[ALSA] make sound/core/control.c:snd_ctl_new() static
[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/smp_lock.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/time.h>
29 #include <sound/core.h>
30 #include <sound/minors.h>
31 #include <sound/info.h>
32 #include <sound/control.h>
33
34 /* max number of user-defined controls */
35 #define MAX_USER_CONTROLS       32
36
37 struct snd_kctl_ioctl {
38         struct list_head list;          /* list of all ioctls */
39         snd_kctl_ioctl_func_t fioctl;
40 };
41
42 static DECLARE_RWSEM(snd_ioctl_rwsem);
43 static LIST_HEAD(snd_control_ioctls);
44 #ifdef CONFIG_COMPAT
45 static LIST_HEAD(snd_control_compat_ioctls);
46 #endif
47
48 static int snd_ctl_open(struct inode *inode, struct file *file)
49 {
50         unsigned long flags;
51         struct snd_card *card;
52         struct snd_ctl_file *ctl;
53         int err;
54
55         card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
56         if (!card) {
57                 err = -ENODEV;
58                 goto __error1;
59         }
60         err = snd_card_file_add(card, file);
61         if (err < 0) {
62                 err = -ENODEV;
63                 goto __error1;
64         }
65         if (!try_module_get(card->module)) {
66                 err = -EFAULT;
67                 goto __error2;
68         }
69         ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
70         if (ctl == NULL) {
71                 err = -ENOMEM;
72                 goto __error;
73         }
74         INIT_LIST_HEAD(&ctl->events);
75         init_waitqueue_head(&ctl->change_sleep);
76         spin_lock_init(&ctl->read_lock);
77         ctl->card = card;
78         ctl->prefer_pcm_subdevice = -1;
79         ctl->prefer_rawmidi_subdevice = -1;
80         ctl->pid = current->pid;
81         file->private_data = ctl;
82         write_lock_irqsave(&card->ctl_files_rwlock, flags);
83         list_add_tail(&ctl->list, &card->ctl_files);
84         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
85         return 0;
86
87       __error:
88         module_put(card->module);
89       __error2:
90         snd_card_file_remove(card, file);
91       __error1:
92         return err;
93 }
94
95 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
96 {
97         struct snd_kctl_event *cread;
98         
99         spin_lock(&ctl->read_lock);
100         while (!list_empty(&ctl->events)) {
101                 cread = snd_kctl_event(ctl->events.next);
102                 list_del(&cread->list);
103                 kfree(cread);
104         }
105         spin_unlock(&ctl->read_lock);
106 }
107
108 static int snd_ctl_release(struct inode *inode, struct file *file)
109 {
110         unsigned long flags;
111         struct snd_card *card;
112         struct snd_ctl_file *ctl;
113         struct snd_kcontrol *control;
114         unsigned int idx;
115
116         ctl = file->private_data;
117         fasync_helper(-1, file, 0, &ctl->fasync);
118         file->private_data = NULL;
119         card = ctl->card;
120         write_lock_irqsave(&card->ctl_files_rwlock, flags);
121         list_del(&ctl->list);
122         write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
123         down_write(&card->controls_rwsem);
124         list_for_each_entry(control, &card->controls, list)
125                 for (idx = 0; idx < control->count; idx++)
126                         if (control->vd[idx].owner == ctl)
127                                 control->vd[idx].owner = NULL;
128         up_write(&card->controls_rwsem);
129         snd_ctl_empty_read_queue(ctl);
130         kfree(ctl);
131         module_put(card->module);
132         snd_card_file_remove(card, file);
133         return 0;
134 }
135
136 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
137                     struct snd_ctl_elem_id *id)
138 {
139         unsigned long flags;
140         struct snd_ctl_file *ctl;
141         struct snd_kctl_event *ev;
142         
143         snd_assert(card != NULL && id != NULL, 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         snd_assert(control != NULL, return NULL);
193         snd_assert(control->count > 0, 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         snd_assert(ncontrol != NULL, return NULL);
223         snd_assert(ncontrol->info != NULL, 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_DINDIRECT|
236                                       SNDRV_CTL_ELEM_ACCESS_INDIRECT|
237                                       SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
238                                       SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
239         kctl.info = ncontrol->info;
240         kctl.get = ncontrol->get;
241         kctl.put = ncontrol->put;
242         kctl.tlv.p = ncontrol->tlv.p;
243         kctl.private_value = ncontrol->private_value;
244         kctl.private_data = private_data;
245         return snd_ctl_new(&kctl, access);
246 }
247
248 EXPORT_SYMBOL(snd_ctl_new1);
249
250 /**
251  * snd_ctl_free_one - release the control instance
252  * @kcontrol: the control instance
253  *
254  * Releases the control instance created via snd_ctl_new()
255  * or snd_ctl_new1().
256  * Don't call this after the control was added to the card.
