regulator: add device tree support for s5m8767

This device tree support is added for PMIC block of S5m8767 multi
function driver. The usage detail is added in the device tree
documentation section. This change is tested on exynos5250 based
arndale platform by regulator voltage set/get API's.

Reviewed-by: Thomas Abraham <[e-mail]>
Signed-off-by: Amit Daniel Kachhap <[e-mail]>
Tested-by: Sachin Kamat <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/regulator/s5m8767-regulator.txt

···
+* Samsung S5M8767 Voltage and Current Regulator
+
+The Samsung S5M8767 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 s5m8767.
+
+Required properties:
+- compatible: Should be "samsung,s5m8767-pmic".
+- reg: Specifies the i2c slave address of the pmic block. It should be 0x66.
+
+- s5m8767,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.
+
+- s5m8767,pmic-buck3-dvs-voltage: A set of 8 voltage values in micro-volt (uV)
+  units for buck3 when changing voltage using gpio dvs. Refer to [1] below
+  for additional information.
+
+- s5m8767,pmic-buck4-dvs-voltage: A set of 8 voltage values in micro-volt (uV)
+  units for buck4 when changing voltage using gpio dvs. Refer to [1] below
+  for additional information.
+
+- s5m8767,pmic-buck-ds-gpios: GPIO specifiers for three host gpio's used
+  for selecting GPIO DVS lines. It is one-to-one mapped to dvs gpio lines.
+
+[1] If none of the 's5m8767,pmic-buck[2/3/4]-uses-gpio-dvs' optional
+    property is specified, the 's5m8767,pmic-buck[2/3/4]-dvs-voltage'
+    property should specify atleast one voltage level (which would be a
+    safe operating voltage).
+
+    If either of the 's5m8767,pmic-buck[2/3/4]-uses-gpio-dvs' optional
+    property is specified, then all the eight voltage values for the
+    's5m8767,pmic-buck[2/3/4]-dvs-voltage' should be specified.
+
+Optional properties:
+- interrupt-parent: Specifies the phandle of the interrupt controller to which
+  the interrupts from s5m8767 are delivered to.
+- interrupts: Interrupt specifiers for two interrupt sources.
+  - First interrupt specifier is for 'irq1' interrupt.
+  - Second interrupt specifier is for 'alert' interrupt.
+- s5m8767,pmic-buck2-uses-gpio-dvs: 'buck2' can be controlled by gpio dvs.
+- s5m8767,pmic-buck3-uses-gpio-dvs: 'buck3' can be controlled by gpio dvs.
+- s5m8767,pmic-buck4-uses-gpio-dvs: 'buck4' can be controlled by gpio dvs.
+
+Additional properties required if either of the optional properties are used:
+
+- s5m8767,pmic-buck234-default-dvs-idx: Default voltage setting selected from
+  the possible 8 options selectable by the dvs gpios. The value of this
+  property should be between 0 and 7. If not specified or if out of range, the
+  default value of this property is set to 0.
+
+- s5m8767,pmic-buck-dvs-gpios: GPIO specifiers for three host gpio's used
+  for dvs. The format of the gpio specifier depends in the gpio controller.
+
+Regulators: The regulators of s5m8767 that have to be instantiated should be
+included in a sub-node named 'regulators'. Regulator nodes included in this
+sub-node should be of the format as listed below.
+
+	regulator_name {
+		ldo1_reg: LDO1 {
+			regulator-name = "VDD_ALIVE_1.0V";
+			regulator-min-microvolt = <1100000>;
+			regulator-max-microvolt = <1100000>;
+			regulator-always-on;
+			regulator-boot-on;
+			op_mode = <1>; /* Normal Mode */
+		};
+	};
+The above regulator entries are defined in regulator bindings documentation
+except op_mode description.
+	- op_mode: describes the different operating modes of the LDO's with
+		power mode change in SOC. The different possible values are,
+		0 - always off mode
+		1 - on in normal mode
+		2 - low power mode
+		3 - suspend mode
+
+The following are the names of the regulators that the s5m8767 pmic block
+supports. Note: The 'n' in LDOn and BUCKn represents the LDO or BUCK number
+as per the datasheet of s5m8767.
+
+	- LDOn
+		  - valid values for n are 1 to 28
+		  - Example: LDO0, LD01, LDO28
+	- BUCKn
+		  - valid values for n are 1 to 9.
+		  - Example: BUCK1, BUCK2, BUCK9
+
+The bindings inside the regulator nodes use the standard regulator bindings
+which are documented elsewhere.
+
+Example:
+
+	s5m8767_pmic@66 {
+		compatible = "samsung,s5m8767-pmic";
+		reg = <0x66>;
+
+		s5m8767,pmic-buck2-uses-gpio-dvs;
+		s5m8767,pmic-buck3-uses-gpio-dvs;
+		s5m8767,pmic-buck4-uses-gpio-dvs;
+
+		s5m8767,pmic-buck-default-dvs-idx = <0>;
+
+		s5m8767,pmic-buck-dvs-gpios = <&gpx0 0 1 0 0>, /* DVS1 */
+						 <&gpx0 1 1 0 0>, /* DVS2 */
+						 <&gpx0 2 1 0 0>; /* DVS3 */
+
+		s5m8767,pmic-buck-ds-gpios = <&gpx2 3 1 0 0>, /* SET1 */
+						<&gpx2 4 1 0 0>, /* SET2 */
+						<&gpx2 5 1 0 0>; /* SET3 */
+
+		s5m8767,pmic-buck2-dvs-voltage = <1350000>, <1300000>,
+						 <1250000>, <1200000>,
+						 <1150000>, <1100000>,
+						 <1000000>, <950000>;
+
+		s5m8767,pmic-buck3-dvs-voltage = <1100000>, <1100000>,
+						 <1100000>, <1100000>,
+						 <1000000>, <1000000>,
+						 <1000000>, <1000000>;
+
+		s5m8767,pmic-buck4-dvs-voltage = <1200000>, <1200000>,
+						 <1200000>, <1200000>,
+						 <1200000>, <1200000>,
+						 <1200000>, <1200000>;
+
+		regulators {
+			ldo1_reg: LDO1 {
+				regulator-name = "VDD_ABB_3.3V";
+				regulator-min-microvolt = <3300000>;
+				regulator-max-microvolt = <3300000>;
+				op_mode = <1>; /* Normal Mode */
+			};
+
+			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_MIF_1.2V";
+				regulator-min-microvolt = <950000>;
+				regulator-max-microvolt = <1350000>;
+				regulator-always-on;
+				regulator-boot-on;
+			};
+		};
+	};

