MinGW/Windows: Serial port portability fixes.

Add serial_read()/serial_write() which have different implementations on
MinGW/Windows.

Add some more error code handling and documentation.

hardware/common/serial.c

@@ -51,11 +51,14 @@ char *serial_port_glob[] = {
 
 GSList *list_serial_ports(void)
 {
+	GSList *ports;
+
 #ifdef _WIN32
 	/* TODO */
+	ports = NULL;
+	ports = g_slist_append(ports, strdup("COM1"));
 #else
 	glob_t g;
-	GSList *ports;
 	unsigned int i, j;
 
 	ports = NULL;
@@ -66,9 +69,9 @@ GSList *list_serial_ports(void)
 			ports = g_slist_append(ports, strdup(g.gl_pathv[j]));
 		globfree(&g);
 	}
+#endif
 
 	return ports;
-#endif
 }
 
 int serial_open(const char *pathname, int flags)
@@ -86,11 +89,17 @@ int serial_open(const char *pathname, int flags)
 #endif
 }
 
+/*
+ * Close the serial port.
+ * Returns 0 upon success, -1 upon failure.
+ */
 int serial_close(int fd)
 {
 #ifdef _WIN32
-	CloseHandle(hdl);
+	/* Returns non-zero upon success, 0 upon failure. */
+	return (CloseHandle(hdl) == 0) ? -1 : 0;
 #else
+	/* Returns 0 upon success, -1 upon failure. */
 	return close(fd);
 #endif
 }
@@ -103,16 +112,49 @@ int serial_flush(int fd)
 {
 #ifdef _WIN32
 	/* Returns non-zero upon success, 0 upon failure. */
-	if (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0)
+	return (PurgeComm(hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0) ? -1 : 0;
-		return -1;
-	else
-		return 0;
 #else
 	/* Returns 0 upon success, -1 upon failure. */
 	return tcflush(fd, TCIOFLUSH);
 #endif
 }
 
+/*
+ * Write a number of bytes to the specified serial port.
+ * Returns the number of bytes written, or -1 upon failure.
+ */
+int serial_write(int fd, const void *buf, size_t count)
+{
+#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. */
+	return write(fd, buf, count);
+#endif
+}
+
+/*
+ * Read a number of bytes from the specified serial port.
+ * Returns the number of bytes read, or -1 upon failure.
+ */
+int serial_read(int fd, void *buf, size_t count)
+{
+#ifdef _WIN32
+	DWORD tmp = 0;
+
+	/* 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. */
+	return read(fd, buf, count);
+#endif
+}
+
 void *serial_backup_params(int fd)
 {
 #ifdef _WIN32
@@ -137,8 +179,10 @@ void serial_restore_params(int fd, void *backup)
 }
 
 /*
- * flowcontrol 1 = rts/cts  2 = xon/xoff
+ * Set serial parameters.
- * parity 0 = none, 1 = even, 2 = odd
+ *
+ * flowcontrol: 1 = rts/cts, 2 = xon/xoff
+ * parity: 0 = none, 1 = even, 2 = odd
  */
 int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,
 		      int flowcontrol)
@@ -148,6 +192,7 @@ int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,
 
 	if (!GetCommState(hdl, &dcb)) {
 		/* TODO: Error handling. */
+		return SIGROK_ERR;
 	}
 
 	/* TODO: Rename 'speed' to 'baudrate'. */
@@ -178,6 +223,7 @@ int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,
 
 	if (!SetCommState(hdl, &dcb)) {
 		/* TODO: Error handling. */
+		return SIGROK_ERR;
 	}
 #else
 	struct termios term;

hardware/link-mso19/link-mso19.c

@@ -83,7 +83,7 @@ static int mso_send_control_message(struct sigrok_device_instance *sdi,
 
 	w = 0;
 	while (w < s) {
-		ret = write(fd, buf + w, s - w);
+		ret = serial_write(fd, buf + w, s - w);
 		if (ret < 0) {
 			ret = SIGROK_ERR;
 			goto free;
@@ -145,7 +145,7 @@ static int mso_check_trigger(struct sigrok_device_instance *sdi,
 		return ret;
 
 	buf[0] = 0;
-	if (read(sdi->serial->fd, buf, 1) != 1) /* FIXME: Need timeout */
+	if (serial_read(sdi->serial->fd, buf, 1) != 1) /* FIXME: Need timeout */
 		ret = SIGROK_ERR;
 	*info = buf[0];
 
@@ -611,7 +611,7 @@ static int receive_data(int fd, int revents, void *user_data)
 
 	revents = revents;
 
-	s = read(fd, in, sizeof(in));
+	s = serial_read(fd, in, sizeof(in));
 	if (s <= 0)
 		return FALSE;
 

hardware/openbench-logic-sniffer/ols.c

@@ -119,7 +119,7 @@ static int send_shortcommand(int fd, uint8_t command)
 
 	g_debug("ols: sending cmd 0x%.2x", command);
 	buf[0] = command;
-	if (write(fd, buf, 1) != 1)
+	if (serial_write(fd, buf, 1) != 1)
 		return SIGROK_ERR;
 
 	return SIGROK_OK;
@@ -135,7 +135,7 @@ static int send_longcommand(int fd, uint8_t command, uint32_t data)
 	buf[2] = (data & 0xff0000) >> 16;
 	buf[3] = (data & 0xff00) >> 8;
 	buf[4] = data & 0xff;
-	if (write(fd, buf, 5) != 5)
+	if (serial_write(fd, buf, 5) != 5)
 		return SIGROK_ERR;
 
 	return SIGROK_OK;
@@ -280,7 +280,7 @@ static int hw_init(char *deviceinfo)
 	g_poll(fds, devcnt, 1);
 	for (i = 0; i < devcnt; i++) {
 		if (fds[i].revents == G_IO_IN) {
-			if (read(fds[i].fd, buf, 4) == 4) {
+			if (serial_read(fds[i].fd, buf, 4) == 4) {
 				if (!strncmp(buf, "1SLO", 4)
 				    || !strncmp(buf, "1ALS", 4)) {
 					if (!strncmp(buf, "1SLO", 4))
@@ -515,7 +515,7 @@ static int receive_data(int fd, int revents, void *user_data)
 
 	if (revents == G_IO_IN
 	    && num_transfers / num_channels <= limit_samples) {
-		if (read(fd, &byte, 1) != 1)
+		if (serial_read(fd, &byte, 1) != 1)
 			return FALSE;
 
 		sample[num_bytes++] = byte;

sigrok-proto.h

@@ -123,6 +123,8 @@ GSList *list_serial_ports(void);
 int serial_open(const char *pathname, int flags);
 int serial_close(int fd);
 int serial_flush(int fd);
+int serial_write(int fd, const void *buf, size_t count);
+int serial_read(int fd, void *buf, size_t count);
 void *serial_backup_params(int fd);
 void serial_restore_params(int fd, void *backup);
 int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,