// SPDX-License-Identifier: GPL-2.0-or-later
/* Texas Instruments TMP108 SMBus temperature sensor driver
 *
 * Copyright (C) 2016 John Muir <john@jmuir.com>
 */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i3c/device.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/util_macros.h>

#define DRIVER_NAME "tmp108"

#define TMP108_REG_TEMP         0x00
#define TMP108_REG_CONF         0x01
#define TMP108_REG_TLOW         0x02
#define TMP108_REG_THIGH        0x03

#define TMP108_TEMP_MIN_MC      -50000 /* Minimum millicelcius. */
#define TMP108_TEMP_MAX_MC      127937 /* Maximum millicelcius. */

/* Configuration register bits.
 * Note: these bit definitions are byte swapped.
 */
#define TMP108_CONF_M0          0x0100 /* Sensor mode. */
#define TMP108_CONF_M1          0x0200
#define TMP108_CONF_TM          0x0400 /* Thermostat mode. */
#define TMP108_CONF_FL          0x0800 /* Watchdog flag - TLOW */
#define TMP108_CONF_FH          0x1000 /* Watchdog flag - THIGH */
#define TMP108_CONF_CR0         0x2000 /* Conversion rate. */
#define TMP108_CONF_CR1         0x4000
#define TMP108_CONF_ID          0x8000
#define TMP108_CONF_HYS0        0x0010 /* Hysteresis. */
#define TMP108_CONF_HYS1        0x0020
#define TMP108_CONF_POL         0x0080 /* Polarity of alert. */

/* Defaults set by the hardware upon reset. */
#define TMP108_CONF_DEFAULTS            (TMP108_CONF_CR0 | TMP108_CONF_TM |\
                                         TMP108_CONF_HYS0 | TMP108_CONF_M1)
/* These bits are read-only. */
#define TMP108_CONF_READ_ONLY           (TMP108_CONF_FL | TMP108_CONF_FH |\
                                         TMP108_CONF_ID)

#define TMP108_CONF_MODE_MASK           (TMP108_CONF_M0|TMP108_CONF_M1)
#define TMP108_MODE_SHUTDOWN            0x0000
#define TMP108_MODE_ONE_SHOT            TMP108_CONF_M0
#define TMP108_MODE_CONTINUOUS          TMP108_CONF_M1          /* Default */
                                        /* When M1 is set, M0 is ignored. */

#define TMP108_CONF_CONVRATE_MASK       (TMP108_CONF_CR0|TMP108_CONF_CR1)
#define TMP108_CONVRATE_0P25HZ          0x0000
#define TMP108_CONVRATE_1HZ             TMP108_CONF_CR0         /* Default */
#define TMP108_CONVRATE_4HZ             TMP108_CONF_CR1
#define TMP108_CONVRATE_16HZ            (TMP108_CONF_CR0|TMP108_CONF_CR1)

#define TMP108_CONF_HYSTERESIS_MASK     (TMP108_CONF_HYS0|TMP108_CONF_HYS1)
#define TMP108_HYSTERESIS_0C            0x0000
#define TMP108_HYSTERESIS_1C            TMP108_CONF_HYS0        /* Default */
#define TMP108_HYSTERESIS_2C            TMP108_CONF_HYS1
#define TMP108_HYSTERESIS_4C            (TMP108_CONF_HYS0|TMP108_CONF_HYS1)

#define TMP108_CONVERSION_TIME_MS       30      /* in milli-seconds */

#define TMP108_CONF_CR0_POS             13
#define TMP108_CONF_CR1_POS             14
#define TMP108_CONF_CONVRATE_FLD        GENMASK(TMP108_CONF_CR1_POS, TMP108_CONF_CR0_POS)

struct tmp108 {
        struct regmap *regmap;
        u16 orig_config;
        unsigned long ready_time;
        const struct tmp108_params *params;
};

struct tmp108_params {
        bool config_reg_16bits;
        const u16 *sample_times;
        size_t n_sample_times;
};

static const u16 p3t1035_sample_times[] = {4000, 1000, 250, 125};
static const u16 tmp108_sample_times[] = {4000, 1000, 250, 63};

static const struct tmp108_params p3t1035_data = {
        .sample_times = p3t1035_sample_times,
        .n_sample_times  = ARRAY_SIZE(p3t1035_sample_times),
        .config_reg_16bits = false,
};

static const struct tmp108_params tmp108_data = {
        .sample_times = tmp108_sample_times,
        .n_sample_times  = ARRAY_SIZE(tmp108_sample_times),
        .config_reg_16bits = true,
};

