978fe1a8e9f0877ece853c788a5ed371f9bdfa77
[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 #define MAX_CONTROL_COUNT       1028
35
36 struct snd_kctl_ioctl {
37         struct list_head list;          /* list of all ioctls */
38         snd_kctl_ioctl_func_t fioctl;
39 };
40
41 static DECLARE_RWSEM(snd_ioctl_rwsem);
42 static LIST_HEAD(snd_control_ioctls);
43 #ifdef CONFIG_COMPAT
44 static LIST_HEAD(snd_control_compat_ioctls);
45 #endif
46
47 static int snd_ctl_open(struct inode *inode, struct file *file)
48 {
49         unsigned long flags;
50         struct snd_card *card;
51         struct snd_ctl_file *ctl;
52         int err;
53
54         err = nonseekable_open(inode, file);
55         if (err < 0)
56                 return err;
57
58         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
59         if (!card) {
60                 err = -ENODEV;
61                 goto __error1;
62         }
63         err = snd_card_file_add(card, file);
64         if (err < 0) {
65                 err = -ENODEV;
66                 goto __error1;
67         }
68         if (!try_module_get(card->module)) {
69                 err = -EFAULT;
70                 goto __error2;
71         }
72         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
73         if (ctl == NULL) {
74                 err = -ENOMEM;
75                 goto __error;
76         }
77         INIT_LIST_HEAD(&ctl->events);
78         init_waitqueue_head(&ctl->change_sleep);
79         spin_lock_init(&ctl->read_lock);
80         ctl->card = card;
81         ctl->prefer_pcm_subdevice = -1;
82         ctl->prefer_rawmidi_subdevice = -1;
83         ctl->pid = get_pid(task_pid(current));
84         file->private_data = ctl;
85         write_lock_irqsave(&card->ctl_files_rwlock, flags);
86         list_add_tail(&ctl->list, &card->ctl_files);
87         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
88         return 0;
89
90       __error:
91         module_put(card->module);
92       __error2:
93         snd_card_file_remove(card, file);
94       __error1:
95         return err;
96 }
97
98 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
99 {
100         unsigned long flags;
101         struct snd_kctl_event *cread;
102         
103         spin_lock_irqsave(&ctl->read_lock, flags);
104         while (!list_empty(&ctl->events)) {
105                 cread = snd_kctl_event(ctl->events.next);
106                 list_del(&cread->list);
107                 kfree(cread);
108         }
109         spin_unlock_irqrestore(&ctl->read_lock, flags);
110 }
111
112 static int snd_ctl_release(struct inode *inode, struct file *file)
113 {
114         unsigned long flags;
115         struct snd_card *card;
116         struct snd_ctl_file *ctl;
117         struct snd_kcontrol *control;
118         unsigned int idx;
119
120         ctl = file->private_data;
121         file->private_data = NULL;
122         card = ctl->card;
123         write_lock_irqsave(&card->ctl_files_rwlock, flags);
124         list_del(&ctl->list);
125         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
126         down_write(&card->controls_rwsem);
127         list_for_each_entry(control, &card->controls, list)
128                 for (idx = 0; idx < control->count; idx++)
129                         if (control->vd[idx].owner == ctl)
130                                 control->vd[idx].owner = NULL;
131         up_write(&card->controls_rwsem);
132         snd_ctl_empty_read_queue(ctl);
133         put_pid(ctl->pid);
134         kfree(ctl);
135         module_put(card->module);
136         snd_card_file_remove(card, file);
137         return 0;
138 }
139
140 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
141                     struct snd_ctl_elem_id *id)
142 {
143         unsigned long flags;
144         struct snd_ctl_file *ctl;
145         struct snd_kctl_event *ev;
146         
147         if (snd_BUG_ON(!card || !id))
148                 return;
149         read_lock(&card->ctl_files_rwlock);
150 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
151         card->mixer_oss_change_count++;
152 #endif
153         list_for_each_entry(ctl, &card->ctl_files, list) {
154                 if (!ctl->subscribed)
155                         continue;
156                 spin_lock_irqsave(&ctl->read_lock, flags);
157                 list_for_each_entry(ev, &ctl->events, list) {
158                         if (ev->id.numid == id->numid) {
159                                 ev->mask |= mask;
160                                 goto _found;
161                         }
162                 }
163                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
164                 if (ev) {
165                         ev->id = *id;
166                         ev->mask = mask;
167                         list_add_tail(&ev->list, &ctl->events);
168                 } else {
169                         snd_printk(KERN_ERR "No memory available to allocate event\n");
170                 }
171         _found:
172                 wake_up(&ctl->change_sleep);
173                 spin_unlock_irqrestore(&ctl->read_lock, flags);
174                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
175         }
176         read_unlock(&card->ctl_files_rwlock);
177 }
178
179 EXPORT_SYMBOL(snd_ctl_notify);
180
181 /**
182  * snd_ctl_new - create a control instance from the template
183  * @control: the control template
184  * @access: the default control access
185  *
186  * Allocates a new struct snd_kcontrol instance and copies the given template 
187  * to the new instance. It does not copy volatile data (access).
188  *
189  * Returns the pointer of the new instance, or NULL on failure.
190  */
191 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
192                                         unsigned int access)
193 {
194         struct snd_kcontrol *kctl;
195         unsigned int idx;
196         
197         if (snd_BUG_ON(!control || !control->count))
198                 return NULL;
199
200         if (control->count > MAX_CONTROL_COUNT)
201                 return NULL;
202
203         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
204         if (kctl == NULL) {
205                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
206                 return NULL;
207         }
208         *kctl = *control;
209         for (idx = 0; idx < kctl->count; idx++)
210                 kctl->vd[idx].access = access;
211         return kctl;
212 }
213
214 /**
215  * snd_ctl_new1 - create a control instance from the template
216  * @ncontrol: the initialization record
217  * @private_data: the private data to set
218  *
219  * Allocates a new struct snd_kcontrol instance and initialize from the given 
220  * template.  When the access field of ncontrol is 0, it's assumed as
221  * READWRITE access. When the count field is 0, it's assumes as one.
222  *
223  * Returns the pointer of the newly generated instance, or NULL on failure.
