[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 <config.h>
#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
6ec6c43b	20	#include <config.h>
ac136b57	21	#include <string.h>
c1aae900	22	#include <libsigrok/libsigrok.h>
ac136b57 BV	23	#include "libsigrok-internal.h"
	24
	25	/* @cond PRIVATE */
	26	#define LOG_PREFIX "soft-trigger"
	27	/* @endcond */
	28
	29	SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
fe5a7355 AJ	30	const struct sr_dev_inst sdi, struct sr_trigger trigger,
fe5a7355 AJ	31	int pre_trigger_samples)
ac136b57 BV	32	{
	33	struct soft_trigger_logic *stl;
	34
	35	stl = g_malloc0(sizeof(struct soft_trigger_logic));
	36	stl->sdi = sdi;
	37	stl->trigger = trigger;
	38	stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
	39	stl->prev_sample = g_malloc0(stl->unitsize);
fe5a7355 AJ	40	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
	41	stl->pre_trigger_buffer = g_malloc(stl->pre_trigger_size);
	42	stl->pre_trigger_head = stl->pre_trigger_buffer;
	43
98fec29e	44	if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
fe5a7355 AJ	45	soft_trigger_logic_free(stl);
	46	return NULL;
	47	}
ac136b57 BV	48
	49	return stl;
	50	}
	51
	52	SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
	53	{
fe5a7355	54	g_free(stl->pre_trigger_buffer);
ac136b57 BV	55	g_free(stl->prev_sample);
	56	g_free(stl);
	57	}
	58
fe5a7355 AJ	59	static void pre_trigger_append(struct soft_trigger_logic *stl,
	60	uint8_t *buf, int len)
	61	{
	62	/* Avoid uselessly copying more than the pre-trigger size. */
	63	if (len > stl->pre_trigger_size) {
	64	buf += len - stl->pre_trigger_size;
	65	len = stl->pre_trigger_size;
	66	}
	67
	68	/* Update the filling level of the pre-trigger circular buffer. */
	69	stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
	70	stl->pre_trigger_size);
	71
	72	/* Actually copy data to the pre-trigger circular buffer. */
	73	while (len > 0) {
	74	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	75	- stl->pre_trigger_head, len);
	76	memcpy(stl->pre_trigger_head, buf, size);
	77	stl->pre_trigger_head += size;
	78	if (stl->pre_trigger_head >= stl->pre_trigger_buffer
	79	+ stl->pre_trigger_size)
	80	stl->pre_trigger_head = stl->pre_trigger_buffer;
	81	buf += size;
	82	len -= size;
	83	}
	84	}
	85
	86	static void pre_trigger_send(struct soft_trigger_logic *stl,
	87	int *pre_trigger_samples)
	88	{
	89	struct sr_datafeed_packet packet;
	90	struct sr_datafeed_logic logic;
	91
	92	packet.type = SR_DF_LOGIC;
	93	packet.payload = &logic;
	94	logic.unitsize = stl->unitsize;
	95
	96	if (pre_trigger_samples)
	97	*pre_trigger_samples = 0;
	98
	99	/* If pre-trigger buffer not full, rewind head to the first valid sample. */
	100	if (stl->pre_trigger_fill < stl->pre_trigger_size)
	101	stl->pre_trigger_head = stl->pre_trigger_buffer;
	102
	103	/* Send logic packets for the pre-trigger circular buffer content. */
	104	while (stl->pre_trigger_fill > 0) {
	105	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	106	- stl->pre_trigger_head, stl->pre_trigger_fill);
	107	logic.length = size;
	108	logic.data = stl->pre_trigger_head;
	109	sr_session_send(stl->sdi, &packet);
	110	stl->pre_trigger_head = stl->pre_trigger_buffer;
	111	stl->pre_trigger_fill -= size;
	112	if (pre_trigger_samples)
	113	*pre_trigger_samples += size / stl->unitsize;
	114	}
	115	}
	116
