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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 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{
Burman Yan95b93a02006-11-15 21:10:29 +020036 struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38 if (!dev)
39 return;
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 dev->mtd = mtd;
42 dev->devnum = mtd->index;
Richard Purdie19187672006-10-27 09:09:33 +010043
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 dev->size = mtd->size >> 9;
45 dev->tr = tr;
Jörn Engelaf63a3b2006-04-13 18:53:55 +020046 dev->readonly = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
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,
Richard Purdie19187672006-10-27 09:09:33 +010061 .blksize = 512,
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 .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");