Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / 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         fasync_helper(-1, file, 0, &ctl->fasync);
117         file->private_data = NULL;
118         card = ctl->card;
119         write_lock_irqsave(&card->ctl_files_rwlock, flags);
120         list_del(&ctl->list);
121         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
122         down_write(&card->controls_rwsem);
123         list_for_each_entry(control, &card->controls, list)
124                 for (idx = 0; idx < control->count; idx++)
125                         if (control->vd[idx].owner == ctl)
126                                 control->vd[idx].owner = NULL;
127         up_write(&card->controls_rwsem);
128         snd_ctl_empty_read_queue(ctl);
129         kfree(ctl);
130         module_put(card->module);
131         snd_card_file_remove(card, file);
132         return 0;
133 }
134
135 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
136                     struct snd_ctl_elem_id *id)
137 {
138         unsigned long flags;
139         struct snd_ctl_file *ctl;
140         struct snd_kctl_event *ev;
141         
142         if (snd_BUG_ON(!card || !id))
143                 return;
144         read_lock(&card->ctl_files_rwlock);
145 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
146         card->mixer_oss_change_count++;
147 #endif
148         list_for_each_entry(ctl, &card->ctl_files, list) {
149                 if (!ctl->subscribed)
150                         continue;
151                 spin_lock_irqsave(&ctl->read_lock, flags);
152                 list_for_each_entry(ev, &ctl->events, list) {
153                         if (ev->id.numid == id->numid) {
154                                 ev->mask |= mask;
155                                 goto _found;
156                         }
157                 }
158                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
159                 if (ev) {
160                         ev->id = *id;
161                         ev->mask = mask;
162                         list_add_tail(&ev->list, &ctl->events);
163                 } else {
164                         snd_printk(KERN_ERR "No memory available to allocate event\n");
165                 }
166         _found:
167                 wake_up(&ctl->change_sleep);
168                 spin_unlock_irqrestore(&ctl->read_lock, flags);
169                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
170         }
171         read_unlock(&card->ctl_files_rwlock);
172 }
173
174 EXPORT_SYMBOL(snd_ctl_notify);
175
176 /**
177  * snd_ctl_new - create a control instance from the template
178  * @control: the control template
179  * @access: the default control access
180  *
181  * Allocates a new struct snd_kcontrol instance and copies the given template 
182  * to the new instance. It does not copy volatile data (access).
183  *
184  * Returns the pointer of the new instance, or NULL on failure.
185  */
186 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
187                                         unsigned int access)
188 {
189         struct snd_kcontrol *kctl;
190         unsigned int idx;
191         
192         if (snd_BUG_ON(!control || !control->count))
193                 return NULL;
194         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
195         if (kctl == NULL) {
196                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
197                 return NULL;
198         }
199         *kctl = *control;
200         for (idx = 0; idx < kctl->count; idx++)
201                 kctl->vd[idx].access = access;
202         return kctl;
203 }
204
205 /**
206  * snd_ctl_new1 - create a control instance from the template
207  * @ncontrol: the initialization record
208  * @private_data: the private data to set
209  *
210  * Allocates a new struct snd_kcontrol instance and initialize from the given 
211  * template.  When the access field of ncontrol is 0, it's assumed as
212  * READWRITE access. When the count field is 0, it's assumes as one.
213  *
214  * Returns the pointer of the newly generated instance, or NULL on failure.
215  */
216 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
217                                   void *private_data)
218 {
219         struct snd_kcontrol kctl;
220         unsigned int access;
221         
222         if (snd_BUG_ON(!ncontrol || !ncontrol->info))
223                 return NULL;
224         memset(&kctl, 0, sizeof(kctl));
225         kctl.id.iface = ncontrol->iface;
226         kctl.id.device = ncontrol->device;
227         kctl.id.subdevice = ncontrol->subdevice;
228         if (ncontrol->name) {
229                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
230                 if (strcmp(ncontrol->name, kctl.id.name) != 0)
231                         snd_printk(KERN_WARNING
232                                    "Control name '%s' truncated to '%s'\n",
233                                    ncontrol->name, kctl.id.name);
234         }
235         kctl.id.index = ncontrol->index;
236         kctl.count = ncontrol->count ? ncontrol->count : 1;
237         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
238                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
239                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
240                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
241                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
242         kctl.info = ncontrol->info;
243         kctl.get = ncontrol->get;
244         kctl.put = ncontrol->put;
245         kctl.tlv.p = ncontrol->tlv.p;
246         kctl.private_value = ncontrol->private_value;
247         kctl.private_data = private_data;
248         return snd_ctl_new(&kctl, access);
249 }
250
251 EXPORT_SYMBOL(snd_ctl_new1);
252
253 /**
254  * snd_ctl_free_one - release the control instance
255  * @kcontrol: the control instance
256  *
257  * Releases the control instance created via snd_ctl_new()
258  * or snd_ctl_new1().
259  * Don't call this after the control was added to the card.
