// SPDX-License-Identifier: GPL-2.0-only
/*
 * isl6271a-regulator.c
 *
 * Support for Intersil ISL6271A voltage regulator
 *
 * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#define ISL6271A_VOLTAGE_MIN    850000
#define ISL6271A_VOLTAGE_MAX    1600000
#define ISL6271A_VOLTAGE_STEP   50000

/* PMIC details */
struct isl_pmic {
        struct i2c_client       *client;
        struct mutex            mtx;
};

static int isl6271a_get_voltage_sel(struct regulator_dev *dev)
{
        struct isl_pmic *pmic = rdev_get_drvdata(dev);
        int idx;

        mutex_lock(&pmic->mtx);

        idx = i2c_smbus_read_byte(pmic->client);
        if (idx < 0)
                dev_err(&pmic->client->dev, "Error getting voltage\n");

        mutex_unlock(&pmic->mtx);
        return idx;
}

static int isl6271a_set_voltage_sel(struct regulator_dev *dev,
                                    unsigned selector)
{
        struct isl_pmic *pmic = rdev_get_drvdata(dev);
        int err;

        mutex_lock(&pmic->mtx);

        err = i2c_smbus_write_byte(pmic->client, selector);
        if (err < 0)
                dev_err(&pmic->client->dev, "Error setting voltage\n");

        mutex_unlock(&pmic->mtx);
        return err;
}

static const struct regulator_ops isl_core_ops = {
        .get_voltage_sel = isl6271a_get_voltage_sel,
        .set_voltage_sel = isl6271a_set_voltage_sel,
        .list_voltage   = regulator_list_voltage_linear,
        .map_voltage    = regulator_map_voltage_linear,
};

static const struct regulator_ops isl_fixed_ops = {
        .list_voltage   = regulator_list_voltage_linear,
};

static const struct regulator_desc isl_rd[] = {
        {
                .name           = "Core Buck",
                .id             = 0,
                .n_voltages     = 16,
                .ops            = &isl_core_ops,
                .type           = REGULATOR_VOLTAGE,
                .owner          = THIS_MODULE,
                .min_uV         = ISL6271A_VOLTAGE_MIN,
                .uV_step        = ISL6271A_VOLTAGE_STEP,
        }, {
                .name           = "LDO1",
                .id             = 1,
                .n_voltages     = 1,
                .ops            = &isl_fixed_ops,
                .type           = REGULATOR_VOLTAGE,
                .owner          = THIS_MODULE,
                .min_uV         = 1100000,
        }, {
                .name           = "LDO2",
                .id             = 2,
                .n_voltages     = 1,
                .ops            = &isl_fixed_ops,
                .type           = REGULATOR_VOLTAGE,
                .owner          = THIS_MODULE,
                .min_uV         = 1300000,
        },
};

static int isl6271a_probe(struct i2c_client *i2c)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
        struct regulator_dev *rdev;
        struct regulator_config config = { };
        struct regulator_init_data *init_data   = dev_get_platdata(&i2c->dev);
        struct isl_pmic *pmic;
        int i;

        if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -EIO;

        pmic = devm_kzalloc(&i2c->dev, sizeof(struct isl_pmic), GFP_KERNEL);
        if (!pmic)
                return -ENOMEM;

        pmic->client = i2c;

        mutex_init(&pmic->mtx);

        for (i = 0; i < 3; i++) {
                config.dev = &i2c->dev;
                if (i == 0)
                        config.init_data = init_data;
                else
                        config.init_data = NULL;
                config.driver_data = pmic;

                rdev = devm_regulator_register(&i2c->dev, &isl_rd[i], &config);
                if (IS_ERR(rdev)) {
                        dev_err(&i2c->dev, "failed to register %s\n", id->name);
                        return PTR_ERR(rdev);
                }
        }

        i2c_set_clientdata(i2c, pmic);

        return 0;
}

static const struct i2c_device_id isl6271a_id[] = {
        { .name = "isl6271a", },
        { }
};

MODULE_DEVICE_TABLE(i2c, isl6271a_id);

static struct i2c_driver isl6271a_i2c_driver = {
        .driver = {
                .name = "isl6271a",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe = isl6271a_probe,
        .id_table = isl6271a_id,
};

static int __init isl6271a_init(void)
{
        return i2c_add_driver(&isl6271a_i2c_driver);
}

static void __exit isl6271a_cleanup(void)
{
        i2c_del_driver(&isl6271a_i2c_driver);
}

subsys_initcall(isl6271a_init);
module_exit(isl6271a_cleanup);

MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
MODULE_LICENSE("GPL v2");