Add device tree based discovery support for max8997.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Rajendra Nayak <redacted>
Cc: Rob Herring <redacted>
Cc: Grant Likely <redacted>
Signed-off-by: Thomas Abraham <redacted>
---
 .../devicetree/bindings/regulator/max8997-pmic.txt |  133 ++++++++++++++++++
 drivers/mfd/max8997.c                              |   73 ++++++++++-
 drivers/regulator/max8997.c                        |  143 +++++++++++++++++++-
 include/linux/mfd/max8997-private.h                |    1 +
 include/linux/mfd/max8997.h                        |    1 +
 5 files changed, 347 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/regulator/max8997-pmic.txt

diff --git a/Documentation/devicetree/bindings/regulator/max8997-pmic.txt b/Documentation/devicetree/bindings/regulator/max8997-pmic.txt
new file mode 100644
index 0000000..90a730b
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/max8997-pmic.txt

@@ -0,0 +1,133 @@
+* Maxim MAX8997 Voltage and Current Regulator
+
+The Maxim MAX8997 is a multi-function device which includes volatage and
+current regulators, rtc, charger controller and other sub-blocks. It is
+interfaced to the host controller using a i2c interface. Each sub-block is
+addressed by the host system using different i2c slave address. This document
+describes the bindings for 'pmic' sub-block of max8997.
+
+Required properties:
+- compatible: Should be "maxim,max8997-pmic".
+- reg: Specifies the i2c slave address of the pmic block. It should be 0x66.
+
+- max8997,pmic-buck1-dvs-voltage: A set of 8 voltage values in micro-volt (uV)
+  units for buck1 when changing voltage using gpio dvs. Refer to [1] below
+  for additional information.
+
+- max8997,pmic-buck2-dvs-voltage: A set of 8 voltage values in micro-volt (uV)
+  units for buck2 when changing voltage using gpio dvs. Refer to [1] below
+  for additional information.
+
+- max8997,pmic-buck5-dvs-voltage: A set of 8 voltage values in micro-volt (uV)
+  units for buck5 when changing voltage using gpio dvs. Refer to [1] below
+  for additional information.