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 DEFAULT_NUM_CHANNELS 8
  71 #define CHUNKSIZE (1024 * 1024)
  72
  73 struct context {
  74         gboolean started;
  75         gboolean got_header;
  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 any initial white-space. */
 110         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 111                 pos++;
 112
 113         /* Section tag should start with $. */
 114         if (buf->str[pos++] != '$')
 115                 return FALSE;
 116
 117         sname = g_string_sized_new(32);
 118         scontent = g_string_sized_new(128);
 119
 120         /* Read the section tag. */
 121         while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
 122                 g_string_append_c(sname, buf->str[pos++]);
 123
 124         /* Skip whitespace before content. */
 125         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 126                 pos++;
 127
 128         /* Read the content. */
 129         while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
 130                 g_string_append_c(scontent, buf->str[pos++]);
 131
 132         if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
 133                 status = TRUE;
 134                 pos += 4;
 135                 while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 136                         pos++;
 137                 g_string_erase(buf, 0, pos);
 138         }
 139
 140         *name = g_string_free(sname, !status);
 141         *contents = g_string_free(scontent, !status);
 142         if (*contents)
 143                 g_strchomp(*contents);
 144
 145         return status;
 146 }
 147
 148 static void free_channel(void *data)
 149 {
 150         struct vcd_channel *vcd_ch = data;
 151         g_free(vcd_ch->name);
 152         g_free(vcd_ch->identifier);
 153         g_free(vcd_ch);
 154 }
 155
 156 /* Remove empty parts from an array returned by g_strsplit. */
 157 static void remove_empty_parts(gchar **parts)
 158 {
 159         gchar **src = parts;
 160         gchar **dest = parts;
 161         while (*src != NULL) {
 162                 if (**src != '\0')
 163                         *dest++ = *src;
 164                 src++;
 165         }
 166
 167         *dest = NULL;
 168 }
 169
 170 /*
 171  * Parse VCD header to get values for context structure.
 172  * The context structure should be zeroed before calling this.
 173  */
 174 static gboolean parse_header(const struct sr_input *in, GString *buf)
 175 {
 176         struct vcd_channel *vcd_ch;
 177         uint64_t p, q;
 178         struct context *inc;
 179         gboolean status;
 180         gchar *name, *contents, **parts;
 181
 182         inc = in->priv;
 183         name = contents = NULL;
 184         status = FALSE;
 185         while (parse_section(buf, &name, &contents)) {
 186                 sr_dbg("Section '%s', contents '%s'.", name, contents);
 187
 188                 if (g_strcmp0(name, "enddefinitions") == 0) {
 189                         status = TRUE;
 190                         break;
 191                 } else if (g_strcmp0(name, "timescale") == 0) {
 192                         /*
 193                          * The standard allows for values 1, 10 or 100
 194                          * and units s, ms, us, ns, ps and fs.
 195                          */
 196                         if (sr_parse_period(contents, &p, &q) == SR_OK) {
 197                                 inc->samplerate = q / p;
 198                                 if (q % p != 0) {
 199                                         /* Does not happen unless time value is non-standard */
 200                                         sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
 201                                                 q, p, inc->samplerate);
 202                                 }
 203
 204                                 sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 205                         } else {
 206                                 sr_err("Parsing timescale failed.");
 207                         }
 208                 } else if (g_strcmp0(name, "var") == 0) {
 209                         /* Format: $var type size identifier reference [opt. index] $end */
 210                         unsigned int length;
 211
 212                         parts = g_strsplit_set(contents, " \r\n\t", 0);
 213                         remove_empty_parts(parts);
 214                         length = g_strv_length(parts);
 215
 216                         if (length != 4 && length != 5)
 217                                 sr_warn("$var section should have 4 or 5 items");
 218                         else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 219                                 sr_info("Unsupported signal type: '%s'", parts[0]);
 220                         else if (strtol(parts[1], NULL, 10) != 1)
 221                                 sr_info("Unsupported signal size: '%s'", parts[1]);
 222                         else if (inc->channelcount >= inc->maxchannels)
 223                                 sr_warn("Skipping '%s%s' because only %d channels requested.",
 224                                         parts[3], parts[4] ? : "", inc->maxchannels);
 225                         else {
 226                                 vcd_ch = g_malloc(sizeof(struct vcd_channel));
 227                                 vcd_ch->identifier = g_strdup(parts[2]);
 228                                 if (length == 4)
 229                                         vcd_ch->name = g_strdup(parts[3]);
 230                                 else
 231                                         vcd_ch->name = g_strconcat(parts[3], parts[4], NULL);
 232
 233                                 sr_info("Channel %d is '%s' identified by '%s'.",
 234                                                 inc->channelcount, vcd_ch->name, vcd_ch->identifier);
 235
 236                                 inc->channels = g_slist_append(inc->channels, vcd_ch);
 237                                 inc->channelcount++;
 238                         }
 239
 240                         g_strfreev(parts);
 241                 }
 242
 243                 g_free(name);
 244                 name = NULL;
 245                 g_free(contents);
 246                 contents = NULL;
 247         }
 248         g_free(name);
 249         g_free(contents);
 250
 251         /*
 252          * Compute how many bytes each sample will have and initialize the
 253          * current levels. The current levels will be updated whenever VCD
 254          * has changes.
