mtdblock_ro.c
2.48 KB
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/*
* Simple read-only (writable only for RAM) mtdblock driver
*
* Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/blktrans.h>
#include <linux/module.h>
#include <linux/major.h>
static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
unsigned long block, char *buf)
{
size_t retlen;
if (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 (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;
if (add_mtd_blktrans_dev(dev))
kfree(dev);
}
static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
{
del_mtd_blktrans_dev(dev);
}
static struct mtd_blktrans_ops mtdblock_tr = {
.name = "mtdblock",
.major = MTD_BLOCK_MAJOR,
.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");