UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity
OpenCloudOS-Kernel/sound/core/init.c

1019 lines
26 KiB
C
Raw Blame History

// 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/completion.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_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
*
* Creates and initializes a soundcard structure.
*
* 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;
if (extra_size > 0)
card->private_data = (char *)card + sizeof(struct snd_card);
if (xid)
strlcpy(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);
kfree(card);
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;
card->module = module;
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);
spin_lock_init(&card->files_lock);
INIT_LIST_HEAD(&card->files_list);
#ifdef CONFIG_PM
init_waitqueue_head(&card->power_sleep);
#endif
init_waitqueue_head(&card->remove_sleep);
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;
}
*card_ret = card;
return 0;
__error_ctl:
snd_device_free_all(card);
__error:
put_device(&card->card_dev);
return err;
}
EXPORT_SYMBOL(snd_card_new);
/**
* 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().
*/
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;
spin_unlock(&card->files_lock);
/* replace file->f_op with special dummy operations */
spin_lock(&card->files_lock);
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);
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);
#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)
{
#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 */
}
if (card->release_completion)
complete(card->release_completion);
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.
*/
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)
{
struct completion released;
int ret;
init_completion(&released);
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)
strlcpy(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
card_id_show_attr(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return scnprintf(buf, PAGE_SIZE, "%s\n", card->id);
}
static ssize_t
card_id_store_attr(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(id, 0644, card_id_show_attr, card_id_store_attr);
static ssize_t
card_number_show_attr(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_card *card = container_of(dev, struct snd_card, card_dev);
return scnprintf(buf, PAGE_SIZE, "%i\n", card->number);
}
static DEVICE_ATTR(number, 0444, card_number_show_attr, NULL);
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
*/
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);
/**
* 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;
}
if ((err = snd_device_register_all(card)) < 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);
if ((card = snd_cards[idx]) != NULL) {
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);
if ((card = snd_cards[idx]) != NULL) {
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);
if ((card = snd_cards[idx]) != NULL)
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_wait - wait until the power-state is changed.
* @card: soundcard structure
* @power_state: expected power state
*
* Waits until the power-state is changed.
*
* Return: Zero if successful, or a negative error code.
*/
int snd_power_wait(struct snd_card *card, unsigned int power_state)
{
wait_queue_entry_t wait;
int result = 0;
/* fastpath */
if (snd_power_get_state(card) == power_state)
return 0;
init_waitqueue_entry(&wait, current);
add_wait_queue(&card->power_sleep, &wait);
while (1) {
if (card->shutdown) {
result = -ENODEV;
break;
}
if (snd_power_get_state(card) == power_state)
break;
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(30 * HZ);
}
remove_wait_queue(&card->power_sleep, &wait);
return result;
}
EXPORT_SYMBOL(snd_power_wait);
#endif /* CONFIG_PM */
Reference in New Issue View Git Blame Copy Permalink