#include <stdio.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>

enum{ERROR=-1,SUCCESS};
typedef unsigned long Ulong;
typedef struct termios TTY;


speed_t baud_konstante[] = {   B0,B50,B75,B110,B134,B150,B200,B300,B600,B1200,
                               B1800,B2400,B4800,B9600,B19200,B38400,B57600,
                               B115200,B230400,B460800
                            };

Ulong baud_werte[] = {   0,50,75,110,134,150,200,300,600,1200,
                         1800,2400,4800,9600,19200,38400,57600,
                         115200,230400,460800
                      };



Ulong baudrate_wert(speed_t baud)
{
  int i;

  for(i=0; i<=19; i++)
    {
       if(baud == baud_konstante[i])
            return(baud_werte[i]);
    }
  return ERROR;
}




int serialopen(char *device, char *baud, int nonblock )
{
	int fd;
	speed_t baud_input, baud_output;
	speed_t newbaud;
	TTY terminal;
	char *p;

/*
  printf("Call: setbaud devicename baudrate!!!\n");
  printf("Valid baudrates are: 0,50,75,110,134,150,200,\n");
  printf("300,600,1200,1800,2400,4800,9600,19200,38400,57600,115200,\n");
  printf("230400,460800\n\n");
*/  

	if( nonblock ) {

		if((fd =open( device , O_RDWR | O_NONBLOCK)) == ERROR){
			printf("Cannot open device %s !!", device);
			return( 0 );
		}

	}
	else {

		if((fd =open( device , O_RDWR )) == ERROR){
			printf("Cannot open device %s !!", device);
			return( 0 );
		}
		
	}

  	if(isatty(fd) == 0){
  		printf("%s is not a tty......",device);
  		close( fd );
		return( 0 );
  	}
	
  	if(tcgetattr(fd, &terminal) == ERROR){
		printf("Error for tcgetattr......\n");
		close( fd );
		return( 0 );
	}
	
  	if(( baud_input = baudrate_wert(cfgetispeed(&terminal))) == ERROR){
		printf("Error for baud_input........\n");
		close( fd );
		return(0);
    }

	if(( baud_output = baudrate_wert(cfgetospeed(&terminal))) == ERROR){
    	printf("Error for baud_output........\n");
    	close( fd );
    	return(0);
	}
	
	
	printf("Current input-baudrate : %lu\n",baud_input);
	printf("Current output-baudrate : %lu\n",baud_output);


	p 		= baud;
	newbaud = -1;
	
	if(strcmp(p,"0")==0){
		newbaud = B0;
	}
	if(strcmp(p,"50")==0){
		newbaud = B50;
	}
	if(strcmp(p,"75")==0){
		newbaud = B75;
	}
	if(strcmp(p,"110")==0){
		newbaud = B110;
	}
	if(strcmp(p,"134")==0){
		newbaud = B134;
	}
	if(strcmp(p,"150")==0){
		newbaud = B150;
	}
	if(strcmp(p,"200")==0){
		newbaud = B200;
	}
	if(strcmp(p,"300")==0){
		newbaud = B300;
	}
	if(strcmp(p,"600")==0){
		newbaud = B600;
	}
	if(strcmp(p,"1200")==0){
		newbaud = B1200;
	}
	if(strcmp(p,"1800")==0){
		newbaud = B1800;
	}
	if(strcmp(p,"2400")==0){
		newbaud = B2400;
	}
	if(strcmp(p,"4800")==0){
		newbaud = B4800;
	}
	if(strcmp(p,"9600")==0){
		newbaud = B9600;
	}
	if(strcmp(p,"19200")==0){
		newbaud = B19200;
	}
	if(strcmp(p,"38400")==0){
		newbaud = B38400;
	}
	if(strcmp(p,"57600")==0){
		newbaud = B57600;
	}
	if(strcmp(p,"115200")==0){
		newbaud = B115200;
	}
	if(strcmp(p,"230400")==0){
		newbaud = B230400;
	}
	if(strcmp(p,"460800")==0){
		newbaud = B460800;
	}


	if(newbaud == -1){
       printf("Invalid baudrate given as argument !!!\n");
       close( fd );
       return( 0 );		
	}

	printf("Changing input-, and output-baudrate to : %lu\n",newbaud);

	if((cfsetispeed(&terminal,newbaud)) == ERROR){
		printf("Error when setting input-baudrate........\n");
		close( fd );
		return(0);
	}

	if((cfsetospeed(&terminal,newbaud)) == ERROR){
       printf("Error when setting output-baudrate........\n");
       close( fd );
       return(0);
    }

	if(tcsetattr(fd,TCSAFLUSH, &terminal) == ERROR){
    	printf("Error for tcsetattr......\n");
    	close( fd );
    	return(0);
    }

	if(tcgetattr(fd, &terminal) == ERROR){
       printf("Error for tcgetattr......\n");
       close(fd);
       return(0);
    }
    
	if(( baud_input = baudrate_wert(cfgetispeed(&terminal))) == ERROR){
    	printf("Error for baud_input........\n");
    	close(fd);
    	return(0);
    }

	if(( baud_output = baudrate_wert(cfgetospeed(&terminal))) == ERROR){
       printf("Error for baud_output........\n");
       close(fd);
       return(0);
    }

  	printf("Input-Baudrate-new : %lu\n",baud_input);
  	printf("Output-Baudrate-new : %lu\n\n",baud_output);

  	return( fd );
}