260  */
261 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
262 {
263         if (kcontrol) {
264                 if (kcontrol->private_free)
265                         kcontrol->private_free(kcontrol);
266                 kfree(kcontrol);
267         }
268 }
269
270 EXPORT_SYMBOL(snd_ctl_free_one);
271
272 static unsigned int snd_ctl_hole_check(struct snd_card *card,
273                                        unsigned int count)
274 {
275         struct snd_kcontrol *kctl;
276
277         list_for_each_entry(kctl, &card->controls, list) {
278                 if ((kctl->id.numid <= card->last_numid &&
279                      kctl->id.numid + kctl->count > card->last_numid) ||
280                     (kctl->id.numid <= card->last_numid + count - 1 &&
281                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
282                         return card->last_numid = kctl->id.numid + kctl->count - 1;
283         }
284         return card->last_numid;
285 }
286
287 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
288 {
289         unsigned int last_numid, iter = 100000;
290
291         last_numid = card->last_numid;
292         while (last_numid != snd_ctl_hole_check(card, count)) {
293                 if (--iter == 0) {
294                         /* this situation is very unlikely */
295                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
296                         return -ENOMEM;
297                 }
298                 last_numid = card->last_numid;
299         }
300         return 0;
301 }
302
303 /**
304  * snd_ctl_add - add the control instance to the card
305  * @card: the card instance
306  * @kcontrol: the control instance to add
307  *
308  * Adds the control instance created via snd_ctl_new() or
309  * snd_ctl_new1() to the given card. Assigns also an unique
310  * numid used for fast search.
311  *
312  * Returns zero if successful, or a negative error code on failure.
313  *
314  * It frees automatically the control which cannot be added.
315  */
316 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
317 {
318         struct snd_ctl_elem_id id;
319         unsigned int idx;
320         int err = -EINVAL;
321
322         if (! kcontrol)
323                 return err;
324         if (snd_BUG_ON(!card || !kcontrol->info))
325                 goto error;
326         id = kcontrol->id;
327         down_write(&card->controls_rwsem);
328         if (snd_ctl_find_id(card, &id)) {
329                 up_write(&card->controls_rwsem);
330                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
331                                         id.iface,
332                                         id.device,
333                                         id.subdevice,
334                                         id.name,
335                                         id.index);
336                 err = -EBUSY;
337                 goto error;
338         }
339         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
340                 up_write(&card->controls_rwsem);
341                 err = -ENOMEM;
342                 goto error;
343         }
344         list_add_tail(&kcontrol->list, &card->controls);
345         card->controls_count += kcontrol->count;
346         kcontrol->id.numid = card->last_numid + 1;
347         card->last_numid += kcontrol->count;
348         up_write(&card->controls_rwsem);
349         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
350                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
351         return 0;
352
353  error:
354         snd_ctl_free_one(kcontrol);
355         return err;
356 }
357
358 EXPORT_SYMBOL(snd_ctl_add);
359
360 /**
361  * snd_ctl_remove - remove the control from the card and release it
362  * @card: the card instance
363  * @kcontrol: the control instance to remove
364  *
365  * Removes the control from the card and then releases the instance.
366  * You don't need to call snd_ctl_free_one(). You must be in
367  * the write lock - down_write(&card->controls_rwsem).
368  * 
369  * Returns 0 if successful, or a negative error code on failure.
370  */
371 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
372 {
373         struct snd_ctl_elem_id id;
374         unsigned int idx;
375
376         if (snd_BUG_ON(!card || !kcontrol))
377                 return -EINVAL;
378         list_del(&kcontrol->list);
379         card->controls_count -= kcontrol->count;
380         id = kcontrol->id;
381         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
382                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
383         snd_ctl_free_one(kcontrol);
384         return 0;
385 }
386
387 EXPORT_SYMBOL(snd_ctl_remove);
388
389 /**
390  * snd_ctl_remove_id - remove the control of the given id and release it
391  * @card: the card instance
392  * @id: the control id to remove
393  *
394  * Finds the control instance with the given id, removes it from the
395  * card list and releases it.
396  * 
397  * Returns 0 if successful, or a negative error code on failure.
398  */
399 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
400 {
401         struct snd_kcontrol *kctl;
402         int ret;
403
404         down_write(&card->controls_rwsem);
405         kctl = snd_ctl_find_id(card, id);
406         if (kctl == NULL) {
407                 up_write(&card->controls_rwsem);
408                 return -ENOENT;
409         }
410         ret = snd_ctl_remove(card, kctl);
411         up_write(&card->controls_rwsem);
412         return ret;
413 }
414
415 EXPORT_SYMBOL(snd_ctl_remove_id);
416
417 /**
418  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
419  * @file: active control handle
420  * @id: the control id to remove
421  *
422  * Finds the control instance with the given id, removes it from the
423  * card list and releases it.
424  * 
425  * Returns 0 if successful, or a negative error code on failure.
426  */
427 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
428                                       struct snd_ctl_elem_id *id)
429 {
430         struct snd_card *card = file->card;
431         struct snd_kcontrol *kctl;
432         int idx, ret;
433
434         down_write(&card->controls_rwsem);
435         kctl = snd_ctl_find_id(card, id);
436         if (kctl == NULL) {
437                 up_write(&card->controls_rwsem);
438                 return -ENOENT;
439         }
440         for (idx = 0; idx < kctl->count; idx++)
441                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
442                         up_write(&card->controls_rwsem);
443                         return -EBUSY;
444                 }
445         ret = snd_ctl_remove(card, kctl);
446         up_write(&card->controls_rwsem);
447         return ret;
448 }
449
450 /**
451  * snd_ctl_rename_id - replace the id of a control on the card
452  * @card: the card instance
453  * @src_id: the old id
454  * @dst_id: the new id
455  *
456  * Finds the control with the old id from the card, and replaces the
457  * id with the new one.
458  *
459  * Returns zero if successful, or a negative error code on failure.
