2 * This file is part of the libsigrok project.
4 * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
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.
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.
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/>.
21 #include <libsigrok/libsigrok.h>
22 #include "libsigrok-internal.h"
25 #define LOG_PREFIX "soft-trigger"
28 SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
29 const struct sr_dev_inst *sdi, struct sr_trigger *trigger,
30 int pre_trigger_samples)
32 struct soft_trigger_logic *stl;
34 stl = g_malloc0(sizeof(struct soft_trigger_logic));
36 stl->trigger = trigger;
37 stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
38 stl->prev_sample = g_malloc0(stl->unitsize);
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;
43 if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
44 soft_trigger_logic_free(stl);
51 SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
53 g_free(stl->pre_trigger_buffer);
54 g_free(stl->prev_sample);
58 static void pre_trigger_append(struct soft_trigger_logic *stl,
59 uint8_t *buf, int len)
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;
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);
71 /* Actually copy data to the pre-trigger circular buffer. */
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;
85 static void pre_trigger_send(struct soft_trigger_logic *stl,
86 int *pre_trigger_samples)
88 struct sr_datafeed_packet packet;
89 struct sr_datafeed_logic logic;
91 packet.type = SR_DF_LOGIC;
92 packet.payload = &logic;
93 logic.unitsize = stl->unitsize;
95 if (pre_trigger_samples)
96 *pre_trigger_samples = 0;
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;
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);
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;
116 static gboolean logic_check_match(struct soft_trigger_logic *stl,
117 uint8_t *sample, struct sr_trigger_match *match)
124 bit = *(sample + match->channel->index / 8)
125 & (1 << (match->channel->index % 8));
126 if (match->match == SR_TRIGGER_ZERO)
128 else if (match->match == SR_TRIGGER_ONE)
133 /* First sample, don't have enough for an edge match yet. */
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;
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,
151 uint8_t *buf, int len, int *pre_trigger_samples)
153 struct sr_datafeed_packet packet;
154 struct sr_trigger_stage *stage;
155 struct sr_trigger_match *match;
159 gboolean match_found;
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;
166 /* No matches supplied, client error. */
170 for (l = stage->matches; l; l = l->next) {
172 if (!match->channel->enabled)
173 /* Ignore disabled channels with a trigger. */
175 if (!logic_check_match(stl, buf + i, match)) {
180 memcpy(stl->prev_sample, buf + i, stl->unitsize);
182 /* Matched on the current stage. */
184 /* Advance to next stage. */
187 /* Matched on last stage, send pre-trigger data. */
188 pre_trigger_append(stl, buf, i);
189 pre_trigger_send(stl, pre_trigger_samples);
192 offset = i / stl->unitsize;
194 packet.type = SR_DF_TRIGGER;
195 packet.payload = NULL;
196 sr_session_send(stl->sdi, &packet);
199 } else if (stl->cur_stage > 0) {
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
209 i -= stl->cur_stage * stl->unitsize;
211 i = -1; /* Oops, went back past this buffer. */
212 /* Reset trigger stage. */
218 pre_trigger_append(stl, buf, len);