224  */
225 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
226                                   void *private_data)
227 {
228         struct snd_kcontrol kctl;
229         unsigned int access;
230         
231         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
232                 return NULL;
233         memset(&kctl, 0, sizeof(kctl));
234         kctl.id.iface = ncontrol->iface;
235         kctl.id.device = ncontrol->device;
236         kctl.id.subdevice = ncontrol->subdevice;
237         if (ncontrol->name) {
238                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
239                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
240                         snd_printk(KERN_WARNING
241                                    "Control name '%s' truncated to '%s'\n",
242                                    ncontrol->name, kctl.id.name);
243         }
244         kctl.id.index = ncontrol->index;
245         kctl.count = ncontrol->count ? ncontrol->count : 1;
246         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
247                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
248                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
249                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
250                                       SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
251                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
252         kctl.info = ncontrol->info;
253         kctl.get = ncontrol->get;
254         kctl.put = ncontrol->put;
255         kctl.tlv.p = ncontrol->tlv.p;
256         kctl.private_value = ncontrol->private_value;
257         kctl.private_data = private_data;
258         return snd_ctl_new(&kctl, access);
259 }
260
261 EXPORT_SYMBOL(snd_ctl_new1);
262
263 /**
264  * snd_ctl_free_one - release the control instance
265  * @kcontrol: the control instance
266  *
267  * Releases the control instance created via snd_ctl_new()
268  * or snd_ctl_new1().
269  * Don't call this after the control was added to the card.
270  */
271 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
272 {
273         if (kcontrol) {
274                 if (kcontrol->private_free)
275                         kcontrol->private_free(kcontrol);
276                 kfree(kcontrol);
277         }
278 }
279
280 EXPORT_SYMBOL(snd_ctl_free_one);
281
282 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
283                                           unsigned int count)
284 {
285         struct snd_kcontrol *kctl;
286
287         list_for_each_entry(kctl, &card->controls, list) {
288                 if (kctl->id.numid < card->last_numid + 1 + count &&
289                     kctl->id.numid + kctl->count > card->last_numid + 1) {
290                         card->last_numid = kctl->id.numid + kctl->count - 1;
291                         return true;
292                 }
293         }
294         return false;
295 }
296
297 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
298 {
299         unsigned int iter = 100000;
300
301         while (snd_ctl_remove_numid_conflict(card, count)) {
302                 if (--iter == 0) {
303                         /* this situation is very unlikely */
304                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
305                         return -ENOMEM;
306                 }
307         }
308         return 0;
309 }
310
311 /**
312  * snd_ctl_add - add the control instance to the card
313  * @card: the card instance
314  * @kcontrol: the control instance to add
315  *
316  * Adds the control instance created via snd_ctl_new() or
317  * snd_ctl_new1() to the given card. Assigns also an unique
318  * numid used for fast search.
319  *
320  * Returns zero if successful, or a negative error code on failure.
321  *
322  * It frees automatically the control which cannot be added.
323  */
324 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
325 {
326         struct snd_ctl_elem_id id;
327         unsigned int idx;
328         int err = -EINVAL;
329
330         if (! kcontrol)
331                 return err;
332         if (snd_BUG_ON(!card || !kcontrol->info))
333                 goto error;
334         id = kcontrol->id;
335         down_write(&card->controls_rwsem);
336         if (snd_ctl_find_id(card, &id)) {
337                 up_write(&card->controls_rwsem);
338                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
339                                         id.iface,
340                                         id.device,
341                                         id.subdevice,
342                                         id.name,
343                                         id.index);
344                 err = -EBUSY;
345                 goto error;
346         }
347         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
348                 up_write(&card->controls_rwsem);
349                 err = -ENOMEM;
350                 goto error;
351         }
352         list_add_tail(&kcontrol->list, &card->controls);
353         card->controls_count += kcontrol->count;
354         kcontrol->id.numid = card->last_numid + 1;
355         card->last_numid += kcontrol->count;
356         up_write(&card->controls_rwsem);
357         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
358                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
359         return 0;
360
361  error:
362         snd_ctl_free_one(kcontrol);
363         return err;
364 }
365
366 EXPORT_SYMBOL(snd_ctl_add);
367
368 /**
369  * snd_ctl_replace - replace the control instance of the card
370  * @card: the card instance
371  * @kcontrol: the control instance to replace
372  * @add_on_replace: add the control if not already added
373  *
374  * Replaces the given control.  If the given control does not exist
375  * and the add_on_replace flag is set, the control is added.  If the
376  * control exists, it is destroyed first.
377  *
378  * Returns zero if successful, or a negative error code on failure.
379  *
380  * It frees automatically the control which cannot be added or replaced.
381  */
382 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
383                     bool add_on_replace)
384 {
385         struct snd_ctl_elem_id id;
386         unsigned int idx;
387         struct snd_kcontrol *old;
388         int ret;
389
390         if (!kcontrol)
391                 return -EINVAL;
392         if (snd_BUG_ON(!card || !kcontrol->info)) {
393                 ret = -EINVAL;
394                 goto error;
395         }
396         id = kcontrol->id;
397         down_write(&card->controls_rwsem);
398         old = snd_ctl_find_id(card, &id);
399         if (!old) {
400                 if (add_on_replace)
401                         goto add;
402                 up_write(&card->controls_rwsem);
403                 ret = -EINVAL;
404                 goto error;
405         }
406         ret = snd_ctl_remove(card, old);
407         if (ret < 0) {
408                 up_write(&card->controls_rwsem);
409                 goto error;
410         }
411 add:
412         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
413                 up_write(&card->controls_rwsem);
414                 ret = -ENOMEM;
415                 goto error;
416         }
417         list_add_tail(&kcontrol->list, &card->controls);
418         card->controls_count += kcontrol->count;
419         kcontrol->id.numid = card->last_numid + 1;
420         card->last_numid += kcontrol->count;
421         up_write(&card->controls_rwsem);
422         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
423                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
424         return 0;
425
426 error:
427         snd_ctl_free_one(kcontrol);
428         return ret;
429 }
430 EXPORT_SYMBOL(snd_ctl_replace);
431
432 /**
433  * snd_ctl_remove - remove the control from the card and release it
434  * @card: the card instance
435  * @kcontrol: the control instance to remove
436  *
437  * Removes the control from the card and then releases the instance.
438  * You don't need to call snd_ctl_free_one(). You must be in
439  * the write lock - down_write(&card->controls_rwsem).
440  * 
441  * Returns 0 if successful, or a negative error code on failure.
