viaenv —
VIA VT82C686A/VT8231 Hardware Monitor and Power Management
  Timer
viaenv* at pci? dev ? function ?
The viaenv is an
  envsys(4) compatible driver for
  the Hardware Monitor and the Power Management timer in the VIA VT82C686A and
  VT8231 South Bridges.
The device has 10 sensors:
  
    | Sensor | Units | Typical Use | 
  
    | TSENS1 | uK | CPU temperature | 
  
    | TSENS2 | uK | System temperature | 
  
    | TSENS3 | uK | ? | 
  
    | FAN1 | RPM | CPU fan | 
  
    | FAN2 | RPM | System fan | 
  
    | VSENS1 | uV DC | CPU core voltage (2.0V) | 
  
    | VSENS2 | uV DC | North Bridge core voltage (2.5V) | 
  
    | Vcore | uV DC | Internal core voltage (3.3V) | 
  
    | VSENS3 | uV DC | +5V | 
  
    | VSENS4 | uV DC | +12V | 
Sensor data is updated every 1.5 seconds.
The viaenv device appeared in NetBSD
  1.5.
Interrupt support is unimplemented, as is support for setting values.