257  */
258 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
259 {
260         if (kcontrol) {
261                 if (kcontrol->private_free)
262                         kcontrol->private_free(kcontrol);
263                 kfree(kcontrol);
264         }
265 }
266
267 EXPORT_SYMBOL(snd_ctl_free_one);
268
269 static unsigned int snd_ctl_hole_check(struct snd_card *card,
270                                        unsigned int count)
271 {
272         struct snd_kcontrol *kctl;
273
274         list_for_each_entry(kctl, &card->controls, list) {
275                 if ((kctl->id.numid <= card->last_numid &&
276                      kctl->id.numid + kctl->count > card->last_numid) ||
277                     (kctl->id.numid <= card->last_numid + count - 1 &&
278                      kctl->id.numid + kctl->count > card->last_numid + count - 1))
279                         return card->last_numid = kctl->id.numid + kctl->count - 1;
280         }
281         return card->last_numid;
282 }
283
284 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
285 {
286         unsigned int last_numid, iter = 100000;
287
288         last_numid = card->last_numid;
289         while (last_numid != snd_ctl_hole_check(card, count)) {
290                 if (--iter == 0) {
291                         /* this situation is very unlikely */
292                         snd_printk(KERN_ERR "unable to allocate new control numid\n");
293                         return -ENOMEM;
294                 }
295                 last_numid = card->last_numid;
296         }
297         return 0;
298 }
299
300 /**
301  * snd_ctl_add - add the control instance to the card
302  * @card: the card instance
303  * @kcontrol: the control instance to add
304  *
305  * Adds the control instance created via snd_ctl_new() or
306  * snd_ctl_new1() to the given card. Assigns also an unique
307  * numid used for fast search.
308  *
309  * Returns zero if successful, or a negative error code on failure.
310  *
311  * It frees automatically the control which cannot be added.
312  */
313 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
314 {
315         struct snd_ctl_elem_id id;
316         unsigned int idx;
317         int err = -EINVAL;
318
319         if (! kcontrol)
320                 return err;
321         snd_assert(card != NULL, goto error);
322         snd_assert(kcontrol->info != NULL, goto error);
323         id = kcontrol->id;
324         down_write(&card->controls_rwsem);
325         if (snd_ctl_find_id(card, &id)) {
326                 up_write(&card->controls_rwsem);
327                 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
328                                         id.iface,
329                                         id.device,
330                                         id.subdevice,
331                                         id.name,
332                                         id.index);
333                 err = -EBUSY;
334                 goto error;
335         }
336         if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
337                 up_write(&card->controls_rwsem);
338                 err = -ENOMEM;
339                 goto error;
340         }
341         list_add_tail(&kcontrol->list, &card->controls);
342         card->controls_count += kcontrol->count;
343         kcontrol->id.numid = card->last_numid + 1;
344         card->last_numid += kcontrol->count;
345         up_write(&card->controls_rwsem);
346         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
347                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
348         return 0;
349
350  error:
351         snd_ctl_free_one(kcontrol);
352         return err;
353 }
354
355 EXPORT_SYMBOL(snd_ctl_add);
356
357 /**
358  * snd_ctl_remove - remove the control from the card and release it
359  * @card: the card instance
360  * @kcontrol: the control instance to remove
361  *
362  * Removes the control from the card and then releases the instance.
363  * You don't need to call snd_ctl_free_one(). You must be in
364  * the write lock - down_write(&card->controls_rwsem).
365  * 
366  * Returns 0 if successful, or a negative error code on failure.
367  */
368 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
369 {
370         struct snd_ctl_elem_id id;
371         unsigned int idx;
372
373         snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
374         list_del(&kcontrol->list);
375         card->controls_count -= kcontrol->count;
376         id = kcontrol->id;
377         for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
378                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
379         snd_ctl_free_one(kcontrol);
380         return 0;
381 }
382
383 EXPORT_SYMBOL(snd_ctl_remove);
384
385 /**
386  * snd_ctl_remove_id - remove the control of the given id and release it
387  * @card: the card instance
388  * @id: the control id to remove
389  *
390  * Finds the control instance with the given id, removes it from the
391  * card list and releases it.
392  * 
393  * Returns 0 if successful, or a negative error code on failure.
394  */
395 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
396 {
397         struct snd_kcontrol *kctl;
398         int ret;
399
400         down_write(&card->controls_rwsem);
401         kctl = snd_ctl_find_id(card, id);
402         if (kctl == NULL) {
403                 up_write(&card->controls_rwsem);
404                 return -ENOENT;
405         }
406         ret = snd_ctl_remove(card, kctl);
407         up_write(&card->controls_rwsem);
408         return ret;
409 }
410
411 EXPORT_SYMBOL(snd_ctl_remove_id);
412
413 /**
414  * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
415  * @file: active control handle
416  * @id: the control id to remove
417  *
418  * Finds the control instance with the given id, removes it from the
419  * card list and releases it.
420  * 
421  * Returns 0 if successful, or a negative error code on failure.
422  */
423 static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
424                                       struct snd_ctl_elem_id *id)
425 {
426         struct snd_card *card = file->card;
427         struct snd_kcontrol *kctl;
428         int idx, ret;
429
430         down_write(&card->controls_rwsem);
431         kctl = snd_ctl_find_id(card, id);
432         if (kctl == NULL) {
433                 up_write(&card->controls_rwsem);
434                 return -ENOENT;
435         }
436         for (idx = 0; idx < kctl->count; idx++)
437                 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
438                         up_write(&card->controls_rwsem);
439                         return -EBUSY;
440                 }
441         ret = snd_ctl_remove(card, kctl);
442         up_write(&card->controls_rwsem);
443         return ret;
444 }
445
446 /**
447  * snd_ctl_rename_id - replace the id of a control on the card
448  * @card: the card instance
449  * @src_id: the old id
450  * @dst_id: the new id
451  *
452  * Finds the control with the old id from the card, and replaces the
453  * id with the new one.
454  *
455  * Returns zero if successful, or a negative error code on failure.
