Merge pull request #598 from dkaukov/dtr-and-rts

Add method to set DTR and RTS together

Author: hedgecrw

src/main/c/Posix/SerialPort_Posix.c

@@ -1141,6 +1141,33 @@ JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_clearDTR(JNI
 	return JNI_TRUE;
 }
 
+JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_setDTRandRTS(JNIEnv *env, jobject obj, jlong serialPortPointer, jboolean dtr, jboolean rts)
+{
+  struct serialPort *port = (serialPort*)(intptr_t)serialPortPointer;
+  int status;
+
+  // Read current status
+  if (ioctl(port->handle, TIOCMGET, &status)) {
+    port->errorNumber = errno;
+    return JNI_FALSE;
+  }
+
+  // Modify bits
+  if (dtr) status |= TIOCM_DTR;
+  else     status &= ~TIOCM_DTR;
+
+  if (rts) status |= TIOCM_RTS;
+  else     status &= ~TIOCM_RTS;
+
+  // Write combined status
+  if (ioctl(port->handle, TIOCMSET, &status)) {
+    port->errorNumber = errno;
+    return JNI_FALSE;
+  }
+
+  return JNI_TRUE;
+}
+
 JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_getCTS(JNIEnv *env, jobject obj, jlong serialPortPointer)
 {
 	int modemBits = 0;

src/main/c/Posix/com_fazecast_jSerialComm_SerialPort.h

@@ -1416,6 +1416,48 @@ JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_clearDTR(JNI
 	return JNI_TRUE;
 }
 
+JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_setDTRandRTS(JNIEnv *env, jobject obj, jlong serialPortPointer, jboolean dtr, jboolean rts)
+{
+    serialPort *port = (serialPort*)(intptr_t)serialPortPointer;
+    HANDLE hComm = (HANDLE)(intptr_t)port->handle;
+
+    port->errorLineNumber = __LINE__ + 1;
+
+    DWORD funcFlags = 0;
+
+    // Unfortunately, Windows API doesn't offer atomic combined DTR/RTS control.
+    // So we must call EscapeCommFunction separately for each line.
+    // This still typically results in a single USB control transfer on Windows CDC drivers.
+
+    // Set or clear DTR
+    if (dtr) {
+        if (!EscapeCommFunction(hComm, SETDTR)) {
+            port->errorNumber = GetLastError();
+            return JNI_FALSE;
+        }
+    } else {
+        if (!EscapeCommFunction(hComm, CLRDTR)) {
+            port->errorNumber = GetLastError();
+            return JNI_FALSE;
+        }
+    }
+
+    // Set or clear RTS
+    if (rts) {
+        if (!EscapeCommFunction(hComm, SETRTS)) {
+            port->errorNumber = GetLastError();
+            return JNI_FALSE;
+        }
+    } else {
+        if (!EscapeCommFunction(hComm, CLRRTS)) {
+            port->errorNumber = GetLastError();
+            return JNI_FALSE;
+        }
+    }
+
+    return JNI_TRUE;
+}
+
 JNIEXPORT jboolean JNICALL Java_com_fazecast_jSerialComm_SerialPort_getCTS(JNIEnv *env, jobject obj, jlong serialPortPointer)
 {
 	DWORD modemStatus = 0;

src/main/c/Windows/SerialPort_Windows.c

@@ -852,6 +852,7 @@ public final int getLastErrorCode()
 	private native boolean clearRTS(long portHandle);					// Clear RTS line to 0
 	private native boolean setDTR(long portHandle);						// Set DTR line to 1
 	private native boolean clearDTR(long portHandle);					// Clear DTR line to 0
+	private native boolean setDTRandRTS(long portHandle, boolean dtr, boolean rts);
 	private native boolean getCTS(long portHandle);						// Returns whether the CTS signal is 1
 	private native boolean getDSR(long portHandle);						// Returns whether the DSR signal is 1
 	private native boolean getDCD(long portHandle);						// Returns whether the DCD signal is 1
@@ -1062,6 +1063,19 @@ public final boolean clearDTR()
 	}
 
 	/**
+	 * Sets the DTR and RTS lines to the specified values.
+	 * @param dtr - the desired state of the DTR line.
+	 * @param rts - the desired state of the RTS line.
+	 * @return true if successful, false if not.
+	 */
+	public final boolean setDTRandRTS(boolean dtr, boolean rts)
+	{
+		isDtrEnabled = dtr;
+		isRtsEnabled = rts;
+		return (androidPort != null) ? androidPort.setDTRandRTS(dtr, rts) : ((portHandle == 0) || setDTRandRTS(portHandle, dtr, rts));
+	}
+
+	 /**
 	 * Returns whether the CTS line is currently asserted.
 	 * @return Whether or not the CTS line is asserted.
 	 */

src/main/java/com/fazecast/jSerialComm/SerialPort.java

@@ -219,6 +219,7 @@ public long closePortNative()
 	public abstract boolean clearRTS();
 	public abstract boolean setDTR();
 	public abstract boolean clearDTR();
+	public abstract boolean setDTRandRTS(boolean dtr, boolean rts);
 	public abstract boolean getCTS();
 	public abstract boolean getDSR();
 	public abstract boolean getDCD();