libsigrok
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vcd.c
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00001 /*
00002  * This file is part of the sigrok project.
00003  *
00004  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
00005  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
00006  *
00007  * This program is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * This program is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
00020  */
00021 
00022 #include <stdlib.h>
00023 #include <string.h>
00024 #include <glib.h>
00025 #include "config.h"
00026 #include "sigrok.h"
00027 #include "sigrok-internal.h"
00028 
00029 struct context {
00030         int num_enabled_probes;
00031         int unitsize;
00032         char *probelist[SR_MAX_NUM_PROBES + 1];
00033         int *prevbits;
00034         GString *header;
00035         uint64_t prevsample;
00036         int period;
00037         uint64_t samplerate;
00038 };
00039 
00040 static const char *vcd_header_comment = "\
00041 $comment\n  Acquisition with %d/%d probes at %s\n$end\n";
00042 
00043 static int init(struct sr_output *o)
00044 {
00045         struct context *ctx;
00046         struct sr_probe *probe;
00047         GSList *l;
00048         int num_probes, i;
00049         char *samplerate_s, *frequency_s, *timestamp;
00050         time_t t;
00051 
00052         if (!(ctx = g_try_malloc0(sizeof(struct context)))) {
00053                 sr_err("vcd out: %s: ctx malloc failed", __func__);
00054                 return SR_ERR_MALLOC;
00055         }
00056 
00057         o->internal = ctx;
00058         ctx->num_enabled_probes = 0;
00059 
00060         for (l = o->dev->probes; l; l = l->next) {
00061                 probe = l->data;
00062                 if (!probe->enabled)
00063                         continue;
00064                 ctx->probelist[ctx->num_enabled_probes++] = probe->name;
00065         }
00066         if (ctx->num_enabled_probes > 94) {
00067                 sr_err("vcd out: VCD only supports 94 probes.");
00068                 return SR_ERR;
00069         }
00070 
00071         ctx->probelist[ctx->num_enabled_probes] = 0;
00072         ctx->unitsize = (ctx->num_enabled_probes + 7) / 8;
00073         ctx->header = g_string_sized_new(512);
00074         num_probes = g_slist_length(o->dev->probes);
00075 
00076         /* timestamp */
00077         t = time(NULL);
00078         timestamp = g_strdup(ctime(&t));
00079         timestamp[strlen(timestamp)-1] = 0;
00080         g_string_printf(ctx->header, "$date %s $end\n", timestamp);
00081         g_free(timestamp);
00082 
00083         /* generator */
00084         g_string_append_printf(ctx->header, "$version %s %s $end\n",
00085                         PACKAGE, PACKAGE_VERSION);
00086 
00087         if (o->dev->driver && sr_dev_has_hwcap(o->dev, SR_HWCAP_SAMPLERATE)) {
00088                 ctx->samplerate = *((uint64_t *) o->dev->driver->dev_info_get(
00089                                 o->dev->driver_index, SR_DI_CUR_SAMPLERATE));
00090                 if (!((samplerate_s = sr_samplerate_string(ctx->samplerate)))) {
00091                         g_string_free(ctx->header, TRUE);
00092                         g_free(ctx);
00093                         return SR_ERR;
00094                 }
00095                 g_string_append_printf(ctx->header, vcd_header_comment,
00096                                  ctx->num_enabled_probes, num_probes, samplerate_s);
00097                 g_free(samplerate_s);
00098         }
00099 
00100         /* timescale */
00101         /* VCD can only handle 1/10/100 (s - fs), so scale up first */
00102         if (ctx->samplerate > SR_MHZ(1))
00103                 ctx->period = SR_GHZ(1);
00104         else if (ctx->samplerate > SR_KHZ(1))
00105                 ctx->period = SR_MHZ(1);
00106         else
00107                 ctx->period = SR_KHZ(1);
00108         if (!(frequency_s = sr_period_string(ctx->period))) {
00109                 g_string_free(ctx->header, TRUE);
00110                 g_free(ctx);
00111                 return SR_ERR;
00112         }
00113         g_string_append_printf(ctx->header, "$timescale %s $end\n", frequency_s);
00114         g_free(frequency_s);
00115 
00116         /* scope */
