X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=blobdiff_plain;f=hardware%2Fcommon%2Fserial.c;h=9a9a0d94fd3b3058e84ba74202db681de8397885;hp=6591ec89527fe45d0210bae85cfe74523ad35793;hb=43cd4637285833706f8a404ca027bcf0ee75b9ae;hpb=71caaad46bf285681d4921db796b81746324ff29

diff --git a/hardware/common/serial.c b/hardware/common/serial.c
index 6591ec89..9a9a0d94 100644
--- a/hardware/common/serial.c
+++ b/hardware/common/serial.c
@@ -1,5 +1,5 @@
 /*
- * This file is part of the sigrok project.
+ * 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>
@@ -20,51 +20,33 @@
  */
 
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#ifdef _WIN32
-#include <windows.h>
-#else
-#include <glob.h>
-#include <termios.h>
-#endif
 #include <stdlib.h>
-#include <errno.h>
-#include <sys/ioctl.h>
 #include <glib.h>
+#include <glib/gstdio.h>
+#include <libserialport.h>
 #include "libsigrok.h"
 #include "libsigrok-internal.h"
 
-/* Message logging helpers with driver-specific prefix string. */
-#define DRIVER_LOG_DOMAIN "serial: "
-#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
-#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
-#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
-
-// FIXME: Must be moved, or rather passed as function argument.
-#ifdef _WIN32
-static HANDLE hdl;
-#endif
+#define LOG_PREFIX "serial"
 
 /**
  * Open the specified serial port.
  *
  * @param serial Previously initialized serial port structure.
- * @param flags Flags to use when opening the serial port.
- * TODO: Abstract 'flags', currently they're OS-specific!
+ * @param[in] 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.
+ * @retval SR_OK Success.
+ * @retval SR_ERR 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.");
@@ -73,21 +55,28 @@ SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
 
 	sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
 
-#ifdef _WIN32
-	hdl = CreateFile(serial->port, GENERIC_READ | GENERIC_WRITE, 0, 0,
-			 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
-	if (hdl == INVALID_HANDLE_VALUE) {
-		sr_err("Error opening serial port '%s'.", serial->port);
+	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 (%d): %s.",
+			sp_last_error_code(), error);
+		sp_free_error_message(error);
 		return SR_ERR;
 	}
-#else
-	if ((serial->fd = open(serial->port, flags)) < 0) {
-		sr_err("Error opening serial port '%s': %s.", serial->port,
-		       strerror(errno));
-		return SR_ERR;
-	} else
-		sr_spew("Opened serial port '%s' (fd %d).", serial->port, serial->fd);
-#endif
 
 	if (serial->serialcomm)
 		return serial_set_paramstr(serial, serial->serialcomm);
@@ -100,42 +89,44 @@ SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags)
  *
  * @param serial Previously initialized serial port structure.
  *
- * @return SR_OK on success, SR_ERR on failure.
+ * @retval SR_OK Success.
+ * @retval SR_ERR 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);
+	if (!serial->data) {
+		sr_dbg("Cannot close unopened serial port %s.", serial->port);
 		return SR_ERR;
 	}
 
-	sr_spew("Closing serial port %s (fd %d).", serial->port, serial->fd);
-	ret = SR_OK;
+	sr_spew("Closing serial port %s.", serial->port);
 
-#ifdef _WIN32
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (CloseHandle(hdl) == 0)
-		ret = SR_ERR;
-#else
-	/* Returns 0 upon success, -1 upon failure. */
-	if (close(serial->fd) < 0) {
-		sr_err("Error closing serial port: %s (fd %d).", strerror(errno),
-				serial->fd);
-		ret = SR_ERR;
+	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 (%d): %s.",
+			sp_last_error_code(), error);
+		sp_free_error_message(error);
+		return SR_ERR;
 	}
-#endif
 
-	serial->fd = -1;
+	sp_free_port(serial->data);
+	serial->data = NULL;
 
-	return ret;
+	return SR_OK;
 }
 
 /**
@@ -143,82 +134,151 @@ SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
  *
  * @param serial Previously initialized serial port structure.
  *
- * @return SR_OK on success, SR_ERR on failure.
+ * @retval SR_OK Success.
+ * @retval SR_ERR 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);
+	if (!serial->data) {
+		sr_dbg("Cannot flush unopened serial port %s.", serial->port);
 		return SR_ERR;
 	}
 
