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 <libsigrok/libsigrok.h>
  26 #include "libsigrok-internal.h"
  27
  28 #define LOG_PREFIX "output/vcd"
  29
  30 struct context {
  31         int num_enabled_channels;
  32         GArray *channelindices;
  33         uint8_t *prevsample;
  34         gboolean header_done;
  35         int period;
  36         int *channel_index;
  37         uint64_t samplerate;
  38         uint64_t samplecount;
  39 };
  40
  41 static int init(struct sr_output *o, GHashTable *options)
  42 {
  43         struct context *ctx;
  44         struct sr_channel *ch;
  45         GSList *l;
  46         int num_enabled_channels, i;
  47
  48         (void)options;
  49
  50         num_enabled_channels = 0;
  51         for (l = o->sdi->channels; l; l = l->next) {
  52                 ch = l->data;
  53                 if (ch->type != SR_CHANNEL_LOGIC)
  54                         continue;
  55                 if (!ch->enabled)
  56                         continue;
  57                 num_enabled_channels++;
  58         }
  59         if (num_enabled_channels > 94) {
  60                 sr_err("VCD only supports 94 channels.");
  61                 return SR_ERR;
  62         }
  63
  64         ctx = g_malloc0(sizeof(struct context));
  65         o->priv = ctx;
  66         ctx->num_enabled_channels = num_enabled_channels;
  67         ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
  68
  69         /* Once more to map the enabled channels. */
  70         for (i = 0, l = o->sdi->channels; l; l = l->next) {
  71                 ch = l->data;
  72                 if (ch->type != SR_CHANNEL_LOGIC)
  73                         continue;
  74                 if (!ch->enabled)
  75                         continue;
  76                 ctx->channel_index[i++] = ch->index;
  77         }
  78
  79         return SR_OK;
  80 }
  81
  82 static GString *gen_header(const struct sr_output *o)
  83 {
  84         struct context *ctx;
  85         struct sr_channel *ch;
  86         GVariant *gvar;
  87         GString *header;
  88         GSList *l;
  89         time_t t;
  90         int num_channels, i;
  91         char *samplerate_s, *frequency_s, *timestamp;
  92
  93         ctx = o->priv;
  94         header = g_string_sized_new(512);
  95         num_channels = g_slist_length(o->sdi->channels);
  96
  97         /* timestamp */
  98         t = time(NULL);
  99         timestamp = g_strdup(ctime(&t));
 100         timestamp[strlen(timestamp)-1] = 0;
 101         g_string_printf(header, "$date %s $end\n", timestamp);
 102         g_free(timestamp);
 103
 104         /* generator */
 105         g_string_append_printf(header, "$version %s %s $end\n",
 106                         PACKAGE_NAME, SR_PACKAGE_VERSION_STRING);
 107         g_string_append_printf(header, "$comment\n  Acquisition with "
 108                         "%d/%d channels", ctx->num_enabled_channels, num_channels);
 109
 110         if (ctx->samplerate == 0) {
 111                 if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
 112                                 &gvar) == SR_OK) {
 113                         ctx->samplerate = g_variant_get_uint64(gvar);
 114                         g_variant_unref(gvar);
 115                 }
 116         }
 117         if (ctx->samplerate != 0) {
 118                 samplerate_s = sr_samplerate_string(ctx->samplerate);
 119                 g_string_append_printf(header, " at %s", samplerate_s);
 120                 g_free(samplerate_s);
 121         }
 122         g_string_append_printf(header, "\n$end\n");
 123
 124         /* timescale */
 125         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
 126         if (ctx->samplerate > SR_MHZ(1))
 127                 ctx->period = SR_GHZ(1);
 128         else if (ctx->samplerate > SR_KHZ(1))
 129                 ctx->period = SR_MHZ(1);
 130         else
 131                 ctx->period = SR_KHZ(1);
 132         frequency_s = sr_period_string(ctx->period);
 133         g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
 134         g_free(frequency_s);
 135
 136         /* scope */
 137         g_string_append_printf(header, "$scope module %s $end\n", PACKAGE_NAME);
 138
 139         /* Wires / channels */
 140         for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
 141                 ch = l->data;
 142                 if (ch->type != SR_CHANNEL_LOGIC)
 143                         continue;
 144                 if (!ch->enabled)
 145                         continue;
 146                 g_string_append_printf(header, "$var wire 1 %c %s $end\n",
 147                                 (char)('!' + i), ch->name);
 148         }
 149
 150         g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
