/* * $Id: mtdblock_ro.c,v 1.2 2007/09/21 03:09:24 quy 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 = kmalloc(sizeof(*dev), GFP_KERNEL);	if (!dev)		return;	memset(dev, 0, sizeof(*dev));	dev->mtd = mtd;	dev->devnum = mtd->index;	dev->blksize = 512;	dev->size = mtd->size >> 9;	dev->tr = tr;	if ((mtd->flags & (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) !=	    (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE))		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);}struct mtd_blktrans_ops mtdblock_tr = {	.name		= "mtdblock",	.major		= 31,	.part_bits	= 0,	.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");