[libsigrok.git] / hardware / common / serial.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
 * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
 * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <stdlib.h>
#include <glib.h>
#include <libserialport.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"

/* Message logging helpers with subsystem-specific prefix string. */
#define LOG_PREFIX "serial: "
#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
#define sr_err(s, args...) sr_err(LOG_PREFIX s, ## args)

/**
 * Open the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param flags Flags to use when opening the serial port. Possible flags
 *              include SERIAL_RDWR, SERIAL_RDONLY, SERIAL_NONBLOCK.
 *
 * If the serial structure contains a serialcomm string, it will be
 * passed to serial_set_paramstr() after the port is opened.
 *
 * @return SR_OK on success, SR_ERR on failure.
 */
SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
{
	int ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);

	sp_get_port_by_name(serial->port, &serial->data);

	ret = sp_open(serial->data, flags);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Attempt to open serial port with invalid parameters.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Error opening port: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

#ifndef _WIN32
	serial->fd = serial->data->fd;
#endif

	if (serial->serialcomm)
		return serial_set_paramstr(serial, serial->serialcomm);
	else
		return SR_OK;
}

/**
 * Close the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 *
 * @return SR_OK on success, SR_ERR on failure.
 */
SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
{
	int ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot close unopened serial port %s (fd %d).",
				serial->port, serial->fd);
		return SR_ERR;
	}

	sr_spew("Closing serial port %s (fd %d).", serial->port, serial->fd);
	ret = SR_OK;

	ret = sp_close(serial->data);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Attempt to close an invalid serial port.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Error closing port: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

	serial->fd = -1;

	return ret;
}

/**
 * Flush serial port buffers.
 *
 * @param serial Previously initialized serial port structure.
 *
 * @return SR_OK on success, SR_ERR on failure.
 */
SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
{
	int ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot flush unopened serial port %s (fd %d).",
				serial->port, serial->fd);
		return SR_ERR;
	}

	sr_spew("Flushing serial port %s (fd %d).", serial->port, serial->fd);

	ret = sp_flush(serial->data);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Attempt to flush an invalid serial port.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Error flushing port: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

	return ret;
}

/**
 * Write a number of bytes to the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param buf Buffer containing the bytes to write.
 * @param count Number of bytes to write.
 *
 * @return The number of bytes written, or -1 upon failure.
 */
SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
		const void *buf, size_t count)
{
	ssize_t ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return -1;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot use unopened serial port %s (fd %d).",
				serial->port, serial->fd);
		return -1;
	}

	ret = sp_write(serial->data, buf, count);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Attempted serial port write with invalid arguments.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Write error: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

	sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);

	return ret;
}

/**
 * Read a number of bytes from the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param buf Buffer where to store the bytes that are read.
 * @param count The number of bytes to read.
 *
 * @return The number of bytes read, or -1 upon failure.
 */
SR_PRIV int serial_read(struct sr_serial_dev_inst *serial, void *buf,
		size_t count)
{
	ssize_t ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return -1;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot use unopened serial port %s (fd %d).",
				serial->port, serial->fd);
		return -1;
	}

	ret = sp_read(serial->data, buf, count);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Attempted serial port read with invalid arguments.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Read error: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

	sr_spew("Read %d/%d bytes (fd %d).", ret, count, serial->fd);

	return ret;
}

/**
 * Set serial parameters for the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param baudrate The baudrate to set.
 * @param bits The number of data bits to use.
 * @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
 * @param stopbits The number of stop bits to use (1 or 2).
 * @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
 *                    2 = XON/XOFF).
 *
 * @return SR_OK upon success, SR_ERR upon failure.
 */
SR_PRIV int serial_set_params(struct sr_serial_dev_inst *serial, int baudrate,
			      int bits, int parity, int stopbits,
			      int flowcontrol, int rts, int dtr)
{
	int ret;
	char *error;

	if (!serial) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot configure unopened serial port %s (fd %d).",
		       serial->port, serial->fd);
		return SR_ERR;
	}

	sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
		serial->fd);

	ret = sp_set_params(serial->data, baudrate, bits, parity, stopbits,
			flowcontrol, rts, dtr);

