/*******************************************************************/
/* Advanced Communication Board Developer Toolkit 1993		   */
/*   For use with Advanced Communication Boards 		   */
/*  DMA.C							   */
/*  This file defines routines that interface to the 8237 DMA	   */
/*   controller.						   */
/*  Source file is DMA.c                                           */
/* .OBJ File Linked to Program for DMA Transfers		   */
/*******************************************************************/

/*******************************************************************/
#include <dos.h>    /*contains FP_SEG and FP_OFF macro*/
#include "dma.h"

#ifdef _BORLAND
        #define     OUT     outportb
        #define     IN      inportb
        #define     FAR     far
#else
        #define     OUT     _outp
        #define     IN      _inp
        #define     FAR     __far
#endif
#define     RESET_DMA_FLIP_FLOP OUT(0x0c, 0);
#define     LOBYTE(w)	     ((unsigned char)(w))
#define     HIBYTE(w)	     ((unsigned char)(((unsigned short)(w) >> 8) & 0xFF))
#define     LOWORD(l)	     ((unsigned short)(unsigned long)(l))
#define     HIWORD(l)	     ((unsigned short)((((unsigned long)(l)) >> 16) & 0xFFFF))
#define     ptrToLong(ptr)  ((((unsigned long)FP_SEG(ptr)) <<4) + FP_OFF(ptr))

/*******************************************************************/
/* SetPageRegister :						   */
/*  Set the DMA Page Register with the correct value		   */
/*  Parameters: wDMA - DMA selection constant from DMA.H	   */
/*		wSEG1 - Segment of DMA Buffer			   */
/*		wOFF1 - Offset of DMA Buffer			   */
/*  Return: Nothing						   */
/*******************************************************************/
/*  Note this is not include in the C module, please see the
    SetPageRegisterEx() routine. */

/*******************************************************************/
/* SetPageRegisterEx :						   */
/*  Set the DMA Page Register with the correct value		   */
/*  Parameters: wDMA - DMA selection constant from DMA.H	   */
/*		fpBUFFER - Far Ptr to DMA Buffer		   */
/*  Return: Nothing						   */
/*******************************************************************/
void SetPageRegisterEx(unsigned short wDMA,unsigned char FAR * fpBUFFER)
{	unsigned char Temp;
	unsigned long BUFF_LONG;

	BUFF_LONG = ptrToLong(fpBUFFER);
	RESET_DMA_FLIP_FLOP	 /*Reset DMA Flip Flop*/
	Temp = (unsigned char)(BUFF_LONG & 0x000000ff);
	OUT(LOBYTE(wDMA) ,Temp);	    /* Low Address */
	Temp = (unsigned char)((BUFF_LONG >> 8) & 0x000000ff);
	OUT(LOBYTE(wDMA) ,Temp);	    /* High Address */
	Temp = (unsigned char)((BUFF_LONG >> 16) & 0x0000000f); /*mhb*/
	OUT(HIBYTE(wDMA) ,Temp);	    /*Page Register*/
}
/*******************************************************************/
/* SetTC :							   */
/*  Set the DMA Terminal Count Register	Contents		   */
/*  Parameters: wDMA - DMA selection constant from DMA.H	   */
/*		wTC - Terminal Count				   */
/*  Return: Nothing						   */
/*******************************************************************/
void SetTC(unsigned short wDMA,unsigned short wTC)
{
	RESET_DMA_FLIP_FLOP
	wDMA = (wDMA & 0x00ff) + 1;
	OUT(wDMA, LOBYTE(wTC));
	OUT(wDMA, HIBYTE(wTC));
}
/*******************************************************************/
/* GetTC :							   */
/*  Get the DMA Terminal Count Register				   */
/*  Parameters: wDMA - DMA selection constant from DMA.H	   */
/*  Return: DMA Terminal Count for selected DMA channel		   */
/*******************************************************************/
unsigned short GetTC(unsigned short wDMA)
{	unsigned short wTemp1, wTemp2;

	RESET_DMA_FLIP_FLOP
	wDMA = (wDMA & 0x00ff) + 1;
	wTemp1 = IN(wDMA);	    /*Get Count - Low Byte*/
	wTemp2 = IN(wDMA);	    /*Get Count - High Byte*/
	wTemp1 = wTemp1 & 0x00ff;    /* Clear off high byte*/
	wTemp2 = wTemp2 << 8;	    /* Shift to high byte to make a word*/ /*mhb*/
	wTemp2 = wTemp2 & 0xff00;    /* Clear off low byte*/
	return( wTemp1 | wTemp2);
}
/*******************************************************************/
/* MaskDMA :							   */
/*  Set the Mask Register					   */
/*  Parameters: bMASK -  D0-D3 = DMA1-DMA3			   */
/*  Return: Nothing						   */
/*******************************************************************/
void MaskDMA(unsigned char bMASK1)
{
	OUT( 0x0f, bMASK1);	/*DMA Mask Reg is at I/O address 0x0f*/
}

/*******************************************************************/
/* SetDMAMode :							   */
/*  Set the DMA Mode Register					   */
/*  Parameters: bDMA - DMA selection constant from DMA.H	   */
/*  Return: Nothing						   */
/*******************************************************************/
void SetDMAMode(unsigned char bDMA)
{
	OUT( 0x0b, bDMA);   /* DMA Mode Reg is at I/O address 0x0b*/
}

/*******************************************************************/
/* SingleMaskDMA :						   */
/*  Set the DMA Single Mask Register				   */
/*  Parameters: bMASK1 - DMA selection constant from DMA.H	   */
/*  Return: Nothing						   */
/*******************************************************************/
void SingleMaskDMA(unsigned char bMASK1)
{
	OUT(0x0a, bMASK1);  /*DMA Single Mask Reg is at I/O address 0x0a*/
}

/*******************************************************************/
/* CheckDMAPage :						   */
/*  Check for buffer on 64K boundary				   */
/*  Parameters: wTC - DMA Terminal Count			   */
/*		wSEG1 - segment of buffer			   */
/*		wOFF1 - offset of buffer			   */
/*  Return: Zero if OK otherwise error				   */
/*******************************************************************/
/* NOTE: This routine is not include in the C module. See CheckDMAPageEx*/

/*******************************************************************/
/* CheckDMAPageEx :						   */
/*  Check for buffer on 64K boundary				   */
/*  Parameters: wTC - DMA Terminal Count			   */
/*	      fpBUFFER - Far Ptr to DMA buffer			   */
/*  Return: Zero if OK otherwise error				   */
/*******************************************************************/
int CheckDMAPageEx(unsigned short wTC, unsigned char FAR * fpBUFFER)
{	unsigned long Temp1, Temp2;

	Temp1 = (unsigned char)((ptrToLong(fpBUFFER) >> 16) & 0x0000000f);
	Temp2 = (unsigned char)(((ptrToLong(fpBUFFER)+wTC) >> 16) & 0x0000000f);
	return(Temp1 - Temp2);

}
/*******************************************************************/