6144d8ae2fff6ce8bd6f5d7a7e67bd0f4a7e28d4
[linux-2.6.git] / sound / core / control.c
1 /*
2  *  Routines for driver control interface
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21
22 #include <sound/driver.h>
23 #include <linux/threads.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/time.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <sound/control.h>
32
33 /* max number of user-defined controls */
34 #define MAX_USER_CONTROLS       32
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         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
55         if (!card) {
56                 err = -ENODEV;
57                 goto __error1;
58         }
59         err = snd_card_file_add(card, file);
60         if (err < 0) {
61                 err = -ENODEV;
62                 goto __error1;
63         }
64         if (!try_module_get(card->module)) {
65                 err = -EFAULT;
66                 goto __error2;
67         }
68         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
69         if (ctl == NULL) {
70                 err = -ENOMEM;
71                 goto __error;
72         }
73         INIT_LIST_HEAD(&ctl->events);
74         init_waitqueue_head(&ctl->change_sleep);
75         spin_lock_init(&ctl->read_lock);
76         ctl->card = card;
77         ctl->prefer_pcm_subdevice = -1;
78         ctl->prefer_rawmidi_subdevice = -1;
79         ctl->pid = current->pid;
80         file->private_data = ctl;
81         write_lock_irqsave(&card->ctl_files_rwlock, flags);
82         list_add_tail(&ctl->list, &card->ctl_files);
83         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
84         return 0;
85
86       __error:
87         module_put(card->module);
88       __error2:
89         snd_card_file_remove(card, file);
90       __error1:
91         return err;
92 }
93
94 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
95 {
96         struct snd_kctl_event *cread;
97         
98         spin_lock(&ctl->read_lock);
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(&ctl->read_lock);
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         snd_assert(card != NULL && id != NULL, return);
143         read_lock(&card->ctl_files_rwlock);
144 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
145         card->mixer_oss_change_count++;
146 #endif
147         list_for_each_entry(ctl, &card->ctl_files, list) {
148                 if (!ctl->subscribed)
149                         continue;
150                 spin_lock_irqsave(&ctl->read_lock, flags);
151                 list_for_each_entry(ev, &ctl->events, list) {
152                         if (ev->id.numid == id->numid) {
153                                 ev->mask |= mask;
154                                 goto _found;
155                         }
156                 }
157                 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
158                 if (ev) {
159                         ev->id = *id;
160                         ev->mask = mask;
161                         list_add_tail(&ev->list, &ctl->events);
162                 } else {
163                         snd_printk(KERN_ERR "No memory available to allocate event\n");
164                 }
165         _found:
166                 wake_up(&ctl->change_sleep);
167                 spin_unlock_irqrestore(&ctl->read_lock, flags);
168                 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
169         }
170         read_unlock(&card->ctl_files_rwlock);
171 }
172
173 EXPORT_SYMBOL(snd_ctl_notify);
174
175 /**
176  * snd_ctl_new - create a control instance from the template
177  * @control: the control template
178  * @access: the default control access
179  *
180  * Allocates a new struct snd_kcontrol instance and copies the given template 
181  * to the new instance. It does not copy volatile data (access).
182  *
183  * Returns the pointer of the new instance, or NULL on failure.
184  */
185 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
186                                         unsigned int access)
187 {
188         struct snd_kcontrol *kctl;
189         unsigned int idx;
190         
191         snd_assert(control != NULL, return NULL);
192         snd_assert(control->count > 0, return NULL);
193         kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
194         if (kctl == NULL) {
195                 snd_printk(KERN_ERR "Cannot allocate control instance\n");
196                 return NULL;
197         }
198         *kctl = *control;
199         for (idx = 0; idx < kctl->count; idx++)
200                 kctl->vd[idx].access = access;
201         return kctl;
202 }
203
204 /**
205  * snd_ctl_new1 - create a control instance from the template
206  * @ncontrol: the initialization record
207  * @private_data: the private data to set
208  *
209  * Allocates a new struct snd_kcontrol instance and initialize from the given 
210  * template.  When the access field of ncontrol is 0, it's assumed as
211  * READWRITE access. When the count field is 0, it's assumes as one.
212  *
213  * Returns the pointer of the newly generated instance, or NULL on failure.
214  */
215 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
216                                   void *private_data)
217 {
218         struct snd_kcontrol kctl;
219         unsigned int access;
220         
221         snd_assert(ncontrol != NULL, return NULL);
222         snd_assert(ncontrol->info != NULL, return NULL);
223         memset(&kctl, 0, sizeof(kctl));
224         kctl.id.iface = ncontrol->iface;
225         kctl.id.device = ncontrol->device;
226         kctl.id.subdevice = ncontrol->subdevice;
227         if (ncontrol->name)
228                 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
229         kctl.id.index = ncontrol->index;
230         kctl.count = ncontrol->count ? ncontrol->count : 1;
231         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
232                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
233                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
234                                       SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
235                                       SNDRV_CTL_ELEM_ACCESS_INDIRECT|
236                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
237                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
238         kctl.info = ncontrol->info;
239         kctl.get = ncontrol->get;
240         kctl.put = ncontrol->put;
241         kctl.tlv.p = ncontrol->tlv.p;
242         kctl.private_value = ncontrol->private_value;
243         kctl.private_data = private_data;
244         return snd_ctl_new(&kctl, access);
245 }
246
247 EXPORT_SYMBOL(snd_ctl_new1);
248
249 /**
250  * snd_ctl_free_one - release the control instance
251  * @kcontrol: the control instance
252  *
253  * Releases the control instance created via snd_ctl_new()
254  * or snd_ctl_new1().