	switch (ret) {
	case SP_ERR_ARG:
		sr_err("Invalid arguments for setting serial port parameters.");
		return SR_ERR_ARG;
	case SP_ERR_FAIL:
		error = sp_last_error_message();
		sr_err("Error setting serial port parameters: %s.", error);
		sp_free_error_message(error);
		return SR_ERR;
	}

	return SR_OK;
}

/**
 * Set serial parameters for the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param paramstr A serial communication parameters string, in the form
 * of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
 * "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
 *
 * @return SR_OK upon success, SR_ERR upon failure.
 */
#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
		const char *paramstr)
{
	GRegex *reg;
	GMatchInfo *match;
	int speed, databits, parity, stopbits, flow, rts, dtr, i;
	char *mstr, **opts, **kv;

	speed = databits = parity = stopbits = flow = 0;
	rts = dtr = -1;
	sr_spew("Parsing parameters from \"%s\".", paramstr);
	reg = g_regex_new(SERIAL_COMM_SPEC, 0, 0, NULL);
	if (g_regex_match(reg, paramstr, 0, &match)) {
		if ((mstr = g_match_info_fetch(match, 1)))
			speed = strtoul(mstr, NULL, 10);
		g_free(mstr);
		if ((mstr = g_match_info_fetch(match, 2)))
			databits = strtoul(mstr, NULL, 10);
		g_free(mstr);
		if ((mstr = g_match_info_fetch(match, 3))) {
			switch (mstr[0]) {
			case 'n':
				parity = SERIAL_PARITY_NONE;
				break;
			case 'e':
				parity = SERIAL_PARITY_EVEN;
				break;
			case 'o':
				parity = SERIAL_PARITY_ODD;
				break;
			}
		}
		g_free(mstr);
		if ((mstr = g_match_info_fetch(match, 4)))
			stopbits = strtoul(mstr, NULL, 10);
		g_free(mstr);
		if ((mstr = g_match_info_fetch(match, 5)) && mstr[0] != '\0') {
			if (mstr[0] != '/') {
				sr_dbg("missing separator before extra options");
				speed = 0;
			} else {
				/* A set of "key=value" options separated by / */
				opts = g_strsplit(mstr + 1, "/", 0);
				for (i = 0; opts[i]; i++) {
					kv = g_strsplit(opts[i], "=", 2);
					if (!strncmp(kv[0], "rts", 3)) {
						if (kv[1][0] == '1')
							rts = 1;
						else if (kv[1][0] == '0')
							rts = 0;
						else {
							sr_dbg("invalid value for rts: %c", kv[1][0]);
							speed = 0;
						}
					} else if (!strncmp(kv[0], "dtr", 3)) {
						if (kv[1][0] == '1')
							dtr = 1;
						else if (kv[1][0] == '0')
							dtr = 0;
						else {
							sr_dbg("invalid value for dtr: %c", kv[1][0]);
							speed = 0;
						}
					} else if (!strncmp(kv[0], "flow", 4)) {
						if (kv[1][0] == '0')
							flow = 0;
						else if (kv[1][0] == '1')
							flow = 1;
						else if (kv[1][0] == '2')
							flow = 2;
						else {
							sr_dbg("invalid value for flow: %c", kv[1][0]);
							speed = 0;
						}
					}
					g_strfreev(kv);
				}
				g_strfreev(opts);
			}
		}
		g_free(mstr);
	}
	g_match_info_unref(match);
	g_regex_unref(reg);

	if (speed) {
		return serial_set_params(serial, speed, databits, parity,
					 stopbits, flow, rts, dtr);
	} else {
		sr_dbg("Could not infer speed from parameter string.");
		return SR_ERR_ARG;
	}
}

