cpupower: Rename package from cpupowerutils to cpupower
[linux-2.6.git] / drivers / mtd / mtdblock_ro.c
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
27 static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
28                               unsigned long block, char *buf)
29 {
30         size_t retlen;
31
32         if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf))
33                 return 1;
34         return 0;
35 }
36
37 static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
38                               unsigned long block, char *buf)
39 {
40         size_t retlen;
41
42         if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf))
43                 return 1;
44         return 0;
45 }
46
47 static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
48 {
49         struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
50
51         if (!dev)
52                 return;
53
54         dev->mtd = mtd;
55         dev->devnum = mtd->index;
56
57         dev->size = mtd->size >> 9;
58         dev->tr = tr;
59         dev->readonly = 1;
60
61         if (add_mtd_blktrans_dev(dev))
62                 kfree(dev);
63 }
64
65 static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
66 {
67         del_mtd_blktrans_dev(dev);
68 }
69
70 static struct mtd_blktrans_ops mtdblock_tr = {
71         .name           = "mtdblock",
72         .major          = 31,
73         .part_bits      = 0,
74         .blksize        = 512,
75         .readsect       = mtdblock_readsect,
76         .writesect      = mtdblock_writesect,
77         .add_mtd        = mtdblock_add_mtd,
78         .remove_dev     = mtdblock_remove_dev,
79         .owner          = THIS_MODULE,
80 };
81
82 static int __init mtdblock_init(void)
83 {
84         return register_mtd_blktrans(&mtdblock_tr);
85 }
86
87 static void __exit mtdblock_exit(void)
88 {
89         deregister_mtd_blktrans(&mtdblock_tr);
90 }
91
92 module_init(mtdblock_init);
93 module_exit(mtdblock_exit);
94
95 MODULE_LICENSE("GPL");
96 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
97 MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");