// SPDX-License-Identifier: GPL-2.0-only
/*
 * tsys02d.c - Support for Measurement-Specialties tsys02d temperature sensor
 *
 * Copyright (c) 2015 Measurement-Specialties
 *
 * (7-bit I2C slave address 0x40)
 *
 * Datasheet:
 *  http://www.meas-spec.com/downloads/Digital_Sensor_TSYS02D.pdf
 */

#include <linux/init.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#include "../common/ms_sensors/ms_sensors_i2c.h"

#define TSYS02D_RESET                           0xFE

static const int tsys02d_samp_freq[4] = { 20, 40, 70, 140 };
/* String copy of the above const for readability purpose */
static const char tsys02d_show_samp_freq[] = "20 40 70 140";

static int tsys02d_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *channel, int *val,
                            int *val2, long mask)
{
        int ret;
        s32 temperature;
        struct ms_ht_dev *dev_data = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_PROCESSED:
                switch (channel->type) {
                case IIO_TEMP:  /* in milli °C */
                        ret = ms_sensors_ht_read_temperature(dev_data,
                                                             &temperature);
                        if (ret)
                                return ret;
                        *val = temperature;

                        return IIO_VAL_INT;
                default:
                        return -EINVAL;
                }
        case IIO_CHAN_INFO_SAMP_FREQ:
                *val = tsys02d_samp_freq[dev_data->res_index];

                return IIO_VAL_INT;
        default:
                return -EINVAL;
        }
}

static int tsys02d_write_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             int val, int val2, long mask)
{
        struct ms_ht_dev *dev_data = iio_priv(indio_dev);
        int i, ret;

        switch (mask) {
        case IIO_CHAN_INFO_SAMP_FREQ:
                i = ARRAY_SIZE(tsys02d_samp_freq);
                while (i-- > 0)
                        if (val == tsys02d_samp_freq[i])
                                break;
                if (i < 0)
                        return -EINVAL;
                mutex_lock(&dev_data->lock);
                dev_data->res_index = i;
                ret = ms_sensors_write_resolution(dev_data, i);
                mutex_unlock(&dev_data->lock);

                return ret;
        default:
                return -EINVAL;
        }
}

static const struct iio_chan_spec tsys02d_channels[] = {
        {
                .type = IIO_TEMP,
                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        }
};

static ssize_t tsys02_read_battery_low(struct device *dev,
                                       struct device_attribute *attr,
                                       char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct ms_ht_dev *dev_data = iio_priv(indio_dev);

        return ms_sensors_show_battery_low(dev_data, buf);
}

static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(tsys02d_show_samp_freq);
static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
                       tsys02_read_battery_low, NULL, 0);

static struct attribute *tsys02d_attributes[] = {
        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
        &iio_dev_attr_battery_low.dev_attr.attr,
        NULL,
};

static const struct attribute_group tsys02d_attribute_group = {
        .attrs = tsys02d_attributes,
};

static const struct iio_info tsys02d_info = {
        .read_raw = tsys02d_read_raw,
        .write_raw = tsys02d_write_raw,
        .attrs = &tsys02d_attribute_group,
};

static int tsys02d_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct ms_ht_dev *dev_data;
        struct iio_dev *indio_dev;
        int ret;
        u64 serial_number;

        if (!i2c_check_functionality(client->adapter,
                                     I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
                                     I2C_FUNC_SMBUS_WRITE_BYTE |
                                     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
                dev_err(&client->dev,
                        "Adapter does not support some i2c transaction\n");
                return -EOPNOTSUPP;
        }

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

        dev_data = iio_priv(indio_dev);
        dev_data->client = client;
        dev_data->res_index = 0;
        mutex_init(&dev_data->lock);

        indio_dev->info = &tsys02d_info;
        indio_dev->name = id->name;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = tsys02d_channels;
        indio_dev->num_channels = ARRAY_SIZE(tsys02d_channels);

        i2c_set_clientdata(client, indio_dev);

        ret = ms_sensors_reset(client, TSYS02D_RESET, 15000);
        if (ret)
                return ret;

        ret = ms_sensors_read_serial(client, &serial_number);
        if (ret)
                return ret;
        dev_info(&client->dev, "Serial number : %llx", serial_number);

        return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct i2c_device_id tsys02d_id[] = {
        { "tsys02d" },
        { }
};
MODULE_DEVICE_TABLE(i2c, tsys02d_id);

static struct i2c_driver tsys02d_driver = {
        .probe = tsys02d_probe,
        .id_table = tsys02d_id,
        .driver = {
                   .name = "tsys02d",
                   },
};

module_i2c_driver(tsys02d_driver);

MODULE_DESCRIPTION("Measurement-Specialties tsys02d temperature driver");
MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("IIO_MEAS_SPEC_SENSORS");