Intel NUC7i[x]BN and NUC6CAY LED Control

This is a simple kernel module to control the power and ring LEDs on Intel NUC7i[x]BN and NUC6CAY kits.

This module is intended as a demonstration/proof-of-concept and may not be maintained further. Perhaps it can act as a jumping off point for a more polished and complete implementation. For testing and basic manipulation of the power LED and ring LED, it ought to work fine, but use with caution none the less. This has only been tested on 4.4.x kernels.

Requirements

Requirements:

• Intel NUC7i[x]BN and NUC6CAY
• BIOS AY0038 or BN0043 or later
• ACPI/WMI support in kernel
• LED(s) set to SW Control in BIOS

Building

THe nuc_led kernel module supports building and installing "from source" directly or using dkms.

Installing Build Dependencies

Ubuntu:

apt-get install build-essential linux-headers-$(uname -r)

# DKMS dependencies
apt-get install debhelper dkms

Redhat:

yum groupinstall "Development Tools"
yum install kernel-devel-$(uname -r)

# Install appropriate EPEL for DKMS if needed by your RHEL variant
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

yum install dkms

Building and Installing "from source"

make clean
make install

Building and Installing Using DKMS

Build and install without system packaging:

make dkms-install

Uninstall without system packaging:

make dkms-uninstall

Build and install using system packaging:

# Ubuntu
make dkms-deb

# RHEL
make dkms-rpm

# Install generated DEB/RPM from the folder specified in the output using system package manager

Usage

This driver works via '/proc/acpi/nuc_led'. To get current LED state:

cat /proc/acpi/nuc_led

To change the LED state:

 echo '<led>,<brightness>,<blink/fade>,<color>' | sudo tee /proc/acpi/nuc_led > /dev/null

LED	Description
power	The power button LED.
ring	The ring LED surrounding the front panel.

Brightness:

• any integer between 0 and 100.

Blink/Fade Option	Description
blink_fast	1Hz blink
blink_medium	0.5Hz blink
blink_slow	0.25Hz blink
fade_fast	1Hz blink
fade_medium	0.5Hz blink
fade_slow	0.25Hz blink
none	solid/always on

LED Color	power	ring
amber	X
cyan		X
blue	X	X
green		X
off	X	X
pink		X
red		X
white		X
yellow		X

Example execution to cause the ring LED blink green at a medium rate at partial intensity:

echo 'ring,80,blink_medium,green' | sudo tee /proc/acpi/nuc_led > /dev/null

Errors in passing parameters will appear as warnings in dmesg.

You can change the owner, group and permissions of /proc/acpi/nuc_led by passing parameters to the nuc_led kernel module. Use:

• nuc_led_uid to set the owner (default is 0, root)
• nuc_led_gid to set the owning group (default is 0, root)
• nuc_led_perms to set the file permissions (default is r+w for group and user and r for others)

Note: Once an LED has been set to SW Control in the BIOS, it will remain off initially until a color is explicitly set, after which the set color is retained across reboots.