mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-19 00:18:51 +09:00
201 lines
6.6 KiB
C
201 lines
6.6 KiB
C
/*
|
|
* This file contains an ECC algorithm from Toshiba that detects and
|
|
* corrects 1 bit errors in a 256 byte block of data.
|
|
*
|
|
* drivers/mtd/nand/nand_ecc.c
|
|
*
|
|
* Copyright (C) 2000-2004 Steven J. Hill (sjhill@realitydiluted.com)
|
|
* Toshiba America Electronics Components, Inc.
|
|
*
|
|
* $Id: nand_ecc.c,v 1.14 2004/06/16 15:34:37 gleixner Exp $
|
|
*
|
|
* This file is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 or (at your option) any
|
|
* later version.
|
|
*
|
|
* This file is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this file; if not, write to the Free Software Foundation, Inc.,
|
|
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
*
|
|
* As a special exception, if other files instantiate templates or use
|
|
* macros or inline functions from these files, or you compile these
|
|
* files and link them with other works to produce a work based on these
|
|
* files, these files do not by themselves cause the resulting work to be
|
|
* covered by the GNU General Public License. However the source code for
|
|
* these files must still be made available in accordance with section (3)
|
|
* of the GNU General Public License.
|
|
*
|
|
* This exception does not invalidate any other reasons why a work based on
|
|
* this file might be covered by the GNU General Public License.
|
|
*/
|
|
|
|
#include <common.h>
|
|
|
|
#if defined(CONFIG_CMD_NAND) && !defined(CFG_NAND_LEGACY)
|
|
|
|
#include<linux/mtd/mtd.h>
|
|
|
|
/*
|
|
* NAND-SPL has no sofware ECC for now, so don't include nand_calculate_ecc(),
|
|
* only nand_correct_data() is needed
|
|
*/
|
|
|
|
#ifndef CONFIG_NAND_SPL
|
|
/*
|
|
* Pre-calculated 256-way 1 byte column parity
|
|
*/
|
|
static const u_char nand_ecc_precalc_table[] = {
|
|
0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
|
|
0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
|
|
0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
|
|
0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
|
|
0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
|
|
0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
|
|
0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
|
|
0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
|
|
0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
|
|
0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
|
|
0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
|
|
0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
|
|
0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
|
|
0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
|
|
0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
|
|
0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00
|
|
};
|
|
|
|
/**
|
|
* nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256-byte block
|
|
* @mtd: MTD block structure
|
|
* @dat: raw data
|
|
* @ecc_code: buffer for ECC
|
|
*/
|
|
int nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
|
|
u_char *ecc_code)
|
|
{
|
|
uint8_t idx, reg1, reg2, reg3, tmp1, tmp2;
|
|
int i;
|
|
|
