Linux 3.12
[linux/fpc-iii.git] / sound / core / control.c
blobd8aa206e8bdece19a337175ee1e4a9f83b8e8569
1 /*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
22 #include <linux/threads.h>
23 #include <linux/interrupt.h>
24 #include <linux/module.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <linux/time.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <sound/control.h>
33 /* max number of user-defined controls */
34 #define MAX_USER_CONTROLS 32
35 #define MAX_CONTROL_COUNT 1028
37 struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
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
48 static int snd_ctl_open(struct inode *inode, struct file *file)
50 unsigned long flags;
51 struct snd_card *card;
52 struct snd_ctl_file *ctl;
53 int err;
55 err = nonseekable_open(inode, file);
56 if (err < 0)
57 return err;
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
60 if (!card) {
61 err = -ENODEV;
62 goto __error1;
64 err = snd_card_file_add(card, file);
65 if (err < 0) {
66 err = -ENODEV;
67 goto __error1;
69 if (!try_module_get(card->module)) {
70 err = -EFAULT;
71 goto __error2;
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
74 if (ctl == NULL) {
75 err = -ENOMEM;
76 goto __error;
78 INIT_LIST_HEAD(&ctl->events);
79 init_waitqueue_head(&ctl->change_sleep);
80 spin_lock_init(&ctl->read_lock);
81 ctl->card = card;
82 ctl->prefer_pcm_subdevice = -1;
83 ctl->prefer_rawmidi_subdevice = -1;
84 ctl->pid = get_pid(task_pid(current));
85 file->private_data = ctl;
86 write_lock_irqsave(&card->ctl_files_rwlock, flags);
87 list_add_tail(&ctl->list, &card->ctl_files);
88 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
89 snd_card_unref(card);
90 return 0;
92 __error:
93 module_put(card->module);
94 __error2:
95 snd_card_file_remove(card, file);
96 __error1:
97 if (card)
98 snd_card_unref(card);
99 return err;
102 static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
104 unsigned long flags;
105 struct snd_kctl_event *cread;
107 spin_lock_irqsave(&ctl->read_lock, flags);
108 while (!list_empty(&ctl->events)) {
109 cread = snd_kctl_event(ctl->events.next);
110 list_del(&cread->list);
111 kfree(cread);
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
116 static int snd_ctl_release(struct inode *inode, struct file *file)
118 unsigned long flags;
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
122 unsigned int idx;
124 ctl = file->private_data;
125 file->private_data = NULL;
126 card = ctl->card;
127 write_lock_irqsave(&card->ctl_files_rwlock, flags);
128 list_del(&ctl->list);
129 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
130 down_write(&card->controls_rwsem);
131 list_for_each_entry(control, &card->controls, list)
132 for (idx = 0; idx < control->count; idx++)
133 if (control->vd[idx].owner == ctl)
134 control->vd[idx].owner = NULL;
135 up_write(&card->controls_rwsem);
136 snd_ctl_empty_read_queue(ctl);
137 put_pid(ctl->pid);
138 kfree(ctl);
139 module_put(card->module);
140 snd_card_file_remove(card, file);
141 return 0;
144 void snd_ctl_notify(struct snd_card *card, unsigned int mask,
145 struct snd_ctl_elem_id *id)
147 unsigned long flags;
148 struct snd_ctl_file *ctl;
149 struct snd_kctl_event *ev;
151 if (snd_BUG_ON(!card || !id))
152 return;
153 read_lock(&card->ctl_files_rwlock);
154 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
155 card->mixer_oss_change_count++;
156 #endif
157 list_for_each_entry(ctl, &card->ctl_files, list) {
158 if (!ctl->subscribed)
159 continue;
160 spin_lock_irqsave(&ctl->read_lock, flags);
161 list_for_each_entry(ev, &ctl->events, list) {
162 if (ev->id.numid == id->numid) {
163 ev->mask |= mask;
164 goto _found;
167 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
168 if (ev) {
169 ev->id = *id;
170 ev->mask = mask;
171 list_add_tail(&ev->list, &ctl->events);
172 } else {
173 snd_printk(KERN_ERR "No memory available to allocate event\n");
175 _found:
176 wake_up(&ctl->change_sleep);
177 spin_unlock_irqrestore(&ctl->read_lock, flags);
178 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
180 read_unlock(&card->ctl_files_rwlock);
183 EXPORT_SYMBOL(snd_ctl_notify);
186 * snd_ctl_new - create a control instance from the template
187 * @control: the control template
188 * @access: the default control access
190 * Allocates a new struct snd_kcontrol instance and copies the given template
191 * to the new instance. It does not copy volatile data (access).
193 * Return: The pointer of the new instance, or %NULL on failure.
195 static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
196 unsigned int access)
198 struct snd_kcontrol *kctl;
199 unsigned int idx;
201 if (snd_BUG_ON(!control || !control->count))
202 return NULL;
204 if (control->count > MAX_CONTROL_COUNT)
205 return NULL;
207 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
208 if (kctl == NULL) {
209 snd_printk(KERN_ERR "Cannot allocate control instance\n");
210 return NULL;
212 *kctl = *control;
213 for (idx = 0; idx < kctl->count; idx++)
214 kctl->vd[idx].access = access;
215 return kctl;
219 * snd_ctl_new1 - create a control instance from the template
220 * @ncontrol: the initialization record
221 * @private_data: the private data to set
223 * Allocates a new struct snd_kcontrol instance and initialize from the given
224 * template. When the access field of ncontrol is 0, it's assumed as
225 * READWRITE access. When the count field is 0, it's assumes as one.
227 * Return: The pointer of the newly generated instance, or %NULL on failure.
