// SPDX-License-Identifier: GPL-2.0-only
/*
 * Fuel gauge driver for Richtek RT5033
 *
 * Copyright (C) 2014 Samsung Electronics, Co., Ltd.
 * Author: Beomho Seo <beomho.seo@samsung.com>
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/regmap.h>
#include <linux/mfd/rt5033-private.h>

struct rt5033_battery {
        struct i2c_client       *client;
        struct regmap           *regmap;
        struct power_supply     *psy;
};

static int rt5033_battery_get_status(struct i2c_client *client)
{
        struct rt5033_battery *battery = i2c_get_clientdata(client);
        union power_supply_propval val;
        int ret;

        ret = power_supply_get_property_from_supplier(battery->psy,
                                                POWER_SUPPLY_PROP_STATUS,
                                                &val);
        if (ret)
                val.intval = POWER_SUPPLY_STATUS_UNKNOWN;

        return val.intval;
}

static int rt5033_battery_get_capacity(struct i2c_client *client)
{
        struct rt5033_battery *battery = i2c_get_clientdata(client);
        u32 msb;

        regmap_read(battery->regmap, RT5033_FUEL_REG_SOC_H, &msb);

        return msb;
}

static int rt5033_battery_get_present(struct i2c_client *client)
{
        struct rt5033_battery *battery = i2c_get_clientdata(client);
        u32 val;

        regmap_read(battery->regmap, RT5033_FUEL_REG_CONFIG_L, &val);

        return (val & RT5033_FUEL_BAT_PRESENT) ? true : false;
}

static int rt5033_battery_get_watt_prop(struct i2c_client *client,
                enum power_supply_property psp)
{
        struct rt5033_battery *battery = i2c_get_clientdata(client);
        unsigned int regh, regl;
        int ret;
        u32 msb, lsb;

        switch (psp) {
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                regh = RT5033_FUEL_REG_VBAT_H;
                regl = RT5033_FUEL_REG_VBAT_L;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_AVG:
                regh = RT5033_FUEL_REG_AVG_VOLT_H;
                regl = RT5033_FUEL_REG_AVG_VOLT_L;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_OCV:
                regh = RT5033_FUEL_REG_OCV_H;
                regl = RT5033_FUEL_REG_OCV_L;
                break;
        default:
                return -EINVAL;
        }

        regmap_read(battery->regmap, regh, &msb);
        regmap_read(battery->regmap, regl, &lsb);

        ret = ((msb << 4) + (lsb >> 4)) * 1250;

        return ret;
}

static int rt5033_battery_get_property(struct power_supply *psy,
                enum power_supply_property psp,
                union power_supply_propval *val)
{
        struct rt5033_battery *battery = power_supply_get_drvdata(psy);

        switch (psp) {
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
        case POWER_SUPPLY_PROP_VOLTAGE_AVG:
        case POWER_SUPPLY_PROP_VOLTAGE_OCV:
                val->intval = rt5033_battery_get_watt_prop(battery->client,
                                                                        psp);
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = rt5033_battery_get_present(battery->client);
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                val->intval = rt5033_battery_get_capacity(battery->client);
                break;
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = rt5033_battery_get_status(battery->client);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static enum power_supply_property rt5033_battery_props[] = {
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_AVG,
        POWER_SUPPLY_PROP_VOLTAGE_OCV,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_STATUS,
};

static const struct regmap_config rt5033_battery_regmap_config = {
        .reg_bits       = 8,
        .val_bits       = 8,
        .max_register   = RT5033_FUEL_REG_END,
};

static const struct power_supply_desc rt5033_battery_desc = {
        .name           = "rt5033-battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .get_property   = rt5033_battery_get_property,
        .properties     = rt5033_battery_props,
        .num_properties = ARRAY_SIZE(rt5033_battery_props),
};

static int rt5033_battery_probe(struct i2c_client *client)
{
        struct i2c_adapter *adapter = client->adapter;
        struct power_supply_config psy_cfg = {};
        struct rt5033_battery *battery;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
                return -EIO;

        battery = devm_kzalloc(&client->dev, sizeof(*battery), GFP_KERNEL);
        if (!battery)
                return -ENOMEM;

        battery->client = client;
        battery->regmap = devm_regmap_init_i2c(client,
                        &rt5033_battery_regmap_config);
        if (IS_ERR(battery->regmap)) {
                dev_err(&client->dev, "Failed to initialize regmap\n");
                return -EINVAL;
        }

        i2c_set_clientdata(client, battery);
        psy_cfg.fwnode = dev_fwnode(&client->dev);
        psy_cfg.drv_data = battery;

        battery->psy = devm_power_supply_register(&client->dev,
                                                  &rt5033_battery_desc,
                                                  &psy_cfg);
        if (IS_ERR(battery->psy))
                return dev_err_probe(&client->dev, PTR_ERR(battery->psy),
                                     "Failed to register power supply\n");

        return 0;
}

static const struct i2c_device_id rt5033_battery_id[] = {
        { "rt5033-battery", },
        { }
};
MODULE_DEVICE_TABLE(i2c, rt5033_battery_id);

static const struct of_device_id rt5033_battery_of_match[] = {
        { .compatible = "richtek,rt5033-battery", },
        { }
};
MODULE_DEVICE_TABLE(of, rt5033_battery_of_match);

static struct i2c_driver rt5033_battery_driver = {
        .driver = {
                .name = "rt5033-battery",
                .of_match_table = rt5033_battery_of_match,
        },
        .probe = rt5033_battery_probe,
        .id_table = rt5033_battery_id,
};
module_i2c_driver(rt5033_battery_driver);

MODULE_DESCRIPTION("Richtek RT5033 fuel gauge driver");
MODULE_AUTHOR("Beomho Seo <beomho.seo@samsung.com>");
MODULE_LICENSE("GPL");