tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
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;
48 if ((mtd->flags & (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) !=
49 (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE))
50 dev->readonly = 1;
51
52 add_mtd_blktrans_dev(dev);
53}
54
55static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
56{
57 del_mtd_blktrans_dev(dev);
58 kfree(dev);
59}
60
61static struct mtd_blktrans_ops mtdblock_tr = {
62 .name = "mtdblock",
63 .major = 31,
64 .part_bits = 0,
65 .readsect = mtdblock_readsect,
66 .writesect = mtdblock_writesect,
67 .add_mtd = mtdblock_add_mtd,
68 .remove_dev = mtdblock_remove_dev,
69 .owner = THIS_MODULE,
70};
71
72static int __init mtdblock_init(void)
73{
74 return register_mtd_blktrans(&mtdblock_tr);
75}
76
77static void __exit mtdblock_exit(void)
78{
79 deregister_mtd_blktrans(&mtdblock_tr);
80}
81
82module_init(mtdblock_init);
83module_exit(mtdblock_exit);
84
85MODULE_LICENSE("GPL");
86MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
87MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");