regulator: max77693: Add max77693 regualtor driver.

This patch adds new regulator driver to support max77693 chip's regulators.
max77693 has two linear voltage regulators and one current regulator which
can be controlled through I2C bus. This driver also supports device tree.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

3 files changed, 334 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 8bb26446037..9744437afe3 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -250,6 +250,15 @@ config REGULATOR_MAX77686
 	  via I2C bus. The provided regulator is suitable for
 	  Exynos-4 chips to control VARM and VINT voltages.
 
+config REGULATOR_MAX77693
+	tristate "Maxim MAX77693 regulator"
+	depends on MFD_MAX77693
+	help
+	  This driver controls a Maxim 77693 regulator via I2C bus.
+	  The regulators include two LDOs, 'SAFEOUT1', 'SAFEOUT2'
+	  and one current regulator 'CHARGER'. This is suitable for
+	  Exynos-4x12 chips.
+
 config REGULATOR_PCAP
 	tristate "Motorola PCAP2 regulator driver"
 	depends on EZX_PCAP
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 47a34ff88f9..a4094cd274b 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_REGULATOR_MAX8973) += max8973-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8997) += max8997.o
 obj-$(CONFIG_REGULATOR_MAX8998) += max8998.o
 obj-$(CONFIG_REGULATOR_MAX77686) += max77686.o
+obj-$(CONFIG_REGULATOR_MAX77693) += max77693.o
 obj-$(CONFIG_REGULATOR_MC13783) += mc13783-regulator.o
 obj-$(CONFIG_REGULATOR_MC13892) += mc13892-regulator.o
 obj-$(CONFIG_REGULATOR_MC13XXX_CORE) +=  mc13xxx-regulator-core.o
diff --git a/drivers/regulator/max77693.c b/drivers/regulator/max77693.c
new file mode 100644
index 00000000000..674ece7c832
--- /dev/null
+++ b/drivers/regulator/max77693.c
@@ -0,0 +1,324 @@
+/*
+ * max77693.c - Regulator driver for the Maxim 77693
+ *
+ * Copyright (C) 2013 Samsung Electronics
+ * Jonghwa Lee <jonghwa3.lee@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * This driver is based on max77686.c
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/mfd/max77693.h>
+#include <linux/mfd/max77693-private.h>
+#include <linux/regulator/of_regulator.h>
+
+#define CHGIN_ILIM_STEP_20mA			20000
+
+struct max77693_pmic_dev {
+	struct device *dev;
+	struct max77693_dev *iodev;
+	int num_regulators;
+	struct regulator_dev **rdev;
+};
+
+/* CHARGER regulator ops */
+/* CHARGER regulator uses two bits for enabling */
+static int max77693_chg_is_enabled(struct regulator_dev *rdev)
+{
+	int ret;
+	u8 val;
+
+	ret = max77693_read_reg(rdev->regmap, rdev->desc->enable_reg, &val);
+	if (ret)
+		return ret;
+
+	return (val & rdev->desc->enable_mask) == rdev->desc->enable_mask;
+}
+
+/*
+ * CHARGER regulator - Min : 20mA, Max : 2580mA, step : 20mA
+ * 0x00, 0x01, 0x2, 0x03	= 60 mA
+ * 0x04 ~ 0x7E			= (60 + (X - 3) * 20) mA
+ */
+static int max77693_chg_get_current_limit(struct regulator_dev *rdev)
+{
+	unsigned int chg_min_uA = rdev->constraints->min_uA;
+	unsigned int chg_max_uA = rdev->constraints->max_uA;
+	u8 reg, sel;
+	unsigned int val;
+	int ret;
+
+	ret = max77693_read_reg(rdev->regmap,
+				MAX77693_CHG_REG_CHG_CNFG_09, &reg);
+	if (ret < 0)
+		return ret;
+