/**
 * Read a line from the specified serial port.
 *
 * @param serial Previously initialized serial port structure.
 * @param buf Buffer where to store the bytes that are read.
 * @param buflen Size of the buffer.
 * @param timeout_ms How long to wait for a line to come in.
 *
 * Reading stops when CR of LR is found, which is stripped from the buffer.
 *
 * @return SR_OK on success, SR_ERR on failure.
 */
SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
		int *buflen, gint64 timeout_ms)
{
	gint64 start;
	int maxlen, len;

	if (!serial || serial->fd == -1) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	if (serial->fd == -1) {
		sr_dbg("Cannot use unopened serial port %s (fd %d).",
				serial->port, serial->fd);
		return -1;
	}

	timeout_ms *= 1000;
	start = g_get_monotonic_time();

	maxlen = *buflen;
	*buflen = len = 0;
	while(1) {
		len = maxlen - *buflen - 1;
		if (len < 1)
			break;
		len = serial_read(serial, *buf + *buflen, 1);
		if (len > 0) {
			*buflen += len;
			*(*buf + *buflen) = '\0';
			if (*buflen > 0 && (*(*buf + *buflen - 1) == '\r'
					|| *(*buf + *buflen - 1) == '\n')) {
				/* Strip CR/LF and terminate. */
				*(*buf + --*buflen) = '\0';
				break;
			}
		}
		if (g_get_monotonic_time() - start > timeout_ms)
			/* Timeout */
			break;
		if (len < 1)
			g_usleep(2000);
	}
	if (*buflen)
		sr_dbg("Received %d: '%s'.", *buflen, *buf);

	return SR_OK;
}

/**
 * Try to find a valid packet in a serial data stream.
 *
 * @param serial Previously initialized serial port structure.
 * @param buf Buffer containing the bytes to write.
 * @param count Size of the buffer.
 * @param packet_size Size, in bytes, of a valid packet.
 * @param is_valid Callback that assesses whether the packet is valid or not.
 * @param timeout_ms The timeout after which, if no packet is detected, to
 *                   abort scanning.
 * @param baudrate The baudrate of the serial port. This parameter is not
 *                 critical, but it helps fine tune the serial port polling
 *                 delay.
 *
 * @return SR_OK if a valid packet is found within the given timeout,
 *         SR_ERR upon failure.
 */
SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
				 uint8_t *buf, size_t *buflen,
				 size_t packet_size, packet_valid_t is_valid,
				 uint64_t timeout_ms, int baudrate)
{
	uint64_t start, time, byte_delay_us;
	size_t ibuf, i, maxlen;
	int len;

	maxlen = *buflen;

	sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
	       "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);

	if (maxlen < (packet_size / 2) ) {
		sr_err("Buffer size must be at least twice the packet size.");
		return SR_ERR;
	}

	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	byte_delay_us = 10 * (1000000 / baudrate);
	start = g_get_monotonic_time();

	i = ibuf = len = 0;
	while (ibuf < maxlen) {
		len = serial_read(serial, &buf[ibuf], 1);
		if (len > 0) {
			ibuf += len;
		} else if (len == 0) {
			/* No logging, already done in serial_read(). */
		} else {
			/* Error reading byte, but continuing anyway. */
		}

		time = g_get_monotonic_time() - start;
		time /= 1000;

		if ((ibuf - i) >= packet_size) {
			/* We have at least a packet's worth of data. */
			if (is_valid(&buf[i])) {
				sr_spew("Found valid %d-byte packet after "
					"%" PRIu64 "ms.", (ibuf - i), time);
				*buflen = ibuf;
				return SR_OK;
			} else {
				sr_spew("Got %d bytes, but not a valid "
					"packet.", (ibuf - i));
			}
			/* Not a valid packet. Continue searching. */
			i++;
		}
		if (time >= timeout_ms) {
			/* Timeout */
			sr_dbg("Detection timed out after %dms.", time);
			break;
		}
		if (len < 1)
			g_usleep(byte_delay_us);
	}

	*buflen = ibuf;

	sr_err("Didn't find a valid packet (read %d bytes).", *buflen);

