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