projects / J-u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 0f2cbe3f JY |
1 | /* |
| 2 | * Copyright 2008 Freescale Semiconductor, Inc. | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or | |
| 5 | * modify it under the terms of the GNU General Public License | |
| 6 | * Version 2 as published by the Free Software Foundation. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <common.h> | |
| 10 | #include <ddr_spd.h> | |
| 11 | ||
| 12 | /* used for ddr1 and ddr2 spd */ | |
| 13 | static int | |
| 14 | spd_check(const u8 *buf, u8 spd_rev, u8 spd_cksum) | |
| 15 | { | |
| 16 | unsigned int cksum = 0; | |
| 17 | unsigned int i; | |
| 18 | ||
| 19 | /* | |
| 20 | * Check SPD revision supported | |
| c7fd27cc | 21 | * Rev 1.X or less supported by this code |
| 0f2cbe3f | 22 | */ |
| bcb6c2bb | 23 | if (spd_rev >= 0x20) { |
| 0f2cbe3f JY |
24 | printf("SPD revision %02X not supported by this code\n", |
| 25 | spd_rev); | |
| 26 | return 1; | |
| 27 | } | |
| bcb6c2bb YS |
28 | if (spd_rev > 0x13) { |
| 29 | printf("SPD revision %02X not verified by this code\n", | |
| 30 | spd_rev); | |
| 31 | } | |
| 0f2cbe3f JY |
32 | |
| 33 | /* | |
| 34 | * Calculate checksum | |
| 35 | */ | |
| 36 | for (i = 0; i < 63; i++) { | |
| 37 | cksum += *buf++; | |
| 38 | } | |
| 39 | cksum &= 0xFF; | |
| 40 | ||
| 41 | if (cksum != spd_cksum) { | |
| 42 | printf("SPD checksum unexpected. " | |
| 43 | "Checksum in SPD = %02X, computed SPD = %02X\n", | |
| 44 | spd_cksum, cksum); | |
| 45 | return 1; | |
| 46 | } | |
| 47 | ||
| 48 | return 0; | |
| 49 | } | |
| 50 | ||
| 51 | unsigned int | |
| 52 | ddr1_spd_check(const ddr1_spd_eeprom_t *spd) | |
| 53 | { | |
| 54 | const u8 *p = (const u8 *)spd; | |
| 55 | ||
| 56 | return spd_check(p, spd->spd_rev, spd->cksum); | |
| 57 | } | |
| 58 | ||
| 59 | unsigned int | |
| 60 | ddr2_spd_check(const ddr2_spd_eeprom_t *spd) | |
| 61 | { | |
| 62 | const u8 *p = (const u8 *)spd; | |
| 63 | ||
| 64 | return spd_check(p, spd->spd_rev, spd->cksum); | |
| 65 | } | |
| c360ceac DL |
66 | |
| 67 | /* | |
| 68 | * CRC16 compute for DDR3 SPD | |
| 69 | * Copied from DDR3 SPD spec. | |
| 70 | */ | |
| 71 | static int | |
| 72 | crc16(char *ptr, int count) | |
| 73 | { | |
| 74 | int crc, i; | |
| 75 | ||
| 76 | crc = 0; | |
| 77 | while (--count >= 0) { | |
| 78 | crc = crc ^ (int)*ptr++ << 8; | |
| 79 | for (i = 0; i < 8; ++i) | |
| 80 | if (crc & 0x8000) | |
| 81 | crc = crc << 1 ^ 0x1021; | |
| 82 | else | |
| 83 | crc = crc << 1; | |
| 84 | } | |
| 85 | return crc & 0xffff; | |
| 86 | } | |
| 87 | ||
| 88 | unsigned int | |
| 89 | ddr3_spd_check(const ddr3_spd_eeprom_t *spd) | |
| 90 | { | |
| 91 | char *p = (char *)spd; | |
| 92 | int csum16; | |
| 93 | int len; | |
| 94 | char crc_lsb; /* byte 126 */ | |
| 95 | char crc_msb; /* byte 127 */ | |
| 96 | ||
| 97 | /* | |
| 98 | * SPD byte0[7] - CRC coverage | |
| 99 | * 0 = CRC covers bytes 0~125 | |
| 100 | * 1 = CRC covers bytes 0~116 | |
| 101 | */ | |
| 102 | ||
| 103 | len = !(spd->info_size_crc & 0x80) ? 126 : 117; | |
| 104 | csum16 = crc16(p, len); | |
| 105 | ||
| 106 | crc_lsb = (char) (csum16 & 0xff); | |
| 107 | crc_msb = (char) (csum16 >> 8); | |
| 108 | ||
| 109 | if (spd->crc[0] == crc_lsb && spd->crc[1] == crc_msb) { | |
| 110 | return 0; | |
| 111 | } else { | |
| 112 | printf("SPD checksum unexpected.\n" | |
| 113 | "Checksum lsb in SPD = %02X, computed SPD = %02X\n" | |
| 114 | "Checksum msb in SPD = %02X, computed SPD = %02X\n", | |
| 115 | spd->crc[0], crc_lsb, spd->crc[1], crc_msb); | |
| 116 | return 1; | |
| 117 | } | |
| 118 | } |