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incubator-nuttx/drivers/sensors/lis3dh.c

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/****************************************************************************
* drivers/sensors/lis3dh.c
*
* Copyright (C) 2018 Extent3D. All rights reserved.
* Author: Matt Thompson <matt@extent3d.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <errno.h>
#include <debug.h>
#include <string.h>
#include <semaphore.h>
#include <nuttx/kmalloc.h>
#include <nuttx/wqueue.h>
#include <nuttx/random.h>
#include <nuttx/fs/fs.h>
#include <nuttx/sensors/lis3dh.h>
#include <nuttx/sensors/ioctl.h>
#if defined(CONFIG_SPI) && defined(CONFIG_LIS3DH)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define LIS3DH_QUEUE_MAX 32
#define LIS3DH_FIFOBUF_SIZE ((32 * 6) + 1)
/****************************************************************************
* Private Types
****************************************************************************/
struct lis3dh_dev_s
{
FAR struct lis3dh_config_s *config; /* Driver configuration */
FAR struct spi_dev_s *spi; /* Pointer to the SPI instance */
struct work_s work; /* Work Queue */
uint8_t power_mode; /* The power mode used to determine mg/digit */
uint8_t odr; /* The current output data rate */
sem_t readsem; /* Read notification semaphore */
uint8_t fifobuf[LIS3DH_FIFOBUF_SIZE]; /* Raw FIFO buffer */
struct lis3dh_sensor_data_s queue[LIS3DH_QUEUE_MAX];
sem_t queuesem; /* Queue exclusive lock */
uint8_t queue_rpos; /* Queue read position */
uint8_t queue_wpos; /* Queue write position */
uint8_t queue_count; /* Number of elements in the queue */
};
struct lis3dh_sample_s
{
int16_t x;
int16_t y;
int16_t z;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void lis3dh_read_register(FAR struct lis3dh_dev_s *dev,
uint8_t const reg_addr, uint8_t *reg_data);
static void lis3dh_write_register(FAR struct lis3dh_dev_s *dev,
uint8_t const reg_addr,
uint8_t const reg_data);
static void lis3dh_reset(FAR struct lis3dh_dev_s *dev);
static int lis3dh_ident(FAR struct lis3dh_dev_s *dev);
static int lis3dh_read_fifo(FAR struct lis3dh_dev_s *dev);
static int lis3dh_interrupt_handler(int irq, FAR void *context, FAR void *arg);
static void lis3dh_worker(FAR void *arg);
static int lis3dh_irq_enable(FAR struct lis3dh_dev_s *dev, bool enable);
static int lis3dh_fifo_enable(FAR struct lis3dh_dev_s *dev);
static int lis3dh_open(FAR struct file *filep);
static int lis3dh_close(FAR struct file *filep);
static ssize_t lis3dh_read(FAR struct file *, FAR char *buffer,
size_t buflen);
static ssize_t lis3dh_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int lis3dh_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_lis3dh_fops =
{
lis3dh_open,
lis3dh_close,
lis3dh_read,
lis3dh_write,
NULL,
lis3dh_ioctl
#ifndef CONFIG_DISABLE_POLL
, NULL
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: lis3dh_read_register
*
* Description:
* Read a single register from the LIS3DH sensor.
*
* Input Parameters:
* dev - Pointer to device driver instance
* reg_addr - LIS3DH register address
* reg_data - Pointer to uint8_t where read value will be stored
*
****************************************************************************/
static void lis3dh_read_register(FAR struct lis3dh_dev_s *dev,
uint8_t const reg_addr, uint8_t * reg_data)
{
uint8_t buffer[2];
/* 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 LIS3DH */
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
buffer[0] = reg_addr | 0x80;
buffer[1] = 0;
SPI_EXCHANGE(dev->spi, buffer, buffer, 2);
*reg_data = buffer[1];
/* Set CS to high which deselects the LIS3DH */
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
}
/****************************************************************************
* Name: lis3dh_write_register
*
* Description:
* Write a single register to the LIS3DH sensor.
