kctl == NULL) {
754                 result = -ENOENT;
755         } else {
756                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
757                 vd = &kctl->vd[index_offset];
758                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
759                     kctl->put == NULL ||
760                     (file && vd->owner && vd->owner != file)) {
761                         result = -EPERM;
762                 } else {
763                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
764                         result = kctl->put(kctl, control);
765                 }
766                 if (result > 0) {
767                         up_read(&card->controls_rwsem);
768                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
769                                        &control->id);
770                         return 0;
771                 }
772         }
773         up_read(&card->controls_rwsem);
774         return result;
775 }
776
777 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
778                                    struct snd_ctl_elem_value __user *_control)
779 {
780         struct snd_ctl_elem_value *control;
781         struct snd_card *card;
782         int result;
783
784         control = memdup_user(_control, sizeof(*control));
785         if (IS_ERR(control))
786                 return PTR_ERR(control);
787
788         card = file->card;
789         snd_power_lock(card);
790         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
791         if (result >= 0)
792                 result = snd_ctl_elem_write(card, file, control);
793         snd_power_unlock(card);
794         if (result >= 0)
795                 if (copy_to_user(_control, control, sizeof(*control)))
796                         result = -EFAULT;
797         kfree(control);
798         return result;
799 }
800
801 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
802                              struct snd_ctl_elem_id __user *_id)
803 {
804         struct snd_card *card = file->card;
805         struct snd_ctl_elem_id id;
806         struct snd_kcontrol *kctl;
807         struct snd_kcontrol_volatile *vd;
808         int result;
809         
810         if (copy_from_user(&id, _id, sizeof(id)))
811                 return -EFAULT;
812         down_write(&card->controls_rwsem);
813         kctl = snd_ctl_find_id(card, &id);
814         if (kctl == NULL) {
815                 result = -ENOENT;
816         } else {
817                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
818                 if (vd->owner != NULL)
819                         result = -EBUSY;
820                 else {
821                         vd->owner = file;
822                         vd->owner_pid = current->pid;
823                         result = 0;
824                 }
825         }
826         up_write(&card->controls_rwsem);
827         return result;
828 }
829
830 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
831                                struct snd_ctl_elem_id __user *_id)
832 {
833         struct snd_card *card = file->card;
834         struct snd_ctl_elem_id id;
835         struct snd_kcontrol *kctl;
836         struct snd_kcontrol_volatile *vd;
837         int result;
838         
839         if (copy_from_user(&id, _id, sizeof(id)))
840                 return -EFAULT;
841         down_write(&card->controls_rwsem);
842         kctl = snd_ctl_find_id(card, &id);
843         if (kctl == NULL) {
844                 result = -ENOENT;
845         } else {
846                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
847                 if (vd->owner == NULL)
848                         result = -EINVAL;
849                 else if (vd->owner != file)
850                         result = -EPERM;
851                 else {
852                         vd->owner = NULL;
853                         vd->owner_pid = 0;
854                         result = 0;
855                 }
856         }
857         up_write(&card->controls_rwsem);
858         return result;
859 }
860
861 struct user_element {
862         struct snd_ctl_elem_info info;
863         void *elem_data;                /* element data */
864         unsigned long elem_data_size;   /* size of element data in bytes */
865         void *tlv_data;                 /* TLV data */
866         unsigned long tlv_data_size;    /* TLV data size */
867         void *priv_data;                /* private data (like strings for enumerated type) */
868         unsigned long priv_data_size;   /* size of private data in bytes */
869 };
870
871 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
872                                   struct snd_ctl_elem_info *uinfo)
