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 CHUNK_SIZE (4 * 1024 * 1024)
  71
  72 struct context {
  73         gboolean started;
  74         gboolean got_header;
  75         uint64_t prev_timestamp;
  76         uint64_t samplerate;
  77         unsigned int maxchannels;
  78         unsigned int channelcount;
  79         int downsample;
  80         unsigned compress;
  81         int64_t skip;
  82         gboolean skip_until_end;
  83         GSList *channels;
  84         size_t bytes_per_sample;
  85         size_t samples_in_buffer;
  86         uint8_t *buffer;
  87         uint8_t *current_levels;
  88 };
  89
  90 struct vcd_channel {
  91         gchar *name;
  92         gchar *identifier;
  93 };
  94
  95 /*
  96  * Reads a single VCD section from input file and parses it to name/contents.
  97  * e.g. $timescale 1ps $end => "timescale" "1ps"
  98  */
  99 static gboolean parse_section(GString *buf, gchar **name, gchar **contents)
 100 {
 101         GString *sname, *scontent;
 102         gboolean status;
 103         unsigned int pos;
 104
 105         *name = *contents = NULL;
 106         status = FALSE;
 107         pos = 0;
 108
 109         /* Skip UTF8 BOM */
 110         if (buf->len >= 3 && !strncmp(buf->str, "\xef\xbb\xbf", 3))
 111                 pos = 3;
 112
 113         /* Skip any initial white-space. */
 114         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 115                 pos++;
 116
 117         /* Section tag should start with $. */
 118         if (buf->str[pos++] != '$')
 119                 return FALSE;
 120
 121         sname = g_string_sized_new(32);
 122         scontent = g_string_sized_new(128);
 123
 124         /* Read the section tag. */
 125         while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
 126                 g_string_append_c(sname, buf->str[pos++]);
 127
 128         /* Skip whitespace before content. */
 129         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 130                 pos++;
 131
 132         /* Read the content. */
 133         while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
 134                 g_string_append_c(scontent, buf->str[pos++]);
 135
 136         if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
 137                 status = TRUE;
 138                 pos += 4;
 139                 while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 140                         pos++;
 141                 g_string_erase(buf, 0, pos);
 142         }
 143
 144         *name = g_string_free(sname, !status);
 145         *contents = g_string_free(scontent, !status);
 146         if (*contents)
 147                 g_strchomp(*contents);
 148
 149         return status;
 150 }
 151
 152 static void free_channel(void *data)
 153 {
 154         struct vcd_channel *vcd_ch = data;
 155         g_free(vcd_ch->name);
 156         g_free(vcd_ch->identifier);
 157         g_free(vcd_ch);
 158 }
 159
 160 /* Remove empty parts from an array returned by g_strsplit. */
 161 static void remove_empty_parts(gchar **parts)
 162 {
 163         gchar **src = parts;
 164         gchar **dest = parts;
 165         while (*src != NULL) {
 166                 if (**src != '\0')
 167                         *dest++ = *src;
 168                 src++;
 169         }
 170
 171         *dest = NULL;
 172 }
 173
 174 /*
 175  * Parse VCD header to get values for context structure.
 176  * The context structure should be zeroed before calling this.
 177  */
 178 static gboolean parse_header(const struct sr_input *in, GString *buf)
 179 {
 180         struct vcd_channel *vcd_ch;
 181         uint64_t p, q;
 182         struct context *inc;
 183         gboolean status;
 184         gchar *name, *contents, **parts;
 185
 186         inc = in->priv;
 187         name = contents = NULL;
 188         status = FALSE;
 189         while (parse_section(buf, &name, &contents)) {
 190                 sr_dbg("Section '%s', contents '%s'.", name, contents);
 191
 192                 if (g_strcmp0(name, "enddefinitions") == 0) {
 193                         status = TRUE;
 194                         break;
 195                 } else if (g_strcmp0(name, "timescale") == 0) {
 196                         /*
 197                          * The standard allows for values 1, 10 or 100
 198                          * and units s, ms, us, ns, ps and fs.
