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1/*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/threads.h>
23#include <linux/interrupt.h>
24#include <linux/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>
32
33/* max number of user-defined controls */
34#define MAX_USER_CONTROLS 32
35#define MAX_CONTROL_COUNT 1028
36
37struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
40};
41
42static DECLARE_RWSEM(snd_ioctl_rwsem);
43static LIST_HEAD(snd_control_ioctls);
44#ifdef CONFIG_COMPAT
45static LIST_HEAD(snd_control_compat_ioctls);
46#endif
47
48static 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 err = nonseekable_open(inode, file);
56 if (err < 0)
57 return err;
58
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
60 if (!card) {
61 err = -ENODEV;
62 goto __error1;
63 }
64 err = snd_card_file_add(card, file);
65 if (err < 0) {
66 err = -ENODEV;
67 goto __error1;
68 }
69 if (!try_module_get(card->module)) {
70 err = -EFAULT;
71 goto __error2;
72 }
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
74 if (ctl == NULL) {
75 err = -ENOMEM;
76 goto __error;
77 }
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;
91
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;
100}
101
102static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
103{
104 unsigned long flags;
105 struct snd_kctl_event *cread;
106
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);
112 }
113 spin_unlock_irqrestore(&ctl->read_lock, flags);
114}
115
116static int snd_ctl_release(struct inode *inode, struct file *file)
117{
118 unsigned long flags;
119 struct snd_card *card;
120 struct snd_ctl_file *ctl;
121 struct snd_kcontrol *control;
122 unsigned int idx;
123
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;
142}
143
144void snd_ctl_notify(struct snd_card *card, unsigned int mask,
145 struct snd_ctl_elem_id *id)
146{
147 unsigned long flags;
148 struct snd_ctl_file *ctl;
149 struct snd_kctl_event *ev;
150
151 if (snd_BUG_ON(!card || !id))
152 return;
153 read_lock(&card->ctl_files_rwlock);
154#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
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;
165 }
166 }
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 dev_err(card->dev, "No memory available to allocate event\n");
174 }
175 _found:
176 wake_up(&ctl->change_sleep);
177 spin_unlock_irqrestore(&ctl->read_lock, flags);
178 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
179 }
180 read_unlock(&card->ctl_files_rwlock);
181}
182
183EXPORT_SYMBOL(snd_ctl_notify);
184
185/**
186 * snd_ctl_new - create a control instance from the template
187 * @control: the control template
188 * @access: the default control access
189 *
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).
192 *
193 * Return: The pointer of the new instance, or %NULL on failure.
194 */
195static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
196 unsigned int access)
197{
198 struct snd_kcontrol *kctl;
199 unsigned int idx;
200
201 if (snd_BUG_ON(!control || !control->count))
202 return NULL;
203
204 if (control->count > MAX_CONTROL_COUNT)
205 return NULL;
206
207 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
208 if (kctl == NULL) {
209 pr_err("ALSA: Cannot allocate control instance\n");
210 return NULL;
211 }
212 *kctl = *control;
213 for (idx = 0; idx < kctl->count; idx++)
214 kctl->vd[idx].access = access;
215 return kctl;
216}
217
218/**
219 * snd_ctl_new1 - create a control instance from the template
220 * @ncontrol: the initialization record
221 * @private_data: the private data to set
222 *
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.
226 *
227 * Return: The pointer of the newly generated instance, or %NULL on failure.
228 */
229struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
230 void *private_data)
231{
232 struct snd_kcontrol kctl;
233 unsigned int access;
234
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 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
245 ncontrol->name, kctl.id.name);
246 }
247 kctl.id.index = ncontrol->index;
248 kctl.count = ncontrol->count ? ncontrol->count : 1;
249 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
250 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
251 SNDRV_CTL_ELEM_ACCESS_VOLATILE|
252 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
253 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
254 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
255 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
256 kctl.info = ncontrol->info;
257 kctl.get = ncontrol->get;
258 kctl.put = ncontrol->put;
259 kctl.tlv.p = ncontrol->tlv.p;
260 kctl.private_value = ncontrol->private_value;
261 kctl.private_data = private_data;
262 return snd_ctl_new(&kctl, access);
263}
264
265EXPORT_SYMBOL(snd_ctl_new1);
266
267/**
268 * snd_ctl_free_one - release the control instance
269 * @kcontrol: the control instance
270 *
271 * Releases the control instance created via snd_ctl_new()
272 * or snd_ctl_new1().
273 * Don't call this after the control was added to the card.
274 */
275void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
276{
277 if (kcontrol) {
278 if (kcontrol->private_free)
279 kcontrol->private_free(kcontrol);
280 kfree(kcontrol);
281 }
282}
283
284EXPORT_SYMBOL(snd_ctl_free_one);
285
286static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
287 unsigned int count)
288{
289 struct snd_kcontrol *kctl;
290
291 list_for_each_entry(kctl, &card->controls, list) {
292 if (kctl->id.numid < card->last_numid + 1 + count &&
293 kctl->id.numid + kctl->count > card->last_numid + 1) {
294 card->last_numid = kctl->id.numid + kctl->count - 1;
295 return true;
296 }
297 }
298 return false;
299}
300
301static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
302{
303 unsigned int iter = 100000;
304
305 while (snd_ctl_remove_numid_conflict(card, count)) {
306 if (--iter == 0) {
307 /* this situation is very unlikely */
308 dev_err(card->dev, "unable to allocate new control numid\n");
309 return -ENOMEM;
310 }
311 }
312 return 0;
313}
314
315/**
316 * snd_ctl_add - add the control instance to the card
317 * @card: the card instance
318 * @kcontrol: the control instance to add
319 *
320 * Adds the control instance created via snd_ctl_new() or
321 * snd_ctl_new1() to the given card. Assigns also an unique
322 * numid used for fast search.
323 *
324 * It frees automatically the control which cannot be added.
325 *
326 * Return: Zero if successful, or a negative error code on failure.
327 *
328 */
329int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
330{
331 struct snd_ctl_elem_id id;
332 unsigned int idx;
333 int err = -EINVAL;
334
335 if (! kcontrol)
336 return err;
337 if (snd_BUG_ON(!card || !kcontrol->info))
338 goto error;
339 id = kcontrol->id;
340 down_write(&card->controls_rwsem);
341 if (snd_ctl_find_id(card, &id)) {
342 up_write(&card->controls_rwsem);
343 dev_err(card->dev, "control %i:%i:%i:%s:%i is already present\n",
344 id.iface,
345 id.device,
346 id.subdevice,
347 id.name,
348 id.index);
349 err = -EBUSY;
350 goto error;
351 }
352 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
353 up_write(&card->controls_rwsem);
354 err = -ENOMEM;
355 goto error;
356 }
357 list_add_tail(&kcontrol->list, &card->controls);
358 card->controls_count += kcontrol->count;
359 kcontrol->id.numid = card->last_numid + 1;
360 card->last_numid += kcontrol->count;
361 up_write(&card->controls_rwsem);
362 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
363 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
364 return 0;
365
366 error:
367 snd_ctl_free_one(kcontrol);
368 return err;
369}
370
371EXPORT_SYMBOL(snd_ctl_add);
372
373/**
374 * snd_ctl_replace - replace the control instance of the card
375 * @card: the card instance
376 * @kcontrol: the control instance to replace
377 * @add_on_replace: add the control if not already added
378 *
379 * Replaces the given control. If the given control does not exist
380 * and the add_on_replace flag is set, the control is added. If the
381 * control exists, it is destroyed first.
382 *
383 * It frees automatically the control which cannot be added or replaced.
384 *
385 * Return: Zero if successful, or a negative error code on failure.
386 */
387int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
388 bool add_on_replace)
389{
390 struct snd_ctl_elem_id id;
391 unsigned int idx;
392 struct snd_kcontrol *old;
393 int ret;
394
395 if (!kcontrol)
396 return -EINVAL;
397 if (snd_BUG_ON(!card || !kcontrol->info)) {
398 ret = -EINVAL;
399 goto error;
400 }
401 id = kcontrol->id;
402 down_write(&card->controls_rwsem);
403 old = snd_ctl_find_id(card, &id);
404 if (!old) {
405 if (add_on_replace)
406 goto add;
407 up_write(&card->controls_rwsem);
408 ret = -EINVAL;
409 goto error;
410 }
411 ret = snd_ctl_remove(card, old);
412 if (ret < 0) {
413 up_write(&card->controls_rwsem);
414 goto error;
415 }
416add:
417 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
418 up_write(&card->controls_rwsem);
419 ret = -ENOMEM;
420 goto error;
421 }
422 list_add_tail(&kcontrol->list, &card->controls);
423 card->controls_count += kcontrol->count;
424 kcontrol->id.numid = card->last_numid + 1;
425 card->last_numid += kcontrol->count;
426 up_write(&card->controls_rwsem);
427 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
428 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
429 return 0;
430
431error:
432 snd_ctl_free_one(kcontrol);
433 return ret;
434}
435EXPORT_SYMBOL(snd_ctl_replace);
436
437/**
438 * snd_ctl_remove - remove the control from the card and release it
439 * @card: the card instance
440 * @kcontrol: the control instance to remove
441 *
442 * Removes the control from the card and then releases the instance.
443 * You don't need to call snd_ctl_free_one(). You must be in
444 * the write lock - down_write(&card->controls_rwsem).
445 *
446 * Return: 0 if successful, or a negative error code on failure.
447 */
448int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
449{
450 struct snd_ctl_elem_id id;
451 unsigned int idx;
452
453 if (snd_BUG_ON(!card || !kcontrol))
454 return -EINVAL;
455 list_del(&kcontrol->list);
456 card->controls_count -= kcontrol->count;
457 id = kcontrol->id;
458 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
459 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
460 snd_ctl_free_one(kcontrol);
461 return 0;
462}
463
464EXPORT_SYMBOL(snd_ctl_remove);
465
466/**
467 * snd_ctl_remove_id - remove the control of the given id and release it
468 * @card: the card instance
469 * @id: the control id to remove
470 *
471 * Finds the control instance with the given id, removes it from the
472 * card list and releases it.
473 *
474 * Return: 0 if successful, or a negative error code on failure.
475 */
476int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
477{
478 struct snd_kcontrol *kctl;
479 int ret;
480
481 down_write(&card->controls_rwsem);
482 kctl = snd_ctl_find_id(card, id);
483 if (kctl == NULL) {
484 up_write(&card->controls_rwsem);
485 return -ENOENT;
486 }
487 ret = snd_ctl_remove(card, kctl);
488 up_write(&card->controls_rwsem);
489 return ret;
490}
491
492EXPORT_SYMBOL(snd_ctl_remove_id);
493
494/**
495 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
496 * @file: active control handle
497 * @id: the control id to remove
498 *
499 * Finds the control instance with the given id, removes it from the
500 * card list and releases it.
501 *
502 * Return: 0 if successful, or a negative error code on failure.
503 */
504static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
505 struct snd_ctl_elem_id *id)
506{
507 struct snd_card *card = file->card;
508 struct snd_kcontrol *kctl;
509 int idx, ret;
510
511 down_write(&card->controls_rwsem);
512 kctl = snd_ctl_find_id(card, id);
513 if (kctl == NULL) {
514 ret = -ENOENT;
515 goto error;
516 }
517 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
518 ret = -EINVAL;
519 goto error;
520 }
521 for (idx = 0; idx < kctl->count; idx++)
522 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
523 ret = -EBUSY;
524 goto error;
525 }
526 ret = snd_ctl_remove(card, kctl);
527 if (ret < 0)
528 goto error;
529 card->user_ctl_count--;
530error:
531 up_write(&card->controls_rwsem);
532 return ret;
533}
534
535/**
536 * snd_ctl_activate_id - activate/inactivate the control of the given id
537 * @card: the card instance
538 * @id: the control id to activate/inactivate
539 * @active: non-zero to activate
540 *
541 * Finds the control instance with the given id, and activate or
542 * inactivate the control together with notification, if changed.
