src/input/vcd.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
   5  * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /* The VCD input module has the following options:
  22  *
  23  * numchannels: Maximum number of channels to use. The channels are
  24  *              detected in the same order as they are listed
  25  *              in the $var sections of the VCD file.
  26  *
  27  * skip:        Allows skipping until given timestamp in the file.
  28  *              This can speed up analyzing of long captures.
  29  *
  30  *              Value < 0: Skip until first timestamp listed in
  31  *              the file. (default)
  32  *
  33  *              Value = 0: Do not skip, instead generate samples
  34  *              beginning from timestamp 0.
  35  *
  36  *              Value > 0: Start at the given timestamp.
  37  *
  38  * downsample:  Divide the samplerate by the given factor.
  39  *              This can speed up analyzing of long captures.
  40  *
  41  * compress:    Compress idle periods longer than this value.
  42  *              This can speed up analyzing of long captures.
  43  *              Default 0 = don't compress.
  44  *
  45  * Based on Verilog standard IEEE Std 1364-2001 Version C
  46  *
  47  * Supported features:
  48  * - $var with 'wire' and 'reg' types of scalar variables
  49  * - $timescale definition for samplerate
  50  * - multiple character variable identifiers
  51  *
  52  * Most important unsupported features:
  53  * - vector variables (bit vectors etc.)
  54  * - analog, integer and real number variables
  55  * - $dumpvars initial value declaration
  56  * - $scope namespaces
  57  * - more than 64 channels
  58  */
  59
  60 #include <config.h>
  61 #include <stdlib.h>
  62 #include <glib.h>
  63 #include <stdio.h>
  64 #include <string.h>
  65 #include <libsigrok/libsigrok.h>
  66 #include "libsigrok-internal.h"
  67
  68 #define LOG_PREFIX "input/vcd"
  69
  70 #define CHUNKSIZE (1024 * 1024)
  71
  72 struct context {
  73         gboolean started;
  74         gboolean got_header;
  75         uint64_t samplerate;
  76         unsigned int maxchannels;
  77         unsigned int channelcount;
  78         int downsample;
  79         unsigned compress;
  80         int64_t skip;
  81         gboolean skip_until_end;
  82         GSList *channels;
  83         size_t bytes_per_sample;
  84         size_t samples_in_buffer;
  85         uint8_t *buffer;
  86         uint8_t *current_levels;
  87 };
  88
  89 struct vcd_channel {
  90         gchar *name;
  91         gchar *identifier;
  92 };
  93
  94 /*
  95  * Reads a single VCD section from input file and parses it to name/contents.
  96  * e.g. $timescale 1ps $end  => "timescale" "1ps"
  97  */
  98 static gboolean parse_section(GString *buf, gchar **name, gchar **contents)
  99 {
 100         GString *sname, *scontent;
 101         gboolean status;
 102         unsigned int pos;
 103
 104         *name = *contents = NULL;
 105         status = FALSE;
 106         pos = 0;
 107
 108         /* Skip any initial white-space. */
 109         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 110                 pos++;
 111
 112         /* Section tag should start with $. */
 113         if (buf->str[pos++] != '$')
 114                 return FALSE;
 115
 116         sname = g_string_sized_new(32);
 117         scontent = g_string_sized_new(128);
 118
 119         /* Read the section tag. */
 120         while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
 121                 g_string_append_c(sname, buf->str[pos++]);
 122
 123         /* Skip whitespace before content. */
 124         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 125                 pos++;
 126
 127         /* Read the content. */
 128         while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
 129                 g_string_append_c(scontent, buf->str[pos++]);
 130
 131         if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
 132                 status = TRUE;
 133                 pos += 4;
 134                 while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 135                         pos++;
 136                 g_string_erase(buf, 0, pos);
 137         }
 138
 139         *name = g_string_free(sname, !status);
 140         *contents = g_string_free(scontent, !status);
 141         if (*contents)
 142                 g_strchomp(*contents);
 143
 144         return status;
 145 }
 146
 147 static void free_channel(void *data)
 148 {
 149         struct vcd_channel *vcd_ch = data;
 150         g_free(vcd_ch->name);
 151         g_free(vcd_ch->identifier);
 152         g_free(vcd_ch);
 153 }
 154
 155 /* Remove empty parts from an array returned by g_strsplit. */
 156 static void remove_empty_parts(gchar **parts)
 157 {
 158         gchar **src = parts;
 159         gchar **dest = parts;
 160         while (*src != NULL) {
 161                 if (**src != '\0')
 162                         *dest++ = *src;
 163                 src++;
 164         }
 165
 166         *dest = NULL;
 167 }
 168
 169 /*
 170  * Parse VCD header to get values for context structure.
