What: /sys/class/hwmon/hwmonX/name
Description:
The chip name.
This should be a short, lowercase string, not containing
whitespace, dashes, or the wildcard character '*'.
This attribute represents the chip name. It is the only
mandatory attribute.
I2C devices get this attribute created automatically.
RO
What: /sys/class/hwmon/hwmonX/label
Description:
A descriptive label that allows to uniquely identify a
device within the system.
The contents of the label are free-form.
RO
What: /sys/class/hwmon/hwmonX/update_interval
Description:
The interval at which the chip will update readings.
Unit: millisecond
RW
Some devices have a variable update rate or interval.
This attribute can be used to change it to the desired value.
What: /sys/class/hwmon/hwmonX/inY_min
Description:
Voltage min value.
Unit: millivolt
RW
What: /sys/class/hwmon/hwmonX/inY_lcrit
Description:
Voltage critical min value.
Unit: millivolt
RW
If voltage drops to or below this limit, the system may
take drastic action such as power down or reset. At the very
least, it should report a fault.
What: /sys/class/hwmon/hwmonX/inY_max
Description:
Voltage max value.
Unit: millivolt
RW
What: /sys/class/hwmon/hwmonX/inY_crit
Description:
Voltage critical max value.
Unit: millivolt
RW
If voltage reaches or exceeds this limit, the system may
take drastic action such as power down or reset. At the very
least, it should report a fault.
What: /sys/class/hwmon/hwmonX/inY_input
Description:
Voltage input value.
Unit: millivolt
RO
Voltage measured on the chip pin.
Actual voltage depends on the scaling resistors on the
motherboard, as recommended in the chip datasheet.
This varies by chip and by motherboard.
Because of this variation, values are generally NOT scaled
by the chip driver, and must be done by the application.
However, some drivers (notably lm87 and via686a)
do scale, because of internal resistors built into a chip.
These drivers will output the actual voltage. Rule of
thumb: drivers should report the voltage values at the
"pins" of the chip.
What: /sys/class/hwmon/hwmonX/inY_average
Description:
Average voltage
Unit: millivolt
RO
What: /sys/class/hwmon/hwmonX/inY_lowest
Description:
Historical minimum voltage
Unit: millivolt
RO
What: /sys/class/hwmon/hwmonX/inY_highest
Description:
Historical maximum voltage
Unit: millivolt
RO
What: /sys/class/hwmon/hwmonX/inY_reset_history
Description:
Reset inX_lowest and inX_highest
WO
What: /sys/class/hwmon/hwmonX/in_reset_history
Description:
Reset inX_lowest and inX_highest for all sensors
WO
What: /sys/class/hwmon/hwmonX/inY_label
Description:
Suggested voltage channel label.
Text string
Should only be created if the driver has hints about what
this voltage channel is being used for, and user-space
doesn't. In all other cases, the label is provided by
user-space.
RO
What: /sys/class/hwmon/hwmonX/inY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return -ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/inY_fault
Description:
Reports a voltage hard failure (eg: shorted component)
- 1: Failed
- 0: Ok
RO
What: /sys/class/hwmon/hwmonX/cpuY_vid
Description:
CPU core reference voltage.
Unit: millivolt
RO
Not always correct.
What: /sys/class/hwmon/hwmonX/vrm
Description:
Voltage Regulator Module version number.
RW (but changing it should no more be necessary)
Originally the VRM standard version multiplied by 10, but now
an arbitrary number, as not all standards have a version
number.
Affects the way the driver calculates the CPU core reference
voltage from the vid pins.
What: /sys/class/hwmon/hwmonX/inY_rated_min
Description:
Minimum rated voltage.
Unit: millivolt
RO
What: /sys/class/hwmon/hwmonX/inY_rated_max
Description:
Maximum rated voltage.
Unit: millivolt
RO
What: /sys/class/hwmon/hwmonX/fanY_min
Description:
Fan minimum value
Unit: revolution/min (RPM)
RW
What: /sys/class/hwmon/hwmonX/fanY_max
Description:
Fan maximum value
Unit: revolution/min (RPM)
Only rarely supported by the hardware.
RW
What: /sys/class/hwmon/hwmonX/fanY_input
Description:
Fan input value.
Unit: revolution/min (RPM)
RO
What: /sys/class/hwmon/hwmonX/fanY_div
Description:
Fan divisor.
Integer value in powers of two (1, 2, 4, 8, 16, 32, 64, 128).
RW
Some chips only support values 1, 2, 4 and 8.
Note that this is actually an internal clock divisor, which
affects the measurable speed range, not the read value.
What: /sys/class/hwmon/hwmonX/fanY_pulses
Description:
Number of tachometer pulses per fan revolution.