*
* Input Parameters:
* dev - Pointer to device driver instance
* reg_addr - LIS3DH register address
* reg_data - Value to write into the specified register address
*
****************************************************************************/
static void lis3dh_write_register(FAR struct lis3dh_dev_s *dev,
uint8_t const reg_addr,
uint8_t const reg_data)
{
uint8_t buffer[2];
/* 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 LIS3DH */
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
buffer[0] = reg_addr;
buffer[1] = reg_data;
SPI_EXCHANGE(dev->spi, buffer, buffer, 2);
/* Set CS to high which deselects the LIS3DH */
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
}
/****************************************************************************
* Name: lis3dh_reset
*
* Description:
* Perform a software reset of the LIS3DH sensor.
*
* Input Parameters:
* dev - Pointer to device driver instance
*
****************************************************************************/
static void lis3dh_reset(FAR struct lis3dh_dev_s *dev)
{
lis3dh_write_register(dev, LIS3DH_CTRL_REG5, LIS3DH_CTRL_REG5_BOOT);
up_mdelay(100);
}
/****************************************************************************
* Name: lis3dh_ident
*
* Description:
* Identify an LIS3DH sensor on the SPI bus using the WHO_AM_I register.
*
* Input Parameters:
* dev - Pointer to device driver instance
*
* Returned Value:
* OK if the device responded with the correct ID
* -ENODEV if the device did not respond with the correct ID
*
****************************************************************************/
static int lis3dh_ident(FAR struct lis3dh_dev_s *dev)
{
uint8_t reg;
lis3dh_read_register(dev, LIS3DH_WHO_AM_I, &reg);
if (reg == LIS3DH_DEVICE_ID)
{
return OK;
}
return -ENODEV;
}
/****************************************************************************
* Name: lis3dh_queue_lock
*
* Description:
* Locks exclusive access to the ring buffer queue
*
* Input Parameters:
* dev - Pointer to device driver instance
*
****************************************************************************/
static void lis3dh_queue_lock(FAR struct lis3dh_dev_s *dev)
{
int ret;
ret = nxsem_wait(&dev->queuesem);
if (ret < 0)
{
snerr("ERROR: queuesem wait error: %d\n", ret);
return;
}
}
/****************************************************************************
* Name: lis3dh_queue_unlock
*
* Description:
* Unlocks exclusive acccess to the ring buffer queue
*
* Input Parameters:
* dev - Pointer to device driver instance
*
****************************************************************************/
static void lis3dh_queue_unlock(FAR struct lis3dh_dev_s *dev)
{
nxsem_post(&dev->queuesem);
}
/****************************************************************************
* Name: lis3dh_queue_push
*
* Description:
* Push a sensor measurement into the queue
*
* Input Parameters:
* dev - Pointer to device driver instance
*
****************************************************************************/
static int lis3dh_queue_push(FAR struct lis3dh_dev_s *dev,
struct lis3dh_sensor_data_s *data)
{
lis3dh_queue_lock(dev);
if (dev->queue_count >= LIS3DH_QUEUE_MAX)
{
lis3dh_queue_unlock(dev);
return -ENOMEM;
}
dev->queue_wpos++;
dev->queue[dev->queue_wpos % LIS3DH_QUEUE_MAX] = *data;
dev->queue_count++;
lis3dh_queue_unlock(dev);
return OK;
}
/****************************************************************************
* Name: lis3dh_queue_pop
*
* Description:
* Pops a sensor measurement from the queue
*
* Input Parameters:
* dev - Pointer to device driver instance
*
* Returned Value:
* OK if a measurement was successfully dequeued
* -EAGAIN if the queue is empty
*
****************************************************************************/
static int lis3dh_queue_pop(FAR struct lis3dh_dev_s *dev,
struct lis3dh_sensor_data_s *data)
{
lis3dh_queue_lock(dev);
if (dev->queue_count == 0)
{
lis3dh_queue_unlock(dev);
return -EAGAIN;
}
dev->queue_rpos++;
*data = dev->queue[dev->queue_rpos % LIS3DH_QUEUE_MAX];
dev->queue_count--;
lis3dh_queue_unlock(dev);
return OK;
}
/****************************************************************************
* Name: lis3dh_read_fifo
*
* Description:
* Reads the FIFO from the LIS3DH sensor, and pushes to the internal queue.
