rs232.c

LINUX的简单应用

		//	break;
		}
		switch(dd)  //com4中断标志寄存器
        {
		case 0x02:    //发送中断
			if ( com4->out.read_index == com4->out.write_index )
			{
				outportb( Com4UartBase + IER, IER_RX_DATA );
				for(i=0;i<500;i++);
				outportb(Com4UartBase + LCR,0x3b);//LCR_NO_PARITY | LCR_8_DATA_BITS);
				outportb(Com4UartBase + MCR,MCR_RTS | MCR_DTR | MCR_OUT2);//0x0b
			}
			else
			{
				c = com4->out.buffer[ com4->out.read_index++ ];
				outportb( Com4UartBase + THR, c );
			}
			break;
		default:
		//case 0x04:   //接收中断
		//case 0x0c:   //接收超时中断，04和0c用来判断接收中断
			while(inportb(Com4UartBase+LSR)&0x01)
			{
				c = (unsigned char) inportb( Com4UartBase+RBR );
				if (((unsigned char)(com4->in.write_index+1 )) != com4->in.read_index)
				{
					com4->in.buffer[ com4->in.write_index++ ] =  c ;
				}
			}
			break;
		//default:
		//	inportb(Com4UartBase+RBR);
		//	break;
        }
		aa=inportb(Com1UartBase+IIR)&0x0f;
		bb=inportb(Com2UartBase+IIR)&0x0f;
		cc=inportb(Com3UartBase+IIR)&0x0f;
		dd=inportb(Com4UartBase+IIR)&0x0f;
	}
	outport(IntEoiReg,Int3NumEoi);  //向中断结束寄存器送串口中断结束标志
}

void port_close( PORT *port )
{
  int mask;
  outportb( port->uart_base + IER, 0 );
  outportb( port->uart_base + MCR, 0 );
  free( port );
  if(port==com1)
	  com1=NULL;
  else if(port==com2)
	  com2=NULL;
  else if(port==com3)
	  com3=NULL;
  else if(port==com4)
	  com4=NULL;
  if(NULL==com1 && NULL==com2 && NULL==com3 && NULL==com4)
  {
    mask=inport(IntMaskReg);
	mask|=0x80;
	outport(IntMaskReg,mask);  //中断屏蔽寄存器中关闭串口中断
	outport(Int3CtrlReg,0x0000);  //IRQ7即串口中断控制寄存器，关中断
	setvect( Int3NumIntr, old_vector );
  }
}

/*int port_putc( unsigned char c, PORT *port )
{
  if (( port->out.write_index+1 ) == port->out.read_index)
    return( -1 );
  port->out.buffer[ port->out.write_index ] = c;
  port->out.write_index += 1;
  if (( inportb( port->uart_base + IER ) & IER_THRE) == 0 )
    outportb( port->uart_base+IER,IER_THRE);
  return( c );
}

int port_getc(PORT *port)
{
  if ( port->in.write_index == port->in.read_index )
    return( -1 );
  else
  {
    return( port->in.buffer[ port->in.read_index++ ] );
  }
}*/

void port_puts(unsigned char str[],int len,PORT *port)
{
int i;
	if (( port->out.write_index+1 ) == port->out.read_index)
		return;
	for(i=0;i<len;i++)
	{
		port->out.buffer[ port->out.write_index ] = str[i];
		port->out.write_index ++;
	}
	if(port==com3 || port==com4)
		return;
	if (( inportb(port->uart_base + IER ) & IER_THRE) == 0 )
		outportb( port->uart_base+IER,IER_THRE);
}

void port_send(PORT *port)
{
int i;
	if(port==com1)
	{
		if (( inportb(port->uart_base + IER ) & IER_THRE) == 0 )
			outportb( port->uart_base+IER,IER_THRE);
	}
	else if(port==com3)
	{
		//485 最低两位用来设置收发状态，最低两位置1为接收，置0为发送
		outportb( port->uart_base + MCR, MCR_OUT2 );
		for(i=0;i<500;i++);
		outportb( com3->uart_base+IER,IER_THRE);
		