 151
 152         return header;
 153 }
 154
 155 static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
 156                 GString **out)
 157 {
 158         const struct sr_datafeed_meta *meta;
 159         const struct sr_datafeed_logic *logic;
 160         const struct sr_config *src;
 161         GSList *l;
 162         struct context *ctx;
 163         unsigned int i;
 164         int p, curbit, prevbit, index;
 165         uint8_t *sample;
 166         gboolean timestamp_written;
 167
 168         *out = NULL;
 169         if (!o || !o->priv)
 170                 return SR_ERR_BUG;
 171         ctx = o->priv;
 172
 173         switch (packet->type) {
 174         case SR_DF_META:
 175                 meta = packet->payload;
 176                 for (l = meta->config; l; l = l->next) {
 177                         src = l->data;
 178                         if (src->key != SR_CONF_SAMPLERATE)
 179                                 continue;
 180                         ctx->samplerate = g_variant_get_uint64(src->data);
 181                 }
 182                 break;
 183         case SR_DF_LOGIC:
 184                 logic = packet->payload;
 185
 186                 if (!ctx->header_done) {
 187                         *out = gen_header(o);
 188                         ctx->header_done = TRUE;
 189                 } else {
 190                         *out = g_string_sized_new(512);
 191                 }
 192
 193                 if (!ctx->prevsample) {
 194                         /* Can't allocate this until we know the stream's unitsize. */
 195                         ctx->prevsample = g_malloc0(logic->unitsize);
 196                 }
 197
 198                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
 199                         sample = logic->data + i;
 200                         timestamp_written = FALSE;
 201
 202                         for (p = 0; p < ctx->num_enabled_channels; p++) {
 203                                 index = ctx->channel_index[p];
 204
 205                                 curbit = ((unsigned)sample[index / 8]
 206                                                 >> (index % 8)) & 1;
 207                                 prevbit = ((unsigned)ctx->prevsample[index / 8]
 208                                                 >> (index % 8)) & 1;
 209
 210                                 /* VCD only contains deltas/changes of signals. */
 211                                 if (prevbit == curbit && ctx->samplecount > 0)
 212                                         continue;
 213
 214                                 /* Output timestamp of subsequent signal changes. */
 215                                 if (!timestamp_written)
 216                                         g_string_append_printf(*out, "#%.0f",
 217                                                 (double)ctx->samplecount /
 218                                                         ctx->samplerate * ctx->period);
 219
 220                                 /* Output which signal changed to which value. */
 221                                 g_string_append_c(*out, ' ');
 222                                 g_string_append_c(*out, '0' + curbit);
 223                                 g_string_append_c(*out, '!' + p);
 224
 225                                 timestamp_written = TRUE;
 226                         }
 227
 228                         if (timestamp_written)
 229                                 g_string_append_c(*out, '\n');
 230
 231                         ctx->samplecount++;
 232                         memcpy(ctx->prevsample, sample, logic->unitsize);
 233                 }
 234                 break;
 235         case SR_DF_END:
 236                 /* Write final timestamp as length indicator. */
 237                 *out = g_string_sized_new(512);
 238                 g_string_printf(*out, "#%.0f\n",
 239                                 (double)ctx->samplecount / ctx->samplerate * ctx->period);
 240                 break;
 241         }
 242
 243         return SR_OK;
 244 }
 245
 246 static int cleanup(struct sr_output *o)
 247 {
 248         struct context *ctx;
 249
 250         if (!o || !o->priv)
 251                 return SR_ERR_ARG;
 252
 253         ctx = o->priv;
 254         g_free(ctx->prevsample);
 255         g_free(ctx->channel_index);
 256         g_free(ctx);
 257
 258         return SR_OK;
 259 }
 260
 261 struct sr_output_module output_vcd = {
 262         .id = "vcd",
 263         .name = "VCD",
 264         .desc = "Value Change Dump",
 265         .exts = (const char*[]){"vcd", NULL},
 266         .flags = 0,
 267         .options = NULL,
 268         .init = init,
 269         .receive = receive,
 270         .cleanup = cleanup,
 271 };