ALSA: use correct lock in snd_ctl_dev_disconnect()
[linux-2.6.git] / sound / core / control.c
1 /*
2  *  Routines for driver control interface
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21
22 #include <linux/threads.h>
23 #include <linux/interrupt.h>
24 #include <linux/slab.h>
25 #include <linux/vmalloc.h>
26 #include <linux/time.h>
27 #include <sound/core.h>
28 #include <sound/minors.h>
29 #include <sound/info.h>
30 #include <sound/control.h>
31
32 /* max number of user-defined controls */
33 #define MAX_USER_CONTROLS       32
34
35 struct snd_kctl_ioctl {
36         struct list_head list;          /* list of all ioctls */
37         snd_kctl_ioctl_func_t fioctl;
38 };
39
40 static DECLARE_RWSEM(snd_ioctl_rwsem);
41 static LIST_HEAD(snd_control_ioctls);
42 #ifdef CONFIG_COMPAT
43 static LIST_HEAD(snd_control_compat_ioctls);
44 #endif
45
46 static int snd_ctl_open(struct inode *inode, struct file *file)
47 {
48         unsigned long flags;
49         struct snd_card *card;
50         struct snd_ctl_file *ctl;
51         int err;
52
53         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
54         if (!card) {
55                 err = -ENODEV;
56                 goto __error1;
57         }
58         err = snd_card_file_add(card, file);
59         if (err < 0) {
60                 err = -ENODEV;
61                 goto __error1;
62         }
63         if (!try_module_get(card->module)) {
64                 err = -EFAULT;
65                 goto __error2;
66         }
67         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
68         if (ctl == NULL) {
69                 err = -ENOMEM;
70                 goto __error;
71         }
72         INIT_LIST_HEAD(&ctl->events);
73         init_waitqueue_head(&ctl->change_sleep);
74         spin_lock_init(&ctl->read_lock);
75         ctl->card = card;
76         ctl->prefer_pcm_subdevice = -1;
77         ctl->prefer_rawmidi_subdevice = -1;
78         ctl->pid = current->pid;
79         file->private_data = ctl;
80         write_lock_irqsave(&card->ctl_files_rwlock, flags);
81         list_add_tail(&ctl->list, &card->ctl_files);
82         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
83         return 0;
84
85       __error:
86         module_put(card->module);
87       __error2:
88         snd_card_file_remove(card, file);
89       __error1:
90         return err;
91 }
92
93 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
94 {
95         unsigned long flags;
96         struct snd_kctl_event *cread;
97         
98         spin_lock_irqsave(&ctl->read_lock, flags);
99         while (!list_empty(&ctl->events)) {
100                 cread = snd_kctl_event(ctl->events.next);
101                 list_del(&cread->list);
102                 kfree(cread);
103         }
104         spin_unlock_irqrestore(&ctl->read_lock, flags);
105 }
106
107 static int snd_ctl_release(struct inode *inode, struct file *file)
108 {
109         unsigned long flags;
110         struct snd_card *card;
111         struct snd_ctl_file *ctl;
112         struct snd_kcontrol *control;
113         unsigned int idx;
114
115         ctl = file->private_data;
116         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         kctl.id.index = ncontrol->index;
231         kctl.count = ncontrol->count ? ncontrol->count : 1;
232         access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
233                  (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
234                                       SNDRV_CTL_ELEM_ACCESS_INACTIVE|
235                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
236                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
237         kctl.info = ncontrol->info;
238         kctl.get = ncontrol->get;
239         kctl.put = ncontrol->put;
240         kctl.tlv.p = ncontrol->tlv.p;
241         kctl.private_value = ncontrol->private_value;
242         kctl.private_data = private_data;
243         return snd_ctl_new(&kctl, access);
244 }
245
246 EXPORT_SYMBOL(snd_ctl_new1);
247
248 /**
249  * snd_ctl_free_one - release the control instance
250  * @kcontrol: the control instance
251  *
252  * Releases the control instance created via snd_ctl_new()
253  * or snd_ctl_new1().
254  * Don't call this after the control was added to the card.
255  */
256 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
257 {
258         if (kcontrol) {
259                 if (kcontrol->private_free)
260                         kcontrol->private_free(kcontrol);
261                 kfree(kcontrol);
262         }
263 }
264
265 EXPORT_SYMBOL(snd_ctl_free_one);
266
267 static unsigned int snd_ctl_hole_check(struct snd_card *card,
268                                        unsigned int count)
269 {
270         struct snd_kcontrol *kctl;
271
272         list_for_each_entry(kctl, &card->controls, list) {
273                 if ((kctl->id.numid <= card->last_numid &&
274                      kctl->id.numid + kctl->count > card->last_numid) ||
275                     (kctl->id.numid <= card->last_numid + count - 1 &&
276                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
277                         return card->last_numid = kctl->id.numid + kctl->count - 1;
278         }
279         return card->last_numid;
280 }
281
282 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
283 {
284         unsigned int last_numid, iter = 100000;
285
286         last_numid = card->last_numid;
287         while (last_numid != snd_ctl_hole_check(card, count)) {
288                 if (--iter == 0) {
289                         /* this situation is very unlikely */
290                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
291                         return -ENOMEM;
292                 }
293                 last_numid = card->last_numid;
294         }
295         return 0;
296 }
297
298 /**
299  * snd_ctl_add - add the control instance to the card
300  * @card: the card instance
301  * @kcontrol: the control instance to add
302  *
303  * Adds the control instance created via snd_ctl_new() or
304  * snd_ctl_new1() to the given card. Assigns also an unique
305  * numid used for fast search.
