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 int init(struct sr_output *o, GHashTable *options)
  43 {
  44         struct context *ctx;
  45         struct sr_channel *ch;
  46         GSList *l;
  47         int num_enabled_channels, i;
  48
  49         (void)options;
  50
  51         num_enabled_channels = 0;
  52         for (l = o->sdi->channels; l; l = l->next) {
  53                 ch = l->data;
  54                 if (ch->type != SR_CHANNEL_LOGIC)
  55                         continue;
  56                 if (!ch->enabled)
  57                         continue;
  58                 num_enabled_channels++;
  59         }
  60         if (num_enabled_channels > 94) {
  61                 sr_err("VCD only supports 94 channels.");
  62                 return SR_ERR;
  63         }
  64
  65         ctx = g_malloc0(sizeof(struct context));
  66         o->priv = ctx;
  67         ctx->num_enabled_channels = num_enabled_channels;
  68         ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
  69
  70         /* Once more to map the enabled channels. */
  71         for (i = 0, l = o->sdi->channels; l; l = l->next) {
  72                 ch = l->data;
  73                 if (ch->type != SR_CHANNEL_LOGIC)
  74                         continue;
  75                 if (!ch->enabled)
  76                         continue;
  77                 ctx->channel_index[i++] = ch->index;
  78         }
  79
  80         return SR_OK;
  81 }
  82
  83 static GString *gen_header(const struct sr_output *o)
  84 {
  85         struct context *ctx;
  86         struct sr_channel *ch;
  87         GVariant *gvar;
  88         GString *header;
  89         GSList *l;
  90         time_t t;
  91         int num_channels, i;
  92         char *samplerate_s, *frequency_s, *timestamp;
  93
  94         ctx = o->priv;
  95         header = g_string_sized_new(512);
  96         num_channels = g_slist_length(o->sdi->channels);
  97
  98         /* timestamp */
  99         t = time(NULL);
 100         timestamp = g_strdup(ctime(&t));
 101         timestamp[strlen(timestamp)-1] = 0;
 102         g_string_printf(header, "$date %s $end\n", timestamp);
 103         g_free(timestamp);
 104
 105         /* generator */
 106         g_string_append_printf(header, "$version %s %s $end\n",
 107                         PACKAGE, PACKAGE_VERSION);
 108         g_string_append_printf(header, "$comment\n  Acquisition with "
 109                         "%d/%d channels", ctx->num_enabled_channels, num_channels);
 110
 111         if (ctx->samplerate == 0) {
 112                 if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
 113                                 &gvar) == SR_OK) {
 114                         ctx->samplerate = g_variant_get_uint64(gvar);
 115                         g_variant_unref(gvar);
 116                 }
 117         }
 118         if (ctx->samplerate != 0) {
 119                 samplerate_s = sr_samplerate_string(ctx->samplerate);
 120                 g_string_append_printf(header, " at %s", samplerate_s);
 121                 g_free(samplerate_s);
 122         }
 123         g_string_append_printf(header, "\n$end\n");
 124
 125         /* timescale */
 126         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
 127         if (ctx->samplerate > SR_MHZ(1))
 128                 ctx->period = SR_GHZ(1);
 129         else if (ctx->samplerate > SR_KHZ(1))
 130                 ctx->period = SR_MHZ(1);
 131         else
 132                 ctx->period = SR_KHZ(1);
 133         frequency_s = sr_period_string(ctx->period);
 134         g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
 135         g_free(frequency_s);
 136
 137         /* scope */
 138         g_string_append_printf(header, "$scope module %s $end\n", PACKAGE);
 139
 140         /* Wires / channels */
 141         for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
 142                 ch = l->data;
 143                 if (ch->type != SR_CHANNEL_LOGIC)
 144                         continue;
 145                 if (!ch->enabled)
 146                         continue;
 147                 g_string_append_printf(header, "$var wire 1 %c %s $end\n",
 148                                 (char)('!' + i), ch->name);
 149         }
 150
 151         g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
 152
 153         return header;
 154 }
 155
 156 static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
 157                 GString **out)
 158 {
 159         const struct sr_datafeed_meta *meta;
