[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 int logic_channel_unitsize(GSList *channels)
{
	int number = 0;
	struct sr_channel *channel;
	GSList *l;

	for (l = channels; l; l = l->next) {
		channel = l->data;
		if (channel->type == SR_CHANNEL_LOGIC)
			number++;
	}

	return (number + 7) / 8;
}

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 = logic_channel_unitsize(sdi->channels);
	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_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;

				std_session_send_df_trigger(stl->sdi);
				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"
ac136b57 BV	24
82b9f3d1	25	/** @cond PRIVATE */
ac136b57	26	#define LOG_PREFIX "soft-trigger"
82b9f3d1	27	/** @endcond */
ac136b57	28
d1078180	29	SR_PRIV int logic_channel_unitsize(GSList *channels)
6fc51fb1	30	{
d1078180	31	int number = 0;
6fc51fb1	32	struct sr_channel *channel;
	33	GSList *l;
	34
	35	for (l = channels; l; l = l->next) {
	36	channel = l->data;
	37	if (channel->type == SR_CHANNEL_LOGIC)
d1078180	38	number++;
6fc51fb1	39	}
6fc51fb1	40
d1078180 SA	41	return (number + 7) / 8;
d1078180 SA	42	}
6fc51fb1	43
ac136b57	44	SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
fe5a7355 AJ	45	const struct sr_dev_inst sdi, struct sr_trigger trigger,
fe5a7355 AJ	46	int pre_trigger_samples)
ac136b57 BV	47	{
	48	struct soft_trigger_logic *stl;
	49
	50	stl = g_malloc0(sizeof(struct soft_trigger_logic));
	51	stl->sdi = sdi;
	52	stl->trigger = trigger;
6fc51fb1	53	stl->unitsize = logic_channel_unitsize(sdi->channels);
ac136b57	54	stl->prev_sample = g_malloc0(stl->unitsize);
fe5a7355	55	stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
d52107a1	56	stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size);
eca97729 UH	57	if (pre_trigger_samples > 0 && !stl->pre_trigger_buffer) {
	58	/*
	59	* Error out if g_try_malloc() failed (or was invoked as
	60	* g_try_malloc(0)) and more than 0 pretrigger samples
	61	* were requested.
	62	*/
d52107a1 UH	63	soft_trigger_logic_free(stl);
	64	return NULL;
	65	}
fe5a7355 AJ	66	stl->pre_trigger_head = stl->pre_trigger_buffer;
fe5a7355 AJ	67
98fec29e	68	if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
fe5a7355 AJ	69	soft_trigger_logic_free(stl);
	70	return NULL;
	71	}
ac136b57 BV	72
	73	return stl;
	74	}
	75
	76	SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
	77	{
fe5a7355	78	g_free(stl->pre_trigger_buffer);
ac136b57 BV	79	g_free(stl->prev_sample);
	80	g_free(stl);
	81	}
	82
fe5a7355 AJ	83	static void pre_trigger_append(struct soft_trigger_logic *stl,
	84	uint8_t *buf, int len)
	85	{
	86	/* Avoid uselessly copying more than the pre-trigger size. */
	87	if (len > stl->pre_trigger_size) {
	88	buf += len - stl->pre_trigger_size;
	89	len = stl->pre_trigger_size;
	90	}
	91
	92	/* Update the filling level of the pre-trigger circular buffer. */
	93	stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
	94	stl->pre_trigger_size);
	95
	96	/* Actually copy data to the pre-trigger circular buffer. */
	97	while (len > 0) {
	98	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	99	- stl->pre_trigger_head, len);
	100	memcpy(stl->pre_trigger_head, buf, size);
	101	stl->pre_trigger_head += size;
	102	if (stl->pre_trigger_head >= stl->pre_trigger_buffer
	103	+ stl->pre_trigger_size)
	104	stl->pre_trigger_head = stl->pre_trigger_buffer;
	105	buf += size;
	106	len -= size;
	107	}
	108	}
	109
	110	static void pre_trigger_send(struct soft_trigger_logic *stl,
	111	int *pre_trigger_samples)
	112	{
	113	struct sr_datafeed_packet packet;
	114	struct sr_datafeed_logic logic;
	115
	116	packet.type = SR_DF_LOGIC;
	117	packet.payload = &logic;
	118	logic.unitsize = stl->unitsize;
	119
	120	if (pre_trigger_samples)
	121	*pre_trigger_samples = 0;
	122
	123	/* If pre-trigger buffer not full, rewind head to the first valid sample. */
	124	if (stl->pre_trigger_fill < stl->pre_trigger_size)
