]> sigrok.org Git - libsigrok.git/blame_incremental - src/hardware/serial-dmm/protocol.c
serial-dmm: fix typo in comment
[libsigrok.git] / src / hardware / serial-dmm / protocol.c
... / ...
CommitLineData
1/*
2 * This file is part of the libsigrok project.
3 *
4 * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
5 * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
6 *
7 * This program is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include <config.h>
22#include <stdlib.h>
23#include <math.h>
24#include <string.h>
25#include <glib.h>
26#include <libsigrok/libsigrok.h>
27#include "libsigrok-internal.h"
28#include "protocol.h"
29
30static void log_dmm_packet(const uint8_t *buf, size_t len)
31{
32 GString *text;
33
34 if (sr_log_loglevel_get() < SR_LOG_DBG)
35 return;
36
37 text = sr_hexdump_new(buf, len);
38 sr_dbg("DMM packet: %s", text->str);
39 sr_hexdump_free(text);
40}
41
42static void handle_packet(struct sr_dev_inst *sdi,
43 const uint8_t *buf, size_t len, void *info)
44{
45 struct dmm_info *dmm;
46 struct dev_context *devc;
47 float floatval;
48 double doubleval;
49 struct sr_datafeed_packet packet;
50 struct sr_datafeed_analog analog;
51 struct sr_analog_encoding encoding;
52 struct sr_analog_meaning meaning;
53 struct sr_analog_spec spec;
54 gboolean sent_sample;
55 struct sr_channel *channel;
56 size_t ch_idx;
57
58 dmm = (struct dmm_info *)sdi->driver;
59
60 log_dmm_packet(buf, len);
61 devc = sdi->priv;
62
63 sent_sample = FALSE;
64 memset(info, 0, dmm->info_size);
65 for (ch_idx = 0; ch_idx < dmm->channel_count; ch_idx++) {
66 /* Note: digits/spec_digits will be overridden by the DMM parsers. */
67 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
68
69 channel = g_slist_nth_data(sdi->channels, ch_idx);
70 analog.meaning->channels = g_slist_append(NULL, channel);
71 analog.num_samples = 1;
72 analog.meaning->mq = 0;
73
74 if (dmm->packet_parse) {
75 dmm->packet_parse(buf, &floatval, &analog, info);
76 analog.data = &floatval;
77 analog.encoding->unitsize = sizeof(floatval);
78 } else if (dmm->packet_parse_len) {
79 dmm->packet_parse_len(dmm->dmm_state, buf, len,
80 &doubleval, &analog, info);
81 analog.data = &doubleval;
82 analog.encoding->unitsize = sizeof(doubleval);
83 }
84
85 /* If this DMM needs additional handling, call the resp. function. */
86 if (dmm->dmm_details)
87 dmm->dmm_details(&analog, info);
88
89 if (analog.meaning->mq != 0 && channel->enabled) {
90 /* Got a measurement. */
91 packet.type = SR_DF_ANALOG;
92 packet.payload = &analog;
93 sr_session_send(sdi, &packet);
94 sent_sample = TRUE;
95 }
96 }
97
98 if (sent_sample) {
99 sr_sw_limits_update_samples_read(&devc->limits, 1);
100 }
101}
102
103/** Request packet, if required. */
104SR_PRIV int req_packet(struct sr_dev_inst *sdi)
105{
106 struct dmm_info *dmm;
107 struct dev_context *devc;
108 struct sr_serial_dev_inst *serial;
109 uint64_t now, left, next;
110 int ret;
111
112 dmm = (struct dmm_info *)sdi->driver;
113 if (!dmm->packet_request)
114 return SR_OK;
115
116 devc = sdi->priv;
117 serial = sdi->conn;
118
119 now = g_get_monotonic_time();
120 if (devc->req_next_at && now < devc->req_next_at) {
121 left = (devc->req_next_at - now) / 1000;
122 sr_spew("Not re-requesting yet, %" PRIu64 "ms left.", left);
123 return SR_OK;
124 }
125
126 sr_spew("Requesting next packet.");
127 ret = dmm->packet_request(serial);
128 if (ret < 0) {
129 sr_err("Failed to request packet: %d.", ret);
130 return ret;
131 }
132
133 if (dmm->req_timeout_ms) {
134 next = now + dmm->req_timeout_ms * 1000;
135 devc->req_next_at = next;
136 }
137
138 return SR_OK;
139}
140
141static void handle_new_data(struct sr_dev_inst *sdi, void *info)
142{
143 struct dmm_info *dmm;
144 struct dev_context *devc;
145 struct sr_serial_dev_inst *serial;
146 int ret;
147 size_t read_len, check_pos, check_len, pkt_size, copy_len;
148 uint8_t *check_ptr;
149 uint64_t deadline;
150
151 dmm = (struct dmm_info *)sdi->driver;
152
153 devc = sdi->priv;
154 serial = sdi->conn;
155
156 /* Add the maximum available RX data we can get to the local buffer. */
157 read_len = DMM_BUFSIZE - devc->buflen;
158 ret = serial_read_nonblocking(serial, &devc->buf[devc->buflen], read_len);
159 if (ret == 0)
160 return; /* No new bytes, nothing to do. */
161 if (ret < 0) {
162 sr_err("Serial port read error: %d.", ret);
163 return;
164 }
165 devc->buflen += ret;
166
167 /*
168 * Process packets when their reception has completed, or keep
169 * trying to synchronize to the stream of input data.
