#include "serial_io.h"

struct termios toptions;

void sWrite(int port, char string[], size_t length)
{
    if(port != -1) write(port, string, length);
    
}

void sWrite(int port, const char string[], size_t length)
{
    if(port != -1) write(port, string, length);
}

ssize_t sRead(int port, void *buf, size_t count)
{
    return (port != -1) ? read(port, buf, count) : 0;
}

int serialport_init(const char* device, int baud)
{
    int fd;
    fd = open(device, O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1)
    {
    perror("init_serialport: Unable to open port ");
    return -1;
    }

    if (tcgetattr(fd, &toptions) < 0)
    {
        perror("init_serialport: Couldn't get term attributes");
        return -1;
    }
    // 8N1
    toptions.c_cflag &= ~PARENB;
    toptions.c_cflag &= ~CSTOPB;
    toptions.c_cflag &= ~CSIZE;
    toptions.c_cflag |= CS8;
    
    // no flow control
    toptions.c_cflag &= ~(CRTSCTS | CLOCAL);

    //Make Raw
    toptions.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
    toptions.c_oflag &= ~OPOST;
    toptions.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
    toptions.c_cflag &= ~(CSIZE | PARENB);
    toptions.c_cflag |= CS8;
    
    cfsetispeed(&toptions, baud);
    cfsetospeed(&toptions, baud);

    // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
    toptions.c_cc[VMIN]  = 0;
    toptions.c_cc[VTIME] = 40;
    fcntl(fd, F_SETFL, FNDELAY);

    if( tcsetattr(fd, TCSANOW, &toptions) < 0)
    {
        perror("init_serialport: Couldn't set term attributes");
        return -1;
    }
    return fd;
}