456  */
457 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
458                       struct snd_ctl_elem_id *dst_id)
459 {
460         struct snd_kcontrol *kctl;
461
462         down_write(&card->controls_rwsem);
463         kctl = snd_ctl_find_id(card, src_id);
464         if (kctl == NULL) {
465                 up_write(&card->controls_rwsem);
466                 return -ENOENT;
467         }
468         kctl->id = *dst_id;
469         kctl->id.numid = card->last_numid + 1;
470         card->last_numid += kctl->count;
471         up_write(&card->controls_rwsem);
472         return 0;
473 }
474
475 EXPORT_SYMBOL(snd_ctl_rename_id);
476
477 /**
478  * snd_ctl_find_numid - find the control instance with the given number-id
479  * @card: the card instance
480  * @numid: the number-id to search
481  *
482  * Finds the control instance with the given number-id from the card.
483  *
484  * Returns the pointer of the instance if found, or NULL if not.
485  *
486  * The caller must down card->controls_rwsem before calling this function
487  * (if the race condition can happen).
488  */
489 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
490 {
491         struct snd_kcontrol *kctl;
492
493         snd_assert(card != NULL && numid != 0, 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         snd_assert(card != NULL && id != NULL, return NULL);
521         if (id->numid != 0)
522                 return snd_ctl_find_numid(card, id->numid);
523         list_for_each_entry(kctl, &card->controls, list) {
524                 if (kctl->id.iface != id->iface)
525                         continue;
526                 if (kctl->id.device != id->device)
527                         continue;
528                 if (kctl->id.subdevice != id->subdevice)
529                         continue;
530                 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
531                         continue;
532                 if (kctl->id.index > id->index)
533                         continue;
534                 if (kctl->id.index + kctl->count <= id->index)
535                         continue;
536                 return kctl;
537         }
538         return NULL;
539 }
540
541 EXPORT_SYMBOL(snd_ctl_find_id);
542
543 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
544                              unsigned int cmd, void __user *arg)
545 {
546         struct snd_ctl_card_info *info;
547
548         info = kzalloc(sizeof(*info), GFP_KERNEL);
549         if (! info)
550                 return -ENOMEM;
551         down_read(&snd_ioctl_rwsem);
552         info->card = card->number;
553         strlcpy(info->id, card->id, sizeof(info->id));
554         strlcpy(info->driver, card->driver, sizeof(info->driver));
555         strlcpy(info->name, card->shortname, sizeof(info->name));
556         strlcpy(info->longname, card->longname, sizeof(info->longname));
557         strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
558         strlcpy(info->components, card->components, sizeof(info->components));
559         up_read(&snd_ioctl_rwsem);
560         if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
561                 kfree(info);
562                 return -EFAULT;
563         }
564         kfree(info);
565         return 0;
566 }
567
568 static int snd_ctl_elem_list(struct snd_card *card,
569                              struct snd_ctl_elem_list __user *_list)
570 {
571         struct list_head *plist;
572         struct snd_ctl_elem_list list;
573         struct snd_kcontrol *kctl;
574         struct snd_ctl_elem_id *dst, *id;
575         unsigned int offset, space, first, jidx;
576         
577         if (copy_from_user(&list, _list, sizeof(list)))
578                 return -EFAULT;
579         offset = list.offset;
580         space = list.space;
581         first = 0;
582         /* try limit maximum space */
583         if (space > 16384)
584                 return -ENOMEM;
585         if (space > 0) {
586                 /* allocate temporary buffer for atomic operation */
587                 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
588                 if (dst == NULL)
589                         return -ENOMEM;
590                 down_read(&card->controls_rwsem);
591                 list.count = card->controls_count;
592                 plist = card->controls.next;
593                 while (plist != &card->controls) {
594                         if (offset == 0)
595                                 break;
596                         kctl = snd_kcontrol(plist);
597                         if (offset < kctl->count)
598                                 break;
599                         offset -= kctl->count;
600                         plist = plist->next;
601                 }
602                 list.used = 0;
603                 id = dst;
604                 while (space > 0 && plist != &card->controls) {
605                         kctl = snd_kcontrol(plist);
606                         for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
607                                 snd_ctl_build_ioff(id, kctl, jidx);
608                                 id++;
609                                 space--;
610                                 list.used++;
611                         }
612                         plist = plist->next;
613                         offset = 0;
614                 }
615                 up_read(&card->controls_rwsem);
616                 if (list.used > 0 &&
617                     copy_to_user(list.pids, dst,
618                                  list.used * sizeof(struct snd_ctl_elem_id))) {
619                         vfree(dst);
620                         return -EFAULT;
621                 }
622                 vfree(dst);
623         } else {
624                 down_read(&card->controls_rwsem);
625                 list.count = card->controls_count;
626                 up_read(&card->controls_rwsem);
627         }
628         if (copy_to_user(_list, &list, sizeof(list)))
629                 return -EFAULT;
630         return 0;
631 }
632
633 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
634                              struct snd_ctl_elem_info *info)
635 {
636         struct snd_card *card = ctl->card;
637         struct snd_kcontrol *kctl;
638         struct snd_kcontrol_volatile *vd;
639         unsigned int index_offset;
640         int result;
641         
642         down_read(&card->controls_rwsem);
643         kctl = snd_ctl_find_id(card, &info->id);
644         if (kctl == NULL) {
645                 up_read(&card->controls_rwsem);
646                 return -ENOENT;
647         }