 171  * The context structure should be zeroed before calling this.
 172  */
 173 static gboolean parse_header(const struct sr_input *in, GString *buf)
 174 {
 175         struct vcd_channel *vcd_ch;
 176         uint64_t p, q;
 177         struct context *inc;
 178         gboolean status;
 179         gchar *name, *contents, **parts;
 180
 181         inc = in->priv;
 182         name = contents = NULL;
 183         status = FALSE;
 184         while (parse_section(buf, &name, &contents)) {
 185                 sr_dbg("Section '%s', contents '%s'.", name, contents);
 186
 187                 if (g_strcmp0(name, "enddefinitions") == 0) {
 188                         status = TRUE;
 189                         break;
 190                 } else if (g_strcmp0(name, "timescale") == 0) {
 191                         /*
 192                          * The standard allows for values 1, 10 or 100
 193                          * and units s, ms, us, ns, ps and fs.
 194                          */
 195                         if (sr_parse_period(contents, &p, &q) == SR_OK) {
 196                                 inc->samplerate = q / p;
 197                                 if (q % p != 0) {
 198                                         /* Does not happen unless time value is non-standard */
 199                                         sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
 200                                                 q, p, inc->samplerate);
 201                                 }
 202
 203                                 sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 204                         } else {
 205                                 sr_err("Parsing timescale failed.");
 206                         }
 207                 } else if (g_strcmp0(name, "var") == 0) {
 208                         /* Format: $var type size identifier reference [opt. index] $end */
 209                         unsigned int length;
 210
 211                         parts = g_strsplit_set(contents, " \r\n\t", 0);
 212                         remove_empty_parts(parts);
 213                         length = g_strv_length(parts);
 214
 215                         if (length != 4 && length != 5)
 216                                 sr_warn("$var section should have 4 or 5 items");
 217                         else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 218                                 sr_info("Unsupported signal type: '%s'", parts[0]);
 219                         else if (strtol(parts[1], NULL, 10) != 1)
 220                                 sr_info("Unsupported signal size: '%s'", parts[1]);
 221                         else if (inc->maxchannels && inc->channelcount >= inc->maxchannels)
 222                                 sr_warn("Skipping '%s%s' because only %d channels requested.",
 223                                         parts[3], parts[4] ? : "", inc->maxchannels);
 224                         else {
 225                                 vcd_ch = g_malloc(sizeof(struct vcd_channel));
 226                                 vcd_ch->identifier = g_strdup(parts[2]);
 227                                 if (length == 4)
 228                                         vcd_ch->name = g_strdup(parts[3]);
 229                                 else
 230                                         vcd_ch->name = g_strconcat(parts[3], parts[4], NULL);
 231
 232                                 sr_info("Channel %d is '%s' identified by '%s'.",
 233                                                 inc->channelcount, vcd_ch->name, vcd_ch->identifier);
 234
 235                                 sr_channel_new(in->sdi, inc->channelcount++, SR_CHANNEL_LOGIC, TRUE, vcd_ch->name);
 236                                 inc->channels = g_slist_append(inc->channels, vcd_ch);
 237                         }
 238
 239                         g_strfreev(parts);
 240                 }
 241
 242                 g_free(name);
 243                 name = NULL;
 244                 g_free(contents);
 245                 contents = NULL;
 246         }
 247         g_free(name);
 248         g_free(contents);
 249
 250         /*
 251          * Compute how many bytes each sample will have and initialize the
 252          * current levels. The current levels will be updated whenever VCD
 253          * has changes.
 254          */
 255         inc->bytes_per_sample = (inc->channelcount + 7) / 8;
 256         inc->current_levels = g_malloc0(inc->bytes_per_sample);
 257
 258         inc->got_header = status;
 259
 260         return status;
 261 }
 262
 263 static int format_match(GHashTable *metadata)
 264 {
 265         GString *buf, *tmpbuf;
 266         gboolean status;
 267         gchar *name, *contents;
 268
 269         buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
 270         tmpbuf = g_string_new_len(buf->str, buf->len);
 271
 272         /*
 273          * If we can parse the first section correctly,
 274          * then it is assumed to be a VCD file.
