1/* 2 * vivid-vbi-gen.c - vbi 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/errno.h> 21#include <linux/kernel.h> 22#include <linux/ktime.h> 23#include <linux/string.h> 24#include <linux/videodev2.h> 25 26#include "vivid-vbi-gen.h" 27 28static void wss_insert(u8 *wss, u32 val, unsigned size) 29{ 30 while (size--) 31 *wss++ = (val & (1 << size)) ? 0xc0 : 0x10; 32} 33 34static void vivid_vbi_gen_wss_raw(const struct v4l2_sliced_vbi_data *data, 35 u8 *buf, unsigned sampling_rate) 36{ 37 const unsigned rate = 5000000; /* WSS has a 5 MHz transmission rate */ 38 u8 wss[29 + 24 + 24 + 24 + 18 + 18] = { 0 }; 39 const unsigned zero = 0x07; 40 const unsigned one = 0x38; 41 unsigned bit = 0; 42 u16 wss_data; 43 int i; 44 45 wss_insert(wss + bit, 0x1f1c71c7, 29); bit += 29; 46 wss_insert(wss + bit, 0x1e3c1f, 24); bit += 24; 47 48 wss_data = (data->data[1] << 8) | data->data[0]; 49 for (i = 0; i <= 13; i++, bit += 6) 50 wss_insert(wss + bit, (wss_data & (1 << i)) ? one : zero, 6); 51 52 for (i = 0, bit = 0; bit < sizeof(wss); bit++) { 53 unsigned n = ((bit + 1) * sampling_rate) / rate; 54 55 while (i < n) 56 buf[i++] = wss[bit]; 57 } 58} 59 60static void vivid_vbi_gen_teletext_raw(const struct v4l2_sliced_vbi_data *data, 61 u8 *buf, unsigned sampling_rate) 62{ 63 const unsigned rate = 6937500 / 10; /* Teletext has a 6.9375 MHz transmission rate */ 64 u8 teletext[45] = { 0x55, 0x55, 0x27 }; 65 unsigned bit = 0; 66 int i; 67 68 memcpy(teletext + 3, data->data, sizeof(teletext) - 3); 69 /* prevents 32 bit overflow */ 70 sampling_rate /= 10; 71 72 for (i = 0, bit = 0; bit < sizeof(teletext) * 8; bit++) { 73 unsigned n = ((bit + 1) * sampling_rate) / rate; 74 u8 val = (teletext[bit / 8] & (1 << (bit & 7))) ? 0xc0 : 0x10; 75 76 while (i < n) 77 buf[i++] = val; 78 } 79} 80 81static void cc_insert(u8 *cc, u8 ch) 82{ 83 unsigned tot = 0; 84 unsigned i; 85 86 for (i = 0; i < 7; i++) { 87 cc[2 * i] = cc[2 * i + 1] = (ch & (1 << i)) ? 1 : 0; 88 tot += cc[2 * i]; 89 } 90 cc[14] = cc[15] = !(tot & 1); 91} 92 93#define CC_PREAMBLE_BITS (14 + 4 + 2) 94 95static void vivid_vbi_gen_cc_raw(const struct v4l2_sliced_vbi_data *data, 96 u8 *buf, unsigned sampling_rate) 97{ 98 const unsigned rate = 1000000; /* CC has a 1 MHz transmission rate */ 99 100 u8 cc[CC_PREAMBLE_BITS + 2 * 16] = { 101 /* Clock run-in: 7 cycles */ 102 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 103 /* 2 cycles of 0 */ 104 0, 0, 0, 0, 105 /* Start bit of 1 (each bit is two cycles) */ 106 1, 1 107 }; 108 unsigned bit, i; 109 110 cc_insert(cc + CC_PREAMBLE_BITS, data->data[0]); 111 cc_insert(cc + CC_PREAMBLE_BITS + 16, data->data[1]); 112 113 for (i = 0, bit = 0; bit < sizeof(cc); bit++) { 114 unsigned n = ((bit + 1) * sampling_rate) / rate; 115 116 while (i < n) 117 buf[i++] = cc[bit] ? 