OpenCloudOS-Kernel/sound/core/info.c

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/*
* Information interface for ALSA driver
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/init.h>
#include <linux/time.h>
2008-07-24 12:28:13 +08:00
#include <linux/mm.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <linux/utsname.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <stdarg.h>
int snd_info_check_reserved_words(const char *str)
{
static char *reserved[] =
{
"version",
"meminfo",
"memdebug",
"detect",
"devices",
"oss",
"cards",
"timers",
"synth",
"pcm",
"seq",
NULL
};
char **xstr = reserved;
while (*xstr) {
if (!strcmp(*xstr, str))
return 0;
xstr++;
}
if (!strncmp(str, "card", 4))
return 0;
return 1;
}
static DEFINE_MUTEX(info_mutex);
struct snd_info_private_data {
struct snd_info_buffer *rbuffer;
struct snd_info_buffer *wbuffer;
struct snd_info_entry *entry;
void *file_private_data;
};
static int snd_info_version_init(void);
static void snd_info_disconnect(struct snd_info_entry *entry);
/*
*/
static struct snd_info_entry *snd_proc_root;
struct snd_info_entry *snd_seq_root;
EXPORT_SYMBOL(snd_seq_root);
#ifdef CONFIG_SND_OSSEMUL
struct snd_info_entry *snd_oss_root;
#endif
static int alloc_info_private(struct snd_info_entry *entry,
struct snd_info_private_data **ret)
{
struct snd_info_private_data *data;
if (!entry || !entry->p)
return -ENODEV;
if (!try_module_get(entry->module))
return -EFAULT;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
module_put(entry->module);
return -ENOMEM;
}
data->entry = entry;
*ret = data;
return 0;
}
static bool valid_pos(loff_t pos, size_t count)
{
if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
return false;
if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
return false;
return true;
}
/*
* file ops for binary proc files
*/
static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
{
struct snd_info_private_data *data;
struct snd_info_entry *entry;
loff_t ret = -EINVAL, size;
data = file->private_data;
entry = data->entry;
mutex_lock(&entry->access);
if (entry->c.ops->llseek) {
offset = entry->c.ops->llseek(entry,
data->file_private_data,
file, offset, orig);
goto out;
}
size = entry->size;
switch (orig) {
case SEEK_SET:
break;
case SEEK_CUR:
offset += file->f_pos;
break;
case SEEK_END:
if (!size)
goto out;
offset += size;
break;
default:
goto out;
}
if (offset < 0)
goto out;
if (size && offset > size)
offset = size;
file->f_pos = offset;
ret = offset;
out:
mutex_unlock(&entry->access);
return ret;
}
static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
size_t count, loff_t * offset)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
size_t size;
loff_t pos;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
if (pos >= entry->size)
return 0;
size = entry->size - pos;
size = min(count, size);
size = entry->c.ops->read(entry, data->file_private_data,
file, buffer, size, pos);
if ((ssize_t) size > 0)
*offset = pos + size;
return size;
}
static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
size_t count, loff_t * offset)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
ssize_t size = 0;
loff_t pos;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
if (count > 0) {
size_t maxsize = entry->size - pos;
count = min(count, maxsize);
size = entry->c.ops->write(entry, data->file_private_data,
file, buffer, count, pos);
}
if (size > 0)
*offset = pos + size;
return size;
}
static unsigned int snd_info_entry_poll(struct file *file, poll_table *wait)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
unsigned int mask = 0;
if (entry->c.ops->poll)
return entry->c.ops->poll(entry,
data->file_private_data,
file, wait);
if (entry->c.ops->read)
mask |= POLLIN | POLLRDNORM;
if (entry->c.ops->write)
mask |= POLLOUT | POLLWRNORM;
return mask;
}
static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
if (!entry->c.ops->ioctl)
return -ENOTTY;
return entry->c.ops->ioctl(entry, data->file_private_data,
file, cmd, arg);
}
static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file_inode(file);
struct snd_info_private_data *data;
struct snd_info_entry *entry;
data = file->private_data;
if (data == NULL)
return 0;
entry = data->entry;
if (!entry->c.ops->mmap)
return -ENXIO;
