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incubator-nuttx/drivers/sensors/bmg160.c

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/****************************************************************************
* drivers/sensors/bmg160.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <string.h>
#include <nuttx/kmalloc.h>
#include <nuttx/wqueue.h>
#include <nuttx/fs/fs.h>
#include <nuttx/mutex.h>
#include <nuttx/sensors/bmg160.h>
#include <nuttx/random.h>
#if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_BMG160)
/****************************************************************************
* Private
****************************************************************************/
struct bmg160_sensor_data_s
{
int16_t x_gyr; /* Measurement result for x axis */
int16_t y_gyr; /* Measurement result for y axis */
int16_t z_gyr; /* Measurement result for z axis */
};
struct bmg160_dev_s
{
FAR struct bmg160_dev_s *flink; /* Supports a singly linked list of
* drivers */
FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */
FAR struct bmg160_config_s *config; /* Pointer to the configuration of the
* BMG160 sensor */
mutex_t datalock; /* Manages exclusive access to this
* structure */
struct bmg160_sensor_data_s data; /* The data as measured by the sensor */
struct work_s work; /* The work queue is responsible for
* retrieving the data from the sensor
* after the arrival of new data was
* signalled in an interrupt */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void bmg160_read_register(FAR struct bmg160_dev_s *dev,
uint8_t const reg_addr, uint8_t * reg_data);
static void bmg160_write_register(FAR struct bmg160_dev_s *dev,
uint8_t const reg_addr,
uint8_t const reg_data);
static void bmg160_reset(FAR struct bmg160_dev_s *dev);
static void bmg160_read_measurement_data(FAR struct bmg160_dev_s *dev);
static void bmg160_read_gyroscope_data(FAR struct bmg160_dev_s *dev,
uint16_t * x_gyr, uint16_t * y_gyr,
uint16_t * z_gyr);
static int bmg160_interrupt_handler(int irq, FAR void *context);
static void bmg160_worker(FAR void *arg);
static int bmg160_open(FAR struct file *filep);
static int bmg160_close(FAR struct file *filep);
static ssize_t bmg160_read(FAR struct file *, FAR char *, size_t);
static ssize_t bmg160_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_bmg160_fops =
{
bmg160_open, /* open */
bmg160_close, /* close */
bmg160_read, /* read */
bmg160_write, /* write */
NULL, /* seek */
NULL, /* ioctl */
NULL /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/* Single linked list to store instances of drivers */
static struct bmg160_dev_s *g_bmg160_list = NULL;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: bmg160_read_register
****************************************************************************/
static void bmg160_read_register(FAR struct bmg160_dev_s *dev,
uint8_t const reg_addr, uint8_t * reg_data)
{
/* Lock the SPI bus so that only one device can access it at the same
* time
*/
SPI_LOCK(dev->spi, true);
/* Set CS to low which selects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
/* Transmit the register address from where we want to read - the MSB needs
* to be set to indicate the read indication.
*/
SPI_SEND(dev->spi, reg_addr | 0x80);
/* Write an idle byte while receiving the required data */
*reg_data = (uint8_t) (SPI_SEND(dev->spi, 0));
/* Set CS to high which deselects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
}
/****************************************************************************
* Name: bmg160_write_register
****************************************************************************/
static void bmg160_write_register(FAR struct bmg160_dev_s *dev,
uint8_t const reg_addr,
uint8_t const reg_data)
{
/* Lock the SPI bus so that only one device can access it at the same
* time
*/
SPI_LOCK(dev->spi, true);
/* Set CS to low which selects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
/* Transmit the register address from where we want to read */
SPI_SEND(dev->spi, reg_addr);
/* Transmit the content which should be written in the register */
SPI_SEND(dev->spi, reg_data);
/* Set CS to high which deselects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
}
/****************************************************************************
* Name: bmg160_reset
****************************************************************************/
static void bmg160_reset(FAR struct bmg160_dev_s *dev)
{
bmg160_write_register(dev, BMG160_BGW_SOFTRESET_REG, 0xb6);
up_mdelay(100);
}
/****************************************************************************
* Name: bmg160_read_measurement_data
****************************************************************************/
static void bmg160_read_measurement_data(FAR struct bmg160_dev_s *dev)
{
int ret;
/* Read Gyroscope */
uint16_t x_gyr = 0;
uint16_t y_gyr = 0;
uint16_t z_gyr = 0;
bmg160_read_gyroscope_data(dev, &x_gyr, &y_gyr, &z_gyr);
/* Acquire the mutex before the data is copied */
ret = nxmutex_lock(&dev->datalock);
if (ret < 0)
{
snerr("ERROR: Could not acquire dev->datalock: %d\n", ret);
return;
}
/* Copy retrieve data to internal data structure */
dev->data.x_gyr = (int16_t) (x_gyr);
dev->data.y_gyr = (int16_t) (y_gyr);
dev->data.z_gyr = (int16_t) (z_gyr);
/* Give back the mutex */
nxmutex_unlock(&dev->datalock);
/* Feed sensor data to entropy pool */
add_sensor_randomness((x_gyr << 16) ^ (y_gyr << 8) ^ z_gyr);
}
/****************************************************************************
* Name: bmg160_read_gyroscope_data
****************************************************************************/
static void bmg160_read_gyroscope_data(FAR struct bmg160_dev_s *dev,
uint16_t * x_gyr, uint16_t * y_gyr,
uint16_t * z_gyr)
{
/* Lock the SPI bus so that only one device can access it at the same
* time
*/
SPI_LOCK(dev->spi, true);
/* Set CS to low which selects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
/* Transmit the register address from where we want to start reading. 0x80
* -> MSB is set -> Read Indication.
