/*
 * i2csensor.cc
 *
 *  Created on: 18.12.2017
 *      Author: steffen
 */

#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>

#include "i2csensor.h"


#define LEN_FILENAME 255
#define LEN_BUFFER 32

I2C::I2C () {
	i2cdev = 1;
};

I2C::~I2C () {
};

bool I2C::ReadByte(int addr, int reg, uint8_t *readval) {
	int file;
	char filename[LEN_FILENAME];
	unsigned char buffer[LEN_BUFFER];

	if (readval == NULL) return false;
	// i2c device
	snprintf(filename, 255, "/dev/i2c-%d", i2cdev);
	file = open(filename, O_RDWR);
	if (file < 0) {
		return false;
	}

	// setup slave addresse
	if (ioctl(file, I2C_SLAVE, addr) < 0) {
		close (file);
		return false;
	}

	usleep (10000);

	// write register
	buffer[0] = reg;
	if (write(file, buffer, 1) != 1) {
		close (file);
		return false;
	}

	// read value
	if (read(file, buffer, 1) != 1) {
		close (file);
		return false;
	}

	*readval = buffer[0];
	close (file);

	return true;
};

bool I2C::SendByte(int addr, int reg, uint8_t data) {
	int file;
	char filename[LEN_FILENAME];
	unsigned char buffer[LEN_BUFFER];

	// i2c device
	snprintf(filename, 255, "/dev/i2c-%d", i2cdev);
	file = open(filename, O_RDWR);
	if (file < 0) {
		return false;
	}

	// setup slave addresse
	if (ioctl(file, I2C_SLAVE, addr) < 0) {
		close (file);
		return false;
	}

	usleep (10000);

	// write register and value
	buffer[0] = reg;
	buffer[1] = data;
	if (write(file, buffer, 2) != 2) {
		close (file);
		return false;
	}
	close (file);

	return true;
};