*
* Input Parameters:
* dev - Pointer to device driver instance
*
* Returned Value:
*
****************************************************************************/
static int lis3dh_read_fifo(FAR struct lis3dh_dev_s *dev)
{
uint8_t fifosrc;
uint8_t count;
int i;
/* Lock the SPI bus */
SPI_LOCK(dev->spi, true);
/* Read the FIFO source register */
dev->fifobuf[0] = LIS3DH_FIFO_SRC_REG | 0x80;
dev->fifobuf[1] = 0;
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
SPI_EXCHANGE(dev->spi, dev->fifobuf, dev->fifobuf, 2);
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
fifosrc = dev->fifobuf[1];
count = fifosrc & 0x1f;
if (fifosrc & LIS3DH_FIFO_SRC_REG_OVRN_FIFO)
{
snerr("FIFO overrun\n");
}
memset(dev->fifobuf, 0, LIS3DH_FIFOBUF_SIZE);
dev->fifobuf[0] = LIS3DH_OUT_X_L | 0xC0;
SPI_SELECT(dev->spi, dev->config->spi_devid, true);
SPI_EXCHANGE(dev->spi, dev->fifobuf, dev->fifobuf, 1 + count*6);
SPI_SELECT(dev->spi, dev->config->spi_devid, false);
/* Unlock the SPI bus */
SPI_LOCK(dev->spi, false);
for (i = 0; i < count; i++)
{
struct lis3dh_sensor_data_s data;
uint16_t x_raw;
uint16_t y_raw;
uint16_t z_raw;
int16_t x_acc;
int16_t y_acc;
int16_t z_acc;
x_raw = (uint16_t)dev->fifobuf[(i*6)+1] |
(uint16_t)dev->fifobuf[(i*6)+2] << 8;
y_raw = (uint16_t)dev->fifobuf[(i*6)+3] |
(uint16_t)dev->fifobuf[(i*6)+4] << 8;
z_raw = (uint16_t)dev->fifobuf[(i*6)+5] |
(uint16_t)dev->fifobuf[(i*6)+6] << 8;
/* The sensor left justifies the data in the register, so we must
* shift it to the right depending on the selected power mode
*/
switch (dev->power_mode)
{
case LIS3DH_POWER_LOW: /* 8 bit measurements */
x_acc = (int16_t)x_raw >> 8;
y_acc = (int16_t)y_raw >> 8;
z_acc = (int16_t)z_raw >> 8;
data.x_acc = (float)x_acc * 0.016;
data.y_acc = (float)y_acc * 0.016;
data.z_acc = (float)z_acc * 0.016;
break;
case LIS3DH_POWER_NORMAL: /* 10 bit measurements */
x_acc = (int16_t)x_raw >> 6;
y_acc = (int16_t)y_raw >> 6;
z_acc = (int16_t)z_raw >> 6;
data.x_acc = (float)x_acc * 0.004;
data.y_acc = (float)y_acc * 0.004;
data.z_acc = (float)z_acc * 0.004;
break;
case LIS3DH_POWER_HIGH: /* 12 bit measurements */
x_acc = (int16_t)x_raw >> 4;
y_acc = (int16_t)y_raw >> 4;
z_acc = (int16_t)z_raw >> 4;
data.x_acc = (float)x_acc * 0.001;
data.y_acc = (float)y_acc * 0.001;
data.z_acc = (float)z_acc * 0.001;
break;
default:
snerr("Unknown power mode\n");
return -EINVAL;
}
if (lis3dh_queue_push(dev, &data) == OK)
{
nxsem_post(&dev->readsem);
}
}
return OK;
}
/****************************************************************************
* Name: lis3dh_interrupt_handler
*
* Description:
* Interrupt service routine, queues work on high priority work queue.
*
* Input Parameters:
* irq - Interrupt request number
* context - Context pointer
* arg - Pointer to device driver instance
*
* Returned Value:
* Returns OK to indicate the interrupt has been serviced.
*
****************************************************************************/
static int lis3dh_interrupt_handler(int irq, FAR void *context, FAR void *arg)
{
/* The interrupt handler is called when the FIFO watermark is reached */
FAR struct lis3dh_dev_s *priv = (FAR struct lis3dh_dev_s *)arg;
int ret;
DEBUGASSERT(priv != NULL);
if (work_available(&priv->work))
{
ret = work_queue(HPWORK, &priv->work, lis3dh_worker, priv, 0);
if (ret < 0)
{
snerr("ERROR: Failed to queue work: %d\n", ret);
return ret;
}
}
return OK;
}
/****************************************************************************
* Name: lis3dh_worker
*
* Description:
* Worker callback executed from high priority work queue.