drivers/mfd/sec-core.c

···
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
+#include <linux/of_irq.h>
 #include <linux/interrupt.h>
 #include <linux/pm_runtime.h>
 #include <linux/mutex.h>
···
 	},
 };
 
+#ifdef CONFIG_OF
+static struct of_device_id sec_dt_match[] = {
+	{	.compatible = "samsung,s5m8767-pmic",
+		.data = (void *)S5M8767X,
+	},
+	{},
+};
+#endif
+
 int sec_reg_read(struct sec_pmic_dev *sec_pmic, u8 reg, void *dest)
 {
 	return regmap_read(sec_pmic->regmap, reg, dest);
···
 	.val_bits = 8,
 };
 
+
+#ifdef CONFIG_OF
+/*
+ * Only the common platform data elements for s5m8767 are parsed here from the
+ * device tree. Other sub-modules of s5m8767 such as pmic, rtc , charger and
+ * others have to parse their own platform data elements from device tree.
+ *
+ * The s5m8767 platform data structure is instantiated here and the drivers for
+ * the sub-modules need not instantiate another instance while parsing their
+ * platform data.
+ */
+static struct sec_platform_data *sec_pmic_i2c_parse_dt_pdata(
+					struct device *dev)
+{
+	struct sec_platform_data *pd;
+
+	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd) {
+		dev_err(dev, "could not allocate memory for pdata\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/*
+	 * ToDo: the 'wakeup' member in the platform data is more of a linux
+	 * specfic information. Hence, there is no binding for that yet and
+	 * not parsed here.
+	 */
+
+	return pd;
+}
+#else
+static struct sec_platform_data *sec_i2c_parse_dt_pdata(
+					struct device *dev)
+{
+	return 0;
+}
+#endif
+
+static inline int sec_i2c_get_driver_data(struct i2c_client *i2c,
+						const struct i2c_device_id *id)
+{
+#ifdef CONFIG_OF
+	if (i2c->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(sec_dt_match, i2c->dev.of_node);
+		return (int)match->data;
+	}
+#endif
+	return (int)id->driver_data;
+}
+
 static int sec_pmic_probe(struct i2c_client *i2c,
 			    const struct i2c_device_id *id)
 {
···
 	sec_pmic->dev = &i2c->dev;
 	sec_pmic->i2c = i2c;
 	sec_pmic->irq = i2c->irq;
-	sec_pmic->type = id->driver_data;
+	sec_pmic->type = sec_i2c_get_driver_data(i2c, id);
 
+	if (sec_pmic->dev->of_node) {
+		pdata = sec_pmic_i2c_parse_dt_pdata(sec_pmic->dev);
+		if (IS_ERR(pdata)) {
+			ret = PTR_ERR(pdata);
+			return ret;
+		}
+		pdata->device_type = sec_pmic->type;
+	}
 	if (pdata) {
 		sec_pmic->device_type = pdata->device_type;
 		sec_pmic->ono = pdata->ono;
 		sec_pmic->irq_base = pdata->irq_base;
 		sec_pmic->wakeup = pdata->wakeup;
+		sec_pmic->pdata = pdata;
 	}
 
 	sec_pmic->regmap = devm_regmap_init_i2c(i2c, &sec_regmap_config);
···
 	.driver = {
 		   .name = "sec_pmic",
 		   .owner = THIS_MODULE,
+		   .of_match_table = of_match_ptr(sec_dt_match),
 	},
 	.probe = sec_pmic_probe,
 	.remove = sec_pmic_remove,

drivers/regulator/s5m8767.c

···
 #include <linux/bug.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
+#include <linux/of_gpio.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
···
 #include <linux/regulator/machine.h>
 #include <linux/mfd/samsung/core.h>
 #include <linux/mfd/samsung/s5m8767.h>
+#include <linux/regulator/of_regulator.h>
+
+#define S5M8767_OPMODE_NORMAL_MODE 0x1
 
 struct s5m8767_info {
 	struct device *dev;
···
 	s5m8767_regulator_desc(BUCK9),
 };
 
