zephyr/drivers/sensor/fxos8700/fxos8700.c

411 lines
10 KiB
C

/*
* Copyright (c) 2016 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include "fxos8700.h"
#include <misc/util.h>
#include <misc/__assert.h>
static int fxos8700_sample_fetch(struct device *dev, enum sensor_channel chan)
{
const struct fxos8700_config *config = dev->config->config_info;
struct fxos8700_data *data = dev->driver_data;
u8_t buffer[FXOS8700_MAX_NUM_BYTES];
u8_t num_bytes;
s16_t *raw;
int ret = 0;
int i;
if (chan != SENSOR_CHAN_ALL) {
SYS_LOG_ERR("Unsupported sensor channel");
return -ENOTSUP;
}
k_sem_take(&data->sem, K_FOREVER);
/* Read all the channels in one I2C transaction. The number of bytes to
* read and the starting register address depend on the mode
* configuration (accel-only, mag-only, or hybrid).
*/
num_bytes = config->num_channels * FXOS8700_BYTES_PER_CHANNEL_NORMAL;
__ASSERT(num_bytes <= sizeof(buffer), "Too many bytes to read");
if (i2c_burst_read(data->i2c, config->i2c_address, config->start_addr,
buffer, num_bytes)) {
SYS_LOG_ERR("Could not fetch sample");
ret = -EIO;
goto exit;
}
/* Parse the buffer into raw channel data (16-bit integers). To save
* RAM, store the data in raw format and wait to convert to the
* normalized sensor_value type until later.
*/
__ASSERT(config->start_channel + config->num_channels
<= ARRAY_SIZE(data->raw),
"Too many channels");
raw = &data->raw[config->start_channel];
for (i = 0; i < num_bytes; i += 2) {
*raw++ = (buffer[i] << 8) | (buffer[i+1]);
}
#ifdef CONFIG_FXOS8700_TEMP
if (i2c_reg_read_byte(data->i2c, config->i2c_address, FXOS8700_REG_TEMP,
&data->temp)) {
SYS_LOG_ERR("Could not fetch temperature");
ret = -EIO;
goto exit;
}
#endif
exit:
k_sem_give(&data->sem);
return ret;
}
static void fxos8700_accel_convert(struct sensor_value *val, s16_t raw,
enum fxos8700_range range)
{
u8_t frac_bits;
s64_t micro_ms2;
/* The range encoding is convenient to compute the number of fractional
* bits:
* - 2g mode (range = 0) has 14 fractional bits
* - 4g mode (range = 1) has 13 fractional bits
* - 8g mode (range = 2) has 12 fractional bits
*/
frac_bits = 14 - range;
/* Convert units to micro m/s^2. Intermediate results before the shift
* are 40 bits wide.
*/
micro_ms2 = (raw * SENSOR_G) >> frac_bits;
/* The maximum possible value is 8g, which in units of micro m/s^2
* always fits into 32-bits. Cast down to s32_t so we can use a
* faster divide.
*/
val->val1 = (s32_t) micro_ms2 / 1000000;
val->val2 = (s32_t) micro_ms2 % 1000000;
}
static void fxos8700_magn_convert(struct sensor_value *val, s16_t raw)
{
s32_t micro_g;
/* Convert units to micro Gauss. Raw magnetic data always has a
* resolution of 0.1 uT/LSB, which is equivalent to 0.001 G/LSB.
*/
micro_g = raw * 1000;
val->val1 = micro_g / 1000000;
val->val2 = micro_g % 1000000;
}
#ifdef CONFIG_FXOS8700_TEMP
static void fxos8700_temp_convert(struct sensor_value *val, s8_t raw)
{
s32_t micro_c;
/* Convert units to micro Celsius. Raw temperature data always has a
* resolution of 0.96 deg C/LSB.
*/
micro_c = raw * 960 * 1000;
val->val1 = micro_c / 1000000;
val->val2 = micro_c % 1000000;
}
#endif
static int fxos8700_channel_get(struct device *dev, enum sensor_channel chan,
struct sensor_value *val)
{
const struct fxos8700_config *config = dev->config->config_info;
struct fxos8700_data *data = dev->driver_data;
int start_channel;
int num_channels;
s16_t *raw;
int ret;
int i;
k_sem_take(&data->sem, K_FOREVER);
/* Start with an error return code by default, then clear it if we find
* a supported sensor channel.
*/
ret = -ENOTSUP;
/* If we're in an accelerometer-enabled mode (accel-only or hybrid),
* then convert raw accelerometer data to the normalized sensor_value
* type.
