1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Initialization routines
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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>
16 #include <linux/debugfs.h>
17 #include <linux/completion.h>
18 #include <linux/interrupt.h>
20 #include <sound/core.h>
21 #include <sound/control.h>
22 #include <sound/info.h>
24 /* monitor files for graceful shutdown (hotplug) */
25 struct snd_monitor_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 */
32 static DEFINE_SPINLOCK(shutdown_lock);
33 static LIST_HEAD(shutdown_files);
35 static const struct file_operations snd_shutdown_f_ops;
37 /* locked for registering/using */
38 static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
39 static struct snd_card *snd_cards[SNDRV_CARDS];
41 static DEFINE_MUTEX(snd_card_mutex);
43 static char *slots[SNDRV_CARDS];
44 module_param_array(slots, charp, NULL, 0444);
45 MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
47 /* return non-zero if the given index is reserved for the given
48 * module via slots option
50 static int module_slot_match(struct module *module, int idx)
56 if (!module || !*module->name || !slots[idx])
62 match = 0; /* negative match */
65 /* compare module name strings
66 * hyphens are handled as equivalent with underscore
84 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
85 int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag);
86 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
89 static int check_empty_slot(struct module *module, int slot)
91 return !slots[slot] || !*slots[slot];
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.
98 static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
99 struct module *module)
103 for (slot = 0; slot < SNDRV_CARDS; slot++) {
104 if (slot < 32 && !(mask & (1U << slot)))
106 if (!test_bit(slot, snd_cards_lock)) {
107 if (check(module, slot))
108 return slot; /* found */
111 return mask; /* unchanged */
114 /* the default release callback set in snd_device_alloc() */
115 static void default_release_alloc(struct device *dev)
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
125 * For releasing the allocated device, call put_device().
127 int snd_device_alloc(struct device **dev_p, struct snd_card *card)
132 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
135 device_initialize(dev);
137 dev->parent = &card->card_dev;
138 dev->class = &sound_class;
139 dev->release = default_release_alloc;
143 EXPORT_SYMBOL_GPL(snd_device_alloc);
145 static int snd_card_init(struct snd_card *card, struct device *parent,
146 int idx, const char *xid, struct module *module,
148 static int snd_card_do_free(struct snd_card *card);
149 static const struct attribute_group card_dev_attr_group;
151 static void release_card_device(struct device *dev)
153 snd_card_do_free(dev_to_snd_card(dev));
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
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.
169 * Return: Zero if successful or a negative error code.
171 int snd_card_new(struct device *parent, int idx, const char *xid,
172 struct module *module, int extra_size,
173 struct snd_card **card_ret)
175 struct snd_card *card;
178 if (snd_BUG_ON(!card_ret))
184 card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
188 err = snd_card_init(card, parent, idx, xid, module, extra_size);
190 return err; /* card is freed by error handler */
195 EXPORT_SYMBOL(snd_card_new);
197 static void __snd_card_release(struct device *dev, void *data)
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
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.
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.
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.
225 * Return: zero if successful, or a negative error code
227 int 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)
231 struct snd_card *card;
235 card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size,
239 card->managed = true;
240 err = snd_card_init(card, parent, idx, xid, module, extra_size);
242 devres_free(card); /* in managed mode, we need to free manually */
246 devres_add(parent, card);
250 EXPORT_SYMBOL_GPL(snd_devm_card_new);
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
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.
