X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Fcommon%2Fserial.c;h=f887194b8a7179d269d74ef0b7af39ac55e80356;hb=50985c2019b2b5a6ce394589d89ee925b4f5e3a9;hp=38d4a5f121e08acaeb35da9340f095a14e1c65de;hpb=886a52b6fbffb0fd06849c928cf9fd31a0d4657b;p=libsigrok.git

diff --git a/hardware/common/serial.c b/hardware/common/serial.c
index 38d4a5f1..f887194b 100644
--- a/hardware/common/serial.c
+++ b/hardware/common/serial.c
@@ -1,7 +1,9 @@
 /*
- * 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>
+ * 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
@@ -27,105 +29,203 @@
 #else
 #include <glob.h>
 #include <termios.h>
+#include <sys/ioctl.h>
 #endif
 #include <stdlib.h>
+#include <errno.h>
 #include <glib.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
 
-static const char *serial_port_glob[] = {
-	/* Linux */
-	"/dev/ttyS*",
-	"/dev/ttyUSB*",
-	"/dev/ttyACM*",
-	/* MacOS X */
-	"/dev/ttys*",
-	"/dev/tty.USB-*",
-	"/dev/tty.Modem-*",
-	NULL,
-};
-
-SR_PRIV GSList *list_serial_ports(void)
+/**
+ * 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)
 {
-	GSList *ports;
-
+	int flags_local = 0;
 #ifdef _WIN32
-	/* TODO */
-	ports = NULL;
-	ports = g_slist_append(ports, g_strdup("COM1"));
-#else
-	glob_t g;
-	unsigned int i, j;
+	DWORD desired_access = 0, flags_and_attributes = 0;
+#endif
 
-	ports = NULL;
-	for (i = 0; serial_port_glob[i]; i++) {
-		if (glob(serial_port_glob[i], 0, NULL, &g))
-			continue;
-		for (j = 0; j < g.gl_pathc; j++)
-			ports = g_slist_append(ports, g_strdup(g.gl_pathv[j]));
-		globfree(&g);
+	if (!serial) {
+		sr_dbg("Invalid serial port.");
+		return SR_ERR;
 	}
-#endif
 
-	return ports;
-}
+	sr_spew("Opening serial port '%s' (flags %d).", serial->port, flags);
 
-SR_PRIV int serial_open(const char *pathname, int flags)
-{
 #ifdef _WIN32
-	/* FIXME: Don't hardcode COM1. */
-	hdl = CreateFile("COM1", GENERIC_READ | GENERIC_WRITE, 0, 0,
-			 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
+	/* Map 'flags' to the OS-specific settings. */
+	desired_access |= GENERIC_READ;
+	flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
+	if (flags & SERIAL_RDWR)
+		desired_access |= GENERIC_WRITE;
+	if (flags & SERIAL_NONBLOCK)
+		flags_and_attributes |= FILE_FLAG_OVERLAPPED;
+
+	hdl = CreateFile(serial->port, desired_access, 0, 0,
+			 OPEN_EXISTING, flags_and_attributes, 0);
 	if (hdl == INVALID_HANDLE_VALUE) {
-		/* TODO: Error handling. */
+		sr_err("Error opening serial port '%s'.", serial->port);
+		return SR_ERR;
 	}
-	return 0;
 #else
-	return open(pathname, flags);
+	/* Map 'flags' to the OS-specific settings. */
+	if (flags & SERIAL_RDWR)
+		flags_local |= O_RDWR;
+	if (flags & SERIAL_RDONLY)
+		flags_local |= O_RDONLY;
+	if (flags & SERIAL_NONBLOCK)
+		flags_local |= O_NONBLOCK;
+
+	if ((serial->fd = open(serial->port, flags_local)) < 0) {
+		sr_err("Error opening serial port '%s': %s.", serial->port,
+		       strerror(errno));
+		return SR_ERR;
+	}
+
+	sr_spew("Opened serial port '%s' (fd %d).", serial->port, serial->fd);
 #endif
+
+	if (serial->serialcomm)
+		return serial_set_paramstr(serial, serial->serialcomm);
+	else
+		return SR_OK;
 }
 
-/*
- * Close the serial port.
- * Returns 0 upon success, -1 upon failure.
+/**
+ * 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(int fd)
+SR_PRIV int serial_close(struct sr_serial_dev_inst *serial)
 {
+	int ret;
+
+	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;
+
 #ifdef _WIN32
 	/* Returns non-zero upon success, 0 upon failure. */
-	return (CloseHandle(hdl) == 0) ? -1 : 0;
+	if (CloseHandle(hdl) == 0)
+		ret = SR_ERR;
 #else
 	/* Returns 0 upon success, -1 upon failure. */
-	return close(fd);
+	if (close(serial->fd) < 0) {
+		sr_err("Error closing serial port: %s (fd %d).", strerror(errno),
+				serial->fd);
+		ret = SR_ERR;
+	}
 #endif
+
+	serial->fd = -1;
+
+	return ret;
 }
 
