Kernel driver `smsc47m1.o'
==========================

Status: Beta.

Supported chips:
  * SMSC 47B27x and 47M1xx Super I/O Controllers
    Addresses scanned: none, address read from Super I/O config space
    Datasheets:
	http://www.smsc.com/main/datasheets/47b27x.pdf
	http://www.smsc.com/main/datasheets/47m10x.pdf
	http://www.smsc.com/main/datasheets/47m13x.pdf
	http://www.smsc.com/main/datasheets/47m14x.pdf

Authors: Mark D. Studebaker <mdsxyz123@yahoo.com>
	 With assistance from Bruce Allen <ballen@uwm.edu> and his
	 fan.c program: http://www.lsc-group.phys.uwm.edu/%7Eballen/driver/

Module Parameters
-----------------

force_addr=0xaddr	Set the I/O base address. Useful for boards
			that don't set the address in the BIOS.
			Don't use this unless the driver complains that the
			base address is not set.
			Example: 'modprobe smsc47m1 force_addr=0x680'


Description
-----------

The Standard Microsystems Corporation (SMSC) 47M1xx Super I/O chips
contain monitoring and PWM control circuitry for two fans.

FAN rotation speeds are reported in RPM (rotations per minute). An alarm is
triggered if the rotation speed has dropped below a programmable limit. FAN 
readings can be divided by a programmable divider (1, 2, 4 or 8) to give
the readings more range or accuracy. This is important because some FANs
report only one 'tick' each rotation, while others report two - making
all readings twice as high. Not all RPM values can accurately be represented,
so some rounding is done. With a divider of 2, the lowest representable
value is around 2600 RPM.

PWM values are from 0 to 255. The first value in the /proc entry is
the pwm value; the second is the enable (0 or 1).

If an alarm triggers, it will remain triggered until the hardware register
is read at least once. This means that the cause for the alarm may 
already have disappeared!  Note that in the current implementation, all
hardware registers are read whenever any data is read (unless it is less
than 1.5 seconds since the last update). This means that you can easily
miss once-only alarms.


**********************
The lm_sensors project gratefully acknowledges the support of
Intel in the development of this driver.