 275          */
 276         status = parse_section(tmpbuf, &name, &contents);
 277         g_string_free(tmpbuf, TRUE);
 278         g_free(name);
 279         g_free(contents);
 280
 281         return status ? SR_OK : SR_ERR;
 282 }
 283
 284 /* Send all accumulated bytes from inc->buffer. */
 285 static void send_buffer(const struct sr_input *in)
 286 {
 287         struct context *inc;
 288         struct sr_datafeed_packet packet;
 289         struct sr_datafeed_logic logic;
 290
 291         inc = in->priv;
 292
 293         if (inc->samples_in_buffer == 0)
 294                 return;
 295
 296         packet.type = SR_DF_LOGIC;
 297         packet.payload = &logic;
 298         logic.unitsize = inc->bytes_per_sample;
 299         logic.data = inc->buffer;
 300         logic.length = inc->bytes_per_sample * inc->samples_in_buffer;
 301         sr_session_send(in->sdi, &packet);
 302         inc->samples_in_buffer = 0;
 303 }
 304
 305 /*
 306  * Add N copies of the current sample to buffer.
 307  * When the buffer fills up, automatically send it.
 308  */
 309 static void add_samples(const struct sr_input *in, size_t count)
 310 {
 311         struct context *inc;
 312         size_t samples_per_chunk;
 313         size_t space_left, i;
 314         uint8_t *p;
 315
 316         inc = in->priv;
 317         samples_per_chunk = CHUNKSIZE / inc->bytes_per_sample;
 318
 319         while (count) {
 320                 space_left = samples_per_chunk - inc->samples_in_buffer;
 321
 322                 if (space_left > count)
 323                         space_left = count;
 324
 325                 p = inc->buffer + inc->samples_in_buffer * inc->bytes_per_sample;
 326                 for (i = 0; i < space_left; i++) {
 327                         memcpy(p, inc->current_levels, inc->bytes_per_sample);
 328                         p += inc->bytes_per_sample;
 329                         inc->samples_in_buffer++;
 330                         count--;
 331                 }
 332
 333                 if (inc->samples_in_buffer == samples_per_chunk)
 334                         send_buffer(in);
 335         }
 336 }
 337
 338 /* Set the channel level depending on the identifier and parsed value. */
 339 static void process_bit(struct context *inc, char *identifier, unsigned int bit)
 340 {
 341         GSList *l;
 342         struct vcd_channel *vcd_ch;
 343         unsigned int j;
 344
 345         for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
 346                 vcd_ch = l->data;
 347                 if (g_strcmp0(identifier, vcd_ch->identifier) == 0) {
 348                         /* Found our channel. */
 349                         size_t byte_idx = (j / 8);
 350                         size_t bit_idx = j - 8 * byte_idx;
 351                         if (bit)
 352                                 inc->current_levels[byte_idx] |= (uint8_t)1 << bit_idx;
 353                         else
 354                                 inc->current_levels[byte_idx] &= ~((uint8_t)1 << bit_idx);
 355                         break;
 356                 }
 357         }
 358         if (j == inc->channelcount)
 359                 sr_dbg("Did not find channel for identifier '%s'.", identifier);
 360 }
 361
 362 /* Parse a set of lines from the data section. */
 363 static void parse_contents(const struct sr_input *in, char *data)
 364 {
 365         struct context *inc;
 366         uint64_t timestamp, prev_timestamp;
 367         unsigned int bit, i;
 368         char **tokens;
 369
 370         inc = in->priv;
 371         prev_timestamp = 0;
 372
 373         /* Read one space-delimited token at a time. */
 374         tokens = g_strsplit_set(data, " \t\r\n", 0);
 375         remove_empty_parts(tokens);
 376         for (i = 0; tokens[i]; i++) {
 377                 if (inc->skip_until_end) {
 378                         if (!strcmp(tokens[i], "$end")) {
 379                                 /* Done with unhandled/unknown section. */
 380                                 inc->skip_until_end = FALSE;
 381                                 break;
 382                         }
 383                 }
 384                 if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 385                         /* Numeric value beginning with # is a new timestamp value */
 386                         timestamp = strtoull(tokens[i] + 1, NULL, 10);
 387
 388                         if (inc->downsample > 1)
 389                                 timestamp /= inc->downsample;
 390
 391                         /*
 392                          * Skip < 0 => skip until first timestamp.
