// SPDX-License-Identifier: GPL-2.0+
//
// max77693.c - Regulator driver for the Maxim 77693 and 77843
//
// Copyright (C) 2013-2015 Samsung Electronics
// Jonghwa Lee <jonghwa3.lee@samsung.com>
// Krzysztof Kozlowski <krzk@kernel.org>
//
// 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-common.h>
#include <linux/mfd/max77693-private.h>
#include <linux/mfd/max77843-private.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regmap.h>

/*
 * ID for MAX77843 regulators.
 * There is no need for such for MAX77693.
 */
enum max77843_regulator_type {
        MAX77843_SAFEOUT1 = 0,
        MAX77843_SAFEOUT2,
        MAX77843_CHARGER,

        MAX77843_NUM,
};

/* Register differences between chargers: MAX77693 and MAX77843 */
struct chg_reg_data {
        unsigned int linear_reg;
        unsigned int linear_mask;
        unsigned int uA_step;
        unsigned int min_sel;
};

/*
 * MAX77693 CHARGER regulator - Min : 20mA, Max : 2580mA, step : 20mA
 * 0x00, 0x01, 0x2, 0x03        = 60 mA
 * 0x04 ~ 0x7E                  = (60 + (X - 3) * 20) mA
 * Actually for MAX77693 the driver manipulates the maximum input current,
 * not the fast charge current (output). This should be fixed.
 *
 * On MAX77843 the calculation formula is the same (except values).
 * Fortunately it properly manipulates the fast charge current.
 */
static int max77693_chg_get_current_limit(struct regulator_dev *rdev)
{
        const struct chg_reg_data *reg_data = rdev_get_drvdata(rdev);
        unsigned int chg_min_uA = rdev->constraints->min_uA;
        unsigned int chg_max_uA = rdev->constraints->max_uA;
        unsigned int reg, sel;
        unsigned int val;
        int ret;

        ret = regmap_read(rdev->regmap, reg_data->linear_reg, &reg);
        if (ret < 0)
                return ret;

        sel = reg & reg_data->linear_mask;

        /* the first four codes for charger current are all 60mA */
        if (sel <= reg_data->min_sel)
                sel = 0;
        else
                sel -= reg_data->min_sel;

        val = chg_min_uA + reg_data->uA_step * 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)
{
        const struct chg_reg_data *reg_data = rdev_get_drvdata(rdev);
        unsigned int chg_min_uA = rdev->constraints->min_uA;
        int sel = 0;

        while (chg_min_uA + reg_data->uA_step * sel < min_uA)
                sel++;

        if (chg_min_uA + reg_data->uA_step * sel > max_uA)
                return -EINVAL;

        /* the first four codes for charger current are all 60mA */
        sel += reg_data->min_sel;

        return regmap_write(rdev->regmap, reg_data->linear_reg, sel);
}
/* end of CHARGER regulator ops */

/* Returns regmap suitable for given regulator on chosen device */
static struct regmap *max77693_get_regmap(enum max77693_types type,
                                          struct max77693_dev *max77693,
                                          int reg_id)
{
        if (type == TYPE_MAX77693)
                return max77693->regmap;

        /* Else: TYPE_MAX77843 */
        switch (reg_id) {
        case MAX77843_SAFEOUT1:
        case MAX77843_SAFEOUT2:
                return max77693->regmap;
        case MAX77843_CHARGER:
                return max77693->regmap_chg;
        default:
                return max77693->regmap;
        }
}

static const unsigned int max77693_safeout_table[] = {
        4850000,
        4900000,
        4950000,
        3300000,
};

static const 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 const struct regulator_ops max77693_charger_ops = {
        .is_enabled             = regulator_is_enabled_regmap,
        .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 max77693_regulator_desc_esafeout(_num)  {               \
        .name           = "ESAFEOUT"#_num,                      \
        .id             = MAX77693_ESAFEOUT##_num,              \
        .of_match       = of_match_ptr("ESAFEOUT"#_num),        \
        .regulators_node        = of_match_ptr("regulators"),   \
        .n_voltages     = 4,                                    \
        .ops            = &max77693_safeout_ops,                \
        .type           = REGULATOR_VOLTAGE,                    \
        .owner          = THIS_MODULE,                          \
        .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 const struct regulator_desc max77693_supported_regulators[] = {
        max77693_regulator_desc_esafeout(1),
        max77693_regulator_desc_esafeout(2),
        {
                .name = "CHARGER",
                .id = MAX77693_CHARGER,
                .of_match = of_match_ptr("CHARGER"),
                .regulators_node = of_match_ptr("regulators"),
                .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,
                .enable_val = CHG_CNFG_00_CHG_MASK | CHG_CNFG_00_BUCK_MASK,
        },
};

static const struct chg_reg_data max77693_chg_reg_data = {
        .linear_reg     = MAX77693_CHG_REG_CHG_CNFG_09,
        .linear_mask    = CHG_CNFG_09_CHGIN_ILIM_MASK,
        .uA_step        = 20000,
        .min_sel        = 3,
};

