regulator: max8952: Add Device Tree support

This patch adds Device Tree support to max8952 regulator driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 126 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/regulator/max8952.txt b/Documentation/devicetree/bindings/regulator/max8952.txt
new file mode 100644
index 000000000000..866fcdd0f4eb
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/max8952.txt
@@ -0,0 +1,52 @@
+Maxim MAX8952 voltage regulator
+
+Required properties:
+- compatible: must be equal to "maxim,max8952"
+- reg: I2C slave address, usually 0x60
+- max8952,dvs-mode-microvolt: array of 4 integer values defining DVS voltages
+  in microvolts. All values must be from range <770000, 1400000>
+- any required generic properties defined in regulator.txt
+
+Optional properties:
+- max8952,vid-gpios: array of two GPIO pins used for DVS voltage selection
+- max8952,en-gpio: GPIO used to control enable status of regulator
+- max8952,default-mode: index of default DVS voltage, from <0, 3> range
+- max8952,sync-freq: sync frequency, must be one of following values:
+    - 0: 26 MHz
+    - 1: 13 MHz
+    - 2: 19.2 MHz
+  Defaults to 26 MHz if not specified.
+- max8952,ramp-speed: voltage ramp speed, must be one of following values:
+    - 0: 32mV/us
+    - 1: 16mV/us
+    - 2: 8mV/us
+    - 3: 4mV/us
+    - 4: 2mV/us
+    - 5: 1mV/us
+    - 6: 0.5mV/us
+    - 7: 0.25mV/us
+  Defaults to 32mV/us if not specified.
+- any available generic properties defined in regulator.txt
+
+Example:
+
+        vdd_arm_reg: pmic@60 {
+                compatible = "maxim,max8952";
+                reg = <0x60>;
+
+                /* max8952-specific properties */
+                max8952,vid-gpios = <&gpx0 3 0>, <&gpx0 4 0>;
+                max8952,en-gpio = <&gpx0 1 0>;
+                max8952,default-mode = <0>;
+                max8952,dvs-mode-microvolt = <1250000>, <1200000>,
+                                                <1050000>, <950000>;
+                max8952,sync-freq = <0>;
+                max8952,ramp-speed = <0>;
+
+                /* generic regulator properties */
+                regulator-name = "vdd_arm";
+                regulator-min-microvolt = <770000>;
+                regulator-max-microvolt = <1400000>;
+                regulator-always-on;
+                regulator-boot-on;
+        };
diff --git a/drivers/regulator/max8952.c b/drivers/regulator/max8952.c
index 100b9177dba1..4259c78abf88 100644
--- a/drivers/regulator/max8952.c
+++ b/drivers/regulator/max8952.c
@@ -28,6 +28,9 @@
 #include <linux/regulator/max8952.h>
 #include <linux/gpio.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/of_regulator.h>
 #include <linux/slab.h>
 
 /* Registers */
@@ -126,6 +129,69 @@ static const struct regulator_desc regulator = {
         .owner          = THIS_MODULE,
 };
 
+#ifdef CONFIG_OF
+static struct of_device_id max8952_dt_match[] = {
+        { .compatible = "maxim,max8952" },
+        {},
+};
+MODULE_DEVICE_TABLE(of, max8952_dt_match);
+
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+        struct max8952_platform_data *pd;
+        struct device_node *np = dev->of_node;
+        int ret;
+        int i;
+
+        pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+        if (!pd) {
+                dev_err(dev, "Failed to allocate platform data\n");
+                return NULL;
+        }
+
+        pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
+        pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
+        pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
+
+        if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
+                dev_warn(dev, "Default mode not specified, assuming 0\n");
+
+        ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
+                                        pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
+        if (ret) {
+                dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
+                return NULL;
+        }
+
+        for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
+                if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
+                        dev_err(dev, "DVS voltage %d out of range\n", i);
+                        return NULL;
+                }
+                pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
+        }
+
+        if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
+                dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
+
+        if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
+                dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
+
+        pd->reg_data = of_get_regulator_init_data(dev, np);
+        if (!pd->reg_data) {
+                dev_err(dev, "Failed to parse regulator init data\n");
+                return NULL;
+        }
+
+        return pd;
+}
+#else
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+        return NULL;
+}
+#endif
+
 static int max8952_pmic_probe(struct i2c_client *client,
                 const struct i2c_device_id *i2c_id)
 {
@@ -136,6 +202,9 @@ static int max8952_pmic_probe(struct i2c_client *client,
 
         int ret = 0, err = 0;
 
+        if (client->dev.of_node)
+                pdata = max8952_parse_dt(&client->dev);
+
         if (!pdata) {
                 dev_err(&client->dev, "Require the platform data\n");
                 return -EINVAL;
@@ -271,6 +340,7 @@ static struct i2c_driver max8952_pmic_driver = {
         .remove         = max8952_pmic_remove,
         .driver         = {
                 .name   = "max8952",
+                .of_match_table = of_match_ptr(max8952_dt_match),
         },
         .id_table       = max8952_ids,
 };
diff --git a/include/linux/regulator/max8952.h b/include/linux/regulator/max8952.h
index c13aa34d9019..4dbb63a1d4ab 100644
--- a/include/linux/regulator/max8952.h
+++ b/include/linux/regulator/max8952.h
@@ -122,11 +122,11 @@ struct max8952_platform_data {
         int gpio_vid1;
         int gpio_en;
 
-        u8 default_mode;
-        u8 dvs_mode[MAX8952_NUM_DVS_MODE]; /* MAX8952_DVS_MODEx_XXXXmV */
+        u32 default_mode;
+        u32 dvs_mode[MAX8952_NUM_DVS_MODE]; /* MAX8952_DVS_MODEx_XXXXmV */
 
-        u8 sync_freq;
-        u8 ramp_speed;
+        u32 sync_freq;
+        u32 ramp_speed;
 
         struct regulator_init_data *reg_data;
 };