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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Routines for driver control interface
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/threads.h>
8#include <linux/interrupt.h>
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/vmalloc.h>
12#include <linux/time.h>
13#include <linux/mm.h>
14#include <linux/sched/signal.h>
15#include <sound/core.h>
16#include <sound/minors.h>
17#include <sound/info.h>
18#include <sound/control.h>
19
20/* max number of user-defined controls */
21#define MAX_USER_CONTROLS 32
22#define MAX_CONTROL_COUNT 1028
23
24struct snd_kctl_ioctl {
25 struct list_head list; /* list of all ioctls */
26 snd_kctl_ioctl_func_t fioctl;
27};
28
29static DECLARE_RWSEM(snd_ioctl_rwsem);
30static LIST_HEAD(snd_control_ioctls);
31#ifdef CONFIG_COMPAT
32static LIST_HEAD(snd_control_compat_ioctls);
33#endif
34
35static int snd_ctl_open(struct inode *inode, struct file *file)
36{
37 unsigned long flags;
38 struct snd_card *card;
39 struct snd_ctl_file *ctl;
40 int i, err;
41
42 err = stream_open(inode, file);
43 if (err < 0)
44 return err;
45
46 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
47 if (!card) {
48 err = -ENODEV;
49 goto __error1;
50 }
51 err = snd_card_file_add(card, file);
52 if (err < 0) {
53 err = -ENODEV;
54 goto __error1;
55 }
56 if (!try_module_get(card->module)) {
57 err = -EFAULT;
58 goto __error2;
59 }
60 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
61 if (ctl == NULL) {
62 err = -ENOMEM;
63 goto __error;
64 }
65 INIT_LIST_HEAD(&ctl->events);
66 init_waitqueue_head(&ctl->change_sleep);
67 spin_lock_init(&ctl->read_lock);
68 ctl->card = card;
69 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
70 ctl->preferred_subdevice[i] = -1;
71 ctl->pid = get_pid(task_pid(current));
72 file->private_data = ctl;
73 write_lock_irqsave(&card->ctl_files_rwlock, flags);
74 list_add_tail(&ctl->list, &card->ctl_files);
75 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
76 snd_card_unref(card);
77 return 0;
78
79 __error:
80 module_put(card->module);
81 __error2:
82 snd_card_file_remove(card, file);
83 __error1:
84 if (card)
85 snd_card_unref(card);
86 return err;
87}
88
89static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
90{
91 unsigned long flags;
92 struct snd_kctl_event *cread;
93
94 spin_lock_irqsave(&ctl->read_lock, flags);
95 while (!list_empty(&ctl->events)) {
96 cread = snd_kctl_event(ctl->events.next);
97 list_del(&cread->list);
98 kfree(cread);
99 }
100 spin_unlock_irqrestore(&ctl->read_lock, flags);
101}
102
103static int snd_ctl_release(struct inode *inode, struct file *file)
104{
105 unsigned long flags;
106 struct snd_card *card;
107 struct snd_ctl_file *ctl;
108 struct snd_kcontrol *control;
109 unsigned int idx;
110
111 ctl = file->private_data;
112 file->private_data = NULL;
113 card = ctl->card;
114 write_lock_irqsave(&card->ctl_files_rwlock, flags);
115 list_del(&ctl->list);
116 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
117 down_write(&card->controls_rwsem);
118 list_for_each_entry(control, &card->controls, list)
119 for (idx = 0; idx < control->count; idx++)
120 if (control->vd[idx].owner == ctl)
121 control->vd[idx].owner = NULL;
122 up_write(&card->controls_rwsem);
123 snd_ctl_empty_read_queue(ctl);
124 put_pid(ctl->pid);
125 kfree(ctl);
126 module_put(card->module);
127 snd_card_file_remove(card, file);
128 return 0;
129}
130
131/**
132 * snd_ctl_notify - Send notification to user-space for a control change
133 * @card: the card to send notification
134 * @mask: the event mask, SNDRV_CTL_EVENT_*
135 * @id: the ctl element id to send notification
136 *
137 * This function adds an event record with the given id and mask, appends
138 * to the list and wakes up the user-space for notification. This can be
139 * called in the atomic context.
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 if (card->shutdown)
151 return;
152 read_lock(&card->ctl_files_rwlock);
153#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
154 card->mixer_oss_change_count++;
155#endif
156 list_for_each_entry(ctl, &card->ctl_files, list) {
157 if (!ctl->subscribed)
158 continue;
159 spin_lock_irqsave(&ctl->read_lock, flags);
160 list_for_each_entry(ev, &ctl->events, list) {
161 if (ev->id.numid == id->numid) {
162 ev->mask |= mask;
163 goto _found;
164 }
165 }
166 ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
167 if (ev) {
168 ev->id = *id;
169 ev->mask = mask;
170 list_add_tail(&ev->list, &ctl->events);
171 } else {
172 dev_err(card->dev, "No memory available to allocate event\n");
173 }
174 _found:
175 wake_up(&ctl->change_sleep);
176 spin_unlock_irqrestore(&ctl->read_lock, flags);
177 kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
178 }
179 read_unlock(&card->ctl_files_rwlock);
180}
181EXPORT_SYMBOL(snd_ctl_notify);
182
183/**
184 * snd_ctl_new - create a new control instance with some elements
185 * @kctl: the pointer to store new control instance
186 * @count: the number of elements in this control
187 * @access: the default access flags for elements in this control
188 * @file: given when locking these elements
189 *
190 * Allocates a memory object for a new control instance. The instance has
191 * elements as many as the given number (@count). Each element has given
192 * access permissions (@access). Each element is locked when @file is given.
193 *
194 * Return: 0 on success, error code on failure
195 */
196static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
197 unsigned int access, struct snd_ctl_file *file)
198{
199 unsigned int idx;
200
201 if (count == 0 || count > MAX_CONTROL_COUNT)
202 return -EINVAL;
203
204 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
205 if (!*kctl)
206 return -ENOMEM;
207
208 for (idx = 0; idx < count; idx++) {
209 (*kctl)->vd[idx].access = access;
210 (*kctl)->vd[idx].owner = file;
211 }
212 (*kctl)->count = count;
213
214 return 0;
215}
216
217/**
218 * snd_ctl_new1 - create a control instance from the template
219 * @ncontrol: the initialization record
220 * @private_data: the private data to set
221 *
222 * Allocates a new struct snd_kcontrol instance and initialize from the given
223 * template. When the access field of ncontrol is 0, it's assumed as
224 * READWRITE access. When the count field is 0, it's assumes as one.
225 *
226 * Return: The pointer of the newly generated instance, or %NULL on failure.
227 */
228struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
229 void *private_data)
230{
231 struct snd_kcontrol *kctl;
232 unsigned int count;
233 unsigned int access;
234 int err;
235
236 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
237 return NULL;
238
239 count = ncontrol->count;
240 if (count == 0)
241 count = 1;
242
243 access = ncontrol->access;
244 if (access == 0)
245 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
246 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
247 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
248 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
249 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE |
250 SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND |
251 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK);
252
253 err = snd_ctl_new(&kctl, count, access, NULL);
254 if (err < 0)
255 return NULL;
256
257 /* The 'numid' member is decided when calling snd_ctl_add(). */
258 kctl->id.iface = ncontrol->iface;
259 kctl->id.device = ncontrol->device;
260 kctl->id.subdevice = ncontrol->subdevice;
261 if (ncontrol->name) {
262 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
263 if (strcmp(ncontrol->name, kctl->id.name) != 0)
264 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
265 ncontrol->name, kctl->id.name);
266 }
267 kctl->id.index = ncontrol->index;
268
269 kctl->info = ncontrol->info;
270 kctl->get = ncontrol->get;
271 kctl->put = ncontrol->put;
272 kctl->tlv.p = ncontrol->tlv.p;
273
274 kctl->private_value = ncontrol->private_value;
275 kctl->private_data = private_data;
276
277 return kctl;
278}
279EXPORT_SYMBOL(snd_ctl_new1);
280
281/**
282 * snd_ctl_free_one - release the control instance
283 * @kcontrol: the control instance
284 *
285 * Releases the control instance created via snd_ctl_new()
286 * or snd_ctl_new1().
287 * Don't call this after the control was added to the card.
288 */
289void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
290{
291 if (kcontrol) {
292 if (kcontrol->private_free)
293 kcontrol->private_free(kcontrol);
294 kfree(kcontrol);
295 }
296}
297EXPORT_SYMBOL(snd_ctl_free_one);
298
299static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
300 unsigned int count)
301{
302 struct snd_kcontrol *kctl;
303
304 /* Make sure that the ids assigned to the control do not wrap around */
305 if (card->last_numid >= UINT_MAX - count)
306 card->last_numid = 0;
307
308 list_for_each_entry(kctl, &card->controls, list) {
309 if (kctl->id.numid < card->last_numid + 1 + count &&
310 kctl->id.numid + kctl->count > card->last_numid + 1) {
311 card->last_numid = kctl->id.numid + kctl->count - 1;
312 return true;
313 }
314 }
315 return false;
316}
317
318static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
319{
320 unsigned int iter = 100000;
321
322 while (snd_ctl_remove_numid_conflict(card, count)) {
323 if (--iter == 0) {
324 /* this situation is very unlikely */
325 dev_err(card->dev, "unable to allocate new control numid\n");
326 return -ENOMEM;
327 }
328 }
329 return 0;
330}
331
332enum snd_ctl_add_mode {
333 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
334};
335
336/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
337static int __snd_ctl_add_replace(struct snd_card *card,
338 struct snd_kcontrol *kcontrol,
339 enum snd_ctl_add_mode mode)
340{
341 struct snd_ctl_elem_id id;
342 unsigned int idx;
343 unsigned int count;
344 struct snd_kcontrol *old;
345 int err;
346
347 id = kcontrol->id;
348 if (id.index > UINT_MAX - kcontrol->count)
349 return -EINVAL;
350
351 old = snd_ctl_find_id(card, &id);
352 if (!old) {
353 if (mode == CTL_REPLACE)
354 return -EINVAL;
355 } else {
356 if (mode == CTL_ADD_EXCLUSIVE) {
357 dev_err(card->dev,
358 "control %i:%i:%i:%s:%i is already present\n",
359 id.iface, id.device, id.subdevice, id.name,
360 id.index);
361 return -EBUSY;
362 }
363
364 err = snd_ctl_remove(card, old);
365 if (err < 0)
366 return err;
367 }
368
369 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
370 return -ENOMEM;
371
372 list_add_tail(&kcontrol->list, &card->controls);
373 card->controls_count += kcontrol->count;
374 kcontrol->id.numid = card->last_numid + 1;
375 card->last_numid += kcontrol->count;
376
377 id = kcontrol->id;
378 count = kcontrol->count;
379 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
380 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
381
382 return 0;
383}
384
385static int snd_ctl_add_replace(struct snd_card *card,
386 struct snd_kcontrol *kcontrol,
387 enum snd_ctl_add_mode mode)
388{
389 int err = -EINVAL;
390
391 if (! kcontrol)
392 return err;
393 if (snd_BUG_ON(!card || !kcontrol->info))
394 goto error;
395
396 down_write(&card->controls_rwsem);
397 err = __snd_ctl_add_replace(card, kcontrol, mode);
398 up_write(&card->controls_rwsem);
399 if (err < 0)
400 goto error;
401 return 0;
402
403 error:
404 snd_ctl_free_one(kcontrol);
405 return err;
406}
407
408/**
409 * snd_ctl_add - add the control instance to the card
410 * @card: the card instance
411 * @kcontrol: the control instance to add
412 *
413 * Adds the control instance created via snd_ctl_new() or
414 * snd_ctl_new1() to the given card. Assigns also an unique
415 * numid used for fast search.
416 *
417 * It frees automatically the control which cannot be added.
418 *
419 * Return: Zero if successful, or a negative error code on failure.
420 *
421 */
422int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
423{
424 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
425}
426EXPORT_SYMBOL(snd_ctl_add);
427
428/**
429 * snd_ctl_replace - replace the control instance of the card
430 * @card: the card instance
431 * @kcontrol: the control instance to replace
432 * @add_on_replace: add the control if not already added
433 *
434 * Replaces the given control. If the given control does not exist
435 * and the add_on_replace flag is set, the control is added. If the
436 * control exists, it is destroyed first.
437 *
438 * It frees automatically the control which cannot be added or replaced.
439 *
440 * Return: Zero if successful, or a negative error code on failure.
441 */
442int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
443 bool add_on_replace)
444{
445 return snd_ctl_add_replace(card, kcontrol,
446 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
447}
448EXPORT_SYMBOL(snd_ctl_replace);
449
450/**
451 * snd_ctl_remove - remove the control from the card and release it
452 * @card: the card instance
453 * @kcontrol: the control instance to remove
454 *
455 * Removes the control from the card and then releases the instance.
456 * You don't need to call snd_ctl_free_one(). You must be in
457 * the write lock - down_write(&card->controls_rwsem).
458 *
459 * Return: 0 if successful, or a negative error code on failure.
460 */
461int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
462{
463 struct snd_ctl_elem_id id;
464 unsigned int idx;
465
466 if (snd_BUG_ON(!card || !kcontrol))
467 return -EINVAL;
468 list_del(&kcontrol->list);
469 card->controls_count -= kcontrol->count;
470 id = kcontrol->id;
471 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
472 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
473 snd_ctl_free_one(kcontrol);
474 return 0;
475}
476EXPORT_SYMBOL(snd_ctl_remove);
477
478/**
479 * snd_ctl_remove_id - remove the control of the given id and release it
480 * @card: the card instance
481 * @id: the control id to remove
482 *
483 * Finds the control instance with the given id, removes it from the
484 * card list and releases it.
485 *
486 * Return: 0 if successful, or a negative error code on failure.
487 */
488int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
489{
490 struct snd_kcontrol *kctl;
491 int ret;
492
493 down_write(&card->controls_rwsem);
494 kctl = snd_ctl_find_id(card, id);
495 if (kctl == NULL) {
496 up_write(&card->controls_rwsem);
497 return -ENOENT;
498 }
499 ret = snd_ctl_remove(card, kctl);
500 up_write(&card->controls_rwsem);
501 return ret;
502}
503EXPORT_SYMBOL(snd_ctl_remove_id);
504
505/**
506 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
507 * @file: active control handle
508 * @id: the control id to remove
509 *
510 * Finds the control instance with the given id, removes it from the
511 * card list and releases it.
512 *
513 * Return: 0 if successful, or a negative error code on failure.
514 */
515static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
516 struct snd_ctl_elem_id *id)
517{
518 struct snd_card *card = file->card;
519 struct snd_kcontrol *kctl;
520 int idx, ret;
521
522 down_write(&card->controls_rwsem);
523 kctl = snd_ctl_find_id(card, id);
524 if (kctl == NULL) {
525 ret = -ENOENT;
526 goto error;
527 }
528 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
529 ret = -EINVAL;
530 goto error;
531 }
532 for (idx = 0; idx < kctl->count; idx++)
533 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
534 ret = -EBUSY;
535 goto error;
536 }
537 ret = snd_ctl_remove(card, kctl);
538 if (ret < 0)
539 goto error;
540 card->user_ctl_count--;
541error:
542 up_write(&card->controls_rwsem);
543 return ret;
544}
545
546/**
547 * snd_ctl_activate_id - activate/inactivate the control of the given id
548 * @card: the card instance
549 * @id: the control id to activate/inactivate
550 * @active: non-zero to activate
551 *
552 * Finds the control instance with the given id, and activate or
553 * inactivate the control together with notification, if changed.