 199                          */
 200                         if (sr_parse_period(contents, &p, &q) == SR_OK) {
 201                                 inc->samplerate = q / p;
 202                                 if (q % p != 0) {
 203                                         /* Does not happen unless time value is non-standard */
 204                                         sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
 205                                                 q, p, inc->samplerate);
 206                                 }
 207
 208                                 sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 209                         } else {
 210                                 sr_err("Parsing timescale failed.");
 211                         }
 212                 } else if (g_strcmp0(name, "var") == 0) {
 213                         /* Format: $var type size identifier reference [opt. index] $end */
 214                         unsigned int length;
 215
 216                         parts = g_strsplit_set(contents, " \r\n\t", 0);
 217                         remove_empty_parts(parts);
 218                         length = g_strv_length(parts);
 219
 220                         if (length != 4 && length != 5)
 221                                 sr_warn("$var section should have 4 or 5 items");
 222                         else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 223                                 sr_info("Unsupported signal type: '%s'", parts[0]);
 224                         else if (strtol(parts[1], NULL, 10) != 1)
 225                                 sr_info("Unsupported signal size: '%s'", parts[1]);
 226                         else if (inc->maxchannels && inc->channelcount >= inc->maxchannels)
 227                                 sr_warn("Skipping '%s%s' because only %d channels requested.",
 228                                         parts[3], parts[4] ? : "", inc->maxchannels);
 229                         else {
 230                                 vcd_ch = g_malloc(sizeof(struct vcd_channel));
 231                                 vcd_ch->identifier = g_strdup(parts[2]);
 232                                 if (length == 4)
 233                                         vcd_ch->name = g_strdup(parts[3]);
 234                                 else
 235                                         vcd_ch->name = g_strconcat(parts[3], parts[4], NULL);
 236
 237                                 sr_info("Channel %d is '%s' identified by '%s'.",
 238                                                 inc->channelcount, vcd_ch->name, vcd_ch->identifier);
 239
 240                                 sr_channel_new(in->sdi, inc->channelcount++, SR_CHANNEL_LOGIC, TRUE, vcd_ch->name);
 241                                 inc->channels = g_slist_append(inc->channels, vcd_ch);
 242                         }
 243
 244                         g_strfreev(parts);
 245                 }
 246
 247                 g_free(name);
 248                 name = NULL;
 249                 g_free(contents);
 250                 contents = NULL;
 251         }
 252         g_free(name);
 253         g_free(contents);
 254
 255         /*
 256          * Compute how many bytes each sample will have and initialize the
 257          * current levels. The current levels will be updated whenever VCD
 258          * has changes.
 259          */
 260         inc->bytes_per_sample = (inc->channelcount + 7) / 8;
 261         inc->current_levels = g_malloc0(inc->bytes_per_sample);
 262
 263         inc->got_header = status;
 264
 265         return status;
 266 }
 267
 268 static int format_match(GHashTable *metadata, unsigned int *confidence)
 269 {
 270         GString *buf, *tmpbuf;
 271         gboolean status;
 272         gchar *name, *contents;
 273
 274         buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
 275         tmpbuf = g_string_new_len(buf->str, buf->len);
 276
 277         /*
 278          * If we can parse the first section correctly,
 279          * then it is assumed to be a VCD file.
 280          */
 281         status = parse_section(tmpbuf, &name, &contents);
 282         g_string_free(tmpbuf, TRUE);
 283         g_free(name);
 284         g_free(contents);
 285
 286         if (!status)
 287                 return SR_ERR;
 288         *confidence = 1;
 289
 290         return SR_OK;
 291 }
 292
 293 /* Send all accumulated bytes from inc->buffer. */
 294 static void send_buffer(const struct sr_input *in)
 295 {
 296         struct context *inc;
 297         struct sr_datafeed_packet packet;
 298         struct sr_datafeed_logic logic;
 299
 300         inc = in->priv;
 301
 302         if (inc->samples_in_buffer == 0)
 303                 return;
 304
 305         packet.type = SR_DF_LOGIC;
 306         packet.payload = &logic;
 307         logic.unitsize = inc->bytes_per_sample;
 308         logic.data = inc->buffer;
 309         logic.length = inc->bytes_per_sample * inc->samples_in_buffer;
 310         sr_session_send(in->sdi, &packet);
 311         inc->samples_in_buffer = 0;
 312 }
 313
 314 /*
 315  * Add N copies of the current sample to buffer.
