[libsigrok.git] / src / 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/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,
		int pre_trigger_samples)
{
	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);
	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
	stl->pre_trigger_buffer = g_malloc(stl->pre_trigger_size);
	stl->pre_trigger_head = stl->pre_trigger_buffer;

	if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
		soft_trigger_logic_free(stl);
		return NULL;
	}

	return stl;
}

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

static void pre_trigger_append(struct soft_trigger_logic *stl,
		uint8_t *buf, int len)
{
	/* Avoid uselessly copying more than the pre-trigger size. */
	if (len > stl->pre_trigger_size) {
		buf += len - stl->pre_trigger_size;
		len = stl->pre_trigger_size;
	}

	/* Update the filling level of the pre-trigger circular buffer. */
	stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
	                            stl->pre_trigger_size);

	/* Actually copy data to the pre-trigger circular buffer. */
	while (len > 0) {
		size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
		                  - stl->pre_trigger_head, len);
		memcpy(stl->pre_trigger_head, buf, size);
		stl->pre_trigger_head += size;
		if (stl->pre_trigger_head >= stl->pre_trigger_buffer
		                             + stl->pre_trigger_size)
			stl->pre_trigger_head = stl->pre_trigger_buffer;
		buf += size;
		len -= size;
	}
}

static void pre_trigger_send(struct soft_trigger_logic *stl,
		int *pre_trigger_samples)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_logic logic;

	packet.type = SR_DF_LOGIC;
	packet.payload = &logic;
	logic.unitsize = stl->unitsize;

	if (pre_trigger_samples)
		*pre_trigger_samples = 0;

	/* If pre-trigger buffer not full, rewind head to the first valid sample. */
	if (stl->pre_trigger_fill < stl->pre_trigger_size)
		stl->pre_trigger_head = stl->pre_trigger_buffer;

	/* Send logic packets for the pre-trigger circular buffer content. */
	while (stl->pre_trigger_fill > 0) {
		size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
		                  - stl->pre_trigger_head, stl->pre_trigger_fill);
		logic.length = size;
		logic.data = stl->pre_trigger_head;
		sr_session_send(stl->sdi, &packet);
		stl->pre_trigger_head = stl->pre_trigger_buffer;
		stl->pre_trigger_fill -= size;
		if (pre_trigger_samples)
			*pre_trigger_samples += size / stl->unitsize;
	}
}

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, int *pre_trigger_samples)
{
	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, send pre-trigger data. */
				pre_trigger_append(stl, buf, i);
				pre_trigger_send(stl, pre_trigger_samples);

				/* 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;
		}
	}

	if (offset == -1)
		pre_trigger_append(stl, buf, len);