* Performs reading the FIFO from the sensor and pushing samples to
* the internal device driver queue.
*
* Input Parameters:
* arg - Pointer to device driver instance
*
****************************************************************************/
static void lis3dh_worker(FAR void *arg)
{
FAR struct lis3dh_dev_s *priv = (FAR struct lis3dh_dev_s *)(arg);
DEBUGASSERT(priv != NULL);
/* Read the FIFO and fill the queue */
lis3dh_read_fifo(priv);
}
/****************************************************************************
* Name: lis3dh_set_power_mode
*
* Description:
* Sets the power mode of the sensor.
*
* Input Parameters:
* dev - Pointer to device driver instance
* power_mode - LIS3DH_POWER_*
*
* Returned Value:
* OK - Power mode was set successfully
* -EINVAL - Invalid power mode argument
*
****************************************************************************/
static int lis3dh_set_power_mode(FAR struct lis3dh_dev_s *dev,
uint8_t power_mode)
{
uint8_t ctrl1;
uint8_t ctrl4;
switch (power_mode)
{
case LIS3DH_POWER_LOW:
lis3dh_read_register(dev, LIS3DH_CTRL_REG1, &ctrl1);
lis3dh_read_register(dev, LIS3DH_CTRL_REG4, &ctrl4);
ctrl1 |= LIS3DH_CTRL_REG1_LPEN;
ctrl4 &= ~LIS3DH_CTRL_REG4_HR;
lis3dh_write_register(dev, LIS3DH_CTRL_REG1, ctrl1);
lis3dh_write_register(dev, LIS3DH_CTRL_REG4, ctrl4);
break;
case LIS3DH_POWER_NORMAL:
lis3dh_read_register(dev, LIS3DH_CTRL_REG1, &ctrl1);
lis3dh_read_register(dev, LIS3DH_CTRL_REG4, &ctrl4);
ctrl1 &= ~LIS3DH_CTRL_REG1_LPEN;
ctrl4 &= ~LIS3DH_CTRL_REG4_HR;
lis3dh_write_register(dev, LIS3DH_CTRL_REG1, ctrl1);
lis3dh_write_register(dev, LIS3DH_CTRL_REG4, ctrl4);
break;
case LIS3DH_POWER_HIGH:
lis3dh_read_register(dev, LIS3DH_CTRL_REG1, &ctrl1);
lis3dh_read_register(dev, LIS3DH_CTRL_REG4, &ctrl4);
ctrl1 &= ~LIS3DH_CTRL_REG1_LPEN;
ctrl4 |= LIS3DH_CTRL_REG4_HR;
lis3dh_write_register(dev, LIS3DH_CTRL_REG1, ctrl1);
lis3dh_write_register(dev, LIS3DH_CTRL_REG4, ctrl4);
break;
default:
return -EINVAL;
break;
}
dev->power_mode = power_mode;
sninfo("Power mode set to %d\n", power_mode);
return OK;
}
/****************************************************************************
* Name: lis3dh_set_odr
*
* Description:
* Sets the output data rate of the sensor.
*
* Input Parameters:
* dev - Pointer to device driver instance
* odr - LIS3DH_ODR_*
*
* Returned Value:
* OK - Power mode was set successfully
* -EINVAL - Invalid odr argument
*
****************************************************************************/
static int lis3dh_set_odr(FAR struct lis3dh_dev_s *dev, uint8_t odr)
{
uint8_t ctrl1;
if (odr > LIS3DH_CTRL_REG1_ODR_LP_5376HZ)
{
return -EINVAL;
}
lis3dh_read_register(dev, LIS3DH_CTRL_REG1, &ctrl1);
ctrl1 |= LIS3DH_CTRL_REG1_ODR(odr) & LIS3DH_CTRL_REG1_ODR_MASK;
lis3dh_write_register(dev, LIS3DH_CTRL_REG1, ctrl1);
/* Cache the current ODR in the device structure */
dev->odr = odr;
sninfo("Output data rate set to %d\n", odr);
return OK;
}
/****************************************************************************
* Name: lis3dh_irq_enable
*
* Description:
* Enable or disable sensor interrupt generation on FIFO watermark.
