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 <stdlib.h>
  61 #include <glib.h>
  62 #include <stdio.h>
  63 #include <string.h>
  64 #include "libsigrok.h"
  65 #include "libsigrok-internal.h"
  66
  67 #define LOG_PREFIX "input/vcd"
  68
  69 #define DEFAULT_NUM_CHANNELS 8
  70 #define CHUNKSIZE 1024
  71
  72 struct context {
  73         gboolean got_header;
  74         uint64_t samplerate;
  75         unsigned int maxchannels;
  76         unsigned int channelcount;
  77         int downsample;
  78         unsigned compress;
  79         int64_t skip;
  80         gboolean skip_until_end;
  81         GSList *channels;
  82 };
  83
  84 struct vcd_channel {
  85         gchar *name;
  86         gchar *identifier;
  87 };
  88
  89
  90 /*
  91  * Reads a single VCD section from input file and parses it to name/contents.
  92  * e.g. $timescale 1ps $end  => "timescale" "1ps"
  93  */
  94 static gboolean parse_section(GString *buf, gchar **name, gchar **contents)
  95 {
  96         GString *sname, *scontent;
  97         gboolean status;
  98         unsigned int pos;
  99
 100         *name = *contents = NULL;
 101         status = FALSE;
 102         pos = 0;
 103
 104         /* Skip any initial white-space. */
 105         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 106                 pos++;
 107
 108         /* Section tag should start with $. */
 109         if (buf->str[pos++] != '$')
 110                 return FALSE;
 111
 112         sname = g_string_sized_new(32);
 113         scontent = g_string_sized_new(128);
 114
 115         /* Read the section tag. */
 116         while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
 117                 g_string_append_c(sname, buf->str[pos++]);
 118
 119         /* Skip whitespace before content. */
 120         while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 121                 pos++;
 122
 123         /* Read the content. */
 124         while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
 125                 g_string_append_c(scontent, buf->str[pos++]);
 126
 127         if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
 128                 status = TRUE;
 129                 pos += 4;
 130                 while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
 131                         pos++;
 132                 g_string_erase(buf, 0, pos);
 133         }
 134
 135         *name = g_string_free(sname, !status);
 136         *contents = g_string_free(scontent, !status);
 137         if (*contents)
 138                 g_strchomp(*contents);
 139
 140         return status;
 141 }
 142
 143 static void free_channel(void *data)
 144 {
 145         struct vcd_channel *vcd_ch = data;
 146         g_free(vcd_ch->name);
 147         g_free(vcd_ch->identifier);
 148         g_free(vcd_ch);
 149 }
 150
 151 /* Remove empty parts from an array returned by g_strsplit. */
 152 static void remove_empty_parts(gchar **parts)
 153 {
 154         gchar **src = parts;
 155         gchar **dest = parts;
 156         while (*src != NULL) {
 157                 if (**src != '\0')
 158                         *dest++ = *src;
 159                 src++;
 160         }
 161
 162         *dest = NULL;
 163 }
 164
 165 /*
 166  * Parse VCD header to get values for context structure.
 167  * The context structure should be zeroed before calling this.
 168  */
 169 static gboolean parse_header(const struct sr_input *in, GString *buf)
 170 {
 171         struct vcd_channel *vcd_ch;
 172         uint64_t p, q;
 173         struct context *inc;
 174         gboolean status;
 175         gchar *name, *contents, **parts;
 176
 177         inc = in->priv;
 178         name = contents = NULL;
 179         status = FALSE;
 180         while (parse_section(buf, &name, &contents)) {
 181                 sr_dbg("Section '%s', contents '%s'.", name, contents);
 182
 183                 if (g_strcmp0(name, "enddefinitions") == 0) {
 184                         status = TRUE;
 185                         break;
 186                 } else if (g_strcmp0(name, "timescale") == 0) {
 187                         /*
 188                          * The standard allows for values 1, 10 or 100
 189                          * and units s, ms, us, ns, ps and fs.