255  * Don't call this after the control was added to the card.
256  */
257 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
258 {
259         if (kcontrol) {
260                 if (kcontrol->private_free)
261                         kcontrol->private_free(kcontrol);
262                 kfree(kcontrol);
263         }
264 }
265
266 EXPORT_SYMBOL(snd_ctl_free_one);
267
268 static unsigned int snd_ctl_hole_check(struct snd_card *card,
269                                        unsigned int count)
270 {
271         struct snd_kcontrol *kctl;
272
273         list_for_each_entry(kctl, &card->controls, list) {
274                 if ((kctl->id.numid <= card->last_numid &&
275                      kctl->id.numid + kctl->count > card->last_numid) ||
276                     (kctl->id.numid <= card->last_numid + count - 1 &&
277                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
278                         return card->last_numid = kctl->id.numid + kctl->count - 1;
279         }
280         return card->last_numid;
281 }
282
283 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
284 {
285         unsigned int last_numid, iter = 100000;
286
287         last_numid = card->last_numid;
288         while (last_numid != snd_ctl_hole_check(card, count)) {
289                 if (--iter == 0) {
290                         /* this situation is very unlikely */
291                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
292                         return -ENOMEM;
293                 }
294                 last_numid = card->last_numid;
295         }
296         return 0;
297 }
298
299 /**
300  * snd_ctl_add - add the control instance to the card
301  * @card: the card instance
302  * @kcontrol: the control instance to add
303  *
304  * Adds the control instance created via snd_ctl_new() or
305  * snd_ctl_new1() to the given card. Assigns also an unique
306  * numid used for fast search.
307  *
308  * Returns zero if successful, or a negative error code on failure.
309  *
310  * It frees automatically the control which cannot be added.
311  */
312 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
313 {
314         struct snd_ctl_elem_id id;
315         unsigned int idx;
316         int err = -EINVAL;
317
318         if (! kcontrol)
319                 return err;
320         snd_assert(card != NULL, goto error);
321         snd_assert(kcontrol->info != NULL, goto error);
322         id = kcontrol->id;
323         down_write(&card->controls_rwsem);
324         if (snd_ctl_find_id(card, &id)) {
325                 up_write(&card->controls_rwsem);
326                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
327                                         id.iface,
328                                         id.device,
329                                         id.subdevice,
330                                         id.name,
331                                         id.index);
332                 err = -EBUSY;
333                 goto error;
334         }
335         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
336                 up_write(&card->controls_rwsem);
337                 err = -ENOMEM;
338                 goto error;
339         }
340         list_add_tail(&kcontrol->list, &card->controls);
341         card->controls_count += kcontrol->count;
342         kcontrol->id.numid = card->last_numid + 1;
343         card->last_numid += kcontrol->count;
344         up_write(&card->controls_rwsem);
345         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
346                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
347         return 0;
348
349  error:
350         snd_ctl_free_one(kcontrol);
351         return err;
352 }
353
354 EXPORT_SYMBOL(snd_ctl_add);
355
356 /**
357  * snd_ctl_remove - remove the control from the card and release it
358  * @card: the card instance
359  * @kcontrol: the control instance to remove
360  *
361  * Removes the control from the card and then releases the instance.
362  * You don't need to call snd_ctl_free_one(). You must be in
363  * the write lock - down_write(&card->controls_rwsem).
364  * 
365  * Returns 0 if successful, or a negative error code on failure.
366  */
367 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
368 {
369         struct snd_ctl_elem_id id;
370         unsigned int idx;
371
372         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
373         list_del(&kcontrol->list);
374         card->controls_count -= kcontrol->count;
375         id = kcontrol->id;
376         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
377                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
378         snd_ctl_free_one(kcontrol);
379         return 0;
380 }
381
382 EXPORT_SYMBOL(snd_ctl_remove);
383
384 /**
385  * snd_ctl_remove_id - remove the control of the given id and release it
386  * @card: the card instance
387  * @id: the control id to remove
388  *
389  * Finds the control instance with the given id, removes it from the
390  * card list and releases it.
391  * 
392  * Returns 0 if successful, or a negative error code on failure.
393  */
394 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
395 {
396         struct snd_kcontrol *kctl;
397         int ret;
398
399         down_write(&card->controls_rwsem);
400         kctl = snd_ctl_find_id(card, id);
401         if (kctl == NULL) {
402                 up_write(&card->controls_rwsem);
403                 return -ENOENT;
404         }
405         ret = snd_ctl_remove(card, kctl);
406         up_write(&card->controls_rwsem);
407         return ret;
408 }
409
410 EXPORT_SYMBOL(snd_ctl_remove_id);
411
412 /**
413  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
414  * @file: active control handle
415  * @id: the control id to remove
416  *
417  * Finds the control instance with the given id, removes it from the
418  * card list and releases it.