306  *
307  * Returns zero if successful, or a negative error code on failure.
308  *
309  * It frees automatically the control which cannot be added.
310  */
311 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
312 {
313         struct snd_ctl_elem_id id;
314         unsigned int idx;
315         int err = -EINVAL;
316
317         if (! kcontrol)
318                 return err;
319         if (snd_BUG_ON(!card || !kcontrol->info))
320                 goto error;
321         id = kcontrol->id;
322         down_write(&card->controls_rwsem);
323         if (snd_ctl_find_id(card, &id)) {
324                 up_write(&card->controls_rwsem);
325                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
326                                         id.iface,
327                                         id.device,
328                                         id.subdevice,
329                                         id.name,
330                                         id.index);
331                 err = -EBUSY;
332                 goto error;
333         }
334         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
335                 up_write(&card->controls_rwsem);
336                 err = -ENOMEM;
337                 goto error;
338         }
339         list_add_tail(&kcontrol->list, &card->controls);
340         card->controls_count += kcontrol->count;
341         kcontrol->id.numid = card->last_numid + 1;
342         card->last_numid += kcontrol->count;
343         up_write(&card->controls_rwsem);
344         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
345                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
346         return 0;
347
348  error:
349         snd_ctl_free_one(kcontrol);
350         return err;
351 }
352
353 EXPORT_SYMBOL(snd_ctl_add);
354
355 /**
356  * snd_ctl_remove - remove the control from the card and release it
357  * @card: the card instance
358  * @kcontrol: the control instance to remove
359  *
360  * Removes the control from the card and then releases the instance.
361  * You don't need to call snd_ctl_free_one(). You must be in
362  * the write lock - down_write(&card->controls_rwsem).
363  * 
364  * Returns 0 if successful, or a negative error code on failure.
365  */
366 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
367 {
368         struct snd_ctl_elem_id id;
369         unsigned int idx;
370
371         if (snd_BUG_ON(!card || !kcontrol))
372                 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         if (snd_BUG_ON(!card || !numid))
493                 return NULL;
494         list_for_each_entry(kctl, &card->controls, list) {
495                 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
496                         return kctl;
497         }
498         return NULL;
499 }
500
501 EXPORT_SYMBOL(snd_ctl_find_numid);
502
503 /**
504  * snd_ctl_find_id - find the control instance with the given id
505  * @card: the card instance
506  * @id: the id to search
507  *
508  * Finds the control instance with the given id from the card.
509  *
510  * Returns the pointer of the instance if found, or NULL if not.
511  *
512  * The caller must down card->controls_rwsem before calling this function
513  * (if the race condition can happen).
514  */
515 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
516                                      struct snd_ctl_elem_id *id)
517 {
518         struct snd_kcontrol *kctl;
519
520         if (snd_BUG_ON(!card || !id))
521                 return NULL;
522         if (id->numid != 0)
523                 return snd_ctl_find_numid(card, id->numid);
524         list_for_each_entry(kctl, &card->controls, list) {
525                 if (kctl->id.iface != id->iface)
526                         continue;
527                 if (kctl->id.device != id->device)
528                         continue;
529                 if (kctl->id.subdevice != id->subdevice)
530                         continue;
531                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
532                         continue;
533                 if (kctl->id.index > id->index)
534                         continue;
535                 if (kctl->id.index + kctl->count <= id->index)
536                         continue;
537                 return kctl;
538         }
539         return NULL;
540 }
541
542 EXPORT_SYMBOL(snd_ctl_find_id);
543
544 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
545                              unsigned int cmd, void __user *arg)
546 {
547         struct snd_ctl_card_info *info;
548
549         info = kzalloc(sizeof(*info), GFP_KERNEL);
550         if (! info)
551                 return -ENOMEM;
552         down_read(&snd_ioctl_rwsem);
553         info->card = card->number;
554         strlcpy(info->id, card->id, sizeof(info->id));
555         strlcpy(info->driver, card->driver, sizeof(info->driver));
556         strlcpy(info->name, card->shortname, sizeof(info->name));
557         strlcpy(info->longname, card->longname, sizeof(info->longname));
558         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
559         strlcpy(info->components, card->components, sizeof(info->components));
560         up_read(&snd_ioctl_rwsem);
561         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
562                 kfree(info);
563                 return -EFAULT;
564         }
565         kfree(info);
566         return 0;
567 }
568
569 static int snd_ctl_elem_list(struct snd_card *card,
570                              struct snd_ctl_elem_list __user *_list)
571 {
572         struct list_head *plist;
573         struct snd_ctl_elem_list list;
574         struct snd_kcontrol *kctl;
575         struct snd_ctl_elem_id *dst, *id;
576         unsigned int offset, space, first, jidx;
577         
578         if (copy_from_user(&list, _list, sizeof(list)))
579                 return -EFAULT;
580         offset = list.offset;
