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/>.
22 #include <libsigrok/libsigrok.h>
23 #include "libsigrok-internal.h"
26 #define LOG_PREFIX "soft-trigger"
29 SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
30 const struct sr_dev_inst *sdi, struct sr_trigger *trigger,
31 int pre_trigger_samples)
33 struct soft_trigger_logic *stl;
35 stl = g_malloc0(sizeof(struct soft_trigger_logic));
37 stl->trigger = trigger;
38 stl->unitsize = (g_slist_length(sdi->channels) + 7) / 8;
39 stl->prev_sample = g_malloc0(stl->unitsize);
40 stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
41 stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size);
42 if (pre_trigger_samples > 0 && !stl->pre_trigger_buffer) {
44 * Error out if g_try_malloc() failed (or was invoked as
45 * g_try_malloc(0)) *and* more than 0 pretrigger samples
48 soft_trigger_logic_free(stl);
51 stl->pre_trigger_head = stl->pre_trigger_buffer;
53 if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
54 soft_trigger_logic_free(stl);
61 SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
63 g_free(stl->pre_trigger_buffer);
64 g_free(stl->prev_sample);
68 static void pre_trigger_append(struct soft_trigger_logic *stl,
69 uint8_t *buf, int len)
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;
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);
81 /* Actually copy data to the pre-trigger circular buffer. */
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;
95 static void pre_trigger_send(struct soft_trigger_logic *stl,
96 int *pre_trigger_samples)
98 struct sr_datafeed_packet packet;
99 struct sr_datafeed_logic logic;
101 packet.type = SR_DF_LOGIC;
102 packet.payload = &logic;
103 logic.unitsize = stl->unitsize;
105 if (pre_trigger_samples)
106 *pre_trigger_samples = 0;
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;
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);
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;
126 static gboolean logic_check_match(struct soft_trigger_logic *stl,
127 uint8_t *sample, struct sr_trigger_match *match)
134 bit = *(sample + match->channel->index / 8)
135 & (1 << (match->channel->index % 8));
136 if (match->match == SR_TRIGGER_ZERO)
138 else if (match->match == SR_TRIGGER_ONE)
143 /* First sample, don't have enough for an edge match yet. */
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;
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,
161 uint8_t *buf, int len, int *pre_trigger_samples)
163 struct sr_datafeed_packet packet;
164 struct sr_trigger_stage *stage;
165 struct sr_trigger_match *match;
169 gboolean match_found;
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;
176 /* No matches supplied, client error. */
180 for (l = stage->matches; l; l = l->next) {
182 if (!match->channel->enabled)
183 /* Ignore disabled channels with a trigger. */
185 if (!logic_check_match(stl, buf + i, match)) {
190 memcpy(stl->prev_sample, buf + i, stl->unitsize);
192 /* Matched on the current stage. */
194 /* Advance to next stage. */
197 /* Matched on last stage, send pre-trigger data. */
198 pre_trigger_append(stl, buf, i);
199 pre_trigger_send(stl, pre_trigger_samples);
202 offset = i / stl->unitsize;
204 packet.type = SR_DF_TRIGGER;
205 packet.payload = NULL;
206 sr_session_send(stl->sdi, &packet);
209 } else if (stl->cur_stage > 0) {
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
219 i -= stl->cur_stage * stl->unitsize;
221 i = -1; /* Oops, went back past this buffer. */
222 /* Reset trigger stage. */
228 pre_trigger_append(stl, buf, len);