blob: 1bf7d5233b2736e7e9c1b104518655491607872c [file] [log] [blame]
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT sensirion_sht3xd
#include <device.h>
#include <drivers/i2c.h>
#include <kernel.h>
#include <drivers/sensor.h>
#include <sys/__assert.h>
#include <logging/log.h>
#include "sht3xd.h"
LOG_MODULE_REGISTER(SHT3XD, CONFIG_SENSOR_LOG_LEVEL);
#ifdef CONFIG_SHT3XD_SINGLE_SHOT_MODE
static const u16_t measure_cmd[3] = {
0x2400, 0x240B, 0x2416
};
#endif
#ifdef CONFIG_SHT3XD_PERIODIC_MODE
static const u16_t measure_cmd[5][3] = {
{ 0x202F, 0x2024, 0x2032 },
{ 0x212D, 0x2126, 0x2130 },
{ 0x222B, 0x2220, 0x2236 },
{ 0x2329, 0x2322, 0x2334 },
{ 0x272A, 0x2721, 0x2737 }
};
#endif
static const int measure_wait[3] = {
4000, 6000, 15000
};
/*
* CRC algorithm parameters were taken from the
* "Checksum Calculation" section of the datasheet.
*/
static u8_t sht3xd_compute_crc(u16_t value)
{
u8_t buf[2] = { value >> 8, value & 0xFF };
u8_t crc = 0xFF;
u8_t polynom = 0x31;
int i, j;
for (i = 0; i < 2; ++i) {
crc = crc ^ buf[i];
for (j = 0; j < 8; ++j) {
if (crc & 0x80) {
crc = (crc << 1) ^ polynom;
} else {
crc = crc << 1;
}
}
}
return crc;
}
int sht3xd_write_command(struct device *dev, u16_t cmd)
{
u8_t tx_buf[2] = { cmd >> 8, cmd & 0xFF };
return i2c_write(sht3xd_i2c_device(dev), tx_buf, sizeof(tx_buf),
sht3xd_i2c_address(dev));
}
int sht3xd_write_reg(struct device *dev, u16_t cmd, u16_t val)
{
u8_t tx_buf[5];
tx_buf[0] = cmd >> 8;
tx_buf[1] = cmd & 0xFF;
tx_buf[2] = val >> 8;
tx_buf[3] = val & 0xFF;
tx_buf[4] = sht3xd_compute_crc(val);
return i2c_write(sht3xd_i2c_device(dev), tx_buf, sizeof(tx_buf),
sht3xd_i2c_address(dev));
}
static int sht3xd_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct sht3xd_data *data = dev->driver_data;
struct device *i2c = sht3xd_i2c_device(dev);
u8_t address = sht3xd_i2c_address(dev);
u8_t rx_buf[6];
u16_t t_sample, rh_sample;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
#ifdef CONFIG_SHT3XD_SINGLE_SHOT_MODE
/* start single shot measurement */
if (sht3xd_write_command(dev,
measure_cmd[SHT3XD_REPEATABILITY_IDX])
< 0) {
LOG_DBG("Failed to set single shot measurement mode!");
return -EIO;
}
k_sleep(K_MSEC(measure_wait[SHT3XD_REPEATABILITY_IDX] / USEC_PER_MSEC));
if (i2c_read(i2c, rx_buf, sizeof(rx_buf), address) < 0) {
LOG_DBG("Failed to read data sample!");
return -EIO;
}
#endif
#ifdef CONFIG_SHT3XD_PERIODIC_MODE
u8_t tx_buf[2] = {
SHT3XD_CMD_FETCH >> 8,
SHT3XD_CMD_FETCH & 0xFF
};
if (i2c_write_read(i2c, address, tx_buf, sizeof(tx_buf),
rx_buf, sizeof(rx_buf)) < 0) {
LOG_DBG("Failed to read data sample!");
return -EIO;
}
#endif
t_sample = (rx_buf[0] << 8) | rx_buf[1];
if (sht3xd_compute_crc(t_sample) != rx_buf[2]) {
LOG_DBG("Received invalid temperature CRC!");
return -EIO;
}
rh_sample = (rx_buf[3] << 8) | rx_buf[4];
if (sht3xd_compute_crc(rh_sample) != rx_buf[5]) {
LOG_DBG("Received invalid relative humidity CRC!");
return -EIO;
}
data->t_sample = t_sample;
data->rh_sample = rh_sample;
return 0;
}
static int sht3xd_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
const struct sht3xd_data *data = dev->driver_data;
u64_t tmp;
/*
* See datasheet "Conversion of Signal Output" section
* for more details on processing sample data.
