[libsigrok.git] / soft-trigger.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"

/* @cond PRIVATE */
#define LOG_PREFIX "soft-trigger"
/* @endcond */

SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
		const struct sr_dev_inst *sdi, struct sr_trigger *trigger)
{
	struct soft_trigger_logic *stl;

	stl = g_malloc0(sizeof(struct soft_trigger_logic));
	stl->sdi = sdi;
	stl->trigger = trigger;
	stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
	stl->prev_sample = g_malloc0(stl->unitsize);

	return stl;
}

SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
{
	g_free(stl->prev_sample);
	g_free(stl);
}

static gboolean logic_check_match(struct soft_trigger_logic *stl,
		uint8_t *sample, struct sr_trigger_match *match)
{
	int bit, prev_bit;
	gboolean result;

	stl->count++;
	result = FALSE;
	bit = *(sample + match->channel->index / 8)
			& (1 << (match->channel->index % 8));
	if (match->match == SR_TRIGGER_ZERO)
		result = bit == 0;
	else if (match->match == SR_TRIGGER_ONE)
		result = bit != 0;
	else {
		/* Edge matches. */
		if (stl->count == 1)
			/* First sample, don't have enough for an edge match yet. */
			return FALSE;
		prev_bit = *(stl->prev_sample + match->channel->index / 8)
				& (1 << (match->channel->index % 8));
		if (match->match == SR_TRIGGER_RISING)
			result = prev_bit == 0 && bit != 0;
		else if (match->match == SR_TRIGGER_FALLING)
			result = prev_bit != 0 && bit == 0;
		else if (match->match == SR_TRIGGER_EDGE)
			result = prev_bit != bit;
	}

	return result;
}

/* Returns the offset (in samples) within buf of where the trigger
 * occurred, or -1 if not triggered. */
SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
		uint8_t *buf, int len)
{
	struct sr_datafeed_packet packet;
	struct sr_trigger_stage *stage;
	struct sr_trigger_match *match;
	GSList *l, *l_stage;
	int offset;
	int i;
	gboolean match_found;

	offset = -1;
	for (i = 0; i < len; i += stl->unitsize) {
		l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
		stage = l_stage->data;
		if (!stage->matches)
			/* No matches supplied, client error. */
			return SR_ERR_ARG;

		match_found = TRUE;
		for (l = stage->matches; l; l = l->next) {
			match = l->data;
			if (!match->channel->enabled)
				/* Ignore disabled channels with a trigger. */
				continue;
			if (!logic_check_match(stl, buf + i, match)) {
				match_found = FALSE;
				break;
			}
		}
		memcpy(stl->prev_sample, buf + i, stl->unitsize);
		if (match_found) {
			/* Matched on the current stage. */
			if (l_stage->next) {
				/* Advance to next stage. */
				stl->cur_stage++;
			} else {
				/* Matched on last stage, fire trigger. */
				offset = i / stl->unitsize;

				packet.type = SR_DF_TRIGGER;
				packet.payload = NULL;
				sr_session_send(stl->sdi, &packet);
				break;
			}
		} else if (stl->cur_stage > 0) {
			/*
			 * We had a match at an earlier stage, but failed on the
			 * current stage. However, we may have a match on this
			 * stage in the next bit -- trigger on 0001 will fail on
			 * seeing 00001, so we need to go back to stage 0 -- but
			 * at the next sample from the one that matched originally,
			 * which the counter increment at the end of the loop
			 * takes care of.
			 */
			i -= stl->cur_stage * stl->unitsize;
			if (i < -1)
				i = -1; /* Oops, went back past this buffer. */
			/* Reset trigger stage. */
			stl->cur_stage = 0;
		}
	}

