mfd: Add device tree support for max77686

This patch adds device tree support for mfd driver and adds
Documentation/devicetree/bindings/mfd/max77686.txt.
This patch also intialize max77686 pointer to NULL in max77686_i2c_probe
to silent a compile time warning.

Signed-off-by: Yadwinder Singh Brar <yadi.brar@samsung.com>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mfd/max77686.txt b/Documentation/devicetree/bindings/mfd/max77686.txt
new file mode 100644
index 0000000..c6a3469
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/max77686.txt
@@ -0,0 +1,59 @@
+Maxim MAX77686 multi-function device
+
+MAX77686 is a Mulitifunction device with PMIC, RTC and Charger on chip. It is
+interfaced to host controller using i2c interface. PMIC and Charger submodules
+are addressed using same i2c slave address whereas RTC submodule uses
+different i2c slave address,presently for which we are statically creating i2c
+client while probing.This document describes the binding for mfd device and
+PMIC submodule.
+
+Required properties:
+- compatible : Must be "maxim,max77686";
+- reg : Specifies the i2c slave address of PMIC block.
+- interrupts : This i2c device has an IRQ line connected to the main SoC.
+- interrupt-parent : The parent interrupt controller.
+
+Optional node:
+- voltage-regulators : The regulators of max77686 have to be instantiated
+  under subnode named "voltage-regulators" using the following format.
+
+	regulator_name {
+		regulator-compatible = LDOn/BUCKn
+		standard regulator constraints....
+	};
+	refer Documentation/devicetree/bindings/regulator/regulator.txt
+
+  The regulator-compatible property of regulator should initialized with string
+to get matched with their hardware counterparts as follow:
+
+	-LDOn 	:	for LDOs, where n can lie in range 1 to 26.
+		 	example: LDO1, LDO2, LDO26.
+	-BUCKn 	:	for BUCKs, where n can lie in range 1 to 9.
+			example: BUCK1, BUCK5, BUCK9.
+
+Example:
+
+	max77686@09 {
+		compatible = "maxim,max77686";
+		interrupt-parent = <&wakeup_eint>;
+		interrupts = <26 0>;
+		reg = <0x09>;
+
+		voltage-regulators {
+			ldo11_reg {
+				regulator-compatible = "LDO11";
+				regulator-name = "vdd_ldo11";
+				regulator-min-microvolt = <1900000>;
+				regulator-max-microvolt = <1900000>;
+				regulator-always-on;
+			};
+
+			buck1_reg {
+				regulator-compatible = "BUCK1";
+				regulator-name = "vdd_mif";
+				regulator-min-microvolt = <950000>;
+				regulator-max-microvolt = <1300000>;
+				regulator-always-on;
+				regulator-boot-on;
+			};
+	}