	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>
c1aae900	21	#include <libsigrok/libsigrok.h>
ac136b57 BV	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(
fe5a7355 AJ	29	const struct sr_dev_inst sdi, struct sr_trigger trigger,
fe5a7355 AJ	30	int pre_trigger_samples)
ac136b57 BV	31	{
	32	struct soft_trigger_logic *stl;
	33
	34	stl = g_malloc0(sizeof(struct soft_trigger_logic));
	35	stl->sdi = sdi;
	36	stl->trigger = trigger;
	37	stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
	38	stl->prev_sample = g_malloc0(stl->unitsize);
fe5a7355 AJ	39	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
	40	stl->pre_trigger_buffer = g_malloc(stl->pre_trigger_size);
	41	stl->pre_trigger_head = stl->pre_trigger_buffer;
	42
98fec29e	43	if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
fe5a7355 AJ	44	soft_trigger_logic_free(stl);
	45	return NULL;
	46	}
ac136b57 BV	47
	48	return stl;
	49	}
	50
	51	SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
	52	{
fe5a7355	53	g_free(stl->pre_trigger_buffer);
ac136b57 BV	54	g_free(stl->prev_sample);
	55	g_free(stl);
	56	}
	57
fe5a7355 AJ	58	static void pre_trigger_append(struct soft_trigger_logic *stl,
	59	uint8_t *buf, int len)
	60	{
	61	/* Avoid uselessly copying more than the pre-trigger size. */
	62	if (len > stl->pre_trigger_size) {
	63	buf += len - stl->pre_trigger_size;
	64	len = stl->pre_trigger_size;
	65	}
	66
	67	/* Update the filling level of the pre-trigger circular buffer. */
	68	stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
	69	stl->pre_trigger_size);
	70
	71	/* Actually copy data to the pre-trigger circular buffer. */
	72	while (len > 0) {
	73	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	74	- stl->pre_trigger_head, len);
	75	memcpy(stl->pre_trigger_head, buf, size);
	76	stl->pre_trigger_head += size;
	77	if (stl->pre_trigger_head >= stl->pre_trigger_buffer
	78	+ stl->pre_trigger_size)
	79	stl->pre_trigger_head = stl->pre_trigger_buffer;
	80	buf += size;
	81	len -= size;
	82	}
	83	}
	84
	85	static void pre_trigger_send(struct soft_trigger_logic *stl,
	86	int *pre_trigger_samples)
	87	{
	88	struct sr_datafeed_packet packet;
	89	struct sr_datafeed_logic logic;
	90
	91	packet.type = SR_DF_LOGIC;
	92	packet.payload = &logic;
	93	logic.unitsize = stl->unitsize;
	94
	95	if (pre_trigger_samples)
	96	*pre_trigger_samples = 0;
	97
	98	/* If pre-trigger buffer not full, rewind head to the first valid sample. */
	99	if (stl->pre_trigger_fill < stl->pre_trigger_size)
	100	stl->pre_trigger_head = stl->pre_trigger_buffer;
	101
	102	/* Send logic packets for the pre-trigger circular buffer content. */
	103	while (stl->pre_trigger_fill > 0) {
	104	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	105	- stl->pre_trigger_head, stl->pre_trigger_fill);
	106	logic.length = size;
	107	logic.data = stl->pre_trigger_head;
	108	sr_session_send(stl->sdi, &packet);
	109	stl->pre_trigger_head = stl->pre_trigger_buffer;
	110	stl->pre_trigger_fill -= size;
	111	if (pre_trigger_samples)
	112	*pre_trigger_samples += size / stl->unitsize;
	113	}
	114	}
	115
ac136b57 BV	116	static gboolean logic_check_match(struct soft_trigger_logic *stl,
	117	uint8_t sample, struct sr_trigger_match match)
	118	{
	119	int bit, prev_bit;
	120	gboolean result;
	121
	122	stl->count++;
	123	result = FALSE;
	124	bit = *(sample + match->channel->index / 8)
	125	& (1 << (match->channel->index % 8));
	126	if (match->match == SR_TRIGGER_ZERO)
	127	result = bit == 0;
	128	else if (match->match == SR_TRIGGER_ONE)
	129	result = bit != 0;
	130	else {
	131	/* Edge matches. */
	132	if (stl->count == 1)
	133	/* First sample, don't have enough for an edge match yet. */
	134	return FALSE;
	135	prev_bit = *(stl->prev_sample + match->channel->index / 8)
	136	& (1 << (match->channel->index % 8));
	137	if (match->match == SR_TRIGGER_RISING)
	138	result = prev_bit == 0 && bit != 0;
	139	else if (match->match == SR_TRIGGER_FALLING)
	140	result = prev_bit != 0 && bit == 0;
	141	else if (match->match == SR_TRIGGER_EDGE)
	142	result = prev_bit != bit;
	143	}
	144
	145	return result;
	146	}
	147
	148	/* Returns the offset (in samples) within buf of where the trigger
	149	* occurred, or -1 if not triggered. */
	150	SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
fe5a7355	151	uint8_t buf, int len, int pre_trigger_samples)
ac136b57 BV	152	{
	153	struct sr_datafeed_packet packet;
	154	struct sr_trigger_stage *stage;
	155	struct sr_trigger_match *match;
	156	GSList l, l_stage;
	157	int offset;
	158	int i;
	159	gboolean match_found;
	160
	161	offset = -1;
	162	for (i = 0; i < len; i += stl->unitsize) {
	163	l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
	164	stage = l_stage->data;
	165	if (!stage->matches)
	166	/* No matches supplied, client error. */
	167	return SR_ERR_ARG;
	168
	169	match_found = TRUE;
	170	for (l = stage->matches; l; l = l->next) {
	171	match = l->data;
	172	if (!match->channel->enabled)
	173	/* Ignore disabled channels with a trigger. */
	174	continue;
	175	if (!logic_check_match(stl, buf + i, match)) {
	176	match_found = FALSE;
	177	break;
	178	}
	179	}
	180	memcpy(stl->prev_sample, buf + i, stl->unitsize);
	181	if (match_found) {
	182	/* Matched on the current stage. */
	183	if (l_stage->next) {
	184	/* Advance to next stage. */
	185	stl->cur_stage++;
	186	} else {
fe5a7355 AJ	187	/* Matched on last stage, send pre-trigger data. */
	188	pre_trigger_append(stl, buf, i);
	189	pre_trigger_send(stl, pre_trigger_samples);
	190
	191	/* Fire trigger. */
ac136b57 BV	192	offset = i / stl->unitsize;
	193
	194	packet.type = SR_DF_TRIGGER;
	195	packet.payload = NULL;
	196	sr_session_send(stl->sdi, &packet);
	197	break;
	198	}
	199	} else if (stl->cur_stage > 0) {
	200	/*
	201	* We had a match at an earlier stage, but failed on the
	202	* current stage. However, we may have a match on this
	203	* stage in the next bit -- trigger on 0001 will fail on
	204	* seeing 00001, so we need to go back to stage 0 -- but
	205	* at the next sample from the one that matched originally,
	206	* which the counter increment at the end of the loop
	207	* takes care of.
	208	*/
	209	i -= stl->cur_stage * stl->unitsize;
	210	if (i < -1)
	211	i = -1; /* Oops, went back past this buffer. */
	212	/* Reset trigger stage. */
	213	stl->cur_stage = 0;
	214	}
	215	}
	216
fe5a7355 AJ	217	if (offset == -1)
	218	pre_trigger_append(stl, buf, len);
	219
ac136b57 BV	220	return offset;
ac136b57 BV	221	}