419  * 
420  * Returns 0 if successful, or a negative error code on failure.
421  */
422 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
423                                       struct snd_ctl_elem_id *id)
424 {
425         struct snd_card *card = file->card;
426         struct snd_kcontrol *kctl;
427         int idx, ret;
428
429         down_write(&card->controls_rwsem);
430         kctl = snd_ctl_find_id(card, id);
431         if (kctl == NULL) {
432                 up_write(&card->controls_rwsem);
433                 return -ENOENT;
434         }
435         for (idx = 0; idx < kctl->count; idx++)
436                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
437                         up_write(&card->controls_rwsem);
438                         return -EBUSY;
439                 }
440         ret = snd_ctl_remove(card, kctl);
441         up_write(&card->controls_rwsem);
442         return ret;
443 }
444
445 /**
446  * snd_ctl_rename_id - replace the id of a control on the card
447  * @card: the card instance
448  * @src_id: the old id
449  * @dst_id: the new id
450  *
451  * Finds the control with the old id from the card, and replaces the
452  * id with the new one.
453  *
454  * Returns zero if successful, or a negative error code on failure.
455  */
456 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
457                       struct snd_ctl_elem_id *dst_id)
458 {
459         struct snd_kcontrol *kctl;
460
461         down_write(&card->controls_rwsem);
462         kctl = snd_ctl_find_id(card, src_id);
463         if (kctl == NULL) {
464                 up_write(&card->controls_rwsem);
465                 return -ENOENT;
466         }
467         kctl->id = *dst_id;
468         kctl->id.numid = card->last_numid + 1;
469         card->last_numid += kctl->count;
470         up_write(&card->controls_rwsem);
471         return 0;
472 }
473
474 EXPORT_SYMBOL(snd_ctl_rename_id);
475
476 /**
477  * snd_ctl_find_numid - find the control instance with the given number-id
478  * @card: the card instance
479  * @numid: the number-id to search
480  *
481  * Finds the control instance with the given number-id from the card.
482  *
483  * Returns the pointer of the instance if found, or NULL if not.
484  *
485  * The caller must down card->controls_rwsem before calling this function
486  * (if the race condition can happen).
487  */
488 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
489 {
490         struct snd_kcontrol *kctl;
491
492         snd_assert(card != NULL && numid != 0, return NULL);
493         list_for_each_entry(kctl, &card->controls, list) {
494                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
495                         return kctl;
496         }
497         return NULL;
498 }
499
500 EXPORT_SYMBOL(snd_ctl_find_numid);
501
502 /**
503  * snd_ctl_find_id - find the control instance with the given id
504  * @card: the card instance
505  * @id: the id to search
506  *
507  * Finds the control instance with the given id from the card.
508  *
509  * Returns the pointer of the instance if found, or NULL if not.
510  *
511  * The caller must down card->controls_rwsem before calling this function
512  * (if the race condition can happen).
513  */
514 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
515                                      struct snd_ctl_elem_id *id)
516 {
517         struct snd_kcontrol *kctl;
518
519         snd_assert(card != NULL && id != NULL, return NULL);
520         if (id->numid != 0)
521                 return snd_ctl_find_numid(card, id->numid);
522         list_for_each_entry(kctl, &card->controls, list) {
523                 if (kctl->id.iface != id->iface)
524                         continue;
525                 if (kctl->id.device != id->device)
526                         continue;
527                 if (kctl->id.subdevice != id->subdevice)
528                         continue;
529                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
530                         continue;
531                 if (kctl->id.index > id->index)
532                         continue;
533                 if (kctl->id.index + kctl->count <= id->index)
534                         continue;
535                 return kctl;
536         }
537         return NULL;
538 }
539
540 EXPORT_SYMBOL(snd_ctl_find_id);
541
542 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
543                              unsigned int cmd, void __user *arg)
544 {
545         struct snd_ctl_card_info *info;
546
547         info = kzalloc(sizeof(*info), GFP_KERNEL);
548         if (! info)
549                 return -ENOMEM;
550         down_read(&snd_ioctl_rwsem);
551         info->card = card->number;
552         strlcpy(info->id, card->id, sizeof(info->id));
553         strlcpy(info->driver, card->driver, sizeof(info->driver));
554         strlcpy(info->name, card->shortname, sizeof(info->name));
555         strlcpy(info->longname, card->longname, sizeof(info->longname));
556         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
557         strlcpy(info->components, card->components, sizeof(info->components));
558         up_read(&snd_ioctl_rwsem);
559         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
560                 kfree(info);
561                 return -EFAULT;
562         }
563         kfree(info);
564         return 0;
565 }
566
567 static int snd_ctl_elem_list(struct snd_card *card,
568                              struct snd_ctl_elem_list __user *_list)
569 {
570         struct list_head *plist;
571         struct snd_ctl_elem_list list;
572         struct snd_kcontrol *kctl;
573         struct snd_ctl_elem_id *dst, *id;
574         unsigned int offset, space, first, jidx;
575         
576         if (copy_from_user(&list, _list, sizeof(list)))
577                 return -EFAULT;
578         offset = list.offset;
579         space = list.space;
580         first = 0;
581         /* try limit maximum space */
582         if (space > 16384)
583                 return -ENOMEM;
584         if (space > 0) {
585                 /* allocate temporary buffer for atomic operation */
586                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
587                 if (dst == NULL)
588                         return -ENOMEM;
589                 down_read(&card->controls_rwsem);
590                 list.count = card->controls_count;
591                 plist = card->controls.next;
592                 while (plist != &card->controls) {
593                         if (offset == 0)
594                                 break;
595                         kctl = snd_kcontrol(plist);