648 #ifdef CONFIG_SND_DEBUG
649         info->access = 0;
650 #endif
651         result = kctl->info(kctl, info);
652         if (result >= 0) {
653                 snd_assert(info->access == 0, );
654                 index_offset = snd_ctl_get_ioff(kctl, &info->id);
655                 vd = &kctl->vd[index_offset];
656                 snd_ctl_build_ioff(&info->id, kctl, index_offset);
657                 info->access = vd->access;
658                 if (vd->owner) {
659                         info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
660                         if (vd->owner == ctl)
661                                 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
662                         info->owner = vd->owner_pid;
663                 } else {
664                         info->owner = -1;
665                 }
666         }
667         up_read(&card->controls_rwsem);
668         return result;
669 }
670
671 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
672                                   struct snd_ctl_elem_info __user *_info)
673 {
674         struct snd_ctl_elem_info info;
675         int result;
676
677         if (copy_from_user(&info, _info, sizeof(info)))
678                 return -EFAULT;
679         snd_power_lock(ctl->card);
680         result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
681         if (result >= 0)
682                 result = snd_ctl_elem_info(ctl, &info);
683         snd_power_unlock(ctl->card);
684         if (result >= 0)
685                 if (copy_to_user(_info, &info, sizeof(info)))
686                         return -EFAULT;
687         return result;
688 }
689
690 int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
691 {
692         struct snd_kcontrol *kctl;
693         struct snd_kcontrol_volatile *vd;
694         unsigned int index_offset;
695         int result, indirect;
696
697         down_read(&card->controls_rwsem);
698         kctl = snd_ctl_find_id(card, &control->id);
699         if (kctl == NULL) {
700                 result = -ENOENT;
701         } else {
702                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
703                 vd = &kctl->vd[index_offset];
704                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
705                 if (control->indirect != indirect) {
706                         result = -EACCES;
707                 } else {
708                         if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
709                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
710                                 result = kctl->get(kctl, control);
711                         } else {
712                                 result = -EPERM;
713                         }
714                 }
715         }
716         up_read(&card->controls_rwsem);
717         return result;
718 }
719
720 EXPORT_SYMBOL(snd_ctl_elem_read);
721
722 static int snd_ctl_elem_read_user(struct snd_card *card,
723                                   struct snd_ctl_elem_value __user *_control)
724 {
725         struct snd_ctl_elem_value *control;
726         int result;
727         
728         control = kmalloc(sizeof(*control), GFP_KERNEL);
729         if (control == NULL)
730                 return -ENOMEM; 
731         if (copy_from_user(control, _control, sizeof(*control))) {
732                 kfree(control);
733                 return -EFAULT;
734         }
735         snd_power_lock(card);
736         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
737         if (result >= 0)
738                 result = snd_ctl_elem_read(card, control);
739         snd_power_unlock(card);
740         if (result >= 0)
741                 if (copy_to_user(_control, control, sizeof(*control)))
742                         result = -EFAULT;
743         kfree(control);
744         return result;
745 }
746
747 int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
748                        struct snd_ctl_elem_value *control)
749 {
750         struct snd_kcontrol *kctl;
751         struct snd_kcontrol_volatile *vd;
752         unsigned int index_offset;
753         int result, indirect;
754
755         down_read(&card->controls_rwsem);
756         kctl = snd_ctl_find_id(card, &control->id);
757         if (kctl == NULL) {
758                 result = -ENOENT;
759         } else {
760                 index_offset = snd_ctl_get_ioff(kctl, &control->id);
761                 vd = &kctl->vd[index_offset];
762                 indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
763                 if (control->indirect != indirect) {
764                         result = -EACCES;
765                 } else {
766                         if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
767                             kctl->put == NULL ||
768                             (file && vd->owner != NULL && vd->owner != file)) {
769                                 result = -EPERM;
770                         } else {
771                                 snd_ctl_build_ioff(&control->id, kctl, index_offset);
772                                 result = kctl->put(kctl, control);
773                         }
774                         if (result > 0) {
775                                 up_read(&card->controls_rwsem);
776                                 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
777                                 return 0;
778                         }
779                 }
780         }
781         up_read(&card->controls_rwsem);
782         return result;
783 }
784
785 EXPORT_SYMBOL(snd_ctl_elem_write);
786
787 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
788                                    struct snd_ctl_elem_value __user *_control)
789 {
790         struct snd_ctl_elem_value *control;
791         struct snd_card *card;
792         int result;
793
794         control = kmalloc(sizeof(*control), GFP_KERNEL);
795         if (control == NULL)
796                 return -ENOMEM; 
797         if (copy_from_user(control, _control, sizeof(*control))) {
798                 kfree(control);
799                 return -EFAULT;
800         }
801         card = file->card;
802         snd_power_lock(card);
803         result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
804         if (result >= 0)
805                 result = snd_ctl_elem_write(card, file, control);
806         snd_power_unlock(card);
807         if (result >= 0)
808                 if (copy_to_user(_control, control, sizeof(*control)))
809                         result = -EFAULT;
810         kfree(control);
811         return result;