return entry->c.ops->mmap(entry, data->file_private_data,
inode, file, vma);
}
static int snd_info_entry_open(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry = PDE_DATA(inode);
struct snd_info_private_data *data;
int mode, err;
mutex_lock(&info_mutex);
err = alloc_info_private(entry, &data);
if (err < 0)
goto unlock;
mode = file->f_flags & O_ACCMODE;
if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
err = -ENODEV;
goto error;
}
if (entry->c.ops->open) {
err = entry->c.ops->open(entry, mode, &data->file_private_data);
if (err < 0)
goto error;
}
file->private_data = data;
mutex_unlock(&info_mutex);
return 0;
error:
kfree(data);
module_put(entry->module);
unlock:
mutex_unlock(&info_mutex);
return err;
}
static int snd_info_entry_release(struct inode *inode, struct file *file)
{
struct snd_info_private_data *data = file->private_data;
struct snd_info_entry *entry = data->entry;
if (entry->c.ops->release)
entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
data->file_private_data);
module_put(entry->module);
kfree(data);
return 0;
}
static const struct file_operations snd_info_entry_operations =
{
.owner = THIS_MODULE,
.llseek = snd_info_entry_llseek,
.read = snd_info_entry_read,
.write = snd_info_entry_write,
.poll = snd_info_entry_poll,
.unlocked_ioctl = snd_info_entry_ioctl,
.mmap = snd_info_entry_mmap,
.open = snd_info_entry_open,
.release = snd_info_entry_release,
};
/*
* file ops for text proc files
*/
static ssize_t snd_info_text_entry_write(struct file *file,
const char __user *buffer,
size_t count, loff_t *offset)
{
struct seq_file *m = file->private_data;
struct snd_info_private_data *data = m->private;
struct snd_info_entry *entry = data->entry;
struct snd_info_buffer *buf;
loff_t pos;
size_t next;
int err = 0;
if (!entry->c.text.write)
return -EIO;
pos = *offset;
if (!valid_pos(pos, count))
return -EIO;
next = pos + count;
/* don't handle too large text inputs */
if (next > 16 * 1024)
return -EIO;
mutex_lock(&entry->access);
buf = data->wbuffer;
if (!buf) {
data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf) {
err = -ENOMEM;
goto error;
}
}
if (next > buf->len) {
char *nbuf = krealloc(buf->buffer, PAGE_ALIGN(next),
GFP_KERNEL | __GFP_ZERO);
if (!nbuf) {
err = -ENOMEM;
goto error;
}
buf->buffer = nbuf;
buf->len = PAGE_ALIGN(next);
}
if (copy_from_user(buf->buffer + pos, buffer, count)) {
err = -EFAULT;
goto error;
}
buf->size = next;
error:
mutex_unlock(&entry->access);
if (err < 0)
return err;
*offset = next;
return count;
}
static int snd_info_seq_show(struct seq_file *seq, void *p)
{
struct snd_info_private_data *data = seq->private;
struct snd_info_entry *entry = data->entry;
if (!entry->c.text.read) {
return -EIO;
} else {
data->rbuffer->buffer = (char *)seq; /* XXX hack! */
entry->c.text.read(entry, data->rbuffer);
}
return 0;
}
static int snd_info_text_entry_open(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry = PDE_DATA(inode);
struct snd_info_private_data *data;
int err;
mutex_lock(&info_mutex);
err = alloc_info_private(entry, &data);
if (err < 0)
goto unlock;
data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
if (!data->rbuffer) {
err = -ENOMEM;
goto error;
}
if (entry->size)
err = single_open_size(file, snd_info_seq_show, data,
entry->size);
else
err = single_open(file, snd_info_seq_show, data);
if (err < 0)
goto error;
mutex_unlock(&info_mutex);
return 0;
error:
kfree(data->rbuffer);
kfree(data);
module_put(entry->module);
unlock:
mutex_unlock(&info_mutex);
return err;
}
static int snd_info_text_entry_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
struct snd_info_private_data *data = m->private;
struct snd_info_entry *entry = data->entry;
if (data->wbuffer && entry->c.text.write)
entry->c.text.write(entry, data->wbuffer);
single_release(inode, file);
kfree(data->rbuffer);
if (data->wbuffer) {
kfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
module_put(entry->module);
kfree(data);
return 0;
}
static const struct file_operations snd_info_text_entry_ops =
{
.owner = THIS_MODULE,
.open = snd_info_text_entry_open,
.release = snd_info_text_entry_release,
.write = snd_info_text_entry_write,
.llseek = seq_lseek,
.read = seq_read,
};
static struct snd_info_entry *create_subdir(struct module *mod,
const char *name)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(mod, name, NULL);
if (!entry)
return NULL;
entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return NULL;
}
return entry;
}
static struct snd_info_entry *
snd_info_create_entry(const char *name, struct snd_info_entry *parent);
int __init snd_info_init(void)
{
snd_proc_root = snd_info_create_entry("asound", NULL);
if (!snd_proc_root)
return -ENOMEM;
snd_proc_root->mode = S_IFDIR | S_IRUGO | S_IXUGO;
snd_proc_root->p = proc_mkdir("asound", NULL);
if (!snd_proc_root->p)
goto error;
#ifdef CONFIG_SND_OSSEMUL
snd_oss_root = create_subdir(THIS_MODULE, "oss");
if (!snd_oss_root)
goto error;
#endif
#if IS_ENABLED(CONFIG_SND_SEQUENCER)
snd_seq_root = create_subdir(THIS_MODULE, "seq");
if (!snd_seq_root)
goto error;
#endif
if (snd_info_version_init() < 0 ||
snd_minor_info_init() < 0 ||
snd_minor_info_oss_init() < 0 ||
snd_card_info_init() < 0 ||
snd_info_minor_register() < 0)
goto error;
return 0;
error:
snd_info_free_entry(snd_proc_root);
return -ENOMEM;
}
int __exit snd_info_done(void)
{
snd_info_free_entry(snd_proc_root);
return 0;
}
/*
* create a card proc file
* called from init.c
*/
int snd_info_card_create(struct snd_card *card)
{
char str[8];
struct snd_info_entry *entry;
if (snd_BUG_ON(!card))
return -ENXIO;
sprintf(str, "card%i", card->number);
entry = create_subdir(card->module, str);
if (!entry)
return -ENOMEM;
card->proc_root = entry;
return 0;
}
/* register all pending info entries */
static int snd_info_register_recursive(struct snd_info_entry *entry)
{
struct snd_info_entry *p;
int err;
if (!entry->p) {
err = snd_info_register(entry);
if (err < 0)
return err;
}
list_for_each_entry(p, &entry->children, list) {
err = snd_info_register_recursive(p);
if (err < 0)
return err;
}
return 0;
}
/*
* register the card proc file
* called from init.c
* can be called multiple times for reinitialization
*/
int snd_info_card_register(struct snd_card *card)
{
struct proc_dir_entry *p;
int err;
if (snd_BUG_ON(!card))
return -ENXIO;
err = snd_info_register_recursive(card->proc_root);
if (err < 0)
return err;
if (!strcmp(card->id, card->proc_root->name))
return 0;
if (card->proc_root_link)
return 0;
p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
if (!p)
return -ENOMEM;
card->proc_root_link = p;
return 0;
}
/*
* called on card->id change
*/
void snd_info_card_id_change(struct snd_card *card)
{
mutex_lock(&info_mutex);
if (card->proc_root_link) {
proc_remove(card->proc_root_link);
card->proc_root_link = NULL;
}
if (strcmp(card->id, card->proc_root->name))
card->proc_root_link = proc_symlink(card->id,
snd_proc_root->p,
card->proc_root->name);
mutex_unlock(&info_mutex);
}
/*
* de-register the card proc file
* called from init.c
*/
void snd_info_card_disconnect(struct snd_card *card)
{
if (!card)
return;
mutex_lock(&info_mutex);
proc_remove(card->proc_root_link);
card->proc_root_link = NULL;
if (card->proc_root)
snd_info_disconnect(card->proc_root);
mutex_unlock(&info_mutex);
}
/*
* release the card proc file resources
* called from init.c
*/
int snd_info_card_free(struct snd_card *card)
{
if (!card)
return 0;
snd_info_free_entry(card->proc_root);
card->proc_root = NULL;
return 0;
}
/**
* snd_info_get_line - read one line from the procfs buffer
* @buffer: the procfs buffer
* @line: the buffer to store
* @len: the max. buffer size
*
* Reads one line from the buffer and stores the string.
*
* Return: Zero if successful, or 1 if error or EOF.
*/
int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
{
int c = -1;
if (snd_BUG_ON(!buffer || !buffer->buffer))
return 1;
if (len <= 0 || buffer->stop || buffer->error)
return 1;
while (!buffer->stop) {
c = buffer->buffer[buffer->curr++];
if (buffer->curr >= buffer->size)
buffer->stop = 1;
if (c == '\n')
break;
if (len > 1) {
len--;
*line++ = c;
}
}
*line = '\0';
return 0;
}
EXPORT_SYMBOL(snd_info_get_line);
/**
* snd_info_get_str - parse a string token
* @dest: the buffer to store the string token
* @src: the original string
* @len: the max. length of token - 1
*
* Parses the original string and copy a token to the given
* string buffer.
*
* Return: The updated pointer of the original string so that
* it can be used for the next call.