460  */
461 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
462                       struct snd_ctl_elem_id *dst_id)
463 {
464         struct snd_kcontrol *kctl;
465
466         down_write(&card->controls_rwsem);
467         kctl = snd_ctl_find_id(card, src_id);
468         if (kctl == NULL) {
469                 up_write(&card->controls_rwsem);
470                 return -ENOENT;
471         }
472         kctl->id = *dst_id;
473         kctl->id.numid = card->last_numid + 1;
474         card->last_numid += kctl->count;
475         up_write(&card->controls_rwsem);
476         return 0;
477 }
478
479 EXPORT_SYMBOL(snd_ctl_rename_id);
480
481 /**
482  * snd_ctl_find_numid - find the control instance with the given number-id
483  * @card: the card instance
484  * @numid: the number-id to search
485  *
486  * Finds the control instance with the given number-id from the card.
487  *
488  * Returns the pointer of the instance if found, or NULL if not.
489  *
490  * The caller must down card->controls_rwsem before calling this function
491  * (if the race condition can happen).
492  */
493 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
494 {
495         struct snd_kcontrol *kctl;
496
497         if (snd_BUG_ON(!card || !numid))
498                 return NULL;
499         list_for_each_entry(kctl, &card->controls, list) {
500                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
501                         return kctl;
502         }
503         return NULL;
504 }
505
506 EXPORT_SYMBOL(snd_ctl_find_numid);
507
508 /**
509  * snd_ctl_find_id - find the control instance with the given id
510  * @card: the card instance
511  * @id: the id to search
512  *
513  * Finds the control instance with the given id from the card.
514  *
515  * Returns the pointer of the instance if found, or NULL if not.
516  *
517  * The caller must down card->controls_rwsem before calling this function
518  * (if the race condition can happen).
519  */
520 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
521                                      struct snd_ctl_elem_id *id)
522 {
523         struct snd_kcontrol *kctl;
524
525         if (snd_BUG_ON(!card || !id))
526                 return NULL;
527         if (id->numid != 0)
528                 return snd_ctl_find_numid(card, id->numid);
529         list_for_each_entry(kctl, &card->controls, list) {
530                 if (kctl->id.iface != id->iface)
531                         continue;
532                 if (kctl->id.device != id->device)
533                         continue;
534                 if (kctl->id.subdevice != id->subdevice)
535                         continue;
536                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
537                         continue;
538                 if (kctl->id.index > id->index)
539                         continue;
540                 if (kctl->id.index + kctl->count <= id->index)
541                         continue;
542                 return kctl;
543         }
544         return NULL;
545 }
546
547 EXPORT_SYMBOL(snd_ctl_find_id);
548
549 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
550                              unsigned int cmd, void __user *arg)
551 {
552         struct snd_ctl_card_info *info;
553
554         info = kzalloc(sizeof(*info), GFP_KERNEL);
555         if (! info)
556                 return -ENOMEM;
557         down_read(&snd_ioctl_rwsem);
558         info->card = card->number;
559         strlcpy(info->id, card->id, sizeof(info->id));
560         strlcpy(info->driver, card->driver, sizeof(info->driver));
561         strlcpy(info->name, card->shortname, sizeof(info->name));
562         strlcpy(info->longname, card->longname, sizeof(info->longname));
563         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
564         strlcpy(info->components, card->components, sizeof(info->components));
565         up_read(&snd_ioctl_rwsem);
566         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
567                 kfree(info);
568                 return -EFAULT;
569         }
570         kfree(info);
571         return 0;
572 }
573
574 static int snd_ctl_elem_list(struct snd_card *card,
575                              struct snd_ctl_elem_list __user *_list)
576 {
577         struct list_head *plist;
578         struct snd_ctl_elem_list list;
579         struct snd_kcontrol *kctl;
580         struct snd_ctl_elem_id *dst, *id;
581         unsigned int offset, space, first, jidx;
582         
583         if (copy_from_user(&list, _list, sizeof(list)))
584                 return -EFAULT;
585         offset = list.offset;
586         space = list.space;
587         first = 0;
588         /* try limit maximum space */
589         if (space > 16384)
590                 return -ENOMEM;
591         if (space > 0) {
592                 /* allocate temporary buffer for atomic operation */
593                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
594                 if (dst == NULL)
595                         return -ENOMEM;
596                 down_read(&card->controls_rwsem);
597                 list.count = card->controls_count;
598                 plist = card->controls.next;
599                 while (plist != &card->controls) {
600                         if (offset == 0)
601                                 break;
602                         kctl = snd_kcontrol(plist);
603                         if (offset < kctl->count)
604                                 break;
605                         offset -= kctl->count;
606                         plist = plist->next;
607                 }
608                 list.used = 0;
609                 id = dst;
610                 while (space > 0 && plist != &card->controls) {
611                         kctl = snd_kcontrol(plist);
612                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
613                                 snd_ctl_build_ioff(id, kctl, jidx);
614                                 id++;
615                                 space--;
616                                 list.used++;
617                         }
618                         plist = plist->next;
619                         offset = 0;
620                 }
621                 up_read(&card->controls_rwsem);
622                 if (list.used > 0 &&
623                     copy_to_user(list.pids, dst,
624                                  list.used * sizeof(struct snd_ctl_elem_id))) {
625                         vfree(dst);
626                         return -EFAULT;
627                 }
628                 vfree(dst);
629         } else {
630                 down_read(&card->controls_rwsem);
631                 list.count = card->controls_count;
632                 up_read(&card->controls_rwsem);
633         }
634         if (copy_to_user(_list, &list, sizeof(list)))
635                 return -EFAULT;
