What: /sys/class/power_supply/twl4030_usb/mode
Description:
	Changing mode for USB port.
	Writing to this can disable charging.

	Possible values are:
		"auto" - draw power as appropriate for detected
			 power source and battery status.
		"off"  - do not draw any power.
		"continuous"
		       - activate mode described as "linear" in
		         TWL data sheets.  This uses whatever
			 current is available and doesn't switch off
			 when voltage drops.

			 This is useful for unstable power sources
			 such as bicycle dynamo, but care should
			 be taken that battery is not over-charged.

What: /sys/class/power_supply/twl4030_ac/mode
Description:
	Changing mode for 'ac' port.
	Writing to this can disable charging.

	Possible values are:
		"auto" - draw power as appropriate for detected
			 power source and battery status.
		"off"  - do not draw any power.