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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/debugfs.h>
17#include <linux/completion.h>
18#include <linux/interrupt.h>
19
20#include <sound/core.h>
21#include <sound/control.h>
22#include <sound/info.h>
23
24/* monitor files for graceful shutdown (hotplug) */
25struct snd_monitor_file {
26 struct file *file;
27 const struct file_operations *disconnected_f_op;
28 struct list_head shutdown_list; /* still need to shutdown */
29 struct list_head list; /* link of monitor files */
30};
31
32static DEFINE_SPINLOCK(shutdown_lock);
33static LIST_HEAD(shutdown_files);
34
35static const struct file_operations snd_shutdown_f_ops;
36
37/* locked for registering/using */
38static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39static struct snd_card *snd_cards[SNDRV_CARDS];
40
41static DEFINE_MUTEX(snd_card_mutex);
42
43static char *slots[SNDRV_CARDS];
44module_param_array(slots, charp, NULL, 0444);
45MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
46
47/* return non-zero if the given index is reserved for the given
48 * module via slots option
49 */
50static int module_slot_match(struct module *module, int idx)
51{
52 int match = 1;
53#ifdef MODULE
54 const char *s1, *s2;
55
56 if (!module || !*module->name || !slots[idx])
57 return 0;
58
59 s1 = module->name;
60 s2 = slots[idx];
61 if (*s2 == '!') {
62 match = 0; /* negative match */
63 s2++;
64 }
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
67 */
68 for (;;) {
69 char c1 = *s1++;
70 char c2 = *s2++;
71 if (c1 == '-')
72 c1 = '_';
73 if (c2 == '-')
74 c2 = '_';
75 if (c1 != c2)
76 return !match;
77 if (!c1)
78 break;
79 }
80#endif /* MODULE */
81 return match;
82}
83
84#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87#endif
88
89static int check_empty_slot(struct module *module, int slot)
90{
91 return !slots[slot] || !*slots[slot];
92}
93
94/* return an empty slot number (>= 0) found in the given bitmask @mask.
95 * @mask == -1 == 0xffffffff means: take any free slot up to 32
96 * when no slot is available, return the original @mask as is.
97 */
98static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100{
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112}
113
114/* the default release callback set in snd_device_initialize() below;
115 * this is just NOP for now, as almost all jobs are already done in
116 * dev_free callback of snd_device chain instead.
117 */
118static void default_release(struct device *dev)
119{
120}
121
122/**
123 * snd_device_initialize - Initialize struct device for sound devices
124 * @dev: device to initialize
125 * @card: card to assign, optional
126 */
127void snd_device_initialize(struct device *dev, struct snd_card *card)
128{
129 device_initialize(dev);
130 if (card)
131 dev->parent = &card->card_dev;
132 dev->class = sound_class;
133 dev->release = default_release;
134}
135EXPORT_SYMBOL_GPL(snd_device_initialize);
136
137static int snd_card_init(struct snd_card *card, struct device *parent,
138 int idx, const char *xid, struct module *module,
139 size_t extra_size);
140static int snd_card_do_free(struct snd_card *card);
141static const struct attribute_group card_dev_attr_group;
142
143static void release_card_device(struct device *dev)
144{
145 snd_card_do_free(dev_to_snd_card(dev));
146}
147
148/**
149 * snd_card_new - create and initialize a soundcard structure
150 * @parent: the parent device object
151 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
152 * @xid: card identification (ASCII string)
153 * @module: top level module for locking
154 * @extra_size: allocate this extra size after the main soundcard structure
155 * @card_ret: the pointer to store the created card instance
156 *
157 * The function allocates snd_card instance via kzalloc with the given
158 * space for the driver to use freely. The allocated struct is stored
159 * in the given card_ret pointer.
160 *
161 * Return: Zero if successful or a negative error code.
162 */
163int snd_card_new(struct device *parent, int idx, const char *xid,
164 struct module *module, int extra_size,
165 struct snd_card **card_ret)
166{
167 struct snd_card *card;
168 int err;
169
170 if (snd_BUG_ON(!card_ret))
171 return -EINVAL;
172 *card_ret = NULL;
173
174 if (extra_size < 0)
175 extra_size = 0;
176 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
177 if (!card)
178 return -ENOMEM;
179
180 err = snd_card_init(card, parent, idx, xid, module, extra_size);
181 if (err < 0)
182 return err; /* card is freed by error handler */
183
184 *card_ret = card;
185 return 0;
186}
187EXPORT_SYMBOL(snd_card_new);
188
189static void __snd_card_release(struct device *dev, void *data)
190{
191 snd_card_free(data);
192}
193
194/**
195 * snd_devm_card_new - managed snd_card object creation
196 * @parent: the parent device object
197 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
198 * @xid: card identification (ASCII string)
199 * @module: top level module for locking
200 * @extra_size: allocate this extra size after the main soundcard structure
201 * @card_ret: the pointer to store the created card instance
202 *
203 * This function works like snd_card_new() but manages the allocated resource
204 * via devres, i.e. you don't need to free explicitly.
205 *
206 * When a snd_card object is created with this function and registered via
207 * snd_card_register(), the very first devres action to call snd_card_free()
208 * is added automatically. In that way, the resource disconnection is assured
209 * at first, then released in the expected order.
210 *
211 * If an error happens at the probe before snd_card_register() is called and
212 * there have been other devres resources, you'd need to free the card manually
213 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
214 * devres call orders. You can use snd_card_free_on_error() helper for
215 * handling it more easily.
216 *
217 * Return: zero if successful, or a negative error code
218 */
219int snd_devm_card_new(struct device *parent, int idx, const char *xid,
220 struct module *module, size_t extra_size,
221 struct snd_card **card_ret)
222{
223 struct snd_card *card;
224 int err;
225
226 *card_ret = NULL;
227 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
228 GFP_KERNEL);
229 if (!card)
230 return -ENOMEM;
231 card->managed = true;
232 err = snd_card_init(card, parent, idx, xid, module, extra_size);
233 if (err < 0) {
234 devres_free(card); /* in managed mode, we need to free manually */
235 return err;
236 }
237
238 devres_add(parent, card);
239 *card_ret = card;
240 return 0;
241}
242EXPORT_SYMBOL_GPL(snd_devm_card_new);
243
244/**
245 * snd_card_free_on_error - a small helper for handling devm probe errors
246 * @dev: the managed device object
247 * @ret: the return code from the probe callback
248 *
249 * This function handles the explicit snd_card_free() call at the error from
250 * the probe callback. It's just a small helper for simplifying the error
251 * handling with the managed devices.
