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diff --git a/Documentation/hwmon/spd5118.rst b/Documentation/hwmon/spd5118.rst new file mode 100644 index 000000000000..ef7338f46575 --- /dev/null +++ b/Documentation/hwmon/spd5118.rst @@ -0,0 +1,63 @@ +.. 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. |