261 * Return: zero if successful, or a negative error code
263 int snd_card_free_on_error(struct device *dev, int ret)
265 struct snd_card *card;
269 card = devres_find(dev, __snd_card_release, NULL, NULL);
274 EXPORT_SYMBOL_GPL(snd_card_free_on_error);
276 static int snd_card_init(struct snd_card *card, struct device *parent,
277 int idx, const char *xid, struct module *module,
281 #ifdef CONFIG_SND_DEBUG
286 card->private_data = (char *)card + sizeof(struct snd_card);
288 strscpy(card->id, xid, sizeof(card->id));
290 mutex_lock(&snd_card_mutex);
291 if (idx < 0) /* first check the matching module-name slot */
292 idx = get_slot_from_bitmask(idx, module_slot_match, module);
293 if (idx < 0) /* if not matched, assign an empty slot */
294 idx = get_slot_from_bitmask(idx, check_empty_slot, module);
297 else if (idx < snd_ecards_limit) {
298 if (test_bit(idx, snd_cards_lock))
299 err = -EBUSY; /* invalid */
300 } else if (idx >= SNDRV_CARDS)
303 mutex_unlock(&snd_card_mutex);
304 dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n",
305 idx, snd_ecards_limit - 1, err);
307 kfree(card); /* manually free here, as no destructor called */
310 set_bit(idx, snd_cards_lock); /* lock it */
311 if (idx >= snd_ecards_limit)
312 snd_ecards_limit = idx + 1; /* increase the limit */
313 mutex_unlock(&snd_card_mutex);
318 card->module = module;
320 INIT_LIST_HEAD(&card->devices);
321 init_rwsem(&card->controls_rwsem);
322 rwlock_init(&card->ctl_files_rwlock);
323 INIT_LIST_HEAD(&card->controls);
324 INIT_LIST_HEAD(&card->ctl_files);
325 #ifdef CONFIG_SND_CTL_FAST_LOOKUP
326 xa_init(&card->ctl_numids);
327 xa_init(&card->ctl_hash);
329 spin_lock_init(&card->files_lock);
330 INIT_LIST_HEAD(&card->files_list);
331 mutex_init(&card->memory_mutex);
333 init_waitqueue_head(&card->power_sleep);
334 init_waitqueue_head(&card->power_ref_sleep);
335 atomic_set(&card->power_ref, 0);
337 init_waitqueue_head(&card->remove_sleep);
340 device_initialize(&card->card_dev);
341 card->card_dev.parent = parent;
342 card->card_dev.class = &sound_class;
343 card->card_dev.release = release_card_device;
344 card->card_dev.groups = card->dev_groups;
345 card->dev_groups[0] = &card_dev_attr_group;
346 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);
350 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",
351 dev_driver_string(card->dev), dev_name(&card->card_dev));
353 /* the control interface cannot be accessed from the user space until */
354 /* snd_cards_bitmask and snd_cards are set with snd_card_register */
355 err = snd_ctl_create(card);
357 dev_err(parent, "unable to register control minors\n");
360 err = snd_info_card_create(card);
362 dev_err(parent, "unable to create card info\n");
366 #ifdef CONFIG_SND_DEBUG
367 sprintf(name, "card%d", idx);
368 card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root);
373 snd_device_free_all(card);
375 put_device(&card->card_dev);
380 * snd_card_ref - Get the card object from the index
381 * @idx: the card index
383 * Returns a card object corresponding to the given index or NULL if not found.
384 * Release the object via snd_card_unref().
386 * Return: a card object or NULL
388 struct snd_card *snd_card_ref(int idx)
390 struct snd_card *card;
392 mutex_lock(&snd_card_mutex);
393 card = snd_cards[idx];
395 get_device(&card->card_dev);
396 mutex_unlock(&snd_card_mutex);
399 EXPORT_SYMBOL_GPL(snd_card_ref);
401 /* return non-zero if a card is already locked */
402 int snd_card_locked(int card)
406 mutex_lock(&snd_card_mutex);
407 locked = test_bit(card, snd_cards_lock);
408 mutex_unlock(&snd_card_mutex);
412 static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)
417 static ssize_t snd_disconnect_read(struct file *file, char __user *buf,
418 size_t count, loff_t *offset)
423 static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,
424 size_t count, loff_t *offset)
429 static int snd_disconnect_release(struct inode *inode, struct file *file)
431 struct snd_monitor_file *df = NULL, *_df;
433 spin_lock(&shutdown_lock);
434 list_for_each_entry(_df, &shutdown_files, shutdown_list) {
435 if (_df->file == file) {
437 list_del_init(&df->shutdown_list);
441 spin_unlock(&shutdown_lock);
444 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)
445 df->disconnected_f_op->fasync(-1, file, 0);
446 return df->disconnected_f_op->release(inode, file);
449 panic("%s(%p, %p) failed!", __func__, inode, file);
452 static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)
454 return EPOLLERR | EPOLLNVAL;
457 static long snd_disconnect_ioctl(struct file *file,
458 unsigned int cmd, unsigned long arg)
463 static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)
468 static int snd_disconnect_fasync(int fd, struct file *file, int on)
473 static const struct file_operations snd_shutdown_f_ops =
475 .owner = THIS_MODULE,
476 .llseek = snd_disconnect_llseek,
477 .read = snd_disconnect_read,
478 .write = snd_disconnect_write,
479 .release = snd_disconnect_release,
480 .poll = snd_disconnect_poll,
481 .unlocked_ioctl = snd_disconnect_ioctl,
483 .compat_ioctl = snd_disconnect_ioctl,
485 .mmap = snd_disconnect_mmap,
486 .fasync = snd_disconnect_fasync
490 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)
491 * @card: soundcard structure
493 * Disconnects all APIs from the file-operations (user space).
