info.c

linux 内核源代码

	}
	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,
};

/**
 * snd_create_proc_entry - create a procfs entry
 * @name: the name of the proc file
 * @mode: the file permission bits, S_Ixxx
 * @parent: the parent proc-directory entry
 *
 * Creates a new proc file entry with the given name and permission
 * on the given directory.
 *
 * Returns the pointer of new instance or NULL on failure.
 */
static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
						    struct proc_dir_entry *parent)
{
	struct proc_dir_entry *p;
	p = create_proc_entry(name, mode, parent);
	if (p)
		snd_info_entry_prepare(p);
	return p;
}

int __init snd_info_init(void)
{
	struct proc_dir_entry *p;

	p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
	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(&proc_root, 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;

	snd_assert(card != NULL, 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;

	snd_assert(card != NULL, 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;
}

/*
 * de-register the card proc file
 * called from init.c
 */
void snd_info_card_disconnect(struct snd_card *card)
{
	snd_assert(card != NULL, 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)
{
	snd_assert(card != NULL, return -ENXIO);
	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.
 */
char *snd_info_get_str(char *dest, 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_assert(root, return);
	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;

	snd_assert(entry != NULL, return -ENXIO);
	root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
	mutex_lock(&info_mutex);
	p = snd_create_proc_entry(entry->name, entry->mode, root);
	if (!p) {
		mutex_unlock(&info_mutex);
		return -ENOMEM;
	}
	p->owner = entry->module;
	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 */