/* convert 12-bit TMP108 register value to milliCelsius */
static inline int tmp108_temp_reg_to_mC(s16 val)
{
        return (val & ~0x0f) * 1000 / 256;
}

/* convert milliCelsius to left adjusted 12-bit TMP108 register value */
static inline u16 tmp108_mC_to_temp_reg(int val)
{
        return (val * 256) / 1000;
}

static int tmp108_read(struct device *dev, enum hwmon_sensor_types type,
                       u32 attr, int channel, long *temp)
{
        struct tmp108 *tmp108 = dev_get_drvdata(dev);
        unsigned int regval;
        int err, hyst;

        if (type == hwmon_chip) {
                if (attr == hwmon_chip_update_interval) {
                        err = regmap_read(tmp108->regmap, TMP108_REG_CONF,
                                          &regval);
                        if (err < 0)
                                return err;
                        *temp = tmp108->params->sample_times[FIELD_GET(TMP108_CONF_CONVRATE_FLD,
                                                                       regval)];
                        return 0;
                }
                return -EOPNOTSUPP;
        }

        switch (attr) {
        case hwmon_temp_input:
                /* Is it too early to return a conversion ? */
                if (time_before(jiffies, tmp108->ready_time)) {
                        dev_dbg(dev, "%s: Conversion not ready yet..\n",
                                __func__);
                        return -EAGAIN;
                }
                err = regmap_read(tmp108->regmap, TMP108_REG_TEMP, &regval);
                if (err < 0)
                        return err;
                *temp = tmp108_temp_reg_to_mC(regval);
                break;
        case hwmon_temp_min:
        case hwmon_temp_max:
                err = regmap_read(tmp108->regmap, attr == hwmon_temp_min ?
                                  TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
                if (err < 0)
                        return err;
                *temp = tmp108_temp_reg_to_mC(regval);
                break;
        case hwmon_temp_min_alarm:
        case hwmon_temp_max_alarm:
                err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
                if (err < 0)
                        return err;
                *temp = !!(regval & (attr == hwmon_temp_min_alarm ?
                                     TMP108_CONF_FL : TMP108_CONF_FH));
                break;
        case hwmon_temp_min_hyst:
        case hwmon_temp_max_hyst:
                err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &regval);
                if (err < 0)
                        return err;
                switch (regval & TMP108_CONF_HYSTERESIS_MASK) {
                case TMP108_HYSTERESIS_0C:
                default:
                        hyst = 0;
                        break;
                case TMP108_HYSTERESIS_1C:
                        hyst = 1000;
                        break;
                case TMP108_HYSTERESIS_2C:
                        hyst = 2000;
                        break;
                case TMP108_HYSTERESIS_4C:
                        hyst = 4000;
                        break;
                }
                err = regmap_read(tmp108->regmap, attr == hwmon_temp_min_hyst ?
                                  TMP108_REG_TLOW : TMP108_REG_THIGH, &regval);
                if (err < 0)
                        return err;
                *temp = tmp108_temp_reg_to_mC(regval);
                if (attr == hwmon_temp_min_hyst)
                        *temp += hyst;
                else
                        *temp -= hyst;
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int tmp108_write(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long temp)
{
        struct tmp108 *tmp108 = dev_get_drvdata(dev);
        u32 regval, mask;
        size_t len;
        u8 index;
        int err;

        if (type == hwmon_chip) {
                if (attr == hwmon_chip_update_interval) {
                        len = tmp108->params->n_sample_times;
                        index = find_closest_descending(temp, tmp108->params->sample_times, len);
                        return regmap_update_bits(tmp108->regmap,
                                                  TMP108_REG_CONF,
                                                  TMP108_CONF_CONVRATE_MASK,
                                                  FIELD_PREP(TMP108_CONF_CONVRATE_FLD, index));
                }
                return -EOPNOTSUPP;
        }

