Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This file contains an ECC algorithm from Toshiba that detects and |
| 3 | * corrects 1 bit errors in a 256 byte block of data. |
| 4 | * |
| 5 | * drivers/mtd/nand/nand_ecc.c |
| 6 | * |
| 7 | * Copyright (C) 2000-2004 Steven J. Hill (sjhill@realitydiluted.com) |
| 8 | * Toshiba America Electronics Components, Inc. |
| 9 | * |
William Juul | cfa460a | 2007-10-31 13:53:06 +0100 | [diff] [blame] | 10 | * Copyright (C) 2006 Thomas Gleixner <tglx@linutronix.de> |
| 11 | * |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 12 | * This file is free software; you can redistribute it and/or modify it |
| 13 | * under the terms of the GNU General Public License as published by the |
| 14 | * Free Software Foundation; either version 2 or (at your option) any |
| 15 | * later version. |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 16 | * |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 17 | * This file is distributed in the hope that it will be useful, but WITHOUT |
| 18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 20 | * for more details. |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 21 | * |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 22 | * You should have received a copy of the GNU General Public License along |
| 23 | * with this file; if not, write to the Free Software Foundation, Inc., |
| 24 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 25 | * |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 26 | * As a special exception, if other files instantiate templates or use |
| 27 | * macros or inline functions from these files, or you compile these |
| 28 | * files and link them with other works to produce a work based on these |
| 29 | * files, these files do not by themselves cause the resulting work to be |
| 30 | * covered by the GNU General Public License. However the source code for |
| 31 | * these files must still be made available in accordance with section (3) |
| 32 | * of the GNU General Public License. |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 33 | * |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 34 | * This exception does not invalidate any other reasons why a work based on |
| 35 | * this file might be covered by the GNU General Public License. |
| 36 | */ |
| 37 | |
| 38 | #include <common.h> |
| 39 | |
Scott Wood | c45912d | 2008-10-24 16:20:43 -0500 | [diff] [blame] | 40 | #include <asm/errno.h> |
| 41 | #include <linux/mtd/mtd.h> |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 42 | |
Stefan Roese | f40f6db | 2009-05-20 10:58:03 +0200 | [diff] [blame] | 43 | /* The PPC4xx NDFC uses Smart Media (SMC) bytes order */ |
| 44 | #ifdef CONFIG_NAND_NDFC |
| 45 | #define CONFIG_MTD_NAND_ECC_SMC |
| 46 | #endif |
| 47 | |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 48 | /* |
| 49 | * NAND-SPL has no sofware ECC for now, so don't include nand_calculate_ecc(), |
| 50 | * only nand_correct_data() is needed |
| 51 | */ |
| 52 | |
| 53 | #ifndef CONFIG_NAND_SPL |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 54 | /* |
| 55 | * Pre-calculated 256-way 1 byte column parity |
| 56 | */ |
| 57 | static const u_char nand_ecc_precalc_table[] = { |
| 58 | 0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00, |
| 59 | 0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65, |
| 60 | 0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66, |
| 61 | 0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03, |
| 62 | 0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69, |
| 63 | 0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c, |
| 64 | 0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f, |
| 65 | 0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a, |
| 66 | 0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30, 0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a, |
| 67 | 0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55, 0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f, |
| 68 | 0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56, 0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c, |
| 69 | 0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33, 0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69, |
| 70 | 0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59, 0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03, |
| 71 | 0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c, 0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66, |
| 72 | 0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f, 0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65, |
| 73 | 0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a, 0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00 |
| 74 | }; |
| 75 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 76 | /** |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 77 | * nand_calculate_ecc - [NAND Interface] Calculate 3-byte ECC for 256-byte block |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 78 | * @mtd: MTD block structure |
| 79 | * @dat: raw data |
| 80 | * @ecc_code: buffer for ECC |
| 81 | */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 82 | int nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat, |
| 83 | u_char *ecc_code) |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 84 | { |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 85 | uint8_t idx, reg1, reg2, reg3, tmp1, tmp2; |
| 86 | int i; |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 87 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 88 | /* Initialize variables */ |