*/
SPI_SEND(dev->spi, (BMG160_RATE_X_LSB_REG | 0x80));
/* RX */
*x_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
*x_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
*y_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
*y_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
*z_gyr = ((uint16_t) (SPI_SEND(dev->spi, 0)) << 0); /* LSB */
*z_gyr |= ((uint16_t) (SPI_SEND(dev->spi, 0)) << 8); /* MSB */
/* Set CS to high which deselects the BMG160 */
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
}
/****************************************************************************
* Name: bmg160_interrupt_handler
****************************************************************************/
static int bmg160_interrupt_handler(int irq, FAR void *context)
{
/* This function should be called upon a rising edge on the BMG160 new data
* interrupt pin since it signals that new data has been measured.
*/
FAR struct bmg160_dev_s *priv = 0;
int ret;
/* Find out which BMG160 device caused the interrupt */
for (priv = g_bmg160_list; priv && priv->config->irq != irq;
priv = priv->flink);
DEBUGASSERT(priv != NULL);
/* Task the worker with retrieving the latest sensor data. We should not do
* this in a interrupt since it might take too long. Also we cannot lock
* the SPI bus from within an interrupt.
*/
DEBUGASSERT(priv->work.worker == NULL);
ret = work_queue(HPWORK, &priv->work, bmg160_worker, priv, 0);
if (ret < 0)
{
snerr("ERROR: Failed to queue work: %d\n", ret);
return ret;
}
return OK;
}
/****************************************************************************
* Name: bmg160_worker
****************************************************************************/
static void bmg160_worker(FAR void *arg)
{
FAR struct bmg160_dev_s *priv = (FAR struct bmg160_dev_s *)(arg);
DEBUGASSERT(priv != NULL);
/* Read out the latest sensor data */
bmg160_read_measurement_data(priv);
}
/****************************************************************************
* Name: bmg160_open
****************************************************************************/
static int bmg160_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct bmg160_dev_s *priv = inode->i_private;
#ifdef CONFIG_DEBUG_SENSORS_INFO
uint8_t reg_content;
#endif
DEBUGASSERT(priv != NULL);
/* Perform a reset */
bmg160_reset(priv);
/* Configure the sensor for our needs */
/* Enable - the full scale range FS = +/- 250 °/s */
bmg160_write_register(priv,
BMG160_RANGE_REG,
BMG160_RANGE_REG_FIX_VAL_BM |
BMG160_RANGE_REG_FSR_1_BM |
BMG160_RANGE_REG_FSR_0_BM);
/* Enable - the fastest data output rate ODR = 2000 Hz -> BW = 230 Hz */
bmg160_write_register(priv, BMG160_BW_REG, BMG160_BW_REG_ODR_0_BM);
/* Enable - new data interrupt 1 */
bmg160_write_register(priv,
BMG160_INT_EN_0_REG, BMG160_INT_EN_0_REG_DATA_EN_BM);
/* Enable - active high level interrupt 1 - push-pull interrupt */
bmg160_write_register(priv,
BMG160_INT_EN_1_REG,
BMG160_INT_EN_1_REG_INT1_LVL_BM);
/* Enable - map new data interrupt to INT1 */
bmg160_write_register(priv,
BMG160_INT_MAP_1_REG,
BMG160_INT_MAP_1_REG_INT1_DATA_BM);
/* Read measurement data to ensure DRDY is low */
bmg160_read_measurement_data(priv);
#ifdef CONFIG_DEBUG_SENSORS_INFO
/* Read back the content of all control registers for debug purposes */
reg_content = 0;
bmg160_read_register(priv, BMG160_RANGE_REG, &reg_content);
sninfo("BMG160_RANGE_REG = %04x\n", reg_content);
bmg160_read_register(priv, BMG160_BW_REG, &reg_content);
sninfo("BMG160_BW_REG = %04x\n", reg_content);
bmg160_read_register(priv, BMG160_INT_EN_0_REG, &reg_content);
sninfo("BMG160_INT_EN_0_REG = %04x\n", reg_content);
bmg160_read_register(priv, BMG160_INT_EN_1_REG, &reg_content);
sninfo("BMG160_INT_EN_1_REG = %04x\n", reg_content);