Integer value, typically between 1 and 4.
RW
This value is a characteristic of the fan connected to the
device's input, so it has to be set in accordance with the fan
model.
Should only be created if the chip has a register to configure
the number of pulses. In the absence of such a register (and
thus attribute) the value assumed by all devices is 2 pulses
per fan revolution.
What: /sys/class/hwmon/hwmonX/fanY_target
Description:
Desired fan speed
Unit: revolution/min (RPM)
RW
Only makes sense if the chip supports closed-loop fan speed
control based on the measured fan speed.
What: /sys/class/hwmon/hwmonX/fanY_label
Description:
Suggested fan channel label.
Text string
Should only be created if the driver has hints about what
this fan channel is being used for, and user-space doesn't.
In all other cases, the label is provided by user-space.
RO
What: /sys/class/hwmon/hwmonX/fanY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return -ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/fanY_fault
Description:
Reports if a fan has reported failure.
- 1: Failed
- 0: Ok
RO
What: /sys/class/hwmon/hwmonX/pwmY
Description:
Pulse width modulation fan control.
Integer value in the range 0 to 255
RW
255 is max or 100%.
What: /sys/class/hwmon/hwmonX/pwmY_enable
Description:
Fan speed control method:
- 0: no fan speed control (i.e. fan at full speed)
- 1: manual fan speed control enabled (using `pwmY`)
- 2+: automatic fan speed control enabled
Check individual chip documentation files for automatic mode
details.
RW
What: /sys/class/hwmon/hwmonX/pwmY_mode
Description:
- 0: DC mode (direct current)
- 1: PWM mode (pulse-width modulation)
RW
What: /sys/class/hwmon/hwmonX/pwmY_freq
Description:
Base PWM frequency in Hz.
Only possibly available when pwmN_mode is PWM, but not always
present even then.
RW
What: /sys/class/hwmon/hwmonX/pwmY_auto_channels_temp
Description:
Select which temperature channels affect this PWM output in
auto mode.
Bitfield, 1 is temp1, 2 is temp2, 4 is temp3 etc...
Which values are possible depend on the chip used.
RW
What: /sys/class/hwmon/hwmonX/pwmY_auto_pointZ_pwm
What: /sys/class/hwmon/hwmonX/pwmY_auto_pointZ_temp
What: /sys/class/hwmon/hwmonX/pwmY_auto_pointZ_temp_hyst
Description:
Define the PWM vs temperature curve.
Number of trip points is chip-dependent. Use this for chips
which associate trip points to PWM output channels.
RW
What: /sys/class/hwmon/hwmonX/tempY_auto_pointZ_pwm
What: /sys/class/hwmon/hwmonX/tempY_auto_pointZ_temp
What: /sys/class/hwmon/hwmonX/tempY_auto_pointZ_temp_hyst
Description:
Define the PWM vs temperature curve.
Number of trip points is chip-dependent. Use this for chips
which associate trip points to temperature channels.
RW
What: /sys/class/hwmon/hwmonX/tempY_type
Description:
Sensor type selection.
Integers 1 to 6
RW
- 1: CPU embedded diode
- 2: 3904 transistor
- 3: thermal diode
- 4: thermistor
- 5: AMD AMDSI
- 6: Intel PECI
Not all types are supported by all chips
What: /sys/class/hwmon/hwmonX/tempY_max
Description:
Temperature max value.
Unit: millidegree Celsius (or millivolt, see below)
RW
What: /sys/class/hwmon/hwmonX/tempY_max_alarm
Description:
Maximum temperature alarm flag.
- 0: OK
- 1: temperature has reached tempY_max
RO
What: /sys/class/hwmon/hwmonX/tempY_min
Description:
Temperature min value.
Unit: millidegree Celsius
RW
What: /sys/class/hwmon/hwmonX/tempY_min_alarm
Description:
Minimum temperature alarm flag.
- 0: OK
- 1: temperature has reached tempY_min
RO
What: /sys/class/hwmon/hwmonX/tempY_max_hyst
Description:
Temperature hysteresis value for max limit.
Unit: millidegree Celsius
Must be reported as an absolute temperature, NOT a delta
from the max value.
RW
What: /sys/class/hwmon/hwmonX/tempY_min_hyst
Description:
Temperature hysteresis value for min limit.
Unit: millidegree Celsius
Must be reported as an absolute temperature, NOT a delta
from the min value.
RW
What: /sys/class/hwmon/hwmonX/tempY_input
Description:
Temperature input value.
Unit: millidegree Celsius
RO
What: /sys/class/hwmon/hwmonX/tempY_crit
Description:
Temperature critical max value, typically greater than
corresponding temp_max values.