442  */
443 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
444 {
445         struct snd_ctl_elem_id id;
446         unsigned int idx;
447
448         if (snd_BUG_ON(!card || !kcontrol))
449                 return -EINVAL;
450         list_del(&kcontrol->list);
451         card->controls_count -= kcontrol->count;
452         id = kcontrol->id;
453         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
454                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
455         snd_ctl_free_one(kcontrol);
456         return 0;
457 }
458
459 EXPORT_SYMBOL(snd_ctl_remove);
460
461 /**
462  * snd_ctl_remove_id - remove the control of the given id and release it
463  * @card: the card instance
464  * @id: the control id to remove
465  *
466  * Finds the control instance with the given id, removes it from the
467  * card list and releases it.
468  * 
469  * Returns 0 if successful, or a negative error code on failure.
470  */
471 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
472 {
473         struct snd_kcontrol *kctl;
474         int ret;
475
476         down_write(&card->controls_rwsem);
477         kctl = snd_ctl_find_id(card, id);
478         if (kctl == NULL) {
479                 up_write(&card->controls_rwsem);
480                 return -ENOENT;
481         }
482         ret = snd_ctl_remove(card, kctl);
483         up_write(&card->controls_rwsem);
484         return ret;
485 }
486
487 EXPORT_SYMBOL(snd_ctl_remove_id);
488
489 /**
490  * snd_ctl_remove_user_ctl - remove and release the unlocked user control
491  * @file: active control handle
492  * @id: the control id to remove
493  *
494  * Finds the control instance with the given id, removes it from the
495  * card list and releases it.
496  * 
497  * Returns 0 if successful, or a negative error code on failure.
498  */
499 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
500                                    struct snd_ctl_elem_id *id)
501 {
502         struct snd_card *card = file->card;
503         struct snd_kcontrol *kctl;
504         int idx, ret;
505
506         down_write(&card->controls_rwsem);
507         kctl = snd_ctl_find_id(card, id);
508         if (kctl == NULL) {
509                 ret = -ENOENT;
510                 goto error;
511         }
512         if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
513                 ret = -EINVAL;
514                 goto error;
515         }
516         for (idx = 0; idx < kctl->count; idx++)
517                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
518                         ret = -EBUSY;
519                         goto error;
520                 }
521         ret = snd_ctl_remove(card, kctl);
522         if (ret < 0)
523                 goto error;
524         card->user_ctl_count--;
525 error:
526         up_write(&card->controls_rwsem);
527         return ret;
528 }
529
530 /**
531  * snd_ctl_activate_id - activate/inactivate the control of the given id
532  * @card: the card instance
533  * @id: the control id to activate/inactivate
534  * @active: non-zero to activate
535  *
536  * Finds the control instance with the given id, and activate or
537  * inactivate the control together with notification, if changed.
538  *
539  * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
540  */
541 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
542                         int active)
543 {
544         struct snd_kcontrol *kctl;
545         struct snd_kcontrol_volatile *vd;
546         unsigned int index_offset;
547         int ret;
548
549         down_write(&card->controls_rwsem);
550         kctl = snd_ctl_find_id(card, id);
551         if (kctl == NULL) {
552                 ret = -ENOENT;
553                 goto unlock;
554         }
555         index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
556         vd = &kctl->vd[index_offset];
557         ret = 0;
558         if (active) {
559                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
560                         goto unlock;
561                 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
562         } else {
563                 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
564                         goto unlock;
565                 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
566         }
567         ret = 1;
568  unlock:
569         up_write(&card->controls_rwsem);
570         if (ret > 0)
571                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
572         return ret;
573 }
574 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
575
576 /**
577  * snd_ctl_rename_id - replace the id of a control on the card
578  * @card: the card instance
579  * @src_id: the old id
580  * @dst_id: the new id
581  *
582  * Finds the control with the old id from the card, and replaces the
583  * id with the new one.
584  *
585  * Returns zero if successful, or a negative error code on failure.
586  */
587 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
588                       struct snd_ctl_elem_id *dst_id)
589 {
590         struct snd_kcontrol *kctl;
591
592         down_write(&card->controls_rwsem);
593         kctl = snd_ctl_find_id(card, src_id);
594         if (kctl == NULL) {
595                 up_write(&card->controls_rwsem);
596                 return -ENOENT;
597         }
598         kctl->id = *dst_id;
599         kctl->id.numid = card->last_numid + 1;
600         card->last_numid += kctl->count;
601         up_write(&card->controls_rwsem);
602         return 0;
603 }
604
605 EXPORT_SYMBOL(snd_ctl_rename_id);
606
607 /**
608  * snd_ctl_find_numid - find the control instance with the given number-id
609  * @card: the card instance
610  * @numid: the number-id to search
611  *
612  * Finds the control instance with the given number-id from the card.
613  *
614  * Returns the pointer of the instance if found, or NULL if not.
615  *
616  * The caller must down card->controls_rwsem before calling this function
617  * (if the race condition can happen).
618  */
619 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
620 {
621         struct snd_kcontrol *kctl;
622
623         if (snd_BUG_ON(!card || !numid))
624                 return NULL;
625         list_for_each_entry(kctl, &card->controls, list) {
626                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
627                         return kctl;
628         }
629         return NULL;
630 }
631
632 EXPORT_SYMBOL(snd_ctl_find_numid);
633
634 /**
635  * snd_ctl_find_id - find the control instance with the given id
636  * @card: the card instance
637  * @id: the id to search
638  *
639  * Finds the control instance with the given id from the card.
640  *
641  * Returns the pointer of the instance if found, or NULL if not.
642  *
643  * The caller must down card->controls_rwsem before calling this function
644  * (if the race condition can happen).