 190                          */
 191                         if (sr_parse_period(contents, &p, &q) == SR_OK) {
 192                                 inc->samplerate = q / p;
 193                                 if (q % p != 0) {
 194                                         /* Does not happen unless time value is non-standard */
 195                                         sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
 196                                                 q, p, inc->samplerate);
 197                                 }
 198
 199                                 sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 200                         } else {
 201                                 sr_err("Parsing timescale failed.");
 202                         }
 203                 } else if (g_strcmp0(name, "var") == 0) {
 204                         /* Format: $var type size identifier reference $end */
 205                         parts = g_strsplit_set(contents, " \r\n\t", 0);
 206                         remove_empty_parts(parts);
 207
 208                         if (g_strv_length(parts) != 4)
 209                                 sr_warn("$var section should have 4 items");
 210                         else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 211                                 sr_info("Unsupported signal type: '%s'", parts[0]);
 212                         else if (strtol(parts[1], NULL, 10) != 1)
 213                                 sr_info("Unsupported signal size: '%s'", parts[1]);
 214                         else if (inc->channelcount >= inc->maxchannels)
 215                                 sr_warn("Skipping '%s' because only %d channels requested.",
 216                                                 parts[3], inc->maxchannels);
 217                         else {
 218                                 sr_info("Channel %d is '%s' identified by '%s'.",
 219                                                 inc->channelcount, parts[3], parts[2]);
 220                                 vcd_ch = g_malloc(sizeof(struct vcd_channel));
 221                                 vcd_ch->identifier = g_strdup(parts[2]);
 222                                 vcd_ch->name = g_strdup(parts[3]);
 223                                 inc->channels = g_slist_append(inc->channels, vcd_ch);
 224                                 inc->channelcount++;
 225                         }
 226
 227                         g_strfreev(parts);
 228                 }
 229
 230                 g_free(name); name = NULL;
 231                 g_free(contents); contents = NULL;
 232         }
 233         g_free(name);
 234         g_free(contents);
 235
 236         inc->got_header = status;
 237
 238         return status;
 239 }
 240
 241 static int format_match(GHashTable *metadata)
 242 {
 243         GString *buf, *tmpbuf;
 244         gboolean status;
 245         gchar *name, *contents;
 246
 247         buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
 248         tmpbuf = g_string_new_len(buf->str, buf->len);
 249
 250         /*
 251          * If we can parse the first section correctly,
 252          * then it is assumed to be a VCD file.
 253          */
 254         status = parse_section(tmpbuf, &name, &contents);
 255         g_string_free(tmpbuf, TRUE);
 256         g_free(name);
 257         g_free(contents);
 258
 259         return status;
 260 }
 261
 262 /* Send N samples of the given value. */
 263 static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_t count)
 264 {
 265         struct sr_datafeed_packet packet;
 266         struct sr_datafeed_logic logic;
 267         uint64_t buffer[CHUNKSIZE];
 268         uint64_t i;
 269         unsigned chunksize = CHUNKSIZE;
 270
 271         if (count < chunksize)
 272                 chunksize = count;
 273
 274         for (i = 0; i < chunksize; i++)
 275                 buffer[i] = sample;
 276
 277         packet.type = SR_DF_LOGIC;
 278         packet.payload = &logic;
 279         logic.unitsize = sizeof(uint64_t);
 280         logic.data = buffer;
 281
 282         while (count) {
 283                 if (count < chunksize)
 284                         chunksize = count;
 285
 286                 logic.length = sizeof(uint64_t) * chunksize;
 287
 288                 sr_session_send(sdi, &packet);
 289                 count -= chunksize;
 290         }
 291 }
 292
 293 /* Parse a set of lines from the data section. */
 294 static void parse_contents(const struct sr_input *in, char *data)
 295 {
 296         struct context *inc;
 297         struct vcd_channel *vcd_ch;
 298         GSList *l;
 299         uint64_t timestamp, prev_timestamp, prev_values;
 300         unsigned int bit, i, j;
 301         char **tokens;
 302
 303         inc = in->priv;
 304         prev_timestamp = prev_values = 0;
 305
 306         /* Read one space-delimited token at a time. */
 307         tokens = g_strsplit_set(data, " \t\r\n", 0);
 308         remove_empty_parts(tokens);
 309         for (i = 0; tokens[i]; i++) {
 310                 if (inc->skip_until_end) {
 311                         if (!strcmp(tokens[i], "$end")) {
 312                                 /* Done with unhandled/unknown section. */
 313                                 inc->skip_until_end = FALSE;
 314                                 break;
 315                         }
 316                 }
 317                 if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 318                         /* Numeric value beginning with # is a new timestamp value */
 319                         timestamp = strtoull(tokens[i] + 1, NULL, 10);
 320
 321                         if (inc->downsample > 1)
 322                                 timestamp /= inc->downsample;
 323
 324                         /*
 325                          * Skip < 0 => skip until first timestamp.