Unit: millidegree Celsius
RW
What: /sys/class/hwmon/hwmonX/tempY_crit_alarm
Description:
Critical high temperature alarm flag.
- 0: OK
- 1: temperature has reached tempY_crit
RO
What: /sys/class/hwmon/hwmonX/tempY_crit_hyst
Description:
Temperature hysteresis value for critical limit.
Unit: millidegree Celsius
Must be reported as an absolute temperature, NOT a delta
from the critical value.
RW
What: /sys/class/hwmon/hwmonX/tempY_emergency
Description:
Temperature emergency max value, for chips supporting more than
two upper temperature limits. Must be equal or greater than
corresponding temp_crit values.
Unit: millidegree Celsius
RW
What: /sys/class/hwmon/hwmonX/tempY_emergency_alarm
Description:
Emergency high temperature alarm flag.
- 0: OK
- 1: temperature has reached tempY_emergency
RO
What: /sys/class/hwmon/hwmonX/tempY_emergency_hyst
Description:
Temperature hysteresis value for emergency limit.
Unit: millidegree Celsius
Must be reported as an absolute temperature, NOT a delta
from the emergency value.
RW
What: /sys/class/hwmon/hwmonX/tempY_lcrit
Description:
Temperature critical min value, typically lower than
corresponding temp_min values.
Unit: millidegree Celsius
RW
What: /sys/class/hwmon/hwmonX/tempY_lcrit_hyst
Description:
Temperature hysteresis value for critical min limit.
Unit: millidegree Celsius
Must be reported as an absolute temperature, NOT a delta
from the critical min value.
RW
What: /sys/class/hwmon/hwmonX/tempY_offset
Description:
Temperature offset which is added to the temperature reading
by the chip.
Unit: millidegree Celsius
Read/Write value.
What: /sys/class/hwmon/hwmonX/tempY_label
Description:
Suggested temperature channel label.
Text string
Should only be created if the driver has hints about what
this temperature channel is being used for, and user-space
doesn't. In all other cases, the label is provided by
user-space.
RO
What: /sys/class/hwmon/hwmonX/tempY_lowest
Description:
Historical minimum temperature
Unit: millidegree Celsius
RO
What: /sys/class/hwmon/hwmonX/tempY_highest
Description:
Historical maximum temperature
Unit: millidegree Celsius
RO
What: /sys/class/hwmon/hwmonX/tempY_reset_history
Description:
Reset temp_lowest and temp_highest
WO
What: /sys/class/hwmon/hwmonX/temp_reset_history
Description:
Reset temp_lowest and temp_highest for all sensors
WO
What: /sys/class/hwmon/hwmonX/tempY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return -ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/tempY_rated_min
Description:
Minimum rated temperature.
Unit: millidegree Celsius
RO
What: /sys/class/hwmon/hwmonX/tempY_rated_max
Description:
Maximum rated temperature.
Unit: millidegree Celsius
RO
What: /sys/class/hwmon/hwmonX/currY_max
Description:
Current max value
Unit: milliampere
RW
What: /sys/class/hwmon/hwmonX/currY_min
Description:
Current min value.
Unit: milliampere
RW
What: /sys/class/hwmon/hwmonX/currY_lcrit
Description:
Current critical low value
Unit: milliampere
RW
What: /sys/class/hwmon/hwmonX/currY_crit
Description:
Current critical high value.
Unit: milliampere
RW
What: /sys/class/hwmon/hwmonX/currY_input
Description:
Current input value
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/currY_average
Description:
Average current use
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/currY_lowest
Description:
Historical minimum current
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/currY_highest
Description:
Historical maximum current
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/currY_reset_history
Description:
Reset currX_lowest and currX_highest
WO
What: /sys/class/hwmon/hwmonX/curr_reset_history
Description:
Reset currX_lowest and currX_highest for all sensors
WO
What: /sys/class/hwmon/hwmonX/currY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return -ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/currY_rated_min
Description:
Minimum rated current.
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/currY_rated_max
Description:
Maximum rated current.
Unit: milliampere
RO
What: /sys/class/hwmon/hwmonX/powerY_average
Description:
Average power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_average_interval
Description:
Power use averaging interval. A poll
notification is sent to this file if the
hardware changes the averaging interval.
Unit: milliseconds
RW
What: /sys/class/hwmon/hwmonX/powerY_average_interval_max
Description:
Maximum power use averaging interval
Unit: milliseconds
RO
What: /sys/class/hwmon/hwmonX/powerY_average_interval_min
Description:
Minimum power use averaging interval
Unit: milliseconds
RO
What: /sys/class/hwmon/hwmonX/powerY_average_highest
Description:
Historical average maximum power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_average_lowest
Description:
Historical average minimum power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_average_max
Description:
A poll notification is sent to
`powerY_average` when power use
rises above this value.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_average_min
Description:
A poll notification is sent to
`powerY_average` when power use
sinks below this value.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_input
Description:
Instantaneous power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_input_highest
Description:
Historical maximum power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_input_lowest
Description:
Historical minimum power use
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_reset_history
Description:
Reset input_highest, input_lowest,
average_highest and average_lowest.