 255          */
 256         inc->bytes_per_sample = (inc->channelcount + 7) / 8;
 257         inc->current_levels = g_malloc0(inc->bytes_per_sample);
 258
 259         inc->got_header = status;
 260
 261         return status;
 262 }
 263
 264 static int format_match(GHashTable *metadata)
 265 {
 266         GString *buf, *tmpbuf;
 267         gboolean status;
 268         gchar *name, *contents;
 269
 270         buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
 271         tmpbuf = g_string_new_len(buf->str, buf->len);
 272
 273         /*
 274          * If we can parse the first section correctly,
 275          * then it is assumed to be a VCD file.
 276          */
 277         status = parse_section(tmpbuf, &name, &contents);
 278         g_string_free(tmpbuf, TRUE);
 279         g_free(name);
 280         g_free(contents);
 281
 282         return status ? SR_OK : SR_ERR;
 283 }
 284
 285 /* Send all accumulated bytes from inc->buffer. */
 286 static void send_buffer(const struct sr_input *in)
 287 {
 288         struct context *inc;
 289         struct sr_datafeed_packet packet;
 290         struct sr_datafeed_logic logic;
 291
 292         inc = in->priv;
 293
 294         if (inc->samples_in_buffer == 0)
 295                 return;
 296
 297         packet.type = SR_DF_LOGIC;
 298         packet.payload = &logic;
 299         logic.unitsize = inc->bytes_per_sample;
 300         logic.data = inc->buffer;
 301         logic.length = inc->bytes_per_sample * inc->samples_in_buffer;
 302         sr_session_send(in->sdi, &packet);
 303         inc->samples_in_buffer = 0;
 304 }
 305
 306 /*
 307  * Add N copies of the current sample to buffer.
 308  * When the buffer fills up, automatically send it.
 309  */
 310 static void add_samples(const struct sr_input *in, size_t count)
 311 {
 312         struct context *inc;
 313         size_t samples_per_chunk;
 314         size_t space_left, i;
 315         uint8_t *p;
 316
 317         inc = in->priv;
 318         samples_per_chunk = CHUNKSIZE / inc->bytes_per_sample;
 319
 320         while (count) {
 321                 space_left = samples_per_chunk - inc->samples_in_buffer;
 322
 323                 if (space_left > count)
 324                         space_left = count;
 325
 326                 p = inc->buffer + inc->samples_in_buffer * inc->bytes_per_sample;
 327                 for (i = 0; i < space_left; i++) {
 328                         memcpy(p, inc->current_levels, inc->bytes_per_sample);
 329                         p += inc->bytes_per_sample;
 330                         inc->samples_in_buffer++;
 331                         count--;
 332                 }
 333
 334                 if (inc->samples_in_buffer == samples_per_chunk)
 335                         send_buffer(in);
 336         }
 337 }
 338
 339 /* Parse a set of lines from the data section. */
 340 static void parse_contents(const struct sr_input *in, char *data)
 341 {
 342         struct context *inc;
 343         struct vcd_channel *vcd_ch;
 344         GSList *l;
 345         uint64_t timestamp, prev_timestamp;
 346         unsigned int bit, i, j;
 347         char **tokens;
 348
 349         inc = in->priv;
 350         prev_timestamp = 0;
 351
 352         /* Read one space-delimited token at a time. */
 353         tokens = g_strsplit_set(data, " \t\r\n", 0);
 354         remove_empty_parts(tokens);
 355         for (i = 0; tokens[i]; i++) {
 356                 if (inc->skip_until_end) {
 357                         if (!strcmp(tokens[i], "$end")) {
 358                                 /* Done with unhandled/unknown section. */
 359                                 inc->skip_until_end = FALSE;
 360                                 break;
 361                         }
 362                 }
 363                 if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 364                         /* Numeric value beginning with # is a new timestamp value */
 365                         timestamp = strtoull(tokens[i] + 1, NULL, 10);
 366
 367                         if (inc->downsample > 1)
 368                                 timestamp /= inc->downsample;
 369
 370                         /*
 371                          * Skip < 0 => skip until first timestamp.
