Removed RTS and DTR handling code since the MC68681 seems to only have

automatic handling of RTS/CTS.  This only protects the on-chip buffers
and FIFOs -- not the termios queues as the RTS/CTS code in here did.  It
may be necessary in the future to enable this automatic support.

Interrupt processing code added.

In some places, channel and duart base addresses were swapped.

6 files changed, 182 insertions, 498 deletions

diff --git a/c/src/lib/libchip/serial/mc68681.c b/c/src/lib/libchip/serial/mc68681.c
index cca44cfc6c..4c8000f567 100644
--- a/c/src/lib/libchip/serial/mc68681.c
+++ b/c/src/lib/libchip/serial/mc68681.c
@@ -30,18 +30,6 @@
  * Flow control is only supported when using interrupts
  */
 
-console_flow mc68681_flow_RTSCTS =
-{
-  mc68681_negate_RTS,             /* deviceStopRemoteTx */
-  mc68681_assert_RTS              /* deviceStartRemoteTx */
-};
-
-console_flow mc68681_flow_DTRCTS =
-{
-  mc68681_negate_DTR,             /* deviceStopRemoteTx */
-  mc68681_assert_DTR              /* deviceStartRemoteTx */
-};
-
 console_fns mc68681_fns =
 {
   mc68681_probe,                  /* deviceProbe */
@@ -122,6 +110,10 @@ static int mc68681_baud_rate(
   }
 
   if ( !acr_bit ) {
+    /*
+     *  Baud Rate Set 1 
+     */
+
     switch (baud & CBAUD) {
       case B50:    baud_mask = 0x00; break;
       case B110:   baud_mask = 0x01; break;
@@ -148,6 +140,10 @@ static int mc68681_baud_rate(
         break;
     }
   } else {
+    /*
+     *  Baud Rate Set 2
+     */
+
     switch (baud & CBAUD) {
       case B75:    baud_mask = 0x00; break;
       case B110:   baud_mask = 0x01; break;
@@ -201,8 +197,8 @@ static int mc68681_set_attributes(
   setRegister_f          setReg;
   rtems_interrupt_level  Irql;
 
-  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort1;
-  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort2;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
   setReg        = Console_Port_Tbl[minor].setRegister;
 
   /*
@@ -293,7 +289,6 @@ static void mc68681_initialize_context(
     }
   }
 
-  pmc68681Context->ucModemCtrl = 0x00;   /* XXX */
 }
 
 /*
@@ -305,7 +300,8 @@ static void mc68681_initialize_context(
  */
 
 static unsigned int mc68681_build_imr(
-  int minor
+  int  minor,
+  int  enable_flag
 )
 {
   int              mate;
@@ -343,11 +339,13 @@ static unsigned int mc68681_build_imr(
    */
 
   mask = 0;
-  if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
-    if ( pMC68681 == pMC68681_port )
-       mask = 0x03;
-    else
-       mask = 0x30;
+  if ( enable_flag ) {
+    if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
+      if ( pMC68681 == pMC68681_port )
+         mask = 0x03;
+      else
+         mask = 0x30;
+    }
   }
 
   return mask | mate_mask;
@@ -373,8 +371,8 @@ static void mc68681_init(int minor)
 
   mc68681_initialize_context( minor, pmc68681Context );
 
-  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort1;
-  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort2;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
   setReg        = Console_Port_Tbl[minor].setRegister;
   getReg        = Console_Port_Tbl[minor].getRegister;
 
@@ -393,6 +391,12 @@ static void mc68681_init(int minor)
 
   (*setReg)( pMC68681, MC68681_MODE_REG_1A, 0x00 );
   (*setReg)( pMC68681, MC68681_MODE_REG_2A, 0x02 );
+
+  /*
+   *  Disable interrupts on RX and TX for this port
+   */
+
+  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 0));
 }
 
 /*
@@ -441,15 +445,7 @@ static int mc68681_open(
 
   (*setReg)( pMC68681, MC68681_INTERRUPT_VECTOR_REG, vector );
 
-  /*
-   * Assert DTR
-   */
-
-  if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_DTRCTS) {
-    mc68681_assert_DTR(minor);
-  }
-
-  return(RTEMS_SUCCESSFUL);
+  return RTEMS_SUCCESSFUL;
 }
 
