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Diffstat (limited to 'src/systemcmds/i2c/i2c.c')
| -rw-r--r-- | src/systemcmds/i2c/i2c.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/systemcmds/i2c/i2c.c b/src/systemcmds/i2c/i2c.c new file mode 100644 index 000000000..4da238039 --- /dev/null +++ b/src/systemcmds/i2c/i2c.c @@ -0,0 +1,140 @@ +/**************************************************************************** + * + * Copyright (c) 2012, 2013 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); + + uint8_t buf[] = { 0, 4}; + int ret = transfer(PX4_I2C_OBDEV_PX4IO, buf, sizeof(buf), NULL, 0); + + if (ret) + errx(1, "send failed - %d", ret); + + uint32_t val; + ret = transfer(PX4_I2C_OBDEV_PX4IO, NULL, 0, (uint8_t *)&val, sizeof(val)); + if (ret) + errx(1, "recive failed - %d", ret); + + errx(0, "got 0x%08x", val); +} + +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; + + // 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, 400000); + ret = I2C_TRANSFER(i2c, &msgv[0], msgs); + + // reset the I2C bus to unwedge on error + if (ret != OK) + up_i2creset(i2c); + + return ret; +} |