*
* Input Parameters:
* dev - Pointer to device driver instance
* enable - Boolean to enable or disable the interrupt generation
*
* Returned Value:
* OK - Interrupt generation register written.
*
****************************************************************************/
static int lis3dh_irq_enable(FAR struct lis3dh_dev_s *dev, bool enable)
{
uint8_t reg;
reg = 0;
if (enable == true)
{
reg = LIS3DH_CTRL_REG3_I1_WTM;
}
lis3dh_write_register(dev, LIS3DH_CTRL_REG3, reg);
return OK;
}
/****************************************************************************
* Name: lis3dh_irq_enable
*
* Description:
* Enable or disable sensor interrupt generation on FIFO watermark.
*
* Input Parameters:
* dev - Pointer to device driver instance
* enable - Boolean to enable or disable the interrupt generation
*
* Returned Value:
* OK - Interrupt generation register written.
*
****************************************************************************/
static int lis3dh_fifo_enable(FAR struct lis3dh_dev_s *dev)
{
uint8_t reg;
lis3dh_write_register(dev, LIS3DH_FIFO_CTRL_REG,
LIS3DH_FIFO_CTRL_REG_MODE_STREAM | 28);
lis3dh_read_register(dev, LIS3DH_CTRL_REG5, &reg);
reg |= LIS3DH_CTRL_REG5_FIFO_EN;
lis3dh_write_register(dev, LIS3DH_CTRL_REG5, reg);
return OK;
}
/****************************************************************************
* Name: lis3dh_enable
*
* Description:
* Enable sensor measurements into the on-chip FIFO.
*
* Input Parameters:
* priv - Pointer to device driver instance
*
* Returned Value:
* OK - Sensor measurements enabled.
*
****************************************************************************/
static int lis3dh_enable(FAR struct lis3dh_dev_s *priv)
{
uint8_t reg;
/* Select the default power mode */
lis3dh_set_power_mode(priv, LIS3DH_POWER_NORMAL);
/* Select the default output data rate */
lis3dh_set_odr(priv, LIS3DH_ODR_1344HZ);
reg = LIS3DH_CTRL_REG4_BDU | LIS3DH_CTRL_REG4_FS_2G;
lis3dh_write_register(priv, LIS3DH_CTRL_REG4, reg);
lis3dh_fifo_enable(priv);
/* Enable X, Y, and Z axes */
lis3dh_read_register(priv, LIS3DH_CTRL_REG1, &reg);
reg |= LIS3DH_CTRL_REG1_ZEN | LIS3DH_CTRL_REG1_YEN | LIS3DH_CTRL_REG1_XEN;
lis3dh_write_register(priv, LIS3DH_CTRL_REG1, reg);
return OK;
}
/****************************************************************************
* Name: lis3dh_open
*
* Description:
* Character device open call.
*
* Input Parameters:
* filep - Pointer to struct file
*
* Returned Value:
* -ENODEV - Device was not identified on the SPI bus.
* OK - Sensor device was opened successfully.
*
****************************************************************************/
static int lis3dh_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lis3dh_dev_s *priv = inode->i_private;
DEBUGASSERT(priv != NULL);
/* Perform a reset */
lis3dh_reset(priv);
if (lis3dh_ident(priv) < 0)
{
snerr("ERROR: Failed to identify LIS3DH on SPI bus\n");
return -ENODEV;
}
/* Attach the interrupt line */
(priv->config->irq_attach)(priv->config, lis3dh_interrupt_handler, priv);
/* Enable interrupt generation on the sensor */
lis3dh_irq_enable(priv, true);
/* Enable measurements on the sensor */
if (lis3dh_enable(priv) < 0)
{
snerr("ERROR: Failed to enable LIS3DH\n");
return -ENODEV;
}
return OK;
}
/****************************************************************************
* Name: lis3dh_close
*
* Description:
* Character device close call.
*
* Input Parameters:
* filep - Pointer to struct file
*
* Returned Value:
* OK - Sensor device was closed successfully.