 /*
@@ -479,14 +475,6 @@ static int mc68681_close(
   (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
   (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
 
-  /*
-   * Negate DTR
-   */
-
-  if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_DTRCTS) {
-    mc68681_negate_DTR(minor);
-  }
-
   return(RTEMS_SUCCESSFUL);
 }
 
@@ -539,211 +527,91 @@ static void mc68681_write_polled(
 }
 
 /*
- * These routines provide control of the RTS and DTR lines
- */
-
-/*
- *  mc68681_assert_RTS
- */
-
-static int mc68681_assert_RTS(int minor)
-{
-/* XXX */
-
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Assert RTS
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl |= SP_MODEM_RTS;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_negate_RTS
- */
-
-static int mc68681_negate_RTS(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Negate RTS
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl &= ~SP_MODEM_RTS;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- * These flow control routines utilize a connection from the local DTR
- * line to the remote CTS line
- */
-
-/*
- *  mc68681_assert_DTR
- */
-
-static int mc68681_assert_DTR(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Assert DTR
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl |= SP_MODEM_DTR;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_negate_DTR
- */
-
-static int mc68681_negate_DTR(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Negate DTR
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl &= ~SP_MODEM_DTR;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL,pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_isr
+ *  mc68681_process
  *
- *  This routine is the console interrupt handler.
+ *  This routine is the per port console interrupt handler.
  */
 
 static void mc68681_process(
-        int             minor
+  int  minor
 )
 {
-/* XXX */
   unsigned32              pMC68681;
+  unsigned32              pMC68681_port;
   volatile unsigned8      ucLineStatus; 
-  volatile unsigned8      ucInterruptId;
   char                    cChar;
   getRegister_f           getReg;
   setRegister_f           setReg;
 
-#if 1
-cChar = ucInterruptId = ucLineStatus = 0;
-#endif
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  getReg   = Console_Port_Tbl[minor].getRegister;
-  setReg   = Console_Port_Tbl[minor].setRegister;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
+  getReg        = Console_Port_Tbl[minor].getRegister;
+  setReg        = Console_Port_Tbl[minor].setRegister;
 
-#if 0
-  do {
+  /*
+   * Deal with any received characters
+   */
+  while(TRUE) {
+    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+    if(!(ucLineStatus & MC68681_RX_READY)) {
+      break;
+    }
     /*
-     * Deal with any received characters
+     *  If there is a RX error, then dump all the data.
      */
-    while(TRUE) {
-      ucLineStatus = (*getReg)(pMC68681, MC68681_LINE_STATUS);
-      if(~ucLineStatus & SP_LSR_RDY) {
-        break;
-      }
-      cChar = (*getReg)(pMC68681, MC68681_RECEIVE_BUFFER);
-      rtems_termios_enqueue_raw_characters( 
-        Console_Port_Data[minor].termios_data,
-        &cChar, 
-        1 
-      );
+    if ( ucLineStatus & MC68681_RX_ERRORS ) {
+      do {
+        cChar = (*getReg)(pMC68681_port, MC68681_RX_BUFFER);
+        ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+      } while ( ucLineStatus & MC68681_RX_READY );
+      continue;
     }
+    cChar = (*getReg)(pMC68681_port, MC68681_RX_BUFFER);
+    rtems_termios_enqueue_raw_characters( 
+      Console_Port_Data[minor].termios_data,
+      &cChar, 
+      1 
+    );
+  }
 
-    while(TRUE) {
-      if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
-        Console_Port_Data[minor].bActive = FALSE;
-        if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-          mc68681_negate_RTS(minor);
-        }
+  /*
+   *  Deal with the transmitter
+   */
 
-        /*
-         * There is no data to transmit
-         */
-        break;
-      }
+  while(TRUE) {
+    if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
+      Console_Port_Data[minor].bActive = FALSE;
 
-      ucLineStatus = (*getReg)(pMC68681, MC68681_LINE_STATUS);
-      if(~ucLineStatus & SP_LSR_THOLD) {
-        /*
-         * We'll get another interrupt when
-         * the transmitter holding reg. becomes
-         * free again
-         */
-        break;
-      }
+      /*
+       * There is no data to transmit
+       */
+      break;
+    }
 