581         space = list.space;
582         first = 0;
583         /* try limit maximum space */
584         if (space > 16384)
585                 return -ENOMEM;
586         if (space > 0) {
587                 /* allocate temporary buffer for atomic operation */
588                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
589                 if (dst == NULL)
590                         return -ENOMEM;
591                 down_read(&card->controls_rwsem);
592                 list.count = card->controls_count;
593                 plist = card->controls.next;
594                 while (plist != &card->controls) {
595                         if (offset == 0)
596                                 break;
597                         kctl = snd_kcontrol(plist);
598                         if (offset < kctl->count)
599                                 break;
600                         offset -= kctl->count;
601                         plist = plist->next;
602                 }
603                 list.used = 0;
604                 id = dst;
605                 while (space > 0 && plist != &card->controls) {
606                         kctl = snd_kcontrol(plist);
607                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
608                                 snd_ctl_build_ioff(id, kctl, jidx);
609                                 id++;
610                                 space--;
611                                 list.used++;
612                         }
613                         plist = plist->next;
614                         offset = 0;
615                 }
616                 up_read(&card->controls_rwsem);
617                 if (list.used > 0 &&
618                     copy_to_user(list.pids, dst,
619                                  list.used * sizeof(struct snd_ctl_elem_id))) {
620                         vfree(dst);
621                         return -EFAULT;
622                 }
623                 vfree(dst);
624         } else {
625                 down_read(&card->controls_rwsem);
626                 list.count = card->controls_count;
627                 up_read(&card->controls_rwsem);
628         }
629         if (copy_to_user(_list, &list, sizeof(list)))
630                 return -EFAULT;
631         return 0;
632 }
633
634 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
635                              struct snd_ctl_elem_info *info)
636 {
637         struct snd_card *card = ctl->card;
638         struct snd_kcontrol *kctl;
639         struct snd_kcontrol_volatile *vd;
640         unsigned int index_offset;
641         int result;
642         
643         down_read(&card->controls_rwsem);
644         kctl = snd_ctl_find_id(card, &info->id);
645         if (kctl == NULL) {
646                 up_read(&card->controls_rwsem);
647                 return -ENOENT;
648         }
649 #ifdef CONFIG_SND_DEBUG
650         info->access = 0;
651 #endif
652         result = kctl->info(kctl, info);
653         if (result >= 0) {
654                 snd_BUG_ON(info->access);
655                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
656                 vd = &kctl->vd[index_offset];
657                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
658                 info->access = vd->access;
659                 if (vd->owner) {
660                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
661                         if (vd->owner == ctl)
662                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
663                         info->owner = vd->owner_pid;
664                 } else {
665                         info->owner = -1;
666                 }
667         }
668         up_read(&card->controls_rwsem);
669         return result;
670 }
671
672 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
673                                   struct snd_ctl_elem_info __user *_info)
674 {
675         struct snd_ctl_elem_info info;
676         int result;
677
678         if (copy_from_user(&info, _info, sizeof(info)))
679                 return -EFAULT;
680         snd_power_lock(ctl->card);
681         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
682         if (result >= 0)
683                 result = snd_ctl_elem_info(ctl, &info);
684         snd_power_unlock(ctl->card);
685         if (result >= 0)
686                 if (copy_to_user(_info, &info, sizeof(info)))
687                         return -EFAULT;
688         return result;
689 }
690
691 static int snd_ctl_elem_read(struct snd_card *card,
692                              struct snd_ctl_elem_value *control)
693 {
694         struct snd_kcontrol *kctl;
695         struct snd_kcontrol_volatile *vd;
696         unsigned int index_offset;
697         int result;
698
699         down_read(&card->controls_rwsem);
700         kctl = snd_ctl_find_id(card, &control->id);
701         if (kctl == NULL) {
702                 result = -ENOENT;
703         } else {
704                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
705                 vd = &kctl->vd[index_offset];
706                 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
707                     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         up_read(&card->controls_rwsem);
714         return result;
715 }
716
717 static int snd_ctl_elem_read_user(struct snd_card *card,
718                                   struct snd_ctl_elem_value __user *_control)
719 {
720         struct snd_ctl_elem_value *control;
721         int result;
722         
723         control = kmalloc(sizeof(*control), GFP_KERNEL);
724         if (control == NULL)
725                 return -ENOMEM; 
726         if (copy_from_user(control, _control, sizeof(*control))) {
727                 kfree(control);
728                 return -EFAULT;
729         }
730         snd_power_lock(card);
731         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
