[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_try_malloc(stl->pre_trigger_size);
	if (pre_trigger_samples > 0 && !stl->pre_trigger_buffer) {
		/*
		 * Error out if g_try_malloc() failed (or was invoked as
		 * g_try_malloc(0)) *and* more than 0 pretrigger samples
		 * were requested.
		 */
		soft_trigger_logic_free(stl);
		return NULL;
	}
	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	40	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
d52107a1	41	stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size);
eca97729 UH	42	if (pre_trigger_samples > 0 && !stl->pre_trigger_buffer) {
	43	/*
	44	* Error out if g_try_malloc() failed (or was invoked as
	45	* g_try_malloc(0)) and more than 0 pretrigger samples
	46	* were requested.
	47	*/
d52107a1 UH	48	soft_trigger_logic_free(stl);
	49	return NULL;
	50	}
fe5a7355 AJ	51	stl->pre_trigger_head = stl->pre_trigger_buffer;
fe5a7355 AJ	52
98fec29e	53	if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
fe5a7355 AJ	54	soft_trigger_logic_free(stl);
	55	return NULL;
	56	}
ac136b57 BV	57
	58	return stl;
	59	}
	60
	61	SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
	62	{
fe5a7355	63	g_free(stl->pre_trigger_buffer);
ac136b57 BV	64	g_free(stl->prev_sample);
	65	g_free(stl);
	66	}
	67
fe5a7355 AJ	68	static void pre_trigger_append(struct soft_trigger_logic *stl,
	69	uint8_t *buf, int len)
	70	{
	71	/* Avoid uselessly copying more than the pre-trigger size. */
	72	if (len > stl->pre_trigger_size) {
	73	buf += len - stl->pre_trigger_size;
	74	len = stl->pre_trigger_size;
	75	}
	76
	77	/* Update the filling level of the pre-trigger circular buffer. */
	78	stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
	79	stl->pre_trigger_size);
	80
	81	/* Actually copy data to the pre-trigger circular buffer. */
	82	while (len > 0) {
	83	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	84	- stl->pre_trigger_head, len);
	85	memcpy(stl->pre_trigger_head, buf, size);
	86	stl->pre_trigger_head += size;
	87	if (stl->pre_trigger_head >= stl->pre_trigger_buffer
	88	+ stl->pre_trigger_size)
	89	stl->pre_trigger_head = stl->pre_trigger_buffer;
	90	buf += size;
	91	len -= size;
	92	}
	93	}
	94
	95	static void pre_trigger_send(struct soft_trigger_logic *stl,
	96	int *pre_trigger_samples)
	97	{
	98	struct sr_datafeed_packet packet;
	99	struct sr_datafeed_logic logic;
	100
	101	packet.type = SR_DF_LOGIC;
	102	packet.payload = &logic;
	103	logic.unitsize = stl->unitsize;
	104
	105	if (pre_trigger_samples)
	106	*pre_trigger_samples = 0;
	107
	108	/* If pre-trigger buffer not full, rewind head to the first valid sample. */
	109	if (stl->pre_trigger_fill < stl->pre_trigger_size)
	110	stl->pre_trigger_head = stl->pre_trigger_buffer;
	111
	112	/* Send logic packets for the pre-trigger circular buffer content. */
	113	while (stl->pre_trigger_fill > 0) {
	114	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	115	- stl->pre_trigger_head, stl->pre_trigger_fill);
	116	logic.length = size;
	117	logic.data = stl->pre_trigger_head;
	118	sr_session_send(stl->sdi, &packet);
	119	stl->pre_trigger_head = stl->pre_trigger_buffer;
	120	stl->pre_trigger_fill -= size;
	121	if (pre_trigger_samples)
	122	*pre_trigger_samples += size / stl->unitsize;
	123	}
	124	}
	125
ac136b57 BV	126	static gboolean logic_check_match(struct soft_trigger_logic *stl,