WO
What: /sys/class/hwmon/hwmonX/powerY_accuracy
Description:
Accuracy of the power meter.
Unit: Percent
RO
What: /sys/class/hwmon/hwmonX/powerY_cap
Description:
If power use rises above this limit, the
system should take action to reduce power use.
A poll notification is sent to this file if the
cap is changed by the hardware. The `*_cap`
files only appear if the cap is known to be
enforced by hardware.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_cap_hyst
Description:
Margin of hysteresis built around capping and
notification.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_cap_max
Description:
Maximum cap that can be set.
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_cap_min
Description:
Minimum cap that can be set.
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_max
Description:
Maximum power.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_crit
Description:
Critical maximum power.
If power rises to or above this limit, the
system is expected take drastic action to reduce
power consumption, such as a system shutdown or
a forced powerdown of some devices.
Unit: microWatt
RW
What: /sys/class/hwmon/hwmonX/powerY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return
-ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/powerY_rated_min
Description:
Minimum rated power.
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/powerY_rated_max
Description:
Maximum rated power.
Unit: microWatt
RO
What: /sys/class/hwmon/hwmonX/energyY_input
Description:
Cumulative energy use
Unit: microJoule
RO
What: /sys/class/hwmon/hwmonX/energyY_enable
Description:
Enable or disable the sensors.
When disabled the sensor read will return
-ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/humidityY_alarm
Description:
Humidity limit detection
- 0: OK
- 1: Humidity limit has been reached
RO
What: /sys/class/hwmon/hwmonX/humidityY_enable
Description:
Enable or disable the sensors
When disabled the sensor read will return
-ENODATA.
- 1: Enable
- 0: Disable
RW
What: /sys/class/hwmon/hwmonX/humidityY_fault
Description:
Reports a humidity sensor failure.
- 1: Failed
- 0: Ok
RO
What: /sys/class/hwmon/hwmonX/humidityY_input
Description:
Humidity
Unit: milli-percent (per cent mille, pcm)
RO
What: /sys/class/hwmon/hwmonX/humidityY_label
Description:
Suggested humidity channel label.
Text string
Should only be created if the driver has hints about what
this humidity channel is being used for, and user-space
doesn't. In all other cases, the label is provided by
user-space.
RO
What: /sys/class/hwmon/hwmonX/humidityY_max
Description:
Humidity max value.
Unit: milli-percent (per cent mille, pcm)
RW
What: /sys/class/hwmon/hwmonX/humidityY_max_alarm
Description:
Maximum humidity detection
- 0: OK
- 1: Maximum humidity detected
RO
What: /sys/class/hwmon/hwmonX/humidityY_max_hyst
Description:
Humidity hysteresis value for max limit.
Unit: milli-percent (per cent mille, pcm)
Must be reported as an absolute humidity, NOT a delta
from the max value.
RW
What: /sys/class/hwmon/hwmonX/humidityY_min
Description:
Humidity min value.
Unit: milli-percent (per cent mille, pcm)
RW
What: /sys/class/hwmon/hwmonX/humidityY_min_alarm
Description:
Minimum humidity detection
- 0: OK
- 1: Minimum humidity detected
RO
What: /sys/class/hwmon/hwmonX/humidityY_min_hyst
Description:
Humidity hysteresis value for min limit.
Unit: milli-percent (per cent mille, pcm)
Must be reported as an absolute humidity, NOT a delta
from the min value.
RW
What: /sys/class/hwmon/hwmonX/humidityY_rated_min
Description:
Minimum rated humidity.
Unit: milli-percent (per cent mille, pcm)
RO
What: /sys/class/hwmon/hwmonX/humidityY_rated_max
Description:
Maximum rated humidity.
Unit: milli-percent (per cent mille, pcm)
RO
What: /sys/class/hwmon/hwmonX/intrusionY_alarm
Description:
Chassis intrusion detection
- 0: OK
- 1: intrusion detected
RW
Contrary to regular alarm flags which clear themselves
automatically when read, this one sticks until cleared by
the user. This is done by writing 0 to the file. Writing
other values is unsupported.
What: /sys/class/hwmon/hwmonX/intrusionY_beep
Description:
Chassis intrusion beep
- 0: disable
- 1: enable
RW
What: /sys/class/hwmon/hwmonX/device/pec
Description:
PEC support on I2C devices
- 0, off, n: disable
- 1, on, y: enable
RW
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