554 * The given ID data is filled with full information.
555 *
556 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
557 */
558int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
559 int active)
560{
561 struct snd_kcontrol *kctl;
562 struct snd_kcontrol_volatile *vd;
563 unsigned int index_offset;
564 int ret;
565
566 down_write(&card->controls_rwsem);
567 kctl = snd_ctl_find_id(card, id);
568 if (kctl == NULL) {
569 ret = -ENOENT;
570 goto unlock;
571 }
572 index_offset = snd_ctl_get_ioff(kctl, id);
573 vd = &kctl->vd[index_offset];
574 ret = 0;
575 if (active) {
576 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
577 goto unlock;
578 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
579 } else {
580 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
581 goto unlock;
582 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
583 }
584 snd_ctl_build_ioff(id, kctl, index_offset);
585 ret = 1;
586 unlock:
587 up_write(&card->controls_rwsem);
588 if (ret > 0)
589 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
590 return ret;
591}
592EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
593
594/**
595 * snd_ctl_rename_id - replace the id of a control on the card
596 * @card: the card instance
597 * @src_id: the old id
598 * @dst_id: the new id
599 *
600 * Finds the control with the old id from the card, and replaces the
601 * id with the new one.
602 *
603 * Return: Zero if successful, or a negative error code on failure.
604 */
605int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
606 struct snd_ctl_elem_id *dst_id)
607{
608 struct snd_kcontrol *kctl;
609
610 down_write(&card->controls_rwsem);
611 kctl = snd_ctl_find_id(card, src_id);
612 if (kctl == NULL) {
613 up_write(&card->controls_rwsem);
614 return -ENOENT;
615 }
616 kctl->id = *dst_id;
617 kctl->id.numid = card->last_numid + 1;
618 card->last_numid += kctl->count;
619 up_write(&card->controls_rwsem);
620 return 0;
621}
622EXPORT_SYMBOL(snd_ctl_rename_id);
623
624/**
625 * snd_ctl_find_numid - find the control instance with the given number-id
626 * @card: the card instance
627 * @numid: the number-id to search
628 *
629 * Finds the control instance with the given number-id from the card.
630 *
631 * The caller must down card->controls_rwsem before calling this function
632 * (if the race condition can happen).
633 *
634 * Return: The pointer of the instance if found, or %NULL if not.
635 *
636 */
637struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
638{
639 struct snd_kcontrol *kctl;
640
641 if (snd_BUG_ON(!card || !numid))
642 return NULL;
643 list_for_each_entry(kctl, &card->controls, list) {
644 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
645 return kctl;
646 }
647 return NULL;
648}
649EXPORT_SYMBOL(snd_ctl_find_numid);
650
651/**
652 * snd_ctl_find_id - find the control instance with the given id
653 * @card: the card instance
654 * @id: the id to search
655 *
656 * Finds the control instance with the given id from the card.
657 *
658 * The caller must down card->controls_rwsem before calling this function
659 * (if the race condition can happen).
660 *
661 * Return: The pointer of the instance if found, or %NULL if not.
662 *
663 */
664struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
665 struct snd_ctl_elem_id *id)
666{
667 struct snd_kcontrol *kctl;
668
669 if (snd_BUG_ON(!card || !id))
670 return NULL;
671 if (id->numid != 0)
672 return snd_ctl_find_numid(card, id->numid);
673 list_for_each_entry(kctl, &card->controls, list) {
674 if (kctl->id.iface != id->iface)
675 continue;
676 if (kctl->id.device != id->device)
677 continue;
678 if (kctl->id.subdevice != id->subdevice)
679 continue;
680 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
681 continue;
682 if (kctl->id.index > id->index)
683 continue;
684 if (kctl->id.index + kctl->count <= id->index)
685 continue;
686 return kctl;
687 }
688 return NULL;
689}
690EXPORT_SYMBOL(snd_ctl_find_id);
691
692static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
693 unsigned int cmd, void __user *arg)
694{
695 struct snd_ctl_card_info *info;
696
697 info = kzalloc(sizeof(*info), GFP_KERNEL);
698 if (! info)
699 return -ENOMEM;
700 down_read(&snd_ioctl_rwsem);
701 info->card = card->number;
702 strlcpy(info->id, card->id, sizeof(info->id));
703 strlcpy(info->driver, card->driver, sizeof(info->driver));
704 strlcpy(info->name, card->shortname, sizeof(info->name));
705 strlcpy(info->longname, card->longname, sizeof(info->longname));
706 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
707 strlcpy(info->components, card->components, sizeof(info->components));
708 up_read(&snd_ioctl_rwsem);
709 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
710 kfree(info);
711 return -EFAULT;
712 }
713 kfree(info);
714 return 0;
715}
716
717static int snd_ctl_elem_list(struct snd_card *card,
718 struct snd_ctl_elem_list __user *_list)
719{
720 struct snd_ctl_elem_list list;
721 struct snd_kcontrol *kctl;
722 struct snd_ctl_elem_id id;
723 unsigned int offset, space, jidx;
724 int err = 0;
725
726 if (copy_from_user(&list, _list, sizeof(list)))
727 return -EFAULT;
728 offset = list.offset;
729 space = list.space;
730
731 down_read(&card->controls_rwsem);
732 list.count = card->controls_count;
733 list.used = 0;
734 if (space > 0) {
735 list_for_each_entry(kctl, &card->controls, list) {
736 if (offset >= kctl->count) {
737 offset -= kctl->count;
738 continue;
739 }
740 for (jidx = offset; jidx < kctl->count; jidx++) {
741 snd_ctl_build_ioff(&id, kctl, jidx);
742 if (copy_to_user(list.pids + list.used, &id,
743 sizeof(id))) {
744 err = -EFAULT;
745 goto out;
746 }
747 list.used++;
748 if (!--space)
749 goto out;
750 }
751 offset = 0;
752 }
753 }
754 out:
755 up_read(&card->controls_rwsem);
756 if (!err && copy_to_user(_list, &list, sizeof(list)))
757 err = -EFAULT;
758 return err;
759}
760
761static bool validate_element_member_dimension(struct snd_ctl_elem_info *info)
762{
763 unsigned int members;
764 unsigned int i;
765
766 if (info->dimen.d[0] == 0)
767 return true;
768
769 members = 1;
770 for (i = 0; i < ARRAY_SIZE(info->dimen.d); ++i) {
771 if (info->dimen.d[i] == 0)
772 break;
773 members *= info->dimen.d[i];
774
775 /*
776 * info->count should be validated in advance, to guarantee
777 * calculation soundness.
778 */
779 if (members > info->count)
780 return false;
781 }
782
783 for (++i; i < ARRAY_SIZE(info->dimen.d); ++i) {
784 if (info->dimen.d[i] > 0)
785 return false;
786 }
787
788 return members == info->count;
789}
790
791static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
792 struct snd_ctl_elem_info *info)
793{
794 struct snd_card *card = ctl->card;
795 struct snd_kcontrol *kctl;
796 struct snd_kcontrol_volatile *vd;
797 unsigned int index_offset;
798 int result;
799
800 down_read(&card->controls_rwsem);
801 kctl = snd_ctl_find_id(card, &info->id);
802 if (kctl == NULL) {
803 up_read(&card->controls_rwsem);
804 return -ENOENT;
805 }
806#ifdef CONFIG_SND_DEBUG
807 info->access = 0;
808#endif
809 result = kctl->info(kctl, info);
810 if (result >= 0) {
811 snd_BUG_ON(info->access);
812 index_offset = snd_ctl_get_ioff(kctl, &info->id);
813 vd = &kctl->vd[index_offset];
814 snd_ctl_build_ioff(&info->id, kctl, index_offset);
815 info->access = vd->access;
816 if (vd->owner) {
817 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
818 if (vd->owner == ctl)
819 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
820 info->owner = pid_vnr(vd->owner->pid);
821 } else {
822 info->owner = -1;
823 }
824 }
825 up_read(&card->controls_rwsem);
826 return result;
827}
828
829static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
830 struct snd_ctl_elem_info __user *_info)
831{
832 struct snd_ctl_elem_info info;
833 int result;
834
835 if (copy_from_user(&info, _info, sizeof(info)))
836 return -EFAULT;
837 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
838 if (result < 0)
839 return result;
840 result = snd_ctl_elem_info(ctl, &info);
841 if (result < 0)
842 return result;
843 if (copy_to_user(_info, &info, sizeof(info)))
844 return -EFAULT;
845 return result;
846}
847
848static int snd_ctl_elem_read(struct snd_card *card,
849 struct snd_ctl_elem_value *control)
850{
851 struct snd_kcontrol *kctl;
852 struct snd_kcontrol_volatile *vd;
853 unsigned int index_offset;
854
855 kctl = snd_ctl_find_id(card, &control->id);
856 if (kctl == NULL)
857 return -ENOENT;
858
859 index_offset = snd_ctl_get_ioff(kctl, &control->id);
860 vd = &kctl->vd[index_offset];
861 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
862 return -EPERM;
863
864 snd_ctl_build_ioff(&control->id, kctl, index_offset);
865 return kctl->get(kctl, control);
866}
867
868static int snd_ctl_elem_read_user(struct snd_card *card,
869 struct snd_ctl_elem_value __user *_control)
870{
871 struct snd_ctl_elem_value *control;
872 int result;
873
874 control = memdup_user(_control, sizeof(*control));
875 if (IS_ERR(control))
876 return PTR_ERR(control);
877
878 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
879 if (result < 0)
880 goto error;
881
882 down_read(&card->controls_rwsem);
883 result = snd_ctl_elem_read(card, control);
884 up_read(&card->controls_rwsem);
885 if (result < 0)
886 goto error;
887
888 if (copy_to_user(_control, control, sizeof(*control)))
889 result = -EFAULT;
890 error:
891 kfree(control);
892 return result;
893}
894
895static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
896 struct snd_ctl_elem_value *control)
897{
898 struct snd_kcontrol *kctl;
899 struct snd_kcontrol_volatile *vd;
900 unsigned int index_offset;
901 int result;
902
903 kctl = snd_ctl_find_id(card, &control->id);
904 if (kctl == NULL)
905 return -ENOENT;
906
907 index_offset = snd_ctl_get_ioff(kctl, &control->id);
908 vd = &kctl->vd[index_offset];
909 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
910 (file && vd->owner && vd->owner != file)) {
911 return -EPERM;
912 }
913
914 snd_ctl_build_ioff(&control->id, kctl, index_offset);
915 result = kctl->put(kctl, control);
916 if (result < 0)
917 return result;
918
919 if (result > 0) {
920 struct snd_ctl_elem_id id = control->id;
921 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
922 }
923
924 return 0;
925}
926
927static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
928 struct snd_ctl_elem_value __user *_control)
929{
930 struct snd_ctl_elem_value *control;
931 struct snd_card *card;
932 int result;
933
934 control = memdup_user(_control, sizeof(*control));
935 if (IS_ERR(control))
936 return PTR_ERR(control);
937
938 card = file->card;
939 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
940 if (result < 0)
941 goto error;
942
943 down_write(&card->controls_rwsem);
944 result = snd_ctl_elem_write(card, file, control);
945 up_write(&card->controls_rwsem);
946 if (result < 0)
947 goto error;
948
949 if (copy_to_user(_control, control, sizeof(*control)))
950 result = -EFAULT;
951 error:
952 kfree(control);
953 return result;
954}
955
956static int snd_ctl_elem_lock(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 = -EBUSY;
975 else {
976 vd->owner = file;
977 result = 0;
978 }
979 }
980 up_write(&card->controls_rwsem);
981 return result;
982}
983
984static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
985 struct snd_ctl_elem_id __user *_id)
986{
987 struct snd_card *card = file->card;
988 struct snd_ctl_elem_id id;
989 struct snd_kcontrol *kctl;
990 struct snd_kcontrol_volatile *vd;
991 int result;
992
993 if (copy_from_user(&id, _id, sizeof(id)))
994 return -EFAULT;
995 down_write(&card->controls_rwsem);
996 kctl = snd_ctl_find_id(card, &id);
997 if (kctl == NULL) {
998 result = -ENOENT;
999 } else {
1000 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1001 if (vd->owner == NULL)
1002 result = -EINVAL;
1003 else if (vd->owner != file)
1004 result = -EPERM;
1005 else {
1006 vd->owner = NULL;
1007 result = 0;
1008 }
1009 }
1010 up_write(&card->controls_rwsem);
1011 return result;
1012}
1013
1014struct user_element {
1015 struct snd_ctl_elem_info info;
1016 struct snd_card *card;
1017 char *elem_data; /* element data */
1018 unsigned long elem_data_size; /* size of element data in bytes */
1019 void *tlv_data; /* TLV data */
1020 unsigned long tlv_data_size; /* TLV data size */
1021 void *priv_data; /* private data (like strings for enumerated type) */
1022};
1023
1024static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1025 struct snd_ctl_elem_info *uinfo)
1026{
1027 struct user_element *ue = kcontrol->private_data;
1028 unsigned int offset;
1029
1030 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1031 *uinfo = ue->info;
1032 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1033
1034 return 0;
1035}
1036
1037static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1038 struct snd_ctl_elem_info *uinfo)
1039{
1040 struct user_element *ue = kcontrol->private_data;
1041 const char *names;
1042 unsigned int item;
1043 unsigned int offset;
1044
1045 item = uinfo->value.enumerated.item;
1046
1047 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1048 *uinfo = ue->info;
1049 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1050
1051 item = min(item, uinfo->value.enumerated.items - 1);
1052 uinfo->value.enumerated.item = item;
1053
1054 names = ue->priv_data;
1055 for (; item > 0; --item)
1056 names += strlen(names) + 1;
1057 strcpy(uinfo->value.enumerated.name, names);
1058
1059 return 0;
1060}
1061
1062static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1063 struct snd_ctl_elem_value *ucontrol)
1064{
1065 struct user_element *ue = kcontrol->private_data;
1066 unsigned int size = ue->elem_data_size;
1067 char *src = ue->elem_data +
1068 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1069
1070 memcpy(&ucontrol->value, src, size);
1071 return 0;
1072}
1073
1074static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1075 struct snd_ctl_elem_value *ucontrol)
1076{
1077 int change;
1078 struct user_element *ue = kcontrol->private_data;
1079 unsigned int size = ue->elem_data_size;
1080 char *dst = ue->elem_data +
1081 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1082
1083 change = memcmp(&ucontrol->value, dst, size) != 0;
1084 if (change)
1085 memcpy(dst, &ucontrol->value, size);
1086 return change;
1087}
1088
1089static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1090 unsigned int size)
1091{
1092 struct user_element *ue = kctl->private_data;
1093 unsigned int *container;
1094 struct snd_ctl_elem_id id;
1095 unsigned int mask = 0;
1096 int i;
1097 int change;
1098
1099 if (size > 1024 * 128) /* sane value */
1100 return -EINVAL;
1101
1102 container = vmemdup_user(buf, size);
1103 if (IS_ERR(container))
1104 return PTR_ERR(container);
1105
1106 change = ue->tlv_data_size != size;
1107 if (!change)
1108 change = memcmp(ue->tlv_data, container, size) != 0;
1109 if (!change) {
1110 kvfree(container);
1111 return 0;
1112 }
1113
1114 if (ue->tlv_data == NULL) {
1115 /* Now TLV data is available. */
1116 for (i = 0; i < kctl->count; ++i)
1117 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1118 mask = SNDRV_CTL_EVENT_MASK_INFO;
1119 }
1120
1121 kvfree(ue->tlv_data);
1122 ue->tlv_data = container;
1123 ue->tlv_data_size = size;
1124
1125 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1126 for (i = 0; i < kctl->count; ++i) {
1127 snd_ctl_build_ioff(&id, kctl, i);
1128 snd_ctl_notify(ue->card, mask, &id);
1129 }
1130
1131 return change;
1132}
1133
1134static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1135 unsigned int size)
1136{
1137 struct user_element *ue = kctl->private_data;
1138
1139 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1140 return -ENXIO;
1141
1142 if (size < ue->tlv_data_size)
1143 return -ENOSPC;
1144
1145 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1146 return -EFAULT;
1147
1148 return 0;
1149}
1150
1151static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1152 unsigned int size, unsigned int __user *buf)
1153{
1154 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1155 return replace_user_tlv(kctl, buf, size);
1156 else
1157 return read_user_tlv(kctl, buf, size);
1158}
1159
1160static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1161{
1162 char *names, *p;
1163 size_t buf_len, name_len;
1164 unsigned int i;
1165 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1166
1167 if (ue->info.value.enumerated.names_length > 64 * 1024)
1168 return -EINVAL;
1169
1170 names = vmemdup_user((const void __user *)user_ptrval,
1171 ue->info.value.enumerated.names_length);
1172 if (IS_ERR(names))
1173 return PTR_ERR(names);
1174
1175 /* check that there are enough valid names */
1176 buf_len = ue->info.value.enumerated.names_length;
1177 p = names;
1178 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1179 name_len = strnlen(p, buf_len);
1180 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1181 kvfree(names);
1182 return -EINVAL;
1183 }
1184 p += name_len + 1;
1185 buf_len -= name_len + 1;
1186 }
1187
1188 ue->priv_data = names;
1189 ue->info.value.enumerated.names_ptr = 0;
1190
1191 return 0;
1192}
1193
1194static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1195{
1196 struct user_element *ue = kcontrol->private_data;
1197
1198 kvfree(ue->tlv_data);
1199 kvfree(ue->priv_data);
1200 kfree(ue);
1201}
1202
1203static int snd_ctl_elem_add(struct snd_ctl_file *file,
1204 struct snd_ctl_elem_info *info, int replace)
1205{
1206 /* The capacity of struct snd_ctl_elem_value.value.*/
1207 static const unsigned int value_sizes[] = {
1208 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
1209 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
1210 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
1211 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
1212 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
1213 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
1214 };
1215 static const unsigned int max_value_counts[] = {
1216 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
1217 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
1218 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
1219 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
1220 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
1221 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
1222 };
1223 struct snd_card *card = file->card;
1224 struct snd_kcontrol *kctl;
1225 unsigned int count;
1226 unsigned int access;
1227 long private_size;
1228 struct user_element *ue;
1229 unsigned int offset;
1230 int err;
1231
1232 if (!*info->id.name)
1233 return -EINVAL;
1234 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1235 return -EINVAL;
1236
1237 /* Delete a control to replace them if needed. */
1238 if (replace) {
1239 info->id.numid = 0;
1240 err = snd_ctl_remove_user_ctl(file, &info->id);
1241 if (err)
1242 return err;
1243 }
1244
1245 /*
1246 * The number of userspace controls are counted control by control,
1247 * not element by element.
