regulator: max77843: Add max77843 regulator driver

This patch adds new regulator driver to support max77843
MFD(Multi Function Device) chip`s regulators.
The Max77843 has two voltage regulators for USB safeout.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 236 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index c3a60b57a865..c1f9c339da7c 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -414,6 +414,14 @@ config REGULATOR_MAX77802
           Exynos5420/Exynos5800 SoCs to control various voltages.
           It includes support for control of voltage and ramp speed.
 
+config REGULATOR_MAX77843
+        tristate "Maxim 77843 regulator"
+        depends on MFD_MAX77843
+        help
+          This driver controls a Maxim 77843 regulator.
+          The regulator include two 'SAFEOUT' for USB(Universal Serial Bus)
+          This is suitable for Exynos5433 SoC chips.
+
 config REGULATOR_MC13XXX_CORE
         tristate
 
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 1f28ebfc6f3a..12408d66ba20 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_REGULATOR_MAX8998) += max8998.o
 obj-$(CONFIG_REGULATOR_MAX77686) += max77686.o
 obj-$(CONFIG_REGULATOR_MAX77693) += max77693.o
 obj-$(CONFIG_REGULATOR_MAX77802) += max77802.o
+obj-$(CONFIG_REGULATOR_MAX77843) += max77843.o
 obj-$(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/max77843.c b/drivers/regulator/max77843.c
new file mode 100644
index 000000000000..c132ef527cdd
--- /dev/null
+++ b/drivers/regulator/max77843.c
@@ -0,0 +1,227 @@
+/*
+ * max77843.c - Regulator driver for the Maxim MAX77843
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Jaewon Kim <jaewon02.kim@samsung.com>
+ * Author: Beomho Seo <beomho.seo@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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/mfd/max77843-private.h>
+#include <linux/regulator/of_regulator.h>
+
+enum max77843_regulator_type {
+        MAX77843_SAFEOUT1 = 0,
+        MAX77843_SAFEOUT2,
+        MAX77843_CHARGER,
+
+        MAX77843_NUM,
+};
+
+static const unsigned int max77843_safeout_voltage_table[] = {
+        4850000,
+        4900000,
+        4950000,
+        3300000,
+};
+
+static int max77843_reg_is_enabled(struct regulator_dev *rdev)
+{
+        struct regmap *regmap = rdev->regmap;
+        int ret;
+        unsigned int reg;
+
+        ret = regmap_read(regmap, rdev->desc->enable_reg, &reg);
+        if (ret) {
+                dev_err(&rdev->dev, "Fialed to read charger register\n");
+                return ret;
+        }
+
+        return (reg & rdev->desc->enable_mask) == rdev->desc->enable_mask;
+}
+
+static int max77843_reg_get_current_limit(struct regulator_dev *rdev)
+{
+        struct regmap *regmap = rdev->regmap;
+        unsigned int chg_min_uA = rdev->constraints->min_uA;
+        unsigned int chg_max_uA = rdev->constraints->max_uA;
+        unsigned int val;
+        int ret;
+        unsigned int reg, sel;
+
+        ret = regmap_read(regmap, MAX77843_CHG_REG_CHG_CNFG_02, &reg);
+        if (ret) {
+                dev_err(&rdev->dev, "Failed to read charger register\n");
+                return ret;
+        }
+
+        sel = reg & MAX77843_CHG_FAST_CHG_CURRENT_MASK;
+
+        if (sel < 0x03)
+                sel = 0;
+        else
+                sel -= 2;
+
+        val = chg_min_uA + MAX77843_CHG_FAST_CHG_CURRENT_STEP * sel;
+        if (val > chg_max_uA)
+                return -EINVAL;
+
+        return val;
+}
+
+static int max77843_reg_set_current_limit(struct regulator_dev *rdev,
+                int min_uA, int max_uA)
+{
+        struct regmap *regmap = rdev->regmap;
+        unsigned int chg_min_uA = rdev->constraints->min_uA;
+        int sel = 0;
+
+        while (chg_min_uA + MAX77843_CHG_FAST_CHG_CURRENT_STEP * sel < min_uA)
+                sel++;
+
+        if (chg_min_uA + MAX77843_CHG_FAST_CHG_CURRENT_STEP * sel > max_uA)
+                return -EINVAL;
+
+        sel += 2;
+
+        return regmap_write(regmap, MAX77843_CHG_REG_CHG_CNFG_02, sel);
+}
+
+static struct regulator_ops max77843_charger_ops = {
+        .is_enabled             = max77843_reg_is_enabled,
+        .enable                 = regulator_enable_regmap,
+        .disable                = regulator_disable_regmap,
+        .get_current_limit      = max77843_reg_get_current_limit,
+        .set_current_limit      = max77843_reg_set_current_limit,
+};
+
+static struct regulator_ops max77843_regulator_ops = {
+        .is_enabled             = regulator_is_enabled_regmap,
+        .enable                 = regulator_enable_regmap,
+        .disable                = regulator_disable_regmap,
+        .list_voltage           = regulator_list_voltage_table,