732         if (result >= 0)
733                 result = snd_ctl_elem_read(card, control);
734         snd_power_unlock(card);
735         if (result >= 0)
736                 if (copy_to_user(_control, control, sizeof(*control)))
737                         result = -EFAULT;
738         kfree(control);
739         return result;
740 }
741
742 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
743                               struct snd_ctl_elem_value *control)
744 {
745         struct snd_kcontrol *kctl;
746         struct snd_kcontrol_volatile *vd;
747         unsigned int index_offset;
748         int result;
749
750         down_read(&card->controls_rwsem);
751         kctl = snd_ctl_find_id(card, &control->id);
752         if (kctl == NULL) {
753                 result = -ENOENT;
754         } else {
755                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
756                 vd = &kctl->vd[index_offset];
757                 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
758                     kctl->put == NULL ||
759                     (file && vd->owner && vd->owner != file)) {
760                         result = -EPERM;
761                 } else {
762                         snd_ctl_build_ioff(&control->id, kctl, index_offset);
763                         result = kctl->put(kctl, control);
764                 }
765                 if (result > 0) {
766                         up_read(&card->controls_rwsem);
767                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
768                                        &control->id);
769                         return 0;
770                 }
771         }
772         up_read(&card->controls_rwsem);
773         return result;
774 }
775
776 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
777                                    struct snd_ctl_elem_value __user *_control)
778 {
779         struct snd_ctl_elem_value *control;
780         struct snd_card *card;
781         int result;
782
783         control = kmalloc(sizeof(*control), GFP_KERNEL);
784         if (control == NULL)
785                 return -ENOMEM; 
786         if (copy_from_user(control, _control, sizeof(*control))) {
787                 kfree(control);
788                 return -EFAULT;
789         }
790         card = file->card;
791         snd_power_lock(card);
792         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
793         if (result >= 0)
794                 result = snd_ctl_elem_write(card, file, control);
795         snd_power_unlock(card);
796         if (result >= 0)
797                 if (copy_to_user(_control, control, sizeof(*control)))
798                         result = -EFAULT;
799         kfree(control);
800         return result;
801 }
802
803 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
804                              struct snd_ctl_elem_id __user *_id)
805 {
806         struct snd_card *card = file->card;
807         struct snd_ctl_elem_id id;
808         struct snd_kcontrol *kctl;
809         struct snd_kcontrol_volatile *vd;
810         int result;
811         
812         if (copy_from_user(&id, _id, sizeof(id)))
813                 return -EFAULT;
814         down_write(&card->controls_rwsem);
815         kctl = snd_ctl_find_id(card, &id);
816         if (kctl == NULL) {
817                 result = -ENOENT;
818         } else {
819                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
820                 if (vd->owner != NULL)
821                         result = -EBUSY;
822                 else {
823                         vd->owner = file;
824                         vd->owner_pid = current->pid;
825                         result = 0;
826                 }
827         }
828         up_write(&card->controls_rwsem);
829         return result;
830 }
831
832 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
833                                struct snd_ctl_elem_id __user *_id)
834 {
835         struct snd_card *card = file->card;
836         struct snd_ctl_elem_id id;
837         struct snd_kcontrol *kctl;
838         struct snd_kcontrol_volatile *vd;
839         int result;
840         
841         if (copy_from_user(&id, _id, sizeof(id)))
842                 return -EFAULT;
843         down_write(&card->controls_rwsem);
844         kctl = snd_ctl_find_id(card, &id);
845         if (kctl == NULL) {
846                 result = -ENOENT;
847         } else {
848                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
849                 if (vd->owner == NULL)
850                         result = -EINVAL;
851                 else if (vd->owner != file)
852                         result = -EPERM;
853                 else {
854                         vd->owner = NULL;
855                         vd->owner_pid = 0;
856                         result = 0;
857                 }
858         }
859         up_write(&card->controls_rwsem);
860         return result;
861 }
862
863 struct user_element {
864         struct snd_ctl_elem_info info;
865         void *elem_data;                /* element data */
866         unsigned long elem_data_size;   /* size of element data in bytes */
867         void *tlv_data;                 /* TLV data */
868         unsigned long tlv_data_size;    /* TLV data size */
869         void *priv_data;                /* private data (like strings for enumerated type) */
870         unsigned long priv_data_size;   /* size of private data in bytes */
871 };
872
873 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
874                                   struct snd_ctl_elem_info *uinfo)
875 {
876         struct user_element *ue = kcontrol->private_data;
877
878         *uinfo = ue->info;
879         return 0;
880 }
881
882 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
883                                  struct snd_ctl_elem_value *ucontrol)
884 {
