1 .. SPDX-License-Identifier: GPL-2.0-or-later 1 .. SPDX-License-Identifier: GPL-2.0-or-later
2 2
3 Kernel driver spd5118 3 Kernel driver spd5118
4 ===================== 4 =====================
5 5
6 Supported chips: 6 Supported chips:
7 7
8 * SPD5118 (JEDEC JESD300) compliant temperat 8 * SPD5118 (JEDEC JESD300) compliant temperature sensor chips
9 9
10 JEDEC standard download: 10 JEDEC standard download:
11 https://www.jedec.org/standards-docume 11 https://www.jedec.org/standards-documents/docs/jesd300-5b01
12 (account required) 12 (account required)
13 13
14 14
15 Prefix: 'spd5118' 15 Prefix: 'spd5118'
16 16
17 Addresses scanned: I2C 0x50 - 0x57 17 Addresses scanned: I2C 0x50 - 0x57
18 18
19 Author: 19 Author:
20 Guenter Roeck <linux@roeck-us.net> 20 Guenter Roeck <linux@roeck-us.net>
21 21
22 22
23 Description 23 Description
24 ----------- 24 -----------
25 25
26 This driver implements support for SPD5118 (JE 26 This driver implements support for SPD5118 (JEDEC JESD300) compliant temperature
27 sensors, which are used on many DDR5 memory mo 27 sensors, which are used on many DDR5 memory modules. Some systems use the sensor
28 to prevent memory overheating by automatically 28 to prevent memory overheating by automatically throttling the memory controller.
29 29
30 The driver auto-detects SPD5118 compliant chip 30 The driver auto-detects SPD5118 compliant chips, but can also be instantiated
31 using devicetree/firmware nodes. 31 using devicetree/firmware nodes.
32 32
33 A SPD5118 compliant chip supports a single tem 33 A SPD5118 compliant chip supports a single temperature sensor. Critical minimum,
34 minimum, maximum, and critical temperature can 34 minimum, maximum, and critical temperature can be configured. There are alarms
35 for low critical, low, high, and critical thre 35 for low critical, low, high, and critical thresholds.
36 36
37 37
38 Hardware monitoring sysfs entries 38 Hardware monitoring sysfs entries
39 --------------------------------- 39 ---------------------------------
40 40
41 ======================= ====================== 41 ======================= ==================================
42 temp1_input Temperature (RO) 42 temp1_input Temperature (RO)
43 temp1_lcrit Low critical high temp 43 temp1_lcrit Low critical high temperature (RW)
44 temp1_min Minimum temperature (R 44 temp1_min Minimum temperature (RW)
45 temp1_max Maximum temperature (R 45 temp1_max Maximum temperature (RW)
46 temp1_crit Critical high temperat 46 temp1_crit Critical high temperature (RW)
47 47
48 temp1_lcrit_alarm Temperature low critic 48 temp1_lcrit_alarm Temperature low critical alarm
49 temp1_min_alarm Temperature low alarm 49 temp1_min_alarm Temperature low alarm
50 temp1_max_alarm Temperature high alarm 50 temp1_max_alarm Temperature high alarm
51 temp1_crit_alarm Temperature critical a 51 temp1_crit_alarm Temperature critical alarm
52 ======================= ====================== 52 ======================= ==================================
53 53
54 Alarm attributes are sticky until read and wil 54 Alarm attributes are sticky until read and will be cleared afterwards
55 unless the alarm condition still applies. 55 unless the alarm condition still applies.
56 56
57 57
58 SPD (Serial Presence Detect) support 58 SPD (Serial Presence Detect) support
59 ------------------------------------ 59 ------------------------------------
60 60
61 The driver also supports reading the SPD NVRAM 61 The driver also supports reading the SPD NVRAM on SPD5118 compatible chips.
62 SPD data is available from the 'eeprom' binary 62 SPD data is available from the 'eeprom' binary attribute file attached to the
63 chip's I2C device. 63 chip's I2C device.
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.