Some consumer devices may need to be able to dynamically configure their supplies. For example, MMC drivers may need to select the correct operating voltage for their cards. This may be done while the regulator is enabled or disabled.
	 The regulator_set_voltage
	  and regulator_set_current_limit
	  functions provide the primary interface for this.
	 Both take ranges of voltages and currents, supporting drivers
	 that do not require a specific value (eg, CPU frequency scaling
	 normally permits the CPU to use a wider range of supply
	 voltages at lower frequencies but does not require that the
	 supply voltage be lowered).  Where an exact value is required
	 both minimum and maximum values should be identical.