linux-imx/Documentation/ABI/testing/sysfs-class-hwmon

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/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_min Description: Temperature min value.

	Unit: millidegree Celsius

	RW

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

	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/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_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_input Description: Humidity

	Unit: milli-percent (per cent mille, pcm)

	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_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