-/*
- * Flush serial port buffers (if any).
- * Returns 0 upon success, -1 upon failure.
+/**
+ * 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(int fd)
+SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
 {
+	int ret;
+
+	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 = SR_OK;
+
 #ifdef _WIN32
 	/* Returns non-zero upon success, 0 upon failure. */
-	return (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) ? -1 : 0;
+	if (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) {
+		sr_err("Error flushing serial port: %s.", strerror(errno));
+		ret = SR_ERR;
+	}
 #else
 	/* Returns 0 upon success, -1 upon failure. */
-	return tcflush(fd, TCIOFLUSH);
+	if (tcflush(serial->fd, TCIOFLUSH) < 0) {
+		sr_err("Error flushing serial port: %s.", strerror(errno));
+		ret = SR_ERR;
+	}
+
+	return ret;
 #endif
 }
 
-/*
+/**
  * Write a number of bytes to the specified serial port.
- * Returns the number of bytes written, or -1 upon failure.
+ *
+ * @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(int fd, const void *buf, size_t count)
+SR_PRIV int serial_write(struct sr_serial_dev_inst *serial,
+		const 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;
 
@@ -134,16 +234,41 @@ SR_PRIV int serial_write(int fd, const void *buf, size_t count)
 	WriteFile(hdl, buf, count, &tmp, NULL);
 #else
 	/* Returns the number of bytes written, or -1 upon failure. */
-	return write(fd, buf, count);
+	ret = write(serial->fd, buf, count);
+	if (ret < 0)
+		sr_err("Write error: %s.", strerror(errno));
+	else
+		sr_spew("Wrote %d/%d bytes (fd %d).", ret, count, serial->fd);
 #endif
+
+	return ret;
 }
 
-/*
+/**
  * Read a number of bytes from the specified serial port.
- * Returns the number of bytes read, or -1 upon failure.
+ *
+ * @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(int fd, void *buf, size_t count)
+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;
 
@@ -152,98 +277,204 @@ SR_PRIV int serial_read(int fd, void *buf, size_t count)
 	return ReadFile(hdl, buf, count, &tmp, NULL);
 #else
 	/* Returns the number of bytes read, or -1 upon failure. */
-	return read(fd, buf, count);
+	ret = read(serial->fd, buf, count);
 #endif
+
+	return ret;
 }
 
-SR_PRIV void *serial_backup_params(int fd)
+/**
+ * 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)
 {
-#ifdef _WIN32
-	/* TODO */
-#else
-	struct termios *term;
-
-	/* TODO: 'term' is never g_free()'d? */
-	if (!(term = g_try_malloc(sizeof(struct termios)))) {
-		sr_err("serial: %s: term malloc failed", __func__);
-		return -1;
+	if (!serial) {
+		sr_dbg("Invalid serial port.");
+		return SR_ERR;
 	}
 
-	tcgetattr(fd, term);
-
-	return term;
-#endif
-}
+	if (serial->fd == -1) {
+		sr_dbg("Cannot configure unopened serial port %s (fd %d).",
+		       serial->port, serial->fd);
+		return SR_ERR;
+	}
 
-SR_PRIV void serial_restore_params(int fd, void *backup)
-{
-#ifdef _WIN32
-	/* TODO */
-#else
-	tcsetattr(fd, TCSADRAIN, (struct termios *)backup);
-#endif
-}
+	sr_spew("Setting serial parameters on port %s (fd %d).", serial->port,
+		serial->fd);
 
-/*
- * Set serial parameters.
- *
- * flowcontrol: 1 = rts/cts, 2 = xon/xoff
- * parity: 0 = none, 1 = even, 2 = odd
- */
-SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
-			      int stopbits, int flowcontrol)
-{
 #ifdef _WIN32
 	DCB dcb;
 
 	if (!GetCommState(hdl, &dcb)) {
-		/* TODO: Error handling. */
+		sr_err("Failed to get comm state on port %s (fd %d): %d.",
+		       serial->port, serial->fd, GetLastError());
 		return SR_ERR;
 	}
 