#define max77843_regulator_desc_esafeout(num)   {                       \
        .name           = "SAFEOUT" # num,                              \
        .id             = MAX77843_SAFEOUT ## num,                      \
        .ops            = &max77693_safeout_ops,                        \
        .of_match       = of_match_ptr("SAFEOUT" # num),                \
        .regulators_node = of_match_ptr("regulators"),                  \
        .type           = REGULATOR_VOLTAGE,                            \
        .owner          = THIS_MODULE,                                  \
        .n_voltages     = ARRAY_SIZE(max77693_safeout_table),           \
        .volt_table     = max77693_safeout_table,                       \
        .enable_reg     = MAX77843_SYS_REG_SAFEOUTCTRL,                 \
        .enable_mask    = MAX77843_REG_SAFEOUTCTRL_ENSAFEOUT ## num,    \
        .vsel_reg       = MAX77843_SYS_REG_SAFEOUTCTRL,                 \
        .vsel_mask      = MAX77843_REG_SAFEOUTCTRL_SAFEOUT ## num ## _MASK, \
}

static const struct regulator_desc max77843_supported_regulators[] = {
        [MAX77843_SAFEOUT1] = max77843_regulator_desc_esafeout(1),
        [MAX77843_SAFEOUT2] = max77843_regulator_desc_esafeout(2),
        [MAX77843_CHARGER] = {
                .name           = "CHARGER",
                .id             = MAX77843_CHARGER,
                .ops            = &max77693_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,
                .enable_val     = MAX77843_CHG_MASK,
        },
};

static const struct chg_reg_data max77843_chg_reg_data = {
        .linear_reg     = MAX77843_CHG_REG_CHG_CNFG_02,
        .linear_mask    = MAX77843_CHG_FAST_CHG_CURRENT_MASK,
        .uA_step        = MAX77843_CHG_FAST_CHG_CURRENT_STEP,
        .min_sel        = 2,
};

static int max77693_pmic_probe(struct platform_device *pdev)
{
        enum max77693_types type = platform_get_device_id(pdev)->driver_data;
        struct max77693_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        const struct regulator_desc *regulators;
        unsigned int regulators_size;
        int i;
        struct regulator_config config = { };

        config.dev = iodev->dev;

        switch (type) {
        case TYPE_MAX77693:
                regulators = max77693_supported_regulators;
                regulators_size = ARRAY_SIZE(max77693_supported_regulators);
                config.driver_data = (void *)&max77693_chg_reg_data;
                break;
        case TYPE_MAX77843:
                regulators = max77843_supported_regulators;
                regulators_size = ARRAY_SIZE(max77843_supported_regulators);
                config.driver_data = (void *)&max77843_chg_reg_data;
                break;
        default:
                dev_err(&pdev->dev, "Unsupported device type: %u\n", type);
                return -ENODEV;
        }

        for (i = 0; i < regulators_size; i++) {
                struct regulator_dev *rdev;

                config.regmap = max77693_get_regmap(type, iodev,
                                                    regulators[i].id);

                rdev = devm_regulator_register(&pdev->dev,
                                                &regulators[i], &config);
                if (IS_ERR(rdev)) {
                        dev_err(&pdev->dev,
                                "Failed to initialize regulator-%d\n", i);
                        return PTR_ERR(rdev);
                }
        }

        return 0;
}

static const struct platform_device_id max77693_pmic_id[] = {
        { "max77693-pmic", TYPE_MAX77693 },
        { "max77843-regulator", TYPE_MAX77843 },
        {},
};

MODULE_DEVICE_TABLE(platform, max77693_pmic_id);

static struct platform_driver max77693_pmic_driver = {
        .driver = {
                   .name = "max77693-pmic",
                   .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                   },
        .probe = max77693_pmic_probe,
        .id_table = max77693_pmic_id,
};

static int __init max77693_pmic_init(void)
{
        return platform_driver_register(&max77693_pmic_driver);
}
subsys_initcall(max77693_pmic_init);

static void __exit max77693_pmic_cleanup(void)
{
        platform_driver_unregister(&max77693_pmic_driver);
}
module_exit(max77693_pmic_cleanup);

MODULE_DESCRIPTION("MAXIM 77693/77843 regulator driver");
MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
MODULE_LICENSE("GPL");