-	sr_spew("Flushing serial port %s (fd %d).", serial->port, serial->fd);
-	ret = SR_OK;
+	sr_spew("Flushing serial port %s.", serial->port);
 
-#ifdef _WIN32
-	/* Returns non-zero upon success, 0 upon failure. */
-	if (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) {
-		sr_err("Error flushing serial port: %s.", strerror(errno));
-		ret = SR_ERR;
+	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 (%d): %s.",
+			sp_last_error_code(), error);
+		sp_free_error_message(error);
+		return SR_ERR;
 	}
-#else
-	/* Returns 0 upon success, -1 upon failure. */
-	if (tcflush(serial->fd, TCIOFLUSH) < 0) {
-		sr_err("Error flushing serial port: %s.", strerror(errno));
-		ret = SR_ERR;
+
+	return SR_OK;
+}
+
+static int _serial_write(struct sr_serial_dev_inst *serial,
+		const void *buf, size_t count, int nonblocking)
+{
+	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 (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 (%d): %s.", sp_last_error_code(), error);
+		sp_free_error_message(error);
+		return SR_ERR;
+	}
+
+	sr_spew("Wrote %d/%d bytes.", ret, count);
+
 	return ret;
-#endif
 }
 
 /**
  * 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.
+ * @param[in] buf Buffer containing the bytes to write.
+ * @param[in] count Number of bytes to write.
  *
- * @return The number of bytes written, or -1 upon failure.
+ * @retval SR_ERR_ARG Invalid argument.
+ * @retval SR_ERR Other error.
+ * @retval other The number of bytes written.
  */
 SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
 		const void *buf, size_t count)
+{
+	return _serial_write(serial, buf, count, serial->nonblocking);
+}
+
+/**
+ * Write a number of bytes to the specified serial port, blocking until finished.
+ * @copydetails serial_write()
+ */
+SR_PRIV int serial_write_blocking(struct sr_serial_dev_inst *serial,
+		const void *buf, size_t count)
+{
+	return _serial_write(serial, buf, count, 0);
+}
+
+/**
+ * Write a number of bytes to the specified serial port, return immediately.
+ * @copydetails serial_write()
+*/
+SR_PRIV int serial_write_nonblocking(struct sr_serial_dev_inst *serial,
+		const void *buf, size_t count)
+{
+	return _serial_write(serial, buf, count, 1);
+}
+
+static int _serial_read(struct sr_serial_dev_inst *serial, void *buf,
+		size_t count, int nonblocking)
 {
 	ssize_t ret;
+	char *error;
 
 	if (!serial) {
 		sr_dbg("Invalid serial port.");
-		return -1;
+		return SR_ERR;
 	}
 
-	if (serial->fd == -1) {
-		sr_dbg("Cannot use unopened serial port %s (fd %d).",
-				serial->port, serial->fd);
-		return -1;
+	if (!serial->data) {
+		sr_dbg("Cannot use unopened serial port %s.", serial->port);
+		return SR_ERR;
 	}
 
-#ifdef _WIN32
-	DWORD tmp = 0;
-
-	/* FIXME */
-	/* Returns non-zero upon success, 0 upon failure. */
-	WriteFile(hdl, buf, count, &tmp, NULL);
-#else
-	/* Returns the number of bytes written, or -1 upon failure. */
-	ret = write(serial->fd, buf, count);
-	if (ret < 0)
-		sr_err("Write error: %s.", strerror(errno));
+	if (nonblocking)
+		ret = sp_nonblocking_read(serial->data, buf, count);
 	else
-		sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);
-#endif
+		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 (%d): %s.", sp_last_error_code(), error);
+		sp_free_error_message(error);
+		return SR_ERR;
+	}
+
+	if (ret > 0)
+		sr_spew("Read %d/%d bytes.", ret, count);
 
 	return ret;
 }
@@ -228,330 +288,149 @@ SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
  *
  * @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.
+ * @param[in] count The number of bytes to read.
  *
- * @return The number of bytes read, or -1 upon failure.
+ * @retval SR_ERR_ARG Invalid argument.
+ * @retval SR_ERR     Other error.
+ * @retval other      The number of bytes read.
  */
 SR_PRIV int serial_read(struct sr_serial_dev_inst *serial, void *buf,
 		size_t count)
 {
-	ssize_t ret;
-
-	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;
-	}
-
-#ifdef _WIN32
-	DWORD tmp = 0;
+	return _serial_read(serial, buf, count, serial->nonblocking);
+}
 