	return SR_ERR;
}
Commit	Line	Data
a1bb33af	1	/*
50985c20	2	* This file is part of the libsigrok project.
a1bb33af	3	*
c73d2ea4	4	* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
b19f4622	5	* Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
766456be	6	* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
a1bb33af UH	7	*
	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.
	12	*
	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.
	17	*
	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/>.
	20	*/
	21
54b38f64	22	#include <string.h>
d02a535e	23	#include <stdlib.h>
a1bb33af	24	#include <glib.h>
0d4405ce	25	#include <libserialport.h>
45c59c8b BV	26	#include "libsigrok.h"
45c59c8b BV	27	#include "libsigrok-internal.h"
a1bb33af	28
29a27196 UH	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)
b19f4622	37
b19f4622 UH	38	/**
	39	* Open the specified serial port.
	40	*
299bdb24	41	* @param serial Previously initialized serial port structure.
a54dd31e UH	42	* @param flags Flags to use when opening the serial port. Possible flags
a54dd31e UH	43	* include SERIAL_RDWR, SERIAL_RDONLY, SERIAL_NONBLOCK.
b19f4622	44	*
299bdb24 BV	45	* If the serial structure contains a serialcomm string, it will be
	46	* passed to serial_set_paramstr() after the port is opened.
	47	*
	48	* @return SR_OK on success, SR_ERR on failure.
b19f4622	49	*/
299bdb24	50	SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
d02a535e	51	{
a9bce5a5 ML	52	int ret;
a9bce5a5 ML	53	char *error;
b19f4622	54
299bdb24 BV	55	if (!serial) {
	56	sr_dbg("Invalid serial port.");
	57	return SR_ERR;
	58	}
	59
	60	sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
b19f4622	61
c9bc57b6 ML	62	sp_get_port_by_name(serial->port, &serial->data);
	63
	64	ret = sp_open(serial->data, flags);
a9bce5a5	65
a0dfaa6c UH	66	switch (ret) {
	67	case SP_ERR_ARG:
	68	sr_err("Attempt to open serial port with invalid parameters.");
	69	return SR_ERR_ARG;
	70	case SP_ERR_FAIL:
	71	error = sp_last_error_message();
	72	sr_err("Error opening port: %s.", error);
	73	sp_free_error_message(error);
	74	return SR_ERR;
a54dd31e UH	75	}
a54dd31e UH	76
a9bce5a5	77	#ifndef _WIN32
c9bc57b6	78	serial->fd = serial->data->fd;
926b866c	79	#endif
299bdb24 BV	80
	81	if (serial->serialcomm)
	82	return serial_set_paramstr(serial, serial->serialcomm);
	83	else
	84	return SR_OK;
d02a535e BV	85	}
d02a535e BV	86
b19f4622 UH	87	/**
	88	* Close the specified serial port.
	89	*
299bdb24	90	* @param serial Previously initialized serial port structure.
b19f4622	91	*
299bdb24	92	* @return SR_OK on success, SR_ERR on failure.
2119ab03	93	*/
299bdb24	94	SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
d02a535e	95	{
299bdb24	96	int ret;
a9bce5a5	97	char *error;
299bdb24 BV	98
	99	if (!serial) {
	100	sr_dbg("Invalid serial port.");
	101	return SR_ERR;
	102	}
	103
	104	if (serial->fd == -1) {
	105	sr_dbg("Cannot close unopened serial port %s (fd %d).",
	106	serial->port, serial->fd);
	107	return SR_ERR;
	108	}
	109
	110	sr_spew("Closing serial port %s (fd %d).", serial->port, serial->fd);
	111	ret = SR_OK;
b19f4622	112
c9bc57b6	113	ret = sp_close(serial->data);
a9bce5a5	114
a0dfaa6c UH	115	switch (ret) {
	116	case SP_ERR_ARG:
	117	sr_err("Attempt to close an invalid serial port.");
	118	return SR_ERR_ARG;
	119	case SP_ERR_FAIL:
	120	error = sp_last_error_message();
	121	sr_err("Error closing port: %s.", error);