        switch (attr) {
        case hwmon_temp_min:
        case hwmon_temp_max:
                temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
                return regmap_write(tmp108->regmap,
                                    attr == hwmon_temp_min ?
                                        TMP108_REG_TLOW : TMP108_REG_THIGH,
                                    tmp108_mC_to_temp_reg(temp));
        case hwmon_temp_min_hyst:
        case hwmon_temp_max_hyst:
                temp = clamp_val(temp, TMP108_TEMP_MIN_MC, TMP108_TEMP_MAX_MC);
                err = regmap_read(tmp108->regmap,
                                  attr == hwmon_temp_min_hyst ?
                                        TMP108_REG_TLOW : TMP108_REG_THIGH,
                                  &regval);
                if (err < 0)
                        return err;
                if (attr == hwmon_temp_min_hyst)
                        temp -= tmp108_temp_reg_to_mC(regval);
                else
                        temp = tmp108_temp_reg_to_mC(regval) - temp;
                if (temp < 500)
                        mask = TMP108_HYSTERESIS_0C;
                else if (temp < 1500)
                        mask = TMP108_HYSTERESIS_1C;
                else if (temp < 3000)
                        mask = TMP108_HYSTERESIS_2C;
                else
                        mask = TMP108_HYSTERESIS_4C;
                return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
                                          TMP108_CONF_HYSTERESIS_MASK, mask);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t tmp108_is_visible(const void *data, enum hwmon_sensor_types type,
                                 u32 attr, int channel)
{
        const struct tmp108 *tmp108 = data;

        if (type == hwmon_chip && attr == hwmon_chip_update_interval)
                return 0644;

        if (type != hwmon_temp)
                return 0;

        switch (attr) {
        case hwmon_temp_input:
        case hwmon_temp_min_alarm:
        case hwmon_temp_max_alarm:
                return 0444;
        case hwmon_temp_min:
        case hwmon_temp_max:
                return 0644;
        case hwmon_temp_min_hyst:
        case hwmon_temp_max_hyst:
                if (!tmp108->params->config_reg_16bits)
                        return 0;
                return 0644;
        default:
                return 0;
        }
}

static const struct hwmon_channel_info * const tmp108_info[] = {
        HWMON_CHANNEL_INFO(chip,
                           HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
                           HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
                           HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM),
        NULL
};

static const struct hwmon_ops tmp108_hwmon_ops = {
        .is_visible = tmp108_is_visible,
        .read = tmp108_read,
        .write = tmp108_write,
};

static const struct hwmon_chip_info tmp108_chip_info = {
        .ops = &tmp108_hwmon_ops,
        .info = tmp108_info,
};

static void tmp108_restore_config(void *data)
{
        struct tmp108 *tmp108 = data;

        regmap_write(tmp108->regmap, TMP108_REG_CONF, tmp108->orig_config);
}

static bool tmp108_is_writeable_reg(struct device *dev, unsigned int reg)
{
        return reg != TMP108_REG_TEMP;
}

static bool tmp108_is_volatile_reg(struct device *dev, unsigned int reg)
{
        /* Configuration register must be volatile to enable FL and FH. */
        return reg == TMP108_REG_TEMP || reg == TMP108_REG_CONF;
}

static int tmp108_i2c_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct i2c_client *client = context;
        struct tmp108 *tmp108 = i2c_get_clientdata(client);
        int ret;

        if (reg == TMP108_REG_CONF && !tmp108->params->config_reg_16bits) {
                ret = i2c_smbus_read_byte_data(client, TMP108_REG_CONF);
                if (ret < 0)
                        return ret;
                *val = ret << 8;
                return 0;
        }

        ret = i2c_smbus_read_word_swapped(client, reg);
        if (ret < 0)
                return ret;
        *val = ret;
        return 0;
}

static int tmp108_i2c_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct i2c_client *client = context;
        struct tmp108 *tmp108 = i2c_get_clientdata(client);

        if (reg == TMP108_REG_CONF && !tmp108->params->config_reg_16bits)
                return i2c_smbus_write_byte_data(client, reg, val >> 8);
        return i2c_smbus_write_word_swapped(client, reg, val);
}

