path: root/sound/core/info.c

/*
 *  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 <sound/driver.h>
#include <linux/init.h>
#include <linux/time.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 = kmalloc(nsize, GFP_KERNEL);
	if (! nbuf)
		return -ENOMEM;

	memcpy(nbuf, buffer->buffer, buffer->len);
	kfree(buffer->buffer);
	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, 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 inline void snd_info_entry_prepare(struct proc_dir_entry *de)
{
	de->owner = THIS_MODULE;
}

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;

	data = file->private_data;
	entry = data->entry;
	lock_kernel();
	switch (entry->content) {
	case SNDRV_INFO_CONTENT_TEXT:
		switch (orig) {
		case SEEK_SET: