[8.09] [kernel] generic-2.6: remove empty patches directory
[openwrt/svn-archive/archive.git] / target / linux / generic-2.6 / files / fs / yaffs2 / yaffs_ecc.h
1 /*
2 * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
3 *
4 * Copyright (C) 2002-2007 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License version 2.1 as
11 * published by the Free Software Foundation.
12 *
13 * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
14 */
15
16 /*
17 * This code implements the ECC algorithm used in SmartMedia.
18 *
19 * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
20 * The two unused bit are set to 1.
21 * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
22 * blocks are used on a 512-byte NAND page.
23 *
24 */
25
26 #ifndef __YAFFS_ECC_H__
27 #define __YAFFS_ECC_H__
28
29 typedef struct {
30 unsigned char colParity;
31 unsigned lineParity;
32 unsigned lineParityPrime;
33 } yaffs_ECCOther;
34
35 void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc);
36 int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
37 const unsigned char *test_ecc);
38
39 void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes,
40 yaffs_ECCOther * ecc);
41 int yaffs_ECCCorrectOther(unsigned char *data, unsigned nBytes,
42 yaffs_ECCOther * read_ecc,
43 const yaffs_ECCOther * test_ecc);
44 #endif