495 * Return: Zero, otherwise a negative error code.
497 * Note: The current implementation replaces all active file->f_op with special
498 * dummy file operations (they do nothing except release).
500 void snd_card_disconnect(struct snd_card *card)
502 struct snd_monitor_file *mfile;
507 spin_lock(&card->files_lock);
508 if (card->shutdown) {
509 spin_unlock(&card->files_lock);
514 /* replace file->f_op with special dummy operations */
515 list_for_each_entry(mfile, &card->files_list, list) {
516 /* it's critical part, use endless loop */
517 /* we have no room to fail */
518 mfile->disconnected_f_op = mfile->file->f_op;
520 spin_lock(&shutdown_lock);
521 list_add(&mfile->shutdown_list, &shutdown_files);
522 spin_unlock(&shutdown_lock);
524 mfile->file->f_op = &snd_shutdown_f_ops;
525 fops_get(mfile->file->f_op);
527 spin_unlock(&card->files_lock);
529 /* notify all connected devices about disconnection */
530 /* at this point, they cannot respond to any calls except release() */
532 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
533 if (snd_mixer_oss_notify_callback)
534 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
537 /* notify all devices that we are disconnected */
538 snd_device_disconnect_all(card);
540 if (card->sync_irq > 0)
541 synchronize_irq(card->sync_irq);
543 snd_info_card_disconnect(card);
544 if (card->registered) {
545 device_del(&card->card_dev);
546 card->registered = false;
549 /* disable fops (user space) operations for ALSA API */
550 mutex_lock(&snd_card_mutex);
551 snd_cards[card->number] = NULL;
552 clear_bit(card->number, snd_cards_lock);
553 mutex_unlock(&snd_card_mutex);
556 wake_up(&card->power_sleep);
557 snd_power_sync_ref(card);
560 EXPORT_SYMBOL(snd_card_disconnect);
563 * snd_card_disconnect_sync - disconnect card and wait until files get closed
564 * @card: card object to disconnect
566 * This calls snd_card_disconnect() for disconnecting all belonging components
567 * and waits until all pending files get closed.
568 * It assures that all accesses from user-space finished so that the driver
569 * can release its resources gracefully.
571 void snd_card_disconnect_sync(struct snd_card *card)
573 snd_card_disconnect(card);
575 spin_lock_irq(&card->files_lock);
576 wait_event_lock_irq(card->remove_sleep,
577 list_empty(&card->files_list),
579 spin_unlock_irq(&card->files_lock);
581 EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);
583 static int snd_card_do_free(struct snd_card *card)
585 card->releasing = true;
586 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
587 if (snd_mixer_oss_notify_callback)
588 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
590 snd_device_free_all(card);
591 if (card->private_free)
592 card->private_free(card);
593 if (snd_info_card_free(card) < 0) {
594 dev_warn(card->dev, "unable to free card info\n");
595 /* Not fatal error */
597 #ifdef CONFIG_SND_DEBUG
598 debugfs_remove(card->debugfs_root);
599 card->debugfs_root = NULL;
601 if (card->release_completion)
602 complete(card->release_completion);
609 * snd_card_free_when_closed - Disconnect the card, free it later eventually
610 * @card: soundcard structure
612 * Unlike snd_card_free(), this function doesn't try to release the card
613 * resource immediately, but tries to disconnect at first. When the card
614 * is still in use, the function returns before freeing the resources.
615 * The card resources will be freed when the refcount gets to zero.
617 * Return: zero if successful, or a negative error code
619 void snd_card_free_when_closed(struct snd_card *card)
624 snd_card_disconnect(card);
625 put_device(&card->card_dev);
628 EXPORT_SYMBOL(snd_card_free_when_closed);
631 * snd_card_free - frees given soundcard structure
632 * @card: soundcard structure
634 * This function releases the soundcard structure and the all assigned
635 * devices automatically. That is, you don't have to release the devices
638 * This function waits until the all resources are properly released.
