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linux/sound/core/info.c
Takashi Iwai 73029e0ff1 ALSA: info - Implement common llseek for binary mode 
The llseek implementation is identical for existing driver implementations,
so let's merge to the common layer.  The same code for the text proc file
can be used even for the binary proc file.

The driver can provide its own llseek method if needed.  Then the common
code will be skipped.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-04-13 12:01:20 +02:00

1017 lines
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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>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/string.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/version.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <stdarg.h>
/*
*
*/
#ifdef CONFIG_PROC_FS
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 int snd_info_version_done(void);
static void snd_info_disconnect(struct snd_info_entry *entry);
/* resize the proc r/w buffer */
static int resize_info_buffer(struct snd_info_buffer *buffer,
unsigned int nsize)
{
char *nbuf;
nsize = PAGE_ALIGN(nsize);
nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL);
if (! nbuf)
return -ENOMEM;
buffer->buffer = nbuf;
buffer->len = nsize;
return 0;
}
/**
* snd_iprintf - printf on the procfs buffer
* @buffer: the procfs buffer
* @fmt: the printf format
*
* Outputs the string on the procfs buffer just like printf().
*
* Returns the size of output string.
*/
int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
{
va_list args;
int len, res;
int err = 0;
might_sleep();
if (buffer->stop || buffer->error)
return 0;
len = buffer->len - buffer->size;
va_start(args, fmt);
for (;;) {
va_list ap;
va_copy(ap, args);
res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
va_end(ap);
if (res < len)
break;
err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
if (err < 0)
break;
len = buffer->len - buffer->size;
}
va_end(args);
if (err < 0)
return err;
buffer->curr += res;
buffer->size += res;
return res;
}
EXPORT_SYMBOL(snd_iprintf);
/*
*/
static struct proc_dir_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 void snd_remove_proc_entry(struct proc_dir_entry *parent,
struct proc_dir_entry *de)
{
if (de)
remove_proc_entry(de->name, parent);
}
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->content == SNDRV_INFO_CONTENT_DATA &&
entry->c.ops->llseek) {
offset = entry->c.ops->llseek(entry,
data->file_private_data,
file, offset, orig);
goto out;
}
if (entry->content == SNDRV_INFO_CONTENT_DATA)
size = entry->size;
else
size = 0;
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;
struct snd_info_entry *entry;
struct snd_info_buffer *buf;
size_t size = 0;
loff_t pos;
data = file->private_data;
if (snd_BUG_ON(!data))
return -ENXIO;
pos = *offset;
if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
return -EIO;
if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
return -EIO;
entry = data->entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT:
buf = data->rbuffer;
if (buf == NULL)
return -EIO;
if (pos >= buf->size)
return 0;
size = buf->size - pos;
size = min(count, size);
if (copy_to_user(buffer, buf->buffer + pos, size))
return -EFAULT;
break;
case SNDRV_INFO_CONTENT_DATA:
if (pos >= entry->size)
return 0;
if (entry->c.ops->read) {
size = entry->size - pos;
size = min(count, size);
size = entry->c.ops->read(entry,
data->file_private_data,
file, buffer, size, pos);
}
break;
}
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;
struct snd_info_entry *entry;
struct snd_info_buffer *buf;
ssize_t size = 0;
loff_t pos;
data = file->private_data;
if (snd_BUG_ON(!data))
return -ENXIO;
entry = data->entry;
pos = *offset;
if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
return -EIO;
if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
return -EIO;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT:
buf = data->wbuffer;
if (buf == NULL)
return -EIO;
mutex_lock(&entry->access);
if (pos + count >= buf->len) {
if (resize_info_buffer(buf, pos + count)) {
mutex_unlock(&entry->access);
return -ENOMEM;
}
}
if (copy_from_user(buf->buffer + pos, buffer, count)) {
mutex_unlock(&entry->access);
return -EFAULT;
}
buf->size = pos + count;
mutex_unlock(&entry->access);
size = count;
break;
case SNDRV_INFO_CONTENT_DATA:
if (entry->c.ops->write && 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);
}
break;
}
if ((ssize_t) size > 0)
*offset = pos + size;
return size;
}
static int snd_info_entry_open(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry;
struct snd_info_private_data *data;
struct snd_info_buffer *buffer;
struct proc_dir_entry *p;
int mode, err;
mutex_lock(&info_mutex);
p = PDE(inode);
entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
if (entry == NULL || ! entry->p) {
mutex_unlock(&info_mutex);
return -ENODEV;
}
if (!try_module_get(entry->module)) {
err = -EFAULT;
goto __error1;
}
mode = file->f_flags & O_ACCMODE;
if (mode == O_RDONLY || mode == O_RDWR) {
if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
entry->c.ops->read == NULL)) {
err = -ENODEV;
goto __error;
}
}
if (mode == O_WRONLY || mode == O_RDWR) {
if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
entry->c.ops->write == NULL)) {
err = -ENODEV;
goto __error;
}
}
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (data == NULL) {
err = -ENOMEM;
goto __error;
