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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Initialization routines4 * 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 given48 * module via slots option49 */50static int module_slot_match(struct module *module, int idx)51{52 int match = 1;53#ifdef CONFIG_MODULES54 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 strings66 * hyphens are handled as equivalent with underscore67 */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 /* CONFIG_MODULES */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#endif88 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 3296 * 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 devices122 * @dev_p: pointer to store the allocated device123 * @card: card to assign, optional124 *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 structure158 * @parent: the parent device object159 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]160 * @xid: card identification (ASCII string)161 * @module: top level module for locking162 * @extra_size: allocate this extra size after the main soundcard structure163 * @card_ret: the pointer to store the created card instance164 *165 * The function allocates snd_card instance via kzalloc with the given166 * space for the driver to use freely. The allocated struct is stored167 * 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 creation204 * @parent: the parent device object205 * @idx: card index (address) [0 ... (SNDRV_CARDS-1)]206 * @xid: card identification (ASCII string)207 * @module: top level module for locking208 * @extra_size: allocate this extra size after the main soundcard structure209 * @card_ret: the pointer to store the created card instance210 *211 * This function works like snd_card_new() but manages the allocated resource212 * 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 via215 * snd_card_register(), the very first devres action to call snd_card_free()216 * is added automatically. In that way, the resource disconnection is assured217 * at first, then released in the expected order.218 *219 * If an error happens at the probe before snd_card_register() is called and220 * there have been other devres resources, you'd need to free the card manually221 * via snd_card_free() call in the error; otherwise it may lead to UAF due to222 * devres call orders. You can use snd_card_free_on_error() helper for223 * handling it more easily.224 *225 * Return: zero if successful, or a negative error code226 */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 errors254 * @dev: the managed device object255 * @ret: the return code from the probe callback256 *257 * This function handles the explicit snd_card_free() call at the error from258 * the probe callback. It's just a small helper for simplifying the error259 * handling with the managed devices.260 *261 * Return: zero if successful, or a negative error code262 */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 WARN_ON(IS_MODULE(CONFIG_SND) && !module);315 card->module = module;316 INIT_LIST_HEAD(&card->devices);317 init_rwsem(&card->controls_rwsem);318 rwlock_init(&card->controls_rwlock);319 INIT_LIST_HEAD(&card->controls);320 INIT_LIST_HEAD(&card->ctl_files);321#ifdef CONFIG_SND_CTL_FAST_LOOKUP322 xa_init(&card->ctl_numids);323 xa_init(&card->ctl_hash);324#endif325 spin_lock_init(&card->files_lock);326 INIT_LIST_HEAD(&card->files_list);327 mutex_init(&card->memory_mutex);328#ifdef CONFIG_PM329 init_waitqueue_head(&card->power_sleep);330 init_waitqueue_head(&card->power_ref_sleep);331 atomic_set(&card->power_ref, 0);332#endif333 init_waitqueue_head(&card->remove_sleep);334 card->sync_irq = -1;335 336 device_initialize(&card->card_dev);337 card->card_dev.parent = parent;338 card->card_dev.class = &sound_class;339 