ben-blinkenlights/swuart-chat/chat.c

/*
 * swuart-chat/chat.c - Simple two-way chat using swuart
 *
 * Written 2012 by Werner Almesberger
 * Copyright 2012 Werner Almesberger
 *
 * 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 <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <strings.h>
#include <termios.h>
#include <fcntl.h>
#include <errno.h>

#include <ubb/ubb.h>
#include <ubb/swuart.h>


#define	DEFAULT_RX	UBB_DAT0
#define	DEFAULT_TX	UBB_DAT1

#define	DEFAULT_BPS	38400


/* ----- TTY raw mode ------------------------------------------------------ */


static struct termios old_term;

static void raw(void)
{
	struct termios term;

	if (tcgetattr(0, &old_term) < 0) {
		perror("tcgetattr");
		exit(1);
	}
	term = old_term;
	cfmakeraw(&term);
	if (tcsetattr(0, TCSAFLUSH, &term) < 0) {
		perror("tcsetattr");
		exit(1);
	}
	if (fcntl(0, F_SETFL, O_NONBLOCK) < 0) {
		perror("fcntl");
		exit(1);
	}
}


static void restore_term(void)
{
	if (tcsetattr(0, TCSAFLUSH, &old_term) < 0)
		perror("tcsetattr");
}


static void at_exit(void)
{
	restore_term();
	swuart_close();
	ubb_close(0);
}


static uint32_t translate(const char *s)
{
	if (!strcasecmp(s, "DAT0"))
		return UBB_DAT0;
	if (!strcasecmp(s, "DAT1"))
		return UBB_DAT1;
	if (!strcasecmp(s, "DAT2"))
		return UBB_DAT2;
	if (!strcasecmp(s, "DAT3"))
		return UBB_DAT3;
	if (!strcasecmp(s, "CMD"))
		return UBB_CMD;
	if (!strcasecmp(s, "CLK"))
		return UBB_CLK;
	if (!strcasecmp(s, "NONE"))
		return 0;
	fprintf(stderr, "unknown pin \"%s\"\n", s);
	exit(1);
}


static void usage(const char *name)
{
	fprintf(stderr, "usage: %s [-r rx_pin] [-t tx_pin] [bps]\n", name);
	exit(1);
}


int main(int argc, char **argv)
{
	uint32_t rx = DEFAULT_RX;
	uint32_t tx = DEFAULT_TX;
	int bps = DEFAULT_BPS;
	uint8_t local[10], remote[100];
	int got, i;
	int c;

	while ((c = getopt(argc, argv, "r:t:")) != EOF)
		switch (c) {
		case 'r':
			rx = translate(optarg);
			break;
		case 't':
			tx = translate(optarg);
			break;
		default:
			usage(*argv);
		}

	switch (argc-optind) {
	case 0:
		break;
	case 1:
		bps = atoi(argv[optind]);
		if (!bps)
			usage(*argv);
		break;
	default:
		usage(*argv);
	}

	if (ubb_open(0) < 0) {
		perror("ubb_open");
		exit(1);
	}
	atexit(at_exit);
	raw();
	if (swuart_open(tx, rx, bps) < 0) {
		perror("swuart_open");
		exit(1);
	}

	while (1) {
		got = read(0, local, sizeof(local));
		if (got < 0 && errno == EAGAIN)
			got = 0;
		if (got < 0) {
			perror("read");
			exit(1);
		}
		if (memchr(local, 3, got))
			break;
		got = swuart_trx(local, got, remote, sizeof(remote),
		    1000, 100);
		for (i = 0; i != got; i++)
			if (remote[i] >= ' ' && remote[i] <= '~')
				printf("%c", remote[i]);
			else if (remote[i] == 13)
				printf("\r\n");
			else if (remote[i] == 8 || remote[i] == 127)
				printf("\b \b");
			else
				printf("\\%02o", remote[i]);
		fflush(stdout);
	}
	printf("\r\n");
	return 0;
}