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