/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.driver.serial;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;
import java.security.PrivilegedExceptionAction;
import javax.naming.NameNotFoundException;
import org.jnode.driver.Device;
import org.jnode.driver.Driver;
import org.jnode.driver.DriverException;
import org.jnode.driver.character.ChannelAlreadyOwnedException;
import org.jnode.naming.InitialNaming;
import org.jnode.system.resource.IOResource;
import org.jnode.system.resource.ResourceManager;
import org.jnode.system.resource.ResourceNotFreeException;
import org.jnode.system.resource.ResourceOwner;
import org.jnode.util.AccessControllerUtils;
/**
* @author mgeisse
*/
public class SerialPortDriver extends Driver implements SerialPortAPI,
ByteChannel {
private Device channelOwner;
private IOResource port;
private int basePort;
/**
* Create new driver instance of this driver
*/
public SerialPortDriver(int basePort) {
this.channelOwner = null;
this.port = null;
this.basePort = basePort;
}
protected void startDevice() throws DriverException {
try {
final ResourceManager rm = InitialNaming.lookup(ResourceManager.NAME);
port = claimPorts(rm, getDevice(), basePort, 8);
configure(BAUD9600);
getDevice().registerAPI(SerialPortAPI.class, this);
} catch (NameNotFoundException nnfex) {
throw new DriverException(nnfex);
} catch (ResourceNotFreeException rnfex) {
throw new DriverException(rnfex);
}
}
protected void stopDevice() {
port.release();
}
public ByteChannel getChannel(Device owner)
throws ChannelAlreadyOwnedException {
if (channelOwner != null)
throw new ChannelAlreadyOwnedException(channelOwner);
channelOwner = owner;
return this;
}
public boolean isOpen() {
return true;
}
public void close() {
}
public void configure(int divisor, int bits, boolean longStop,
boolean parity, boolean pEven) {
if (divisor < 1 || divisor > 65535)
throw new IllegalArgumentException(
"invalid baud rate divisor: " + divisor);
int control;
switch (bits) {
case 5:
control = 0;
break;
case 6:
control = 1;
break;
case 7:
control = 2;
break;
case 8:
control = 3;
break;
default:
throw new IllegalArgumentException("invalid data block bits: "
+ bits);
}
if (longStop) control |= 4;
if (parity) control |= 8;
if (pEven) control |= 16;
flush();
port.outPortByte(basePort + 3, control | 128);
port.outPortByte(basePort + 0, divisor);
port.outPortByte(basePort + 1, divisor >> 8);
port.outPortByte(basePort + 3, control);
}
public void configure(int divisor) {
configure(divisor, 8, false, false, false);
}
public int readSingle() {
// should detect overruns, maybe parity errors, framing errors, and
// breaks.
// FIXME: busy waiting for a bit block to arrive
while ((port.inPortByte(basePort + 5) & 1) == 0)
;
return port.inPortByte(basePort);
}
public void writeSingle(int value) {
// FIXME: busy waiting for the transmitter buffer to be empty
while ((port.inPortByte(basePort + 5) & 32) == 0)
;
port.outPortByte(basePort, value);
}
/**
* Wait for all physically cached bit blocks to be sent. This flushes only
* the hardware buffers, but no waiting data from the input channel.
*/
private void flushHardware() {
// FIXME: busy waiting for the holding and shift registers to be empty
int b;
do
b = port.inPortByte(basePort + 5); while ((b & 96) != 96);
}
public void flush() {
// FIXME: currently flushes only the hardware as input buffers are not
// yet used. This is only relevant to non-blocking I/O.
flushHardware();
}
/**
* @see java.nio.channels.ByteChannel#read(java.nio.ByteBuffer)
*/
public int read(ByteBuffer dst) {
int n = dst.remaining();
for (int i = 0; i < n; i++)
dst.put((byte) readSingle());
return n;
}
/**
* @see java.nio.channels.ByteChannel#write(ByteBuffer)
*/
public int write(ByteBuffer src) {
int n = src.remaining();
for (int i = 0; i < n; i++)
writeSingle(src.get());
return n;
}
private IOResource claimPorts(final ResourceManager rm,
final ResourceOwner owner, final int low, final int length)
throws ResourceNotFreeException, DriverException {
try {
return AccessControllerUtils
.doPrivileged(new PrivilegedExceptionAction<IOResource>() {
public IOResource run() throws ResourceNotFreeException {
return rm.claimIOResource(owner, low, length);
}
});
} catch (ResourceNotFreeException ex) {
throw ex;
} catch (Exception ex) {
throw new DriverException("Unknown exception", ex);
}
}
}