Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 888 insertions, 0 deletions

diff --git a/sound/core/info.c b/sound/core/info.c
new file mode 100644
index 000000000..3fa833679
--- /dev/null
+++ b/sound/core/info.c
@@ -0,0 +1,888 @@
+/*
+ *  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 <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 __poll_t 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;
+	__poll_t 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 |= EPOLLIN | EPOLLRDNORM;
+	if (entry->c.ops->write)
+		mask |= EPOLLOUT | EPOLLWRNORM;
+	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 = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
+		if (!nbuf) {
+			err = -ENOMEM;
+			goto error;
+		}
+		kvfree(buf->buffer);
+		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) {
+		kvfree(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 | 0555;
+	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 | 0555;
+	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))
+		return 1;
+	if (!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 | 0444;
+	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) {
+		mutex_lock(&parent->access);
+		list_add_tail(&entry->list, &parent->children);
+		mutex_unlock(&parent->access);
+	}
+	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);
+
+	p = entry->parent;
+	if (p) {
+		mutex_lock(&p->access);
+		list_del(&entry->list);
+		mutex_unlock(&p->access);
+	}
+	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 */
+}