mfd: max8998: Add support for Device Tree

This patch adds Device Tree support to max8998 driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mfd/max8998.txt b/Documentation/devicetree/bindings/mfd/max8998.txt
new file mode 100644
index 000000000000..23a3650ff2a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/max8998.txt
@@ -0,0 +1,119 @@
+* Maxim MAX8998, National/TI LP3974 multi-function device
+
+The Maxim MAX8998 is a multi-function device which includes voltage/current
+regulators, real time clock, battery charging controller and several
+other sub-blocks. It is interfaced using an I2C interface. Each sub-block
+is addressed by the host system using different i2c slave address.
+
+PMIC sub-block
+--------------
+
+The PMIC sub-block contains a number of voltage and current regulators,
+with controllable parameters and dynamic voltage scaling capability.
+In addition, it includes a real time clock and battery charging controller
+as well. It is accessible at I2C address 0x66.
+
+Required properties:
+- compatible: Should be one of the following:
+    - "maxim,max8998" for Maxim MAX8998
+    - "national,lp3974" or "ti,lp3974" for National/TI LP3974.
+- 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 MAX8998 are routed to.
+- interrupts: Interrupt specifiers for two interrupt sources.
+  - First interrupt specifier is for main interrupt.
+  - Second interrupt specifier is for power-on/-off interrupt.
+- max8998,pmic-buck1-dvs-gpios: GPIO specifiers for two host gpios used
+  for buck 1 dvs. The format of the gpio specifier depends on the gpio
+  controller.
+- max8998,pmic-buck2-dvs-gpio: GPIO specifier for host gpio used
+  for buck 2 dvs. The format of the gpio specifier depends on the gpio
+  controller.
+- max8998,pmic-buck1-default-dvs-idx: Default voltage setting selected from
+  the possible 4 options selectable by the dvs gpios. The value of this
+  property should be 0, 1, 2 or 3. If not specified or out of range,
+  a default value of 0 is taken.
+- max8998,pmic-buck2-default-dvs-idx: Default voltage setting selected from
+  the possible 2 options selectable by the dvs gpios. The value of this
+  property should be 0 or 1. If not specified or out of range, a default
+  value of 0 is taken.
+- max8998,pmic-buck-voltage-lock: If present, disallows changing of
+  preprogrammed buck dvfs voltages.
+
+Additional properties required if max8998,pmic-buck1-dvs-gpios is defined:
+- max8998,pmic-buck1-dvs-voltage: An array of 4 voltage values in microvolts
+  for buck1 regulator that can be selected using dvs gpio.
+
+Additional properties required if max8998,pmic-buck2-dvs-gpio is defined:
+- max8998,pmic-buck2-dvs-voltage: An array of 2 voltage values in microvolts
+  for buck2 regulator that can be selected using dvs gpio.
+
+Regulators: All the regulators of MAX8998 to be instantiated shall be
+listed in a child node named 'regulators'. Each regulator is represented
+by a child node of the 'regulators' node.
+
+	regulator-name {
+		/* standard regulator bindings here */
+	};
+
+Following regulators of the MAX8998 PMIC block are supported. Note that
+the 'n' in regulator name, as in LDOn or BUCKn, represents the LDO or BUCK
+number as described in MAX8998 datasheet.
+
+	- LDOn
+		  - valid values for n are 2 to 17
+		  - Example: LDO2, LDO10, LDO17
+	- BUCKn
+		  - valid values for n are 1 to 4.
+		  - Example: BUCK1, BUCK2, BUCK3, BUCK4
+
+	- ENVICHG: Battery Charging Current Monitor Output. This is a fixed
+		   voltage type regulator
+
+	- ESAFEOUT1: (ldo19)
+	- ESAFEOUT2: (ld020)
+
+Standard regulator bindings are used inside regulator subnodes. Check
+  Documentation/devicetree/bindings/regulator/regulator.txt
+for more details.
+
+Example:
+
+	pmic@66 {
+		compatible = "maxim,max8998-pmic";
+		reg = <0x66>;
+		interrupt-parent = <&wakeup_eint>;
+		interrupts = <4 0>, <3 0>;
+
+		/* Buck 1 DVS settings */
+		max8998,pmic-buck1-default-dvs-idx = <0>;
+		max8998,pmic-buck1-dvs-gpios = <&gpx0 0 1 0 0>, /* SET1 */
+					       <&gpx0 1 1 0 0>; /* SET2 */
+		max8998,pmic-buck1-dvs-voltage = <1350000>, <1300000>,
+						 <1000000>, <950000>;
+
+		/* Buck 2 DVS settings */
+		max8998,pmic-buck2-default-dvs-idx = <0>;
+		max8998,pmic-buck2-dvs-gpio = <&gpx0 0 3 0 0>; /* SET3 */
+		max8998,pmic-buck2-dvs-voltage = <1350000>, <1300000>;
+
+		/* Regulators to instantiate */
+		regulators {
+			ldo2_reg: LDO2 {
+				regulator-name = "VDD_ALIVE_1.1V";
+				regulator-min-microvolt = <1100000>;
+				regulator-max-microvolt = <1100000>;
+				regulator-always-on;
+			};
+
+			buck1_reg: BUCK1 {
+				regulator-name = "VDD_ARM_1.2V";
+				regulator-min-microvolt = <950000>;
+				regulator-max-microvolt = <1350000>;
+				regulator-always-on;
+				regulator-boot-on;
+			};
+		};
+	};