 372                          * Skip = 0 => don't skip
 373                          * Skip > 0 => skip until timestamp >= skip.
 374                          */
 375                         if (inc->skip < 0) {
 376                                 inc->skip = timestamp;
 377                                 prev_timestamp = timestamp;
 378                         } else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
 379                                 prev_timestamp = inc->skip;
 380                         } else if (timestamp == prev_timestamp) {
 381                                 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
 382                         } else {
 383                                 if (inc->compress != 0 && timestamp - prev_timestamp > inc->compress) {
 384                                         /* Compress long idle periods */
 385                                         prev_timestamp = timestamp - inc->compress;
 386                                 }
 387
 388                                 sr_dbg("New timestamp: %" PRIu64, timestamp);
 389
 390                                 /* Generate samples from prev_timestamp up to timestamp - 1. */
 391                                 add_samples(in, timestamp - prev_timestamp);
 392                                 prev_timestamp = timestamp;
 393                         }
 394                 } else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
 395                         /*
 396                          * This is probably a $dumpvars, $comment or similar.
 397                          * $dump* contain useful data.
 398                          */
 399                         if (g_strcmp0(tokens[i], "$dumpvars") == 0
 400                                         || g_strcmp0(tokens[i], "$dumpon") == 0
 401                                         || g_strcmp0(tokens[i], "$dumpoff") == 0
 402                                         || g_strcmp0(tokens[i], "$end") == 0) {
 403                                 /* Ignore, parse contents as normally. */
 404                         } else {
 405                                 /* Ignore this and future lines until $end. */
 406                                 inc->skip_until_end = TRUE;
 407                                 break;
 408                         }
 409                 } else if (strchr("bBrR", tokens[i][0]) != NULL) {
 410                         /* A vector value, not supported yet. */
 411                         break;
 412                 } else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
 413                         /* A new 1-bit sample value */
 414                         bit = (tokens[i][0] == '1');
 415
 416                         /*
 417                          * The identifier is either the next character, or, if
 418                          * there was whitespace after the bit, the next token.
 419                          */
 420                         if (tokens[i][1] == '\0') {
 421                                 if (!tokens[++i])
 422                                         /* Missing identifier */
 423                                         continue;
 424                         } else {
 425                                 for (j = 1; tokens[i][j]; j++)
 426                                         tokens[i][j - 1] = tokens[i][j];
 427                                 tokens[i][j - 1] = '\0';
 428                         }
 429
 430                         for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
 431                                 vcd_ch = l->data;
 432                                 if (g_strcmp0(tokens[i], vcd_ch->identifier) == 0) {
 433                                         /* Found our channel */
 434                                         size_t byte_idx = (j / 8);
 435                                         size_t bit_idx = j - 8 * byte_idx;
 436                                         if (bit)
 437                                                 inc->current_levels[byte_idx] |= (uint8_t)1 << bit_idx;
 438                                         else
 439                                                 inc->current_levels[byte_idx] &= ~((uint8_t)1 << bit_idx);
 440                                         break;
 441                                 }
 442                         }
 443                         if (j == inc->channelcount)
 444                                 sr_dbg("Did not find channel for identifier '%s'.", tokens[i]);
 445                 } else {
 446                         sr_warn("Skipping unknown token '%s'.", tokens[i]);
 447                 }
 448         }
 449         g_strfreev(tokens);
 450 }
 451
 452 static int init(struct sr_input *in, GHashTable *options)
 453 {
 454         int num_channels, i;
 455         char name[16];
 456         struct context *inc;
 457
 458         num_channels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
 459         if (num_channels < 1) {
 460                 sr_err("Invalid value for numchannels: must be at least 1.");
 461                 return SR_ERR_ARG;
 462         }
 463         inc = in->priv = g_malloc0(sizeof(struct context));
 464         inc->maxchannels = num_channels;
 465
 466         inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
 467         if (inc->downsample < 1)
 468                 inc->downsample = 1;
 469
 470         inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
