dosbox-wii/include/dma.h

/*
 *  Copyright (C) 2002-2019  The DOSBox Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */


#ifndef DOSBOX_DMA_H
#define DOSBOX_DMA_H

enum DMAEvent {
	DMA_REACHED_TC,
	DMA_MASKED,
	DMA_UNMASKED,
//	DMA_TRANSFEREND, this shouldn't really be a ignal
};

class DmaChannel;
typedef void (* DMA_CallBack)(DmaChannel * chan,DMAEvent event);

class DmaChannel {
public:
	Bit32u pagebase;
	Bit16u baseaddr;
	Bit32u curraddr;
	Bit16u basecnt;
	Bit16u currcnt;
	Bit8u channum;
	Bit8u pagenum;
	Bit8u DMA16;
	bool increment;
	bool autoinit;
	Bit8u trantype;
	bool masked;
	bool tcount;
	bool request;
	DMA_CallBack callback;

	DmaChannel(Bit8u num, bool dma16);
	void DoCallBack(DMAEvent event) {
		if (callback)	(*callback)(this,event);
	}
	void SetMask(bool _mask) {
		masked=_mask;
		DoCallBack(masked ? DMA_MASKED : DMA_UNMASKED);
	}
	void Register_Callback(DMA_CallBack _cb) { 
		callback = _cb; 
		SetMask(masked);
		if (callback) Raise_Request();
		else Clear_Request();
	}
	void ReachedTC(void) {
		tcount=true;
		DoCallBack(DMA_REACHED_TC);
	}
	void SetPage(Bit8u val) {
		pagenum=val;
		pagebase=(pagenum >> DMA16) << (16+DMA16);
	}
	void Raise_Request(void) {
		request=true;
	}
	void Clear_Request(void) {
		request=false;
	}
	Bitu Read(Bitu size, Bit8u * buffer);
	Bitu Write(Bitu size, Bit8u * buffer);
};

class DmaController {
private:
	Bit8u ctrlnum;
	bool flipflop;
	DmaChannel *DmaChannels[4];
public:
	IO_ReadHandleObject DMA_ReadHandler[0x12];
	IO_WriteHandleObject DMA_WriteHandler[0x12];
	DmaController(Bit8u num) {
		flipflop = false;
		ctrlnum = num;		/* first or second DMA controller */
		for(Bit8u i=0;i<4;i++) {
			DmaChannels[i] = new DmaChannel(i+ctrlnum*4,ctrlnum==1);
		}
	}
	~DmaController(void) {
		for(Bit8u i=0;i<4;i++) {
			delete DmaChannels[i];
		}
	}
	DmaChannel * GetChannel(Bit8u chan) {
		if (chan<4) return DmaChannels[chan];
		else return NULL;
	}
	void WriteControllerReg(Bitu reg,Bitu val,Bitu len);
	Bitu ReadControllerReg(Bitu reg,Bitu len);
};

DmaChannel * GetDMAChannel(Bit8u chan);

void CloseSecondDMAController(void);
bool SecondDMAControllerAvailable(void);

void DMA_SetWrapping(Bitu wrap);

#endif