	127	uint8_t sample, struct sr_trigger_match match)
	128	{
	129	int bit, prev_bit;
	130	gboolean result;
	131
	132	stl->count++;
	133	result = FALSE;
	134	bit = *(sample + match->channel->index / 8)
	135	& (1 << (match->channel->index % 8));
	136	if (match->match == SR_TRIGGER_ZERO)
	137	result = bit == 0;
	138	else if (match->match == SR_TRIGGER_ONE)
	139	result = bit != 0;
	140	else {
	141	/* Edge matches. */
	142	if (stl->count == 1)
	143	/* First sample, don't have enough for an edge match yet. */
	144	return FALSE;
	145	prev_bit = *(stl->prev_sample + match->channel->index / 8)
	146	& (1 << (match->channel->index % 8));
	147	if (match->match == SR_TRIGGER_RISING)
	148	result = prev_bit == 0 && bit != 0;
	149	else if (match->match == SR_TRIGGER_FALLING)
	150	result = prev_bit != 0 && bit == 0;
	151	else if (match->match == SR_TRIGGER_EDGE)
	152	result = prev_bit != bit;
	153	}
	154
	155	return result;
	156	}
	157
	158	/* Returns the offset (in samples) within buf of where the trigger
	159	* occurred, or -1 if not triggered. */
	160	SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
fe5a7355	161	uint8_t buf, int len, int pre_trigger_samples)
ac136b57 BV	162	{
	163	struct sr_datafeed_packet packet;
	164	struct sr_trigger_stage *stage;
	165	struct sr_trigger_match *match;
	166	GSList l, l_stage;
	167	int offset;
	168	int i;
	169	gboolean match_found;
	170
	171	offset = -1;
	172	for (i = 0; i < len; i += stl->unitsize) {
	173	l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
	174	stage = l_stage->data;
	175	if (!stage->matches)
	176	/* No matches supplied, client error. */
	177	return SR_ERR_ARG;
	178
	179	match_found = TRUE;
	180	for (l = stage->matches; l; l = l->next) {
	181	match = l->data;
	182	if (!match->channel->enabled)
	183	/* Ignore disabled channels with a trigger. */
	184	continue;
	185	if (!logic_check_match(stl, buf + i, match)) {
	186	match_found = FALSE;
	187	break;
	188	}
	189	}
	190	memcpy(stl->prev_sample, buf + i, stl->unitsize);
	191	if (match_found) {
	192	/* Matched on the current stage. */
	193	if (l_stage->next) {
	194	/* Advance to next stage. */
	195	stl->cur_stage++;
	196	} else {
fe5a7355 AJ	197	/* Matched on last stage, send pre-trigger data. */
	198	pre_trigger_append(stl, buf, i);
	199	pre_trigger_send(stl, pre_trigger_samples);
	200
	201	/* Fire trigger. */
ac136b57 BV	202	offset = i / stl->unitsize;
	203
	204	packet.type = SR_DF_TRIGGER;
	205	packet.payload = NULL;
	206	sr_session_send(stl->sdi, &packet);
	207	break;
	208	}
	209	} else if (stl->cur_stage > 0) {
	210	/*
	211	* We had a match at an earlier stage, but failed on the
	212	* current stage. However, we may have a match on this
	213	* stage in the next bit -- trigger on 0001 will fail on
	214	* seeing 00001, so we need to go back to stage 0 -- but
	215	* at the next sample from the one that matched originally,
	216	* which the counter increment at the end of the loop
	217	* takes care of.
	218	*/
	219	i -= stl->cur_stage * stl->unitsize;
	220	if (i < -1)
	221	i = -1; /* Oops, went back past this buffer. */
	222	/* Reset trigger stage. */
	223	stl->cur_stage = 0;
	224	}
	225	}
	226
fe5a7355 AJ	227	if (offset == -1)
	228	pre_trigger_append(stl, buf, len);
	229
ac136b57 BV	230	return offset;
ac136b57 BV	231	}