static const struct regmap_bus tmp108_i2c_regmap_bus = {
        .reg_read = tmp108_i2c_reg_read,
        .reg_write = tmp108_i2c_reg_write,
};

static int tmp108_i3c_reg_read(void *context, unsigned int reg, unsigned int *val)
{
        struct i3c_device *i3cdev = context;
        struct tmp108 *tmp108 = i3cdev_get_drvdata(i3cdev);
        u8 reg_buf[1], val_buf[2];
        struct i3c_xfer xfers[] = {
                {
                        .rnw = false,
                        .len = 1,
                        .data.out = reg_buf,
                },
                {
                        .rnw = true,
                        .len = 2,
                        .data.in = val_buf,
                },
        };
        int ret;

        reg_buf[0] = reg;

        if (reg == TMP108_REG_CONF && !tmp108->params->config_reg_16bits)
                xfers[1].len--;

        ret = i3c_device_do_xfers(i3cdev, xfers, 2, I3C_SDR);
        if (ret < 0)
                return ret;

        *val = val_buf[0] << 8;
        if (reg != TMP108_REG_CONF || tmp108->params->config_reg_16bits)
                *val |= val_buf[1];

        return 0;
}

static int tmp108_i3c_reg_write(void *context, unsigned int reg, unsigned int val)
{
        struct i3c_device *i3cdev = context;
        struct tmp108 *tmp108 = i3cdev_get_drvdata(i3cdev);
        u8 val_buf[3];
        struct i3c_xfer xfers[] = {
                {
                        .rnw = false,
                        .len = 3,
                        .data.out = val_buf,
                },
        };

        val_buf[0] = reg;
        val_buf[1] = (val >> 8) & 0xff;

        if (reg == TMP108_REG_CONF && !tmp108->params->config_reg_16bits)
                xfers[0].len--;
        else
                val_buf[2] = val & 0xff;

        return i3c_device_do_xfers(i3cdev, xfers, 1, I3C_SDR);
}

static const struct regmap_bus tmp108_i3c_regmap_bus = {
        .reg_read = tmp108_i3c_reg_read,
        .reg_write = tmp108_i3c_reg_write,
};

static const struct regmap_config tmp108_regmap_config = {
        .reg_bits = 8,
        .val_bits = 16,
        .max_register = TMP108_REG_THIGH,
        .writeable_reg = tmp108_is_writeable_reg,
        .volatile_reg = tmp108_is_volatile_reg,
        .val_format_endian = REGMAP_ENDIAN_BIG,
        .cache_type = REGCACHE_MAPLE,
        .use_single_read = true,
        .use_single_write = true,
};

static int tmp108_common_probe(struct device *dev, struct regmap *regmap, char *name,
                               const struct tmp108_params *params)
{
        struct device *hwmon_dev;
        struct tmp108 *tmp108;
        u32 config;
        int err;

        err = devm_regulator_get_enable(dev, "vcc");
        if (err)
                return dev_err_probe(dev, err, "Failed to enable regulator\n");

        tmp108 = devm_kzalloc(dev, sizeof(*tmp108), GFP_KERNEL);
        if (!tmp108)
                return -ENOMEM;

        dev_set_drvdata(dev, tmp108);
        tmp108->regmap = regmap;
        tmp108->params = params;

        err = regmap_read(tmp108->regmap, TMP108_REG_CONF, &config);
        if (err < 0) {
                dev_err(dev, "error reading config register: %d", err);
                return err;
        }
        tmp108->orig_config = config;

        /* Only continuous mode is supported. */
        config &= ~TMP108_CONF_MODE_MASK;
        config |= TMP108_MODE_CONTINUOUS;
        /* Only comparator mode is supported. */
        config &= ~TMP108_CONF_TM;

        err = regmap_write(tmp108->regmap, TMP108_REG_CONF, config);
        if (err < 0) {
                dev_err(dev, "error writing config register: %d", err);
                return err;
        }

        tmp108->ready_time = jiffies;
        if ((tmp108->orig_config & TMP108_CONF_MODE_MASK) ==
            TMP108_MODE_SHUTDOWN)
                tmp108->ready_time +=
                        msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);

        err = devm_add_action_or_reset(dev, tmp108_restore_config, tmp108);
        if (err) {
                dev_err(dev, "add action or reset failed: %d", err);
                return err;
        }

        hwmon_dev = devm_hwmon_device_register_with_info(dev, name,
                                                         tmp108,
                                                         &tmp108_chip_info,
                                                         NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

static int tmp108_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct regmap *regmap;