+	sel = reg & CHG_CNFG_09_CHGIN_ILIM_MASK;
+
+	/* the first four codes for charger current are all 60mA */
+	if (sel <= 3)
+		sel = 0;
+	else
+		sel -= 3;
+
+	val = chg_min_uA + CHGIN_ILIM_STEP_20mA * sel;
+	if (val > chg_max_uA)
+		return -EINVAL;
+
+	return val;
+}
+
+static int max77693_chg_set_current_limit(struct regulator_dev *rdev,
+						int min_uA, int max_uA)
+{
+	unsigned int chg_min_uA = rdev->constraints->min_uA;
+	int sel = 0;
+
+	while (chg_min_uA + CHGIN_ILIM_STEP_20mA * sel < min_uA)
+		sel++;
+
+	if (chg_min_uA * CHGIN_ILIM_STEP_20mA * sel > max_uA)
+		return -EINVAL;
+
+	/* the first four codes for charger current are all 60mA */
+	sel += 3;
+
+	return max77693_write_reg(rdev->regmap,
+				MAX77693_CHG_REG_CHG_CNFG_09, sel);
+}
+/* end of CHARGER regulator ops */
+
+static const unsigned int max77693_safeout_table[] = {
+	4850000,
+	4900000,
+	4950000,
+	3300000,
+};
+
+static struct regulator_ops max77693_safeout_ops = {
+	.list_voltage		= regulator_list_voltage_table,
+	.is_enabled		= regulator_is_enabled_regmap,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+};
+
+static struct regulator_ops max77693_charger_ops = {
+	.is_enabled		= max77693_chg_is_enabled,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.get_current_limit	= max77693_chg_get_current_limit,
+	.set_current_limit	= max77693_chg_set_current_limit,
+};
+
+#define regulator_desc_esafeout(_num)	{			\
+	.name		= "ESAFEOUT"#_num,			\
+	.id		= MAX77693_ESAFEOUT##_num,		\
+	.n_voltages	= 4,					\
+	.ops		= &max77693_safeout_ops,		\
+	.type		= REGULATOR_VOLTAGE,			\
+	.volt_table	= max77693_safeout_table,		\
+	.vsel_reg	= MAX77693_CHG_REG_SAFEOUT_CTRL,	\
+	.vsel_mask	= SAFEOUT_CTRL_SAFEOUT##_num##_MASK,	\
+	.enable_reg	= MAX77693_CHG_REG_SAFEOUT_CTRL,	\
+	.enable_mask	= SAFEOUT_CTRL_ENSAFEOUT##_num##_MASK ,	\
+}
+
+static struct regulator_desc regulators[] = {
+	regulator_desc_esafeout(1),
+	regulator_desc_esafeout(2),
+	{
+		.name = "CHARGER",
+		.id = MAX77693_CHARGER,
+		.ops = &max77693_charger_ops,
+		.type = REGULATOR_CURRENT,
+		.owner = THIS_MODULE,
+		.enable_reg = MAX77693_CHG_REG_CHG_CNFG_00,
+		.enable_mask = CHG_CNFG_00_CHG_MASK |
+				CHG_CNFG_00_BUCK_MASK,
+	},
+};
+
+#ifdef CONFIG_OF
+static int max77693_pmic_dt_parse_rdata(struct device *dev,
+					struct max77693_regulator_data **rdata)
+{
+	struct device_node *np;
+	struct of_regulator_match *rmatch;
+	struct max77693_regulator_data *tmp;
+	int i, matched = 0;
+
+	np = of_find_node_by_name(dev->parent->of_node, "regulators");
+	if (!np)
+		return -EINVAL;
+
+	rmatch = devm_kzalloc(dev,
+		 sizeof(*rmatch) * ARRAY_SIZE(regulators), GFP_KERNEL);
+	if (!rmatch)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(regulators); i++)
+		rmatch[i].name = regulators[i].name;
+
+	matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(regulators));
+	if (matched <= 0)
+		return matched;
+	*rdata = devm_kzalloc(dev, sizeof(**rdata) * matched, GFP_KERNEL);
+	if (!(*rdata))
+		return -ENOMEM;
+
+	tmp = *rdata;
+
+	for (i = 0; i < ARRAY_SIZE(regulators); i++) {
+		if (!rmatch[i].init_data)
+			continue;
+		tmp->initdata = rmatch[i].init_data;
+		tmp->of_node = rmatch[i].of_node;