1248 */
1249 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1250 return -ENOMEM;
1251
1252 /* Check the number of elements for this userspace control. */
1253 count = info->owner;
1254 if (count == 0)
1255 count = 1;
1256
1257 /* Arrange access permissions if needed. */
1258 access = info->access;
1259 if (access == 0)
1260 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1261 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1262 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1263 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1264
1265 /* In initial state, nothing is available as TLV container. */
1266 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1267 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1268 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1269
1270 /*
1271 * Check information and calculate the size of data specific to
1272 * this userspace control.
1273 */
1274 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
1275 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64)
1276 return -EINVAL;
1277 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
1278 info->value.enumerated.items == 0)
1279 return -EINVAL;
1280 if (info->count < 1 ||
1281 info->count > max_value_counts[info->type])
1282 return -EINVAL;
1283 if (!validate_element_member_dimension(info))
1284 return -EINVAL;
1285 private_size = value_sizes[info->type] * info->count;
1286
1287 /*
1288 * Keep memory object for this userspace control. After passing this
1289 * code block, the instance should be freed by snd_ctl_free_one().
1290 *
1291 * Note that these elements in this control are locked.
1292 */
1293 err = snd_ctl_new(&kctl, count, access, file);
1294 if (err < 0)
1295 return err;
1296 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1297 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1298 GFP_KERNEL);
1299 if (kctl->private_data == NULL) {
1300 kfree(kctl);
1301 return -ENOMEM;
1302 }
1303 kctl->private_free = snd_ctl_elem_user_free;
1304
1305 /* Set private data for this userspace control. */
1306 ue = (struct user_element *)kctl->private_data;
1307 ue->card = card;
1308 ue->info = *info;
1309 ue->info.access = 0;
1310 ue->elem_data = (char *)ue + sizeof(*ue);
1311 ue->elem_data_size = private_size;
1312 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1313 err = snd_ctl_elem_init_enum_names(ue);
1314 if (err < 0) {
1315 snd_ctl_free_one(kctl);
1316 return err;
1317 }
1318 }
1319
1320 /* Set callback functions. */
1321 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1322 kctl->info = snd_ctl_elem_user_enum_info;
1323 else
1324 kctl->info = snd_ctl_elem_user_info;
1325 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1326 kctl->get = snd_ctl_elem_user_get;
1327 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1328 kctl->put = snd_ctl_elem_user_put;
1329 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1330 kctl->tlv.c = snd_ctl_elem_user_tlv;
1331
1332 /* This function manage to free the instance on failure. */
1333 down_write(&card->controls_rwsem);
1334 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1335 if (err < 0) {
1336 snd_ctl_free_one(kctl);
1337 goto unlock;
1338 }
1339 offset = snd_ctl_get_ioff(kctl, &info->id);
1340 snd_ctl_build_ioff(&info->id, kctl, offset);
1341 /*
1342 * Here we cannot fill any field for the number of elements added by
1343 * this operation because there're no specific fields. The usage of
1344 * 'owner' field for this purpose may cause any bugs to userspace
1345 * applications because the field originally means PID of a process
1346 * which locks the element.
1347 */
1348
1349 card->user_ctl_count++;
1350
1351 unlock:
1352 up_write(&card->controls_rwsem);
1353 return 0;
1354}
1355
1356static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1357 struct snd_ctl_elem_info __user *_info, int replace)
1358{
1359 struct snd_ctl_elem_info info;
1360 int err;
1361
1362 if (copy_from_user(&info, _info, sizeof(info)))
1363 return -EFAULT;
1364 err = snd_ctl_elem_add(file, &info, replace);
1365 if (err < 0)
1366 return err;
1367 if (copy_to_user(_info, &info, sizeof(info))) {
1368 snd_ctl_remove_user_ctl(file, &info.id);
1369 return -EFAULT;
1370 }
1371
1372 return 0;
1373}
1374
1375static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1376 struct snd_ctl_elem_id __user *_id)
1377{
1378 struct snd_ctl_elem_id id;
1379
1380 if (copy_from_user(&id, _id, sizeof(id)))
1381 return -EFAULT;
1382 return snd_ctl_remove_user_ctl(file, &id);
1383}
1384
1385static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1386{
1387 int subscribe;
1388 if (get_user(subscribe, ptr))
1389 return -EFAULT;
1390 if (subscribe < 0) {
1391 subscribe = file->subscribed;
1392 if (put_user(subscribe, ptr))
1393 return -EFAULT;
1394 return 0;
1395 }
1396 if (subscribe) {
1397 file->subscribed = 1;
1398 return 0;
1399 } else if (file->subscribed) {
1400 snd_ctl_empty_read_queue(file);
1401 file->subscribed = 0;
1402 }
1403 return 0;
1404}
1405
1406static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1407 struct snd_kcontrol *kctl,
1408 struct snd_ctl_elem_id *id,
1409 unsigned int __user *buf, unsigned int size)
1410{
1411 static const struct {
1412 int op;
1413 int perm;
1414 } pairs[] = {
1415 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1416 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1417 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1418 };
1419 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1420 int i;
1421
1422 /* Check support of the request for this element. */
1423 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1424 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1425 break;
1426 }
1427 if (i == ARRAY_SIZE(pairs))
1428 return -ENXIO;
1429
1430 if (kctl->tlv.c == NULL)
1431 return -ENXIO;
1432
1433 /* When locked, this is unavailable. */
1434 if (vd->owner != NULL && vd->owner != file)
1435 return -EPERM;
1436
1437 return kctl->tlv.c(kctl, op_flag, size, buf);
1438}
1439
1440static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1441 unsigned int __user *buf, unsigned int size)
1442{
1443 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1444 unsigned int len;
1445
1446 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1447 return -ENXIO;
1448
1449 if (kctl->tlv.p == NULL)
1450 return -ENXIO;
1451
1452 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1453 if (size < len)
1454 return -ENOMEM;
1455
1456 if (copy_to_user(buf, kctl->tlv.p, len))
1457 return -EFAULT;
1458
1459 return 0;
1460}
1461
1462static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1463 struct snd_ctl_tlv __user *buf,
1464 int op_flag)
1465{
1466 struct snd_ctl_tlv header;
1467 unsigned int __user *container;
1468 unsigned int container_size;
1469 struct snd_kcontrol *kctl;
1470 struct snd_ctl_elem_id id;
1471 struct snd_kcontrol_volatile *vd;
1472
1473 if (copy_from_user(&header, buf, sizeof(header)))
1474 return -EFAULT;
1475
1476 /* In design of control core, numerical ID starts at 1. */
1477 if (header.numid == 0)
1478 return -EINVAL;
1479
1480 /* At least, container should include type and length fields. */
1481 if (header.length < sizeof(unsigned int) * 2)
1482 return -EINVAL;
1483 container_size = header.length;
1484 container = buf->tlv;
1485
1486 kctl = snd_ctl_find_numid(file->card, header.numid);
1487 if (kctl == NULL)
1488 return -ENOENT;
1489
1490 /* Calculate index of the element in this set. */
1491 id = kctl->id;
1492 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1493 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1494
1495 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1496 return call_tlv_handler(file, op_flag, kctl, &id, container,
1497 container_size);
1498 } else {
1499 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1500 return read_tlv_buf(kctl, &id, container,
1501 container_size);
1502 }
1503 }
1504
1505 /* Not supported. */
1506 return -ENXIO;
1507}
1508
1509static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1510{
1511 struct snd_ctl_file *ctl;
1512 struct snd_card *card;
1513 struct snd_kctl_ioctl *p;
1514 void __user *argp = (void __user *)arg;
1515 int __user *ip = argp;
1516 int err;
1517
1518 ctl = file->private_data;
1519 card = ctl->card;
1520 if (snd_BUG_ON(!card))
1521 return -ENXIO;
1522 switch (cmd) {
1523 case SNDRV_CTL_IOCTL_PVERSION:
1524 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1525 case SNDRV_CTL_IOCTL_CARD_INFO:
1526 return snd_ctl_card_info(card, ctl, cmd, argp);
1527 case SNDRV_CTL_IOCTL_ELEM_LIST:
1528 return snd_ctl_elem_list(card, argp);
1529 case SNDRV_CTL_IOCTL_ELEM_INFO:
1530 return snd_ctl_elem_info_user(ctl, argp);
1531 case SNDRV_CTL_IOCTL_ELEM_READ:
1532 return snd_ctl_elem_read_user(card, argp);
1533 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1534 return snd_ctl_elem_write_user(ctl, argp);
1535 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1536 return snd_ctl_elem_lock(ctl, argp);
1537 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1538 return snd_ctl_elem_unlock(ctl, argp);
1539 case SNDRV_CTL_IOCTL_ELEM_ADD:
1540 return snd_ctl_elem_add_user(ctl, argp, 0);
1541 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1542 return snd_ctl_elem_add_user(ctl, argp, 1);
1543 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1544 return snd_ctl_elem_remove(ctl, argp);
1545 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1546 return snd_ctl_subscribe_events(ctl, ip);
1547 case SNDRV_CTL_IOCTL_TLV_READ:
1548 down_read(&ctl->card->controls_rwsem);
1549 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1550 up_read(&ctl->card->controls_rwsem);
1551 return err;
1552 case SNDRV_CTL_IOCTL_TLV_WRITE:
1553 down_write(&ctl->card->controls_rwsem);
1554 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1555 up_write(&ctl->card->controls_rwsem);
1556 return err;
1557 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1558 down_write(&ctl->card->controls_rwsem);
1559 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1560 up_write(&ctl->card->controls_rwsem);
1561 return err;
1562 case SNDRV_CTL_IOCTL_POWER:
1563 return -ENOPROTOOPT;
1564 case SNDRV_CTL_IOCTL_POWER_STATE:
1565#ifdef CONFIG_PM
1566 return put_user(card->power_state, ip) ? -EFAULT : 0;
1567#else
1568 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1569#endif
1570 }
1571 down_read(&snd_ioctl_rwsem);
1572 list_for_each_entry(p, &snd_control_ioctls, list) {
1573 err = p->fioctl(card, ctl, cmd, arg);
1574 if (err != -ENOIOCTLCMD) {
1575 up_read(&snd_ioctl_rwsem);
1576 return err;
1577 }
1578 }
1579 up_read(&snd_ioctl_rwsem);
1580 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1581 return -ENOTTY;
1582}
1583
1584static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1585 size_t count, loff_t * offset)
1586{
1587 struct snd_ctl_file *ctl;
1588 int err = 0;
1589 ssize_t result = 0;
1590
1591 ctl = file->private_data;
1592 if (snd_BUG_ON(!ctl || !ctl->card))
1593 return -ENXIO;
1594 if (!ctl->subscribed)
1595 return -EBADFD;
1596 if (count < sizeof(struct snd_ctl_event))
1597 return -EINVAL;
1598 spin_lock_irq(&ctl->read_lock);
1599 while (count >= sizeof(struct snd_ctl_event)) {
1600 struct snd_ctl_event ev;
1601 struct snd_kctl_event *kev;
1602 while (list_empty(&ctl->events)) {
1603 wait_queue_entry_t wait;
1604 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1605 err = -EAGAIN;
1606 goto __end_lock;
1607 }
1608 init_waitqueue_entry(&wait, current);
1609 add_wait_queue(&ctl->change_sleep, &wait);
1610 set_current_state(TASK_INTERRUPTIBLE);
1611 spin_unlock_irq(&ctl->read_lock);
1612 schedule();
1613 remove_wait_queue(&ctl->change_sleep, &wait);
1614 if (ctl->card->shutdown)
1615 return -ENODEV;
1616 if (signal_pending(current))
1617 return -ERESTARTSYS;
1618 spin_lock_irq(&ctl->read_lock);
1619 }
1620 kev = snd_kctl_event(ctl->events.next);
1621 ev.type = SNDRV_CTL_EVENT_ELEM;
1622 ev.data.elem.mask = kev->mask;
1623 ev.data.elem.id = kev->id;
1624 list_del(&kev->list);
1625 spin_unlock_irq(&ctl->read_lock);
1626 kfree(kev);
1627 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1628 err = -EFAULT;
1629 goto __end;
1630 }
1631 spin_lock_irq(&ctl->read_lock);
1632 buffer += sizeof(struct snd_ctl_event);
1633 count -= sizeof(struct snd_ctl_event);
1634 result += sizeof(struct snd_ctl_event);
1635 }
1636 __end_lock:
1637 spin_unlock_irq(&ctl->read_lock);
1638 __end:
1639 return result > 0 ? result : err;
1640}
1641
1642static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1643{
1644 __poll_t mask;
1645 struct snd_ctl_file *ctl;
1646
1647 ctl = file->private_data;
1648 if (!ctl->subscribed)
1649 return 0;
1650 poll_wait(file, &ctl->change_sleep, wait);
1651
1652 mask = 0;
1653 if (!list_empty(&ctl->events))
1654 mask |= EPOLLIN | EPOLLRDNORM;
1655
1656 return mask;
1657}
1658
1659/*
1660 * register the device-specific control-ioctls.