 	switch (baudrate) {
-	/* TODO: Support for higher baud rates. */
-	case 115200:
-		dcb.BaudRate = CBR_115200;
+	/*
+	 * The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
+	 * have documented CBR_* macros.
+	 */
+	case 110:
+		dcb.BaudRate = CBR_110;
 		break;
-	case 57600:
-		dcb.BaudRate = CBR_57600;
+	case 300:
+		dcb.BaudRate = CBR_300;
 		break;
-	case 38400:
-		dcb.BaudRate = CBR_38400;
+	case 600:
+		dcb.BaudRate = CBR_600;
 		break;
-	case 19200:
-		dcb.BaudRate = CBR_19200;
+	case 1200:
+		dcb.BaudRate = CBR_1200;
 		break;
-	case 9600:
-		dcb.BaudRate = CBR_9600;
+	case 2400:
+		dcb.BaudRate = CBR_2400;
 		break;
 	case 4800:
 		dcb.BaudRate = CBR_4800;
 		break;
-	case 2400:
-		dcb.BaudRate = CBR_2400;
+	case 9600:
+		dcb.BaudRate = CBR_9600;
 		break;
-	default:
-		/* TODO: Error handling. */
+	case 14400:
+		dcb.BaudRate = CBR_14400; /* Not available on Unix? */
+		break;
+	case 19200:
+		dcb.BaudRate = CBR_19200;
+		break;
+	case 38400:
+		dcb.BaudRate = CBR_38400;
+		break;
+	case 57600:
+		dcb.BaudRate = CBR_57600;
+		break;
+	case 115200:
+		dcb.BaudRate = CBR_115200;
+		break;
+	case 128000:
+		dcb.BaudRate = CBR_128000; /* Not available on Unix? */
 		break;
+	case 256000:
+		dcb.BaudRate = CBR_256000; /* Not available on Unix? */
+		break;
+	default:
+		sr_err("Unsupported baudrate: %d.", baudrate);
+		return SR_ERR;
 	}
+	sr_spew("Configuring baudrate to %d (%d).", baudrate, dcb.BaudRate);
+
+	sr_spew("Configuring %d data bits.", bits);
 	dcb.ByteSize = bits;
-	dcb.Parity = NOPARITY; /* TODO: Don't hardcode. */
-	dcb.StopBits = ONESTOPBIT; /* TODO: Don't hardcode. */
+
+	sr_spew("Configuring %d stop bits.", stopbits);
+	switch (stopbits) {
+	/* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
+	case 1:
+		dcb.StopBits = ONESTOPBIT;
+		break;
+	case 2:
+		dcb.StopBits = TWOSTOPBITS;
+		break;
+	default:
+		sr_err("Unsupported stopbits number: %d.", stopbits);
+		return SR_ERR;
+	}
+
+	switch (parity) {
+	/* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
+	case SERIAL_PARITY_NONE:
+		sr_spew("Configuring no parity.");
+		dcb.Parity = NOPARITY;
+		break;
+	case SERIAL_PARITY_EVEN:
+		sr_spew("Configuring even parity.");
+		dcb.Parity = EVENPARITY;
+		break;
+	case SERIAL_PARITY_ODD:
+		sr_spew("Configuring odd parity.");
+		dcb.Parity = ODDPARITY;
+		break;
+	default:
+		sr_err("Unsupported parity setting: %d.", parity);
+		return SR_ERR;
+	}
+
+	if (rts != -1) {
+		sr_spew("Setting RTS %s.", rts ? "high" : "low");
+		if (rts)
+			dcb.fRtsControl = RTS_CONTROL_ENABLE;
+		else
+			dcb.fRtsControl = RTS_CONTROL_DISABLE;
+	}
+
+	if (dtr != -1) {
+		sr_spew("Setting DTR %s.", dtr ? "high" : "low");
+		if (dtr)
+			dcb.fDtrControl = DTR_CONTROL_ENABLE;
+		else
+			dcb.fDtrControl = DTR_CONTROL_DISABLE;
+	}
 
 	if (!SetCommState(hdl, &dcb)) {
-		/* TODO: Error handling. */
+		sr_err("Failed to set comm state on port %s (fd %d): %d.",
+		       serial->port, serial->fd, GetLastError());
 		return SR_ERR;
 	}
 #else
 	struct termios term;
 	speed_t baud;
+	int ret, controlbits;
 
