#include<conio.h>
#include<stdio.h>
#include<dos.h>
#include"uart.h"

#ifndef __TURBOC__
 #define enable()  _enable()
 #define disable() _disable()
#endif

#define InBufSize  1024
#define OutBufSize  128

int iBase1=0,iBase2=0;		/* com port base address */
int err1=0,err2=0;
static unsigned long OldIntVect1=0L,OldIntVect2=0L;

static unsigned char InData1[InBufSize];
static unsigned char OutData1[OutBufSize];
static unsigned char InData2[InBufSize];
static unsigned char OutData2[OutBufSize];
int In_InIdx1,In_OutIdx1,Out_InIdx1,Out_OutIdx1;
int In_InIdx2,In_OutIdx2,Out_InIdx2,Out_OutIdx2;
int save232[2][4];
unsigned long far *IntVect=(unsigned long far *)0L;


void interrupt Serial1_Isr(void)
{
  do{
     switch(inp(iBase1+Iir)&0x07){
      case 0:
/*	   inp(iBase1+Msr); */
	   break;
      case 1: /* No interrupt to be service */
	   goto end;
      case 2: /* can send data  */
	   if(Out_InIdx1!=Out_OutIdx1){
	      outp(iBase1,OutData1[Out_OutIdx1++]);
	      Out_OutIdx1&=OutBufSize-1;
	      if(Out_OutIdx1==Out_InIdx1) outp(iBase1+Ier, 0x01);
	   }
	   else {
	      outp(iBase1+Ier, 0x01);
	   }
	   break;
      case 4: /* receive data */
ReadAgain:
	   InData1[In_InIdx1++]=inp(iBase1);   /* receive next char */
	   In_InIdx1&=(InBufSize-1);
	   if(In_InIdx1==In_OutIdx1) {
	      In_InIdx1--;
	      In_InIdx1&=(InBufSize-1);
	      err1=1;
	   }
	   if(inp(iBase1+Lsr) & 1) goto ReadAgain;
	   break;
      case 6:
	   inp(iBase1+Lsr);
	   break;
      default:
	   /* error status */
	   goto end;
     }
   }while(1);
end:
  outp(0x20,0x20);
}


static unsigned char ratehi,ratelo,format;
int GetBaudData(unsigned long baud, int data, int parity, int stop)
{ int cc;

  format=0;
  switch(data) {
    case 5:  break; /* format+=0; */
    case 6: format+=1; break;
    case 7: format+=2; break;
    case 8: format+=3; break;
    default: return(DataError);
  }

  switch(parity) {
    case 0: break;  /* format+=0; */
    case 1: format+=0x18; break;
    case 2: format+=0x10; break;
    default: return(ParityError);
  }

  switch(stop) {
      case 1: break; /* format+=0; */
      case 2: format+=4;    break;
      default: return(StopError);
  }

  switch(baud){
    case 1200L : ratehi=0; ratelo=96; break;
    case 2400L : ratehi=0; ratelo=48; break;
    case 4800L : ratehi=0; ratelo=24; break;
    case 9600L : ratehi=0; ratelo=12; break;
    case 19200L: ratehi=0; ratelo=6; break;
    case 38400L: ratehi=0; ratelo=3; break;
    case 57600L: ratehi=0; ratelo=2; break;
    case 115200L: ratehi=0; ratelo=1; break;
    default    : return BaudRateError;		/* baud rate error */
  }
  return NoError;
}

int InstallCom1(unsigned long baud, int data, int parity, int stop)
{ int cc;

  err1=0;
  cc=GetBaudData(baud,data,parity,stop);
  if(cc) return cc;
  /* _asm cli */          disable(); 
  save232[0][2]=inp(iBase1+Lcr); /* format                 */
  outp(iBase1+Lcr,0x80);	 /* 1 set DLAB (baud rate)   */
  save232[0][0]=inp(iBase1+Dll); /* baud rate              */
  save232[0][1]=inp(iBase1+Dlh);
  outp(iBase1+Dll,ratelo);
  outp(iBase1+Dlh,ratehi);
  outp(iBase1+Lcr,format);	 /* 2. data format  */
  save232[0][3]=inp(iBase1+Ier); /* interrupt status*/

  outp(iBase1+Fcr, 0x87);	/* 3. enable & clear FIFO   */
  outp(iBase1+Ier, 0x01);	/* 4. enable COM1 interrupt */
  outp(iBase1+Mcr,0x0b);        /* set DTR line active      */

