src/output/vcd.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
   5  * Copyright (C) 2013 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 2 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, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  20  */
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <glib.h>
  25 #include "config.h" /* Needed for PACKAGE and others. */
  26 #include "libsigrok.h"
  27 #include "libsigrok-internal.h"
  28
  29 #define LOG_PREFIX "output/vcd"
  30
  31 struct context {
  32         int num_enabled_channels;
  33         GArray *channelindices;
  34         uint8_t *prevsample;
  35         gboolean header_done;
  36         int period;
  37         int *channel_index;
  38         uint64_t samplerate;
  39         uint64_t samplecount;
  40 };
  41
  42 static const char *const vcd_header_comment =
  43         "$comment\n  Acquisition with %d/%d channels at %s\n$end\n";
  44
  45 static int init(struct sr_output *o)
  46 {
  47         struct context *ctx;
  48         struct sr_channel *ch;
  49         GSList *l;
  50         int num_enabled_channels, i;
  51
  52         num_enabled_channels = 0;
  53         for (l = o->sdi->channels; l; l = l->next) {
  54                 ch = l->data;
  55                 if (ch->type != SR_CHANNEL_LOGIC)
  56                         continue;
  57                 if (!ch->enabled)
  58                         continue;
  59                 num_enabled_channels++;
  60         }
  61         if (num_enabled_channels > 94) {
  62                 sr_err("VCD only supports 94 channels.");
  63                 return SR_ERR;
  64         }
  65
  66         ctx = g_malloc0(sizeof(struct context));
  67         o->internal = ctx;
  68         ctx->num_enabled_channels = num_enabled_channels;
  69         ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
  70
  71         /* Once more to map the enabled channels. */
  72         for (i = 0, l = o->sdi->channels; l; l = l->next) {
  73                 ch = l->data;
  74                 if (ch->type != SR_CHANNEL_LOGIC)
  75                         continue;
  76                 if (!ch->enabled)
  77                         continue;
  78                 ctx->channel_index[i++] = ch->index;
  79         }
  80
  81         return SR_OK;
  82 }
  83
  84 static GString *gen_header(struct sr_output *o)
  85 {
  86         struct context *ctx;
  87         struct sr_channel *ch;
  88         GVariant *gvar;
  89         GString *header;
  90         GSList *l;
  91         time_t t;
  92         int num_channels, i;
  93         char *samplerate_s, *frequency_s, *timestamp;
  94
  95         ctx = o->internal;
  96         header = g_string_sized_new(512);
  97         num_channels = g_slist_length(o->sdi->channels);
  98
  99         /* timestamp */
 100         t = time(NULL);
 101         timestamp = g_strdup(ctime(&t));
 102         timestamp[strlen(timestamp)-1] = 0;
 103         g_string_printf(header, "$date %s $end\n", timestamp);
 104         g_free(timestamp);
 105
 106         /* generator */
 107         g_string_append_printf(header, "$version %s %s $end\n",
 108                         PACKAGE, PACKAGE_VERSION);
 109         g_string_append_printf(header, "$comment\n  Acquisition with "
 110                         "%d/%d channels", ctx->num_enabled_channels, num_channels);
 111
 112         if (ctx->samplerate == 0) {
 113                 if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
 114                                 &gvar) == SR_OK) {
 115                         ctx->samplerate = g_variant_get_uint64(gvar);
 116                         g_variant_unref(gvar);
 117                 }
 118         }
 119         if (ctx->samplerate != 0) {
 120                 samplerate_s = sr_samplerate_string(ctx->samplerate);
 121                 g_string_append_printf(header, " at %s", samplerate_s);
 122                 g_free(samplerate_s);
 123         }
 124         g_string_append_printf(header, "\n$end\n");
 125
 126         /* timescale */
 127         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
 128         if (ctx->samplerate > SR_MHZ(1))
 129                 ctx->period = SR_GHZ(1);
 130         else if (ctx->samplerate > SR_KHZ(1))
 131                 ctx->period = SR_MHZ(1);
 132         else
 133                 ctx->period = SR_KHZ(1);
 134         frequency_s = sr_period_string(ctx->period);
 135         g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
 136         g_free(frequency_s);
 137
 138         /* scope */
 139         g_string_append_printf(header, "$scope module %s $end\n", PACKAGE);
 140
 141         /* Wires / channels */
 142         for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
 143                 ch = l->data;
 144                 if (ch->type != SR_CHANNEL_LOGIC)
 145                         continue;
 146                 if (!ch->enabled)