 471         inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
 472         inc->skip /= inc->downsample;
 473
 474         in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
 475         in->priv = inc;
 476
 477         inc->buffer = g_malloc(CHUNKSIZE);
 478
 479         for (i = 0; i < num_channels; i++) {
 480                 snprintf(name, 16, "%d", i);
 481                 sr_channel_new(in->sdi, i, SR_CHANNEL_LOGIC, TRUE, name);
 482         }
 483
 484         return SR_OK;
 485 }
 486
 487 static gboolean have_header(GString *buf)
 488 {
 489         unsigned int pos;
 490         char *p;
 491
 492         if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
 493                 return FALSE;
 494         pos = p - buf->str + 15;
 495         while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
 496                 pos++;
 497         if (!strncmp(buf->str + pos, "$end", 4))
 498                 return TRUE;
 499
 500         return FALSE;
 501 }
 502
 503 static int process_buffer(struct sr_input *in)
 504 {
 505         struct sr_datafeed_packet packet;
 506         struct sr_datafeed_meta meta;
 507         struct sr_config *src;
 508         struct context *inc;
 509         uint64_t samplerate;
 510         char *p;
 511
 512         inc = in->priv;
 513         if (!inc->started) {
 514                 std_session_send_df_header(in->sdi, LOG_PREFIX);
 515
 516                 packet.type = SR_DF_META;
 517                 packet.payload = &meta;
 518                 samplerate = inc->samplerate / inc->downsample;
 519                 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
 520                 meta.config = g_slist_append(NULL, src);
 521                 sr_session_send(in->sdi, &packet);
 522                 g_slist_free(meta.config);
 523                 sr_config_free(src);
 524
 525                 inc->started = TRUE;
 526         }
 527
 528         while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
 529                 *p = '\0';
 530                 g_strstrip(in->buf->str);
 531                 if (in->buf->str[0] != '\0')
 532                         parse_contents(in, in->buf->str);
 533                 g_string_erase(in->buf, 0, p - in->buf->str + 1);
 534         }
 535
 536         return SR_OK;
 537 }
 538
 539 static int receive(struct sr_input *in, GString *buf)
 540 {
 541         struct context *inc;
 542         int ret;
 543
 544         g_string_append_len(in->buf, buf->str, buf->len);
 545
 546         inc = in->priv;
 547         if (!inc->got_header) {
 548                 if (!have_header(in->buf))
 549                         return SR_OK;
 550                 if (!parse_header(in, in->buf))
 551                         /* There was a header in there, but it was malformed. */
 552                         return SR_ERR;
 553
 554                 in->sdi_ready = TRUE;
 555                 /* sdi is ready, notify frontend. */
 556                 return SR_OK;
 557         }
 558
 559         ret = process_buffer(in);
 560
 561         return ret;
 562 }
 563
 564 static int end(struct sr_input *in)
 565 {
 566         struct sr_datafeed_packet packet;
 567         struct context *inc;
 568         int ret;
 569
 570         inc = in->priv;
 571
 572         if (in->sdi_ready)
 573                 ret = process_buffer(in);
 574         else
 575                 ret = SR_OK;
 576
 577         /* Send any samples that haven't been sent yet. */
 578         send_buffer(in);
 579
 580         if (inc->started) {
 581                 packet.type = SR_DF_END;
 582                 sr_session_send(in->sdi, &packet);
 583         }
 584
 585         return ret;
 586 }
 587
 588 static void cleanup(struct sr_input *in)
 589 {
 590         struct context *inc;
 591
 592         inc = in->priv;
 593         g_slist_free_full(inc->channels, free_channel);
 594         g_free(inc->buffer);
 595         inc->buffer = NULL;
 596         g_free(inc->current_levels);
 597         inc->current_levels = NULL;
 598 }
 599
 600 static struct sr_option options[] = {
 601         { "numchannels", "Number of channels", "Number of channels", NULL, NULL },
 602         { "skip", "Skip", "Skip until timestamp", NULL, NULL },
 603         { "downsample", "Downsample", "Divide samplerate by factor", NULL, NULL },
 604         { "compress", "Compress", "Compress idle periods longer than this value", NULL, NULL },
 605         ALL_ZERO
 606 };
 607
 608 static const struct sr_option *get_options(void)
 609 {
 610         if (!options[0].def) {
 611                 options[0].def = g_variant_ref_sink(g_variant_new_int32(DEFAULT_NUM_CHANNELS));
 612                 options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
 613                 options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
 614                 options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
 615         }
 616
 617         return options;
 618 }
 619
 620 SR_PRIV struct sr_input_module input_vcd = {
 621         .id = "vcd",
 622         .name = "VCD",
 623         .desc = "Value Change Dump",
 624         .exts = (const char*[]){"vcd", NULL},
 625         .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 626         .options = get_options,
 627         .format_match = format_match,
 628         .init = init,
 629         .receive = receive,
 630         .end = end,
 631         .cleanup = cleanup,
 632 };