	return offset;
}
Commit	Line	Data
ac136b57 BV	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 3 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <string.h>
	21	#include "libsigrok.h"
	22	#include "libsigrok-internal.h"
	23
	24	/* @cond PRIVATE */
	25	#define LOG_PREFIX "soft-trigger"
	26	/* @endcond */
	27
	28	SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
	29	const struct sr_dev_inst sdi, struct sr_trigger trigger)
	30	{
	31	struct soft_trigger_logic *stl;
	32
	33	stl = g_malloc0(sizeof(struct soft_trigger_logic));
	34	stl->sdi = sdi;
	35	stl->trigger = trigger;
	36	stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
	37	stl->prev_sample = g_malloc0(stl->unitsize);
	38
	39	return stl;
	40	}
	41
	42	SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
	43	{
	44	g_free(stl->prev_sample);
	45	g_free(stl);
	46	}
	47
	48	static gboolean logic_check_match(struct soft_trigger_logic *stl,
	49	uint8_t sample, struct sr_trigger_match match)
	50	{
	51	int bit, prev_bit;
	52	gboolean result;
	53
	54	stl->count++;
	55	result = FALSE;
	56	bit = *(sample + match->channel->index / 8)
	57	& (1 << (match->channel->index % 8));
	58	if (match->match == SR_TRIGGER_ZERO)
	59	result = bit == 0;
	60	else if (match->match == SR_TRIGGER_ONE)
	61	result = bit != 0;
	62	else {
	63	/* Edge matches. */
	64	if (stl->count == 1)
65	/* First sample, don't have enough for an edge match yet. */
66	return FALSE;
67	prev_bit = *(stl->prev_sample + match->channel->index / 8)
68	& (1 << (match->channel->index % 8));
69	if (match->match == SR_TRIGGER_RISING)
70	result = prev_bit == 0 && bit != 0;
71	else if (match->match == SR_TRIGGER_FALLING)
72	result = prev_bit != 0 && bit == 0;
73	else if (match->match == SR_TRIGGER_EDGE)
74	result = prev_bit != bit;
75	}
76
77	return result;
78	}
79
80	/* Returns the offset (in samples) within buf of where the trigger
81	* occurred, or -1 if not triggered. */
82	SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
83	uint8_t *buf, int len)
84	{
85	struct sr_datafeed_packet packet;
86	struct sr_trigger_stage *stage;
87	struct sr_trigger_match *match;
88	GSList l, l_stage;
89	int offset;
90	int i;
91	gboolean match_found;
92
93	offset = -1;
94	for (i = 0; i < len; i += stl->unitsize) {
95	l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
96	stage = l_stage->data;
97	if (!stage->matches)
98	/* No matches supplied, client error. */
99	return SR_ERR_ARG;
100
101	match_found = TRUE;
102	for (l = stage->matches; l; l = l->next) {
103	match = l->data;
104	if (!match->channel->enabled)
105	/* Ignore disabled channels with a trigger. */
106	continue;
107	if (!logic_check_match(stl, buf + i, match)) {
108	match_found = FALSE;
109	break;
110	}
111	}
112	memcpy(stl->prev_sample, buf + i, stl->unitsize);
113	if (match_found) {
114	/* Matched on the current stage. */
115	if (l_stage->next) {
116	/* Advance to next stage. */
117	stl->cur_stage++;
118	} else {
119	/* Matched on last stage, fire trigger. */
120	offset = i / stl->unitsize;
121
122	packet.type = SR_DF_TRIGGER;
123	packet.payload = NULL;
124	sr_session_send(stl->sdi, &packet);
125	break;
126	}
127	} else if (stl->cur_stage > 0) {
128	/*
129	* We had a match at an earlier stage, but failed on the
130	* current stage. However, we may have a match on this
131	* stage in the next bit -- trigger on 0001 will fail on
132	* seeing 00001, so we need to go back to stage 0 -- but
133	* at the next sample from the one that matched originally,
134	* which the counter increment at the end of the loop
135	* takes care of.
136	*/
137	i -= stl->cur_stage * stl->unitsize;
138	if (i < -1)
139	i = -1; /* Oops, went back past this buffer. */
140	/* Reset trigger stage. */
141	stl->cur_stage = 0;
142	}
143	}
144
145	return offset;
146	}
147