1661 * called from each device manager like pcm.c, hwdep.c, etc.
1662 */
1663static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1664{
1665 struct snd_kctl_ioctl *pn;
1666
1667 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1668 if (pn == NULL)
1669 return -ENOMEM;
1670 pn->fioctl = fcn;
1671 down_write(&snd_ioctl_rwsem);
1672 list_add_tail(&pn->list, lists);
1673 up_write(&snd_ioctl_rwsem);
1674 return 0;
1675}
1676
1677/**
1678 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1679 * @fcn: ioctl callback function
1680 *
1681 * called from each device manager like pcm.c, hwdep.c, etc.
1682 */
1683int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1684{
1685 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1686}
1687EXPORT_SYMBOL(snd_ctl_register_ioctl);
1688
1689#ifdef CONFIG_COMPAT
1690/**
1691 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1692 * control-ioctls
1693 * @fcn: ioctl callback function
1694 */
1695int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1696{
1697 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1698}
1699EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1700#endif
1701
1702/*
1703 * de-register the device-specific control-ioctls.
1704 */
1705static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1706 struct list_head *lists)
1707{
1708 struct snd_kctl_ioctl *p;
1709
1710 if (snd_BUG_ON(!fcn))
1711 return -EINVAL;
1712 down_write(&snd_ioctl_rwsem);
1713 list_for_each_entry(p, lists, list) {
1714 if (p->fioctl == fcn) {
1715 list_del(&p->list);
1716 up_write(&snd_ioctl_rwsem);
1717 kfree(p);
1718 return 0;
1719 }
1720 }
1721 up_write(&snd_ioctl_rwsem);
1722 snd_BUG();
1723 return -EINVAL;
1724}
1725
1726/**
1727 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1728 * @fcn: ioctl callback function to unregister
1729 */
1730int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1731{
1732 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1733}
1734EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1735
1736#ifdef CONFIG_COMPAT
1737/**
1738 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1739 * control-ioctls
1740 * @fcn: ioctl callback function to unregister
1741 */
1742int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1743{
1744 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1745}
1746EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1747#endif
1748
1749static int snd_ctl_fasync(int fd, struct file * file, int on)
1750{
1751 struct snd_ctl_file *ctl;
1752
1753 ctl = file->private_data;
1754 return fasync_helper(fd, file, on, &ctl->fasync);
1755}
1756
1757/* return the preferred subdevice number if already assigned;
1758 * otherwise return -1
1759 */
1760int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1761{
1762 struct snd_ctl_file *kctl;
1763 int subdevice = -1;
1764
1765 read_lock(&card->ctl_files_rwlock);
1766 list_for_each_entry(kctl, &card->ctl_files, list) {
1767 if (kctl->pid == task_pid(current)) {
1768 subdevice = kctl->preferred_subdevice[type];
1769 if (subdevice != -1)
1770 break;
1771 }
1772 }
1773 read_unlock(&card->ctl_files_rwlock);
1774 return subdevice;
1775}
1776EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1777
1778/*
1779 * ioctl32 compat
1780 */
1781#ifdef CONFIG_COMPAT
1782#include "control_compat.c"
1783#else
1784#define snd_ctl_ioctl_compat NULL
1785#endif
1786
1787/*
1788 * INIT PART
1789 */
1790
1791static const struct file_operations snd_ctl_f_ops =
1792{
1793 .owner = THIS_MODULE,
1794 .read = snd_ctl_read,
1795 .open = snd_ctl_open,
1796 .release = snd_ctl_release,
1797 .llseek = no_llseek,
1798 .poll = snd_ctl_poll,
1799 .unlocked_ioctl = snd_ctl_ioctl,
1800 .compat_ioctl = snd_ctl_ioctl_compat,
1801 .fasync = snd_ctl_fasync,
1802};
1803
1804/*
1805 * registration of the control device
1806 */
1807static int snd_ctl_dev_register(struct snd_device *device)
1808{
1809 struct snd_card *card = device->device_data;
1810
1811 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1812 &snd_ctl_f_ops, card, &card->ctl_dev);
1813}
1814
1815/*
1816 * disconnection of the control device
1817 */
1818static int snd_ctl_dev_disconnect(struct snd_device *device)
1819{
1820 struct snd_card *card = device->device_data;
1821 struct snd_ctl_file *ctl;
1822
1823 read_lock(&card->ctl_files_rwlock);
1824 list_for_each_entry(ctl, &card->ctl_files, list) {
1825 wake_up(&ctl->change_sleep);
1826 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
1827 }
1828 read_unlock(&card->ctl_files_rwlock);
1829
1830 return snd_unregister_device(&card->ctl_dev);
1831}
1832
1833/*
1834 * free all controls
1835 */
1836static int snd_ctl_dev_free(struct snd_device *device)
1837{
1838 struct snd_card *card = device->device_data;
1839 struct snd_kcontrol *control;
1840
1841 down_write(&card->controls_rwsem);
1842 while (!list_empty(&card->controls)) {
1843 control = snd_kcontrol(card->controls.next);
1844 snd_ctl_remove(card, control);
1845 }
1846 up_write(&card->controls_rwsem);
1847 put_device(&card->ctl_dev);
1848 return 0;
1849}
1850
1851/*
1852 * create control core:
1853 * called from init.c
1854 */
1855int snd_ctl_create(struct snd_card *card)
1856{
1857 static struct snd_device_ops ops = {
1858 .dev_free = snd_ctl_dev_free,
1859 .dev_register = snd_ctl_dev_register,
1860 .dev_disconnect = snd_ctl_dev_disconnect,
1861 };
1862 int err;
1863
1864 if (snd_BUG_ON(!card))
1865 return -ENXIO;
1866 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
1867 return -ENXIO;
1868
1869 snd_device_initialize(&card->ctl_dev, card);
1870 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
1871
1872 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
1873 if (err < 0)
1874 put_device(&card->ctl_dev);
1875 return err;
1876}
1877
1878/*
1879 * Frequently used control callbacks/helpers
1880 */
1881
1882/**
1883 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
1884 * callback with a mono channel
1885 * @kcontrol: the kcontrol instance
1886 * @uinfo: info to store
1887 *
1888 * This is a function that can be used as info callback for a standard
1889 * boolean control with a single mono channel.
1890 */
1891int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
1892 struct snd_ctl_elem_info *uinfo)
1893{
1894 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1895 uinfo->count = 1;
1896 uinfo->value.integer.min = 0;
1897 uinfo->value.integer.max = 1;
1898 return 0;
1899}
1900EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
1901
1902/**
1903 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
1904 * callback with stereo two channels
1905 * @kcontrol: the kcontrol instance
1906 * @uinfo: info to store
1907 *
1908 * This is a function that can be used as info callback for a standard
1909 * boolean control with stereo two channels.
1910 */
1911int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
1912 struct snd_ctl_elem_info *uinfo)
1913{
1914 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
1915 uinfo->count = 2;
1916 uinfo->value.integer.min = 0;
1917 uinfo->value.integer.max = 1;
1918 return 0;
1919}
1920EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
1921
1922/**
1923 * snd_ctl_enum_info - fills the info structure for an enumerated control
1924 * @info: the structure to be filled
1925 * @channels: the number of the control's channels; often one
1926 * @items: the number of control values; also the size of @names
1927 * @names: an array containing the names of all control values
1928 *
1929 * Sets all required fields in @info to their appropriate values.
1930 * If the control's accessibility is not the default (readable and writable),
1931 * the caller has to fill @info->access.
1932 *
1933 * Return: Zero.
1934 */
1935int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
1936 unsigned int items, const char *const names[])
1937{
1938 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
1939 info->count = channels;
1940 info->value.enumerated.items = items;
1941 if (!items)
1942 return 0;
1943 if (info->value.enumerated.item >= items)
1944 info->value.enumerated.item = items - 1;
1945 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
1946 "ALSA: too long item name '%s'\n",
1947 names[info->value.enumerated.item]);
1948 strlcpy(info->value.enumerated.name,
1949 names[info->value.enumerated.item],
1950 sizeof(info->value.enumerated.name));
1951 return 0;
1952}
1953EXPORT_SYMBOL(snd_ctl_enum_info);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Routines for driver control interface
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/threads.h>
8#include <linux/interrupt.h>
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/vmalloc.h>
12#include <linux/time.h>
13#include <linux/mm.h>
14#include <linux/math64.h>
15#include <linux/sched/signal.h>
16#include <sound/core.h>
17#include <sound/minors.h>
18#include <sound/info.h>
19#include <sound/control.h>
20
21/* max number of user-defined controls */
22#define MAX_USER_CONTROLS 32
23#define MAX_CONTROL_COUNT 1028
24
25struct snd_kctl_ioctl {
26 struct list_head list; /* list of all ioctls */
27 snd_kctl_ioctl_func_t fioctl;
28};
29
30static DECLARE_RWSEM(snd_ioctl_rwsem);
31static LIST_HEAD(snd_control_ioctls);
32#ifdef CONFIG_COMPAT
33static LIST_HEAD(snd_control_compat_ioctls);
34#endif
35
36static int snd_ctl_open(struct inode *inode, struct file *file)
37{
38 unsigned long flags;
39 struct snd_card *card;
40 struct snd_ctl_file *ctl;
41 int i, err;
42
43 err = stream_open(inode, file);
44 if (err < 0)
45 return err;
46
47 card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
48 if (!card) {
49 err = -ENODEV;
50 goto __error1;
51 }
52 err = snd_card_file_add(card, file);
53 if (err < 0) {
54 err = -ENODEV;
55 goto __error1;
56 }
57 if (!try_module_get(card->module)) {
58 err = -EFAULT;
59 goto __error2;
60 }
61 ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
62 if (ctl == NULL) {
63 err = -ENOMEM;
64 goto __error;
65 }
66 INIT_LIST_HEAD(&ctl->events);
67 init_waitqueue_head(&ctl->change_sleep);
68 spin_lock_init(&ctl->read_lock);
69 ctl->card = card;
70 for (i = 0; i < SND_CTL_SUBDEV_ITEMS; i++)
71 ctl->preferred_subdevice[i] = -1;
72 ctl->pid = get_pid(task_pid(current));
73 file->private_data = ctl;
74 write_lock_irqsave(&card->ctl_files_rwlock, flags);
75 list_add_tail(&ctl->list, &card->ctl_files);
76 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
77 snd_card_unref(card);
78 return 0;
79
80 __error:
81 module_put(card->module);
82 __error2:
83 snd_card_file_remove(card, file);
84 __error1:
85 if (card)
86 snd_card_unref(card);
87 return err;
88}
89
90static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
91{
92 unsigned long flags;
93 struct snd_kctl_event *cread;
94
95 spin_lock_irqsave(&ctl->read_lock, flags);
96 while (!list_empty(&ctl->events)) {
97 cread = snd_kctl_event(ctl->events.next);
98 list_del(&cread->list);
99 kfree(cread);
100 }
101 spin_unlock_irqrestore(&ctl->read_lock, flags);
102}
103
104static int snd_ctl_release(struct inode *inode, struct file *file)
105{
106 unsigned long flags;
107 struct snd_card *card;
108 struct snd_ctl_file *ctl;
109 struct snd_kcontrol *control;
110 unsigned int idx;
111
112 ctl = file->private_data;
113 file->private_data = NULL;
114 card = ctl->card;
115 write_lock_irqsave(&card->ctl_files_rwlock, flags);
116 list_del(&ctl->list);
117 write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
118 down_write(&card->controls_rwsem);
119 list_for_each_entry(control, &card->controls, list)
120 for (idx = 0; idx < control->count; idx++)
121 if (control->vd[idx].owner == ctl)
122 control->vd[idx].owner = NULL;
123 up_write(&card->controls_rwsem);
124 snd_ctl_empty_read_queue(ctl);
125 put_pid(ctl->pid);
126 kfree(ctl);
127 module_put(card->module);
128 snd_card_file_remove(card, file);
129 return 0;
130}
131
132/**
133 * snd_ctl_notify - Send notification to user-space for a control change
134 * @card: the card to send notification
135 * @mask: the event mask, SNDRV_CTL_EVENT_*
136 * @id: the ctl element id to send notification
137 *
138 * This function adds an event record with the given id and mask, appends
139 * to the list and wakes up the user-space for notification. This can be
140 * called in the atomic context.
141 */
142void snd_ctl_notify(struct snd_card *card, unsigned int mask,
143 struct snd_ctl_elem_id *id)
144{
145 unsigned long flags;
146 struct snd_ctl_file *ctl;
147 struct snd_kctl_event *ev;
148
149 if (snd_BUG_ON(!card || !id))
150 return;
151 if (card->shutdown)
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}
182EXPORT_SYMBOL(snd_ctl_notify);
183
184/**
185 * snd_ctl_new - create a new control instance with some elements
186 * @kctl: the pointer to store new control instance
187 * @count: the number of elements in this control
188 * @access: the default access flags for elements in this control
189 * @file: given when locking these elements
190 *
191 * Allocates a memory object for a new control instance. The instance has
192 * elements as many as the given number (@count). Each element has given
193 * access permissions (@access). Each element is locked when @file is given.