card->card_dev.release = release_card_device;340 card->card_dev.groups = card->dev_groups;341 card->dev_groups[0] = &card_dev_attr_group;342 err = kobject_set_name(&card->card_dev.kobj, "card%d", idx);343 if (err < 0)344 goto __error;345 346 snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s",347 dev_driver_string(card->dev), dev_name(&card->card_dev));348 349 /* the control interface cannot be accessed from the user space until */350 /* snd_cards_bitmask and snd_cards are set with snd_card_register */351 err = snd_ctl_create(card);352 if (err < 0) {353 dev_err(parent, "unable to register control minors\n");354 goto __error;355 }356 err = snd_info_card_create(card);357 if (err < 0) {358 dev_err(parent, "unable to create card info\n");359 goto __error_ctl;360 }361 362#ifdef CONFIG_SND_DEBUG363 card->debugfs_root = debugfs_create_dir(dev_name(&card->card_dev),364 sound_debugfs_root);365#endif366 return 0;367 368 __error_ctl:369 snd_device_free_all(card);370 __error:371 put_device(&card->card_dev);372 return err;373}374 375/**376 * snd_card_ref - Get the card object from the index377 * @idx: the card index378 *379 * Returns a card object corresponding to the given index or NULL if not found.380 * Release the object via snd_card_unref().381 *382 * Return: a card object or NULL383 */384struct snd_card *snd_card_ref(int idx)385{386 struct snd_card *card;387 388 guard(mutex)(&snd_card_mutex);389 card = snd_cards[idx];390 if (card)391 get_device(&card->card_dev);392 return card;393}394EXPORT_SYMBOL_GPL(snd_card_ref);395 396/* return non-zero if a card is already locked */397int snd_card_locked(int card)398{399 guard(mutex)(&snd_card_mutex);400 return test_bit(card, snd_cards_lock);401}402 403static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig)404{405 return -ENODEV;406}407 408static ssize_t snd_disconnect_read(struct file *file, char __user *buf,409 size_t count, loff_t *offset)410{411 return -ENODEV;412}413 414static ssize_t snd_disconnect_write(struct file *file, const char __user *buf,415 size_t count, loff_t *offset)416{417 return -ENODEV;418}419 420static int snd_disconnect_release(struct inode *inode, struct file *file)421{422 struct snd_monitor_file *df = NULL, *_df;423 424 scoped_guard(spinlock, &shutdown_lock) {425 list_for_each_entry(_df, &shutdown_files, shutdown_list) {426 if (_df->file == file) {427 df = _df;428 list_del_init(&df->shutdown_list);429 break;430 }431 }432 }433 434 if (likely(df)) {435 if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync)436 df->disconnected_f_op->fasync(-1, file, 0);437 return df->disconnected_f_op->release(inode, file);438 }439 440 panic("%s(%p, %p) failed!", __func__, inode, file);441}442 443static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait)444{445 return EPOLLERR | EPOLLNVAL;446}447 448static long snd_disconnect_ioctl(struct file *file,449 unsigned int cmd, unsigned long arg)450{451 return -ENODEV;452}453 454static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma)455{456 return -ENODEV;457}458 459static int snd_disconnect_fasync(int fd, struct file *file, int on)460{461 return -ENODEV;462}463 464static const struct file_operations snd_shutdown_f_ops =465{466 .owner = THIS_MODULE,467 .llseek = snd_disconnect_llseek,468 .read = snd_disconnect_read,469 .write = snd_disconnect_write,470 .release = snd_disconnect_release,471 .poll = snd_disconnect_poll,472 .unlocked_ioctl = snd_disconnect_ioctl,473#ifdef CONFIG_COMPAT474 .compat_ioctl = snd_disconnect_ioctl,475#endif476 .mmap = snd_disconnect_mmap,477 .fasync = snd_disconnect_fasync478};479 480/**481 * snd_card_disconnect - disconnect all APIs from the file-operations (user space)482 * @card: soundcard structure483 *484 * Disconnects all APIs from the file-operations (user space).485 *486 * Return: Zero, otherwise a negative error code.487 *488 * Note: The current implementation replaces all active file->f_op with special489 * dummy file operations (they do nothing except release).490 */491void snd_card_disconnect(struct snd_card *card)492{493 struct snd_monitor_file *mfile;494 495 if (!card)496 return;497 498 scoped_guard(spinlock, &card->files_lock) {499 if (card->shutdown)500 return;501 card->shutdown = 1;502 503 /* replace file->f_op with special dummy operations */504 list_for_each_entry(mfile, &card->files_list, list) {505 /* it's critical part, use endless loop */506 /* we have no room to fail */507 mfile->disconnected_f_op = mfile->file->f_op;508 509 scoped_guard(spinlock, &shutdown_lock)510 list_add(&mfile->shutdown_list, &shutdown_files);511 512 mfile->file->f_op = &snd_shutdown_f_ops;513 fops_get(mfile->file->f_op);514 }515 }516 517#ifdef CONFIG_PM518 /* wake up sleepers here before other callbacks for avoiding potential519 * deadlocks with other locks (e.g. in kctls);520 * then this notifies the shutdown and sleepers would abort immediately521 */522 wake_up_all(&card->power_sleep);523#endif524 525 /* notify all connected devices about disconnection */526 /* at this point, they cannot respond to any calls except release() */527 528#if IS_ENABLED(CONFIG_SND_MIXER_OSS)529 if (snd_mixer_oss_notify_callback)530 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);531#endif532 533 /* notify all devices that we are disconnected */534 snd_device_disconnect_all(card);535 536 if (card->sync_irq > 0)537 synchronize_irq(card->sync_irq);538 539 snd_info_card_disconnect(card);540#ifdef CONFIG_SND_DEBUG541 debugfs_remove(card->debugfs_root);542 card->debugfs_root = NULL;543#endif544 545 if (card->registered) {546 device_del(&card->card_dev);547 card->registered = false;548 }549 550 /* disable fops (user space) operations for ALSA API */551 scoped_guard(mutex, &snd_card_mutex) {552 snd_cards[card->number] = NULL;553 clear_bit(card->number, snd_cards_lock);554 }555 556 snd_power_sync_ref(card);557}558EXPORT_SYMBOL(snd_card_disconnect);559 560/**561 * snd_card_disconnect_sync - disconnect card and wait until files get closed562 * @card: card object to disconnect563 *564 * This calls snd_card_disconnect() for disconnecting all belonging components565 * and waits until all pending files get closed.566 * It assures that all accesses from user-space finished so that the driver567 * can release its resources gracefully.568 */569void snd_card_disconnect_sync(struct snd_card *card)570{571 snd_card_disconnect(card);572 573 guard(spinlock_irq)(&card->files_lock);574 wait_event_lock_irq(card->remove_sleep,575 list_empty(&card->files_list),576 card->files_lock);577}578EXPORT_SYMBOL_GPL(snd_card_disconnect_sync);579 580static int snd_card_do_free(struct snd_card *card)581{582 card->releasing = true;583#if IS_ENABLED(CONFIG_SND_MIXER_OSS)584 if (snd_mixer_oss_notify_callback)585 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);586#endif587 snd_device_free_all(card);588 if (card->private_free)589 card->private_free(card);590 if (snd_info_card_free(card) < 0) {591 dev_warn(card->dev, "unable to free card info\n");592 /* Not fatal error */593 }594 if (card->release_completion)595 complete(card->release_completion);596 if (!card->managed)597 kfree(card);598 return 0;599}600 601/**602 * snd_card_free_when_closed - Disconnect the card, free it later eventually603 * @card: soundcard structure604 *605 * Unlike snd_card_free(), this function doesn't try to release the card606 * resource immediately, but tries to disconnect at first. When the card607 * is still in use, the function returns before freeing the resources.608 * The card resources will be freed when the refcount gets to zero.609 *610 * Return: zero if successful, or a