Introduce serialport_config()

This allows to easily reconfigure a serial port as needed in
the Bus Pirate speedup patch.

Corresponding to flashrom svn r1717.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

programmer.h

@@ -660,6 +660,7 @@ typedef int fdtype;
 
 void sp_flush_incoming(void);
 fdtype sp_openserport(char *dev, unsigned int baud);
+int serialport_config(fdtype fd, unsigned int baud);
 void __attribute__((noreturn)) sp_die(char *msg);
 extern fdtype sp_fd;
 /* expose serialport_shutdown as it's currently used by buspirate */

serial.c

@@ -158,35 +158,18 @@ static void msg_perr_strerror(const char *msg)
 #endif
 }
 
-fdtype sp_openserport(char *dev, unsigned int baud)
+int serialport_config(fdtype fd, unsigned int baud)
 {
-#ifdef _WIN32
-	HANDLE fd;
-	char *dev2 = dev;
-	if ((strlen(dev) > 3) &&
-	    (tolower((unsigned char)dev[0]) == 'c') &&
-	    (tolower((unsigned char)dev[1]) == 'o') &&
-	    (tolower((unsigned char)dev[2]) == 'm')) {
-		dev2 = malloc(strlen(dev) + 5);
-		if (!dev2) {
-			msg_perr_strerror("Out of memory: ");
-			return SER_INV_FD;
-		}
-		strcpy(dev2, "\\\\.\\");
-		strcpy(dev2 + 4, dev);
-	}
-	fd = CreateFile(dev2, GENERIC_READ | GENERIC_WRITE, 0, NULL,
-			OPEN_EXISTING, 0, NULL);
-	if (dev2 != dev)
-		free(dev2);
-	if (fd == INVALID_HANDLE_VALUE) {
-		msg_perr_strerror("Cannot open serial port: ");
-		return SER_INV_FD;
+	if (fd == SER_INV_FD) {
+		msg_perr("%s: File descriptor is invalid.\n", __func__);
+		return 1;
 	}
+
+#ifdef _WIN32
 	DCB dcb;
 	if (!GetCommState(fd, &dcb)) {
 		msg_perr_strerror("Could not fetch original serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	const struct baudentry *entry = round_baud(baud);
 	dcb.BaudRate = entry->flag;
@@ -195,35 +178,25 @@ fdtype sp_openserport(char *dev, unsigned int baud)
 	dcb.StopBits = ONESTOPBIT;
 	if (!SetCommState(fd, &dcb)) {
 		msg_perr_strerror("Could not change serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	if (!GetCommState(fd, &dcb)) {
 		msg_perr_strerror("Could not fetch new serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	msg_pdbg("Baud rate is %ld.\n", dcb.BaudRate);
-	return fd;
-out_close:
-	CloseHandle(sp_fd);
-	return SER_INV_FD;
 #else
 	struct termios wanted, observed;
-	int fd;
-	fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY);
-	if (fd < 0) {
-		msg_perr_strerror("Cannot open serial port: ");
-		return SER_INV_FD;
-	}
 	fcntl(fd, F_SETFL, 0);
 	if (tcgetattr(fd, &observed) != 0) {
 		msg_perr_strerror("Could not fetch original serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	wanted = observed;
 	const struct baudentry *entry = round_baud(baud);
 	if (cfsetispeed(&wanted, entry->flag) != 0 || cfsetospeed(&wanted, entry->flag) != 0) {
 		msg_perr_strerror("Could not set serial baud rate: ");
-		goto out_close;
+		return 1;
 	}
 	wanted.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
 	wanted.c_cflag |= (CS8 | CLOCAL | CREAD);
@@ -232,11 +205,11 @@ out_close:
 	wanted.c_oflag &= ~OPOST;
 	if (tcsetattr(fd, TCSANOW, &wanted) != 0) {
 		msg_perr_strerror("Could not change serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	if (tcgetattr(fd, &observed) != 0) {
 		msg_perr_strerror("Could not fetch new serial port configuration: ");
-		goto out_close;
+		return 1;
 	}
 	if (observed.c_cflag != wanted.c_cflag ||
 	    observed.c_lflag != wanted.c_lflag ||
@@ -244,14 +217,54 @@ out_close:
 	    observed.c_oflag != wanted.c_oflag ||
 	    cfgetispeed(&observed) != cfgetispeed(&wanted)) {
 		msg_perr("%s: Some requested options did not stick.\n", __func__);
-		goto out_close;
+		return 1;
 	}
-	msg_pdbg("Baud rate is %d.\n", entry->baud);
-	return fd;
+	msg_pdbg("Baud rate is %d now.\n", entry->baud);
+#endif
+	return 0;
+}
 
-out_close:
-	close(sp_fd);
-	return SER_INV_FD;
+fdtype sp_openserport(char *dev, unsigned int baud)
+{
+	fdtype fd;
+#ifdef _WIN32
+	char *dev2 = dev;
+	if ((strlen(dev) > 3) &&
+	    (tolower((unsigned char)dev[0]) == 'c') &&
+	    (tolower((unsigned char)dev[1]) == 'o') &&
+	    (tolower((unsigned char)dev[2]) == 'm')) {
+		dev2 = malloc(strlen(dev) + 5);
+		if (!dev2) {
+			msg_perr_strerror("Out of memory: ");
+			return SER_INV_FD;
+		}
+		strcpy(dev2, "\\\\.\\");
+		strcpy(dev2 + 4, dev);
+	}
+	fd = CreateFile(dev2, GENERIC_READ | GENERIC_WRITE, 0, NULL,
+			OPEN_EXISTING, 0, NULL);
+	if (dev2 != dev)
+		free(dev2);
+	if (fd == INVALID_HANDLE_VALUE) {
+		msg_perr_strerror("Cannot open serial port: ");
+		return SER_INV_FD;
+	}
+	if (serialport_config(fd, baud) != 0) {
+		CloseHandle(fd);
+		return SER_INV_FD;
+	}
+	return fd;
+#else
+	fd = open(dev, O_RDWR | O_NOCTTY | O_NDELAY);
+	if (fd < 0) {
+		msg_perr_strerror("Cannot open serial port: ");
+		return SER_INV_FD;
+	}
+	if (serialport_config(fd, baud) != 0) {
+		close(fd);
+		return SER_INV_FD;
+	}
+	return fd;
 #endif
 }