// SPDX-License-Identifier: GPL-2.0+
/*
 * mpq7932.c - hwmon with optional regulator driver for mps mpq7932
 * Copyright 2022 Monolithic Power Systems, Inc
 *
 * Author: Saravanan Sekar <saravanan@linumiz.com>
 */

#include <linux/bits.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pmbus.h>
#include "pmbus.h"

#define MPQ7932_BUCK_UV_MIN             206250
#define MPQ7932_UV_STEP                 6250
#define MPQ7932_N_VOLTAGES              256
#define MPQ7932_VOUT_MAX                0xFF
#define MPQ7932_NUM_PAGES               6
#define MPQ2286_NUM_PAGES               1

#define MPQ7932_TON_DELAY               0x60
#define MPQ7932_VOUT_STARTUP_SLEW       0xA3
#define MPQ7932_VOUT_SHUTDOWN_SLEW      0xA5
#define MPQ7932_VOUT_SLEW_MASK          GENMASK(1, 0)
#define MPQ7932_TON_DELAY_MASK          GENMASK(4, 0)

struct mpq7932_data {
        struct pmbus_driver_info info;
        struct pmbus_platform_data pdata;
};

#if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
static const struct regulator_desc mpq7932_regulators_desc[] = {
        PMBUS_REGULATOR_STEP("buck", 0, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
        PMBUS_REGULATOR_STEP("buck", 1, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
        PMBUS_REGULATOR_STEP("buck", 2, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
        PMBUS_REGULATOR_STEP("buck", 3, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
        PMBUS_REGULATOR_STEP("buck", 4, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
        PMBUS_REGULATOR_STEP("buck", 5, MPQ7932_N_VOLTAGES,
                             MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
};

static const struct regulator_desc mpq7932_regulators_desc_one[] = {
        PMBUS_REGULATOR_STEP_ONE_NODE("buck", MPQ7932_N_VOLTAGES,
                                      MPQ7932_UV_STEP, MPQ7932_BUCK_UV_MIN),
};
#endif

static int mpq7932_write_word_data(struct i2c_client *client, int page, int reg,
                                   u16 word)
{
        switch (reg) {
        /*
         * chip supports only byte access for VOUT_COMMAND otherwise
         * access results -EREMOTEIO
         */
        case PMBUS_VOUT_COMMAND:
                return pmbus_write_byte_data(client, page, reg, word & 0xFF);

        default:
                return -ENODATA;
        }
}

static int mpq7932_read_word_data(struct i2c_client *client, int page,
                                  int phase, int reg)
{
        switch (reg) {
        /*
         * chip supports neither (PMBUS_VOUT_MARGIN_HIGH, PMBUS_VOUT_MARGIN_LOW)
         * nor (PMBUS_MFR_VOUT_MIN, PMBUS_MFR_VOUT_MAX). As a result set voltage
         * fails due to error in pmbus_regulator_get_low_margin, so faked.
         */
        case PMBUS_MFR_VOUT_MIN:
                return 0;

        case PMBUS_MFR_VOUT_MAX:
                return MPQ7932_VOUT_MAX;

        /*
         * chip supports only byte access for VOUT_COMMAND otherwise
         * access results in -EREMOTEIO
         */
        case PMBUS_READ_VOUT:
                return pmbus_read_byte_data(client, page, PMBUS_VOUT_COMMAND);

        default:
                return -ENODATA;
        }
}

static int mpq7932_probe(struct i2c_client *client)
{
        struct mpq7932_data *data;
        struct pmbus_driver_info *info;
        struct device *dev = &client->dev;
        int i;

        data = devm_kzalloc(dev, sizeof(struct mpq7932_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        info = &data->info;
        info->pages = (int)(unsigned long)device_get_match_data(&client->dev);
        info->format[PSC_VOLTAGE_OUT] = direct;
        info->m[PSC_VOLTAGE_OUT] = 160;
        info->b[PSC_VOLTAGE_OUT] = -33;
        for (i = 0; i < info->pages; i++) {
                info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
                                | PMBUS_HAVE_STATUS_TEMP;
        }

#if IS_ENABLED(CONFIG_SENSORS_MPQ7932_REGULATOR)
        info->num_regulators = info->pages;
        if (info->num_regulators == 1)
                info->reg_desc = mpq7932_regulators_desc_one;
        else
                info->reg_desc = mpq7932_regulators_desc;
#endif

        info->read_word_data = mpq7932_read_word_data;
        info->write_word_data = mpq7932_write_word_data;

        data->pdata.flags = PMBUS_NO_CAPABILITY;
        dev->platform_data = &data->pdata;

        return pmbus_do_probe(client, info);
}

static const struct of_device_id mpq7932_of_match[] = {
        { .compatible = "mps,mpq2286", .data = (void *)MPQ2286_NUM_PAGES },
        { .compatible = "mps,mpq7932", .data = (void *)MPQ7932_NUM_PAGES },
        {},
};
MODULE_DEVICE_TABLE(of, mpq7932_of_match);

static const struct i2c_device_id mpq7932_id[] = {
        { "mpq2286", },
        { "mpq7932", },
        { },
};
MODULE_DEVICE_TABLE(i2c, mpq7932_id);

static struct i2c_driver mpq7932_regulator_driver = {
        .driver = {
                .name = "mpq7932",
                .of_match_table = mpq7932_of_match,
        },
        .probe = mpq7932_probe,
        .id_table = mpq7932_id,
};
module_i2c_driver(mpq7932_regulator_driver);

MODULE_AUTHOR("Saravanan Sekar <saravanan@linumiz.com>");
MODULE_DESCRIPTION("MPQ7932 PMIC regulator driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");