873 {
874         struct user_element *ue = kcontrol->private_data;
875
876         *uinfo = ue->info;
877         return 0;
878 }
879
880 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
881                                  struct snd_ctl_elem_value *ucontrol)
882 {
883         struct user_element *ue = kcontrol->private_data;
884
885         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
886         return 0;
887 }
888
889 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
890                                  struct snd_ctl_elem_value *ucontrol)
891 {
892         int change;
893         struct user_element *ue = kcontrol->private_data;
894         
895         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
896         if (change)
897                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
898         return change;
899 }
900
901 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
902                                  int op_flag,
903                                  unsigned int size,
904                                  unsigned int __user *tlv)
905 {
906         struct user_element *ue = kcontrol->private_data;
907         int change = 0;
908         void *new_data;
909
910         if (op_flag > 0) {
911                 if (size > 1024 * 128)  /* sane value */
912                         return -EINVAL;
913
914                 new_data = memdup_user(tlv, size);
915                 if (IS_ERR(new_data))
916                         return PTR_ERR(new_data);
917                 change = ue->tlv_data_size != size;
918                 if (!change)
919                         change = memcmp(ue->tlv_data, new_data, size);
920                 kfree(ue->tlv_data);
921                 ue->tlv_data = new_data;
922                 ue->tlv_data_size = size;
923         } else {
924                 if (! ue->tlv_data_size || ! ue->tlv_data)
925                         return -ENXIO;
926                 if (size < ue->tlv_data_size)
927                         return -ENOSPC;
928                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
929                         return -EFAULT;
930         }
931         return change;
932 }
933
934 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
935 {
936         struct user_element *ue = kcontrol->private_data;
937         if (ue->tlv_data)
938                 kfree(ue->tlv_data);
939         kfree(ue);
940 }
941
942 static int snd_ctl_elem_add(struct snd_ctl_file *file,
943                             struct snd_ctl_elem_info *info, int replace)
944 {
945         struct snd_card *card = file->card;
946         struct snd_kcontrol kctl, *_kctl;
947         unsigned int access;
948         long private_size;
949         struct user_element *ue;
950         int idx, err;
951         
952         if (card->user_ctl_count >= MAX_USER_CONTROLS)
953                 return -ENOMEM;
954         if (info->count < 1)
955                 return -EINVAL;
956         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
957                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
958                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
959                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
960         info->id.numid = 0;
961         memset(&kctl, 0, sizeof(kctl));
962         down_write(&card->controls_rwsem);
963         _kctl = snd_ctl_find_id(card, &info->id);
964         err = 0;
965         if (_kctl) {
966                 if (replace)
967                         err = snd_ctl_remove(card, _kctl);
968                 else
969                         err = -EBUSY;
970         } else {
971                 if (replace)
972                         err = -ENOENT;
973         }
974         up_write(&card->controls_rwsem);
975         if (err < 0)
976                 return err;
977         memcpy(&kctl.id, &info->id, sizeof(info->id));
978         kctl.count = info->owner ? info->owner : 1;
979         access |= SNDRV_CTL_ELEM_ACCESS_USER;
980         kctl.info = snd_ctl_elem_user_info;
981         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
982                 kctl.get = snd_ctl_elem_user_get;
983         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
984                 kctl.put = snd_ctl_elem_user_put;
985         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
986                 kctl.tlv.c = snd_ctl_elem_user_tlv;
987                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
988         }
989         switch (info->type) {
990         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
991         case SNDRV_CTL_ELEM_TYPE_INTEGER:
992                 private_size = sizeof(long);