  In_InIdx1=In_OutIdx1=Out_InIdx1=Out_OutIdx1=0; /* 5. init QUEUE */
  OldIntVect1=IntVect[12];	                 /* save old ISR  */
  IntVect[12]=(unsigned long)Serial1_Isr;        /* install new ISR */
  outp(0x21,inp(0x21) & 0xef);    /* enable IRQ 4 for COM1 */
  /*_asm sti  */  enable(); 
  return(NoError);
}

void interrupt Serial2_Isr(void)
{
  do{
     switch(inp(iBase2+Iir)&0x07){
      case 0:
/*	   inp(iBase2+Msr);  */
	   break;
      case 1: /* No interrupt to be service */
	   goto end;
      case 2: /* can send data   */
	   if(Out_InIdx2!=Out_OutIdx2){
	      outp(iBase2,OutData2[Out_OutIdx2++]);
	      Out_OutIdx2&=OutBufSize-1;
	      if(Out_OutIdx2==Out_InIdx2) outp(iBase2+Ier, 0x01);
	   }
	   else {
	      outp(iBase2+Ier, 0x01);
	   }
	   break;
      case 4: /* receive data */
ReadAgain:
	   InData2[In_InIdx2++]=inp(iBase2);   /* receive next char */
	   In_InIdx2&=(InBufSize-1);
	   if(In_InIdx2==In_OutIdx2) {
	      In_InIdx2--;
	      In_InIdx2&=(InBufSize-1);
	      err2=1;
	   }
	   if(inp(iBase2+Lsr) & 1) goto ReadAgain;
	   break;
      case 6:
	   inp(iBase2+Lsr);
	   break;
      default:
	   /* error status  */
	   goto end;
     }
   }while(1);
end:
  outp(0x20,0x20);
}

int InstallCom2(unsigned long baud, int data, int parity, int stop)
{ int cc;

  err2=0;
  cc=GetBaudData(baud,data,parity,stop);
  if(cc) return cc;
  /* _asm cli */ disable();
  save232[1][2]=inp(iBase2+Lcr); /* format  */
  outp(iBase2+Lcr,0x80);	 /* 1. set DLAB (baud rate) */
  save232[1][0]=inp(iBase2+Dll); /* baud rate   */
  save232[1][1]=inp(iBase2+Dlh);
  outp(iBase2+Dll,ratelo);
  outp(iBase2+Dlh,ratehi);
  outp(iBase2+Lcr,format);	 /* 2. data format */
  save232[1][3]=inp(iBase2+Ier); /* interrupt status */

  outp(iBase2+Fcr, 0x87);	/* 3. enable & clear FIFO */
  outp(iBase2+Ier, 0x01);	/* 4. enable COM1 interrupt */
  outp(iBase2+Mcr,0x0b);        /* set DTR line active      */
  In_InIdx2=In_OutIdx2=Out_InIdx2=Out_OutIdx2=0; /* 5. init QUEUE */
  OldIntVect2=IntVect[11];	/* save old ISR  */
  IntVect[11]=(unsigned long)Serial2_Isr; /* install new ISR */
  outp(0x21,inp(0x21) & 0xf7);    /* enable IRQ 3 for COM2   */
  /* _asm sti */ enable();
  return(NoError);
}

/* ----------------------------------------------------------------------- //
// input  : port   = 1/2,   3/4 not support
//	    baud   = 1200/2400/4800/9600/19200/38400
//	    chksum = 0 is DISABLE, others is ENABLE
//   return : 0 --> OK
//	    1 --> port value error
//	    2 --> baud rate  error
*/
int InstallCom(int iPort,unsigned long lBaudRate,int iData,int iParity,int iStop)
{ int uart,i;
  char ratehi,ratelo;
  int cc;
  int far *ComBase=(int far *)0x00400000L;
  switch(iPort)	{
    case 1 :
	 if(OldIntVect1) RestoreCom(1);
	 iBase1=ComBase[0];
	 return InstallCom1(lBaudRate,iData,iParity,iStop);
    case 2 :
	 if(OldIntVect2) RestoreCom(2);
	 iBase2=ComBase[1];
	 return InstallCom2(lBaudRate,iData,iParity,iStop);
    default: printf("Error:PortError,(iPort=%d)",iPort); getch();
	     return PortError;	/* port must 1/2 */
  }
/*?  for (i=0; i<8; i++) inportb(iBase+i);  */	 /* clear R */
}


