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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
31struct 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
41static const char *const vcd_header_comment =
42 "$comment\n Acquisition with %d/%d channels at %s\n$end\n";
43
44static 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
142static int receive(struct sr_output *o, const struct sr_datafeed_packet *packet,
143 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 *out = NULL;
153 if (!o || !o->internal)
154 return SR_ERR_BUG;
155 ctx = o->internal;
156
157 if (ctx->header) {
158 /* The header is still here, this must be the first packet. */
159 *out = ctx->header;
160 ctx->header = NULL;
161 ctx->samplecount = 0;
162 } else {
163 *out = g_string_sized_new(512);
164 }
165
166 if (packet->type != SR_DF_LOGIC) {
167 if (packet->type == SR_DF_END)
168 /* Write final timestamp as length indicator. */
169 g_string_append_printf(*out, "#%.0f\n",
170 (double)ctx->samplecount /
171 ctx->samplerate * ctx->period);
172 return SR_OK;
173 }
174
175 logic = packet->payload;
176
177 if (!ctx->prevsample) {
178 /* Can't allocate this until we know the stream's unitsize. */
179 if (!(ctx->prevsample = g_malloc0(logic->unitsize))) {
180 g_free(ctx);
181 sr_err("%s: ctx->prevsample malloc failed", __func__);
182 return SR_ERR_MALLOC;
183 }
184 }
185
186 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
187 sample = logic->data + i;
188 timestamp_written = FALSE;
189
190 for (p = 0; p < ctx->num_enabled_channels; p++) {
191 index = g_array_index(ctx->channelindices, int, p);
192
193 curbit = ((unsigned)sample[index / 8]
194 >> (index % 8)) & 1;
195 prevbit = ((unsigned)ctx->prevsample[index / 8]
196 >> (index % 8)) & 1;
197
198 /* VCD only contains deltas/changes of signals. */
199 if (prevbit == curbit && ctx->samplecount > 0)
200 continue;
201
202 /* Output timestamp of subsequent signal changes. */
203 if (!timestamp_written)
204 g_string_append_printf(*out, "#%.0f",
205 (double)ctx->samplecount /
206 ctx->samplerate * ctx->period);
207
208 /* Output which signal changed to which value. */
209 g_string_append_c(*out, ' ');
210 g_string_append_c(*out, '0' + curbit);
211 g_string_append_c(*out, '!' + p);
212
213 timestamp_written = TRUE;
214 }
215
216 if (timestamp_written)
217 g_string_append_c(*out, '\n');
218
219 ctx->samplecount++;
220 memcpy(ctx->prevsample, sample, logic->unitsize);
221 }
222
223 return SR_OK;
224}
225
226static int cleanup(struct sr_output *o)
227{
228 struct context *ctx;
229
230 if (!o || !o->internal)
231 return SR_ERR_ARG;
232
233 ctx = o->internal;
234 g_free(ctx->prevsample);
235 g_array_free(ctx->channelindices, TRUE);
236 g_free(ctx);
237
238 return SR_OK;
239}
240
241struct sr_output_format output_vcd = {
242 .id = "vcd",
243 .description = "Value Change Dump (VCD)",
244 .init = init,
245 .receive = receive,
246 .cleanup = cleanup,
247};