-      Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
+    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+    if(!(ucLineStatus & (MC68681_TX_EMPTY|MC68681_TX_READY))) {
       /*
-       * transmit character
+       *  We'll get another interrupt when the TX can take another character.
        */
-      (*setReg)(pMC68681, MC68681_TRANSMIT_BUFFER, cChar);
+      break;
     }
 
-    ucInterruptId = (*getReg)(pMC68681, MC68681_INTERRUPT_ID);
+    Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
+    /*
+     * transmit character
+     */
+    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, cChar);
   }
-  while((ucInterruptId&0xf) != 0x1);
-#endif
+
 }
 
+/*
+ *  mc68681_isr
+ *
+ *  This is the single interrupt entry point which parcels interrupts
+ *  out to the various ports.
+ */
+
 static rtems_isr mc68681_isr(
   rtems_vector_number vector
 )
@@ -802,7 +670,7 @@ static void mc68681_enable_interrupts(
    *  Enable interrupts on RX and TX -- not break
    */
 
-  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr( minor ));
+  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 1));
 }
 
 /*
@@ -848,9 +716,6 @@ static int mc68681_write_support_int(
          */
         rtems_interrupt_disable(Irql);
         Console_Port_Data[minor].bActive = TRUE;
-        if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-          mc68681_assert_RTS(minor);
-        }
         mc68681_process(minor);
         rtems_interrupt_enable(Irql);
       } else {
@@ -881,9 +746,6 @@ static int mc68681_write_support_int(
      */
     rtems_interrupt_disable(Irql);
     Console_Port_Data[minor].bActive = TRUE;
-    if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-      mc68681_assert_RTS(minor);
-    }
     mc68681_process(minor);
     rtems_interrupt_enable(Irql);
   }
diff --git a/c/src/lib/libchip/serial/mc68681.h b/c/src/lib/libchip/serial/mc68681.h
index 753e52e811..c4c6ac28b1 100644
--- a/c/src/lib/libchip/serial/mc68681.h
+++ b/c/src/lib/libchip/serial/mc68681.h
@@ -46,13 +46,6 @@ extern "C" {
 extern console_fns mc68681_fns;
 extern console_fns mc68681_fns_polled;
 
-/*
- * Flow control function tables
- */
-
-extern console_flow mc68681_flow_RTSCTS;
-extern console_flow mc68681_flow_DTRCTS;
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/c/src/lib/libchip/serial/mc68681_p.h b/c/src/lib/libchip/serial/mc68681_p.h
index 14ab682251..e9010199ff 100644
--- a/c/src/lib/libchip/serial/mc68681_p.h
+++ b/c/src/lib/libchip/serial/mc68681_p.h
@@ -165,6 +165,10 @@ extern "C" {
 #define MC68681_FRAMING_ERROR                               0x40
 #define MC68681_RECEIVED_BREAK                              0x80
 
+#define MC68681_RX_ERRORS \
+  (MC68681_OVERRUN_ERROR|MC68681_PARITY_ERROR| \
+   MC68681_FRAMING_ERROR|MC68681_RECEIVED_BREAK)
+
 /*
  * Interupt Status Register Definitions.
  *
@@ -225,7 +229,6 @@ extern "C" {
 typedef struct _mc68681_context
 {
   int        mate;
-  unsigned8  ucModemCtrl;
 } mc68681_context;
 
 /*
@@ -257,22 +260,6 @@ static void mc68681_write_polled(
   char  cChar
 );
 
-static int mc68681_assert_RTS(
-  int minor
-);
-
-static int mc68681_negate_RTS(
-  int minor
-);
-
-static int mc68681_assert_DTR(
-  int minor
-);
-
-static int mc68681_negate_DTR(
-  int minor
-);
-
 static void mc68681_initialize_interrupts(int minor);
 
 static int mc68681_flush(int major, int minor, void *arg);
diff --git a/c/src/libchip/serial/mc68681.c b/c/src/libchip/serial/mc68681.c
index cca44cfc6c..4c8000f567 100644
--- a/c/src/libchip/serial/mc68681.c
+++ b/c/src/libchip/serial/mc68681.c
@@ -30,18 +30,6 @@
  * Flow control is only supported when using interrupts
  */
 