194 *
195 * Return: 0 on success, error code on failure
196 */
197static int snd_ctl_new(struct snd_kcontrol **kctl, unsigned int count,
198 unsigned int access, struct snd_ctl_file *file)
199{
200 unsigned int idx;
201
202 if (count == 0 || count > MAX_CONTROL_COUNT)
203 return -EINVAL;
204
205 *kctl = kzalloc(struct_size(*kctl, vd, count), GFP_KERNEL);
206 if (!*kctl)
207 return -ENOMEM;
208
209 for (idx = 0; idx < count; idx++) {
210 (*kctl)->vd[idx].access = access;
211 (*kctl)->vd[idx].owner = file;
212 }
213 (*kctl)->count = count;
214
215 return 0;
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 count;
234 unsigned int access;
235 int err;
236
237 if (snd_BUG_ON(!ncontrol || !ncontrol->info))
238 return NULL;
239
240 count = ncontrol->count;
241 if (count == 0)
242 count = 1;
243
244 access = ncontrol->access;
245 if (access == 0)
246 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
247 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
248 SNDRV_CTL_ELEM_ACCESS_VOLATILE |
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 SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK);
254
255 err = snd_ctl_new(&kctl, count, access, NULL);
256 if (err < 0)
257 return NULL;
258
259 /* The 'numid' member is decided when calling snd_ctl_add(). */
260 kctl->id.iface = ncontrol->iface;
261 kctl->id.device = ncontrol->device;
262 kctl->id.subdevice = ncontrol->subdevice;
263 if (ncontrol->name) {
264 strlcpy(kctl->id.name, ncontrol->name, sizeof(kctl->id.name));
265 if (strcmp(ncontrol->name, kctl->id.name) != 0)
266 pr_warn("ALSA: Control name '%s' truncated to '%s'\n",
267 ncontrol->name, kctl->id.name);
268 }
269 kctl->id.index = ncontrol->index;
270
271 kctl->info = ncontrol->info;
272 kctl->get = ncontrol->get;
273 kctl->put = ncontrol->put;
274 kctl->tlv.p = ncontrol->tlv.p;
275
276 kctl->private_value = ncontrol->private_value;
277 kctl->private_data = private_data;
278
279 return kctl;
280}
281EXPORT_SYMBOL(snd_ctl_new1);
282
283/**
284 * snd_ctl_free_one - release the control instance
285 * @kcontrol: the control instance
286 *
287 * Releases the control instance created via snd_ctl_new()
288 * or snd_ctl_new1().
289 * Don't call this after the control was added to the card.
290 */
291void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
292{
293 if (kcontrol) {
294 if (kcontrol->private_free)
295 kcontrol->private_free(kcontrol);
296 kfree(kcontrol);
297 }
298}
299EXPORT_SYMBOL(snd_ctl_free_one);
300
301static bool snd_ctl_remove_numid_conflict(struct snd_card *card,
302 unsigned int count)
303{
304 struct snd_kcontrol *kctl;
305
306 /* Make sure that the ids assigned to the control do not wrap around */
307 if (card->last_numid >= UINT_MAX - count)
308 card->last_numid = 0;
309
310 list_for_each_entry(kctl, &card->controls, list) {
311 if (kctl->id.numid < card->last_numid + 1 + count &&
312 kctl->id.numid + kctl->count > card->last_numid + 1) {
313 card->last_numid = kctl->id.numid + kctl->count - 1;
314 return true;
315 }
316 }
317 return false;
318}
319
320static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
321{
322 unsigned int iter = 100000;
323
324 while (snd_ctl_remove_numid_conflict(card, count)) {
325 if (--iter == 0) {
326 /* this situation is very unlikely */
327 dev_err(card->dev, "unable to allocate new control numid\n");
328 return -ENOMEM;
329 }
330 }
331 return 0;
332}
333
334enum snd_ctl_add_mode {
335 CTL_ADD_EXCLUSIVE, CTL_REPLACE, CTL_ADD_ON_REPLACE,
336};
337
338/* add/replace a new kcontrol object; call with card->controls_rwsem locked */
339static int __snd_ctl_add_replace(struct snd_card *card,
340 struct snd_kcontrol *kcontrol,
341 enum snd_ctl_add_mode mode)
342{
343 struct snd_ctl_elem_id id;
344 unsigned int idx;
345 unsigned int count;
346 struct snd_kcontrol *old;
347 int err;
348
349 id = kcontrol->id;
350 if (id.index > UINT_MAX - kcontrol->count)
351 return -EINVAL;
352
353 old = snd_ctl_find_id(card, &id);
354 if (!old) {
355 if (mode == CTL_REPLACE)
356 return -EINVAL;
357 } else {
358 if (mode == CTL_ADD_EXCLUSIVE) {
359 dev_err(card->dev,
360 "control %i:%i:%i:%s:%i is already present\n",
361 id.iface, id.device, id.subdevice, id.name,
362 id.index);
363 return -EBUSY;
364 }
365
366 err = snd_ctl_remove(card, old);
367 if (err < 0)
368 return err;
369 }
370
371 if (snd_ctl_find_hole(card, kcontrol->count) < 0)
372 return -ENOMEM;
373
374 list_add_tail(&kcontrol->list, &card->controls);
375 card->controls_count += kcontrol->count;
376 kcontrol->id.numid = card->last_numid + 1;
377 card->last_numid += kcontrol->count;
378
379 id = kcontrol->id;
380 count = kcontrol->count;
381 for (idx = 0; idx < count; idx++, id.index++, id.numid++)
382 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
383
384 return 0;
385}
386
387static int snd_ctl_add_replace(struct snd_card *card,
388 struct snd_kcontrol *kcontrol,
389 enum snd_ctl_add_mode mode)
390{
391 int err = -EINVAL;
392
393 if (! kcontrol)
394 return err;
395 if (snd_BUG_ON(!card || !kcontrol->info))
396 goto error;
397
398 down_write(&card->controls_rwsem);
399 err = __snd_ctl_add_replace(card, kcontrol, mode);
400 up_write(&card->controls_rwsem);
401 if (err < 0)
402 goto error;
403 return 0;
404
405 error:
406 snd_ctl_free_one(kcontrol);
407 return err;
408}
409
410/**
411 * snd_ctl_add - add the control instance to the card
412 * @card: the card instance
413 * @kcontrol: the control instance to add
414 *
415 * Adds the control instance created via snd_ctl_new() or
416 * snd_ctl_new1() to the given card. Assigns also an unique
417 * numid used for fast search.
418 *
419 * It frees automatically the control which cannot be added.
420 *
421 * Return: Zero if successful, or a negative error code on failure.
422 *
423 */
424int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
425{
426 return snd_ctl_add_replace(card, kcontrol, CTL_ADD_EXCLUSIVE);
427}
428EXPORT_SYMBOL(snd_ctl_add);
429
430/**
431 * snd_ctl_replace - replace the control instance of the card
432 * @card: the card instance
433 * @kcontrol: the control instance to replace
434 * @add_on_replace: add the control if not already added
435 *
436 * Replaces the given control. If the given control does not exist
437 * and the add_on_replace flag is set, the control is added. If the
438 * control exists, it is destroyed first.
439 *
440 * It frees automatically the control which cannot be added or replaced.
441 *
442 * Return: Zero if successful, or a negative error code on failure.
443 */
444int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol,
445 bool add_on_replace)
446{
447 return snd_ctl_add_replace(card, kcontrol,
448 add_on_replace ? CTL_ADD_ON_REPLACE : CTL_REPLACE);
449}
450EXPORT_SYMBOL(snd_ctl_replace);
451
452/**
453 * snd_ctl_remove - remove the control from the card and release it
454 * @card: the card instance
455 * @kcontrol: the control instance to remove
456 *
457 * Removes the control from the card and then releases the instance.
458 * You don't need to call snd_ctl_free_one(). You must be in
459 * the write lock - down_write(&card->controls_rwsem).
460 *
461 * Return: 0 if successful, or a negative error code on failure.
462 */
463int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
464{
465 struct snd_ctl_elem_id id;
466 unsigned int idx;
467
468 if (snd_BUG_ON(!card || !kcontrol))
469 return -EINVAL;
470 list_del(&kcontrol->list);
471 card->controls_count -= kcontrol->count;
472 id = kcontrol->id;
473 for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
474 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
475 snd_ctl_free_one(kcontrol);
476 return 0;
477}
478EXPORT_SYMBOL(snd_ctl_remove);
479
480/**
481 * snd_ctl_remove_id - remove the control of the given id and release it
482 * @card: the card instance
483 * @id: the control id to remove
484 *
485 * Finds the control instance with the given id, removes it from the
486 * card list and releases it.
487 *
488 * Return: 0 if successful, or a negative error code on failure.
489 */
490int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
491{
492 struct snd_kcontrol *kctl;
493 int ret;
494
495 down_write(&card->controls_rwsem);
496 kctl = snd_ctl_find_id(card, id);
497 if (kctl == NULL) {
498 up_write(&card->controls_rwsem);
499 return -ENOENT;
500 }
501 ret = snd_ctl_remove(card, kctl);
502 up_write(&card->controls_rwsem);
503 return ret;
504}
505EXPORT_SYMBOL(snd_ctl_remove_id);
506
507/**
508 * snd_ctl_remove_user_ctl - remove and release the unlocked user control
509 * @file: active control handle
510 * @id: the control id to remove
511 *
512 * Finds the control instance with the given id, removes it from the
513 * card list and releases it.
514 *
515 * Return: 0 if successful, or a negative error code on failure.
516 */
517static int snd_ctl_remove_user_ctl(struct snd_ctl_file * file,
518 struct snd_ctl_elem_id *id)
519{
520 struct snd_card *card = file->card;
521 struct snd_kcontrol *kctl;
522 int idx, ret;
523
524 down_write(&card->controls_rwsem);
525 kctl = snd_ctl_find_id(card, id);
526 if (kctl == NULL) {
527 ret = -ENOENT;
528 goto error;
529 }
530 if (!(kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_USER)) {
531 ret = -EINVAL;
532 goto error;
533 }
534 for (idx = 0; idx < kctl->count; idx++)
535 if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
536 ret = -EBUSY;
537 goto error;
538 }
539 ret = snd_ctl_remove(card, kctl);
540 if (ret < 0)
541 goto error;
542 card->user_ctl_count--;
543error:
544 up_write(&card->controls_rwsem);
545 return ret;
546}
547
548/**
549 * snd_ctl_activate_id - activate/inactivate the control of the given id
550 * @card: the card instance
551 * @id: the control id to activate/inactivate
552 * @active: non-zero to activate
553 *
554 * Finds the control instance with the given id, and activate or
555 * inactivate the control together with notification, if changed.
556 * The given ID data is filled with full information.
557 *
558 * Return: 0 if unchanged, 1 if changed, or a negative error code on failure.
559 */
560int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
561 int active)
562{
563 struct snd_kcontrol *kctl;
564 struct snd_kcontrol_volatile *vd;
565 unsigned int index_offset;
566 int ret;
567
568 down_write(&card->controls_rwsem);
569 kctl = snd_ctl_find_id(card, id);
570 if (kctl == NULL) {
571 ret = -ENOENT;
572 goto unlock;
573 }
574 index_offset = snd_ctl_get_ioff(kctl, id);
575 vd = &kctl->vd[index_offset];
576 ret = 0;
577 if (active) {
578 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE))
579 goto unlock;
580 vd->access &= ~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
581 } else {
582 if (vd->access & SNDRV_CTL_ELEM_ACCESS_INACTIVE)
583 goto unlock;
584 vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
585 }
586 snd_ctl_build_ioff(id, kctl, index_offset);
587 ret = 1;
588 unlock:
589 up_write(&card->controls_rwsem);
590 if (ret > 0)
591 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
592 return ret;
593}
594EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
595
596/**
597 * snd_ctl_rename_id - replace the id of a control on the card
598 * @card: the card instance
599 * @src_id: the old id
600 * @dst_id: the new id
601 *
602 * Finds the control with the old id from the card, and replaces the
603 * id with the new one.
604 *
605 * Return: Zero if successful, or a negative error code on failure.
606 */
607int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
608 struct snd_ctl_elem_id *dst_id)
609{
610 struct snd_kcontrol *kctl;
611
612 down_write(&card->controls_rwsem);
613 kctl = snd_ctl_find_id(card, src_id);
614 if (kctl == NULL) {
615 up_write(&card->controls_rwsem);
616 return -ENOENT;
617 }
618 kctl->id = *dst_id;
619 kctl->id.numid = card->last_numid + 1;
620 card->last_numid += kctl->count;
621 up_write(&card->controls_rwsem);
622 return 0;
623}
624EXPORT_SYMBOL(snd_ctl_rename_id);
625
626/**
627 * snd_ctl_find_numid - find the control instance with the given number-id
628 * @card: the card instance
629 * @numid: the number-id to search
630 *
631 * Finds the control instance with the given number-id from the card.
632 *
633 * The caller must down card->controls_rwsem before calling this function
634 * (if the race condition can happen).
635 *
636 * Return: The pointer of the instance if found, or %NULL if not.
637 *
638 */
639struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
640{
641 struct snd_kcontrol *kctl;
642
643 if (snd_BUG_ON(!card || !numid))
644 return NULL;
645 list_for_each_entry(kctl, &card->controls, list) {
646 if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
647 return kctl;
648 }
649 return NULL;
650}
651EXPORT_SYMBOL(snd_ctl_find_numid);
652
653/**
654 * snd_ctl_find_id - find the control instance with the given id
655 * @card: the card instance
656 * @id: the id to search
657 *
658 * Finds the control instance with the given id from the card.
659 *
660 * The caller must down card->controls_rwsem before calling this function
661 * (if the race condition can happen).
662 *
663 * Return: The pointer of the instance if found, or %NULL if not.