596                         if (offset < kctl->count)
597                                 break;
598                         offset -= kctl->count;
599                         plist = plist->next;
600                 }
601                 list.used = 0;
602                 id = dst;
603                 while (space > 0 && plist != &card->controls) {
604                         kctl = snd_kcontrol(plist);
605                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
606                                 snd_ctl_build_ioff(id, kctl, jidx);
607                                 id++;
608                                 space--;
609                                 list.used++;
610                         }
611                         plist = plist->next;
612                         offset = 0;
613                 }
614                 up_read(&card->controls_rwsem);
615                 if (list.used > 0 &&
616                     copy_to_user(list.pids, dst,
617                                  list.used * sizeof(struct snd_ctl_elem_id))) {
618                         vfree(dst);
619                         return -EFAULT;
620                 }
621                 vfree(dst);
622         } else {
623                 down_read(&card->controls_rwsem);
624                 list.count = card->controls_count;
625                 up_read(&card->controls_rwsem);
626         }
627         if (copy_to_user(_list, &list, sizeof(list)))
628                 return -EFAULT;
629         return 0;
630 }
631
632 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
633                              struct snd_ctl_elem_info *info)
634 {
635         struct snd_card *card = ctl->card;
636         struct snd_kcontrol *kctl;
637         struct snd_kcontrol_volatile *vd;
638         unsigned int index_offset;
639         int result;
640         
641         down_read(&card->controls_rwsem);
642         kctl = snd_ctl_find_id(card, &info->id);
643         if (kctl == NULL) {
644                 up_read(&card->controls_rwsem);
645                 return -ENOENT;
646         }
647 #ifdef CONFIG_SND_DEBUG
648         info->access = 0;
649 #endif
650         result = kctl->info(kctl, info);
651         if (result >= 0) {
652                 snd_assert(info->access == 0, );
653                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
654                 vd = &kctl->vd[index_offset];
655                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
656                 info->access = vd->access;
657                 if (vd->owner) {
658                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
659                         if (vd->owner == ctl)
660                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
661                         info->owner = vd->owner_pid;
662                 } else {
663                         info->owner = -1;
664                 }
665         }
666         up_read(&card->controls_rwsem);
667         return result;
668 }
669
670 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
671                                   struct snd_ctl_elem_info __user *_info)
672 {
673         struct snd_ctl_elem_info info;
674         int result;
675
676         if (copy_from_user(&info, _info, sizeof(info)))
677                 return -EFAULT;
678         snd_power_lock(ctl->card);
679         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
680         if (result >= 0)
681                 result = snd_ctl_elem_info(ctl, &info);
682         snd_power_unlock(ctl->card);
683         if (result >= 0)
684                 if (copy_to_user(_info, &info, sizeof(info)))
685                         return -EFAULT;
686         return result;
687 }
688
689 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
690 {
691         struct snd_kcontrol *kctl;
692         struct snd_kcontrol_volatile *vd;
693         unsigned int index_offset;
694         int result, indirect;
695
696         down_read(&card->controls_rwsem);
697         kctl = snd_ctl_find_id(card, &control->id);
698         if (kctl == NULL) {
699                 result = -ENOENT;
700         } else {
701                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
702                 vd = &kctl->vd[index_offset];
703                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
704                 if (control->indirect != indirect) {
705                         result = -EACCES;
706                 } else {
707                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
708                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
709                                 result = kctl->get(kctl, control);
710                         } else {
711                                 result = -EPERM;
712                         }
713                 }
714         }
715         up_read(&card->controls_rwsem);
716         return result;
717 }
718
719 static int snd_ctl_elem_read_user(struct snd_card *card,
720                                   struct snd_ctl_elem_value __user *_control)
721 {
722         struct snd_ctl_elem_value *control;
723         int result;
724         
725         control = kmalloc(sizeof(*control), GFP_KERNEL);
726         if (control == NULL)
727                 return -ENOMEM; 
728         if (copy_from_user(control, _control, sizeof(*control))) {
729                 kfree(control);
730                 return -EFAULT;
731         }
732         snd_power_lock(card);
733         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
734         if (result >= 0)
735                 result = snd_ctl_elem_read(card, control);
736         snd_power_unlock(card);
737         if (result >= 0)
738                 if (copy_to_user(_control, control, sizeof(*control)))
739                         result = -EFAULT;
740         kfree(control);
741         return result;
742 }
743
744 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
745                        struct snd_ctl_elem_value *control)
746 {
747         struct snd_kcontrol *kctl;
748         struct snd_kcontrol_volatile *vd;
749         unsigned int index_offset;
750         int result, indirect;
751
752         down_read(&card->controls_rwsem);
753         kctl = snd_ctl_find_id(card, &control->id);
754         if (kctl == NULL) {
755                 result = -ENOENT;
756         } else {
757                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
758                 vd = &kctl->vd[index_offset];
759                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
760                 if (control->indirect != indirect) {
761                         result = -EACCES;
