source: rtems/c/src/lib/libbsp/mips/jmr3904/console/console-io.c @ c8471315

/*
 *  This file contains the hardware specific portions of the TTY driver
 *  for the serial ports on the jmr3904.
 *
 *  Logic based on the jmr3904-io.c file in newlib 1.8.2
 *
 *  COPYRIGHT (c) 1989-2000.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id$
 */

#include <bsp.h>
#include <rtems/libio.h>
#include <stdlib.h>
#include <assert.h>

/* external prototypes for monitor interface routines */

void outbyte( char );
char inbyte( void );

#define READ_UINT8( _register_, _value_ ) \
        ((_value_) = *((volatile unsigned char *)(_register_)))

#define WRITE_UINT8( _register_, _value_ ) \
        (*((volatile unsigned char *)(_register_)) = (_value_))

#define READ_UINT16( _register_, _value_ ) \
     ((_value_) = *((volatile unsigned short *)(_register_)))

#define WRITE_UINT16( _register_, _value_ ) \
     (*((volatile unsigned short *)(_register_)) = (_value_))


 /* - Board specific addresses for serial chip */
#define DIAG_BASE       0xfffff300
#define DIAG_SLCR       (DIAG_BASE+0x00)
#define DIAG_SLSR       (DIAG_BASE+0x04)
#define DIAG_SLDICR     (DIAG_BASE+0x08)
#define DIAG_SLDISR     (DIAG_BASE+0x0C)
#define DIAG_SFCR       (DIAG_BASE+0x10)
#define DIAG_SBRG       (DIAG_BASE+0x14)
#define DIAG_TFIFO      (DIAG_BASE+0x20)
#define DIAG_RFIFO      (DIAG_BASE+0x30)

#define BRG_T0          0x0000
#define BRG_T2          0x0100
#define BRG_T4          0x0200
#define BRG_T5          0x0300

/*
 *  Eventually console-polled.c should hook to this better.
 */

static char initialized = 0;

void board_serial_init (void)
{
  initialized = 1;
  WRITE_UINT16 (DIAG_SLCR, 0x0020);
  WRITE_UINT16 (DIAG_SLDICR, 0x0000);
  WRITE_UINT16 (DIAG_SFCR, 0x0000);
  WRITE_UINT16 (DIAG_SBRG, BRG_T2 | 5);
}

/*
 *  console_outbyte_polled
 *
 *  This routine transmits a character using polling.
 */

void console_outbyte_polled(
  int  port,
  char ch
)
{
  unsigned short disr;

  if ( !initialized )
    board_serial_init();

  for (;;)
    {
      READ_UINT16 (DIAG_SLDISR, disr);
      if (disr & 0x0002)
        break;
    }
  disr = disr & ~0x0002;
  WRITE_UINT8 (DIAG_TFIFO, (unsigned char) ch);
  WRITE_UINT16 (DIAG_SLDISR, disr);
}

/*
 *  console_inbyte_nonblocking 
 *
 *  This routine polls for a character.
 */

int console_inbyte_nonblocking(
  int port
)
{
  unsigned char c;
  unsigned short disr;

  if ( !initialized )
    board_serial_init();

  READ_UINT16 (DIAG_SLDISR, disr);
  if (disr & 0x0001) {
    disr = disr & ~0x0001;
    READ_UINT8 (DIAG_RFIFO, c);
    WRITE_UINT16 (DIAG_SLDISR, disr);
    return (char) c;
  }
  return -1;
}