info.c

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/*
 *  Information interface for ALSA driver
 *  Copyright (c) by Jaroslav Kysela <[email protected]>
 *
 *
 *   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/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>

/*
 *
 */

#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;
}

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 = proc_mkdir("asound", 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;
}


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);

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);

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;
}

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);

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);
}

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);

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);

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 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;
    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 */