229 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
230 void *private_data)
232 struct snd_kcontrol kctl;
233 unsigned int access;
235 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
236 return NULL;
237 memset(&kctl, 0, sizeof(kctl));
238 kctl.id.iface = ncontrol->iface;
239 kctl.id.device = ncontrol->device;
240 kctl.id.subdevice = ncontrol->subdevice;
241 if (ncontrol->name) {
242 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
243 if (strcmp(ncontrol->name, kctl.id.name) != 0)
244 snd_printk(KERN_WARNING
245 "Control name '%s' truncated to '%s'\n",
246 ncontrol->name, kctl.id.name);
248 kctl.id.index = ncontrol->index;
249 kctl.count = ncontrol->count ? ncontrol->count : 1;
250 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
251 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
252 SNDRV_CTL_ELEM_ACCESS_VOLATILE|
253 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
254 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
255 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
256 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
257 kctl.info = ncontrol->info;
258 kctl.get = ncontrol->get;
259 kctl.put = ncontrol->put;
260 kctl.tlv.p = ncontrol->tlv.p;
261 kctl.private_value = ncontrol->private_value;
262 kctl.private_data = private_data;
263 return snd_ctl_new(&kctl, access);
266 EXPORT_SYMBOL(snd_ctl_new1);
269 * snd_ctl_free_one - release the control instance
270 * @kcontrol: the control instance
272 * Releases the control instance created via snd_ctl_new()
273 * or snd_ctl_new1().
274 * Don't call this after the control was added to the card.
276 void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
278 if (kcontrol) {
279 if (kcontrol->private_free)
280 kcontrol->private_free(kcontrol);
281 kfree(kcontrol);
285 EXPORT_SYMBOL(snd_ctl_free_one);
287 static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
288 unsigned int count)
290 struct snd_kcontrol *kctl;
292 list_for_each_entry(kctl, &card->controls, list) {
293 if (kctl->id.numid < card->last_numid + 1 + count &&
294 kctl->id.numid + kctl->count > card->last_numid + 1) {
295 card->last_numid = kctl->id.numid + kctl->count - 1;
296 return true;
299 return false;
302 static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
304 unsigned int iter = 100000;
306 while (snd_ctl_remove_numid_conflict(card, count)) {
307 if (--iter == 0) {
308 /* this situation is very unlikely */
309 snd_printk(KERN_ERR "unable to allocate new control numid\n");
310 return -ENOMEM;
313 return 0;
317 * snd_ctl_add - add the control instance to the card
318 * @card: the card instance
319 * @kcontrol: the control instance to add
321 * Adds the control instance created via snd_ctl_new() or
322 * snd_ctl_new1() to the given card. Assigns also an unique
323 * numid used for fast search.
325 * It frees automatically the control which cannot be added.
327 * Return: Zero if successful, or a negative error code on failure.
330 int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
332 struct snd_ctl_elem_id id;
333 unsigned int idx;
334 int err = -EINVAL;
336 if (! kcontrol)
337 return err;
338 if (snd_BUG_ON(!card || !kcontrol->info))
339 goto error;
340 id = kcontrol->id;
341 down_write(&card->controls_rwsem);
342 if (snd_ctl_find_id(card, &id)) {
343 up_write(&card->controls_rwsem);
344 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
345 id.iface,
346 id.device,
347 id.subdevice,
348 id.name,
349 id.index);
350 err = -EBUSY;
351 goto error;
353 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
354 up_write(&card->controls_rwsem);
355 err = -ENOMEM;
356 goto error;
358 list_add_tail(&kcontrol->list, &card->controls);
359 card->controls_count += kcontrol->count;
360 kcontrol->id.numid = card->last_numid + 1;
361 card->last_numid += kcontrol->count;
362 up_write(&card->controls_rwsem);
363 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
364 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
365 return 0;
367 error:
368 snd_ctl_free_one(kcontrol);
369 return err;
372 EXPORT_SYMBOL(snd_ctl_add);
375 * snd_ctl_replace - replace the control instance of the card
376 * @card: the card instance
377 * @kcontrol: the control instance to replace
378 * @add_on_replace: add the control if not already added
380 * Replaces the given control. If the given control does not exist
381 * and the add_on_replace flag is set, the control is added. If the
382 * control exists, it is destroyed first.
384 * It frees automatically the control which cannot be added or replaced.
386 * Return: Zero if successful, or a negative error code on failure.
388 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
389 bool add_on_replace)
391 struct snd_ctl_elem_id id;
392 unsigned int idx;
393 struct snd_kcontrol *old;
394 int ret;
396 if (!kcontrol)
397 return -EINVAL;
398 if (snd_BUG_ON(!card || !kcontrol->info)) {
399 ret = -EINVAL;
400 goto error;
402 id = kcontrol->id;
403 down_write(&card->controls_rwsem);
404 old = snd_ctl_find_id(card, &id);
405 if (!old) {
406 if (add_on_replace)
407 goto add;
408 up_write(&card->controls_rwsem);
409 ret = -EINVAL;
410 goto error;
412 ret = snd_ctl_remove(card, old);
413 if (ret < 0) {
414 up_write(&card->controls_rwsem);
415 goto error;
417 add:
418 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
419 up_write(&card->controls_rwsem);
420 ret = -ENOMEM;
421 goto error;
423 list_add_tail(&kcontrol->list, &card->controls);
424 card->controls_count += kcontrol->count;
425 kcontrol->id.numid = card->last_numid + 1;
426 card->last_numid += kcontrol->count;
427 up_write(&card->controls_rwsem);
428 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
429 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
430 return 0;
432 error:
433 snd_ctl_free_one(kcontrol);
434 return ret;
436 EXPORT_SYMBOL(snd_ctl_replace);
439 * snd_ctl_remove - remove the control from the card and release it
440 * @card: the card instance
441 * @kcontrol: the control instance to remove
443 * Removes the control from the card and then releases the instance.
444 * You don't need to call snd_ctl_free_one(). You must be in
445 * the write lock - down_write(&card->controls_rwsem).
447 * Return: 0 if successful, or a negative error code on failure.
