// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for IR35221
 *
 * Copyright (C) IBM Corporation 2017.
 */

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

#define IR35221_MFR_VIN_PEAK            0xc5
#define IR35221_MFR_VOUT_PEAK           0xc6
#define IR35221_MFR_IOUT_PEAK           0xc7
#define IR35221_MFR_TEMP_PEAK           0xc8
#define IR35221_MFR_VIN_VALLEY          0xc9
#define IR35221_MFR_VOUT_VALLEY         0xca
#define IR35221_MFR_IOUT_VALLEY         0xcb
#define IR35221_MFR_TEMP_VALLEY         0xcc

static int ir35221_read_word_data(struct i2c_client *client, int page,
                                  int phase, int reg)
{
        int ret;

        switch (reg) {
        case PMBUS_VIRT_READ_VIN_MAX:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_VIN_PEAK);
                break;
        case PMBUS_VIRT_READ_VOUT_MAX:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_VOUT_PEAK);
                break;
        case PMBUS_VIRT_READ_IOUT_MAX:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_IOUT_PEAK);
                break;
        case PMBUS_VIRT_READ_TEMP_MAX:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_TEMP_PEAK);
                break;
        case PMBUS_VIRT_READ_VIN_MIN:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_VIN_VALLEY);
                break;
        case PMBUS_VIRT_READ_VOUT_MIN:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_VOUT_VALLEY);
                break;
        case PMBUS_VIRT_READ_IOUT_MIN:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_IOUT_VALLEY);
                break;
        case PMBUS_VIRT_READ_TEMP_MIN:
                ret = pmbus_read_word_data(client, page, phase,
                                           IR35221_MFR_TEMP_VALLEY);
                break;
        default:
                ret = -ENODATA;
                break;
        }

        return ret;
}

static int ir35221_probe(struct i2c_client *client)
{
        struct pmbus_driver_info *info;
        u8 buf[I2C_SMBUS_BLOCK_MAX];
        int ret;

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_READ_BYTE_DATA
                                | I2C_FUNC_SMBUS_READ_WORD_DATA
                                | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
                return -ENODEV;

        ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to read PMBUS_MFR_ID\n");
                return ret;
        }
        if (ret != 2 || strncmp(buf, "RI", strlen("RI"))) {
                dev_err(&client->dev, "MFR_ID unrecognised\n");
                return -ENODEV;
        }

        ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to read PMBUS_MFR_MODEL\n");
                return ret;
        }
        if (ret != 2 || !(buf[0] == 0x6c && buf[1] == 0x00)) {
                dev_err(&client->dev, "MFR_MODEL unrecognised\n");
                return -ENODEV;
        }

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

        info->read_word_data = ir35221_read_word_data;

        info->pages = 2;
        info->format[PSC_VOLTAGE_IN] = linear;
        info->format[PSC_VOLTAGE_OUT] = linear;
        info->format[PSC_CURRENT_IN] = linear;
        info->format[PSC_CURRENT_OUT] = linear;
        info->format[PSC_POWER] = linear;
        info->format[PSC_TEMPERATURE] = linear;

        info->func[0] = PMBUS_HAVE_VIN
                | PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
                | PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
                | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
                | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
                | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP;
        info->func[1] = info->func[0];

        return pmbus_do_probe(client, info);
}

static const struct i2c_device_id ir35221_id[] = {
        { .name = "ir35221" },
        { }
};

MODULE_DEVICE_TABLE(i2c, ir35221_id);

static struct i2c_driver ir35221_driver = {
        .driver = {
                .name   = "ir35221",
        },
        .probe          = ir35221_probe,
        .id_table       = ir35221_id,
};

module_i2c_driver(ir35221_driver);

MODULE_AUTHOR("Samuel Mendoza-Jonas <sam@mendozajonas.com");
MODULE_DESCRIPTION("PMBus driver for IR35221");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("PMBUS");