645  */
646 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
647                                      struct snd_ctl_elem_id *id)
648 {
649         struct snd_kcontrol *kctl;
650
651         if (snd_BUG_ON(!card || !id))
652                 return NULL;
653         if (id->numid != 0)
654                 return snd_ctl_find_numid(card, id->numid);
655         list_for_each_entry(kctl, &card->controls, list) {
656                 if (kctl->id.iface != id->iface)
657                         continue;
658                 if (kctl->id.device != id->device)
659                         continue;
660                 if (kctl->id.subdevice != id->subdevice)
661                         continue;
662                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
663                         continue;
664                 if (kctl->id.index > id->index)
665                         continue;
666                 if (kctl->id.index + kctl->count <= id->index)
667                         continue;
668                 return kctl;
669         }
670         return NULL;
671 }
672
673 EXPORT_SYMBOL(snd_ctl_find_id);
674
675 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
676                              unsigned int cmd, void __user *arg)
677 {
678         struct snd_ctl_card_info *info;
679
680         info = kzalloc(sizeof(*info), GFP_KERNEL);
681         if (! info)
682                 return -ENOMEM;
683         down_read(&snd_ioctl_rwsem);
684         info->card = card->number;
685         strlcpy(info->id, card->id, sizeof(info->id));
686         strlcpy(info->driver, card->driver, sizeof(info->driver));
687         strlcpy(info->name, card->shortname, sizeof(info->name));
688         strlcpy(info->longname, card->longname, sizeof(info->longname));
689         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
690         strlcpy(info->components, card->components, sizeof(info->components));
691         up_read(&snd_ioctl_rwsem);
692         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
693                 kfree(info);
694                 return -EFAULT;
695         }
696         kfree(info);
697         return 0;
698 }
699
700 static int snd_ctl_elem_list(struct snd_card *card,
701                              struct snd_ctl_elem_list __user *_list)
702 {
703         struct list_head *plist;
704         struct snd_ctl_elem_list list;
705         struct snd_kcontrol *kctl;
706         struct snd_ctl_elem_id *dst, *id;
707         unsigned int offset, space, jidx;
708         
709         if (copy_from_user(&list, _list, sizeof(list)))
710                 return -EFAULT;
711         offset = list.offset;
712         space = list.space;
713         /* try limit maximum space */
714         if (space > 16384)
715                 return -ENOMEM;
716         if (space > 0) {
717                 /* allocate temporary buffer for atomic operation */
718                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
719                 if (dst == NULL)
720                         return -ENOMEM;
721                 down_read(&card->controls_rwsem);
722                 list.count = card->controls_count;
723                 plist = card->controls.next;
724                 while (plist != &card->controls) {
725                         if (offset == 0)
726                                 break;
727                         kctl = snd_kcontrol(plist);
728                         if (offset < kctl->count)
729                                 break;
730                         offset -= kctl->count;
731                         plist = plist->next;
732                 }
733                 list.used = 0;
734                 id = dst;
735                 while (space > 0 && plist != &card->controls) {
736                         kctl = snd_kcontrol(plist);
737                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
738                                 snd_ctl_build_ioff(id, kctl, jidx);
739                                 id++;
740                                 space--;
741                                 list.used++;
742                         }
743                         plist = plist->next;
744                         offset = 0;
745                 }
746                 up_read(&card->controls_rwsem);
747                 if (list.used > 0 &&
748                     copy_to_user(list.pids, dst,
749                                  list.used * sizeof(struct snd_ctl_elem_id))) {
750                         vfree(dst);
751                         return -EFAULT;
752                 }
753                 vfree(dst);
754         } else {
755                 down_read(&card->controls_rwsem);
756                 list.count = card->controls_count;
757                 up_read(&card->controls_rwsem);
758         }
759         if (copy_to_user(_list, &list, sizeof(list)))
760                 return -EFAULT;
761         return 0;
762 }
763
764 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
765                              struct snd_ctl_elem_info *info)
766 {
767         struct snd_card *card = ctl->card;
768         struct snd_kcontrol *kctl;
769         struct snd_kcontrol_volatile *vd;
770         unsigned int index_offset;
771         int result;
772         
773         down_read(&card->controls_rwsem);
774         kctl = snd_ctl_find_id(card, &info->id);
775         if (kctl == NULL) {
776                 up_read(&card->controls_rwsem);
777                 return -ENOENT;
778         }
779 #ifdef CONFIG_SND_DEBUG
780         info->access = 0;
781 #endif
782         result = kctl->info(kctl, info);
783         if (result >= 0) {
784                 snd_BUG_ON(info->access);
785                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
786                 vd = &kctl->vd[index_offset];
787                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
788                 info->access = vd->access;
789                 if (vd->owner) {
790                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
791                         if (vd->owner == ctl)
792                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
793                         info->owner = pid_vnr(vd->owner->pid);
794                 } else {
795                         info->owner = -1;
796                 }
797         }
798         up_read(&card->controls_rwsem);
799         return result;
800 }
801
802 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
803                                   struct snd_ctl_elem_info __user *_info)
804 {
805         struct snd_ctl_elem_info info;
806         int result;
807
808         if (copy_from_user(&info, _info, sizeof(info)))
809                 return -EFAULT;
810         snd_power_lock(ctl->card);
811         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
812         if (result >= 0)
813                 result = snd_ctl_elem_info(ctl, &info);
814         snd_power_unlock(ctl->card);
815         if (result >= 0)
816                 if (copy_to_user(_info, &info, sizeof(info)))
817                         return -EFAULT;
818         return result;
819 }
820
821 static int snd_ctl_elem_read(struct snd_card *card,
822                              struct snd_ctl_elem_value *control)
823 {
824         struct snd_kcontrol *kctl;
825         struct snd_kcontrol_volatile *vd;
826         unsigned int index_offset;
827         int result;
828
829         down_read(&card->controls_rwsem);
830         kctl = snd_ctl_find_id(card, &control->id);
831         if (kctl == NULL) {
832                 result = -ENOENT;
833         } else {
834                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
835                 vd = &kctl->vd[index_offset];
836                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
837                     kctl->get != NULL) {
838                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
839                         result = kctl->get(kctl, control);
840                 } else
841                         result = -EPERM;
842         }
843         up_read(&card->controls_rwsem);
844         return result;
845 }
846
847 static int snd_ctl_elem_read_user(struct snd_card *card,
848                                   struct snd_ctl_elem_value __user *_control)
849 {
850         struct snd_ctl_elem_value *control;