 316  * When the buffer fills up, automatically send it.
 317  */
 318 static void add_samples(const struct sr_input *in, size_t count)
 319 {
 320         struct context *inc;
 321         size_t samples_per_chunk;
 322         size_t space_left, i;
 323         uint8_t *p;
 324
 325         inc = in->priv;
 326         samples_per_chunk = CHUNK_SIZE / inc->bytes_per_sample;
 327
 328         while (count) {
 329                 space_left = samples_per_chunk - inc->samples_in_buffer;
 330
 331                 if (space_left > count)
 332                         space_left = count;
 333
 334                 p = inc->buffer + inc->samples_in_buffer * inc->bytes_per_sample;
 335                 for (i = 0; i < space_left; i++) {
 336                         memcpy(p, inc->current_levels, inc->bytes_per_sample);
 337                         p += inc->bytes_per_sample;
 338                         inc->samples_in_buffer++;
 339                         count--;
 340                 }
 341
 342                 if (inc->samples_in_buffer == samples_per_chunk)
 343                         send_buffer(in);
 344         }
 345 }
 346
 347 /* Set the channel level depending on the identifier and parsed value. */
 348 static void process_bit(struct context *inc, char *identifier, unsigned int bit)
 349 {
 350         GSList *l;
 351         struct vcd_channel *vcd_ch;
 352         unsigned int j;
 353
 354         for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
 355                 vcd_ch = l->data;
 356                 if (g_strcmp0(identifier, vcd_ch->identifier) == 0) {
 357                         /* Found our channel. */
 358                         size_t byte_idx = (j / 8);
 359                         size_t bit_idx = j - 8 * byte_idx;
 360                         if (bit)
 361                                 inc->current_levels[byte_idx] |= (uint8_t)1 << bit_idx;
 362                         else
 363                                 inc->current_levels[byte_idx] &= ~((uint8_t)1 << bit_idx);
 364                         break;
 365                 }
 366         }
 367         if (j == inc->channelcount)
 368                 sr_dbg("Did not find channel for identifier '%s'.", identifier);
 369 }
 370
 371 /* Parse a set of lines from the data section. */
 372 static void parse_contents(const struct sr_input *in, char *data)
 373 {
 374         struct context *inc;
 375         uint64_t timestamp;
 376         unsigned int bit, i;
 377         char **tokens;
 378
 379         inc = in->priv;
 380
 381         /* Read one space-delimited token at a time. */
 382         tokens = g_strsplit_set(data, " \t\r\n", 0);
 383         remove_empty_parts(tokens);
 384         for (i = 0; tokens[i]; i++) {
 385                 if (inc->skip_until_end) {
 386                         if (!strcmp(tokens[i], "$end")) {
 387                                 /* Done with unhandled/unknown section. */
 388                                 inc->skip_until_end = FALSE;
 389                                 break;
 390                         }
 391                 }
 392                 if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 393                         /* Numeric value beginning with # is a new timestamp value */
 394                         timestamp = strtoull(tokens[i] + 1, NULL, 10);
 395
 396                         if (inc->downsample > 1)
 397                                 timestamp /= inc->downsample;
 398
 399                         /*
 400                          * Skip < 0 => skip until first timestamp.
 401                          * Skip = 0 => don't skip
 402                          * Skip > 0 => skip until timestamp >= skip.
 403                          */
 404                         if (inc->skip < 0) {
 405                                 inc->skip = timestamp;
 406                                 inc->prev_timestamp = timestamp;
 407                         } else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
 408                                 inc->prev_timestamp = inc->skip;
 409                         } else if (timestamp == inc->prev_timestamp) {
 410                                 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
 411                         } else {
 412                                 if (inc->compress != 0 && timestamp - inc->prev_timestamp > inc->compress) {
 413                                         /* Compress long idle periods */
 414                                         inc->prev_timestamp = timestamp - inc->compress;
 415                                 }
 416
 417                                 sr_dbg("New timestamp: %" PRIu64, timestamp);
 418
 419                                 /* Generate samples from prev_timestamp up to timestamp - 1. */
 420                                 add_samples(in, timestamp - inc->prev_timestamp);
 421                                 inc->prev_timestamp = timestamp;
 422                         }
 423                 } else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
 424                         /*
 425                          * This is probably a $dumpvars, $comment or similar.
