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, GHashTable *options)
  46 {
  47         struct context *ctx;
  48         struct sr_channel *ch;
  49         GSList *l;
  50         int num_enabled_channels, i;
  51
  52         (void)options;
  53
  54         num_enabled_channels = 0;
  55         for (l = o->sdi->channels; l; l = l->next) {
  56                 ch = l->data;
  57                 if (ch->type != SR_CHANNEL_LOGIC)
  58                         continue;
  59                 if (!ch->enabled)
  60                         continue;
  61                 num_enabled_channels++;
  62         }
  63         if (num_enabled_channels > 94) {
  64                 sr_err("VCD only supports 94 channels.");
  65                 return SR_ERR;
  66         }
  67
  68         ctx = g_malloc0(sizeof(struct context));
  69         o->priv = ctx;
  70         ctx->num_enabled_channels = num_enabled_channels;
  71         ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
  72
  73         /* Once more to map the enabled channels. */
  74         for (i = 0, l = o->sdi->channels; l; l = l->next) {
  75                 ch = l->data;
  76                 if (ch->type != SR_CHANNEL_LOGIC)
  77                         continue;
  78                 if (!ch->enabled)
  79                         continue;
  80                 ctx->channel_index[i++] = ch->index;
  81         }
  82
  83         return SR_OK;
  84 }
  85
  86 static GString *gen_header(const struct sr_output *o)
  87 {
  88         struct context *ctx;
  89         struct sr_channel *ch;
  90         GVariant *gvar;
  91         GString *header;
  92         GSList *l;
  93         time_t t;
  94         int num_channels, i;
  95         char *samplerate_s, *frequency_s, *timestamp;
  96
  97         ctx = o->priv;
  98         header = g_string_sized_new(512);
  99         num_channels = g_slist_length(o->sdi->channels);
 100
 101         /* timestamp */
 102         t = time(NULL);
 103         timestamp = g_strdup(ctime(&t));
 104         timestamp[strlen(timestamp)-1] = 0;
 105         g_string_printf(header, "$date %s $end\n", timestamp);
 106         g_free(timestamp);
 107
 108         /* generator */
 109         g_string_append_printf(header, "$version %s %s $end\n",
 110                         PACKAGE, PACKAGE_VERSION);
 111         g_string_append_printf(header, "$comment\n  Acquisition with "
 112                         "%d/%d channels", ctx->num_enabled_channels, num_channels);
 113
 114         if (ctx->samplerate == 0) {
 115                 if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
 116                                 &gvar) == SR_OK) {
 117                         ctx->samplerate = g_variant_get_uint64(gvar);
 118                         g_variant_unref(gvar);
 119                 }
 120         }
 121         if (ctx->samplerate != 0) {
 122                 samplerate_s = sr_samplerate_string(ctx->samplerate);
 123                 g_string_append_printf(header, " at %s", samplerate_s);
 124                 g_free(samplerate_s);
 125         }
 126         g_string_append_printf(header, "\n$end\n");
 127
 128         /* timescale */
 129         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
 130         if (ctx->samplerate > SR_MHZ(1))
 131                 ctx->period = SR_GHZ(1);
 132         else if (ctx->samplerate > SR_KHZ(1))
 133                 ctx->period = SR_MHZ(1);
 134         else
 135                 ctx->period = SR_KHZ(1);
 136         frequency_s = sr_period_string(ctx->period);
 137         g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
 138         g_free(frequency_s);
 139
 140         /* scope */
 141         g_string_append_printf(header, "$scope module %s $end\n", PACKAGE);
 142
 143         /* Wires / channels */
 144         for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
 145                 ch = l->data;
 146                 if (ch->type != SR_CHANNEL_LOGIC)
 147                         continue;
 148                 if (!ch->enabled)
 149                         continue;
 150                 g_string_append_printf(header, "$var wire 1 %c %s $end\n",
 151                                 (char)('!' + i), ch->name);
 152         }
 153
 154         g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
 155
 156         return header;
 157 }
 158
 159 static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
 160                 GString **out)
 161 {
 162         const struct sr_datafeed_meta *meta;
