// SPDX-License-Identifier: GPL-2.0-or-later
/* tmp401.c
 *
 * Copyright (C) 2007,2008 Hans de Goede <hdegoede@redhat.com>
 * Preliminary tmp411 support by:
 * Gabriel Konat, Sander Leget, Wouter Willems
 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
 *
 * Cleanup and support for TMP431 and TMP432 by Guenter Roeck
 * Copyright (c) 2013 Guenter Roeck <linux@roeck-us.net>
 */

/*
 * Driver for the Texas Instruments TMP401 SMBUS temperature sensor IC.
 *
 * Note this IC is in some aspect similar to the LM90, but it has quite a
 * few differences too, for example the local temp has a higher resolution
 * and thus has 16 bits registers for its value and limit instead of 8 bits.
 */

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

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, 0x4d,
        0x4e, 0x4f, I2C_CLIENT_END };

enum chips { tmp401, tmp411, tmp431, tmp432, tmp435 };

/*
 * The TMP401 registers, note some registers have different addresses for
 * reading and writing
 */
#define TMP401_STATUS                           0x02
#define TMP401_CONFIG                           0x03
#define TMP401_CONVERSION_RATE                  0x04
#define TMP401_TEMP_CRIT_HYST                   0x21
#define TMP401_MANUFACTURER_ID_REG              0xFE
#define TMP401_DEVICE_ID_REG                    0xFF

static const u8 TMP401_TEMP_MSB[7][3] = {
        { 0x00, 0x01, 0x23 },   /* temp */
        { 0x06, 0x08, 0x16 },   /* low limit */
        { 0x05, 0x07, 0x15 },   /* high limit */
        { 0x20, 0x19, 0x1a },   /* therm (crit) limit */
        { 0x30, 0x34, 0x00 },   /* lowest */
        { 0x32, 0xf6, 0x00 },   /* highest */
};

/* [0] = fault, [1] = low, [2] = high, [3] = therm/crit */
static const u8 TMP432_STATUS_REG[] = {
        0x1b, 0x36, 0x35, 0x37 };

/* Flags */
#define TMP401_CONFIG_RANGE                     BIT(2)
#define TMP401_CONFIG_SHUTDOWN                  BIT(6)
#define TMP401_STATUS_LOCAL_CRIT                BIT(0)
#define TMP401_STATUS_REMOTE_CRIT               BIT(1)
#define TMP401_STATUS_REMOTE_OPEN               BIT(2)
#define TMP401_STATUS_REMOTE_LOW                BIT(3)
#define TMP401_STATUS_REMOTE_HIGH               BIT(4)
#define TMP401_STATUS_LOCAL_LOW                 BIT(5)
#define TMP401_STATUS_LOCAL_HIGH                BIT(6)

/* On TMP432, each status has its own register */
#define TMP432_STATUS_LOCAL                     BIT(0)
#define TMP432_STATUS_REMOTE1                   BIT(1)
#define TMP432_STATUS_REMOTE2                   BIT(2)

/* Manufacturer / Device ID's */
#define TMP401_MANUFACTURER_ID                  0x55
#define TMP401_DEVICE_ID                        0x11
#define TMP411A_DEVICE_ID                       0x12
#define TMP411B_DEVICE_ID                       0x13
#define TMP411C_DEVICE_ID                       0x10
#define TMP431_DEVICE_ID                        0x31
#define TMP432_DEVICE_ID                        0x32
#define TMP435_DEVICE_ID                        0x35

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id tmp401_id[] = {
        { "tmp401", tmp401 },
        { "tmp411", tmp411 },
        { "tmp431", tmp431 },
        { "tmp432", tmp432 },
        { "tmp435", tmp435 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tmp401_id);

/*
 * Client data (each client gets its own)
 */

struct tmp401_data {
        struct i2c_client *client;
        struct regmap *regmap;
        struct mutex update_lock;
        enum chips kind;

        bool extended_range;

        /* hwmon API configuration data */
        u32 chip_channel_config[4];
        struct hwmon_channel_info chip_info;
        u32 temp_channel_config[4];
        struct hwmon_channel_info temp_info;
        const struct hwmon_channel_info *info[3];
        struct hwmon_chip_info chip;
};

