zephyr/drivers/sensor/sensor_lis3dh.c

135 lines
3.5 KiB
C

/*
* Copyright (c) 2016 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <i2c.h>
#include <init.h>
#include <sensor.h>
#include <misc/__assert.h>
#include "sensor_lis3dh.h"
static int lis3dh_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct lis3dh_data *drv_data = dev->driver_data;
int64_t raw_val;
if (chan == SENSOR_CHAN_ACCEL_X) {
raw_val = drv_data->x_sample;
} else if (chan == SENSOR_CHAN_ACCEL_Y) {
raw_val = drv_data->y_sample;
} else if (chan == SENSOR_CHAN_ACCEL_Z) {
raw_val = drv_data->z_sample;
} else {
return -ENOTSUP;
}
/* val = raw_val * LIS3DH_ACCEL_SCALE / (10^6 * (2^16 - 1)) */
val->type = SENSOR_VALUE_TYPE_INT_PLUS_MICRO;
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;
}
return 0;
}
int lis3dh_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct lis3dh_data *drv_data = dev->driver_data;
uint8_t buf[6];
int rc;
__ASSERT(chan == SENSOR_CHAN_ALL || chan == SENSOR_CHAN_ACCEL_ANY);
/*
* since all accel data register addresses are consecutive,
* a burst read can be used to read all the samples
*/
rc = i2c_burst_read(drv_data->i2c, LIS3DH_I2C_ADDRESS,
LIS3DH_REG_ACCEL_X_LSB, buf, 6);
if (rc != 0) {
SYS_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 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;
int rc;
drv_data->i2c = device_get_binding(CONFIG_LIS3DH_I2C_MASTER_DEV_NAME);
if (drv_data->i2c == NULL) {
SYS_LOG_DBG("Could not get pointer to %s device",
CONFIG_LIS3DH_I2C_MASTER_DEV_NAME);
return -EINVAL;
}
/* enable accel measurements and set power mode and data rate */
rc = i2c_reg_write_byte(drv_data->i2c, LIS3DH_I2C_ADDRESS,
LIS3DH_REG_CTRL1, LIS3DH_ACCEL_EN_BITS |
LIS3DH_LP_EN_BIT | LIS3DH_ODR_BITS);
if (rc != 0) {
SYS_LOG_DBG("Failed to configure chip.");
}
/* set full scale range */
rc = i2c_reg_write_byte(drv_data->i2c, LIS3DH_I2C_ADDRESS,
LIS3DH_REG_CTRL4, LIS3DH_FS_BITS);
if (rc != 0) {
SYS_LOG_DBG("Failed to set full scale range.");
return -EIO;
}
#ifdef CONFIG_LIS3DH_TRIGGER
rc = lis3dh_init_interrupt(dev);
if (rc != 0) {
SYS_LOG_DBG("Failed to initialize interrupts.");
return -EIO;
}
#endif
dev->driver_api = &lis3dh_driver_api;
return 0;
}
struct lis3dh_data lis3dh_driver;
DEVICE_INIT(lis3dh, CONFIG_LIS3DH_NAME, lis3dh_init, &lis3dh_driver,
NULL, SECONDARY, CONFIG_LIS3DH_INIT_PRIORITY);