-	/* FIXME */
-	/* Returns non-zero upon success, 0 upon failure. */
-	return ReadFile(hdl, buf, count, &tmp, NULL);
-#else
-	/* Returns the number of bytes read, or -1 upon failure. */
-	ret = read(serial->fd, buf, count);
-	if (ret < 0)
-		/*
- 		 * Should be sr_err(), but that would yield lots of
-		 * "Resource temporarily unavailable" messages.
-		 */
-		sr_spew("Read error: %s (fd %d).", strerror(errno), serial->fd);
-	else
-		sr_spew("Read %d/%d bytes (fd %d).", ret, count, serial->fd);
-#endif
+/**
+ * Read a number of bytes from the specified serial port, block until finished.
+ * @copydetails serial_read()
+ */
+SR_PRIV int serial_read_blocking(struct sr_serial_dev_inst *serial, void *buf,
+		size_t count)
+{
+	return _serial_read(serial, buf, count, 0);
+}
 
-	return ret;
+/**
+ * Try to read up to @a count bytes from the specified serial port, return
+ * immediately with what's available.
+ * @copydetails serial_read()
+ */
+SR_PRIV int serial_read_nonblocking(struct sr_serial_dev_inst *serial, void *buf,
+		size_t count)
+{
+	return _serial_read(serial, buf, count, 1);
 }
 
 /**
  * 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).
+ * @param[in] baudrate The baudrate to set.
+ * @param[in] bits The number of data bits to use (5, 6, 7 or 8).
+ * @param[in] parity The parity setting to use (0 = none, 1 = even, 2 = odd).
+ * @param[in] stopbits The number of stop bits to use (1 or 2).
+ * @param[in] flowcontrol The flow control settings to use (0 = none,
+ *                      1 = RTS/CTS, 2 = XON/XOFF).
+ * @param[in] rts Status of RTS line (0 or 1; required by some interfaces).
+ * @param[in] dtr Status of DTR line (0 or 1; required by some interfaces).
  *
- * @return SR_OK upon success, SR_ERR upon failure.
+ * @retval SR_OK Success.
+ * @retval SR_ERR 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 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->fd == -1) {
-		sr_dbg("Cannot configure unopened serial port %s (fd %d).",
-				serial->port, serial->fd);
+	if (!serial->data) {
+		sr_dbg("Cannot configure unopened serial port %s.", serial->port);
 		return SR_ERR;
 	}
 
-	sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
-			serial->fd);
-
-#ifdef _WIN32
-	DCB dcb;
+	sr_spew("Setting serial parameters on port %s.", serial->port);
 
