epp.c

代码有点长,需细心阅读,仅供影音视听类产品的开发人员参考

/*
** FILE
** epp.c
**
** DESCRIPTION
** Support EPP (ok, this is only a standard bi-directional
** parallel port interface, but who cares?) send/receive
** functions.
*/
#include "config.h"
#include "regmap.h"
#include "global.h"
#include "dma.h"
#include "uart.h"
#include "stdlib.h"

#ifdef SUPPORT_EPP_DBG
#if UART_DEBUG
#define EPP_GETC()      (regs0->uart0_data)
#define EPP_PUTC(c)     (write_uart0(c))
#define IsEPPRxEmpty()      (!UART0_rx_rdy())
#define IsEPPTxFull()       (is_uart0_fifo_full())
#define IsEPPTxEmpty()      (is_uart0_fifo_empty())
#else
#define EPP_STATUS      (regs0->epp_status)
#define EPP_GETC()      (regs0->epp_data)
#define EPP_PUTC(c)     (regs0->epp_data = c)
#define IsEPPRxFull()       (EPP_STATUS & RF_EPP_IN_FULL)
#define IsEPPRxEmpty()      (EPP_STATUS & RF_EPP_IN_EMPTY)
#define IsEPPTxFull()       (EPP_STATUS & RF_EPP_OUT_FULL)
#define IsEPPTxEmpty()      (EPP_STATUS & RF_EPP_OUT_EMPTY)
#endif
#endif


#if     (SUPPORT_EPP==0)
#undef  IsEPPRxEmpty()
#undef  EPP_GETC()
#undef  IsEPPTxFull()
#undef  IsEPPTxEmpty()
#undef  EPP_PUTC()
#define IsEPPRxEmpty()      (1)
#define EPP_GETC()      (0)
#define IsEPPTxFull()       (0)
#define IsEPPTxEmpty()      (1)
#define EPP_PUTC(c)     ((void)(c))
#endif

//JJDing 2002/08/28
#if CONFIG==CONFIG_COMBO_SVCD
#define	UART_BUF_START	0x88000000+1024*2036+512
#else
#define	UART_BUF_START	0x88000000+1024*7+512
#endif
BYTE   *uart_buf = (BYTE *) (UART_BUF_START);



#ifdef SUPPORT_EPP_DBG
#define CMD_LENGTH  16
char  cmdbuf[CMD_LENGTH];

static  int mon_in();
void UART_Response();

int polling_epp(void)
{
	if(uart_rp != uart_wp)
	{
		if(!IsUARTCmdTxFull())
		{
			regs0->uart0_data = uart_buf[uart_rp];
			uart_rp++;
			uart_rp &= FIFOS;
		}
	}

#ifdef SUPPORT_DOUBLEWAY_DBG
	mon_in();
#endif

	return 0;
}

void epp_write_wait(const char *s)
{
	int     c;

	while(1)
	{
		c = *s++;
		if(c == 0)
			break;
		if(c == '\n')
		{
			uart_buf[uart_wp] = '\r';
			uart_wp++;
			uart_wp &= FIFOS;
		}
		uart_buf[uart_wp] = c;
		uart_wp++;
		uart_wp &= FIFOS;

	}
}

void reset_epp(void)
{

}

void epp_flush(void)
{

}
void epp_write(const char *s)
{
	epp_write_wait(s);
}

void epp_write_slow(const char *s)
{
	epp_write_wait(s);
}

#define MON_OUT(c)  (regs0->epp_data=(c))
#define MON_IN()    (regs0->epp_data)
#define MON_EMPTY() (regs0->epp_status & RF_EPP_IN_EMPTY)
#define MON_OUT_FULL()  (regs0->epp_status & RF_EPP_OUT_FULL)

#ifndef NULL
#define NULL    ((void *)0)
#endif


#ifdef  SUPPORT_DOUBLEWAY_DBG

static  int mon_in()
{
  static int i=0;
  while (1)
  {
    BYTE c,d;

    if (IsUARTCmdRxEmpty()) 
   	return;

    c = UART_DATA;
    d = regs0->epp_status;
    if (c==27)
       return -1;
	
    if (c=='\r' || c=='\n')
    {
       
       cmdbuf[i] = '\0';
	   UART_Response();
	i=0;  
       break;
    }
    else 
    {
    
      cmdbuf[i++] = c;
	  if(i==CMD_LENGTH)
	  i=0;
	  
    }
  }
  return 0;
} 

void UART_Response()
{
	epp_write_wait("Cmd: ");
	epp_write_wait(cmdbuf);
	epp_write_wait("\n");
	/*switch(cmdbuf[0])
	{
		case 'R':
		{
			UINT32 REG;
  			asm volatile ("mfc0 $16, $13; nop; move %0, $16":"=r" (REG)::"$16");

   			 psprintf(linebuf, "CAUSE  %08x\n", REG);
   			 epp_write_wait(linebuf);
		}
		

		break;
			

	}*/
	if(strcmp(cmdbuf,"cause")==0)
	{
			UINT32 REG;
  			asm volatile ("mfc0 $16, $13; nop; move %0, $16":"=r" (REG)::"$16");

   			 psprintf(linebuf, "CAUSE  %08x\n", REG);
   			 epp_write_wait(linebuf);
	}

	return;

}

#endif

#endif