asus-fan

ASUS (Zenbook) fan(s) control kernel module. The following Zenbooks are supported:

Single Fan	Two Fans (NVIDIA)
UX21E	UX32VD
UX31E	UX42VS
UX21A	UX52VS
UX31A	U500VZ
UX32A	NX500
UX301LA
UX302LA

Quickstart

• Build - just run make inside the directory
• Install - copy the resulting asus_fan.ko file somewhere below /lib/modules/$(uname -r)/ and rebuild module dependencies:

cp asus_fan.ko /lib/modules/$(uname -r)/
depmod -a

• Load - simply as usual:

modprobe asus_fan

• Interface - the fan(s) is/are exposed as cooling_device, thus available in:

/sys/devices/virtual/thermal/cooling_deviceX/

• Find X - the X changes from boot to boot, a small bash script is found inside the repository as a simpler interface:

basepath=/sys/devices/virtual/thermal/
fpath=$(grep -r '^Fan$' ${basepath}/cooling_device*/type 2> /dev/null | \
        cut -d ":" -f 1 | xargs  --no-run-if-empty dirname)
gfxfanpath=$(grep -r '^GFX Fan$' ${basepath}/cooling_device*/type 2> /dev/null | \
        cut -d ":" -f 1 | xargs  --no-run-if-empty dirname)

• Read Fan - the files cur_state, max_state provide the obvious, ranging from 0 - 255:

cat ${fpath}/cur_state          # get current fan speed
cat ${fpath}/max_state          # get max fan speed

• Set Fan Speed - write anything from 0 to 255 to cur_state, like:

echo 123 > ${fpath}/cur_state   # set to 123
echo 0 > ${fpath}/cur_state     # switch fan off (DANGEROUS!)
echo 255 > ${fpath}/cur_state   # set to max speed

• ATTENTION - the fan is now in manual mode - do not burn your machine!
• Set Auto-Fan(s): to reactivate the automatic fan control write "256" to cur_state:

echo 256 > ${fpath}/cur_state   # reset to auto-mode (always for all fans)

TODOs:

• expose fan RPMs (once I get to know where, cooling_device api allows only cur/max_state)
• read and set threshold for maximum speed while automatically controlled (actually works, but have no idea how to interface with the userland, thermal_cooling_device_* function family seems to not provide anything beside cur-/max_state files inside /sys/...
• submit an upstream patch - any howtos?? wtf, write acpi-devel kernel-mailinglist ??

THANKS TO:

• To Felipe Contreras (felipec) for providing the initial version (https://gist.github.com/felipec/6169047)