543 *
544 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
545 */
546int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
547 int active)
548{
549 struct snd_kcontrol *kctl;
550 struct snd_kcontrol_volatile *vd;
551 unsigned int index_offset;
552 int ret;
553
554 down_write(&card->controls_rwsem);
555 kctl = snd_ctl_find_id(card, id);
556 if (kctl == NULL) {
557 ret = -ENOENT;
558 goto unlock;
559 }
560 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
561 vd = &kctl->vd[index_offset];
562 ret = 0;
563 if (active) {
564 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
565 goto unlock;
566 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
567 } else {
568 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
569 goto unlock;
570 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
571 }
572 ret = 1;
573 unlock:
574 up_write(&card->controls_rwsem);
575 if (ret > 0)
576 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
577 return ret;
578}
579EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
580
581/**
582 * snd_ctl_rename_id - replace the id of a control on the card
583 * @card: the card instance
584 * @src_id: the old id
585 * @dst_id: the new id
586 *
587 * Finds the control with the old id from the card, and replaces the
588 * id with the new one.
589 *
590 * Return: Zero if successful, or a negative error code on failure.
591 */
592int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
593 struct snd_ctl_elem_id *dst_id)
594{
595 struct snd_kcontrol *kctl;
596
597 down_write(&card->controls_rwsem);
598 kctl = snd_ctl_find_id(card, src_id);
599 if (kctl == NULL) {
600 up_write(&card->controls_rwsem);
601 return -ENOENT;
602 }
603 kctl->id = *dst_id;
604 kctl->id.numid = card->last_numid + 1;
605 card->last_numid += kctl->count;
606 up_write(&card->controls_rwsem);
607 return 0;
608}
609
610EXPORT_SYMBOL(snd_ctl_rename_id);
611
612/**
613 * snd_ctl_find_numid - find the control instance with the given number-id
614 * @card: the card instance
615 * @numid: the number-id to search
616 *
617 * Finds the control instance with the given number-id from the card.
618 *
619 * The caller must down card->controls_rwsem before calling this function
620 * (if the race condition can happen).
621 *
622 * Return: The pointer of the instance if found, or %NULL if not.
623 *
624 */
625struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
626{
627 struct snd_kcontrol *kctl;
628
629 if (snd_BUG_ON(!card || !numid))
630 return NULL;
631 list_for_each_entry(kctl, &card->controls, list) {
632 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
633 return kctl;
634 }
635 return NULL;
636}
637
638EXPORT_SYMBOL(snd_ctl_find_numid);
639
640/**
641 * snd_ctl_find_id - find the control instance with the given id
642 * @card: the card instance
643 * @id: the id to search
644 *
645 * Finds the control instance with the given id from the card.
646 *
647 * The caller must down card->controls_rwsem before calling this function
648 * (if the race condition can happen).
649 *
650 * Return: The pointer of the instance if found, or %NULL if not.
651 *
652 */
653struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
654 struct snd_ctl_elem_id *id)
655{
656 struct snd_kcontrol *kctl;
657
658 if (snd_BUG_ON(!card || !id))
659 return NULL;
660 if (id->numid != 0)
661 return snd_ctl_find_numid(card, id->numid);
662 list_for_each_entry(kctl, &card->controls, list) {
663 if (kctl->id.iface != id->iface)
664 continue;
665 if (kctl->id.device != id->device)
666 continue;
667 if (kctl->id.subdevice != id->subdevice)
668 continue;
669 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
670 continue;
671 if (kctl->id.index > id->index)
672 continue;
673 if (kctl->id.index + kctl->count <= id->index)
674 continue;
675 return kctl;
676 }
677 return NULL;
678}
679
680EXPORT_SYMBOL(snd_ctl_find_id);
681
682static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
683 unsigned int cmd, void __user *arg)
684{
685 struct snd_ctl_card_info *info;
686
687 info = kzalloc(sizeof(*info), GFP_KERNEL);
688 if (! info)
689 return -ENOMEM;
690 down_read(&snd_ioctl_rwsem);
691 info->card = card->number;
692 strlcpy(info->id, card->id, sizeof(info->id));
693 strlcpy(info->driver, card->driver, sizeof(info->driver));
694 strlcpy(info->name, card->shortname, sizeof(info->name));
695 strlcpy(info->longname, card->longname, sizeof(info->longname));
696 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
697 strlcpy(info->components, card->components, sizeof(info->components));
698 up_read(&snd_ioctl_rwsem);
699 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
700 kfree(info);
701 return -EFAULT;
702 }
703 kfree(info);
704 return 0;
705}
706
707static int snd_ctl_elem_list(struct snd_card *card,
708 struct snd_ctl_elem_list __user *_list)
709{
710 struct list_head *plist;
711 struct snd_ctl_elem_list list;
712 struct snd_kcontrol *kctl;
713 struct snd_ctl_elem_id *dst, *id;
714 unsigned int offset, space, jidx;
715
716 if (copy_from_user(&list, _list, sizeof(list)))
717 return -EFAULT;
718 offset = list.offset;
719 space = list.space;
720 /* try limit maximum space */
721 if (space > 16384)
722 return -ENOMEM;
723 if (space > 0) {
724 /* allocate temporary buffer for atomic operation */
725 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
726 if (dst == NULL)
727 return -ENOMEM;
728 down_read(&card->controls_rwsem);
729 list.count = card->controls_count;
730 plist = card->controls.next;
731 while (plist != &card->controls) {
732 if (offset == 0)
733 break;
734 kctl = snd_kcontrol(plist);
735 if (offset < kctl->count)
736 break;
737 offset -= kctl->count;
738 plist = plist->next;
739 }
740 list.used = 0;
741 id = dst;
742 while (space > 0 && plist != &card->controls) {
743 kctl = snd_kcontrol(plist);
744 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
745 snd_ctl_build_ioff(id, kctl, jidx);
746 id++;
747 space--;
748 list.used++;
749 }
750 plist = plist->next;
751 offset = 0;
752 }
753 up_read(&card->controls_rwsem);
754 if (list.used > 0 &&
755 copy_to_user(list.pids, dst,
756 list.used * sizeof(struct snd_ctl_elem_id))) {
757 vfree(dst);
758 return -EFAULT;
759 }
760 vfree(dst);
761 } else {
762 down_read(&card->controls_rwsem);
763 list.count = card->controls_count;
764 up_read(&card->controls_rwsem);
765 }
766 if (copy_to_user(_list, &list, sizeof(list)))
767 return -EFAULT;
768 return 0;
769}
770
771static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
772 struct snd_ctl_elem_info *info)
773{
774 struct snd_card *card = ctl->card;
775 struct snd_kcontrol *kctl;
776 struct snd_kcontrol_volatile *vd;
777 unsigned int index_offset;
778 int result;
779
780 down_read(&card->controls_rwsem);
781 kctl = snd_ctl_find_id(card, &info->id);
782 if (kctl == NULL) {
783 up_read(&card->controls_rwsem);
784 return -ENOENT;
785 }
786#ifdef CONFIG_SND_DEBUG
787 info->access = 0;
788#endif
789 result = kctl->info(kctl, info);
790 if (result >= 0) {
791 snd_BUG_ON(info->access);
792 index_offset = snd_ctl_get_ioff(kctl, &info->id);
793 vd = &kctl->vd[index_offset];
794 snd_ctl_build_ioff(&info->id, kctl, index_offset);
795 info->access = vd->access;
796 if (vd->owner) {
797 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
798 if (vd->owner == ctl)
799 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
800 info->owner = pid_vnr(vd->owner->pid);
801 } else {
802 info->owner = -1;
803 }
804 }
805 up_read(&card->controls_rwsem);
806 return result;
807}
808
809static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
810 struct snd_ctl_elem_info __user *_info)
811{
812 struct snd_ctl_elem_info info;
813 int result;
814
815 if (copy_from_user(&info, _info, sizeof(info)))
816 return -EFAULT;
817 snd_power_lock(ctl->card);
818 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
819 if (result >= 0)
820 result = snd_ctl_elem_info(ctl, &info);
821 snd_power_unlock(ctl->card);
822 if (result >= 0)
823 if (copy_to_user(_info, &info, sizeof(info)))
824 return -EFAULT;
825 return result;
826}
827
828static int snd_ctl_elem_read(struct snd_card *card,
829 struct snd_ctl_elem_value *control)
830{
831 struct snd_kcontrol *kctl;
832 struct snd_kcontrol_volatile *vd;
833 unsigned int index_offset;
834 int result;
835
836 down_read(&card->controls_rwsem);
837 kctl = snd_ctl_find_id(card, &control->id);
838 if (kctl == NULL) {
839 result = -ENOENT;
840 } else {
841 index_offset = snd_ctl_get_ioff(kctl, &control->id);
842 vd = &kctl->vd[index_offset];
843 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
844 kctl->get != NULL) {
845 snd_ctl_build_ioff(&control->id, kctl, index_offset);
846 result = kctl->get(kctl, control);
847 } else
848 result = -EPERM;
849 }
850 up_read(&card->controls_rwsem);
851 return result;
852}
853
854static int snd_ctl_elem_read_user(struct snd_card *card,
855 struct snd_ctl_elem_value __user *_control)
856{
857 struct snd_ctl_elem_value *control;
858 int result;
859
860 control = memdup_user(_control, sizeof(*control));
861 if (IS_ERR(control))
862 return PTR_ERR(control);
863
864 snd_power_lock(card);
865 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
866 if (result >= 0)
867 result = snd_ctl_elem_read(card, control);
868 snd_power_unlock(card);
869 if (result >= 0)
870 if (copy_to_user(_control, control, sizeof(*control)))
871 result = -EFAULT;
872 kfree(control);
873 return result;
874}
875
876static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
877 struct snd_ctl_elem_value *control)
878{
879 struct snd_kcontrol *kctl;
880 struct snd_kcontrol_volatile *vd;
881 unsigned int index_offset;
882 int result;
883
884 down_read(&card->controls_rwsem);
885 kctl = snd_ctl_find_id(card, &control->id);
886 if (kctl == NULL) {
887 result = -ENOENT;
888 } else {
889 index_offset = snd_ctl_get_ioff(kctl, &control->id);
890 vd = &kctl->vd[index_offset];
891 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
892 kctl->put == NULL ||
893 (file && vd->owner && vd->owner != file)) {
894 result = -EPERM;
895 } else {
896 snd_ctl_build_ioff(&control->id, kctl, index_offset);
897 result = kctl->put(kctl, control);
898 }
899 if (result > 0) {
900 up_read(&card->controls_rwsem);
901 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
902 &control->id);
903 return 0;
904 }
905 }
906 up_read(&card->controls_rwsem);
907 return result;
908}
909
910static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
911 struct snd_ctl_elem_value __user *_control)
912{
913 struct snd_ctl_elem_value *control;
914 struct snd_card *card;
915 int result;
916
917 control = memdup_user(_control, sizeof(*control));
918 if (IS_ERR(control))
919 return PTR_ERR(control);
920
921 card = file->card;
922 snd_power_lock(card);
923 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
924 if (result >= 0)
925 result = snd_ctl_elem_write(card, file, control);
926 snd_power_unlock(card);
927 if (result >= 0)
928 if (copy_to_user(_control, control, sizeof(*control)))
929 result = -EFAULT;
930 kfree(control);
931 return result;
932}
933
934static int snd_ctl_elem_lock(struct snd_ctl_file *file,
935 struct snd_ctl_elem_id __user *_id)
