// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
 * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
 * Copyright (c) 2024 Linaro Limited
 */

#include <linux/array_size.h>
#include <linux/bits.h>
#include <linux/device.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>

#include <asm/byteorder.h>

#define DEFAULT_VOLTAGE_STEPPER_RATE    38400

#define LDO_STEPPER_CTL_REG             0x3b
#define STEP_RATE_MASK                  GENMASK(1, 0)

#define LDO_VSET_LB_REG                 0x40

#define LDO_ENABLE_REG                  0x46
#define ENABLE_BIT                      BIT(7)

struct pm8008_regulator {
        struct regmap           *regmap;
        struct regulator_desc   desc;
        unsigned int            base;
};

struct pm8008_regulator_data {
        const char                      *name;
        const char                      *supply_name;
        unsigned int                    base;
        int                             min_dropout_uV;
        const struct linear_range       *voltage_range;
};

static const struct linear_range nldo_ranges[] = {
        REGULATOR_LINEAR_RANGE(528000, 0, 122, 8000),
};

static const struct linear_range pldo_ranges[] = {
        REGULATOR_LINEAR_RANGE(1504000, 0, 237, 8000),
};

static const struct pm8008_regulator_data pm8008_reg_data[] = {
        { "ldo1", "vdd-l1-l2", 0x4000, 225000, nldo_ranges, },
        { "ldo2", "vdd-l1-l2", 0x4100, 225000, nldo_ranges, },
        { "ldo3", "vdd-l3-l4", 0x4200, 300000, pldo_ranges, },
        { "ldo4", "vdd-l3-l4", 0x4300, 300000, pldo_ranges, },
        { "ldo5", "vdd-l5",    0x4400, 200000, pldo_ranges, },
        { "ldo6", "vdd-l6",    0x4500, 200000, pldo_ranges, },
        { "ldo7", "vdd-l7",    0x4600, 200000, pldo_ranges, },
};

static int pm8008_regulator_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
{
        struct pm8008_regulator *preg = rdev_get_drvdata(rdev);
        unsigned int mV;
        __le16 val;
        int ret;

        ret = regulator_list_voltage_linear_range(rdev, sel);
        if (ret < 0)
                return ret;

        mV = DIV_ROUND_UP(ret, 1000);

        val = cpu_to_le16(mV);

        ret = regmap_bulk_write(preg->regmap, preg->base + LDO_VSET_LB_REG,
                        &val, sizeof(val));
        if (ret < 0)
                return ret;

        return 0;
}

static int pm8008_regulator_get_voltage_sel(struct regulator_dev *rdev)
{
        struct pm8008_regulator *preg = rdev_get_drvdata(rdev);
        unsigned int uV;
        __le16 val;
        int ret;

        ret = regmap_bulk_read(preg->regmap, preg->base + LDO_VSET_LB_REG,
                        &val, sizeof(val));
        if (ret < 0)
                return ret;

        uV = le16_to_cpu(val) * 1000;

        return regulator_map_voltage_linear_range(rdev, uV, INT_MAX);
}

static const struct regulator_ops pm8008_regulator_ops = {
        .list_voltage           = regulator_list_voltage_linear,
        .set_voltage_sel        = pm8008_regulator_set_voltage_sel,
        .get_voltage_sel        = pm8008_regulator_get_voltage_sel,
        .enable                 = regulator_enable_regmap,
        .disable                = regulator_disable_regmap,
        .is_enabled             = regulator_is_enabled_regmap,
};

static int pm8008_regulator_probe(struct platform_device *pdev)
{
        const struct pm8008_regulator_data *data;
        struct regulator_config config = {};
        struct device *dev = &pdev->dev;
        struct pm8008_regulator *preg;
        struct regulator_desc *desc;
        struct regulator_dev *rdev;
        struct regmap *regmap;
        unsigned int val;
        int ret, i;

        regmap = dev_get_regmap(dev->parent, "secondary");
        if (!regmap)
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(pm8008_reg_data); i++) {
                data = &pm8008_reg_data[i];

                preg = devm_kzalloc(dev, sizeof(*preg), GFP_KERNEL);
                if (!preg)
                        return -ENOMEM;

                preg->regmap = regmap;
                preg->base = data->base;

                desc = &preg->desc;

                desc->name = data->name;
                desc->supply_name = data->supply_name;
                desc->of_match = data->name;
                desc->regulators_node = of_match_ptr("regulators");
                desc->ops = &pm8008_regulator_ops;
                desc->type = REGULATOR_VOLTAGE;
                desc->owner = THIS_MODULE;

                desc->linear_ranges = data->voltage_range;
                desc->n_linear_ranges = 1;
                desc->uV_step = desc->linear_ranges[0].step;
                desc->min_uV = desc->linear_ranges[0].min;
                desc->n_voltages = linear_range_values_in_range(&desc->linear_ranges[0]);

                ret = regmap_read(regmap, preg->base + LDO_STEPPER_CTL_REG, &val);
                if (ret < 0) {
                        dev_err(dev, "failed to read step rate: %d\n", ret);
                        return ret;
                }
                val &= STEP_RATE_MASK;
                desc->ramp_delay = DEFAULT_VOLTAGE_STEPPER_RATE >> val;

                desc->min_dropout_uV = data->min_dropout_uV;

                desc->enable_reg = preg->base + LDO_ENABLE_REG;
                desc->enable_mask = ENABLE_BIT;

                config.dev = dev->parent;
                config.driver_data = preg;
                config.regmap = regmap;

                rdev = devm_regulator_register(dev, desc, &config);
                if (IS_ERR(rdev)) {
                        ret = PTR_ERR(rdev);
                        dev_err(dev, "failed to register regulator %s: %d\n",
                                        desc->name, ret);
                        return ret;
                }
        }

        return 0;
}

static const struct platform_device_id pm8008_regulator_id_table[] = {
        { "pm8008-regulator" },
        { }
};
MODULE_DEVICE_TABLE(platform, pm8008_regulator_id_table);

static struct platform_driver pm8008_regulator_driver = {
        .driver = {
                .name = "qcom-pm8008-regulator",
        },
        .probe = pm8008_regulator_probe,
        .id_table = pm8008_regulator_id_table,
};
module_platform_driver(pm8008_regulator_driver);

MODULE_DESCRIPTION("Qualcomm PM8008 PMIC regulator driver");
MODULE_LICENSE("GPL");