/* regmap */

static bool tmp401_regmap_is_volatile(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case 0:                 /* local temp msb */
        case 1:                 /* remote temp msb */
        case 2:                 /* status */
        case 0x10:              /* remote temp lsb */
        case 0x15:              /* local temp lsb */
        case 0x1b:              /* status (tmp432) */
        case 0x23 ... 0x24:     /* remote temp 2 msb / lsb */
        case 0x30 ... 0x37:     /* lowest/highest temp; status (tmp432) */
                return true;
        default:
                return false;
        }
}

static int tmp401_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct tmp401_data *data = context;
        struct i2c_client *client = data->client;
        int regval;

        switch (reg) {
        case 0:                 /* local temp msb */
        case 1:                 /* remote temp msb */
        case 5:                 /* local temp high limit msb */
        case 6:                 /* local temp low limit msb */
        case 7:                 /* remote temp ligh limit msb */
        case 8:                 /* remote temp low limit msb */
        case 0x15:              /* remote temp 2 high limit msb */
        case 0x16:              /* remote temp 2 low limit msb */
        case 0x23:              /* remote temp 2 msb */
        case 0x30:              /* local temp minimum, tmp411 */
        case 0x32:              /* local temp maximum, tmp411 */
        case 0x34:              /* remote temp minimum, tmp411 */
        case 0xf6:              /* remote temp maximum, tmp411 (really 0x36) */
                /* work around register overlap between TMP411 and TMP432 */
                if (reg == 0xf6)
                        reg = 0x36;
                regval = i2c_smbus_read_word_swapped(client, reg);
                if (regval < 0)
                        return regval;
                *val = regval;
                break;
        case 0x19:              /* critical limits, 8-bit registers */
        case 0x1a:
        case 0x20:
                regval = i2c_smbus_read_byte_data(client, reg);
                if (regval < 0)
                        return regval;
                *val = regval << 8;
                break;
        case 0x1b:
        case 0x35 ... 0x37:
                if (data->kind == tmp432) {
                        regval = i2c_smbus_read_byte_data(client, reg);
                        if (regval < 0)
                                return regval;
                        *val = regval;
                        break;
                }
                /* simulate TMP432 status registers */
                regval = i2c_smbus_read_byte_data(client, TMP401_STATUS);
                if (regval < 0)
                        return regval;
                *val = 0;
                switch (reg) {
                case 0x1b:      /* open / fault */
                        if (regval & TMP401_STATUS_REMOTE_OPEN)
                                *val |= BIT(1);
                        break;
                case 0x35:      /* high limit */
                        if (regval & TMP401_STATUS_LOCAL_HIGH)
                                *val |= BIT(0);
                        if (regval & TMP401_STATUS_REMOTE_HIGH)
                                *val |= BIT(1);
                        break;
                case 0x36:      /* low limit */
                        if (regval & TMP401_STATUS_LOCAL_LOW)
                                *val |= BIT(0);
                        if (regval & TMP401_STATUS_REMOTE_LOW)
                                *val |= BIT(1);
                        break;
                case 0x37:      /* therm / crit limit */
                        if (regval & TMP401_STATUS_LOCAL_CRIT)
                                *val |= BIT(0);
                        if (regval & TMP401_STATUS_REMOTE_CRIT)
                                *val |= BIT(1);
                        break;
                }
                break;
        default:
                regval = i2c_smbus_read_byte_data(client, reg);
                if (regval < 0)
                        return regval;
                *val = regval;
                break;
        }
        return 0;
}

static int tmp401_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct tmp401_data *data = context;
        struct i2c_client *client = data->client;

        switch (reg) {
        case 0x05:              /* local temp high limit msb */
        case 0x06:              /* local temp low limit msb */
        case 0x07:              /* remote temp ligh limit msb */
        case 0x08:              /* remote temp low limit msb */
                reg += 6;       /* adjust for register write address */
                fallthrough;
        case 0x15:              /* remote temp 2 high limit msb */
        case 0x16:              /* remote temp 2 low limit msb */
                return i2c_smbus_write_word_swapped(client, reg, val);
        case 0x19:              /* critical limits, 8-bit registers */
        case 0x1a:
        case 0x20:
                return i2c_smbus_write_byte_data(client, reg, val >> 8);
        case TMP401_CONVERSION_RATE:
        case TMP401_CONFIG:
                reg += 6;       /* adjust for register write address */
                fallthrough;
        default:
                return i2c_smbus_write_byte_data(client, reg, val);
        }
}

static const struct regmap_config tmp401_regmap_config = {
        .reg_bits = 8,
        .val_bits = 16,
        .cache_type = REGCACHE_RBTREE,
        .volatile_reg = tmp401_regmap_is_volatile,
        .reg_read = tmp401_reg_read,
        .reg_write = tmp401_reg_write,
};

/* temperature conversion */

static int tmp401_register_to_temp(u16 reg, bool extended)
{
        int temp = reg;

        if (extended)
                temp -= 64 * 256;

        return DIV_ROUND_CLOSEST(temp * 125, 32);
}

static u16 tmp401_temp_to_register(long temp, bool extended, int zbits)
{
        if (extended) {
                temp = clamp_val(temp, -64000, 191000);
                temp += 64000;
        } else {
                temp = clamp_val(temp, 0, 127000);
        }

        return DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits;
}

/* hwmon API functions */

static const u8 tmp401_temp_reg_index[] = {
        [hwmon_temp_input] = 0,
        [hwmon_temp_min] = 1,
        [hwmon_temp_max] = 2,
        [hwmon_temp_crit] = 3,
        [hwmon_temp_lowest] = 4,
        [hwmon_temp_highest] = 5,
};

static const u8 tmp401_status_reg_index[] = {
        [hwmon_temp_fault] = 0,
        [hwmon_temp_min_alarm] = 1,
        [hwmon_temp_max_alarm] = 2,
        [hwmon_temp_crit_alarm] = 3,
};

static int tmp401_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct tmp401_data *data = dev_get_drvdata(dev);
        struct regmap *regmap = data->regmap;
        unsigned int regval;
        int reg, ret;

        switch (attr) {
        case hwmon_temp_input:
        case hwmon_temp_min:
        case hwmon_temp_max:
        case hwmon_temp_crit:
        case hwmon_temp_lowest:
        case hwmon_temp_highest:
                reg = TMP401_TEMP_MSB[tmp401_temp_reg_index[attr]][channel];
                ret = regmap_read(regmap, reg, &regval);
                if (ret < 0)
                        return ret;
                *val = tmp401_register_to_temp(regval, data->extended_range);
                break;
        case hwmon_temp_crit_hyst:
                mutex_lock(&data->update_lock);
                reg = TMP401_TEMP_MSB[3][channel];
                ret = regmap_read(regmap, reg, &regval);
                if (ret < 0)
                        goto unlock;
                *val = tmp401_register_to_temp(regval, data->extended_range);
                ret = regmap_read(regmap, TMP401_TEMP_CRIT_HYST, &regval);
                if (ret < 0)
                        goto unlock;
                *val -= regval * 1000;
unlock:
                mutex_unlock(&data->update_lock);
                if (ret < 0)
                        return ret;
                break;
        case hwmon_temp_fault:
        case hwmon_temp_min_alarm:
        case hwmon_temp_max_alarm:
        case hwmon_temp_crit_alarm:
                reg = TMP432_STATUS_REG[tmp401_status_reg_index[attr]];
                ret = regmap_read(regmap, reg, &regval);
                if (ret < 0)
                        return ret;
                *val = !!(regval & BIT(channel));
                break;
        default:
                return -EOPNOTSUPP;
        }
        return 0;
}

static int tmp401_temp_write(struct device *dev, u32 attr, int channel,
                             long val)
{
        struct tmp401_data *data = dev_get_drvdata(dev);
        struct regmap *regmap = data->regmap;
        unsigned int regval;
        int reg, ret, temp;

        mutex_lock(&data->update_lock);
        switch (attr) {
        case hwmon_temp_min:
        case hwmon_temp_max:
        case hwmon_temp_crit:
                reg = TMP401_TEMP_MSB[tmp401_temp_reg_index[attr]][channel];
                regval = tmp401_temp_to_register(val, data->extended_range,
                                                 attr == hwmon_temp_crit ? 8 : 4);
                ret = regmap_write(regmap, reg, regval);
                break;
        case hwmon_temp_crit_hyst:
                if (data->extended_range)
                        val = clamp_val(val, -64000, 191000);
                else
                        val = clamp_val(val, 0, 127000);

                reg = TMP401_TEMP_MSB[3][channel];
                ret = regmap_read(regmap, reg, &regval);
                if (ret < 0)
                        break;
                temp = tmp401_register_to_temp(regval, data->extended_range);
                val = clamp_val(val, temp - 255000, temp);
                regval = ((temp - val) + 500) / 1000;
                ret = regmap_write(regmap, TMP401_TEMP_CRIT_HYST, regval);
                break;
        default:
                ret = -EOPNOTSUPP;
                break;
        }
        mutex_unlock(&data->update_lock);
        return ret;
}

static int tmp401_chip_read(struct device *dev, u32 attr, int channel, long *val)
{
        struct tmp401_data *data = dev_get_drvdata(dev);
        u32 regval;
        int ret;

        switch (attr) {
        case hwmon_chip_update_interval:
                ret = regmap_read(data->regmap, TMP401_CONVERSION_RATE, &regval);
                if (ret < 0)
                        return ret;
                *val = (1 << (7 - regval)) * 125;
                break;
        case hwmon_chip_temp_reset_history:
                *val = 0;
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int tmp401_set_convrate(struct regmap *regmap, long val)
{
        int rate;