+		tmp->id = regulators[i].id;
+		tmp++;
+	}
+
+	return matched;
+}
+#else
+static int max77693_pmic_dt_parse_rdata(struct device *dev,
+					struct max77693_regulator_data **rdata)
+{
+	return 0;
+}
+#endif /* CONFIG_OF */
+
+static int max77693_pmic_init_rdata(struct device *dev,
+				    struct max77693_regulator_data **rdata)
+{
+	struct max77693_platform_data *pdata;
+	int num_regulators = 0;
+
+	pdata = dev_get_platdata(dev->parent);
+	if (pdata) {
+		*rdata = pdata->regulators;
+		num_regulators = pdata->num_regulators;
+	}
+
+	if (!(*rdata) && dev->parent->of_node)
+		num_regulators = max77693_pmic_dt_parse_rdata(dev, rdata);
+
+	return num_regulators;
+}
+
+static int max77693_pmic_probe(struct platform_device *pdev)
+{
+	struct max77693_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+	struct max77693_pmic_dev *max77693_pmic;
+	struct max77693_regulator_data *rdata = NULL;
+	int num_rdata, i, ret;
+	struct regulator_config config;
+
+	num_rdata = max77693_pmic_init_rdata(&pdev->dev, &rdata);
+	if (!rdata || num_rdata <= 0) {
+		dev_err(&pdev->dev, "No init data supplied.\n");
+		return -ENODEV;
+	}
+
+	max77693_pmic = devm_kzalloc(&pdev->dev,
+				sizeof(struct max77693_pmic_dev),
+				GFP_KERNEL);
+	if (!max77693_pmic)
+		return -ENOMEM;
+
+	max77693_pmic->rdev = devm_kzalloc(&pdev->dev,
+				sizeof(struct regulator_dev *) * num_rdata,
+				GFP_KERNEL);
+	if (!max77693_pmic->rdev)
+		return -ENOMEM;
+
+	max77693_pmic->dev = &pdev->dev;
+	max77693_pmic->iodev = iodev;
+	max77693_pmic->num_regulators = num_rdata;
+
+	config.dev = &pdev->dev;
+	config.regmap = iodev->regmap;
+	config.driver_data = max77693_pmic;
+	platform_set_drvdata(pdev, max77693_pmic);
+
+	for (i = 0; i < max77693_pmic->num_regulators; i++) {
+		int id = rdata[i].id;
+
+		config.init_data = rdata[i].initdata;
+		config.of_node = rdata[i].of_node;
+
+		max77693_pmic->rdev[i] = regulator_register(&regulators[id],
+							    &config);
+		if (IS_ERR(max77693_pmic->rdev[i])) {
+			ret = PTR_ERR(max77693_pmic->rdev[i]);
+			dev_err(max77693_pmic->dev,
+				"Failed to initialize regulator-%d\n", id);
+			max77693_pmic->rdev[i] = NULL;
+			goto err;
+		}
+	}
+
+	return 0;
+ err:
+	while (--i >= 0)
+		regulator_unregister(max77693_pmic->rdev[i]);
+
+	return ret;
+}
+
+static int max77693_pmic_remove(struct platform_device *pdev)
+{
+	struct max77693_pmic_dev *max77693_pmic = platform_get_drvdata(pdev);
+	struct regulator_dev **rdev = max77693_pmic->rdev;
+	int i;
+
+	for (i = 0; i < max77693_pmic->num_regulators; i++)
+		if (rdev[i])
+			regulator_unregister(rdev[i]);
+
+	return 0;
+}
+
+static const struct platform_device_id max77693_pmic_id[] = {
+	{"max77693-pmic", 0},
+	{},
+};
+
+MODULE_DEVICE_TABLE(platform, max77693_pmic_id);
+
+static struct platform_driver max77693_pmic_driver = {
+	.driver = {
+		   .name = "max77693-pmic",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = max77693_pmic_probe,
+	.remove = max77693_pmic_remove,
+	.id_table = max77693_pmic_id,
+};
+
+module_platform_driver(max77693_pmic_driver);
+
+MODULE_DESCRIPTION("MAXIM MAX77693 regulator driver");
+MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
+MODULE_LICENSE("GPL");