| 89 | reg1 = reg2 = reg3 = 0; |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 90 | |
| 91 | /* Build up column parity */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 92 | for(i = 0; i < 256; i++) { |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 93 | /* Get CP0 - CP5 from table */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 94 | idx = nand_ecc_precalc_table[*dat++]; |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 95 | reg1 ^= (idx & 0x3f); |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 96 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 97 | /* All bit XOR = 1 ? */ |
| 98 | if (idx & 0x40) { |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 99 | reg3 ^= (uint8_t) i; |
| 100 | reg2 ^= ~((uint8_t) i); |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 101 | } |
| 102 | } |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 103 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 104 | /* Create non-inverted ECC code from line parity */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 105 | tmp1 = (reg3 & 0x80) >> 0; /* B7 -> B7 */ |
| 106 | tmp1 |= (reg2 & 0x80) >> 1; /* B7 -> B6 */ |
| 107 | tmp1 |= (reg3 & 0x40) >> 1; /* B6 -> B5 */ |
| 108 | tmp1 |= (reg2 & 0x40) >> 2; /* B6 -> B4 */ |
| 109 | tmp1 |= (reg3 & 0x20) >> 2; /* B5 -> B3 */ |
| 110 | tmp1 |= (reg2 & 0x20) >> 3; /* B5 -> B2 */ |
| 111 | tmp1 |= (reg3 & 0x10) >> 3; /* B4 -> B1 */ |
| 112 | tmp1 |= (reg2 & 0x10) >> 4; /* B4 -> B0 */ |
| 113 | |
| 114 | tmp2 = (reg3 & 0x08) << 4; /* B3 -> B7 */ |
| 115 | tmp2 |= (reg2 & 0x08) << 3; /* B3 -> B6 */ |
| 116 | tmp2 |= (reg3 & 0x04) << 3; /* B2 -> B5 */ |
| 117 | tmp2 |= (reg2 & 0x04) << 2; /* B2 -> B4 */ |
| 118 | tmp2 |= (reg3 & 0x02) << 2; /* B1 -> B3 */ |
| 119 | tmp2 |= (reg2 & 0x02) << 1; /* B1 -> B2 */ |
| 120 | tmp2 |= (reg3 & 0x01) << 1; /* B0 -> B1 */ |
| 121 | tmp2 |= (reg2 & 0x01) << 0; /* B7 -> B0 */ |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 122 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 123 | /* Calculate final ECC code */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 124 | #ifdef CONFIG_MTD_NAND_ECC_SMC |
| 125 | ecc_code[0] = ~tmp2; |
| 126 | ecc_code[1] = ~tmp1; |
| 127 | #else |
| 128 | ecc_code[0] = ~tmp1; |
| 129 | ecc_code[1] = ~tmp2; |
| 130 | #endif |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 131 | ecc_code[2] = ((~reg1) << 2) | 0x03; |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 132 | |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 133 | return 0; |
| 134 | } |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 135 | #endif /* CONFIG_NAND_SPL */ |
| 136 | |
| 137 | static inline int countbits(uint32_t byte) |
| 138 | { |
| 139 | int res = 0; |
| 140 | |
| 141 | for (;byte; byte >>= 1) |
| 142 | res += byte & 0x01; |
| 143 | return res; |
| 144 | } |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 145 | |
| 146 | /** |
| 147 | * nand_correct_data - [NAND Interface] Detect and correct bit error(s) |
| 148 | * @mtd: MTD block structure |
| 149 | * @dat: raw data read from the chip |
| 150 | * @read_ecc: ECC from the chip |
| 151 | * @calc_ecc: the ECC calculated from raw data |
| 152 | * |
| 153 | * Detect and correct a 1 bit error for 256 byte block |
| 154 | */ |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 155 | int nand_correct_data(struct mtd_info *mtd, u_char *dat, |
| 156 | u_char *read_ecc, u_char *calc_ecc) |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 157 | { |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 158 | uint8_t s0, s1, s2; |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 159 | |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 160 | #ifdef CONFIG_MTD_NAND_ECC_SMC |
| 161 | s0 = calc_ecc[0] ^ read_ecc[0]; |
| 162 | s1 = calc_ecc[1] ^ read_ecc[1]; |
| 163 | s2 = calc_ecc[2] ^ read_ecc[2]; |
| 164 | #else |
| 165 | s1 = calc_ecc[0] ^ read_ecc[0]; |
| 166 | s0 = calc_ecc[1] ^ read_ecc[1]; |
| 167 | s2 = calc_ecc[2] ^ read_ecc[2]; |
| 168 | #endif |
| 169 | if ((s0 | s1 | s2) == 0) |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 170 | return 0; |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 171 | |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 172 | /* Check for a single bit error */ |
| 173 | if( ((s0 ^ (s0 >> 1)) & 0x55) == 0x55 && |
| 174 | ((s1 ^ (s1 >> 1)) & 0x55) == 0x55 && |
| 175 | ((s2 ^ (s2 >> 1)) & 0x54) == 0x54) { |
| 176 | |
| 177 | uint32_t byteoffs, bitnum; |
| 178 | |
| 179 | byteoffs = (s1 << 0) & 0x80; |
| 180 | byteoffs |= (s1 << 1) & 0x40; |
| 181 | byteoffs |= (s1 << 2) & 0x20; |
| 182 | byteoffs |= (s1 << 3) & 0x10; |
| 183 | |
| 184 | byteoffs |= (s0 >> 4) & 0x08; |
| 185 | byteoffs |= (s0 >> 3) & 0x04; |
| 186 | byteoffs |= (s0 >> 2) & 0x02; |
| 187 | byteoffs |= (s0 >> 1) & 0x01; |
| 188 | |
| 189 | bitnum = (s2 >> 5) & 0x04; |
| 190 | bitnum |= (s2 >> 4) & 0x02; |
| 191 | bitnum |= (s2 >> 3) & 0x01; |
| 192 | |
| 193 | dat[byteoffs] ^= (1 << bitnum); |
| 194 | |
| 195 | return 1; |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 196 | } |
Wolfgang Denk | ac7eb8a3 | 2005-09-14 23:53:32 +0200 | [diff] [blame] | 197 | |
Stefan Roese | 17b5e86 | 2007-06-01 15:12:15 +0200 | [diff] [blame] | 198 | if(countbits(s0 | ((uint32_t)s1 << 8) | ((uint32_t)s2 <<16)) == 1) |
| 199 | return 1; |
| 200 | |
Scott Wood | c45912d | 2008-10-24 16:20:43 -0500 | [diff] [blame] | 201 | return -EBADMSG; |
Wolfgang Denk | 932394a | 2005-08-17 12:55:25 +0200 | [diff] [blame] | 202 | } |