// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for Texas Instruments / National Semiconductor LM95234
 *
 * Copyright (c) 2013, 2014 Guenter Roeck <linux@roeck-us.net>
 *
 * Derived from lm95241.c
 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
 */

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

#define DRVNAME "lm95234"

enum chips { lm95233, lm95234 };

static const unsigned short normal_i2c[] = {
        0x18, 0x2a, 0x2b, 0x4d, 0x4e, I2C_CLIENT_END };

/* LM95234 registers */
#define LM95234_REG_MAN_ID              0xFE
#define LM95234_REG_CHIP_ID             0xFF
#define LM95234_REG_STATUS              0x02
#define LM95234_REG_CONFIG              0x03
#define LM95234_REG_CONVRATE            0x04
#define LM95234_REG_ENABLE              0x05
#define LM95234_REG_FILTER              0x06
#define LM95234_REG_STS_FAULT           0x07
#define LM95234_REG_STS_TCRIT1          0x08
#define LM95234_REG_STS_TCRIT2          0x09
#define LM95234_REG_TEMPH(x)            ((x) + 0x10)
#define LM95234_REG_TEMPL(x)            ((x) + 0x20)
#define LM95234_REG_UTEMPH(x)           ((x) + 0x19)    /* Remote only */
#define LM95234_REG_UTEMPL(x)           ((x) + 0x29)
#define LM95234_REG_REM_MODEL           0x30
#define LM95234_REG_REM_MODEL_STS       0x38
#define LM95234_REG_OFFSET(x)           ((x) + 0x31)    /* Remote only */
#define LM95234_REG_TCRIT1(x)           ((x) + 0x40)
#define LM95234_REG_TCRIT2(x)           ((x) + 0x49)    /* Remote channel 1,2 */
#define LM95234_REG_TCRIT_HYST          0x5a

#define NATSEMI_MAN_ID                  0x01
#define LM95233_CHIP_ID                 0x89
#define LM95234_CHIP_ID                 0x79

/* Client data (each client gets its own) */
struct lm95234_data {
        struct regmap *regmap;
        enum chips type;
};

static int lm95234_read_temp(struct regmap *regmap, int index, long *t)
{
        unsigned int regs[2];
        int temp = 0, ret;
        u8 regvals[2];

        if (index) {
                regs[0] = LM95234_REG_UTEMPH(index - 1);
                regs[1] = LM95234_REG_UTEMPL(index - 1);
                ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
                if (ret)
                        return ret;
                temp = (regvals[0] << 8) | regvals[1];
        }
        /*
         * Read signed temperature if unsigned temperature is 0,
         * or if this is the local sensor.
         */
        if (!temp) {
                regs[0] = LM95234_REG_TEMPH(index);
                regs[1] = LM95234_REG_TEMPL(index);
                ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
                if (ret)
                        return ret;
                temp = (regvals[0] << 8) | regvals[1];
                temp = sign_extend32(temp, 15);
        }
        *t = DIV_ROUND_CLOSEST(temp * 125, 32);
        return 0;
}

static int lm95234_hyst_get(struct regmap *regmap, int reg, long *val)
{
        unsigned int regs[2] = {reg, LM95234_REG_TCRIT_HYST};
        u8 regvals[2];
        int ret;

        ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
        if (ret)
                return ret;
        *val = (regvals[0] - regvals[1]) * 1000;
        return 0;
}

static ssize_t lm95234_hyst_set(struct lm95234_data *data, long val)
{
        u32 tcrit;
        int ret;

        ret = regmap_read(data->regmap, LM95234_REG_TCRIT1(0), &tcrit);
        if (ret)
                return ret;

        val = DIV_ROUND_CLOSEST(clamp_val(val, -255000, 255000), 1000);
        val = clamp_val((int)tcrit - val, 0, 31);

        return regmap_write(data->regmap, LM95234_REG_TCRIT_HYST, val);
}

static int lm95234_crit_reg(int channel)
{
        if (channel == 1 || channel == 2)
                return LM95234_REG_TCRIT2(channel - 1);
        return LM95234_REG_TCRIT1(channel);
}

static int lm95234_temp_write(struct device *dev, u32 attr, int channel, long val)
{
        struct lm95234_data *data = dev_get_drvdata(dev);
        struct regmap *regmap = data->regmap;

