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/*
* 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 "bma280.h"
static int bma280_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct bma280_data *drv_data = dev->driver_data;
uint8_t buf[6];
uint8_t lsb;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
/*
* 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, BMA280_I2C_ADDRESS,
BMA280_REG_ACCEL_X_LSB, buf, 6) < 0) {
SYS_LOG_DBG("Could not read accel axis data");
return -EIO;
}
lsb = (buf[0] & BMA280_ACCEL_LSB_MASK) >> BMA280_ACCEL_LSB_SHIFT;
drv_data->x_sample = (((int8_t)buf[1]) << BMA280_ACCEL_LSB_BITS) | lsb;
lsb = (buf[2] & BMA280_ACCEL_LSB_MASK) >> BMA280_ACCEL_LSB_SHIFT;
drv_data->y_sample = (((int8_t)buf[3]) << BMA280_ACCEL_LSB_BITS) | lsb;
lsb = (buf[4] & BMA280_ACCEL_LSB_MASK) >> BMA280_ACCEL_LSB_SHIFT;
drv_data->z_sample = (((int8_t)buf[5]) << BMA280_ACCEL_LSB_BITS) | lsb;
if (i2c_reg_read_byte(drv_data->i2c, BMA280_I2C_ADDRESS,
BMA280_REG_TEMP,
(uint8_t *)&drv_data->temp_sample) < 0) {
SYS_LOG_DBG("Could not read temperature data");
return -EIO;
}
return 0;
}
static void bma280_channel_accel_convert(struct sensor_value *val,
int64_t raw_val)
{
/*
* accel_val = (sample * BMA280_PMU_FULL_RAGE) /
* (2^data_width * 10^6)
*/
val->type = SENSOR_VALUE_TYPE_INT_PLUS_MICRO;
raw_val = (raw_val * BMA280_PMU_FULL_RANGE) /
(1 << (8 + BMA280_ACCEL_LSB_BITS));
val->val1 = raw_val / 1000000;
val->val2 = raw_val % 1000000;
/* normalize val to make sure val->val2 is positive */
if (val->val2 < 0) {
val->val1 -= 1;
val->val2 += 1000000;
}
}
static int bma280_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct bma280_data *drv_data = dev->driver_data;
/*
* See datasheet "Sensor data" section for
* more details on processing sample data.
*/
if (chan == SENSOR_CHAN_ACCEL_X) {
bma280_channel_accel_convert(val, drv_data->x_sample);
} else if (chan == SENSOR_CHAN_ACCEL_Y) {
bma280_channel_accel_convert(val, drv_data->y_sample);
} else if (chan == SENSOR_CHAN_ACCEL_Z) {
bma280_channel_accel_convert(val, drv_data->z_sample);
} else if (chan == SENSOR_CHAN_ACCEL_ANY) {
bma280_channel_accel_convert(val, drv_data->x_sample);
bma280_channel_accel_convert(val + 1, drv_data->y_sample);
bma280_channel_accel_convert(val + 2, drv_data->z_sample);
} else if (chan == SENSOR_CHAN_TEMP) {
/* temperature_val = 23 + sample / 2 */
val->type = SENSOR_VALUE_TYPE_INT_PLUS_MICRO;
val->val1 = (drv_data->temp_sample >> 1) + 23;
val->val2 = 500000 * (drv_data->temp_sample & 1);
return 0;
} else {
return -ENOTSUP;
}
return 0;
}
static const struct sensor_driver_api bma280_driver_api = {
#if CONFIG_BMA280_TRIGGER
.attr_set = bma280_attr_set,
.trigger_set = bma280_trigger_set,
#endif
.sample_fetch = bma280_sample_fetch,
.channel_get = bma280_channel_get,
};
int bma280_init(struct device *dev)
{
struct bma280_data *drv_data = dev->driver_data;
uint8_t id = 0;
drv_data->i2c = device_get_binding(CONFIG_BMA280_I2C_MASTER_DEV_NAME);
if (drv_data->i2c == NULL) {
SYS_LOG_DBG("Could not get pointer to %s device",
CONFIG_BMA280_I2C_MASTER_DEV_NAME);
return -EINVAL;
}
/* read device ID */
if (i2c_reg_read_byte(drv_data->i2c, BMA280_I2C_ADDRESS,
BMA280_REG_CHIP_ID, &id) < 0) {
SYS_LOG_DBG("Could not read chip id");
return -EIO;
}
if (id != BMA280_CHIP_ID) {
SYS_LOG_DBG("Unexpected chip id (%x)", id);
return -EIO;
}
if (i2c_reg_write_byte(drv_data->i2c, BMA280_I2C_ADDRESS,
BMA280_REG_PMU_BW, BMA280_PMU_BW) < 0) {
SYS_LOG_DBG("Could not set data filter bandwidth");
return -EIO;
}
/* set g-range */
if (i2c_reg_write_byte(drv_data->i2c, BMA280_I2C_ADDRESS,
BMA280_REG_PMU_RANGE, BMA280_PMU_RANGE) < 0) {
SYS_LOG_DBG("Could not set data g-range");
return -EIO;
}
#ifdef CONFIG_BMA280_TRIGGER
if (bma280_init_interrupt(dev) < 0) {
SYS_LOG_DBG("Could not initialize interrupts");
return -EIO;
}
#endif
dev->driver_api = &bma280_driver_api;
return 0;
}
struct bma280_data bma280_driver;
DEVICE_INIT(bma280, CONFIG_BMA280_NAME, bma280_init, &bma280_driver,
NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY);
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