-console_flow mc68681_flow_RTSCTS =
-{
-  mc68681_negate_RTS,             /* deviceStopRemoteTx */
-  mc68681_assert_RTS              /* deviceStartRemoteTx */
-};
-
-console_flow mc68681_flow_DTRCTS =
-{
-  mc68681_negate_DTR,             /* deviceStopRemoteTx */
-  mc68681_assert_DTR              /* deviceStartRemoteTx */
-};
-
 console_fns mc68681_fns =
 {
   mc68681_probe,                  /* deviceProbe */
@@ -122,6 +110,10 @@ static int mc68681_baud_rate(
   }
 
   if ( !acr_bit ) {
+    /*
+     *  Baud Rate Set 1 
+     */
+
     switch (baud & CBAUD) {
       case B50:    baud_mask = 0x00; break;
       case B110:   baud_mask = 0x01; break;
@@ -148,6 +140,10 @@ static int mc68681_baud_rate(
         break;
     }
   } else {
+    /*
+     *  Baud Rate Set 2
+     */
+
     switch (baud & CBAUD) {
       case B75:    baud_mask = 0x00; break;
       case B110:   baud_mask = 0x01; break;
@@ -201,8 +197,8 @@ static int mc68681_set_attributes(
   setRegister_f          setReg;
   rtems_interrupt_level  Irql;
 
-  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort1;
-  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort2;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
   setReg        = Console_Port_Tbl[minor].setRegister;
 
   /*
@@ -293,7 +289,6 @@ static void mc68681_initialize_context(
     }
   }
 
-  pmc68681Context->ucModemCtrl = 0x00;   /* XXX */
 }
 
 /*
@@ -305,7 +300,8 @@ static void mc68681_initialize_context(
  */
 
 static unsigned int mc68681_build_imr(
-  int minor
+  int  minor,
+  int  enable_flag
 )
 {
   int              mate;
@@ -343,11 +339,13 @@ static unsigned int mc68681_build_imr(
    */
 
   mask = 0;
-  if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
-    if ( pMC68681 == pMC68681_port )
-       mask = 0x03;
-    else
-       mask = 0x30;
+  if ( enable_flag ) {
+    if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
+      if ( pMC68681 == pMC68681_port )
+         mask = 0x03;
+      else
+         mask = 0x30;
+    }
   }
 
   return mask | mate_mask;
@@ -373,8 +371,8 @@ static void mc68681_init(int minor)
 
   mc68681_initialize_context( minor, pmc68681Context );
 
-  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort1;
-  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort2;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
   setReg        = Console_Port_Tbl[minor].setRegister;
   getReg        = Console_Port_Tbl[minor].getRegister;
 
@@ -393,6 +391,12 @@ static void mc68681_init(int minor)
 
   (*setReg)( pMC68681, MC68681_MODE_REG_1A, 0x00 );
   (*setReg)( pMC68681, MC68681_MODE_REG_2A, 0x02 );
+
+  /*
+   *  Disable interrupts on RX and TX for this port
+   */
+
+  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 0));
 }
 
 /*
@@ -441,15 +445,7 @@ static int mc68681_open(
 
   (*setReg)( pMC68681, MC68681_INTERRUPT_VECTOR_REG, vector );
 
-  /*
-   * Assert DTR
-   */
-
-  if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_DTRCTS) {
-    mc68681_assert_DTR(minor);
-  }
-
-  return(RTEMS_SUCCESSFUL);
+  return RTEMS_SUCCESSFUL;
 }
 
 /*
@@ -479,14 +475,6 @@ static int mc68681_close(
   (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
   (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
 
-  /*
-   * Negate DTR
-   */
-
-  if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_DTRCTS) {
-    mc68681_negate_DTR(minor);
-  }
-
   return(RTEMS_SUCCESSFUL);
 }
 