812 }
813
814 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
815                              struct snd_ctl_elem_id __user *_id)
816 {
817         struct snd_card *card = file->card;
818         struct snd_ctl_elem_id id;
819         struct snd_kcontrol *kctl;
820         struct snd_kcontrol_volatile *vd;
821         int result;
822         
823         if (copy_from_user(&id, _id, sizeof(id)))
824                 return -EFAULT;
825         down_write(&card->controls_rwsem);
826         kctl = snd_ctl_find_id(card, &id);
827         if (kctl == NULL) {
828                 result = -ENOENT;
829         } else {
830                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
831                 if (vd->owner != NULL)
832                         result = -EBUSY;
833                 else {
834                         vd->owner = file;
835                         vd->owner_pid = current->pid;
836                         result = 0;
837                 }
838         }
839         up_write(&card->controls_rwsem);
840         return result;
841 }
842
843 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
844                                struct snd_ctl_elem_id __user *_id)
845 {
846         struct snd_card *card = file->card;
847         struct snd_ctl_elem_id id;
848         struct snd_kcontrol *kctl;
849         struct snd_kcontrol_volatile *vd;
850         int result;
851         
852         if (copy_from_user(&id, _id, sizeof(id)))
853                 return -EFAULT;
854         down_write(&card->controls_rwsem);
855         kctl = snd_ctl_find_id(card, &id);
856         if (kctl == NULL) {
857                 result = -ENOENT;
858         } else {
859                 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
860                 if (vd->owner == NULL)
861                         result = -EINVAL;
862                 else if (vd->owner != file)
863                         result = -EPERM;
864                 else {
865                         vd->owner = NULL;
866                         vd->owner_pid = 0;
867                         result = 0;
868                 }
869         }
870         up_write(&card->controls_rwsem);
871         return result;
872 }
873
874 struct user_element {
875         struct snd_ctl_elem_info info;
876         void *elem_data;                /* element data */
877         unsigned long elem_data_size;   /* size of element data in bytes */
878         void *tlv_data;                 /* TLV data */
879         unsigned long tlv_data_size;    /* TLV data size */
880         void *priv_data;                /* private data (like strings for enumerated type) */
881         unsigned long priv_data_size;   /* size of private data in bytes */
882 };
883
884 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
885                                   struct snd_ctl_elem_info *uinfo)
886 {
887         struct user_element *ue = kcontrol->private_data;
888
889         *uinfo = ue->info;
890         return 0;
891 }
892
893 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
894                                  struct snd_ctl_elem_value *ucontrol)
895 {
896         struct user_element *ue = kcontrol->private_data;
897
898         memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
899         return 0;
900 }
901
902 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
903                                  struct snd_ctl_elem_value *ucontrol)
904 {
905         int change;
906         struct user_element *ue = kcontrol->private_data;
907         
908         change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
909         if (change)
910                 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
911         return change;
912 }
913
914 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
915                                  int op_flag,
916                                  unsigned int size,
917                                  unsigned int __user *tlv)
918 {
919         struct user_element *ue = kcontrol->private_data;
920         int change = 0;
921         void *new_data;
922
923         if (op_flag > 0) {
924                 if (size > 1024 * 128)  /* sane value */
925                         return -EINVAL;
926                 new_data = kmalloc(size, GFP_KERNEL);
927                 if (new_data == NULL)
928                         return -ENOMEM;
929                 if (copy_from_user(new_data, tlv, size)) {
930                         kfree(new_data);
931                         return -EFAULT;
932                 }
933                 change = ue->tlv_data_size != size;
934                 if (!change)
935                         change = memcmp(ue->tlv_data, new_data, size);
936                 kfree(ue->tlv_data);
937                 ue->tlv_data = new_data;
938                 ue->tlv_data_size = size;
939         } else {
940                 if (! ue->tlv_data_size || ! ue->tlv_data)
941                         return -ENXIO;
942                 if (size < ue->tlv_data_size)
943                         return -ENOSPC;
944                 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
945                         return -EFAULT;
946         }
947         return change;
948 }
949
950 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
951 {
952         struct user_element *ue = kcontrol->private_data;
953         if (ue->tlv_data)
954                 kfree(ue->tlv_data);
955         kfree(ue);
956 }
957
958 static int snd_ctl_elem_add(struct snd_ctl_file *file,
959                             struct snd_ctl_elem_info *info, int replace)
960 {
961         struct snd_card *card = file->card;
962         struct snd_kcontrol kctl, *_kctl;
963         unsigned int access;
964         long private_size;
965         struct user_element *ue;
966         int idx, err;
967         
968         if (card->user_ctl_count >= MAX_USER_CONTROLS)
969                 return -ENOMEM;
970         if (info->count > 1024)
971                 return -EINVAL;
972         access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
973                 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
974                                  SNDRV_CTL_ELEM_ACCESS_INACTIVE|
975                                  SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
976         info->id.numid = 0;
977         memset(&kctl, 0, sizeof(kctl));
978         down_write(&card->controls_rwsem);
979         _kctl = snd_ctl_find_id(card, &info->id);
980         err = 0;
981         if (_kctl) {
982                 if (replace)
983                         err = snd_ctl_remove(card, _kctl);
