359 lines
9.9 KiB
C
359 lines
9.9 KiB
C
/****************************************************************************
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* drivers/sensors/mb7040.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <assert.h>
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#include <errno.h>
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#include <debug.h>
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#include <stdlib.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/i2c/i2c_master.h>
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#include <nuttx/sensors/mb7040.h>
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#include <nuttx/random.h>
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#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_MB7040)
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#ifndef CONFIG_MB7040_I2C_FREQUENCY
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# define CONFIG_MB7040_I2C_FREQUENCY 400000
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#endif
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/****************************************************************************
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* Private Types
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****************************************************************************/
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struct mb7040_dev_s
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{
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FAR struct i2c_master_s *i2c; /* I2C interface */
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uint8_t addr; /* I2C address */
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};
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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/* I2C Helpers */
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static int mb7040_measurerange(FAR struct mb7040_dev_s *priv);
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static int mb7040_readrange(FAR struct mb7040_dev_s *priv,
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FAR uint16_t *range);
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static int mb7040_changeaddr(FAR struct mb7040_dev_s *priv, uint8_t addr);
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/* Character Driver Methods */
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static ssize_t mb7040_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen);
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static ssize_t mb7040_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen);
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static int mb7040_ioctl(FAR struct file *filep, int cmd,
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unsigned long arg);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations g_fops =
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{
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NULL, /* open */
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NULL, /* close */
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mb7040_read, /* read */
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mb7040_write, /* write */
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NULL, /* seek */
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mb7040_ioctl, /* ioctl */
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: mb7040_measurerange
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*
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* Description:
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* Command the device to measure the range.
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*
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****************************************************************************/
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static int mb7040_measurerange(FAR struct mb7040_dev_s *priv)
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{
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struct i2c_config_s config;
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uint8_t regaddr;
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int ret;
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sninfo("addr: %02x\n", regaddr);
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/* Set up the I2C configuration */
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config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
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config.address = priv->addr;
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config.addrlen = 7;
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/* Write the register address */
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regaddr = MB7040_RANGE_REG;
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ret = i2c_write(priv->i2c, &config, ®addr, sizeof(regaddr));
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if (ret < 0)
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{
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snerr("ERROR: i2c_write failed: %d\n", ret);
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}
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return ret;
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}
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/****************************************************************************
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* Name: mb7040_readrange
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*
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* Description:
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* Read the range last measured by the device. The units are centimeters.
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*
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****************************************************************************/
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static int mb7040_readrange(FAR struct mb7040_dev_s *priv,
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FAR uint16_t *range)
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{
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struct i2c_config_s config;
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uint8_t buffer[2];
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int ret;
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/* Set up the I2C configuration */
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config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
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config.address = priv->addr;
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config.addrlen = 7;
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/* Read two bytes */
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ret = i2c_read(priv->i2c, &config, buffer, sizeof(buffer));
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if (ret < 0)
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{
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snerr("ERROR: i2c_read failed: %d\n", ret);
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return ret;
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}
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*range = (uint16_t)buffer[0] << 8 | (uint16_t)buffer[1];
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sninfo("range: %04x ret: %d\n", *range, ret);
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return ret;
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}
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/****************************************************************************
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* Name: mb7040_changeaddr
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*
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* Description:
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* Change the device's I2C address.