252 *
253 * Return: zero if successful, or a negative error code
254 */
255int snd_card_free_on_error(struct device *dev, int ret)
256{
257 struct snd_card *card;
258
259 if (!ret)
260 return 0;
261 card = devres_find(dev, __snd_card_release, NULL, NULL);
262 if (card)
263 snd_card_free(card);
264 return ret;
265}
266EXPORT_SYMBOL_GPL(snd_card_free_on_error);
267
268static int snd_card_init(struct snd_card *card, struct device *parent,
269 int idx, const char *xid, struct module *module,
270 size_t extra_size)
271{
272 int err;
273#ifdef CONFIG_SND_DEBUG
274 char name[8];
275#endif
276
277 if (extra_size > 0)
278 card->private_data = (char *)card + sizeof(struct snd_card);
279 if (xid)
280 strscpy(card->id, xid, sizeof(card->id));
281 err = 0;
282 mutex_lock(&snd_card_mutex);
283 if (idx < 0) /* first check the matching module-name slot */
284 idx = get_slot_from_bitmask(idx, module_slot_match, module);
285 if (idx < 0) /* if not matched, assign an empty slot */
286 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
287 if (idx < 0)
288 err = -ENODEV;
289 else if (idx < snd_ecards_limit) {
290 if (test_bit(idx, snd_cards_lock))
291 err = -EBUSY; /* invalid */
292 } else if (idx >= SNDRV_CARDS)
293 err = -ENODEV;
294 if (err < 0) {
295 mutex_unlock(&snd_card_mutex);
296 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
297 idx, snd_ecards_limit - 1, err);
298 if (!card->managed)
299 kfree(card); /* manually free here, as no destructor called */
300 return err;
301 }
302 set_bit(idx, snd_cards_lock); /* lock it */
303 if (idx >= snd_ecards_limit)
304 snd_ecards_limit = idx + 1; /* increase the limit */
305 mutex_unlock(&snd_card_mutex);
306 card->dev = parent;
307 card->number = idx;
308#ifdef MODULE
309 WARN_ON(!module);
310 card->module = module;
311#endif
312 INIT_LIST_HEAD(&card->devices);
313 init_rwsem(&card->controls_rwsem);
314 rwlock_init(&card->ctl_files_rwlock);
315 INIT_LIST_HEAD(&card->controls);
316 INIT_LIST_HEAD(&card->ctl_files);
317#ifdef CONFIG_SND_CTL_FAST_LOOKUP
318 xa_init(&card->ctl_numids);
319 xa_init(&card->ctl_hash);
320#endif
321 spin_lock_init(&card->files_lock);
322 INIT_LIST_HEAD(&card->files_list);
323 mutex_init(&card->memory_mutex);
324#ifdef CONFIG_PM
325 init_waitqueue_head(&card->power_sleep);
326 init_waitqueue_head(&card->power_ref_sleep);
327 atomic_set(&card->power_ref, 0);
328#endif
329 init_waitqueue_head(&card->remove_sleep);
330 card->sync_irq = -1;
331
332 device_initialize(&card->card_dev);
333 card->card_dev.parent = parent;
334 card->card_dev.class = sound_class;
335 card->card_dev.release = release_card_device;
336 card->card_dev.groups = card->dev_groups;
337 card->dev_groups[0] = &card_dev_attr_group;
338 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
339 if (err < 0)
340 goto __error;
341
342 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
343 dev_driver_string(card->dev), dev_name(&card->card_dev));
344
345 /* the control interface cannot be accessed from the user space until */
346 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
347 err = snd_ctl_create(card);
348 if (err < 0) {
349 dev_err(parent, "unable to register control minors\n");
350 goto __error;
351 }
352 err = snd_info_card_create(card);
353 if (err < 0) {
354 dev_err(parent, "unable to create card info\n");
355 goto __error_ctl;
356 }
357
358#ifdef CONFIG_SND_DEBUG
359 sprintf(name, "card%d", idx);
360 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
361#endif
362 return 0;
363
364 __error_ctl:
365 snd_device_free_all(card);
366 __error:
367 put_device(&card->card_dev);
368 return err;
369}
370
371/**
372 * snd_card_ref - Get the card object from the index
373 * @idx: the card index
374 *
375 * Returns a card object corresponding to the given index or NULL if not found.
376 * Release the object via snd_card_unref().
377 *
378 * Return: a card object or NULL
379 */
380struct snd_card *snd_card_ref(int idx)
381{
382 struct snd_card *card;
383
384 mutex_lock(&snd_card_mutex);
385 card = snd_cards[idx];
386 if (card)
387 get_device(&card->card_dev);
388 mutex_unlock(&snd_card_mutex);
389 return card;
390}
391EXPORT_SYMBOL_GPL(snd_card_ref);
392
393/* return non-zero if a card is already locked */
394int snd_card_locked(int card)
395{
396 int locked;
397
398 mutex_lock(&snd_card_mutex);
399 locked = test_bit(card, snd_cards_lock);
400 mutex_unlock(&snd_card_mutex);
401 return locked;
402}
403
404static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
405{
406 return -ENODEV;
407}
408
409static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
410 size_t count, loff_t *offset)
411{
412 return -ENODEV;
413}
414
415static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
416 size_t count, loff_t *offset)
417{
418 return -ENODEV;
419}
420
421static int snd_disconnect_release(struct inode *inode, struct file *file)
422{
423 struct snd_monitor_file *df = NULL, *_df;
424
425 spin_lock(&shutdown_lock);
426 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
427 if (_df->file == file) {
428 df = _df;
429 list_del_init(&df->shutdown_list);
430 break;
431 }
432 }
433 spin_unlock(&shutdown_lock);
434
435 if (likely(df)) {
436 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
437 df->disconnected_f_op->fasync(-1, file, 0);
438 return df->disconnected_f_op->release(inode, file);
439 }
440
441 panic("%s(%p, %p) failed!", __func__, inode, file);
442}
443
444static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
445{
446 return EPOLLERR | EPOLLNVAL;
447}
448
449static long snd_disconnect_ioctl(struct file *file,
450 unsigned int cmd, unsigned long arg)
451{
452 return -ENODEV;
453}
454
455static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
456{
457 return -ENODEV;
458}
459
460static int snd_disconnect_fasync(int fd, struct file *file, int on)
461{
462 return -ENODEV;
463}
464
465static const struct file_operations snd_shutdown_f_ops =
466{
467 .owner = THIS_MODULE,
468 .llseek = snd_disconnect_llseek,
469 .read = snd_disconnect_read,
470 .write = snd_disconnect_write,
471 .release = snd_disconnect_release,
472 .poll = snd_disconnect_poll,
473 .unlocked_ioctl = snd_disconnect_ioctl,
474#ifdef CONFIG_COMPAT
475 .compat_ioctl = snd_disconnect_ioctl,
476#endif
477 .mmap = snd_disconnect_mmap,
478 .fasync = snd_disconnect_fasync
479};
480
481/**
482 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
483 * @card: soundcard structure
484 *
485 * Disconnects all APIs from the file-operations (user space).
486 *
487 * Return: Zero, otherwise a negative error code.
488 *
489 * Note: The current implementation replaces all active file->f_op with special
490 * dummy file operations (they do nothing except release).
491 */
492int snd_card_disconnect(struct snd_card *card)
493{
494 struct snd_monitor_file *mfile;
495
496 if (!card)
497 return -EINVAL;
498
499 spin_lock(&card->files_lock);
500 if (card->shutdown) {
501 spin_unlock(&card->files_lock);
502 return 0;
503 }
504 card->shutdown = 1;
505
506 /* replace file->f_op with special dummy operations */
507 list_for_each_entry(mfile, &card->files_list, list) {
508 /* it's critical part, use endless loop */
509 /* we have no room to fail */
510 mfile->disconnected_f_op = mfile->file->f_op;
511
512 spin_lock(&shutdown_lock);
513 list_add(&mfile->shutdown_list, &shutdown_files);
514 spin_unlock(&shutdown_lock);
515
516 mfile->file->f_op = &snd_shutdown_f_ops;
517 fops_get(mfile->file->f_op);
518 }
519 spin_unlock(&card->files_lock);
520
521 /* notify all connected devices about disconnection */
522 /* at this point, they cannot respond to any calls except release() */
523
524#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
525 if (snd_mixer_oss_notify_callback)
526 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
527#endif
528
529 /* notify all devices that we are disconnected */
530 snd_device_disconnect_all(card);
531
532 if (card->sync_irq > 0)
533 synchronize_irq(card->sync_irq);
534
535 snd_info_card_disconnect(card);
536 if (card->registered) {
537 device_del(&card->card_dev);
538 card->registered = false;
539 }
540
541 /* disable fops (user space) operations for ALSA API */
542 mutex_lock(&snd_card_mutex);
543 snd_cards[card->number] = NULL;
544 clear_bit(card->number, snd_cards_lock);
545 mutex_unlock(&snd_card_mutex);
546
547#ifdef CONFIG_PM
548 wake_up(&card->power_sleep);
549 snd_power_sync_ref(card);
550#endif
551 return 0;
552}
553EXPORT_SYMBOL(snd_card_disconnect);
554
555/**
556 * snd_card_disconnect_sync - disconnect card and wait until files get closed
557 * @card: card object to disconnect
558 *
559 * This calls snd_card_disconnect() for disconnecting all belonging components
560 * and waits until all pending files get closed.
561 * It assures that all accesses from user-space finished so that the driver
562 * can release its resources gracefully.
563 */
564void snd_card_disconnect_sync(struct snd_card *card)
565{
566 int err;
567
568 err = snd_card_disconnect(card);
569 if (err < 0) {
570 dev_err(card->dev,
571 "snd_card_disconnect error (%d), skipping sync\n",
572 err);
573 return;
574 }
575
576 spin_lock_irq(&card->files_lock);
577 wait_event_lock_irq(card->remove_sleep,
578 list_empty(&card->files_list),
579 card->files_lock);
580 spin_unlock_irq(&card->files_lock);
581}
582EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
583
584static int snd_card_do_free(struct snd_card *card)
585{
586 card->releasing = true;
587#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
588 if (snd_mixer_oss_notify_callback)
589 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
590#endif
591 snd_device_free_all(card);
592 if (card->private_free)
593 card->private_free(card);
594 if (snd_info_card_free(card) < 0) {
595 dev_warn(card->dev, "unable to free card info\n");
596 /* Not fatal error */
597 }
598#ifdef CONFIG_SND_DEBUG
599 debugfs_remove(card->debugfs_root);
600 card->debugfs_root = NULL;
601#endif
602 if (card->release_completion)
603 complete(card->release_completion);
604 if (!card->managed)
605 kfree(card);
606 return 0;
607}
608
609/**
610 * snd_card_free_when_closed - Disconnect the card, free it later eventually
611 * @card: soundcard structure
612 *
613 * Unlike snd_card_free(), this function doesn't try to release the card
614 * resource immediately, but tries to disconnect at first. When the card
615 * is still in use, the function returns before freeing the resources.
616 * The card resources will be freed when the refcount gets to zero.
617 *
618 * Return: zero if successful, or a negative error code
619 */
620int snd_card_free_when_closed(struct snd_card *card)
621{
622 int ret = snd_card_disconnect(card);
623 if (ret)
624 return ret;
625 put_device(&card->card_dev);
626 return 0;
627}
628EXPORT_SYMBOL(snd_card_free_when_closed);
629
630/**
631 * snd_card_free - frees given soundcard structure
632 * @card: soundcard structure
633 *
634 * This function releases the soundcard structure and the all assigned
635 * devices automatically. That is, you don't have to release the devices
636 * by yourself.
637 *
638 * This function waits until the all resources are properly released.
639 *
640 * Return: Zero. Frees all associated devices and frees the control
641 * interface associated to given soundcard.
642 */
643int snd_card_free(struct snd_card *card)
644{
645 DECLARE_COMPLETION_ONSTACK(released);
646 int ret;
647
648 /* The call of snd_card_free() is allowed from various code paths;
649 * a manual call from the driver and the call via devres_free, and
650 * we need to avoid double-free. Moreover, the release via devres
651 * may call snd_card_free() twice due to its nature, we need to have
652 * the check here at the beginning.
653 */
654 if (card->releasing)
655 return 0;
656
657 card->release_completion = &released;
658 ret = snd_card_free_when_closed(card);
659 if (ret)
660 return ret;
661 /* wait, until all devices are ready for the free operation */
662 wait_for_completion(&released);
663
664 return 0;
665}
666EXPORT_SYMBOL(snd_card_free);
667
668/* retrieve the last word of shortname or longname */
669static const char *retrieve_id_from_card_name(const char *name)
670{
671 const char *spos = name;
672
673 while (*name) {
674 if (isspace(*name) && isalnum(name[1]))
675 spos = name + 1;
676 name++;
677 }
678 return spos;
679}
680
681/* return true if the given id string doesn't conflict any other card ids */
682static bool card_id_ok(struct snd_card *card, const char *id)
683{
684 int i;
685 if (!snd_info_check_reserved_words(id))
686 return false;
687 for (i = 0; i < snd_ecards_limit; i++) {
688 if (snd_cards[i] && snd_cards[i] != card &&
689 !strcmp(snd_cards[i]->id, id))
690 return false;
691 }
692 return true;
693}
694
695/* copy to card->id only with valid letters from nid */
696static void copy_valid_id_string(struct snd_card *card, const char *src,
697 const char *nid)
698{
699 char *id = card->id;
700
701 while (*nid && !isalnum(*nid))
702 nid++;
703 if (isdigit(*nid))
704 *id++ = isalpha(*src) ? *src : 'D';
705 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
706 if (isalnum(*nid))
707 *id++ = *nid;
708 nid++;
709 }
710 *id = 0;
711}
712
713/* Set card->id from the given string
714 * If the string conflicts with other ids, add a suffix to make it unique.
715 */
716static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
717 const char *nid)
718{
719 int len, loops;
720 bool is_default = false;
721 char *id;
722
723 copy_valid_id_string(card, src, nid);
724 id = card->id;
725
726 again:
727 /* use "Default" for obviously invalid strings
728 * ("card" conflicts with proc directories)
729 */
730 if (!*id || !strncmp(id, "card", 4)) {
731 strcpy(id, "Default");
732 is_default = true;
733 }
734
735 len = strlen(id);
736 for (loops = 0; loops < SNDRV_CARDS; loops++) {
737 char *spos;
738 char sfxstr[5]; /* "_012" */
739 int sfxlen;
740
741 if (card_id_ok(card, id))
742 return; /* OK */
743
744 /* Add _XYZ suffix */
745 sprintf(sfxstr, "_%X", loops + 1);
746 sfxlen = strlen(sfxstr);
747 if (len + sfxlen >= sizeof(card->id))
748 spos = id + sizeof(card->id) - sfxlen - 1;
749 else
750 spos = id + len;
751 strcpy(spos, sfxstr);
752 }
753 /* fallback to the default id */
754 if (!is_default) {
755 *id = 0;
756 goto again;
757 }
758 /* last resort... */
759 dev_err(card->dev, "unable to set card id (%s)\n", id);
760 if (card->proc_root->name)
761 strscpy(card->id, card->proc_root->name, sizeof(card->id));
762}
763
764/**
765 * snd_card_set_id - set card identification name
766 * @card: soundcard structure
767 * @nid: new identification string
768 *
769 * This function sets the card identification and checks for name
770 * collisions.
771 */
772void snd_card_set_id(struct snd_card *card, const char *nid)
773{
774 /* check if user specified own card->id */
775 if (card->id[0] != '\0')
776 return;
777 mutex_lock(&snd_card_mutex);
778 snd_card_set_id_no_lock(card, nid, nid);
779 mutex_unlock(&snd_card_mutex);
780}
781EXPORT_SYMBOL(snd_card_set_id);
782
783static ssize_t id_show(struct device *dev,
784 struct device_attribute *attr, char *buf)
785{
786 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
787 return sysfs_emit(buf, "%s\n", card->id);
788}
789
790static ssize_t id_store(struct device *dev, struct device_attribute *attr,
791 const char *buf, size_t count)
792{
793 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
794 char buf1[sizeof(card->id)];
795 size_t copy = count > sizeof(card->id) - 1 ?
796 sizeof(card->id) - 1 : count;
797 size_t idx;
798 int c;
799
800 for (idx = 0; idx < copy; idx++) {
801 c = buf[idx];
802 if (!isalnum(c) && c != '_' && c != '-')
803 return -EINVAL;
804 }
805 memcpy(buf1, buf, copy);
806 buf1[copy] = '\0';
807 mutex_lock(&snd_card_mutex);
808 if (!card_id_ok(NULL, buf1)) {
809 mutex_unlock(&snd_card_mutex);
810 return -EEXIST;
811 }
812 strcpy(card->id, buf1);
813 snd_info_card_id_change(card);
814 mutex_unlock(&snd_card_mutex);
815
816 return count;
817}
818
819static DEVICE_ATTR_RW(id);
820
821static ssize_t number_show(struct device *dev,
822 struct device_attribute *attr, char *buf)
823{
824 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
825 return sysfs_emit(buf, "%i\n", card->number);
826}
827
828static DEVICE_ATTR_RO(number);
829
830static struct attribute *card_dev_attrs[] = {
831 &dev_attr_id.attr,
832 &dev_attr_number.attr,
833 NULL
834};
835
836static const struct attribute_group card_dev_attr_group = {
837 .attrs = card_dev_attrs,
838};
839
840/**
841 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
842 * @card: card instance
843 * @group: attribute group to append
844 *
845 * Return: zero if successful, or a negative error code
846 */
847int snd_card_add_dev_attr(struct snd_card *card,
848 const struct attribute_group *group)
849{
850 int i;
851
852 /* loop for (arraysize-1) here to keep NULL at the last entry */
853 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
854 if (!card->dev_groups[i]) {
855 card->dev_groups[i] = group;
856 return 0;
857 }
858 }
859
860 dev_err(card->dev, "Too many groups assigned\n");
861 return -ENOSPC;
862}
863EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
864
865static void trigger_card_free(void *data)
866{
867 snd_card_free(data);
868}
869
870/**
871 * snd_card_register - register the soundcard
872 * @card: soundcard structure
873 *
874 * This function registers all the devices assigned to the soundcard.
875 * Until calling this, the ALSA control interface is blocked from the
876 * external accesses. Thus, you should call this function at the end
877 * of the initialization of the card.
878 *
879 * Return: Zero otherwise a negative error code if the registration failed.