449 int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
451 struct snd_ctl_elem_id id;
452 unsigned int idx;
454 if (snd_BUG_ON(!card || !kcontrol))
455 return -EINVAL;
456 list_del(&kcontrol->list);
457 card->controls_count -= kcontrol->count;
458 id = kcontrol->id;
459 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
460 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
461 snd_ctl_free_one(kcontrol);
462 return 0;
465 EXPORT_SYMBOL(snd_ctl_remove);
468 * snd_ctl_remove_id - remove the control of the given id and release it
469 * @card: the card instance
470 * @id: the control id to remove
472 * Finds the control instance with the given id, removes it from the
473 * card list and releases it.
475 * Return: 0 if successful, or a negative error code on failure.
477 int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
479 struct snd_kcontrol *kctl;
480 int ret;
482 down_write(&card->controls_rwsem);
483 kctl = snd_ctl_find_id(card, id);
484 if (kctl == NULL) {
485 up_write(&card->controls_rwsem);
486 return -ENOENT;
488 ret = snd_ctl_remove(card, kctl);
489 up_write(&card->controls_rwsem);
490 return ret;
493 EXPORT_SYMBOL(snd_ctl_remove_id);
496 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
497 * @file: active control handle
498 * @id: the control id to remove
500 * Finds the control instance with the given id, removes it from the
501 * card list and releases it.
503 * Return: 0 if successful, or a negative error code on failure.
505 static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
506 struct snd_ctl_elem_id *id)
508 struct snd_card *card = file->card;
509 struct snd_kcontrol *kctl;
510 int idx, ret;
512 down_write(&card->controls_rwsem);
513 kctl = snd_ctl_find_id(card, id);
514 if (kctl == NULL) {
515 ret = -ENOENT;
516 goto error;
518 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
519 ret = -EINVAL;
520 goto error;
522 for (idx = 0; idx < kctl->count; idx++)
523 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
524 ret = -EBUSY;
525 goto error;
527 ret = snd_ctl_remove(card, kctl);
528 if (ret < 0)
529 goto error;
530 card->user_ctl_count--;
531 error:
532 up_write(&card->controls_rwsem);
533 return ret;
537 * snd_ctl_activate_id - activate/inactivate the control of the given id
538 * @card: the card instance
539 * @id: the control id to activate/inactivate
540 * @active: non-zero to activate
542 * Finds the control instance with the given id, and activate or
543 * inactivate the control together with notification, if changed.
545 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
547 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
548 int active)
550 struct snd_kcontrol *kctl;
551 struct snd_kcontrol_volatile *vd;
552 unsigned int index_offset;
553 int ret;
555 down_write(&card->controls_rwsem);
556 kctl = snd_ctl_find_id(card, id);
557 if (kctl == NULL) {
558 ret = -ENOENT;
559 goto unlock;
561 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
562 vd = &kctl->vd[index_offset];
563 ret = 0;
564 if (active) {
565 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
566 goto unlock;
567 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
568 } else {
569 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
570 goto unlock;
571 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
573 ret = 1;
574 unlock:
575 up_write(&card->controls_rwsem);
576 if (ret > 0)
577 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
578 return ret;
580 EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
583 * snd_ctl_rename_id - replace the id of a control on the card
584 * @card: the card instance
585 * @src_id: the old id
586 * @dst_id: the new id
588 * Finds the control with the old id from the card, and replaces the
589 * id with the new one.
591 * Return: Zero if successful, or a negative error code on failure.
593 int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
594 struct snd_ctl_elem_id *dst_id)
596 struct snd_kcontrol *kctl;
598 down_write(&card->controls_rwsem);
599 kctl = snd_ctl_find_id(card, src_id);
600 if (kctl == NULL) {
601 up_write(&card->controls_rwsem);
602 return -ENOENT;
604 kctl->id = *dst_id;
605 kctl->id.numid = card->last_numid + 1;
606 card->last_numid += kctl->count;
607 up_write(&card->controls_rwsem);
608 return 0;
611 EXPORT_SYMBOL(snd_ctl_rename_id);
614 * snd_ctl_find_numid - find the control instance with the given number-id
615 * @card: the card instance
616 * @numid: the number-id to search
618 * Finds the control instance with the given number-id from the card.
620 * The caller must down card->controls_rwsem before calling this function
621 * (if the race condition can happen).
623 * Return: The pointer of the instance if found, or %NULL if not.
626 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
628 struct snd_kcontrol *kctl;
630 if (snd_BUG_ON(!card || !numid))
631 return NULL;
632 list_for_each_entry(kctl, &card->controls, list) {
633 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
634 return kctl;
636 return NULL;
639 EXPORT_SYMBOL(snd_ctl_find_numid);
642 * snd_ctl_find_id - find the control instance with the given id
643 * @card: the card instance
644 * @id: the id to search
646 * Finds the control instance with the given id from the card.
648 * The caller must down card->controls_rwsem before calling this function
649 * (if the race condition can happen).
651 * Return: The pointer of the instance if found, or %NULL if not.
