xref: /freebsd/sys/dev/jedec_dimm/jedec_dimm.h (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Authors: Ravi Pokala (rpokala@freebsd.org)
5  *
6  * Copyright (c) 2018-2023 Panasas
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
31 #define _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
32 
33 /* JEDEC DIMMs include one or more SMBus devices.
34  *
35  * At a minimum, they have an EEPROM containing either 256 bytes (DDR3) or 512
36  * bytes (DDR4) of "Serial Presence Detect" (SPD) information. The SPD contains
37  * data used by the memory controller to configure itself, and it also includes
38  * asset information. The layout of SPD data is defined in:
39  *
40  * JEDEC Standard 21-C, Annex K (DDR3)
41  * JEDEC Standard 21-C, Annex L (DDR4)
42  *
43  * DIMMs may also include a "Thermal Sensor on DIMM" (TSOD), which reports
44  * temperature data. While not strictly required, the TSOD is so often included
45  * that JEDEC defined standards for single chips which include both SPD and TSOD
46  * functions. They respond on multiple SMBus addresses, depending on the
47  * function.
48  *
49  * JEDEC Standard 21-C, TSE2002av (DDR3)
50  * JEDEC Standard 21-C, TSE2004av (DDR4)
51  */
52 
53 /* TSE2004av defines several Device Type Identifiers (DTIs), which are the high
54  * nybble of the SMBus address. Addresses with DTIs of PROTECT (or PAGE, which
55  * has the same value) are essentially "broadcast" addresses; all SPD devices
56  * respond to them, changing their mode based on the Logical Serial Address
57  * (LSA) encoded in bits [3:1]. For normal SPD access, bits [3:1] encode the
58  * DIMM slot number.
59  */
60 #define JEDEC_SPD_PAGE_SIZE	256
61 #define JEDEC_DTI_SPD		0xa0
62 #define JEDEC_DTI_TSOD		0x30
63 #define JEDEC_DTI_PROTECT	0x60
64 #define JEDEC_LSA_PROTECT_SET0	0x02
65 #define JEDEC_LSA_PROTECT_SET1	0x08
66 #define JEDEC_LSA_PROTECT_SET2	0x0a
67 #define JEDEC_LSA_PROTECT_SET3	0x00
68 #define JEDEC_LSA_PROTECT_CLR	0x06
69 #define JEDEC_LSA_PROTECT_GET0	0x03
70 #define JEDEC_LSA_PROTECT_GET1	0x09
71 #define JEDEC_LSA_PROTECT_GET2	0x0b
72 #define JEDEC_LSA_PROTECT_GET3	0x01
73 #define JEDEC_DTI_PAGE		0x60
74 #define JEDEC_LSA_PAGE_SET0	0x0c
75 #define JEDEC_LSA_PAGE_SET1	0x0e
76 #define JEDEC_LSA_PAGE_GET	0x0d
77 
78 /* The offsets and lengths of various SPD bytes are defined in Annex K (DDR3)
79  * and Annex L (DDR4). Conveniently, the DRAM type is at the same offset for
80  * both versions.
81  *
82  * This list only includes information needed to get the asset information and
83  * calculate the DIMM capacity.
84  */
85 #define SPD_OFFSET_DRAM_TYPE 		2
86 #define SPD_OFFSET_DDR3_SDRAM_CAPACITY	4
87 #define SPD_OFFSET_DDR3_DIMM_RANKS	7
88 #define SPD_OFFSET_DDR3_SDRAM_WIDTH	7
89 #define SPD_OFFSET_DDR3_BUS_WIDTH	8
90 #define SPD_OFFSET_DDR3_TSOD_PRESENT	32
91 #define SPD_OFFSET_DDR3_MOD_MFG_YEAR	120
92 #define SPD_OFFSET_DDR3_MOD_MFG_WEEK	121
93 #define SPD_OFFSET_DDR3_SERIAL		122
94 #define SPD_LEN_DDR3_SERIAL		4
95 #define SPD_OFFSET_DDR3_PARTNUM		128
96 #define SPD_LEN_DDR3_PARTNUM		18
97 #define SPD_OFFSET_DDR4_SDRAM_CAPACITY	4
98 #define SPD_OFFSET_DDR4_SDRAM_PKG_TYPE	6
99 #define SPD_OFFSET_DDR4_DIMM_RANKS	12
100 #define SPD_OFFSET_DDR4_SDRAM_WIDTH	12
101 #define SPD_OFFSET_DDR4_BUS_WIDTH	13
102 #define SPD_OFFSET_DDR4_TSOD_PRESENT	14
103 #define SPD_OFFSET_DDR4_MOD_MFG_YEAR	323
104 #define SPD_OFFSET_DDR4_MOD_MFG_WEEK	324
105 #define SPD_OFFSET_DDR4_SERIAL		325
106 #define SPD_LEN_DDR4_SERIAL		4
107 #define SPD_OFFSET_DDR4_PARTNUM		329
108 #define SPD_LEN_DDR4_PARTNUM		20
109 
110 /* The "DRAM Type" field of the SPD enumerates various memory technologies which
111  * have been used over the years. The list is append-only, so we need only refer
112  * to the latest SPD specification. In this case, Annex L for DDR4.
113  */
114 enum dram_type {
115 	DRAM_TYPE_RESERVED = 			0x00,
116 	DRAM_TYPE_FAST_PAGE_MODE = 		0x01,
117 	DRAM_TYPE_EDO = 			0x02,
118 	DRAM_TYPE_PIPLEINED_NYBBLE = 		0x03,
119 	DRAM_TYPE_SDRAM = 			0x04,
120 	DRAM_TYPE_ROM = 			0x05,
121 	DRAM_TYPE_DDR_SGRAM = 			0x06,
122 	DRAM_TYPE_DDR_SDRAM = 			0x07,
123 	DRAM_TYPE_DDR2_SDRAM = 			0x08,
124 	DRAM_TYPE_DDR2_SDRAM_FBDIMM = 		0x09,
125 	DRAM_TYPE_DDR2_SDRAM_FBDIMM_PROBE =	0x0a,
126 	DRAM_TYPE_DDR3_SDRAM = 			0x0b,
127 	DRAM_TYPE_DDR4_SDRAM = 			0x0c,
128 	DRAM_TYPE_RESERVED_0D = 		0x0d,
129 	DRAM_TYPE_DDR4E_SDRAM = 		0x0e,
130 	DRAM_TYPE_LPDDR3_SDRAM = 		0x0f,
131 	DRAM_TYPE_LPDDR4_SDRAM = 		0x10,
132 };
133 
134 /* The TSOD is accessed using a simple word interface, which is identical
135  * between TSE2002av (DDR3) and TSE2004av (DDR4).
136  */
137 #define TSOD_REG_CAPABILITES	0
138 #define TSOD_REG_CONFIG		1
139 #define TSOD_REG_LIM_HIGH	2
140 #define TSOD_REG_LIM_LOW	3
141 #define TSOD_REG_LIM_CRIT	4
142 #define TSOD_REG_TEMPERATURE	5
143 #define TSOD_REG_MANUFACTURER	6
144 #define TSOD_REG_DEV_REV	7
145 
146 #endif /* _DEV__JEDEC_DIMM__JEDEC_DIMM_H_ */
147 
148 /* vi: set ts=8 sw=4 sts=8 noet: */
149