blob: 136fe6b3362c0190b609beb0c0162ddad069da3c [file] [log] [blame]
/*
* Copyright (c) 2020 Laird Connectivity
* Copyright (c) 2019 Electronut Labs
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT silabs_si7055
#include <zephyr/drivers/sensor.h>
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/logging/log.h>
#include <zephyr/drivers/i2c.h>
#include "si7055.h"
#if CONFIG_SI7055_ENABLE_CHECKSUM
#include <zephyr/sys/crc.h>
#endif
LOG_MODULE_REGISTER(si7055, CONFIG_SENSOR_LOG_LEVEL);
struct si7055_data {
uint16_t temperature;
};
struct si7055_config {
struct i2c_dt_spec i2c;
};
/**
* @brief function to get temperature
*
* @return int 0 on success
* -EIO for I/O and checksum errors
*/
static int si7055_get_temperature(const struct device *dev)
{
struct si7055_data *si_data = dev->data;
const struct si7055_config *config = dev->config;
int retval;
#if CONFIG_SI7055_ENABLE_CHECKSUM
uint8_t temp[SI7055_TEMPERATURE_READ_WITH_CHECKSUM_SIZE];
#else
uint8_t temp[SI7055_TEMPERATURE_READ_NO_CHECKSUM_SIZE];
#endif
retval = i2c_burst_read_dt(&config->i2c, SI7055_MEAS_TEMP_MASTER_MODE,
temp, sizeof(temp));
/* Refer to
* https://www.silabs.com/documents/public/data-sheets/Si7050-1-3-4-5-A20.pdf
*/
if (retval == 0) {
#if CONFIG_SI7055_ENABLE_CHECKSUM
if (crc8(temp, SI7055_DATA_SIZE, SI7055_CRC_POLY,
SI7055_CRC_INIT, false) != temp[SI7055_DATA_SIZE]){
LOG_ERR("checksum failed.\n");
return(-EIO);
}
#endif
si_data->temperature = (temp[SI7055_TEMPERATURE_DATA_BYTE_0]
<< 8) |
temp[SI7055_TEMPERATURE_DATA_BYTE_1];
} else {
LOG_ERR("read register err");
}
return retval;
}
/**
* @brief fetch a sample from the sensor
*
* @return 0
*/
static int si7055_sample_fetch(const struct device *dev,
enum sensor_channel chan)
{
int retval;
retval = si7055_get_temperature(dev);
return retval;
}
/**
* @brief sensor value get
*
* @return -ENOTSUP for unsupported channels
*/
static int si7055_channel_get(const struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct si7055_data *si_data = dev->data;
/* Refer to
* https://www.silabs.com/documents/public/data-sheets/Si7050-1-3-4-5-A20.pdf
*/
if (chan == SENSOR_CHAN_AMBIENT_TEMP) {
int32_t temp_ucelcius = (((SI7055_CONV_FACTOR_1 *
(int32_t)si_data->temperature) /
(__UINT16_MAX__ + 1)) -
SI7055_CONV_FACTOR_2) *
SI7055_MULTIPLIER;
val->val1 = temp_ucelcius / SI7055_DIVIDER;
val->val2 = temp_ucelcius % SI7055_DIVIDER;
LOG_DBG("temperature = val1:%d, val2:%d",
val->val1, val->val2);
return 0;
} else {
return -ENOTSUP;
}
}
static const struct sensor_driver_api si7055_api = {
.sample_fetch = &si7055_sample_fetch,
.channel_get = &si7055_channel_get,
};
/**
* @brief initialize the sensor
*
* @return 0 for success
*/
static int si7055_init(const struct device *dev)
{
const struct si7055_config *config = dev->config;
if (!device_is_ready(config->i2c.bus)) {
LOG_ERR("Bus device is not ready");
return -ENODEV;
}
LOG_DBG("si7055 init ok");
return 0;
}
#define SI7055_DEFINE(inst) \
static struct si7055_data si7055_data_##inst; \
\
static const struct si7055_config si7055_config_##inst = { \
.i2c = I2C_DT_SPEC_INST_GET(inst), \
}; \
\
SENSOR_DEVICE_DT_INST_DEFINE(inst, si7055_init, NULL, \
&si7055_data_##inst, &si7055_config_##inst, POST_KERNEL, \
CONFIG_SENSOR_INIT_PRIORITY, &si7055_api); \
DT_INST_FOREACH_STATUS_OKAY(SI7055_DEFINE)