2 * This file is part of the libsigrok project.
4 * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
5 * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
6 * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
25 #include <libserialport.h>
26 #include "libsigrok.h"
27 #include "libsigrok-internal.h"
29 /* Message logging helpers with subsystem-specific prefix string. */
30 #define LOG_PREFIX "serial: "
31 #define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
32 #define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
33 #define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
34 #define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
35 #define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
36 #define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)
39 * Open the specified serial port.
41 * @param serial Previously initialized serial port structure.
42 * @param flags Flags to use when opening the serial port. Possible flags
43 * include SERIAL_RDWR, SERIAL_RDONLY, SERIAL_NONBLOCK.
45 * If the serial structure contains a serialcomm string, it will be
46 * passed to serial_set_paramstr() after the port is opened.
48 * @return SR_OK on success, SR_ERR on failure.
50 SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
56 sr_dbg("Invalid serial port.");
60 sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
62 sp_get_port_by_name(serial->port, &serial->data);
64 ret = sp_open(serial->data, flags);
68 sr_err("Attempt to open serial port with invalid parameters.");
71 error = sp_last_error_message();
72 sr_err("Error opening port: %s.", error);
73 sp_free_error_message(error);
78 serial->fd = serial->data->fd;
81 if (serial->serialcomm)
82 return serial_set_paramstr(serial, serial->serialcomm);
88 * Close the specified serial port.
90 * @param serial Previously initialized serial port structure.
92 * @return SR_OK on success, SR_ERR on failure.
94 SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
100 sr_dbg("Invalid serial port.");
104 if (serial->fd == -1) {
105 sr_dbg("Cannot close unopened serial port %s (fd %d).",
106 serial->port, serial->fd);
110 sr_spew("Closing serial port %s (fd %d).", serial->port, serial->fd);
112 ret = sp_close(serial->data);
116 sr_err("Attempt to close an invalid serial port.");
119 error = sp_last_error_message();
120 sr_err("Error closing port: %s.", error);
121 sp_free_error_message(error);
131 * Flush serial port buffers.
133 * @param serial Previously initialized serial port structure.
135 * @return SR_OK on success, SR_ERR on failure.
137 SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
143 sr_dbg("Invalid serial port.");
147 if (serial->fd == -1) {
148 sr_dbg("Cannot flush unopened serial port %s (fd %d).",
149 serial->port, serial->fd);
153 sr_spew("Flushing serial port %s (fd %d).", serial->port, serial->fd);
155 ret = sp_flush(serial->data);
159 sr_err("Attempt to flush an invalid serial port.");
162 error = sp_last_error_message();
163 sr_err("Error flushing port: %s.", error);
164 sp_free_error_message(error);
172 * Write a number of bytes to the specified serial port.
174 * @param serial Previously initialized serial port structure.
175 * @param buf Buffer containing the bytes to write.
176 * @param count Number of bytes to write.
178 * @return The number of bytes written, or a negative error code upon failure.
180 SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
181 const void *buf, size_t count)
187 sr_dbg("Invalid serial port.");
191 if (serial->fd == -1) {
192 sr_dbg("Cannot use unopened serial port %s (fd %d).",
193 serial->port, serial->fd);
197 ret = sp_write(serial->data, buf, count);
201 sr_err("Attempted serial port write with invalid arguments.");
204 error = sp_last_error_message();
205 sr_err("Write error: %s.", error);
206 sp_free_error_message(error);
210 sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);
216 * Read a number of bytes from the specified serial port.
218 * @param serial Previously initialized serial port structure.
219 * @param buf Buffer where to store the bytes that are read.
220 * @param count The number of bytes to read.
222 * @return The number of bytes read, or a negative error code upon failure.
224 SR_PRIV int serial_read(struct sr_serial_dev_inst *serial, void *buf,
231 sr_dbg("Invalid serial port.");
235 if (serial->fd == -1) {
236 sr_dbg("Cannot use unopened serial port %s (fd %d).",
237 serial->port, serial->fd);
241 ret = sp_read(serial->data, buf, count);
245 sr_err("Attempted serial port read with invalid arguments.");
248 error = sp_last_error_message();
249 sr_err("Read error: %s.", error);
250 sp_free_error_message(error);
254 sr_spew("Read %d/%d bytes (fd %d).", ret, count, serial->fd);
260 * Set serial parameters for the specified serial port.
262 * @param serial Previously initialized serial port structure.
263 * @param baudrate The baudrate to set.
264 * @param bits The number of data bits to use.
265 * @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
266 * @param stopbits The number of stop bits to use (1 or 2).
267 * @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
270 * @return SR_OK upon success, SR_ERR upon failure.
272 SR_PRIV int serial_set_params(struct sr_serial_dev_inst *serial, int baudrate,
273 int bits, int parity, int stopbits,
274 int flowcontrol, int rts, int dtr)
280 sr_dbg("Invalid serial port.");
284 if (serial->fd == -1) {
285 sr_dbg("Cannot configure unopened serial port %s (fd %d).",
286 serial->port, serial->fd);
290 sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
293 ret = sp_set_params(serial->data, baudrate, bits, parity, stopbits,
294 flowcontrol, rts, dtr);
298 sr_err("Invalid arguments for setting serial port parameters.");
301 error = sp_last_error_message();
302 sr_err("Error setting serial port parameters: %s.", error);
303 sp_free_error_message(error);
311 * Set serial parameters for the specified serial port.
313 * @param serial Previously initialized serial port structure.
314 * @param paramstr A serial communication parameters string, in the form
315 * of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
316 * "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
318 * @return SR_OK upon success, SR_ERR upon failure.
