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/*
 * $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 Exp $
 *
 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
 *
 * Simple read-only (writable only for RAM) mtdblock driver
 */
 
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/blktrans.h>
 
static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
			      unsigned long block, char *buf)
{
	size_t retlen;
 
	if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
		return 1;
	return 0;
}
 
static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
			      unsigned long block, char *buf)
{
	size_t retlen;
 
	if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
		return 1;
	return 0;
}
 
static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
	struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 
	if (!dev)
		return;
 
	dev->mtd = mtd;
	dev->devnum = mtd->index;
 
	dev->size = mtd->size >> 9;
	dev->tr = tr;
	dev->readonly = 1;
 
	add_mtd_blktrans_dev(dev);
}
 
static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
{
	del_mtd_blktrans_dev(dev);
	kfree(dev);
}
 
static struct mtd_blktrans_ops mtdblock_tr = {
	.name		= "mtdblock",
	.major		= 31,
	.part_bits	= 0,
	.blksize 	= 512,
	.readsect	= mtdblock_readsect,
	.writesect	= mtdblock_writesect,
	.add_mtd	= mtdblock_add_mtd,
	.remove_dev	= mtdblock_remove_dev,
	.owner		= THIS_MODULE,
};
 
static int __init mtdblock_init(void)
{
	return register_mtd_blktrans(&mtdblock_tr);
}
 
static void __exit mtdblock_exit(void)
{
	deregister_mtd_blktrans(&mtdblock_tr);
}
 
module_init(mtdblock_init);
module_exit(mtdblock_exit);
 
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");