880 */
881int snd_card_register(struct snd_card *card)
882{
883 int err;
884
885 if (snd_BUG_ON(!card))
886 return -EINVAL;
887
888 if (!card->registered) {
889 err = device_add(&card->card_dev);
890 if (err < 0)
891 return err;
892 card->registered = true;
893 } else {
894 if (card->managed)
895 devm_remove_action(card->dev, trigger_card_free, card);
896 }
897
898 if (card->managed) {
899 err = devm_add_action(card->dev, trigger_card_free, card);
900 if (err < 0)
901 return err;
902 }
903
904 err = snd_device_register_all(card);
905 if (err < 0)
906 return err;
907 mutex_lock(&snd_card_mutex);
908 if (snd_cards[card->number]) {
909 /* already registered */
910 mutex_unlock(&snd_card_mutex);
911 return snd_info_card_register(card); /* register pending info */
912 }
913 if (*card->id) {
914 /* make a unique id name from the given string */
915 char tmpid[sizeof(card->id)];
916 memcpy(tmpid, card->id, sizeof(card->id));
917 snd_card_set_id_no_lock(card, tmpid, tmpid);
918 } else {
919 /* create an id from either shortname or longname */
920 const char *src;
921 src = *card->shortname ? card->shortname : card->longname;
922 snd_card_set_id_no_lock(card, src,
923 retrieve_id_from_card_name(src));
924 }
925 snd_cards[card->number] = card;
926 mutex_unlock(&snd_card_mutex);
927 err = snd_info_card_register(card);
928 if (err < 0)
929 return err;
930
931#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
932 if (snd_mixer_oss_notify_callback)
933 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
934#endif
935 return 0;
936}
937EXPORT_SYMBOL(snd_card_register);
938
939#ifdef CONFIG_SND_PROC_FS
940static void snd_card_info_read(struct snd_info_entry *entry,
941 struct snd_info_buffer *buffer)
942{
943 int idx, count;
944 struct snd_card *card;
945
946 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
947 mutex_lock(&snd_card_mutex);
948 card = snd_cards[idx];
949 if (card) {
950 count++;
951 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
952 idx,
953 card->id,
954 card->driver,
955 card->shortname);
956 snd_iprintf(buffer, " %s\n",
957 card->longname);
958 }
959 mutex_unlock(&snd_card_mutex);
960 }
961 if (!count)
962 snd_iprintf(buffer, "--- no soundcards ---\n");
963}
964
965#ifdef CONFIG_SND_OSSEMUL
966void snd_card_info_read_oss(struct snd_info_buffer *buffer)
967{
968 int idx, count;
969 struct snd_card *card;
970
971 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
972 mutex_lock(&snd_card_mutex);
973 card = snd_cards[idx];
974 if (card) {
975 count++;
976 snd_iprintf(buffer, "%s\n", card->longname);
977 }
978 mutex_unlock(&snd_card_mutex);
979 }
980 if (!count) {
981 snd_iprintf(buffer, "--- no soundcards ---\n");
982 }
983}
984
985#endif
986
987#ifdef MODULE
988static void snd_card_module_info_read(struct snd_info_entry *entry,
989 struct snd_info_buffer *buffer)
990{
991 int idx;
992 struct snd_card *card;
993
994 for (idx = 0; idx < SNDRV_CARDS; idx++) {
995 mutex_lock(&snd_card_mutex);
996 card = snd_cards[idx];
997 if (card)
998 snd_iprintf(buffer, "%2i %s\n",
999 idx, card->module->name);
1000 mutex_unlock(&snd_card_mutex);
1001 }
1002}
1003#endif
1004
1005int __init snd_card_info_init(void)
1006{
1007 struct snd_info_entry *entry;
1008
1009 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
1010 if (! entry)
1011 return -ENOMEM;
1012 entry->c.text.read = snd_card_info_read;
1013 if (snd_info_register(entry) < 0)
1014 return -ENOMEM; /* freed in error path */
1015
1016#ifdef MODULE
1017 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1018 if (!entry)
1019 return -ENOMEM;
1020 entry->c.text.read = snd_card_module_info_read;
1021 if (snd_info_register(entry) < 0)
1022 return -ENOMEM; /* freed in error path */
1023#endif
1024
1025 return 0;
1026}
1027#endif /* CONFIG_SND_PROC_FS */
1028
1029/**
1030 * snd_component_add - add a component string
1031 * @card: soundcard structure
1032 * @component: the component id string
1033 *
1034 * This function adds the component id string to the supported list.
1035 * The component can be referred from the alsa-lib.
1036 *
1037 * Return: Zero otherwise a negative error code.
1038 */
1039
1040int snd_component_add(struct snd_card *card, const char *component)
1041{
1042 char *ptr;
1043 int len = strlen(component);
1044
1045 ptr = strstr(card->components, component);
1046 if (ptr != NULL) {
1047 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1048 return 1;
1049 }
1050 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1051 snd_BUG();
1052 return -ENOMEM;
1053 }
1054 if (card->components[0] != '\0')
1055 strcat(card->components, " ");
1056 strcat(card->components, component);
1057 return 0;
1058}
1059EXPORT_SYMBOL(snd_component_add);
1060
1061/**
1062 * snd_card_file_add - add the file to the file list of the card
1063 * @card: soundcard structure
1064 * @file: file pointer
1065 *
1066 * This function adds the file to the file linked-list of the card.
1067 * This linked-list is used to keep tracking the connection state,
1068 * and to avoid the release of busy resources by hotplug.
1069 *
1070 * Return: zero or a negative error code.
1071 */
1072int snd_card_file_add(struct snd_card *card, struct file *file)
1073{
1074 struct snd_monitor_file *mfile;
1075
1076 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1077 if (mfile == NULL)
1078 return -ENOMEM;
1079 mfile->file = file;
1080 mfile->disconnected_f_op = NULL;
1081 INIT_LIST_HEAD(&mfile->shutdown_list);
1082 spin_lock(&card->files_lock);
1083 if (card->shutdown) {
1084 spin_unlock(&card->files_lock);
1085 kfree(mfile);
1086 return -ENODEV;
1087 }
1088 list_add(&mfile->list, &card->files_list);
1089 get_device(&card->card_dev);
1090 spin_unlock(&card->files_lock);
1091 return 0;
1092}
1093EXPORT_SYMBOL(snd_card_file_add);
1094
1095/**
1096 * snd_card_file_remove - remove the file from the file list
1097 * @card: soundcard structure
1098 * @file: file pointer
1099 *
1100 * This function removes the file formerly added to the card via
1101 * snd_card_file_add() function.
1102 * If all files are removed and snd_card_free_when_closed() was
1103 * called beforehand, it processes the pending release of
1104 * resources.
1105 *
1106 * Return: Zero or a negative error code.
1107 */
1108int snd_card_file_remove(struct snd_card *card, struct file *file)
1109{
1110 struct snd_monitor_file *mfile, *found = NULL;
1111
1112 spin_lock(&card->files_lock);
1113 list_for_each_entry(mfile, &card->files_list, list) {
1114 if (mfile->file == file) {
1115 list_del(&mfile->list);
1116 spin_lock(&shutdown_lock);
1117 list_del(&mfile->shutdown_list);
1118 spin_unlock(&shutdown_lock);
1119 if (mfile->disconnected_f_op)
1120 fops_put(mfile->disconnected_f_op);
1121 found = mfile;
1122 break;
1123 }
1124 }
1125 if (list_empty(&card->files_list))
1126 wake_up_all(&card->remove_sleep);
1127 spin_unlock(&card->files_lock);
1128 if (!found) {
1129 dev_err(card->dev, "card file remove problem (%p)\n", file);
1130 return -ENOENT;
1131 }
1132 kfree(found);
1133 put_device(&card->card_dev);
1134 return 0;
1135}
1136EXPORT_SYMBOL(snd_card_file_remove);
1137
1138#ifdef CONFIG_PM
1139/**
1140 * snd_power_ref_and_wait - wait until the card gets powered up
1141 * @card: soundcard structure
1142 *
1143 * Take the power_ref reference count of the given card, and
1144 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1145 * The refcount is down again while sleeping until power-up, hence this
1146 * function can be used for syncing the floating control ops accesses,
1147 * typically around calling control ops.
1148 *
1149 * The caller needs to pull down the refcount via snd_power_unref() later
1150 * no matter whether the error is returned from this function or not.
1151 *
1152 * Return: Zero if successful, or a negative error code.
1153 */
1154int snd_power_ref_and_wait(struct snd_card *card)
1155{
1156 snd_power_ref(card);
1157 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1158 return 0;
1159 wait_event_cmd(card->power_sleep,
1160 card->shutdown ||
1161 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1162 snd_power_unref(card), snd_power_ref(card));
1163 return card->shutdown ? -ENODEV : 0;
1164}
1165EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1166
1167/**
1168 * snd_power_wait - wait until the card gets powered up (old form)
1169 * @card: soundcard structure
1170 *
1171 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1172 *
1173 * Return: Zero if successful, or a negative error code.
1174 */
1175int snd_power_wait(struct snd_card *card)
1176{
1177 int ret;
1178
1179 ret = snd_power_ref_and_wait(card);
1180 snd_power_unref(card);
1181 return ret;
1182}
1183EXPORT_SYMBOL(snd_power_wait);
1184#endif /* CONFIG_PM */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/module.h>
10#include <linux/device.h>
11#include <linux/file.h>
12#include <linux/slab.h>
13#include <linux/time.h>
14#include <linux/ctype.h>
15#include <linux/pm.h>
16#include <linux/debugfs.h>
17#include <linux/completion.h>
18#include <linux/interrupt.h>
19
20#include <sound/core.h>
21#include <sound/control.h>
22#include <sound/info.h>
23
24/* monitor files for graceful shutdown (hotplug) */
25struct snd_monitor_file {
26 struct file *file;
27 const struct file_operations *disconnected_f_op;
28 struct list_head shutdown_list; /* still need to shutdown */
29 struct list_head list; /* link of monitor files */
30};
31
32static DEFINE_SPINLOCK(shutdown_lock);
33static LIST_HEAD(shutdown_files);
34
35static const struct file_operations snd_shutdown_f_ops;
36
37/* locked for registering/using */
38static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39static struct snd_card *snd_cards[SNDRV_CARDS];
40
41static DEFINE_MUTEX(snd_card_mutex);
42
43static char *slots[SNDRV_CARDS];
44module_param_array(slots, charp, NULL, 0444);
45MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
46
47/* return non-zero if the given index is reserved for the given
48 * module via slots option
49 */
50static int module_slot_match(struct module *module, int idx)
51{
52 int match = 1;
53#ifdef MODULE
54 const char *s1, *s2;
55
56 if (!module || !*module->name || !slots[idx])
57 return 0;
58
59 s1 = module->name;
60 s2 = slots[idx];
61 if (*s2 == '!') {
62 match = 0; /* negative match */
63 s2++;
64 }
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
67 */
68 for (;;) {
69 char c1 = *s1++;
70 char c2 = *s2++;
71 if (c1 == '-')
72 c1 = '_';
73 if (c2 == '-')
74 c2 = '_';
75 if (c1 != c2)
76 return !match;
77 if (!c1)
78 break;
79 }
80#endif /* MODULE */
81 return match;
82}
83
84#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
87#endif
88
89static int check_empty_slot(struct module *module, int slot)
90{
91 return !slots[slot] || !*slots[slot];
92}
93
94/* return an empty slot number (>= 0) found in the given bitmask @mask.
95 * @mask == -1 == 0xffffffff means: take any free slot up to 32
96 * when no slot is available, return the original @mask as is.
97 */
98static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
100{
101 int slot;
102
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
105 continue;
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
109 }
110 }
111 return mask; /* unchanged */
112}
113
114/* the default release callback set in snd_device_alloc() */
115static void default_release_alloc(struct device *dev)
116{
117 kfree(dev);
118}
119
120/**
121 * snd_device_alloc - Allocate and initialize struct device for sound devices
122 * @dev_p: pointer to store the allocated device
123 * @card: card to assign, optional
124 *
125 * For releasing the allocated device, call put_device().
126 */
127int snd_device_alloc(struct device **dev_p, struct snd_card *card)
128{
129 struct device *dev;
130
131 *dev_p = NULL;
132 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
133 if (!dev)
134 return -ENOMEM;
135 device_initialize(dev);
136 if (card)
137 dev->parent = &card->card_dev;
138 dev->class = &sound_class;
139 dev->release = default_release_alloc;
140 *dev_p = dev;
141 return 0;
142}
143EXPORT_SYMBOL_GPL(snd_device_alloc);
144
145static int snd_card_init(struct snd_card *card, struct device *parent,
146 int idx, const char *xid, struct module *module,
147 size_t extra_size);
148static int snd_card_do_free(struct snd_card *card);
149static const struct attribute_group card_dev_attr_group;
150
151static void release_card_device(struct device *dev)
152{
153 snd_card_do_free(dev_to_snd_card(dev));
154}
155
156/**
157 * snd_card_new - create and initialize a soundcard structure
158 * @parent: the parent device object
159 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
160 * @xid: card identification (ASCII string)
161 * @module: top level module for locking
162 * @extra_size: allocate this extra size after the main soundcard structure
163 * @card_ret: the pointer to store the created card instance
164 *
165 * The function allocates snd_card instance via kzalloc with the given
166 * space for the driver to use freely. The allocated struct is stored
167 * in the given card_ret pointer.
168 *
169 * Return: Zero if successful or a negative error code.
170 */
171int snd_card_new(struct device *parent, int idx, const char *xid,
172 struct module *module, int extra_size,
173 struct snd_card **card_ret)
174{
175 struct snd_card *card;
176 int err;
177
178 if (snd_BUG_ON(!card_ret))
179 return -EINVAL;
180 *card_ret = NULL;
181
182 if (extra_size < 0)
183 extra_size = 0;
184 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
185 if (!card)
186 return -ENOMEM;
187
188 err = snd_card_init(card, parent, idx, xid, module, extra_size);
189 if (err < 0)
190 return err; /* card is freed by error handler */
191
192 *card_ret = card;
193 return 0;
194}
195EXPORT_SYMBOL(snd_card_new);
196
197static void __snd_card_release(struct device *dev, void *data)
198{
199 snd_card_free(data);
200}
201
202/**
203 * snd_devm_card_new - managed snd_card object creation
204 * @parent: the parent device object
205 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
206 * @xid: card identification (ASCII string)
207 * @module: top level module for locking
208 * @extra_size: allocate this extra size after the main soundcard structure
209 * @card_ret: the pointer to store the created card instance
210 *
211 * This function works like snd_card_new() but manages the allocated resource
212 * via devres, i.e. you don't need to free explicitly.
213 *
214 * When a snd_card object is created with this function and registered via
215 * snd_card_register(), the very first devres action to call snd_card_free()
216 * is added automatically. In that way, the resource disconnection is assured
217 * at first, then released in the expected order.
218 *
219 * If an error happens at the probe before snd_card_register() is called and
220 * there have been other devres resources, you'd need to free the card manually
221 * via snd_card_free() call in the error; otherwise it may lead to UAF due to
222 * devres call orders. You can use snd_card_free_on_error() helper for
223 * handling it more easily.
224 *
225 * Return: zero if successful, or a negative error code
226 */
227int snd_devm_card_new(struct device *parent, int idx, const char *xid,
228 struct module *module, size_t extra_size,
229 struct snd_card **card_ret)
230{
231 struct snd_card *card;
232 int err;
233
234 *card_ret = NULL;
235 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
236 GFP_KERNEL);
237 if (!card)
238 return -ENOMEM;
239 card->managed = true;
240 err = snd_card_init(card, parent, idx, xid, module, extra_size);
241 if (err < 0) {
242 devres_free(card); /* in managed mode, we need to free manually */
243 return err;
244 }
245
246 devres_add(parent, card);
247 *card_ret = card;
248 return 0;
249}
250EXPORT_SYMBOL_GPL(snd_devm_card_new);
251
252/**
253 * snd_card_free_on_error - a small helper for handling devm probe errors
254 * @dev: the managed device object
255 * @ret: the return code from the probe callback
256 *
257 * This function handles the explicit snd_card_free() call at the error from
258 * the probe callback. It's just a small helper for simplifying the error
259 * handling with the managed devices.