00117         g_string_append_printf(ctx->header, "$scope module %s $end\n", PACKAGE);
00118 
00119         /* Wires / channels */
00120         for (i = 0; i < ctx->num_enabled_probes; i++) {
00121                 g_string_append_printf(ctx->header, "$var wire 1 %c %s $end\n",
00122                                 (char)('!' + i), ctx->probelist[i]);
00123         }
00124 
00125         g_string_append(ctx->header, "$upscope $end\n"
00126                         "$enddefinitions $end\n$dumpvars\n");
00127 
00128         if (!(ctx->prevbits = g_try_malloc0(sizeof(int) * num_probes))) {
00129                 g_string_free(ctx->header, TRUE);
00130                 g_free(ctx);
00131                 sr_err("vcd out: %s: ctx->prevbits malloc failed", __func__);
00132                 return SR_ERR_MALLOC;
00133         }
00134 
00135         return SR_OK;
00136 }
00137 
00138 static int event(struct sr_output *o, int event_type, uint8_t **data_out,
00139                  uint64_t *length_out)
00140 {
00141         uint8_t *outbuf;
00142 
00143         switch (event_type) {
00144         case SR_DF_END:
00145                 outbuf = (uint8_t *)g_strdup("$dumpoff\n$end\n");
00146                 *data_out = outbuf;
00147                 *length_out = strlen((const char *)outbuf);
00148                 g_free(o->internal);
00149                 o->internal = NULL;
00150                 break;
00151         default:
00152                 *data_out = NULL;
00153                 *length_out = 0;
00154                 break;
00155         }
00156 
00157         return SR_OK;
00158 }
00159 
00160 static int data(struct sr_output *o, const uint8_t *data_in,
00161                 uint64_t length_in, uint8_t **data_out, uint64_t *length_out)
00162 {
00163         struct context *ctx;
00164         unsigned int i;
00165         int p, curbit, prevbit;
00166         uint64_t sample;
00167         static uint64_t samplecount = 0;
00168         GString *out;
00169         int first_sample = 0;
00170 
00171         ctx = o->internal;
00172         out = g_string_sized_new(512);
00173 
00174         if (ctx->header) {
00175                 /* The header is still here, this must be the first packet. */
00176                 g_string_append(out, ctx->header->str);
00177                 g_string_free(ctx->header, TRUE);
00178                 ctx->header = NULL;
00179                 first_sample = 1;
00180         }
00181 
00182         for (i = 0; i <= length_in - ctx->unitsize; i += ctx->unitsize) {
00183                 samplecount++;
00184 
00185                 memcpy(&sample, data_in + i, ctx->unitsize);
00186 
00187                 if (first_sample) {
00188                         /* First packet. We neg to make sure sample is stored. */
00189                         ctx->prevsample = ~sample;
00190                         first_sample = 0;
00191                 }
00192 
00193                 for (p = 0; p < ctx->num_enabled_probes; p++) {
00194                         curbit = (sample & ((uint64_t) (1 << p))) >> p;
00195                         prevbit = (ctx->prevsample & ((uint64_t) (1 << p))) >> p;
00196 
00197                         /* VCD only contains deltas/changes of signals. */
00198                         if (prevbit == curbit)
00199                                 continue;
00200 
00201                         /* Output which signal changed to which value. */
00202                         g_string_append_printf(out, "#%" PRIu64 "\n%i%c\n",
00203                                         (uint64_t)(((float)samplecount / ctx->samplerate)
00204                                         * ctx->period), curbit, (char)('!' + p));
00205                 }
00206 
00207                 ctx->prevsample = sample;
00208         }
00209 
00210         *data_out = (uint8_t *)out->str;
00211         *length_out = out->len;
00212         g_string_free(out, FALSE);
00213 
00214         return SR_OK;
00215 }
00216 
00217 struct sr_output_format output_vcd = {
00218         .id = "vcd",
00219         .description = "Value Change Dump (VCD)",
00220         .df_type = SR_DF_LOGIC,
00221         .init = init,
00222         .data = data,
00223         .event = event,
00224 };
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