zephyr/drivers/sensor/lis3dh/lis3dh.c

129 lines
3.3 KiB
C

/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <i2c.h>
#include <init.h>
#include <sensor.h>
#include <misc/__assert.h>
#include <logging/log.h>
#include "lis3dh.h"
#define LOG_LEVEL CONFIG_SENSOR_LOG_LEVEL
LOG_MODULE_REGISTER(LIS3DH);
static void lis3dh_convert(struct sensor_value *val, s64_t raw_val)
{
/* val = raw_val * LIS3DH_ACCEL_SCALE / (10^6 * (2^16 - 1)) */
raw_val = raw_val * LIS3DH_ACCEL_SCALE / 1000000;
val->val1 = raw_val / 0xFFFF;
val->val2 = (raw_val % 0xFFFF) * 1000000 / 0xFFFF;
/* normalize val to make sure val->val2 is positive */
if (val->val2 < 0) {
val->val1 -= 1;
val->val2 += 1000000;
}
}
static int lis3dh_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct lis3dh_data *drv_data = dev->driver_data;
if (chan == SENSOR_CHAN_ACCEL_X) {
lis3dh_convert(val, drv_data->x_sample);
} else if (chan == SENSOR_CHAN_ACCEL_Y) {
lis3dh_convert(val, drv_data->y_sample);
} else if (chan == SENSOR_CHAN_ACCEL_Z) {
lis3dh_convert(val, drv_data->z_sample);
} else if (chan == SENSOR_CHAN_ACCEL_XYZ) {
lis3dh_convert(val, drv_data->x_sample);
lis3dh_convert(val + 1, drv_data->y_sample);
lis3dh_convert(val + 2, drv_data->z_sample);
} else {
return -ENOTSUP;
}
return 0;
}
int lis3dh_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct lis3dh_data *drv_data = dev->driver_data;
u8_t buf[6];
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL ||
chan == SENSOR_CHAN_ACCEL_XYZ);
/*
* since all accel data register addresses are consecutive,
* a burst read can be used to read all the samples
*/
if (i2c_burst_read(drv_data->i2c, LIS3DH_I2C_ADDRESS,
(LIS3DH_REG_ACCEL_X_LSB | LIS3DH_AUTOINCREMENT_ADDR),
buf, 6) < 0) {
LOG_DBG("Could not read accel axis data");
return -EIO;
}
drv_data->x_sample = (buf[1] << 8) | buf[0];
drv_data->y_sample = (buf[3] << 8) | buf[2];
drv_data->z_sample = (buf[5] << 8) | buf[4];
return 0;
}
static const struct sensor_driver_api lis3dh_driver_api = {
#if CONFIG_LIS3DH_TRIGGER
.trigger_set = lis3dh_trigger_set,
#endif
.sample_fetch = lis3dh_sample_fetch,
.channel_get = lis3dh_channel_get,
};
int lis3dh_init(struct device *dev)
{
struct lis3dh_data *drv_data = dev->driver_data;
drv_data->i2c = device_get_binding(DT_LIS3DH_I2C_MASTER_DEV_NAME);
if (drv_data->i2c == NULL) {
LOG_DBG("Could not get pointer to %s device",
DT_LIS3DH_I2C_MASTER_DEV_NAME);
return -EINVAL;
}
/* enable accel measurements and set power mode and data rate */
if (i2c_reg_write_byte(drv_data->i2c, LIS3DH_I2C_ADDRESS,
LIS3DH_REG_CTRL1, LIS3DH_ACCEL_EN_BITS |
LIS3DH_LP_EN_BIT | LIS3DH_ODR_BITS) < 0) {
LOG_DBG("Failed to configure chip.");
}
/* set full scale range */
if (i2c_reg_write_byte(drv_data->i2c, LIS3DH_I2C_ADDRESS,
LIS3DH_REG_CTRL4, LIS3DH_FS_BITS) < 0) {
LOG_DBG("Failed to set full scale range.");
return -EIO;
}
#ifdef CONFIG_LIS3DH_TRIGGER
if (lis3dh_init_interrupt(dev) < 0) {
LOG_DBG("Failed to initialize interrupts.");
return -EIO;
}
#endif
return 0;
}
struct lis3dh_data lis3dh_driver;
DEVICE_AND_API_INIT(lis3dh, DT_LIS3DH_DEV_NAME, lis3dh_init, &lis3dh_driver,
NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
&lis3dh_driver_api);