dma.c

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 $Id: dma_8c-source.html 88 2016-01-12 00:11:29Z reddawg $

*****************************************************************************************/

#include <sys/dma.h>
#include <sys/io.h>
#include <ubixos/types.h>

#define lowByte(x)  (x & 0x00FF)
#define highByte(x) ((x & 0xFF00) >> 8)
   
static uInt8 maskReg[8]   = { 0x0A, 0x0A, 0x0A, 0x0A, 0xD4, 0xD4, 0xD4, 0xD4 };
static uInt8 clearReg[8]  = { 0x0C, 0x0C, 0x0C, 0x0C, 0xD8, 0xD8, 0xD8, 0xD8 };
static uInt8 modeReg[8]   = { 0x0B, 0x0B, 0x0B, 0x0B, 0xD6, 0xD6, 0xD6, 0xD6 };
static uInt8 addrPort[8]  = { 0x00, 0x02, 0x04, 0x06, 0xC0, 0xC4, 0xC8, 0xCC };
static uInt8 pagePort[8]  = { 0x87, 0x83, 0x81, 0x82, 0x8F, 0x8B, 0x89, 0x8A };
static uInt8 countPort[8] = { 0x01, 0x03, 0x05, 0x07, 0xC2, 0xC6, 0xCA, 0xCE };

void dmaXfer(uInt8 channel,uInt32 address,uInt length,uInt8 read) {
  unsigned char page=0, mode=0;
  unsigned int offset = 0;
  if (read) {
    mode = 0x48 + channel;
    }
  else {
    mode = 0x44 + channel;
    }
  page = address >> 16;
  offset = address & 0xFFFF;
  length--;
  _dmaXfer(channel, page, offset, length, mode);
  }

void _dmaXfer(uInt8 dmaChannel,uInt8 page,uInt offset,uInt length,uInt8 mode) {
  //asm("cli");
  outportByte(maskReg[dmaChannel], 0x04 | dmaChannel);
  outportByte(clearReg[dmaChannel], 0x00);
  outportByte(modeReg[dmaChannel], mode);
  outportByte(addrPort[dmaChannel], lowByte(offset));
  outportByte(addrPort[dmaChannel], highByte(offset));
  outportByte(pagePort[dmaChannel], page);
  outportByte(countPort[dmaChannel], lowByte(length));
  outportByte(countPort[dmaChannel], highByte(length));
  outportByte(maskReg[dmaChannel], dmaChannel);
  //asm("sti");
  }

/***
 END
 ***/

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