	122	sp_free_error_message(error);
	123	return SR_ERR;
b19f4622	124	}
299bdb24 BV	125
299bdb24 BV	126	serial->fd = -1;
b19f4622 UH	127
b19f4622 UH	128	return ret;
d02a535e BV	129	}
d02a535e BV	130
b19f4622	131	/**
299bdb24	132	* Flush serial port buffers.
b19f4622	133	*
299bdb24	134	* @param serial Previously initialized serial port structure.
b19f4622	135	*
299bdb24	136	* @return SR_OK on success, SR_ERR on failure.
1fdb75e1	137	*/
299bdb24	138	SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
06d64eb8	139	{
299bdb24	140	int ret;
a9bce5a5	141	char *error;
299bdb24 BV	142
	143	if (!serial) {
	144	sr_dbg("Invalid serial port.");
	145	return SR_ERR;
	146	}
	147
	148	if (serial->fd == -1) {
	149	sr_dbg("Cannot flush unopened serial port %s (fd %d).",
	150	serial->port, serial->fd);
	151	return SR_ERR;
	152	}
	153
	154	sr_spew("Flushing serial port %s (fd %d).", serial->port, serial->fd);
b19f4622	155
c9bc57b6	156	ret = sp_flush(serial->data);
a9bce5a5	157
a0dfaa6c UH	158	switch (ret) {
	159	case SP_ERR_ARG:
	160	sr_err("Attempt to flush an invalid serial port.");
	161	return SR_ERR_ARG;
	162	case SP_ERR_FAIL:
	163	error = sp_last_error_message();
	164	sr_err("Error flushing port: %s.", error);
	165	sp_free_error_message(error);
	166	return SR_ERR;
299bdb24	167	}
b19f4622 UH	168
b19f4622 UH	169	return ret;
06d64eb8 BV	170	}
06d64eb8 BV	171
b19f4622	172	/**
2119ab03	173	* Write a number of bytes to the specified serial port.
b19f4622	174	*
299bdb24	175	* @param serial Previously initialized serial port structure.
b19f4622 UH	176	* @param buf Buffer containing the bytes to write.
	177	* @param count Number of bytes to write.
	178	*
	179	* @return The number of bytes written, or -1 upon failure.
2119ab03	180	*/
299bdb24 BV	181	SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
299bdb24 BV	182	const void *buf, size_t count)
2119ab03	183	{
299bdb24	184	ssize_t ret;
a9bce5a5	185	char *error;
299bdb24 BV	186
	187	if (!serial) {
	188	sr_dbg("Invalid serial port.");
	189	return -1;
	190	}
	191
	192	if (serial->fd == -1) {
	193	sr_dbg("Cannot use unopened serial port %s (fd %d).",
	194	serial->port, serial->fd);
	195	return -1;
	196	}
	197
c9bc57b6	198	ret = sp_write(serial->data, buf, count);
a9bce5a5	199
a0dfaa6c UH	200	switch (ret) {
	201	case SP_ERR_ARG:
	202	sr_err("Attempted serial port write with invalid arguments.");
	203	return SR_ERR_ARG;
	204	case SP_ERR_FAIL:
	205	error = sp_last_error_message();
	206	sr_err("Write error: %s.", error);
	207	sp_free_error_message(error);
	208	return SR_ERR;
a9bce5a5 ML	209	}
	210
	211	sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);
b19f4622 UH	212
b19f4622 UH	213	return ret;
2119ab03 UH	214	}
2119ab03 UH	215
b19f4622	216	/**
2119ab03	217	* Read a number of bytes from the specified serial port.
b19f4622	218	*
299bdb24	219	* @param serial Previously initialized serial port structure.
b19f4622 UH	220	* @param buf Buffer where to store the bytes that are read.
	221	* @param count The number of bytes to read.
	222	*
	223	* @return The number of bytes read, or -1 upon failure.
2119ab03	224	*/
299bdb24 BV	225	SR_PRIV int serial_read(struct sr_serial_dev_inst serial, void buf,
299bdb24 BV	226	size_t count)
2119ab03	227	{
299bdb24	228	ssize_t ret;
a9bce5a5	229	char *error;
299bdb24 BV	230
	231	if (!serial) {
	232	sr_dbg("Invalid serial port.");
	233	return -1;
	234	}
	235
	236	if (serial->fd == -1) {