654 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
655 struct snd_ctl_elem_id *id)
657 struct snd_kcontrol *kctl;
659 if (snd_BUG_ON(!card || !id))
660 return NULL;
661 if (id->numid != 0)
662 return snd_ctl_find_numid(card, id->numid);
663 list_for_each_entry(kctl, &card->controls, list) {
664 if (kctl->id.iface != id->iface)
665 continue;
666 if (kctl->id.device != id->device)
667 continue;
668 if (kctl->id.subdevice != id->subdevice)
669 continue;
670 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
671 continue;
672 if (kctl->id.index > id->index)
673 continue;
674 if (kctl->id.index + kctl->count <= id->index)
675 continue;
676 return kctl;
678 return NULL;
681 EXPORT_SYMBOL(snd_ctl_find_id);
683 static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
684 unsigned int cmd, void __user *arg)
686 struct snd_ctl_card_info *info;
688 info = kzalloc(sizeof(*info), GFP_KERNEL);
689 if (! info)
690 return -ENOMEM;
691 down_read(&snd_ioctl_rwsem);
692 info->card = card->number;
693 strlcpy(info->id, card->id, sizeof(info->id));
694 strlcpy(info->driver, card->driver, sizeof(info->driver));
695 strlcpy(info->name, card->shortname, sizeof(info->name));
696 strlcpy(info->longname, card->longname, sizeof(info->longname));
697 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
698 strlcpy(info->components, card->components, sizeof(info->components));
699 up_read(&snd_ioctl_rwsem);
700 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
701 kfree(info);
702 return -EFAULT;
704 kfree(info);
705 return 0;
708 static int snd_ctl_elem_list(struct snd_card *card,
709 struct snd_ctl_elem_list __user *_list)
711 struct list_head *plist;
712 struct snd_ctl_elem_list list;
713 struct snd_kcontrol *kctl;
714 struct snd_ctl_elem_id *dst, *id;
715 unsigned int offset, space, jidx;
717 if (copy_from_user(&list, _list, sizeof(list)))
718 return -EFAULT;
719 offset = list.offset;
720 space = list.space;
721 /* try limit maximum space */
722 if (space > 16384)
723 return -ENOMEM;
724 if (space > 0) {
725 /* allocate temporary buffer for atomic operation */
726 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
727 if (dst == NULL)
728 return -ENOMEM;
729 down_read(&card->controls_rwsem);
730 list.count = card->controls_count;
731 plist = card->controls.next;
732 while (plist != &card->controls) {
733 if (offset == 0)
734 break;
735 kctl = snd_kcontrol(plist);
736 if (offset < kctl->count)
737 break;
738 offset -= kctl->count;
739 plist = plist->next;
741 list.used = 0;
742 id = dst;
743 while (space > 0 && plist != &card->controls) {
744 kctl = snd_kcontrol(plist);
745 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
746 snd_ctl_build_ioff(id, kctl, jidx);
747 id++;
748 space--;
749 list.used++;
751 plist = plist->next;
752 offset = 0;
754 up_read(&card->controls_rwsem);
755 if (list.used > 0 &&
756 copy_to_user(list.pids, dst,
757 list.used * sizeof(struct snd_ctl_elem_id))) {
758 vfree(dst);
759 return -EFAULT;
761 vfree(dst);
762 } else {
763 down_read(&card->controls_rwsem);
764 list.count = card->controls_count;
765 up_read(&card->controls_rwsem);
767 if (copy_to_user(_list, &list, sizeof(list)))
768 return -EFAULT;
769 return 0;
772 static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
773 struct snd_ctl_elem_info *info)
775 struct snd_card *card = ctl->card;
776 struct snd_kcontrol *kctl;
777 struct snd_kcontrol_volatile *vd;
778 unsigned int index_offset;
779 int result;
781 down_read(&card->controls_rwsem);
782 kctl = snd_ctl_find_id(card, &info->id);
783 if (kctl == NULL) {
784 up_read(&card->controls_rwsem);
785 return -ENOENT;
787 #ifdef CONFIG_SND_DEBUG
788 info->access = 0;
789 #endif
790 result = kctl->info(kctl, info);
791 if (result >= 0) {
792 snd_BUG_ON(info->access);
793 index_offset = snd_ctl_get_ioff(kctl, &info->id);
794 vd = &kctl->vd[index_offset];
795 snd_ctl_build_ioff(&info->id, kctl, index_offset);
796 info->access = vd->access;
797 if (vd->owner) {
798 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
799 if (vd->owner == ctl)
800 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
801 info->owner = pid_vnr(vd->owner->pid);
802 } else {
803 info->owner = -1;
806 up_read(&card->controls_rwsem);
807 return result;
810 static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
811 struct snd_ctl_elem_info __user *_info)
813 struct snd_ctl_elem_info info;
814 int result;
816 if (copy_from_user(&info, _info, sizeof(info)))
817 return -EFAULT;
818 snd_power_lock(ctl->card);
819 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
820 if (result >= 0)
821 result = snd_ctl_elem_info(ctl, &info);
822 snd_power_unlock(ctl->card);
823 if (result >= 0)
824 if (copy_to_user(_info, &info, sizeof(info)))
825 return -EFAULT;
826 return result;
829 static int snd_ctl_elem_read(struct snd_card *card,
830 struct snd_ctl_elem_value *control)
832 struct snd_kcontrol *kctl;
833 struct snd_kcontrol_volatile *vd;
834 unsigned int index_offset;
835 int result;
837 down_read(&card->controls_rwsem);
838 kctl = snd_ctl_find_id(card, &control->id);
839 if (kctl == NULL) {
840 result = -ENOENT;
841 } else {
842 index_offset = snd_ctl_get_ioff(kctl, &control->id);
843 vd = &kctl->vd[index_offset];
844 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
845 kctl->get != NULL) {
846 snd_ctl_build_ioff(&control->id, kctl, index_offset);
847 result = kctl->get(kctl, control);
848 } else
849 result = -EPERM;
851 up_read(&card->controls_rwsem);
852 return result;
855 static int snd_ctl_elem_read_user(struct snd_card *card,
856 struct snd_ctl_elem_value __user *_control)
858 struct snd_ctl_elem_value *control;
859 int result;
861 control = memdup_user(_control, sizeof(*control));
862 if (IS_ERR(control))
863 return PTR_ERR(control);
865 snd_power_lock(card);
866 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