936{
937 struct snd_card *card = file->card;
938 struct snd_ctl_elem_id id;
939 struct snd_kcontrol *kctl;
940 struct snd_kcontrol_volatile *vd;
941 int result;
942
943 if (copy_from_user(&id, _id, sizeof(id)))
944 return -EFAULT;
945 down_write(&card->controls_rwsem);
946 kctl = snd_ctl_find_id(card, &id);
947 if (kctl == NULL) {
948 result = -ENOENT;
949 } else {
950 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
951 if (vd->owner != NULL)
952 result = -EBUSY;
953 else {
954 vd->owner = file;
955 result = 0;
956 }
957 }
958 up_write(&card->controls_rwsem);
959 return result;
960}
961
962static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
963 struct snd_ctl_elem_id __user *_id)
964{
965 struct snd_card *card = file->card;
966 struct snd_ctl_elem_id id;
967 struct snd_kcontrol *kctl;
968 struct snd_kcontrol_volatile *vd;
969 int result;
970
971 if (copy_from_user(&id, _id, sizeof(id)))
972 return -EFAULT;
973 down_write(&card->controls_rwsem);
974 kctl = snd_ctl_find_id(card, &id);
975 if (kctl == NULL) {
976 result = -ENOENT;
977 } else {
978 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
979 if (vd->owner == NULL)
980 result = -EINVAL;
981 else if (vd->owner != file)
982 result = -EPERM;
983 else {
984 vd->owner = NULL;
985 result = 0;
986 }
987 }
988 up_write(&card->controls_rwsem);
989 return result;
990}
991
992struct user_element {
993 struct snd_ctl_elem_info info;
994 void *elem_data; /* element data */
995 unsigned long elem_data_size; /* size of element data in bytes */
996 void *tlv_data; /* TLV data */
997 unsigned long tlv_data_size; /* TLV data size */
998 void *priv_data; /* private data (like strings for enumerated type) */
999};
1000
1001static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1002 struct snd_ctl_elem_info *uinfo)
1003{
1004 struct user_element *ue = kcontrol->private_data;
1005
1006 *uinfo = ue->info;
1007 return 0;
1008}
1009
1010static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1011 struct snd_ctl_elem_info *uinfo)
1012{
1013 struct user_element *ue = kcontrol->private_data;
1014 const char *names;
1015 unsigned int item;
1016
1017 item = uinfo->value.enumerated.item;
1018
1019 *uinfo = ue->info;
1020
1021 item = min(item, uinfo->value.enumerated.items - 1);
1022 uinfo->value.enumerated.item = item;
1023
1024 names = ue->priv_data;
1025 for (; item > 0; --item)
1026 names += strlen(names) + 1;
1027 strcpy(uinfo->value.enumerated.name, names);
1028
1029 return 0;
1030}
1031
1032static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1033 struct snd_ctl_elem_value *ucontrol)
1034{
1035 struct user_element *ue = kcontrol->private_data;
1036
1037 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1038 return 0;
1039}
1040
1041static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1042 struct snd_ctl_elem_value *ucontrol)
1043{
1044 int change;
1045 struct user_element *ue = kcontrol->private_data;
1046
1047 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1048 if (change)
1049 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1050 return change;
1051}
1052
1053static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1054 int op_flag,
1055 unsigned int size,
1056 unsigned int __user *tlv)
1057{
1058 struct user_element *ue = kcontrol->private_data;
1059 int change = 0;
1060 void *new_data;
1061
1062 if (op_flag > 0) {
1063 if (size > 1024 * 128) /* sane value */
1064 return -EINVAL;
1065
1066 new_data = memdup_user(tlv, size);
1067 if (IS_ERR(new_data))
1068 return PTR_ERR(new_data);
1069 change = ue->tlv_data_size != size;
1070 if (!change)
1071 change = memcmp(ue->tlv_data, new_data, size);
1072 kfree(ue->tlv_data);
1073 ue->tlv_data = new_data;
1074 ue->tlv_data_size = size;
1075 } else {
1076 if (! ue->tlv_data_size || ! ue->tlv_data)
1077 return -ENXIO;
1078 if (size < ue->tlv_data_size)
1079 return -ENOSPC;
1080 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1081 return -EFAULT;
1082 }
1083 return change;
1084}
1085
1086static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1087{
1088 char *names, *p;
1089 size_t buf_len, name_len;
1090 unsigned int i;
1091 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1092
1093 if (ue->info.value.enumerated.names_length > 64 * 1024)
1094 return -EINVAL;
1095
1096 names = memdup_user((const void __user *)user_ptrval,
1097 ue->info.value.enumerated.names_length);
1098 if (IS_ERR(names))
1099 return PTR_ERR(names);
1100
1101 /* check that there are enough valid names */
1102 buf_len = ue->info.value.enumerated.names_length;
1103 p = names;
1104 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1105 name_len = strnlen(p, buf_len);
1106 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1107 kfree(names);
1108 return -EINVAL;
1109 }
1110 p += name_len + 1;
1111 buf_len -= name_len + 1;
1112 }
1113
1114 ue->priv_data = names;
1115 ue->info.value.enumerated.names_ptr = 0;
1116
1117 return 0;
1118}
1119
1120static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1121{
1122 struct user_element *ue = kcontrol->private_data;
1123
1124 kfree(ue->tlv_data);
1125 kfree(ue->priv_data);
1126 kfree(ue);
1127}
1128
1129static int snd_ctl_elem_add(struct snd_ctl_file *file,
1130 struct snd_ctl_elem_info *info, int replace)
1131{
1132 struct snd_card *card = file->card;
1133 struct snd_kcontrol kctl, *_kctl;
1134 unsigned int access;
1135 long private_size;
1136 struct user_element *ue;
1137 int idx, err;
1138
1139 if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1140 return -ENOMEM;
1141 if (info->count < 1)
1142 return -EINVAL;
1143 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1144 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1145 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1146 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1147 info->id.numid = 0;
1148 memset(&kctl, 0, sizeof(kctl));
1149 down_write(&card->controls_rwsem);
1150 _kctl = snd_ctl_find_id(card, &info->id);
1151 err = 0;
1152 if (_kctl) {
1153 if (replace)
1154 err = snd_ctl_remove(card, _kctl);
1155 else
1156 err = -EBUSY;
1157 } else {
1158 if (replace)
1159 err = -ENOENT;
1160 }
1161 up_write(&card->controls_rwsem);
1162 if (err < 0)
1163 return err;
1164 memcpy(&kctl.id, &info->id, sizeof(info->id));
1165 kctl.count = info->owner ? info->owner : 1;
1166 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1167 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1168 kctl.info = snd_ctl_elem_user_enum_info;
1169 else
1170 kctl.info = snd_ctl_elem_user_info;
1171 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1172 kctl.get = snd_ctl_elem_user_get;
1173 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1174 kctl.put = snd_ctl_elem_user_put;
1175 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1176 kctl.tlv.c = snd_ctl_elem_user_tlv;
1177 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1178 }
1179 switch (info->type) {
1180 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1181 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1182 private_size = sizeof(long);
1183 if (info->count > 128)
1184 return -EINVAL;
1185 break;
1186 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1187 private_size = sizeof(long long);
1188 if (info->count > 64)
1189 return -EINVAL;
1190 break;
1191 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1192 private_size = sizeof(unsigned int);
1193 if (info->count > 128 || info->value.enumerated.items == 0)
1194 return -EINVAL;
1195 break;
1196 case SNDRV_CTL_ELEM_TYPE_BYTES:
1197 private_size = sizeof(unsigned char);
1198 if (info->count > 512)
1199 return -EINVAL;
1200 break;
1201 case SNDRV_CTL_ELEM_TYPE_IEC958:
1202 private_size = sizeof(struct snd_aes_iec958);
1203 if (info->count != 1)
1204 return -EINVAL;
1205 break;
1206 default:
1207 return -EINVAL;
1208 }
1209 private_size *= info->count;
1210 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1211 if (ue == NULL)
1212 return -ENOMEM;
1213 ue->info = *info;
1214 ue->info.access = 0;
1215 ue->elem_data = (char *)ue + sizeof(*ue);
1216 ue->elem_data_size = private_size;
1217 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1218 err = snd_ctl_elem_init_enum_names(ue);
1219 if (err < 0) {
1220 kfree(ue);
1221 return err;
1222 }
1223 }
1224 kctl.private_free = snd_ctl_elem_user_free;
1225 _kctl = snd_ctl_new(&kctl, access);
1226 if (_kctl == NULL) {
1227 kfree(ue->priv_data);
1228 kfree(ue);
1229 return -ENOMEM;
1230 }
1231 _kctl->private_data = ue;
1232 for (idx = 0; idx < _kctl->count; idx++)
1233 _kctl->vd[idx].owner = file;
1234 err = snd_ctl_add(card, _kctl);
1235 if (err < 0)
1236 return err;
1237
1238 down_write(&card->controls_rwsem);
1239 card->user_ctl_count++;
1240 up_write(&card->controls_rwsem);
1241
1242 return 0;
1243}
1244
1245static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1246 struct snd_ctl_elem_info __user *_info, int replace)
1247{
1248 struct snd_ctl_elem_info info;
1249 if (copy_from_user(&info, _info, sizeof(info)))
1250 return -EFAULT;
1251 return snd_ctl_elem_add(file, &info, replace);
1252}
1253
1254static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1255 struct snd_ctl_elem_id __user *_id)
1256{
1257 struct snd_ctl_elem_id id;
1258
1259 if (copy_from_user(&id, _id, sizeof(id)))
1260 return -EFAULT;
1261 return snd_ctl_remove_user_ctl(file, &id);
1262}
1263
1264static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1265{
1266 int subscribe;
1267 if (get_user(subscribe, ptr))
1268 return -EFAULT;
1269 if (subscribe < 0) {
1270 subscribe = file->subscribed;
1271 if (put_user(subscribe, ptr))
1272 return -EFAULT;
1273 return 0;
1274 }
1275 if (subscribe) {
1276 file->subscribed = 1;
1277 return 0;
1278 } else if (file->subscribed) {
1279 snd_ctl_empty_read_queue(file);
1280 file->subscribed = 0;
1281 }
1282 return 0;
1283}
1284
1285static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1286 struct snd_ctl_tlv __user *_tlv,
1287 int op_flag)
1288{
1289 struct snd_card *card = file->card;
1290 struct snd_ctl_tlv tlv;
1291 struct snd_kcontrol *kctl;
1292 struct snd_kcontrol_volatile *vd;
1293 unsigned int len;
1294 int err = 0;
1295
1296 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1297 return -EFAULT;
1298 if (tlv.length < sizeof(unsigned int) * 2)
1299 return -EINVAL;
1300 down_read(&card->controls_rwsem);
1301 kctl = snd_ctl_find_numid(card, tlv.numid);
1302 if (kctl == NULL) {
1303 err = -ENOENT;
1304 goto __kctl_end;
1305 }
1306 if (kctl->tlv.p == NULL) {
1307 err = -ENXIO;
1308 goto __kctl_end;
1309 }
1310 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1311 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1312 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1313 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1314 err = -ENXIO;
1315 goto __kctl_end;
1316 }
1317 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1318 if (vd->owner != NULL && vd->owner != file) {
1319 err = -EPERM;
1320 goto __kctl_end;
1321 }
1322 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1323 if (err > 0) {
1324 up_read(&card->controls_rwsem);
1325 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1326 return 0;
