Commit 057bc350 authored by Rudolf Marek's avatar Rudolf Marek Committed by Greg Kroah-Hartman
Browse files

[PATCH] hwmon: Sysfs interface documentation update, 1 of 2 



This patch cleans up hwmon sysfs documentation file, plus introduces
the description of DC/PWM selection for fan speed control.

Signed-off-by: default avatarRudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 18f98b1e

Documentation/hwmon/sysfs-interface

+107 −74
Original line number Diff line number Diff line
@@ -69,28 +69,37 @@ to cause an alarm) is chip-dependent. 


-------------------------------------------------------------------------



[0-*]	denotes any positive number starting from 0

[1-*]	denotes any positive number starting from 1

RO	read only value

RW	read/write value



Read/write values may be read-only for some chips, depending on the

hardware implementation.



************

* Voltages *

************



in[0-8]_min	Voltage min value.

in[0-*]_min	Voltage min value.

		Unit: millivolt

		Read/Write

		RW

		

in[0-8]_max	Voltage max value.

in[0-*]_max	Voltage max value.

		Unit: millivolt

		Read/Write

		RW

		

in[0-8]_input	Voltage input value.

in[0-*]_input	Voltage input value.

		Unit: millivolt

		Read only

		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, with various degrees of success.

		do scale, because of internal resistors built into a chip.

		These drivers will output the actual voltage.



		Typical usage:
@@ -104,58 +113,72 @@ in[0-8]_input Voltage input value. 
			in7_*	varies

			in8_*	varies



cpu[0-1]_vid	CPU core reference voltage.

cpu[0-*]_vid	CPU core reference voltage.

		Unit: millivolt

		Read only.

		RO

		Not always correct.



vrm		Voltage Regulator Module version number. 

		Read only.

		Two digit number, first is major version, second is

		minor version.

		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.



Also see the Alarms section for status flags associated with voltages.





********

* Fans *

********



fan[1-3]_min	Fan minimum value

fan[1-*]_min	Fan minimum value

		Unit: revolution/min (RPM)

		Read/Write.

		RW



fan[1-3]_input	Fan input value.

fan[1-*]_input	Fan input value.

		Unit: revolution/min (RPM)

		Read only.

		RO



fan[1-3]_div	Fan divisor.

fan[1-*]_div	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.



Also see the Alarms section for status flags associated with fans.





*******

* PWM *

*******



pwm[1-3]	Pulse width modulation fan control.

pwm[1-*]	Pulse width modulation fan control.

		Integer value in the range 0 to 255

		Read/Write

		RW

		255 is max or 100%.



pwm[1-3]_enable

pwm[1-*]_enable

		Switch PWM on and off.

		Not always present even if fan*_pwm is.

		0 to turn off

		1 to turn on in manual mode

		2 to turn on in automatic mode

		Read/Write

		0: turn off

		1: turn on in manual mode

		2+: turn on in automatic mode

		Check individual chip documentation files for automatic mode details.

		RW



pwm[1-*]_mode

		0: DC mode

		1: PWM mode

		RW



pwm[1-*]_auto_channels_temp

		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



pwm[1-*]_auto_point[1-*]_pwm

pwm[1-*]_auto_point[1-*]_temp
@@ -163,6 +186,7 @@ pwm[1-*]_auto_point[1-*]_temp_hyst 
		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



OR
@@ -172,51 +196,52 @@ temp[1-*]_auto_point[1-*]_temp_hyst 
		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





****************

* Temperatures *

****************



temp[1-3]_type	Sensor type selection.

temp[1-*]_type	Sensor type selection.

		Integers 1 to 4 or thermistor Beta value (typically 3435)

		Read/Write.

		RW

		1: PII/Celeron Diode

		2: 3904 transistor

		3: thermal diode

		4: thermistor (default/unknown Beta)

		Not all types are supported by all chips



temp[1-4]_max	Temperature max value.

temp[1-*]_max	Temperature max value.

		Unit: millidegree Celcius

		Read/Write value.

		RW



temp[1-3]_min	Temperature min value.

temp[1-*]_min	Temperature min value.

		Unit: millidegree Celcius

		Read/Write value.

		RW



temp[1-3]_max_hyst

temp[1-*]_max_hyst

		Temperature hysteresis value for max limit.

		Unit: millidegree Celcius

		Must be reported as an absolute temperature, NOT a delta

		from the max value.