762                 } else {
763                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
764                             kctl->put == NULL ||
765                             (file && vd->owner != NULL && vd->owner != file)) {
766                                 result = -EPERM;
767                         } else {
768                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
769                                 result = kctl->put(kctl, control);
770                         }
771                         if (result > 0) {
772                                 up_read(&card->controls_rwsem);
773                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
774                                 return 0;
775                         }
776                 }
777         }
778         up_read(&card->controls_rwsem);
779         return result;
780 }
781
782 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
783                                    struct snd_ctl_elem_value __user *_control)
784 {
785         struct snd_ctl_elem_value *control;
786         struct snd_card *card;
787         int result;
788
789         control = kmalloc(sizeof(*control), GFP_KERNEL);
790         if (control == NULL)
791                 return -ENOMEM; 
792         if (copy_from_user(control, _control, sizeof(*control))) {
793                 kfree(control);
794                 return -EFAULT;
795         }
796         card = file->card;
797         snd_power_lock(card);
798         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
799         if (result >= 0)
800                 result = snd_ctl_elem_write(card, file, control);
801         snd_power_unlock(card);
802         if (result >= 0)
803                 if (copy_to_user(_control, control, sizeof(*control)))
804                         result = -EFAULT;
805         kfree(control);
806         return result;
807 }
808
809 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
810                              struct snd_ctl_elem_id __user *_id)
811 {
812         struct snd_card *card = file->card;
813         struct snd_ctl_elem_id id;
814         struct snd_kcontrol *kctl;
815         struct snd_kcontrol_volatile *vd;
816         int result;
817         
818         if (copy_from_user(&id, _id, sizeof(id)))
819                 return -EFAULT;
820         down_write(&card->controls_rwsem);
821         kctl = snd_ctl_find_id(card, &id);
822         if (kctl == NULL) {
823                 result = -ENOENT;
824         } else {
825                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
826                 if (vd->owner != NULL)
827                         result = -EBUSY;
828                 else {
829                         vd->owner = file;
830                         vd->owner_pid = current->pid;
831                         result = 0;
832                 }
833         }
834         up_write(&card->controls_rwsem);
835         return result;
836 }
837
838 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
839                                struct snd_ctl_elem_id __user *_id)
840 {
841         struct snd_card *card = file->card;
842         struct snd_ctl_elem_id id;
843         struct snd_kcontrol *kctl;
844         struct snd_kcontrol_volatile *vd;
845         int result;
846         
847         if (copy_from_user(&id, _id, sizeof(id)))
848                 return -EFAULT;
849         down_write(&card->controls_rwsem);
850         kctl = snd_ctl_find_id(card, &id);
851         if (kctl == NULL) {
852                 result = -ENOENT;
853         } else {
854                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
855                 if (vd->owner == NULL)
856                         result = -EINVAL;
857                 else if (vd->owner != file)
858                         result = -EPERM;
859                 else {
860                         vd->owner = NULL;
861                         vd->owner_pid = 0;
862                         result = 0;
863                 }
864         }
865         up_write(&card->controls_rwsem);
866         return result;
867 }
868
869 struct user_element {
870         struct snd_ctl_elem_info info;
871         void *elem_data;                /* element data */
872         unsigned long elem_data_size;   /* size of element data in bytes */
873         void *tlv_data;                 /* TLV data */
874         unsigned long tlv_data_size;    /* TLV data size */
875         void *priv_data;                /* private data (like strings for enumerated type) */
876         unsigned long priv_data_size;   /* size of private data in bytes */
877 };
878
879 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
880                                   struct snd_ctl_elem_info *uinfo)
881 {
882         struct user_element *ue = kcontrol->private_data;
883
884         *uinfo = ue->info;
885         return 0;
886 }
887
888 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
889                                  struct snd_ctl_elem_value *ucontrol)
890 {
891         struct user_element *ue = kcontrol->private_data;
892
893         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
894         return 0;
895 }
896
897 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
898                                  struct snd_ctl_elem_value *ucontrol)
899 {
900         int change;
901         struct user_element *ue = kcontrol->private_data;
902         
903         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
904         if (change)
905                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
906         return change;
907 }
908
909 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
910                                  int op_flag,
911                                  unsigned int size,
912                                  unsigned int __user *tlv)
913 {
914         struct user_element *ue = kcontrol->private_data;
915         int change = 0;
916         void *new_data;
917
918         if (op_flag > 0) {
919                 if (size > 1024 * 128)  /* sane value */
920                         return -EINVAL;
921                 new_data = kmalloc(size, GFP_KERNEL);
922                 if (new_data == NULL)
923                         return -ENOMEM;
924                 if (copy_from_user(new_data, tlv, size)) {
925                         kfree(new_data);
926                         return -EFAULT;
927                 }
928                 change = ue->tlv_data_size != size;
929                 if (!change)
930                         change = memcmp(ue->tlv_data, new_data, size);
931                 kfree(ue->tlv_data);