ac136b57 BV	117	static gboolean logic_check_match(struct soft_trigger_logic *stl,
	118	uint8_t sample, struct sr_trigger_match match)
	119	{
	120	int bit, prev_bit;
	121	gboolean result;
	122
	123	stl->count++;
	124	result = FALSE;
	125	bit = *(sample + match->channel->index / 8)
	126	& (1 << (match->channel->index % 8));
	127	if (match->match == SR_TRIGGER_ZERO)
	128	result = bit == 0;
	129	else if (match->match == SR_TRIGGER_ONE)
	130	result = bit != 0;
	131	else {
	132	/* Edge matches. */
	133	if (stl->count == 1)
	134	/* First sample, don't have enough for an edge match yet. */
	135	return FALSE;
	136	prev_bit = *(stl->prev_sample + match->channel->index / 8)
	137	& (1 << (match->channel->index % 8));
	138	if (match->match == SR_TRIGGER_RISING)
	139	result = prev_bit == 0 && bit != 0;
	140	else if (match->match == SR_TRIGGER_FALLING)
	141	result = prev_bit != 0 && bit == 0;
	142	else if (match->match == SR_TRIGGER_EDGE)
	143	result = prev_bit != bit;
	144	}
	145
	146	return result;
	147	}
	148
	149	/* Returns the offset (in samples) within buf of where the trigger
	150	* occurred, or -1 if not triggered. */
	151	SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
fe5a7355	152	uint8_t buf, int len, int pre_trigger_samples)
ac136b57 BV	153	{
	154	struct sr_datafeed_packet packet;
	155	struct sr_trigger_stage *stage;
	156	struct sr_trigger_match *match;
	157	GSList l, l_stage;
	158	int offset;
	159	int i;
	160	gboolean match_found;
	161
	162	offset = -1;
	163	for (i = 0; i < len; i += stl->unitsize) {
	164	l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
	165	stage = l_stage->data;
	166	if (!stage->matches)
	167	/* No matches supplied, client error. */
	168	return SR_ERR_ARG;
	169
	170	match_found = TRUE;
	171	for (l = stage->matches; l; l = l->next) {
	172	match = l->data;
	173	if (!match->channel->enabled)
	174	/* Ignore disabled channels with a trigger. */
	175	continue;
	176	if (!logic_check_match(stl, buf + i, match)) {
	177	match_found = FALSE;
	178	break;
	179	}
	180	}
	181	memcpy(stl->prev_sample, buf + i, stl->unitsize);
	182	if (match_found) {
	183	/* Matched on the current stage. */
	184	if (l_stage->next) {
	185	/* Advance to next stage. */
	186	stl->cur_stage++;
	187	} else {
fe5a7355 AJ	188	/* Matched on last stage, send pre-trigger data. */
	189	pre_trigger_append(stl, buf, i);
	190	pre_trigger_send(stl, pre_trigger_samples);
	191
	192	/* Fire trigger. */
ac136b57 BV	193	offset = i / stl->unitsize;
	194
	195	packet.type = SR_DF_TRIGGER;
	196	packet.payload = NULL;
	197	sr_session_send(stl->sdi, &packet);
	198	break;
	199	}
	200	} else if (stl->cur_stage > 0) {
	201	/*
	202	* We had a match at an earlier stage, but failed on the
	203	* current stage. However, we may have a match on this
	204	* stage in the next bit -- trigger on 0001 will fail on
	205	* seeing 00001, so we need to go back to stage 0 -- but
	206	* at the next sample from the one that matched originally,
	207	* which the counter increment at the end of the loop
	208	* takes care of.
	209	*/
	210	i -= stl->cur_stage * stl->unitsize;
	211	if (i < -1)
	212	i = -1; /* Oops, went back past this buffer. */
	213	/* Reset trigger stage. */
	214	stl->cur_stage = 0;
	215	}
	216	}
	217
fe5a7355 AJ	218	if (offset == -1)
	219	pre_trigger_append(stl, buf, len);
	220
ac136b57 BV	221	return offset;
ac136b57 BV	222	}