640 * Return: Zero. Frees all associated devices and frees the control
641 * interface associated to given soundcard.
643 void snd_card_free(struct snd_card *card)
645 DECLARE_COMPLETION_ONSTACK(released);
647 /* The call of snd_card_free() is allowed from various code paths;
648 * a manual call from the driver and the call via devres_free, and
649 * we need to avoid double-free. Moreover, the release via devres
650 * may call snd_card_free() twice due to its nature, we need to have
651 * the check here at the beginning.
656 card->release_completion = &released;
657 snd_card_free_when_closed(card);
659 /* wait, until all devices are ready for the free operation */
660 wait_for_completion(&released);
662 EXPORT_SYMBOL(snd_card_free);
664 /* retrieve the last word of shortname or longname */
665 static const char *retrieve_id_from_card_name(const char *name)
667 const char *spos = name;
670 if (isspace(*name) && isalnum(name[1]))
677 /* return true if the given id string doesn't conflict any other card ids */
678 static bool card_id_ok(struct snd_card *card, const char *id)
681 if (!snd_info_check_reserved_words(id))
683 for (i = 0; i < snd_ecards_limit; i++) {
684 if (snd_cards[i] && snd_cards[i] != card &&
685 !strcmp(snd_cards[i]->id, id))
691 /* copy to card->id only with valid letters from nid */
692 static void copy_valid_id_string(struct snd_card *card, const char *src,
697 while (*nid && !isalnum(*nid))
700 *id++ = isalpha(*src) ? *src : 'D';
701 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
709 /* Set card->id from the given string
710 * If the string conflicts with other ids, add a suffix to make it unique.
712 static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
716 bool is_default = false;
719 copy_valid_id_string(card, src, nid);
723 /* use "Default" for obviously invalid strings
724 * ("card" conflicts with proc directories)
726 if (!*id || !strncmp(id, "card", 4)) {
727 strcpy(id, "Default");
732 for (loops = 0; loops < SNDRV_CARDS; loops++) {
734 char sfxstr[5]; /* "_012" */
737 if (card_id_ok(card, id))
740 /* Add _XYZ suffix */
741 sprintf(sfxstr, "_%X", loops + 1);
742 sfxlen = strlen(sfxstr);
743 if (len + sfxlen >= sizeof(card->id))
744 spos = id + sizeof(card->id) - sfxlen - 1;
747 strcpy(spos, sfxstr);
749 /* fallback to the default id */
755 dev_err(card->dev, "unable to set card id (%s)\n", id);
756 if (card->proc_root->name)
757 strscpy(card->id, card->proc_root->name, sizeof(card->id));
761 * snd_card_set_id - set card identification name
762 * @card: soundcard structure
763 * @nid: new identification string
765 * This function sets the card identification and checks for name
768 void snd_card_set_id(struct snd_card *card, const char *nid)
770 /* check if user specified own card->id */
771 if (card->id[0] != '\0')
773 mutex_lock(&snd_card_mutex);
774 snd_card_set_id_no_lock(card, nid, nid);
775 mutex_unlock(&snd_card_mutex);
777 EXPORT_SYMBOL(snd_card_set_id);
779 static ssize_t id_show(struct device *dev,
780 struct device_attribute *attr, char *buf)
782 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
783 return sysfs_emit(buf, "%s\n", card->id);
786 static ssize_t id_store(struct device *dev, struct device_attribute *attr,
787 const char *buf, size_t count)
789 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
790 char buf1[sizeof(card->id)];
791 size_t copy = count > sizeof(card->id) - 1 ?
