diff options
Diffstat (limited to 'sound/core/init.c')
| -rw-r--r-- | sound/core/init.c | 1184 |
1 files changed, 1184 insertions, 0 deletions
diff --git a/sound/core/init.c b/sound/core/init.c new file mode 100644 index 000000000..5377f94eb --- /dev/null +++ b/sound/core/init.c @@ -0,0 +1,1184 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Initialization routines + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/file.h> +#include <linux/slab.h> +#include <linux/time.h> +#include <linux/ctype.h> +#include <linux/pm.h> +#include <linux/debugfs.h> +#include <linux/completion.h> +#include <linux/interrupt.h> + +#include <sound/core.h> +#include <sound/control.h> +#include <sound/info.h> + +/* monitor files for graceful shutdown (hotplug) */ +struct snd_monitor_file { + struct file *file; + const struct file_operations *disconnected_f_op; + struct list_head shutdown_list; /* still need to shutdown */ + struct list_head list; /* link of monitor files */ +}; + +static DEFINE_SPINLOCK(shutdown_lock); +static LIST_HEAD(shutdown_files); + +static const struct file_operations snd_shutdown_f_ops; + +/* locked for registering/using */ +static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS); +static struct snd_card *snd_cards[SNDRV_CARDS]; + +static DEFINE_MUTEX(snd_card_mutex); + +static char *slots[SNDRV_CARDS]; +module_param_array(slots, charp, NULL, 0444); +MODULE_PARM_DESC(slots, "Module names assigned to the slots."); + +/* return non-zero if the given index is reserved for the given + * module via slots option + */ +static int module_slot_match(struct module *module, int idx) +{ + int match = 1; +#ifdef MODULE + const char *s1, *s2; + + if (!module || !*module->name || !slots[idx]) + return 0; + + s1 = module->name; + s2 = slots[idx]; + if (*s2 == '!') { + match = 0; /* negative match */ + s2++; + } + /* compare module name strings + * hyphens are handled as equivalent with underscore + */ + for (;;) { + char c1 = *s1++; + char c2 = *s2++; + if (c1 == '-') + c1 = '_'; + if (c2 == '-') + c2 = '_'; + if (c1 != c2) + return !match; + if (!c1) + break; + } +#endif /* MODULE */ + return match; +} + +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) +int (*snd_mixer_oss_notify_callback)(struct snd_card *card, int free_flag); +EXPORT_SYMBOL(snd_mixer_oss_notify_callback); +#endif + +static int check_empty_slot(struct module *module, int slot) +{ + return !slots[slot] || !*slots[slot]; +} + +/* return an empty slot number (>= 0) found in the given bitmask @mask. + * @mask == -1 == 0xffffffff means: take any free slot up to 32 + * when no slot is available, return the original @mask as is. + */ +static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int), + struct module *module) +{ + int slot; + + for (slot = 0; slot < SNDRV_CARDS; slot++) { + if (slot < 32 && !(mask & (1U << slot))) + continue; + if (!test_bit(slot, snd_cards_lock)) { + if (check(module, slot)) + return slot; /* found */ + } + } + return mask; /* unchanged */ +} + +/* the default release callback set in snd_device_initialize() below; + * this is just NOP for now, as almost all jobs are already done in + * dev_free callback of snd_device chain instead. + */ +static void default_release(struct device *dev) +{ +} + +/** + * snd_device_initialize - Initialize struct device for sound devices + * @dev: device to initialize + * @card: card to assign, optional + */ +void snd_device_initialize(struct device *dev, struct snd_card *card) +{ + device_initialize(dev); + if (card) + dev->parent = &card->card_dev; + dev->class = sound_class; + dev->release = default_release; +} +EXPORT_SYMBOL_GPL(snd_device_initialize); + +static int snd_card_init(struct snd_card *card, struct device *parent, + int idx, const char *xid, struct module *module, + size_t extra_size); +static int snd_card_do_free(struct snd_card *card); +static const struct attribute_group card_dev_attr_group; + +static void release_card_device(struct device *dev) +{ + snd_card_do_free(dev_to_snd_card(dev)); +} + +/** + * snd_card_new - create and initialize a soundcard structure + * @parent: the parent device object + * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] + * @xid: card identification (ASCII string) + * @module: top level module for locking + * @extra_size: allocate this extra size after the main soundcard structure + * @card_ret: the pointer to store the created card instance + * + * The function allocates snd_card instance via kzalloc with the given + * space for the driver to use freely. The allocated struct is stored + * in the given card_ret pointer. + * + * Return: Zero if successful or a negative error code. + */ +int snd_card_new(struct device *parent, int idx, const char *xid, + struct module *module, int extra_size, + struct snd_card **card_ret) +{ + struct snd_card *card; + int err; + + if (snd_BUG_ON(!card_ret)) + return -EINVAL; + *card_ret = NULL; + + if (extra_size < 0) + extra_size = 0; + card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL); + if (!card) + return -ENOMEM; + + err = snd_card_init(card, parent, idx, xid, module, extra_size); + if (err < 0) + return err; /* card is freed by error handler */ + + *card_ret = card; + return 0; +} +EXPORT_SYMBOL(snd_card_new); + +static void __snd_card_release(struct device *dev, void *data) +{ + snd_card_free(data); +} + +/** + * snd_devm_card_new - managed snd_card object creation + * @parent: the parent device object + * @idx: card index (address) [0 ... (SNDRV_CARDS-1)] + * @xid: card identification (ASCII string) + * @module: top level module for locking + * @extra_size: allocate this extra size after the main soundcard structure + * @card_ret: the pointer to store the created card instance + * + * This function works like snd_card_new() but manages the allocated resource + * via devres, i.e. you don't need to free explicitly. + * + * When a snd_card object is created with this function and registered via + * snd_card_register(), the very first devres action to call snd_card_free() + * is added automatically. In that way, the resource disconnection is assured + * at first, then released in the expected order. + * + * If an error happens at the probe before snd_card_register() is called and + * there have been other devres resources, you'd need to free the card manually + * via snd_card_free() call in the error; otherwise it may lead to UAF due to + * devres call orders. You can use snd_card_free_on_error() helper for + * handling it more easily. + * + * Return: zero if successful, or a negative error code + */ +int snd_devm_card_new(struct device *parent, int idx, const char *xid, + struct module *module, size_t extra_size, + struct snd_card **card_ret) +{ + struct snd_card *card; + int err; + + *card_ret = NULL; + card = devres_alloc(__snd_card_release, sizeof(*card) + extra_size, + GFP_KERNEL); + if (!card) + return -ENOMEM; + card->managed = true; + err = snd_card_init(card, parent, idx, xid, module, extra_size); + if (err < 0) { + devres_free(card); /* in managed mode, we need to free manually */ + return err; + } + + devres_add(parent, card); + *card_ret = card; + return 0; +} +EXPORT_SYMBOL_GPL(snd_devm_card_new); + +/** + * snd_card_free_on_error - a small helper for handling devm probe errors + * @dev: the managed device object + * @ret: the return code from the probe callback + * + * This function handles the explicit snd_card_free() call at the error from + * the probe callback. It's just a small helper for simplifying the error + * handling with the managed devices. + * + * Return: zero if successful, or a negative error code + */ +int snd_card_free_on_error(struct device *dev, int ret) +{ + struct snd_card *card; + + if (!ret) + return 0; + card = devres_find(dev, __snd_card_release, NULL, NULL); + if (card) + snd_card_free(card); + return ret; +} +EXPORT_SYMBOL_GPL(snd_card_free_on_error); + +static int snd_card_init(struct snd_card *card, struct device *parent, + int idx, const char *xid, struct module *module, + size_t extra_size) +{ + int err; +#ifdef CONFIG_SND_DEBUG + char name[8]; +#endif + + if (extra_size > 0) + card->private_data = (char *)card + sizeof(struct snd_card); + if (xid) + strscpy(card->id, xid, sizeof(card->id)); + err = 0; + mutex_lock(&snd_card_mutex); + if (idx < 0) /* first check the matching module-name slot */ + idx = get_slot_from_bitmask(idx, module_slot_match, module); + if (idx < 0) /* if not matched, assign an empty slot */ + idx = get_slot_from_bitmask(idx, check_empty_slot, module); + if (idx < 0) + err = -ENODEV; + else if (idx < snd_ecards_limit) { + if (test_bit(idx, snd_cards_lock)) + err = -EBUSY; /* invalid */ + } else if (idx >= SNDRV_CARDS) + err = -ENODEV; + if (err < 0) { + mutex_unlock(&snd_card_mutex); + dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n", + idx, snd_ecards_limit - 1, err); + if (!card->managed) + kfree(card); /* manually free here, as no destructor called */ + return err; + } + set_bit(idx, snd_cards_lock); /* lock it */ + if (idx >= snd_ecards_limit) + snd_ecards_limit = idx + 1; /* increase the limit */ + mutex_unlock(&snd_card_mutex); + card->dev = parent; + card->number = idx; +#ifdef MODULE + WARN_ON(!module); + card->module = module; +#endif + INIT_LIST_HEAD(&card->devices); + init_rwsem(&card->controls_rwsem); + rwlock_init(&card->ctl_files_rwlock); + INIT_LIST_HEAD(&card->controls); + INIT_LIST_HEAD(&card->ctl_files); +#ifdef CONFIG_SND_CTL_FAST_LOOKUP + xa_init(&card->ctl_numids); + xa_init(&card->ctl_hash); +#endif + spin_lock_init(&card->files_lock); + INIT_LIST_HEAD(&card->files_list); + mutex_init(&card->memory_mutex); +#ifdef CONFIG_PM + init_waitqueue_head(&card->power_sleep); + init_waitqueue_head(&card->power_ref_sleep); + atomic_set(&card->power_ref, 0); +#endif + init_waitqueue_head(&card->remove_sleep); + card->sync_irq = -1; + + device_initialize(&card->card_dev); + card->card_dev.parent = parent; + card->card_dev.class = sound_class; + card->card_dev.release = release_card_device; + card->card_dev.groups = card->dev_groups; + card->dev_groups[0] = &card_dev_attr_group; + err = kobject_set_name(&card->card_dev.kobj, "card%d", idx); + if (err < 0) + goto __error; + + snprintf(card->irq_descr, sizeof(card->irq_descr), "%s:%s", + dev_driver_string(card->dev), dev_name(&card->card_dev)); + + /* the control interface cannot be accessed from the user space until */ + /* snd_cards_bitmask and snd_cards are set with snd_card_register */ + err = snd_ctl_create(card); + if (err < 0) { + dev_err(parent, "unable to register control minors\n"); + goto __error; + } + err = snd_info_card_create(card); + if (err < 0) { + dev_err(parent, "unable to create card info\n"); + goto __error_ctl; + } + +#ifdef CONFIG_SND_DEBUG + sprintf(name, "card%d", idx); + card->debugfs_root = debugfs_create_dir(name, sound_debugfs_root); +#endif + return 0; + + __error_ctl: + snd_device_free_all(card); + __error: + put_device(&card->card_dev); + return err; +} + +/** + * snd_card_ref - Get the card object from the index + * @idx: the card index + * + * Returns a card object corresponding to the given index or NULL if not found. + * Release the object via snd_card_unref(). + * + * Return: a card object or NULL + */ +struct snd_card *snd_card_ref(int idx) +{ + struct snd_card *card; + + mutex_lock(&snd_card_mutex); + card = snd_cards[idx]; + if (card) + get_device(&card->card_dev); + mutex_unlock(&snd_card_mutex); + return card; +} +EXPORT_SYMBOL_GPL(snd_card_ref); + +/* return non-zero if a card is already locked */ +int snd_card_locked(int card) +{ + int locked; + + mutex_lock(&snd_card_mutex); + locked = test_bit(card, snd_cards_lock); + mutex_unlock(&snd_card_mutex); + return locked; +} + +static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig) +{ + return -ENODEV; +} + +static ssize_t snd_disconnect_read(struct file *file, char __user *buf, + size_t count, loff_t *offset) +{ + return -ENODEV; +} + +static ssize_t snd_disconnect_write(struct file *file, const char __user *buf, + size_t count, loff_t *offset) +{ + return -ENODEV; +} + +static int snd_disconnect_release(struct inode *inode, struct file *file) +{ + struct snd_monitor_file *df = NULL, *_df; + + spin_lock(&shutdown_lock); + list_for_each_entry(_df, &shutdown_files, shutdown_list) { + if (_df->file == file) { + df = _df; + list_del_init(&df->shutdown_list); + break; + } + } + spin_unlock(&shutdown_lock); + + if (likely(df)) { + if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync) + df->disconnected_f_op->fasync(-1, file, 0); + return df->disconnected_f_op->release(inode, file); + } + + panic("%s(%p, %p) failed!", __func__, inode, file); +} + +static __poll_t snd_disconnect_poll(struct file * file, poll_table * wait) +{ + return EPOLLERR | EPOLLNVAL; +} + +static long snd_disconnect_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + return -ENODEV; +} + +static int snd_disconnect_mmap(struct file *file, struct vm_area_struct *vma) +{ + return -ENODEV; +} + +static int snd_disconnect_fasync(int fd, struct file *file, int on) +{ + return -ENODEV; +} + +static const struct file_operations snd_shutdown_f_ops = +{ + .owner = THIS_MODULE, + .llseek = snd_disconnect_llseek, + .read = snd_disconnect_read, + .write = snd_disconnect_write, + .release = snd_disconnect_release, + .poll = snd_disconnect_poll, + .unlocked_ioctl = snd_disconnect_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = snd_disconnect_ioctl, +#endif + .mmap = snd_disconnect_mmap, + .fasync = snd_disconnect_fasync +}; + +/** + * snd_card_disconnect - disconnect all APIs from the file-operations (user space) + * @card: soundcard structure + * + * Disconnects all APIs from the file-operations (user space). + * + * Return: Zero, otherwise a negative error code. + * + * Note: The current implementation replaces all active file->f_op with special + * dummy file operations (they do nothing except release). + */ +int snd_card_disconnect(struct snd_card *card) +{ + struct snd_monitor_file *mfile; + + if (!card) + return -EINVAL; + + spin_lock(&card->files_lock); + if (card->shutdown) { + spin_unlock(&card->files_lock); + return 0; + } + card->shutdown = 1; + + /* replace file->f_op with special dummy operations */ + list_for_each_entry(mfile, &card->files_list, list) { + /* it's critical part, use endless loop */ + /* we have no room to fail */ + mfile->disconnected_f_op = mfile->file->f_op; + + spin_lock(&shutdown_lock); + list_add(&mfile->shutdown_list, &shutdown_files); + spin_unlock(&shutdown_lock); + + mfile->file->f_op = &snd_shutdown_f_ops; + fops_get(mfile->file->f_op); + } + spin_unlock(&card->files_lock); + + /* notify all connected devices about disconnection */ + /* at this point, they cannot respond to any calls except release() */ + +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) + if (snd_mixer_oss_notify_callback) + snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT); +#endif + + /* notify all devices that we are disconnected */ + snd_device_disconnect_all(card); + + if (card->sync_irq > 0) + synchronize_irq(card->sync_irq); + + snd_info_card_disconnect(card); + if (card->registered) { + device_del(&card->card_dev); + card->registered = false; + } + + /* disable fops (user space) operations for ALSA API */ + mutex_lock(&snd_card_mutex); + snd_cards[card->number] = NULL; + clear_bit(card->number, snd_cards_lock); + mutex_unlock(&snd_card_mutex); + +#ifdef CONFIG_PM + wake_up(&card->power_sleep); + snd_power_sync_ref(card); +#endif + return 0; +} +EXPORT_SYMBOL(snd_card_disconnect); + +/** + * snd_card_disconnect_sync - disconnect card and wait until files get closed + * @card: card object to disconnect + * + * This calls snd_card_disconnect() for disconnecting all belonging components + * and waits until all pending files get closed. + * It assures that all accesses from user-space finished so that the driver + * can release its resources gracefully. + */ +void snd_card_disconnect_sync(struct snd_card *card) +{ + int err; + + err = snd_card_disconnect(card); + if (err < 0) { + dev_err(card->dev, + "snd_card_disconnect error (%d), skipping sync\n", + err); + return; + } + + spin_lock_irq(&card->files_lock); + wait_event_lock_irq(card->remove_sleep, + list_empty(&card->files_list), + card->files_lock); + spin_unlock_irq(&card->files_lock); +} +EXPORT_SYMBOL_GPL(snd_card_disconnect_sync); + +static int snd_card_do_free(struct snd_card *card) +{ + card->releasing = true; +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) + if (snd_mixer_oss_notify_callback) + snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE); +#endif + snd_device_free_all(card); + if (card->private_free) + card->private_free(card); + if (snd_info_card_free(card) < 0) { + dev_warn(card->dev, "unable to free card info\n"); + /* Not fatal error */ + } +#ifdef CONFIG_SND_DEBUG + debugfs_remove(card->debugfs_root); + card->debugfs_root = NULL; +#endif + if (card->release_completion) + complete(card->release_completion); + if (!card->managed) + kfree(card); + return 0; +} + +/** + * snd_card_free_when_closed - Disconnect the card, free it later eventually + * @card: soundcard structure + * + * Unlike snd_card_free(), this function doesn't try to release the card + * resource immediately, but tries to disconnect at first. When the card + * is still in use, the function returns before freeing the resources. + * The card resources will be freed when the refcount gets to zero. + * + * Return: zero if successful, or a negative error code + */ +int snd_card_free_when_closed(struct snd_card *card) +{ + int ret = snd_card_disconnect(card); + if (ret) + return ret; + put_device(&card->card_dev); + return 0; +} +EXPORT_SYMBOL(snd_card_free_when_closed); + +/** + * snd_card_free - frees given soundcard structure + * @card: soundcard structure + * + * This function releases the soundcard structure and the all assigned + * devices automatically. That is, you don't have to release the devices + * by yourself. + * + * This function waits until the all resources are properly released. + * + * Return: Zero. Frees all associated devices and frees the control + * interface associated to given soundcard. + */ +int snd_card_free(struct snd_card *card) +{ + DECLARE_COMPLETION_ONSTACK(released); + int ret; + + /* The call of snd_card_free() is allowed from various code paths; + * a manual call from the driver and the call via devres_free, and + * we need to avoid double-free. Moreover, the release via devres + * may call snd_card_free() twice due to its nature, we need to have + * the check here at the beginning. + */ + if (card->releasing) + return 0; + + card->release_completion = &released; + ret = snd_card_free_when_closed(card); + if (ret) + return ret; + /* wait, until all devices are ready for the free operation */ + wait_for_completion(&released); + + return 0; +} +EXPORT_SYMBOL(snd_card_free); + +/* retrieve the last word of shortname or longname */ +static const char *retrieve_id_from_card_name(const char *name) +{ + const char *spos = name; + + while (*name) { + if (isspace(*name) && isalnum(name[1])) + spos = name + 1; + name++; + } + return spos; +} + +/* return true if the given id string doesn't conflict any other card ids */ +static bool card_id_ok(struct snd_card *card, const char *id) +{ + int i; + if (!snd_info_check_reserved_words(id)) + return false; + for (i = 0; i < snd_ecards_limit; i++) { + if (snd_cards[i] && snd_cards[i] != card && + !strcmp(snd_cards[i]->id, id)) + return false; + } + return true; +} + +/* copy to card->id only with valid letters from nid */ +static void copy_valid_id_string(struct snd_card *card, const char *src, + const char *nid) +{ + char *id = card->id; + + while (*nid && !isalnum(*nid)) + nid++; + if (isdigit(*nid)) + *id++ = isalpha(*src) ? *src : 'D'; + while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) { + if (isalnum(*nid)) + *id++ = *nid; + nid++; + } + *id = 0; +} + +/* Set card->id from the given string + * If the string conflicts with other ids, add a suffix to make it unique. + */ +static void snd_card_set_id_no_lock(struct snd_card *card, const char *src, + const char *nid) +{ + int len, loops; + bool is_default = false; + char *id; + + copy_valid_id_string(card, src, nid); + id = card->id; + + again: + /* use "Default" for obviously invalid strings + * ("card" conflicts with proc directories) + */ + if (!