932                 ue->tlv_data = new_data;
933                 ue->tlv_data_size = size;
934         } else {
935                 if (! ue->tlv_data_size || ! ue->tlv_data)
936                         return -ENXIO;
937                 if (size < ue->tlv_data_size)
938                         return -ENOSPC;
939                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
940                         return -EFAULT;
941         }
942         return change;
943 }
944
945 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
946 {
947         struct user_element *ue = kcontrol->private_data;
948         if (ue->tlv_data)
949                 kfree(ue->tlv_data);
950         kfree(ue);
951 }
952
953 static int snd_ctl_elem_add(struct snd_ctl_file *file,
954                             struct snd_ctl_elem_info *info, int replace)
955 {
956         struct snd_card *card = file->card;
957         struct snd_kcontrol kctl, *_kctl;
958         unsigned int access;
959         long private_size;
960         struct user_element *ue;
961         int idx, err;
962         
963         if (card->user_ctl_count >= MAX_USER_CONTROLS)
964                 return -ENOMEM;
965         if (info->count > 1024)
966                 return -EINVAL;
967         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
968                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
969                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
970                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
971         info->id.numid = 0;
972         memset(&kctl, 0, sizeof(kctl));
973         down_write(&card->controls_rwsem);
974         _kctl = snd_ctl_find_id(card, &info->id);
975         err = 0;
976         if (_kctl) {
977                 if (replace)
978                         err = snd_ctl_remove(card, _kctl);
979                 else
980                         err = -EBUSY;
981         } else {
982                 if (replace)
983                         err = -ENOENT;
984         }
985         up_write(&card->controls_rwsem);
986         if (err < 0)
987                 return err;
988         memcpy(&kctl.id, &info->id, sizeof(info->id));
989         kctl.count = info->owner ? info->owner : 1;
990         access |= SNDRV_CTL_ELEM_ACCESS_USER;
991         kctl.info = snd_ctl_elem_user_info;
992         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
993                 kctl.get = snd_ctl_elem_user_get;
994         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
995                 kctl.put = snd_ctl_elem_user_put;
996         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
997                 kctl.tlv.c = snd_ctl_elem_user_tlv;
998                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
999         }
1000         switch (info->type) {
1001         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1002         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1003                 private_size = sizeof(long);
1004                 if (info->count > 128)
1005                         return -EINVAL;
1006                 break;
1007         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1008                 private_size = sizeof(long long);
1009                 if (info->count > 64)
1010                         return -EINVAL;
1011                 break;
1012         case SNDRV_CTL_ELEM_TYPE_BYTES:
1013                 private_size = sizeof(unsigned char);
1014                 if (info->count > 512)
1015                         return -EINVAL;
1016                 break;
1017         case SNDRV_CTL_ELEM_TYPE_IEC958:
1018                 private_size = sizeof(struct snd_aes_iec958);
1019                 if (info->count != 1)
1020                         return -EINVAL;
1021                 break;
1022         default:
1023                 return -EINVAL;
1024         }
1025         private_size *= info->count;
1026         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1027         if (ue == NULL)
1028                 return -ENOMEM;
1029         ue->info = *info;
1030         ue->info.access = 0;
1031         ue->elem_data = (char *)ue + sizeof(*ue);
1032         ue->elem_data_size = private_size;
1033         kctl.private_free = snd_ctl_elem_user_free;
1034         _kctl = snd_ctl_new(&kctl, access);
1035         if (_kctl == NULL) {
1036                 kfree(ue);
1037                 return -ENOMEM;
1038         }
1039         _kctl->private_data = ue;
1040         for (idx = 0; idx < _kctl->count; idx++)
1041                 _kctl->vd[idx].owner = file;
1042         err = snd_ctl_add(card, _kctl);
1043         if (err < 0)
1044                 return err;
1045
1046         down_write(&card->controls_rwsem);
1047         card->user_ctl_count++;
1048         up_write(&card->controls_rwsem);
1049
1050         return 0;
1051 }
1052
1053 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1054                                  struct snd_ctl_elem_info __user *_info, int replace)
1055 {
1056         struct snd_ctl_elem_info info;
1057         if (copy_from_user(&info, _info, sizeof(info)))
1058                 return -EFAULT;
1059         return snd_ctl_elem_add(file, &info, replace);
1060 }
1061
1062 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1063                                struct snd_ctl_elem_id __user *_id)
1064 {
1065         struct snd_ctl_elem_id id;
1066         int err;
1067
1068         if (copy_from_user(&id, _id, sizeof(id)))
1069                 return -EFAULT;
1070         err = snd_ctl_remove_unlocked_id(file, &id);
1071         if (! err) {
1072                 struct snd_card *card = file->card;
1073                 down_write(&card->controls_rwsem);
1074                 card->user_ctl_count--;
1075                 up_write(&card->controls_rwsem);
1076         }
1077         return err;
1078 }
1079
1080 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1081 {
1082         int subscribe;
1083         if (get_user(subscribe, ptr))
1084                 return -EFAULT;
1085         if (subscribe < 0) {
1086                 subscribe = file->subscribed;
1087                 if (put_user(subscribe, ptr))
1088                         return -EFAULT;
1089                 return 0;
1090         }
1091         if (subscribe) {
1092                 file->subscribed = 1;
1093                 return 0;
1094         } else if (file->subscribed) {
1095                 snd_ctl_empty_read_queue(file);
1096                 file->subscribed = 0;
1097         }
1098         return 0;
1099 }
1100
1101 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1102                              struct snd_ctl_tlv __user *_tlv,