+#ifdef CONFIG_OF
+static int s5m8767_pmic_dt_parse_dvs_gpio(struct sec_pmic_dev *iodev,
+			struct sec_platform_data *pdata,
+			struct device_node *pmic_np)
+{
+	int i, gpio;
+
+	for (i = 0; i < 3; i++) {
+		gpio = of_get_named_gpio(pmic_np,
+					"s5m8767,pmic-buck-dvs-gpios", i);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(iodev->dev, "invalid gpio[%d]: %d\n", i, gpio);
+			return -EINVAL;
+		}
+		pdata->buck_gpios[i] = gpio;
+	}
+	return 0;
+}
+
+static int s5m8767_pmic_dt_parse_ds_gpio(struct sec_pmic_dev *iodev,
+			struct sec_platform_data *pdata,
+			struct device_node *pmic_np)
+{
+	int i, gpio;
+
+	for (i = 0; i < 3; i++) {
+		gpio = of_get_named_gpio(pmic_np,
+					"s5m8767,pmic-buck-ds-gpios", i);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(iodev->dev, "invalid gpio[%d]: %d\n", i, gpio);
+			return -EINVAL;
+		}
+		pdata->buck_ds[i] = gpio;
+	}
+	return 0;
+}
+
+static int s5m8767_pmic_dt_parse_pdata(struct sec_pmic_dev *iodev,
+					struct sec_platform_data *pdata)
+{
+	struct device_node *pmic_np, *regulators_np, *reg_np;
+	struct sec_regulator_data *rdata;
+	struct sec_opmode_data *rmode;
+	unsigned int i, dvs_voltage_nr = 1, ret;
+
+	pmic_np = iodev->dev->of_node;
+	if (!pmic_np) {
+		dev_err(iodev->dev, "could not find pmic sub-node\n");
+		return -ENODEV;
+	}
+
+	regulators_np = of_find_node_by_name(pmic_np, "regulators");
+	if (!regulators_np) {
+		dev_err(iodev->dev, "could not find regulators sub-node\n");
+		return -EINVAL;
+	}
+
+	/* count the number of regulators to be supported in pmic */
+	pdata->num_regulators = 0;
+	for_each_child_of_node(regulators_np, reg_np)
+		pdata->num_regulators++;
+
+	rdata = devm_kzalloc(iodev->dev, sizeof(*rdata) *
+				pdata->num_regulators, GFP_KERNEL);
+	if (!rdata) {
+		dev_err(iodev->dev,
+			"could not allocate memory for regulator data\n");
+		return -ENOMEM;
+	}
+
+	rmode = devm_kzalloc(iodev->dev, sizeof(*rmode) *
+				pdata->num_regulators, GFP_KERNEL);
+	if (!rdata) {
+		dev_err(iodev->dev,
+			"could not allocate memory for regulator mode\n");
+		return -ENOMEM;
+	}
+
+	pdata->regulators = rdata;
+	pdata->opmode = rmode;
+	for_each_child_of_node(regulators_np, reg_np) {
+		for (i = 0; i < ARRAY_SIZE(regulators); i++)
+			if (!of_node_cmp(reg_np->name, regulators[i].name))
+				break;
+
+		if (i == ARRAY_SIZE(regulators)) {
+			dev_warn(iodev->dev,
+			"don't know how to configure regulator %s\n",
+			reg_np->name);
+			continue;
+		}
+
+		rdata->id = i;
+		rdata->initdata = of_get_regulator_init_data(
+						iodev->dev, reg_np);