 160         const struct sr_datafeed_logic *logic;
 161         const struct sr_config *src;
 162         GSList *l;
 163         struct context *ctx;
 164         unsigned int i;
 165         int p, curbit, prevbit, index;
 166         uint8_t *sample;
 167         gboolean timestamp_written;
 168
 169         *out = NULL;
 170         if (!o || !o->priv)
 171                 return SR_ERR_BUG;
 172         ctx = o->priv;
 173
 174         switch (packet->type) {
 175         case SR_DF_META:
 176                 meta = packet->payload;
 177                 for (l = meta->config; l; l = l->next) {
 178                         src = l->data;
 179                         if (src->key != SR_CONF_SAMPLERATE)
 180                                 continue;
 181                         ctx->samplerate = g_variant_get_uint64(src->data);
 182                 }
 183                 break;
 184         case SR_DF_LOGIC:
 185                 logic = packet->payload;
 186
 187                 if (!ctx->header_done) {
 188                         *out = gen_header(o);
 189                         ctx->header_done = TRUE;
 190                 } else {
 191                         *out = g_string_sized_new(512);
 192                 }
 193
 194                 if (!ctx->prevsample) {
 195                         /* Can't allocate this until we know the stream's unitsize. */
 196                         ctx->prevsample = g_malloc0(logic->unitsize);
 197                 }
 198
 199                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
 200                         sample = logic->data + i;
 201                         timestamp_written = FALSE;
 202
 203                         for (p = 0; p < ctx->num_enabled_channels; p++) {
 204                                 index = ctx->channel_index[p];
 205
 206                                 curbit = ((unsigned)sample[index / 8]
 207                                                 >> (index % 8)) & 1;
 208                                 prevbit = ((unsigned)ctx->prevsample[index / 8]
 209                                                 >> (index % 8)) & 1;
 210
 211                                 /* VCD only contains deltas/changes of signals. */
 212                                 if (prevbit == curbit && ctx->samplecount > 0)
 213                                         continue;
 214
 215                                 /* Output timestamp of subsequent signal changes. */
 216                                 if (!timestamp_written)
 217                                         g_string_append_printf(*out, "#%.0f",
 218                                                 (double)ctx->samplecount /
 219                                                         ctx->samplerate * ctx->period);
 220
 221                                 /* Output which signal changed to which value. */
 222                                 g_string_append_c(*out, ' ');
 223                                 g_string_append_c(*out, '0' + curbit);
 224                                 g_string_append_c(*out, '!' + p);
 225
 226                                 timestamp_written = TRUE;
 227                         }
 228
 229                         if (timestamp_written)
 230                                 g_string_append_c(*out, '\n');
 231
 232                         ctx->samplecount++;
 233                         memcpy(ctx->prevsample, sample, logic->unitsize);
 234                 }
 235                 break;
 236         case SR_DF_END:
 237                 /* Write final timestamp as length indicator. */
 238                 *out = g_string_sized_new(512);
 239                 g_string_printf(*out, "#%.0f\n",
 240                                 (double)ctx->samplecount / ctx->samplerate * ctx->period);
 241                 break;
 242         }
 243
 244         return SR_OK;
 245 }
 246
 247 static int cleanup(struct sr_output *o)
 248 {
 249         struct context *ctx;
 250
 251         if (!o || !o->priv)
 252                 return SR_ERR_ARG;
 253
 254         ctx = o->priv;
 255         g_free(ctx->prevsample);
 256         g_free(ctx->channel_index);
 257         g_free(ctx);
 258
 259         return SR_OK;
 260 }
 261
 262 struct sr_output_module output_vcd = {
 263         .id = "vcd",
 264         .name = "VCD",
 265         .desc = "Value Change Dump",
 266         .exts = (const char*[]){"vcd", NULL},
 267         .flags = 0,
 268         .options = NULL,
 269         .init = init,
 270         .receive = receive,
 271         .cleanup = cleanup,
 272 };