negative error code611 */612void snd_card_free_when_closed(struct snd_card *card)613{614 if (!card)615 return;616 617 snd_card_disconnect(card);618 put_device(&card->card_dev);619 return;620}621EXPORT_SYMBOL(snd_card_free_when_closed);622 623/**624 * snd_card_free - frees given soundcard structure625 * @card: soundcard structure626 *627 * This function releases the soundcard structure and the all assigned628 * devices automatically. That is, you don't have to release the devices629 * by yourself.630 *631 * This function waits until the all resources are properly released.632 *633 * Return: Zero. Frees all associated devices and frees the control634 * interface associated to given soundcard.635 */636void snd_card_free(struct snd_card *card)637{638 DECLARE_COMPLETION_ONSTACK(released);639 640 /* The call of snd_card_free() is allowed from various code paths;641 * a manual call from the driver and the call via devres_free, and642 * we need to avoid double-free. Moreover, the release via devres643 * may call snd_card_free() twice due to its nature, we need to have644 * the check here at the beginning.645 */646 if (card->releasing)647 return;648 649 card->release_completion = &released;650 snd_card_free_when_closed(card);651 652 /* wait, until all devices are ready for the free operation */653 wait_for_completion(&released);654}655EXPORT_SYMBOL(snd_card_free);656 657/* check, if the character is in the valid ASCII range */658static inline bool safe_ascii_char(char c)659{660 return isascii(c) && isalnum(c);661}662 663/* retrieve the last word of shortname or longname */664static const char *retrieve_id_from_card_name(const char *name)665{666 const char *spos = name;667 668 while (*name) {669 if (isspace(*name) && safe_ascii_char(name[1]))670 spos = name + 1;671 name++;672 }673 return spos;674}675 676/* return true if the given id string doesn't conflict any other card ids */677static bool card_id_ok(struct snd_card *card, const char *id)678{679 int i;680 if (!snd_info_check_reserved_words(id))681 return false;682 for (i = 0; i < snd_ecards_limit; i++) {683 if (snd_cards[i] && snd_cards[i] != card &&684 !strcmp(snd_cards[i]->id, id))685 return false;686 }687 return true;688}689 690/* copy to card->id only with valid letters from nid */691static void copy_valid_id_string(struct snd_card *card, const char *src,692 const char *nid)693{694 char *id = card->id;695 696 while (*nid && !safe_ascii_char(*nid))697 nid++;698 if (isdigit(*nid))699 *id++ = isalpha(*src) ? *src : 'D';700 while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {701 if (safe_ascii_char(*nid))702 *id++ = *nid;703 nid++;704 }705 *id = 0;706}707 708/* Set card->id from the given string709 * If the string conflicts with other ids, add a suffix to make it unique.710 */711static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,712 const char *nid)713{714 int len, loops;715 bool is_default = false;716 char *id;717 718 copy_valid_id_string(card, src, nid);719 id = card->id;720 721 again:722 /* use "Default" for obviously invalid strings723 * ("card" conflicts with proc directories)724 */725 if (!*id || !strncmp(id, "card", 4)) {726 strcpy(id, "Default");727 is_default = true;728 }729 730 len = strlen(id);731 for (loops = 0; loops < SNDRV_CARDS; loops++) {732 char *spos;733 char sfxstr[5]; /* "_012" */734 int sfxlen;735 736 if (card_id_ok(card, id))737 return; /* OK */738 739 /* Add _XYZ suffix */740 sprintf(sfxstr, "_%X", loops + 1);741 sfxlen = strlen(sfxstr);742 if (len + sfxlen >= sizeof(card->id))743 spos = id + sizeof(card->id) - sfxlen - 1;744 else745 spos = id + len;746 strcpy(spos, sfxstr);747 }748 /* fallback to the default id */749 if (!is_default) {750 *id = 0;751 goto again;752 }753 /* last resort... */754 dev_err(card->dev, "unable to set card id (%s)\n", id);755 