// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Texas Instruments TMP103 SMBus temperature sensor driver
 * Copyright (C) 2014 Heiko Schocher <hs@denx.de>
 *
 * Based on:
 * Texas Instruments TMP102 SMBus temperature sensor driver
 *
 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/regmap.h>

#define TMP103_TEMP_REG         0x00
#define TMP103_CONF_REG         0x01
#define TMP103_TLOW_REG         0x02
#define TMP103_THIGH_REG        0x03

#define TMP103_CONF_M0          0x01
#define TMP103_CONF_M1          0x02
#define TMP103_CONF_LC          0x04
#define TMP103_CONF_FL          0x08
#define TMP103_CONF_FH          0x10
#define TMP103_CONF_CR0         0x20
#define TMP103_CONF_CR1         0x40
#define TMP103_CONF_ID          0x80
#define TMP103_CONF_SD          (TMP103_CONF_M1)
#define TMP103_CONF_SD_MASK     (TMP103_CONF_M0 | TMP103_CONF_M1)

#define TMP103_CONFIG           (TMP103_CONF_CR1 | TMP103_CONF_M1)
#define TMP103_CONFIG_MASK      (TMP103_CONF_CR0 | TMP103_CONF_CR1 | \
                                 TMP103_CONF_M0 | TMP103_CONF_M1)

static inline int tmp103_reg_to_mc(s8 val)
{
        return val * 1000;
}

static inline u8 tmp103_mc_to_reg(int val)
{
        return DIV_ROUND_CLOSEST(val, 1000);
}

static int tmp103_read(struct device *dev, enum hwmon_sensor_types type,
                       u32 attr, int channel, long *temp)
{
        struct regmap *regmap = dev_get_drvdata(dev);
        unsigned int regval;
        int err, reg;

        switch (attr) {
        case hwmon_temp_input:
                reg = TMP103_TEMP_REG;
                break;
        case hwmon_temp_min:
                reg = TMP103_TLOW_REG;
                break;
        case hwmon_temp_max:
                reg = TMP103_THIGH_REG;
                break;
        default:
                return -EOPNOTSUPP;
        }

        err = regmap_read(regmap, reg, &regval);
        if (err < 0)
                return err;

        *temp = tmp103_reg_to_mc(regval);

        return 0;
}

static int tmp103_write(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long temp)
{
        struct regmap *regmap = dev_get_drvdata(dev);
        int reg;

        switch (attr) {
        case hwmon_temp_min:
                reg = TMP103_TLOW_REG;
                break;
        case hwmon_temp_max:
                reg = TMP103_THIGH_REG;
                break;
        default:
                return -EOPNOTSUPP;
        }

        temp = clamp_val(temp, -55000, 127000);
        return regmap_write(regmap, reg, tmp103_mc_to_reg(temp));
}

static umode_t tmp103_is_visible(const void *data, enum hwmon_sensor_types type,
                                 u32 attr, int channel)
{
        if (type != hwmon_temp)
                return 0;

        switch (attr) {
        case hwmon_temp_input:
                return 0444;
        case hwmon_temp_min:
        case hwmon_temp_max:
                return 0644;
        default:
                return 0;
        }
}

static const struct hwmon_channel_info * const tmp103_info[] = {
        HWMON_CHANNEL_INFO(chip,
                           HWMON_C_REGISTER_TZ),
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN),
        NULL
};

static const struct hwmon_ops tmp103_hwmon_ops = {
        .is_visible = tmp103_is_visible,
        .read = tmp103_read,
        .write = tmp103_write,
};

static const struct hwmon_chip_info tmp103_chip_info = {
        .ops = &tmp103_hwmon_ops,
        .info = tmp103_info,
};

static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
{
        return reg == TMP103_TEMP_REG;
}

static const struct regmap_config tmp103_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = TMP103_THIGH_REG,
        .volatile_reg = tmp103_regmap_is_volatile,
};

static int tmp103_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct device *hwmon_dev;
        struct regmap *regmap;
        int ret;

        regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
        if (IS_ERR(regmap)) {
                dev_err(dev, "failed to allocate register map\n");
                return PTR_ERR(regmap);
        }

        ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG_MASK,
                                 TMP103_CONFIG);
        if (ret < 0) {
                dev_err(&client->dev, "error writing config register\n");
                return ret;
        }

        i2c_set_clientdata(client, regmap);
        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
                                                         regmap,
                                                         &tmp103_chip_info,
                                                         NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

static int tmp103_suspend(struct device *dev)
{
        struct regmap *regmap = dev_get_drvdata(dev);

        return regmap_update_bits(regmap, TMP103_CONF_REG,
                                  TMP103_CONF_SD_MASK, 0);
}

static int tmp103_resume(struct device *dev)
{
        struct regmap *regmap = dev_get_drvdata(dev);

        return regmap_update_bits(regmap, TMP103_CONF_REG,
                                  TMP103_CONF_SD_MASK, TMP103_CONF_SD);
}

static DEFINE_SIMPLE_DEV_PM_OPS(tmp103_dev_pm_ops, tmp103_suspend, tmp103_resume);

static const struct i2c_device_id tmp103_id[] = {
        { "tmp103" },
        { }
};
MODULE_DEVICE_TABLE(i2c, tmp103_id);

static const struct of_device_id __maybe_unused tmp103_of_match[] = {
        { .compatible = "ti,tmp103" },
        { },
};
MODULE_DEVICE_TABLE(of, tmp103_of_match);

static struct i2c_driver tmp103_driver = {
        .driver = {
                .name   = "tmp103",
                .of_match_table = of_match_ptr(tmp103_of_match),
                .pm     = pm_sleep_ptr(&tmp103_dev_pm_ops),
        },
        .probe          = tmp103_probe,
        .id_table       = tmp103_id,
};

module_i2c_driver(tmp103_driver);

MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
MODULE_LICENSE("GPL");