What:		/sys/devices/platform/<I2C controller address>/rainbow_enable
Date:		October 2017
Contact:	Xu Han <xuhanyz@google.com>
Description:
		Write to this file to enable/disable rainbow sensor vd6281
		0 - Enable
		1 - Disable

What:		/sys/devices/platform/<I2C controller address>/rainbow_write_byte
Date:		October 2017
Contact:	Xu Han <xuhanyz@google.com>
Description:
		Write to this file to write a byte to rainbow sensor vd6281. The
		1st byte is the address and 2nd byte is the data. A negative error
		is returned in case of failure.

What:		/sys/devices/platform/<I2C controller address>/rainbow_read_byte
Date:		October 2017
Contact:	Xu Han <xuhanyz@google.com>
Description:
		Write to this file to read a byte to rainbow sensor vd6281. The
		1st byte is the address to read. Read data is returned in case of
		success. A negative error is returned in case of failure.