851         int result;
852
853         control = memdup_user(_control, sizeof(*control));
854         if (IS_ERR(control))
855                 return PTR_ERR(control);
856
857         snd_power_lock(card);
858         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
859         if (result >= 0)
860                 result = snd_ctl_elem_read(card, control);
861         snd_power_unlock(card);
862         if (result >= 0)
863                 if (copy_to_user(_control, control, sizeof(*control)))
864                         result = -EFAULT;
865         kfree(control);
866         return result;
867 }
868
869 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
870                               struct snd_ctl_elem_value *control)
871 {
872         struct snd_kcontrol *kctl;
873         struct snd_kcontrol_volatile *vd;
874         unsigned int index_offset;
875         int result;
876
877         down_read(&card->controls_rwsem);
878         kctl = snd_ctl_find_id(card, &control->id);
879         if (kctl == NULL) {
880                 result = -ENOENT;
881         } else {
882                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
883                 vd = &kctl->vd[index_offset];
884                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
885                     kctl->put == NULL ||
886                     (file && vd->owner && vd->owner != file)) {
887                         result = -EPERM;
888                 } else {
889                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
890                         result = kctl->put(kctl, control);
891                 }
892                 if (result > 0) {
893                         up_read(&card->controls_rwsem);
894                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
895                                        &control->id);
896                         return 0;
897                 }
898         }
899         up_read(&card->controls_rwsem);
900         return result;
901 }
902
903 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
904                                    struct snd_ctl_elem_value __user *_control)
905 {
906         struct snd_ctl_elem_value *control;
907         struct snd_card *card;
908         int result;
909
910         control = memdup_user(_control, sizeof(*control));
911         if (IS_ERR(control))
912                 return PTR_ERR(control);
913
914         card = file->card;
915         snd_power_lock(card);
916         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
917         if (result >= 0)
918                 result = snd_ctl_elem_write(card, file, control);
919         snd_power_unlock(card);
920         if (result >= 0)
921                 if (copy_to_user(_control, control, sizeof(*control)))
922                         result = -EFAULT;
923         kfree(control);
924         return result;
925 }
926
927 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
928                              struct snd_ctl_elem_id __user *_id)
929 {
930         struct snd_card *card = file->card;
931         struct snd_ctl_elem_id id;
932         struct snd_kcontrol *kctl;
933         struct snd_kcontrol_volatile *vd;
934         int result;
935         
936         if (copy_from_user(&id, _id, sizeof(id)))
937                 return -EFAULT;
938         down_write(&card->controls_rwsem);
939         kctl = snd_ctl_find_id(card, &id);
940         if (kctl == NULL) {
941                 result = -ENOENT;
942         } else {
943                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
944                 if (vd->owner != NULL)
945                         result = -EBUSY;
946                 else {
947                         vd->owner = file;
948                         result = 0;
949                 }
950         }
951         up_write(&card->controls_rwsem);
952         return result;
953 }
954
955 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
956                                struct snd_ctl_elem_id __user *_id)
957 {
958         struct snd_card *card = file->card;
959         struct snd_ctl_elem_id id;
960         struct snd_kcontrol *kctl;
961         struct snd_kcontrol_volatile *vd;
962         int result;
963         
964         if (copy_from_user(&id, _id, sizeof(id)))
965                 return -EFAULT;
966         down_write(&card->controls_rwsem);
967         kctl = snd_ctl_find_id(card, &id);
968         if (kctl == NULL) {
969                 result = -ENOENT;
970         } else {
971                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
972                 if (vd->owner == NULL)
973                         result = -EINVAL;
974                 else if (vd->owner != file)
975                         result = -EPERM;
976                 else {
977                         vd->owner = NULL;
978                         result = 0;
979                 }
980         }
981         up_write(&card->controls_rwsem);
982         return result;
983 }
984
985 struct user_element {
986         struct snd_ctl_elem_info info;
987         void *elem_data;                /* element data */
988         unsigned long elem_data_size;   /* size of element data in bytes */
989         void *tlv_data;                 /* TLV data */
990         unsigned long tlv_data_size;    /* TLV data size */
991         void *priv_data;                /* private data (like strings for enumerated type) */
992 };
993
994 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
995                                   struct snd_ctl_elem_info *uinfo)
996 {
997         struct user_element *ue = kcontrol->private_data;
998
999         *uinfo = ue->info;
1000         return 0;
1001 }
1002
1003 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1004                                        struct snd_ctl_elem_info *uinfo)
1005 {
1006         struct user_element *ue = kcontrol->private_data;
1007         const char *names;
1008         unsigned int item;
1009
1010         item = uinfo->value.enumerated.item;
1011
1012         *uinfo = ue->info;
1013
1014         item = min(item, uinfo->value.enumerated.items - 1);
1015         uinfo->value.enumerated.item = item;
1016
1017         names = ue->priv_data;
1018         for (; item > 0; --item)
1019                 names += strlen(names) + 1;
1020         strcpy(uinfo->value.enumerated.name, names);
1021
1022         return 0;
1023 }
1024
1025 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1026                                  struct snd_ctl_elem_value *ucontrol)
1027 {
1028         struct user_element *ue = kcontrol->private_data;
1029
1030         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1031         return 0;
1032 }
1033
1034 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1035                                  struct snd_ctl_elem_value *ucontrol)
1036 {
1037         int change;
1038         struct user_element *ue = kcontrol->private_data;
1039         
1040         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1041         if (change)
1042                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1043         return change;
1044 }
1045
1046 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1047                                  int op_flag,
1048                                  unsigned int size,
1049                                  unsigned int __user *tlv)
1050 {
1051         struct user_element *ue = kcontrol->private_data;
1052         int change = 0;
1053         void *new_data;
1054
1055         if (op_flag > 0) {
1056                 if (size > 1024 * 128)  /* sane value */
1057                         return -EINVAL;
1058
1059                 new_data = memdup_user(tlv, size);
1060                 if (IS_ERR(new_data))
1061                         return PTR_ERR(new_data);
1062                 change = ue->tlv_data_size != size;
1063                 if (!change)
1064                         change = memcmp(ue->tlv_data, new_data, size);
1065                 kfree(ue->tlv_data);
1066                 ue->tlv_data = new_data;
1067                 ue->tlv_data_size = size;
1068         } else {
1069                 if (! ue->tlv_data_size || ! ue->tlv_data)
1070                         return -ENXIO;
1071                 if (size < ue->tlv_data_size)
1072                         return -ENOSPC;