1327 }
1328 } else {
1329 if (op_flag) {
1330 err = -ENXIO;
1331 goto __kctl_end;
1332 }
1333 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1334 if (tlv.length < len) {
1335 err = -ENOMEM;
1336 goto __kctl_end;
1337 }
1338 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1339 err = -EFAULT;
1340 }
1341 __kctl_end:
1342 up_read(&card->controls_rwsem);
1343 return err;
1344}
1345
1346static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1347{
1348 struct snd_ctl_file *ctl;
1349 struct snd_card *card;
1350 struct snd_kctl_ioctl *p;
1351 void __user *argp = (void __user *)arg;
1352 int __user *ip = argp;
1353 int err;
1354
1355 ctl = file->private_data;
1356 card = ctl->card;
1357 if (snd_BUG_ON(!card))
1358 return -ENXIO;
1359 switch (cmd) {
1360 case SNDRV_CTL_IOCTL_PVERSION:
1361 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1362 case SNDRV_CTL_IOCTL_CARD_INFO:
1363 return snd_ctl_card_info(card, ctl, cmd, argp);
1364 case SNDRV_CTL_IOCTL_ELEM_LIST:
1365 return snd_ctl_elem_list(card, argp);
1366 case SNDRV_CTL_IOCTL_ELEM_INFO:
1367 return snd_ctl_elem_info_user(ctl, argp);
1368 case SNDRV_CTL_IOCTL_ELEM_READ:
1369 return snd_ctl_elem_read_user(card, argp);
1370 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1371 return snd_ctl_elem_write_user(ctl, argp);
1372 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1373 return snd_ctl_elem_lock(ctl, argp);
1374 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1375 return snd_ctl_elem_unlock(ctl, argp);
1376 case SNDRV_CTL_IOCTL_ELEM_ADD:
1377 return snd_ctl_elem_add_user(ctl, argp, 0);
1378 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1379 return snd_ctl_elem_add_user(ctl, argp, 1);
1380 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1381 return snd_ctl_elem_remove(ctl, argp);
1382 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1383 return snd_ctl_subscribe_events(ctl, ip);
1384 case SNDRV_CTL_IOCTL_TLV_READ:
1385 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1386 case SNDRV_CTL_IOCTL_TLV_WRITE:
1387 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1388 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1389 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1390 case SNDRV_CTL_IOCTL_POWER:
1391 return -ENOPROTOOPT;
1392 case SNDRV_CTL_IOCTL_POWER_STATE:
1393#ifdef CONFIG_PM
1394 return put_user(card->power_state, ip) ? -EFAULT : 0;
1395#else
1396 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1397#endif
1398 }
1399 down_read(&snd_ioctl_rwsem);
1400 list_for_each_entry(p, &snd_control_ioctls, list) {
1401 err = p->fioctl(card, ctl, cmd, arg);
1402 if (err != -ENOIOCTLCMD) {
1403 up_read(&snd_ioctl_rwsem);
1404 return err;
1405 }
1406 }
1407 up_read(&snd_ioctl_rwsem);
1408 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1409 return -ENOTTY;
1410}
1411
1412static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1413 size_t count, loff_t * offset)
1414{
1415 struct snd_ctl_file *ctl;
1416 int err = 0;
1417 ssize_t result = 0;
1418
1419 ctl = file->private_data;
1420 if (snd_BUG_ON(!ctl || !ctl->card))
1421 return -ENXIO;
1422 if (!ctl->subscribed)
1423 return -EBADFD;
1424 if (count < sizeof(struct snd_ctl_event))
1425 return -EINVAL;
1426 spin_lock_irq(&ctl->read_lock);
1427 while (count >= sizeof(struct snd_ctl_event)) {
1428 struct snd_ctl_event ev;
1429 struct snd_kctl_event *kev;
1430 while (list_empty(&ctl->events)) {
1431 wait_queue_t wait;
1432 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1433 err = -EAGAIN;
1434 goto __end_lock;
1435 }
1436 init_waitqueue_entry(&wait, current);
1437 add_wait_queue(&ctl->change_sleep, &wait);
1438 set_current_state(TASK_INTERRUPTIBLE);
1439 spin_unlock_irq(&ctl->read_lock);
1440 schedule();
1441 remove_wait_queue(&ctl->change_sleep, &wait);
1442 if (ctl->card->shutdown)
1443 return -ENODEV;
1444 if (signal_pending(current))
1445 return -ERESTARTSYS;
1446 spin_lock_irq(&ctl->read_lock);
1447 }
1448 kev = snd_kctl_event(ctl->events.next);
1449 ev.type = SNDRV_CTL_EVENT_ELEM;
1450 ev.data.elem.mask = kev->mask;
1451 ev.data.elem.id = kev->id;
1452 list_del(&kev->list);
1453 spin_unlock_irq(&ctl->read_lock);
1454 kfree(kev);
1455 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1456 err = -EFAULT;
1457 goto __end;
1458 }
1459 spin_lock_irq(&ctl->read_lock);
1460 buffer += sizeof(struct snd_ctl_event);
1461 count -= sizeof(struct snd_ctl_event);
1462 result += sizeof(struct snd_ctl_event);
1463 }
1464 __end_lock:
1465 spin_unlock_irq(&ctl->read_lock);
1466 __end:
1467 return result > 0 ? result : err;
1468}
1469
1470static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1471{
1472 unsigned int mask;
1473 struct snd_ctl_file *ctl;
1474
1475 ctl = file->private_data;
1476 if (!ctl->subscribed)
1477 return 0;
1478 poll_wait(file, &ctl->change_sleep, wait);
1479
1480 mask = 0;
1481 if (!list_empty(&ctl->events))
1482 mask |= POLLIN | POLLRDNORM;
1483
1484 return mask;
1485}
1486
1487/*
1488 * register the device-specific control-ioctls.
1489 * called from each device manager like pcm.c, hwdep.c, etc.
1490 */
1491static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1492{
1493 struct snd_kctl_ioctl *pn;
1494
1495 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1496 if (pn == NULL)
1497 return -ENOMEM;
1498 pn->fioctl = fcn;
1499 down_write(&snd_ioctl_rwsem);
1500 list_add_tail(&pn->list, lists);
1501 up_write(&snd_ioctl_rwsem);
1502 return 0;
1503}
1504
1505int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1506{
1507 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1508}
1509
1510EXPORT_SYMBOL(snd_ctl_register_ioctl);
1511
1512#ifdef CONFIG_COMPAT
1513int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1514{
1515 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1516}
1517
1518EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1519#endif
1520
1521/*
1522 * de-register the device-specific control-ioctls.
1523 */
1524static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1525 struct list_head *lists)
1526{
1527 struct snd_kctl_ioctl *p;
1528
1529 if (snd_BUG_ON(!fcn))
1530 return -EINVAL;
1531 down_write(&snd_ioctl_rwsem);
1532 list_for_each_entry(p, lists, list) {
1533 if (p->fioctl == fcn) {
1534 list_del(&p->list);
1535 up_write(&snd_ioctl_rwsem);
1536 kfree(p);
1537 return 0;
1538 }
1539 }
1540 up_write(&snd_ioctl_rwsem);
1541 snd_BUG();
1542 return -EINVAL;
1543}
1544
1545int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1546{
1547 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1548}
1549
1550EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1551
1552#ifdef CONFIG_COMPAT
1553int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1554{
1555 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1556}
1557
1558EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1559#endif
1560
1561static int snd_ctl_fasync(int fd, struct file * file, int on)
1562{
1563 struct snd_ctl_file *ctl;
1564
1565 ctl = file->private_data;
1566 return fasync_helper(fd, file, on, &ctl->fasync);
1567}
1568
1569/*
1570 * ioctl32 compat
1571 */
1572#ifdef CONFIG_COMPAT
1573#include "control_compat.c"
1574#else
1575#define snd_ctl_ioctl_compat NULL
1576#endif
1577
1578/*
1579 * INIT PART
1580 */
1581
1582static const struct file_operations snd_ctl_f_ops =
1583{
1584 .owner = THIS_MODULE,
1585 .read = snd_ctl_read,
1586 .open = snd_ctl_open,
1587 .release = snd_ctl_release,
1588 .llseek = no_llseek,
1589 .poll = snd_ctl_poll,
1590 .unlocked_ioctl = snd_ctl_ioctl,
1591 .compat_ioctl = snd_ctl_ioctl_compat,
1592 .fasync = snd_ctl_fasync,
1593};
1594
1595/*
1596 * registration of the control device
1597 */
1598static int snd_ctl_dev_register(struct snd_device *device)
1599{
1600 struct snd_card *card = device->device_data;
1601 int err, cardnum;
1602 char name[16];
1603
1604 if (snd_BUG_ON(!card))
1605 return -ENXIO;
1606 cardnum = card->number;
1607 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1608 return -ENXIO;
1609 sprintf(name, "controlC%i", cardnum);
1610 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1611 &snd_ctl_f_ops, card, name)) < 0)
1612 return err;
1613 return 0;
1614}
1615
1616/*
1617 * disconnection of the control device
1618 */
1619static int snd_ctl_dev_disconnect(struct snd_device *device)
1620{
1621 struct snd_card *card = device->device_data;
1622 struct snd_ctl_file *ctl;
1623 int err, cardnum;
1624
1625 if (snd_BUG_ON(!card))
1626 return -ENXIO;
1627 cardnum = card->number;
1628 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1629 return -ENXIO;
1630
1631 read_lock(&card->ctl_files_rwlock);
1632 list_for_each_entry(ctl, &card->ctl_files, list) {
1633 wake_up(&ctl->change_sleep);
1634 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1635 }
1636 read_unlock(&card->ctl_files_rwlock);
1637
1638 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1639 card, -1)) < 0)
1640 return err;
1641 return 0;
1642}
1643
1644/*
1645 * free all controls
1646 */
1647static int snd_ctl_dev_free(struct snd_device *device)
1648{
1649 struct snd_card *card = device->device_data;
1650 struct snd_kcontrol *control;
1651
1652 down_write(&card->controls_rwsem);
1653 while (!list_empty(&card->controls)) {
1654 control = snd_kcontrol(card->controls.next);
1655 snd_ctl_remove(card, control);
1656 }
1657 up_write(&card->controls_rwsem);
1658 return 0;
1659}
1660
1661/*
1662 * create control core:
1663 * called from init.c
1664 */
1665int snd_ctl_create(struct snd_card *card)
1666{
1667 static struct snd_device_ops ops = {
1668 .dev_free = snd_ctl_dev_free,
1669 .dev_register = snd_ctl_dev_register,
1670 .dev_disconnect = snd_ctl_dev_disconnect,
1671 };
1672
1673 if (snd_BUG_ON(!card))
1674 return -ENXIO;
1675 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1676}
1677
1678/*
1679 * Frequently used control callbacks/helpers
1680 */
1681int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1682 struct snd_ctl_elem_info *uinfo)
1683{
1684 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1685 uinfo->count = 1;
1686 uinfo->value.integer.min = 0;
1687 uinfo->value.integer.max = 1;
1688 return 0;
1689}
1690
1691EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1692
1693int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1694 struct snd_ctl_elem_info *uinfo)
1695{
1696 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1697 uinfo->count = 2;
1698 uinfo->value.integer.min = 0;
1699 uinfo->value.integer.max = 1;
1700 return 0;
1701}
1702
1703EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1704
1705/**
1706 * snd_ctl_enum_info - fills the info structure for an enumerated control
1707 * @info: the structure to be filled
1708 * @channels: the number of the control's channels; often one
1709 * @items: the number of control values; also the size of @names
1710 * @names: an array containing the names of all control values
1711 *
1712 * Sets all required fields in @info to their appropriate values.
1713 * If the control's accessibility is not the default (readable and writable),
1714 * the caller has to fill @info->access.
1715 *
1716 * Return: Zero.
