adding support for export data into multiple formats

libsigrok4DSL/output/vcd.c

@@ -0,0 +1,271 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <glib.h>
+#include "config.h" /* Needed for PACKAGE and others. */
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#define LOG_PREFIX "output/vcd"
+
+struct context {
+	int num_enabled_channels;
+	GArray *channelindices;
+	uint8_t *prevsample;
+	gboolean header_done;
+	int period;
+	int *channel_index;
+	uint64_t samplerate;
+	uint64_t samplecount;
+};
+
+static int init(struct sr_output *o, GHashTable *options)
+{
+	struct context *ctx;
+	struct sr_channel *ch;
+	GSList *l;
+	int num_enabled_channels, i;
+
+	(void)options;
+
+	num_enabled_channels = 0;
+	for (l = o->sdi->channels; l; l = l->next) {
+		ch = l->data;
+		if (ch->type != SR_CHANNEL_LOGIC)
+			continue;
+		if (!ch->enabled)
+			continue;
+		num_enabled_channels++;
+	}
+	if (num_enabled_channels > 94) {
+		sr_err("VCD only supports 94 channels.");
+		return SR_ERR;
+	}
+
+	ctx = g_malloc0(sizeof(struct context));
+	o->priv = ctx;
+	ctx->num_enabled_channels = num_enabled_channels;
+	ctx->channel_index = g_malloc(sizeof(int) * ctx->num_enabled_channels);
+
+	/* Once more to map the enabled channels. */
+	for (i = 0, l = o->sdi->channels; l; l = l->next) {
+		ch = l->data;
+		if (ch->type != SR_CHANNEL_LOGIC)
+			continue;
+		if (!ch->enabled)
+			continue;
+		ctx->channel_index[i++] = ch->index;
+	}
+
+	return SR_OK;
+}
+
+static GString *gen_header(const struct sr_output *o)
+{
+	struct context *ctx;
+	struct sr_channel *ch;
+	GVariant *gvar;
+	GString *header;
+	GSList *l;
+	time_t t;
+	int num_channels, i;
+	char *samplerate_s, *frequency_s, *timestamp;
+
+	ctx = o->priv;
+	header = g_string_sized_new(512);
+	num_channels = g_slist_length(o->sdi->channels);
+
+	/* timestamp */
+	t = time(NULL);
+	timestamp = g_strdup(ctime(&t));
+	timestamp[strlen(timestamp)-1] = 0;
+	g_string_printf(header, "$date %s $end\n", timestamp);
+	g_free(timestamp);
+
+	/* generator */
+	g_string_append_printf(header, "$version %s %s $end\n",
+			PACKAGE, PACKAGE_VERSION);
+	g_string_append_printf(header, "$comment\n  Acquisition with "
+			"%d/%d channels", ctx->num_enabled_channels, num_channels);
+
+	if (ctx->samplerate == 0) {
+		if (sr_config_get(o->sdi->driver, o->sdi, NULL, NULL, SR_CONF_SAMPLERATE,
+				&gvar) == SR_OK) {
+			ctx->samplerate = g_variant_get_uint64(gvar);
+			g_variant_unref(gvar);
+		}
+	}
+	if (ctx->samplerate != 0) {
+		samplerate_s = sr_samplerate_string(ctx->samplerate);
+		g_string_append_printf(header, " at %s", samplerate_s);
+		g_free(samplerate_s);
+	}
+	g_string_append_printf(header, "\n$end\n");
+
+	/* timescale */
+	/* VCD can only handle 1/10/100 (s - fs), so scale up first */
+	if (ctx->samplerate > SR_MHZ(1))
+		ctx->period = SR_GHZ(1);
+	else if (ctx->samplerate > SR_KHZ(1))
+		ctx->period = SR_MHZ(1);
+	else
+		ctx->period = SR_KHZ(1);
+	frequency_s = sr_period_string(ctx->period);
+	g_string_append_printf(header, "$timescale %s $end\n", frequency_s);
+	g_free(frequency_s);
+
+	/* scope */
+	g_string_append_printf(header, "$scope module %s $end\n", PACKAGE);
+