-	if (!GetCommState(hdl, &dcb))
-		return SR_ERR;
-
-	switch (baudrate) {
-	case 115200:
-		dcb.BaudRate = CBR_115200;
-		break;
-	case 57600:
-		dcb.BaudRate = CBR_57600;
-		break;
-	case 38400:
-		dcb.BaudRate = CBR_38400;
-		break;
-	case 19200:
-		dcb.BaudRate = CBR_19200;
-		break;
-	case 9600:
-		dcb.BaudRate = CBR_9600;
-		break;
-	case 4800:
-		dcb.BaudRate = CBR_4800;
-		break;
-	case 2400:
-		dcb.BaudRate = CBR_2400;
-		break;
-	default:
-		sr_err("Unsupported baudrate %d.", baudrate);
-		return SR_ERR;
-	}
-	dcb.ByteSize = bits;
-	dcb.Parity = NOPARITY; /* TODO: Don't hardcode. */
-	dcb.StopBits = ONESTOPBIT; /* TODO: Don't hardcode. */
-
-	if (!SetCommState(hdl, &dcb))
-		return SR_ERR;
-#else
-	struct termios term;
-	speed_t baud;
-	int ret, controlbits;
-
-	if (tcgetattr(serial->fd, &term) < 0) {
-		sr_err("tcgetattr() error on port %s (fd %d): %s.",
-				serial->port, serial->fd, strerror(errno));
-		return SR_ERR;
-	}
-
-	switch (baudrate) {
-	case 50:
-		baud = B50;
-		break;
-	case 75:
-		baud = B75;
-		break;
-	case 110:
-		baud = B110;
-		break;
-	case 134:
-		baud = B134;
-		break;
-	case 150:
-		baud = B150;
-		break;
-	case 200:
-		baud = B200;
-		break;
-	case 300:
-		baud = B300;
-		break;
-	case 600:
-		baud = B600;
-		break;
-	case 1200:
-		baud = B1200;
-		break;
-	case 1800:
-		baud = B1800;
-		break;
-	case 2400:
-		baud = B2400;
-		break;
-	case 4800:
-		baud = B4800;
-		break;
-	case 9600:
-		baud = B9600;
-		break;
-	case 19200:
-		baud = B19200;
-		break;
-	case 38400:
-		baud = B38400;
-		break;
-	case 57600:
-		baud = B57600;
-		break;
-	case 115200:
-		baud = B115200;
-		break;
-	case 230400:
-		baud = B230400;
-		break;
-#ifndef __APPLE__
-	case 460800:
-		baud = B460800;
-		break;
-#endif
-	default:
-		sr_err("Unsupported baudrate %d.", baudrate);
-		return SR_ERR;
-	}
-
-	sr_spew("Configuring output baudrate to %d (%d).", baudrate, baud);
-	if (cfsetospeed(&term, baud) < 0) {
-		sr_err("cfsetospeed() error: %s.", strerror(errno));
-		return SR_ERR;
-	}
-
-	sr_spew("Configuring input baudrate to %d (%d).", baudrate, baud);
-	if (cfsetispeed(&term, baud) < 0) {
-		sr_err("cfsetispeed() error: %s.", strerror(errno));
-		return SR_ERR;
-	}
-
-	sr_spew("Configuring %d data bits.", bits);
-	term.c_cflag &= ~CSIZE;
-	switch (bits) {
-	case 8:
-		term.c_cflag |= CS8;
-		break;
-	case 7:
-		term.c_cflag |= CS7;
-		break;
-	default:
-		sr_err("Unsupported data bits number %d.", bits);
-		return SR_ERR;
-	}
-
-	sr_spew("Configuring %d stop bits.", stopbits);
-	term.c_cflag &= ~CSTOPB;
-	switch (stopbits) {
-	case 1:
-		term.c_cflag &= ~CSTOPB;
-		break;
-	case 2:
-		term.c_cflag |= CSTOPB;
-		break;
-	default:
-		sr_err("Unsupported stopbits number %d.", stopbits);
-		return SR_ERR;
-	}
-
-	term.c_iflag &= ~(IXON | IXOFF);
-	term.c_cflag &= ~CRTSCTS;
-	switch (flowcontrol) {
+	sp_new_config(&config);
+	sp_set_config_baudrate(config, baudrate);
+	sp_set_config_bits(config, bits);
+	switch (parity) {
 	case 0:
-		/* No flow control. */
-		sr_spew("Configuring no flow control.");
+		sp_set_config_parity(config, SP_PARITY_NONE);
 		break;
 	case 1:
-		sr_spew("Configuring RTS/CTS flow control.");
-		term.c_cflag |= CRTSCTS;
+		sp_set_config_parity(config, SP_PARITY_EVEN);
 		break;
 	case 2:
-		sr_spew("Configuring XON/XOFF flow control.");
-		term.c_iflag |= IXON | IXOFF;
-		break;
-	default:
-		sr_err("Unsupported flow control setting %d.", flowcontrol);
-		return SR_ERR;
-	}
-
-	term.c_iflag &= ~IGNPAR;
-	term.c_cflag &= ~(PARODD | PARENB);
-	switch (parity) {
-	case SERIAL_PARITY_NONE:
-		sr_spew("Configuring no parity.");
-		term.c_iflag |= IGNPAR;
-		break;
-	case SERIAL_PARITY_EVEN:
-		sr_spew("Configuring even parity.");
-		term.c_cflag |= PARENB;
-		break;
-	case SERIAL_PARITY_ODD:
-		sr_spew("Configuring odd parity.");
-		term.c_cflag |= PARENB | PARODD;
+		sp_set_config_parity(config, SP_PARITY_ODD);
 		break;
 	default:
-		sr_err("Unsupported parity setting %d.", parity);
-		return SR_ERR;
+		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);
 