+		rdata->reg_node = reg_np;
+		rdata++;
+		rmode->id = i;
+		if (of_property_read_u32(reg_np, "op_mode",
+				&rmode->mode)) {
+			dev_warn(iodev->dev,
+				"no op_mode property property at %s\n",
+				reg_np->full_name);
+
+			rmode->mode = S5M8767_OPMODE_NORMAL_MODE;
+		}
+		rmode++;
+	}
+
+	if (of_get_property(pmic_np, "s5m8767,pmic-buck2-uses-gpio-dvs", NULL))
+		pdata->buck2_gpiodvs = true;
+
+	if (of_get_property(pmic_np, "s5m8767,pmic-buck3-uses-gpio-dvs", NULL))
+		pdata->buck3_gpiodvs = true;
+
+	if (of_get_property(pmic_np, "s5m8767,pmic-buck4-uses-gpio-dvs", NULL))
+		pdata->buck4_gpiodvs = true;
+
+	if (pdata->buck2_gpiodvs || pdata->buck3_gpiodvs ||
+						pdata->buck4_gpiodvs) {
+		ret = s5m8767_pmic_dt_parse_dvs_gpio(iodev, pdata, pmic_np);
+		if (ret)
+			return -EINVAL;
+
+		if (of_property_read_u32(pmic_np,
+				"s5m8767,pmic-buck-default-dvs-idx",
+				&pdata->buck_default_idx)) {
+			pdata->buck_default_idx = 0;
+		} else {
+			if (pdata->buck_default_idx >= 8) {
+				pdata->buck_default_idx = 0;
+				dev_info(iodev->dev,
+				"invalid value for default dvs index, use 0\n");
+			}
+		}
+		dvs_voltage_nr = 8;
+	}
+
+	ret = s5m8767_pmic_dt_parse_ds_gpio(iodev, pdata, pmic_np);
+	if (ret)
+		return -EINVAL;
+
+	if (of_property_read_u32_array(pmic_np,
+				"s5m8767,pmic-buck2-dvs-voltage",
+				pdata->buck2_voltage, dvs_voltage_nr)) {
+		dev_err(iodev->dev, "buck2 voltages not specified\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32_array(pmic_np,
+				"s5m8767,pmic-buck3-dvs-voltage",
+				pdata->buck3_voltage, dvs_voltage_nr)) {
+		dev_err(iodev->dev, "buck3 voltages not specified\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32_array(pmic_np,
+				"s5m8767,pmic-buck4-dvs-voltage",
+				pdata->buck4_voltage, dvs_voltage_nr)) {
+		dev_err(iodev->dev, "buck4 voltages not specified\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+#else
+static int s5m8767_pmic_dt_parse_pdata(struct sec_pmic_dev *iodev,
+					struct sec_platform_data *pdata)
+{
+	return 0;
+}
+#endif /* CONFIG_OF */
+
 static int s5m8767_pmic_probe(struct platform_device *pdev)
 {
 	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
-	struct sec_platform_data *pdata = dev_get_platdata(iodev->dev);
+	struct sec_platform_data *pdata = iodev->pdata;
 	struct regulator_config config = { };
 	struct regulator_dev **rdev;
 	struct s5m8767_info *s5m8767;
 	int i, ret, size, buck_init;
+
+	if (iodev->dev->of_node) {
+		ret = s5m8767_pmic_dt_parse_pdata(iodev, pdata);
+		if (ret)
+			return ret;
+	}
 