        switch (attr) {
        case hwmon_temp_enable:
                if (val && val != 1)
                        return -EINVAL;
                return regmap_update_bits(regmap, LM95234_REG_ENABLE,
                                          BIT(channel), val ? BIT(channel) : 0);
        case hwmon_temp_type:
                if (val != 1 && val != 2)
                        return -EINVAL;
                return regmap_update_bits(regmap, LM95234_REG_REM_MODEL,
                                          BIT(channel),
                                          val == 1 ? BIT(channel) : 0);
        case hwmon_temp_offset:
                val = DIV_ROUND_CLOSEST(clamp_val(val, -64000, 63500), 500);
                return regmap_write(regmap, LM95234_REG_OFFSET(channel - 1), val);
        case hwmon_temp_max:
                val = clamp_val(val, 0, channel == 1 ? 127000 : 255000);
                val = DIV_ROUND_CLOSEST(val, 1000);
                return regmap_write(regmap, lm95234_crit_reg(channel), val);
        case hwmon_temp_max_hyst:
                return lm95234_hyst_set(data, val);
        case hwmon_temp_crit:
                val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 255000), 1000);
                return regmap_write(regmap, LM95234_REG_TCRIT1(channel), val);
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static int lm95234_alarm_reg(int channel)
{
        if (channel == 1 || channel == 2)
                return LM95234_REG_STS_TCRIT2;
        return LM95234_REG_STS_TCRIT1;
}

static int lm95234_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct lm95234_data *data = dev_get_drvdata(dev);
        struct regmap *regmap = data->regmap;
        u32 regval, mask;
        int ret;

        switch (attr) {
        case hwmon_temp_enable:
                ret = regmap_read(regmap, LM95234_REG_ENABLE, &regval);
                if (ret)
                        return ret;
                *val = !!(regval & BIT(channel));
                break;
        case hwmon_temp_input:
                return lm95234_read_temp(regmap, channel, val);
        case hwmon_temp_max_alarm:
                ret =  regmap_read(regmap, lm95234_alarm_reg(channel), &regval);
                if (ret)
                        return ret;
                *val = !!(regval & BIT(channel));
                break;
        case hwmon_temp_crit_alarm:
                ret =  regmap_read(regmap, LM95234_REG_STS_TCRIT1, &regval);
                if (ret)
                        return ret;
                *val = !!(regval & BIT(channel));
                break;
        case hwmon_temp_crit_hyst:
                return lm95234_hyst_get(regmap, LM95234_REG_TCRIT1(channel), val);
        case hwmon_temp_type:
                ret = regmap_read(regmap, LM95234_REG_REM_MODEL, &regval);
                if (ret)
                        return ret;
                *val = (regval & BIT(channel)) ? 1 : 2;
                break;
        case hwmon_temp_offset:
                ret = regmap_read(regmap, LM95234_REG_OFFSET(channel - 1), &regval);
                if (ret)
                        return ret;
                *val = sign_extend32(regval, 7) * 500;
                break;
        case hwmon_temp_fault:
                ret = regmap_read(regmap, LM95234_REG_STS_FAULT, &regval);
                if (ret)
                        return ret;
                mask = (BIT(0) | BIT(1)) << ((channel - 1) << 1);
                *val = !!(regval & mask);
                break;
        case hwmon_temp_max:
                ret = regmap_read(regmap, lm95234_crit_reg(channel), &regval);
                if (ret)
                        return ret;
                *val = regval * 1000;
                break;
        case hwmon_temp_max_hyst:
                return lm95234_hyst_get(regmap, lm95234_crit_reg(channel), val);
        case hwmon_temp_crit:
                ret = regmap_read(regmap, LM95234_REG_TCRIT1(channel), &regval);
                if (ret)
                        return ret;
                *val = regval * 1000;
                break;
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static u16 update_intervals[] = { 143, 364, 1000, 2500 };

static int lm95234_chip_write(struct device *dev, u32 attr, long val)
{
        struct lm95234_data *data = dev_get_drvdata(dev);

        switch (attr) {
        case hwmon_chip_update_interval:
                val = find_closest(val, update_intervals, ARRAY_SIZE(update_intervals));
                return regmap_write(data->regmap, LM95234_REG_CONVRATE, val);
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static int lm95234_chip_read(struct device *dev, u32 attr, long *val)
{
        struct lm95234_data *data = dev_get_drvdata(dev);
        u32 convrate;
        int ret;

        switch (attr) {
        case hwmon_chip_update_interval:
                ret = regmap_read(data->regmap, LM95234_REG_CONVRATE, &convrate);
                if (ret)
                        return ret;

