path: root/c/src/lib/libbsp/m68k/gen68302/console/console.c

/*
 * Initialize the MC68302 SCC2 for console IO board support package.
 */

/*
 *  COPYRIGHT (c) 1989-2014.
 *  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.org/license/LICENSE.
 */

#define GEN68302_INIT

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

#include <rtems/m68k/m68302.h>

/*  console_initialize
 *
 *  This routine initializes the console IO driver.
 */
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 =
      (uint8_t*) &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 =
      (uint8_t*) &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;

}

/*  inbyte
 *
 *  Receive a character from the MC68302's SCC2.
 */
static 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.
 */
static 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;
}