664 *
665 */
666struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
667 struct snd_ctl_elem_id *id)
668{
669 struct snd_kcontrol *kctl;
670
671 if (snd_BUG_ON(!card || !id))
672 return NULL;
673 if (id->numid != 0)
674 return snd_ctl_find_numid(card, id->numid);
675 list_for_each_entry(kctl, &card->controls, list) {
676 if (kctl->id.iface != id->iface)
677 continue;
678 if (kctl->id.device != id->device)
679 continue;
680 if (kctl->id.subdevice != id->subdevice)
681 continue;
682 if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
683 continue;
684 if (kctl->id.index > id->index)
685 continue;
686 if (kctl->id.index + kctl->count <= id->index)
687 continue;
688 return kctl;
689 }
690 return NULL;
691}
692EXPORT_SYMBOL(snd_ctl_find_id);
693
694static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
695 unsigned int cmd, void __user *arg)
696{
697 struct snd_ctl_card_info *info;
698
699 info = kzalloc(sizeof(*info), GFP_KERNEL);
700 if (! info)
701 return -ENOMEM;
702 down_read(&snd_ioctl_rwsem);
703 info->card = card->number;
704 strlcpy(info->id, card->id, sizeof(info->id));
705 strlcpy(info->driver, card->driver, sizeof(info->driver));
706 strlcpy(info->name, card->shortname, sizeof(info->name));
707 strlcpy(info->longname, card->longname, sizeof(info->longname));
708 strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
709 strlcpy(info->components, card->components, sizeof(info->components));
710 up_read(&snd_ioctl_rwsem);
711 if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
712 kfree(info);
713 return -EFAULT;
714 }
715 kfree(info);
716 return 0;
717}
718
719static int snd_ctl_elem_list(struct snd_card *card,
720 struct snd_ctl_elem_list __user *_list)
721{
722 struct snd_ctl_elem_list list;
723 struct snd_kcontrol *kctl;
724 struct snd_ctl_elem_id id;
725 unsigned int offset, space, jidx;
726 int err = 0;
727
728 if (copy_from_user(&list, _list, sizeof(list)))
729 return -EFAULT;
730 offset = list.offset;
731 space = list.space;
732
733 down_read(&card->controls_rwsem);
734 list.count = card->controls_count;
735 list.used = 0;
736 if (space > 0) {
737 list_for_each_entry(kctl, &card->controls, list) {
738 if (offset >= kctl->count) {
739 offset -= kctl->count;
740 continue;
741 }
742 for (jidx = offset; jidx < kctl->count; jidx++) {
743 snd_ctl_build_ioff(&id, kctl, jidx);
744 if (copy_to_user(list.pids + list.used, &id,
745 sizeof(id))) {
746 err = -EFAULT;
747 goto out;
748 }
749 list.used++;
750 if (!--space)
751 goto out;
752 }
753 offset = 0;
754 }
755 }
756 out:
757 up_read(&card->controls_rwsem);
758 if (!err && copy_to_user(_list, &list, sizeof(list)))
759 err = -EFAULT;
760 return err;
761}
762
763/* Check whether the given kctl info is valid */
764static int snd_ctl_check_elem_info(struct snd_card *card,
765 const struct snd_ctl_elem_info *info)
766{
767 static const unsigned int max_value_counts[] = {
768 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = 128,
769 [SNDRV_CTL_ELEM_TYPE_INTEGER] = 128,
770 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = 128,
771 [SNDRV_CTL_ELEM_TYPE_BYTES] = 512,
772 [SNDRV_CTL_ELEM_TYPE_IEC958] = 1,
773 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = 64,
774 };
775
776 if (info->type < SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
777 info->type > SNDRV_CTL_ELEM_TYPE_INTEGER64) {
778 if (card)
779 dev_err(card->dev,
780 "control %i:%i:%i:%s:%i: invalid type %d\n",
781 info->id.iface, info->id.device,
782 info->id.subdevice, info->id.name,
783 info->id.index, info->type);
784 return -EINVAL;
785 }
786 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED &&
787 info->value.enumerated.items == 0) {
788 if (card)
789 dev_err(card->dev,
790 "control %i:%i:%i:%s:%i: zero enum items\n",
791 info->id.iface, info->id.device,
792 info->id.subdevice, info->id.name,
793 info->id.index);
794 return -EINVAL;
795 }
796 if (info->count > max_value_counts[info->type]) {
797 if (card)
798 dev_err(card->dev,
799 "control %i:%i:%i:%s:%i: invalid count %d\n",
800 info->id.iface, info->id.device,
801 info->id.subdevice, info->id.name,
802 info->id.index, info->count);
803 return -EINVAL;
804 }
805
806 return 0;
807}
808
809/* The capacity of struct snd_ctl_elem_value.value.*/
810static const unsigned int value_sizes[] = {
811 [SNDRV_CTL_ELEM_TYPE_BOOLEAN] = sizeof(long),
812 [SNDRV_CTL_ELEM_TYPE_INTEGER] = sizeof(long),
813 [SNDRV_CTL_ELEM_TYPE_ENUMERATED] = sizeof(unsigned int),
814 [SNDRV_CTL_ELEM_TYPE_BYTES] = sizeof(unsigned char),
815 [SNDRV_CTL_ELEM_TYPE_IEC958] = sizeof(struct snd_aes_iec958),
816 [SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
817};
818
819#ifdef CONFIG_SND_CTL_VALIDATION
820/* fill the remaining snd_ctl_elem_value data with the given pattern */
821static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
822 struct snd_ctl_elem_info *info,
823 u32 pattern)
824{
825 size_t offset = value_sizes[info->type] * info->count;
826
827 offset = (offset + sizeof(u32) - 1) / sizeof(u32);
828 memset32((u32 *)control->value.bytes.data + offset, pattern,
829 sizeof(control->value) / sizeof(u32) - offset);
830}
831
832/* check whether the given integer ctl value is valid */
833static int sanity_check_int_value(struct snd_card *card,
834 const struct snd_ctl_elem_value *control,
835 const struct snd_ctl_elem_info *info,
836 int i)
837{
838 long long lval, lmin, lmax, lstep;
839 u64 rem;
840
841 switch (info->type) {
842 default:
843 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
844 lval = control->value.integer.value[i];
845 lmin = 0;
846 lmax = 1;
847 lstep = 0;
848 break;
849 case SNDRV_CTL_ELEM_TYPE_INTEGER:
850 lval = control->value.integer.value[i];
851 lmin = info->value.integer.min;
852 lmax = info->value.integer.max;
853 lstep = info->value.integer.step;
854 break;
855 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
856 lval = control->value.integer64.value[i];
857 lmin = info->value.integer64.min;
858 lmax = info->value.integer64.max;
859 lstep = info->value.integer64.step;
860 break;
861 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
862 lval = control->value.enumerated.item[i];
863 lmin = 0;
864 lmax = info->value.enumerated.items - 1;
865 lstep = 0;
866 break;
867 }
868
869 if (lval < lmin || lval > lmax) {
870 dev_err(card->dev,
871 "control %i:%i:%i:%s:%i: value out of range %lld (%lld/%lld) at count %i\n",
872 control->id.iface, control->id.device,
873 control->id.subdevice, control->id.name,
874 control->id.index, lval, lmin, lmax, i);
875 return -EINVAL;
876 }
877 if (lstep) {
878 div64_u64_rem(lval, lstep, &rem);
879 if (rem) {
880 dev_err(card->dev,
881 "control %i:%i:%i:%s:%i: unaligned value %lld (step %lld) at count %i\n",
882 control->id.iface, control->id.device,
883 control->id.subdevice, control->id.name,
884 control->id.index, lval, lstep, i);
885 return -EINVAL;
886 }
887 }
888
889 return 0;
890}
891
892/* perform sanity checks to the given snd_ctl_elem_value object */
893static int sanity_check_elem_value(struct snd_card *card,
894 const struct snd_ctl_elem_value *control,
895 const struct snd_ctl_elem_info *info,
896 u32 pattern)
897{
898 size_t offset;
899 int i, ret = 0;
900 u32 *p;
901
902 switch (info->type) {
903 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
904 case SNDRV_CTL_ELEM_TYPE_INTEGER:
905 case SNDRV_CTL_ELEM_TYPE_INTEGER64:
906 case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
907 for (i = 0; i < info->count; i++) {
908 ret = sanity_check_int_value(card, control, info, i);
909 if (ret < 0)
910 return ret;
911 }
912 break;
913 default:
914 break;
915 }
916
917 /* check whether the remaining area kept untouched */
918 offset = value_sizes[info->type] * info->count;
919 offset = (offset + sizeof(u32) - 1) / sizeof(u32);
920 p = (u32 *)control->value.bytes.data + offset;
921 for (; offset < sizeof(control->value) / sizeof(u32); offset++, p++) {
922 if (*p != pattern) {
923 ret = -EINVAL;
924 break;
925 }
926 *p = 0; /* clear the checked area */
927 }
928
929 return ret;
930}
931#else
932static inline void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
933 struct snd_ctl_elem_info *info,
934 u32 pattern)
935{
936}
937
938static inline int sanity_check_elem_value(struct snd_card *card,
939 struct snd_ctl_elem_value *control,
940 struct snd_ctl_elem_info *info,
941 u32 pattern)
942{
943 return 0;
944}
945#endif
946
947static int __snd_ctl_elem_info(struct snd_card *card,
948 struct snd_kcontrol *kctl,
949 struct snd_ctl_elem_info *info,
950 struct snd_ctl_file *ctl)
951{
952 struct snd_kcontrol_volatile *vd;
953 unsigned int index_offset;
954 int result;
955
956#ifdef CONFIG_SND_DEBUG
957 info->access = 0;
958#endif
959 result = kctl->info(kctl, info);
960 if (result >= 0) {
961 snd_BUG_ON(info->access);
962 index_offset = snd_ctl_get_ioff(kctl, &info->id);
963 vd = &kctl->vd[index_offset];
964 snd_ctl_build_ioff(&info->id, kctl, index_offset);
965 info->access = vd->access;
966 if (vd->owner) {
967 info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
968 if (vd->owner == ctl)
969 info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
970 info->owner = pid_vnr(vd->owner->pid);
971 } else {
972 info->owner = -1;
973 }
974 if (!snd_ctl_skip_validation(info) &&
975 snd_ctl_check_elem_info(card, info) < 0)
976 result = -EINVAL;
977 }
978 return result;
979}
980
981static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
982 struct snd_ctl_elem_info *info)
983{
984 struct snd_card *card = ctl->card;
985 struct snd_kcontrol *kctl;
986 int result;
987
988 down_read(&card->controls_rwsem);
989 kctl = snd_ctl_find_id(card, &info->id);
990 if (kctl == NULL)
991 result = -ENOENT;
992 else
993 result = __snd_ctl_elem_info(card, kctl, info, ctl);
994 up_read(&card->controls_rwsem);
995 return result;
996}
997
998static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
999 struct snd_ctl_elem_info __user *_info)
1000{
1001 struct snd_ctl_elem_info info;
1002 int result;
1003
1004 if (copy_from_user(&info, _info, sizeof(info)))
1005 return -EFAULT;
1006 result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
1007 if (result < 0)
1008 return result;
1009 result = snd_ctl_elem_info(ctl, &info);
1010 if (result < 0)
1011 return result;
1012 /* drop internal access flags */
1013 info.access &= ~SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK;
1014 if (copy_to_user(_info, &info, sizeof(info)))
1015 return -EFAULT;
1016 return result;
1017}
1018
1019static int snd_ctl_elem_read(struct snd_card *card,
1020 struct snd_ctl_elem_value *control)
1021{
1022 struct snd_kcontrol *kctl;
1023 struct snd_kcontrol_volatile *vd;
1024 unsigned int index_offset;
1025 struct snd_ctl_elem_info info;
1026 const u32 pattern = 0xdeadbeef;
1027 int ret;
1028
1029 kctl = snd_ctl_find_id(card, &control->id);
1030 if (kctl == NULL)
1031 return -ENOENT;
1032
1033 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1034 vd = &kctl->vd[index_offset];
1035 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_READ) || kctl->get == NULL)
1036 return -EPERM;
1037
1038 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1039
1040#ifdef CONFIG_SND_CTL_VALIDATION
1041 /* info is needed only for validation */
1042 memset(&info, 0, sizeof(info));
1043 info.id = control->id;
1044 ret = __snd_ctl_elem_info(card, kctl, &info, NULL);
1045 if (ret < 0)
1046 return ret;
1047#endif
1048
1049 if (!snd_ctl_skip_validation(&info))
1050 fill_remaining_elem_value(control, &info, pattern);
1051 ret = kctl->get(kctl, control);
1052 if (ret < 0)
1053 return ret;
1054 if (!snd_ctl_skip_validation(&info) &&
1055 sanity_check_elem_value(card, control, &info, pattern) < 0) {
1056 dev_err(card->dev,
1057 "control %i:%i:%i:%s:%i: access overflow\n",
1058 control->id.iface, control->id.device,
1059 control->id.subdevice, control->id.name,
1060 control->id.index);
1061 return -EINVAL;
1062 }
1063 return ret;
1064}
1065
1066static int snd_ctl_elem_read_user(struct snd_card *card,
1067 struct snd_ctl_elem_value __user *_control)
1068{
1069 struct snd_ctl_elem_value *control;
1070 int result;
1071
1072 control = memdup_user(_control, sizeof(*control));
1073 if (IS_ERR(control))
1074 return PTR_ERR(control);
1075
1076 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1077 if (result < 0)
1078 goto error;
1079
1080 down_read(&card->controls_rwsem);
1081 result = snd_ctl_elem_read(card, control);
1082 up_read(&card->controls_rwsem);
1083 if (result < 0)
1084 goto error;
1085
1086 if (copy_to_user(_control, control, sizeof(*control)))
1087 result = -EFAULT;
1088 error:
1089 kfree(control);
1090 return result;
1091}
1092
1093static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
1094 struct snd_ctl_elem_value *control)
1095{
1096 struct snd_kcontrol *kctl;
1097 struct snd_kcontrol_volatile *vd;
1098 unsigned int index_offset;
1099 int result;
1100
1101 kctl = snd_ctl_find_id(card, &control->id);
1102 if (kctl == NULL)
1103 return -ENOENT;
1104
1105 index_offset = snd_ctl_get_ioff(kctl, &control->id);
1106 vd = &kctl->vd[index_offset];
1107 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
1108 (file && vd->owner && vd->owner != file)) {
1109 return -EPERM;
1110 }
1111
1112 snd_ctl_build_ioff(&control->id, kctl, index_offset);
1113 result = kctl->put(kctl, control);
1114 if (result < 0)
1115 return result;
1116
1117 if (result > 0) {
1118 struct snd_ctl_elem_id id = control->id;
1119 snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
1120 }
1121
1122 return 0;
1123}
1124
1125static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
1126 struct snd_ctl_elem_value __user *_control)
1127{
1128 struct snd_ctl_elem_value *control;
1129 struct snd_card *card;
1130 int result;
1131
1132 control = memdup_user(_control, sizeof(*control));
1133 if (IS_ERR(control))
1134 return PTR_ERR(control);
1135
1136 card = file->card;
1137 result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
1138 if (result < 0)
1139 goto error;
1140
1141 down_write(&card->controls_rwsem);
1142 result = snd_ctl_elem_write(card, file, control);
1143 up_write(&card->controls_rwsem);
1144 if (result < 0)
1145 goto error;
1146
1147 if (copy_to_user(_control, control, sizeof(*control)))
1148 result = -EFAULT;
1149 error:
1150 kfree(control);
1151 return result;
1152}
1153
1154static int snd_ctl_elem_lock(struct snd_ctl_file *file,
1155 struct snd_ctl_elem_id __user *_id)
1156{
1157 struct snd_card *card = file->card;
1158 struct snd_ctl_elem_id id;
1159 struct snd_kcontrol *kctl;