885         struct user_element *ue = kcontrol->private_data;
886
887         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
888         return 0;
889 }
890
891 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
892                                  struct snd_ctl_elem_value *ucontrol)
893 {
894         int change;
895         struct user_element *ue = kcontrol->private_data;
896         
897         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
898         if (change)
899                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
900         return change;
901 }
902
903 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
904                                  int op_flag,
905                                  unsigned int size,
906                                  unsigned int __user *tlv)
907 {
908         struct user_element *ue = kcontrol->private_data;
909         int change = 0;
910         void *new_data;
911
912         if (op_flag > 0) {
913                 if (size > 1024 * 128)  /* sane value */
914                         return -EINVAL;
915                 new_data = kmalloc(size, GFP_KERNEL);
916                 if (new_data == NULL)
917                         return -ENOMEM;
918                 if (copy_from_user(new_data, tlv, size)) {
919                         kfree(new_data);
920                         return -EFAULT;
921                 }
922                 change = ue->tlv_data_size != size;
923                 if (!change)
924                         change = memcmp(ue->tlv_data, new_data, size);
925                 kfree(ue->tlv_data);
926                 ue->tlv_data = new_data;
927                 ue->tlv_data_size = size;
928         } else {
929                 if (! ue->tlv_data_size || ! ue->tlv_data)
930                         return -ENXIO;
931                 if (size < ue->tlv_data_size)
932                         return -ENOSPC;
933                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
934                         return -EFAULT;
935         }
936         return change;
937 }
938
939 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
940 {
941         struct user_element *ue = kcontrol->private_data;
942         if (ue->tlv_data)
943                 kfree(ue->tlv_data);
944         kfree(ue);
945 }
946
947 static int snd_ctl_elem_add(struct snd_ctl_file *file,
948                             struct snd_ctl_elem_info *info, int replace)
949 {
950         struct snd_card *card = file->card;
951         struct snd_kcontrol kctl, *_kctl;
952         unsigned int access;
953         long private_size;
954         struct user_element *ue;
955         int idx, err;
956         
957         if (card->user_ctl_count >= MAX_USER_CONTROLS)
958                 return -ENOMEM;
959         if (info->count > 1024)
960                 return -EINVAL;
961         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
962                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
963                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
964                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
965         info->id.numid = 0;
966         memset(&kctl, 0, sizeof(kctl));
967         down_write(&card->controls_rwsem);
968         _kctl = snd_ctl_find_id(card, &info->id);
969         err = 0;
970         if (_kctl) {
971                 if (replace)
972                         err = snd_ctl_remove(card, _kctl);
973                 else
974                         err = -EBUSY;
975         } else {
976                 if (replace)
977                         err = -ENOENT;
978         }
979         up_write(&card->controls_rwsem);
980         if (err < 0)
981                 return err;
982         memcpy(&kctl.id, &info->id, sizeof(info->id));
983         kctl.count = info->owner ? info->owner : 1;
984         access |= SNDRV_CTL_ELEM_ACCESS_USER;
985         kctl.info = snd_ctl_elem_user_info;
986         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
987                 kctl.get = snd_ctl_elem_user_get;
988         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
989                 kctl.put = snd_ctl_elem_user_put;
990         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
991                 kctl.tlv.c = snd_ctl_elem_user_tlv;
992                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
993         }
994         switch (info->type) {
995         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
996         case SNDRV_CTL_ELEM_TYPE_INTEGER:
997                 private_size = sizeof(long);
998                 if (info->count > 128)
999                         return -EINVAL;
1000                 break;
1001         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1002                 private_size = sizeof(long long);
1003                 if (info->count > 64)
1004                         return -EINVAL;
1005                 break;
1006         case SNDRV_CTL_ELEM_TYPE_BYTES:
1007                 private_size = sizeof(unsigned char);
1008                 if (info->count > 512)
1009                         return -EINVAL;
1010                 break;
1011         case SNDRV_CTL_ELEM_TYPE_IEC958:
1012                 private_size = sizeof(struct snd_aes_iec958);
1013                 if (info->count != 1)
1014                         return -EINVAL;
1015                 break;
1016         default:
1017                 return -EINVAL;
1018         }
1019         private_size *= info->count;
1020         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1021         if (ue == NULL)
1022                 return -ENOMEM;
1023         ue->info = *info;
1024         ue->info.access = 0;
1025         ue->elem_data = (char *)ue + sizeof(*ue);
1026         ue->elem_data_size = private_size;
1027         kctl.private_free = snd_ctl_elem_user_free;
1028         _kctl = snd_ctl_new(&kctl, access);
1029         if (_kctl == NULL) {