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*
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****************************************************************************/
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static int mb7040_changeaddr(FAR struct mb7040_dev_s *priv, uint8_t addr)
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{
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struct i2c_config_s config;
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uint8_t buffer[3];
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int ret;
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sninfo("new addr: %02x\n", addr);
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/* Sanity check */
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DEBUGASSERT((addr & 1) == 0);
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DEBUGASSERT(addr != 0x00 && addr != 0x50 && addr != 0xa4 && addr != 0xaa);
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/* Set up a 3-byte message to send */
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buffer[0] = MB7040_ADDRUNLOCK1_REG;
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buffer[1] = MB7040_ADDRUNLOCK2_REG;
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buffer[2] = addr;
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/* Set up the I2C configuration */
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config.frequency = CONFIG_MB7040_I2C_FREQUENCY;
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config.address = priv->addr;
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config.addrlen = 7;
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/* Write the register address followed by the data (no RESTART) */
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ret = i2c_write(priv->i2c, &config, buffer, sizeof(buffer));
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if (ret < 0)
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{
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snerr("ERROR: i2c_write failed: %d\n", ret);
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return ret;
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}
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priv->addr = addr;
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return ret;
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}
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/****************************************************************************
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* Name: mb7040_read
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*
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* Description:
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* A dummy read method.
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*
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****************************************************************************/
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static ssize_t mb7040_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen)
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{
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return 0;
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}
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/****************************************************************************
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* Name: mb7040_write
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*
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* Description:
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* A dummy write method.
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*
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****************************************************************************/
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static ssize_t mb7040_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen)
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{
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return -ENOSYS;
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}
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/****************************************************************************
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* Name: mb7040_ioctl
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*
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* Description:
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* The standard ioctl method.
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*
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****************************************************************************/
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static int mb7040_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct mb7040_dev_s *priv = inode->i_private;
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int ret = OK;
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/* Handle ioctl commands */
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switch (cmd)
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{
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/* Command the device to measure the range. Arg: None. */
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case SNIOC_MEASURE:
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DEBUGASSERT(arg == 0);
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ret = mb7040_measurerange(priv);
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break;
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/* Read the range last measured by the device. Arg: int32_t* pointer. */
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case SNIOC_RANGE:
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{
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FAR int32_t *ptr = (FAR int32_t *)((uintptr_t)arg);
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uint16_t range = 0;
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DEBUGASSERT(ptr != NULL);
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ret = mb7040_readrange(priv, &range);
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if (ret == OK)
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{
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*ptr = (int32_t)range;
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/* Feed sensor data to entropy pool */
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add_sensor_randomness(range);
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}
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sninfo("range: %04x ret: %d\n", *ptr, ret);
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}
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break;
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/* Change the device's I2C address. Arg: uint8_t value. */
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case SNIOC_CHANGEADDR:
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ret = mb7040_changeaddr(priv, (uint8_t)arg);
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sninfo("new addr: %02x ret: %d\n", *(uint8_t *)arg, ret);
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break;
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/* Unrecognized commands */
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default:
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snerr("ERROR: Unrecognized cmd: %d arg: %ld\n", cmd, arg);
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ret = -ENOTTY;
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break;
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}
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return ret;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: mb7040_register
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*
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* Description:
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* Register the MB7040 character device as 'devpath'.
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*
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* Input Parameters:
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* devpath - The full path to the driver to register, e.g., "/dev/sonar0".
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* i2c - An I2C driver instance.
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* addr - The I2C address of the MB7040.
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*
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* Returned Value:
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* Zero (OK) on success; a negated errno value on failure.
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*
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****************************************************************************/
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int mb7040_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
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uint8_t addr)
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{
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FAR struct mb7040_dev_s *priv;
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int ret;
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/* Sanity check */
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DEBUGASSERT(i2c != NULL);
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/* Initialize the device's structure */
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priv = (FAR struct mb7040_dev_s *)kmm_malloc(sizeof(*priv));
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if (priv == NULL)
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{
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snerr("ERROR: Failed to allocate instance\n");
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return -ENOMEM;
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}
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priv->i2c = i2c;
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priv->addr = addr;
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/* Register the character driver */
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ret = register_driver(devpath, &g_fops, 0666, priv);
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if (ret < 0)
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{
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snerr("ERROR: Failed to register driver: %d\n", ret);
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kmm_free(priv);
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}
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return ret;
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}
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#endif /* CONFIG_I2C && CONFIG_SENSORS_MB7040 */
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