[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;
	int sp_flags = 0;

	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);

	if (flags & SERIAL_RDWR)
		sp_flags = (SP_MODE_READ | SP_MODE_WRITE);
	else if (flags & SERIAL_RDONLY)
		sp_flags = SP_MODE_READ;

	serial->nonblocking = (flags & SERIAL_NONBLOCK) ? 1 : 0;

	ret = sp_open(serial->data, sp_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;
	}

	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->data) {
		sr_dbg("Cannot close unopened serial port %s.", serial->port);
		return SR_ERR;
	}

	sr_spew("Closing serial port %s.", serial->port);

	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;
	}

	sp_free_port(serial->data);
	serial->data = NULL;

	return SR_OK;
}

/**
 * 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->data) {
		sr_dbg("Cannot flush unopened serial port %s.", serial->port);
		return SR_ERR;
	}

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

	ret = sp_flush(serial->data, SP_BUF_BOTH);

	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 SR_OK;
}

/**
 * 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 a negative error code 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 SR_ERR;
	}

	if (!serial->data) {
		sr_dbg("Cannot use unopened serial port %s.", serial->port);
		return SR_ERR;
	}

	if (serial->nonblocking)
		ret = sp_nonblocking_write(serial->data, buf, count);
	else
		ret = sp_blocking_write(serial->data, buf, count, 0);

	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.", ret, count);

	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 a negative error code 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 SR_ERR;
	}

	if (!serial->data) {
		sr_dbg("Cannot use unopened serial port %s.", serial->port);
		return SR_ERR;
	}

	if (serial->nonblocking)
		ret = sp_nonblocking_read(serial->data, buf, count);
	else
		ret = sp_blocking_read(serial->data, buf, count, 0);

	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;
	}

	if (ret > 0)
		sr_spew("Read %d/%d bytes.", ret, count);

	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;
	struct sp_port_config *config;

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

	if (!serial->data) {
		sr_dbg("Cannot configure unopened serial port %s.", serial->port);
		return SR_ERR;
	}

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

	sp_new_config(&config);
	sp_set_config_baudrate(config, baudrate);
	sp_set_config_bits(config, bits);
	switch (parity) {
	case 0:
		sp_set_config_parity(config, SP_PARITY_NONE);
		break;
	case 1:
		sp_set_config_parity(config, SP_PARITY_EVEN);
		break;
	case 2:
		sp_set_config_parity(config, SP_PARITY_ODD);
		break;
	default:
		return SR_ERR_ARG;
	}
	sp_set_config_stopbits(config, stopbits);
	sp_set_config_rts(config, flowcontrol == 1 ? SP_RTS_FLOW_CONTROL : rts);
	sp_set_config_cts(config, flowcontrol == 1 ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE);
	sp_set_config_dtr(config, dtr);
	sp_set_config_dsr(config, SP_DSR_IGNORE);
	sp_set_config_xon_xoff(config, flowcontrol == 2 ? SP_XONXOFF_INOUT : SP_XONXOFF_DISABLED);

	ret = sp_set_config(serial->data, config);
	sp_free_config(config);

	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+)/([5678])([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) {
		sr_dbg("Invalid serial port.");
		return SR_ERR;
	}

	if (!serial->data) {
		sr_dbg("Cannot use unopened serial port %s.", serial->port);
		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 %s (timeout = %" PRIu64
	       "ms, baudrate = %d).", serial->port, 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;
}

/**
 * Extract the serial device and options from the options linked list.
 *
 * @param options List of options passed from the command line.
 * @param serial_device Pointer where to store the exctracted serial device.
 * @param serial_options Pointer where to store the optional extracted serial
 * options.
 *
 * @return SR_OK if a serial_device is found, SR_ERR if no device is found. The
 * returned string should not be freed by the caller.
 */
SR_PRIV int sr_serial_extract_options(GSList *options, const char **serial_device,
				      const char **serial_options)
{
	GSList *l;
	struct sr_config *src;