1717 */
1718int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1719 unsigned int items, const char *const names[])
1720{
1721 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1722 info->count = channels;
1723 info->value.enumerated.items = items;
1724 if (info->value.enumerated.item >= items)
1725 info->value.enumerated.item = items - 1;
1726 strlcpy(info->value.enumerated.name,
1727 names[info->value.enumerated.item],
1728 sizeof(info->value.enumerated.name));
1729 return 0;
1730}
1731EXPORT_SYMBOL(snd_ctl_enum_info);
1/*
2 * Routines for driver control interface
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include <linux/threads.h>
23#include <linux/interrupt.h>
24#include <linux/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>
32
33/* max number of user-defined controls */
34#define MAX_USER_CONTROLS 32
35#define MAX_CONTROL_COUNT 1028
36
37struct snd_kctl_ioctl {
38 struct list_head list; /* list of all ioctls */
39 snd_kctl_ioctl_func_t fioctl;
40};
41
42static DECLARE_RWSEM(snd_ioctl_rwsem);
43static LIST_HEAD(snd_control_ioctls);
44#ifdef CONFIG_COMPAT
45static LIST_HEAD(snd_control_compat_ioctls);
46#endif
47
48static 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 err = nonseekable_open(inode, file);
56 if (err < 0)
57 return err;
58
59 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
60 if (!card) {
61 err = -ENODEV;
62 goto __error1;
63 }
64 err = snd_card_file_add(card, file);
65 if (err < 0) {
66 err = -ENODEV;
67 goto __error1;
68 }
69 if (!try_module_get(card->module)) {
70 err = -EFAULT;
71 goto __error2;
72 }
73 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
74 if (ctl == NULL) {
75 err = -ENOMEM;
76 goto __error;
77 }
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 return 0;
90
91 __error:
92 module_put(card->module);
93 __error2:
94 snd_card_file_remove(card, file);
95 __error1:
96 return err;
97}
98
99static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
100{
101 unsigned long flags;
102 struct snd_kctl_event *cread;
103
104 spin_lock_irqsave(&ctl->read_lock, flags);
105 while (!list_empty(&ctl->events)) {
106 cread = snd_kctl_event(ctl->events.next);
107 list_del(&cread->list);
108 kfree(cread);
109 }
110 spin_unlock_irqrestore(&ctl->read_lock, flags);
111}
112
113static int snd_ctl_release(struct inode *inode, struct file *file)
114{
115 unsigned long flags;
116 struct snd_card *card;
117 struct snd_ctl_file *ctl;
118 struct snd_kcontrol *control;
119 unsigned int idx;
120
121 ctl = file->private_data;
122 file->private_data = NULL;
123 card = ctl->card;
124 write_lock_irqsave(&card->ctl_files_rwlock, flags);
125 list_del(&ctl->list);
126 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
127 down_write(&card->controls_rwsem);
128 list_for_each_entry(control, &card->controls, list)
129 for (idx = 0; idx < control->count; idx++)
130 if (control->vd[idx].owner == ctl)
131 control->vd[idx].owner = NULL;
132 up_write(&card->controls_rwsem);
133 snd_ctl_empty_read_queue(ctl);
134 put_pid(ctl->pid);
135 kfree(ctl);
136 module_put(card->module);
137 snd_card_file_remove(card, file);
138 return 0;
139}
140
141void snd_ctl_notify(struct snd_card *card, unsigned int mask,
142 struct snd_ctl_elem_id *id)
143{
144 unsigned long flags;
145 struct snd_ctl_file *ctl;
146 struct snd_kctl_event *ev;
147
148 if (snd_BUG_ON(!card || !id))
149 return;
150 read_lock(&card->ctl_files_rwlock);
151#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
152 card->mixer_oss_change_count++;
153#endif
154 list_for_each_entry(ctl, &card->ctl_files, list) {
155 if (!ctl->subscribed)
156 continue;
157 spin_lock_irqsave(&ctl->read_lock, flags);
158 list_for_each_entry(ev, &ctl->events, list) {
159 if (ev->id.numid == id->numid) {
160 ev->mask |= mask;
161 goto _found;
162 }
163 }
164 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
165 if (ev) {
166 ev->id = *id;
167 ev->mask = mask;
168 list_add_tail(&ev->list, &ctl->events);
169 } else {
170 snd_printk(KERN_ERR "No memory available to allocate event\n");
171 }
172 _found:
173 wake_up(&ctl->change_sleep);
174 spin_unlock_irqrestore(&ctl->read_lock, flags);
175 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
176 }
177 read_unlock(&card->ctl_files_rwlock);
178}
179
180EXPORT_SYMBOL(snd_ctl_notify);
181
182/**
183 * snd_ctl_new - create a control instance from the template
184 * @control: the control template
185 * @access: the default control access
186 *
187 * Allocates a new struct snd_kcontrol instance and copies the given template
188 * to the new instance. It does not copy volatile data (access).
189 *
190 * Returns the pointer of the new instance, or NULL on failure.
191 */
192static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
193 unsigned int access)
194{
195 struct snd_kcontrol *kctl;
196 unsigned int idx;
197
198 if (snd_BUG_ON(!control || !control->count))
199 return NULL;
200
201 if (control->count > MAX_CONTROL_COUNT)
202 return NULL;
203
204 kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
205 if (kctl == NULL) {
206 snd_printk(KERN_ERR "Cannot allocate control instance\n");
207 return NULL;
208 }
209 *kctl = *control;
210 for (idx = 0; idx < kctl->count; idx++)
211 kctl->vd[idx].access = access;
212 return kctl;
213}
214
215/**
216 * snd_ctl_new1 - create a control instance from the template
217 * @ncontrol: the initialization record
218 * @private_data: the private data to set
219 *
220 * Allocates a new struct snd_kcontrol instance and initialize from the given
221 * template. When the access field of ncontrol is 0, it's assumed as
222 * READWRITE access. When the count field is 0, it's assumes as one.
223 *
224 * Returns the pointer of the newly generated instance, or NULL on failure.
225 */
226struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
227 void *private_data)
228{
229 struct snd_kcontrol kctl;
230 unsigned int access;
231
232 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
233 return NULL;
234 memset(&kctl, 0, sizeof(kctl));
235 kctl.id.iface = ncontrol->iface;
236 kctl.id.device = ncontrol->device;
237 kctl.id.subdevice = ncontrol->subdevice;
238 if (ncontrol->name) {
239 strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
240 if (strcmp(ncontrol->name, kctl.id.name) != 0)
241 snd_printk(KERN_WARNING
242 "Control name '%s' truncated to '%s'\n",
243 ncontrol->name, kctl.id.name);
244 }
245 kctl.id.index = ncontrol->index;
246 kctl.count = ncontrol->count ? ncontrol->count : 1;
247 access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
248 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
249 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
250 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
251 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND|
252 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
253 kctl.info = ncontrol->info;
254 kctl.get = ncontrol->get;
255 kctl.put = ncontrol->put;
256 kctl.tlv.p = ncontrol->tlv.p;
257 kctl.private_value = ncontrol->private_value;
258 kctl.private_data = private_data;
259 return snd_ctl_new(&kctl, access);
260}
261
262EXPORT_SYMBOL(snd_ctl_new1);
263
264/**
265 * snd_ctl_free_one - release the control instance
266 * @kcontrol: the control instance
267 *
268 * Releases the control instance created via snd_ctl_new()
269 * or snd_ctl_new1().
270 * Don't call this after the control was added to the card.
271 */
272void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
273{
274 if (kcontrol) {
275 if (kcontrol->private_free)
276 kcontrol->private_free(kcontrol);
277 kfree(kcontrol);
278 }
279}
280
281EXPORT_SYMBOL(snd_ctl_free_one);
282
283static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
284 unsigned int count)
285{
286 struct snd_kcontrol *kctl;
287
288 list_for_each_entry(kctl, &card->controls, list) {
289 if (kctl->id.numid < card->last_numid + 1 + count &&
290 kctl->id.numid + kctl->count > card->last_numid + 1) {
291 card->last_numid = kctl->id.numid + kctl->count - 1;
292 return true;
293 }
294 }
295 return false;
296}
297
298static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
299{
300 unsigned int iter = 100000;
301
302 while (snd_ctl_remove_numid_conflict(card, count)) {
303 if (--iter == 0) {
304 /* this situation is very unlikely */
305 snd_printk(KERN_ERR "unable to allocate new control numid\n");
306 return -ENOMEM;
307 }
308 }
309 return 0;
310}
311
312/**
313 * snd_ctl_add - add the control instance to the card
314 * @card: the card instance
315 * @kcontrol: the control instance to add
316 *
317 * Adds the control instance created via snd_ctl_new() or
318 * snd_ctl_new1() to the given card. Assigns also an unique
319 * numid used for fast search.
320 *
321 * Returns zero if successful, or a negative error code on failure.
322 *
323 * It frees automatically the control which cannot be added.
324 */
325int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
326{
327 struct snd_ctl_elem_id id;
328 unsigned int idx;
329 int err = -EINVAL;
330
331 if (! kcontrol)
332 return err;
333 if (snd_BUG_ON(!card || !kcontrol->info))
334 goto error;
335 id = kcontrol->id;
336 down_write(&card->controls_rwsem);
337 if (snd_ctl_find_id(card, &id)) {
338 up_write(&card->controls_rwsem);
339 snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
340 id.iface,
341 id.device,
342 id.subdevice,
343 id.name,
344 id.index);
345 err = -EBUSY;
346 goto error;
347 }
348 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
349 up_write(&card->controls_rwsem);
350 err = -ENOMEM;
351 goto error;
352 }
353 list_add_tail(&kcontrol->list, &card->controls);
354 card->controls_count += kcontrol->count;
355 kcontrol->id.numid = card->last_numid + 1;
356 card->last_numid += kcontrol->count;
357 up_write(&card->controls_rwsem);
358 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
359 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
360 return 0;
361
362 error:
363 snd_ctl_free_one(kcontrol);
364 return err;
365}
366
367EXPORT_SYMBOL(snd_ctl_add);
368
369/**
370 * snd_ctl_replace - replace the control instance of the card
371 * @card: the card instance
372 * @kcontrol: the control instance to replace
373 * @add_on_replace: add the control if not already added
374 *
375 * Replaces the given control. If the given control does not exist
376 * and the add_on_replace flag is set, the control is added. If the
377 * control exists, it is destroyed first.
378 *
379 * Returns zero if successful, or a negative error code on failure.
380 *
381 * It frees automatically the control which cannot be added or replaced.
382 */
383int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
384 bool add_on_replace)
385{
386 struct snd_ctl_elem_id id;
387 unsigned int idx;
388 struct snd_kcontrol *old;
389 int ret;
390
391 if (!kcontrol)
392 return -EINVAL;
393 if (snd_BUG_ON(!card || !kcontrol->info)) {
394 ret = -EINVAL;
395 goto error;
396 }
397 id = kcontrol->id;
398 down_write(&card->controls_rwsem);
399 old = snd_ctl_find_id(card, &id);
400 if (!old) {
401 if (add_on_replace)
402 goto add;
403 up_write(&card->controls_rwsem);
404 ret = -EINVAL;
405 goto error;
406 }
407 ret = snd_ctl_remove(card, old);
408 if (ret < 0) {
409 up_write(&card->controls_rwsem);
410 goto error;
411 }
412add:
413 if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
414 up_write(&card->controls_rwsem);
415 ret = -ENOMEM;
416 goto error;
417 }
418 list_add_tail(&kcontrol->list, &card->controls);
419 card->controls_count += kcontrol->count;
420 kcontrol->id.numid = card->last_numid + 1;
421 card->last_numid += kcontrol->count;
422 up_write(&card->controls_rwsem);
423 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
424 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
425 return 0;
426
427error:
428 snd_ctl_free_one(kcontrol);
429 return ret;
430}
431EXPORT_SYMBOL(snd_ctl_replace);
432
433/**
434 * snd_ctl_remove - remove the control from the card and release it
435 * @card: the card instance
436 * @kcontrol: the control instance to remove
437 *
438 * Removes the control from the card and then releases the instance.
439 * You don't need to call snd_ctl_free_one(). You must be in
440 * the write lock - down_write(&card->controls_rwsem).
441 *
442 * Returns 0 if successful, or a negative error code on failure.
443 */
444int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
445{
446 struct snd_ctl_elem_id id;
447 unsigned int idx;
448
449 if (snd_BUG_ON(!card || !kcontrol))
450 return -EINVAL;
451 list_del(&kcontrol->list);
452 card->controls_count -= kcontrol->count;
453 id = kcontrol->id;
454 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
455 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
456 snd_ctl_free_one(kcontrol);
457 return 0;
458}
459
460EXPORT_SYMBOL(snd_ctl_remove);
461
462/**
463 * snd_ctl_remove_id - remove the control of the given id and release it
464 * @card: the card instance
465 * @id: the control id to remove
466 *
467 * Finds the control instance with the given id, removes it from the
468 * card list and releases it.
469 *
470 * Returns 0 if successful, or a negative error code on failure.
471 */
472int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
473{
474 struct snd_kcontrol *kctl;
475 int ret;
476
477 down_write(&card->controls_rwsem);
478 kctl = snd_ctl_find_id(card, id);
479 if (kctl == NULL) {
480 up_write(&card->controls_rwsem);
481 return -ENOENT;
482 }
483 ret = snd_ctl_remove(card, kctl);
484 up_write(&card->controls_rwsem);
485 return ret;
486}
487
488EXPORT_SYMBOL(snd_ctl_remove_id);
489
490/**
491 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
492 * @file: active control handle
493 * @id: the control id to remove
494 *
495 * Finds the control instance with the given id, removes it from the
496 * card list and releases it.
497 *
498 * Returns 0 if successful, or a negative error code on failure.