260 *
261 * Return: zero if successful, or a negative error code
262 */
263int snd_card_free_on_error(struct device *dev, int ret)
264{
265 struct snd_card *card;
266
267 if (!ret)
268 return 0;
269 card = devres_find(dev, __snd_card_release, NULL, NULL);
270 if (card)
271 snd_card_free(card);
272 return ret;
273}
274EXPORT_SYMBOL_GPL(snd_card_free_on_error);
275
276static int snd_card_init(struct snd_card *card, struct device *parent,
277 int idx, const char *xid, struct module *module,
278 size_t extra_size)
279{
280 int err;
281
282 if (extra_size > 0)
283 card->private_data = (char *)card + sizeof(struct snd_card);
284 if (xid)
285 strscpy(card->id, xid, sizeof(card->id));
286 err = 0;
287 scoped_guard(mutex, &snd_card_mutex) {
288 if (idx < 0) /* first check the matching module-name slot */
289 idx = get_slot_from_bitmask(idx, module_slot_match, module);
290 if (idx < 0) /* if not matched, assign an empty slot */
291 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
292 if (idx < 0)
293 err = -ENODEV;
294 else if (idx < snd_ecards_limit) {
295 if (test_bit(idx, snd_cards_lock))
296 err = -EBUSY; /* invalid */
297 } else if (idx >= SNDRV_CARDS)
298 err = -ENODEV;
299 if (!err) {
300 set_bit(idx, snd_cards_lock); /* lock it */
301 if (idx >= snd_ecards_limit)
302 snd_ecards_limit = idx + 1; /* increase the limit */
303 }
304 }
305 if (err < 0) {
306 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
307 idx, snd_ecards_limit - 1, err);
308 if (!card->managed)
309 kfree(card); /* manually free here, as no destructor called */
310 return err;
311 }
312 card->dev = parent;
313 card->number = idx;
314#ifdef MODULE
315 WARN_ON(!module);
316#endif
317 card->module = module;
318 INIT_LIST_HEAD(&card->devices);
319 init_rwsem(&card->controls_rwsem);
320 rwlock_init(&card->ctl_files_rwlock);
321 INIT_LIST_HEAD(&card->controls);
322 INIT_LIST_HEAD(&card->ctl_files);
323#ifdef CONFIG_SND_CTL_FAST_LOOKUP
324 xa_init(&card->ctl_numids);
325 xa_init(&card->ctl_hash);
326#endif
327 spin_lock_init(&card->files_lock);
328 INIT_LIST_HEAD(&card->files_list);
329 mutex_init(&card->memory_mutex);
330#ifdef CONFIG_PM
331 init_waitqueue_head(&card->power_sleep);
332 init_waitqueue_head(&card->power_ref_sleep);
333 atomic_set(&card->power_ref, 0);
334#endif
335 init_waitqueue_head(&card->remove_sleep);
336 card->sync_irq = -1;
337
338 device_initialize(&card->card_dev);
339 card->card_dev.parent = parent;
340 card->card_dev.class = &sound_class;
341 card->card_dev.release = release_card_device;
342 card->card_dev.groups = card->dev_groups;
343 card->dev_groups[0] = &card_dev_attr_group;
344 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
345 if (err < 0)
346 goto __error;
347
348 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
349 dev_driver_string(card->dev), dev_name(&card->card_dev));
350
351 /* the control interface cannot be accessed from the user space until */
352 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
353 err = snd_ctl_create(card);
354 if (err < 0) {
355 dev_err(parent, "unable to register control minors\n");
356 goto __error;
357 }
358 err = snd_info_card_create(card);
359 if (err < 0) {
360 dev_err(parent, "unable to create card info\n");
361 goto __error_ctl;
362 }
363
364#ifdef CONFIG_SND_DEBUG
365 card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),
366 sound_debugfs_root);
367#endif
368 return 0;
369
370 __error_ctl:
371 snd_device_free_all(card);
372 __error:
373 put_device(&card->card_dev);
374 return err;
375}
376
377/**
378 * snd_card_ref - Get the card object from the index
379 * @idx: the card index
380 *
381 * Returns a card object corresponding to the given index or NULL if not found.
382 * Release the object via snd_card_unref().
383 *
384 * Return: a card object or NULL
385 */
386struct snd_card *snd_card_ref(int idx)
387{
388 struct snd_card *card;
389
390 guard(mutex)(&snd_card_mutex);
391 card = snd_cards[idx];
392 if (card)
393 get_device(&card->card_dev);
394 return card;
395}
396EXPORT_SYMBOL_GPL(snd_card_ref);
397
398/* return non-zero if a card is already locked */
399int snd_card_locked(int card)
400{
401 guard(mutex)(&snd_card_mutex);
402 return test_bit(card, snd_cards_lock);
403}
404
405static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
406{
407 return -ENODEV;
408}
409
410static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
411 size_t count, loff_t *offset)
412{
413 return -ENODEV;
414}
415
416static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
417 size_t count, loff_t *offset)
418{
419 return -ENODEV;
420}
421
422static int snd_disconnect_release(struct inode *inode, struct file *file)
423{
424 struct snd_monitor_file *df = NULL, *_df;
425
426 scoped_guard(spinlock, &shutdown_lock) {
427 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
428 if (_df->file == file) {
429 df = _df;
430 list_del_init(&df->shutdown_list);
431 break;
432 }
433 }
434 }
435
436 if (likely(df)) {
437 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
438 df->disconnected_f_op->fasync(-1, file, 0);
439 return df->disconnected_f_op->release(inode, file);
440 }
441
442 panic("%s(%p, %p) failed!", __func__, inode, file);
443}
444
445static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
446{
447 return EPOLLERR | EPOLLNVAL;
448}
449
450static long snd_disconnect_ioctl(struct file *file,
451 unsigned int cmd, unsigned long arg)
452{
453 return -ENODEV;
454}
455
456static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
457{
458 return -ENODEV;
459}
460
461static int snd_disconnect_fasync(int fd, struct file *file, int on)
462{
463 return -ENODEV;
464}
465
466static const struct file_operations snd_shutdown_f_ops =
467{
468 .owner = THIS_MODULE,
469 .llseek = snd_disconnect_llseek,
470 .read = snd_disconnect_read,
471 .write = snd_disconnect_write,
472 .release = snd_disconnect_release,
473 .poll = snd_disconnect_poll,
474 .unlocked_ioctl = snd_disconnect_ioctl,
475#ifdef CONFIG_COMPAT
476 .compat_ioctl = snd_disconnect_ioctl,
477#endif
478 .mmap = snd_disconnect_mmap,
479 .fasync = snd_disconnect_fasync
480};
481
482/**
483 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
484 * @card: soundcard structure
485 *
486 * Disconnects all APIs from the file-operations (user space).
487 *
488 * Return: Zero, otherwise a negative error code.
489 *
490 * Note: The current implementation replaces all active file->f_op with special
491 * dummy file operations (they do nothing except release).
492 */
493void snd_card_disconnect(struct snd_card *card)
494{
495 struct snd_monitor_file *mfile;
496
497 if (!card)
498 return;
499
500 scoped_guard(spinlock, &card->files_lock) {
501 if (card->shutdown)
502 return;
503 card->shutdown = 1;
504
505 /* replace file->f_op with special dummy operations */
506 list_for_each_entry(mfile, &card->files_list, list) {
507 /* it's critical part, use endless loop */
508 /* we have no room to fail */
509 mfile->disconnected_f_op = mfile->file->f_op;
510
511 scoped_guard(spinlock, &shutdown_lock)
512 list_add(&mfile->shutdown_list, &shutdown_files);
513
514 mfile->file->f_op = &snd_shutdown_f_ops;
515 fops_get(mfile->file->f_op);
516 }
517 }
518
519#ifdef CONFIG_PM
520 /* wake up sleepers here before other callbacks for avoiding potential
521 * deadlocks with other locks (e.g. in kctls);
522 * then this notifies the shutdown and sleepers would abort immediately
523 */
524 wake_up_all(&card->power_sleep);
525#endif
526
527 /* notify all connected devices about disconnection */
528 /* at this point, they cannot respond to any calls except release() */
529
530#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
531 if (snd_mixer_oss_notify_callback)
532 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
533#endif
534
535 /* notify all devices that we are disconnected */
536 snd_device_disconnect_all(card);
537
538 if (card->sync_irq > 0)
539 synchronize_irq(card->sync_irq);
540
541 snd_info_card_disconnect(card);
542#ifdef CONFIG_SND_DEBUG
543 debugfs_remove(card->debugfs_root);
544 card->debugfs_root = NULL;
545#endif
546
547 if (card->registered) {
548 device_del(&card->card_dev);
549 card->registered = false;
550 }
551
552 /* disable fops (user space) operations for ALSA API */
553 scoped_guard(mutex, &snd_card_mutex) {
554 snd_cards[card->number] = NULL;
555 clear_bit(card->number, snd_cards_lock);
556 }
557
558#ifdef CONFIG_PM
559 snd_power_sync_ref(card);
560#endif
561}
562EXPORT_SYMBOL(snd_card_disconnect);
563
564/**
565 * snd_card_disconnect_sync - disconnect card and wait until files get closed
566 * @card: card object to disconnect
567 *
568 * This calls snd_card_disconnect() for disconnecting all belonging components
569 * and waits until all pending files get closed.
570 * It assures that all accesses from user-space finished so that the driver
571 * can release its resources gracefully.