		Read/Write value.

		RW



temp[1-4]_input Temperature input value.

temp[1-*]_input Temperature input value.

		Unit: millidegree Celcius

		Read only value.

		RO



temp[1-4]_crit	Temperature critical value, typically greater than

temp[1-*]_crit	Temperature critical value, typically greater than

		corresponding temp_max values.

		Unit: millidegree Celcius

		Read/Write value.

		RW



temp[1-2]_crit_hyst

temp[1-*]_crit_hyst

		Temperature hysteresis value for critical limit.

		Unit: millidegree Celcius

		Must be reported as an absolute temperature, NOT a delta

		from the critical value.

		Read/Write value.

		RW



temp[1-4]_offset

		Temperature offset which is added to the temperature reading
@@ -231,6 +256,8 @@ temp[1-4]_offset 
		itself, for example the thermal diode inside the CPU or

		a thermistor nearby.



Also see the Alarms section for status flags associated with temperatures.





************

* Currents *
@@ -239,17 +266,17 @@ temp[1-4]_offset 
Note that no known chip provides current measurements as of writing,

so this part is theoretical, so to say.



curr[1-n]_max	Current max value

curr[1-*]_max	Current max value

		Unit: milliampere

		Read/Write.

		RW



curr[1-n]_min	Current min value.

curr[1-*]_min	Current min value.

		Unit: milliampere

		Read/Write.

		RW



curr[1-n]_input	Current input value

curr[1-*]_input	Current input value

		Unit: milliampere

		Read only.

		RO





**********
@@ -263,50 +290,54 @@ Usually a given chip will either use channel-related alarms, or 
limit-related alarms, not both. The driver should just reflect the hardware

implementation.



in[0-n]_alarm

fan[1-n]_alarm

temp[1-n]_alarm

in[0-*]_alarm

fan[1-*]_alarm

temp[1-*]_alarm

		Channel alarm

		Boolean

		Read-only

		0: no alarm

		1: alarm

		RO



OR



in[0-n]_min_alarm

in[0-n]_max_alarm

fan[1-n]_min_alarm

temp[1-n]_min_alarm

temp[1-n]_max_alarm

temp[1-n]_crit_alarm

in[0-*]_min_alarm

in[0-*]_max_alarm

fan[1-*]_min_alarm

temp[1-*]_min_alarm

temp[1-*]_max_alarm

temp[1-*]_crit_alarm

		Limit alarm

		Boolean

		Read-only

		0: no alarm

		1: alarm

		RO



Each input channel may have an associated fault file. This can be used

to notify open diodes, unconnected fans etc. where the hardware

supports it. When this boolean has value 1, the measurement for that

channel should not be trusted.



in[0-n]_input_fault

fan[1-n]_input_fault

temp[1-n]_input_fault

in[0-*]_input_fault

fan[1-*]_input_fault

temp[1-*]_input_fault

		Input fault condition

		Boolean

		Read-only

		0: no fault occured

		1: fault condition

		RO



Some chips also offer the possibility to get beeped when an alarm occurs:



beep_enable	Master beep enable

		Boolean

		Read/Write

		0: no beeps

		1: beeps

		RW



in[0-n]_beep

fan[1-n]_beep

temp[1-n]_beep

in[0-*]_beep

fan[1-*]_beep

temp[1-*]_beep

		Channel beep

		0 to disable.

		1 to enable.

		Read/write

		0: disable

		1: enable

		RW



In theory, a chip could provide per-limit beep masking, but no such chip

was seen so far.
@@ -316,7 +347,7 @@ beeps. These interface files are deprecated, but will be kept around 
for compatibility reasons:



alarms		Alarm bitmask.

		Read only.

		RO

		Integer representation of one to four bytes.

		A '1' bit means an alarm.

		Chips should be programmed for 'comparator' mode so that
@@ -333,7 +364,7 @@ beep_mask Bitmask for beep. 
		Same format as 'alarms' with the same bit locations,

		use discouraged for the same reason. Use individual

		*_beep files instead.

		Read/Write

		RW





*********
@@ -341,7 +372,9 @@ beep_mask Bitmask for beep. 
*********



eeprom		Raw EEPROM data in binary form.

		Read only.

		RO



pec		Enable or disable PEC (SMBus only)

		Read/Write
 
		0: disable

		1: enable

		RW