/*//////////////////////////////////////////////////////////////////////////
Orgnization:	Emtronix Incorporated
Filename:	T6963C.CPP
Compiler:	BC3.1
Authors:	ZHL & CS
Date:		October, 2002
Revised:	...
Description:	function implementations of LCD module based on T6963C
///////////////////////////////////////////////////////////////////////////*/
#include <dos.h>
#include "t6963c.h"

#define DatPort0     0x30
#define CmdPort0     0x31

#define LcdDatPort   DatPort0
#define LcdComPort   CmdPort0
#define LcdCtlPort   CmdPort0

#define GWidth	     0x20

union LCDAddr
{
   unsigned int   AbsAddr;
   unsigned char  Pos[2];
};

int StatusReady( )
{
   for(int i=0;i<1000;i++)
   {
      if (inportb(LcdComPort) & 0x03==0x03) return 1;
   }
   return 0;
}

int StatusReady2()
{
   for(int i=0;i<1000;i++)
   {
      if (inportb(LcdComPort) & 0x04==0x04) return 1;
   }
   return 0;
}

int StatusReady3()
{
   for(int i=0;i<1000;i++)
   {
      if (inportb(LcdComPort) & 0x08==0x08) return 1;
   }
   return 0;
}

int SendData( char Dat )
{
   if( StatusReady( ) )
      {
      outportb(LcdDatPort, Dat);
      return 1;
      }
   return 0;
}

int SendCmd( char Cmd )
{
   if( StatusReady( ) )
      {
      outportb(LcdComPort, Cmd);
      return 1;
      }
   return 0;
}

void InitLCDinText( )
{
   SendData( 0 );
   SendData( 0 );
   SendCmd( 0x40 );

   SendData( 0x40 );
   SendData( 0 );
   SendCmd( 0x41 );

   SendData( 0 );
   SendData( 0x08 );
   SendCmd( 0x42 );

   SendData( GWidth );
   SendData( 0 );
   SendCmd( 0x43 );

   SendCmd( 0xa1 );
   SendCmd( 0x84 );
   SendCmd( 0x9f );
}

// return =  0: init ok
//        = -1: init fail
int InitLCD( )
{
   // set start address of text area
   SendData( 0 );
   SendData( 0 );
   SendCmd( 0x40 );

   // set width of text area
   SendData( 0x40 );
   SendData( 0 );
   SendCmd( 0x41 );

   // set start address of graphics area
   SendData( 0 );
   SendData( 0x08 );
   SendCmd( 0x42 );

   // set width of graphics area
   SendData( GWidth );
   SendData( 0 );
   SendCmd( 0x43 );

   SendCmd( 0xa1 );		// cursor shap
   SendCmd( 0x80 );		//

   //graphic on, text off
   SendCmd( 0x98 );

   return ClearScreen( );
}

// return =  0: init ok
//        = -1: LCD fail
int ClearScreen( )
{
   SendData( 0 );
   SendData( 0 );
   SendCmd( 0x24 );

   SendCmd(0xb0);		// start auto writing
   for (int i=0;i<0x4000;i++)
   {
      if (StatusReady3())
      {
	 outportb(LcdDatPort,0);
      }
   }
   SendCmd(0xb2);	       // end auto writing

   return 0;
}

// input: DotColor = 0:    write 0;
//                 = 1:    write 1;
//                 = 0x81: XOR write
// input x = 0 -- 239
//       y = 0 -- 63
// return =  0: ok
//        = -1: LCD fail
int WritePixel( int x, int y, int DotColor )
{
   LCDAddr Addr;
   unsigned char  rem, cmd, N3, abyte, mask;
   unsigned int   col, row;

   N3 = 0x08;

   col = x / 8;
   row = y;

   // set addr
   Addr.AbsAddr = row*GWidth + col + 0x800;
   SendData( Addr.Pos[0] );
   SendData( Addr.Pos[1] );
   SendCmd( 0x24 );

   // read the byte containing the dot need to operation
   //SendCmd( 0xc5 );	// read data without changing address
   //if( !StatusReady( ) ) return -1;
   //abyte = inportb( LcdDatPort );

   // bit operation
   rem = x % 8;
   mask = 1<<rem;
   rem = (~rem) & 0x07;
   cmd = 0xf0 | rem;
   if( DotColor == 0 )        cmd = cmd & ~N3;
   else                       cmd = cmd | N3;
   /*
   else if( DotColor == 1 )   cmd = cmd | N3;
   else
      {
      abyte = abyte & mask;
      if( abyte == 0 ) cmd = cmd | N3;
      else             cmd = cmd & ~N3;
      }
   */
   SendCmd( cmd );

   return 0;
}

// input col = 0 -- 29 => column
//       row = 0 -- 63
int WriteByte( int col, int row, unsigned char aByte )
{
   LCDAddr Addr;

   // set graphics addr
   Addr.AbsAddr = row * GWidth + col + 0x800;
   SendData( Addr.Pos[0] );
   SendData( Addr.Pos[1] );
   SendCmd( 0x24 );

   SendData( aByte );
   SendCmd( 0xc4 );
   return 0;
}

// input col = 0 -- 29 => column
//       row = 0 -- 63
// return = 0x0000 -- 0x00ff: ok
//        = 0xffff (-1):      fail
int ReadByte( int col, int row )
{
   LCDAddr Addr;
   char abyte;

   // set graphics addr
   Addr.AbsAddr = row * GWidth + col + 0x800;
   SendData( Addr.Pos[0] );
   SendData( Addr.Pos[1] );
   SendCmd( 0x24 );

   SendCmd( 0xc5 );	// read data without changing address
   if( !StatusReady( ) ) return -1;

   //SendCmd(0xb1);		// set auto read
   //if( StatusReady2() )	 Buf = inportb( LcdDatPort ) + 0x20;
   //SendCmd(0xb2);		// end auto read

   abyte = inportb( LcdDatPort );
   return abyte;
}