transferdescriptor.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 300 行

/*
 * $Id: TransferDescriptor.java,v 1.1 2003/11/25 11:42:17 epr Exp $
 */
package org.jnode.driver.usb.uhci;

import org.jnode.system.ResourceManager;
import org.jnode.util.NumberUtils;
import org.jnode.vm.Address;

/**
 * A wrapper of the UHCI Transfer Descriptor layout.
 * 
 * @author Ewout Prangsma ([e-mail])
 */
public final class TransferDescriptor extends AbstractTreeStructure implements UHCIConstants {

	/** The transfer data buffer */
	private final byte[] dataBuffer;
	/** Offset in the data buffer */
	private final int dataBufferOffset;
	/** The link pointer */
	private AbstractTreeStructure linkPointer;
	/** Is the link a TD */
	private boolean linkIsTD;
	/** The original ctrl value */
	private final int origCtrl;

	/**
	 * Create a new instance
	 * 
	 * @param rm
	 *            The resource manager
	 * @param deviceAddress
	 *            The destination device address
	 * @param endPt
	 *            The destination endpoint address
	 * @param packetId
	 *            The packet id.
	 * @param data0
	 *            Data Toggle, if true data0, otherwise data1
	 * @param dataBuffer
	 *            The data buffer
	 * @param dataBufferOffset
	 *            The offset within the databuffer
	 * @param isochronous
	 *            Isochronous transfer yes/no
	 * @param lowspeed
	 *            Lowspeed device yes/no
	 * @param ioc
	 *            Interrupt on complete yes/no
	 */
	public TransferDescriptor(
		ResourceManager rm,
		int deviceAddress,
		int endPt,
		int packetId,
		boolean data0,
		byte[] dataBuffer,
		int dataBufferOffset,
		int bufLength,
		boolean isochronous,
		boolean lowspeed,
		boolean ioc) {
		super(rm, 32, 16);
		this.dataBuffer = dataBuffer;
		this.dataBufferOffset = dataBufferOffset;
		final int maxLen;
		if (bufLength > 0) {
			maxLen = bufLength - 1;
		} else {
			maxLen = 0x7FF;
		}
		// Set Linkpointer to invalid
		setInt(0, 1);
		// Set Control & Status
		int ctrl = TD_CTRL_C_ERR_MASK | TD_CTRL_ACTIVE | TD_CTRL_SPD;
		if (ioc) {
			ctrl |= TD_CTRL_IOC;
		}
		if (isochronous) {
			ctrl |= TD_CTRL_IOS;
		}
		if (lowspeed) {
			ctrl |= TD_CTRL_LS;
		}
		this.origCtrl = ctrl;
		setInt(4, ctrl); //
		// Set Token
		int token = packetId & 0xFF;
		token |= (deviceAddress & 0x7F) << 8;
		token |= (endPt & 0xF) << 15;
		token |= (data0 ? 0 : 1) << 19;
		token |= (maxLen << 21);
		setInt(8, token);
		// Set Buffer pointer
		if (dataBuffer == null) {
			setInt(12, 0);
		} else {
			setInt(12, dataBufferOffset + Address.as32bit(rm.asMemoryResource(dataBuffer).getAddress()));
		}
	}

	/**
	 * Reset thestatus of this TD.
	 * The Active bit is set, the Error bits are cleared, the Error Counter
	 * is set.
	 * The SPD, LS, ISO and IOC bits are preserved.
	 */
	public final void resetStatus() {
		setInt(4, origCtrl);
	}
	
	/**
	 * Set the link pointer to the given transfer descriptor.
	 * 
	 * @param td
	 */
	public final void setLink(TransferDescriptor td, boolean depthFirst) {
		final int ptr = td.getDescriptorAddress() & 0xFFFFFFF0 | (depthFirst ? 0x4 : 0x0);
		this.linkPointer = td;
		this.linkIsTD = true;
		setInt(0, ptr);
	}

