/* implements the Parallel Interface operation under interrupts */

#include "SparcSoftcard.h"
#include "SparcSoftcardOps.h"

extern BOOLEAN VersatecOnLine();

long pILock, newPIByteAddress, newPIByteCount;
unsigned char tempPIBuffer[16];

void PISetMode (mode)
SparcSoftcardOps_VersatecMode mode;
{
while (pILock != 0) {};
pILock = 1;
SetVersatecMode (mode);
pILock = 0;
};

static void SendOneByte (data)
unsigned char data;
{
unsigned char *p;
long tempByteAddress;

tempByteAddress = (long) tempPIBuffer;
tempByteAddress = (tempByteAddress + 7) & (~ 7);
p = ( unsigned char * ) tempByteAddress;
*p = data;
SparcSoftcardOps_SetDMAState(DMAState_inactive);
SparcSoftcardOps_SetDMAMode(DMAMode_versatecOneShot);
SparcSoftcardOps_DMAAddressRegisterLoad(tempByteAddress);
SparcSoftcardOps_SetDMAState(DMAState_active);
};

BOOLEAN PISendOneByte (data)
unsigned char data;
{
while (pILock != 0) {};        /*    Wait for pILock to be released */
if (VersatecOnLine() == FALSE) {
return(FALSE);            /* bad termination */
};
pILock = 1;                     /* take the pILock  (will be released by the interrupt) */
newPIByteCount = 0;        /* tells to the interrupt routine that the transfert is finished */
SendOneByte (data);        /* actually send the byte */
return (VersatecOnLine());    /* don't wait to return*/
};

BOOLEAN PISendBuffer (byteAddress, byteCount)
long byteAddress, byteCount;
{
unsigned char *p;
long bytesToSend, remainCount;

while (pILock != 0) {};        /*    Wait for pILock to be released */
if (VersatecOnLine() == FALSE) {
return(FALSE);            /* bad termination */
};
if (byteCount == 0 ) {
return(TRUE);            /* nothing to do */
};
if ( (byteAddress % 16) != 0 || (byteCount < 96)) {
/* not aligned on an 16 bytes word bondary or buffer too small */
/* send one byte at a time */
pILock = 1;
newPIByteAddress = byteAddress + 1; /* tells the int routine to continue */
newPIByteCount = byteCount - 1;
p = (unsigned char *) byteAddress;
SendOneByte (*p);
return (VersatecOnLine());  /* don't wait to return*/
};
/* buffer bigger than 96 aligned on an 16 bytes word bondary */
if ( byteCount > 1024 * 1024 ) {        /* send 1 mega byte max at a time */
bytesToSend = 1024 * 1024;
remainCount = byteCount - 1024 * 1024;
if (remainCount < 96) bytesToSend -= 96; /* extend the last chunk to more than 96 */
}
else {                                        /* buffer smaller than 1 mega */
bytesToSend = byteCount - (byteCount % 16);
};
newPIByteAddress = byteAddress + bytesToSend;
newPIByteCount = byteCount - bytesToSend;
pILock = 1;                 /* take the pILock  (will be released by the interrupt) */
SparcSoftcardOps_SetDMAState(DMAState_inactive);
SparcSoftcardOps_SetDMAMode(DMAMode_versatecStream);
SparcSoftcardOps_DMAAddressRegisterLoad(byteAddress);
SetTimer(bytesToSend);
SparcSoftcardOps_SetDMAState(DMAState_active);
return (VersatecOnLine());  /* don't wait to return*/
};

void PIInterrupt ()
{
pILock = 0;        /* release lock */
if (newPIByteCount == 0) {        /* transfert done */
return;
};
/* restart transfert */
(void) PISendBuffer (newPIByteAddress, newPIByteCount);
};