792 sizeof(card->id) - 1 : count;
796 for (idx = 0; idx < copy; idx++) {
798 if (!isalnum(c) && c != '_' && c != '-')
801 memcpy(buf1, buf, copy);
803 mutex_lock(&snd_card_mutex);
804 if (!card_id_ok(NULL, buf1)) {
805 mutex_unlock(&snd_card_mutex);
808 strcpy(card->id, buf1);
809 snd_info_card_id_change(card);
810 mutex_unlock(&snd_card_mutex);
815 static DEVICE_ATTR_RW(id);
817 static ssize_t number_show(struct device *dev,
818 struct device_attribute *attr, char *buf)
820 struct snd_card *card = container_of(dev, struct snd_card, card_dev);
821 return sysfs_emit(buf, "%i\n", card->number);
824 static DEVICE_ATTR_RO(number);
826 static struct attribute *card_dev_attrs[] = {
828 &dev_attr_number.attr,
832 static const struct attribute_group card_dev_attr_group = {
833 .attrs = card_dev_attrs,
837 * snd_card_add_dev_attr - Append a new sysfs attribute group to card
838 * @card: card instance
839 * @group: attribute group to append
841 * Return: zero if successful, or a negative error code
843 int snd_card_add_dev_attr(struct snd_card *card,
844 const struct attribute_group *group)
848 /* loop for (arraysize-1) here to keep NULL at the last entry */
849 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {
850 if (!card->dev_groups[i]) {
851 card->dev_groups[i] = group;
856 dev_err(card->dev, "Too many groups assigned\n");
859 EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);
861 static void trigger_card_free(void *data)
867 * snd_card_register - register the soundcard
868 * @card: soundcard structure
870 * This function registers all the devices assigned to the soundcard.
871 * Until calling this, the ALSA control interface is blocked from the
872 * external accesses. Thus, you should call this function at the end
873 * of the initialization of the card.
875 * Return: Zero otherwise a negative error code if the registration failed.
877 int snd_card_register(struct snd_card *card)
881 if (snd_BUG_ON(!card))
884 if (!card->registered) {
885 err = device_add(&card->card_dev);
888 card->registered = true;
891 devm_remove_action(card->dev, trigger_card_free, card);
895 err = devm_add_action(card->dev, trigger_card_free, card);
900 err = snd_device_register_all(card);
903 mutex_lock(&snd_card_mutex);
904 if (snd_cards[card->number]) {
905 /* already registered */
906 mutex_unlock(&snd_card_mutex);
907 return snd_info_card_register(card); /* register pending info */
910 /* make a unique id name from the given string */
911 char tmpid[sizeof(card->id)];
912 memcpy(tmpid, card->id, sizeof(card->id));
913 snd_card_set_id_no_lock(card, tmpid, tmpid);
915 /* create an id from either shortname or longname */
917 src = *card->shortname ? card->shortname : card->longname;
918 snd_card_set_id_no_lock(card, src,
919 retrieve_id_from_card_name(src));
921 snd_cards[card->number] = card;
922 mutex_unlock(&snd_card_mutex);
923 err = snd_info_card_register(card);
927 #if IS_ENABLED(CONFIG_SND_MIXER_OSS)
928 if (snd_mixer_oss_notify_callback)
929 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
933 EXPORT_SYMBOL(snd_card_register);
935 #ifdef CONFIG_SND_PROC_FS
936 static void snd_card_info_read(struct snd_info_entry *entry,
937 struct snd_info_buffer *buffer)
940 struct snd_card *card;
942 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
943 mutex_lock(&snd_card_mutex);
944 card = snd_cards[idx];
947 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",
952 snd_iprintf(buffer, " %s\n",
955 mutex_unlock(&snd_card_mutex);
958 snd_iprintf(buffer, "--- no soundcards ---\n");
961 #ifdef CONFIG_SND_OSSEMUL
962 void snd_card_info_read_oss(struct snd_info_buffer *buffer)
965 struct snd_card *card;
967 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
968 mutex_lock(&snd_card_mutex);
969 card = snd_cards[idx];
972 snd_iprintf(buffer, "%s\n", card->longname);
974 mutex_unlock(&snd_card_mutex);
977 snd_iprintf(buffer, "--- no soundcards ---\n");
984 static void snd_card_module_info_read(struct snd_info_entry *entry,
985 struct snd_info_buffer *buffer)
988 struct snd_card *card;
990 for (idx = 0; idx < SNDRV_CARDS; idx++) {
991 mutex_lock(&snd_card_mutex);
992 card = snd_cards[idx];
994 snd_iprintf(buffer, "%2i %s\n",
995 idx, card->module->name);
996 mutex_unlock(&snd_card_mutex);
1001 int __init snd_card_info_init(void)
1003 struct snd_info_entry *entry;
1005 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
1008 entry->c.text.read = snd_card_info_read;
1009 if (snd_info_register(entry) < 0)
1010 return -ENOMEM; /* freed in error path */
1013 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
1016 entry->c.text.read = snd_card_module_info_read;
1017 if (snd_info_register(entry) < 0)
1018 return -ENOMEM; /* freed in error path */
1023 #endif /* CONFIG_SND_PROC_FS */
1026 * snd_component_add - add a component string
1027 * @card: soundcard structure
1028 * @component: the component id string
1030 * This function adds the component id string to the supported list.