1103                              int op_flag)
1104 {
1105         struct snd_card *card = file->card;
1106         struct snd_ctl_tlv tlv;
1107         struct snd_kcontrol *kctl;
1108         struct snd_kcontrol_volatile *vd;
1109         unsigned int len;
1110         int err = 0;
1111
1112         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1113                 return -EFAULT;
1114         if (tlv.length < sizeof(unsigned int) * 3)
1115                 return -EINVAL;
1116         down_read(&card->controls_rwsem);
1117         kctl = snd_ctl_find_numid(card, tlv.numid);
1118         if (kctl == NULL) {
1119                 err = -ENOENT;
1120                 goto __kctl_end;
1121         }
1122         if (kctl->tlv.p == NULL) {
1123                 err = -ENXIO;
1124                 goto __kctl_end;
1125         }
1126         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1127         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1128             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1129             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1130                 err = -ENXIO;
1131                 goto __kctl_end;
1132         }
1133         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1134                 if (file && vd->owner != NULL && vd->owner != file) {
1135                         err = -EPERM;
1136                         goto __kctl_end;
1137                 }
1138                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1139                 if (err > 0) {
1140                         up_read(&card->controls_rwsem);
1141                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1142                         return 0;
1143                 }
1144         } else {
1145                 if (op_flag) {
1146                         err = -ENXIO;
1147                         goto __kctl_end;
1148                 }
1149                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1150                 if (tlv.length < len) {
1151                         err = -ENOMEM;
1152                         goto __kctl_end;
1153                 }
1154                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1155                         err = -EFAULT;
1156         }
1157       __kctl_end:
1158         up_read(&card->controls_rwsem);
1159         return err;
1160 }
1161
1162 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1163 {
1164         struct snd_ctl_file *ctl;
1165         struct snd_card *card;
1166         struct snd_kctl_ioctl *p;
1167         void __user *argp = (void __user *)arg;
1168         int __user *ip = argp;
1169         int err;
1170
1171         ctl = file->private_data;
1172         card = ctl->card;
1173         snd_assert(card != NULL, 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         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1236         if (!ctl->subscribed)
1237                 return -EBADFD;
1238         if (count < sizeof(struct snd_ctl_event))
1239                 return -EINVAL;
1240         spin_lock_irq(&ctl->read_lock);
1241         while (count >= sizeof(struct snd_ctl_event)) {
1242                 struct snd_ctl_event ev;
1243                 struct snd_kctl_event *kev;
1244                 while (list_empty(&ctl->events)) {
1245                         wait_queue_t wait;
1246                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1247                                 err = -EAGAIN;
1248                                 goto __end_lock;
1249                         }
1250                         init_waitqueue_entry(&wait, current);
1251                         add_wait_queue(&ctl->change_sleep, &wait);
1252                         set_current_state(TASK_INTERRUPTIBLE);
1253                         spin_unlock_irq(&ctl->read_lock);
1254                         schedule();
1255                         remove_wait_queue(&ctl->change_sleep, &wait);
1256                         if (signal_pending(current))
1257                                 return -ERESTARTSYS;
1258                         spin_lock_irq(&ctl->read_lock);
1259                 }
1260                 kev = snd_kctl_event(ctl->events.next);
1261                 ev.type = SNDRV_CTL_EVENT_ELEM;
1262                 ev.data.elem.mask = kev->mask;
1263                 ev.data.elem.id = kev->id;
1264                 list_del(&kev->list);
1265                 spin_unlock_irq(&ctl->read_lock);
1266                 kfree(kev);
1267                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1268                         err = -EFAULT;
1269                         goto __end;
1270                 }
1271                 spin_lock_irq(&ctl->read_lock);
1272                 buffer += sizeof(struct snd_ctl_event);
1273                 count -= sizeof(struct snd_ctl_event);
1274                 result += sizeof(struct snd_ctl_event);
1275         }
1276       __end_lock:
1277         spin_unlock_irq(&ctl->read_lock);
1278       __end:
1279         return result > 0 ? result : err;
1280 }
1281
1282 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1283 {
1284         unsigned int mask;
1285         struct snd_ctl_file *ctl;
1286
1287         ctl = file->private_data;
1288         if (!ctl->subscribed)
1289                 return 0;
1290         poll_wait(file, &ctl->change_sleep, wait);
1291
1292         mask = 0;
1293         if (!list_empty(&ctl->events))
1294                 mask |= POLLIN | POLLRDNORM;
1295
1296         return mask;
1297 }
1298
1299 /*
1300  * register the device-specific control-ioctls.
1301  * called from each device manager like pcm.c, hwdep.c, etc.
1302  */
1303 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1304 {
1305         struct snd_kctl_ioctl *pn;
1306
1307         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1308         if (pn == NULL)
1309                 return -ENOMEM;
1310         pn->fioctl = fcn;
1311         down_write(&snd_ioctl_rwsem);
1312         list_add_tail(&pn->list, lists);
1313         up_write(&snd_ioctl_rwsem);
1314         return 0;
1315 }
1316
1317 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1318 {
1319         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1320 }
1321
1322 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1323
1324 #ifdef CONFIG_COMPAT
1325 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1326 {
1327         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1328 }
1329
1330 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1331 #endif
1332
1333 /*
1334  * de-register the device-specific control-ioctls.