984                 else
985                         err = -EBUSY;
986         } else {
987                 if (replace)
988                         err = -ENOENT;
989         }
990         up_write(&card->controls_rwsem);
991         if (err < 0)
992                 return err;
993         memcpy(&kctl.id, &info->id, sizeof(info->id));
994         kctl.count = info->owner ? info->owner : 1;
995         access |= SNDRV_CTL_ELEM_ACCESS_USER;
996         kctl.info = snd_ctl_elem_user_info;
997         if (access & SNDRV_CTL_ELEM_ACCESS_READ)
998                 kctl.get = snd_ctl_elem_user_get;
999         if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1000                 kctl.put = snd_ctl_elem_user_put;
1001         if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1002                 kctl.tlv.c = snd_ctl_elem_user_tlv;
1003                 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1004         }
1005         switch (info->type) {
1006         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1007         case SNDRV_CTL_ELEM_TYPE_INTEGER:
1008                 private_size = sizeof(long);
1009                 if (info->count > 128)
1010                         return -EINVAL;
1011                 break;
1012         case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1013                 private_size = sizeof(long long);
1014                 if (info->count > 64)
1015                         return -EINVAL;
1016                 break;
1017         case SNDRV_CTL_ELEM_TYPE_BYTES:
1018                 private_size = sizeof(unsigned char);
1019                 if (info->count > 512)
1020                         return -EINVAL;
1021                 break;
1022         case SNDRV_CTL_ELEM_TYPE_IEC958:
1023                 private_size = sizeof(struct snd_aes_iec958);
1024                 if (info->count != 1)
1025                         return -EINVAL;
1026                 break;
1027         default:
1028                 return -EINVAL;
1029         }
1030         private_size *= info->count;
1031         ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1032         if (ue == NULL)
1033                 return -ENOMEM;
1034         ue->info = *info;
1035         ue->info.access = 0;
1036         ue->elem_data = (char *)ue + sizeof(*ue);
1037         ue->elem_data_size = private_size;
1038         kctl.private_free = snd_ctl_elem_user_free;
1039         _kctl = snd_ctl_new(&kctl, access);
1040         if (_kctl == NULL) {
1041                 kfree(ue);
1042                 return -ENOMEM;
1043         }
1044         _kctl->private_data = ue;
1045         for (idx = 0; idx < _kctl->count; idx++)
1046                 _kctl->vd[idx].owner = file;
1047         err = snd_ctl_add(card, _kctl);
1048         if (err < 0)
1049                 return err;
1050
1051         down_write(&card->controls_rwsem);
1052         card->user_ctl_count++;
1053         up_write(&card->controls_rwsem);
1054
1055         return 0;
1056 }
1057
1058 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1059                                  struct snd_ctl_elem_info __user *_info, int replace)
1060 {
1061         struct snd_ctl_elem_info info;
1062         if (copy_from_user(&info, _info, sizeof(info)))
1063                 return -EFAULT;
1064         return snd_ctl_elem_add(file, &info, replace);
1065 }
1066
1067 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1068                                struct snd_ctl_elem_id __user *_id)
1069 {
1070         struct snd_ctl_elem_id id;
1071         int err;
1072
1073         if (copy_from_user(&id, _id, sizeof(id)))
1074                 return -EFAULT;
1075         err = snd_ctl_remove_unlocked_id(file, &id);
1076         if (! err) {
1077                 struct snd_card *card = file->card;
1078                 down_write(&card->controls_rwsem);
1079                 card->user_ctl_count--;
1080                 up_write(&card->controls_rwsem);
1081         }
1082         return err;
1083 }
1084
1085 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1086 {
1087         int subscribe;
1088         if (get_user(subscribe, ptr))
1089                 return -EFAULT;
1090         if (subscribe < 0) {
1091                 subscribe = file->subscribed;
1092                 if (put_user(subscribe, ptr))
1093                         return -EFAULT;
1094                 return 0;
1095         }
1096         if (subscribe) {
1097                 file->subscribed = 1;
1098                 return 0;
1099         } else if (file->subscribed) {
1100                 snd_ctl_empty_read_queue(file);
1101                 file->subscribed = 0;
1102         }
1103         return 0;
1104 }
1105
1106 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1107                              struct snd_ctl_tlv __user *_tlv,
1108                              int op_flag)
1109 {
1110         struct snd_card *card = file->card;
1111         struct snd_ctl_tlv tlv;
1112         struct snd_kcontrol *kctl;
1113         struct snd_kcontrol_volatile *vd;
1114         unsigned int len;
1115         int err = 0;
1116
1117         if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1118                 return -EFAULT;
1119         if (tlv.length < sizeof(unsigned int) * 3)
1120                 return -EINVAL;
1121         down_read(&card->controls_rwsem);
1122         kctl = snd_ctl_find_numid(card, tlv.numid);
1123         if (kctl == NULL) {
1124                 err = -ENOENT;
1125                 goto __kctl_end;
1126         }
1127         if (kctl->tlv.p == NULL) {
1128                 err = -ENXIO;
1129                 goto __kctl_end;
1130         }
1131         vd = &kctl->vd[tlv.numid - kctl->id.numid];
1132         if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1133             (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1134             (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1135                 err = -ENXIO;
1136                 goto __kctl_end;
1137         }
1138         if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1139                 if (file && vd->owner != NULL && vd->owner != file) {
1140                         err = -EPERM;
1141                         goto __kctl_end;
1142                 }
1143                 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
1144                 if (err > 0) {
1145                         up_read(&card->controls_rwsem);
1146                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1147                         return 0;
1148                 }
1149         } else {
1150                 if (op_flag) {
