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/* Copyright (C) 1994, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Joel Sherrill (jsherril@redstone-emh2.army.mil),
On-Line Applications Research Corporation.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <standalone.h>
#include "m68020.h"
/* Console IO routines for a Motorola MVME135/MVME136 board.
They currently use the B port. It should be possible to
use the A port by filling in the reset of the chip structure,
adding an ifdef for PORTA/PORTB, and switching the addresses,
and maybe the macros based on the macro. */
/* M68681 DUART chip register structures and constants */
typedef struct {
volatile unsigned char fill1[ 5 ]; /* channel A regs ( not used ) */
volatile unsigned char isr; /* interrupt status reg */
volatile unsigned char fill2[ 2 ]; /* counter regs (not used) */
volatile unsigned char mr1mr2b; /* MR1B and MR2B regs */
volatile unsigned char srb; /* status reg channel B */
volatile unsigned char fill3; /* do not access */
volatile unsigned char rbb; /* receive buffer channel B */
volatile unsigned char ivr; /* interrupt vector register */
} r_m681_info;
typedef struct {
volatile unsigned char fill1[ 4 ]; /* channel A regs (not used) */
volatile unsigned char acr; /* auxillary control reg */
volatile unsigned char imr; /* interrupt mask reg */
volatile unsigned char fill2[ 2 ]; /* counter regs (not used) */
volatile unsigned char mr1mr2b; /* MR1B and MR2B regs */
volatile unsigned char csrb; /* clock select reg */
volatile unsigned char crb; /* command reg */
volatile unsigned char tbb; /* transmit buffer channel B */
volatile unsigned char ivr; /* interrupt vector register */
} w_m681_info;
#define RD_M68681 ((r_m681_info *)0xfffb0040) /* ptr to the M68681 */
#define WR_M68681 ((w_m681_info *)0xfffb0040) /* ptr to the M68681 */
#define RXRDYB 0x01 /* status reg recv ready mask */
#define TXRDYB 0x04 /* status reg trans ready mask */
/* _Console_Putc
This routine transmits a character out the M68681. It supports
XON/XOFF flow control. */
#define XON 0x11 /* control-Q */
#define XOFF 0x13 /* control-S */
int
_Console_Putc (ch)
char ch;
{
while ( ! (RD_M68681->srb & TXRDYB) ) ;
while ( RD_M68681->srb & RXRDYB ) /* must be an XOFF */
if ( RD_M68681->rbb == XOFF )
do {
while ( ! (RD_M68681->srb & RXRDYB) ) ;
} while ( RD_M68681->rbb != XON );
WR_M68681->tbb = ch;
return( 0 );
}
/* _Console_Getc
This routine reads a character from the UART and returns it. */
int
_Console_Getc (poll)
int poll;
{
if ( poll ) {
if ( !(RD_M68681->srb & RXRDYB) )
return -1;
else
return RD_M68681->rbb;
} else {
while ( !(RD_M68681->srb & RXRDYB) );
return RD_M68681->rbb;
}
}
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