499 */
500static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
501 struct snd_ctl_elem_id *id)
502{
503 struct snd_card *card = file->card;
504 struct snd_kcontrol *kctl;
505 int idx, ret;
506
507 down_write(&card->controls_rwsem);
508 kctl = snd_ctl_find_id(card, id);
509 if (kctl == NULL) {
510 ret = -ENOENT;
511 goto error;
512 }
513 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
514 ret = -EINVAL;
515 goto error;
516 }
517 for (idx = 0; idx < kctl->count; idx++)
518 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
519 ret = -EBUSY;
520 goto error;
521 }
522 ret = snd_ctl_remove(card, kctl);
523 if (ret < 0)
524 goto error;
525 card->user_ctl_count--;
526error:
527 up_write(&card->controls_rwsem);
528 return ret;
529}
530
531/**
532 * snd_ctl_activate_id - activate/inactivate the control of the given id
533 * @card: the card instance
534 * @id: the control id to activate/inactivate
535 * @active: non-zero to activate
536 *
537 * Finds the control instance with the given id, and activate or
538 * inactivate the control together with notification, if changed.
539 *
540 * Returns 0 if unchanged, 1 if changed, or a negative error code on failure.
541 */
542int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
543 int active)
544{
545 struct snd_kcontrol *kctl;
546 struct snd_kcontrol_volatile *vd;
547 unsigned int index_offset;
548 int ret;
549
550 down_write(&card->controls_rwsem);
551 kctl = snd_ctl_find_id(card, id);
552 if (kctl == NULL) {
553 ret = -ENOENT;
554 goto unlock;
555 }
556 index_offset = snd_ctl_get_ioff(kctl, &kctl->id);
557 vd = &kctl->vd[index_offset];
558 ret = 0;
559 if (active) {
560 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
561 goto unlock;
562 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
563 } else {
564 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
565 goto unlock;
566 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
567 }
568 ret = 1;
569 unlock:
570 up_write(&card->controls_rwsem);
571 if (ret > 0)
572 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
573 return ret;
574}
575EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
576
577/**
578 * snd_ctl_rename_id - replace the id of a control on the card
579 * @card: the card instance
580 * @src_id: the old id
581 * @dst_id: the new id
582 *
583 * Finds the control with the old id from the card, and replaces the
584 * id with the new one.
585 *
586 * Returns zero if successful, or a negative error code on failure.
587 */
588int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
589 struct snd_ctl_elem_id *dst_id)
590{
591 struct snd_kcontrol *kctl;
592
593 down_write(&card->controls_rwsem);
594 kctl = snd_ctl_find_id(card, src_id);
595 if (kctl == NULL) {
596 up_write(&card->controls_rwsem);
597 return -ENOENT;
598 }
599 kctl->id = *dst_id;
600 kctl->id.numid = card->last_numid + 1;
601 card->last_numid += kctl->count;
602 up_write(&card->controls_rwsem);
603 return 0;
604}
605
606EXPORT_SYMBOL(snd_ctl_rename_id);
607
608/**
609 * snd_ctl_find_numid - find the control instance with the given number-id
610 * @card: the card instance
611 * @numid: the number-id to search
612 *
613 * Finds the control instance with the given number-id from the card.
614 *
615 * Returns the pointer of the instance if found, or NULL if not.
616 *
617 * The caller must down card->controls_rwsem before calling this function
618 * (if the race condition can happen).
619 */
620struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
621{
622 struct snd_kcontrol *kctl;
623
624 if (snd_BUG_ON(!card || !numid))
625 return NULL;
626 list_for_each_entry(kctl, &card->controls, list) {
627 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
628 return kctl;
629 }
630 return NULL;
631}
632
633EXPORT_SYMBOL(snd_ctl_find_numid);
634
635/**
636 * snd_ctl_find_id - find the control instance with the given id
637 * @card: the card instance
638 * @id: the id to search
639 *
640 * Finds the control instance with the given id from the card.
641 *
642 * Returns the pointer of the instance if found, or NULL if not.
643 *
644 * The caller must down card->controls_rwsem before calling this function
645 * (if the race condition can happen).
646 */
647struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
648 struct snd_ctl_elem_id *id)
649{
650 struct snd_kcontrol *kctl;
651
652 if (snd_BUG_ON(!card || !id))
653 return NULL;
654 if (id->numid != 0)
655 return snd_ctl_find_numid(card, id->numid);
656 list_for_each_entry(kctl, &card->controls, list) {
657 if (kctl->id.iface != id->iface)
658 continue;
659 if (kctl->id.device != id->device)
660 continue;
661 if (kctl->id.subdevice != id->subdevice)
662 continue;
663 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
664 continue;
665 if (kctl->id.index > id->index)
666 continue;
667 if (kctl->id.index + kctl->count <= id->index)
668 continue;
669 return kctl;
670 }
671 return NULL;
672}
673
674EXPORT_SYMBOL(snd_ctl_find_id);
675
676static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
677 unsigned int cmd, void __user *arg)
678{
679 struct snd_ctl_card_info *info;
680
681 info = kzalloc(sizeof(*info), GFP_KERNEL);
682 if (! info)
683 return -ENOMEM;
684 down_read(&snd_ioctl_rwsem);
685 info->card = card->number;
686 strlcpy(info->id, card->id, sizeof(info->id));
687 strlcpy(info->driver, card->driver, sizeof(info->driver));
688 strlcpy(info->name, card->shortname, sizeof(info->name));
689 strlcpy(info->longname, card->longname, sizeof(info->longname));
690 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
691 strlcpy(info->components, card->components, sizeof(info->components));
692 up_read(&snd_ioctl_rwsem);
693 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
694 kfree(info);
695 return -EFAULT;
696 }
697 kfree(info);
698 return 0;
699}
700
701static int snd_ctl_elem_list(struct snd_card *card,
702 struct snd_ctl_elem_list __user *_list)
703{
704 struct list_head *plist;
705 struct snd_ctl_elem_list list;
706 struct snd_kcontrol *kctl;
707 struct snd_ctl_elem_id *dst, *id;
708 unsigned int offset, space, jidx;
709
710 if (copy_from_user(&list, _list, sizeof(list)))
711 return -EFAULT;
712 offset = list.offset;
713 space = list.space;
714 /* try limit maximum space */
715 if (space > 16384)
716 return -ENOMEM;
717 if (space > 0) {
718 /* allocate temporary buffer for atomic operation */
719 dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
720 if (dst == NULL)
721 return -ENOMEM;
722 down_read(&card->controls_rwsem);
723 list.count = card->controls_count;
724 plist = card->controls.next;
725 while (plist != &card->controls) {
726 if (offset == 0)
727 break;
728 kctl = snd_kcontrol(plist);
729 if (offset < kctl->count)
730 break;
731 offset -= kctl->count;
732 plist = plist->next;
733 }
734 list.used = 0;
735 id = dst;
736 while (space > 0 && plist != &card->controls) {
737 kctl = snd_kcontrol(plist);
738 for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
739 snd_ctl_build_ioff(id, kctl, jidx);
740 id++;
741 space--;
742 list.used++;
743 }
744 plist = plist->next;
745 offset = 0;
746 }
747 up_read(&card->controls_rwsem);
748 if (list.used > 0 &&
749 copy_to_user(list.pids, dst,
750 list.used * sizeof(struct snd_ctl_elem_id))) {
751 vfree(dst);
752 return -EFAULT;
753 }
754 vfree(dst);
755 } else {
756 down_read(&card->controls_rwsem);
757 list.count = card->controls_count;
758 up_read(&card->controls_rwsem);
759 }
760 if (copy_to_user(_list, &list, sizeof(list)))
761 return -EFAULT;
762 return 0;
763}
764
765static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
766 struct snd_ctl_elem_info *info)
767{
768 struct snd_card *card = ctl->card;
769 struct snd_kcontrol *kctl;
770 struct snd_kcontrol_volatile *vd;
771 unsigned int index_offset;
772 int result;
773
774 down_read(&card->controls_rwsem);
775 kctl = snd_ctl_find_id(card, &info->id);
776 if (kctl == NULL) {
777 up_read(&card->controls_rwsem);
778 return -ENOENT;
779 }
780#ifdef CONFIG_SND_DEBUG
781 info->access = 0;
782#endif
783 result = kctl->info(kctl, info);
784 if (result >= 0) {
785 snd_BUG_ON(info->access);
786 index_offset = snd_ctl_get_ioff(kctl, &info->id);
787 vd = &kctl->vd[index_offset];
788 snd_ctl_build_ioff(&info->id, kctl, index_offset);
789 info->access = vd->access;
790 if (vd->owner) {
791 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
792 if (vd->owner == ctl)
793 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
794 info->owner = pid_vnr(vd->owner->pid);
795 } else {
796 info->owner = -1;
797 }
798 }
799 up_read(&card->controls_rwsem);
800 return result;
801}
802
803static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
804 struct snd_ctl_elem_info __user *_info)
805{
806 struct snd_ctl_elem_info info;
807 int result;
808
809 if (copy_from_user(&info, _info, sizeof(info)))
810 return -EFAULT;
811 snd_power_lock(ctl->card);
812 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
813 if (result >= 0)
814 result = snd_ctl_elem_info(ctl, &info);
815 snd_power_unlock(ctl->card);
816 if (result >= 0)
817 if (copy_to_user(_info, &info, sizeof(info)))
818 return -EFAULT;
819 return result;
820}
821
822static int snd_ctl_elem_read(struct snd_card *card,
823 struct snd_ctl_elem_value *control)
824{
825 struct snd_kcontrol *kctl;
826 struct snd_kcontrol_volatile *vd;
827 unsigned int index_offset;
828 int result;
829
830 down_read(&card->controls_rwsem);
831 kctl = snd_ctl_find_id(card, &control->id);
832 if (kctl == NULL) {
833 result = -ENOENT;
834 } else {
835 index_offset = snd_ctl_get_ioff(kctl, &control->id);
836 vd = &kctl->vd[index_offset];
837 if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) &&
838 kctl->get != NULL) {
839 snd_ctl_build_ioff(&control->id, kctl, index_offset);
840 result = kctl->get(kctl, control);
841 } else
842 result = -EPERM;
843 }
844 up_read(&card->controls_rwsem);
845 return result;
846}
847
848static int snd_ctl_elem_read_user(struct snd_card *card,
849 struct snd_ctl_elem_value __user *_control)
850{
851 struct snd_ctl_elem_value *control;
852 int result;
853
854 control = memdup_user(_control, sizeof(*control));
855 if (IS_ERR(control))
856 return PTR_ERR(control);
857
858 snd_power_lock(card);
859 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
860 if (result >= 0)
861 result = snd_ctl_elem_read(card, control);
862 snd_power_unlock(card);
863 if (result >= 0)
864 if (copy_to_user(_control, control, sizeof(*control)))
865 result = -EFAULT;
866 kfree(control);
867 return result;
868}
869
870static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
871 struct snd_ctl_elem_value *control)
872{
873 struct snd_kcontrol *kctl;
874 struct snd_kcontrol_volatile *vd;
875 unsigned int index_offset;
876 int result;
877
878 down_read(&card->controls_rwsem);
879 kctl = snd_ctl_find_id(card, &control->id);
880 if (kctl == NULL) {
881 result = -ENOENT;
882 } else {
883 index_offset = snd_ctl_get_ioff(kctl, &control->id);
884 vd = &kctl->vd[index_offset];
885 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
886 kctl->put == NULL ||
887 (file && vd->owner && vd->owner != file)) {
888 result = -EPERM;
889 } else {
890 snd_ctl_build_ioff(&control->id, kctl, index_offset);
891 result = kctl->put(kctl, control);
892 }
893 if (result > 0) {
894 up_read(&card->controls_rwsem);
895 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
896 &control->id);
897 return 0;
898 }
899 }
900 up_read(&card->controls_rwsem);
901 return result;
902}
903
904static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
905 struct snd_ctl_elem_value __user *_control)
906{
907 struct snd_ctl_elem_value *control;
908 struct snd_card *card;