993                 if (info->count > 128)
994                         return -EINVAL;
995                 break;
996         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
997                 private_size = sizeof(long long);
998                 if (info->count > 64)
999                         return -EINVAL;
1000                 break;
1001         case SNDRV_CTL_ELEM_TYPE_BYTES:
1002                 private_size = sizeof(unsigned char);
1003                 if (info->count > 512)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_IEC958:
1007                 private_size = sizeof(struct snd_aes_iec958);
1008                 if (info->count != 1)
1009                         return -EINVAL;
1010                 break;
1011         default:
1012                 return -EINVAL;
1013         }
1014         private_size *= info->count;
1015         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1016         if (ue == NULL)
1017                 return -ENOMEM;
1018         ue->info = *info;
1019         ue->info.access = 0;
1020         ue->elem_data = (char *)ue + sizeof(*ue);
1021         ue->elem_data_size = private_size;
1022         kctl.private_free = snd_ctl_elem_user_free;
1023         _kctl = snd_ctl_new(&kctl, access);
1024         if (_kctl == NULL) {
1025                 kfree(ue);
1026                 return -ENOMEM;
1027         }
1028         _kctl->private_data = ue;
1029         for (idx = 0; idx < _kctl->count; idx++)
1030                 _kctl->vd[idx].owner = file;
1031         err = snd_ctl_add(card, _kctl);
1032         if (err < 0)
1033                 return err;
1034
1035         down_write(&card->controls_rwsem);
1036         card->user_ctl_count++;
1037         up_write(&card->controls_rwsem);
1038
1039         return 0;
1040 }
1041
1042 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1043                                  struct snd_ctl_elem_info __user *_info, int replace)
1044 {
1045         struct snd_ctl_elem_info info;
1046         if (copy_from_user(&info, _info, sizeof(info)))
1047                 return -EFAULT;
1048         return snd_ctl_elem_add(file, &info, replace);
1049 }
1050
1051 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1052                                struct snd_ctl_elem_id __user *_id)
1053 {
1054         struct snd_ctl_elem_id id;
1055         int err;
1056
1057         if (copy_from_user(&id, _id, sizeof(id)))
1058                 return -EFAULT;
1059         err = snd_ctl_remove_unlocked_id(file, &id);
1060         if (! err) {
1061                 struct snd_card *card = file->card;
1062                 down_write(&card->controls_rwsem);
1063                 card->user_ctl_count--;
1064                 up_write(&card->controls_rwsem);
1065         }
1066         return err;
1067 }
1068
1069 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1070 {
1071         int subscribe;
1072         if (get_user(subscribe, ptr))
1073                 return -EFAULT;
1074         if (subscribe < 0) {
1075                 subscribe = file->subscribed;
1076                 if (put_user(subscribe, ptr))
1077                         return -EFAULT;
1078                 return 0;
1079         }
1080         if (subscribe) {
1081                 file->subscribed = 1;
1082                 return 0;
1083         } else if (file->subscribed) {
1084                 snd_ctl_empty_read_queue(file);
1085                 file->subscribed = 0;
1086         }
1087         return 0;
1088 }
1089
1090 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1091                              struct snd_ctl_tlv __user *_tlv,
1092                              int op_flag)
1093 {
1094         struct snd_card *card = file->card;
1095         struct snd_ctl_tlv tlv;
1096         struct snd_kcontrol *kctl;
1097         struct snd_kcontrol_volatile *vd;
1098         unsigned int len;
1099         int err = 0;
1100
1101         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1102                 return -EFAULT;
1103         if (tlv.length < sizeof(unsigned int) * 3)
1104                 return -EINVAL;
1105         down_read(&card->controls_rwsem);
1106         kctl = snd_ctl_find_numid(card, tlv.numid);
1107         if (kctl == NULL) {
1108                 err = -ENOENT;
1109                 goto __kctl_end;
1110         }
1111         if (kctl->tlv.p == NULL) {
1112                 err = -ENXIO;
1113                 goto __kctl_end;
1114         }
1115         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1116         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1117             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1118             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1119                 err = -ENXIO;