@@ -539,211 +527,91 @@ static void mc68681_write_polled(
 }
 
 /*
- * These routines provide control of the RTS and DTR lines
- */
-
-/*
- *  mc68681_assert_RTS
- */
-
-static int mc68681_assert_RTS(int minor)
-{
-/* XXX */
-
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Assert RTS
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl |= SP_MODEM_RTS;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_negate_RTS
- */
-
-static int mc68681_negate_RTS(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Negate RTS
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl &= ~SP_MODEM_RTS;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- * These flow control routines utilize a connection from the local DTR
- * line to the remote CTS line
- */
-
-/*
- *  mc68681_assert_DTR
- */
-
-static int mc68681_assert_DTR(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Assert DTR
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl |= SP_MODEM_DTR;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL, pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_negate_DTR
- */
-
-static int mc68681_negate_DTR(int minor)
-{
-/* XXX */
-  unsigned32              pMC68681;
-  unsigned32              Irql;
-  mc68681_context        *pmc68681Context;
-  setRegister_f           setReg;
-
-  pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   * Negate DTR
-   */
-  rtems_interrupt_disable(Irql);
-#if 0
-  pmc68681Context->ucModemCtrl &= ~SP_MODEM_DTR;
-  (*setReg)(pMC68681, MC68681_MODEM_CONTROL,pmc68681Context->ucModemCtrl);
-#endif
-  rtems_interrupt_enable(Irql);
-  return 0;
-}
-
-/*
- *  mc68681_isr
+ *  mc68681_process
  *
- *  This routine is the console interrupt handler.
+ *  This routine is the per port console interrupt handler.
  */
 
 static void mc68681_process(
-        int             minor
+  int  minor
 )
 {
-/* XXX */
   unsigned32              pMC68681;
+  unsigned32              pMC68681_port;
   volatile unsigned8      ucLineStatus; 
-  volatile unsigned8      ucInterruptId;
   char                    cChar;
   getRegister_f           getReg;
   setRegister_f           setReg;
 
-#if 1
-cChar = ucInterruptId = ucLineStatus = 0;
-#endif
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  getReg   = Console_Port_Tbl[minor].getRegister;
-  setReg   = Console_Port_Tbl[minor].setRegister;
+  pMC68681      = Console_Port_Tbl[minor].ulCtrlPort1;
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
+  getReg        = Console_Port_Tbl[minor].getRegister;
+  setReg        = Console_Port_Tbl[minor].setRegister;
 
-#if 0
-  do {
+  /*
+   * Deal with any received characters
+   */
+  while(TRUE) {
+    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+    if(!(ucLineStatus & MC68681_RX_READY)) {
+      break;
+    }
     /*
-     * Deal with any received characters
+     *  If there is a RX error, then dump all the data.
      */
-    while(TRUE) {
-      ucLineStatus = (*getReg)(pMC68681, MC68681_LINE_STATUS);
-      if(~ucLineStatus & SP_LSR_RDY) {
-        break;
-      }
-      cChar = (*getReg)(pMC68681, MC68681_RECEIVE_BUFFER);
-      rtems_termios_enqueue_raw_characters( 
-        Console_Port_Data[minor].termios_data,
-        &cChar, 
-        1 
-      );
+    if ( ucLineStatus & MC68681_RX_ERRORS ) {
+      do {
+        cChar = (*getReg)(pMC68681_port, MC68681_RX_BUFFER);
+        ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+      } while ( ucLineStatus & MC68681_RX_READY );
+      continue;
     }
+    cChar = (*getReg)(pMC68681_port, MC68681_RX_BUFFER);
+    rtems_termios_enqueue_raw_characters( 
+      Console_Port_Data[minor].termios_data,
+      &cChar, 
+      1 
+    );
+  }
 
-    while(TRUE) {
-      if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
-        Console_Port_Data[minor].bActive = FALSE;
-        if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-          mc68681_negate_RTS(minor);
-        }
+  /*
+   *  Deal with the transmitter
+   */
 
-        /*
-         * There is no data to transmit
-         */
-        break;
-      }
+  while(TRUE) {
+    if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
+      Console_Port_Data[minor].bActive = FALSE;
 