 147                         continue;
 148                 g_string_append_printf(header, "$var wire 1 %c %s $end\n",
 149                                 (char)('!' + i), ch->name);
 150         }
 151
 152         g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
 153
 154         return header;
 155 }
 156
 157 static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
 158                 GString **out)
 159 {
 160         const struct sr_datafeed_meta *meta;
 161         const struct sr_datafeed_logic *logic;
 162         const struct sr_config *src;
 163         GSList *l;
 164         struct context *ctx;
 165         unsigned int i;
 166         int p, curbit, prevbit, index;
 167         uint8_t *sample;
 168         gboolean timestamp_written;
 169
 170         *out = NULL;
 171         if (!o || !o->internal)
 172                 return SR_ERR_BUG;
 173         ctx = o->internal;
 174
 175         switch (packet->type) {
 176         case SR_DF_META:
 177                 meta = packet->payload;
 178                 for (l = meta->config; l; l = l->next) {
 179                         src = l->data;
 180                         if (src->key != SR_CONF_SAMPLERATE)
 181                                 continue;
 182                         ctx->samplerate = g_variant_get_uint64(src->data);
 183                 }
 184                 break;
 185         case SR_DF_LOGIC:
 186                 logic = packet->payload;
 187
 188                 if (!ctx->header_done) {
 189                         *out = gen_header(o);
 190                         ctx->header_done = TRUE;
 191                 } else {
 192                         *out = g_string_sized_new(512);
 193                 }
 194
 195                 if (!ctx->prevsample) {
 196                         /* Can't allocate this until we know the stream's unitsize. */
 197                         ctx->prevsample = g_malloc0(logic->unitsize);
 198                 }
 199
 200                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
 201                         sample = logic->data + i;
 202                         timestamp_written = FALSE;
 203
 204                         for (p = 0; p < ctx->num_enabled_channels; p++) {
 205                                 index = ctx->channel_index[p];
 206
 207                                 curbit = ((unsigned)sample[index / 8]
 208                                                 >> (index % 8)) & 1;
 209                                 prevbit = ((unsigned)ctx->prevsample[index / 8]
 210                                                 >> (index % 8)) & 1;
 211
 212                                 /* VCD only contains deltas/changes of signals. */
 213                                 if (prevbit == curbit && ctx->samplecount > 0)
 214                                         continue;
 215
 216                                 /* Output timestamp of subsequent signal changes. */
 217                                 if (!timestamp_written)
 218                                         g_string_append_printf(*out, "#%.0f",
 219                                                 (double)ctx->samplecount /
 220                                                         ctx->samplerate * ctx->period);
 221
 222                                 /* Output which signal changed to which value. */
 223                                 g_string_append_c(*out, ' ');
 224                                 g_string_append_c(*out, '0' + curbit);
 225                                 g_string_append_c(*out, '!' + p);
 226
 227                                 timestamp_written = TRUE;
 228                         }
 229
 230                         if (timestamp_written)
 231                                 g_string_append_c(*out, '\n');
 232
 233                         ctx->samplecount++;
 234                         memcpy(ctx->prevsample, sample, logic->unitsize);
 235                 }
 236                 break;
 237         case SR_DF_END:
 238                 /* Write final timestamp as length indicator. */
 239                 *out = g_string_sized_new(512);
 240                 g_string_printf(*out, "#%.0f\n",
 241                                 (double)ctx->samplecount / ctx->samplerate * ctx->period);
 242                 break;
 243         }
 244
 245         return SR_OK;
 246 }
 247
 248 static int cleanup(struct sr_output *o)
 249 {
 250         struct context *ctx;
 251
 252         if (!o || !o->internal)
 253                 return SR_ERR_ARG;
 254
 255         ctx = o->internal;
 256         g_free(ctx->prevsample);
 257         g_free(ctx->channel_index);
 258         g_free(ctx);
 259
 260         return SR_OK;
 261 }
 262
 263 struct sr_output_format output_vcd = {
 264         .id = "vcd",
 265         .description = "Value Change Dump (VCD)",
 266         .init = init,
 267         .receive = receive,
 268         .cleanup = cleanup,
 269 };