console.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 * Initialize the MC68302 SCC2 for console IO board support package.
 *
 *  COPYRIGHT (c) 1989-1999.
 *  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.rtems.com/license/LICENSE.
 *
 *  $Id: console.c,v 1.8.8.1 2003/09/04 18:44:22 joel Exp $
 */

#define GEN68302_INIT

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

#include "m68302.h"

/*  console_initialize
 *
 *  This routine initializes the console IO driver.
 *
 *  Input parameters: NONE
 *
 *  Output parameters:  NONE
 *
 *  Return values:
 */

rtems_device_driver console_initialize(
  rtems_device_major_number  major,
  rtems_device_minor_number  minor,
  void                      *arg
)
{
  rtems_status_code status;
  volatile m302_dualPortRAM_t *p = &m302;

  p->reg.pacnt |= 0x0003;		/* enable RXD2 and TXD2 signals */
  /*
   * TODO: Check assembly code.  I think gcc's volatile semantics force
   * this to not use a CLR.
   */
  p->reg.simode = 0;			/* NMSI mode */

  p->reg.scc[1].scon = 0x00d8;		/* 9600 baud */
  p->reg.scc[1].scm  = 0x01b1;

  p->scc2.parm.rfcr = 0x50;		/* Rx buffers in supervisor data */
  p->scc2.parm.tfcr = 0x50;		/* Tx buffers in supervisor data */
  p->scc2.parm.mrblr = 0x0001;		/* Max Rx buffer length is 1 byte */

  p->scc2.prot.uart.max_idl = 0x0000;	/* 0 = maximum timeout value */
  p->scc2.prot.uart.brkcr = 0x0001;	/* send 1 break char on STOP TX cmd */
  p->scc2.prot.uart.parec = 0x0000;	/* reset parity error counter */
  p->scc2.prot.uart.frmec = 0x0000;	/* reset framing error counter */
  p->scc2.prot.uart.nosec = 0x0000;	/* reset noise error counter */
  p->scc2.prot.uart.brkec = 0x0000;	/* reset break condition counter */

  p->scc2.prot.uart.character[0] = 0x0003; /* use <ctrl>c as control char */
  p->scc2.prot.uart.character[1] = 0x8000; /* set end of cntrl char table */

  p->scc2.bd.rx[0].status = 0xA000;	/* RxBD0 empty, wrap, no intr */
  p->scc2.bd.rx[0].length = 0x0000;
  p->scc2.bd.rx[0].buffer =
      (rtems_unsigned8 *) &m302.scc2.bd.rx[1]; /* RxBD1 is Rx buffer */

  p->reg.scc[1].dsr = 0x7000;		/* set full-length last stop bit */

  p->scc2.bd.tx[0].status = 0x3000;	/* TxBD0 not ready, wrap, intr */
  p->scc2.bd.tx[0].length = 0x0001;
  p->scc2.bd.tx[0].buffer =
      (rtems_unsigned8 *) &m302.scc2.bd.tx[1]; /* TxBD1 is Tx buffer */

  p->reg.scc[1].scce = 0xFF;		/* clear all SCC event flags */
  p->reg.scc[1].sccm = 0x03;		/* enable only Tx & Rx interrupts */
  p->reg.scc[1].scm  = 0x01BD;

  status = rtems_io_register_name(
    "/dev/console",
    major,
    (rtems_device_minor_number) 0
  );
 
  if (status != RTEMS_SUCCESSFUL)
    rtems_fatal_error_occurred(status);
 
  return RTEMS_SUCCESSFUL;

}

/*  is_character_ready
 *
 *  Check to see if a character is available on the MC68302's SCC2.  If so,
 *  then return a TRUE (along with the character).  Otherwise return FALSE.
 *
 *  Input parameters:   pointer to location in which to return character
 *
 *  Output parameters:  character (if available)
 *
 *  Return values:      TRUE - character available
 *                      FALSE - no character available
 */

rtems_boolean is_character_ready(
  char *ch				/* -> character  */
)
{
#define RXS (m302.scc2.bd.rx[0].status)
#define RXD (* ((volatile char *) m302.scc2.bd.rx[0].buffer))

    for (;;) {
	if (RXS & RBIT_HDLC_EMPTY_BIT)
	    return FALSE;