if (card->proc_root->name)756 strscpy(card->id, card->proc_root->name, sizeof(card->id));757}758 759/**760 * snd_card_set_id - set card identification name761 * @card: soundcard structure762 * @nid: new identification string763 *764 * This function sets the card identification and checks for name765 * collisions.766 */767void snd_card_set_id(struct snd_card *card, const char *nid)768{769 /* check if user specified own card->id */770 if (card->id[0] != '\0')771 return;772 guard(mutex)(&snd_card_mutex);773 snd_card_set_id_no_lock(card, nid, nid);774}775EXPORT_SYMBOL(snd_card_set_id);776 777static ssize_t id_show(struct device *dev,778 struct device_attribute *attr, char *buf)779{780 struct snd_card *card = container_of(dev, struct snd_card, card_dev);781 return sysfs_emit(buf, "%s\n", card->id);782}783 784static ssize_t id_store(struct device *dev, struct device_attribute *attr,785 const char *buf, size_t count)786{787 struct snd_card *card = container_of(dev, struct snd_card, card_dev);788 char buf1[sizeof(card->id)];789 size_t copy = count > sizeof(card->id) - 1 ?790 sizeof(card->id) - 1 : count;791 size_t idx;792 int c;793 794 for (idx = 0; idx < copy; idx++) {795 c = buf[idx];796 if (!safe_ascii_char(c) && c != '_' && c != '-')797 return -EINVAL;798 }799 memcpy(buf1, buf, copy);800 buf1[copy] = '\0';801 guard(mutex)(&snd_card_mutex);802 if (!card_id_ok(NULL, buf1))803 return -EEXIST;804 strcpy(card->id, buf1);805 snd_info_card_id_change(card);806 807 return count;808}809 810static DEVICE_ATTR_RW(id);811 812static ssize_t number_show(struct device *dev,813 struct device_attribute *attr, char *buf)814{815 struct snd_card *card = container_of(dev, struct snd_card, card_dev);816 return sysfs_emit(buf, "%i\n", card->number);817}818 819static DEVICE_ATTR_RO(number);820 821static struct attribute *card_dev_attrs[] = {822 &dev_attr_id.attr,823 &dev_attr_number.attr,824 NULL825};826 827static const struct attribute_group card_dev_attr_group = {828 .attrs = card_dev_attrs,829};830 831/**832 * snd_card_add_dev_attr - Append a new sysfs attribute group to card833 * @card: card instance834 * @group: attribute group to append835 *836 * Return: zero if successful, or a negative error code837 */838int snd_card_add_dev_attr(struct snd_card *card,839 const struct attribute_group *group)840{841 int i;842 843 /* loop for (arraysize-1) here to keep NULL at the last entry */844 for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) {845 if (!card->dev_groups[i]) {846 card->dev_groups[i] = group;847 return 0;848 }849 }850 851 dev_err(card->dev, "Too many groups assigned\n");852 return -ENOSPC;853}854EXPORT_SYMBOL_GPL(snd_card_add_dev_attr);855 856static void trigger_card_free(void *data)857{858 snd_card_free(data);859}860 861/**862 * snd_card_register - register the soundcard863 * @card: soundcard structure864 *865 * This function registers all the devices assigned to the soundcard.866 * Until calling this, the ALSA control interface is blocked from the867 * external accesses. Thus, you should call this function at the end868 * of the initialization of the card.869 *870 * Return: Zero otherwise a negative error code if the registration failed.871 */872int snd_card_register(struct snd_card *card)873{874 int err;875 876 if (snd_BUG_ON(!card))877 return -EINVAL;878 879 if (!card->registered) {880 err = device_add(&card->card_dev);881 if (err < 0)882 return err;883 card->registered = true;884 } else {885 if (card->managed)886 devm_remove_action(card->dev, trigger_card_free, card);887 }888 889 if (card->managed) {890 err = devm_add_action(card->dev, trigger_card_free, card);891 if (err < 0)892 return err;893 }894 895 err = snd_device_register_all(card);896 if (err < 0)897 return err;898 scoped_guard(mutex, &snd_card_mutex) {899 if (snd_cards[card->number]) {900 /* already registered */901 return snd_info_card_register(card); /* register pending info */902 }903 if (*card->id) {904 /* make a unique id name from the given string */905 char tmpid[sizeof(card->id)];906 907 memcpy(tmpid, card->id, sizeof(card->id));908 snd_card_set_id_no_lock(card, tmpid, tmpid);909 } else {910 /* create an id from either shortname or longname */911 const char *src;912 913 src = *card->shortname ? card->shortname : card->longname;914 snd_card_set_id_no_lock(card, src,915 retrieve_id_from_card_name(src));916 }917 snd_cards[card->number] = card;918 }919 err = snd_info_card_register(card);920 if (err < 0)921 return err;922 923#if IS_ENABLED(CONFIG_SND_MIXER_OSS)924 if (snd_mixer_oss_notify_callback)925 snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);926#endif927 return 0;928}929EXPORT_SYMBOL(snd_card_register);930 931#ifdef CONFIG_SND_PROC_FS932static void snd_card_info_read(struct snd_info_entry *entry,933 struct snd_info_buffer *buffer)934{935 int idx, count;936 struct snd_card *card;937 938 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {939 guard(mutex)(&snd_card_mutex);940 card = snd_cards[idx];941 if (card) {942 count++;943 snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n",944 idx,945 card->id,946 card->driver,947 card->shortname);948 snd_iprintf(buffer, " %s\n",949 card->longname);950 }951 }952 if (!count)953 snd_iprintf(buffer, "--- no soundcards ---\n");954}955 956#ifdef CONFIG_SND_OSSEMUL957void snd_card_info_read_oss(struct snd_info_buffer *buffer)958{959 int idx, count;960 struct snd_card *card;961 962 for (idx = count = 0; idx < SNDRV_CARDS; idx++) {963 guard(mutex)(&snd_card_mutex);964 card = snd_cards[idx];965 if (card) {966 count++;967 snd_iprintf(buffer, "%s\n", card->longname);968 }969 }970 if (!count) {971 snd_iprintf(buffer, "--- no soundcards ---\n");972 }973}974 975#endif976 977#ifdef CONFIG_MODULES978static void snd_card_module_info_read(struct snd_info_entry *entry,979 struct snd_info_buffer *buffer)980{981 int idx;982 struct snd_card *card;983 984 for (idx = 0; idx < SNDRV_CARDS; idx++) {985 guard(mutex)(&snd_card_mutex);986 card = snd_cards[idx];987 if (card)988 snd_iprintf(buffer, "%2i %s\n",989 idx, card->module->name);990 }991}992#endif993 994int __init snd_card_info_init(void)995{996 struct snd_info_entry *entry;997 998 entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);999 if (! entry)1000 return -ENOMEM;1001 entry->c.text.read = snd_card_info_read;1002 if (snd_info_register(entry) < 0)1003 return -ENOMEM; /* freed in error path */1004 1005#ifdef CONFIG_MODULES1006 entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);1007 if (!entry)1008 return -ENOMEM;1009 entry->c.text.read = snd_card_module_info_read;1010 if (snd_info_register(entry) < 0)1011 return -ENOMEM; /* freed in error path */1012#endif1013 1014 return 0;1015}1016#endif /* CONFIG_SND_PROC_FS */1017 1018/**1019 * snd_component_add - add a component string1020 * @card: soundcard structure1021 * @component: the component id string1022 *1023 * This function adds the component id string to the supported list.1024 * The component can be referred from the alsa-lib.1025 *1026 * Return: Zero otherwise a negative error code.1027 */1028 1029int snd_component_add(struct snd_card *card, const char *component)1030{1031 char *ptr;1032 int len = strlen(component);1033 1034 ptr = strstr(card->components, component);1035 if (ptr != NULL) {1036 if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */1037 return 1;1038 }1039 if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {1040 snd_BUG();1041 return -ENOMEM;1042 }1043 if (card->components[0] != '\0')1044 strcat(card->components, " ");1045 strcat(card->components, component);1046 return 0;1047}1048EXPORT_SYMBOL(snd_component_add);1049 