// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for MPS MP5990 Hot-Swap Controller
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include "pmbus.h"

enum chips { mp5990, mp5998 };

#define MP5990_EFUSE_CFG        (0xC4)
#define MP5990_VOUT_FORMAT      BIT(9)

struct mp5990_data {
        struct pmbus_driver_info info;
        u8 vout_mode;
        u8 vout_linear_exponent;
};

#define to_mp5990_data(x)  container_of(x, struct mp5990_data, info)

static int mp5990_read_byte_data(struct i2c_client *client, int page, int reg)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        struct mp5990_data *data = to_mp5990_data(info);

        switch (reg) {
        case PMBUS_VOUT_MODE:
                if (data->vout_mode == linear) {
                        /*
                         * The VOUT format used by the chip is linear11,
                         * not linear16. Report that VOUT is in linear mode
                         * and return exponent value extracted while probing
                         * the chip.
                         */
                        return data->vout_linear_exponent;
                }

                /*
                 * The datasheet does not support the VOUT command,
                 * but the device responds with a default value of 0x17.
                 * In the standard, 0x17 represents linear mode.
                 * Therefore, we should report that VOUT is in direct
                 * format when the chip is configured for it.
                 */
                return PB_VOUT_MODE_DIRECT;

        default:
                return -ENODATA;
        }
}

static int mp5990_read_word_data(struct i2c_client *client, int page,
                                 int phase, int reg)
{
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
        struct mp5990_data *data = to_mp5990_data(info);
        int ret;
        s32 mantissa;

        switch (reg) {
        case PMBUS_READ_VOUT:
                ret = pmbus_read_word_data(client, page, phase, reg);
                if (ret < 0)
                        return ret;
                /*
                 * Because the VOUT format used by the chip is linear11 and not
                 * linear16, we disregard bits[15:11]. The exponent is reported
                 * as part of the VOUT_MODE command.
                 */
                if (data->vout_mode == linear) {
                        mantissa = ((s16)((ret & 0x7ff) << 5)) >> 5;
                        ret = mantissa;
                }
                break;
        default:
                return -ENODATA;
        }

        return ret;
}

static struct pmbus_driver_info mp5990_info = {
        .pages = 1,
        .format[PSC_VOLTAGE_IN] = direct,
        .format[PSC_VOLTAGE_OUT] = direct,
        .format[PSC_CURRENT_OUT] = direct,
        .format[PSC_POWER] = direct,
        .format[PSC_TEMPERATURE] = direct,
        .m[PSC_VOLTAGE_IN] = 32,
        .b[PSC_VOLTAGE_IN] = 0,
        .R[PSC_VOLTAGE_IN] = 0,
        .m[PSC_VOLTAGE_OUT] = 32,
        .b[PSC_VOLTAGE_OUT] = 0,
        .R[PSC_VOLTAGE_OUT] = 0,
        .m[PSC_CURRENT_OUT] = 16,
        .b[PSC_CURRENT_OUT] = 0,
        .R[PSC_CURRENT_OUT] = 0,
        .m[PSC_POWER] = 1,
        .b[PSC_POWER] = 0,
        .R[PSC_POWER] = 0,
        .m[PSC_TEMPERATURE] = 1,
        .b[PSC_TEMPERATURE] = 0,
        .R[PSC_TEMPERATURE] = 0,
        .func[0] =
                PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN |
                PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT |
                PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
        .read_byte_data = mp5990_read_byte_data,
        .read_word_data = mp5990_read_word_data,
};

static struct pmbus_driver_info mp5998_info = {
        .pages = 1,
        .format[PSC_VOLTAGE_IN] = direct,
        .format[PSC_VOLTAGE_OUT] = direct,
        .format[PSC_CURRENT_IN] = direct,
        .format[PSC_CURRENT_OUT] = direct,
        .format[PSC_POWER] = direct,
        .format[PSC_TEMPERATURE] = direct,
        .m[PSC_VOLTAGE_IN] = 64,
        .b[PSC_VOLTAGE_IN] = 0,
        .R[PSC_VOLTAGE_IN] = 0,
        .m[PSC_VOLTAGE_OUT] = 64,
        .b[PSC_VOLTAGE_OUT] = 0,
        .R[PSC_VOLTAGE_OUT] = 0,
        .m[PSC_CURRENT_IN] = 16,
        .b[PSC_CURRENT_IN] = 0,
        .R[PSC_CURRENT_IN] = 0,
        .m[PSC_CURRENT_OUT] = 16,
        .b[PSC_CURRENT_OUT] = 0,
        .R[PSC_CURRENT_OUT] = 0,
        .m[PSC_POWER] = 2,
        .b[PSC_POWER] = 0,
        .R[PSC_POWER] = 0,
        .m[PSC_TEMPERATURE] = 1,
        .b[PSC_TEMPERATURE] = 0,
        .R[PSC_TEMPERATURE] = 0,
        .func[0] =
                PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
                PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
                PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_IOUT |
                PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
        .read_byte_data = mp5990_read_byte_data,
        .read_word_data = mp5990_read_word_data,
};

static const struct i2c_device_id mp5990_id[] = {
        {"mp5990", mp5990},
        {"mp5998", mp5998},
        { }
};
MODULE_DEVICE_TABLE(i2c, mp5990_id);

static int mp5990_probe(struct i2c_client *client)
{
        struct pmbus_driver_info *info;
        struct mp5990_data *data;
        enum chips chip;
        int ret;

        data = devm_kzalloc(&client->dev, sizeof(struct mp5990_data),
                            GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        if (client->dev.of_node)
                chip = (uintptr_t)of_device_get_match_data(&client->dev);
        else
                chip = i2c_match_id(mp5990_id, client)->driver_data;

        if (chip == mp5990)
                memcpy(&data->info, &mp5990_info, sizeof(*info));
        else
                memcpy(&data->info, &mp5998_info, sizeof(*info));
        info = &data->info;

        /* Read Vout Config */
        ret = i2c_smbus_read_word_data(client, MP5990_EFUSE_CFG);
        if (ret < 0) {
                dev_err(&client->dev, "Can't get vout mode.");
                return ret;
        }

        /*
         * EFUSE_CFG (0xC4) bit9=1 is linear mode, bit=0 is direct mode.
         */
        if (ret & MP5990_VOUT_FORMAT) {
                data->vout_mode = linear;
                data->info.format[PSC_VOLTAGE_IN] = linear;
                data->info.format[PSC_VOLTAGE_OUT] = linear;
                data->info.format[PSC_CURRENT_OUT] = linear;
                data->info.format[PSC_POWER] = linear;
                if (chip == mp5998)
                        data->info.format[PSC_CURRENT_IN] = linear;

                ret = i2c_smbus_read_word_data(client, PMBUS_READ_VOUT);
                if (ret < 0) {
                        dev_err(&client->dev, "Can't get vout exponent.");
                        return ret;
                }
                data->vout_linear_exponent = (u8)((ret >> 11) & 0x1f);
        } else {
                data->vout_mode = direct;
        }
        return pmbus_do_probe(client, info);
}

static const struct of_device_id mp5990_of_match[] = {
        { .compatible = "mps,mp5990", .data = (void *)mp5990 },
        { .compatible = "mps,mp5998", .data = (void *)mp5998 },
        {}
};

static struct i2c_driver mp5990_driver = {
        .driver = {
                   .name = "mp5990",
                   .of_match_table = mp5990_of_match,
        },
        .probe = mp5990_probe,
        .id_table = mp5990_id,
};
module_i2c_driver(mp5990_driver);

MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");
MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");