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hmc5883l.c
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hmc5883l.c
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/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/i2c.h>
#include <init.h>
#include <sys/__assert.h>
#include <sys/byteorder.h>
#include <drivers/sensor.h>
#include <string.h>
#include <logging/log.h>
#include "hmc5883l.h"
#define LOG_LEVEL CONFIG_SENSOR_LOG_LEVEL
LOG_MODULE_REGISTER(HMC5883L);
static void hmc5883l_convert(struct sensor_value *val, s16_t raw_val,
u16_t divider)
{
/* val = raw_val / divider */
val->val1 = raw_val / divider;
val->val2 = (((s64_t)raw_val % divider) * 1000000L) / divider;
}
static int hmc5883l_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
struct hmc5883l_data *drv_data = dev->driver_data;
if (chan == SENSOR_CHAN_MAGN_X) {
hmc5883l_convert(val, drv_data->x_sample,
hmc5883l_gain[drv_data->gain_idx]);
} else if (chan == SENSOR_CHAN_MAGN_Y) {
hmc5883l_convert(val, drv_data->y_sample,
hmc5883l_gain[drv_data->gain_idx]);
} else if (chan == SENSOR_CHAN_MAGN_Z) {
hmc5883l_convert(val, drv_data->z_sample,
hmc5883l_gain[drv_data->gain_idx]);
} else { /* chan == SENSOR_CHAN_MAGN_XYZ */
hmc5883l_convert(val, drv_data->x_sample,
hmc5883l_gain[drv_data->gain_idx]);
hmc5883l_convert(val + 1, drv_data->y_sample,
hmc5883l_gain[drv_data->gain_idx]);
hmc5883l_convert(val + 2, drv_data->z_sample,
hmc5883l_gain[drv_data->gain_idx]);
}
return 0;
}
static int hmc5883l_sample_fetch(struct device *dev, enum sensor_channel chan)
{
struct hmc5883l_data *drv_data = dev->driver_data;
s16_t buf[3];
__ASSERT_NO_MSG(chan == SENSOR_CHAN_ALL);
/* fetch magnetometer sample */
if (i2c_burst_read(drv_data->i2c, HMC5883L_I2C_ADDR,
HMC5883L_REG_DATA_START, (u8_t *)buf, 6) < 0) {
LOG_ERR("Failed to fetch megnetometer sample.");
return -EIO;
}
drv_data->x_sample = sys_be16_to_cpu(buf[0]);
drv_data->z_sample = sys_be16_to_cpu(buf[1]);
drv_data->y_sample = sys_be16_to_cpu(buf[2]);
return 0;
}
static const struct sensor_driver_api hmc5883l_driver_api = {
#if CONFIG_HMC5883L_TRIGGER
.trigger_set = hmc5883l_trigger_set,
#endif
.sample_fetch = hmc5883l_sample_fetch,
.channel_get = hmc5883l_channel_get,
};
int hmc5883l_init(struct device *dev)
{
struct hmc5883l_data *drv_data = dev->driver_data;
u8_t chip_cfg[3], id[3], idx;
drv_data->i2c = device_get_binding(CONFIG_HMC5883L_I2C_MASTER_DEV_NAME);
if (drv_data->i2c == NULL) {
LOG_ERR("Failed to get pointer to %s device.",
CONFIG_HMC5883L_I2C_MASTER_DEV_NAME);
return -EINVAL;
}
/* check chip ID */
if (i2c_burst_read(drv_data->i2c, HMC5883L_I2C_ADDR,
HMC5883L_REG_CHIP_ID, id, 3) < 0) {
LOG_ERR("Failed to read chip ID.");
return -EIO;
}
if (id[0] != HMC5883L_CHIP_ID_A || id[1] != HMC5883L_CHIP_ID_B ||
id[2] != HMC5883L_CHIP_ID_C) {
LOG_ERR("Invalid chip ID.");
return -EINVAL;
}
/* check if CONFIG_HMC5883L_FS is valid */
for (idx = 0U; idx < ARRAY_SIZE(hmc5883l_fs_strings); idx++) {
if (!strcmp(hmc5883l_fs_strings[idx], CONFIG_HMC5883L_FS)) {
break;
}
}
if (idx == ARRAY_SIZE(hmc5883l_fs_strings)) {
LOG_ERR("Invalid full-scale range value.");
return -EINVAL;
}
drv_data->gain_idx = idx;
/* check if CONFIG_HMC5883L_ODR is valid */
for (idx = 0U; idx < ARRAY_SIZE(hmc5883l_odr_strings); idx++) {
if (!strcmp(hmc5883l_odr_strings[idx], CONFIG_HMC5883L_ODR)) {
break;
}
}
if (idx == ARRAY_SIZE(hmc5883l_odr_strings)) {
LOG_ERR("Invalid ODR value.");
return -EINVAL;
}
/* configure device */
chip_cfg[0] = idx << HMC5883L_ODR_SHIFT;
chip_cfg[1] = drv_data->gain_idx << HMC5883L_GAIN_SHIFT;
chip_cfg[2] = HMC5883L_MODE_CONTINUOUS;
if (i2c_burst_write(drv_data->i2c, HMC5883L_I2C_ADDR,
HMC5883L_REG_CONFIG_A, chip_cfg, 3) < 0) {
LOG_ERR("Failed to configure chip.");
return -EIO;
}
#ifdef CONFIG_HMC5883L_TRIGGER
if (hmc5883l_init_interrupt(dev) < 0) {
LOG_ERR("Failed to initialize interrupts.");
return -EIO;
}
#endif
return 0;
}
struct hmc5883l_data hmc5883l_driver;
DEVICE_AND_API_INIT(hmc5883l, CONFIG_HMC5883L_NAME, hmc5883l_init,
&hmc5883l_driver, NULL, POST_KERNEL,
CONFIG_SENSOR_INIT_PRIORITY, &hmc5883l_driver_api);