 326                          * Skip = 0 => don't skip
 327                          * Skip > 0 => skip until timestamp >= skip.
 328                          */
 329                         if (inc->skip < 0) {
 330                                 inc->skip = timestamp;
 331                                 prev_timestamp = timestamp;
 332                         } else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
 333                                 prev_timestamp = inc->skip;
 334                         } else if (timestamp == prev_timestamp) {
 335                                 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
 336                         } else {
 337                                 if (inc->compress != 0 && timestamp - prev_timestamp > inc->compress) {
 338                                         /* Compress long idle periods */
 339                                         prev_timestamp = timestamp - inc->compress;
 340                                 }
 341
 342                                 sr_dbg("New timestamp: %" PRIu64, timestamp);
 343
 344                                 /* Generate samples from prev_timestamp up to timestamp - 1. */
 345                                 send_samples(in->sdi, prev_values, timestamp - prev_timestamp);
 346                                 prev_timestamp = timestamp;
 347                         }
 348                 } else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
 349                         /*
 350                          * This is probably a $dumpvars, $comment or similar.
 351                          * $dump* contain useful data.
 352                          */
 353                         if (g_strcmp0(tokens[i], "$dumpvars") == 0
 354                                         || g_strcmp0(tokens[i], "$dumpon") == 0
 355                                         || g_strcmp0(tokens[i], "$dumpoff") == 0
 356                                         || g_strcmp0(tokens[i], "$end") == 0) {
 357                                 /* Ignore, parse contents as normally. */
 358                         } else {
 359                                 /* Ignore this and future lines until $end. */
 360                                 inc->skip_until_end = TRUE;
 361                                 break;
 362                         }
 363                 } else if (strchr("bBrR", tokens[i][0]) != NULL) {
 364                         /* A vector value, not supported yet. */
 365                         break;
 366                 } else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
 367                         /* A new 1-bit sample value */
 368                         bit = (tokens[i][0] == '1');
 369
 370                         /*
 371                          * The identifier is either the next character, or, if
 372                          * there was whitespace after the bit, the next token.
 373                          */
 374                         if (tokens[i][1] == '\0') {
 375                                 if (!tokens[++i])
 376                                         /* Missing identifier */
 377                                         continue;
 378                         } else {
 379                                 for (j = 1; tokens[i][j]; j++)
 380                                         tokens[i][j - 1] = tokens[i][j];
 381                                 tokens[i][j - 1] = '\0';
 382                         }
 383
 384                         for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
 385                                 vcd_ch = l->data;
 386                                 if (g_strcmp0(tokens[i], vcd_ch->identifier) == 0) {
 387                                         /* Found our channel */
 388                                         if (bit)
 389                                                 prev_values |= (uint64_t)1 << j;
 390                                         else
 391                                                 prev_values &= ~((uint64_t)1 << j);
 392                                         break;
 393                                 }
 394                         }
 395                         if (j == inc->channelcount)
 396                                 sr_dbg("Did not find channel for identifier '%s'.", tokens[i]);
 397                 } else {
 398                         sr_warn("Skipping unknown token '%s'.", tokens[i]);
 399                 }
 400         }
 401         g_strfreev(tokens);
 402 }
 403
 404 static int init(struct sr_input *in, GHashTable *options)
 405 {
 406         struct sr_channel *ch;
 407         int num_channels, i;
 408         char name[16];
 409         struct context *inc;
 410
 411         inc = g_malloc0(sizeof(struct context));
 412
 413         num_channels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
 414         if (num_channels < 1) {
 415                 sr_err("Invalid value for numchannels: must be at least 1.");