	*serial_device = NULL;

	for (l = options; l; l = l->next) {
		src = l->data;
		switch (src->key) {
		case SR_CONF_CONN:
			*serial_device = g_variant_get_string(src->data, NULL);
			sr_dbg("Parsed serial device: %s", *serial_device);
			break;

		case SR_CONF_SERIALCOMM:
			*serial_options = g_variant_get_string(src->data, NULL);
			sr_dbg("Parsed serial options: %s", *serial_options);
			break;
		}
	}

	if (!*serial_device) {
		sr_dbg("No serial device specified");
		return SR_ERR;
	}

	return SR_OK;
}

SR_PRIV int serial_source_add(struct sr_serial_dev_inst *serial, int events,
		int timeout, sr_receive_data_callback_t cb, void *cb_data)
{
#ifdef _WIN32
	return SR_ERR;
#else
	int fd;
	sp_get_port_handle(serial->data, &fd);
	return sr_source_add(fd, events, timeout, cb, cb_data);
#endif
}

SR_PRIV int serial_source_remove(struct sr_serial_dev_inst *serial)
{
#ifdef _WIN32
	return SR_ERR;
#else
	int fd;
	sp_get_port_handle(serial->data, &fd);
	return sr_source_remove(fd);
#endif
}
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	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>
	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
	22	#include <string.h>
	23	#include <stdlib.h>
	24	#include <glib.h>
	25	#include <libserialport.h>
	26	#include "libsigrok.h"
	27	#include "libsigrok-internal.h"
	28
	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)
	37
	38	/**
	39	* Open the specified serial port.
	40	*
	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.
	44	*
	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.
	49	*/
	50	SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
	51	{
	52	int ret;
	53	char *error;
	54	int sp_flags = 0;
	55
	56	if (!serial) {
	57	sr_dbg("Invalid serial port.");
	58	return SR_ERR;
	59	}
	60
	61	sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
	62
	63	sp_get_port_by_name(serial->port, &serial->data);
	64
	65	if (flags & SERIAL_RDWR)
	66	sp_flags = (SP_MODE_READ \| SP_MODE_WRITE);
	67	else if (flags & SERIAL_RDONLY)
	68	sp_flags = SP_MODE_READ;
	69
	70	serial->nonblocking = (flags & SERIAL_NONBLOCK) ? 1 : 0;
	71
	72	ret = sp_open(serial->data, sp_flags);
	73
	74	switch (ret) {
	75	case SP_ERR_ARG:
	76	sr_err("Attempt to open serial port with invalid parameters.");
	77	return SR_ERR_ARG;
	78	case SP_ERR_FAIL:
	79	error = sp_last_error_message();
	80	sr_err("Error opening port: %s.", error);
	81	sp_free_error_message(error);
	82	return SR_ERR;
	83	}
	84
	85	if (serial->serialcomm)
	86	return serial_set_paramstr(serial, serial->serialcomm);
	87	else
	88	return SR_OK;
	89	}
	90
	91	/**
	92	* Close the specified serial port.
	93	*
	94	* @param serial Previously initialized serial port structure.
	95	*
	96	* @return SR_OK on success, SR_ERR on failure.
	97	*/
	98	SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
	99	{
	100	int ret;
	101	char *error;
	102
	103	if (!serial) {
	104	sr_dbg("Invalid serial port.");
	105	return SR_ERR;
	106	}
	107
	108	if (!serial->data) {
	109	sr_dbg("Cannot close unopened serial port %s.", serial->port);
	110	return SR_ERR;
	111	}
	112
	113	sr_spew("Closing serial port %s.", serial->port);
	114
	115	ret = sp_close(serial->data);
	116
	117	switch (ret) {
	118	case SP_ERR_ARG:
	119	sr_err("Attempt to close an invalid serial port.");
	120	return SR_ERR_ARG;
	121	case SP_ERR_FAIL:
	122	error = sp_last_error_message();
	123	sr_err("Error closing port: %s.", error);
	124	sp_free_error_message(error);
	125	return SR_ERR;
	126	}
	127
	128	sp_free_port(serial->data);
	129	serial->data = NULL;
	130
	131	return SR_OK;
	132	}
	133
	134	/**
	135	* Flush serial port buffers.
	136	*
	137	* @param serial Previously initialized serial port structure.
