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>

2 files changed, 98 insertions, 6 deletions

diff --git a/Documentation/devicetree/bindings/mfd/max77686.txt b/Documentation/devicetree/bindings/mfd/max77686.txt
new file mode 100644
index 000000000000..c6a3469d3436
--- /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;
+                        };
+        }
diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c
index c66639d681e9..3e31d05906b2 100644
--- a/drivers/mfd/max77686.c
+++ b/drivers/mfd/max77686.c
@@ -34,6 +34,11 @@
 
 #define I2C_ADDR_RTC    (0x0C >> 1)
 
+static struct of_device_id __devinitdata max77686_pmic_dt_match[] = {
+        {.compatible = "maxim,max77686",        .data = 0},
+        {},
+};
+
 static struct mfd_cell max77686_devs[] = {
         { .name = "max77686-pmic", },
         { .name = "max77686-rtc", },
@@ -44,14 +49,46 @@ static struct regmap_config max77686_regmap_config = {
         .val_bits = 8,
 };
 
+#ifdef CONFIG_OF
+static struct max77686_platform_data *max77686_i2c_parse_dt_pdata(struct device
+                                                                  *dev)
+{
+        struct max77686_platform_data *pd;
+
+        pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+        if (!pd) {
+                dev_err(dev, "could not allocate memory for pdata\n");
+                return NULL;
+        }
+
+        dev->platform_data = pd;
+        return pd;
+}
+#else
+static struct max77686_platform_data *max77686_i2c_parse_dt_pdata(struct device
+                                                                  *dev)
+{
+        return 0;
+}
+#endif
+
 static int max77686_i2c_probe(struct i2c_client *i2c,
                               const struct i2c_device_id *id)
 {
-        struct max77686_dev *max77686;
+        struct max77686_dev *max77686 = NULL;
         struct max77686_platform_data *pdata = i2c->dev.platform_data;
         unsigned int data;
         int ret = 0;
 
+        if (i2c->dev.of_node)
+                pdata = max77686_i2c_parse_dt_pdata(&i2c->dev);
+
+        if (!pdata) {
+                ret = -EIO;
+                dev_err(&i2c->dev, "No platform data found.\n");
+                goto err;
+        }
+
         max77686 = kzalloc(sizeof(struct max77686_dev), GFP_KERNEL);
         if (max77686 == NULL)
                 return -ENOMEM;
@@ -70,11 +107,6 @@ static int max77686_i2c_probe(struct i2c_client *i2c,
         max77686->i2c = i2c;
         max77686->type = id->driver_data;
 
-        if (!pdata) {
-                ret = -EIO;
-                goto err;
-        }
-
         max77686->wakeup = pdata->wakeup;
         max77686->irq_gpio = pdata->irq_gpio;
         max77686->irq = i2c->irq;
@@ -130,6 +162,7 @@ static struct i2c_driver max77686_i2c_driver = {
         .driver = {
                    .name = "max77686",
                    .owner = THIS_MODULE,
+                   .of_match_table = of_match_ptr(max77686_pmic_dt_match),
         },
         .probe = max77686_i2c_probe,
         .remove = max77686_i2c_remove,