	237	sr_dbg("Cannot use unopened serial port %s (fd %d).",
	238	serial->port, serial->fd);
	239	return -1;
	240	}
	241
c9bc57b6	242	ret = sp_read(serial->data, buf, count);
2119ab03	243
a0dfaa6c UH	244	switch (ret) {
	245	case SP_ERR_ARG:
	246	sr_err("Attempted serial port read with invalid arguments.");
	247	return SR_ERR_ARG;
	248	case SP_ERR_FAIL:
	249	error = sp_last_error_message();
	250	sr_err("Read error: %s.", error);
	251	sp_free_error_message(error);
	252	return SR_ERR;
a9bce5a5 ML	253	}
	254
	255	sr_spew("Read %d/%d bytes (fd %d).", ret, count, serial->fd);
b19f4622 UH	256
b19f4622 UH	257	return ret;
2119ab03 UH	258	}
2119ab03 UH	259
b19f4622 UH	260	/**
	261	* Set serial parameters for the specified serial port.
	262	*
299bdb24	263	* @param serial Previously initialized serial port structure.
b19f4622 UH	264	* @param baudrate The baudrate to set.
	265	* @param bits The number of data bits to use.
	266	* @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
	267	* @param stopbits The number of stop bits to use (1 or 2).
	268	* @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
	269	* 2 = XON/XOFF).
2119ab03	270	*
b19f4622	271	* @return SR_OK upon success, SR_ERR upon failure.
1ff7712c	272	*/
299bdb24	273	SR_PRIV int serial_set_params(struct sr_serial_dev_inst *serial, int baudrate,
39e5d798 UH	274	int bits, int parity, int stopbits,
39e5d798 UH	275	int flowcontrol, int rts, int dtr)
d02a535e	276	{
a9bce5a5 ML	277	int ret;
	278	char *error;
	279
299bdb24 BV	280	if (!serial) {
	281	sr_dbg("Invalid serial port.");
	282	return SR_ERR;
	283	}
	284
	285	if (serial->fd == -1) {
	286	sr_dbg("Cannot configure unopened serial port %s (fd %d).",
39e5d798	287	serial->port, serial->fd);
299bdb24 BV	288	return SR_ERR;
	289	}
	290
	291	sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
39e5d798	292	serial->fd);
b19f4622	293
c9bc57b6	294	ret = sp_set_params(serial->data, baudrate, bits, parity, stopbits,
a9bce5a5 ML	295	flowcontrol, rts, dtr);
a9bce5a5 ML	296
a0dfaa6c UH	297	switch (ret) {
	298	case SP_ERR_ARG:
	299	sr_err("Invalid arguments for setting serial port parameters.");
	300	return SR_ERR_ARG;
	301	case SP_ERR_FAIL:
	302	error = sp_last_error_message();
	303	sr_err("Error setting serial port parameters: %s.", error);
	304	sp_free_error_message(error);
	305	return SR_ERR;
700dcd5c UH	306	}
700dcd5c UH	307
e46b8fb1	308	return SR_OK;
d02a535e	309	}
792fc686	310
299bdb24 BV	311	/**
	312	* Set serial parameters for the specified serial port.
	313	*
	314	* @param serial Previously initialized serial port structure.
	315	* @param paramstr A serial communication parameters string, in the form
26ddb5ba	316	* of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
26ddb5ba	317	* "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
299bdb24 BV	318	*
	319	* @return SR_OK upon success, SR_ERR upon failure.
	320	*/
71caaad4	321	#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
299bdb24 BV	322	SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
299bdb24 BV	323	const char *paramstr)
792fc686 BV	324	{
	325	GRegex *reg;
	326	GMatchInfo *match;
26ddb5ba	327	int speed, databits, parity, stopbits, flow, rts, dtr, i;
71caaad4	328	char mstr, opts, *kv;
792fc686	329
26ddb5ba	330	speed = databits = parity = stopbits = flow = 0;
71caaad4	331	rts = dtr = -1;
ea088bb6	332	sr_spew("Parsing parameters from \"%s\".", paramstr);
