dma.h

一个微型操作系统源码

/*
 * OSV
 * Copyright (C) 2002 Ciprian DOSOFTEI <[e-mail]>
 * All rights reserved.
 * 
 * http://backster.free.fr/osv
 *
 * This file is part of the OSV project. OSV is free software, also known as
 * "open source"; you can redistribute it and/or modify it under the terms 
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF). To explore alternate licensing terms, contact 
 * the author at [e-mail] or [phone].
 * 
 * OSV 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 GPL for more details.  You should have
 * received a copy of the GPL along with OSV; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

#ifndef INCDMA
#define INCDMA

#include <types.h>

typedef struct {
    unsigned channel:2;
    unsigned mask:1;
    unsigned dont_care:5;
} NOALIGN _MASK_REG;

#define CHANNEL0 0
#define CHANNEL1 1
#define CHANNEL2 2
#define CHANNEL3 3

typedef union {
    _MASK_REG fields;
    byte value;
} MASK_REG;

typedef struct {
    unsigned channel:2;
    unsigned transfer_type:2;
    unsigned auto_init:1;
    unsigned address_inc:1;
    unsigned mode:2;
} NOALIGN _MODE_REG;

#define VERIFY_TRANSFER 0
#define WRITE_TRANSFER 1
#define READ_TRANSFER 2

typedef enum {VERIFY, WRITE, READ} transfer_type;

#define DEMAND_MODE 0
#define SINGLE_MODE 1
#define BLOCK_MODE 2
#define CASCADE_MODE 3

typedef enum {DEMAND, SINGLE, BLOCK, CASCADE} mode_type;

typedef union {
    _MODE_REG fields;
    byte value;
} 	MODE_REG;

void setup_dma (dword channel, dword data_ptr, word length, 
		transfer_type trans, mode_type mode,
		BOOL auto_init, BOOL address_inc);
void pause_dma (byte channel);
void unpause_dma (byte channel);
void stop_dma (byte channel);

#endif