/****************************************************************************
* drivers/sensors/mb7040.c
* Character driver for the MaxBotix MB7040 Sonar
*
* Copyright (C) 2015 Omni Hoverboards Inc. All rights reserved.
* Author: Paul Alexander Patience <paul-a.patience@polymtl.ca>
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <stdlib.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/sensors/mb7040.h>
#if defined(CONFIG_I2C) && defined(CONFIG_MB7040)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_MB7040_I2C_FREQUENCY
# define CONFIG_MB7040_I2C_FREQUENCY 400000
#endif
/****************************************************************************
* Private Types
****************************************************************************/
struct mb7040_dev_s
{
FAR struct i2c_master_s *i2c; /* I2C interface */
uint8_t addr; /* I2C address */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* I2C Helpers */
static int mb7040_measurerange(FAR struct mb7040_dev_s *priv);
static int mb7040_readrange(FAR struct mb7040_dev_s *priv,
FAR uint16_t *range);
static int mb7040_changeaddr(FAR struct mb7040_dev_s *priv, uint8_t addr);
/* Character Driver Methods */
static int mb7040_open(FAR struct file *filep);
static int mb7040_close(FAR struct file *filep);
static ssize_t mb7040_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t mb7040_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int mb7040_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_fops =
{
mb7040_open,
mb7040_close,
mb7040_read,
mb7040_write,
NULL,
mb7040_ioctl
#ifndef CONFIG_DISABLE_POLL
, NULL
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mb7040_measurerange
*
* Description:
* Command the device to measure the range.
*
****************************************************************************/
static int mb7040_measurerange(FAR struct mb7040_dev_s *priv)
{
struct i2c_config_s config;
uint8_t regaddr;
int ret;
sninfo("addr: %02x\n", regaddr);
/* Set up the I2C configuration */
config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Write the register address */
regaddr = MB7040_RANGE_REG;
ret = i2c_write(priv->i2c, &config, ®addr, sizeof(regaddr));
if (ret < 0)
{
snerr("ERROR: i2c_write failed: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: mb7040_readrange
*
* Description:
* Read the range last measured by the device. The units are centimeters.
*
****************************************************************************/
static int mb7040_readrange(FAR struct mb7040_dev_s *priv,
FAR uint16_t *range)
{
struct i2c_config_s config;
uint8_t buffer[2];
int ret;
/* Set up the I2C configuration */
config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Read two bytes */
ret = i2c_read(priv->i2c, &config, buffer, sizeof(buffer));
if (ret < 0)
{
snerr("ERROR: i2c_read failed: %d\n", ret);
return ret;
}
*range = (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1];
sninfo("range: %04x ret: %d\n", *range, ret);
return ret;
}
/****************************************************************************
* Name: mb7040_changeaddr
*
* Description:
* Change the device's I2C address.
*
****************************************************************************/
static int mb7040_changeaddr(FAR struct mb7040_dev_s *priv, uint8_t addr)
{
struct i2c_config_s config;
uint8_t buffer[3];
int ret;
sninfo("new addr: %02x\n", addr);
/* Sanity check */
DEBUGASSERT((addr & 1) == 0);
DEBUGASSERT(addr != 0x00 && addr != 0x50 && addr != 0xa4 && addr != 0xaa);
/* Set up a 3-byte message to send */
buffer[0] = MB7040_ADDRUNLOCK1_REG;
buffer[1] = MB7040_ADDRUNLOCK2_REG;
buffer[2] = addr;
/* Set up the I2C configuration */
config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
config.address = priv->addr;
config.addrlen = 7;
/* Write the register address followed by the data (no RESTART) */
ret = i2c_write(priv->i2c, &config, buffer, sizeof(buffer));
if (ret < 0)
{
snerr("ERROR: i2c_write failed: %d\n", ret);
return ret;
}
priv->addr = addr;
return ret;
}
/****************************************************************************
* Name: mb7040_open
*
* Description:
* This method is called when the device is opened.
*
****************************************************************************/
static int mb7040_open(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: mb7040_close
*
* Description:
* This method is called when the device is closed.
*
****************************************************************************/
static int mb7040_close(FAR struct file *filep)
{
return OK;
}
/****************************************************************************
* Name: mb7040_read
*
* Description:
* A dummy read method.
*
****************************************************************************/
static ssize_t mb7040_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
return 0;
}
/****************************************************************************
* Name: mb7040_write
*
* Description:
* A dummy write method.
*
****************************************************************************/
static ssize_t mb7040_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
return -ENOSYS;
}
/****************************************************************************
* Name: mb7040_ioctl
*
* Description:
* The standard ioctl method.
*
****************************************************************************/
static int mb7040_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct mb7040_dev_s *priv = inode->i_private;
int ret = OK;
/* Handle ioctl commands */
switch (cmd)
{
/* Command the device to measure the range. Arg: None. */
case SNIOC_MEASURE:
DEBUGASSERT(arg == 0);
ret = mb7040_measurerange(priv);
break;
/* Read the range last measured by the device. Arg: int32_t* pointer. */
case SNIOC_RANGE:
{
FAR int32_t *ptr = (FAR int32_t *)((uintptr_t)arg);
uint16_t range = 0;
DEBUGASSERT(ptr != NULL);
ret = mb7040_readrange(priv, &range);
if (ret == OK)
{
*ptr = (int32_t)range;
}
sninfo("range: %04x ret: %d\n", *ptr, ret);
}
break;
/* Change the device's I2C address. Arg: uint8_t value. */
case SNIOC_CHANGEADDR:
ret = mb7040_changeaddr(priv, (uint8_t)arg);
sninfo("new addr: %02x ret: %d\n", *(uint8_t *)arg, ret);
break;
/* Unrecognized commands */
default:
snerr("ERROR: Unrecognized cmd: %d arg: %ld\n", cmd, arg);
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mb7040_register
*
* Description:
* Register the MB7040 character device as 'devpath'.
*
* Input Parameters:
* devpath - The full path to the driver to register, e.g., "/dev/sonar0".
* i2c - An I2C driver instance.
* addr - The I2C address of the MB7040.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure.
*
****************************************************************************/
int mb7040_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
uint8_t addr)
{
FAR struct mb7040_dev_s *priv;
int ret;
/* Sanity check */
DEBUGASSERT(i2c != NULL);
/* Initialize the device's structure */
priv = (FAR struct mb7040_dev_s *)kmm_malloc(sizeof(*priv));
if (priv == NULL)
{
snerr("ERROR: Failed to allocate instance\n");
return -ENOMEM;
}
priv->i2c = i2c;
priv->addr = addr;
/* Register the character driver */
ret = register_driver(devpath, &g_fops, 0666, priv);
if (ret < 0)
{
snerr("ERROR: Failed to register driver: %d\n", ret);
kmm_free(priv);
}
return ret;
}
#endif /* CONFIG_I2C && CONFIG_MB7040 */