572 */
573void snd_card_disconnect_sync(struct snd_card *card)
574{
575 snd_card_disconnect(card);
576
577 guard(spinlock_irq)(&card->files_lock);
578 wait_event_lock_irq(card->remove_sleep,
579 list_empty(&card->files_list),
580 card->files_lock);
581}
582EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
583
584static int snd_card_do_free(struct snd_card *card)
585{
586 card->releasing = true;
587#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
588 if (snd_mixer_oss_notify_callback)
589 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
590#endif
591 snd_device_free_all(card);
592 if (card->private_free)
593 card->private_free(card);
594 if (snd_info_card_free(card) < 0) {
595 dev_warn(card->dev, "unable to free card info\n");
596 /* Not fatal error */
597 }
598 if (card->release_completion)
599 complete(card->release_completion);
600 if (!card->managed)
601 kfree(card);
602 return 0;
603}
604
605/**
606 * snd_card_free_when_closed - Disconnect the card, free it later eventually
607 * @card: soundcard structure
608 *
609 * Unlike snd_card_free(), this function doesn't try to release the card
610 * resource immediately, but tries to disconnect at first. When the card
611 * is still in use, the function returns before freeing the resources.
612 * The card resources will be freed when the refcount gets to zero.
613 *
614 * Return: zero if successful, or a negative error code
615 */
616void snd_card_free_when_closed(struct snd_card *card)
617{
618 if (!card)
619 return;
620
621 snd_card_disconnect(card);
622 put_device(&card->card_dev);
623 return;
624}
625EXPORT_SYMBOL(snd_card_free_when_closed);
626
627/**
628 * snd_card_free - frees given soundcard structure
629 * @card: soundcard structure
630 *
631 * This function releases the soundcard structure and the all assigned
632 * devices automatically. That is, you don't have to release the devices
633 * by yourself.
634 *
635 * This function waits until the all resources are properly released.
636 *
637 * Return: Zero. Frees all associated devices and frees the control
638 * interface associated to given soundcard.
639 */
640void snd_card_free(struct snd_card *card)
641{
642 DECLARE_COMPLETION_ONSTACK(released);
643
644 /* The call of snd_card_free() is allowed from various code paths;
645 * a manual call from the driver and the call via devres_free, and
646 * we need to avoid double-free. Moreover, the release via devres
647 * may call snd_card_free() twice due to its nature, we need to have
648 * the check here at the beginning.
649 */
650 if (card->releasing)
651 return;
652
653 card->release_completion = &released;
654 snd_card_free_when_closed(card);
655
656 /* wait, until all devices are ready for the free operation */
657 wait_for_completion(&released);
658}
659EXPORT_SYMBOL(snd_card_free);
660
661/* retrieve the last word of shortname or longname */
662static const char *retrieve_id_from_card_name(const char *name)
663{
664 const char *spos = name;
665
666 while (*name) {
667 if (isspace(*name) && isalnum(name[1]))
668 spos = name + 1;
669 name++;
670 }
671 return spos;
672}
673
674/* return true if the given id string doesn't conflict any other card ids */
675static bool card_id_ok(struct snd_card *card, const char *id)
676{
677 int i;
678 if (!snd_info_check_reserved_words(id))
679 return false;
680 for (i = 0; i < snd_ecards_limit; i++) {
681 if (snd_cards[i] && snd_cards[i] != card &&
682 !strcmp(snd_cards[i]->id, id))
683 return false;
684 }
685 return true;
686}
687
688/* copy to card->id only with valid letters from nid */
689static void copy_valid_id_string(struct snd_card *card, const char *src,
690 const char *nid)
691{
692 char *id = card->id;
693
694 while (*nid && !isalnum(*nid))
695 nid++;
696 if (isdigit(*nid))
697 *id++ = isalpha(*src) ? *src : 'D';
698 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
699 if (isalnum(*nid))
700 *id++ = *nid;
701 nid++;
702 }
703 *id = 0;
704}
705
706/* Set card->id from the given string
707 * If the string conflicts with other ids, add a suffix to make it unique.
708 */
709static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
710 const char *nid)
711{
712 int len, loops;
713 bool is_default = false;
714 char *id;
715
716 copy_valid_id_string(card, src, nid);
717 id = card->id;
718
719 again:
720 /* use "Default" for obviously invalid strings
721 * ("card" conflicts with proc directories)
722 */
723 if (!*id || !strncmp(id, "card", 4)) {
724 strcpy(id, "Default");
725 is_default = true;
726 }
727
728 len = strlen(id);
729 for (loops = 0; loops < SNDRV_CARDS; loops++) {
730 char *spos;
731 char sfxstr[5]; /* "_012" */
732 int sfxlen;
733
734 if (card_id_ok(card, id))
735 return; /* OK */
736
737 /* Add _XYZ suffix */
738 sprintf(sfxstr, "_%X", loops + 1);
739 sfxlen = strlen(sfxstr);
740 if (len + sfxlen >= sizeof(card->id))
741 spos = id + sizeof(card->id) - sfxlen - 1;
742 else
743 spos = id + len;
744 strcpy(spos, sfxstr);
745 }
746 /* fallback to the default id */
747 if (!is_default) {
748 *id = 0;
749 goto again;
750 }
751 /* last resort... */
752 dev_err(card->dev, "unable to set card id (%s)\n", id);
753 if (card->proc_root->name)
754 strscpy(card->id, card->proc_root->name, sizeof(card->id));
755}
756
757/**
758 * snd_card_set_id - set card identification name
759 * @card: soundcard structure
760 * @nid: new identification string
761 *
762 * This function sets the card identification and checks for name
763 * collisions.
764 */
765void snd_card_set_id(struct snd_card *card, const char *nid)
766{
767 /* check if user specified own card->id */
768 if (card->id[0] != '\0')
769 return;
770 guard(mutex)(&snd_card_mutex);
771 snd_card_set_id_no_lock(card, nid, nid);
772}
773EXPORT_SYMBOL(snd_card_set_id);
774
775static ssize_t id_show(struct device *dev,
776 struct device_attribute *attr, char *buf)
777{
778 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
779 return sysfs_emit(buf, "%s\n", card->id);
780}
781
782static ssize_t id_store(struct device *dev, struct device_attribute *attr,
783 const char *buf, size_t count)
784{
785 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
786 char buf1[sizeof(card->id)];
787 size_t copy = count > sizeof(card->id) - 1 ?
788 sizeof(card->id) - 1 : count;
789 size_t idx;
790 int c;
791
792 for (idx = 0; idx < copy; idx++) {
793 c = buf[idx];
794 if (!isalnum(c) && c != '_' && c != '-')
795 return -EINVAL;
796 }
797 memcpy(buf1, buf, copy);
798 buf1[copy] = '\0';
799 guard(mutex)(&snd_card_mutex);
800 if (!card_id_ok(NULL, buf1))
801 return -EEXIST;
802 strcpy(card->id, buf1);
803 snd_info_card_id_change(card);
804
805 return count;
806}
807
808static DEVICE_ATTR_RW(id);
809
810static ssize_t number_show(struct device *dev,
811 struct device_attribute *attr, char *buf)
812{
813 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
814 return sysfs_emit(buf, "%i\n", card->number);
815}
816
817static DEVICE_ATTR_RO(number);
818
819static struct attribute *card_dev_attrs[] = {
820 &dev_attr_id.attr,
821 &dev_attr_number.attr,
822 NULL
823};
824
825static const struct attribute_group card_dev_attr_group = {
826 .attrs = card_dev_attrs,
827};
828
829/**
830 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
831 * @card: card instance
832 * @group: attribute group to append
833 *
834 * Return: zero if successful, or a negative error code
835 */
836int snd_card_add_dev_attr(struct snd_card *card,
837 const struct attribute_group *group)
838{
839 int i;
840
841 /* loop for (arraysize-1) here to keep NULL at the last entry */
842 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
843 if (!card->dev_groups[i]) {
844 card->dev_groups[i] = group;
845 return 0;
846 }
847 }
848
849 dev_err(card->dev, "Too many groups assigned\n");
850 return -ENOSPC;
851}
852EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
853
854static void trigger_card_free(void *data)
855{
856 snd_card_free(data);
857}
858
859/**
860 * snd_card_register - register the soundcard
861 * @card: soundcard structure
862 *
863 * This function registers all the devices assigned to the soundcard.
864 * Until calling this, the ALSA control interface is blocked from the
865 * external accesses. Thus, you should call this function at the end
866 * of the initialization of the card.
867 *
868 * Return: Zero otherwise a negative error code if the registration failed.
