2 * This file is part of the libsigrok project.
4 * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.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 static void handle_packet(const uint8_t *buf, struct sr_dev_inst *sdi)
25 struct dev_context *devc;
26 struct sr_datafeed_packet packet;
27 struct sr_datafeed_analog analog;
31 analog.num_samples = 1;
34 if (brymen_parse(buf, &floatval, &analog, NULL) != SR_OK)
36 analog.data = &floatval;
38 analog.channels = sdi->channels;
40 if (analog.mq != -1) {
41 /* Got a measurement. */
42 packet.type = SR_DF_ANALOG;
43 packet.payload = &analog;
44 sr_session_send(devc->cb_data, &packet);
49 static void handle_new_data(struct sr_dev_inst *sdi)
51 struct dev_context *devc;
52 int len, status, offset = 0;
53 struct sr_serial_dev_inst *serial;
58 /* Try to get as much data as the buffer can hold. */
59 len = DMM_BUFSIZE - devc->buflen;
60 len = serial_read_nonblocking(serial, devc->buf + devc->buflen, len);
62 sr_err("Serial port read error: %d.", len);
66 status = PACKET_INVALID_HEADER;
68 /* Now look for packets in that data. */
69 while (status != PACKET_NEED_MORE_DATA) {
70 /* We don't have a header, look for one. */
71 if (devc->next_packet_len == 0) {
72 len = devc->buflen - offset;
73 status = brymen_packet_length(devc->buf + offset, &len);
74 if (status == PACKET_HEADER_OK) {
75 /* We know how large the packet will be. */
76 devc->next_packet_len = len;
77 } else if (status == PACKET_NEED_MORE_DATA) {
78 /* We didn't yet receive the full header. */
79 devc->next_packet_len = 0;
82 /* Invalid header. Move on. */
83 devc->next_packet_len = 0;
89 /* We know how the packet size, but did we receive all of it? */
90 if (devc->buflen - offset < devc->next_packet_len)
93 /* We should have a full packet here, so we can check it. */
94 if (brymen_packet_is_valid(devc->buf + offset)) {
95 handle_packet(devc->buf + offset, sdi);
96 offset += devc->next_packet_len;
101 /* We are done with this packet. Look for a new one. */
102 devc->next_packet_len = 0;
105 /* If we have any data left, move it to the beginning of our buffer. */
106 memmove(devc->buf, devc->buf + offset, devc->buflen - offset);
107 devc->buflen -= offset;
110 SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
112 struct sr_dev_inst *sdi;
113 struct dev_context *devc;
114 struct sr_serial_dev_inst *serial;
120 if (!(sdi = cb_data))
123 if (!(devc = sdi->priv))
128 if (revents == G_IO_IN) {
129 /* Serial data arrived. */
130 handle_new_data(sdi);
132 /* Timeout, send another packet request. */
133 if ((ret = brymen_packet_request(serial)) < 0) {
134 sr_err("Failed to request packet: %d.", ret);
139 if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
140 sr_info("Requested number of samples reached, stopping.");
141 sdi->driver->dev_acquisition_stop(sdi, cb_data);
145 if (devc->limit_msec) {
146 time = (g_get_monotonic_time() - devc->starttime) / 1000;
147 if (time > (int64_t)devc->limit_msec) {
148 sr_info("Requested time limit reached, stopping.");
149 sdi->driver->dev_acquisition_stop(sdi, cb_data);
158 * Try to find a valid packet in a serial data stream.
160 * @param serial Previously initialized serial port structure.
161 * @param buf Buffer containing the bytes to write.
162 * @param buflen Size of the buffer.
163 * @param get_packet_size Callback that assesses the size of incoming packets.
164 * @param is_valid Callback that assesses whether the packet is valid or not.
165 * @param timeout_ms The timeout after which, if no packet is detected, to
167 * @param baudrate The baudrate of the serial port. This parameter is not
168 * critical, but it helps fine tune the serial port polling
171 * @return SR_OK if a valid packet is found within the given timeout,
172 * SR_ERR upon failure.
174 SR_PRIV int brymen_stream_detect(struct sr_serial_dev_inst *serial,
175 uint8_t *buf, size_t *buflen,
176 packet_length_t get_packet_size,
177 packet_valid_callback is_valid,
178 uint64_t timeout_ms, int baudrate)
180 int64_t start, time, byte_delay_us;
181 size_t ibuf, i, maxlen;
182 int status, len, packet_len, stream_len;
186 sr_dbg("Detecting packets on %s (timeout = %" PRIu64
187 "ms, baudrate = %d).", serial->port, timeout_ms, baudrate);
189 /* Assume 8n1 transmission. That is 10 bits for every byte. */
190 byte_delay_us = 10 * (1000000 / baudrate);
191 start = g_get_monotonic_time();
193 packet_len = i = ibuf = len = 0;
194 while (ibuf < maxlen) {
195 len = serial_read_nonblocking(serial, &buf[ibuf], maxlen - ibuf);
198 sr_spew("Read %d bytes.", len);
201 time = g_get_monotonic_time() - start;
204 stream_len = ibuf - i;
205 if (stream_len > 0 && packet_len == 0) {
206 /* How large of a packet are we expecting? */
207 packet_len = stream_len;
208 status = get_packet_size(&buf[i], &packet_len);
210 case PACKET_HEADER_OK:
211 /* We know how much data we need to wait for. */
213 case PACKET_NEED_MORE_DATA:
214 /* We did not receive the full header. */
217 case PACKET_INVALID_HEADER:
220 * We had enough data, but here was an error in
221 * parsing the header. Restart parsing from the
230 if ((stream_len >= packet_len) && (packet_len != 0)) {
231 /* We have at least a packet's worth of data. */
232 if (is_valid(&buf[i])) {
233 sr_spew("Found valid %d-byte packet after "
234 "%" PRIu64 "ms.", packet_len, time);
238 sr_spew("Got %d bytes, but not a valid "
239 "packet.", packet_len);
243 /* Not a valid packet. Continue searching. */
248 if (time >= (int64_t)timeout_ms) {
250 sr_dbg("Detection timed out after %dms.", time);
253 g_usleep(byte_delay_us);
257 sr_err("Didn't find a valid packet (read %d bytes).", ibuf);