/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
* Author: Lorenz Meier <lm@inf.ethz.ch>
*
* 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 PX4 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.
*
****************************************************************************/
/**
* @file i2c.c
*
* i2c hacking tool
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <nuttx/i2c.h>
#include <arch/board/board.h>
#include "systemlib/systemlib.h"
#include "systemlib/err.h"
#ifndef PX4_I2C_BUS_ONBOARD
# error PX4_I2C_BUS_ONBOARD not defined, no device interface
#endif
#ifndef PX4_I2C_OBDEV_PX4IO
# error PX4_I2C_OBDEV_PX4IO not defined
#endif
__EXPORT int i2c_main(int argc, char *argv[]);
static int transfer(uint8_t address, uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len);
static struct i2c_dev_s *i2c;
int i2c_main(int argc, char *argv[])
{
/* find the right I2C */
i2c = up_i2cinitialize(PX4_I2C_BUS_ONBOARD);
if (i2c == NULL)
errx(1, "failed to locate I2C bus");
usleep(100000);
uint32_t val = 0x12345678;
int ret = transfer(PX4_I2C_OBDEV_PX4IO, (uint8_t *)&val, sizeof(val), NULL, 0);
if (ret)
errx(1, "transfer failed");
exit(0);
}
static int
transfer(uint8_t address, uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len)
{
struct i2c_msg_s msgv[2];
unsigned msgs;
int ret;
unsigned tries = 0;
do {
// debug("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len);
msgs = 0;
if (send_len > 0) {
msgv[msgs].addr = address;
msgv[msgs].flags = 0;
msgv[msgs].buffer = send;
msgv[msgs].length = send_len;
msgs++;
}
if (recv_len > 0) {
msgv[msgs].addr = address;
msgv[msgs].flags = I2C_M_READ;
msgv[msgs].buffer = recv;
msgv[msgs].length = recv_len;
msgs++;
}
if (msgs == 0)
return -1;
/*
* I2C architecture means there is an unavoidable race here
* if there are any devices on the bus with a different frequency
* preference. Really, this is pointless.
*/
I2C_SETFREQUENCY(i2c, 320000);
ret = I2C_TRANSFER(i2c, &msgv[0], msgs);
if (ret == OK)
break;
// reset the I2C bus to unwedge on error
up_i2creset(i2c);
} while (tries++ < 5);
return ret;
}
