// SPDX-License-Identifier: GPL-2.0
/*
 * MS5611 pressure and temperature sensor driver (I2C bus)
 *
 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
 *
 * 7-bit I2C slave addresses:
 *
 * 0x77 (CSB pin low)
 * 0x76 (CSB pin high)
 *
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>

#include <linux/unaligned.h>

#include "ms5611.h"

static int ms5611_i2c_reset(struct ms5611_state *st)
{
        return i2c_smbus_write_byte(st->client, MS5611_RESET);
}

static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
                                     u16 *word)
{
        int ret;

        ret = i2c_smbus_read_word_swapped(st->client,
                        MS5611_READ_PROM_WORD + (index << 1));
        if (ret < 0)
                return ret;

        *word = ret;

        return 0;
}

static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
{
        int ret;
        u8 buf[3];

        ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
                                            3, buf);
        if (ret < 0)
                return ret;

        *val = get_unaligned_be24(&buf[0]);

        return 0;
}

static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
                                                 s32 *temp, s32 *pressure)
{
        int ret;
        const struct ms5611_osr *osr = st->temp_osr;

        ret = i2c_smbus_write_byte(st->client, osr->cmd);
        if (ret < 0)
                return ret;

        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
        ret = ms5611_i2c_read_adc(st, temp);
        if (ret < 0)
                return ret;

        osr = st->pressure_osr;
        ret = i2c_smbus_write_byte(st->client, osr->cmd);
        if (ret < 0)
                return ret;

        usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
        return ms5611_i2c_read_adc(st, pressure);
}

static int ms5611_i2c_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct ms5611_state *st;
        struct iio_dev *indio_dev;

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_WRITE_BYTE |
                                     I2C_FUNC_SMBUS_READ_WORD_DATA |
                                     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
                return -EOPNOTSUPP;

        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
        if (!indio_dev)
                return -ENOMEM;

        st = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        st->reset = ms5611_i2c_reset;
        st->read_prom_word = ms5611_i2c_read_prom_word;
        st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
        st->client = client;

        return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
}

static const struct of_device_id ms5611_i2c_matches[] = {
        { .compatible = "meas,ms5611" },
        { .compatible = "meas,ms5607" },
        { }
};
MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);

static const struct i2c_device_id ms5611_id[] = {
        { "ms5611", MS5611 },
        { "ms5607", MS5607 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ms5611_id);

static struct i2c_driver ms5611_driver = {
        .driver = {
                .name = "ms5611",
                .of_match_table = ms5611_i2c_matches,
        },
        .id_table = ms5611_id,
        .probe = ms5611_i2c_probe,
};
module_i2c_driver(ms5611_driver);

MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 i2c driver");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_MS5611");