-      ucLineStatus = (*getReg)(pMC68681, MC68681_LINE_STATUS);
-      if(~ucLineStatus & SP_LSR_THOLD) {
-        /*
-         * We'll get another interrupt when
-         * the transmitter holding reg. becomes
-         * free again
-         */
-        break;
-      }
+      /*
+       * There is no data to transmit
+       */
+      break;
+    }
 
-      Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
+    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
+    if(!(ucLineStatus & (MC68681_TX_EMPTY|MC68681_TX_READY))) {
       /*
-       * transmit character
+       *  We'll get another interrupt when the TX can take another character.
        */
-      (*setReg)(pMC68681, MC68681_TRANSMIT_BUFFER, cChar);
+      break;
     }
 
-    ucInterruptId = (*getReg)(pMC68681, MC68681_INTERRUPT_ID);
+    Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
+    /*
+     * transmit character
+     */
+    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, cChar);
   }
-  while((ucInterruptId&0xf) != 0x1);
-#endif
+
 }
 
+/*
+ *  mc68681_isr
+ *
+ *  This is the single interrupt entry point which parcels interrupts
+ *  out to the various ports.
+ */
+
 static rtems_isr mc68681_isr(
   rtems_vector_number vector
 )
@@ -802,7 +670,7 @@ static void mc68681_enable_interrupts(
    *  Enable interrupts on RX and TX -- not break
    */
 
-  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr( minor ));
+  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 1));
 }
 
 /*
@@ -848,9 +716,6 @@ static int mc68681_write_support_int(
          */
         rtems_interrupt_disable(Irql);
         Console_Port_Data[minor].bActive = TRUE;
-        if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-          mc68681_assert_RTS(minor);
-        }
         mc68681_process(minor);
         rtems_interrupt_enable(Irql);
       } else {
@@ -881,9 +746,6 @@ static int mc68681_write_support_int(
      */
     rtems_interrupt_disable(Irql);
     Console_Port_Data[minor].bActive = TRUE;
-    if(Console_Port_Tbl[minor].pDeviceFlow != &mc68681_flow_RTSCTS) {
-      mc68681_assert_RTS(minor);
-    }
     mc68681_process(minor);
     rtems_interrupt_enable(Irql);
   }
diff --git a/c/src/libchip/serial/mc68681.h b/c/src/libchip/serial/mc68681.h
index 753e52e811..c4c6ac28b1 100644
--- a/c/src/libchip/serial/mc68681.h
+++ b/c/src/libchip/serial/mc68681.h
@@ -46,13 +46,6 @@ extern "C" {
 extern console_fns mc68681_fns;
 extern console_fns mc68681_fns_polled;
 
-/*
- * Flow control function tables
- */
-
-extern console_flow mc68681_flow_RTSCTS;
-extern console_flow mc68681_flow_DTRCTS;
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/c/src/libchip/serial/mc68681_p.h b/c/src/libchip/serial/mc68681_p.h
index 14ab682251..e9010199ff 100644
--- a/c/src/libchip/serial/mc68681_p.h
+++ b/c/src/libchip/serial/mc68681_p.h
@@ -165,6 +165,10 @@ extern "C" {
 #define MC68681_FRAMING_ERROR                               0x40
 #define MC68681_RECEIVED_BREAK                              0x80
 
+#define MC68681_RX_ERRORS \
+  (MC68681_OVERRUN_ERROR|MC68681_PARITY_ERROR| \
+   MC68681_FRAMING_ERROR|MC68681_RECEIVED_BREAK)
+
 /*
  * Interupt Status Register Definitions.
  *
@@ -225,7 +229,6 @@ extern "C" {
 typedef struct _mc68681_context
 {
   int        mate;
-  unsigned8  ucModemCtrl;
 } mc68681_context;
 
 /*
@@ -257,22 +260,6 @@ static void mc68681_write_polled(
   char  cChar
 );
 
-static int mc68681_assert_RTS(
-  int minor
-);
-
-static int mc68681_negate_RTS(
-  int minor
-);
-
-static int mc68681_assert_DTR(
-  int minor
-);
-
-static int mc68681_negate_DTR(
-  int minor
-);
-
 static void mc68681_initialize_interrupts(int minor);
 
 static int mc68681_flush(int major, int minor, void *arg);