1151                         err = -ENXIO;
1152                         goto __kctl_end;
1153                 }
1154                 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1155                 if (tlv.length < len) {
1156                         err = -ENOMEM;
1157                         goto __kctl_end;
1158                 }
1159                 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1160                         err = -EFAULT;
1161         }
1162       __kctl_end:
1163         up_read(&card->controls_rwsem);
1164         return err;
1165 }
1166
1167 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1168 {
1169         struct snd_ctl_file *ctl;
1170         struct snd_card *card;
1171         struct snd_kctl_ioctl *p;
1172         void __user *argp = (void __user *)arg;
1173         int __user *ip = argp;
1174         int err;
1175
1176         ctl = file->private_data;
1177         card = ctl->card;
1178         snd_assert(card != NULL, return -ENXIO);
1179         switch (cmd) {
1180         case SNDRV_CTL_IOCTL_PVERSION:
1181                 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1182         case SNDRV_CTL_IOCTL_CARD_INFO:
1183                 return snd_ctl_card_info(card, ctl, cmd, argp);
1184         case SNDRV_CTL_IOCTL_ELEM_LIST:
1185                 return snd_ctl_elem_list(card, argp);
1186         case SNDRV_CTL_IOCTL_ELEM_INFO:
1187                 return snd_ctl_elem_info_user(ctl, argp);
1188         case SNDRV_CTL_IOCTL_ELEM_READ:
1189                 return snd_ctl_elem_read_user(card, argp);
1190         case SNDRV_CTL_IOCTL_ELEM_WRITE:
1191                 return snd_ctl_elem_write_user(ctl, argp);
1192         case SNDRV_CTL_IOCTL_ELEM_LOCK:
1193                 return snd_ctl_elem_lock(ctl, argp);
1194         case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1195                 return snd_ctl_elem_unlock(ctl, argp);
1196         case SNDRV_CTL_IOCTL_ELEM_ADD:
1197                 return snd_ctl_elem_add_user(ctl, argp, 0);
1198         case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1199                 return snd_ctl_elem_add_user(ctl, argp, 1);
1200         case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1201                 return snd_ctl_elem_remove(ctl, argp);
1202         case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1203                 return snd_ctl_subscribe_events(ctl, ip);
1204         case SNDRV_CTL_IOCTL_TLV_READ:
1205                 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1206         case SNDRV_CTL_IOCTL_TLV_WRITE:
1207                 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1208         case SNDRV_CTL_IOCTL_TLV_COMMAND:
1209                 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1210         case SNDRV_CTL_IOCTL_POWER:
1211                 return -ENOPROTOOPT;
1212         case SNDRV_CTL_IOCTL_POWER_STATE:
1213 #ifdef CONFIG_PM
1214                 return put_user(card->power_state, ip) ? -EFAULT : 0;
1215 #else
1216                 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1217 #endif
1218         }
1219         down_read(&snd_ioctl_rwsem);
1220         list_for_each_entry(p, &snd_control_ioctls, list) {
1221                 err = p->fioctl(card, ctl, cmd, arg);
1222                 if (err != -ENOIOCTLCMD) {
1223                         up_read(&snd_ioctl_rwsem);
1224                         return err;
1225                 }
1226         }
1227         up_read(&snd_ioctl_rwsem);
1228         snd_printdd("unknown ioctl = 0x%x\n", cmd);
1229         return -ENOTTY;
1230 }
1231
1232 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1233                             size_t count, loff_t * offset)
1234 {
1235         struct snd_ctl_file *ctl;
1236         int err = 0;
1237         ssize_t result = 0;
1238
1239         ctl = file->private_data;
1240         snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
1241         if (!ctl->subscribed)
1242                 return -EBADFD;
1243         if (count < sizeof(struct snd_ctl_event))
1244                 return -EINVAL;
1245         spin_lock_irq(&ctl->read_lock);
1246         while (count >= sizeof(struct snd_ctl_event)) {
1247                 struct snd_ctl_event ev;
1248                 struct snd_kctl_event *kev;
1249                 while (list_empty(&ctl->events)) {
1250                         wait_queue_t wait;
1251                         if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1252                                 err = -EAGAIN;
1253                                 goto __end_lock;
1254                         }
1255                         init_waitqueue_entry(&wait, current);
1256                         add_wait_queue(&ctl->change_sleep, &wait);
1257                         set_current_state(TASK_INTERRUPTIBLE);
1258                         spin_unlock_irq(&ctl->read_lock);
1259                         schedule();
1260                         remove_wait_queue(&ctl->change_sleep, &wait);
1261                         if (signal_pending(current))
1262                                 return -ERESTARTSYS;
1263                         spin_lock_irq(&ctl->read_lock);
1264                 }
1265                 kev = snd_kctl_event(ctl->events.next);
1266                 ev.type = SNDRV_CTL_EVENT_ELEM;
1267                 ev.data.elem.mask = kev->mask;
1268                 ev.data.elem.id = kev->id;
1269                 list_del(&kev->list);
1270                 spin_unlock_irq(&ctl->read_lock);
1271                 kfree(kev);
1272                 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1273                         err = -EFAULT;
1274                         goto __end;
1275                 }
1276                 spin_lock_irq(&ctl->read_lock);
1277                 buffer += sizeof(struct snd_ctl_event);
1278                 count -= sizeof(struct snd_ctl_event);
1279                 result += sizeof(struct snd_ctl_event);
1280         }
1281       __end_lock:
1282         spin_unlock_irq(&ctl->read_lock);
1283       __end:
1284         return result > 0 ? result : err;
1285 }
1286
1287 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1288 {
1289         unsigned int mask;
1290         struct snd_ctl_file *ctl;
1291
1292         ctl = file->private_data;
1293         if (!ctl->subscribed)
1294                 return 0;
1295         poll_wait(file, &ctl->change_sleep, wait);
1296
1297         mask = 0;
1298         if (!list_empty(&ctl->events))
1299                 mask |= POLLIN | POLLRDNORM;
1300
1301         return mask;
1302 }
1303
1304 /*
1305  * register the device-specific control-ioctls.