792fc686 BV	333	reg = g_regex_new(SERIAL_COMM_SPEC, 0, 0, NULL);
	334	if (g_regex_match(reg, paramstr, 0, &match)) {
	335	if ((mstr = g_match_info_fetch(match, 1)))
	336	speed = strtoul(mstr, NULL, 10);
	337	g_free(mstr);
	338	if ((mstr = g_match_info_fetch(match, 2)))
	339	databits = strtoul(mstr, NULL, 10);
	340	g_free(mstr);
	341	if ((mstr = g_match_info_fetch(match, 3))) {
	342	switch (mstr[0]) {
	343	case 'n':
	344	parity = SERIAL_PARITY_NONE;
	345	break;
	346	case 'e':
	347	parity = SERIAL_PARITY_EVEN;
	348	break;
	349	case 'o':
	350	parity = SERIAL_PARITY_ODD;
	351	break;
	352	}
	353	}
	354	g_free(mstr);
	355	if ((mstr = g_match_info_fetch(match, 4)))
	356	stopbits = strtoul(mstr, NULL, 10);
	357	g_free(mstr);
71caaad4 BV	358	if ((mstr = g_match_info_fetch(match, 5)) && mstr[0] != '\0') {
	359	if (mstr[0] != '/') {
	360	sr_dbg("missing separator before extra options");
	361	speed = 0;
	362	} else {
	363	/* A set of "key=value" options separated by / */
	364	opts = g_strsplit(mstr + 1, "/", 0);
	365	for (i = 0; opts[i]; i++) {
	366	kv = g_strsplit(opts[i], "=", 2);
	367	if (!strncmp(kv[0], "rts", 3)) {
	368	if (kv[1][0] == '1')
	369	rts = 1;
	370	else if (kv[1][0] == '0')
	371	rts = 0;
	372	else {
	373	sr_dbg("invalid value for rts: %c", kv[1][0]);
	374	speed = 0;
	375	}
	376	} else if (!strncmp(kv[0], "dtr", 3)) {
	377	if (kv[1][0] == '1')
	378	dtr = 1;
	379	else if (kv[1][0] == '0')
	380	dtr = 0;
	381	else {
	382	sr_dbg("invalid value for dtr: %c", kv[1][0]);
	383	speed = 0;
	384	}
26ddb5ba	385	} else if (!strncmp(kv[0], "flow", 4)) {
	386	if (kv[1][0] == '0')
	387	flow = 0;
	388	else if (kv[1][0] == '1')
	389	flow = 1;
	390	else if (kv[1][0] == '2')
	391	flow = 2;
	392	else {
	393	sr_dbg("invalid value for flow: %c", kv[1][0]);
	394	speed = 0;
	395	}
71caaad4 BV	396	}
	397	g_strfreev(kv);
	398	}
	399	g_strfreev(opts);
	400	}
	401	}
	402	g_free(mstr);
792fc686 BV	403	}
	404	g_match_info_unref(match);
	405	g_regex_unref(reg);
	406
ea088bb6 AG	407	if (speed) {
ea088bb6 AG	408	return serial_set_params(serial, speed, databits, parity,
26ddb5ba	409	stopbits, flow, rts, dtr);
ea088bb6 AG	410	} else {
ea088bb6 AG	411	sr_dbg("Could not infer speed from parameter string.");
792fc686	412	return SR_ERR_ARG;
ea088bb6	413	}
792fc686 BV	414	}
792fc686 BV	415
299bdb24 BV	416	/**
	417	* Read a line from the specified serial port.
	418	*
	419	* @param serial Previously initialized serial port structure.
	420	* @param buf Buffer where to store the bytes that are read.
	421	* @param buflen Size of the buffer.
	422	* @param timeout_ms How long to wait for a line to come in.
	423	*
	424	* Reading stops when CR of LR is found, which is stripped from the buffer.
	425	*
	426	* @return SR_OK on success, SR_ERR on failure.
	427	*/
	428	SR_PRIV int serial_readline(struct sr_serial_dev_inst serial, char *buf,
	429	int *buflen, gint64 timeout_ms)
6f22a8ef	430	{
b87f8504	431	gint64 start;
6f22a8ef UH	432	int maxlen, len;
6f22a8ef UH	433
299bdb24 BV	434	if (!serial \|\| serial->fd == -1) {
	435	sr_dbg("Invalid serial port.");
	436	return SR_ERR;
	437	}
	438
	439	if (serial->fd == -1) {
	440	sr_dbg("Cannot use unopened serial port %s (fd %d).",
	441	serial->port, serial->fd);
	442	return -1;
	443	}
	444
6f22a8ef UH	445	timeout_ms *= 1000;
	446	start = g_get_monotonic_time();
	447
	448	maxlen = *buflen;
	449	*buflen = len = 0;
	450	while(1) {
	451	len = maxlen - *buflen - 1;