        /*
         * For valid rates, interval can be calculated as
         *      interval = (1 << (7 - rate)) * 125;
         * Rounded rate is therefore
         *      rate = 7 - __fls(interval * 4 / (125 * 3));
         * Use clamp_val() to avoid overflows, and to ensure valid input
         * for __fls.
         */
        val = clamp_val(val, 125, 16000);
        rate = 7 - __fls(val * 4 / (125 * 3));
        return regmap_write(regmap, TMP401_CONVERSION_RATE, rate);
}

static int tmp401_chip_write(struct device *dev, u32 attr, int channel, long val)
{
        struct tmp401_data *data = dev_get_drvdata(dev);
        struct regmap *regmap = data->regmap;
        int err;

        mutex_lock(&data->update_lock);
        switch (attr) {
        case hwmon_chip_update_interval:
                err = tmp401_set_convrate(regmap, val);
                break;
        case hwmon_chip_temp_reset_history:
                if (val != 1) {
                        err = -EINVAL;
                        break;
                }
                /*
                 * Reset history by writing any value to any of the
                 * minimum/maximum registers (0x30-0x37).
                 */
                err = regmap_write(regmap, 0x30, 0);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        mutex_unlock(&data->update_lock);

        return err;
}

static int tmp401_read(struct device *dev, enum hwmon_sensor_types type,
                       u32 attr, int channel, long *val)
{
        switch (type) {
        case hwmon_chip:
                return tmp401_chip_read(dev, attr, channel, val);
        case hwmon_temp:
                return tmp401_temp_read(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static int tmp401_write(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long val)
{
        switch (type) {
        case hwmon_chip:
                return tmp401_chip_write(dev, attr, channel, val);
        case hwmon_temp:
                return tmp401_temp_write(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t tmp401_is_visible(const void *data, enum hwmon_sensor_types type,
                                 u32 attr, int channel)
{
        switch (type) {
        case hwmon_chip:
                switch (attr) {
                case hwmon_chip_update_interval:
                case hwmon_chip_temp_reset_history:
                        return 0644;
                default:
                        break;
                }
                break;
        case hwmon_temp:
                switch (attr) {
                case hwmon_temp_input:
                case hwmon_temp_min_alarm:
                case hwmon_temp_max_alarm:
                case hwmon_temp_crit_alarm:
                case hwmon_temp_fault:
                case hwmon_temp_lowest:
                case hwmon_temp_highest:
                        return 0444;
                case hwmon_temp_min:
                case hwmon_temp_max:
                case hwmon_temp_crit:
                case hwmon_temp_crit_hyst:
                        return 0644;
                default:
                        break;
                }
                break;
        default:
                break;
        }
        return 0;
}

static const struct hwmon_ops tmp401_ops = {
        .is_visible = tmp401_is_visible,
        .read = tmp401_read,
        .write = tmp401_write,
};

/* chip initialization, detect, probe */

static int tmp401_init_client(struct tmp401_data *data)
{
        struct regmap *regmap = data->regmap;
        u32 config, config_orig;
        int ret;

        /* Set conversion rate to 2 Hz */
        ret = regmap_write(regmap, TMP401_CONVERSION_RATE, 5);
        if (ret < 0)
                return ret;

        /* Start conversions (disable shutdown if necessary) */
        ret = regmap_read(regmap, TMP401_CONFIG, &config);
        if (ret < 0)
                return ret;

        config_orig = config;
        config &= ~TMP401_CONFIG_SHUTDOWN;

        data->extended_range = !!(config & TMP401_CONFIG_RANGE);

        if (config != config_orig)
                ret = regmap_write(regmap, TMP401_CONFIG, config);

        return ret;
}

static int tmp401_detect(struct i2c_client *client,
                         struct i2c_board_info *info)
{
        enum chips kind;
        struct i2c_adapter *adapter = client->adapter;
        u8 reg;

