Merge git://git.denx.de/u-boot-riscv
[platform/kernel/u-boot.git] / common / ddr_spd.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2008-2014 Freescale Semiconductor, Inc.
4  */
5
6 #include <common.h>
7 #include <ddr_spd.h>
8
9 /* used for ddr1 and ddr2 spd */
10 static int
11 spd_check(const u8 *buf, u8 spd_rev, u8 spd_cksum)
12 {
13         unsigned int cksum = 0;
14         unsigned int i;
15
16         /*
17          * Check SPD revision supported
18          * Rev 1.X or less supported by this code
19          */
20         if (spd_rev >= 0x20) {
21                 printf("SPD revision %02X not supported by this code\n",
22                        spd_rev);
23                 return 1;
24         }
25         if (spd_rev > 0x13) {
26                 printf("SPD revision %02X not verified by this code\n",
27                        spd_rev);
28         }
29
30         /*
31          * Calculate checksum
32          */
33         for (i = 0; i < 63; i++) {
34                 cksum += *buf++;
35         }
36         cksum &= 0xFF;
37
38         if (cksum != spd_cksum) {
39                 printf("SPD checksum unexpected. "
40                         "Checksum in SPD = %02X, computed SPD = %02X\n",
41                         spd_cksum, cksum);
42                 return 1;
43         }
44
45         return 0;
46 }
47
48 unsigned int
49 ddr1_spd_check(const ddr1_spd_eeprom_t *spd)
50 {
51         const u8 *p = (const u8 *)spd;
52
53         return spd_check(p, spd->spd_rev, spd->cksum);
54 }
55
56 unsigned int
57 ddr2_spd_check(const ddr2_spd_eeprom_t *spd)
58 {
59         const u8 *p = (const u8 *)spd;
60
61         return spd_check(p, spd->spd_rev, spd->cksum);
62 }
63
64 /*
65  * CRC16 compute for DDR3 SPD
66  * Copied from DDR3 SPD spec.
67  */
68 static int
69 crc16(char *ptr, int count)
70 {
71         int crc, i;
72
73         crc = 0;
74         while (--count >= 0) {
75                 crc = crc ^ (int)*ptr++ << 8;
76                 for (i = 0; i < 8; ++i)
77                         if (crc & 0x8000)
78                                 crc = crc << 1 ^ 0x1021;
79                         else
80                                 crc = crc << 1;
81         }
82         return crc & 0xffff;
83 }
84
85 unsigned int
86 ddr3_spd_check(const ddr3_spd_eeprom_t *spd)
87 {
88         char *p = (char *)spd;
89         int csum16;
90         int len;
91         char crc_lsb;   /* byte 126 */
92         char crc_msb;   /* byte 127 */
93
94         /*
95          * SPD byte0[7] - CRC coverage
96          * 0 = CRC covers bytes 0~125
97          * 1 = CRC covers bytes 0~116
98          */
99
100         len = !(spd->info_size_crc & 0x80) ? 126 : 117;
101         csum16 = crc16(p, len);
102
103         crc_lsb = (char) (csum16 & 0xff);
104         crc_msb = (char) (csum16 >> 8);
105
106         if (spd->crc[0] == crc_lsb && spd->crc[1] == crc_msb) {
107                 return 0;
108         } else {
109                 printf("SPD checksum unexpected.\n"
110                         "Checksum lsb in SPD = %02X, computed SPD = %02X\n"
111                         "Checksum msb in SPD = %02X, computed SPD = %02X\n",
112                         spd->crc[0], crc_lsb, spd->crc[1], crc_msb);
113                 return 1;
114         }
115 }
116
117 unsigned int ddr4_spd_check(const struct ddr4_spd_eeprom_s *spd)
118 {
119         char *p = (char *)spd;
120         int csum16;
121         int len;
122         char crc_lsb;   /* byte 126 */
123         char crc_msb;   /* byte 127 */
124
125         len = 126;
126         csum16 = crc16(p, len);
127
128         crc_lsb = (char) (csum16 & 0xff);
129         crc_msb = (char) (csum16 >> 8);
130
131         if (spd->crc[0] != crc_lsb || spd->crc[1] != crc_msb) {
132                 printf("SPD checksum unexpected.\n"
133                         "Checksum lsb in SPD = %02X, computed SPD = %02X\n"
134                         "Checksum msb in SPD = %02X, computed SPD = %02X\n",
135                         spd->crc[0], crc_lsb, spd->crc[1], crc_msb);
136                 return 1;
137         }
138
139         p = (char *)((ulong)spd + 128);
140         len = 126;
141         csum16 = crc16(p, len);
142
143         crc_lsb = (char) (csum16 & 0xff);
144         crc_msb = (char) (csum16 >> 8);
145
146         if (spd->mod_section.uc[126] != crc_lsb ||
147             spd->mod_section.uc[127] != crc_msb) {
148                 printf("SPD checksum unexpected.\n"
149                         "Checksum lsb in SPD = %02X, computed SPD = %02X\n"
150                         "Checksum msb in SPD = %02X, computed SPD = %02X\n",
151                         spd->mod_section.uc[126],
152                         crc_lsb, spd->mod_section.uc[127],
153                         crc_msb);
154                 return 1;
155         }
156
157         return 0;
158 }