zephyr/drivers/sensor/ak8975/ak8975.c

156 lines
4.0 KiB
C

/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT asahi_kasei_ak8975
#include <zephyr/device.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/kernel.h>
#include <zephyr/drivers/sensor.h>
#include <zephyr/sys/__assert.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/sys/util.h>
#include <zephyr/logging/log.h>
#include "ak8975.h"
LOG_MODULE_REGISTER(AK8975, CONFIG_SENSOR_LOG_LEVEL);
static int ak8975_sample_fetch(const struct device *dev,
enum sensor_channel chan)
{
struct ak8975_data *drv_data = dev->data;
const struct ak8975_config *drv_config = dev->config;
uint8_t buf[6];
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
if (i2c_reg_write_byte_dt(&drv_config->i2c, AK8975_REG_CNTL, AK8975_MODE_MEASURE) < 0) {
LOG_ERR("Failed to start measurement.");
return -EIO;
}
k_busy_wait(AK8975_MEASURE_TIME_US);
if (i2c_burst_read_dt(&drv_config->i2c, AK8975_REG_DATA_START, buf, 6) < 0) {
LOG_ERR("Failed to read sample data.");
return -EIO;
}
drv_data->x_sample = sys_le16_to_cpu(buf[0] | (buf[1] << 8));
drv_data->y_sample = sys_le16_to_cpu(buf[2] | (buf[3] << 8));
drv_data->z_sample = sys_le16_to_cpu(buf[4] | (buf[5] << 8));
return 0;
}
static void ak8975_convert(struct sensor_value *val, int16_t sample,
uint8_t adjustment)
{
int32_t conv_val;
conv_val = sample * AK8975_MICRO_GAUSS_PER_BIT *
((uint16_t)adjustment + 128) / 256;
val->val1 = conv_val / 1000000;
val->val2 = conv_val % 1000000;
}
static int ak8975_channel_get(const struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct ak8975_data *drv_data = dev->data;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_MAGN_XYZ ||
chan == SENSOR_CHAN_MAGN_X ||
chan == SENSOR_CHAN_MAGN_Y ||
chan == SENSOR_CHAN_MAGN_Z);
if (chan == SENSOR_CHAN_MAGN_XYZ) {
ak8975_convert(val, drv_data->x_sample, drv_data->x_adj);
ak8975_convert(val + 1, drv_data->y_sample, drv_data->y_adj);
ak8975_convert(val + 2, drv_data->z_sample, drv_data->z_adj);
} else if (chan == SENSOR_CHAN_MAGN_X) {
ak8975_convert(val, drv_data->x_sample, drv_data->x_adj);
} else if (chan == SENSOR_CHAN_MAGN_Y) {
ak8975_convert(val, drv_data->y_sample, drv_data->y_adj);
} else { /* chan == SENSOR_CHAN_MAGN_Z */
ak8975_convert(val, drv_data->z_sample, drv_data->z_adj);
}
return 0;
}
static const struct sensor_driver_api ak8975_driver_api = {
.sample_fetch = ak8975_sample_fetch,
.channel_get = ak8975_channel_get,
};
static int ak8975_read_adjustment_data(const struct device *dev)
{
struct ak8975_data *drv_data = dev->data;
const struct ak8975_config *drv_config = dev->config;
uint8_t buf[3];
if (i2c_reg_write_byte_dt(&drv_config->i2c, AK8975_REG_CNTL, AK8975_MODE_FUSE_ACCESS) < 0) {
LOG_ERR("Failed to set chip in fuse access mode.");
return -EIO;
}
if (i2c_burst_read_dt(&drv_config->i2c, AK8975_REG_ADJ_DATA_START, buf, 3) < 0) {
LOG_ERR("Failed to read adjustment data.");
return -EIO;
}
drv_data->x_adj = buf[0];
drv_data->y_adj = buf[1];
drv_data->z_adj = buf[2];
return 0;
}
int ak8975_init(const struct device *dev)
{
const struct ak8975_config *drv_config = dev->config;
uint8_t id;
if (!device_is_ready(drv_config->i2c.bus)) {
LOG_ERR("I2C bus device not ready");
return -ENODEV;
}
/* check chip ID */
if (i2c_reg_read_byte_dt(&drv_config->i2c, AK8975_REG_CHIP_ID, &id) < 0) {
LOG_ERR("Failed to read chip ID.");
return -EIO;
}
if (id != AK8975_CHIP_ID) {
LOG_ERR("Invalid chip ID.");
return -EINVAL;
}
if (ak8975_read_adjustment_data(dev) < 0) {
return -EIO;
}
return 0;
}
#define AK8975_DEFINE(inst) \
static struct ak8975_data ak8975_data_##inst; \
\
static const struct ak8975_config ak8975_config_##inst = { \
.i2c = I2C_DT_SPEC_INST_GET(inst), \
}; \
\
DEVICE_DT_INST_DEFINE(inst, ak8975_init, NULL, \
&ak8975_data_##inst, &ak8975_config_##inst, \
POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY, \
&ak8975_driver_api); \
DT_INST_FOREACH_STATUS_OKAY(AK8975_DEFINE)