 	if (!pdata) {
 		dev_err(pdev->dev.parent, "Platform data not supplied\n");
···
 		config.init_data = pdata->regulators[i].initdata;
 		config.driver_data = s5m8767;
 		config.regmap = iodev->regmap;
+		config.of_node = pdata->regulators[i].reg_node;
 
 		rdev[i] = regulator_register(&regulators[id], &config);
 		if (IS_ERR(rdev[i])) {

include/linux/mfd/samsung/core.h

···
 /**
  * struct sec_pmic_dev - s5m87xx master device for sub-drivers
  * @dev: master device of the chip (can be used to access platform data)
+ * @pdata: pointer to private data used to pass platform data to child
  * @i2c: i2c client private data for regulator
  * @rtc: i2c client private data for rtc
  * @iolock: mutex for serializing io access
···
  */
 struct sec_pmic_dev {
 	struct device *dev;
+	struct sec_platform_data *pdata;
 	struct regmap *regmap;
 	struct i2c_client *i2c;
 	struct i2c_client *rtc;
···
 
 	int				buck_gpios[3];
 	int				buck_ds[3];
-	int				buck2_voltage[8];
+	unsigned int			buck2_voltage[8];
 	bool				buck2_gpiodvs;
-	int				buck3_voltage[8];
+	unsigned int			buck3_voltage[8];
 	bool				buck3_gpiodvs;
-	int				buck4_voltage[8];
+	unsigned int			buck4_voltage[8];
 	bool				buck4_gpiodvs;
 
 	int				buck_set1;
···
 struct sec_regulator_data {
 	int				id;
 	struct regulator_init_data	*initdata;
+	struct device_node *reg_node;
 };
 
 /*
···
  */
 struct sec_opmode_data {
 	int id;
-	int mode;
+	unsigned int mode;
 };
 
 /*