1306  * called from each device manager like pcm.c, hwdep.c, etc.
1307  */
1308 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1309 {
1310         struct snd_kctl_ioctl *pn;
1311
1312         pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1313         if (pn == NULL)
1314                 return -ENOMEM;
1315         pn->fioctl = fcn;
1316         down_write(&snd_ioctl_rwsem);
1317         list_add_tail(&pn->list, lists);
1318         up_write(&snd_ioctl_rwsem);
1319         return 0;
1320 }
1321
1322 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1323 {
1324         return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1325 }
1326
1327 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1328
1329 #ifdef CONFIG_COMPAT
1330 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1331 {
1332         return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1333 }
1334
1335 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1336 #endif
1337
1338 /*
1339  * de-register the device-specific control-ioctls.
1340  */
1341 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1342                                      struct list_head *lists)
1343 {
1344         struct snd_kctl_ioctl *p;
1345
1346         snd_assert(fcn != NULL, return -EINVAL);
1347         down_write(&snd_ioctl_rwsem);
1348         list_for_each_entry(p, lists, list) {
1349                 if (p->fioctl == fcn) {
1350                         list_del(&p->list);
1351                         up_write(&snd_ioctl_rwsem);
1352                         kfree(p);
1353                         return 0;
1354                 }
1355         }
1356         up_write(&snd_ioctl_rwsem);
1357         snd_BUG();
1358         return -EINVAL;
1359 }
1360
1361 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1362 {
1363         return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1364 }
1365
1366 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1367
1368 #ifdef CONFIG_COMPAT
1369 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1370 {
1371         return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1372 }
1373
1374 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1375 #endif
1376
1377 static int snd_ctl_fasync(int fd, struct file * file, int on)
1378 {
1379         struct snd_ctl_file *ctl;
1380         int err;
1381         ctl = file->private_data;
1382         err = fasync_helper(fd, file, on, &ctl->fasync);
1383         if (err < 0)
1384                 return err;
1385         return 0;
1386 }
1387
1388 /*
1389  * ioctl32 compat
1390  */
1391 #ifdef CONFIG_COMPAT
1392 #include "control_compat.c"
1393 #else
1394 #define snd_ctl_ioctl_compat    NULL
1395 #endif
1396
1397 /*
1398  *  INIT PART
1399  */
1400
1401 static struct file_operations snd_ctl_f_ops =
1402 {
1403         .owner =        THIS_MODULE,
1404         .read =         snd_ctl_read,
1405         .open =         snd_ctl_open,
1406         .release =      snd_ctl_release,
1407         .poll =         snd_ctl_poll,
1408         .unlocked_ioctl =       snd_ctl_ioctl,
1409         .compat_ioctl = snd_ctl_ioctl_compat,
1410         .fasync =       snd_ctl_fasync,
1411 };
1412
1413 /*
1414  * registration of the control device
1415  */
1416 static int snd_ctl_dev_register(struct snd_device *device)
1417 {
1418         struct snd_card *card = device->device_data;
1419         int err, cardnum;
1420         char name[16];
1421
1422         snd_assert(card != NULL, return -ENXIO);
1423         cardnum = card->number;
1424         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1425         sprintf(name, "controlC%i", cardnum);
1426         if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1427                                        &snd_ctl_f_ops, card, name)) < 0)
1428                 return err;
1429         return 0;
1430 }
1431
1432 /*
1433  * disconnection of the control device
1434  */
1435 static int snd_ctl_dev_disconnect(struct snd_device *device)
1436 {
1437         struct snd_card *card = device->device_data;
1438         struct snd_ctl_file *ctl;
1439         int err, cardnum;
1440
1441         snd_assert(card != NULL, return -ENXIO);
1442         cardnum = card->number;
1443         snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
1444
1445         down_read(&card->controls_rwsem);
1446         list_for_each_entry(ctl, &card->ctl_files, list) {
1447                 wake_up(&ctl->change_sleep);
1448                 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1449         }
1450         up_read(&card->controls_rwsem);
1451
1452         if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1453                                          card, -1)) < 0)
1454                 return err;
1455         return 0;
1456 }
1457
1458 /*
1459  * free all controls
1460  */
1461 static int snd_ctl_dev_free(struct snd_device *device)
1462 {
1463         struct snd_card *card = device->device_data;
1464         struct snd_kcontrol *control;
1465
1466         down_write(&card->controls_rwsem);
1467         while (!list_empty(&card->controls)) {
1468                 control = snd_kcontrol(card->controls.next);
1469                 snd_ctl_remove(card, control);
1470         }
1471         up_write(&card->controls_rwsem);
1472         return 0;
1473 }
1474
1475 /*
1476  * create control core:
1477  * called from init.c
1478  */
1479 int snd_ctl_create(struct snd_card *card)
1480 {
1481         static struct snd_device_ops ops = {
1482                 .dev_free = snd_ctl_dev_free,
1483                 .dev_register = snd_ctl_dev_register,
1484                 .dev_disconnect = snd_ctl_dev_disconnect,
1485         };
1486
1487         snd_assert(card != NULL, return -ENXIO);
1488         return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1489 }