[PATCH 3/3] Documentation: mfd: Add binding document for S2MPA01

[Sachin Kamat <sachin.kamat@linaro.org>]

Added initial binding documentation for S2MPA01 MFD.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
---
 Documentation/devicetree/bindings/mfd/s2mpa01.txt |   91 +++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/s2mpa01.txt

diff --git a/Documentation/devicetree/bindings/mfd/s2mpa01.txt b/Documentation/devicetree/bindings/mfd/s2mpa01.txt
new file mode 100644
index 000000000000..ae750a28821b
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@@ -0,0 +1,91 @@
+
+* 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: Interrupt specifiers for interrupt sources.
+
+Optional nodes:
+- regulators: The regulators of s2mpa01 that have to be instantiated should be
+included in a sub-node named 'regulators'. Regulator nodes included in this
+sub-node should be of the format as listed below.
+
+	regulator_name {
+		[standard regulator constraints....];
+	};
+
+ regulator-ramp-delay for BUCKs = [6250/12500(default)/25000/50000] uV/us
+
+ BUCK[1/2/3/4] supports disabling ramp delay on hardware, so explictly
+ regulator-ramp-delay = <0> can be used for them to disable ramp delay.
+ 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>.
+Grouping of BUCKs sharing ramp rate setting is as follow : BUCK[1, 6],
+BUCK[2, 4], and BUCK[8, 9, 10]
+
+The regulator constraints inside the regulator nodes use the standard regulator
+bindings which are documented elsewhere.
+
+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>;
+			};
+		};
+	};
-- 
1.7.9.5