+	/* Wires / channels */
+	for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
+		ch = l->data;
+		if (ch->type != SR_CHANNEL_LOGIC)
+			continue;
+		if (!ch->enabled)
+			continue;
+		g_string_append_printf(header, "$var wire 1 %c %s $end\n",
+				(char)('!' + i), ch->name);
+	}
+
+	g_string_append(header, "$upscope $end\n$enddefinitions $end\n");
+
+	return header;
+}
+
+static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
+		GString **out)
+{
+	const struct sr_datafeed_meta *meta;
+	const struct sr_datafeed_logic *logic;
+	const struct sr_config *src;
+	GSList *l;
+	struct context *ctx;
+	unsigned int i;
+	int p, curbit, prevbit, index;
+	uint8_t *sample;
+	gboolean timestamp_written;
+
+	*out = NULL;
+	if (!o || !o->priv)
+		return SR_ERR_BUG;
+	ctx = o->priv;
+
+	switch (packet->type) {
+	case SR_DF_META:
+		meta = packet->payload;
+		for (l = meta->config; l; l = l->next) {
+			src = l->data;
+			if (src->key != SR_CONF_SAMPLERATE)
+				continue;
+			ctx->samplerate = g_variant_get_uint64(src->data);
+		}
+		break;
+	case SR_DF_LOGIC:
+		logic = packet->payload;
+
+		if (!ctx->header_done) {
+			*out = gen_header(o);
+			ctx->header_done = TRUE;
+		} else {
+			*out = g_string_sized_new(512);
+		}
+
+		if (!ctx->prevsample) {
+			/* Can't allocate this until we know the stream's unitsize. */
+			ctx->prevsample = g_malloc0(logic->unitsize);
+		}
+
+		for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
+			sample = logic->data + i;
+			timestamp_written = FALSE;
+
+			for (p = 0; p < ctx->num_enabled_channels; p++) {
+				index = ctx->channel_index[p];
+
+				curbit = ((unsigned)sample[index / 8]
+						>> (index % 8)) & 1;
+				prevbit = ((unsigned)ctx->prevsample[index / 8]
+						>> (index % 8)) & 1;
+
+				/* VCD only contains deltas/changes of signals. */
+				if (prevbit == curbit && ctx->samplecount > 0)
+					continue;
+
+				/* Output timestamp of subsequent signal changes. */
+				if (!timestamp_written)
+					g_string_append_printf(*out, "#%.0f",
+						(double)ctx->samplecount /
+							ctx->samplerate * ctx->period);
+
+				/* Output which signal changed to which value. */
+				g_string_append_c(*out, ' ');
+				g_string_append_c(*out, '0' + curbit);
+				g_string_append_c(*out, '!' + p);
+
+				timestamp_written = TRUE;
+			}
+
+			if (timestamp_written)
+				g_string_append_c(*out, '\n');
+
+			ctx->samplecount++;
+			memcpy(ctx->prevsample, sample, logic->unitsize);
+		}
+		break;
+	case SR_DF_END:
+		/* Write final timestamp as length indicator. */
+		*out = g_string_sized_new(512);
+		g_string_printf(*out, "#%.0f\n",
+				(double)ctx->samplecount / ctx->samplerate * ctx->period);
+		break;
+	}
+
+	return SR_OK;
+}
+
+static int cleanup(struct sr_output *o)
+{
+	struct context *ctx;
+
+	if (!o || !o->priv)
+		return SR_ERR_ARG;
+
+	ctx = o->priv;
+	g_free(ctx->prevsample);
+	g_free(ctx->channel_index);
+	g_free(ctx);
+
+	return SR_OK;
+}
+
+struct sr_output_module output_vcd = {
+	.id = "vcd",
+	.name = "VCD",
+	.desc = "Value Change Dump",
+	.exts = (const char*[]){"vcd", NULL},
+	.options = NULL,
+	.init = init,
+	.receive = receive,
+	.cleanup = cleanup,
+};