| .. SPDX-License-Identifier: GPL-2.0-or-later |
| |
| Kernel driver spd5118 |
| ===================== |
| |
| Supported chips: |
| |
| * SPD5118 (JEDEC JESD300) compliant temperature sensor chips |
| |
| JEDEC standard download: |
| https://www.jedec.org/standards-documents/docs/jesd300-5b01 |
| (account required) |
| |
| |
| Prefix: 'spd5118' |
| |
| Addresses scanned: I2C 0x50 - 0x57 |
| |
| Author: |
| Guenter Roeck <linux@roeck-us.net> |
| |
| |
| Description |
| ----------- |
| |
| This driver implements support for SPD5118 (JEDEC JESD300) compliant temperature |
| sensors, which are used on many DDR5 memory modules. Some systems use the sensor |
| to prevent memory overheating by automatically throttling the memory controller. |
| |
| The driver auto-detects SPD5118 compliant chips, but can also be instantiated |
| using devicetree/firmware nodes. |
| |
| A SPD5118 compliant chip supports a single temperature sensor. Critical minimum, |
| minimum, maximum, and critical temperature can be configured. There are alarms |
| for low critical, low, high, and critical thresholds. |
| |
| |
| Hardware monitoring sysfs entries |
| --------------------------------- |
| |
| ======================= ================================== |
| temp1_input Temperature (RO) |
| temp1_lcrit Low critical high temperature (RW) |
| temp1_min Minimum temperature (RW) |
| temp1_max Maximum temperature (RW) |
| temp1_crit Critical high temperature (RW) |
| |
| temp1_lcrit_alarm Temperature low critical alarm |
| temp1_min_alarm Temperature low alarm |
| temp1_max_alarm Temperature high alarm |
| temp1_crit_alarm Temperature critical alarm |
| ======================= ================================== |
| |
| Alarm attributes are sticky until read and will be cleared afterwards |
| unless the alarm condition still applies. |
| |
| |
| SPD (Serial Presence Detect) support |
| ------------------------------------ |
| |
| The driver also supports reading the SPD NVRAM on SPD5118 compatible chips. |
| SPD data is available from the 'eeprom' binary attribute file attached to the |
| chip's I2C device. |