	138	*
	139	* @return SR_OK on success, SR_ERR on failure.
	140	*/
	141	SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
	142	{
	143	int ret;
	144	char *error;
	145
	146	if (!serial) {
	147	sr_dbg("Invalid serial port.");
	148	return SR_ERR;
	149	}
	150
	151	if (!serial->data) {
	152	sr_dbg("Cannot flush unopened serial port %s.", serial->port);
	153	return SR_ERR;
	154	}
	155
	156	sr_spew("Flushing serial port %s.", serial->port);
	157
	158	ret = sp_flush(serial->data, SP_BUF_BOTH);
	159
	160	switch (ret) {
	161	case SP_ERR_ARG:
	162	sr_err("Attempt to flush an invalid serial port.");
	163	return SR_ERR_ARG;
	164	case SP_ERR_FAIL:
	165	error = sp_last_error_message();
	166	sr_err("Error flushing port: %s.", error);
	167	sp_free_error_message(error);
	168	return SR_ERR;
	169	}
	170
	171	return SR_OK;
	172	}
	173
	174	/**
	175	* Write a number of bytes to the specified serial port.
	176	*
	177	* @param serial Previously initialized serial port structure.
	178	* @param buf Buffer containing the bytes to write.
	179	* @param count Number of bytes to write.
	180	*
	181	* @return The number of bytes written, or a negative error code upon failure.
	182	*/
	183	SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
	184	const void *buf, size_t count)
	185	{
	186	ssize_t ret;
	187	char *error;
	188
	189	if (!serial) {
	190	sr_dbg("Invalid serial port.");
	191	return SR_ERR;
	192	}
	193
	194	if (!serial->data) {
	195	sr_dbg("Cannot use unopened serial port %s.", serial->port);
	196	return SR_ERR;
	197	}
	198
	199	if (serial->nonblocking)
	200	ret = sp_nonblocking_write(serial->data, buf, count);
	201	else
	202	ret = sp_blocking_write(serial->data, buf, count, 0);
	203
	204	switch (ret) {
	205	case SP_ERR_ARG:
	206	sr_err("Attempted serial port write with invalid arguments.");
	207	return SR_ERR_ARG;
	208	case SP_ERR_FAIL:
	209	error = sp_last_error_message();
	210	sr_err("Write error: %s.", error);
	211	sp_free_error_message(error);
	212	return SR_ERR;
	213	}
	214
	215	sr_spew("Wrote %d/%d bytes.", ret, count);
	216
	217	return ret;
	218	}
	219
	220	/**
	221	* Read a number of bytes from the specified serial port.
	222	*
	223	* @param serial Previously initialized serial port structure.
	224	* @param buf Buffer where to store the bytes that are read.
	225	* @param count The number of bytes to read.
	226	*
	227	* @return The number of bytes read, or a negative error code upon failure.
	228	*/
	229	SR_PRIV int serial_read(struct sr_serial_dev_inst serial, void buf,
	230	size_t count)
	231	{
	232	ssize_t ret;
	233	char *error;
	234
	235	if (!serial) {
	236	sr_dbg("Invalid serial port.");
	237	return SR_ERR;
	238	}
	239
	240	if (!serial->data) {
	241	sr_dbg("Cannot use unopened serial port %s.", serial->port);
	242	return SR_ERR;
	243	}
	244
	245	if (serial->nonblocking)
	246	ret = sp_nonblocking_read(serial->data, buf, count);
	247	else
	248	ret = sp_blocking_read(serial->data, buf, count, 0);
	249
	250	switch (ret) {
	251	case SP_ERR_ARG:
	252	sr_err("Attempted serial port read with invalid arguments.");
	253	return SR_ERR_ARG;
	254	case SP_ERR_FAIL:
	255	error = sp_last_error_message();
	256	sr_err("Read error: %s.", error);
	257	sp_free_error_message(error);
	258	return SR_ERR;
	259	}
	260
	261	if (ret > 0)
	262	sr_spew("Read %d/%d bytes.", ret, count);
	263
	264	return ret;
	265	}
	266
	267	/**
	268	* Set serial parameters for the specified serial port.
	269	*
	270	* @param serial Previously initialized serial port structure.
	271	* @param baudrate The baudrate to set.
	272	* @param bits The number of data bits to use.
	273	* @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
