// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for Maxim MAX8688
 *
 * Copyright (c) 2011 Ericsson AB.
 */

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

#define MAX8688_MFR_VOUT_PEAK           0xd4
#define MAX8688_MFR_IOUT_PEAK           0xd5
#define MAX8688_MFR_TEMPERATURE_PEAK    0xd6
#define MAX8688_MFG_STATUS              0xd8

#define MAX8688_STATUS_OC_FAULT         BIT(4)
#define MAX8688_STATUS_OV_FAULT         BIT(5)
#define MAX8688_STATUS_OV_WARNING       BIT(8)
#define MAX8688_STATUS_UV_FAULT         BIT(9)
#define MAX8688_STATUS_UV_WARNING       BIT(10)
#define MAX8688_STATUS_UC_FAULT         BIT(11)
#define MAX8688_STATUS_OC_WARNING       BIT(12)
#define MAX8688_STATUS_OT_FAULT         BIT(13)
#define MAX8688_STATUS_OT_WARNING       BIT(14)

static int max8688_read_word_data(struct i2c_client *client, int page,
                                  int phase, int reg)
{
        int ret;

        if (page > 0)
                return -ENXIO;

        switch (reg) {
        case PMBUS_VIRT_READ_VOUT_MAX:
                ret = pmbus_read_word_data(client, 0, 0xff,
                                           MAX8688_MFR_VOUT_PEAK);
                break;
        case PMBUS_VIRT_READ_IOUT_MAX:
                ret = pmbus_read_word_data(client, 0, 0xff,
                                           MAX8688_MFR_IOUT_PEAK);
                break;
        case PMBUS_VIRT_READ_TEMP_MAX:
                ret = pmbus_read_word_data(client, 0, 0xff,
                                           MAX8688_MFR_TEMPERATURE_PEAK);
                break;
        case PMBUS_VIRT_RESET_VOUT_HISTORY:
        case PMBUS_VIRT_RESET_IOUT_HISTORY:
        case PMBUS_VIRT_RESET_TEMP_HISTORY:
                ret = 0;
                break;
        default:
                ret = -ENODATA;
                break;
        }
        return ret;
}

static int max8688_write_word_data(struct i2c_client *client, int page, int reg,
                                   u16 word)
{
        int ret;

        switch (reg) {
        case PMBUS_VIRT_RESET_VOUT_HISTORY:
                ret = pmbus_write_word_data(client, 0, MAX8688_MFR_VOUT_PEAK,
                                            0);
                break;
        case PMBUS_VIRT_RESET_IOUT_HISTORY:
                ret = pmbus_write_word_data(client, 0, MAX8688_MFR_IOUT_PEAK,
                                            0);
                break;
        case PMBUS_VIRT_RESET_TEMP_HISTORY:
                ret = pmbus_write_word_data(client, 0,
                                            MAX8688_MFR_TEMPERATURE_PEAK,
                                            0xffff);
                break;
        default:
                ret = -ENODATA;
                break;
        }
        return ret;
}

static int max8688_read_byte_data(struct i2c_client *client, int page, int reg)
{
        int ret = 0;
        int mfg_status;

        if (page > 0)
                return -ENXIO;

        switch (reg) {
        case PMBUS_STATUS_VOUT:
                mfg_status = pmbus_read_word_data(client, 0, 0xff,
                                                  MAX8688_MFG_STATUS);
                if (mfg_status < 0)
                        return mfg_status;
                if (mfg_status & MAX8688_STATUS_UV_WARNING)
                        ret |= PB_VOLTAGE_UV_WARNING;
                if (mfg_status & MAX8688_STATUS_UV_FAULT)
                        ret |= PB_VOLTAGE_UV_FAULT;
                if (mfg_status & MAX8688_STATUS_OV_WARNING)
                        ret |= PB_VOLTAGE_OV_WARNING;
                if (mfg_status & MAX8688_STATUS_OV_FAULT)
                        ret |= PB_VOLTAGE_OV_FAULT;
                break;
        case PMBUS_STATUS_IOUT:
                mfg_status = pmbus_read_word_data(client, 0, 0xff,
                                                  MAX8688_MFG_STATUS);
                if (mfg_status < 0)
                        return mfg_status;
                if (mfg_status & MAX8688_STATUS_UC_FAULT)
                        ret |= PB_IOUT_UC_FAULT;
                if (mfg_status & MAX8688_STATUS_OC_WARNING)
                        ret |= PB_IOUT_OC_WARNING;
                if (mfg_status & MAX8688_STATUS_OC_FAULT)
                        ret |= PB_IOUT_OC_FAULT;
                break;
        case PMBUS_STATUS_TEMPERATURE:
                mfg_status = pmbus_read_word_data(client, 0, 0xff,
                                                  MAX8688_MFG_STATUS);
                if (mfg_status < 0)
                        return mfg_status;
                if (mfg_status & MAX8688_STATUS_OT_WARNING)
                        ret |= PB_TEMP_OT_WARNING;
                if (mfg_status & MAX8688_STATUS_OT_FAULT)
                        ret |= PB_TEMP_OT_FAULT;
                break;
        default:
                ret = -ENODATA;
                break;
        }
        return ret;
}

static struct pmbus_driver_info max8688_info = {
        .pages = 1,
        .format[PSC_VOLTAGE_IN] = direct,
        .format[PSC_VOLTAGE_OUT] = direct,
        .format[PSC_TEMPERATURE] = direct,
        .format[PSC_CURRENT_OUT] = direct,
        .m[PSC_VOLTAGE_IN] = 19995,
        .b[PSC_VOLTAGE_IN] = 0,
        .R[PSC_VOLTAGE_IN] = -1,
        .m[PSC_VOLTAGE_OUT] = 19995,
        .b[PSC_VOLTAGE_OUT] = 0,
        .R[PSC_VOLTAGE_OUT] = -1,
        .m[PSC_CURRENT_OUT] = 23109,
        .b[PSC_CURRENT_OUT] = 0,
        .R[PSC_CURRENT_OUT] = -2,
        .m[PSC_TEMPERATURE] = -7612,
        .b[PSC_TEMPERATURE] = 335,
        .R[PSC_TEMPERATURE] = -3,
        .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP
                | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
                | PMBUS_HAVE_STATUS_TEMP,
        .read_byte_data = max8688_read_byte_data,
        .read_word_data = max8688_read_word_data,
        .write_word_data = max8688_write_word_data,
};

static int max8688_probe(struct i2c_client *client)
{
        return pmbus_do_probe(client, &max8688_info);
}

static const struct i2c_device_id max8688_id[] = {
        {"max8688"},
        { }
};

MODULE_DEVICE_TABLE(i2c, max8688_id);

/* This is the driver that will be inserted */
static struct i2c_driver max8688_driver = {
        .driver = {
                   .name = "max8688",
                   },
        .probe = max8688_probe,
        .id_table = max8688_id,
};

module_i2c_driver(max8688_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for Maxim MAX8688");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");