867 if (result >= 0)
868 result = snd_ctl_elem_read(card, control);
869 snd_power_unlock(card);
870 if (result >= 0)
871 if (copy_to_user(_control, control, sizeof(*control)))
872 result = -EFAULT;
873 kfree(control);
874 return result;
877 static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
878 struct snd_ctl_elem_value *control)
880 struct snd_kcontrol *kctl;
881 struct snd_kcontrol_volatile *vd;
882 unsigned int index_offset;
883 int result;
885 down_read(&card->controls_rwsem);
886 kctl = snd_ctl_find_id(card, &control->id);
887 if (kctl == NULL) {
888 result = -ENOENT;
889 } else {
890 index_offset = snd_ctl_get_ioff(kctl, &control->id);
891 vd = &kctl->vd[index_offset];
892 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
893 kctl->put == NULL ||
894 (file && vd->owner && vd->owner != file)) {
895 result = -EPERM;
896 } else {
897 snd_ctl_build_ioff(&control->id, kctl, index_offset);
898 result = kctl->put(kctl, control);
900 if (result > 0) {
901 up_read(&card->controls_rwsem);
902 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
903 &control->id);
904 return 0;
907 up_read(&card->controls_rwsem);
908 return result;
911 static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
912 struct snd_ctl_elem_value __user *_control)
914 struct snd_ctl_elem_value *control;
915 struct snd_card *card;
916 int result;
918 control = memdup_user(_control, sizeof(*control));
919 if (IS_ERR(control))
920 return PTR_ERR(control);
922 card = file->card;
923 snd_power_lock(card);
924 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
925 if (result >= 0)
926 result = snd_ctl_elem_write(card, file, control);
927 snd_power_unlock(card);
928 if (result >= 0)
929 if (copy_to_user(_control, control, sizeof(*control)))
930 result = -EFAULT;
931 kfree(control);
932 return result;
935 static int snd_ctl_elem_lock(struct snd_ctl_file *file,
936 struct snd_ctl_elem_id __user *_id)
938 struct snd_card *card = file->card;
939 struct snd_ctl_elem_id id;
940 struct snd_kcontrol *kctl;
941 struct snd_kcontrol_volatile *vd;
942 int result;
944 if (copy_from_user(&id, _id, sizeof(id)))
945 return -EFAULT;
946 down_write(&card->controls_rwsem);
947 kctl = snd_ctl_find_id(card, &id);
948 if (kctl == NULL) {
949 result = -ENOENT;
950 } else {
951 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
952 if (vd->owner != NULL)
953 result = -EBUSY;
954 else {
955 vd->owner = file;
956 result = 0;
959 up_write(&card->controls_rwsem);
960 return result;
963 static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
964 struct snd_ctl_elem_id __user *_id)
966 struct snd_card *card = file->card;
967 struct snd_ctl_elem_id id;
968 struct snd_kcontrol *kctl;
969 struct snd_kcontrol_volatile *vd;
970 int result;
972 if (copy_from_user(&id, _id, sizeof(id)))
973 return -EFAULT;
974 down_write(&card->controls_rwsem);
975 kctl = snd_ctl_find_id(card, &id);
976 if (kctl == NULL) {
977 result = -ENOENT;
978 } else {
979 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
980 if (vd->owner == NULL)
981 result = -EINVAL;
982 else if (vd->owner != file)
983 result = -EPERM;
984 else {
985 vd->owner = NULL;
986 result = 0;
989 up_write(&card->controls_rwsem);
990 return result;
993 struct user_element {
994 struct snd_ctl_elem_info info;
995 void *elem_data; /* element data */
996 unsigned long elem_data_size; /* size of element data in bytes */
997 void *tlv_data; /* TLV data */
998 unsigned long tlv_data_size; /* TLV data size */
999 void *priv_data; /* private data (like strings for enumerated type) */
1002 static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1003 struct snd_ctl_elem_info *uinfo)
1005 struct user_element *ue = kcontrol->private_data;
1007 *uinfo = ue->info;
1008 return 0;
1011 static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1012 struct snd_ctl_elem_info *uinfo)
1014 struct user_element *ue = kcontrol->private_data;
1015 const char *names;
1016 unsigned int item;
1018 item = uinfo->value.enumerated.item;
1020 *uinfo = ue->info;
1022 item = min(item, uinfo->value.enumerated.items - 1);
1023 uinfo->value.enumerated.item = item;
1025 names = ue->priv_data;
1026 for (; item > 0; --item)
1027 names += strlen(names) + 1;
1028 strcpy(uinfo->value.enumerated.name, names);
1030 return 0;
1033 static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1034 struct snd_ctl_elem_value *ucontrol)
1036 struct user_element *ue = kcontrol->private_data;
1038 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1039 return 0;
1042 static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1043 struct snd_ctl_elem_value *ucontrol)
1045 int change;
1046 struct user_element *ue = kcontrol->private_data;
1048 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1049 if (change)
1050 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1051 return change;
1054 static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1055 int op_flag,
1056 unsigned int size,
1057 unsigned int __user *tlv)
1059 struct user_element *ue = kcontrol->private_data;
1060 int change = 0;
1061 void *new_data;
1063 if (op_flag > 0) {
1064 if (size > 1024 * 128) /* sane value */
1065 return -EINVAL;
1067 new_data = memdup_user(tlv, size);
1068 if (IS_ERR(new_data))
1069 return PTR_ERR(new_data);
1070 change = ue->tlv_data_size != size;
1071 if (!change)
1072 change = memcmp(ue->tlv_data, new_data, size);
1073 kfree(ue->tlv_data);
1074 ue->tlv_data = new_data;
1075 ue->tlv_data_size = size;
1076 } else {
1077 if (! ue->tlv_data_size || ! ue->tlv_data)
1078 return -ENXIO;
1079 if (size < ue->tlv_data_size)
1080 return -ENOSPC;
1081 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1082 return -EFAULT;
1084 return change;
1087 static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1089 char *names, *p;