	274	* @param stopbits The number of stop bits to use (1 or 2).
	275	* @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
	276	* 2 = XON/XOFF).
	277	*
	278	* @return SR_OK upon success, SR_ERR upon failure.
	279	*/
	280	SR_PRIV int serial_set_params(struct sr_serial_dev_inst *serial, int baudrate,
	281	int bits, int parity, int stopbits,
	282	int flowcontrol, int rts, int dtr)
	283	{
	284	int ret;
	285	char *error;
	286	struct sp_port_config *config;
	287
	288	if (!serial) {
	289	sr_dbg("Invalid serial port.");
	290	return SR_ERR;
	291	}
	292
	293	if (!serial->data) {
	294	sr_dbg("Cannot configure unopened serial port %s.", serial->port);
	295	return SR_ERR;
	296	}
	297
	298	sr_spew("Setting serial parameters on port %s.", serial->port);
	299
	300	sp_new_config(&config);
	301	sp_set_config_baudrate(config, baudrate);
	302	sp_set_config_bits(config, bits);
	303	switch (parity) {
	304	case 0:
	305	sp_set_config_parity(config, SP_PARITY_NONE);
	306	break;
	307	case 1:
	308	sp_set_config_parity(config, SP_PARITY_EVEN);
	309	break;
	310	case 2:
	311	sp_set_config_parity(config, SP_PARITY_ODD);
	312	break;
	313	default:
	314	return SR_ERR_ARG;
	315	}
	316	sp_set_config_stopbits(config, stopbits);
	317	sp_set_config_rts(config, flowcontrol == 1 ? SP_RTS_FLOW_CONTROL : rts);
	318	sp_set_config_cts(config, flowcontrol == 1 ? SP_CTS_FLOW_CONTROL : SP_CTS_IGNORE);
	319	sp_set_config_dtr(config, dtr);
	320	sp_set_config_dsr(config, SP_DSR_IGNORE);
	321	sp_set_config_xon_xoff(config, flowcontrol == 2 ? SP_XONXOFF_INOUT : SP_XONXOFF_DISABLED);
	322
	323	ret = sp_set_config(serial->data, config);
	324	sp_free_config(config);
	325
	326	switch (ret) {
	327	case SP_ERR_ARG:
	328	sr_err("Invalid arguments for setting serial port parameters.");
	329	return SR_ERR_ARG;
	330	case SP_ERR_FAIL:
	331	error = sp_last_error_message();
	332	sr_err("Error setting serial port parameters: %s.", error);
	333	sp_free_error_message(error);
	334	return SR_ERR;
	335	}
	336
	337	return SR_OK;
	338	}
	339
	340	/**
	341	* Set serial parameters for the specified serial port.
	342	*
	343	* @param serial Previously initialized serial port structure.
	344	* @param paramstr A serial communication parameters string, in the form
	345	* of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
	346	* "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
	347	*
	348	* @return SR_OK upon success, SR_ERR upon failure.
	349	*/
	350	#define SERIAL_COMM_SPEC "^(\\d+)/([5678])([neo])([12])(.*)$"
	351	SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
	352	const char *paramstr)
	353	{
	354	GRegex *reg;
	355	GMatchInfo *match;
	356	int speed, databits, parity, stopbits, flow, rts, dtr, i;
	357	char mstr, opts, *kv;
	358
	359	speed = databits = parity = stopbits = flow = 0;
	360	rts = dtr = -1;
	361	sr_spew("Parsing parameters from \"%s\".", paramstr);
	362	reg = g_regex_new(SERIAL_COMM_SPEC, 0, 0, NULL);
	363	if (g_regex_match(reg, paramstr, 0, &match)) {
	364	if ((mstr = g_match_info_fetch(match, 1)))
	365	speed = strtoul(mstr, NULL, 10);
	366	g_free(mstr);
	367	if ((mstr = g_match_info_fetch(match, 2)))
	368	databits = strtoul(mstr, NULL, 10);
	369	g_free(mstr);
	370	if ((mstr = g_match_info_fetch(match, 3))) {
	371	switch (mstr[0]) {
	372	case 'n':
	373	parity = SERIAL_PARITY_NONE;
	374	break;
	375	case 'e':
	376	parity = SERIAL_PARITY_EVEN;
	377	break;
	378	case 'o':
	379	parity = SERIAL_PARITY_ODD;
	380	break;
	381	}
	382	}
	383	g_free(mstr);
	384	if ((mstr = g_match_info_fetch(match, 4)))
	385	stopbits = strtoul(mstr, NULL, 10);
	386	g_free(mstr);
	387	if ((mstr = g_match_info_fetch(match, 5)) && mstr[0] != '\0') {
	388	if (mstr[0] != '/') {