	*ch = RXD;
	RXS = RBIT_HDLC_EMPTY_BIT | RBIT_HDLC_WRAP_BIT;
	if ( *ch >= ' ' &&  *ch <= '~' )
	    return TRUE;
    }
}


/*  inbyte
 *
 *  Receive a character from the MC68302's SCC2.
 *
 *  Input parameters:   NONE
 *
 *  Output parameters:  NONE
 *
 *  Return values:      character read
 */

char inbyte( void )
{
    char ch;

#define RXS (m302.scc2.bd.rx[0].status)
#define RXD (* ((volatile char *) m302.scc2.bd.rx[0].buffer))

    do {
	while (RXS & RBIT_HDLC_EMPTY_BIT)
	    /* Wait until character received */ ;

	ch = RXD;
	RXS = RBIT_HDLC_EMPTY_BIT | RBIT_HDLC_WRAP_BIT;

	if (ch == '\r' || ch == '\n')
	    break;
    } while (ch < ' ' ||  ch > '~');

    return ch;
}


/*  outbyte
 *
 *  Transmit a character out on the MC68302's SCC2.
 *  It may support XON/XOFF flow control.
 *
 *  Input parameters:
 *    ch  - character to be transmitted
 *
 *  Output parameters:  NONE
 */

void outbyte(
  char ch
)
{
#define TXS (m302.scc2.bd.tx[0].status)
#define TXD (* ((volatile char *) m302.scc2.bd.tx[0].buffer))

#define RXS (m302.scc2.bd.rx[0].status)
#define RXD (* ((volatile char *) m302.scc2.bd.rx[0].buffer))

    while (TXS & RBIT_HDLC_READY_BIT)
	/* Wait until okay to transmit */ ;

    /*
     * Check for flow control requests and process.
     */
    while ( ! (RXS & RBIT_HDLC_EMPTY_BIT)) {
	if (RXD == XOFF)
	    do {
		RXS = RBIT_HDLC_EMPTY_BIT | RBIT_HDLC_WRAP_BIT;
		while (RXS & RBIT_HDLC_EMPTY_BIT)
		    /* Wait until character received */ ;
	    } while (RXD != XON);
	RXS = RBIT_HDLC_EMPTY_BIT | RBIT_HDLC_WRAP_BIT;
    }

    TXD = ch;
    TXS = RBIT_HDLC_READY_BIT | RBIT_HDLC_WRAP_BIT;
    if (ch == '\n')
	outbyte('\r');
}

/*
 *  Open entry point
 */

rtems_device_driver console_open(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
  return RTEMS_SUCCESSFUL;
}
 
/*
 *  Close entry point
 */

rtems_device_driver console_close(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
  return RTEMS_SUCCESSFUL;
}

/*
 * read bytes from the serial port. We only have stdin.
 */

rtems_device_driver console_read(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
  rtems_libio_rw_args_t *rw_args;
  char *buffer;
  int maximum;
  int count = 0;
 
  rw_args = (rtems_libio_rw_args_t *) arg;

  buffer = rw_args->buffer;
  maximum = rw_args->count;

  for (count = 0; count < maximum; count++) {
    buffer[ count ] = inbyte();
    if (buffer[ count ] == '\n' || buffer[ count ] == '\r') {
      buffer[ count++ ]  = '\n';
      break;
    }
  }

  rw_args->bytes_moved = count;
  return (count >= 0) ? RTEMS_SUCCESSFUL : RTEMS_UNSATISFIED;
}

/*
 * write bytes to the serial port. Stdout and stderr are the same. 
 */

rtems_device_driver console_write(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
  int count;
  int maximum;
  rtems_libio_rw_args_t *rw_args;
  char *buffer;

  rw_args = (rtems_libio_rw_args_t *) arg;

  buffer = rw_args->buffer;
  maximum = rw_args->count;

  for (count = 0; count < maximum; count++) {
    if ( buffer[ count ] == '\n') {
      outbyte('\r');
    }
    outbyte( buffer[ count ] );
  }

  rw_args->bytes_moved = maximum;
  return 0;
}

/*
 *  IO Control entry point
 */

rtems_device_driver console_control(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void                    * arg
)
{
  return RTEMS_SUCCESSFUL;
}