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//
// Copyright 2018 Ettus Research, a National Instruments Company
// Copyright 2019 Ettus Research, a National Instruments Brand
//
// SPDX-License-Identifier: GPL-3.0-or-later
//
#include "i2cdev.h"
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <stdio.h>
int i2cdev_open(int *fd, const char *device, const unsigned int timeout_ms)
{
if (!fd)
{
fprintf(stderr, "%s: was passed a null pointer\n",
__func__);
return -EINVAL;
}
*fd = open(device, O_RDWR | O_LARGEFILE);
if (*fd < 0) {
fprintf(stderr, "%s: Failed to open device. %s\n",
__func__, strerror(*fd));
return *fd;
}
if (ioctl(*fd, I2C_TIMEOUT, timeout_ms) < 0)
{
int err = errno;
fprintf(stderr, "%s: Failed to set timeout. %s\n",
__func__, strerror(err));
return err;
}
return 0;
}
int i2cdev_transfer(int fd, uint16_t addr, int ten_bit_addr,
uint8_t *tx, size_t tx_len,
uint8_t *rx, size_t rx_len)
{
int err;
struct i2c_msg msgs[2];
int num_msgs = 0;
struct i2c_rdwr_ioctl_data i2c_data = {
.msgs = msgs,
};
if (tx && tx_len > 0) {
msgs[num_msgs].addr = addr;
msgs[num_msgs].buf = tx;
msgs[num_msgs].len = tx_len;
msgs[num_msgs].flags = ten_bit_addr ? I2C_M_TEN : 0;
num_msgs++;
}
if (rx && rx_len > 0) {
msgs[num_msgs].addr = addr;
msgs[num_msgs].buf = rx;
msgs[num_msgs].len = rx_len;
msgs[num_msgs].flags = ten_bit_addr ? I2C_M_TEN : 0;
msgs[num_msgs].flags |= I2C_M_RD;
num_msgs++;
}
i2c_data.nmsgs = num_msgs;
if (num_msgs <= 0)
return -EINVAL;
err = ioctl(fd, I2C_RDWR, &i2c_data);
if (err < 0) {
fprintf(stderr, "%s: Failed I2C_RDWR: %d\n", __func__, err);
perror("ioctl: \n");
return err;
}
return 0;
}
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