1090 size_t buf_len, name_len;
1091 unsigned int i;
1092 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1094 if (ue->info.value.enumerated.names_length > 64 * 1024)
1095 return -EINVAL;
1097 names = memdup_user((const void __user *)user_ptrval,
1098 ue->info.value.enumerated.names_length);
1099 if (IS_ERR(names))
1100 return PTR_ERR(names);
1102 /* check that there are enough valid names */
1103 buf_len = ue->info.value.enumerated.names_length;
1104 p = names;
1105 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1106 name_len = strnlen(p, buf_len);
1107 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1108 kfree(names);
1109 return -EINVAL;
1111 p += name_len + 1;
1112 buf_len -= name_len + 1;
1115 ue->priv_data = names;
1116 ue->info.value.enumerated.names_ptr = 0;
1118 return 0;
1121 static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1123 struct user_element *ue = kcontrol->private_data;
1125 kfree(ue->tlv_data);
1126 kfree(ue->priv_data);
1127 kfree(ue);
1130 static int snd_ctl_elem_add(struct snd_ctl_file *file,
1131 struct snd_ctl_elem_info *info, int replace)
1133 struct snd_card *card = file->card;
1134 struct snd_kcontrol kctl, *_kctl;
1135 unsigned int access;
1136 long private_size;
1137 struct user_element *ue;
1138 int idx, err;
1140 if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1141 return -ENOMEM;
1142 if (info->count < 1)
1143 return -EINVAL;
1144 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1145 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1146 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1147 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1148 info->id.numid = 0;
1149 memset(&kctl, 0, sizeof(kctl));
1150 down_write(&card->controls_rwsem);
1151 _kctl = snd_ctl_find_id(card, &info->id);
1152 err = 0;
1153 if (_kctl) {
1154 if (replace)
1155 err = snd_ctl_remove(card, _kctl);
1156 else
1157 err = -EBUSY;
1158 } else {
1159 if (replace)
1160 err = -ENOENT;
1162 up_write(&card->controls_rwsem);
1163 if (err < 0)
1164 return err;
1165 memcpy(&kctl.id, &info->id, sizeof(info->id));
1166 kctl.count = info->owner ? info->owner : 1;
1167 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1168 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1169 kctl.info = snd_ctl_elem_user_enum_info;
1170 else
1171 kctl.info = snd_ctl_elem_user_info;
1172 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1173 kctl.get = snd_ctl_elem_user_get;
1174 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1175 kctl.put = snd_ctl_elem_user_put;
1176 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1177 kctl.tlv.c = snd_ctl_elem_user_tlv;
1178 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1180 switch (info->type) {
1181 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1182 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1183 private_size = sizeof(long);
1184 if (info->count > 128)
1185 return -EINVAL;
1186 break;
1187 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1188 private_size = sizeof(long long);
1189 if (info->count > 64)
1190 return -EINVAL;
1191 break;
1192 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1193 private_size = sizeof(unsigned int);
1194 if (info->count > 128 || info->value.enumerated.items == 0)
1195 return -EINVAL;
1196 break;
1197 case SNDRV_CTL_ELEM_TYPE_BYTES:
1198 private_size = sizeof(unsigned char);
1199 if (info->count > 512)
1200 return -EINVAL;
1201 break;
1202 case SNDRV_CTL_ELEM_TYPE_IEC958:
1203 private_size = sizeof(struct snd_aes_iec958);
1204 if (info->count != 1)
1205 return -EINVAL;
1206 break;
1207 default:
1208 return -EINVAL;
1210 private_size *= info->count;
1211 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1212 if (ue == NULL)
1213 return -ENOMEM;
1214 ue->info = *info;
1215 ue->info.access = 0;
1216 ue->elem_data = (char *)ue + sizeof(*ue);
1217 ue->elem_data_size = private_size;
1218 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1219 err = snd_ctl_elem_init_enum_names(ue);
1220 if (err < 0) {
1221 kfree(ue);
1222 return err;
1225 kctl.private_free = snd_ctl_elem_user_free;
1226 _kctl = snd_ctl_new(&kctl, access);
1227 if (_kctl == NULL) {
1228 kfree(ue->priv_data);
1229 kfree(ue);
1230 return -ENOMEM;
1232 _kctl->private_data = ue;
1233 for (idx = 0; idx < _kctl->count; idx++)
1234 _kctl->vd[idx].owner = file;
1235 err = snd_ctl_add(card, _kctl);
1236 if (err < 0)
1237 return err;
1239 down_write(&card->controls_rwsem);
1240 card->user_ctl_count++;
1241 up_write(&card->controls_rwsem);
1243 return 0;
1246 static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1247 struct snd_ctl_elem_info __user *_info, int replace)
1249 struct snd_ctl_elem_info info;
1250 if (copy_from_user(&info, _info, sizeof(info)))
1251 return -EFAULT;
1252 return snd_ctl_elem_add(file, &info, replace);
1255 static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1256 struct snd_ctl_elem_id __user *_id)
1258 struct snd_ctl_elem_id id;
1260 if (copy_from_user(&id, _id, sizeof(id)))
1261 return -EFAULT;
1262 return snd_ctl_remove_user_ctl(file, &id);
1265 static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1267 int subscribe;
1268 if (get_user(subscribe, ptr))
1269 return -EFAULT;
1270 if (subscribe < 0) {
1271 subscribe = file->subscribed;
1272 if (put_user(subscribe, ptr))
1273 return -EFAULT;
1274 return 0;
1276 if (subscribe) {
1277 file->subscribed = 1;
1278 return 0;
1279 } else if (file->subscribed) {
1280 snd_ctl_empty_read_queue(file);
1281 file->subscribed = 0;
1283 return 0;
1286 static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1287 struct snd_ctl_tlv __user *_tlv,
1288 int op_flag)
1290 struct snd_card *card = file->card;
1291 struct snd_ctl_tlv tlv;
1292 struct snd_kcontrol *kctl;
1293 struct snd_kcontrol_volatile *vd;
1294 unsigned int len;
1295 int err = 0;