                *val = update_intervals[convrate & 0x03];
                break;
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static int lm95234_write(struct device *dev, enum hwmon_sensor_types type,
                         u32 attr, int channel, long val)
{
        switch (type) {
        case hwmon_chip:
                return lm95234_chip_write(dev, attr, val);
        case hwmon_temp:
                return lm95234_temp_write(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static int lm95234_read(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long *val)
{
        switch (type) {
        case hwmon_chip:
                return lm95234_chip_read(dev, attr, val);
        case hwmon_temp:
                return lm95234_temp_read(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t lm95234_is_visible(const void *_data, enum hwmon_sensor_types type,
                                  u32 attr, int channel)
{
        const struct lm95234_data *data = _data;

        if (data->type == lm95233 && channel > 2)
                return 0;

        switch (type) {
        case hwmon_chip:
                switch (attr) {
                case hwmon_chip_update_interval:
                        return 0644;
                default:
                        break;
                }
                break;
        case hwmon_temp:
                switch (attr) {
                case hwmon_temp_input:
                case hwmon_temp_max_alarm:
                        return 0444;
                case hwmon_temp_crit_alarm:
                case hwmon_temp_crit_hyst:
                        return (channel && channel < 3) ? 0444 : 0;
                case hwmon_temp_type:
                case hwmon_temp_offset:
                        return channel ? 0644 : 0;
                case hwmon_temp_fault:
                        return channel ? 0444 : 0;
                case hwmon_temp_max:
                case hwmon_temp_enable:
                        return 0644;
                case hwmon_temp_max_hyst:
                        return channel ? 0444 : 0644;
                case hwmon_temp_crit:
                        return (channel && channel < 3) ? 0644 : 0;
                default:
                        break;
                }
                break;
        default:
                break;
        }
        return 0;
}

static const struct hwmon_channel_info * const lm95234_info[] = {
        HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
                           HWMON_T_MAX_ALARM | HWMON_T_ENABLE,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
                           HWMON_T_MAX_ALARM | HWMON_T_FAULT | HWMON_T_TYPE |
                           HWMON_T_CRIT | HWMON_T_CRIT_HYST |
                           HWMON_T_CRIT_ALARM | HWMON_T_OFFSET | HWMON_T_ENABLE,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
                           HWMON_T_MAX_ALARM | HWMON_T_FAULT | HWMON_T_TYPE |
                           HWMON_T_CRIT | HWMON_T_CRIT_HYST |
                           HWMON_T_CRIT_ALARM | HWMON_T_OFFSET | HWMON_T_ENABLE,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
                           HWMON_T_MAX_ALARM | HWMON_T_FAULT | HWMON_T_TYPE |
                           HWMON_T_OFFSET | HWMON_T_ENABLE,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
                           HWMON_T_MAX_ALARM | HWMON_T_FAULT | HWMON_T_TYPE |
                           HWMON_T_OFFSET | HWMON_T_ENABLE),
        NULL
};

static const struct hwmon_ops lm95234_hwmon_ops = {
        .is_visible = lm95234_is_visible,
        .read = lm95234_read,
        .write = lm95234_write,
};

static const struct hwmon_chip_info lm95234_chip_info = {
        .ops = &lm95234_hwmon_ops,
        .info = lm95234_info,
};

static bool lm95234_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LM95234_REG_TEMPH(0) ... LM95234_REG_TEMPH(4):
        case LM95234_REG_TEMPL(0) ... LM95234_REG_TEMPL(4):
        case LM95234_REG_UTEMPH(0) ... LM95234_REG_UTEMPH(3):
        case LM95234_REG_UTEMPL(0) ... LM95234_REG_UTEMPL(3):
        case LM95234_REG_STS_FAULT:
        case LM95234_REG_STS_TCRIT1:
        case LM95234_REG_STS_TCRIT2:
        case LM95234_REG_REM_MODEL_STS:
                return true;
        default:
                return false;
        }
}

