ACPIFAN(4) Kernel Interfaces Manual ACPIFAN(4)
acpifan -- ACPI Fan
acpifan* at acpi?
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
The acpifan device driver appeared in NetBSD 6.0.
Jukka Ruohonen <jruohonenATiki.fi>
The acpifan driver does not yet support additional functionality
introduced in the ACPI 4.0 specification.
NetBSD 6.1.5 January 9, 2011 NetBSD 6.1.5