DevTerm/Code/devterm_keyboard/upload/upload-reset.c

/* Copyright (C) 2015 Roger Clark <www.rogerclark.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 *
 * Utility to send the reset sequence on RTS and DTR and chars
 * which resets the libmaple and causes the bootloader to be run
 *
 *
 *
 * Terminal control code by Heiko Noordhof (see copyright below)
 */

/* Copyright (C) 2003 Heiko Noordhof <heikyAusers.sf.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <stdbool.h>

/* Function prototypes (belong in a seperate header file) */
int openserial(char *devicename);
void closeserial(void);
int setDTR(unsigned short level);
int setRTS(unsigned short level);

/* Two globals for use by this module only */
static int fd;
static struct termios oldterminfo;

void closeserial(void)
{
    tcsetattr(fd, TCSANOW, &oldterminfo);
    close(fd);
}

int openserial(char *devicename)
{
    struct termios attr;

    if ((fd = open(devicename, O_RDWR)) == -1)
        return 0; /* Error */
    atexit(closeserial);

    if (tcgetattr(fd, &oldterminfo) == -1)
        return 0; /* Error */
    attr = oldterminfo;
    attr.c_cflag |= CRTSCTS | CLOCAL;
    attr.c_oflag = 0;
    if (tcflush(fd, TCIOFLUSH) == -1)
        return 0; /* Error */
    if (tcsetattr(fd, TCSANOW, &attr) == -1)
        return 0; /* Error */

    /* Set the lines to a known state, and */
    /* finally return non-zero is successful. */
    return setRTS(0) && setDTR(0);
}

/* For the two functions below:
 *     level=0 to set line to LOW
 *     level=1 to set line to HIGH
 */

int setRTS(unsigned short level)
{
    int status;

    if (ioctl(fd, TIOCMGET, &status) == -1)
    {
        perror("setRTS(): TIOCMGET");
        return 0;
    }
    if (level)
        status |= TIOCM_RTS;
    else
        status &= ~TIOCM_RTS;
    if (ioctl(fd, TIOCMSET, &status) == -1)
    {
        perror("setRTS(): TIOCMSET");
        return 0;
    }
    return 1;
}

int setDTR(unsigned short level)
{
    int status;

    if (ioctl(fd, TIOCMGET, &status) == -1)
    {
        perror("setDTR(): TIOCMGET");
        return 0;
    }
    if (level)
        status |= TIOCM_DTR;
    else
        status &= ~TIOCM_DTR;
    if (ioctl(fd, TIOCMSET, &status) == -1)
    {
        perror("setDTR: TIOCMSET");
        return 0;
    }
    return 1;
}

/* This portion of code was written by Roger Clark
 * It was informed by various other pieces of code written by Leaflabs to reset their
 * Maple and Maple mini boards
 */

main(int argc, char *argv[])
{

    if (argc < 2 || argc > 3)
    {
        printf("Usage upload-reset <serial_device> <Optional_delay_in_milliseconds>\n\r");
        return;
    }

    if (openserial(argv[1]))
    {
        // Send magic sequence of DTR and RTS followed by the magic word "1EAF"
        setRTS(false);
        setDTR(false);
        setDTR(true);

        usleep(50000L);

        setDTR(false);
        setRTS(true);
        setDTR(true);

        usleep(50000L);

        setDTR(false);

        usleep(50000L);

        write(fd, "1EAF", 4);

        closeserial();
        if (argc == 3)
        {
            usleep(atol(argv[2]) * 1000L);
        }
    }
    else
    {
        printf("Failed to open serial device.\n\r");
    }
}