[PATCH] ia64: const f_ops fix
[sfrench/cifs-2.6.git] / drivers / mtd / mtdblock_ro.c
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
14 static 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
24 static 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
34 static 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
55 static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
56 {
57         del_mtd_blktrans_dev(dev);
58         kfree(dev);
59 }
60
61 static 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
72 static int __init mtdblock_init(void)
73 {
74         return register_mtd_blktrans(&mtdblock_tr);
75 }
76
77 static void __exit mtdblock_exit(void)
78 {
79         deregister_mtd_blktrans(&mtdblock_tr);
80 }
81
82 module_init(mtdblock_init);
83 module_exit(mtdblock_exit);
84
85 MODULE_LICENSE("GPL");
86 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
87 MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");