 163         const struct sr_datafeed_logic *logic;
 164         const struct sr_config *src;
 165         GSList *l;
 166         struct context *ctx;
 167         unsigned int i;
 168         int p, curbit, prevbit, index;
 169         uint8_t *sample;
 170         gboolean timestamp_written;
 171
 172         *out = NULL;
 173         if (!o || !o->priv)
 174                 return SR_ERR_BUG;
 175         ctx = o->priv;
 176
 177         switch (packet->type) {
 178         case SR_DF_META:
 179                 meta = packet->payload;
 180                 for (l = meta->config; l; l = l->next) {
 181                         src = l->data;
 182                         if (src->key != SR_CONF_SAMPLERATE)
 183                                 continue;
 184                         ctx->samplerate = g_variant_get_uint64(src->data);
 185                 }
 186                 break;
 187         case SR_DF_LOGIC:
 188                 logic = packet->payload;
 189
 190                 if (!ctx->header_done) {
 191                         *out = gen_header(o);
 192                         ctx->header_done = TRUE;
 193                 } else {
 194                         *out = g_string_sized_new(512);
 195                 }
 196
 197                 if (!ctx->prevsample) {
 198                         /* Can't allocate this until we know the stream's unitsize. */
 199                         ctx->prevsample = g_malloc0(logic->unitsize);
 200                 }
 201
 202                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
 203                         sample = logic->data + i;
 204                         timestamp_written = FALSE;
 205
 206                         for (p = 0; p < ctx->num_enabled_channels; p++) {
 207                                 index = ctx->channel_index[p];
 208
 209                                 curbit = ((unsigned)sample[index / 8]
 210                                                 >> (index % 8)) & 1;
 211                                 prevbit = ((unsigned)ctx->prevsample[index / 8]
 212                                                 >> (index % 8)) & 1;
 213
 214                                 /* VCD only contains deltas/changes of signals. */
 215                                 if (prevbit == curbit && ctx->samplecount > 0)
 216                                         continue;
 217
 218                                 /* Output timestamp of subsequent signal changes. */
 219                                 if (!timestamp_written)
 220                                         g_string_append_printf(*out, "#%.0f",
 221                                                 (double)ctx->samplecount /
 222                                                         ctx->samplerate * ctx->period);
 223
 224                                 /* Output which signal changed to which value. */
 225                                 g_string_append_c(*out, ' ');
 226                                 g_string_append_c(*out, '0' + curbit);
 227                                 g_string_append_c(*out, '!' + p);
 228
 229                                 timestamp_written = TRUE;
 230                         }
 231
 232                         if (timestamp_written)
 233                                 g_string_append_c(*out, '\n');
 234
 235                         ctx->samplecount++;
 236                         memcpy(ctx->prevsample, sample, logic->unitsize);
 237                 }
 238                 break;
 239         case SR_DF_END:
 240                 /* Write final timestamp as length indicator. */
 241                 *out = g_string_sized_new(512);
 242                 g_string_printf(*out, "#%.0f\n",
 243                                 (double)ctx->samplecount / ctx->samplerate * ctx->period);
 244                 break;
 245         }
 246
 247         return SR_OK;
 248 }
 249
 250 static int cleanup(struct sr_output *o)
 251 {
 252         struct context *ctx;
 253
 254         if (!o || !o->priv)
 255                 return SR_ERR_ARG;
 256
 257         ctx = o->priv;
 258         g_free(ctx->prevsample);
 259         g_free(ctx->channel_index);
 260         g_free(ctx);
 261
 262         return SR_OK;
 263 }
 264
 265 struct sr_output_module output_vcd = {
 266         .id = "vcd",
 267         .name = "VCD",
 268         .desc = "Value Change Dump",
 269         .options = NULL,
 270         .init = init,
 271         .receive = receive,
 272         .cleanup = cleanup,
 273 };