909 int result;
910
911 control = memdup_user(_control, sizeof(*control));
912 if (IS_ERR(control))
913 return PTR_ERR(control);
914
915 card = file->card;
916 snd_power_lock(card);
917 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
918 if (result >= 0)
919 result = snd_ctl_elem_write(card, file, control);
920 snd_power_unlock(card);
921 if (result >= 0)
922 if (copy_to_user(_control, control, sizeof(*control)))
923 result = -EFAULT;
924 kfree(control);
925 return result;
926}
927
928static int snd_ctl_elem_lock(struct snd_ctl_file *file,
929 struct snd_ctl_elem_id __user *_id)
930{
931 struct snd_card *card = file->card;
932 struct snd_ctl_elem_id id;
933 struct snd_kcontrol *kctl;
934 struct snd_kcontrol_volatile *vd;
935 int result;
936
937 if (copy_from_user(&id, _id, sizeof(id)))
938 return -EFAULT;
939 down_write(&card->controls_rwsem);
940 kctl = snd_ctl_find_id(card, &id);
941 if (kctl == NULL) {
942 result = -ENOENT;
943 } else {
944 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
945 if (vd->owner != NULL)
946 result = -EBUSY;
947 else {
948 vd->owner = file;
949 result = 0;
950 }
951 }
952 up_write(&card->controls_rwsem);
953 return result;
954}
955
956static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
957 struct snd_ctl_elem_id __user *_id)
958{
959 struct snd_card *card = file->card;
960 struct snd_ctl_elem_id id;
961 struct snd_kcontrol *kctl;
962 struct snd_kcontrol_volatile *vd;
963 int result;
964
965 if (copy_from_user(&id, _id, sizeof(id)))
966 return -EFAULT;
967 down_write(&card->controls_rwsem);
968 kctl = snd_ctl_find_id(card, &id);
969 if (kctl == NULL) {
970 result = -ENOENT;
971 } else {
972 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
973 if (vd->owner == NULL)
974 result = -EINVAL;
975 else if (vd->owner != file)
976 result = -EPERM;
977 else {
978 vd->owner = NULL;
979 result = 0;
980 }
981 }
982 up_write(&card->controls_rwsem);
983 return result;
984}
985
986struct user_element {
987 struct snd_ctl_elem_info info;
988 void *elem_data; /* element data */
989 unsigned long elem_data_size; /* size of element data in bytes */
990 void *tlv_data; /* TLV data */
991 unsigned long tlv_data_size; /* TLV data size */
992 void *priv_data; /* private data (like strings for enumerated type) */
993};
994
995static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
996 struct snd_ctl_elem_info *uinfo)
997{
998 struct user_element *ue = kcontrol->private_data;
999
1000 *uinfo = ue->info;
1001 return 0;
1002}
1003
1004static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1005 struct snd_ctl_elem_info *uinfo)
1006{
1007 struct user_element *ue = kcontrol->private_data;
1008 const char *names;
1009 unsigned int item;
1010
1011 item = uinfo->value.enumerated.item;
1012
1013 *uinfo = ue->info;
1014
1015 item = min(item, uinfo->value.enumerated.items - 1);
1016 uinfo->value.enumerated.item = item;
1017
1018 names = ue->priv_data;
1019 for (; item > 0; --item)
1020 names += strlen(names) + 1;
1021 strcpy(uinfo->value.enumerated.name, names);
1022
1023 return 0;
1024}
1025
1026static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1027 struct snd_ctl_elem_value *ucontrol)
1028{
1029 struct user_element *ue = kcontrol->private_data;
1030
1031 memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
1032 return 0;
1033}
1034
1035static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1036 struct snd_ctl_elem_value *ucontrol)
1037{
1038 int change;
1039 struct user_element *ue = kcontrol->private_data;
1040
1041 change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
1042 if (change)
1043 memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
1044 return change;
1045}
1046
1047static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
1048 int op_flag,
1049 unsigned int size,
1050 unsigned int __user *tlv)
1051{
1052 struct user_element *ue = kcontrol->private_data;
1053 int change = 0;
1054 void *new_data;
1055
1056 if (op_flag > 0) {
1057 if (size > 1024 * 128) /* sane value */
1058 return -EINVAL;
1059
1060 new_data = memdup_user(tlv, size);
1061 if (IS_ERR(new_data))
1062 return PTR_ERR(new_data);
1063 change = ue->tlv_data_size != size;
1064 if (!change)
1065 change = memcmp(ue->tlv_data, new_data, size);
1066 kfree(ue->tlv_data);
1067 ue->tlv_data = new_data;
1068 ue->tlv_data_size = size;
1069 } else {
1070 if (! ue->tlv_data_size || ! ue->tlv_data)
1071 return -ENXIO;
1072 if (size < ue->tlv_data_size)
1073 return -ENOSPC;
1074 if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
1075 return -EFAULT;
1076 }
1077 return change;
1078}
1079
1080static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1081{
1082 char *names, *p;
1083 size_t buf_len, name_len;
1084 unsigned int i;
1085 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1086
1087 if (ue->info.value.enumerated.names_length > 64 * 1024)
1088 return -EINVAL;
1089
1090 names = memdup_user((const void __user *)user_ptrval,
1091 ue->info.value.enumerated.names_length);
1092 if (IS_ERR(names))
1093 return PTR_ERR(names);
1094
1095 /* check that there are enough valid names */
1096 buf_len = ue->info.value.enumerated.names_length;
1097 p = names;
1098 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1099 name_len = strnlen(p, buf_len);
1100 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1101 kfree(names);
1102 return -EINVAL;
1103 }
1104 p += name_len + 1;
1105 buf_len -= name_len + 1;
1106 }
1107
1108 ue->priv_data = names;
1109 ue->info.value.enumerated.names_ptr = 0;
1110
1111 return 0;
1112}
1113
1114static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1115{
1116 struct user_element *ue = kcontrol->private_data;
1117
1118 kfree(ue->tlv_data);
1119 kfree(ue->priv_data);
1120 kfree(ue);
1121}
1122
1123static int snd_ctl_elem_add(struct snd_ctl_file *file,
1124 struct snd_ctl_elem_info *info, int replace)
1125{
1126 struct snd_card *card = file->card;
1127 struct snd_kcontrol kctl, *_kctl;
1128 unsigned int access;
1129 long private_size;
1130 struct user_element *ue;
1131 int idx, err;
1132
1133 if (!replace && card->user_ctl_count >= MAX_USER_CONTROLS)
1134 return -ENOMEM;
1135 if (info->count < 1)
1136 return -EINVAL;
1137 access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
1138 (info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
1139 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
1140 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
1141 info->id.numid = 0;
1142 memset(&kctl, 0, sizeof(kctl));
1143 down_write(&card->controls_rwsem);
1144 _kctl = snd_ctl_find_id(card, &info->id);
1145 err = 0;
1146 if (_kctl) {
1147 if (replace)
1148 err = snd_ctl_remove(card, _kctl);
1149 else
1150 err = -EBUSY;
1151 } else {
1152 if (replace)
1153 err = -ENOENT;
1154 }
1155 up_write(&card->controls_rwsem);
1156 if (err < 0)
1157 return err;
1158 memcpy(&kctl.id, &info->id, sizeof(info->id));
1159 kctl.count = info->owner ? info->owner : 1;
1160 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1161 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1162 kctl.info = snd_ctl_elem_user_enum_info;
1163 else
1164 kctl.info = snd_ctl_elem_user_info;
1165 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1166 kctl.get = snd_ctl_elem_user_get;
1167 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1168 kctl.put = snd_ctl_elem_user_put;
1169 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
1170 kctl.tlv.c = snd_ctl_elem_user_tlv;
1171 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1172 }
1173 switch (info->type) {
1174 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
1175 case SNDRV_CTL_ELEM_TYPE_INTEGER:
1176 private_size = sizeof(long);
1177 if (info->count > 128)
1178 return -EINVAL;
1179 break;
1180 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
1181 private_size = sizeof(long long);
1182 if (info->count > 64)
1183 return -EINVAL;
1184 break;
1185 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
1186 private_size = sizeof(unsigned int);
1187 if (info->count > 128 || info->value.enumerated.items == 0)
1188 return -EINVAL;
1189 break;
1190 case SNDRV_CTL_ELEM_TYPE_BYTES:
1191 private_size = sizeof(unsigned char);
1192 if (info->count > 512)
1193 return -EINVAL;
1194 break;
1195 case SNDRV_CTL_ELEM_TYPE_IEC958:
1196 private_size = sizeof(struct snd_aes_iec958);
1197 if (info->count != 1)
1198 return -EINVAL;
1199 break;
1200 default:
1201 return -EINVAL;
1202 }
1203 private_size *= info->count;
1204 ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
1205 if (ue == NULL)
1206 return -ENOMEM;
1207 ue->info = *info;
1208 ue->info.access = 0;
1209 ue->elem_data = (char *)ue + sizeof(*ue);
1210 ue->elem_data_size = private_size;
1211 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1212 err = snd_ctl_elem_init_enum_names(ue);
1213 if (err < 0) {
1214 kfree(ue);
1215 return err;
1216 }
1217 }
1218 kctl.private_free = snd_ctl_elem_user_free;
1219 _kctl = snd_ctl_new(&kctl, access);
1220 if (_kctl == NULL) {
1221 kfree(ue->priv_data);
1222 kfree(ue);
1223 return -ENOMEM;
1224 }
1225 _kctl->private_data = ue;
1226 for (idx = 0; idx < _kctl->count; idx++)
1227 _kctl->vd[idx].owner = file;
1228 err = snd_ctl_add(card, _kctl);
1229 if (err < 0)
1230 return err;
1231
1232 down_write(&card->controls_rwsem);
1233 card->user_ctl_count++;
1234 up_write(&card->controls_rwsem);
1235
1236 return 0;
1237}
1238
1239static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1240 struct snd_ctl_elem_info __user *_info, int replace)
1241{
1242 struct snd_ctl_elem_info info;
1243 if (copy_from_user(&info, _info, sizeof(info)))
1244 return -EFAULT;
1245 return snd_ctl_elem_add(file, &info, replace);
1246}
1247
1248static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1249 struct snd_ctl_elem_id __user *_id)
1250{
1251 struct snd_ctl_elem_id id;
1252
1253 if (copy_from_user(&id, _id, sizeof(id)))
1254 return -EFAULT;
1255 return snd_ctl_remove_user_ctl(file, &id);
1256}
1257
1258static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1259{
1260 int subscribe;
1261 if (get_user(subscribe, ptr))
1262 return -EFAULT;
1263 if (subscribe < 0) {
1264 subscribe = file->subscribed;
1265 if (put_user(subscribe, ptr))
1266 return -EFAULT;
1267 return 0;
1268 }
1269 if (subscribe) {
1270 file->subscribed = 1;
1271 return 0;
1272 } else if (file->subscribed) {
1273 snd_ctl_empty_read_queue(file);
1274 file->subscribed = 0;
1275 }
1276 return 0;
1277}
1278
1279static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1280 struct snd_ctl_tlv __user *_tlv,
1281 int op_flag)
1282{
1283 struct snd_card *card = file->card;
1284 struct snd_ctl_tlv tlv;
1285 struct snd_kcontrol *kctl;
1286 struct snd_kcontrol_volatile *vd;
1287 unsigned int len;
1288 int err = 0;
1289
1290 if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
1291 return -EFAULT;
1292 if (tlv.length < sizeof(unsigned int) * 2)
1293 return -EINVAL;
1294 down_read(&card->controls_rwsem);
1295 kctl = snd_ctl_find_numid(card, tlv.numid);
1296 if (kctl == NULL) {
1297 err = -ENOENT;
1298 goto __kctl_end;
1299 }
1300 if (kctl->tlv.p == NULL) {
1301 err = -ENXIO;
1302 goto __kctl_end;
1303 }
1304 vd = &kctl->vd[tlv.numid - kctl->id.numid];
1305 if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
1306 (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
1307 (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
1308 err = -ENXIO;
1309 goto __kctl_end;
1310 }
1311 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1312 if (vd->owner != NULL && vd->owner != file) {
1313 err = -EPERM;
1314 goto __kctl_end;
1315 }
1316 err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