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

        /* Detect and identify the chip */
        reg = i2c_smbus_read_byte_data(client, TMP401_MANUFACTURER_ID_REG);
        if (reg != TMP401_MANUFACTURER_ID)
                return -ENODEV;

        reg = i2c_smbus_read_byte_data(client, TMP401_DEVICE_ID_REG);

        switch (reg) {
        case TMP401_DEVICE_ID:
                if (client->addr != 0x4c)
                        return -ENODEV;
                kind = tmp401;
                break;
        case TMP411A_DEVICE_ID:
                if (client->addr != 0x4c)
                        return -ENODEV;
                kind = tmp411;
                break;
        case TMP411B_DEVICE_ID:
                if (client->addr != 0x4d)
                        return -ENODEV;
                kind = tmp411;
                break;
        case TMP411C_DEVICE_ID:
                if (client->addr != 0x4e)
                        return -ENODEV;
                kind = tmp411;
                break;
        case TMP431_DEVICE_ID:
                if (client->addr != 0x4c && client->addr != 0x4d)
                        return -ENODEV;
                kind = tmp431;
                break;
        case TMP432_DEVICE_ID:
                if (client->addr != 0x4c && client->addr != 0x4d)
                        return -ENODEV;
                kind = tmp432;
                break;
        case TMP435_DEVICE_ID:
                kind = tmp435;
                break;
        default:
                return -ENODEV;
        }

        reg = i2c_smbus_read_byte_data(client, TMP401_CONFIG);
        if (reg & 0x1b)
                return -ENODEV;

        reg = i2c_smbus_read_byte_data(client, TMP401_CONVERSION_RATE);
        /* Datasheet says: 0x1-0x6 */
        if (reg > 15)
                return -ENODEV;

        strlcpy(info->type, tmp401_id[kind].name, I2C_NAME_SIZE);

        return 0;
}

static int tmp401_probe(struct i2c_client *client)
{
        static const char * const names[] = {
                "TMP401", "TMP411", "TMP431", "TMP432", "TMP435"
        };
        struct device *dev = &client->dev;
        struct hwmon_channel_info *info;
        struct device *hwmon_dev;
        struct tmp401_data *data;
        int status;

        data = devm_kzalloc(dev, sizeof(struct tmp401_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->client = client;
        mutex_init(&data->update_lock);
        data->kind = i2c_match_id(tmp401_id, client)->driver_data;

        data->regmap = devm_regmap_init(dev, NULL, data, &tmp401_regmap_config);
        if (IS_ERR(data->regmap))
                return PTR_ERR(data->regmap);

        /* initialize configuration data */
        data->chip.ops = &tmp401_ops;
        data->chip.info = data->info;

        data->info[0] = &data->chip_info;
        data->info[1] = &data->temp_info;

        info = &data->chip_info;
        info->type = hwmon_chip;
        info->config = data->chip_channel_config;

        data->chip_channel_config[0] = HWMON_C_UPDATE_INTERVAL;

        info = &data->temp_info;
        info->type = hwmon_temp;
        info->config = data->temp_channel_config;

        data->temp_channel_config[0] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
                HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
                HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM;
        data->temp_channel_config[1] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
                HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
                HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;

        if (data->kind == tmp411) {
                data->temp_channel_config[0] |= HWMON_T_HIGHEST | HWMON_T_LOWEST;
                data->temp_channel_config[1] |= HWMON_T_HIGHEST | HWMON_T_LOWEST;
                data->chip_channel_config[0] |= HWMON_C_TEMP_RESET_HISTORY;
        }

        if (data->kind == tmp432) {
                data->temp_channel_config[2] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
                        HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
                        HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
        }

        /* Initialize the TMP401 chip */
        status = tmp401_init_client(data);
        if (status < 0)
                return status;

        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
                                                         &data->chip, NULL);
        if (IS_ERR(hwmon_dev))
                return PTR_ERR(hwmon_dev);

        dev_info(dev, "Detected TI %s chip\n", names[data->kind]);

        return 0;
}

static const struct of_device_id __maybe_unused tmp4xx_of_match[] = {
        { .compatible = "ti,tmp401", },
        { .compatible = "ti,tmp411", },
        { .compatible = "ti,tmp431", },
        { .compatible = "ti,tmp432", },
        { .compatible = "ti,tmp435", },
        { },
};
MODULE_DEVICE_TABLE(of, tmp4xx_of_match);

static struct i2c_driver tmp401_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = "tmp401",
                .of_match_table = of_match_ptr(tmp4xx_of_match),
        },
        .probe_new      = tmp401_probe,
        .id_table       = tmp401_id,
        .detect         = tmp401_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(tmp401_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("Texas Instruments TMP401 temperature sensor driver");
MODULE_LICENSE("GPL");