bmg160_read_register(priv, BMG160_INT_MAP_1_REG, &reg_content);
sninfo("BMG160_INT_MAP_1_REG = %04x\n", reg_content);
#endif
return OK;
}
/****************************************************************************
* Name: bmg160_close
****************************************************************************/
static int bmg160_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct bmg160_dev_s *priv = inode->i_private;
DEBUGASSERT(priv != NULL);
/* Perform a reset */
bmg160_reset(priv);
return OK;
}
/****************************************************************************
* Name: bmg160_read
****************************************************************************/
static ssize_t bmg160_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct bmg160_dev_s *priv = inode->i_private;
FAR struct bmg160_sensor_data_s *data;
int ret;
DEBUGASSERT(priv != NULL);
/* Check if enough memory was provided for the read call */
if (buflen < sizeof(FAR struct bmg160_sensor_data_s))
{
snerr("ERROR: "
"Not enough memory for reading out a sensor data sample\n");
return -ENOSYS;
}
/* Acquire the mutex before the data is copied */
ret = nxmutex_lock(&priv->datalock);
if (ret < 0)
{
snerr("ERROR: Could not acquire priv->datalock: %d\n", ret);
return ret;
}
/* Copy the sensor data into the buffer */
data = (FAR struct bmg160_sensor_data_s *)buffer;
memset(data, 0, sizeof(FAR struct bmg160_sensor_data_s));
data->x_gyr = priv->data.x_gyr;
data->y_gyr = priv->data.y_gyr;
data->z_gyr = priv->data.z_gyr;
/* Give back the mutex */
nxmutex_unlock(&priv->datalock);
return sizeof(FAR struct bmg160_sensor_data_s);
}
/****************************************************************************
* Name: bmg160_write
****************************************************************************/
static ssize_t bmg160_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: bmg160_register
*
* Description:
* Register the BMG160 character device as 'devpath'
*
* Input Parameters:
* devpath - The full path to the driver to register. E.g., "/dev/gyr0"
* spi - An instance of the SPI interface to use to communicate with
* BMG160
* config - configuration for the BMG160 driver. For details see
* description above.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int bmg160_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
FAR struct bmg160_config_s *config)
{
FAR struct bmg160_dev_s *priv;
int ret;
/* Sanity check */
DEBUGASSERT(spi != NULL);
DEBUGASSERT(config != NULL);
/* Initialize the BMG160 device structure */
priv = (FAR struct bmg160_dev_s *)kmm_malloc(sizeof(struct bmg160_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->spi = spi;
priv->config = config;
priv->work.worker = NULL;
/* Initialize sensor data access mutex */
nxmutex_init(&priv->datalock);
/* Setup SPI frequency and mode */
SPI_SETFREQUENCY(spi, BMG160_SPI_FREQUENCY);
SPI_SETMODE(spi, BMG160_SPI_MODE);
/* Attach the interrupt handler */
ret = priv->config->attach(priv->config, &bmg160_interrupt_handler);
if (ret < 0)
{
snerr("ERROR: Failed to attach interrupt\n");
nxmutex_destroy(&priv->datalock);
kmm_free(priv);
return ret;
}
/* Register the character driver */
ret = register_driver(devpath, &g_bmg160_fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
nxmutex_destroy(&priv->datalock);
kmm_free(priv);
return ret;
}
/* Since we support multiple BMG160 devices, we will need to add this new
* instance to a list of device instances so that it can be found by the
* interrupt handler based on the received IRQ number.
*/
priv->flink = g_bmg160_list;
g_bmg160_list = priv;
return OK;
}
#endif /* CONFIG_SPI && CONFIG_SENSORS_BMG160 */
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