blob: 29563ed258a4788bf86eb03341b4fad0440ed2d0 [file] [log] [blame]
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{
36 struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
37
38 if (!dev)
39 return;
40
41 memset(dev, 0, sizeof(*dev));
42
43 dev->mtd = mtd;
44 dev->devnum = mtd->index;
45 dev->blksize = 512;
46 dev->size = mtd->size >> 9;
47 dev->tr = tr;
Jörn Engelaf63a3b2006-04-13 18:53:55 +020048 dev->readonly = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
50 add_mtd_blktrans_dev(dev);
51}
52
53static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
54{
55 del_mtd_blktrans_dev(dev);
56 kfree(dev);
57}
58
59static struct mtd_blktrans_ops mtdblock_tr = {
60 .name = "mtdblock",
61 .major = 31,
62 .part_bits = 0,
63 .readsect = mtdblock_readsect,
64 .writesect = mtdblock_writesect,
65 .add_mtd = mtdblock_add_mtd,
66 .remove_dev = mtdblock_remove_dev,
67 .owner = THIS_MODULE,
68};
69
70static int __init mtdblock_init(void)
71{
72 return register_mtd_blktrans(&mtdblock_tr);
73}
74
75static void __exit mtdblock_exit(void)
76{
77 deregister_mtd_blktrans(&mtdblock_tr);
78}
79
80module_init(mtdblock_init);
81module_exit(mtdblock_exit);
82
83MODULE_LICENSE("GPL");
84MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
85MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");