* Samsung S2MPA01 Voltage and Current Regulator

The Samsung S2MPA01 is a multi-function device which includes high
efficiency buck converters including Dual-Phase buck converter, various LDOs,
and an RTC. It is interfaced to the host controller using an I2C interface.
Each sub-block is addressed by the host system using different I2C slave
addresses.

Required properties:
- compatible: Should be "samsung,s2mpa01-pmic".
- reg: Specifies the I2C slave address of the PMIC block. It should be 0x66.

Optional properties:
- interrupt-parent: Specifies the phandle of the interrupt controller to which
  the interrupts from s2mpa01 are delivered to.
- interrupts: An interrupt specifier for the sole interrupt generated by the
  device.

Optional nodes:
- regulators: The regulators of s2mpa01 that have to be instantiated should be
  included in a sub-node named 'regulators'. Regulator nodes and constraints
  included in this sub-node use the standard regulator bindings which are
  documented elsewhere.

Properties for BUCK regulator nodes:
- regulator-ramp-delay: ramp delay in uV/us. May be 6250, 12500
  (default), 25000, or 50000. May be 0 for disabling the ramp delay on
  BUCK{1,2,3,4}.

 In the absence of the regulator-ramp-delay property, the default ramp
 delay will be used.

  NOTE: Some BUCKs share the ramp rate setting i.e. same ramp value will be set
  for a particular group of BUCKs. So provide same regulator-ramp-delay=<value>.

  The following BUCKs share ramp settings:
  * 1 and 6
  * 2 and 4
  * 8, 9, and 10

The following are the names of the regulators that the s2mpa01 PMIC block
supports. Note: The 'n' in LDOn and BUCKn represents the LDO or BUCK number
as per the datasheet of s2mpa01.

	- LDOn
		  - valid values for n are 1 to 26
		  - Example: LDO1, LD02, LDO26
	- BUCKn
		  - valid values for n are 1 to 10.
		  - Example: BUCK1, BUCK2, BUCK9

Example:

	s2mpa01_pmic@66 {
		compatible = "samsung,s2mpa01-pmic";
		reg = <0x66>;

		regulators {
			ldo1_reg: LDO1 {
				regulator-name = "VDD_ALIVE";
				regulator-min-microvolt = <1000000>;
				regulator-max-microvolt = <1000000>;
			};

			ldo2_reg: LDO2 {
				regulator-name = "VDDQ_MMC2";
				regulator-min-microvolt = <2800000>;
				regulator-max-microvolt = <2800000>;
				regulator-always-on;
			};

			buck1_reg: BUCK1 {
				regulator-name = "vdd_mif";
				regulator-min-microvolt = <950000>;
				regulator-max-microvolt = <1350000>;
				regulator-always-on;
				regulator-boot-on;
			};

			buck2_reg: BUCK2 {
				regulator-name = "vdd_arm";
				regulator-min-microvolt = <950000>;
				regulator-max-microvolt = <1350000>;
				regulator-always-on;
				regulator-boot-on;
				regulator-ramp-delay = <50000>;
			};
		};
	};