/**************************************************************************** * drivers/sensors/mb7040.c * Character driver for the MaxBotix MB7040 Sonar * * Copyright (C) 2015 Omni Hoverboards Inc. All rights reserved. * Author: Paul Alexander Patience * * 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 #include #include #include #include #include #include #include #if defined(CONFIG_I2C) && defined(CONFIG_MB7040) /**************************************************************************** * Private Types ****************************************************************************/ struct mb7040_dev_s { FAR struct i2c_dev_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) { uint8_t regaddr; int ret; regaddr = MB7040_RANGE_REG; sndbg("addr: %02x\n", regaddr); /* Write the register address */ I2C_SETADDRESS(priv->i2c, priv->addr, 7); ret = I2C_WRITE(priv->i2c, ®addr, sizeof(regaddr)); if (ret < 0) { sndbg("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) { uint8_t buffer[2]; int ret; /* Read two bytes */ I2C_SETADDRESS(priv->i2c, priv->addr, 7); ret = I2C_READ(priv->i2c, buffer, sizeof(buffer)); if (ret < 0) { sndbg("I2C_READ failed: %d\n", ret); return ret; } *range = (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1]; sndbg("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) { uint8_t buffer[3]; int ret; sndbg("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; /* Write the register address followed by the data (no RESTART) */ I2C_SETADDRESS(priv->i2c, priv->addr, 7); ret = I2C_WRITE(priv->i2c, buffer, sizeof(buffer)); if (ret < 0) { sndbg("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; } sndbg("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); sndbg("new addr: %02x ret: %d\n", *(uint8_t *)arg, ret); break; /* Unrecognized commands */ default: sndbg("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_dev_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) { sndbg("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) { sndbg("Failed to register driver: %d\n", ret); kmm_free(priv); } return ret; } #endif /* CONFIG_I2C && CONFIG_MB7040 */