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         unsigned int unitsize;
  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         GVariant *gvar;
  51         int num_channels, i;
  52         char *samplerate_s, *frequency_s, *timestamp;
  53         time_t t;
  54
  55         if (!(ctx = g_try_malloc0(sizeof(struct context)))) {
  56                 sr_err("%s: ctx malloc failed", __func__);
  57                 return SR_ERR_MALLOC;
  58         }
  59
  60         o->internal = ctx;
  61         ctx->num_enabled_channels = 0;
  62         ctx->channelindices = g_array_new(FALSE, FALSE, sizeof(int));
  63
  64         for (l = o->sdi->channels; l; l = l->next) {
  65                 ch = l->data;
  66                 if (ch->type != SR_PROBE_LOGIC)
  67                         continue;
  68                 if (!ch->enabled)
  69                         continue;
  70                 ctx->channelindices = g_array_append_val(
  71                                 ctx->channelindices, ch->index);
  72                 ctx->num_enabled_channels++;
  73         }
  74         if (ctx->num_enabled_channels > 94) {
  75                 sr_err("VCD only supports 94 channels.");
  76                 return SR_ERR;
  77         }
  78
  79         ctx->unitsize = (ctx->num_enabled_channels + 7) / 8;
  80         ctx->header = g_string_sized_new(512);
  81         num_channels = g_slist_length(o->sdi->channels);
  82
  83         /* timestamp */
  84         t = time(NULL);
  85         timestamp = g_strdup(ctime(&t));
  86         timestamp[strlen(timestamp)-1] = 0;
  87         g_string_printf(ctx->header, "$date %s $end\n", timestamp);
  88         g_free(timestamp);
  89
  90         /* generator */
  91         g_string_append_printf(ctx->header, "$version %s %s $end\n",
  92                         PACKAGE, PACKAGE_VERSION);
  93
  94         if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
  95                         &gvar) == SR_OK) {
  96                 ctx->samplerate = g_variant_get_uint64(gvar);
  97                 g_variant_unref(gvar);
  98                 if (!((samplerate_s = sr_samplerate_string(ctx->samplerate)))) {
  99                         g_string_free(ctx->header, TRUE);
 100                         g_free(ctx);
 101                         return SR_ERR;
 102                 }
 103                 g_string_append_printf(ctx->header, vcd_header_comment,
 104                                  ctx->num_enabled_channels, num_channels, samplerate_s);
 105                 g_free(samplerate_s);
 106         }
 107
 108         /* timescale */
 109         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
 110         if (ctx->samplerate > SR_MHZ(1))
 111                 ctx->period = SR_GHZ(1);
 112         else if (ctx->samplerate > SR_KHZ(1))
 113                 ctx->period = SR_MHZ(1);
 114         else
 115                 ctx->period = SR_KHZ(1);
 116         if (!(frequency_s = sr_period_string(ctx->period))) {
 117                 g_string_free(ctx->header, TRUE);
 118                 g_free(ctx);
 119                 return SR_ERR;
 120         }
 121         g_string_append_printf(ctx->header, "$timescale %s $end\n", frequency_s);
 122         g_free(frequency_s);
 123
 124         /* scope */
 125         g_string_append_printf(ctx->header, "$scope module %s $end\n", PACKAGE);
 126
 127         /* Wires / channels */
 128         for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
 129                 ch = l->data;
 130                 if (ch->type != SR_PROBE_LOGIC)
 131                         continue;
 132                 if (!ch->enabled)
 133                         continue;
 134                 g_string_append_printf(ctx->header, "$var wire 1 %c %s $end\n",
 135                                 (char)('!' + i), ch->name);
 136         }
 137
 138         g_string_append(ctx->header, "$upscope $end\n"
 139                         "$enddefinitions $end\n");
 140
 141         if (!(ctx->prevsample = g_try_malloc0(ctx->unitsize))) {
 142                 g_string_free(ctx->header, TRUE);
 143                 g_free(ctx);
 144                 sr_err("%s: ctx->prevsample malloc failed", __func__);
 145                 return SR_ERR_MALLOC;
 146         }
 147
 148         return SR_OK;
 149 }
 150
 151 static int receive(struct sr_output *o, const struct sr_dev_inst *sdi,
 152                 const struct sr_datafeed_packet *packet, GString **out)
 153 {
 154         const struct sr_datafeed_logic *logic;
 155         struct context *ctx;
 156         unsigned int i;
 157         int p, curbit, prevbit, index;
 158         uint8_t *sample;
 159         gboolean timestamp_written;
 160
 161         (void)sdi;
 162
 163         *out = NULL;
 164         if (!o || !o->internal)
 165                 return SR_ERR_BUG;
 166         ctx = o->internal;
 167
 168         if (ctx->header) {
 169                 /* The header is still here, this must be the first packet. */
 170                 *out = ctx->header;
 171                 ctx->header = NULL;
 172                 ctx->samplecount = 0;
 173         } else {
 174                 *out = g_string_sized_new(512);
 175         }
 176
 177         if (packet->type != SR_DF_LOGIC) {
 178                 if (packet->type == SR_DF_END)
 179                         /* Write final timestamp as length indicator. */
 180                         g_string_append_printf(*out, "#%.0f\n",
 181                                 (double)ctx->samplecount /
 182                                         ctx->samplerate * ctx->period);
 183                 return SR_OK;
 184         }
 185
 186         logic = packet->payload;
 187         for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
 188                 sample = logic->data + i;
 189                 timestamp_written = FALSE;
 190
 191                 for (p = 0; p < ctx->num_enabled_channels; p++) {
 192                         index = g_array_index(ctx->channelindices, int, p);
 193
 194                         curbit = ((unsigned)sample[index / 8]
 195                                         >> (index % 8)) & 1;
 196                         prevbit = ((unsigned)ctx->prevsample[index / 8]
 197                                         >> (index % 8)) & 1;
 198
 199                         /* VCD only contains deltas/changes of signals. */
 200                         if (prevbit == curbit && ctx->samplecount > 0)
 201                                 continue;
 202
 203                         /* Output timestamp of subsequent signal changes. */
 204                         if (!timestamp_written)
 205                                 g_string_append_printf(*out, "#%.0f",
 206                                         (double)ctx->samplecount /
 207                                                 ctx->samplerate * ctx->period);
 208
 209                         /* Output which signal changed to which value. */
 210                         g_string_append_c(*out, ' ');
 211                         g_string_append_c(*out, '0' + curbit);
 212                         g_string_append_c(*out, '!' + p);
 213
 214                         timestamp_written = TRUE;
 215                 }
 216
 217                 if (timestamp_written)
 218                         g_string_append_c(*out, '\n');
 219
 220                 ctx->samplecount++;
 221                 memcpy(ctx->prevsample, sample, ctx->unitsize);
 222         }
 223
 224         return SR_OK;
 225 }
 226
 227 static int cleanup(struct sr_output *o)
 228 {
 229         struct context *ctx;
 230
 231         if (!o || !o->internal)
 232                 return SR_ERR_ARG;
 233
 234         ctx = o->internal;
 235         g_free(ctx);
 236
 237         return SR_OK;
 238 }
 239
 240 struct sr_output_format output_vcd = {
 241         .id = "vcd",
 242         .description = "Value Change Dump (VCD)",
 243         .df_type = SR_DF_LOGIC,
 244         .init = init,
 245         .receive = receive,
 246         .cleanup = cleanup,
 247 };