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