636         return 0;
637 }
638
639 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
640                              struct snd_ctl_elem_info *info)
641 {
642         struct snd_card *card = ctl->card;
643         struct snd_kcontrol *kctl;
644         struct snd_kcontrol_volatile *vd;
645         unsigned int index_offset;
646         int result;
647         
648         down_read(&card->controls_rwsem);
649         kctl = snd_ctl_find_id(card, &info->id);
650         if (kctl == NULL) {
651                 up_read(&card->controls_rwsem);
652                 return -ENOENT;
653         }
654 #ifdef CONFIG_SND_DEBUG
655         info->access = 0;
656 #endif
657         result = kctl->info(kctl, info);
658         if (result >= 0) {
659                 snd_BUG_ON(info->access);
660                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
661                 vd = &kctl->vd[index_offset];
662                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
663                 info->access = vd->access;
664                 if (vd->owner) {
665                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
666                         if (vd->owner == ctl)
667                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
668                         info->owner = vd->owner_pid;
669                 } else {
670                         info->owner = -1;
671                 }
672         }
673         up_read(&card->controls_rwsem);
674         return result;
675 }
676
677 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
678                                   struct snd_ctl_elem_info __user *_info)
679 {
680         struct snd_ctl_elem_info info;
681         int result;
682
683         if (copy_from_user(&info, _info, sizeof(info)))
684                 return -EFAULT;
685         snd_power_lock(ctl->card);
686         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
687         if (result >= 0)
688                 result = snd_ctl_elem_info(ctl, &info);
689         snd_power_unlock(ctl->card);
690         if (result >= 0)
691                 if (copy_to_user(_info, &info, sizeof(info)))
692                         return -EFAULT;
693         return result;
694 }
695
696 static int snd_ctl_elem_read(struct snd_card *card,
697                              struct snd_ctl_elem_value *control)
698 {
699         struct snd_kcontrol *kctl;
700         struct snd_kcontrol_volatile *vd;
701         unsigned int index_offset;
702         int result;
703
704         down_read(&card->controls_rwsem);
705         kctl = snd_ctl_find_id(card, &control->id);
706         if (kctl == NULL) {
707                 result = -ENOENT;
708         } else {
709                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
710                 vd = &kctl->vd[index_offset];
711                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
712                     kctl->get != NULL) {
713                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
714                         result = kctl->get(kctl, control);
715                 } else
716                         result = -EPERM;
717         }
718         up_read(&card->controls_rwsem);
719         return result;
720 }
721
722 static int snd_ctl_elem_read_user(struct snd_card *card,
723                                   struct snd_ctl_elem_value __user *_control)
724 {
725         struct snd_ctl_elem_value *control;
726         int result;
727         
728         control = kmalloc(sizeof(*control), GFP_KERNEL);
729         if (control == NULL)
730                 return -ENOMEM; 
731         if (copy_from_user(control, _control, sizeof(*control))) {
732                 kfree(control);
733                 return -EFAULT;
734         }
735         snd_power_lock(card);
736         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
737         if (result >= 0)
738                 result = snd_ctl_elem_read(card, control);
739         snd_power_unlock(card);
740         if (result >= 0)
741                 if (copy_to_user(_control, control, sizeof(*control)))
742                         result = -EFAULT;
743         kfree(control);
744         return result;
745 }
746
747 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
748                               struct snd_ctl_elem_value *control)
749 {
750         struct snd_kcontrol *kctl;
751         struct snd_kcontrol_volatile *vd;
752         unsigned int index_offset;
753         int result;
754
755         down_read(&card->controls_rwsem);
756         kctl = snd_ctl_find_id(card, &control->id);
757         if (kctl == NULL) {
758                 result = -ENOENT;
759         } else {
760                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
761                 vd = &kctl->vd[index_offset];
762                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
763                     kctl->put == NULL ||
764                     (file && vd->owner && vd->owner != file)) {
765                         result = -EPERM;
766                 } else {
767                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
768                         result = kctl->put(kctl, control);
769                 }
770                 if (result > 0) {
771                         up_read(&card->controls_rwsem);
772                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
773                                        &control->id);
774                         return 0;
775                 }
776         }
777         up_read(&card->controls_rwsem);
778         return result;
779 }
780
781 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
782                                    struct snd_ctl_elem_value __user *_control)
783 {
784         struct snd_ctl_elem_value *control;
785         struct snd_card *card;
786         int result;
787
788         control = kmalloc(sizeof(*control), GFP_KERNEL);
789         if (control == NULL)
790                 return -ENOMEM; 
791         if (copy_from_user(control, _control, sizeof(*control))) {
792                 kfree(control);
793                 return -EFAULT;
794         }
795         card = file->card;
796         snd_power_lock(card);
797         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
798         if (result >= 0)
799                 result = snd_ctl_elem_write(card, file, control);
800         snd_power_unlock(card);
801         if (result >= 0)
802                 if (copy_to_user(_control, control, sizeof(*control)))
803                         result = -EFAULT;
804         kfree(control);
805         return result;
806 }
807
808 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
809                              struct snd_ctl_elem_id __user *_id)
810 {
811         struct snd_card *card = file->card;
812         struct snd_ctl_elem_id id;
813         struct snd_kcontrol *kctl;