1031 * The component can be referred from the alsa-lib.
1033 * Return: Zero otherwise a negative error code.
1036 int snd_component_add(struct snd_card *card, const char *component)
1039 int len = strlen(component);
1041 ptr = strstr(card->components, component);
1043 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */
1046 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
1050 if (card->components[0] != '\0')
1051 strcat(card->components, " ");
1052 strcat(card->components, component);
1055 EXPORT_SYMBOL(snd_component_add);
1058 * snd_card_file_add - add the file to the file list of the card
1059 * @card: soundcard structure
1060 * @file: file pointer
1062 * This function adds the file to the file linked-list of the card.
1063 * This linked-list is used to keep tracking the connection state,
1064 * and to avoid the release of busy resources by hotplug.
1066 * Return: zero or a negative error code.
1068 int snd_card_file_add(struct snd_card *card, struct file *file)
1070 struct snd_monitor_file *mfile;
1072 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
1076 mfile->disconnected_f_op = NULL;
1077 INIT_LIST_HEAD(&mfile->shutdown_list);
1078 spin_lock(&card->files_lock);
1079 if (card->shutdown) {
1080 spin_unlock(&card->files_lock);
1084 list_add(&mfile->list, &card->files_list);
1085 get_device(&card->card_dev);
1086 spin_unlock(&card->files_lock);
1089 EXPORT_SYMBOL(snd_card_file_add);
1092 * snd_card_file_remove - remove the file from the file list
1093 * @card: soundcard structure
1094 * @file: file pointer
1096 * This function removes the file formerly added to the card via
1097 * snd_card_file_add() function.
1098 * If all files are removed and snd_card_free_when_closed() was
1099 * called beforehand, it processes the pending release of
1102 * Return: Zero or a negative error code.
1104 int snd_card_file_remove(struct snd_card *card, struct file *file)
1106 struct snd_monitor_file *mfile, *found = NULL;
1108 spin_lock(&card->files_lock);
1109 list_for_each_entry(mfile, &card->files_list, list) {
1110 if (mfile->file == file) {
1111 list_del(&mfile->list);
1112 spin_lock(&shutdown_lock);
1113 list_del(&mfile->shutdown_list);
1114 spin_unlock(&shutdown_lock);
1115 if (mfile->disconnected_f_op)
1116 fops_put(mfile->disconnected_f_op);
1121 if (list_empty(&card->files_list))
1122 wake_up_all(&card->remove_sleep);
1123 spin_unlock(&card->files_lock);
1125 dev_err(card->dev, "card file remove problem (%p)\n", file);
1129 put_device(&card->card_dev);
1132 EXPORT_SYMBOL(snd_card_file_remove);
1136 * snd_power_ref_and_wait - wait until the card gets powered up
1137 * @card: soundcard structure
1139 * Take the power_ref reference count of the given card, and
1140 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1141 * The refcount is down again while sleeping until power-up, hence this
1142 * function can be used for syncing the floating control ops accesses,
1143 * typically around calling control ops.
1145 * The caller needs to pull down the refcount via snd_power_unref() later
1146 * no matter whether the error is returned from this function or not.
1148 * Return: Zero if successful, or a negative error code.
1150 int snd_power_ref_and_wait(struct snd_card *card)
1152 snd_power_ref(card);
1153 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)
1155 wait_event_cmd(card->power_sleep,
1157 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,
1158 snd_power_unref(card), snd_power_ref(card));
1159 return card->shutdown ? -ENODEV : 0;
1161 EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);
1164 * snd_power_wait - wait until the card gets powered up (old form)
1165 * @card: soundcard structure
1167 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.
1169 * Return: Zero if successful, or a negative error code.
1171 int snd_power_wait(struct snd_card *card)
1175 ret = snd_power_ref_and_wait(card);
1176 snd_power_unref(card);
1179 EXPORT_SYMBOL(snd_power_wait);
1180 #endif /* CONFIG_PM */