static bool lm95234_writeable_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LM95234_REG_CONFIG ... LM95234_REG_FILTER:
        case LM95234_REG_REM_MODEL ... LM95234_REG_OFFSET(3):
        case LM95234_REG_TCRIT1(0) ... LM95234_REG_TCRIT1(4):
        case LM95234_REG_TCRIT2(0) ... LM95234_REG_TCRIT2(1):
        case LM95234_REG_TCRIT_HYST:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config lm95234_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .writeable_reg = lm95234_writeable_reg,
        .volatile_reg = lm95234_volatile_reg,
        .cache_type = REGCACHE_MAPLE,
};

static int lm95234_detect(struct i2c_client *client,
                          struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        int address = client->addr;
        u8 config_mask, model_mask;
        int mfg_id, chip_id, val;
        const char *name;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        mfg_id = i2c_smbus_read_byte_data(client, LM95234_REG_MAN_ID);
        if (mfg_id != NATSEMI_MAN_ID)
                return -ENODEV;

        chip_id = i2c_smbus_read_byte_data(client, LM95234_REG_CHIP_ID);
        switch (chip_id) {
        case LM95233_CHIP_ID:
                if (address != 0x18 && address != 0x2a && address != 0x2b)
                        return -ENODEV;
                config_mask = 0xbf;
                model_mask = 0xf9;
                name = "lm95233";
                break;
        case LM95234_CHIP_ID:
                if (address != 0x18 && address != 0x4d && address != 0x4e)
                        return -ENODEV;
                config_mask = 0xbc;
                model_mask = 0xe1;
                name = "lm95234";
                break;
        default:
                return -ENODEV;
        }

        val = i2c_smbus_read_byte_data(client, LM95234_REG_STATUS);
        if (val & 0x30)
                return -ENODEV;

        val = i2c_smbus_read_byte_data(client, LM95234_REG_CONFIG);
        if (val & config_mask)
                return -ENODEV;

        val = i2c_smbus_read_byte_data(client, LM95234_REG_CONVRATE);
        if (val & 0xfc)
                return -ENODEV;

        val = i2c_smbus_read_byte_data(client, LM95234_REG_REM_MODEL);
        if (val & model_mask)
                return -ENODEV;

        val = i2c_smbus_read_byte_data(client, LM95234_REG_REM_MODEL_STS);
        if (val & model_mask)
                return -ENODEV;

        strscpy(info->type, name, I2C_NAME_SIZE);
        return 0;
}

static int lm95234_init_client(struct device *dev, struct regmap *regmap)
{
        u32 val, model;
        int ret;

        /* start conversion if necessary */
        ret = regmap_clear_bits(regmap, LM95234_REG_CONFIG, 0x40);
        if (ret)
                return ret;

        /* If diode type status reports an error, try to fix it */
        ret = regmap_read(regmap, LM95234_REG_REM_MODEL_STS, &val);
        if (ret < 0)
                return ret;
        ret = regmap_read(regmap, LM95234_REG_REM_MODEL, &model);
        if (ret < 0)
                return ret;
        if (model & val) {
                dev_notice(dev,
                           "Fixing remote diode type misconfiguration (0x%x)\n",
                           val);
                ret = regmap_write(regmap, LM95234_REG_REM_MODEL, model & ~val);
        }
        return ret;
}

static int lm95234_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct lm95234_data *data;
        struct device *hwmon_dev;
        struct regmap *regmap;
        int err;

        data = devm_kzalloc(dev, sizeof(struct lm95234_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->type = (uintptr_t)i2c_get_match_data(client);

        regmap = devm_regmap_init_i2c(client, &lm95234_regmap_config);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        data->regmap = regmap;

        /* Initialize the LM95234 chip */
        err = lm95234_init_client(dev, regmap);
        if (err < 0)
                return err;

        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
                                                         data, &lm95234_chip_info, NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

/* Driver data (common to all clients) */
static const struct i2c_device_id lm95234_id[] = {
        { "lm95233", lm95233 },
        { "lm95234", lm95234 },
        { }
};
MODULE_DEVICE_TABLE(i2c, lm95234_id);

static struct i2c_driver lm95234_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = DRVNAME,
        },
        .probe          = lm95234_probe,
        .id_table       = lm95234_id,
        .detect         = lm95234_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(lm95234_driver);

MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("LM95233/LM95234 sensor driver");
MODULE_LICENSE("GPL");