+        .get_voltage_sel        = regulator_get_voltage_sel_regmap,
+        .set_voltage_sel        = regulator_set_voltage_sel_regmap,
+};
+
+static const struct regulator_desc max77843_supported_regulators[] = {
+        [MAX77843_SAFEOUT1] = {
+                .name           = "SAFEOUT1",
+                .id             = MAX77843_SAFEOUT1,
+                .ops            = &max77843_regulator_ops,
+                .of_match       = of_match_ptr("SAFEOUT1"),
+                .regulators_node = of_match_ptr("regulators"),
+                .type           = REGULATOR_VOLTAGE,
+                .owner          = THIS_MODULE,
+                .n_voltages     = ARRAY_SIZE(max77843_safeout_voltage_table),
+                .volt_table     = max77843_safeout_voltage_table,
+                .enable_reg     = MAX77843_SYS_REG_SAFEOUTCTRL,
+                .enable_mask    = MAX77843_REG_SAFEOUTCTRL_ENSAFEOUT1,
+                .vsel_reg       = MAX77843_SYS_REG_SAFEOUTCTRL,
+                .vsel_mask      = MAX77843_REG_SAFEOUTCTRL_SAFEOUT1_MASK,
+        },
+        [MAX77843_SAFEOUT2] = {
+                .name           = "SAFEOUT2",
+                .id             = MAX77843_SAFEOUT2,
+                .ops            = &max77843_regulator_ops,
+                .of_match       = of_match_ptr("SAFEOUT2"),
+                .regulators_node = of_match_ptr("regulators"),
+                .type           = REGULATOR_VOLTAGE,
+                .owner          = THIS_MODULE,
+                .n_voltages     = ARRAY_SIZE(max77843_safeout_voltage_table),
+                .volt_table     = max77843_safeout_voltage_table,
+                .enable_reg     = MAX77843_SYS_REG_SAFEOUTCTRL,
+                .enable_mask    = MAX77843_REG_SAFEOUTCTRL_ENSAFEOUT2,
+                .vsel_reg       = MAX77843_SYS_REG_SAFEOUTCTRL,
+                .vsel_mask      = MAX77843_REG_SAFEOUTCTRL_SAFEOUT2_MASK,
+        },
+        [MAX77843_CHARGER] = {
+                .name           = "CHARGER",
+                .id             = MAX77843_CHARGER,
+                .ops            = &max77843_charger_ops,
+                .of_match       = of_match_ptr("CHARGER"),
+                .regulators_node = of_match_ptr("regulators"),
+                .type           = REGULATOR_CURRENT,
+                .owner          = THIS_MODULE,
+                .enable_reg     = MAX77843_CHG_REG_CHG_CNFG_00,
+                .enable_mask    = MAX77843_CHG_MASK,
+        },
+};
+
+static struct regmap *max77843_get_regmap(struct max77843 *max77843, int reg_id)
+{
+        switch (reg_id) {
+        case MAX77843_SAFEOUT1:
+        case MAX77843_SAFEOUT2:
+                return max77843->regmap;
+        case MAX77843_CHARGER:
+                return max77843->regmap_chg;
+        default:
+                return max77843->regmap;
+        }
+}
+
+static int max77843_regulator_probe(struct platform_device *pdev)
+{
+        struct max77843 *max77843 = dev_get_drvdata(pdev->dev.parent);
+        struct regulator_config config = {};
+        int i;
+
+        config.dev = max77843->dev;
+        config.driver_data = max77843;
+
+        for (i = 0; i < ARRAY_SIZE(max77843_supported_regulators); i++) {
+                struct regulator_dev *regulator;
+
+                config.regmap = max77843_get_regmap(max77843,
+                                max77843_supported_regulators[i].id);
+
+                regulator = devm_regulator_register(&pdev->dev,
+                                &max77843_supported_regulators[i], &config);
+                if (IS_ERR(regulator)) {
+                        dev_err(&pdev->dev,
+                                        "Failed to regiser regulator-%d\n", i);
+                        return PTR_ERR(regulator);
+                }
+        }
+
+        return 0;
+}
+
+static const struct platform_device_id max77843_regulator_id[] = {
+        { "max77843-regulator", },
+        { /* sentinel */ },
+};
+
+static struct platform_driver max77843_regulator_driver = {
+        .driver = {
+                .name = "max77843-regulator",
+        },
+        .probe          = max77843_regulator_probe,
+        .id_table       = max77843_regulator_id,
+};
+
+static int __init max77843_regulator_init(void)
+{
+        return platform_driver_register(&max77843_regulator_driver);
+}
+subsys_initcall(max77843_regulator_init);
+
+static void __exit max77843_regulator_exit(void)
+{
+        platform_driver_unregister(&max77843_regulator_driver);
+}
+module_exit(max77843_regulator_exit);
+
+MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
+MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
+MODULE_DESCRIPTION("Maxim MAX77843 regulator driver");
+MODULE_LICENSE("GPL");