Naming and data standards under /proc
-------------------------------------

The libsensors library offers an interface to the raw sensors data
through the sysctl interface. See the 'sysctl' file and the libsensors
source for further information.

An alternative method that some programs use is to access the /proc
files directly. This document briefly describes the standards that
the drivers follow, so that a program can access this data in a consistent way.

Note that not all chip drivers adhere to this standard.
We will attempt to migrate older drivers to this standard,
and ensure that new drivers follow this standard.

As each chip gets its own directory under /proc/sys/dev/sensors.
The format is either chip-i2c-bus-hexaddress or chip-isa-hexaddress.
(Exception - chip lm78-j has a '-' in it - should this be changed??)

/proc entries are as follows:


Entry	Values	Function
-----	------	--------
alarms	  1	Alarm bitmask.
		Read only.
		Integer representation of one, two, or three bytes.
		A '1' bit means an alarm.
		Generally a straight representation of a chips' internal
		alarm registers; no standard.

beep	  2     Beep or interrupt bitmask.
		Same format as 'alarms' with same bit locations.
		
fan[1-3]  2	Fan min and input value.
		Two integers indicating RPM.
		First value is read/write and second is read only.

fan_div	  3	Fan divisor.
		Integers in powers of two (1,2,4,8,16,32,64,128).
		Some chips only support values 1,2,4,8.
		Entries correspond to the fans[1-3].

in[0-8]   3	Voltage min, max, and input value.
		Floating point values X.XX in volts from 0 to 4.01 volts.
		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 do scale, with various success.
		First two values are read/write and third is read only.
		Typical usage:
			in0	CPU #1 voltage (not scaled)
			in1	CPU #1 voltage (not scaled)
			in2	3.3V nominal (not scaled)
			in3	5.0V nominal (scaled)
			in4	12.0V nominal (scaled)
			in5	-12.0V nominal (scaled)
			in6	-5.0V nominal (scaled)
			in7	varies
			in8	varies

pwm[1-3]   1	Pulse width modulation fan control.
		Integer 0 - 255, read/write.
		Corresponds to the fans 1-3.

sensor[1-3]  1	Sensor type selection.
		Integers 1,2,3, or thermistor Beta value (3435); read/write.

temp,
temp[1-3]  3	Temperature max, min or hysteresis, and input value.
	       	Floating point values XXX.X or XXX.XX in degrees Celcius.
		'temp' is used if there is only one temperature sensor on the chip.
		Temp1 is generally the sensor inside the chip itself,
		generally reported as "motherboard temperature".
		temp2 and temp3 are generally external sensors, 
		the thermal diode inside the CPU, generally reported as
		"CPU temperature".

vid	   1	CPU core voltage.
		Read only.
		Floating point X.XX corresponding to CPU core voltage as
		told to the sensor chip. Not always correct.
		Possible values are 1.30 - 2.05 in 0.05 increments
		or 2.1 - 3.5 in 0.1 increments.