-	/* Do not translate carriage return to newline on input. */
-	term.c_iflag &= ~(ICRNL);
-
-	/* Disable canonical mode, and don't echo input characters. */
-	term.c_lflag &= ~(ICANON | ECHO);
+	ret = sp_set_config(serial->data, config);
+	sp_free_config(config);
 
-	/* Write the configured settings. */
-	if (tcsetattr(serial->fd, TCSADRAIN, &term) < 0) {
-		sr_err("tcsetattr() error: %s.", strerror(errno));
+	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 (%d): %s.",
+			sp_last_error_code(), error);
+		sp_free_error_message(error);
 		return SR_ERR;
 	}
 
-	if (rts != -1) {
-		sr_spew("Setting RTS %s.", rts ? "high" : "low");
-		controlbits = TIOCM_RTS;
-		if ((ret = ioctl(serial->fd, rts ? TIOCMBIS : TIOCMBIC,
-				&controlbits)) < 0) {
-			sr_err("Error setting RTS: %s.", strerror(errno));
-			return SR_ERR;
-		}
-	}
-
-	if (dtr != -1) {
-		sr_spew("Setting DTR %s.", dtr ? "high" : "low");
-		controlbits = TIOCM_DTR;
-		if ((ret = ioctl(serial->fd, dtr ? TIOCMBIS : TIOCMBIC,
-				&controlbits)) < 0) {
-			sr_err("Error setting DTR: %s.", strerror(errno));
-			return SR_ERR;
-		}
-	}
-
-#endif
-
 	return SR_OK;
 }
 
 /**
- * Set serial parameters for the specified serial port.
+ * Set serial parameters for the specified serial port from parameter string.
  *
  * @param serial Previously initialized serial port structure.
- * @param paramstr A serial communication parameters string, in the form
- * of <speed>/<data bits><parity><stopbits>, for example "9600/8n1" or
- * "600/7o2".
- *
- * @return SR_OK upon success, SR_ERR upon failure.
+ * @param[in] paramstr A serial communication parameters string of the form
+ * "<baudrate>/<bits><parity><stopbits>{/<option>}".\n
+ *  Examples: "9600/8n1", "600/7o2/dtr=1/rts=0" or "460800/8n1/flow=2".\n
+ * \<baudrate\>=integer Baud rate.\n
+ * \<bits\>=5|6|7|8 Number of data bits.\n
+ * \<parity\>=n|e|o None, even, odd.\n
+ * \<stopbits\>=1|2 One or two stop bits.\n
+ * Options:\n
+ * dtr=0|1 Set DTR off resp. on.\n
+ * flow=0|1|2 Flow control. 0 for none, 1 for RTS/CTS, 2 for XON/XOFF.\n
+ * rts=0|1 Set RTS off resp. on.\n
+ * Please note that values and combinations of these parameters must be
+ * supported by the concrete serial interface hardware and the drivers for it.
+ * @retval SR_OK Success.
+ * @retval SR_ERR Failure.
  */
-#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
 SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
 		const char *paramstr)
 {
+#define SERIAL_COMM_SPEC "^(\\d+)/([5678])([neo])([12])(.*)$"
+
 	GRegex *reg;
 	GMatchInfo *match;
-	int speed, databits, parity, stopbits, rts, dtr, i;
+	int speed, databits, parity, stopbits, flow, rts, dtr, i;
 	char *mstr, **opts, **kv;
 
-	speed = databits = parity = stopbits = 0;
+	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)))
@@ -604,6 +483,17 @@ SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
 							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);
 				}
@@ -615,11 +505,13 @@ SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
 	g_match_info_unref(match);
 	g_regex_unref(reg);
 
-	if (speed)
-		return serial_set_params(serial, speed, databits, parity, stopbits,
-				0, rts, dtr);
-	else
+	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;
+	}
 }
 
 /**
@@ -628,11 +520,12 @@ SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
  * @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.
+ * @param[in] 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.
+ * @retval SR_OK Success.
+ * @retval SR_ERR Failure.
  */
 SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
 		int *buflen, gint64 timeout_ms)
@@ -640,14 +533,13 @@ SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
 	gint64 start;
 	int maxlen, len;
 
-	if (!serial || serial->fd == -1) {
+	if (!serial) {
 		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);
+	if (!serial->data) {
+		sr_dbg("Cannot use unopened serial port %s.", serial->port);
 		return -1;
 	}
 