	125	stl->pre_trigger_head = stl->pre_trigger_buffer;
	126
	127	/* Send logic packets for the pre-trigger circular buffer content. */
	128	while (stl->pre_trigger_fill > 0) {
	129	size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
	130	- stl->pre_trigger_head, stl->pre_trigger_fill);
	131	logic.length = size;
	132	logic.data = stl->pre_trigger_head;
	133	sr_session_send(stl->sdi, &packet);
	134	stl->pre_trigger_head = stl->pre_trigger_buffer;
	135	stl->pre_trigger_fill -= size;
	136	if (pre_trigger_samples)
	137	*pre_trigger_samples += size / stl->unitsize;
	138	}
	139	}
	140
ac136b57 BV	141	static gboolean logic_check_match(struct soft_trigger_logic *stl,
	142	uint8_t sample, struct sr_trigger_match match)
	143	{
	144	int bit, prev_bit;
	145	gboolean result;
	146
	147	stl->count++;
	148	result = FALSE;
	149	bit = *(sample + match->channel->index / 8)
	150	& (1 << (match->channel->index % 8));
	151	if (match->match == SR_TRIGGER_ZERO)
	152	result = bit == 0;
	153	else if (match->match == SR_TRIGGER_ONE)
	154	result = bit != 0;
	155	else {
	156	/* Edge matches. */
	157	if (stl->count == 1)
	158	/* First sample, don't have enough for an edge match yet. */
	159	return FALSE;
	160	prev_bit = *(stl->prev_sample + match->channel->index / 8)
	161	& (1 << (match->channel->index % 8));
	162	if (match->match == SR_TRIGGER_RISING)
	163	result = prev_bit == 0 && bit != 0;
	164	else if (match->match == SR_TRIGGER_FALLING)
	165	result = prev_bit != 0 && bit == 0;
	166	else if (match->match == SR_TRIGGER_EDGE)
	167	result = prev_bit != bit;
	168	}
	169
	170	return result;
	171	}
	172
	173	/* Returns the offset (in samples) within buf of where the trigger
	174	* occurred, or -1 if not triggered. */
	175	SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
fe5a7355	176	uint8_t buf, int len, int pre_trigger_samples)
ac136b57	177	{
ac136b57 BV	178	struct sr_trigger_stage *stage;
	179	struct sr_trigger_match *match;
	180	GSList l, l_stage;
	181	int offset;
	182	int i;
	183	gboolean match_found;
	184
	185	offset = -1;
	186	for (i = 0; i < len; i += stl->unitsize) {
	187	l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
	188	stage = l_stage->data;
	189	if (!stage->matches)
	190	/* No matches supplied, client error. */
	191	return SR_ERR_ARG;
	192
	193	match_found = TRUE;
	194	for (l = stage->matches; l; l = l->next) {
	195	match = l->data;
	196	if (!match->channel->enabled)
	197	/* Ignore disabled channels with a trigger. */
	198	continue;
	199	if (!logic_check_match(stl, buf + i, match)) {
	200	match_found = FALSE;
	201	break;
	202	}
	203	}
	204	memcpy(stl->prev_sample, buf + i, stl->unitsize);
	205	if (match_found) {
	206	/* Matched on the current stage. */
	207	if (l_stage->next) {
	208	/* Advance to next stage. */
	209	stl->cur_stage++;
	210	} else {
fe5a7355 AJ	211	/* Matched on last stage, send pre-trigger data. */
	212	pre_trigger_append(stl, buf, i);
	213	pre_trigger_send(stl, pre_trigger_samples);
	214
	215	/* Fire trigger. */
ac136b57 BV	216	offset = i / stl->unitsize;
ac136b57 BV	217
0fa71943	218	std_session_send_df_trigger(stl->sdi);
ac136b57 BV	219	break;
	220	}
	221	} else if (stl->cur_stage > 0) {
	222	/*
	223	* We had a match at an earlier stage, but failed on the
	224	* current stage. However, we may have a match on this
	225	* stage in the next bit -- trigger on 0001 will fail on
	226	* seeing 00001, so we need to go back to stage 0 -- but
	227	* at the next sample from the one that matched originally,
	228	* which the counter increment at the end of the loop
	229	* takes care of.
	230	*/
	231	i -= stl->cur_stage * stl->unitsize;
	232	if (i < -1)
	233	i = -1; /* Oops, went back past this buffer. */
	234	/* Reset trigger stage. */
	235	stl->cur_stage = 0;
	236	}
	237	}
	238
fe5a7355 AJ	239	if (offset == -1)
	240	pre_trigger_append(stl, buf, len);
	241
ac136b57 BV	242	return offset;
ac136b57 BV	243	}