nes-proj/os/dev/serial-line.c
2017-10-08 17:00:37 +01:00

143 lines
4.3 KiB
C

/*
* Copyright (c) 2005, Swedish Institute of Computer Science
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system.
*
*/
#include "dev/serial-line.h"
#include <string.h> /* for memcpy() */
#include "lib/ringbuf.h"
#ifdef SERIAL_LINE_CONF_BUFSIZE
#define BUFSIZE SERIAL_LINE_CONF_BUFSIZE
#else /* SERIAL_LINE_CONF_BUFSIZE */
#define BUFSIZE 128
#endif /* SERIAL_LINE_CONF_BUFSIZE */
#if (BUFSIZE & (BUFSIZE - 1)) != 0
#error SERIAL_LINE_CONF_BUFSIZE must be a power of two (i.e., 1, 2, 4, 8, 16, 32, 64, ...).
#error Change SERIAL_LINE_CONF_BUFSIZE in contiki-conf.h.
#endif
#ifndef IGNORE_CHAR
#define IGNORE_CHAR(c) (c == 0x0d)
#endif
#ifndef END
#define END 0x0a
#endif
static struct ringbuf rxbuf;
static uint8_t rxbuf_data[BUFSIZE];
PROCESS(serial_line_process, "Serial driver");
process_event_t serial_line_event_message;
/*---------------------------------------------------------------------------*/
int
serial_line_input_byte(unsigned char c)
{
static uint8_t overflow = 0; /* Buffer overflow: ignore until END */
if(IGNORE_CHAR(c)) {
return 0;
}
if(!overflow) {
/* Add character */
if(ringbuf_put(&rxbuf, c) == 0) {
/* Buffer overflow: ignore the rest of the line */
overflow = 1;
}
} else {
/* Buffer overflowed:
* Only (try to) add terminator characters, otherwise skip */
if(c == END && ringbuf_put(&rxbuf, c) != 0) {
overflow = 0;
}
}
/* Wake up consumer process */
process_poll(&serial_line_process);
return 1;
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(serial_line_process, ev, data)
{
static char buf[BUFSIZE];
static int ptr;
PROCESS_BEGIN();
serial_line_event_message = process_alloc_event();
ptr = 0;
while(1) {
/* Fill application buffer until newline or empty */
int c = ringbuf_get(&rxbuf);
if(c == -1) {
/* Buffer empty, wait for poll */
PROCESS_YIELD();
} else {
if(c != END) {
if(ptr < BUFSIZE-1) {
buf[ptr++] = (uint8_t)c;
} else {
/* Ignore character (wait for EOL) */
}
} else {
/* Terminate */
buf[ptr++] = (uint8_t)'\0';
/* Broadcast event */
process_post(PROCESS_BROADCAST, serial_line_event_message, buf);
/* Wait until all processes have handled the serial line event */
if(PROCESS_ERR_OK ==
process_post(PROCESS_CURRENT(), PROCESS_EVENT_CONTINUE, NULL)) {
PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_CONTINUE);
}
ptr = 0;
}
}
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
void
serial_line_init(void)
{
ringbuf_init(&rxbuf, rxbuf_data, sizeof(rxbuf_data));
process_start(&serial_line_process, NULL);
}
/*---------------------------------------------------------------------------*/