1317 if (err > 0) {
1318 up_read(&card->controls_rwsem);
1319 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
1320 return 0;
1321 }
1322 } else {
1323 if (op_flag) {
1324 err = -ENXIO;
1325 goto __kctl_end;
1326 }
1327 len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
1328 if (tlv.length < len) {
1329 err = -ENOMEM;
1330 goto __kctl_end;
1331 }
1332 if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
1333 err = -EFAULT;
1334 }
1335 __kctl_end:
1336 up_read(&card->controls_rwsem);
1337 return err;
1338}
1339
1340static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1341{
1342 struct snd_ctl_file *ctl;
1343 struct snd_card *card;
1344 struct snd_kctl_ioctl *p;
1345 void __user *argp = (void __user *)arg;
1346 int __user *ip = argp;
1347 int err;
1348
1349 ctl = file->private_data;
1350 card = ctl->card;
1351 if (snd_BUG_ON(!card))
1352 return -ENXIO;
1353 switch (cmd) {
1354 case SNDRV_CTL_IOCTL_PVERSION:
1355 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1356 case SNDRV_CTL_IOCTL_CARD_INFO:
1357 return snd_ctl_card_info(card, ctl, cmd, argp);
1358 case SNDRV_CTL_IOCTL_ELEM_LIST:
1359 return snd_ctl_elem_list(card, argp);
1360 case SNDRV_CTL_IOCTL_ELEM_INFO:
1361 return snd_ctl_elem_info_user(ctl, argp);
1362 case SNDRV_CTL_IOCTL_ELEM_READ:
1363 return snd_ctl_elem_read_user(card, argp);
1364 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1365 return snd_ctl_elem_write_user(ctl, argp);
1366 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1367 return snd_ctl_elem_lock(ctl, argp);
1368 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1369 return snd_ctl_elem_unlock(ctl, argp);
1370 case SNDRV_CTL_IOCTL_ELEM_ADD:
1371 return snd_ctl_elem_add_user(ctl, argp, 0);
1372 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1373 return snd_ctl_elem_add_user(ctl, argp, 1);
1374 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1375 return snd_ctl_elem_remove(ctl, argp);
1376 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1377 return snd_ctl_subscribe_events(ctl, ip);
1378 case SNDRV_CTL_IOCTL_TLV_READ:
1379 return snd_ctl_tlv_ioctl(ctl, argp, 0);
1380 case SNDRV_CTL_IOCTL_TLV_WRITE:
1381 return snd_ctl_tlv_ioctl(ctl, argp, 1);
1382 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1383 return snd_ctl_tlv_ioctl(ctl, argp, -1);
1384 case SNDRV_CTL_IOCTL_POWER:
1385 return -ENOPROTOOPT;
1386 case SNDRV_CTL_IOCTL_POWER_STATE:
1387#ifdef CONFIG_PM
1388 return put_user(card->power_state, ip) ? -EFAULT : 0;
1389#else
1390 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1391#endif
1392 }
1393 down_read(&snd_ioctl_rwsem);
1394 list_for_each_entry(p, &snd_control_ioctls, list) {
1395 err = p->fioctl(card, ctl, cmd, arg);
1396 if (err != -ENOIOCTLCMD) {
1397 up_read(&snd_ioctl_rwsem);
1398 return err;
1399 }
1400 }
1401 up_read(&snd_ioctl_rwsem);
1402 snd_printdd("unknown ioctl = 0x%x\n", cmd);
1403 return -ENOTTY;
1404}
1405
1406static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1407 size_t count, loff_t * offset)
1408{
1409 struct snd_ctl_file *ctl;
1410 int err = 0;
1411 ssize_t result = 0;
1412
1413 ctl = file->private_data;
1414 if (snd_BUG_ON(!ctl || !ctl->card))
1415 return -ENXIO;
1416 if (!ctl->subscribed)
1417 return -EBADFD;
1418 if (count < sizeof(struct snd_ctl_event))
1419 return -EINVAL;
1420 spin_lock_irq(&ctl->read_lock);
1421 while (count >= sizeof(struct snd_ctl_event)) {
1422 struct snd_ctl_event ev;
1423 struct snd_kctl_event *kev;
1424 while (list_empty(&ctl->events)) {
1425 wait_queue_t wait;
1426 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1427 err = -EAGAIN;
1428 goto __end_lock;
1429 }
1430 init_waitqueue_entry(&wait, current);
1431 add_wait_queue(&ctl->change_sleep, &wait);
1432 set_current_state(TASK_INTERRUPTIBLE);
1433 spin_unlock_irq(&ctl->read_lock);
1434 schedule();
1435 remove_wait_queue(&ctl->change_sleep, &wait);
1436 if (signal_pending(current))
1437 return -ERESTARTSYS;
1438 spin_lock_irq(&ctl->read_lock);
1439 }
1440 kev = snd_kctl_event(ctl->events.next);
1441 ev.type = SNDRV_CTL_EVENT_ELEM;
1442 ev.data.elem.mask = kev->mask;
1443 ev.data.elem.id = kev->id;
1444 list_del(&kev->list);
1445 spin_unlock_irq(&ctl->read_lock);
1446 kfree(kev);
1447 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1448 err = -EFAULT;
1449 goto __end;
1450 }
1451 spin_lock_irq(&ctl->read_lock);
1452 buffer += sizeof(struct snd_ctl_event);
1453 count -= sizeof(struct snd_ctl_event);
1454 result += sizeof(struct snd_ctl_event);
1455 }
1456 __end_lock:
1457 spin_unlock_irq(&ctl->read_lock);
1458 __end:
1459 return result > 0 ? result : err;
1460}
1461
1462static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
1463{
1464 unsigned int mask;
1465 struct snd_ctl_file *ctl;
1466
1467 ctl = file->private_data;
1468 if (!ctl->subscribed)
1469 return 0;
1470 poll_wait(file, &ctl->change_sleep, wait);
1471
1472 mask = 0;
1473 if (!list_empty(&ctl->events))
1474 mask |= POLLIN | POLLRDNORM;
1475
1476 return mask;
1477}
1478
1479/*
1480 * register the device-specific control-ioctls.
1481 * called from each device manager like pcm.c, hwdep.c, etc.
1482 */
1483static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1484{
1485 struct snd_kctl_ioctl *pn;
1486
1487 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1488 if (pn == NULL)
1489 return -ENOMEM;
1490 pn->fioctl = fcn;
1491 down_write(&snd_ioctl_rwsem);
1492 list_add_tail(&pn->list, lists);
1493 up_write(&snd_ioctl_rwsem);
1494 return 0;
1495}
1496
1497int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1498{
1499 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1500}
1501
1502EXPORT_SYMBOL(snd_ctl_register_ioctl);
1503
1504#ifdef CONFIG_COMPAT
1505int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1506{
1507 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1508}
1509
1510EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1511#endif
1512
1513/*
1514 * de-register the device-specific control-ioctls.
1515 */
1516static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1517 struct list_head *lists)
1518{
1519 struct snd_kctl_ioctl *p;
1520
1521 if (snd_BUG_ON(!fcn))
1522 return -EINVAL;
1523 down_write(&snd_ioctl_rwsem);
1524 list_for_each_entry(p, lists, list) {
1525 if (p->fioctl == fcn) {
1526 list_del(&p->list);
1527 up_write(&snd_ioctl_rwsem);
1528 kfree(p);
1529 return 0;
1530 }
1531 }
1532 up_write(&snd_ioctl_rwsem);
1533 snd_BUG();
1534 return -EINVAL;
1535}
1536
1537int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1538{
1539 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1540}
1541
1542EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1543
1544#ifdef CONFIG_COMPAT
1545int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1546{
1547 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1548}
1549
1550EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1551#endif
1552
1553static int snd_ctl_fasync(int fd, struct file * file, int on)
1554{
1555 struct snd_ctl_file *ctl;
1556
1557 ctl = file->private_data;
1558 return fasync_helper(fd, file, on, &ctl->fasync);
1559}
1560
1561/*
1562 * ioctl32 compat
1563 */
1564#ifdef CONFIG_COMPAT
1565#include "control_compat.c"
1566#else
1567#define snd_ctl_ioctl_compat NULL
1568#endif
1569
1570/*
1571 * INIT PART
1572 */
1573
1574static const struct file_operations snd_ctl_f_ops =
1575{
1576 .owner = THIS_MODULE,
1577 .read = snd_ctl_read,
1578 .open = snd_ctl_open,
1579 .release = snd_ctl_release,
1580 .llseek = no_llseek,
1581 .poll = snd_ctl_poll,
1582 .unlocked_ioctl = snd_ctl_ioctl,
1583 .compat_ioctl = snd_ctl_ioctl_compat,
1584 .fasync = snd_ctl_fasync,
1585};
1586
1587/*
1588 * registration of the control device
1589 */
1590static int snd_ctl_dev_register(struct snd_device *device)
1591{
1592 struct snd_card *card = device->device_data;
1593 int err, cardnum;
1594 char name[16];
1595
1596 if (snd_BUG_ON(!card))
1597 return -ENXIO;
1598 cardnum = card->number;
1599 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1600 return -ENXIO;
1601 sprintf(name, "controlC%i", cardnum);
1602 if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1603 &snd_ctl_f_ops, card, name)) < 0)
1604 return err;
1605 return 0;
1606}
1607
1608/*
1609 * disconnection of the control device
1610 */
1611static int snd_ctl_dev_disconnect(struct snd_device *device)
1612{
1613 struct snd_card *card = device->device_data;
1614 struct snd_ctl_file *ctl;
1615 int err, cardnum;
1616
1617 if (snd_BUG_ON(!card))
1618 return -ENXIO;
1619 cardnum = card->number;
1620 if (snd_BUG_ON(cardnum < 0 || cardnum >= SNDRV_CARDS))
1621 return -ENXIO;
1622
1623 read_lock(&card->ctl_files_rwlock);
1624 list_for_each_entry(ctl, &card->ctl_files, list) {
1625 wake_up(&ctl->change_sleep);
1626 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1627 }
1628 read_unlock(&card->ctl_files_rwlock);
1629
1630 if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
1631 card, -1)) < 0)
1632 return err;
1633 return 0;
1634}
1635
1636/*
1637 * free all controls
1638 */
1639static int snd_ctl_dev_free(struct snd_device *device)
1640{
1641 struct snd_card *card = device->device_data;
1642 struct snd_kcontrol *control;
1643
1644 down_write(&card->controls_rwsem);
1645 while (!list_empty(&card->controls)) {
1646 control = snd_kcontrol(card->controls.next);
1647 snd_ctl_remove(card, control);
1648 }
1649 up_write(&card->controls_rwsem);
1650 return 0;
1651}
1652
1653/*
1654 * create control core:
1655 * called from init.c
1656 */
1657int snd_ctl_create(struct snd_card *card)
1658{
1659 static struct snd_device_ops ops = {
1660 .dev_free = snd_ctl_dev_free,
1661 .dev_register = snd_ctl_dev_register,
1662 .dev_disconnect = snd_ctl_dev_disconnect,
1663 };
1664
1665 if (snd_BUG_ON(!card))
1666 return -ENXIO;
1667 return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1668}
1669
1670/*
1671 * Frequently used control callbacks/helpers
1672 */
1673int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1674 struct snd_ctl_elem_info *uinfo)
1675{
1676 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1677 uinfo->count = 1;
1678 uinfo->value.integer.min = 0;
1679 uinfo->value.integer.max = 1;
1680 return 0;
1681}
1682
1683EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1684
1685int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1686 struct snd_ctl_elem_info *uinfo)
1687{
1688 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1689 uinfo->count = 2;
1690 uinfo->value.integer.min = 0;
1691 uinfo->value.integer.max = 1;
1692 return 0;
1693}
1694
1695EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1696
1697/**
1698 * snd_ctl_enum_info - fills the info structure for an enumerated control
1699 * @info: the structure to be filled
1700 * @channels: the number of the control's channels; often one
1701 * @items: the number of control values; also the size of @names
1702 * @names: an array containing the names of all control values
1703 *
1704 * Sets all required fields in @info to their appropriate values.
1705 * If the control's accessibility is not the default (readable and writable),
1706 * the caller has to fill @info->access.
1707 */
1708int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1709 unsigned int items, const char *const names[])
1710{
1711 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1712 info->count = channels;
1713 info->value.enumerated.items = items;
1714 if (info->value.enumerated.item >= items)
1715 info->value.enumerated.item = items - 1;
1716 strlcpy(info->value.enumerated.name,
1717 names[info->value.enumerated.item],
1718 sizeof(info->value.enumerated.name));
1719 return 0;
1720}
1721EXPORT_SYMBOL(snd_ctl_enum_info);