 426                          * $dump* contain useful data.
 427                          */
 428                         if (g_strcmp0(tokens[i], "$dumpvars") == 0
 429                                         || g_strcmp0(tokens[i], "$dumpon") == 0
 430                                         || g_strcmp0(tokens[i], "$dumpoff") == 0
 431                                         || g_strcmp0(tokens[i], "$end") == 0) {
 432                                 /* Ignore, parse contents as normally. */
 433                         } else {
 434                                 /* Ignore this and future lines until $end. */
 435                                 inc->skip_until_end = TRUE;
 436                                 break;
 437                         }
 438                 } else if (strchr("rR", tokens[i][0]) != NULL) {
 439                         sr_dbg("Real type vector values not supported yet!");
 440                         if (!tokens[++i])
 441                                 /* No tokens left, bail out */
 442                                 break;
 443                         else
 444                                 /* Process next token */
 445                                 continue;
 446                 } else if (strchr("bB", tokens[i][0]) != NULL) {
 447                         bit = (tokens[i][1] == '1');
 448
 449                         /*
 450                          * Bail out if a) char after 'b' is NUL, or b) there is
 451                          * a second character after 'b', or c) there is no
 452                          * identifier.
 453                          */
 454                         if (!tokens[i][1] || tokens[i][2] || !tokens[++i]) {
 455                                 sr_dbg("Unexpected vector format!");
 456                                 break;
 457                         }
 458
 459                         process_bit(inc, tokens[i], bit);
 460                 } else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
 461                         char *identifier;
 462
 463                         /* A new 1-bit sample value */
 464                         bit = (tokens[i][0] == '1');
 465
 466                         /*
 467                          * The identifier is either the next character, or, if
 468                          * there was whitespace after the bit, the next token.
 469                          */
 470                         if (tokens[i][1] == '\0') {
 471                                 if (!tokens[++i]) {
 472                                         sr_dbg("Identifier missing!");
 473                                         break;
 474                                 }
 475                                 identifier = tokens[i];
 476                         } else {
 477                                 identifier = tokens[i] + 1;
 478                         }
 479                         process_bit(inc, identifier, bit);
 480                 } else {
 481                         sr_warn("Skipping unknown token '%s'.", tokens[i]);
 482                 }
 483         }
 484         g_strfreev(tokens);
 485 }
 486
 487 static int init(struct sr_input *in, GHashTable *options)
 488 {
 489         struct context *inc;
 490
 491         inc = in->priv = g_malloc0(sizeof(struct context));
 492
 493         inc->maxchannels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
 494         inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
 495         if (inc->downsample < 1)
 496                 inc->downsample = 1;
 497
 498         inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
 499         inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
 500         inc->skip /= inc->downsample;
 501
 502         in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
 503         in->priv = inc;
 504
 505         inc->buffer = g_malloc(CHUNK_SIZE);
 506
 507         return SR_OK;
 508 }
 509
 510 static gboolean have_header(GString *buf)
 511 {
 512         unsigned int pos;
 513         char *p;
 514
 515         if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
 516                 return FALSE;
 517         pos = p - buf->str + 15;
 518         while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
 519                 pos++;
 520         if (!strncmp(buf->str + pos, "$end", 4))
 521                 return TRUE;
 522
 523         return FALSE;
 524 }
 525
 526 static int process_buffer(struct sr_input *in)
 527 {
 528         struct sr_datafeed_packet packet;
 529         struct sr_datafeed_meta meta;
 530         struct sr_config *src;