@@ -674,7 +566,8 @@ SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
 		if (g_get_monotonic_time() - start > timeout_ms)
 			/* Timeout */
 			break;
-		g_usleep(2000);
+		if (len < 1)
+			g_usleep(2000);
 	}
 	if (*buflen)
 		sr_dbg("Received %d: '%s'.", *buflen, *buf);
@@ -687,21 +580,22 @@ SR_PRIV int serial_readline(struct sr_serial_dev_inst *serial, char **buf,
  *
  * @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 buflen Size of the buffer.
+ * @param[in] 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
+ * @param[in] 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
+ * @param[in] 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.
+ * @retval SR_OK Valid packet was found within the given timeout.
+ * @retval SR_ERR 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,
+				 size_t packet_size,
+				 packet_valid_callback is_valid,
 				 uint64_t timeout_ms, int baudrate)
 {
 	uint64_t start, time, byte_delay_us;
@@ -710,8 +604,8 @@ SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
 
 	maxlen = *buflen;
 
-	sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
-	       "ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
+	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.");
@@ -728,7 +622,7 @@ SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
 		if (len > 0) {
 			ibuf += len;
 		} else if (len == 0) {
-			sr_spew("Error: Only read 0 bytes.");
+			/* No logging, already done in serial_read(). */
 		} else {
 			/* Error reading byte, but continuing anyway. */
 		}
@@ -755,7 +649,8 @@ SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
 			sr_dbg("Detection timed out after %dms.", time);
 			break;
 		}
-		g_usleep(byte_delay_us);
+		if (len < 1)
+			g_usleep(byte_delay_us);
 	}
 
 	*buflen = ibuf;
@@ -764,3 +659,253 @@ SR_PRIV int serial_stream_detect(struct sr_serial_dev_inst *serial,
 