	452	if (len < 1)
	453	break;
299bdb24	454	len = serial_read(serial, buf + buflen, 1);
6f22a8ef UH	455	if (len > 0) {
	456	*buflen += len;
	457	(buf + *buflen) = '\0';
318dd53c BV	458	if (buflen > 0 && ((buf + buflen - 1) == '\r'
	459	\|\| (buf + *buflen - 1) == '\n')) {
	460	/* Strip CR/LF and terminate. */
6f22a8ef UH	461	(buf + --*buflen) = '\0';
	462	break;
	463	}
	464	}
	465	if (g_get_monotonic_time() - start > timeout_ms)
	466	/* Timeout */
	467	break;
5715e84f DT	468	if (len < 1)
5715e84f DT	469	g_usleep(2000);
6f22a8ef	470	}
318dd53c BV	471	if (*buflen)
318dd53c BV	472	sr_dbg("Received %d: '%s'.", buflen, buf);
6f22a8ef UH	473
	474	return SR_OK;
	475	}
766456be UH	476
	477	/**
	478	* Try to find a valid packet in a serial data stream.
	479	*
	480	* @param serial Previously initialized serial port structure.
	481	* @param buf Buffer containing the bytes to write.
	482	* @param count Size of the buffer.
	483	* @param packet_size Size, in bytes, of a valid packet.
	484	* @param is_valid Callback that assesses whether the packet is valid or not.
	485	* @param timeout_ms The timeout after which, if no packet is detected, to
	486	* abort scanning.
	487	* @param baudrate The baudrate of the serial port. This parameter is not
	488	* critical, but it helps fine tune the serial port polling
	489	* delay.
	490	*
	491	* @return SR_OK if a valid packet is found within the given timeout,
	492	* SR_ERR upon failure.
	493	*/
	494	SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
	495	uint8_t buf, size_t buflen,
	496	size_t packet_size, packet_valid_t is_valid,
	497	uint64_t timeout_ms, int baudrate)
	498	{
	499	uint64_t start, time, byte_delay_us;
	500	size_t ibuf, i, maxlen;
	501	int len;
	502
	503	maxlen = *buflen;
	504
	505	sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
	506	"ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
	507
	508	if (maxlen < (packet_size / 2) ) {
	509	sr_err("Buffer size must be at least twice the packet size.");
	510	return SR_ERR;
	511	}
	512
766456be UH	513	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	514	byte_delay_us = 10 * (1000000 / baudrate);
	515	start = g_get_monotonic_time();
	516
	517	i = ibuf = len = 0;
	518	while (ibuf < maxlen) {
	519	len = serial_read(serial, &buf[ibuf], 1);
	520	if (len > 0) {
	521	ibuf += len;
	522	} else if (len == 0) {
006dbe55	523	/* No logging, already done in serial_read(). */
766456be UH	524	} else {
	525	/* Error reading byte, but continuing anyway. */
	526	}
551c3d8c AG	527
	528	time = g_get_monotonic_time() - start;
	529	time /= 1000;
	530
766456be UH	531	if ((ibuf - i) >= packet_size) {
	532	/* We have at least a packet's worth of data. */
	533	if (is_valid(&buf[i])) {
766456be UH	534	sr_spew("Found valid %d-byte packet after "
	535	"%" PRIu64 "ms.", (ibuf - i), time);
	536	*buflen = ibuf;
	537	return SR_OK;
	538	} else {
	539	sr_spew("Got %d bytes, but not a valid "
	540	"packet.", (ibuf - i));
	541	}
	542	/* Not a valid packet. Continue searching. */
	543	i++;
	544	}
551c3d8c	545	if (time >= timeout_ms) {
766456be	546	/* Timeout */
551c3d8c	547	sr_dbg("Detection timed out after %dms.", time);
766456be UH	548	break;
766456be UH	549	}
5715e84f DT	550	if (len < 1)
5715e84f DT	551	g_usleep(byte_delay_us);
766456be UH	552	}
	553
	554	*buflen = ibuf;
	555
	556	sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
	557
	558	return SR_ERR;
	559	}