-	if (tcgetattr(fd, &term) < 0)
+	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;
@@ -253,6 +484,9 @@ SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
 	case 9600:
 		baud = B9600;
 		break;
+	case 19200:
+		baud = B19200;
+		break;
 	case 38400:
 		baud = B38400;
 		break;
@@ -262,19 +496,32 @@ SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
 	case 115200:
 		baud = B115200;
 		break;
-#ifndef __APPLE__
+	case 230400:
+		baud = B230400;
+		break;
+#if !defined(__APPLE__) && !defined(__OpenBSD__)
 	case 460800:
 		baud = B460800;
 		break;
 #endif
 	default:
+		sr_err("Unsupported baudrate: %d.", baudrate);
 		return SR_ERR;
 	}
-	if (cfsetospeed(&term, baud) < 0)
+
+	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;
-	if (cfsetispeed(&term, baud) < 0)
+	}
+
+	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:
@@ -284,16 +531,21 @@ SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
 		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;
 	}
 
@@ -302,13 +554,18 @@ SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
 	switch (flowcontrol) {
 	case 0:
 		/* No flow control. */
+		sr_spew("Configuring no flow control.");
 		break;
 	case 1:
+		sr_spew("Configuring RTS/CTS flow control.");
 		term.c_cflag |= CRTSCTS;
+		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;
 	}
 
@@ -316,38 +573,85 @@ SR_PRIV int serial_set_params(int fd, int baudrate, int bits, int parity,
 	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;
 		break;
 	default:
+		sr_err("Unsupported parity setting %d.", parity);
 		return SR_ERR;
 	}
 
-	/* Some default parameters */
-	term.c_iflag &= ~(ICRNL);
+	/* Turn off all serial port cooking. */
+	term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
+	term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
+#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
+	term.c_oflag &= ~OFILL;
+#endif
+
+	/* Disable canonical mode, and don't echo input characters. */
 	term.c_lflag &= ~(ICANON | ECHO);
 
-	if (tcsetattr(fd, TCSADRAIN, &term) < 0)
+	/* Write the configured settings. */
+	if (tcsetattr(serial->fd, TCSADRAIN, &term) < 0) {
+		sr_err("tcsetattr() error: %s.", strerror(errno));
 		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;
 }
 
-#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])$"
-SR_PRIV int serial_set_paramstr(int fd, const char *paramstr)
+/**
+ * Set serial parameters for the specified serial port.
+ *
+ * @param serial Previously initialized serial port structure.
+ * @param paramstr A serial communication parameters string, in the form
+ * of <speed>/<data bits><parity><stopbits><flow>, for example "9600/8n1" or
+ * "600/7o2" or "460800/8n1/flow=2" where flow is 0 for none, 1 for rts/cts and 2 for xon/xoff.
+ *
+ * @return SR_OK upon success, SR_ERR upon failure.
+ */
+#define SERIAL_COMM_SPEC "^(\\d+)/([78])([neo])([12])(.*)$"
+SR_PRIV int serial_set_paramstr(struct sr_serial_dev_inst *serial,
+		const char *paramstr)
 {
 	GRegex *reg;
 	GMatchInfo *match;
-	int speed, databits, parity, stopbits;
-	char *mstr;
+	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)))
@@ -373,22 +677,93 @@ SR_PRIV int serial_set_paramstr(int fd, const char *paramstr)
 		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(fd, speed, databits, parity, stopbits, 0);
-	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;
+	}
 }
 
-SR_PRIV int serial_readline(int fd, char **buf, int *buflen,
-			    uint64_t timeout_ms)
+/**
+ * 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)
 {
-	uint64_t start;
+	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();
 
@@ -398,12 +773,13 @@ SR_PRIV int serial_readline(int fd, char **buf, int *buflen,
 		len = maxlen - *buflen - 1;
 		if (len < 1)
 			break;
-		len = serial_read(fd, *buf + *buflen, 1);
+		len = serial_read(serial, *buf + *buflen, 1);
 		if (len > 0) {
 			*buflen += len;
 			*(*buf + *buflen) = '\0';
-			if (*buflen > 0 && *(*buf + *buflen - 1) == '\r') {
-				/* Strip LF and terminate. */
+			if (*buflen > 0 && (*(*buf + *buflen - 1) == '\r'
+					|| *(*buf + *buflen - 1) == '\n')) {
+				/* Strip CR/LF and terminate. */
 				*(*buf + --*buflen) = '\0';
 				break;
 			}
@@ -413,7 +789,91 @@ SR_PRIV int serial_readline(int fd, char **buf, int *buflen,
 			break;
 		g_usleep(2000);
 	}
-	sr_dbg("Received %d: '%s'.", *buflen, *buf);
+	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;
+		}
+		g_usleep(byte_delay_us);
+	}
+
+	*buflen = ibuf;
+
+	sr_err("Didn't find a valid packet (read %d bytes).", *buflen);
+
+	return SR_ERR;
+}