1073                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1074                         return -EFAULT;
1075         }
1076         return change;
1077 }
1078
1079 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1080 {
1081         char *names, *p;
1082         size_t buf_len, name_len;
1083         unsigned int i;
1084
1085         if (ue->info.value.enumerated.names_length > 64 * 1024)
1086                 return -EINVAL;
1087
1088         names = memdup_user(
1089                 (const void __user *)ue->info.value.enumerated.names_ptr,
1090                 ue->info.value.enumerated.names_length);
1091         if (IS_ERR(names))
1092                 return PTR_ERR(names);
1093
1094         /* check that there are enough valid names */
1095         buf_len = ue->info.value.enumerated.names_length;
1096         p = names;
1097         for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1098                 name_len = strnlen(p, buf_len);
1099                 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1100                         kfree(names);
1101                         return -EINVAL;
1102                 }
1103                 p += name_len + 1;
1104                 buf_len -= name_len + 1;
1105         }
1106
1107         ue->priv_data = names;
1108         ue->info.value.enumerated.names_ptr = 0;
1109
1110         return 0;
1111 }
1112
1113 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1114 {
1115         struct user_element *ue = kcontrol->private_data;
1116
1117         kfree(ue->tlv_data);
1118         kfree(ue->priv_data);
1119         kfree(ue);
1120 }
1121
1122 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1123                             struct snd_ctl_elem_info *info, int replace)
1124 {
1125         struct snd_card *card = file->card;
1126         struct snd_kcontrol kctl, *_kctl;
1127         unsigned int access;
1128         long private_size;
1129         struct user_element *ue;
1130         int idx, err;
1131
1132         if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1133                 return -ENOMEM;
1134         if (info->count < 1)
1135                 return -EINVAL;
1136         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1137                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1138                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1139                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1140         info->id.numid = 0;
1141         memset(&kctl, 0, sizeof(kctl));
1142         down_write(&card->controls_rwsem);
1143         _kctl = snd_ctl_find_id(card, &info->id);
1144         err = 0;
1145         if (_kctl) {
1146                 if (replace)
1147                         err = snd_ctl_remove(card, _kctl);
1148                 else
1149                         err = -EBUSY;
1150         } else {
1151                 if (replace)
1152                         err = -ENOENT;
1153         }
1154         up_write(&card->controls_rwsem);
1155         if (err < 0)
1156                 return err;
1157         memcpy(&kctl.id, &info->id, sizeof(info->id));
1158         kctl.count = info->owner ? info->owner : 1;
1159         access |= SNDRV_CTL_ELEM_ACCESS_USER;
1160         if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1161                 kctl.info = snd_ctl_elem_user_enum_info;
1162         else
1163                 kctl.info = snd_ctl_elem_user_info;
1164         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1165                 kctl.get = snd_ctl_elem_user_get;
1166         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1167                 kctl.put = snd_ctl_elem_user_put;
1168         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1169                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1170                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1171         }
1172         switch (info->type) {
1173         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1174         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1175                 private_size = sizeof(long);
1176                 if (info->count > 128)
1177                         return -EINVAL;
1178                 break;
1179         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1180                 private_size = sizeof(long long);
1181                 if (info->count > 64)
1182                         return -EINVAL;
1183                 break;
1184         case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1185                 private_size = sizeof(unsigned int);
1186                 if (info->count > 128 || info->value.enumerated.items == 0)
1187                         return -EINVAL;
1188                 break;
1189         case SNDRV_CTL_ELEM_TYPE_BYTES:
1190                 private_size = sizeof(unsigned char);
1191                 if (info->count > 512)
1192                         return -EINVAL;
1193                 break;
1194         case SNDRV_CTL_ELEM_TYPE_IEC958:
1195                 private_size = sizeof(struct snd_aes_iec958);
1196                 if (info->count != 1)
1197                         return -EINVAL;
1198                 break;
1199         default:
1200                 return -EINVAL;
1201         }
1202         private_size *= info->count;
1203         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1204         if (ue == NULL)
1205                 return -ENOMEM;
1206         ue->info = *info;
1207         ue->info.access = 0;
1208         ue->elem_data = (char *)ue + sizeof(*ue);
1209         ue->elem_data_size = private_size;
1210         if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1211                 err = snd_ctl_elem_init_enum_names(ue);
1212                 if (err < 0) {
1213                         kfree(ue);
1214                         return err;
1215                 }
1216         }
1217         kctl.private_free = snd_ctl_elem_user_free;
1218         _kctl = snd_ctl_new(&kctl, access);
1219         if (_kctl == NULL) {
1220                 kfree(ue->priv_data);
1221                 kfree(ue);
1222                 return -ENOMEM;
1223         }
1224         _kctl->private_data = ue;
1225         for (idx = 0; idx < _kctl->count; idx++)
1226                 _kctl->vd[idx].owner = file;
1227         err = snd_ctl_add(card, _kctl);
1228         if (err < 0)
1229                 return err;
1230
1231         down_write(&card->controls_rwsem);
1232         card->user_ctl_count++;
1233         up_write(&card->controls_rwsem);
1234
1235         return 0;
1236 }
1237
1238 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1239                                  struct snd_ctl_elem_info __user *_info, int replace)
1240 {
1241         struct snd_ctl_elem_info info;
1242         if (copy_from_user(&info, _info, sizeof(info)))
1243                 return -EFAULT;
1244         return snd_ctl_elem_add(file, &info, replace);
1245 }
1246
1247 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1248                                struct snd_ctl_elem_id __user *_id)
1249 {
1250         struct snd_ctl_elem_id id;
1251
1252         if (copy_from_user(&id, _id, sizeof(id)))
1253                 return -EFAULT;
1254         return snd_ctl_remove_user_ctl(file, &id);
1255 }
1256
1257 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1258 {
1259         int subscribe;
1260         if (get_user(subscribe, ptr))
1261                 return -EFAULT;
1262         if (subscribe < 0) {
1263                 subscribe = file->subscribed;
1264                 if (put_user(subscribe, ptr))
1265                         return -EFAULT;
1266                 return 0;
1267         }
1268         if (subscribe) {
1269                 file->subscribed = 1;
1270                 return 0;
1271         } else if (file->subscribed) {
1272                 snd_ctl_empty_read_queue(file);
1273                 file->subscribed = 0;
1274         }
1275         return 0;
1276 }
1277
1278 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1279                              struct snd_ctl_tlv __user *_tlv,
1280                              int op_flag)
1281 {
1282         struct snd_card *card = file->card;
1283         struct snd_ctl_tlv tlv;
1284         struct snd_kcontrol *kctl;
1285         struct snd_kcontrol_volatile *vd;
1286         unsigned int len;
1287         int err = 0;
1288
1289         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1290                 return -EFAULT;
1291         if (tlv.length < sizeof(unsigned int) * 2)
1292                 return -EINVAL;
1293         down_read(&card->controls_rwsem);
1294         kctl = snd_ctl_find_numid(card, tlv.numid);
1295         if (kctl == NULL) {
1296                 err = -ENOENT;
1297                 goto __kctl_end;
1298         }
1299         if (kctl->tlv.p == NULL) {
1300                 err = -ENXIO;
1301                 goto __kctl_end;
1302         }
1303         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1304         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1305             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1306             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1307                 err = -ENXIO;
1308                 goto __kctl_end;
1309         }
1310         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1311                 if (vd->owner != NULL && vd->owner != file) {
1312                         err = -EPERM;
1313                         goto __kctl_end;
1314                 }
1315                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1316                 if (err > 0) {
1317                         up_read(&card->controls_rwsem);
1318                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1319                         return 0;
1320                 }
1321         } else {
1322                 if (op_flag) {
1323                         err = -ENXIO;
1324                         goto __kctl_end;
1325                 }
1326                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1327                 if (tlv.length < len) {
1328                         err = -ENOMEM;
1329                         goto __kctl_end;
1330                 }
1331                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1332                         err = -EFAULT;
1333         }
1334       __kctl_end:
1335         up_read(&card->controls_rwsem);
1336         return err;
1337 }
1338
1339 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1340 {
1341         struct snd_ctl_file *ctl;
1342         struct snd_card *card;
1343         struct snd_kctl_ioctl *p;
1344         void __user *argp = (void __user *)arg;
1345         int __user *ip = argp;
1346         int err;
1347
1348         ctl = file->private_data;
1349         card = ctl->card;
1350         if (snd_BUG_ON(!card))
1351                 return -ENXIO;
1352         switch (cmd) {
1353         case SNDRV_CTL_IOCTL_PVERSION:
1354                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1355         case SNDRV_CTL_IOCTL_CARD_INFO:
1356                 return snd_ctl_card_info(card, ctl, cmd, argp);
1357         case SNDRV_CTL_IOCTL_ELEM_LIST:
1358                 return snd_ctl_elem_list(card, argp);
1359         case SNDRV_CTL_IOCTL_ELEM_INFO:
1360                 return snd_ctl_elem_info_user(ctl, argp);
1361         case SNDRV_CTL_IOCTL_ELEM_READ:
1362                 return snd_ctl_elem_read_user(card, argp);
1363         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1364                 return snd_ctl_elem_write_user(ctl, argp);
1365         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1366                 return snd_ctl_elem_lock(ctl, argp);
1367         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1368                 return snd_ctl_elem_unlock(ctl, argp);
1369         case SNDRV_CTL_IOCTL_ELEM_ADD:
1370                 return snd_ctl_elem_add_user(ctl, argp, 0);
1371         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1372                 return snd_ctl_elem_add_user(ctl, argp, 1);
1373         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1374                 return snd_ctl_elem_remove(ctl, argp);
1375         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1376                 return snd_ctl_subscribe_events(ctl, ip);
1377         case SNDRV_CTL_IOCTL_TLV_READ:
1378                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1379         case SNDRV_CTL_IOCTL_TLV_WRITE:
1380                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1381         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1382                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1383         case SNDRV_CTL_IOCTL_POWER:
1384                 return -ENOPROTOOPT;
1385         case SNDRV_CTL_IOCTL_POWER_STATE:
1386 #ifdef CONFIG_PM
1387                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1388 #else
1389                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1390 #endif
1391         }
1392         down_read(&snd_ioctl_rwsem);
1393         list_for_each_entry(p, &snd_control_ioctls, list) {
1394                 err = p->fioctl(card, ctl, cmd, arg);
1395                 if (err != -ENOIOCTLCMD) {
1396                         up_read(&snd_ioctl_rwsem);
1397                         return err;
1398                 }
1399         }
1400         up_read(&snd_ioctl_rwsem);
1401         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1402         return -ENOTTY;
1403 }
1404
1405 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1406                             size_t count, loff_t * offset)
1407 {
1408         struct snd_ctl_file *ctl;
1409         int err = 0;
1410         ssize_t result = 0;
1411
1412         ctl = file->private_data;
1413         if (snd_BUG_ON(!ctl || !ctl->card))
1414                 return -ENXIO;
1415         if (!ctl->subscribed)
1416                 return -EBADFD;
1417         if (count < sizeof(struct snd_ctl_event))
1418                 return -EINVAL;
1419         spin_lock_irq(&ctl->read_lock);
1420         while (count >= sizeof(struct snd_ctl_event)) {
1421                 struct snd_ctl_event ev;
1422                 struct snd_kctl_event *kev;
1423                 while (list_empty(&ctl->events)) {
1424                         wait_queue_t wait;
1425                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1426                                 err = -EAGAIN;
1427                                 goto __end_lock;
1428                         }
1429                         init_waitqueue_entry(&wait, current);
1430                         add_wait_queue(&ctl->change_sleep, &wait);
1431                         set_current_state(TASK_INTERRUPTIBLE);
1432                         spin_unlock_irq(&ctl->read_lock);
1433                         schedule();
1434                         remove_wait_queue(&ctl->change_sleep, &wait);
1435                         if (signal_pending(current))
1436                                 return -ERESTARTSYS;
1437                         spin_lock_irq(&ctl->read_lock);
1438                 }
1439                 kev = snd_kctl_event(ctl->events.next);
1440                 ev.type = SNDRV_CTL_EVENT_ELEM;
1441                 ev.data.elem.mask = kev->mask;
1442                 ev.data.elem.id = kev->id;
1443                 list_del(&kev->list);
1444                 spin_unlock_irq(&ctl->read_lock);
1445                 kfree(kev);
1446                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1447                         err = -EFAULT;
1448                         goto __end;
1449                 }
1450                 spin_lock_irq(&ctl->read_lock);
1451                 buffer += sizeof(struct snd_ctl_event);
1452                 count -= sizeof(struct snd_ctl_event);
1453                 result += sizeof(struct snd_ctl_event);
1454         }
1455       __end_lock:
1456         spin_unlock_irq(&ctl->read_lock);
1457       __end:
1458         return result > 0 ? result : err;
1459 }
1460
1461 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1462 {
1463         unsigned int mask;
1464         struct snd_ctl_file *ctl;
1465
1466         ctl = file->private_data;
1467         if (!ctl->subscribed)
1468                 return 0;
1469         poll_wait(file, &ctl->change_sleep, wait);
1470
1471         mask = 0;
1472         if (!list_empty(&ctl->events))
1473                 mask |= POLLIN | POLLRDNORM;
1474
1475         return mask;
1476 }
1477
1478 /*
1479  * register the device-specific control-ioctls.
1480  * called from each device manager like pcm.c, hwdep.c, etc.