*
****************************************************************************/
static int lis3dh_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lis3dh_dev_s *priv = inode->i_private;
DEBUGASSERT(priv != NULL);
/* Perform a reset */
lis3dh_reset(priv);
/* Detach the interrupt line */
(priv->config->irq_detach)(priv->config);
return OK;
}
/****************************************************************************
* Name: lis3dh_read
*
* Description:
* Character device read call. Blocks until requested buffer size is full.
*
* Input Parameters:
* filep - Pointer to struct file
* buffer - Pointer to user buffer
* buflen - Size of user buffer in bytes
*
* Returned Value:
* Returns the number of bytes written to the buffer.
* -EINVAL - Supplied buffer length invalid
*
****************************************************************************/
static ssize_t lis3dh_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lis3dh_dev_s *priv = inode->i_private;
FAR struct lis3dh_sensor_data_s *data;
int count;
int remain;
DEBUGASSERT(priv != NULL);
if ((buflen % sizeof(FAR struct lis3dh_sensor_data_s)) != 0)
{
snerr("ERROR: Provided buffer must be multiple of sensor data size\n");
return -EINVAL;
}
/* Get the number of samples the user has requested */
count = buflen / sizeof(struct lis3dh_sensor_data_s);
/* Cast a pointer into the user buffer */
data = (FAR struct lis3dh_sensor_data_s *)buffer;
for (remain=count;remain > 0;remain--)
{
/* Wait for data to be available in the queue */
nxsem_wait(&priv->readsem);
/* Pop a sample off of the queue */
lis3dh_queue_pop(priv, data);
data++;
}
return count * sizeof(struct lis3dh_sensor_data_s);
}
/****************************************************************************
* Name: lis3dh_write
*
* Description:
* Character device write call. Not supported.
*
* Input Parameters:
* filep - Pointer to struct file
* buffer - Pointer to user buffer
* buflen - Size of user buffer in bytes
*
* Returned Value:
* -ENOSYS
*
****************************************************************************/
static ssize_t lis3dh_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Name: lis3dh_ioctl
*
* Description:
* Character device ioctl call. Sets device parameters.
*
* Input Parameters:
* filep - Pointer to struct file
* cmd - SNIOC_*
* arg - ioctl specific argument
*
* Returned Value:
* OK - The command was executed successfully.
* -ENOTTY - The request command is not applicable to the driver.
*
****************************************************************************/
static int lis3dh_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct lis3dh_dev_s *priv = inode->i_private;
int ret = OK;
switch (cmd)
{
case SNIOC_SET_POWER_MODE:
ret = lis3dh_set_power_mode(priv, arg);
break;
case SNIOC_SET_DATA_RATE:
ret = lis3dh_set_odr(priv, arg);
break;
default:
snerr("ERROR: Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lis3dh_register
*
* Description:
* Register the LIS3DH character device at the specified device path
*
* Input Parameters:
* devpath - Full path of device node to register ie "/dev/accel0"
* spi - SPI bus device instance
* config - Driver instance configuration structure
*
* Returned Value:
* OK on success or a negative errno value on failure.
*
****************************************************************************/
int lis3dh_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
FAR struct lis3dh_config_s *config)
{
FAR struct lis3dh_dev_s *priv;
int ret;
DEBUGASSERT(spi != NULL);
/* Initialize the LIS3DH device structure */
priv = (FAR struct lis3dh_dev_s *)kmm_malloc(sizeof(struct lis3dh_dev_s));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->config = config;
priv->spi = spi;
priv->work.worker = NULL;
priv->queue_count = 0;
/* Initialize queue semaphore */
nxsem_init(&priv->queuesem, 0, 1);
/* Initialize read notification semaphore */
nxsem_init(&priv->readsem, 0, 0);
nxsem_setprotocol(&priv->readsem, SEM_PRIO_NONE);
/* Setup SPI frequency and mode */
SPI_SETFREQUENCY(spi, LIS3DH_SPI_FREQUENCY);
SPI_SETMODE(spi, LIS3DH_SPI_MODE);
/* Register the character driver */
ret = register_driver(devpath, &g_lis3dh_fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
nxsem_destroy(&priv->queuesem);
nxsem_destroy(&priv->readsem);
return ret;
}
return OK;
}
#endif /* CONFIG_SPI && CONFIG_LIS3DH */
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