1120                 goto __kctl_end;
1121         }
1122         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1123                 if (file && vd->owner != NULL && vd->owner != file) {
1124                         err = -EPERM;
1125                         goto __kctl_end;
1126                 }
1127                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1128                 if (err > 0) {
1129                         up_read(&card->controls_rwsem);
1130                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1131                         return 0;
1132                 }
1133         } else {
1134                 if (op_flag) {
1135                         err = -ENXIO;
1136                         goto __kctl_end;
1137                 }
1138                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1139                 if (tlv.length < len) {
1140                         err = -ENOMEM;
1141                         goto __kctl_end;
1142                 }
1143                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1144                         err = -EFAULT;
1145         }
1146       __kctl_end:
1147         up_read(&card->controls_rwsem);
1148         return err;
1149 }
1150
1151 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1152 {
1153         struct snd_ctl_file *ctl;
1154         struct snd_card *card;
1155         struct snd_kctl_ioctl *p;
1156         void __user *argp = (void __user *)arg;
1157         int __user *ip = argp;
1158         int err;
1159
1160         ctl = file->private_data;
1161         card = ctl->card;
1162         if (snd_BUG_ON(!card))
1163                 return -ENXIO;
1164         switch (cmd) {
1165         case SNDRV_CTL_IOCTL_PVERSION:
1166                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1167         case SNDRV_CTL_IOCTL_CARD_INFO:
1168                 return snd_ctl_card_info(card, ctl, cmd, argp);
1169         case SNDRV_CTL_IOCTL_ELEM_LIST:
1170                 return snd_ctl_elem_list(card, argp);
1171         case SNDRV_CTL_IOCTL_ELEM_INFO:
1172                 return snd_ctl_elem_info_user(ctl, argp);
1173         case SNDRV_CTL_IOCTL_ELEM_READ:
1174                 return snd_ctl_elem_read_user(card, argp);
1175         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1176                 return snd_ctl_elem_write_user(ctl, argp);
1177         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1178                 return snd_ctl_elem_lock(ctl, argp);
1179         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1180                 return snd_ctl_elem_unlock(ctl, argp);
1181         case SNDRV_CTL_IOCTL_ELEM_ADD:
1182                 return snd_ctl_elem_add_user(ctl, argp, 0);
1183         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1184                 return snd_ctl_elem_add_user(ctl, argp, 1);
1185         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1186                 return snd_ctl_elem_remove(ctl, argp);
1187         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1188                 return snd_ctl_subscribe_events(ctl, ip);
1189         case SNDRV_CTL_IOCTL_TLV_READ:
1190                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1191         case SNDRV_CTL_IOCTL_TLV_WRITE:
1192                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1193         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1194                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1195         case SNDRV_CTL_IOCTL_POWER:
1196                 return -ENOPROTOOPT;
1197         case SNDRV_CTL_IOCTL_POWER_STATE:
1198 #ifdef CONFIG_PM
1199                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1200 #else
1201                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1202 #endif
1203         }
1204         down_read(&snd_ioctl_rwsem);
1205         list_for_each_entry(p, &snd_control_ioctls, list) {
1206                 err = p->fioctl(card, ctl, cmd, arg);
1207                 if (err != -ENOIOCTLCMD) {
1208                         up_read(&snd_ioctl_rwsem);
1209                         return err;
1210                 }
1211         }
1212         up_read(&snd_ioctl_rwsem);
1213         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1214         return -ENOTTY;
1215 }
1216
1217 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1218                             size_t count, loff_t * offset)
1219 {
1220         struct snd_ctl_file *ctl;
1221         int err = 0;
1222         ssize_t result = 0;
1223
1224         ctl = file->private_data;
1225         if (snd_BUG_ON(!ctl || !ctl->card))