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
                return dev_err_probe(dev, -ENODEV,
                                     "adapter doesn't support SMBus word transactions\n");

        regmap = devm_regmap_init(dev, &tmp108_i2c_regmap_bus, client, &tmp108_regmap_config);
        if (IS_ERR(regmap))
                return dev_err_probe(dev, PTR_ERR(regmap), "regmap init failed");

        return tmp108_common_probe(dev, regmap, client->name, i2c_get_match_data(client));
}

static int tmp108_suspend(struct device *dev)
{
        struct tmp108 *tmp108 = dev_get_drvdata(dev);

        return regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
                                  TMP108_CONF_MODE_MASK, TMP108_MODE_SHUTDOWN);
}

static int tmp108_resume(struct device *dev)
{
        struct tmp108 *tmp108 = dev_get_drvdata(dev);
        int err;

        err = regmap_update_bits(tmp108->regmap, TMP108_REG_CONF,
                                 TMP108_CONF_MODE_MASK, TMP108_MODE_CONTINUOUS);
        tmp108->ready_time = jiffies +
                             msecs_to_jiffies(TMP108_CONVERSION_TIME_MS);
        return err;
}

static DEFINE_SIMPLE_DEV_PM_OPS(tmp108_dev_pm_ops, tmp108_suspend, tmp108_resume);

static const struct i2c_device_id tmp108_i2c_ids[] = {
        { "p3t1035", (unsigned long)&p3t1035_data },
        { "p3t1085", (unsigned long)&tmp108_data },
        { "tmp108", (unsigned long)&tmp108_data },
        {}
};
MODULE_DEVICE_TABLE(i2c, tmp108_i2c_ids);

static const struct of_device_id tmp108_of_ids[] = {
        { .compatible = "nxp,p3t1035", .data = &p3t1035_data },
        { .compatible = "nxp,p3t1085", .data = &tmp108_data },
        { .compatible = "ti,tmp108", .data = &tmp108_data },
        {}
};
MODULE_DEVICE_TABLE(of, tmp108_of_ids);

static struct i2c_driver tmp108_driver = {
        .driver = {
                .name   = DRIVER_NAME,
                .pm     = pm_sleep_ptr(&tmp108_dev_pm_ops),
                .of_match_table = tmp108_of_ids,
        },
        .probe          = tmp108_probe,
        .id_table       = tmp108_i2c_ids,
};

static const struct i3c_device_id p3t1085_i3c_ids[] = {
        I3C_DEVICE(0x011B, 0x1529, &tmp108_data),
        I3C_DEVICE(0x011B, 0x152B, &p3t1035_data),
        {}
};
MODULE_DEVICE_TABLE(i3c, p3t1085_i3c_ids);

static int p3t1085_i3c_probe(struct i3c_device *i3cdev)
{
        struct device *dev = i3cdev_to_dev(i3cdev);
        struct regmap *regmap;
        const struct i3c_device_id *id;

        regmap = devm_regmap_init(dev, &tmp108_i3c_regmap_bus, i3cdev, &tmp108_regmap_config);
        if (IS_ERR(regmap))
                return dev_err_probe(dev, PTR_ERR(regmap),
                                     "Failed to register i3c regmap\n");

        id = i3c_device_match_id(i3cdev, p3t1085_i3c_ids);

        return tmp108_common_probe(dev, regmap, "p3t1085_i3c", id->data);
}

static struct i3c_driver p3t1085_driver = {
        .driver = {
                .name = "p3t1085_i3c",
        },
        .probe = p3t1085_i3c_probe,
        .id_table = p3t1085_i3c_ids,
};

module_i3c_i2c_driver(p3t1085_driver, &tmp108_driver)

MODULE_AUTHOR("John Muir <john@jmuir.com>");
MODULE_DESCRIPTION("Texas Instruments TMP108 temperature sensor driver");
MODULE_LICENSE("GPL");