[go: nahoru, domu]

1/*
2 * Copyright © 2009 - Maxim Levitsky
3 * Common routines & support for SmartMedia/xD format
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9#include <linux/bitops.h>
10#include <linux/mtd/mtd.h>
11
12/* Full oob structure as written on the flash */
13struct sm_oob {
14	uint32_t reserved;
15	uint8_t data_status;
16	uint8_t block_status;
17	uint8_t lba_copy1[2];
18	uint8_t ecc2[3];
19	uint8_t lba_copy2[2];
20	uint8_t ecc1[3];
21} __packed;
22
23
24/* one sector is always 512 bytes, but it can consist of two nand pages */
25#define SM_SECTOR_SIZE		512
26
27/* oob area is also 16 bytes, but might be from two pages */
28#define SM_OOB_SIZE		16
29
30/* This is maximum zone size, and all devices that have more that one zone
31   have this size */
32#define SM_MAX_ZONE_SIZE 	1024
33
34/* support for small page nand */
35#define SM_SMALL_PAGE 		256
36#define SM_SMALL_OOB_SIZE	8
37
38
39extern int sm_register_device(struct mtd_info *mtd, int smartmedia);
40
41
42static inline int sm_sector_valid(struct sm_oob *oob)
43{
44	return hweight16(oob->data_status) >= 5;
45}
46
47static inline int sm_block_valid(struct sm_oob *oob)
48{
49	return hweight16(oob->block_status) >= 7;
50}
51
52static inline int sm_block_erased(struct sm_oob *oob)
53{
54	static const uint32_t erased_pattern[4] = {
55		0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
56
57	/* First test for erased block */
58	if (!memcmp(oob, erased_pattern, sizeof(*oob)))
59		return 1;
60	return 0;
61}
62