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 static size_t logic_channel_unitsize(GSList *channels)
32 struct sr_channel *channel;
35 for (l = channels; l; l = l->next) {
37 if (channel->type == SR_CHANNEL_LOGIC)
40 sr_dbg("number of logic channels: %d", (int) number);
41 return (number + 7) / 8;
45 SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new(
46 const struct sr_dev_inst *sdi, struct sr_trigger *trigger,
47 int pre_trigger_samples)
49 struct soft_trigger_logic *stl;
51 stl = g_malloc0(sizeof(struct soft_trigger_logic));
53 stl->trigger = trigger;
54 /* Retreive number of logic channels, unitsize */
55 stl->unitsize = logic_channel_unitsize(sdi->channels);
56 stl->prev_sample = g_malloc0(stl->unitsize);
57 stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
58 stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size);
59 if (pre_trigger_samples > 0 && !stl->pre_trigger_buffer) {
61 * Error out if g_try_malloc() failed (or was invoked as
62 * g_try_malloc(0)) *and* more than 0 pretrigger samples
65 soft_trigger_logic_free(stl);
68 stl->pre_trigger_head = stl->pre_trigger_buffer;
70 if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) {
71 soft_trigger_logic_free(stl);
78 SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl)
80 g_free(stl->pre_trigger_buffer);
81 g_free(stl->prev_sample);
85 static void pre_trigger_append(struct soft_trigger_logic *stl,
86 uint8_t *buf, int len)
88 /* Avoid uselessly copying more than the pre-trigger size. */
89 if (len > stl->pre_trigger_size) {
90 buf += len - stl->pre_trigger_size;
91 len = stl->pre_trigger_size;
94 /* Update the filling level of the pre-trigger circular buffer. */
95 stl->pre_trigger_fill = MIN(stl->pre_trigger_fill + len,
96 stl->pre_trigger_size);
98 /* Actually copy data to the pre-trigger circular buffer. */
100 size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
101 - stl->pre_trigger_head, len);
102 memcpy(stl->pre_trigger_head, buf, size);
103 stl->pre_trigger_head += size;
104 if (stl->pre_trigger_head >= stl->pre_trigger_buffer
105 + stl->pre_trigger_size)
106 stl->pre_trigger_head = stl->pre_trigger_buffer;
112 static void pre_trigger_send(struct soft_trigger_logic *stl,
113 int *pre_trigger_samples)
115 struct sr_datafeed_packet packet;
116 struct sr_datafeed_logic logic;
118 packet.type = SR_DF_LOGIC;
119 packet.payload = &logic;
120 logic.unitsize = stl->unitsize;
122 if (pre_trigger_samples)
123 *pre_trigger_samples = 0;
125 /* If pre-trigger buffer not full, rewind head to the first valid sample. */
126 if (stl->pre_trigger_fill < stl->pre_trigger_size)
127 stl->pre_trigger_head = stl->pre_trigger_buffer;
129 /* Send logic packets for the pre-trigger circular buffer content. */
130 while (stl->pre_trigger_fill > 0) {
131 size_t size = MIN(stl->pre_trigger_buffer + stl->pre_trigger_size
132 - stl->pre_trigger_head, stl->pre_trigger_fill);
134 logic.data = stl->pre_trigger_head;
135 sr_session_send(stl->sdi, &packet);
136 stl->pre_trigger_head = stl->pre_trigger_buffer;
137 stl->pre_trigger_fill -= size;
138 if (pre_trigger_samples)
139 *pre_trigger_samples += size / stl->unitsize;
143 static gboolean logic_check_match(struct soft_trigger_logic *stl,
144 uint8_t *sample, struct sr_trigger_match *match)
151 bit = *(sample + match->channel->index / 8)
152 & (1 << (match->channel->index % 8));
153 if (match->match == SR_TRIGGER_ZERO)
155 else if (match->match == SR_TRIGGER_ONE)
160 /* First sample, don't have enough for an edge match yet. */
162 prev_bit = *(stl->prev_sample + match->channel->index / 8)
163 & (1 << (match->channel->index % 8));
164 if (match->match == SR_TRIGGER_RISING)
165 result = prev_bit == 0 && bit != 0;
166 else if (match->match == SR_TRIGGER_FALLING)
167 result = prev_bit != 0 && bit == 0;
168 else if (match->match == SR_TRIGGER_EDGE)
169 result = prev_bit != bit;
175 /* Returns the offset (in samples) within buf of where the trigger
176 * occurred, or -1 if not triggered. */
177 SR_PRIV int soft_trigger_logic_check(struct soft_trigger_logic *stl,
178 uint8_t *buf, int len, int *pre_trigger_samples)
180 struct sr_datafeed_packet packet;
181 struct sr_trigger_stage *stage;
182 struct sr_trigger_match *match;
186 gboolean match_found;
189 for (i = 0; i < len; i += stl->unitsize) {
190 l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage);
191 stage = l_stage->data;
193 /* No matches supplied, client error. */
197 for (l = stage->matches; l; l = l->next) {
199 if (!match->channel->enabled)
200 /* Ignore disabled channels with a trigger. */
202 if (!logic_check_match(stl, buf + i, match)) {
207 memcpy(stl->prev_sample, buf + i, stl->unitsize);
209 /* Matched on the current stage. */
211 /* Advance to next stage. */
214 /* Matched on last stage, send pre-trigger data. */
215 pre_trigger_append(stl, buf, i);
216 pre_trigger_send(stl, pre_trigger_samples);
219 offset = i / stl->unitsize;
221 packet.type = SR_DF_TRIGGER;
222 packet.payload = NULL;
223 sr_session_send(stl->sdi, &packet);
226 } else if (stl->cur_stage > 0) {
228 * We had a match at an earlier stage, but failed on the
229 * current stage. However, we may have a match on this
230 * stage in the next bit -- trigger on 0001 will fail on
231 * seeing 00001, so we need to go back to stage 0 -- but
232 * at the next sample from the one that matched originally,
233 * which the counter increment at the end of the loop
236 i -= stl->cur_stage * stl->unitsize;
238 i = -1; /* Oops, went back past this buffer. */
239 /* Reset trigger stage. */
245 pre_trigger_append(stl, buf, len);