int RestoreCom(int iPort)
{
  switch(iPort){
    case 1:
      if(!OldIntVect1) return NoError;
      /* _asm cli */ disable();
      IntVect[12]=OldIntVect1;	  /* 1. restore OLD ISR */
      OldIntVect1=0L;
      outp(iBase1+Lcr,0x80);	  /* 2. restore baud rate */
      outp(iBase1+Dll,save232[0][0]);
      outp(iBase1+Dlh,save232[0][1]);
      outp(iBase1+Lcr,(save232[0][2])&0x7f); /* 3. restore data format */

      outp(iBase1+Ier, save232[0][3]);/* 4. restore enable COM1's interrupt */
      outp(0x21,inp(0x21) | 0x10);    /* mask IRQ 4 for COM1 */
      /* _asm sti */ enable();
      break;
    case 2:
      if(!OldIntVect2) return NoError;
      /* _asm cli */ disable();
      IntVect[11]=OldIntVect2;	  /* 1. restore OLD ISR */
      OldIntVect2=0L;
      outp(iBase2+Lcr,0x80);	  /* 2. restore baud rate */
      outp(iBase2+Lcr,(save232[1][2])&0x7f); /* 3. restore data format */
      outp(iBase2+Ier, save232[1][3]);/* 4. restore enable COM2's interrupt*/
      outp(0x21,inp(0x21) | 0x08);    /* mask IRQ 3 for COM2 */
      /* _asm sti */ enable();
      break;
    default:
	 return PortError;
  }
  return NoError;
}


int IsCom(int iPort)
{
  switch(iPort){
    case 1: return In_InIdx1-In_OutIdx1;
    case 2: return In_InIdx2-In_OutIdx2;
    default:
	 return PortError;
  }
}

long ToComTimeOut=100000L;
int ToCom(int iPort, char data)
{ long t=ToComTimeOut;
  int nextidx,done;

  switch(iPort){
   case 1:
	do{
	   _asm cli
	   done=(nextidx=(Out_InIdx1+1)&(OutBufSize-1)) != Out_OutIdx1;
	   if(done){
	      OutData1[Out_InIdx1]=data;
	      Out_InIdx1=nextidx;
	   }
	   _asm sti
	   t--;
	   if(!t) break;
	} while(!done);

	if(done){
	   outp(iBase1+Lcr,inp(iBase1+Lcr)&0x7f);
	   outp(iBase1+Ier, 0x03);	/*  enable COM1 interrupt */
	   return NoError;
	}
	else return TimeOut;
	break;
   case 2:
	do{
	   _asm cli
	   done=(nextidx=(Out_InIdx2+1)&(OutBufSize-1)) != Out_OutIdx2;
	   if(done){
	      OutData2[Out_InIdx2]=data;
	      Out_InIdx2=nextidx;
	   }
	   _asm sti
	   t--;
	   if(!t) break;
	} while(!done);

	if(done){
	   outp(iBase2+Lcr,inp(iBase2+Lcr)&0x7f);
	   outp(iBase2+Ier, 0x03);	/*  enable COM1 interrupt */
	   return NoError;
	}
	else return TimeOut;
	break;
   default:
	return PortError;
  }
  return NoError;
}

int ReadCom(int iPort)
{ unsigned data;

  switch(iPort){
   case 1:
     while(!IsCom(iPort)){ ; }
     data=InData1[In_OutIdx1++];
     In_OutIdx1&=(InBufSize-1);
     return data;
   case 2:
     while(!IsCom(iPort)){ ; }
     data=InData2[In_OutIdx2++];
     In_OutIdx2&=(InBufSize-1);
     return data;
   default:
     return PortError;
  }
}

int ClearCom(int iPort)
{
  switch(iPort){
   case 1: In_OutIdx1=In_InIdx1=0; return NoError;
   case 2: In_OutIdx2=In_InIdx2=0; return NoError;
   default: return PortError;
  }
}