814         struct snd_kcontrol_volatile *vd;
815         int result;
816         
817         if (copy_from_user(&id, _id, sizeof(id)))
818                 return -EFAULT;
819         down_write(&card->controls_rwsem);
820         kctl = snd_ctl_find_id(card, &id);
821         if (kctl == NULL) {
822                 result = -ENOENT;
823         } else {
824                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
825                 if (vd->owner != NULL)
826                         result = -EBUSY;
827                 else {
828                         vd->owner = file;
829                         vd->owner_pid = current->pid;
830                         result = 0;
831                 }
832         }
833         up_write(&card->controls_rwsem);
834         return result;
835 }
836
837 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
838                                struct snd_ctl_elem_id __user *_id)
839 {
840         struct snd_card *card = file->card;
841         struct snd_ctl_elem_id id;
842         struct snd_kcontrol *kctl;
843         struct snd_kcontrol_volatile *vd;
844         int result;
845         
846         if (copy_from_user(&id, _id, sizeof(id)))
847                 return -EFAULT;
848         down_write(&card->controls_rwsem);
849         kctl = snd_ctl_find_id(card, &id);
850         if (kctl == NULL) {
851                 result = -ENOENT;
852         } else {
853                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
854                 if (vd->owner == NULL)
855                         result = -EINVAL;
856                 else if (vd->owner != file)
857                         result = -EPERM;
858                 else {
859                         vd->owner = NULL;
860                         vd->owner_pid = 0;
861                         result = 0;
862                 }
863         }
864         up_write(&card->controls_rwsem);
865         return result;
866 }
867
868 struct user_element {
869         struct snd_ctl_elem_info info;
870         void *elem_data;                /* element data */
871         unsigned long elem_data_size;   /* size of element data in bytes */
872         void *tlv_data;                 /* TLV data */
873         unsigned long tlv_data_size;    /* TLV data size */
874         void *priv_data;                /* private data (like strings for enumerated type) */
875         unsigned long priv_data_size;   /* size of private data in bytes */
876 };
877
878 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
879                                   struct snd_ctl_elem_info *uinfo)
880 {
881         struct user_element *ue = kcontrol->private_data;
882
883         *uinfo = ue->info;
884         return 0;
885 }
886
887 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
888                                  struct snd_ctl_elem_value *ucontrol)
889 {
890         struct user_element *ue = kcontrol->private_data;
891
892         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
893         return 0;
894 }
895
896 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
897                                  struct snd_ctl_elem_value *ucontrol)
898 {
899         int change;
900         struct user_element *ue = kcontrol->private_data;
901         
902         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
903         if (change)
904                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
905         return change;
906 }
907
908 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
909                                  int op_flag,
910                                  unsigned int size,
911                                  unsigned int __user *tlv)
912 {
913         struct user_element *ue = kcontrol->private_data;
914         int change = 0;
915         void *new_data;
916
917         if (op_flag > 0) {
918                 if (size > 1024 * 128)  /* sane value */
919                         return -EINVAL;
920                 new_data = kmalloc(size, GFP_KERNEL);
921                 if (new_data == NULL)
922                         return -ENOMEM;
923                 if (copy_from_user(new_data, tlv, size)) {
924                         kfree(new_data);
925                         return -EFAULT;
926                 }
927                 change = ue->tlv_data_size != size;
928                 if (!change)
929                         change = memcmp(ue->tlv_data, new_data, size);
930                 kfree(ue->tlv_data);
931                 ue->tlv_data = new_data;
932                 ue->tlv_data_size = size;
933         } else {
934                 if (! ue->tlv_data_size || ! ue->tlv_data)
935                         return -ENXIO;
936                 if (size < ue->tlv_data_size)
937                         return -ENOSPC;
938                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
939                         return -EFAULT;
940         }
941         return change;
942 }
943
944 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
945 {
946         struct user_element *ue = kcontrol->private_data;
947         if (ue->tlv_data)
948                 kfree(ue->tlv_data);
949         kfree(ue);
950 }
951
952 static int snd_ctl_elem_add(struct snd_ctl_file *file,
953                             struct snd_ctl_elem_info *info, int replace)
954 {
955         struct snd_card *card = file->card;
956         struct snd_kcontrol kctl, *_kctl;
957         unsigned int access;
958         long private_size;
959         struct user_element *ue;
960         int idx, err;
961         
962         if (card->user_ctl_count >= MAX_USER_CONTROLS)
963                 return -ENOMEM;
964         if (info->count > 1024)
965                 return -EINVAL;
966         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
967                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
968                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
969                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
970         info->id.numid = 0;
971         memset(&kctl, 0, sizeof(kctl));
972         down_write(&card->controls_rwsem);
973         _kctl = snd_ctl_find_id(card, &info->id);
974         err = 0;
975         if (_kctl) {
976                 if (replace)
977                         err = snd_ctl_remove(card, _kctl);
978                 else
979                         err = -EBUSY;
980         } else {
981                 if (replace)
982                         err = -ENOENT;
983         }
984         up_write(&card->controls_rwsem);
985         if (err < 0)
986                 return err;
987         memcpy(&kctl.id, &info->id, sizeof(info->id));
988         kctl.count = info->owner ? info->owner : 1;
989         access |= SNDRV_CTL_ELEM_ACCESS_USER;
990         kctl.info = snd_ctl_elem_user_info;
991         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
