tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Simple read-only (writable only for RAM) mtdblock driver
3 *
4 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 */
21
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/mtd/mtd.h>
25#include <linux/mtd/blktrans.h>
26#include <linux/module.h>
27
28static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
29 unsigned long block, char *buf)
30{
31 size_t retlen;
32
33 if (mtd_read(dev->mtd, (block * 512), 512, &retlen, buf))
34 return 1;
35 return 0;
36}
37
38static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
39 unsigned long block, char *buf)
40{
41 size_t retlen;
42
43 if (mtd_write(dev->mtd, (block * 512), 512, &retlen, buf))
44 return 1;
45 return 0;
46}
47
48static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
49{
50 struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
51
52 if (!dev)
53 return;
54
55 dev->mtd = mtd;
56 dev->devnum = mtd->index;
57
58 dev->size = mtd->size >> 9;
59 dev->tr = tr;
60 dev->readonly = 1;
61
62 if (add_mtd_blktrans_dev(dev))
63 kfree(dev);
64}
65
66static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
67{
68 del_mtd_blktrans_dev(dev);
69}
70
71static struct mtd_blktrans_ops mtdblock_tr = {
72 .name = "mtdblock",
73 .major = 31,
74 .part_bits = 0,
75 .blksize = 512,
76 .readsect = mtdblock_readsect,
77 .writesect = mtdblock_writesect,
78 .add_mtd = mtdblock_add_mtd,
79 .remove_dev = mtdblock_remove_dev,
80 .owner = THIS_MODULE,
81};
82
83static int __init mtdblock_init(void)
84{
85 return register_mtd_blktrans(&mtdblock_tr);
86}
87
88static void __exit mtdblock_exit(void)
89{
90 deregister_mtd_blktrans(&mtdblock_tr);
91}
92
93module_init(mtdblock_init);
94module_exit(mtdblock_exit);
95
96MODULE_LICENSE("GPL");
97MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
98MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");