	389	sr_dbg("missing separator before extra options");
	390	speed = 0;
	391	} else {
	392	/* A set of "key=value" options separated by / */
	393	opts = g_strsplit(mstr + 1, "/", 0);
	394	for (i = 0; opts[i]; i++) {
	395	kv = g_strsplit(opts[i], "=", 2);
	396	if (!strncmp(kv[0], "rts", 3)) {
	397	if (kv[1][0] == '1')
	398	rts = 1;
	399	else if (kv[1][0] == '0')
	400	rts = 0;
	401	else {
	402	sr_dbg("invalid value for rts: %c", kv[1][0]);
	403	speed = 0;
	404	}
	405	} else if (!strncmp(kv[0], "dtr", 3)) {
	406	if (kv[1][0] == '1')
	407	dtr = 1;
	408	else if (kv[1][0] == '0')
	409	dtr = 0;
	410	else {
	411	sr_dbg("invalid value for dtr: %c", kv[1][0]);
	412	speed = 0;
	413	}
	414	} else if (!strncmp(kv[0], "flow", 4)) {
	415	if (kv[1][0] == '0')
	416	flow = 0;
	417	else if (kv[1][0] == '1')
	418	flow = 1;
	419	else if (kv[1][0] == '2')
	420	flow = 2;
	421	else {
	422	sr_dbg("invalid value for flow: %c", kv[1][0]);
	423	speed = 0;
	424	}
	425	}
	426	g_strfreev(kv);
	427	}
	428	g_strfreev(opts);
	429	}
	430	}
	431	g_free(mstr);
	432	}
	433	g_match_info_unref(match);
	434	g_regex_unref(reg);
	435
	436	if (speed) {
	437	return serial_set_params(serial, speed, databits, parity,
	438	stopbits, flow, rts, dtr);
	439	} else {
	440	sr_dbg("Could not infer speed from parameter string.");
	441	return SR_ERR_ARG;
	442	}
	443	}
	444
	445	/**
	446	* Read a line from the specified serial port.
	447	*
	448	* @param serial Previously initialized serial port structure.
	449	* @param buf Buffer where to store the bytes that are read.
	450	* @param buflen Size of the buffer.
	451	* @param timeout_ms How long to wait for a line to come in.
	452	*
	453	* Reading stops when CR of LR is found, which is stripped from the buffer.
	454	*
	455	* @return SR_OK on success, SR_ERR on failure.
	456	*/
	457	SR_PRIV int serial_readline(struct sr_serial_dev_inst serial, char *buf,
	458	int *buflen, gint64 timeout_ms)
	459	{
	460	gint64 start;
	461	int maxlen, len;
	462
	463	if (!serial) {
	464	sr_dbg("Invalid serial port.");
	465	return SR_ERR;
	466	}
	467
	468	if (!serial->data) {
	469	sr_dbg("Cannot use unopened serial port %s.", serial->port);
	470	return -1;
	471	}
	472
	473	timeout_ms *= 1000;
	474	start = g_get_monotonic_time();
	475
	476	maxlen = *buflen;
	477	*buflen = len = 0;
	478	while(1) {
	479	len = maxlen - *buflen - 1;
	480	if (len < 1)
	481	break;
	482	len = serial_read(serial, buf + buflen, 1);
	483	if (len > 0) {
	484	*buflen += len;
	485	(buf + *buflen) = '\0';
	486	if (buflen > 0 && ((buf + buflen - 1) == '\r'
	487	\|\| (buf + *buflen - 1) == '\n')) {
	488	/* Strip CR/LF and terminate. */
	489	(buf + --*buflen) = '\0';
	490	break;
	491	}
	492	}
	493	if (g_get_monotonic_time() - start > timeout_ms)
	494	/* Timeout */
	495	break;
	496	if (len < 1)
	497	g_usleep(2000);
	498	}
	499	if (*buflen)
	500	sr_dbg("Received %d: '%s'.", buflen, buf);
	501
	502	return SR_OK;
	503	}
	504
	505	/**
	506	* Try to find a valid packet in a serial data stream.
	507	*
	508	* @param serial Previously initialized serial port structure.
	509	* @param buf Buffer containing the bytes to write.
	510	* @param count Size of the buffer.
	511	* @param packet_size Size, in bytes, of a valid packet.
	512	* @param is_valid Callback that assesses whether the packet is valid or not.
	513	* @param timeout_ms The timeout after which, if no packet is detected, to
	514	* abort scanning.
	515	* @param baudrate The baudrate of the serial port. This parameter is not
	516	* critical, but it helps fine tune the serial port polling
	517	* delay.
	518	*
	519	* @return SR_OK if a valid packet is found within the given timeout,
	520	* SR_ERR upon failure.
	521	*/