1030                 kfree(ue);
1031                 return -ENOMEM;
1032         }
1033         _kctl->private_data = ue;
1034         for (idx = 0; idx < _kctl->count; idx++)
1035                 _kctl->vd[idx].owner = file;
1036         err = snd_ctl_add(card, _kctl);
1037         if (err < 0)
1038                 return err;
1039
1040         down_write(&card->controls_rwsem);
1041         card->user_ctl_count++;
1042         up_write(&card->controls_rwsem);
1043
1044         return 0;
1045 }
1046
1047 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1048                                  struct snd_ctl_elem_info __user *_info, int replace)
1049 {
1050         struct snd_ctl_elem_info info;
1051         if (copy_from_user(&info, _info, sizeof(info)))
1052                 return -EFAULT;
1053         return snd_ctl_elem_add(file, &info, replace);
1054 }
1055
1056 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1057                                struct snd_ctl_elem_id __user *_id)
1058 {
1059         struct snd_ctl_elem_id id;
1060         int err;
1061
1062         if (copy_from_user(&id, _id, sizeof(id)))
1063                 return -EFAULT;
1064         err = snd_ctl_remove_unlocked_id(file, &id);
1065         if (! err) {
1066                 struct snd_card *card = file->card;
1067                 down_write(&card->controls_rwsem);
1068                 card->user_ctl_count--;
1069                 up_write(&card->controls_rwsem);
1070         }
1071         return err;
1072 }
1073
1074 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1075 {
1076         int subscribe;
1077         if (get_user(subscribe, ptr))
1078                 return -EFAULT;
1079         if (subscribe < 0) {
1080                 subscribe = file->subscribed;
1081                 if (put_user(subscribe, ptr))
1082                         return -EFAULT;
1083                 return 0;
1084         }
1085         if (subscribe) {
1086                 file->subscribed = 1;
1087                 return 0;
1088         } else if (file->subscribed) {
1089                 snd_ctl_empty_read_queue(file);
1090                 file->subscribed = 0;
1091         }
1092         return 0;
1093 }
1094
1095 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1096                              struct snd_ctl_tlv __user *_tlv,
1097                              int op_flag)
1098 {
1099         struct snd_card *card = file->card;
1100         struct snd_ctl_tlv tlv;
1101         struct snd_kcontrol *kctl;
1102         struct snd_kcontrol_volatile *vd;
1103         unsigned int len;
1104         int err = 0;
1105
1106         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1107                 return -EFAULT;
1108         if (tlv.length < sizeof(unsigned int) * 3)
1109                 return -EINVAL;
1110         down_read(&card->controls_rwsem);
1111         kctl = snd_ctl_find_numid(card, tlv.numid);
1112         if (kctl == NULL) {
1113                 err = -ENOENT;
1114                 goto __kctl_end;
1115         }
1116         if (kctl->tlv.p == NULL) {
1117                 err = -ENXIO;
1118                 goto __kctl_end;
1119         }
1120         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1121         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1122             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1123             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1124                 err = -ENXIO;
1125                 goto __kctl_end;
1126         }
1127         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1128                 if (file && vd->owner != NULL && vd->owner != file) {
1129                         err = -EPERM;
1130                         goto __kctl_end;
1131                 }
1132                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1133                 if (err > 0) {
1134                         up_read(&card->controls_rwsem);
1135                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1136                         return 0;
1137                 }
1138         } else {
1139                 if (op_flag) {
1140                         err = -ENXIO;
1141                         goto __kctl_end;
1142                 }
1143                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1144                 if (tlv.length < len) {
1145                         err = -ENOMEM;
1146                         goto __kctl_end;
1147                 }
1148                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1149                         err = -EFAULT;
1150         }
1151       __kctl_end:
1152         up_read(&card->controls_rwsem);
1153         return err;
1154 }
1155
1156 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1157 {
1158         struct snd_ctl_file *ctl;
1159         struct snd_card *card;
1160         struct snd_kctl_ioctl *p;
1161         void __user *argp = (void __user *)arg;
1162         int __user *ip = argp;
1163         int err;
1164
1165         ctl = file->private_data;
1166         card = ctl->card;
1167         if (snd_BUG_ON(!card))
1168                 return -ENXIO;
1169         switch (cmd) {
1170         case SNDRV_CTL_IOCTL_PVERSION:
1171                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1172         case SNDRV_CTL_IOCTL_CARD_INFO:
1173                 return snd_ctl_card_info(card, ctl, cmd, argp);
1174         case SNDRV_CTL_IOCTL_ELEM_LIST:
1175                 return snd_ctl_elem_list(card, argp);
1176         case SNDRV_CTL_IOCTL_ELEM_INFO:
1177                 return snd_ctl_elem_info_user(ctl, argp);
1178         case SNDRV_CTL_IOCTL_ELEM_READ:
1179                 return snd_ctl_elem_read_user(card, argp);
1180         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1181                 return snd_ctl_elem_write_user(ctl, argp);
1182         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1183                 return snd_ctl_elem_lock(ctl, argp);
