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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 <device.h>
#include <i2c.h>
#include <kernel.h>
#include <sensor.h>
#include <misc/__assert.h>
#include <misc/byteorder.h>
#include <misc/util.h>
#include "ak8975.h"
static int ak8975_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct ak8975_data *drv_data = dev->driver_data;
uint8_t buf[6];
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
AK8975_REG_CNTL, AK8975_MODE_MEASURE) < 0) {
SYS_LOG_ERR("Failed to start measurement.");
return -EIO;
}
k_busy_wait(AK8975_MEASURE_TIME_US);
if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
AK8975_REG_DATA_START, buf, 6) < 0) {
SYS_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(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct ak8975_data *drv_data = dev->driver_data;
__ASSERT_NO_MSG(chan == SENSOR_CHAN_MAGN_ANY || chan == SENSOR_CHAN_MAGN_X ||
chan == SENSOR_CHAN_MAGN_Y || chan == SENSOR_CHAN_MAGN_Z);
if (chan == SENSOR_CHAN_MAGN_ANY) {
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(struct ak8975_data *drv_data)
{
uint8_t buf[3];
if (i2c_reg_write_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
AK8975_REG_CNTL, AK8975_MODE_FUSE_ACCESS) < 0) {
SYS_LOG_ERR("Failed to set chip in fuse access mode.");
return -EIO;
}
if (i2c_burst_read(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
AK8975_REG_ADJ_DATA_START, buf, 3) < 0) {
SYS_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(struct device *dev)
{
struct ak8975_data *drv_data = dev->driver_data;
uint8_t id;
drv_data->i2c = device_get_binding(CONFIG_AK8975_I2C_MASTER_DEV_NAME);
if (drv_data->i2c == NULL) {
SYS_LOG_ERR("Failed to get pointer to %s device!",
CONFIG_AK8975_I2C_MASTER_DEV_NAME);
return -EINVAL;
}
#ifdef CONFIG_MPU9150
/* wake up MPU9150 chip */
if (i2c_reg_update_byte(drv_data->i2c, MPU9150_I2C_ADDR,
MPU9150_REG_PWR_MGMT1, MPU9150_SLEEP_EN,
0) < 0) {
SYS_LOG_ERR("Failed to wake up MPU9150 chip.");
return -EIO;
}
/* enable MPU9150 pass-though to have access to AK8975 */
if (i2c_reg_update_byte(drv_data->i2c, MPU9150_I2C_ADDR,
MPU9150_REG_BYPASS_CFG, MPU9150_I2C_BYPASS_EN,
MPU9150_I2C_BYPASS_EN) < 0) {
SYS_LOG_ERR("Failed to enable pass-through mode for MPU9150.");
return -EIO;
}
#endif
/* check chip ID */
if (i2c_reg_read_byte(drv_data->i2c, CONFIG_AK8975_I2C_ADDR,
AK8975_REG_CHIP_ID, &id) < 0) {
SYS_LOG_ERR("Failed to read chip ID.");
return -EIO;
}
if (id != AK8975_CHIP_ID) {
SYS_LOG_ERR("Invalid chip ID.");
return -EINVAL;
}
if (ak8975_read_adjustment_data(drv_data) < 0) {
return -EIO;
}
dev->driver_api = &ak8975_driver_api;
return 0;
}
struct ak8975_data ak8975_data;
DEVICE_INIT(ak8975, CONFIG_AK8975_NAME, ak8975_init, &ak8975_data,
NULL, POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY);
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