 	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;
+}
+
+#ifdef _WIN32
+typedef HANDLE event_handle;
+#else
+typedef int event_handle;
+#endif
+
+SR_PRIV int serial_source_add(struct sr_session *session,
+		struct sr_serial_dev_inst *serial, int events, int timeout,
+		sr_receive_data_callback cb, void *cb_data)
+{
+	enum sp_event mask = 0;
+	unsigned int i;
+
+	if (sp_new_event_set(&serial->event_set) != SP_OK)
+		return SR_ERR;
+
+	if (events & G_IO_IN)
+		mask |= SP_EVENT_RX_READY;
+	if (events & G_IO_OUT)
+		mask |= SP_EVENT_TX_READY;
+	if (events & G_IO_ERR)
+		mask |= SP_EVENT_ERROR;
+
+	if (sp_add_port_events(serial->event_set, serial->data, mask) != SP_OK) {
+		sp_free_event_set(serial->event_set);
+		return SR_ERR;
+	}
+
+	serial->pollfds = (GPollFD *) g_malloc0(sizeof(GPollFD) * serial->event_set->count);
+
+	for (i = 0; i < serial->event_set->count; i++) {
+
+		serial->pollfds[i].fd = ((event_handle *) serial->event_set->handles)[i];
+
+		mask = serial->event_set->masks[i];
+
+		if (mask & SP_EVENT_RX_READY)
+			serial->pollfds[i].events |= G_IO_IN;
+		if (mask & SP_EVENT_TX_READY)
+			serial->pollfds[i].events |= G_IO_OUT;
+		if (mask & SP_EVENT_ERROR)
+			serial->pollfds[i].events |= G_IO_ERR;
+
+		if (sr_session_source_add_pollfd(session, &serial->pollfds[i],
+					timeout, cb, cb_data) != SR_OK)
+			return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+SR_PRIV int serial_source_remove(struct sr_session *session,
+		struct sr_serial_dev_inst *serial)
+{
+	unsigned int i;
+
+	for (i = 0; i < serial->event_set->count; i++)
+		if (sr_session_source_remove_pollfd(session, &serial->pollfds[i]) != SR_OK)
+			return SR_ERR;
+
+	g_free(serial->pollfds);
+	sp_free_event_set(serial->event_set);
+
+	serial->pollfds = NULL;
+	serial->event_set = NULL;
+
+	return SR_OK;
+}
+
+/**
+ * Find USB serial devices via the USB vendor ID and product ID.
+ *
+ * @param[in] vendor_id Vendor ID of the USB device.
+ * @param[in] product_id Product ID of the USB device.
+ *
+ * @return A GSList of strings containing the path of the serial device or
+ *         NULL if no serial device is found. The returned list must be freed
+ *         by the caller.
+ */
+SR_PRIV GSList *sr_serial_find_usb(uint16_t vendor_id, uint16_t product_id)
+{
+#ifdef __linux__
+	const gchar *usb_dev;
+	const char device_tree[] = "/sys/bus/usb/devices/";
+	GDir *devices_dir, *device_dir;
+	GSList *l = NULL;
+	GSList *tty_devs;
+	GSList *matched_paths;
+	FILE *fd;
+	char tmp[5];
+	gchar *vendor_path, *product_path, *path_copy;
+	gchar *prefix, *subdir_path, *device_path, *tty_path;
+	unsigned long read_vendor_id, read_product_id;
+	const char *file;
+
+	l = NULL;
+	tty_devs = NULL;
+	matched_paths = NULL;
+
+	if (!(devices_dir = g_dir_open(device_tree, 0, NULL)))
+		return NULL;
+
+	/*
+	 * Find potential candidates using the vendor ID and product ID
+	 * and store them in matched_paths.
+	 */
+	while ((usb_dev = g_dir_read_name(devices_dir))) {
+		vendor_path = g_strconcat(device_tree,
+					  usb_dev, "/idVendor", NULL);
+		product_path = g_strconcat(device_tree,
+					   usb_dev, "/idProduct", NULL);
+
+		if (!g_file_test(vendor_path, G_FILE_TEST_EXISTS) ||
+		    !g_file_test(product_path, G_FILE_TEST_EXISTS))
+			goto skip_device;
+
+		if ((fd = g_fopen(vendor_path, "r")) == NULL)
+			goto skip_device;
+
+		if (fgets(tmp, sizeof(tmp), fd) == NULL) {
+			fclose(fd);
+			goto skip_device;
+		}
+		read_vendor_id = strtoul(tmp, NULL, 16);
+
+		fclose(fd);
+
+		if ((fd = g_fopen(product_path, "r")) == NULL)
+			goto skip_device;
+
+		if (fgets(tmp, sizeof(tmp), fd) == NULL) {
+			fclose(fd);
+			goto skip_device;
+		}
+		read_product_id = strtoul(tmp, NULL, 16);
+
+		fclose(fd);
+
+		if (vendor_id == read_vendor_id &&
+		    product_id == read_product_id) {
+			path_copy = g_strdup(usb_dev);
+			matched_paths = g_slist_prepend(matched_paths,
+							path_copy);
+		}
+
+skip_device:
+		g_free(vendor_path);
+		g_free(product_path);
+	}
+	g_dir_close(devices_dir);
+
+	/* For every matched device try to find a ttyUSBX subfolder. */
+	for (l = matched_paths; l; l = l->next) {
+		subdir_path = NULL;
+
+		device_path = g_strconcat(device_tree, l->data, NULL);
+
+		if (!(device_dir = g_dir_open(device_path, 0, NULL))) {
+			g_free(device_path);
+			continue;
+		}
+
+		prefix = g_strconcat(l->data, ":", NULL);
+
+		while ((file = g_dir_read_name(device_dir))) {
+			if (g_str_has_prefix(file, prefix)) {
+				subdir_path = g_strconcat(device_path,
+						"/", file, NULL);
+				break;
+			}
+		}
+		g_dir_close(device_dir);
+
+		g_free(prefix);
+		g_free(device_path);
+
+		if (subdir_path) {
+			if (!(device_dir = g_dir_open(subdir_path, 0, NULL))) {
+				g_free(subdir_path);
+				continue;
+			}
+			g_free(subdir_path);
+
+			while ((file = g_dir_read_name(device_dir))) {
+				if (g_str_has_prefix(file, "ttyUSB")) {
+					tty_path = g_strconcat("/dev/",
+							       file, NULL);
+					sr_dbg("Found USB device %04x:%04x attached to %s.",
+					       vendor_id, product_id, tty_path);
+					tty_devs = g_slist_prepend(tty_devs,
+							tty_path);
+					break;
+				}
+			}
+			g_dir_close(device_dir);
+		}
+	}
+	g_slist_free_full(matched_paths, g_free);
+
+	return tty_devs;
+#else
+	(void)vendor_id;
+	(void)product_id;
+
+	return NULL;
+#endif
+}