1335  */
1336 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1337                                      struct list_head *lists)
1338 {
1339         struct snd_kctl_ioctl *p;
1340
1341         snd_assert(fcn != NULL, return -EINVAL);
1342         down_write(&snd_ioctl_rwsem);
1343         list_for_each_entry(p, lists, list) {
1344                 if (p->fioctl == fcn) {
1345                         list_del(&p->list);
1346                         up_write(&snd_ioctl_rwsem);
1347                         kfree(p);
1348                         return 0;
1349                 }
1350         }
1351         up_write(&snd_ioctl_rwsem);
1352         snd_BUG();
1353         return -EINVAL;
1354 }
1355
1356 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1357 {
1358         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1359 }
1360
1361 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1362
1363 #ifdef CONFIG_COMPAT
1364 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1365 {
1366         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1367 }
1368
1369 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1370 #endif
1371
1372 static int snd_ctl_fasync(int fd, struct file * file, int on)
1373 {
1374         struct snd_ctl_file *ctl;
1375         int err;
1376         ctl = file->private_data;
1377         err = fasync_helper(fd, file, on, &ctl->fasync);
1378         if (err < 0)
1379                 return err;
1380         return 0;
1381 }
1382
1383 /*
1384  * ioctl32 compat
1385  */
1386 #ifdef CONFIG_COMPAT
1387 #include "control_compat.c"
1388 #else
1389 #define snd_ctl_ioctl_compat    NULL
1390 #endif
1391
1392 /*
1393  *  INIT PART
1394  */
1395
1396 static const struct file_operations snd_ctl_f_ops =
1397 {
1398         .owner =        THIS_MODULE,
1399         .read =         snd_ctl_read,
1400         .open =         snd_ctl_open,
1401         .release =      snd_ctl_release,
1402         .poll =         snd_ctl_poll,
1403         .unlocked_ioctl =       snd_ctl_ioctl,
1404         .compat_ioctl = snd_ctl_ioctl_compat,
1405         .fasync =       snd_ctl_fasync,
1406 };
1407
1408 /*
1409  * registration of the control device
1410  */
1411 static int snd_ctl_dev_register(struct snd_device *device)
1412 {
1413         struct snd_card *card = device->device_data;
1414         int err, cardnum;
1415         char name[16];
1416
1417         snd_assert(card != NULL, return -ENXIO);
1418         cardnum = card->number;
1419         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1420         sprintf(name, "controlC%i", cardnum);
1421         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1422                                        &snd_ctl_f_ops, card, name)) < 0)
1423                 return err;
1424         return 0;
1425 }
1426
1427 /*
1428  * disconnection of the control device
1429  */
1430 static int snd_ctl_dev_disconnect(struct snd_device *device)
1431 {
1432         struct snd_card *card = device->device_data;
1433         struct snd_ctl_file *ctl;
1434         int err, cardnum;
1435
1436         snd_assert(card != NULL, return -ENXIO);
1437         cardnum = card->number;
1438         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1439
1440         down_read(&card->controls_rwsem);
1441         list_for_each_entry(ctl, &card->ctl_files, list) {
1442                 wake_up(&ctl->change_sleep);
1443                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1444         }
1445         up_read(&card->controls_rwsem);
1446
1447         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1448                                          card, -1)) < 0)
1449                 return err;
1450         return 0;
1451 }
1452
1453 /*
1454  * free all controls
1455  */
1456 static int snd_ctl_dev_free(struct snd_device *device)
1457 {
1458         struct snd_card *card = device->device_data;
1459         struct snd_kcontrol *control;
1460
1461         down_write(&card->controls_rwsem);
1462         while (!list_empty(&card->controls)) {
1463                 control = snd_kcontrol(card->controls.next);
1464                 snd_ctl_remove(card, control);
1465         }
1466         up_write(&card->controls_rwsem);
1467         return 0;
1468 }
1469
1470 /*
1471  * create control core:
1472  * called from init.c
1473  */
1474 int snd_ctl_create(struct snd_card *card)
1475 {
1476         static struct snd_device_ops ops = {
1477                 .dev_free = snd_ctl_dev_free,
1478                 .dev_register = snd_ctl_dev_register,
1479                 .dev_disconnect = snd_ctl_dev_disconnect,
1480         };
1481
1482         snd_assert(card != NULL, return -ENXIO);
1483         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1484 }
1485
1486 /*
1487  * Frequently used control callbacks
1488  */
1489 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1490                               struct snd_ctl_elem_info *uinfo)
1491 {
1492         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1493         uinfo->count = 1;
1494         uinfo->value.integer.min = 0;
1495         uinfo->value.integer.max = 1;
1496         return 0;
1497 }
1498
1499 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1500
1501 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1502                                 struct snd_ctl_elem_info *uinfo)
1503 {
1504         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1505         uinfo->count = 2;
1506         uinfo->value.integer.min = 0;
1507         uinfo->value.integer.max = 1;
1508         return 0;
1509 }
1510
1511 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);