*id || !strncmp(id, "card", 4)) { + strcpy(id, "Default"); + is_default = true; + } + + len = strlen(id); + for (loops = 0; loops < SNDRV_CARDS; loops++) { + char *spos; + char sfxstr[5]; /* "_012" */ + int sfxlen; + + if (card_id_ok(card, id)) + return; /* OK */ + + /* Add _XYZ suffix */ + sprintf(sfxstr, "_%X", loops + 1); + sfxlen = strlen(sfxstr); + if (len + sfxlen >= sizeof(card->id)) + spos = id + sizeof(card->id) - sfxlen - 1; + else + spos = id + len; + strcpy(spos, sfxstr); + } + /* fallback to the default id */ + if (!is_default) { + *id = 0; + goto again; + } + /* last resort... */ + dev_err(card->dev, "unable to set card id (%s)\n", id); + if (card->proc_root->name) + strscpy(card->id, card->proc_root->name, sizeof(card->id)); +} + +/** + * snd_card_set_id - set card identification name + * @card: soundcard structure + * @nid: new identification string + * + * This function sets the card identification and checks for name + * collisions. + */ +void snd_card_set_id(struct snd_card *card, const char *nid) +{ + /* check if user specified own card->id */ + if (card->id[0] != '\0') + return; + mutex_lock(&snd_card_mutex); + snd_card_set_id_no_lock(card, nid, nid); + mutex_unlock(&snd_card_mutex); +} +EXPORT_SYMBOL(snd_card_set_id); + +static ssize_t id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = container_of(dev, struct snd_card, card_dev); + return sysfs_emit(buf, "%s\n", card->id); +} + +static ssize_t id_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct snd_card *card = container_of(dev, struct snd_card, card_dev); + char buf1[sizeof(card->id)]; + size_t copy = count > sizeof(card->id) - 1 ? + sizeof(card->id) - 1 : count; + size_t idx; + int c; + + for (idx = 0; idx < copy; idx++) { + c = buf[idx]; + if (!isalnum(c) && c != '_' && c != '-') + return -EINVAL; + } + memcpy(buf1, buf, copy); + buf1[copy] = '\0'; + mutex_lock(&snd_card_mutex); + if (!card_id_ok(NULL, buf1)) { + mutex_unlock(&snd_card_mutex); + return -EEXIST; + } + strcpy(card->id, buf1); + snd_info_card_id_change(card); + mutex_unlock(&snd_card_mutex); + + return count; +} + +static DEVICE_ATTR_RW(id); + +static ssize_t number_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = container_of(dev, struct snd_card, card_dev); + return sysfs_emit(buf, "%i\n", card->number); +} + +static DEVICE_ATTR_RO(number); + +static struct attribute *card_dev_attrs[] = { + &dev_attr_id.attr, + &dev_attr_number.attr, + NULL +}; + +static const struct attribute_group card_dev_attr_group = { + .attrs = card_dev_attrs, +}; + +/** + * snd_card_add_dev_attr - Append a new sysfs attribute group to card + * @card: card instance + * @group: attribute group to append + * + * Return: zero if successful, or a negative error code + */ +int snd_card_add_dev_attr(struct snd_card *card, + const struct attribute_group *group) +{ + int i; + + /* loop for (arraysize-1) here to keep NULL at the last entry */ + for (i = 0; i < ARRAY_SIZE(card->dev_groups) - 1; i++) { + if (!card->dev_groups[i]) { + card->dev_groups[i] = group; + return 0; + } + } + + dev_err(card->dev, "Too many groups assigned\n"); + return -ENOSPC; +} +EXPORT_SYMBOL_GPL(snd_card_add_dev_attr); + +static void trigger_card_free(void *data) +{ + snd_card_free(data); +} + +/** + * snd_card_register - register the soundcard + * @card: soundcard structure + * + * This function registers all the devices assigned to the soundcard. + * Until calling this, the ALSA control interface is blocked from the + * external accesses. Thus, you should call this function at the end + * of the initialization of the