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/*
* Copyright 2018 Ettus Research, a National Instruments Company
*
* SPDX-License-Identifier: GPL-3.0-or-later
*/
#ifndef _I2CDEV_H_FOUND_
#define _I2CDEV_H_FOUND_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stddef.h>
/*
* This API provides access to i2c devices. It uses the character device API
* from the Linux kernel and i2c-tools
*
* The kernel documentation can be found at
* https://www.kernel.org/doc/Documentation/i2c/dev-interface
*/
/*! Initialize a i2cdev interface
*
* \param fd Return value of the file descriptor
* \param device Path of i2cdev device, e.g. "/dev/i2c0"
* \param timeout_ms Timeout to wait for ACK in ms
*
* \returns 0 if all is good, or an error code otherwise
*/
int i2cdev_open(int *fd, const char *device, const unsigned int timeout_ms);
/*! Do an i2c transaction over i2cdev
* If both tx and rx are to be done in one transaction, first tx data is
* transmitted, followed by a repeated start condition, then the rx data is
* read.
*
* \param fd File descriptor for the i2cdev bus segment
* \param addr i2c device address
* \param ten_bit_addr Nonzero if true (typically 0)
* \param tx Buffer of data to be written to device
* \param tx_len Total number of non-addr bytes to be written
* \param rx Buffer where read data can be stored
* \param rx_len Total number of bytes to be read
*
* Assumption: spidev was configured properly beforehand.
*
* \returns 0 if all is golden
*/
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);
#ifdef __cplusplus
}
#endif
#endif /* _I2CDEV_H_FOUND_ */
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