*/
const char *snd_info_get_str(char *dest, const char *src, int len)
{
int c;
while (*src == ' ' || *src == '\t')
src++;
if (*src == '"' || *src == '\'') {
c = *src++;
while (--len > 0 && *src && *src != c) {
*dest++ = *src++;
}
if (*src == c)
src++;
} else {
while (--len > 0 && *src && *src != ' ' && *src != '\t') {
*dest++ = *src++;
}
}
*dest = 0;
while (*src == ' ' || *src == '\t')
src++;
return src;
}
EXPORT_SYMBOL(snd_info_get_str);
/*
* snd_info_create_entry - create an info entry
* @name: the proc file name
* @parent: the parent directory
*
* Creates an info entry with the given file name and initializes as
* the default state.
*
* Usually called from other functions such as
* snd_info_create_card_entry().
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
static struct snd_info_entry *
snd_info_create_entry(const char *name, struct snd_info_entry *parent)
{
struct snd_info_entry *entry;
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry == NULL)
return NULL;
entry->name = kstrdup(name, GFP_KERNEL);
if (entry->name == NULL) {
kfree(entry);
return NULL;
}
entry->mode = S_IFREG | S_IRUGO;
entry->content = SNDRV_INFO_CONTENT_TEXT;
mutex_init(&entry->access);
INIT_LIST_HEAD(&entry->children);
INIT_LIST_HEAD(&entry->list);
entry->parent = parent;
if (parent)
list_add_tail(&entry->list, &parent->children);
return entry;
}
/**
* snd_info_create_module_entry - create an info entry for the given module
* @module: the module pointer
* @name: the file name
* @parent: the parent directory
*
* Creates a new info entry and assigns it to the given module.
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
struct snd_info_entry *snd_info_create_module_entry(struct module * module,
const char *name,
struct snd_info_entry *parent)
{
struct snd_info_entry *entry = snd_info_create_entry(name, parent);
if (entry)
entry->module = module;
return entry;
}
EXPORT_SYMBOL(snd_info_create_module_entry);
/**
* snd_info_create_card_entry - create an info entry for the given card
* @card: the card instance
* @name: the file name
* @parent: the parent directory
*
* Creates a new info entry and assigns it to the given card.
*
* Return: The pointer of the new instance, or %NULL on failure.
*/
struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
const char *name,
struct snd_info_entry * parent)
{
struct snd_info_entry *entry = snd_info_create_entry(name, parent);
if (entry) {
entry->module = card->module;
entry->card = card;
}
return entry;
}
EXPORT_SYMBOL(snd_info_create_card_entry);
static void snd_info_disconnect(struct snd_info_entry *entry)
{
struct snd_info_entry *p;
if (!entry->p)
return;
list_for_each_entry(p, &entry->children, list)
snd_info_disconnect(p);
proc_remove(entry->p);
entry->p = NULL;
}
/**
* snd_info_free_entry - release the info entry
* @entry: the info entry
*
* Releases the info entry.
*/
void snd_info_free_entry(struct snd_info_entry * entry)
{
struct snd_info_entry *p, *n;
if (!entry)
return;
if (entry->p) {
mutex_lock(&info_mutex);
snd_info_disconnect(entry);
mutex_unlock(&info_mutex);
}
/* free all children at first */
list_for_each_entry_safe(p, n, &entry->children, list)
snd_info_free_entry(p);
list_del(&entry->list);
kfree(entry->name);
if (entry->private_free)
entry->private_free(entry);
kfree(entry);
}
EXPORT_SYMBOL(snd_info_free_entry);
/**
* snd_info_register - register the info entry
* @entry: the info entry
*
* Registers the proc info entry.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_info_register(struct snd_info_entry * entry)
{
struct proc_dir_entry *root, *p = NULL;
if (snd_BUG_ON(!entry))
return -ENXIO;
root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
mutex_lock(&info_mutex);
if (S_ISDIR(entry->mode)) {
p = proc_mkdir_mode(entry->name, entry->mode, root);
if (!p) {
mutex_unlock(&info_mutex);
return -ENOMEM;
}
} else {
const struct file_operations *ops;
if (entry->content == SNDRV_INFO_CONTENT_DATA)
ops = &snd_info_entry_operations;
else
ops = &snd_info_text_entry_ops;
p = proc_create_data(entry->name, entry->mode, root,
ops, entry);
if (!p) {
mutex_unlock(&info_mutex);
return -ENOMEM;
}
proc_set_size(p, entry->size);
}
entry->p = p;
mutex_unlock(&info_mutex);
return 0;
}
EXPORT_SYMBOL(snd_info_register);
/*
*/
static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
{
snd_iprintf(buffer,
"Advanced Linux Sound Architecture Driver Version k%s.\n",
init_utsname()->release);
}
static int __init snd_info_version_init(void)
{
struct snd_info_entry *entry;
entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
if (entry == NULL)
return -ENOMEM;
entry->c.text.read = snd_info_version_read;
return snd_info_register(entry); /* freed in error path */
}