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55d58e98 HV |
1 | /* |
2 | * vivid-rds-gen.c - rds (radio data system) generator support functions. | |
3 | * | |
4 | * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved. | |
5 | * | |
6 | * This program is free software; you may redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; version 2 of the License. | |
9 | * | |
10 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
11 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
12 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
13 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS | |
14 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN | |
15 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
16 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
17 | * SOFTWARE. | |
18 | */ | |
19 | ||
20 | #include <linux/kernel.h> | |
21 | #include <linux/ktime.h> | |
5754d0d5 | 22 | #include <linux/string.h> |
55d58e98 HV |
23 | #include <linux/videodev2.h> |
24 | ||
25 | #include "vivid-rds-gen.h" | |
26 | ||
27 | static u8 vivid_get_di(const struct vivid_rds_gen *rds, unsigned grp) | |
28 | { | |
29 | switch (grp) { | |
30 | case 0: | |
31 | return (rds->dyn_pty << 2) | (grp & 3); | |
32 | case 1: | |
33 | return (rds->compressed << 2) | (grp & 3); | |
34 | case 2: | |
35 | return (rds->art_head << 2) | (grp & 3); | |
36 | case 3: | |
37 | return (rds->mono_stereo << 2) | (grp & 3); | |
38 | } | |
39 | return 0; | |
40 | } | |
41 | ||
42 | /* | |
43 | * This RDS generator creates 57 RDS groups (one group == four RDS blocks). | |
44 | * Groups 0-3, 22-25 and 44-47 (spaced 22 groups apart) are filled with a | |
45 | * standard 0B group containing the PI code and PS name. | |
46 | * | |
47 | * Groups 4-19 and 26-41 use group 2A for the radio text. | |
48 | * | |
49 | * Group 56 contains the time (group 4A). | |
50 | * | |
51 | * All remaining groups use a filler group 15B block that just repeats | |
52 | * the PI and PTY codes. | |
53 | */ | |
54 | void vivid_rds_generate(struct vivid_rds_gen *rds) | |
55 | { | |
56 | struct v4l2_rds_data *data = rds->data; | |
57 | unsigned grp; | |
86b2749b | 58 | unsigned idx; |
55d58e98 HV |
59 | struct tm tm; |
60 | unsigned date; | |
61 | unsigned time; | |
62 | int l; | |
63 | ||
64 | for (grp = 0; grp < VIVID_RDS_GEN_GROUPS; grp++, data += VIVID_RDS_GEN_BLKS_PER_GRP) { | |
65 | data[0].lsb = rds->picode & 0xff; | |
66 | data[0].msb = rds->picode >> 8; | |
67 | data[0].block = V4L2_RDS_BLOCK_A | (V4L2_RDS_BLOCK_A << 3); | |
68 | data[1].lsb = rds->pty << 5; | |
69 | data[1].msb = (rds->pty >> 3) | (rds->tp << 2); | |
70 | data[1].block = V4L2_RDS_BLOCK_B | (V4L2_RDS_BLOCK_B << 3); | |
71 | data[3].block = V4L2_RDS_BLOCK_D | (V4L2_RDS_BLOCK_D << 3); | |
72 | ||
73 | switch (grp) { | |
74 | case 0 ... 3: | |
75 | case 22 ... 25: | |
76 | case 44 ... 47: /* Group 0B */ | |
86b2749b | 77 | idx = (grp % 22) % 4; |
55d58e98 | 78 | data[1].lsb |= (rds->ta << 4) | (rds->ms << 3); |
86b2749b | 79 | data[1].lsb |= vivid_get_di(rds, idx); |
55d58e98 HV |
80 | data[1].msb |= 1 << 3; |
81 | data[2].lsb = rds->picode & 0xff; | |
82 | data[2].msb = rds->picode >> 8; | |
83 | data[2].block = V4L2_RDS_BLOCK_C_ALT | (V4L2_RDS_BLOCK_C_ALT << 3); | |
86b2749b HV |