992                 kctl.get = snd_ctl_elem_user_get;
993         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
994                 kctl.put = snd_ctl_elem_user_put;
995         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
996                 kctl.tlv.c = snd_ctl_elem_user_tlv;
997                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
998         }
999         switch (info->type) {
1000         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1001         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1002                 private_size = sizeof(long);
1003                 if (info->count > 128)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1007                 private_size = sizeof(long long);
1008                 if (info->count > 64)
1009                         return -EINVAL;
1010                 break;
1011         case SNDRV_CTL_ELEM_TYPE_BYTES:
1012                 private_size = sizeof(unsigned char);
1013                 if (info->count > 512)
1014                         return -EINVAL;
1015                 break;
1016         case SNDRV_CTL_ELEM_TYPE_IEC958:
1017                 private_size = sizeof(struct snd_aes_iec958);
1018                 if (info->count != 1)
1019                         return -EINVAL;
1020                 break;
1021         default:
1022                 return -EINVAL;
1023         }
1024         private_size *= info->count;
1025         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1026         if (ue == NULL)
1027                 return -ENOMEM;
1028         ue->info = *info;
1029         ue->info.access = 0;
1030         ue->elem_data = (char *)ue + sizeof(*ue);
1031         ue->elem_data_size = private_size;
1032         kctl.private_free = snd_ctl_elem_user_free;
1033         _kctl = snd_ctl_new(&kctl, access);
1034         if (_kctl == NULL) {
1035                 kfree(ue);
1036                 return -ENOMEM;
1037         }
1038         _kctl->private_data = ue;
1039         for (idx = 0; idx < _kctl->count; idx++)
1040                 _kctl->vd[idx].owner = file;
1041         err = snd_ctl_add(card, _kctl);
1042         if (err < 0)
1043                 return err;
1044
1045         down_write(&card->controls_rwsem);
1046         card->user_ctl_count++;
1047         up_write(&card->controls_rwsem);
1048
1049         return 0;
1050 }
1051
1052 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1053                                  struct snd_ctl_elem_info __user *_info, int replace)
1054 {
1055         struct snd_ctl_elem_info info;
1056         if (copy_from_user(&info, _info, sizeof(info)))
1057                 return -EFAULT;
1058         return snd_ctl_elem_add(file, &info, replace);
1059 }
1060
1061 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1062                                struct snd_ctl_elem_id __user *_id)
1063 {
1064         struct snd_ctl_elem_id id;
1065         int err;
1066
1067         if (copy_from_user(&id, _id, sizeof(id)))
1068                 return -EFAULT;
1069         err = snd_ctl_remove_unlocked_id(file, &id);
1070         if (! err) {
1071                 struct snd_card *card = file->card;
1072                 down_write(&card->controls_rwsem);
1073                 card->user_ctl_count--;
1074                 up_write(&card->controls_rwsem);
1075         }
1076         return err;
1077 }
1078
1079 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1080 {
1081         int subscribe;
1082         if (get_user(subscribe, ptr))
1083                 return -EFAULT;
1084         if (subscribe < 0) {
1085                 subscribe = file->subscribed;
1086                 if (put_user(subscribe, ptr))
1087                         return -EFAULT;
1088                 return 0;
1089         }
1090         if (subscribe) {
1091                 file->subscribed = 1;
1092                 return 0;
1093         } else if (file->subscribed) {
1094                 snd_ctl_empty_read_queue(file);
1095                 file->subscribed = 0;
1096         }
1097         return 0;
1098 }
1099
1100 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1101                              struct snd_ctl_tlv __user *_tlv,
1102                              int op_flag)
1103 {
1104         struct snd_card *card = file->card;
1105         struct snd_ctl_tlv tlv;
1106         struct snd_kcontrol *kctl;
1107         struct snd_kcontrol_volatile *vd;
1108         unsigned int len;
1109         int err = 0;
1110
1111         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1112                 return -EFAULT;
1113         if (tlv.length < sizeof(unsigned int) * 3)
1114                 return -EINVAL;
1115         down_read(&card->controls_rwsem);
1116         kctl = snd_ctl_find_numid(card, tlv.numid);
1117         if (kctl == NULL) {
1118                 err = -ENOENT;
1119                 goto __kctl_end;
1120         }
1121         if (kctl->tlv.p == NULL) {
1122                 err = -ENXIO;
1123                 goto __kctl_end;
1124         }
1125         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1126         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1127             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1128             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1129                 err = -ENXIO;
1130                 goto __kctl_end;
1131         }
1132         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1133                 if (file && vd->owner != NULL && vd->owner != file) {
1134                         err = -EPERM;
1135                         goto __kctl_end;
1136                 }
1137                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1138                 if (err > 0) {
1139                         up_read(&card->controls_rwsem);
1140                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1141                         return 0;
1142                 }
1143         } else {
1144                 if (op_flag) {
1145                         err = -ENXIO;
1146                         goto __kctl_end;
1147                 }
1148                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1149                 if (tlv.length < len) {
1150                         err = -ENOMEM;
1151                         goto __kctl_end;
1152                 }
1153                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1154                         err = -EFAULT;
1155         }
1156       __kctl_end:
1157         up_read(&card->controls_rwsem);
1158         return err;
1159 }
1160
1161 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1162 {
1163         struct snd_ctl_file *ctl;
1164         struct snd_card *card;
1165         struct snd_kctl_ioctl *p;
1166         void __user *argp = (void __user *)arg;
1167         int __user *ip = argp;
1168         int err;