170 */
171 check_pos = 0;
172 while (check_pos < devc->buflen) {
173 /* Got the (minimum) amount of receive data for a packet? */
174 check_len = devc->buflen - check_pos;
175 if (check_len < dmm->packet_size)
176 break;
177 sr_dbg("Checking: pos %zu, len %zu.", check_pos, check_len);
178
179 /* Is it a valid packet? */
180 check_ptr = &devc->buf[check_pos];
181 if (dmm->packet_valid_len) {
182 ret = dmm->packet_valid_len(dmm->dmm_state,
183 check_ptr, check_len, &pkt_size);
184 if (ret == SR_PACKET_NEED_RX) {
185 sr_dbg("Need more RX data.");
186 break;
187 }
188 if (ret == SR_PACKET_INVALID) {
189 sr_dbg("Not a valid packet, searching.");
190 check_pos++;
191 continue;
192 }
193 } else if (dmm->packet_valid) {
194 if (!dmm->packet_valid(check_ptr)) {
195 sr_dbg("Not a valid packet, searching.");
196 check_pos++;
197 continue;
198 }
199 pkt_size = dmm->packet_size;
200 }
201
202 /* Process the packet. */
203 sr_dbg("Valid packet, size %zu, processing", pkt_size);
204 handle_packet(sdi, check_ptr, pkt_size, info);
205 check_pos += pkt_size;
206
207 /* Arrange for the next packet request if needed. */
208 if (!dmm->packet_request)
209 continue;
210 if (dmm->req_timeout_ms || dmm->req_delay_ms) {
211 deadline = g_get_monotonic_time();
212 deadline += dmm->req_delay_ms * 1000;
213 devc->req_next_at = deadline;
214 }
215 req_packet(sdi);
216 continue;
217 }
218
219 /* If we have any data left, move it to the beginning of our buffer. */
220 if (devc->buflen > check_pos) {
221 copy_len = devc->buflen - check_pos;
222 memmove(&devc->buf[0], &devc->buf[check_pos], copy_len);
223 }
224 devc->buflen -= check_pos;
225
226 /*
227 * If the complete buffer filled up and none of it got processed,
228 * discard the unprocessed buffer, re-sync to the stream in later
229 * calls again.
230 */
231 if (devc->buflen == sizeof(devc->buf)) {
232 sr_info("Drop unprocessed RX data, try to re-sync to stream.");
233 devc->buflen = 0;
234 }
235}
236
237int receive_data(int fd, int revents, void *cb_data)
238{
239 struct sr_dev_inst *sdi;
240 struct dev_context *devc;
241 struct dmm_info *dmm;
242 void *info;
243
244 (void)fd;
245
246 if (!(sdi = cb_data))
247 return TRUE;
248
249 if (!(devc = sdi->priv))
250 return TRUE;
251
252 dmm = (struct dmm_info *)sdi->driver;
253
254 if (revents == G_IO_IN) {
255 /* Serial data arrived. */
256 info = g_malloc(dmm->info_size);
257 handle_new_data(sdi, info);
258 g_free(info);
259 } else {
260 /* Timeout; send another packet request if DMM needs it. */
261 if (dmm->packet_request && (req_packet(sdi) < 0))
262 return FALSE;
263 }
264
265 if (sr_sw_limits_check(&devc->limits))
266 sr_dev_acquisition_stop(sdi);
267
268 return TRUE;
269}