869 */
870int snd_card_register(struct snd_card *card)
871{
872 int err;
873
874 if (snd_BUG_ON(!card))
875 return -EINVAL;
876
877 if (!card->registered) {
878 err = device_add(&card->card_dev);
879 if (err < 0)
880 return err;
881 card->registered = true;
882 } else {
883 if (card->managed)
884 devm_remove_action(card->dev, trigger_card_free, card);
885 }
886
887 if (card->managed) {
888 err = devm_add_action(card->dev, trigger_card_free, card);
889 if (err < 0)
890 return err;
891 }
892
893 err = snd_device_register_all(card);
894 if (err < 0)
895 return err;
896 scoped_guard(mutex, &snd_card_mutex) {
897 if (snd_cards[card->number]) {
898 /* already registered */
899 return snd_info_card_register(card); /* register pending info */
900 }
901 if (*card->id) {
902 /* make a unique id name from the given string */
903 char tmpid[sizeof(card->id)];
904
905 memcpy(tmpid, card->id, sizeof(card->id));
906 snd_card_set_id_no_lock(card, tmpid, tmpid);
907 } else {
908 /* create an id from either shortname or longname */
909 const char *src;
910
911 src = *card->shortname ? card->shortname : card->longname;
912 snd_card_set_id_no_lock(card, src,
913 retrieve_id_from_card_name(src));
914 }
915 snd_cards[card->number] = card;
916 }
917 err = snd_info_card_register(card);
918 if (err < 0)
919 return err;
920
921#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
922 if (snd_mixer_oss_notify_callback)
923 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
924#endif
925 return 0;
926}
927EXPORT_SYMBOL(snd_card_register);
928
929#ifdef CONFIG_SND_PROC_FS
930static void snd_card_info_read(struct snd_info_entry *entry,
931 struct snd_info_buffer *buffer)
932{
933 int idx, count;
934 struct snd_card *card;
935
936 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
937 guard(mutex)(&snd_card_mutex);
938 card = snd_cards[idx];
939 if (card) {
940 count++;
941 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
942 idx,
943 card->id,
944 card->driver,
945 card->shortname);
946 snd_iprintf(buffer, " %s\n",
947 card->longname);
948 }
949 }
950 if (!count)
951 snd_iprintf(buffer, "--- no soundcards ---\n");
952}
953
954#ifdef CONFIG_SND_OSSEMUL
955void snd_card_info_read_oss(struct snd_info_buffer *buffer)
956{
957 int idx, count;
958 struct snd_card *card;
959
960 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
961 guard(mutex)(&snd_card_mutex);
962 card = snd_cards[idx];
963 if (card) {
964 count++;
965 snd_iprintf(buffer, "%s\n", card->longname);
966 }
967 }
968 if (!count) {
969 snd_iprintf(buffer, "--- no soundcards ---\n");
970 }
971}
972
973#endif
974
975#ifdef MODULE
976static void snd_card_module_info_read(struct snd_info_entry *entry,
977 struct snd_info_buffer *buffer)
978{
979 int idx;
980 struct snd_card *card;
981
982 for (idx = 0; idx < SNDRV_CARDS; idx++) {
983 guard(mutex)(&snd_card_mutex);
984 card = snd_cards[idx];
985 if (card)
986 snd_iprintf(buffer, "%2i %s\n",
987 idx, card->module->name);
988 }
989}
990#endif
991
992int __init snd_card_info_init(void)
993{
994 struct snd_info_entry *entry;
995
996 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
997 if (! entry)
998 return -ENOMEM;
999 entry->c.text.read = snd_card_info_read;
1000 if (snd_info_register(entry) < 0)
1001 return -ENOMEM; /* freed in error path */
1002
1003#ifdef MODULE
1004 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1005 if (!entry)
1006 return -ENOMEM;
1007 entry->c.text.read = snd_card_module_info_read;
1008 if (snd_info_register(entry) < 0)
1009 return -ENOMEM; /* freed in error path */
1010#endif
1011
1012 return 0;
1013}
1014#endif /* CONFIG_SND_PROC_FS */
1015
1016/**
1017 * snd_component_add - add a component string
1018 * @card: soundcard structure
1019 * @component: the component id string
1020 *
1021 * This function adds the component id string to the supported list.
1022 * The component can be referred from the alsa-lib.
1023 *
1024 * Return: Zero otherwise a negative error code.
1025 */
1026
1027int snd_component_add(struct snd_card *card, const char *component)
1028{
1029 char *ptr;
1030 int len = strlen(component);
1031
1032 ptr = strstr(card->components, component);
1033 if (ptr != NULL) {
1034 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1035 return 1;
1036 }
1037 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1038 snd_BUG();
1039 return -ENOMEM;
1040 }
1041 if (card->components[0] != '\0')
1042 strcat(card->components, " ");
1043 strcat(card->components, component);
1044 return 0;
1045}
1046EXPORT_SYMBOL(snd_component_add);
1047
1048/**
1049 * snd_card_file_add - add the file to the file list of the card
1050 * @card: soundcard structure
1051 * @file: file pointer
1052 *
1053 * This function adds the file to the file linked-list of the card.
1054 * This linked-list is used to keep tracking the connection state,
1055 * and to avoid the release of busy resources by hotplug.
1056 *
1057 * Return: zero or a negative error code.
1058 */
1059int snd_card_file_add(struct snd_card *card, struct file *file)
1060{
1061 struct snd_monitor_file *mfile;
1062
1063 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1064 if (mfile == NULL)
1065 return -ENOMEM;
1066 mfile->file = file;
1067 mfile->disconnected_f_op = NULL;
1068 INIT_LIST_HEAD(&mfile->shutdown_list);
1069 guard(spinlock)(&card->files_lock);
1070 if (card->shutdown) {
1071 kfree(mfile);
1072 return -ENODEV;
1073 }
1074 list_add(&mfile->list, &card->files_list);
1075 get_device(&card->card_dev);
1076 return 0;
1077}
1078EXPORT_SYMBOL(snd_card_file_add);
1079
1080/**
1081 * snd_card_file_remove - remove the file from the file list
1082 * @card: soundcard structure
1083 * @file: file pointer
1084 *
1085 * This function removes the file formerly added to the card via
1086 * snd_card_file_add() function.
1087 * If all files are removed and snd_card_free_when_closed() was
1088 * called beforehand, it processes the pending release of
1089 * resources.
1090 *
1091 * Return: Zero or a negative error code.
1092 */
1093int snd_card_file_remove(struct snd_card *card, struct file *file)
1094{
1095 struct snd_monitor_file *mfile, *found = NULL;
1096
1097 scoped_guard(spinlock, &card->files_lock) {
1098 list_for_each_entry(mfile, &card->files_list, list) {
1099 if (mfile->file == file) {
1100 list_del(&mfile->list);
1101 scoped_guard(spinlock, &shutdown_lock)
1102 list_del(&mfile->shutdown_list);
1103 if (mfile->disconnected_f_op)
1104 fops_put(mfile->disconnected_f_op);
1105 found = mfile;
1106 break;
1107 }
1108 }
1109 if (list_empty(&card->files_list))
1110 wake_up_all(&card->remove_sleep);
1111 }
1112 if (!found) {
1113 dev_err(card->dev, "card file remove problem (%p)\n", file);
1114 return -ENOENT;
1115 }
1116 kfree(found);
1117 put_device(&card->card_dev);
1118 return 0;
1119}
1120EXPORT_SYMBOL(snd_card_file_remove);
1121
1122#ifdef CONFIG_PM
1123/**
1124 * snd_power_ref_and_wait - wait until the card gets powered up
1125 * @card: soundcard structure
1126 *
1127 * Take the power_ref reference count of the given card, and
1128 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1129 * The refcount is down again while sleeping until power-up, hence this
1130 * function can be used for syncing the floating control ops accesses,
1131 * typically around calling control ops.
1132 *
1133 * The caller needs to pull down the refcount via snd_power_unref() later
1134 * no matter whether the error is returned from this function or not.
1135 *
1136 * Return: Zero if successful, or a negative error code.
1137 */
1138int snd_power_ref_and_wait(struct snd_card *card)
1139{
1140 snd_power_ref(card);
1141 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1142 return 0;
1143 wait_event_cmd(card->power_sleep,
1144 card->shutdown ||
1145 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1146 snd_power_unref(card), snd_power_ref(card));
1147 return card->shutdown ? -ENODEV : 0;
1148}
1149EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1150
1151/**
1152 * snd_power_wait - wait until the card gets powered up (old form)
1153 * @card: soundcard structure
1154 *
1155 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1156 *
1157 * Return: Zero if successful, or a negative error code.
1158 */
1159int snd_power_wait(struct snd_card *card)
1160{
1161 int ret;
1162
1163 ret = snd_power_ref_and_wait(card);
1164 snd_power_unref(card);
1165 return ret;
1166}
1167EXPORT_SYMBOL(snd_power_wait);
1168#endif /* CONFIG_PM */