*/
if (chan == SENSOR_CHAN_AMBIENT_TEMP) {
/* val = -45 + 175 * sample / (2^16 -1) */
tmp = (u64_t)data->t_sample * 175U;
val->val1 = (s32_t)(tmp / 0xFFFF) - 45;
val->val2 = ((tmp % 0xFFFF) * 1000000U) / 0xFFFF;
} else if (chan == SENSOR_CHAN_HUMIDITY) {
/* val = 100 * sample / (2^16 -1) */
u32_t tmp2 = (u32_t)data->rh_sample * 100U;
val->val1 = tmp2 / 0xFFFF;
/* x * 100000 / 65536 == x * 15625 / 1024 */
val->val2 = (tmp2 % 0xFFFF) * 15625U / 1024;
} else {
return -ENOTSUP;
}
return 0;
}
static const struct sensor_driver_api sht3xd_driver_api = {
#ifdef CONFIG_SHT3XD_TRIGGER
.attr_set = sht3xd_attr_set,
.trigger_set = sht3xd_trigger_set,
#endif
.sample_fetch = sht3xd_sample_fetch,
.channel_get = sht3xd_channel_get,
};
static int sht3xd_init(struct device *dev)
{
struct sht3xd_data *data = dev->driver_data;
const struct sht3xd_config *cfg = dev->config_info;
struct device *i2c = device_get_binding(cfg->bus_name);
if (i2c == NULL) {
LOG_DBG("Failed to get pointer to %s device!",
cfg->bus_name);
return -EINVAL;
}
data->bus = i2c;
if (!cfg->base_address) {
LOG_DBG("No I2C address");
return -EINVAL;
}
data->dev = dev;
/* clear status register */
if (sht3xd_write_command(dev, SHT3XD_CMD_CLEAR_STATUS) < 0) {
LOG_DBG("Failed to clear status register!");
return -EIO;
}
k_busy_wait(SHT3XD_CLEAR_STATUS_WAIT_USEC);
#ifdef CONFIG_SHT3XD_PERIODIC_MODE
/* set periodic measurement mode */
if (sht3xd_write_command(dev,
measure_cmd[SHT3XD_MPS_IDX][SHT3XD_REPEATABILITY_IDX])
< 0) {
LOG_DBG("Failed to set measurement mode!");
return -EIO;
}
k_busy_wait(measure_wait[SHT3XD_REPEATABILITY_IDX]);
#endif
#ifdef CONFIG_SHT3XD_TRIGGER
if (sht3xd_init_interrupt(dev) < 0) {
LOG_DBG("Failed to initialize interrupt");
return -EIO;
}
#endif
return 0;
}
struct sht3xd_data sht3xd0_driver;
static const struct sht3xd_config sht3xd0_cfg = {
.bus_name = DT_INST_BUS_LABEL(0),
#ifdef CONFIG_SHT3XD_TRIGGER
.alert_gpio_name = DT_INST_GPIO_LABEL(0, alert_gpios),
#endif
.base_address = DT_INST_REG_ADDR(0),
#ifdef CONFIG_SHT3XD_TRIGGER
.alert_pin = DT_INST_GPIO_PIN(0, alert_gpios),
.alert_flags = DT_INST_GPIO_FLAGS(0, alert_gpios),
#endif
};
DEVICE_AND_API_INIT(sht3xd0, DT_INST_LABEL(0),
sht3xd_init, &sht3xd0_driver, &sht3xd0_cfg,
POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
&sht3xd_driver_api);