1297 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1298 return -EFAULT;
1299 if (tlv.length < sizeof(unsigned int) * 2)
1300 return -EINVAL;
1301 down_read(&card->controls_rwsem);
1302 kctl = snd_ctl_find_numid(card, tlv.numid);
1303 if (kctl == NULL) {
1304 err = -ENOENT;
1305 goto __kctl_end;
1307 if (kctl->tlv.p == NULL) {
1308 err = -ENXIO;
1309 goto __kctl_end;
1311 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1312 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1313 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1314 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1315 err = -ENXIO;
1316 goto __kctl_end;
1318 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1319 if (vd->owner != NULL && vd->owner != file) {
1320 err = -EPERM;
1321 goto __kctl_end;
1323 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1324 if (err > 0) {
1325 up_read(&card->controls_rwsem);
1326 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1327 return 0;
1329 } else {
1330 if (op_flag) {
1331 err = -ENXIO;
1332 goto __kctl_end;
1334 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1335 if (tlv.length < len) {
1336 err = -ENOMEM;
1337 goto __kctl_end;
1339 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1340 err = -EFAULT;
1342 __kctl_end:
1343 up_read(&card->controls_rwsem);
1344 return err;
1347 static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1349 struct snd_ctl_file *ctl;
1350 struct snd_card *card;
1351 struct snd_kctl_ioctl *p;
1352 void __user *argp = (void __user *)arg;
1353 int __user *ip = argp;
1354 int err;
1356 ctl = file->private_data;
1357 card = ctl->card;
1358 if (snd_BUG_ON(!card))
1359 return -ENXIO;
1360 switch (cmd) {
1361 case SNDRV_CTL_IOCTL_PVERSION:
1362 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1363 case SNDRV_CTL_IOCTL_CARD_INFO:
1364 return snd_ctl_card_info(card, ctl, cmd, argp);
1365 case SNDRV_CTL_IOCTL_ELEM_LIST:
1366 return snd_ctl_elem_list(card, argp);
1367 case SNDRV_CTL_IOCTL_ELEM_INFO:
1368 return snd_ctl_elem_info_user(ctl, argp);
1369 case SNDRV_CTL_IOCTL_ELEM_READ:
1370 return snd_ctl_elem_read_user(card, argp);
1371 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1372 return snd_ctl_elem_write_user(ctl, argp);
1373 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1374 return snd_ctl_elem_lock(ctl, argp);
1375 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1376 return snd_ctl_elem_unlock(ctl, argp);
1377 case SNDRV_CTL_IOCTL_ELEM_ADD:
1378 return snd_ctl_elem_add_user(ctl, argp, 0);
1379 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1380 return snd_ctl_elem_add_user(ctl, argp, 1);
1381 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1382 return snd_ctl_elem_remove(ctl, argp);
1383 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1384 return snd_ctl_subscribe_events(ctl, ip);
1385 case SNDRV_CTL_IOCTL_TLV_READ:
1386 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1387 case SNDRV_CTL_IOCTL_TLV_WRITE:
1388 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1389 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1390 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1391 case SNDRV_CTL_IOCTL_POWER:
1392 return -ENOPROTOOPT;
1393 case SNDRV_CTL_IOCTL_POWER_STATE:
1394 #ifdef CONFIG_PM
1395 return put_user(card->power_state, ip) ? -EFAULT : 0;
1396 #else
1397 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1398 #endif
1400 down_read(&snd_ioctl_rwsem);
1401 list_for_each_entry(p, &snd_control_ioctls, list) {
1402 err = p->fioctl(card, ctl, cmd, arg);
1403 if (err != -ENOIOCTLCMD) {
1404 up_read(&snd_ioctl_rwsem);
1405 return err;
1408 up_read(&snd_ioctl_rwsem);
1409 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1410 return -ENOTTY;
1413 static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1414 size_t count, loff_t * offset)
1416 struct snd_ctl_file *ctl;
1417 int err = 0;
1418 ssize_t result = 0;
1420 ctl = file->private_data;
1421 if (snd_BUG_ON(!ctl || !ctl->card))
1422 return -ENXIO;
1423 if (!ctl->subscribed)
1424 return -EBADFD;
1425 if (count < sizeof(struct snd_ctl_event))
1426 return -EINVAL;
1427 spin_lock_irq(&ctl->read_lock);
1428 while (count >= sizeof(struct snd_ctl_event)) {
1429 struct snd_ctl_event ev;
1430 struct snd_kctl_event *kev;
1431 while (list_empty(&ctl->events)) {
1432 wait_queue_t wait;
1433 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1434 err = -EAGAIN;
1435 goto __end_lock;
1437 init_waitqueue_entry(&wait, current);
1438 add_wait_queue(&ctl->change_sleep, &wait);
1439 set_current_state(TASK_INTERRUPTIBLE);
1440 spin_unlock_irq(&ctl->read_lock);
1441 schedule();
1442 remove_wait_queue(&ctl->change_sleep, &wait);
1443 if (ctl->card->shutdown)
1444 return -ENODEV;
1445 if (signal_pending(current))
1446 return -ERESTARTSYS;
1447 spin_lock_irq(&ctl->read_lock);
1449 kev = snd_kctl_event(ctl->events.next);
1450 ev.type = SNDRV_CTL_EVENT_ELEM;
1451 ev.data.elem.mask = kev->mask;
1452 ev.data.elem.id = kev->id;
1453 list_del(&kev->list);
1454 spin_unlock_irq(&ctl->read_lock);
1455 kfree(kev);
1456 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1457 err = -EFAULT;
1458 goto __end;
1460 spin_lock_irq(&ctl->read_lock);
1461 buffer += sizeof(struct snd_ctl_event);
1462 count -= sizeof(struct snd_ctl_event);
1463 result += sizeof(struct snd_ctl_event);
1465 __end_lock:
1466 spin_unlock_irq(&ctl->read_lock);
1467 __end:
1468 return result > 0 ? result : err;
1471 static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1473 unsigned int mask;
1474 struct snd_ctl_file *ctl;
1476 ctl = file->private_data;
1477 if (!ctl->subscribed)
1478 return 0;
1479 poll_wait(file, &ctl->change_sleep, wait);
1481 mask = 0;
1482 if (!list_empty(&ctl->events))
1483 mask |= POLLIN | POLLRDNORM;
1485 return mask;
1489 * register the device-specific control-ioctls.
