diff options
Diffstat (limited to 'drivers/nand/nand_ecc.c')
| -rw-r--r-- | drivers/nand/nand_ecc.c | 244 |
1 files changed, 0 insertions, 244 deletions
diff --git a/drivers/nand/nand_ecc.c b/drivers/nand/nand_ecc.c deleted file mode 100644 index f33be9655d..0000000000 --- a/drivers/nand/nand_ecc.c +++ /dev/null @@ -1,244 +0,0 @@ -/* - * 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 (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined(CFG_NAND_LEGACY) - -#include<linux/mtd/mtd.h> -/* - * 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_trans_result - [GENERIC] create non-inverted ECC - * @reg2: line parity reg 2 - * @reg3: line parity reg 3 - * @ecc_code: ecc - * - * Creates non-inverted ECC code from line parity - */ -static void nand_trans_result(u_char reg2, u_char reg3, - u_char *ecc_code) -{ - u_char a, b, i, tmp1, tmp2; - - /* Initialize variables */ - a = b = 0x80; - tmp1 = tmp2 = 0; - - /* Calculate first ECC byte */ - for (i = 0; i < 4; i++) { - if (reg3 & a) /* LP15,13,11,9 --> ecc_code[0] */ - tmp1 |= b; - b >>= 1; - if (reg2 & a) /* LP14,12,10,8 --> ecc_code[0] */ - tmp1 |= b; - b >>= 1; - a >>= 1; - } - - /* Calculate second ECC byte */ - b = 0x80; - for (i = 0; i < 4; i++) { - if (reg3 & a) /* LP7,5,3,1 --> ecc_code[1] */ - tmp2 |= b; - b >>= 1; - if (reg2 & a) /* LP6,4,2,0 --> ecc_code[1] */ - tmp2 |= b; - b >>= 1; - a >>= 1; - } - - /* Store two of the ECC bytes */ - ecc_code[0] = tmp1; - ecc_code[1] = tmp2; -} - -/** - * nand_calculate_ecc - [NAND Interface] Calculate 3 byte ECC code 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) -{ - u_char idx, reg1, reg2, reg3; - int j; - - /* Initialize variables */ - reg1 = reg2 = reg3 = 0; - ecc_code[0] = ecc_code[1] = ecc_code[2] = 0; - - /* Build up column parity */ - for(j = 0; j < 256; j++) { - - /* Get CP0 - CP5 from table */ - idx = nand_ecc_precalc_table[dat[j]]; - reg1 ^= (idx & 0x3f); - - /* All bit XOR = 1 ? */ - if (idx & 0x40) { - reg3 ^= (u_char) j; - reg2 ^= ~((u_char) j); - } - } - - /* Create non-inverted ECC code from line parity */ - nand_trans_result(reg2, reg3, ecc_code); - - /* Calculate final ECC code */ - ecc_code[0] = ~ecc_code[0]; - ecc_code[1] = ~ecc_code[1]; - ecc_code[2] = ((~reg1) << 2) | 0x03; - return 0; -} - -/** - * 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) -{ - u_char a, b, c, d1, d2, d3, add, bit, i; - - /* Do error detection */ - d1 = calc_ecc[0] ^ read_ecc[0]; - d2 = calc_ecc[1] ^ read_ecc[1]; - d3 = calc_ecc[2] ^ read_ecc[2]; - - if ((d1 | d2 | d3) == 0) { - /* No errors */ - return 0; - } - else { - a = (d1 ^ (d1 >> 1)) & 0x55; - b = (d2 ^ (d2 >> 1)) & 0x55; - c = (d3 ^ (d3 >> 1)) & 0x54; - - /* Found and will correct single bit error in the data */ - if ((a == 0x55) && (b == 0x55) && (c == 0x54)) { - c = 0x80; - add = 0; - a = 0x80; - for (i=0; i<4; i++) { - if (d1 & c) - add |= a; - c >>= 2; - a >>= 1; - } - c = 0x80; - for (i=0; i<4; i++) { - if (d2 & c) - add |= a; - c >>= 2; - a >>= 1; - } - bit = 0; - b = 0x04; - c = 0x80; - for (i=0; i<3; i++) { - if (d3 & c) - bit |= b; - c >>= 2; - b >>= 1; - } - b = 0x01; - a = dat[add]; - a ^= (b << bit); - dat[add] = a; - return 1; - } else { - i = 0; - while (d1) { - if (d1 & 0x01) - ++i; - d1 >>= 1; - } - while (d2) { - if (d2 & 0x01) - ++i; - d2 >>= 1; - } - while (d3) { - if (d3 & 0x01) - ++i; - d3 >>= 1; - } - if (i == 1) { - /* ECC Code Error Correction */ - read_ecc[0] = calc_ecc[0]; - read_ecc[1] = calc_ecc[1]; - read_ecc[2] = calc_ecc[2]; - return 2; - } - else { - /* Uncorrectable Error */ - return -1; - } - } - } - - /* Should never happen */ - return -1; -} - -#endif /* CONFIG_COMMANDS & CFG_CMD_NAND */ |