1160 struct snd_kcontrol_volatile *vd;
1161 int result;
1162
1163 if (copy_from_user(&id, _id, sizeof(id)))
1164 return -EFAULT;
1165 down_write(&card->controls_rwsem);
1166 kctl = snd_ctl_find_id(card, &id);
1167 if (kctl == NULL) {
1168 result = -ENOENT;
1169 } else {
1170 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1171 if (vd->owner != NULL)
1172 result = -EBUSY;
1173 else {
1174 vd->owner = file;
1175 result = 0;
1176 }
1177 }
1178 up_write(&card->controls_rwsem);
1179 return result;
1180}
1181
1182static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
1183 struct snd_ctl_elem_id __user *_id)
1184{
1185 struct snd_card *card = file->card;
1186 struct snd_ctl_elem_id id;
1187 struct snd_kcontrol *kctl;
1188 struct snd_kcontrol_volatile *vd;
1189 int result;
1190
1191 if (copy_from_user(&id, _id, sizeof(id)))
1192 return -EFAULT;
1193 down_write(&card->controls_rwsem);
1194 kctl = snd_ctl_find_id(card, &id);
1195 if (kctl == NULL) {
1196 result = -ENOENT;
1197 } else {
1198 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1199 if (vd->owner == NULL)
1200 result = -EINVAL;
1201 else if (vd->owner != file)
1202 result = -EPERM;
1203 else {
1204 vd->owner = NULL;
1205 result = 0;
1206 }
1207 }
1208 up_write(&card->controls_rwsem);
1209 return result;
1210}
1211
1212struct user_element {
1213 struct snd_ctl_elem_info info;
1214 struct snd_card *card;
1215 char *elem_data; /* element data */
1216 unsigned long elem_data_size; /* size of element data in bytes */
1217 void *tlv_data; /* TLV data */
1218 unsigned long tlv_data_size; /* TLV data size */
1219 void *priv_data; /* private data (like strings for enumerated type) */
1220};
1221
1222static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
1223 struct snd_ctl_elem_info *uinfo)
1224{
1225 struct user_element *ue = kcontrol->private_data;
1226 unsigned int offset;
1227
1228 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1229 *uinfo = ue->info;
1230 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1231
1232 return 0;
1233}
1234
1235static int snd_ctl_elem_user_enum_info(struct snd_kcontrol *kcontrol,
1236 struct snd_ctl_elem_info *uinfo)
1237{
1238 struct user_element *ue = kcontrol->private_data;
1239 const char *names;
1240 unsigned int item;
1241 unsigned int offset;
1242
1243 item = uinfo->value.enumerated.item;
1244
1245 offset = snd_ctl_get_ioff(kcontrol, &uinfo->id);
1246 *uinfo = ue->info;
1247 snd_ctl_build_ioff(&uinfo->id, kcontrol, offset);
1248
1249 item = min(item, uinfo->value.enumerated.items - 1);
1250 uinfo->value.enumerated.item = item;
1251
1252 names = ue->priv_data;
1253 for (; item > 0; --item)
1254 names += strlen(names) + 1;
1255 strcpy(uinfo->value.enumerated.name, names);
1256
1257 return 0;
1258}
1259
1260static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
1261 struct snd_ctl_elem_value *ucontrol)
1262{
1263 struct user_element *ue = kcontrol->private_data;
1264 unsigned int size = ue->elem_data_size;
1265 char *src = ue->elem_data +
1266 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1267
1268 memcpy(&ucontrol->value, src, size);
1269 return 0;
1270}
1271
1272static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
1273 struct snd_ctl_elem_value *ucontrol)
1274{
1275 int change;
1276 struct user_element *ue = kcontrol->private_data;
1277 unsigned int size = ue->elem_data_size;
1278 char *dst = ue->elem_data +
1279 snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
1280
1281 change = memcmp(&ucontrol->value, dst, size) != 0;
1282 if (change)
1283 memcpy(dst, &ucontrol->value, size);
1284 return change;
1285}
1286
1287static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1288 unsigned int size)
1289{
1290 struct user_element *ue = kctl->private_data;
1291 unsigned int *container;
1292 struct snd_ctl_elem_id id;
1293 unsigned int mask = 0;
1294 int i;
1295 int change;
1296
1297 if (size > 1024 * 128) /* sane value */
1298 return -EINVAL;
1299
1300 container = vmemdup_user(buf, size);
1301 if (IS_ERR(container))
1302 return PTR_ERR(container);
1303
1304 change = ue->tlv_data_size != size;
1305 if (!change)
1306 change = memcmp(ue->tlv_data, container, size) != 0;
1307 if (!change) {
1308 kvfree(container);
1309 return 0;
1310 }
1311
1312 if (ue->tlv_data == NULL) {
1313 /* Now TLV data is available. */
1314 for (i = 0; i < kctl->count; ++i)
1315 kctl->vd[i].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1316 mask = SNDRV_CTL_EVENT_MASK_INFO;
1317 }
1318
1319 kvfree(ue->tlv_data);
1320 ue->tlv_data = container;
1321 ue->tlv_data_size = size;
1322
1323 mask |= SNDRV_CTL_EVENT_MASK_TLV;
1324 for (i = 0; i < kctl->count; ++i) {
1325 snd_ctl_build_ioff(&id, kctl, i);
1326 snd_ctl_notify(ue->card, mask, &id);
1327 }
1328
1329 return change;
1330}
1331
1332static int read_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
1333 unsigned int size)
1334{
1335 struct user_element *ue = kctl->private_data;
1336
1337 if (ue->tlv_data_size == 0 || ue->tlv_data == NULL)
1338 return -ENXIO;
1339
1340 if (size < ue->tlv_data_size)
1341 return -ENOSPC;
1342
1343 if (copy_to_user(buf, ue->tlv_data, ue->tlv_data_size))
1344 return -EFAULT;
1345
1346 return 0;
1347}
1348
1349static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kctl, int op_flag,
1350 unsigned int size, unsigned int __user *buf)
1351{
1352 if (op_flag == SNDRV_CTL_TLV_OP_WRITE)
1353 return replace_user_tlv(kctl, buf, size);
1354 else
1355 return read_user_tlv(kctl, buf, size);
1356}
1357
1358static int snd_ctl_elem_init_enum_names(struct user_element *ue)
1359{
1360 char *names, *p;
1361 size_t buf_len, name_len;
1362 unsigned int i;
1363 const uintptr_t user_ptrval = ue->info.value.enumerated.names_ptr;
1364
1365 if (ue->info.value.enumerated.names_length > 64 * 1024)
1366 return -EINVAL;
1367
1368 names = vmemdup_user((const void __user *)user_ptrval,
1369 ue->info.value.enumerated.names_length);
1370 if (IS_ERR(names))
1371 return PTR_ERR(names);
1372
1373 /* check that there are enough valid names */
1374 buf_len = ue->info.value.enumerated.names_length;
1375 p = names;
1376 for (i = 0; i < ue->info.value.enumerated.items; ++i) {
1377 name_len = strnlen(p, buf_len);
1378 if (name_len == 0 || name_len >= 64 || name_len == buf_len) {
1379 kvfree(names);
1380 return -EINVAL;
1381 }
1382 p += name_len + 1;
1383 buf_len -= name_len + 1;
1384 }
1385
1386 ue->priv_data = names;
1387 ue->info.value.enumerated.names_ptr = 0;
1388
1389 return 0;
1390}
1391
1392static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
1393{
1394 struct user_element *ue = kcontrol->private_data;
1395
1396 kvfree(ue->tlv_data);
1397 kvfree(ue->priv_data);
1398 kfree(ue);
1399}
1400
1401static int snd_ctl_elem_add(struct snd_ctl_file *file,
1402 struct snd_ctl_elem_info *info, int replace)
1403{
1404 struct snd_card *card = file->card;
1405 struct snd_kcontrol *kctl;
1406 unsigned int count;
1407 unsigned int access;
1408 long private_size;
1409 struct user_element *ue;
1410 unsigned int offset;
1411 int err;
1412
1413 if (!*info->id.name)
1414 return -EINVAL;
1415 if (strnlen(info->id.name, sizeof(info->id.name)) >= sizeof(info->id.name))
1416 return -EINVAL;
1417
1418 /* Delete a control to replace them if needed. */
1419 if (replace) {
1420 info->id.numid = 0;
1421 err = snd_ctl_remove_user_ctl(file, &info->id);
1422 if (err)
1423 return err;
1424 }
1425
1426 /*
1427 * The number of userspace controls are counted control by control,
1428 * not element by element.
1429 */
1430 if (card->user_ctl_count + 1 > MAX_USER_CONTROLS)
1431 return -ENOMEM;
1432
1433 /* Check the number of elements for this userspace control. */
1434 count = info->owner;
1435 if (count == 0)
1436 count = 1;
1437
1438 /* Arrange access permissions if needed. */
1439 access = info->access;
1440 if (access == 0)
1441 access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
1442 access &= (SNDRV_CTL_ELEM_ACCESS_READWRITE |
1443 SNDRV_CTL_ELEM_ACCESS_INACTIVE |
1444 SNDRV_CTL_ELEM_ACCESS_TLV_WRITE);
1445
1446 /* In initial state, nothing is available as TLV container. */
1447 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1448 access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1449 access |= SNDRV_CTL_ELEM_ACCESS_USER;
1450
1451 /*
1452 * Check information and calculate the size of data specific to
1453 * this userspace control.
1454 */
1455 /* pass NULL to card for suppressing error messages */
1456 err = snd_ctl_check_elem_info(NULL, info);
1457 if (err < 0)
1458 return err;
1459 /* user-space control doesn't allow zero-size data */
1460 if (info->count < 1)
1461 return -EINVAL;
1462 private_size = value_sizes[info->type] * info->count;
1463
1464 /*
1465 * Keep memory object for this userspace control. After passing this
1466 * code block, the instance should be freed by snd_ctl_free_one().
1467 *
1468 * Note that these elements in this control are locked.
1469 */
1470 err = snd_ctl_new(&kctl, count, access, file);
1471 if (err < 0)
1472 return err;
1473 memcpy(&kctl->id, &info->id, sizeof(kctl->id));
1474 kctl->private_data = kzalloc(sizeof(struct user_element) + private_size * count,
1475 GFP_KERNEL);
1476 if (kctl->private_data == NULL) {
1477 kfree(kctl);
1478 return -ENOMEM;
1479 }
1480 kctl->private_free = snd_ctl_elem_user_free;
1481
1482 /* Set private data for this userspace control. */
1483 ue = (struct user_element *)kctl->private_data;
1484 ue->card = card;
1485 ue->info = *info;
1486 ue->info.access = 0;
1487 ue->elem_data = (char *)ue + sizeof(*ue);
1488 ue->elem_data_size = private_size;
1489 if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
1490 err = snd_ctl_elem_init_enum_names(ue);
1491 if (err < 0) {
1492 snd_ctl_free_one(kctl);
1493 return err;
1494 }
1495 }
1496
1497 /* Set callback functions. */
1498 if (info->type == SNDRV_CTL_ELEM_TYPE_ENUMERATED)
1499 kctl->info = snd_ctl_elem_user_enum_info;
1500 else
1501 kctl->info = snd_ctl_elem_user_info;
1502 if (access & SNDRV_CTL_ELEM_ACCESS_READ)
1503 kctl->get = snd_ctl_elem_user_get;
1504 if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
1505 kctl->put = snd_ctl_elem_user_put;
1506 if (access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
1507 kctl->tlv.c = snd_ctl_elem_user_tlv;
1508
1509 /* This function manage to free the instance on failure. */
1510 down_write(&card->controls_rwsem);
1511 err = __snd_ctl_add_replace(card, kctl, CTL_ADD_EXCLUSIVE);
1512 if (err < 0) {
1513 snd_ctl_free_one(kctl);
1514 goto unlock;
1515 }
1516 offset = snd_ctl_get_ioff(kctl, &info->id);
1517 snd_ctl_build_ioff(&info->id, kctl, offset);
1518 /*
1519 * Here we cannot fill any field for the number of elements added by
1520 * this operation because there're no specific fields. The usage of
1521 * 'owner' field for this purpose may cause any bugs to userspace
1522 * applications because the field originally means PID of a process
1523 * which locks the element.
1524 */
1525
1526 card->user_ctl_count++;
1527
1528 unlock:
1529 up_write(&card->controls_rwsem);
1530 return 0;
1531}
1532
1533static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
1534 struct snd_ctl_elem_info __user *_info, int replace)
1535{
1536 struct snd_ctl_elem_info info;
1537 int err;
1538
1539 if (copy_from_user(&info, _info, sizeof(info)))
1540 return -EFAULT;
1541 err = snd_ctl_elem_add(file, &info, replace);
1542 if (err < 0)
1543 return err;
1544 if (copy_to_user(_info, &info, sizeof(info))) {
1545 snd_ctl_remove_user_ctl(file, &info.id);
1546 return -EFAULT;
1547 }
1548
1549 return 0;
1550}
1551
1552static int snd_ctl_elem_remove(struct snd_ctl_file *file,
1553 struct snd_ctl_elem_id __user *_id)
1554{
1555 struct snd_ctl_elem_id id;
1556
1557 if (copy_from_user(&id, _id, sizeof(id)))
1558 return -EFAULT;
1559 return snd_ctl_remove_user_ctl(file, &id);
1560}
1561
1562static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
1563{
1564 int subscribe;
1565 if (get_user(subscribe, ptr))
1566 return -EFAULT;
1567 if (subscribe < 0) {
1568 subscribe = file->subscribed;
1569 if (put_user(subscribe, ptr))
1570 return -EFAULT;
1571 return 0;
1572 }
1573 if (subscribe) {
1574 file->subscribed = 1;
1575 return 0;
1576 } else if (file->subscribed) {
1577 snd_ctl_empty_read_queue(file);
1578 file->subscribed = 0;
1579 }
1580 return 0;
1581}
1582
1583static int call_tlv_handler(struct snd_ctl_file *file, int op_flag,
1584 struct snd_kcontrol *kctl,
1585 struct snd_ctl_elem_id *id,
1586 unsigned int __user *buf, unsigned int size)
1587{
1588 static const struct {
1589 int op;
1590 int perm;
1591 } pairs[] = {
1592 {SNDRV_CTL_TLV_OP_READ, SNDRV_CTL_ELEM_ACCESS_TLV_READ},
1593 {SNDRV_CTL_TLV_OP_WRITE, SNDRV_CTL_ELEM_ACCESS_TLV_WRITE},
1594 {SNDRV_CTL_TLV_OP_CMD, SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND},
1595 };
1596 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1597 int i;
1598
1599 /* Check support of the request for this element. */
1600 for (i = 0; i < ARRAY_SIZE(pairs); ++i) {
1601 if (op_flag == pairs[i].op && (vd->access & pairs[i].perm))
1602 break;
1603 }
1604 if (i == ARRAY_SIZE(pairs))
1605 return -ENXIO;
1606
1607 if (kctl->tlv.c == NULL)
1608 return -ENXIO;
1609
1610 /* Write and command operations are not allowed for locked element. */
1611 if (op_flag != SNDRV_CTL_TLV_OP_READ &&
1612 vd->owner != NULL && vd->owner != file)
1613 return -EPERM;
1614
1615 return kctl->tlv.c(kctl, op_flag, size, buf);
1616}
1617
1618static int read_tlv_buf(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id,
1619 unsigned int __user *buf, unsigned int size)
1620{
1621 struct snd_kcontrol_volatile *vd = &kctl->vd[snd_ctl_get_ioff(kctl, id)];
1622 unsigned int len;
1623
1624 if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ))
1625 return -ENXIO;
1626
1627 if (kctl->tlv.p == NULL)
1628 return -ENXIO;
1629
1630 len = sizeof(unsigned int) * 2 + kctl->tlv.p[1];
1631 if (size < len)
1632 return -ENOMEM;
1633
1634 if (copy_to_user(buf, kctl->tlv.p, len))
1635 return -EFAULT;
1636
1637 return 0;
1638}
1639
1640static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
1641 struct snd_ctl_tlv __user *buf,
1642 int op_flag)
1643{
1644 struct snd_ctl_tlv header;
1645 unsigned int __user *container;
1646 unsigned int container_size;
1647 struct snd_kcontrol *kctl;
1648 struct snd_ctl_elem_id id;
1649 struct snd_kcontrol_volatile *vd;
1650
1651 if (copy_from_user(&header, buf, sizeof(header)))
1652 return -EFAULT;
1653
1654 /* In design of control core, numerical ID starts at 1. */