1490 * called from each device manager like pcm.c, hwdep.c, etc.
1492 static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1494 struct snd_kctl_ioctl *pn;
1496 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1497 if (pn == NULL)
1498 return -ENOMEM;
1499 pn->fioctl = fcn;
1500 down_write(&snd_ioctl_rwsem);
1501 list_add_tail(&pn->list, lists);
1502 up_write(&snd_ioctl_rwsem);
1503 return 0;
1506 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1508 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1511 EXPORT_SYMBOL(snd_ctl_register_ioctl);
1513 #ifdef CONFIG_COMPAT
1514 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1516 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1519 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1520 #endif
1523 * de-register the device-specific control-ioctls.
1525 static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1526 struct list_head *lists)
1528 struct snd_kctl_ioctl *p;
1530 if (snd_BUG_ON(!fcn))
1531 return -EINVAL;
1532 down_write(&snd_ioctl_rwsem);
1533 list_for_each_entry(p, lists, list) {
1534 if (p->fioctl == fcn) {
1535 list_del(&p->list);
1536 up_write(&snd_ioctl_rwsem);
1537 kfree(p);
1538 return 0;
1541 up_write(&snd_ioctl_rwsem);
1542 snd_BUG();
1543 return -EINVAL;
1546 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1548 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1551 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1553 #ifdef CONFIG_COMPAT
1554 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1556 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1559 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1560 #endif
1562 static int snd_ctl_fasync(int fd, struct file * file, int on)
1564 struct snd_ctl_file *ctl;
1566 ctl = file->private_data;
1567 return fasync_helper(fd, file, on, &ctl->fasync);
1571 * ioctl32 compat
1573 #ifdef CONFIG_COMPAT
1574 #include "control_compat.c"
1575 #else
1576 #define snd_ctl_ioctl_compat NULL
1577 #endif
1580 * INIT PART
1583 static const struct file_operations snd_ctl_f_ops =
1585 .owner = THIS_MODULE,
1586 .read = snd_ctl_read,
1587 .open = snd_ctl_open,
1588 .release = snd_ctl_release,
1589 .llseek = no_llseek,
1590 .poll = snd_ctl_poll,
1591 .unlocked_ioctl = snd_ctl_ioctl,
1592 .compat_ioctl = snd_ctl_ioctl_compat,
1593 .fasync = snd_ctl_fasync,
1597 * registration of the control device
1599 static int snd_ctl_dev_register(struct snd_device *device)
1601 struct snd_card *card = device->device_data;
1602 int err, cardnum;
1603 char name[16];
1605 if (snd_BUG_ON(!card))
1606 return -ENXIO;
1607 cardnum = card->number;
1608 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1609 return -ENXIO;
1610 sprintf(name, "controlC%i", cardnum);
1611 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1612 &snd_ctl_f_ops, card, name)) < 0)
1613 return err;
1614 return 0;
1618 * disconnection of the control device
1620 static int snd_ctl_dev_disconnect(struct snd_device *device)
1622 struct snd_card *card = device->device_data;
1623 struct snd_ctl_file *ctl;
1624 int err, cardnum;
1626 if (snd_BUG_ON(!card))
1627 return -ENXIO;
1628 cardnum = card->number;
1629 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1630 return -ENXIO;
1632 read_lock(&card->ctl_files_rwlock);
1633 list_for_each_entry(ctl, &card->ctl_files, list) {
1634 wake_up(&ctl->change_sleep);
1635 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1637 read_unlock(&card->ctl_files_rwlock);
1639 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1640 card, -1)) < 0)
1641 return err;
1642 return 0;
1646 * free all controls
1648 static int snd_ctl_dev_free(struct snd_device *device)
1650 struct snd_card *card = device->device_data;
1651 struct snd_kcontrol *control;
1653 down_write(&card->controls_rwsem);
1654 while (!list_empty(&card->controls)) {
1655 control = snd_kcontrol(card->controls.next);
1656 snd_ctl_remove(card, control);
1658 up_write(&card->controls_rwsem);
1659 return 0;
1663 * create control core:
1664 * called from init.c
1666 int snd_ctl_create(struct snd_card *card)
1668 static struct snd_device_ops ops = {
1669 .dev_free = snd_ctl_dev_free,
1670 .dev_register = snd_ctl_dev_register,
1671 .dev_disconnect = snd_ctl_dev_disconnect,
1674 if (snd_BUG_ON(!card))
1675 return -ENXIO;
1676 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1680 * Frequently used control callbacks/helpers
1682 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1683 struct snd_ctl_elem_info *uinfo)
1685 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1686 uinfo->count = 1;
1687 uinfo->value.integer.min = 0;
1688 uinfo->value.integer.max = 1;
1689 return 0;
1692 EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1694 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1695 struct snd_ctl_elem_info *uinfo)
1697 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1698 uinfo->count = 2;
1699 uinfo->value.integer.min = 0;
1700 uinfo->value.integer.max = 1;
1701 return 0;
1704 EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1707 * snd_ctl_enum_info - fills the info structure for an enumerated control
1708 * @info: the structure to be filled
1709 * @channels: the number of the control's channels; often one
1710 * @items: the number of control values; also the size of @names
1711 * @names: an array containing the names of all control values
1713 * Sets all required fields in @info to their appropriate values.
1714 * If the control's accessibility is not the default (readable and writable),
1715 * the caller has to fill @info->access.
1717 * Return: Zero.
1719 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1720 unsigned int items, const char *const names[])
1722 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1723 info->count = channels;
1724 info->value.enumerated.items = items;
1725 if (info->value.enumerated.item >= items)
1726 info->value.enumerated.item = items - 1;
1727 strlcpy(info->value.enumerated.name,
1728 names[info->value.enumerated.item],
1729 sizeof(info->value.enumerated.name));
1730 return 0;
1732 EXPORT_SYMBOL(snd_ctl_enum_info);