card. + * + * Return: Zero otherwise a negative error code if the registration failed. + */ +int snd_card_register(struct snd_card *card) +{ + int err; + + if (snd_BUG_ON(!card)) + return -EINVAL; + + if (!card->registered) { + err = device_add(&card->card_dev); + if (err < 0) + return err; + card->registered = true; + } else { + if (card->managed) + devm_remove_action(card->dev, trigger_card_free, card); + } + + if (card->managed) { + err = devm_add_action(card->dev, trigger_card_free, card); + if (err < 0) + return err; + } + + err = snd_device_register_all(card); + if (err < 0) + return err; + mutex_lock(&snd_card_mutex); + if (snd_cards[card->number]) { + /* already registered */ + mutex_unlock(&snd_card_mutex); + return snd_info_card_register(card); /* register pending info */ + } + if (*card->id) { + /* make a unique id name from the given string */ + char tmpid[sizeof(card->id)]; + memcpy(tmpid, card->id, sizeof(card->id)); + snd_card_set_id_no_lock(card, tmpid, tmpid); + } else { + /* create an id from either shortname or longname */ + const char *src; + src = *card->shortname ? card->shortname : card->longname; + snd_card_set_id_no_lock(card, src, + retrieve_id_from_card_name(src)); + } + snd_cards[card->number] = card; + mutex_unlock(&snd_card_mutex); + err = snd_info_card_register(card); + if (err < 0) + return err; + +#if IS_ENABLED(CONFIG_SND_MIXER_OSS) + if (snd_mixer_oss_notify_callback) + snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER); +#endif + return 0; +} +EXPORT_SYMBOL(snd_card_register); + +#ifdef CONFIG_SND_PROC_FS +static void snd_card_info_read(struct snd_info_entry *entry, + struct snd_info_buffer *buffer) +{ + int idx, count; + struct snd_card *card; + + for (idx = count = 0; idx < SNDRV_CARDS; idx++) { + mutex_lock(&snd_card_mutex); + card = snd_cards[idx]; + if (card) { + count++; + snd_iprintf(buffer, "%2i [%-15s]: %s - %s\n", + idx, + card->id, + card->driver, + card->shortname); + snd_iprintf(buffer, " %s\n", + card->longname); + } + mutex_unlock(&snd_card_mutex); + } + if (!count) + snd_iprintf(buffer, "--- no soundcards ---\n"); +} + +#ifdef CONFIG_SND_OSSEMUL +void snd_card_info_read_oss(struct snd_info_buffer *buffer) +{ + int idx, count; + struct snd_card *card; + + for (idx = count = 0; idx < SNDRV_CARDS; idx++) { + mutex_lock(&snd_card_mutex); + card = snd_cards[idx]; + if (card) { + count++; + snd_iprintf(buffer, "%s\n", card->longname); + } + mutex_unlock(&snd_card_mutex); + } + if (!count) { + snd_iprintf(buffer, "--- no soundcards ---\n"); + } +} + +#endif + +#ifdef MODULE +static void snd_card_module_info_read(struct snd_info_entry *entry, + struct snd_info_buffer *buffer) +{ + int idx; + struct snd_card *card; + + for (idx = 0; idx < SNDRV_CARDS; idx++) { + mutex_lock(&snd_card_mutex); + card = snd_cards[idx]; + if (card) + snd_iprintf(buffer, "%2i %s\n", + idx, card->module->name); + mutex_unlock(&snd_card_mutex); + } +} +#endif + +int __init snd_card_info_init(void) +{ + struct snd_info_entry *entry; + + entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL); + if (! entry) + return -ENOMEM; + entry->c.text.read = snd_card_info_read; + if (snd_info_register(entry) < 0) + return -ENOMEM; /* freed in error path */ + +#ifdef MODULE + entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL); + if (!entry) + return -ENOMEM; + entry->c.text.read = snd_card_module_info_read; + if (snd_info_register(entry) < 0) + return -ENOMEM; /* freed in error path */ +#endif + + return 0; +} +#endif /* CONFIG_SND_PROC_FS */ + +/** + * snd_component_add - add a component string + * @card: soundcard structure + * @component: the component id string + * + * This function adds the component id string to the supported list. + * The component can be referred from the alsa-lib. + * + * Return: Zero otherwise a negative error code. + */ + +int snd_component_add(struct snd_card *card, const char *component) +{ + char *ptr; + int len = strlen(component); + + ptr = strstr(card->components, component); + if (ptr != NULL) { + if (ptr[len] == '\0' || ptr[len] == ' ') /* already there */ + return 1; + } + if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) { + snd_BUG(); + return -ENOMEM; + } + if (card->components[0] != '\0') + strcat(card->components, " "); + strcat(card->components, component); + return 0; +} +EXPORT_SYMBOL(snd_component_add); + +/** + * snd_card_file_add - add the file to the file list of the card + * @card: soundcard structure + * @file: file pointer + * + * This function adds the file to the file linked-list of the card. + * This linked-list is used to keep tracking the connection state, + * and to avoid the release of busy resources by hotplug. + * + * Return: zero or a negative error code. + */ +int snd_card_file_add(struct snd_card *card, struct file *file) +{ + struct snd_monitor_file *mfile; + + mfile = kmalloc(sizeof(*mfile), GFP_KERNEL); + if (mfile == NULL) + return -ENOMEM; + mfile->file = file; + mfile->disconnected_f_op = NULL; + INIT_LIST_HEAD(&mfile->shutdown_list); + spin_lock(&card->files_lock); + if (card->shutdown) { + spin_unlock(&card->files_lock); + kfree(mfile); + return -ENODEV; + } + list_add(&mfile->list, &card->files_list); + get_device(&card->card_dev); + spin_unlock(&card->files_lock); + return 0; +} +EXPORT_SYMBOL(snd_card_file_add); + +/** + * snd_card_file_remove - remove the file from the file list + * @card: soundcard structure + * @file: file pointer + * + * This function removes the file formerly added to the card via + * snd_card_file_add() function. + * If all files are removed and snd_card_free_when_closed() was + * called beforehand, it processes the pending release of + * resources. + * + * Return: Zero or a negative error code. + */ +int snd_card_file_remove(struct snd_card *card, struct file *file) +{ + struct snd_monitor_file *mfile, *found = NULL; + + spin_lock(&card->files_lock); + list_for_each_entry(mfile, &card->files_list, list) { + if (mfile->file == file) { + list_del(&mfile->list); + spin_lock(&shutdown_lock); + list_del(&mfile->shutdown_list); + spin_unlock(&shutdown_lock); + if (mfile->disconnected_f_op) + fops_put(mfile->disconnected_f_op); + found = mfile; + break; + } + } + if (list_empty(&card->files_list)) + wake_up_all(&card->remove_sleep); + spin_unlock(&card->files_lock); + if (!found) { + dev_err(card->dev, "card file remove problem (%p)\n", file); + return -ENOENT; + } + kfree(found); + put_device(&card->card_dev); + return 0; +} +EXPORT_SYMBOL(snd_card_file_remove); + +#ifdef CONFIG_PM +/** + * snd_power_ref_and_wait - wait until the card gets powered up + * @card: soundcard structure + * + * Take the power_ref reference count of the given card, and + * wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. + * The refcount is down again while sleeping until power-up, hence this + * function can be used for syncing the floating control ops accesses, + * typically around calling control ops. + * + * The caller needs to pull down the refcount via snd_power_unref() later + * no matter whether the error is returned from this function or not. + * + * Return: Zero if successful, or a negative error code. + */ +int snd_power_ref_and_wait(struct snd_card *card) +{ + snd_power_ref(card); + if (snd_power_get_state(card) == SNDRV_CTL_POWER_D0) + return 0; + wait_event_cmd(card->power_sleep, + card->shutdown || + snd_power_get_state(card) == SNDRV_CTL_POWER_D0, + snd_power_unref(card), snd_power_ref(card)); + return card->shutdown ? -ENODEV : 0; +} +EXPORT_SYMBOL_GPL(snd_power_ref_and_wait); + +/** + * snd_power_wait - wait until the card gets powered up (old form) + * @card: soundcard structure + * + * Wait until the card gets powered up to SNDRV_CTL_POWER_D0 state. + * + * Return: Zero if successful, or a negative error code. + */ +int snd_power_wait(struct snd_card *card) +{ + int ret; + + ret = snd_power_ref_and_wait(card); + snd_power_unref(card); + return ret; +} +EXPORT_SYMBOL(snd_power_wait); +#endif /* CONFIG_PM */ |