1/*
2 * $Id: mtdblock_ro.c,v 1.1.1.1 2007/08/03 18:52:43 Exp $
3 *
4 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
5 *
6 * Simple read-only (writable only for RAM) mtdblock driver
7 */
8
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/mtd/mtd.h>
12#include <linux/mtd/blktrans.h>
13
14static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
15			      unsigned long block, char *buf)
16{
17	size_t retlen;
18
19	if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
20		return 1;
21	return 0;
22}
23
24static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
25			      unsigned long block, char *buf)
26{
27	size_t retlen;
28
29	if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
30		return 1;
31	return 0;
32}
33
34static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
35{
36	struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
37
38	if (!dev)
39		return;
40
41	dev->mtd = mtd;
42	dev->devnum = mtd->index;
43
44	dev->size = mtd->size >> 9;
45	dev->tr = tr;
46	dev->readonly = 1;
47
48	add_mtd_blktrans_dev(dev);
49}
50
51static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
52{
53	del_mtd_blktrans_dev(dev);
54	kfree(dev);
55}
56
57static struct mtd_blktrans_ops mtdblock_tr = {
58	.name		= "mtdblock",
59	.major		= 31,
60	.part_bits	= 0,
61	.blksize 	= 512,
62	.readsect	= mtdblock_readsect,
63	.writesect	= mtdblock_writesect,
64	.add_mtd	= mtdblock_add_mtd,
65	.remove_dev	= mtdblock_remove_dev,
66	.owner		= THIS_MODULE,
67};
68
69static int __init mtdblock_init(void)
70{
71	return register_mtd_blktrans(&mtdblock_tr);
72}
73
74static void __exit mtdblock_exit(void)
75{
76	deregister_mtd_blktrans(&mtdblock_tr);
77}
78
79module_init(mtdblock_init);
80module_exit(mtdblock_exit);
81
82MODULE_LICENSE("GPL");
83MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
84MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");
85