}
data->entry = entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT:
if (mode == O_RDONLY || mode == O_RDWR) {
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (buffer == NULL)
goto __nomem;
data->rbuffer = buffer;
buffer->len = PAGE_SIZE;
buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
if (buffer->buffer == NULL)
goto __nomem;
}
if (mode == O_WRONLY || mode == O_RDWR) {
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (buffer == NULL)
goto __nomem;
data->wbuffer = buffer;
buffer->len = PAGE_SIZE;
buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
if (buffer->buffer == NULL)
goto __nomem;
}
break;
case SNDRV_INFO_CONTENT_DATA: /* data */
if (entry->c.ops->open) {
if ((err = entry->c.ops->open(entry, mode,
&data->file_private_data)) < 0) {
kfree(data);
goto __error;
}
}
break;
}
file->private_data = data;
mutex_unlock(&info_mutex);
if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
(mode == O_RDONLY || mode == O_RDWR)) {
if (entry->c.text.read) {
mutex_lock(&entry->access);
entry->c.text.read(entry, data->rbuffer);
mutex_unlock(&entry->access);
}
}
return 0;
__nomem:
if (data->rbuffer) {
kfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
if (data->wbuffer) {
kfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
kfree(data);
err = -ENOMEM;
__error:
module_put(entry->module);
__error1:
mutex_unlock(&info_mutex);
return err;
}
static int snd_info_entry_release(struct inode *inode, struct file *file)
{
struct snd_info_entry *entry;
struct snd_info_private_data *data;
int mode;
mode = file->f_flags & O_ACCMODE;
data = file->private_data;
entry = data->entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT:
if (data->rbuffer) {
kfree(data->rbuffer->buffer);
kfree(data->rbuffer);
}
if (data->wbuffer) {
if (entry->c.text.write) {
entry->c.text.write(entry, data->wbuffer);
if (data->wbuffer->error) {
snd_printk(KERN_WARNING "data write error to %s (%i)\n",
entry->name,
data->wbuffer->error);
}
}
kfree(data->wbuffer->buffer);
kfree(data->wbuffer);
}
break;
case SNDRV_INFO_CONTENT_DATA:
if (entry->c.ops->release)
entry->c.ops->release(entry, mode,
data->file_private_data);
break;
}
module_put(entry->module);
kfree(data);
return 0;
}
static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
{
struct snd_info_private_data *data;
struct snd_info_entry *entry;
unsigned int mask;
data = file->private_data;
if (data == NULL)
return 0;
entry = data->entry;
mask = 0;
switch (entry->content) {
case SNDRV_INFO_CONTENT_DATA:
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;
break;
}
return mask;
}
static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct snd_info_private_data *data;
struct snd_info_entry *entry;
data = file->private_data;
if (data == NULL)
return 0;
entry = data->entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_DATA:
if (entry->c.ops->ioctl)
return entry->c.ops->ioctl(entry,
data->file_private_data,
file, cmd, arg);
break;
}
return -ENOTTY;
}
static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct snd_info_private_data *data;
struct snd_info_entry *entry;
data = file->private_data;
if (data == NULL)
return 0;
entry = data->entry;
switch (entry->content) {
case SNDRV_INFO_CONTENT_DATA:
if (entry->c.ops->mmap)
return entry->c.ops->mmap(entry,
data->file_private_data,
inode, file, vma);
break;
}
return -ENXIO;
}
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,
};
int __init snd_info_init(void)
{
struct proc_dir_entry *p;
p = create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
if (p == NULL)
return -ENOMEM;
snd_proc_root = p;
#ifdef CONFIG_SND_OSSEMUL
{
struct snd_info_entry *entry;
if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
return -ENOMEM;
entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
snd_oss_root = entry;
}
#endif
#if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
{
struct snd_info_entry *entry;
if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
return -ENOMEM;
entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
snd_seq_root = entry;
}
#endif
snd_info_version_init();
snd_minor_info_init();
snd_minor_info_oss_init();
snd_card_info_init();
return 0;
}
int __exit snd_info_done(void)
{
snd_card_info_done();
snd_minor_info_oss_done();
snd_minor_info_done();
snd_info_version_done();
if (snd_proc_root) {
#if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
snd_info_free_entry(snd_seq_root);
#endif
#ifdef CONFIG_SND_OSSEMUL
snd_info_free_entry(snd_oss_root);
#endif
snd_remove_proc_entry(NULL, 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);
if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
return -ENOMEM;
entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
card->proc_root = entry;
return 0;
}
/*
* register the card proc file
* called from init.c
*/
int snd_info_card_register(struct snd_card *card)
{
struct proc_dir_entry *p;
if (snd_BUG_ON(!card))
return -ENXIO;
if (!strcmp(card->id, card->proc_root->name))
return 0;
p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
if (p == NULL)
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) {
snd_remove_proc_entry(snd_proc_root, 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,
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);
if (card->proc_root_link) {
snd_remove_proc_entry(snd_proc_root, 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 - 1
*
* Reads one line from the buffer and stores the string.
