Contiki-NG
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serial-line.c
1/*
2 * Copyright (c) 2005, Swedish Institute of Computer Science
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the Institute nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * This file is part of the Contiki operating system.
30 *
31 */
32#include "dev/serial-line.h"
33#include <string.h> /* for memcpy() */
34
35#include "lib/ringbuf.h"
36
37#ifdef SERIAL_LINE_CONF_BUFSIZE
38#define BUFSIZE SERIAL_LINE_CONF_BUFSIZE
39#else /* SERIAL_LINE_CONF_BUFSIZE */
40#define BUFSIZE 128
41#endif /* SERIAL_LINE_CONF_BUFSIZE */
42
43#if (BUFSIZE & (BUFSIZE - 1)) != 0
44#error SERIAL_LINE_CONF_BUFSIZE must be a power of two (i.e., 1, 2, 4, 8, 16, 32, 64, ...).
45#error Change SERIAL_LINE_CONF_BUFSIZE in contiki-conf.h.
46#endif
47
48#ifndef END
49#define END 0x0a
50#endif
51#ifndef END2
52#define END2 0x0d
53#endif
54
55static struct ringbuf rxbuf;
56static uint8_t rxbuf_data[BUFSIZE];
57
58PROCESS(serial_line_process, "Serial driver");
59
60process_event_t serial_line_event_message;
61
62/*---------------------------------------------------------------------------*/
63int
64serial_line_input_byte(unsigned char c)
65{
66 static uint8_t overflow = 0; /* Buffer overflow: ignore until END */
67
68 if(!overflow) {
69 /* Add character */
70 if(ringbuf_put(&rxbuf, c) == 0) {
71 /* Buffer overflow: ignore the rest of the line */
72 overflow = 1;
73 }
74 } else {
75 /* Buffer overflowed:
76 * Only (try to) add terminator characters, otherwise skip */
77 if((c == END || c == END2) && ringbuf_put(&rxbuf, c) != 0) {
78 overflow = 0;
79 }
80 }
81
82 /* Wake up consumer process */
83 process_poll(&serial_line_process);
84 return 1;
85}
86/*---------------------------------------------------------------------------*/
87PROCESS_THREAD(serial_line_process, ev, data)
88{
89 static char buf[BUFSIZE];
90 static int ptr;
91
93
94 serial_line_event_message = process_alloc_event();
95 ptr = 0;
96
97 while(1) {
98 /* Fill application buffer until newline or empty */
99 int c = ringbuf_get(&rxbuf);
100
101 if(c == -1) {
102 /* Buffer empty, wait for poll */
104 } else {
105 if((c != END && c != END2)) {
106 if(ptr < BUFSIZE-1) {
107 buf[ptr++] = (uint8_t)c;
108 } else {
109 /* Ignore character (wait for EOL) */
110 }
111 } else {
112 /* Terminate */
113 buf[ptr++] = (uint8_t)'\0';
114
115 /* Broadcast event */
116 process_post(PROCESS_BROADCAST, serial_line_event_message, buf);
117
118 /* Wait until all processes have handled the serial line event */
119 if(PROCESS_ERR_OK ==
120 process_post(PROCESS_CURRENT(), PROCESS_EVENT_CONTINUE, NULL)) {
121 PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_CONTINUE);
122 }
123 ptr = 0;
124 }
125 }
126 }
127
128 PROCESS_END();
129}
130/*---------------------------------------------------------------------------*/
131void
132serial_line_init(void)
133{
134 ringbuf_init(&rxbuf, rxbuf_data, sizeof(rxbuf_data));
135 process_start(&serial_line_process, NULL);
136}
137/*---------------------------------------------------------------------------*/
#define PROCESS(name, strname)
Declare a process.
Definition process.h:307
int process_post(struct process *p, process_event_t ev, process_data_t data)
Post an asynchronous event.
Definition process.c:325
#define PROCESS_CURRENT()
Get a pointer to the currently running process.
Definition process.h:402
process_event_t process_alloc_event(void)
Allocate a global event number.
Definition process.c:98
#define PROCESS_BEGIN()
Define the beginning of a process.
Definition process.h:120
#define PROCESS_WAIT_EVENT_UNTIL(c)
Wait for an event to be posted to the process, with an extra condition.
Definition process.h:157
#define PROCESS_END()
Define the end of a process.
Definition process.h:131
void process_start(struct process *p, process_data_t data)
Start a process.
Definition process.c:107
#define PROCESS_THREAD(name, ev, data)
Define the body of a process.
Definition process.h:273
#define PROCESS_ERR_OK
Return value indicating that an operation was successful.
Definition process.h:74
#define PROCESS_YIELD()
Yield the currently running process.
Definition process.h:164
void process_poll(struct process *p)
Request a process to be polled.
Definition process.c:375
int ringbuf_get(struct ringbuf *r)
Get a byte from the ring buffer.
Definition ringbuf.c:71
int ringbuf_put(struct ringbuf *r, uint8_t c)
Insert a byte into the ring buffer.
Definition ringbuf.c:44
static void ringbuf_init(struct ringbuf *r, uint8_t *a, uint8_t size_power_of_two)
Initialize a ring buffer.
Definition ringbuf.h:90
Header file for the ring buffer library.
Generic serial I/O process header filer.
Structure that holds the state of a ring buffer.
Definition ringbuf.h:68