| ACPIFAN(4) | Kernel Interfaces Manual | ACPIFAN(4) | 
NAME
 acpifan — ACPI Fan
SYNOPSIS
 acpifan* at acpi?
DESCRIPTION
 The 
acpifan device driver supports fans possibly exposed by the BIOS. Even if a system contains only one physical fan, multiple 
acpifan instances may be present. In such cases each 
acpifan typically represents an 
acpitz(4) thermal zone, and the combined state of all instances reveals the speed of the fan.
The acpifan driver does not support controlling the fan. The current state (on or off) is made available through the envsys(4) API and the envstat(8) command.
 
HISTORY
 The acpifan device driver appeared in NetBSD 6.0.
AUTHORS
 Jukka Ruohonen <jruohonen@iki.fi>
BUGS
 The acpifan driver does not yet support additional functionality introduced in the ACPI 4.0 specification.