 531         struct context *inc;
 532         uint64_t samplerate;
 533         char *p;
 534
 535         inc = in->priv;
 536         if (!inc->started) {
 537                 std_session_send_df_header(in->sdi);
 538
 539                 packet.type = SR_DF_META;
 540                 packet.payload = &meta;
 541                 samplerate = inc->samplerate / inc->downsample;
 542                 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
 543                 meta.config = g_slist_append(NULL, src);
 544                 sr_session_send(in->sdi, &packet);
 545                 g_slist_free(meta.config);
 546                 sr_config_free(src);
 547
 548                 inc->started = TRUE;
 549         }
 550
 551         while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
 552                 *p = '\0';
 553                 g_strstrip(in->buf->str);
 554                 if (in->buf->str[0] != '\0')
 555                         parse_contents(in, in->buf->str);
 556                 g_string_erase(in->buf, 0, p - in->buf->str + 1);
 557         }
 558
 559         return SR_OK;
 560 }
 561
 562 static int receive(struct sr_input *in, GString *buf)
 563 {
 564         struct context *inc;
 565         int ret;
 566
 567         g_string_append_len(in->buf, buf->str, buf->len);
 568
 569         inc = in->priv;
 570         if (!inc->got_header) {
 571                 if (!have_header(in->buf))
 572                         return SR_OK;
 573                 if (!parse_header(in, in->buf))
 574                         /* There was a header in there, but it was malformed. */
 575                         return SR_ERR;
 576
 577                 in->sdi_ready = TRUE;
 578                 /* sdi is ready, notify frontend. */
 579                 return SR_OK;
 580         }
 581
 582         ret = process_buffer(in);
 583
 584         return ret;
 585 }
 586
 587 static int end(struct sr_input *in)
 588 {
 589         struct context *inc;
 590         int ret;
 591
 592         inc = in->priv;
 593
 594         if (in->sdi_ready)
 595                 ret = process_buffer(in);
 596         else
 597                 ret = SR_OK;
 598
 599         /* Send any samples that haven't been sent yet. */
 600         send_buffer(in);
 601
 602         if (inc->started)
 603                 std_session_send_df_end(in->sdi);
 604
 605         return ret;
 606 }
 607
 608 static void cleanup(struct sr_input *in)
 609 {
 610         struct context *inc;
 611
 612         inc = in->priv;
 613         g_slist_free_full(inc->channels, free_channel);
 614         g_free(inc->buffer);
 615         inc->buffer = NULL;
 616         g_free(inc->current_levels);
 617         inc->current_levels = NULL;
 618 }
 619
 620 static int reset(struct sr_input *in)
 621 {
 622         struct context *inc = in->priv;
 623
 624         cleanup(in);
 625         inc->started = FALSE;
 626         g_string_truncate(in->buf, 0);
 627
 628         return SR_OK;
 629 }
 630
 631 static struct sr_option options[] = {
 632         { "numchannels", "Number of logic channels", "The number of (logic) channels in the data", NULL, NULL },
 633         { "skip", "Skip samples until timestamp", "Skip samples until the specified timestamp; "
 634                 "< 0: Skip until first timestamp listed; 0: Don't skip", NULL, NULL },
 635         { "downsample", "Downsampling factor", "Downsample, i.e. divide the samplerate by the specified factor", NULL, NULL },
 636         { "compress", "Compress idle periods", "Compress idle periods longer than the specified value", NULL, NULL },
 637         ALL_ZERO
 638 };
 639
 640 static const struct sr_option *get_options(void)
 641 {
 642         if (!options[0].def) {
 643                 options[0].def = g_variant_ref_sink(g_variant_new_int32(0));
 644                 options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
 645                 options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
 646                 options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
 647         }
 648
 649         return options;
 650 }
 651
 652 SR_PRIV struct sr_input_module input_vcd = {
 653         .id = "vcd",
 654         .name = "VCD",
 655         .desc = "Value Change Dump data",
 656         .exts = (const char*[]){"vcd", NULL},
 657         .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 658         .options = get_options,
 659         .format_match = format_match,
 660         .init = init,
 661         .receive = receive,
 662         .end = end,
 663         .cleanup = cleanup,
 664         .reset = reset,
 665 };