145 lines
4.5 KiB
C
145 lines
4.5 KiB
C
/****************************************************************************
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* apps/system/i2c/i2c_devif.c
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*
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* Copyright (C) 2016 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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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 <sys/stat.h>
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#include <sys/ioctl.h>
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#include <stdbool.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <nuttx/i2c/i2c_master.h>
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#include "i2ctool.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/* Device naming */
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#define DEVNAME_FMT "/dev/i2c%d"
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#define DEVNAME_FMTLEN (8 + 3 + 1)
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static char g_devname[DEVNAME_FMTLEN];
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: i2cdev_path
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****************************************************************************/
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FAR char *i2cdev_path(int bus)
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{
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snprintf(g_devname, DEVNAME_FMTLEN, DEVNAME_FMT, bus);
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return g_devname;
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}
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/****************************************************************************
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* Name: i2cdev_exists
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****************************************************************************/
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bool i2cdev_exists(int bus)
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{
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struct stat buf;
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FAR char *devpath;
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int ret;
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/* Get the device path */
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devpath = i2cdev_path(bus);
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/* Check if something exists at that path */
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ret = stat(devpath, &buf);
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if (ret >= 0)
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{
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/* Return TRUE only if it is a character driver */
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if (S_ISCHR(buf.st_mode))
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{
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return true;
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}
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}
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return false;
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}
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/****************************************************************************
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* Name: i2cdev_open
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****************************************************************************/
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int i2cdev_open(int bus)
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{
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FAR char *devpath;
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/* Get the device path */
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devpath = i2cdev_path(bus);
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/* Open the file for read-only access (we need only IOCTLs) */
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return open(devpath, O_RDONLY);
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}
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/****************************************************************************
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* Name: i2cdev_transfer
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****************************************************************************/
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int i2cdev_transfer(int fd, FAR struct i2c_msg_s *msgv, int msgc)
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{
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struct i2c_transfer_s xfer;
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/* Set up the IOCTL argument */
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xfer.msgv = msgv;
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xfer.msgc = msgc;
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/* Perform the IOCTL */
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return ioctl(fd, I2CIOC_TRANSFER, (unsigned long)((uintptr_t)&xfer));
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}
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