1184         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1185                 return snd_ctl_elem_unlock(ctl, argp);
1186         case SNDRV_CTL_IOCTL_ELEM_ADD:
1187                 return snd_ctl_elem_add_user(ctl, argp, 0);
1188         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1189                 return snd_ctl_elem_add_user(ctl, argp, 1);
1190         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1191                 return snd_ctl_elem_remove(ctl, argp);
1192         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1193                 return snd_ctl_subscribe_events(ctl, ip);
1194         case SNDRV_CTL_IOCTL_TLV_READ:
1195                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1196         case SNDRV_CTL_IOCTL_TLV_WRITE:
1197                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1198         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1199                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1200         case SNDRV_CTL_IOCTL_POWER:
1201                 return -ENOPROTOOPT;
1202         case SNDRV_CTL_IOCTL_POWER_STATE:
1203 #ifdef CONFIG_PM
1204                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1205 #else
1206                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1207 #endif
1208         }
1209         down_read(&snd_ioctl_rwsem);
1210         list_for_each_entry(p, &snd_control_ioctls, list) {
1211                 err = p->fioctl(card, ctl, cmd, arg);
1212                 if (err != -ENOIOCTLCMD) {
1213                         up_read(&snd_ioctl_rwsem);
1214                         return err;
1215                 }
1216         }
1217         up_read(&snd_ioctl_rwsem);
1218         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1219         return -ENOTTY;
1220 }
1221
1222 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1223                             size_t count, loff_t * offset)
1224 {
1225         struct snd_ctl_file *ctl;
1226         int err = 0;
1227         ssize_t result = 0;
1228
1229         ctl = file->private_data;
1230         if (snd_BUG_ON(!ctl || !ctl->card))
1231                 return -ENXIO;
1232         if (!ctl->subscribed)
1233                 return -EBADFD;
1234         if (count < sizeof(struct snd_ctl_event))
1235                 return -EINVAL;
1236         spin_lock_irq(&ctl->read_lock);
1237         while (count >= sizeof(struct snd_ctl_event)) {
1238                 struct snd_ctl_event ev;
1239                 struct snd_kctl_event *kev;
1240                 while (list_empty(&ctl->events)) {
1241                         wait_queue_t wait;
1242                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1243                                 err = -EAGAIN;
1244                                 goto __end_lock;
1245                         }
1246                         init_waitqueue_entry(&wait, current);
1247                         add_wait_queue(&ctl->change_sleep, &wait);
1248                         set_current_state(TASK_INTERRUPTIBLE);
1249                         spin_unlock_irq(&ctl->read_lock);
1250                         schedule();
1251                         remove_wait_queue(&ctl->change_sleep, &wait);
1252                         if (signal_pending(current))
1253                                 return -ERESTARTSYS;
1254                         spin_lock_irq(&ctl->read_lock);
1255                 }
1256                 kev = snd_kctl_event(ctl->events.next);
1257                 ev.type = SNDRV_CTL_EVENT_ELEM;
1258                 ev.data.elem.mask = kev->mask;
1259                 ev.data.elem.id = kev->id;
1260                 list_del(&kev->list);
1261                 spin_unlock_irq(&ctl->read_lock);
1262                 kfree(kev);
1263                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1264                         err = -EFAULT;
1265                         goto __end;
1266                 }
1267                 spin_lock_irq(&ctl->read_lock);
1268                 buffer += sizeof(struct snd_ctl_event);
1269                 count -= sizeof(struct snd_ctl_event);
1270                 result += sizeof(struct snd_ctl_event);
1271         }
1272       __end_lock:
1273         spin_unlock_irq(&ctl->read_lock);
1274       __end:
1275         return result > 0 ? result : err;
1276 }
1277
1278 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1279 {
1280         unsigned int mask;
1281         struct snd_ctl_file *ctl;
1282
1283         ctl = file->private_data;
1284         if (!ctl->subscribed)
1285                 return 0;
1286         poll_wait(file, &ctl->change_sleep, wait);
1287
1288         mask = 0;
1289         if (!list_empty(&ctl->events))
1290                 mask |= POLLIN | POLLRDNORM;
1291
1292         return mask;
1293 }
1294
1295 /*
1296  * register the device-specific control-ioctls.
1297  * called from each device manager like pcm.c, hwdep.c, etc.
1298  */
1299 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1300 {
1301         struct snd_kctl_ioctl *pn;
1302
1303         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1304         if (pn == NULL)
1305                 return -ENOMEM;
1306         pn->fioctl = fcn;
1307         down_write(&snd_ioctl_rwsem);
1308         list_add_tail(&pn->list, lists);
1309         up_write(&snd_ioctl_rwsem);
1310         return 0;
1311 }
1312
1313 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1314 {
1315         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1316 }
1317
1318 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1319
1320 #ifdef CONFIG_COMPAT
1321 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1322 {
1323         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1324 }
1325
1326 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1327 #endif
1328
1329 /*
1330  * de-register the device-specific control-ioctls.
