/* Test all POSIX defined bitrates on a given serial port */

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

typedef struct
{
    speed_t s;
    int speed;
} speedlist_t;

speedlist_t speedlist[] = {
    {B0,0},{B50,50},{B75,75},{B110,110}, {B134,134}, {B150,150}, 
    {B200,200}, {B300,300}, {B600,600}, {B1200,1200},{B1800,1800},
    {B2400,2400},{B4800,4800},{B9600,9600},{B19200,19200},{B38400,38400},
    {B57600,57600},{B115200,115200},{B128000,128000},
#ifdef B230400
    {B230400,230400},
#endif
    {B256000,256000}
};

int main(int argc,char **argv)
{
    struct termios dcb;
    int fd,i;

    if (argc != 2)
    {
        fprintf(stderr,"Usage: %s serial_port_name\n",argv[0]);
        return(1);                                 
    }

    // Try opening the port (and validate its tty status)
    if ((fd = open(argv[1],O_RDWR|O_NOCTTY|O_NONBLOCK)) != -1)
    {
        if (isatty(fd))
        {
            fprintf(stderr,"Testing all POSIX bitrates for port: %s\n",argv[1]);
            // Grab the existing DCB/termios parameters (to be safe)
            if (tcgetattr(fd,&dcb) == -1)
            {
                perror("Can't get port settings");
                close(fd);
                return(1);
            }
            // 8N1, raw access
            dcb.c_cflag = CLOCAL|CS8|CREAD;
            // No min # chars
            dcb.c_cc[VMIN] = 0;
            // No max timeout
            dcb.c_cc[VTIME] = 0;
            // No postprocessing
            dcb.c_oflag = dcb.c_iflag = dcb.c_lflag = 0;
            // iterate through all POSIX-defined bitrates
            for (i=0;i<(sizeof(speedlist)/sizeof(speedlist_t));i++)
            {
                dcb.c_ispeed = dcb.c_ospeed = speedlist[i].s;
                fprintf(stderr,"Trying %u bps    \t: ",speedlist[i].speed);
                // Make the DCB/termios settings effective and report error/success
                if (tcsetattr(fd, TCSANOW, &dcb) < 0) perror("Can't set port settings");
                else fprintf(stderr,"Success\n");
            }
        } else
        {
            perror("Port isn't a serial port");
            close(fd);
            return(1);
        }
    } else
    {
        perror("Can't open port");
        return(1);
    }
    // Close up and exit cleanly
    close(fd);
    return(0);
}