zephyr/drivers/sensor/si7006/si7006.c

168 lines
3.4 KiB
C

/*
* Copyright (c) 2019 Electronut Labs
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT silabs_si7006
#include <drivers/sensor.h>
#include <kernel.h>
#include <device.h>
#include <init.h>
#include <string.h>
#include <sys/byteorder.h>
#include <sys/__assert.h>
#include <logging/log.h>
#include <drivers/i2c.h>
#include <logging/log.h>
#include <stdio.h>
#include <stdlib.h>
#include "si7006.h"
LOG_MODULE_REGISTER(si7006, CONFIG_SENSOR_LOG_LEVEL);
struct si7006_data {
struct device *i2c_dev;
u16_t temperature;
u16_t humidity;
};
/**
* @brief function to get relative humidity
*
* @return int 0 on success
*/
static int si7006_get_humidity(struct device *i2c_dev,
struct si7006_data *si_data)
{
int retval;
u8_t hum[2];
retval = i2c_burst_read(i2c_dev, DT_INST_REG_ADDR(0),
SI7006_MEAS_REL_HUMIDITY_MASTER_MODE, hum, sizeof(hum));
if (retval == 0) {
si_data->humidity = (hum[0] << 8) | hum[1];
} else {
LOG_ERR("read register err");
}
return retval;
}
/**
* @brief function to get temperature
*
* Note that si7006_get_humidity must be called before calling
* si7006_get_old_temperature.
*
* @return int 0 on success
*/
static int si7006_get_old_temperature(struct device *i2c_dev,
struct si7006_data *si_data)
{
u8_t temp[2];
int retval;
retval = i2c_burst_read(i2c_dev, DT_INST_REG_ADDR(0),
SI7006_READ_OLD_TEMP, temp, sizeof(temp));
if (retval == 0) {
si_data->temperature = (temp[0] << 8) | temp[1];
} else {
LOG_ERR("read register err");
}
return retval;
}
/**
* @brief fetch a sample from the sensor
*
* @return 0
*/
static int si7006_sample_fetch(struct device *dev, enum sensor_channel chan)
{
int retval;
struct si7006_data *si_data = dev->driver_data;
retval = si7006_get_humidity(si_data->i2c_dev, si_data);
if (retval == 0) {
retval = si7006_get_old_temperature(si_data->i2c_dev, si_data);
}
return retval;
}
/**
* @brief sensor value get
*
* @return -ENOTSUP for unsupported channels
*/
static int si7006_channel_get(struct device *dev, enum sensor_channel chan,
struct sensor_value *val)
{
struct si7006_data *si_data = dev->driver_data;
if (chan == SENSOR_CHAN_AMBIENT_TEMP) {
s32_t temp_ucelcius = (((17572 * (s32_t)si_data->temperature)
/ 65536) - 4685) * 10000;
val->val1 = temp_ucelcius / 1000000;
val->val2 = temp_ucelcius % 1000000;
LOG_DBG("temperature = val1:%d, val2:%d", val->val1, val->val2);
return 0;
} else if (chan == SENSOR_CHAN_HUMIDITY) {
s32_t relative_humidity = (((125 * (s32_t)si_data->humidity)
/ 65536) - 6) * 1000000;
val->val1 = relative_humidity / 1000000;
val->val2 = relative_humidity % 1000000;
LOG_DBG("humidity = val1:%d, val2:%d", val->val1, val->val2);
return 0;
} else {
return -ENOTSUP;
}
}
static const struct sensor_driver_api si7006_api = {
.sample_fetch = &si7006_sample_fetch,
.channel_get = &si7006_channel_get,
};
/**
* @brief initiasize the sensor
*
* @return 0 for success
*/
static int si7006_init(struct device *dev)
{
struct si7006_data *drv_data = dev->driver_data;
drv_data->i2c_dev = device_get_binding(
DT_INST_BUS_LABEL(0));
if (!drv_data->i2c_dev) {
LOG_ERR("i2c master not found.");
return -EINVAL;
}
LOG_DBG("si7006 init ok");
return 0;
}
static struct si7006_data si_data;
DEVICE_AND_API_INIT(si7006, DT_INST_LABEL(0), si7006_init,
&si_data, NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, &si7006_api);