2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Authors: Ravi Pokala (rpokala@freebsd.org)
6 * Copyright (c) 2018 Panasas
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 #ifndef _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
34 #define _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
36 /* JEDEC DIMMs include one or more SMBus devices.
38 * At a minimum, they have an EEPROM containing either 256 bytes (DDR3) or 512
39 * bytes (DDR4) of "Serial Presence Detect" (SPD) information. The SPD contains
40 * data used by the memory controller to configure itself, and it also includes
41 * asset information. The layout of SPD data is defined in:
43 * JEDEC Standard 21-C, Annex K (DDR3)
44 * JEDEC Standard 21-C, Annex L (DDR4)
46 * DIMMs may also include a "Thermal Sensor on DIMM" (TSOD), which reports
47 * temperature data. While not strictly required, the TSOD is so often included
48 * that JEDEC defined standards for single chips which include both SPD and TSOD
49 * functions. They respond on multiple SMBus addresses, depending on the
52 * JEDEC Standard 21-C, TSE2002av (DDR3)
53 * JEDEC Standard 21-C, TSE2004av (DDR4)
56 /* TSE2004av defines several Device Type Identifiers (DTIs), which are the high
57 * nybble of the SMBus address. Addresses with DTIs of PROTECT (or PAGE, which
58 * has the same value) are essentially "broadcast" addresses; all SPD devices
59 * respond to them, changing their mode based on the Logical Serial Address
60 * (LSA) encoded in bits [3:1]. For normal SPD access, bits [3:1] encode the
63 #define JEDEC_SPD_PAGE_SIZE 256
64 #define JEDEC_DTI_SPD 0xa0
65 #define JEDEC_DTI_TSOD 0x30
66 #define JEDEC_DTI_PROTECT 0x60
67 #define JEDEC_LSA_PROTECT_SET0 0x02
68 #define JEDEC_LSA_PROTECT_SET1 0x08
69 #define JEDEC_LSA_PROTECT_SET2 0x0a
70 #define JEDEC_LSA_PROTECT_SET3 0x00
71 #define JEDEC_LSA_PROTECT_CLR 0x06
72 #define JEDEC_LSA_PROTECT_GET0 0x03
73 #define JEDEC_LSA_PROTECT_GET1 0x09
74 #define JEDEC_LSA_PROTECT_GET2 0x0b
75 #define JEDEC_LSA_PROTECT_GET3 0x01
76 #define JEDEC_DTI_PAGE 0x60
77 #define JEDEC_LSA_PAGE_SET0 0x0c
78 #define JEDEC_LSA_PAGE_SET1 0x0e
79 #define JEDEC_LSA_PAGE_GET 0x0d
81 /* The offsets and lengths of various SPD bytes are defined in Annex K (DDR3)
82 * and Annex L (DDR4). Conveniently, the DRAM type is at the same offset for
85 * This list only includes information needed to get the asset information and
86 * calculate the DIMM capacity.
88 #define SPD_OFFSET_DRAM_TYPE 2
89 #define SPD_OFFSET_DDR3_SDRAM_CAPACITY 4
90 #define SPD_OFFSET_DDR3_DIMM_RANKS 7
91 #define SPD_OFFSET_DDR3_SDRAM_WIDTH 7
92 #define SPD_OFFSET_DDR3_BUS_WIDTH 8
93 #define SPD_OFFSET_DDR3_TSOD_PRESENT 32
94 #define SPD_OFFSET_DDR3_SERIAL 122
95 #define SPD_LEN_DDR3_SERIAL 4
96 #define SPD_OFFSET_DDR3_PARTNUM 128
97 #define SPD_LEN_DDR3_PARTNUM 18
98 #define SPD_OFFSET_DDR4_SDRAM_CAPACITY 4
99 #define SPD_OFFSET_DDR4_SDRAM_PKG_TYPE 6
100 #define SPD_OFFSET_DDR4_DIMM_RANKS 12
101 #define SPD_OFFSET_DDR4_SDRAM_WIDTH 12
102 #define SPD_OFFSET_DDR4_BUS_WIDTH 13
103 #define SPD_OFFSET_DDR4_TSOD_PRESENT 14
104 #define SPD_OFFSET_DDR4_SERIAL 325
105 #define SPD_LEN_DDR4_SERIAL 4
106 #define SPD_OFFSET_DDR4_PARTNUM 329
107 #define SPD_LEN_DDR4_PARTNUM 20
109 /* The "DRAM Type" field of the SPD enumerates various memory technologies which
110 * have been used over the years. The list is append-only, so we need only refer
111 * to the latest SPD specification. In this case, Annex L for DDR4.
114 DRAM_TYPE_RESERVED = 0x00,
115 DRAM_TYPE_FAST_PAGE_MODE = 0x01,
116 DRAM_TYPE_EDO = 0x02,
117 DRAM_TYPE_PIPLEINED_NYBBLE = 0x03,
118 DRAM_TYPE_SDRAM = 0x04,
119 DRAM_TYPE_ROM = 0x05,
120 DRAM_TYPE_DDR_SGRAM = 0x06,
121 DRAM_TYPE_DDR_SDRAM = 0x07,
122 DRAM_TYPE_DDR2_SDRAM = 0x08,
123 DRAM_TYPE_DDR2_SDRAM_FBDIMM = 0x09,
124 DRAM_TYPE_DDR2_SDRAM_FBDIMM_PROBE = 0x0a,
125 DRAM_TYPE_DDR3_SDRAM = 0x0b,
126 DRAM_TYPE_DDR4_SDRAM = 0x0c,
127 DRAM_TYPE_RESERVED_0D = 0x0d,
128 DRAM_TYPE_DDR4E_SDRAM = 0x0e,
129 DRAM_TYPE_LPDDR3_SDRAM = 0x0f,
130 DRAM_TYPE_LPDDR4_SDRAM = 0x10,
133 /* The TSOD is accessed using a simple word interface, which is identical
134 * between TSE2002av (DDR3) and TSE2004av (DDR4).
136 #define TSOD_REG_CAPABILITES 0
137 #define TSOD_REG_CONFIG 1
138 #define TSOD_REG_LIM_HIGH 2
139 #define TSOD_REG_LIM_LOW 3
140 #define TSOD_REG_LIM_CRIT 4
141 #define TSOD_REG_TEMPERATURE 5
142 #define TSOD_REG_MANUFACTURER 6
143 #define TSOD_REG_DEV_REV 7
145 #endif /* _DEV__JEDEC_DIMM__JEDEC_DIMM_H_ */
147 /* vi: set ts=8 sw=4 sts=8 noet: */