320 #define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
321 SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
322 const char *paramstr)
326 int speed, databits, parity, stopbits, flow, rts, dtr, i;
327 char *mstr, **opts, **kv;
329 speed = databits = parity = stopbits = flow = 0;
331 sr_spew("Parsing parameters from \"%s\".", paramstr);
332 reg = g_regex_new(SERIAL_COMM_SPEC, 0, 0, NULL);
333 if (g_regex_match(reg, paramstr, 0, &match)) {
334 if ((mstr = g_match_info_fetch(match, 1)))
335 speed = strtoul(mstr, NULL, 10);
337 if ((mstr = g_match_info_fetch(match, 2)))
338 databits = strtoul(mstr, NULL, 10);
340 if ((mstr = g_match_info_fetch(match, 3))) {
343 parity = SERIAL_PARITY_NONE;
346 parity = SERIAL_PARITY_EVEN;
349 parity = SERIAL_PARITY_ODD;
354 if ((mstr = g_match_info_fetch(match, 4)))
355 stopbits = strtoul(mstr, NULL, 10);
357 if ((mstr = g_match_info_fetch(match, 5)) && mstr[0] != '\0') {
358 if (mstr[0] != '/') {
359 sr_dbg("missing separator before extra options");
362 /* A set of "key=value" options separated by / */
363 opts = g_strsplit(mstr + 1, "/", 0);
364 for (i = 0; opts[i]; i++) {
365 kv = g_strsplit(opts[i], "=", 2);
366 if (!strncmp(kv[0], "rts", 3)) {
369 else if (kv[1][0] == '0')
372 sr_dbg("invalid value for rts: %c", kv[1][0]);
375 } else if (!strncmp(kv[0], "dtr", 3)) {
378 else if (kv[1][0] == '0')
381 sr_dbg("invalid value for dtr: %c", kv[1][0]);
384 } else if (!strncmp(kv[0], "flow", 4)) {
387 else if (kv[1][0] == '1')
389 else if (kv[1][0] == '2')
392 sr_dbg("invalid value for flow: %c", kv[1][0]);
403 g_match_info_unref(match);
407 return serial_set_params(serial, speed, databits, parity,
408 stopbits, flow, rts, dtr);
410 sr_dbg("Could not infer speed from parameter string.");
416 * Read a line from the specified serial port.
418 * @param serial Previously initialized serial port structure.
419 * @param buf Buffer where to store the bytes that are read.
420 * @param buflen Size of the buffer.
421 * @param timeout_ms How long to wait for a line to come in.
423 * Reading stops when CR of LR is found, which is stripped from the buffer.
425 * @return SR_OK on success, SR_ERR on failure.
427 SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
428 int *buflen, gint64 timeout_ms)
433 if (!serial || serial->fd == -1) {
434 sr_dbg("Invalid serial port.");
438 if (serial->fd == -1) {
439 sr_dbg("Cannot use unopened serial port %s (fd %d).",
440 serial->port, serial->fd);
445 start = g_get_monotonic_time();
450 len = maxlen - *buflen - 1;
453 len = serial_read(serial, *buf + *buflen, 1);
456 *(*buf + *buflen) = '\0';
457 if (*buflen > 0 && (*(*buf + *buflen - 1) == '\r'
458 || *(*buf + *buflen - 1) == '\n')) {
459 /* Strip CR/LF and terminate. */
460 *(*buf + --*buflen) = '\0';
464 if (g_get_monotonic_time() - start > timeout_ms)
471 sr_dbg("Received %d: '%s'.", *buflen, *buf);
477 * Try to find a valid packet in a serial data stream.
479 * @param serial Previously initialized serial port structure.
480 * @param buf Buffer containing the bytes to write.
481 * @param count Size of the buffer.
482 * @param packet_size Size, in bytes, of a valid packet.
483 * @param is_valid Callback that assesses whether the packet is valid or not.
484 * @param timeout_ms The timeout after which, if no packet is detected, to
486 * @param baudrate The baudrate of the serial port. This parameter is not
487 * critical, but it helps fine tune the serial port polling
490 * @return SR_OK if a valid packet is found within the given timeout,
491 * SR_ERR upon failure.
493 SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
494 uint8_t *buf, size_t *buflen,
495 size_t packet_size, packet_valid_t is_valid,
496 uint64_t timeout_ms, int baudrate)
498 uint64_t start, time, byte_delay_us;
499 size_t ibuf, i, maxlen;
504 sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
505 "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
507 if (maxlen < (packet_size / 2) ) {
508 sr_err("Buffer size must be at least twice the packet size.");
512 /* Assume 8n1 transmission. That is 10 bits for every byte. */
513 byte_delay_us = 10 * (1000000 / baudrate);
514 start = g_get_monotonic_time();
517 while (ibuf < maxlen) {
518 len = serial_read(serial, &buf[ibuf], 1);
521 } else if (len == 0) {
522 /* No logging, already done in serial_read(). */
524 /* Error reading byte, but continuing anyway. */
527 time = g_get_monotonic_time() - start;
530 if ((ibuf - i) >= packet_size) {
531 /* We have at least a packet's worth of data. */
532 if (is_valid(&buf[i])) {
533 sr_spew("Found valid %d-byte packet after "
534 "%" PRIu64 "ms.", (ibuf - i), time);
538 sr_spew("Got %d bytes, but not a valid "
539 "packet.", (ibuf - i));
541 /* Not a valid packet. Continue searching. */
544 if (time >= timeout_ms) {
546 sr_dbg("Detection timed out after %dms.", time);
550 g_usleep(byte_delay_us);
555 sr_err("Didn't find a valid packet (read %d bytes).", *buflen);