	}
	else if(port==com4)
	{
		outportb( port->uart_base + MCR, MCR_OUT2 );
		for(i=0;i<500;i++);
		outportb( com4->uart_base+IER,IER_THRE);
	}
}

int port_gets(unsigned char str[],int len,PORT * port)
{
int i;
	i=0;
	str[0]=0;
	if(port==NULL || len==0)
		return(0);
	if(port->in.read_index== port->in.write_index)
		return(0);
	for(i=0;i<len;i++)
	{
		   if(port->in.read_index== port->in.write_index)
			   break;
	       str[i]=port->in.buffer[port->in.read_index];
		   port->in.read_index++;
	}
	//str[i]=0;
	if(i)
		return(i);
	else
		return(0);
}

void port_clear(PORT *port)
{
	//com1->in.buffer[0]=0;
	//com1->in.buffer[1]=0;
	port->in.read_index=0;
	port->in.write_index=0;
}

int port_getlen(PORT *port)
{
int len;
	if(port->in.write_index>=port->in.read_index)
		len=port->in.write_index-port->in.read_index;
	else
		len=256-port->in.read_index+port->in.write_index;
	return(len);
}

void port_reset(int comid,long speed,char parity,int data,int stopbits)
{
PORT *port;
int mask;
unsigned char temp;
unsigned char lcr_out;
unsigned char mcr_out;
unsigned char low_divisor;
unsigned char high_divisor;

	if(comid<1 || comid>4)
		return;
	switch(comid)
	{
		case 0x01:	
			port=com1;
			port->uart_base=Com1UartBase;
			break;
		case 0x02:
			port=com2;
			port->uart_base=Com2UartBase;
			break;
		case 0x03:
			port=com3;
			port->uart_base=Com3UartBase;
			break;
		case 0x04:
			port=com4;
			port->uart_base=Com4UartBase;
			break;
		default:	break;
	}

	port->in.write_index = port->in.read_index = 0;
	port->out.write_index = port->out.read_index = 0;
	
	if(NULL==old_vector)
		old_vector = getvect( Int3NumIntr );
	setvect( Int3NumIntr, com_int);
	
	mask=inport(IntMaskReg);
	mask&=0xff7c;
	outport(IntMaskReg,mask);  //中断屏蔽寄存器中允许串口中断
	outport(Int3CtrlReg,0x0006);  //IRQ7即串口中断控制寄存器，允许中断，中断级别6

	outportb( port->uart_base + IER, 0 );
	inportb( port->uart_base );

	low_divisor = (char) (115200L / speed ) & 0xff;
	high_divisor = (char) ((115200L /  speed ) >> 8);
	outportb( port->uart_base + LCR, LCR_DLAB );
	outportb( port->uart_base + DLL, low_divisor );
	outportb( port->uart_base + DLM, high_divisor );
	outportb( port->uart_base + LCR, 0 );

	if ( parity== 'E' )
		lcr_out = LCR_EVEN_PARITY;
	else if ( parity == 'O' )
		lcr_out = LCR_ODD_PARITY;
	else
		lcr_out = LCR_NO_PARITY;

	if ( stopbits == 2 )
		lcr_out |= LCR_2_STOP_BITS;

	if ( data == 6 )
		lcr_out |= LCR_6_DATA_BITS;
	else if ( data == 7 )
		lcr_out |= LCR_7_DATA_BITS;
	else if ( data == 8 )
		lcr_out |= LCR_8_DATA_BITS;

	if(comid==3)
			outportb( port->uart_base + LCR,0x3b);
	else
		outportb( port->uart_base + LCR, lcr_out );
	outportb(port->uart_base+2,0x07);	//set FCR.FIFO控制寄存器，DMA=0,Enable FIFO，初始化时复位接收与保持寄存器
	outportb(port->uart_base+2,0x01);	//open FIFO
	if(comid==1 || comid==2)		//232
		mcr_out=MCR_OUT2;//8
	if(comid==3 || comid==4)		//485 注意，最低两位用来设置收发状态，但和标准的相反，最低两位置1为接收，置0为发送
		mcr_out = MCR_RTS | MCR_DTR | MCR_OUT2 ;//0x0b
	outportb( port->uart_base + MCR, mcr_out );
	outportb( port->uart_base + IER, IER_RX_DATA );//允许接收中断
}

PORT* init_port(int comid,long speed,char parity,int data,int stopbits)
{
PORT *port;
	if ((port = malloc( sizeof( PORT ))) == NULL)
		return( NULL );
	switch(comid)
	{
	case 1:
		com1=port;
		break;
	case 2:
		com2=port;
		break;
	case 3:
		com3=port;
		break;
	case 4:
		com4=port;
		break;
	default:
		return(NULL);
	}
	port_reset(comid,speed,parity,data,stopbits);
	return(port);
}