|
/* Initialize variables */
|
|
reg1 = reg2 = reg3 = 0;
|
|
|
|
/* Build up column parity */
|
|
for(i = 0; i < 256; i++) {
|
|
/* Get CP0 - CP5 from table */
|
|
idx = nand_ecc_precalc_table[*dat++];
|
|
reg1 ^= (idx & 0x3f);
|
|
|
|
/* All bit XOR = 1 ? */
|
|
if (idx & 0x40) {
|
|
reg3 ^= (uint8_t) i;
|
|
reg2 ^= ~((uint8_t) i);
|
|
}
|
|
}
|
|
|
|
/* Create non-inverted ECC code from line parity */
|
|
tmp1 = (reg3 & 0x80) >> 0; /* B7 -> B7 */
|
|
tmp1 |= (reg2 & 0x80) >> 1; /* B7 -> B6 */
|
|
tmp1 |= (reg3 & 0x40) >> 1; /* B6 -> B5 */
|
|
tmp1 |= (reg2 & 0x40) >> 2; /* B6 -> B4 */
|
|
tmp1 |= (reg3 & 0x20) >> 2; /* B5 -> B3 */
|
|
tmp1 |= (reg2 & 0x20) >> 3; /* B5 -> B2 */
|
|
tmp1 |= (reg3 & 0x10) >> 3; /* B4 -> B1 */
|
|
tmp1 |= (reg2 & 0x10) >> 4; /* B4 -> B0 */
|
|
|
|
tmp2 = (reg3 & 0x08) << 4; /* B3 -> B7 */
|
|
tmp2 |= (reg2 & 0x08) << 3; /* B3 -> B6 */
|
|
tmp2 |= (reg3 & 0x04) << 3; /* B2 -> B5 */
|
|
tmp2 |= (reg2 & 0x04) << 2; /* B2 -> B4 */
|
|
tmp2 |= (reg3 & 0x02) << 2; /* B1 -> B3 */
|
|
tmp2 |= (reg2 & 0x02) << 1; /* B1 -> B2 */
|
|
tmp2 |= (reg3 & 0x01) << 1; /* B0 -> B1 */
|
|
tmp2 |= (reg2 & 0x01) << 0; /* B7 -> B0 */
|
|
|
|
/* Calculate final ECC code */
|
|
#ifdef CONFIG_MTD_NAND_ECC_SMC
|
|
ecc_code[0] = ~tmp2;
|
|
ecc_code[1] = ~tmp1;
|
|
#else
|
|
ecc_code[0] = ~tmp1;
|
|
ecc_code[1] = ~tmp2;
|
|
#endif
|
|
ecc_code[2] = ((~reg1) << 2) | 0x03;
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NAND_SPL */
|
|
|
|
static inline int countbits(uint32_t byte)
|
|
{
|
|
int res = 0;
|
|
|
|
for (;byte; byte >>= 1)
|
|
res += byte & 0x01;
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* nand_correct_data - [NAND Interface] Detect and correct bit error(s)
|
|
* @mtd: MTD block structure
|
|
* @dat: raw data read from the chip
|
|
* @read_ecc: ECC from the chip
|
|
* @calc_ecc: the ECC calculated from raw data
|
|
*
|
|
* Detect and correct a 1 bit error for 256 byte block
|
|
*/
|
|
int nand_correct_data(struct mtd_info *mtd, u_char *dat,
|
|
u_char *read_ecc, u_char *calc_ecc)
|
|
{
|
|
uint8_t s0, s1, s2;
|
|
|
|
#ifdef CONFIG_MTD_NAND_ECC_SMC
|
|
s0 = calc_ecc[0] ^ read_ecc[0];
|
|
s1 = calc_ecc[1] ^ read_ecc[1];
|
|
s2 = calc_ecc[2] ^ read_ecc[2];
|
|
#else
|
|
s1 = calc_ecc[0] ^ read_ecc[0];
|
|
s0 = calc_ecc[1] ^ read_ecc[1];
|
|
s2 = calc_ecc[2] ^ read_ecc[2];
|
|
#endif
|
|
if ((s0 | s1 | s2) == 0)
|
|
return 0;
|
|
|
|
/* Check for a single bit error */
|
|
if( ((s0 ^ (s0 >> 1)) & 0x55) == 0x55 &&
|
|
((s1 ^ (s1 >> 1)) & 0x55) == 0x55 &&
|
|
((s2 ^ (s2 >> 1)) & 0x54) == 0x54) {
|
|
|
|
uint32_t byteoffs, bitnum;
|
|
|
|
byteoffs = (s1 << 0) & 0x80;
|
|
byteoffs |= (s1 << 1) & 0x40;
|
|
byteoffs |= (s1 << 2) & 0x20;
|
|
byteoffs |= (s1 << 3) & 0x10;
|
|
|
|
byteoffs |= (s0 >> 4) & 0x08;
|
|
byteoffs |= (s0 >> 3) & 0x04;
|
|
byteoffs |= (s0 >> 2) & 0x02;
|
|
byteoffs |= (s0 >> 1) & 0x01;
|
|
|
|
bitnum = (s2 >> 5) & 0x04;
|
|
bitnum |= (s2 >> 4) & 0x02;
|
|
bitnum |= (s2 >> 3) & 0x01;
|
|
|
|
dat[byteoffs] ^= (1 << bitnum);
|
|
|
|
return 1;
|
|
}
|
|
|
|
if(countbits(s0 | ((uint32_t)s1 << 8) | ((uint32_t)s2 <<16)) == 1)
|
|
return 1;
|
|
|
|
return -1;
|
|
}
|
|
|
|
#endif
|