1481  */
1482 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1483 {
1484         struct snd_kctl_ioctl *pn;
1485
1486         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1487         if (pn == NULL)
1488                 return -ENOMEM;
1489         pn->fioctl = fcn;
1490         down_write(&snd_ioctl_rwsem);
1491         list_add_tail(&pn->list, lists);
1492         up_write(&snd_ioctl_rwsem);
1493         return 0;
1494 }
1495
1496 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1497 {
1498         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1502
1503 #ifdef CONFIG_COMPAT
1504 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1505 {
1506         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1507 }
1508
1509 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1510 #endif
1511
1512 /*
1513  * de-register the device-specific control-ioctls.
1514  */
1515 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1516                                      struct list_head *lists)
1517 {
1518         struct snd_kctl_ioctl *p;
1519
1520         if (snd_BUG_ON(!fcn))
1521                 return -EINVAL;
1522         down_write(&snd_ioctl_rwsem);
1523         list_for_each_entry(p, lists, list) {
1524                 if (p->fioctl == fcn) {
1525                         list_del(&p->list);
1526                         up_write(&snd_ioctl_rwsem);
1527                         kfree(p);
1528                         return 0;
1529                 }
1530         }
1531         up_write(&snd_ioctl_rwsem);
1532         snd_BUG();
1533         return -EINVAL;
1534 }
1535
1536 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1537 {
1538         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1539 }
1540
1541 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1542
1543 #ifdef CONFIG_COMPAT
1544 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1545 {
1546         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1547 }
1548
1549 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1550 #endif
1551
1552 static int snd_ctl_fasync(int fd, struct file * file, int on)
1553 {
1554         struct snd_ctl_file *ctl;
1555
1556         ctl = file->private_data;
1557         return fasync_helper(fd, file, on, &ctl->fasync);
1558 }
1559
1560 /*
1561  * ioctl32 compat
1562  */
1563 #ifdef CONFIG_COMPAT
1564 #include "control_compat.c"
1565 #else
1566 #define snd_ctl_ioctl_compat    NULL
1567 #endif
1568
1569 /*
1570  *  INIT PART
1571  */
1572
1573 static const struct file_operations snd_ctl_f_ops =
1574 {
1575         .owner =        THIS_MODULE,
1576         .read =         snd_ctl_read,
1577         .open =         snd_ctl_open,
1578         .release =      snd_ctl_release,
1579         .llseek =       no_llseek,
1580         .poll =         snd_ctl_poll,
1581         .unlocked_ioctl =       snd_ctl_ioctl,
1582         .compat_ioctl = snd_ctl_ioctl_compat,
1583         .fasync =       snd_ctl_fasync,
1584 };
1585
1586 /*
1587  * registration of the control device
1588  */
1589 static int snd_ctl_dev_register(struct snd_device *device)
1590 {
1591         struct snd_card *card = device->device_data;
1592         int err, cardnum;
1593         char name[16];
1594
1595         if (snd_BUG_ON(!card))
1596                 return -ENXIO;
1597         cardnum = card->number;
1598         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1599                 return -ENXIO;
1600         sprintf(name, "controlC%i", cardnum);
1601         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1602                                        &snd_ctl_f_ops, card, name)) < 0)
1603                 return err;
1604         return 0;
1605 }
1606
1607 /*
1608  * disconnection of the control device
1609  */
1610 static int snd_ctl_dev_disconnect(struct snd_device *device)
1611 {
1612         struct snd_card *card = device->device_data;
1613         struct snd_ctl_file *ctl;
1614         int err, cardnum;
1615
1616         if (snd_BUG_ON(!card))
1617                 return -ENXIO;
1618         cardnum = card->number;
1619         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1620                 return -ENXIO;
1621
1622         read_lock(&card->ctl_files_rwlock);
1623         list_for_each_entry(ctl, &card->ctl_files, list) {
1624                 wake_up(&ctl->change_sleep);
1625                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1626         }
1627         read_unlock(&card->ctl_files_rwlock);
1628
1629         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1630                                          card, -1)) < 0)
1631                 return err;
1632         return 0;
1633 }
1634
1635 /*
1636  * free all controls
1637  */
1638 static int snd_ctl_dev_free(struct snd_device *device)
1639 {
1640         struct snd_card *card = device->device_data;
1641         struct snd_kcontrol *control;
1642
1643         down_write(&card->controls_rwsem);
1644         while (!list_empty(&card->controls)) {
1645                 control = snd_kcontrol(card->controls.next);
1646                 snd_ctl_remove(card, control);
1647         }
1648         up_write(&card->controls_rwsem);
1649         return 0;
1650 }
1651
1652 /*
1653  * create control core:
1654  * called from init.c
1655  */
1656 int snd_ctl_create(struct snd_card *card)
1657 {
1658         static struct snd_device_ops ops = {
1659                 .dev_free = snd_ctl_dev_free,
1660                 .dev_register = snd_ctl_dev_register,
1661                 .dev_disconnect = snd_ctl_dev_disconnect,
1662         };
1663
1664         if (snd_BUG_ON(!card))
1665                 return -ENXIO;
1666         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1667 }
1668
1669 /*
1670  * Frequently used control callbacks/helpers
1671  */
1672 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1673                               struct snd_ctl_elem_info *uinfo)
1674 {
1675         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1676         uinfo->count = 1;
1677         uinfo->value.integer.min = 0;
1678         uinfo->value.integer.max = 1;
1679         return 0;
1680 }
1681
1682 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1683
1684 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1685                                 struct snd_ctl_elem_info *uinfo)
1686 {
1687         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1688         uinfo->count = 2;
1689         uinfo->value.integer.min = 0;
1690         uinfo->value.integer.max = 1;
1691         return 0;
1692 }
1693
1694 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1695
1696 /**
1697  * snd_ctl_enum_info - fills the info structure for an enumerated control
1698  * @info: the structure to be filled
1699  * @channels: the number of the control's channels; often one
1700  * @items: the number of control values; also the size of @names
1701  * @names: an array containing the names of all control values
1702  *
1703  * Sets all required fields in @info to their appropriate values.
1704  * If the control's accessibility is not the default (readable and writable),
1705  * the caller has to fill @info->access.
1706  */
1707 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1708                       unsigned int items, const char *const names[])
1709 {
1710         info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1711         info->count = channels;
1712         info->value.enumerated.items = items;
1713         if (info->value.enumerated.item >= items)
1714                 info->value.enumerated.item = items - 1;
1715         strlcpy(info->value.enumerated.name,
1716                 names[info->value.enumerated.item],
1717                 sizeof(info->value.enumerated.name));
1718         return 0;
1719 }
1720 EXPORT_SYMBOL(snd_ctl_enum_info);