/*
 * $Id$
 *
 * Copyright (C) 2003-2015 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.system.x86;

import org.jnode.system.resource.DMAException;
import org.jnode.system.resource.DMAResource;
import org.jnode.system.resource.MemoryResource;
import org.jnode.system.resource.Resource;
import org.jnode.system.resource.ResourceOwner;

/**
 * @author epr
 */
public class X86DMAChannel implements DMAResource, DMAConstants {

    /**
     * The parent
     */
    private final DMAPlugin service;
    /**
     * The owner of this channel
     */
    private final ResourceOwner owner;
    /**
     * Channel nr
     */
    private final int dmanr;

    public X86DMAChannel(DMAPlugin service, ResourceOwner owner, int dmanr) {
        this.service = service;
        this.owner = owner;
        this.dmanr = dmanr;
    }

    /**
     * @param address
     * @param length
     * @param mode
     * @throws IllegalArgumentException
     * @throws DMAException
     * @see org.jnode.system.resource.DMAResource#setup(MemoryResource, int, int)
     */
    public void setup(MemoryResource address, int length, int mode)
        throws IllegalArgumentException, DMAException {
        final int x86Mode;
        switch (mode) {
            case MODE_READ:
                x86Mode = DMA_MODE_READ;
                break;
            case MODE_WRITE:
                x86Mode = DMA_MODE_WRITE;
                break;
            default:
                throw new IllegalArgumentException("Invalid mode");
        }
        service.setup(dmanr, address, length, x86Mode);
    }

    /**
     * Enable the datatransfer of this channel. This may only be called
     * after a succesful call to setup.
     *
     * @throws DMAException
     */
    public void enable()
        throws DMAException {
        service.enable(dmanr);
    }

    /**
     * Gets the remaining length for this channel
     *
     * @return the remaining length
     * @throws DMAException
     */
    public int getLength()
        throws DMAException {
        return service.getLength(dmanr);
    }

    /**
     * @return the owner of this resource
     * @see org.jnode.system.resource.Resource#getOwner()
     */
    public ResourceOwner getOwner() {
        return owner;
    }

    /**
     * @see org.jnode.system.resource.Resource#release()
     */
    public void release() {
        service.release(this);
    }

    /**
     * The DMA number of this channel
     *
     * @return the DMA number
     */
    public int getDmaNr() {
        return dmanr;
    }

    /**
     * @see org.jnode.system.resource.Resource#getParent()
     */
    public Resource getParent() {
        return null;
    }
}