	/**
	 * Set the link pointer to the given queue head.
	 * 
	 * @param qh
	 * @param depthFirst
	 *            If true, the next queue is processed depth first, otherwise the next queue is
	 *            processed breadth first
	 */
	public final void setLink(QueueHead qh, boolean depthFirst) {
		final int ptr = (qh.getDescriptorAddress() & 0xFFFFFFF0) | 0x2 | (depthFirst ? 0x4 : 0x0);
		this.linkPointer = qh;
		this.linkIsTD = false;
		setInt(0, ptr);
	}

	/**
	 * Set the link pointer as invalid
	 */
	public final void removeLink() {
		setInt(0, 1);
		this.linkIsTD = false;
		this.linkPointer = null;
	}

	/**
	 * Set the active bit of this descriptor
	 * 
	 * @param active
	 */
	public final void setActive(boolean active) {
		int ctrl = getInt(4);
		if (active) {
			ctrl |= TD_CTRL_ACTIVE;
		} else {
			ctrl &= ~TD_CTRL_ACTIVE;
		}
		setInt(4, ctrl);
	}

	/**
	 * Is the active bit of this descriptor set.
	 */
	public final boolean isActive() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_ACTIVE) != 0);
	}

	/**
	 * Is the stalled bit of this descriptor set.
	 */
	public final boolean isStalled() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_STALLED) != 0);
	}

	/**
	 * Is the data buffer error bit of this descriptor set.
	 */
	public final boolean isDataBufferError() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_DBUFERR) != 0);
	}

	/**
	 * Is the babble detected bit of this descriptor set.
	 */
	public final boolean isBabbleDetected() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_BABBLE) != 0);
	}

	/**
	 * Is the NAK received bit of this descriptor set.
	 */
	public final boolean isNAKReceived() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_NAK) != 0);
	}

	/**
	 * Is the CRC/Time Out Error bit of this descriptor set.
	 */
	public final boolean isCRCTimeOutError() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_CRCTIMEO) != 0);
	}

	/**
	 * Is the Bitstuff Error bit of this descriptor set.
	 */
	public final boolean isBitstuffError() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_BITSTUFF) != 0);
	}

	/**
	 * Is any of the error flags set.
	 */
	public final boolean isAnyError() {
		final int ctrl = getInt(4);
		return ((ctrl & TD_CTRL_ANY_ERROR) != 0);
	}

	/**
	 * Gets the actual length that is set by the HC.
	 */
	public final int getActualLength() {
		final int len = getInt(4) & TD_CTRL_ACTLEN_MASK;
		if (len == 0x7FF) {
			return 0;
		} else {
			return len + 1;
		}
	}

	/**
	 * @return Returns the dataBuffer.
	 */
	public final byte[] getDataBuffer() {
		return this.dataBuffer;
	}

	/**
	 * @return Returns the offset in the dataBuffer.
	 */
	public final int getDataBufferOffset() {
		return this.dataBufferOffset;
	}

	/**
	 * @return Returns the linkPointer.
	 */
	public final AbstractTreeStructure getLink() {
		return this.linkPointer;
	}

	/**
	 * Gets the linked TransferDescriptor, if any.
	 * @return The linked TransferDescriptor, or null if the link is null or not a TD.
	 */
	public final TransferDescriptor getNextTD() {
		if (linkIsTD) {
			return (TransferDescriptor)this.linkPointer;
		} else {
			return null;
		}
	}

	/**
	 * Append the given TD to the end of the list I'm a part of.
	 * 
	 * @param td
	 */
	public final void append(TransferDescriptor td, boolean depthFirst) {
		AbstractTreeStructure ptr = this;
		while (ptr instanceof TransferDescriptor) {
			final TransferDescriptor ptrTD = (TransferDescriptor) ptr;
			if (ptrTD.linkPointer == null) {
				ptrTD.setLink(td, depthFirst);
				return;
			} else {
				ptr = ptrTD.getLink();
			}
		}
	}

	/**
	 * Convert to a String representation
	 * 
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return "TD[" + NumberUtils.hex(getInt(0)) + ", " + NumberUtils.hex(getInt(4)) + ", " + NumberUtils.hex(getInt(8)) + ", " + NumberUtils.hex(getInt(12)) + "->" + linkPointer + "]";
	}
}