*/
if (config->mode != FXOS8700_MODE_MAGN) {
switch (chan) {
case SENSOR_CHAN_ACCEL_X:
start_channel = FXOS8700_CHANNEL_ACCEL_X;
num_channels = 1;
break;
case SENSOR_CHAN_ACCEL_Y:
start_channel = FXOS8700_CHANNEL_ACCEL_Y;
num_channels = 1;
break;
case SENSOR_CHAN_ACCEL_Z:
start_channel = FXOS8700_CHANNEL_ACCEL_Z;
num_channels = 1;
break;
case SENSOR_CHAN_ACCEL_XYZ:
start_channel = FXOS8700_CHANNEL_ACCEL_X;
num_channels = 3;
break;
default:
start_channel = 0;
num_channels = 0;
break;
}
raw = &data->raw[start_channel];
for (i = 0; i < num_channels; i++) {
fxos8700_accel_convert(val++, *raw++, config->range);
}
if (num_channels > 0) {
ret = 0;
}
}
/* If we're in an magnetometer-enabled mode (mag-only or hybrid), then
* convert raw magnetometer data to the normalized sensor_value type.
*/
if (config->mode != FXOS8700_MODE_ACCEL) {
switch (chan) {
case SENSOR_CHAN_MAGN_X:
start_channel = FXOS8700_CHANNEL_MAGN_X;
num_channels = 1;
break;
case SENSOR_CHAN_MAGN_Y:
start_channel = FXOS8700_CHANNEL_MAGN_Y;
num_channels = 1;
break;
case SENSOR_CHAN_MAGN_Z:
start_channel = FXOS8700_CHANNEL_MAGN_Z;
num_channels = 1;
break;
case SENSOR_CHAN_MAGN_XYZ:
start_channel = FXOS8700_CHANNEL_MAGN_X;
num_channels = 3;
break;
default:
start_channel = 0;
num_channels = 0;
break;
}
raw = &data->raw[start_channel];
for (i = 0; i < num_channels; i++) {
fxos8700_magn_convert(val++, *raw++);
}
if (num_channels > 0) {
ret = 0;
}
#ifdef CONFIG_FXOS8700_TEMP
if (chan == SENSOR_CHAN_DIE_TEMP) {
fxos8700_temp_convert(val, data->temp);
ret = 0;
}
#endif
}
if (ret != 0) {
SYS_LOG_ERR("Unsupported sensor channel");
}
k_sem_give(&data->sem);
return ret;
}
int fxos8700_get_power(struct device *dev, enum fxos8700_power *power)
{
const struct fxos8700_config *config = dev->config->config_info;
struct fxos8700_data *data = dev->driver_data;
u8_t val = *power;
if (i2c_reg_read_byte(data->i2c, config->i2c_address,
FXOS8700_REG_CTRLREG1,
&val)) {
SYS_LOG_ERR("Could not get power setting");
return -EIO;
}
val &= FXOS8700_M_CTRLREG1_MODE_MASK;
*power = val;
return 0;
}
int fxos8700_set_power(struct device *dev, enum fxos8700_power power)
{
const struct fxos8700_config *config = dev->config->config_info;
struct fxos8700_data *data = dev->driver_data;
return i2c_reg_update_byte(data->i2c, config->i2c_address,
FXOS8700_REG_CTRLREG1,
FXOS8700_CTRLREG1_ACTIVE_MASK,
power);
}
static int fxos8700_init(struct device *dev)
{
const struct fxos8700_config *config = dev->config->config_info;
struct fxos8700_data *data = dev->driver_data;
u8_t whoami;
/* Get the I2C device */
data->i2c = device_get_binding(config->i2c_name);
if (data->i2c == NULL) {
SYS_LOG_ERR("Could not find I2C device");
return -EINVAL;
}
/* Read the WHOAMI register to make sure we are talking to FXOS8700 and
* not some other type of device that happens to have the same I2C
* address.
*/
if (i2c_reg_read_byte(data->i2c, config->i2c_address,
FXOS8700_REG_WHOAMI, &whoami)) {
SYS_LOG_ERR("Could not get WHOAMI value");
return -EIO;
}
if (whoami != config->whoami) {
SYS_LOG_ERR("WHOAMI value received 0x%x, expected 0x%x",
whoami, FXOS8700_REG_WHOAMI);
return -EIO;
}
/* Reset the sensor. Upon issuing a software reset command over the I2C
* interface, the sensor immediately resets and does not send any
* acknowledgment (ACK) of the written byte to the master. Therefore,
* do not check the return code of the I2C transaction.
*/
i2c_reg_write_byte(data->i2c, config->i2c_address,
FXOS8700_REG_CTRLREG2, FXOS8700_CTRLREG2_RST_MASK);
/* The sensor requires us to wait 1 ms after a software reset before
* attempting further communications.
