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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 | ||
20 | #include <config.h> | |
21 | #include <string.h> | |
22 | #include <libsigrok/libsigrok.h> | |
23 | #include "libsigrok-internal.h" | |
24 | ||
25 | /* @cond PRIVATE */ | |
26 | #define LOG_PREFIX "soft-trigger" | |
27 | /* @endcond */ | |
28 | ||
29 | SR_PRIV int logic_channel_unitsize(GSList *channels) | |
30 | { | |
31 | int number = 0; | |
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) | |
38 | number++; | |
39 | } | |
40 | ||
41 | return (number + 7) / 8; | |
42 | } | |
43 | ||
44 | SR_PRIV struct soft_trigger_logic *soft_trigger_logic_new( | |
45 | const struct sr_dev_inst *sdi, struct sr_trigger *trigger, | |
46 | int pre_trigger_samples) | |
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; | |
53 | stl->unitsize = logic_channel_unitsize(sdi->channels); | |
54 | stl->prev_sample = g_malloc0(stl->unitsize); | |
55 | stl->pre_trigger_size = stl->unitsize * pre_trigger_samples; | |
56 | stl->pre_trigger_buffer = g_try_malloc(stl->pre_trigger_size); | |
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 | */ | |
63 | soft_trigger_logic_free(stl); | |
64 | return NULL; | |
65 | } | |
66 | stl->pre_trigger_head = stl->pre_trigger_buffer; | |
67 | ||
68 | if (stl->pre_trigger_size > 0 && !stl->pre_trigger_buffer) { | |
69 | soft_trigger_logic_free(stl); | |
70 | return NULL; | |
71 | } | |
72 | ||
73 | return stl; | |
74 | } | |
75 | ||
76 | SR_PRIV void soft_trigger_logic_free(struct soft_trigger_logic *stl) | |
77 | { | |
78 | g_free(stl->pre_trigger_buffer); | |
79 | g_free(stl->prev_sample); | |
80 | g_free(stl); | |
81 | } | |
82 | ||
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 | ||
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, | |
176 | uint8_t *buf, int len, int *pre_trigger_samples) | |
177 | { | |
178 | struct sr_datafeed_packet packet; | |
179 | struct sr_trigger_stage *stage; | |
180 | struct sr_trigger_match *match; | |
181 | GSList *l, *l_stage; | |
182 | int offset; | |
183 | int i; | |
184 | gboolean match_found; | |
185 | ||
186 | offset = -1; | |
187 | for (i = 0; i < len; i += stl->unitsize) { | |
188 | l_stage = g_slist_nth(stl->trigger->stages, stl->cur_stage); | |
189 | stage = l_stage->data; | |
190 | if (!stage->matches) | |
191 | /* No matches supplied, client error. */ | |
192 | return SR_ERR_ARG; | |
193 | ||
194 | match_found = TRUE; | |
195 | for (l = stage->matches; l; l = l->next) { | |
196 | match = l->data; | |
197 | if (!match->channel->enabled) | |
198 | /* Ignore disabled channels with a trigger. */ | |
199 | continue; | |
200 | if (!logic_check_match(stl, buf + i, match)) { | |
201 | match_found = FALSE; | |
202 | break; | |
203 | } | |
204 | } | |
205 | memcpy(stl->prev_sample, buf + i, stl->unitsize); | |
206 | if (match_found) { | |
207 | /* Matched on the current stage. */ | |
208 | if (l_stage->next) { | |
209 | /* Advance to next stage. */ | |
210 | stl->cur_stage++; | |
211 | } else { | |
212 | /* Matched on last stage, send pre-trigger data. */ | |
213 | pre_trigger_append(stl, buf, i); | |
214 | pre_trigger_send(stl, pre_trigger_samples); | |
215 | ||
216 | /* Fire trigger. */ | |
217 | offset = i / stl->unitsize; | |
218 | ||
219 | packet.type = SR_DF_TRIGGER; | |
220 | packet.payload = NULL; | |
221 | sr_session_send(stl->sdi, &packet); | |
222 | break; | |
223 | } | |
224 | } else if (stl->cur_stage > 0) { | |
225 | /* | |
226 | * We had a match at an earlier stage, but failed on the | |
227 | * current stage. However, we may have a match on this | |
228 | * stage in the next bit -- trigger on 0001 will fail on | |
229 | * seeing 00001, so we need to go back to stage 0 -- but | |
230 | * at the next sample from the one that matched originally, | |
231 | * which the counter increment at the end of the loop | |
232 | * takes care of. | |
233 | */ | |
234 | i -= stl->cur_stage * stl->unitsize; | |
235 | if (i < -1) | |
236 | i = -1; /* Oops, went back past this buffer. */ | |
237 | /* Reset trigger stage. */ | |
238 | stl->cur_stage = 0; | |
239 | } | |
240 | } | |
241 | ||
242 | if (offset == -1) | |
243 | pre_trigger_append(stl, buf, len); | |
244 | ||
245 | return offset; | |
246 | } |