path: root/src/rs232dev.c

/*
 * Copyright (c) 2001, Adam Dunkels.
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Adam Dunkels.
 * 4. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.  
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
 *
 * This file is part of the uIP TCP/IP stack.
 *
 * $Id: rs232dev.c,v 1.1 2001/11/20 20:49:45 adam Exp $
 *
 */

/*
 * This is a generic implementation of the SLIP protocol over an RS232
 * (serial) device. While initially intented for the C64, the code can
 * easily be ported to other platforms as well.
 *
 * Huge thanks to Ullrich von Bassewitz <uz@cc65.org> of cc65 fame for
 * and endless supply of bugfixes, insightsful comments and
 * suggestions, and improvements to this code!
 */

#include <rs232.h>
#include <time.h>
#include <string.h>

 /* This will include the system specific header files as well */
#if defined(__CBM__)
#  include <cbm.h>
#elif defined(__ATARI__)
#  include <atari.h>
#endif

#include "uip.h"

#include "features.h"

#ifdef FEAT_KEYBOARD_BUFFER
#include "keybuf.h"
#endif

#define SLIP_END     0300
#define SLIP_ESC     0333
#define SLIP_ESC_END 0334
#define SLIP_ESC_ESC 0335


#define SIO_RECV(c)  while(rs232_get(&c) == RS_ERR_NO_DATA)
#define SIO_POLL(c)  (rs232_get(&c) != RS_ERR_NO_DATA)
#define SIO_SEND(c)  rs232_put(c)

#define MAX_SIZE UIP_BUFSIZE

static u8_t slip_buf[MAX_SIZE];

#if MAX_SIZE > 255
static u16_t len, tmplen;
#else
static u8_t len, tmplen;
#endif /* MAX_SIZE > 255 */

#if 0
#define printf(x)
#else
#include <stdio.h>
#endif

#ifdef FEAT_TRAFFIC_INDICATOR
#include <peekpoke.h>
/* FujiChat screen stuff */
static u16_t traffic_indicator;
static char old_char;

#define DOWN_ARROW 0xdd
#define UP_ARROW 0xdc

#endif

/*-----------------------------------------------------------------------------------*/
static void rs232_err(char err) {
	switch(err) {
		case RS_ERR_OK:
			// printf("RS232 OK\n");
			break;
		case RS_ERR_NOT_INITIALIZED:
			printf("RS232 not initialized\n");
			break;
		case RS_ERR_BAUD_TOO_FAST:
			printf("RS232 baud too fast\n");
			break;
		case RS_ERR_BAUD_NOT_AVAIL:
			printf("RS232 baud rate not available\n");
			break;
		case RS_ERR_NO_DATA:
			printf("RS232 nothing to read\n");
			break;
		case RS_ERR_OVERFLOW:
			printf("RS232 overflow\n");
			break;
	}
}

/*-----------------------------------------------------------------------------------*/
/*
 * rs232dev_send():
 *
 * Sends the packet in the uip_buf and uip_appdata buffers. The first
 * 40 bytes of the packet (the IP and TCP headers) are read from the
 * uip_buf buffer, and the following bytes (the application data) are
 * read from the uip_appdata buffer.
 *
 */
/*-----------------------------------------------------------------------------------*/

void rs232dev_send(void) {
#if MAX_SIZE > 255
	u16_t i;
#else
	u8_t i;
#endif /* MAX_SIZE > 255 */
	volatile u8_t *ptr;
	u8_t c;

#ifdef FEAT_TRAFFIC_INDICATOR
	old_char = PEEK(traffic_indicator);
	POKE(traffic_indicator, UP_ARROW);
#endif

	SIO_SEND(SLIP_END);

	ptr = uip_buf;
	for(i = 0; i < uip_len; ++i) {
		if(i == 40) {
			ptr = uip_appdata;
		}
		c = *ptr++;
		switch(c) {
			case SLIP_END:
				SIO_SEND(SLIP_ESC);
				SIO_SEND(SLIP_ESC_END);
				break;
			case SLIP_ESC:
				SIO_SEND(SLIP_ESC);
				SIO_SEND(SLIP_ESC_ESC);
				break;
			default:
				SIO_SEND(c);
				break;
		}
#ifdef FEAT_KEYBOARD_BUFFER
		keybuf_poll_kbd();
#endif
	}
	SIO_SEND(SLIP_END);

#ifdef FEAT_TRAFFIC_INDICATOR
	POKE(traffic_indicator, old_char);
#endif
}

/*-----------------------------------------------------------------------------------*/
/*
 * rs232dev_poll():
 *
 * Read all avaliable bytes from the RS232 interface into the slip_buf
 * buffer. If no more bytes are avaliable, it returns with 0 to
 * indicate that no packet was immediately ready. When a full packet
 * has been read into the buffer, the packet is copied into the
 * uip_buf buffer and the length of the packet is returned.
 *
 */
/*-----------------------------------------------------------------------------------*/

#if MAX_SIZE > 255
u16_t
#else 
u8_t
#endif /* MAX_SIZE > 255 */
rs232dev_poll(void) {
	u8_t c;
	static u8_t lastc;

#ifdef FEAT_TRAFFIC_INDICATOR
	old_char = PEEK(traffic_indicator);
#endif

	while(SIO_POLL(c)) {
#ifdef FEAT_TRAFFIC_INDICATOR
		POKE(traffic_indicator, DOWN_ARROW);
#endif
#ifdef FEAT_KEYBOARD_BUFFER
		keybuf_poll_kbd();
#endif
		switch(c) {
			case SLIP_ESC:
				lastc = c;
				break;

			case SLIP_END:
				lastc = c;
				/* End marker found, we copy our input buffer to the uip_buf
					buffer and return the size of the packet we copied. */
				memcpy(uip_buf, slip_buf, len);
				tmplen = len;
				len = 0;
#ifdef FEAT_TRAFFIC_INDICATOR
				POKE(traffic_indicator, old_char);
#endif
				return tmplen;

			default:     
				if(lastc == SLIP_ESC) {
					lastc = c;
					/* Previous read byte was an escape byte, so this byte will be
						interpreted differently from others. */
					switch(c) {
						case SLIP_ESC_END:
							c = SLIP_END;
							break;
						case SLIP_ESC_ESC:
							c = SLIP_ESC;
							break;
					}
				} else {
					lastc = c;
				}

				slip_buf[len] = c;
				++len;

				if(len > MAX_SIZE) {
					len = 0;
				}

				break;
		}
	}

#ifdef FEAT_TRAFFIC_INDICATOR
	POKE(traffic_indicator, old_char);
#endif
	return 0;
}

/*-----------------------------------------------------------------------------------*/
/*
 * rs232dev_init():
 *
 * Initializes the RS232 device and sets the parameters of the device.
 *
 */ 
/*-----------------------------------------------------------------------------------*/

char rs232dev_init(unsigned char baud) {
	char err;

#ifdef FEAT_TRAFFIC_INDICATOR
	traffic_indicator = PEEKW(0x58) + 39; /* upper-right corner */
#endif

	err = rs232_init(0);
	rs232_err(err);
	err = rs232_params(baud, RS_PAR_NONE);
	rs232_err(err);

	len = 0;

	return err;
}
/*-----------------------------------------------------------------------------------*/

void rs232dev_close(void) {
	rs232_done();
}