 416                 return SR_ERR_ARG;
 417         }
 418         if (num_channels > 64) {
 419                 sr_err("No more than 64 channels supported.");
 420                 return SR_ERR_ARG;
 421         }
 422         inc->maxchannels = num_channels;
 423
 424         inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
 425         if (inc->downsample < 1)
 426                 inc->downsample = 1;
 427
 428         inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
 429         inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
 430         inc->skip /= inc->downsample;
 431
 432         /* Create a virtual device. */
 433         in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
 434         in->priv = inc;
 435
 436         for (i = 0; i < num_channels; i++) {
 437                 snprintf(name, 16, "%d", i);
 438                 ch = sr_channel_new(i, SR_CHANNEL_LOGIC, TRUE, name);
 439                 in->sdi->channels = g_slist_append(in->sdi->channels, ch);
 440         }
 441
 442         return SR_OK;
 443 }
 444
 445 static gboolean have_header(GString *buf)
 446 {
 447         unsigned int pos;
 448         char *p;
 449
 450         if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
 451                 return FALSE;
 452         pos = p - buf->str + 15;
 453         while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
 454                 pos++;
 455         if (!strncmp(buf->str + pos, "$end", 4))
 456                 return TRUE;
 457
 458         return FALSE;
 459 }
 460
 461 static int receive(const struct sr_input *in, GString *buf)
 462 {
 463         struct sr_datafeed_packet packet;
 464         struct sr_datafeed_meta meta;
 465         struct sr_config *src;
 466         struct context *inc;
 467         uint64_t samplerate;
 468         char *p;
 469
 470         if (buf->len == 0) {
 471                 /* End of stream. */
 472                 packet.type = SR_DF_END;
 473                 sr_session_send(in->sdi, &packet);
 474                 return SR_OK;
 475         }
 476
 477         g_string_append_len(in->buf, buf->str, buf->len);
 478
 479         inc = in->priv;
 480         if (!inc->got_header) {
 481                 if (!have_header(in->buf))
 482                         return SR_OK;
 483                 if (!parse_header(in, in->buf) != SR_OK)
 484                         /* There was a header in there, but it was malformed. */
 485                         return SR_ERR;
 486
 487                 std_session_send_df_header(in->sdi, LOG_PREFIX);
 488
 489                 packet.type = SR_DF_META;
 490                 packet.payload = &meta;
 491                 samplerate = inc->samplerate / inc->downsample;
 492                 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
 493                 meta.config = g_slist_append(NULL, src);
 494                 sr_session_send(in->sdi, &packet);
 495                 sr_config_free(src);
 496         }
 497
 498         while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
 499                 *p = '\0';
 500                 g_strstrip(in->buf->str);
 501                 if (in->buf->str[0] != '\0')
 502                         parse_contents(in, in->buf->str);
 503                 g_string_erase(in->buf, 0, p - in->buf->str + 1);
 504         }
 505
 506         return SR_OK;
 507 }
 508
 509 static int cleanup(struct sr_input *in)
 510 {
 511         struct context *inc;
 512
 513         inc = in->priv;
 514         g_slist_free_full(inc->channels, free_channel);
 515         g_free(inc);
 516         in->priv = NULL;
 517
 518         return SR_OK;
 519 }
 520
 521 static struct sr_option options[] = {
 522         { "numchannels", "Max channels", "Maximum number of channels", NULL, NULL },
 523         { "skip", "Skip", "Skip until timestamp", NULL, NULL },
 524         { "downsample", "Downsample", "Divide samplerate by factor", NULL, NULL },
 525         { "compress", "Compress", "Compress idle periods longer than this value", NULL, NULL },
 526         { 0 }
 527 };
 528
 529 static struct sr_option *get_options(void)
 530 {
 531         if (!options[0].def) {
 532                 options[0].def = g_variant_ref_sink(g_variant_new_int32(DEFAULT_NUM_CHANNELS));
 533                 options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
 534                 options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
 535                 options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
 536         }
 537
 538         return options;
 539 }
 540
 541 SR_PRIV struct sr_input_module input_vcd = {
 542         .id = "vcd",
 543         .name = "VCD",
 544         .desc = "Value Change Dump",
 545         .metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 546         .options = get_options,
 547         .format_match = format_match,
 548         .init = init,
 549         .receive = receive,
 550         .cleanup = cleanup,
 551 };