*
* Returns 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 (len <= 0 || buffer->stop || buffer->error)
return 1;
while (--len > 0) {
c = buffer->buffer[buffer->curr++];
if (c == '\n') {
if (buffer->curr >= buffer->size)
buffer->stop = 1;
break;
}
*line++ = c;
if (buffer->curr >= buffer->size) {
buffer->stop = 1;
break;
}
}
while (c != '\n' && !buffer->stop) {
c = buffer->buffer[buffer->curr++];
if (buffer->curr >= buffer->size)
buffer->stop = 1;
}
*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.
*
* Returns 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
*
* 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().
*
* Returns 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 *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);
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.
*
* Returns 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);
if (entry) {
entry->module = module;
entry->parent = parent;
}
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.
*
* Returns 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);
if (entry) {
entry->module = card->module;
entry->card = card;
entry->parent = parent;
}
return entry;
}
EXPORT_SYMBOL(snd_info_create_card_entry);
static void snd_info_disconnect(struct snd_info_entry *entry)
{
struct list_head *p, *n;
struct proc_dir_entry *root;
list_for_each_safe(p, n, &entry->children) {
snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
}
if (! entry->p)
return;
list_del_init(&entry->list);
root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
snd_BUG_ON(!root);
snd_remove_proc_entry(root, entry->p);
entry->p = NULL;
}
static int snd_info_dev_free_entry(struct snd_device *device)
{
struct snd_info_entry *entry = device->device_data;
snd_info_free_entry(entry);
return 0;
}
static int snd_info_dev_register_entry(struct snd_device *device)
{
struct snd_info_entry *entry = device->device_data;
return snd_info_register(entry);
}
/**
* snd_card_proc_new - create an info entry for the given card
* @card: the card instance
* @name: the file name
* @entryp: the pointer to store the new info entry
*
* Creates a new info entry and assigns it to the given card.
* Unlike snd_info_create_card_entry(), this function registers the
* info entry as an ALSA device component, so that it can be
* unregistered/released without explicit call.
* Also, you don't have to register this entry via snd_info_register(),
* since this will be registered by snd_card_register() automatically.
*
* The parent is assumed as card->proc_root.
*
* For releasing this entry, use snd_device_free() instead of
* snd_info_free_entry().
*
* Returns zero if successful, or a negative error code on failure.
*/
int snd_card_proc_new(struct snd_card *card, const char *name,
struct snd_info_entry **entryp)
{
static struct snd_device_ops ops = {
.dev_free = snd_info_dev_free_entry,
.dev_register = snd_info_dev_register_entry,
/* disconnect is done via snd_info_card_disconnect() */
};
struct snd_info_entry *entry;
int err;
entry = snd_info_create_card_entry(card, name, card->proc_root);
if (! entry)
return -ENOMEM;
if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
snd_info_free_entry(entry);
return err;
}
if (entryp)
*entryp = entry;
return 0;
}
EXPORT_SYMBOL(snd_card_proc_new);
/**
* snd_info_free_entry - release the info entry
* @entry: the info entry
*
* Releases the info entry. Don't call this after registered.
*/
void snd_info_free_entry(struct snd_info_entry * entry)
{
if (entry == NULL)
return;
if (entry->p) {
mutex_lock(&info_mutex);
snd_info_disconnect(entry);
mutex_unlock(&info_mutex);
}
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.
*
* Returns 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 : entry->parent->p;
mutex_lock(&info_mutex);
p = create_proc_entry(entry->name, entry->mode, root);
if (!p) {
mutex_unlock(&info_mutex);
return -ENOMEM;
}
if (!S_ISDIR(entry->mode))
p->proc_fops = &snd_info_entry_operations;
p->size = entry->size;
p->data = entry;
entry->p = p;
if (entry->parent)
list_add_tail(&entry->list, &entry->parent->children);
mutex_unlock(&info_mutex);
return 0;
}
EXPORT_SYMBOL(snd_info_register);
/*
*/
static struct snd_info_entry *snd_info_version_entry;
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 "
CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
);
}
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;
if (snd_info_register(entry) < 0) {
snd_info_free_entry(entry);
return -ENOMEM;
}
snd_info_version_entry = entry;
return 0;
}
static int __exit snd_info_version_done(void)
{
snd_info_free_entry(snd_info_version_entry);
return 0;
}
#endif /* CONFIG_PROC_FS */
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