1050/**1051 * snd_card_file_add - add the file to the file list of the card1052 * @card: soundcard structure1053 * @file: file pointer1054 *1055 * This function adds the file to the file linked-list of the card.1056 * This linked-list is used to keep tracking the connection state,1057 * and to avoid the release of busy resources by hotplug.1058 *1059 * Return: zero or a negative error code.1060 */1061int snd_card_file_add(struct snd_card *card, struct file *file)1062{1063 struct snd_monitor_file *mfile;1064 1065 mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);1066 if (mfile == NULL)1067 return -ENOMEM;1068 mfile->file = file;1069 mfile->disconnected_f_op = NULL;1070 INIT_LIST_HEAD(&mfile->shutdown_list);1071 guard(spinlock)(&card->files_lock);1072 if (card->shutdown) {1073 kfree(mfile);1074 return -ENODEV;1075 }1076 list_add(&mfile->list, &card->files_list);1077 get_device(&card->card_dev);1078 return 0;1079}1080EXPORT_SYMBOL(snd_card_file_add);1081 1082/**1083 * snd_card_file_remove - remove the file from the file list1084 * @card: soundcard structure1085 * @file: file pointer1086 *1087 * This function removes the file formerly added to the card via1088 * snd_card_file_add() function.1089 * If all files are removed and snd_card_free_when_closed() was1090 * called beforehand, it processes the pending release of1091 * resources.1092 *1093 * Return: Zero or a negative error code.1094 */1095int snd_card_file_remove(struct snd_card *card, struct file *file)1096{1097 struct snd_monitor_file *mfile, *found = NULL;1098 1099 scoped_guard(spinlock, &card->files_lock) {1100 list_for_each_entry(mfile, &card->files_list, list) {1101 if (mfile->file == file) {1102 list_del(&mfile->list);1103 scoped_guard(spinlock, &shutdown_lock)1104 list_del(&mfile->shutdown_list);1105 if (mfile->disconnected_f_op)1106 fops_put(mfile->disconnected_f_op);1107 found = mfile;1108 break;1109 }1110 }1111 if (list_empty(&card->files_list))1112 wake_up_all(&card->remove_sleep);1113 }1114 if (!found) {1115 dev_err(card->dev, "card file remove problem (%p)\n", file);1116 return -ENOENT;1117 }1118 kfree(found);1119 put_device(&card->card_dev);1120 return 0;1121}1122EXPORT_SYMBOL(snd_card_file_remove);1123 1124#ifdef CONFIG_PM1125/**1126 * snd_power_ref_and_wait - wait until the card gets powered up1127 * @card: soundcard structure1128 *1129 * Take the power_ref reference count of the given card, and1130 * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.1131 * The refcount is down again while sleeping until power-up, hence this1132 * function can be used for syncing the floating control ops accesses,1133 * typically around calling control ops.1134 *1135 * The caller needs to pull down the refcount via snd_power_unref() later1136 * no matter whether the error is returned from this function or not.1137 *1138 * Return: Zero if successful, or a negative error code.1139 */1140int snd_power_ref_and_wait(struct snd_card *card)1141{1142 snd_power_ref(card);1143 if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0)1144 return 0;1145 wait_event_cmd(card->power_sleep,1146 card->shutdown ||1147 snd_power_get_state(card) == SNDRV_CTL_POWER_D0,1148 snd_power_unref(card), snd_power_ref(card));1149 return card->shutdown ? -ENODEV : 0;1150}1151EXPORT_SYMBOL_GPL(snd_power_ref_and_wait);1152 1153/**1154 * snd_power_wait - wait until the card gets powered up (old form)1155 * @card: soundcard structure1156 *1157 * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state.1158 *1159 * Return: Zero if successful, or a negative error code.1160 */1161int snd_power_wait(struct snd_card *card)1162{1163 int ret;1164 1165 ret = snd_power_ref_and_wait(card);1166 snd_power_unref(card);1167 return ret;1168}1169EXPORT_SYMBOL(snd_power_wait);1170#endif /* CONFIG_PM */1171