*/
k_busy_wait(USEC_PER_MSEC);
/* Set the mode (accel-only, mag-only, or hybrid) */
if (i2c_reg_update_byte(data->i2c, config->i2c_address,
FXOS8700_REG_M_CTRLREG1,
FXOS8700_M_CTRLREG1_MODE_MASK,
config->mode)) {
SYS_LOG_ERR("Could not set mode");
return -EIO;
}
/* Set hybrid autoincrement so we can read accel and mag channels in
* one I2C transaction.
*/
if (i2c_reg_update_byte(data->i2c, config->i2c_address,
FXOS8700_REG_M_CTRLREG2,
FXOS8700_M_CTRLREG2_AUTOINC_MASK,
FXOS8700_M_CTRLREG2_AUTOINC_MASK)) {
SYS_LOG_ERR("Could not set hybrid autoincrement");
return -EIO;
}
/* Set the full-scale range */
if (i2c_reg_update_byte(data->i2c, config->i2c_address,
FXOS8700_REG_XYZ_DATA_CFG,
FXOS8700_XYZ_DATA_CFG_FS_MASK,
config->range)) {
SYS_LOG_ERR("Could not set range");
return -EIO;
}
#if CONFIG_FXOS8700_TRIGGER
if (fxos8700_trigger_init(dev)) {
SYS_LOG_ERR("Could not initialize interrupts");
return -EIO;
}
#endif
/* Set active */
if (fxos8700_set_power(dev, FXOS8700_POWER_ACTIVE)) {
SYS_LOG_ERR("Could not set active");
return -EIO;
}
k_sem_init(&data->sem, 1, UINT_MAX);
SYS_LOG_DBG("Init complete");
return 0;
}
static const struct sensor_driver_api fxos8700_driver_api = {
.sample_fetch = fxos8700_sample_fetch,
.channel_get = fxos8700_channel_get,
#if CONFIG_FXOS8700_TRIGGER
.trigger_set = fxos8700_trigger_set,
#endif
};
static const struct fxos8700_config fxos8700_config = {
.i2c_name = CONFIG_FXOS8700_I2C_NAME,
.i2c_address = CONFIG_FXOS8700_I2C_ADDRESS,
.whoami = CONFIG_FXOS8700_WHOAMI,
#ifdef CONFIG_FXOS8700_MODE_ACCEL
.mode = FXOS8700_MODE_ACCEL,
.start_addr = FXOS8700_REG_OUTXMSB,
.start_channel = FXOS8700_CHANNEL_ACCEL_X,
.num_channels = FXOS8700_NUM_ACCEL_CHANNELS,
#elif CONFIG_FXOS8700_MODE_MAGN
.mode = FXOS8700_MODE_MAGN,
.start_addr = FXOS8700_REG_M_OUTXMSB,
.start_channel = FXOS8700_CHANNEL_MAGN_X,
.num_channels = FXOS8700_NUM_MAG_CHANNELS,
#else
.mode = FXOS8700_MODE_HYBRID,
.start_addr = FXOS8700_REG_OUTXMSB,
.start_channel = FXOS8700_CHANNEL_ACCEL_X,
.num_channels = FXOS8700_NUM_HYBRID_CHANNELS,
#endif
#if CONFIG_FXOS8700_RANGE_8G
.range = FXOS8700_RANGE_8G,
#elif CONFIG_FXOS8700_RANGE_4G
.range = FXOS8700_RANGE_4G,
#else
.range = FXOS8700_RANGE_2G,
#endif
#ifdef CONFIG_FXOS8700_TRIGGER
.gpio_name = CONFIG_FXOS8700_GPIO_NAME,
.gpio_pin = CONFIG_FXOS8700_GPIO_PIN,
#endif
#ifdef CONFIG_FXOS8700_PULSE
.pulse_cfg = CONFIG_FXOS8700_PULSE_CFG,
.pulse_ths[0] = CONFIG_FXOS8700_PULSE_THSX,
.pulse_ths[1] = CONFIG_FXOS8700_PULSE_THSY,
.pulse_ths[2] = CONFIG_FXOS8700_PULSE_THSZ,
.pulse_tmlt = CONFIG_FXOS8700_PULSE_TMLT,
.pulse_ltcy = CONFIG_FXOS8700_PULSE_LTCY,
.pulse_wind = CONFIG_FXOS8700_PULSE_WIND,
#endif
};
static struct fxos8700_data fxos8700_data;
DEVICE_AND_API_INIT(fxos8700, CONFIG_FXOS8700_NAME, fxos8700_init,
&fxos8700_data, &fxos8700_config,
POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
&fxos8700_driver_api);