 393                          * Skip = 0 => don't skip
 394                          * Skip > 0 => skip until timestamp >= skip.
 395                          */
 396                         if (inc->skip < 0) {
 397                                 inc->skip = timestamp;
 398                                 prev_timestamp = timestamp;
 399                         } else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
 400                                 prev_timestamp = inc->skip;
 401                         } else if (timestamp == prev_timestamp) {
 402                                 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
 403                         } else {
 404                                 if (inc->compress != 0 && timestamp - prev_timestamp > inc->compress) {
 405                                         /* Compress long idle periods */
 406                                         prev_timestamp = timestamp - inc->compress;
 407                                 }
 408
 409                                 sr_dbg("New timestamp: %" PRIu64, timestamp);
 410
 411                                 /* Generate samples from prev_timestamp up to timestamp - 1. */
 412                                 add_samples(in, timestamp - prev_timestamp);
 413                                 prev_timestamp = timestamp;
 414                         }
 415                 } else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
 416                         /*
 417                          * This is probably a $dumpvars, $comment or similar.
 418                          * $dump* contain useful data.
 419                          */
 420                         if (g_strcmp0(tokens[i], "$dumpvars") == 0
 421                                         || g_strcmp0(tokens[i], "$dumpon") == 0
 422                                         || g_strcmp0(tokens[i], "$dumpoff") == 0
 423                                         || g_strcmp0(tokens[i], "$end") == 0) {
 424                                 /* Ignore, parse contents as normally. */
 425                         } else {
 426                                 /* Ignore this and future lines until $end. */
 427                                 inc->skip_until_end = TRUE;
 428                                 break;
 429                         }
 430                 } else if (strchr("rR", tokens[i][0]) != NULL) {
 431                         sr_dbg("Real type vector values not supported yet!");
 432                         if (!tokens[++i])
 433                                 /* No tokens left, bail out */
 434                                 break;
 435                         else
 436                                 /* Process next token */
 437                                 continue;
 438                 } else if (strchr("bB", tokens[i][0]) != NULL) {
 439                         bit = (tokens[i][1] == '1');
 440
 441                         /*
 442                          * Bail out if a) char after 'b' is NUL, or b) there is
 443                          * a second character after 'b', or c) there is no
 444                          * identifier.
 445                          */
 446                         if (!tokens[i][1] || tokens[i][2] || !tokens[++i]) {
 447                                 sr_dbg("Unexpected vector format!");
 448                                 break;
 449                         }
 450
 451                         process_bit(inc, tokens[i], bit);
 452                 } else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
 453                         char *identifier;
 454
 455                         /* A new 1-bit sample value */
 456                         bit = (tokens[i][0] == '1');
 457
 458                         /*
 459                          * The identifier is either the next character, or, if
 460                          * there was whitespace after the bit, the next token.
