sysfs interface for Texas Instruments lm3639 backlight + flash led driver chip
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What:		/sys/class/backlight/<backlight>/bled_mode
Date:		Oct, 2012
KernelVersion:	v3.10
Contact:	dri-devel@lists.freedesktop.org
Description:
		(WO) Write to the backlight mapping mode. The backlight current
		can be mapped for either exponential (value "0") or linear
		mapping modes (default).