1331  */
1332 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1333                                      struct list_head *lists)
1334 {
1335         struct snd_kctl_ioctl *p;
1336
1337         if (snd_BUG_ON(!fcn))
1338                 return -EINVAL;
1339         down_write(&snd_ioctl_rwsem);
1340         list_for_each_entry(p, lists, list) {
1341                 if (p->fioctl == fcn) {
1342                         list_del(&p->list);
1343                         up_write(&snd_ioctl_rwsem);
1344                         kfree(p);
1345                         return 0;
1346                 }
1347         }
1348         up_write(&snd_ioctl_rwsem);
1349         snd_BUG();
1350         return -EINVAL;
1351 }
1352
1353 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1354 {
1355         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1356 }
1357
1358 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1359
1360 #ifdef CONFIG_COMPAT
1361 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1362 {
1363         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1364 }
1365
1366 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1367 #endif
1368
1369 static int snd_ctl_fasync(int fd, struct file * file, int on)
1370 {
1371         struct snd_ctl_file *ctl;
1372         int err;
1373         ctl = file->private_data;
1374         err = fasync_helper(fd, file, on, &ctl->fasync);
1375         if (err < 0)
1376                 return err;
1377         return 0;
1378 }
1379
1380 /*
1381  * ioctl32 compat
1382  */
1383 #ifdef CONFIG_COMPAT
1384 #include "control_compat.c"
1385 #else
1386 #define snd_ctl_ioctl_compat    NULL
1387 #endif
1388
1389 /*
1390  *  INIT PART
1391  */
1392
1393 static const struct file_operations snd_ctl_f_ops =
1394 {
1395         .owner =        THIS_MODULE,
1396         .read =         snd_ctl_read,
1397         .open =         snd_ctl_open,
1398         .release =      snd_ctl_release,
1399         .poll =         snd_ctl_poll,
1400         .unlocked_ioctl =       snd_ctl_ioctl,
1401         .compat_ioctl = snd_ctl_ioctl_compat,
1402         .fasync =       snd_ctl_fasync,
1403 };
1404
1405 /*
1406  * registration of the control device
1407  */
1408 static int snd_ctl_dev_register(struct snd_device *device)
1409 {
1410         struct snd_card *card = device->device_data;
1411         int err, cardnum;
1412         char name[16];
1413
1414         if (snd_BUG_ON(!card))
1415                 return -ENXIO;
1416         cardnum = card->number;
1417         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1418                 return -ENXIO;
1419         sprintf(name, "controlC%i", cardnum);
1420         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1421                                        &snd_ctl_f_ops, card, name)) < 0)
1422                 return err;
1423         return 0;
1424 }
1425
1426 /*
1427  * disconnection of the control device
1428  */
1429 static int snd_ctl_dev_disconnect(struct snd_device *device)
1430 {
1431         struct snd_card *card = device->device_data;
1432         struct snd_ctl_file *ctl;
1433         int err, cardnum;
1434
1435         if (snd_BUG_ON(!card))
1436                 return -ENXIO;
1437         cardnum = card->number;
1438         if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1439                 return -ENXIO;
1440
1441         read_lock(&card->ctl_files_rwlock);
1442         list_for_each_entry(ctl, &card->ctl_files, list) {
1443                 wake_up(&ctl->change_sleep);
1444                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1445         }
1446         read_unlock(&card->ctl_files_rwlock);
1447
1448         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1449                                          card, -1)) < 0)
1450                 return err;
1451         return 0;
1452 }
1453
1454 /*
1455  * free all controls
1456  */
1457 static int snd_ctl_dev_free(struct snd_device *device)
1458 {
1459         struct snd_card *card = device->device_data;
1460         struct snd_kcontrol *control;
1461
1462         down_write(&card->controls_rwsem);
1463         while (!list_empty(&card->controls)) {
1464                 control = snd_kcontrol(card->controls.next);
1465                 snd_ctl_remove(card, control);
1466         }
1467         up_write(&card->controls_rwsem);
1468         return 0;
1469 }
1470
1471 /*
1472  * create control core:
1473  * called from init.c
1474  */
1475 int snd_ctl_create(struct snd_card *card)
1476 {
1477         static struct snd_device_ops ops = {
1478                 .dev_free = snd_ctl_dev_free,
1479                 .dev_register = snd_ctl_dev_register,
1480                 .dev_disconnect = snd_ctl_dev_disconnect,
1481         };
1482
1483         if (snd_BUG_ON(!card))
1484                 return -ENXIO;
1485         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1486 }
1487
1488 /*
1489  * Frequently used control callbacks
1490  */
1491 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1492                               struct snd_ctl_elem_info *uinfo)
1493 {
1494         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1495         uinfo->count = 1;
1496         uinfo->value.integer.min = 0;
1497         uinfo->value.integer.max = 1;
1498         return 0;
1499 }
1500
1501 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1502
1503 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1504                                 struct snd_ctl_elem_info *uinfo)
1505 {
1506         uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1507         uinfo->count = 2;
1508         uinfo->value.integer.min = 0;
1509         uinfo->value.integer.max = 1;
1510         return 0;
1511 }
1512
1513 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);