1169
1170         ctl = file->private_data;
1171         card = ctl->card;
1172         if (snd_BUG_ON(!card))
1173                 return -ENXIO;
1174         switch (cmd) {
1175         case SNDRV_CTL_IOCTL_PVERSION:
1176                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1177         case SNDRV_CTL_IOCTL_CARD_INFO:
1178                 return snd_ctl_card_info(card, ctl, cmd, argp);
1179         case SNDRV_CTL_IOCTL_ELEM_LIST:
1180                 return snd_ctl_elem_list(card, argp);
1181         case SNDRV_CTL_IOCTL_ELEM_INFO:
1182                 return snd_ctl_elem_info_user(ctl, argp);
1183         case SNDRV_CTL_IOCTL_ELEM_READ:
1184                 return snd_ctl_elem_read_user(card, argp);
1185         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1186                 return snd_ctl_elem_write_user(ctl, argp);
1187         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1188                 return snd_ctl_elem_lock(ctl, argp);
1189         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1190                 return snd_ctl_elem_unlock(ctl, argp);
1191         case SNDRV_CTL_IOCTL_ELEM_ADD:
1192                 return snd_ctl_elem_add_user(ctl, argp, 0);
1193         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1194                 return snd_ctl_elem_add_user(ctl, argp, 1);
1195         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1196                 return snd_ctl_elem_remove(ctl, argp);
1197         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1198                 return snd_ctl_subscribe_events(ctl, ip);
1199         case SNDRV_CTL_IOCTL_TLV_READ:
1200                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1201         case SNDRV_CTL_IOCTL_TLV_WRITE:
1202                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1203         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1204                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1205         case SNDRV_CTL_IOCTL_POWER:
1206                 return -ENOPROTOOPT;
1207         case SNDRV_CTL_IOCTL_POWER_STATE:
1208 #ifdef CONFIG_PM
1209                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1210 #else
1211                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1212 #endif
1213         }
1214         down_read(&snd_ioctl_rwsem);
1215         list_for_each_entry(p, &snd_control_ioctls, list) {
1216                 err = p->fioctl(card, ctl, cmd, arg);
1217                 if (err != -ENOIOCTLCMD) {
1218                         up_read(&snd_ioctl_rwsem);
1219                         return err;
1220                 }
1221         }
1222         up_read(&snd_ioctl_rwsem);
1223         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1224         return -ENOTTY;
1225 }
1226
1227 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1228                             size_t count, loff_t * offset)
1229 {
1230         struct snd_ctl_file *ctl;
1231         int err = 0;
1232         ssize_t result = 0;
1233
1234         ctl = file->private_data;
1235         if (snd_BUG_ON(!ctl || !ctl->card))
1236                 return -ENXIO;
1237         if (!ctl->subscribed)
1238                 return -EBADFD;
1239         if (count < sizeof(struct snd_ctl_event))
1240                 return -EINVAL;
1241         spin_lock_irq(&ctl->read_lock);
1242         while (count >= sizeof(struct snd_ctl_event)) {
1243                 struct snd_ctl_event ev;
1244                 struct snd_kctl_event *kev;
1245                 while (list_empty(&ctl->events)) {
1246                         wait_queue_t wait;
1247                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1248                                 err = -EAGAIN;
1249                                 goto __end_lock;
1250                         }
1251                         init_waitqueue_entry(&wait, current);
1252                         add_wait_queue(&ctl->change_sleep, &wait);
1253                         set_current_state(TASK_INTERRUPTIBLE);
1254                         spin_unlock_irq(&ctl->read_lock);
1255                         schedule();
1256                         remove_wait_queue(&ctl->change_sleep, &wait);
1257                         if (signal_pending(current))
1258                                 return -ERESTARTSYS;
1259                         spin_lock_irq(&ctl->read_lock);
1260                 }
1261                 kev = snd_kctl_event(ctl->events.next);
1262                 ev.type = SNDRV_CTL_EVENT_ELEM;
1263                 ev.data.elem.mask = kev->mask;
1264                 ev.data.elem.id = kev->id;
1265                 list_del(&kev->list);
1266                 spin_unlock_irq(&ctl->read_lock);
1267                 kfree(kev);
1268                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1269                         err = -EFAULT;
1270                         goto __end;
1271                 }
1272                 spin_lock_irq(&ctl->read_lock);
1273                 buffer += sizeof(struct snd_ctl_event);
1274                 count -= sizeof(struct snd_ctl_event);
1275                 result += sizeof(struct snd_ctl_event);
1276         }
1277       __end_lock:
1278         spin_unlock_irq(&ctl->read_lock);
1279       __end:
1280         return result > 0 ? result : err;
1281 }
1282
1283 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1284 {
1285         unsigned int mask;
1286         struct snd_ctl_file *ctl;
1287
1288         ctl = file->private_data;
1289         if (!ctl->subscribed)
1290                 return 0;
1291         poll_wait(file, &ctl->change_sleep, wait);
1292
1293         mask = 0;
1294         if (!list_empty(&ctl->events))
1295                 mask |= POLLIN | POLLRDNORM;
1296
1297         return mask;
1298 }
1299
1300 /*
1301  * register the device-specific control-ioctls.
1302  * called from each device manager like pcm.c, hwdep.c, etc.
1303  */
1304 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1305 {
1306         struct snd_kctl_ioctl *pn;
1307
1308         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1309         if (pn == NULL)
1310                 return -ENOMEM;
1311         pn->fioctl = fcn;
1312         down_write(&snd_ioctl_rwsem);
1313         list_add_tail(&pn->list, lists);
1314         up_write(&snd_ioctl_rwsem);
1315         return 0;
1316 }
1317
1318 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1319 {
1320         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1321 }
1322
1323 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1324
1325 #ifdef CONFIG_COMPAT
1326 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1327 {
1328         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1329 }
1330
1331 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1332 #endif
1333
1334 /*
1335  * de-register the device-specific control-ioctls.
