/*
 *  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/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 */