xref: /freebsd/sys/dev/jedec_dimm/jedec_dimm.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Authors: Ravi Pokala (rpokala@freebsd.org)
5  *
6  * Copyright (c) 2018 Panasas
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
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.
17  *
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
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
34 #define _DEV__JEDEC_DIMM__JEDEC_DIMM_H_
35 
36 /* JEDEC DIMMs include one or more SMBus devices.
37  *
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:
42  *
43  * JEDEC Standard 21-C, Annex K (DDR3)
44  * JEDEC Standard 21-C, Annex L (DDR4)
45  *
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
50  * function.
51  *
52  * JEDEC Standard 21-C, TSE2002av (DDR3)
53  * JEDEC Standard 21-C, TSE2004av (DDR4)
54  */
55 
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
61  * DIMM slot number.
62  */
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
80 
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
83  * both versions.
84  *
85  * This list only includes information needed to get the asset information and
86  * calculate the DIMM capacity.
87  */
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
108 
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.
112  */
113 enum dram_type {
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,
131 };
132 
133 /* The TSOD is accessed using a simple word interface, which is identical
134  * between TSE2002av (DDR3) and TSE2004av (DDR4).
135  */
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
144 
145 #endif /* _DEV__JEDEC_DIMM__JEDEC_DIMM_H_ */
146 
147 /* vi: set ts=8 sw=4 sts=8 noet: */
148