What:		/sys/class/leds/dell::kbd_backlight/als_enabled
Date:		December 2014
KernelVersion:	3.19
Contact:	Gabriele Mazzotta <gabriele.mzt@gmail.com>,
		Pali Rohár <pali.rohar@gmail.com>
Description:
		This file allows to control the automatic keyboard
		illumination mode on some systems that have an ambient
		light sensor. Write 1 to this file to enable the auto
		mode, 0 to disable it.

What:		/sys/class/leds/dell::kbd_backlight/als_setting
Date:		December 2014
KernelVersion:	3.19
Contact:	Gabriele Mazzotta <gabriele.mzt@gmail.com>,
		Pali Rohár <pali.rohar@gmail.com>
Description:
		This file allows to specifiy the on/off threshold value,
		as reported by the ambient light sensor.

What:		/sys/class/leds/dell::kbd_backlight/start_triggers
Date:		December 2014
KernelVersion:	3.19
Contact:	Gabriele Mazzotta <gabriele.mzt@gmail.com>,
		Pali Rohár <pali.rohar@gmail.com>
Description:
		This file allows to control the input triggers that
		turn on the keyboard backlight illumination that is
		disabled because of inactivity.
		Read the file to see the triggers available. The ones
		enabled are preceded by '+', those disabled by '-'.

		To enable a trigger, write its name preceded by '+' to
		this file. To disable a trigger, write its name preceded
		by '-' instead.

		For example, to enable the keyboard as trigger run:
		    echo +keyboard > /sys/class/leds/dell::kbd_backlight/start_triggers
		To disable it:
		    echo -keyboard > /sys/class/leds/dell::kbd_backlight/start_triggers

		Note that not all the available triggers can be configured.

What:		/sys/class/leds/dell::kbd_backlight/stop_timeout
Date:		December 2014
KernelVersion:	3.19
Contact:	Gabriele Mazzotta <gabriele.mzt@gmail.com>,
		Pali Rohár <pali.rohar@gmail.com>
Description:
		This file allows to specify the interval after which the
		keyboard illumination is disabled because of inactivity.
		The timeouts are expressed in seconds, minutes, hours and
		days, for which the symbols are 's', 'm', 'h' and 'd'
		respectively.

		To configure the timeout, write to this file a value along
		with any the above units. If no unit is specified, the value
		is assumed to be expressed in seconds.

		For example, to set the timeout to 10 minutes run:
		    echo 10m > /sys/class/leds/dell::kbd_backlight/stop_timeout

		Note that when this file is read, the returned value might be
		expressed in a different unit than the one used when the timeout
		was set.

		Also note that only some timeouts are supported and that
		some systems might fall back to a specific timeout in case
		an invalid timeout is written to this file.