0xc0 : 0x10; 118 } 119} 120 121void vivid_vbi_gen_raw(const struct vivid_vbi_gen_data *vbi, 122 const struct v4l2_vbi_format *vbi_fmt, u8 *buf) 123{ 124 unsigned idx; 125 126 for (idx = 0; idx < 25; idx++) { 127 const struct v4l2_sliced_vbi_data *data = vbi->data + idx; 128 unsigned start_2nd_field; 129 unsigned line = data->line; 130 u8 *linebuf = buf; 131 132 start_2nd_field = (data->id & V4L2_SLICED_VBI_525) ? 263 : 313; 133 if (data->field) 134 line += start_2nd_field; 135 line -= vbi_fmt->start[data->field]; 136 137 if (vbi_fmt->flags & V4L2_VBI_INTERLACED) 138 linebuf += (line * 2 + data->field) * 139 vbi_fmt->samples_per_line; 140 else 141 linebuf += (line + data->field * vbi_fmt->count[0]) * 142 vbi_fmt->samples_per_line; 143 if (data->id == V4L2_SLICED_CAPTION_525) 144 vivid_vbi_gen_cc_raw(data, linebuf, vbi_fmt->sampling_rate); 145 else if (data->id == V4L2_SLICED_WSS_625) 146 vivid_vbi_gen_wss_raw(data, linebuf, vbi_fmt->sampling_rate); 147 else if (data->id == V4L2_SLICED_TELETEXT_B) 148 vivid_vbi_gen_teletext_raw(data, linebuf, vbi_fmt->sampling_rate); 149 } 150} 151 152static const u8 vivid_cc_sequence1[30] = { 153 0x14, 0x20, /* Resume Caption Loading */ 154 'H', 'e', 155 'l', 'l', 156 'o', ' ', 157 'w', 'o', 158 'r', 'l', 159 'd', '!', 160 0x14, 0x2f, /* End of Caption */ 161}; 162 163static const u8 vivid_cc_sequence2[30] = { 164 0x14, 0x20, /* Resume Caption Loading */ 165 'C', 'l', 166 'o', 's', 167 'e', 'd', 168 ' ', 'c', 169 'a', 'p', 170 't', 'i', 171 'o', 'n', 172 's', ' ', 173 't', 'e', 174 's', 't', 175 0x14, 0x2f, /* End of Caption */ 176}; 177 178static u8 calc_parity(u8 val) 179{ 180 unsigned i; 181 unsigned tot = 0; 182 183 for (i = 0; i < 7; i++) 184 tot += (val & (1 << i)) ? 1 : 0; 185 return val | ((tot & 1) ? 0 : 0x80); 186} 187 188static void vivid_vbi_gen_set_time_of_day(u8 *packet) 189{ 190 struct tm tm; 191 u8 checksum, i; 192 193 time_to_tm(get_seconds(), 0, &tm); 194 packet[0] = calc_parity(0x07); 195 packet[1] = calc_parity(0x01); 196 packet[2] = calc_parity(0x40 | tm.tm_min); 197 packet[3] = calc_parity(0x40 | tm.tm_hour); 198 packet[4] = calc_parity(0x40 | tm.tm_mday); 199 if (tm.tm_mday == 1 && tm.tm_mon == 2 && 200 sys_tz.tz_minuteswest > tm.tm_min + tm.tm_hour * 60) 201 packet[4] = calc_parity(0x60 | tm.tm_mday); 202 packet[5] = calc_parity(0x40 | (1 + tm.tm_mon)); 203 packet[6] = calc_parity(0x40 | (1 + tm.tm_wday)); 204 packet[7] = calc_parity(0x40 | ((tm.tm_year - 90) & 0x3f)); 205 packet[8] = calc_parity(0x0f); 206 for (checksum = i = 0; i <= 8; i++) 207 checksum += packet[i] & 0x7f; 208 packet[9] = calc_parity(0x100 - checksum); 209 checksum = 0; 210 packet[10] = calc_parity(0x07); 211 packet[11] = calc_parity(0x04); 212 if (sys_tz.tz_minuteswest >= 0) 213 packet[12] = calc_parity(0x40 | ((sys_tz.tz_minuteswest / 60) & 0x1f)); 214 else 215 packet[12] = calc_parity(0x40 | ((24 + sys_tz.tz_minuteswest / 60) & 0x1f)); 216 packet[13] = calc_parity(0); 217 packet[14] = calc_parity(0x0f); 218 for (checksum = 0, i = 10; i <= 14; i++) 219 checksum += packet[i] & 0x7f; 220 packet[15] = calc_parity(0x100 - checksum); 221} 222 223static const u8 hamming[16] = { 224 0x15, 0x02, 0x49, 0x5e, 0x64, 0x73, 0x38, 0x2f, 225 0xd0, 0xc7, 0x8c, 0x9b, 0xa1, 0xb6, 0xfd, 0xea 226}; 227 228static void vivid_vbi_gen_teletext(u8 *packet, unsigned line, unsigned frame) 229{ 230 unsigned offset = 2; 231 unsigned i; 232 233 packet[0] = hamming[1 + ((line & 1) << 3)]; 234 packet[1] = hamming[line >> 1]; 235 memset(packet + 2, 0x20, 40); 236 if (line == 0) { 237 /* subcode */ 238 packet[2] = hamming[frame % 10]; 239 packet[3] = hamming[frame / 10]; 240 packet[4] = hamming[0]; 241 packet[5] = hamming[0]; 242 packet[6] = hamming[0]; 243 packet[7] = hamming[0]; 244 packet[8] = hamming[0]; 245 packet[9] = hamming[1]; 246 offset = 10; 247 } 248 packet += offset; 249 memcpy(packet, "Page: 100 Row: 10", 17); 250 packet[7] = '0' + frame / 10; 251 packet[8] = '0' + frame % 10; 252 packet[15] = '0' + line / 10; 253 packet[16] = '0' + line % 10; 254 for (i = 0; i < 42 - offset; i++) 255 packet[i] = calc_parity(packet[i]); 256} 257 258void vivid_vbi_gen_sliced(struct vivid_vbi_gen_data *vbi, 259 bool is_60hz, unsigned seqnr) 260{ 261 struct v4l2_sliced_vbi_data *data0 = vbi->data; 262 struct v4l2_sliced_vbi_data *data1 = vbi->data + 1; 263 unsigned frame = seqnr % 60; 264 265 memset(vbi->data, 0, sizeof(vbi->data)); 266 267 if (!is_60hz) { 268 unsigned i; 269 270 for (i = 0; i <= 11; i++) { 271 data0->id = V4L2_SLICED_TELETEXT_B; 272 data0->line = 7 + i; 273 vivid_vbi_gen_teletext(data0->data, i, frame); 274 data0++; 275 } 276 data0->id = V4L2_SLICED_WSS_625; 277 data0->line = 23; 278 /* 4x3 video aspect ratio */ 279 data0->data[0] = 0x08; 280 data0++; 281 for (i = 0; i <= 11; i++) { 282 data0->id = V4L2_SLICED_TELETEXT_B; 283 data0->field = 1; 284 data0->line = 7 + i; 285 vivid_vbi_gen_teletext(data0->data, 12 + i, frame); 286 data0++; 287 } 288 return; 289 } 290 291 data0->id = V4L2_SLICED_CAPTION_525; 292 data0->line = 21; 293 data1->id = V4L2_SLICED_CAPTION_525; 294 data1->field = 1; 295 data1->line = 21; 296 297 if (frame < 15) { 298 data0->data[0] = calc_parity(vivid_cc_sequence1[2 * frame]); 299 data0->data[1] = calc_parity(vivid_cc_sequence1[2 * frame + 1]); 300 } else if (frame >= 30 && frame < 45) { 301 frame -= 30; 302 data0->data[0] = calc_parity(vivid_cc_sequence2[2 * frame]); 303 data0->data[1] = calc_parity(vivid_cc_sequence2[2 * frame + 1]); 304 } else { 305 data0->data[0] = calc_parity(0); 306 data0->data[1] = calc_parity(0); 307 } 308 309 frame = seqnr % (30 * 60); 310 switch (frame) { 311 case 0: 312 vivid_vbi_gen_set_time_of_day(vbi->time_of_day_packet); 313 /* fall through */ 314 case 1 ... 7: 315 data1->data[0] = vbi->time_of_day_packet[frame * 2]; 316 data1->data[1] = vbi->time_of_day_packet[frame * 2 + 1]; 317 break; 318 default: 319 data1->data[0] = calc_parity(0); 320 data1->data[1] = calc_parity(0); 321 break; 322 } 323} 324