1655 if (header.numid == 0)
1656 return -EINVAL;
1657
1658 /* At least, container should include type and length fields. */
1659 if (header.length < sizeof(unsigned int) * 2)
1660 return -EINVAL;
1661 container_size = header.length;
1662 container = buf->tlv;
1663
1664 kctl = snd_ctl_find_numid(file->card, header.numid);
1665 if (kctl == NULL)
1666 return -ENOENT;
1667
1668 /* Calculate index of the element in this set. */
1669 id = kctl->id;
1670 snd_ctl_build_ioff(&id, kctl, header.numid - id.numid);
1671 vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
1672
1673 if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
1674 return call_tlv_handler(file, op_flag, kctl, &id, container,
1675 container_size);
1676 } else {
1677 if (op_flag == SNDRV_CTL_TLV_OP_READ) {
1678 return read_tlv_buf(kctl, &id, container,
1679 container_size);
1680 }
1681 }
1682
1683 /* Not supported. */
1684 return -ENXIO;
1685}
1686
1687static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1688{
1689 struct snd_ctl_file *ctl;
1690 struct snd_card *card;
1691 struct snd_kctl_ioctl *p;
1692 void __user *argp = (void __user *)arg;
1693 int __user *ip = argp;
1694 int err;
1695
1696 ctl = file->private_data;
1697 card = ctl->card;
1698 if (snd_BUG_ON(!card))
1699 return -ENXIO;
1700 switch (cmd) {
1701 case SNDRV_CTL_IOCTL_PVERSION:
1702 return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
1703 case SNDRV_CTL_IOCTL_CARD_INFO:
1704 return snd_ctl_card_info(card, ctl, cmd, argp);
1705 case SNDRV_CTL_IOCTL_ELEM_LIST:
1706 return snd_ctl_elem_list(card, argp);
1707 case SNDRV_CTL_IOCTL_ELEM_INFO:
1708 return snd_ctl_elem_info_user(ctl, argp);
1709 case SNDRV_CTL_IOCTL_ELEM_READ:
1710 return snd_ctl_elem_read_user(card, argp);
1711 case SNDRV_CTL_IOCTL_ELEM_WRITE:
1712 return snd_ctl_elem_write_user(ctl, argp);
1713 case SNDRV_CTL_IOCTL_ELEM_LOCK:
1714 return snd_ctl_elem_lock(ctl, argp);
1715 case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
1716 return snd_ctl_elem_unlock(ctl, argp);
1717 case SNDRV_CTL_IOCTL_ELEM_ADD:
1718 return snd_ctl_elem_add_user(ctl, argp, 0);
1719 case SNDRV_CTL_IOCTL_ELEM_REPLACE:
1720 return snd_ctl_elem_add_user(ctl, argp, 1);
1721 case SNDRV_CTL_IOCTL_ELEM_REMOVE:
1722 return snd_ctl_elem_remove(ctl, argp);
1723 case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
1724 return snd_ctl_subscribe_events(ctl, ip);
1725 case SNDRV_CTL_IOCTL_TLV_READ:
1726 down_read(&ctl->card->controls_rwsem);
1727 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_READ);
1728 up_read(&ctl->card->controls_rwsem);
1729 return err;
1730 case SNDRV_CTL_IOCTL_TLV_WRITE:
1731 down_write(&ctl->card->controls_rwsem);
1732 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_WRITE);
1733 up_write(&ctl->card->controls_rwsem);
1734 return err;
1735 case SNDRV_CTL_IOCTL_TLV_COMMAND:
1736 down_write(&ctl->card->controls_rwsem);
1737 err = snd_ctl_tlv_ioctl(ctl, argp, SNDRV_CTL_TLV_OP_CMD);
1738 up_write(&ctl->card->controls_rwsem);
1739 return err;
1740 case SNDRV_CTL_IOCTL_POWER:
1741 return -ENOPROTOOPT;
1742 case SNDRV_CTL_IOCTL_POWER_STATE:
1743#ifdef CONFIG_PM
1744 return put_user(card->power_state, ip) ? -EFAULT : 0;
1745#else
1746 return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
1747#endif
1748 }
1749 down_read(&snd_ioctl_rwsem);
1750 list_for_each_entry(p, &snd_control_ioctls, list) {
1751 err = p->fioctl(card, ctl, cmd, arg);
1752 if (err != -ENOIOCTLCMD) {
1753 up_read(&snd_ioctl_rwsem);
1754 return err;
1755 }
1756 }
1757 up_read(&snd_ioctl_rwsem);
1758 dev_dbg(card->dev, "unknown ioctl = 0x%x\n", cmd);
1759 return -ENOTTY;
1760}
1761
1762static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
1763 size_t count, loff_t * offset)
1764{
1765 struct snd_ctl_file *ctl;
1766 int err = 0;
1767 ssize_t result = 0;
1768
1769 ctl = file->private_data;
1770 if (snd_BUG_ON(!ctl || !ctl->card))
1771 return -ENXIO;
1772 if (!ctl->subscribed)
1773 return -EBADFD;
1774 if (count < sizeof(struct snd_ctl_event))
1775 return -EINVAL;
1776 spin_lock_irq(&ctl->read_lock);
1777 while (count >= sizeof(struct snd_ctl_event)) {
1778 struct snd_ctl_event ev;
1779 struct snd_kctl_event *kev;
1780 while (list_empty(&ctl->events)) {
1781 wait_queue_entry_t wait;
1782 if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
1783 err = -EAGAIN;
1784 goto __end_lock;
1785 }
1786 init_waitqueue_entry(&wait, current);
1787 add_wait_queue(&ctl->change_sleep, &wait);
1788 set_current_state(TASK_INTERRUPTIBLE);
1789 spin_unlock_irq(&ctl->read_lock);
1790 schedule();
1791 remove_wait_queue(&ctl->change_sleep, &wait);
1792 if (ctl->card->shutdown)
1793 return -ENODEV;
1794 if (signal_pending(current))
1795 return -ERESTARTSYS;
1796 spin_lock_irq(&ctl->read_lock);
1797 }
1798 kev = snd_kctl_event(ctl->events.next);
1799 ev.type = SNDRV_CTL_EVENT_ELEM;
1800 ev.data.elem.mask = kev->mask;
1801 ev.data.elem.id = kev->id;
1802 list_del(&kev->list);
1803 spin_unlock_irq(&ctl->read_lock);
1804 kfree(kev);
1805 if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
1806 err = -EFAULT;
1807 goto __end;
1808 }
1809 spin_lock_irq(&ctl->read_lock);
1810 buffer += sizeof(struct snd_ctl_event);
1811 count -= sizeof(struct snd_ctl_event);
1812 result += sizeof(struct snd_ctl_event);
1813 }
1814 __end_lock:
1815 spin_unlock_irq(&ctl->read_lock);
1816 __end:
1817 return result > 0 ? result : err;
1818}
1819
1820static __poll_t snd_ctl_poll(struct file *file, poll_table * wait)
1821{
1822 __poll_t mask;
1823 struct snd_ctl_file *ctl;
1824
1825 ctl = file->private_data;
1826 if (!ctl->subscribed)
1827 return 0;
1828 poll_wait(file, &ctl->change_sleep, wait);
1829
1830 mask = 0;
1831 if (!list_empty(&ctl->events))
1832 mask |= EPOLLIN | EPOLLRDNORM;
1833
1834 return mask;
1835}
1836
1837/*
1838 * register the device-specific control-ioctls.
1839 * called from each device manager like pcm.c, hwdep.c, etc.
1840 */
1841static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
1842{
1843 struct snd_kctl_ioctl *pn;
1844
1845 pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
1846 if (pn == NULL)
1847 return -ENOMEM;
1848 pn->fioctl = fcn;
1849 down_write(&snd_ioctl_rwsem);
1850 list_add_tail(&pn->list, lists);
1851 up_write(&snd_ioctl_rwsem);
1852 return 0;
1853}
1854
1855/**
1856 * snd_ctl_register_ioctl - register the device-specific control-ioctls
1857 * @fcn: ioctl callback function
1858 *
1859 * called from each device manager like pcm.c, hwdep.c, etc.
1860 */
1861int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
1862{
1863 return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
1864}
1865EXPORT_SYMBOL(snd_ctl_register_ioctl);
1866
1867#ifdef CONFIG_COMPAT
1868/**
1869 * snd_ctl_register_ioctl_compat - register the device-specific 32bit compat
1870 * control-ioctls
1871 * @fcn: ioctl callback function
1872 */
1873int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1874{
1875 return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
1876}
1877EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
1878#endif
1879
1880/*
1881 * de-register the device-specific control-ioctls.
1882 */
1883static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
1884 struct list_head *lists)
1885{
1886 struct snd_kctl_ioctl *p;
1887
1888 if (snd_BUG_ON(!fcn))
1889 return -EINVAL;
1890 down_write(&snd_ioctl_rwsem);
1891 list_for_each_entry(p, lists, list) {
1892 if (p->fioctl == fcn) {
1893 list_del(&p->list);
1894 up_write(&snd_ioctl_rwsem);
1895 kfree(p);
1896 return 0;
1897 }
1898 }
1899 up_write(&snd_ioctl_rwsem);
1900 snd_BUG();
1901 return -EINVAL;
1902}
1903
1904/**
1905 * snd_ctl_unregister_ioctl - de-register the device-specific control-ioctls
1906 * @fcn: ioctl callback function to unregister
1907 */
1908int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
1909{
1910 return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
1911}
1912EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
1913
1914#ifdef CONFIG_COMPAT
1915/**
1916 * snd_ctl_unregister_ioctl - de-register the device-specific compat 32bit
1917 * control-ioctls
1918 * @fcn: ioctl callback function to unregister
1919 */
1920int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
1921{
1922 return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
1923}
1924EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
1925#endif
1926
1927static int snd_ctl_fasync(int fd, struct file * file, int on)
1928{
1929 struct snd_ctl_file *ctl;
1930
1931 ctl = file->private_data;
1932 return fasync_helper(fd, file, on, &ctl->fasync);
1933}
1934
1935/* return the preferred subdevice number if already assigned;
1936 * otherwise return -1
1937 */
1938int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type)
1939{
1940 struct snd_ctl_file *kctl;
1941 int subdevice = -1;
1942
1943 read_lock(&card->ctl_files_rwlock);
1944 list_for_each_entry(kctl, &card->ctl_files, list) {
1945 if (kctl->pid == task_pid(current)) {
1946 subdevice = kctl->preferred_subdevice[type];
1947 if (subdevice != -1)
1948 break;
1949 }
1950 }
1951 read_unlock(&card->ctl_files_rwlock);
1952 return subdevice;
1953}
1954EXPORT_SYMBOL_GPL(snd_ctl_get_preferred_subdevice);
1955
1956/*
1957 * ioctl32 compat
1958 */
1959#ifdef CONFIG_COMPAT
1960#include "control_compat.c"
1961#else
1962#define snd_ctl_ioctl_compat NULL
1963#endif
1964
1965/*
1966 * INIT PART
1967 */
1968
1969static const struct file_operations snd_ctl_f_ops =
1970{
1971 .owner = THIS_MODULE,
1972 .read = snd_ctl_read,
1973 .open = snd_ctl_open,
1974 .release = snd_ctl_release,
1975 .llseek = no_llseek,
1976 .poll = snd_ctl_poll,
1977 .unlocked_ioctl = snd_ctl_ioctl,
1978 .compat_ioctl = snd_ctl_ioctl_compat,
1979 .fasync = snd_ctl_fasync,
1980};
1981
1982/*
1983 * registration of the control device
1984 */
1985static int snd_ctl_dev_register(struct snd_device *device)
1986{
1987 struct snd_card *card = device->device_data;
1988
1989 return snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
1990 &snd_ctl_f_ops, card, &card->ctl_dev);
1991}
1992
1993/*
1994 * disconnection of the control device
1995 */
1996static int snd_ctl_dev_disconnect(struct snd_device *device)
1997{
1998 struct snd_card *card = device->device_data;
1999 struct snd_ctl_file *ctl;
2000
2001 read_lock(&card->ctl_files_rwlock);
2002 list_for_each_entry(ctl, &card->ctl_files, list) {
2003 wake_up(&ctl->change_sleep);
2004 kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
2005 }
2006 read_unlock(&card->ctl_files_rwlock);
2007
2008 return snd_unregister_device(&card->ctl_dev);
2009}
2010
2011/*
2012 * free all controls
2013 */
2014static int snd_ctl_dev_free(struct snd_device *device)
2015{
2016 struct snd_card *card = device->device_data;
2017 struct snd_kcontrol *control;
2018
2019 down_write(&card->controls_rwsem);
2020 while (!list_empty(&card->controls)) {
2021 control = snd_kcontrol(card->controls.next);
2022 snd_ctl_remove(card, control);
2023 }
2024 up_write(&card->controls_rwsem);
2025 put_device(&card->ctl_dev);
2026 return 0;
2027}
2028
2029/*
2030 * create control core:
2031 * called from init.c
2032 */
2033int snd_ctl_create(struct snd_card *card)
2034{
2035 static const struct snd_device_ops ops = {
2036 .dev_free = snd_ctl_dev_free,
2037 .dev_register = snd_ctl_dev_register,
2038 .dev_disconnect = snd_ctl_dev_disconnect,
2039 };
2040 int err;
2041
2042 if (snd_BUG_ON(!card))
2043 return -ENXIO;
2044 if (snd_BUG_ON(card->number < 0 || card->number >= SNDRV_CARDS))
2045 return -ENXIO;
2046
2047 snd_device_initialize(&card->ctl_dev, card);
2048 dev_set_name(&card->ctl_dev, "controlC%d", card->number);
2049
2050 err = snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
2051 if (err < 0)
2052 put_device(&card->ctl_dev);
2053 return err;
2054}
2055
2056/*
2057 * Frequently used control callbacks/helpers
2058 */
2059
2060/**
2061 * snd_ctl_boolean_mono_info - Helper function for a standard boolean info
2062 * callback with a mono channel
2063 * @kcontrol: the kcontrol instance
2064 * @uinfo: info to store
2065 *
2066 * This is a function that can be used as info callback for a standard
2067 * boolean control with a single mono channel.
2068 */
2069int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
2070 struct snd_ctl_elem_info *uinfo)
2071{
2072 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2073 uinfo->count = 1;
2074 uinfo->value.integer.min = 0;
2075 uinfo->value.integer.max = 1;
2076 return 0;
2077}
2078EXPORT_SYMBOL(snd_ctl_boolean_mono_info);
2079
2080/**
2081 * snd_ctl_boolean_stereo_info - Helper function for a standard boolean info
2082 * callback with stereo two channels
2083 * @kcontrol: the kcontrol instance
2084 * @uinfo: info to store
2085 *
2086 * This is a function that can be used as info callback for a standard
2087 * boolean control with stereo two channels.
2088 */
2089int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
2090 struct snd_ctl_elem_info *uinfo)
2091{
2092 uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
2093 uinfo->count = 2;
2094 uinfo->value.integer.min = 0;
2095 uinfo->value.integer.max = 1;
2096 return 0;
2097}
2098EXPORT_SYMBOL(snd_ctl_boolean_stereo_info);
2099
2100/**
2101 * snd_ctl_enum_info - fills the info structure for an enumerated control
2102 * @info: the structure to be filled
2103 * @channels: the number of the control's channels; often one
2104 * @items: the number of control values; also the size of @names
2105 * @names: an array containing the names of all control values
2106 *
2107 * Sets all required fields in @info to their appropriate values.
2108 * If the control's accessibility is not the default (readable and writable),
2109 * the caller has to fill @info->access.
2110 *
2111 * Return: Zero.
2112 */
2113int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
2114 unsigned int items, const char *const names[])
2115{
2116 info->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
2117 info->count = channels;
2118 info->value.enumerated.items = items;
2119 if (!items)
2120 return 0;
2121 if (info->value.enumerated.item >= items)
2122 info->value.enumerated.item = items - 1;
2123 WARN(strlen(names[info->value.enumerated.item]) >= sizeof(info->value.enumerated.name),
2124 "ALSA: too long item name '%s'\n",
2125 names[info->value.enumerated.item]);
2126 strlcpy(info->value.enumerated.name,
2127 names[info->value.enumerated.item],
2128 sizeof(info->value.enumerated.name));
2129 return 0;
2130}
2131EXPORT_SYMBOL(snd_ctl_enum_info);