	522	SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
	523	uint8_t buf, size_t buflen,
	524	size_t packet_size, packet_valid_t is_valid,
	525	uint64_t timeout_ms, int baudrate)
	526	{
	527	uint64_t start, time, byte_delay_us;
	528	size_t ibuf, i, maxlen;
	529	int len;
	530
	531	maxlen = *buflen;
	532
	533	sr_dbg("Detecting packets on %s (timeout = %" PRIu64
	534	"ms, baudrate = %d).", serial->port, timeout_ms, baudrate);
	535
	536	if (maxlen < (packet_size / 2) ) {
	537	sr_err("Buffer size must be at least twice the packet size.");
	538	return SR_ERR;
	539	}
	540
	541	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	542	byte_delay_us = 10 * (1000000 / baudrate);
	543	start = g_get_monotonic_time();
	544
	545	i = ibuf = len = 0;
	546	while (ibuf < maxlen) {
	547	len = serial_read(serial, &buf[ibuf], 1);
	548	if (len > 0) {
	549	ibuf += len;
	550	} else if (len == 0) {
	551	/* No logging, already done in serial_read(). */
	552	} else {
	553	/* Error reading byte, but continuing anyway. */
	554	}
	555
	556	time = g_get_monotonic_time() - start;
	557	time /= 1000;
	558
	559	if ((ibuf - i) >= packet_size) {
	560	/* We have at least a packet's worth of data. */
	561	if (is_valid(&buf[i])) {
	562	sr_spew("Found valid %d-byte packet after "
	563	"%" PRIu64 "ms.", (ibuf - i), time);
	564	*buflen = ibuf;
	565	return SR_OK;
	566	} else {
	567	sr_spew("Got %d bytes, but not a valid "
	568	"packet.", (ibuf - i));
	569	}
	570	/* Not a valid packet. Continue searching. */
	571	i++;
	572	}
	573	if (time >= timeout_ms) {
	574	/* Timeout */
	575	sr_dbg("Detection timed out after %dms.", time);
	576	break;
	577	}
	578	if (len < 1)
	579	g_usleep(byte_delay_us);
	580	}
	581
	582	*buflen = ibuf;
	583
	584	sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
	585
	586	return SR_ERR;
	587	}
	588
	589	/**
	590	* Extract the serial device and options from the options linked list.
	591	*
	592	* @param options List of options passed from the command line.
	593	* @param serial_device Pointer where to store the exctracted serial device.
	594	* @param serial_options Pointer where to store the optional extracted serial
	595	* options.
	596	*
	597	* @return SR_OK if a serial_device is found, SR_ERR if no device is found. The
	598	* returned string should not be freed by the caller.
	599	*/
	600	SR_PRIV int sr_serial_extract_options(GSList options, const char *serial_device,
	601	const char **serial_options)
	602	{
	603	GSList *l;
	604	struct sr_config *src;
	605
	606	*serial_device = NULL;
	607
	608	for (l = options; l; l = l->next) {
	609	src = l->data;
	610	switch (src->key) {
	611	case SR_CONF_CONN:
	612	*serial_device = g_variant_get_string(src->data, NULL);
	613	sr_dbg("Parsed serial device: %s", *serial_device);
	614	break;
	615
	616	case SR_CONF_SERIALCOMM:
	617	*serial_options = g_variant_get_string(src->data, NULL);
	618	sr_dbg("Parsed serial options: %s", *serial_options);
	619	break;
	620	}
	621	}
	622
	623	if (!*serial_device) {
	624	sr_dbg("No serial device specified");
	625	return SR_ERR;
	626	}
	627
	628	return SR_OK;
	629	}
	630
	631	SR_PRIV int serial_source_add(struct sr_serial_dev_inst *serial, int events,
	632	int timeout, sr_receive_data_callback_t cb, void *cb_data)
	633	{
	634	#ifdef _WIN32
	635	return SR_ERR;
	636	#else
	637	int fd;
	638	sp_get_port_handle(serial->data, &fd);
	639	return sr_source_add(fd, events, timeout, cb, cb_data);
	640	#endif
	641	}
	642
	643	SR_PRIV int serial_source_remove(struct sr_serial_dev_inst *serial)
	644	{
	645	#ifdef _WIN32
	646	return SR_ERR;
	647	#else
	648	int fd;
	649	sp_get_port_handle(serial->data, &fd);
	650	return sr_source_remove(fd);
	651	#endif
	652	}