84 | data[3].lsb = rds->psname[2 * idx + 1]; |
85 | data[3].msb = rds->psname[2 * idx]; | |
55d58e98 HV |
86 | break; |
87 | case 4 ... 19: | |
88 | case 26 ... 41: /* Group 2A */ | |
86b2749b HV |
89 | idx = ((grp - 4) % 22) % 16; |
90 | data[1].lsb |= idx; | |
55d58e98 | 91 | data[1].msb |= 4 << 3; |
86b2749b HV |
92 | data[2].msb = rds->radiotext[4 * idx]; |
93 | data[2].lsb = rds->radiotext[4 * idx + 1]; | |
55d58e98 | 94 | data[2].block = V4L2_RDS_BLOCK_C | (V4L2_RDS_BLOCK_C << 3); |
86b2749b HV |
95 | data[3].msb = rds->radiotext[4 * idx + 2]; |
96 | data[3].lsb = rds->radiotext[4 * idx + 3]; | |
55d58e98 HV |
97 | break; |
98 | case 56: | |
99 | /* | |
100 | * Group 4A | |
101 | * | |
102 | * Uses the algorithm from Annex G of the RDS standard | |
103 | * EN 50067:1998 to convert a UTC date to an RDS Modified | |
104 | * Julian Day. | |
105 | */ | |
106 | time_to_tm(get_seconds(), 0, &tm); | |
107 | l = tm.tm_mon <= 1; | |
108 | date = 14956 + tm.tm_mday + ((tm.tm_year - l) * 1461) / 4 + | |
109 | ((tm.tm_mon + 2 + l * 12) * 306001) / 10000; | |
110 | time = (tm.tm_hour << 12) | | |
111 | (tm.tm_min << 6) | | |
112 | (sys_tz.tz_minuteswest >= 0 ? 0x20 : 0) | | |
113 | (abs(sys_tz.tz_minuteswest) / 30); | |
114 | data[1].lsb &= ~3; | |
115 | data[1].lsb |= date >> 15; | |
116 | data[1].msb |= 8 << 3; | |
117 | data[2].lsb = (date << 1) & 0xfe; | |
118 | data[2].lsb |= (time >> 16) & 1; | |
119 | data[2].msb = (date >> 7) & 0xff; | |
120 | data[2].block = V4L2_RDS_BLOCK_C | (V4L2_RDS_BLOCK_C << 3); | |
121 | data[3].lsb = time & 0xff; | |
122 | data[3].msb = (time >> 8) & 0xff; | |
123 | break; | |
124 | default: /* Group 15B */ | |
125 | data[1].lsb |= (rds->ta << 4) | (rds->ms << 3); | |
126 | data[1].lsb |= vivid_get_di(rds, grp % 22); | |
127 | data[1].msb |= 0x1f << 3; | |
128 | data[2].lsb = rds->picode & 0xff; | |
129 | data[2].msb = rds->picode >> 8; | |
130 | data[2].block = V4L2_RDS_BLOCK_C_ALT | (V4L2_RDS_BLOCK_C_ALT << 3); | |
131 | data[3].lsb = rds->pty << 5; | |
132 | data[3].lsb |= (rds->ta << 4) | (rds->ms << 3); | |
133 | data[3].lsb |= vivid_get_di(rds, grp % 22); | |
134 | data[3].msb |= rds->pty >> 3; | |
135 | data[3].msb |= 0x1f << 3; | |
136 | break; | |
137 | } | |
138 | } | |
139 | } | |
140 | ||
141 | void vivid_rds_gen_fill(struct vivid_rds_gen *rds, unsigned freq, | |
142 | bool alt) | |
143 | { | |
144 | /* Alternate PTY between Info and Weather */ | |
145 | if (rds->use_rbds) { | |
146 | rds->picode = 0x2e75; /* 'KLNX' call sign */ | |
147 | rds->pty = alt ? 29 : 2; | |
148 | } else { | |
149 | rds->picode = 0x8088; | |
150 | rds->pty = alt ? 16 : 3; | |
151 | } | |
152 | rds->mono_stereo = true; | |
153 | rds->art_head = false; | |
154 | rds->compressed = false; | |
155 | rds->dyn_pty = false; | |
156 | rds->tp = true; | |
157 | rds->ta = alt; | |
158 | rds->ms = true; | |
159 | snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d", | |
160 | freq / 16, ((freq & 0xf) * 10) / 16); | |
161 | if (alt) | |
162 | strlcpy(rds->radiotext, | |
163 | " The Radio Data System can switch between different Radio Texts ", | |
164 | sizeof(rds->radiotext)); | |
165 | else | |
166 | strlcpy(rds->radiotext, | |
167 | "An example of Radio Text as transmitted by the Radio Data System", | |
168 | sizeof(rds->radiotext)); | |
169 | } |