1226                 return -ENXIO;
1227         if (!ctl->subscribed)
1228                 return -EBADFD;
1229         if (count < sizeof(struct snd_ctl_event))
1230                 return -EINVAL;
1231         spin_lock_irq(&ctl->read_lock);
1232         while (count >= sizeof(struct snd_ctl_event)) {
1233                 struct snd_ctl_event ev;
1234                 struct snd_kctl_event *kev;
1235                 while (list_empty(&ctl->events)) {
1236                         wait_queue_t wait;
1237                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1238                                 err = -EAGAIN;
1239                                 goto __end_lock;
1240                         }
1241                         init_waitqueue_entry(&wait, current);
1242                         add_wait_queue(&ctl->change_sleep, &wait);
1243                         set_current_state(TASK_INTERRUPTIBLE);
1244                         spin_unlock_irq(&ctl->read_lock);
1245                         schedule();
1246                         remove_wait_queue(&ctl->change_sleep, &wait);
1247                         if (signal_pending(current))
1248                                 return -ERESTARTSYS;
1249                         spin_lock_irq(&ctl->read_lock);
1250                 }
1251                 kev = snd_kctl_event(ctl->events.next);
1252                 ev.type = SNDRV_CTL_EVENT_ELEM;
1253                 ev.data.elem.mask = kev->mask;
1254                 ev.data.elem.id = kev->id;
1255                 list_del(&kev->list);
1256                 spin_unlock_irq(&ctl->read_lock);
1257                 kfree(kev);
1258                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1259                         err = -EFAULT;
1260                         goto __end;
1261                 }
1262                 spin_lock_irq(&ctl->read_lock);
1263                 buffer += sizeof(struct snd_ctl_event);
1264                 count -= sizeof(struct snd_ctl_event);
1265                 result += sizeof(struct snd_ctl_event);
1266         }
1267       __end_lock:
1268         spin_unlock_irq(&ctl->read_lock);
1269       __end:
1270         return result > 0 ? result : err;
1271 }
1272
1273 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1274 {
1275         unsigned int mask;
1276         struct snd_ctl_file *ctl;
1277
1278         ctl = file->private_data;
1279         if (!ctl->subscribed)
1280                 return 0;
1281         poll_wait(file, &ctl->change_sleep, wait);
1282
1283         mask = 0;
1284         if (!list_empty(&ctl->events))
1285                 mask |= POLLIN | POLLRDNORM;
1286
1287         return mask;
1288 }
1289
1290 /*
1291  * register the device-specific control-ioctls.
1292  * called from each device manager like pcm.c, hwdep.c, etc.
1293  */
1294 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1295 {
1296         struct snd_kctl_ioctl *pn;
1297
1298         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1299         if (pn == NULL)
1300                 return -ENOMEM;
1301         pn->fioctl = fcn;
1302         down_write(&snd_ioctl_rwsem);
1303         list_add_tail(&pn->list, lists);
1304         up_write(&snd_ioctl_rwsem);
1305         return 0;
1306 }
1307
1308 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1309 {
1310         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1311 }
1312
1313 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1314
1315 #ifdef CONFIG_COMPAT
1316 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1317 {
1318         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1319 }
1320
1321 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1322 #endif
1323
1324 /*
1325  * de-register the device-specific control-ioctls.
1326  */
1327 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1328                                      struct list_head *lists)
1329 {
1330         struct snd_kctl_ioctl *p;
1331
1332         if (snd_BUG_ON(!fcn))
1333                 return -EINVAL;
1334         down_write(&snd_ioctl_rwsem);
1335         list_for_each_entry(p, lists, list) {
1336                 if (p->fioctl == fcn) {
1337                         list_del(&p->list);
1338                         up_write(&snd_ioctl_rwsem);
1339                         kfree(p);
1340                         return 0;
1341                 }
1342         }
1343         up_write(&snd_ioctl_rwsem);
1344         snd_BUG();
1345         return -EINVAL;
1346 }
1347
1348 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1349 {
1350         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1351 }
1352
1353 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1354
1355 #ifdef CONFIG_COMPAT