 461                          */
 462                         if (tokens[i][1] == '\0') {
 463                                 if (!tokens[++i]) {
 464                                         sr_dbg("Identifier missing!");
 465                                         break;
 466                                 }
 467                                 identifier = tokens[i];
 468                         } else {
 469                                 identifier = tokens[i] + 1;
 470                         }
 471                         process_bit(inc, identifier, bit);
 472                 } else {
 473                         sr_warn("Skipping unknown token '%s'.", tokens[i]);
 474                 }
 475         }
 476         g_strfreev(tokens);
 477 }
 478
 479 static int init(struct sr_input *in, GHashTable *options)
 480 {
 481         struct context *inc;
 482
 483         inc = in->priv = g_malloc0(sizeof(struct context));
 484
 485         inc->maxchannels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
 486         inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
 487         if (inc->downsample < 1)
 488                 inc->downsample = 1;
 489
 490         inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
 491         inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
 492         inc->skip /= inc->downsample;
 493
 494         in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
 495         in->priv = inc;
 496
 497         inc->buffer = g_malloc(CHUNKSIZE);
 498
 499         return SR_OK;
 500 }
 501
 502 static gboolean have_header(GString *buf)
 503 {
 504         unsigned int pos;
 505         char *p;
 506
 507         if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
 508                 return FALSE;
 509         pos = p - buf->str + 15;
 510         while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
 511                 pos++;
 512         if (!strncmp(buf->str + pos, "$end", 4))
 513                 return TRUE;
 514
 515         return FALSE;
 516 }
 517
 518 static int process_buffer(struct sr_input *in)
 519 {
 520         struct sr_datafeed_packet packet;
 521         struct sr_datafeed_meta meta;
 522         struct sr_config *src;
 523         struct context *inc;
 524         uint64_t samplerate;
 525         char *p;
 526
 527         inc = in->priv;
 528         if (!inc->started) {
 529                 std_session_send_df_header(in->sdi, LOG_PREFIX);
 530
 531                 packet.type = SR_DF_META;
 532                 packet.payload = &meta;
 533                 samplerate = inc->samplerate / inc->downsample;
 534                 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
 535                 meta.config = g_slist_append(NULL, src);
 536                 sr_session_send(in->sdi, &packet);
 537                 g_slist_free(meta.config);
 538                 sr_config_free(src);
 539
 540                 inc->started = TRUE;
 541         }
 542
 543         while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
 544                 *p = '\0';
 545                 g_strstrip(in->buf->str);
 546                 if (in->buf->str[0] != '\0')
 547                         parse_contents(in, in->buf->str);
 548                 g_string_erase(in->buf, 0, p - in->buf->str + 1);
 549         }
 550
 551         return SR_OK;
 552 }
 553
 554 static int receive(struct sr_input *in, GString *buf)
 555 {
 556         struct context *inc;
 557         int ret;
 558
 559         g_string_append_len(in->buf, buf->str, buf->len);
 560
 561         inc = in->priv;
 562         if (!inc->got_header) {
 563                 if (!have_header(in->buf))
 564                         return SR_OK;
 565                 if (!parse_header(in, in->buf))
 566                         /* There was a header in there, but it was malformed. */
 567                         return SR_ERR;
 568
 569                 in->sdi_ready = TRUE;
 570                 /* sdi is ready, notify frontend. */
 571                 return SR_OK;
 572         }
 573
 574         ret = process_buffer(in);
 575
 576         return ret;
 577 }
 578
 579 static int end(struct sr_input *in)
 580 {
 581         struct sr_datafeed_packet packet;
 582         struct context *inc;
 583         int ret;
 584
 585         inc = in->priv;
 586
 587         if (in->sdi_ready)
 588                 ret = process_buffer(in);
 589         else
 590                 ret = SR_OK;
 591
 592         /* Send any samples that haven't been sent yet. */
 593         send_buffer(in);
 594
 595         if (inc->started) {
 596                 packet.type = SR_DF_END;
 597                 sr_session_send(in->sdi, &packet);
 598         }
 599
 600         return ret;
 601 }
 602
 603 static void cleanup(struct sr_input *in)
 604 {
 605         struct context *inc;
 606
 607         inc = in->priv;
 608         g_slist_free_full(inc->channels, free_channel);
 609         g_free(inc->buffer);
 610         inc->buffer = NULL;
 611         g_free(inc->current_levels);
 612         inc->current_levels = NULL;
 613 }
 614
 615 static struct sr_option options[] = {
 616         { "numchannels", "Number of channels", "Number of channels", NULL, NULL },
 617         { "skip", "Skip", "Skip until timestamp", NULL, NULL },
 618         { "downsample", "Downsample", "Divide samplerate by factor", NULL, NULL },
 619         { "compress", "Compress", "Compress idle periods longer than this value", NULL, NULL },
 620         ALL_ZERO
 621 };
 622
 623 static const struct sr_option *get_options(void)
 624 {
 625         if (!options[0].def) {
 626                 options[0].def = g_variant_ref_sink(g_variant_new_int32(0));
 627                 options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
 628                 options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
 629                 options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
 630         }
 631
 632         return options;
 633 }
 634
 635 SR_PRIV struct sr_input_module input_vcd = {
 636         .id = "vcd",
 637         .name = "VCD",
 638         .desc = "Value Change Dump",
 639         .exts = (const char*[]){"vcd", NULL},
 640         .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 641         .options = get_options,
 642         .format_match = format_match,
 643         .init = init,
 644         .receive = receive,
 645         .end = end,
 646         .cleanup = cleanup,
 647 };