1336  */
1337 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1338                                      struct list_head *lists)
1339 {
1340         struct snd_kctl_ioctl *p;
1341
1342         if (snd_BUG_ON(!fcn))
1343                 return -EINVAL;
1344         down_write(&snd_ioctl_rwsem);
1345         list_for_each_entry(p, lists, list) {
1346                 if (p->fioctl == fcn) {
1347                         list_del(&p->list);
1348                         up_write(&snd_ioctl_rwsem);
1349                         kfree(p);
1350                         return 0;
1351                 }
1352         }
1353         up_write(&snd_ioctl_rwsem);
1354         snd_BUG();
1355         return -EINVAL;
1356 }
1357
1358 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1359 {
1360         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1361 }
1362
1363 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1364
1365 #ifdef CONFIG_COMPAT
1366 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1367 {
1368         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1369 }
1370
1371 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1372 #endif
1373
1374 static int snd_ctl_fasync(int fd, struct file * file, int on)
1375 {
1376         struct snd_ctl_file *ctl;
1377         int err;
1378         ctl = file->private_data;
1379         err = fasync_helper(fd, file, on, &ctl->fasync);
1380         if (err < 0)
1381                 return err;
1382         return 0;
1383 }
1384
1385 /*
1386  * ioctl32 compat
1387  */
1388 #ifdef CONFIG_COMPAT
1389 #include "control_compat.c"
1390 #else
1391 #define snd_ctl_ioctl_compat    NULL
1392 #endif
1393
1394 /*
1395  *  INIT PART
1396  */
1397
1398 static const struct file_operations snd_ctl_f_ops =
1399 {
1400         .owner =        THIS_MODULE,
1401         .read =         snd_ctl_read,
1402         .open =         snd_ctl_open,
1403         .release =      snd_ctl_release,
1404         .poll =         snd_ctl_poll,
1405         .unlocked_ioctl =       snd_ctl_ioctl,
1406         .compat_ioctl = snd_ctl_ioctl_compat,
1407         .fasync =       snd_ctl_fasync,
1408 };
1409
1410 /*
1411  * registration of the control device
1412  */
1413 static int snd_ctl_dev_register(struct snd_device *device)
1414 {
1415         struct snd_card *card = device->device_data;
1416         int err, cardnum;
1417         char name[16];
1418
1419         if (snd_BUG_ON(!card))
1420                 return -ENXIO;
1421         cardnum = card->number;
1422         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1423                 return -ENXIO;
1424         sprintf(name, "controlC%i", cardnum);
1425         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1426                                        &snd_ctl_f_ops, card, name)) < 0)
1427                 return err;
1428         return 0;
1429 }
1430
1431 /*
1432  * disconnection of the control device
1433  */
1434 static int snd_ctl_dev_disconnect(struct snd_device *device)
1435 {
1436         struct snd_card *card = device->device_data;
1437         struct snd_ctl_file *ctl;
1438         int err, cardnum;
1439
1440         if (snd_BUG_ON(!card))
1441                 return -ENXIO;
1442         cardnum = card->number;
1443         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1444                 return -ENXIO;
1445
1446         read_lock(&card->ctl_files_rwlock);
1447         list_for_each_entry(ctl, &card->ctl_files, list) {
1448                 wake_up(&ctl->change_sleep);
1449                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1450         }
1451         read_unlock(&card->ctl_files_rwlock);
1452
1453         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1454                                          card, -1)) < 0)
1455                 return err;
1456         return 0;
1457 }
1458
1459 /*
1460  * free all controls
1461  */
1462 static int snd_ctl_dev_free(struct snd_device *device)
1463 {
1464         struct snd_card *card = device->device_data;
1465         struct snd_kcontrol *control;
1466
1467         down_write(&card->controls_rwsem);
1468         while (!list_empty(&card->controls)) {
1469                 control = snd_kcontrol(card->controls.next);
1470                 snd_ctl_remove(card, control);
1471         }
1472         up_write(&card->controls_rwsem);
1473         return 0;
1474 }
1475
1476 /*
1477  * create control core:
1478  * called from init.c
1479  */
1480 int snd_ctl_create(struct snd_card *card)
1481 {
1482         static struct snd_device_ops ops = {
1483                 .dev_free = snd_ctl_dev_free,
1484                 .dev_register = snd_ctl_dev_register,
1485                 .dev_disconnect = snd_ctl_dev_disconnect,
1486         };
1487
1488         if (snd_BUG_ON(!card))
1489                 return -ENXIO;
1490         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1491 }
1492
1493 /*
1494  * Frequently used control callbacks
1495  */
1496 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1497                               struct snd_ctl_elem_info *uinfo)
1498 {
1499         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1500         uinfo->count = 1;
1501         uinfo->value.integer.min = 0;
1502         uinfo->value.integer.max = 1;
1503         return 0;
1504 }
1505
1506 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1507
1508 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1509                                 struct snd_ctl_elem_info *uinfo)
1510 {
1511         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1512         uinfo->count = 2;
1513         uinfo->value.integer.min = 0;
1514         uinfo->value.integer.max = 1;
1515         return 0;
1516 }
1517
1518 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);