1356 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1357 {
1358         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1359 }
1360
1361 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1362 #endif
1363
1364 static int snd_ctl_fasync(int fd, struct file * file, int on)
1365 {
1366         struct snd_ctl_file *ctl;
1367
1368         ctl = file->private_data;
1369         return fasync_helper(fd, file, on, &ctl->fasync);
1370 }
1371
1372 /*
1373  * ioctl32 compat
1374  */
1375 #ifdef CONFIG_COMPAT
1376 #include "control_compat.c"
1377 #else
1378 #define snd_ctl_ioctl_compat    NULL
1379 #endif
1380
1381 /*
1382  *  INIT PART
1383  */
1384
1385 static const struct file_operations snd_ctl_f_ops =
1386 {
1387         .owner =        THIS_MODULE,
1388         .read =         snd_ctl_read,
1389         .open =         snd_ctl_open,
1390         .release =      snd_ctl_release,
1391         .poll =         snd_ctl_poll,
1392         .unlocked_ioctl =       snd_ctl_ioctl,
1393         .compat_ioctl = snd_ctl_ioctl_compat,
1394         .fasync =       snd_ctl_fasync,
1395 };
1396
1397 /*
1398  * registration of the control device
1399  */
1400 static int snd_ctl_dev_register(struct snd_device *device)
1401 {
1402         struct snd_card *card = device->device_data;
1403         int err, cardnum;
1404         char name[16];
1405
1406         if (snd_BUG_ON(!card))
1407                 return -ENXIO;
1408         cardnum = card->number;
1409         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1410                 return -ENXIO;
1411         sprintf(name, "controlC%i", cardnum);
1412         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1413                                        &snd_ctl_f_ops, card, name)) < 0)
1414                 return err;
1415         return 0;
1416 }
1417
1418 /*
1419  * disconnection of the control device
1420  */
1421 static int snd_ctl_dev_disconnect(struct snd_device *device)
1422 {
1423         struct snd_card *card = device->device_data;
1424         struct snd_ctl_file *ctl;
1425         int err, cardnum;
1426
1427         if (snd_BUG_ON(!card))
1428                 return -ENXIO;
1429         cardnum = card->number;
1430         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1431                 return -ENXIO;
1432
1433         read_lock(&card->ctl_files_rwlock);
1434         list_for_each_entry(ctl, &card->ctl_files, list) {
1435                 wake_up(&ctl->change_sleep);
1436                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1437         }
1438         read_unlock(&card->ctl_files_rwlock);
1439
1440         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1441                                          card, -1)) < 0)
1442                 return err;
1443         return 0;
1444 }
1445
1446 /*
1447  * free all controls
1448  */
1449 static int snd_ctl_dev_free(struct snd_device *device)
1450 {
1451         struct snd_card *card = device->device_data;
1452         struct snd_kcontrol *control;
1453
1454         down_write(&card->controls_rwsem);
1455         while (!list_empty(&card->controls)) {
1456                 control = snd_kcontrol(card->controls.next);
1457                 snd_ctl_remove(card, control);
1458         }
1459         up_write(&card->controls_rwsem);
1460         return 0;
1461 }
1462
1463 /*
1464  * create control core:
1465  * called from init.c
1466  */
1467 int snd_ctl_create(struct snd_card *card)
1468 {
1469         static struct snd_device_ops ops = {
1470                 .dev_free = snd_ctl_dev_free,
1471                 .dev_register = snd_ctl_dev_register,
1472                 .dev_disconnect = snd_ctl_dev_disconnect,
1473         };
1474
1475         if (snd_BUG_ON(!card))
1476                 return -ENXIO;
1477         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1478 }
1479
1480 /*
1481  * Frequently used control callbacks
1482  */
1483 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1484                               struct snd_ctl_elem_info *uinfo)
1485 {
1486         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1487         uinfo->count = 1;
1488         uinfo->value.integer.min = 0;
1489         uinfo->value.integer.max = 1;
1490         return 0;
1491 }
1492
1493 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1494
1495 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1496                                 struct snd_ctl_elem_info *uinfo)
1497 {
1498         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1499         uinfo->count = 2;
1500         uinfo->value.integer.min = 0;
1501         uinfo->value.integer.max = 1;
1502         return 0;
1503 }
1504
1505 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);