1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Simple read-only (writable only for RAM) mtdblock driver
 4 *
 5 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 6 */
 7
 8#include <linux/init.h>
 9#include <linux/slab.h>
10#include <linux/mtd/mtd.h>
11#include <linux/mtd/blktrans.h>
12#include <linux/module.h>
13#include <linux/major.h>
14
15static int mtdblock_readsect(struct mtd_blktrans_dev *dev,
16			      unsigned long block, char *buf)
17{
18	size_t retlen;
19	int err;
20
21	err = mtd_read(dev->mtd, (block * 512), 512, &retlen, buf);
22	if (err && !mtd_is_bitflip(err))
23		return 1;
24	return 0;
25}
26
27static int mtdblock_writesect(struct mtd_blktrans_dev *dev,
28			      unsigned long block, char *buf)
29{
30	size_t retlen;
31
32	if (mtd_write(dev->mtd, (block * 512), 512, &retlen, buf))
33		return 1;
34	return 0;
35}
36
37static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
38{
39	struct mtd_blktrans_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
40
41	if (!dev)
42		return;
43
44	dev->mtd = mtd;
45	dev->devnum = mtd->index;
46
47	dev->size = mtd->size >> 9;
48	dev->tr = tr;
49	dev->readonly = 1;
50
51	if (mtd_type_is_nand(mtd))
52		pr_warn_ratelimited("%s: MTD device '%s' is NAND, please consider using UBI block devices instead.\n",
53			tr->name, mtd->name);
54
55	if (add_mtd_blktrans_dev(dev))
56		kfree(dev);
57}
58
59static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
60{
61	del_mtd_blktrans_dev(dev);
62}
63
64static struct mtd_blktrans_ops mtdblock_tr = {
65	.name		= "mtdblock",
66	.major		= MTD_BLOCK_MAJOR,
67	.part_bits	= 0,
68	.blksize 	= 512,
69	.readsect	= mtdblock_readsect,
70	.writesect	= mtdblock_writesect,
71	.add_mtd	= mtdblock_add_mtd,
72	.remove_dev	= mtdblock_remove_dev,
73	.owner		= THIS_MODULE,
74};
75
76module_mtd_blktrans(mtdblock_tr);
 
 
 
 
 
 
 
 
 
 
 
77
78MODULE_LICENSE("GPL");
79MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
80MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");

 
 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
27static 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
37static 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
47static 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
65static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev)
66{
67	del_mtd_blktrans_dev(dev);
68}
69
70static 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
82static int __init mtdblock_init(void)
83{
84	return register_mtd_blktrans(&mtdblock_tr);
85}
86
87static void __exit mtdblock_exit(void)
88{
89	deregister_mtd_blktrans(&mtdblock_tr);
90}
91
92module_init(mtdblock_init);
93module_exit(mtdblock_exit);
94
95MODULE_LICENSE("GPL");
96MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
97MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices");