1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (c) 2011 by Bertrik Sikken
*
* 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.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <strlcpy.h>
#include "rds.h"
/* programme identification */
static uint16_t pi;
/* program service name */
static char ps_data[9];
static char ps_copy[9];
static int ps_segment;
/* radio text */
static char rt_data[65];
static char rt_copy[65];
static int rt_segment;
static int rt_abflag;
#ifdef SI4700_RDS_ASYNC
/* Functions are called in ISR context */
#define rds_disable_irq_save() disable_irq_save()
#define rds_restore_irq(old) restore_irq(old)
/* Need triple buffer so string isn't clobbered while caller is using it */
static inline char * get_ps(void)
{
static char ps_out[9];
int oldlevel = rds_disable_irq_save();
strcpy(ps_out, ps_copy);
rds_restore_irq(oldlevel);
return ps_out;
}
static inline char * get_rt(void)
{
static char rt_out[65];
int oldlevel = rds_disable_irq_save();
strcpy(rt_out, rt_copy);
rds_restore_irq(oldlevel);
return rt_out;
}
#else /* ndef SI4700_RDS_ASYNC */
#define rds_disable_irq_save() 0
#define rds_restore_irq(old) ((void)(old))
static inline char * get_ps(void) { return ps_copy; }
static inline char * get_rt(void) { return rt_copy; }
#endif /* SI4700_RDS_ASYNC */
/* resets the rds parser */
void rds_reset(void)
{
int oldlevel = rds_disable_irq_save();
ps_copy[0] = '\0';
ps_segment = 0;
rt_copy[0] = '\0';
rt_segment = 0;
pi = 0;
rds_restore_irq(oldlevel);
}
/* initialises the rds parser */
void rds_init(void)
{
rds_reset();
}
/* handles a group 0 packet, returns true if a new message was received */
static bool handle_group0(uint16_t data[4])
{
int segment, pos;
segment = data[1] & 3;
/* reset parsing if not in expected order */
if (segment != ps_segment) {
ps_segment = 0;
if (segment != 0) {
return false;
}
}
/* store data */
pos = segment * 2;
ps_data[pos++] = (data[3] >> 8) & 0xFF;
ps_data[pos++] = (data[3] >> 0) & 0xFF;
if (++ps_segment == 4) {
ps_data[pos] = '\0';
if (strcmp(ps_copy, ps_data) != 0) {
/* we got an updated message */
strcpy(ps_copy, ps_data);
return true;
}
}
return false;
}
/* handles a radio text characters, returns true if end-of-line found */
static bool handle_rt(int pos, char c)
{
switch (c) {
case 0x0A:
/* line break hint */
rt_data[pos] = ' ';
return false;
case 0x0D:
/* end of line */
rt_data[pos] = '\0';
return true;
default:
rt_data[pos] = c;
return false;
}
}
/* handles a group 2 packet, returns true if a new message was received */
static bool handle_group2(uint16_t data[4])
{
int abflag, segment, version, pos;
bool done;
/* reset parsing if not in expected order */
abflag = (data[1] >> 4) & 1;
segment = data[1] & 0xF;
if ((abflag != rt_abflag) || (segment != rt_segment)) {
rt_abflag = abflag;
rt_segment = 0;
if (segment != 0) {
return false;
}
}
/* store data */
version = (data[1] >> 11) & 1;
done = false;
if (version == 0) {
pos = segment * 4;
done = done || handle_rt(pos++, (data[2] >> 8) & 0xFF);
done = done || handle_rt(pos++, (data[2] >> 0) & 0xFF);
done = done || handle_rt(pos++, (data[3] >> 8) & 0xFF);
done = done || handle_rt(pos++, (data[3] >> 0) & 0xFF);
} else {
pos = segment * 2;
done = done || handle_rt(pos++, (data[3] >> 8) & 0xFF);
done = done || handle_rt(pos++, (data[3] >> 0) & 0xFF);
}
if ((++rt_segment == 16) || done) {
rt_data[pos] = '\0';
if (strcmp(rt_copy, rt_data) != 0) {
/* we got an updated message */
strcpy(rt_copy, rt_data);
return true;
}
}
return false;
}
/* processes one rds packet, returns true if a new message was received */
bool rds_process(uint16_t data[4])
{
int group;
/* get programme identification */
if (pi == 0) {
pi = data[0];
}
/* handle rds data based on group */
group = (data[1] >> 11) & 0x1F;
switch (group) {
case 0: /* group 0A: basic info */
case 1: /* group 0B: basic info */
return handle_group0(data);
case 4: /* group 2A: radio text */
case 5: /* group 2B: radio text */
return handle_group2(data);
default:
break;
}
return false;
}
/* TODO: The caller really should provide the buffer in order to regulate
access */
/* returns the programme identification code */
uint16_t rds_get_pi(void)
{
return pi;
}
/* returns the most recent valid programme service name */
char* rds_get_ps(void)
{
return get_ps();
}
/* returns the most recent valid RadioText message */
char* rds_get_rt(void)
{
return get_rt();
}
|
