Switched from driver's own buffering to using termios. This eliminated

the need for the ringbuffer manipulation in this driver.  It should
also allow the removal of mc68681_flush.  This greatly simplified the
interrupt processing.

Reworked Interrupt Mask Register handling.  Added imr field to the device
context.  This handling makes sure that the IMR accurately reflects the
state of the port in use and its mate.  This required the reworking of
the mc68681_enable_interrupts() routine to allow for the specification
of which interrupt sources were being enabled/disabled.

Reworked initialization to reset using port address rather than chip
base address.  Basically we were always resetting port 0.

Added deviceType field which allows for multiple chips of the same
class to have the same vector number.

2 files changed, 186 insertions, 242 deletions

diff --git a/c/src/lib/libchip/serial/mc68681.c b/c/src/lib/libchip/serial/mc68681.c
index 9793015c6d..19e9509a79 100644
--- a/c/src/lib/libchip/serial/mc68681.c
+++ b/c/src/lib/libchip/serial/mc68681.c
@@ -35,7 +35,7 @@ console_fns mc68681_fns =
 {
   libchip_serial_default_probe,   /* deviceProbe */
   mc68681_open,                   /* deviceFirstOpen */
-  mc68681_flush,                  /* deviceLastClose */
+  NULL,                           /* deviceLastClose */
   NULL,                           /* deviceRead */
   mc68681_write_support_int,      /* deviceWrite */
   mc68681_initialize_interrupts,  /* deviceInitialize */
@@ -293,6 +293,7 @@ MC68681_STATIC void mc68681_initialize_context(
     if ( Console_Port_Tbl[port].ulCtrlPort1 == pMC68681 && 
          Console_Port_Tbl[port].ulCtrlPort2 != pMC68681_port ) {
       pmc68681Context->mate = port;
+      pmc68681Context->imr  = 0;
       break;
     }
   }
@@ -328,23 +329,23 @@ MC68681_STATIC void mc68681_init(int minor)
    *  Reset everything and leave this port disabled.
    */
 
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_RX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_TX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_ERROR );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_BREAK );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_STOP_BREAK );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_RX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_TX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_ERROR );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_BREAK );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_STOP_BREAK );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
 
 
-  (*setReg)( pMC68681, MC68681_MODE_REG_1A, 0x00 );
-  (*setReg)( pMC68681, MC68681_MODE_REG_2A, 0x02 );
+  (*setReg)( pMC68681_port, MC68681_MODE_REG_1A, 0x00 );
+  (*setReg)( pMC68681_port, 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));
+  mc68681_enable_interrupts( minor, MC68681_IMR_DISABLE_ALL );
 }
 
 /*
@@ -498,7 +499,8 @@ MC68681_STATIC rtems_isr mc68681_isr(
   int     minor;
 
   for(minor=0 ; minor<Console_Port_Count ; minor++) {
-    if(vector == Console_Port_Tbl[minor].ulIntVector) {
+    if(Console_Port_Tbl[minor].ulIntVector == vector && 
+       Console_Port_Tbl[minor].deviceType == SERIAL_MC68681 ) {
       mc68681_process(minor);
     }
   }
@@ -513,8 +515,10 @@ MC68681_STATIC rtems_isr mc68681_isr(
  *  NOTE:  This is the "interrupt mode" close entry point.
  */
 
+/* XXX remove me */
 MC68681_STATIC int mc68681_flush(int major, int minor, void *arg)
 {
+#if 0
   while(!Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
     /*
      * Yield while we wait
@@ -526,33 +530,11 @@ MC68681_STATIC int mc68681_flush(int major, int minor, void *arg)
 
   mc68681_close(major, minor, arg);
 
+#endif
   return(RTEMS_SUCCESSFUL);
 }
 
 /*
- *  mc68681_enable_interrupts
- *
- *  This function initializes the hardware for this port to use interrupts.
- */
-
-MC68681_STATIC void mc68681_enable_interrupts(
-  int minor
-)
-{
-  unsigned32            pMC68681;
-  setRegister_f         setReg;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   *  Enable interrupts on RX and TX -- not break
-   */
-
-  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 1));
-}
-
-/*
  *  mc68681_initialize_interrupts
  *
  *  This routine initializes the console's receive and transmit
@@ -563,13 +545,11 @@ MC68681_STATIC void mc68681_initialize_interrupts(int minor)
 {
   mc68681_init(minor);
 
-  Ring_buffer_Initialize(&Console_Port_Data[minor].TxBuffer);
-
   Console_Port_Data[minor].bActive = FALSE;
 
   set_vector(mc68681_isr, Console_Port_Tbl[minor].ulIntVector, 1);
 
-  mc68681_enable_interrupts(minor);
+  mc68681_enable_interrupts(minor,MC68681_IMR_ENABLE_ALL_EXCEPT_TX);
 }
 
 /* 
@@ -584,52 +564,30 @@ MC68681_STATIC int mc68681_write_support_int(
   int         len
 )
 {
-  int i;
-  unsigned32 Irql;
-
-  for(i=0 ; i<len ;) {
-    if(Ring_buffer_Is_full(&Console_Port_Data[minor].TxBuffer)) {
-      if(!Console_Port_Data[minor].bActive) {
-        /*
-         * Wake up the device
-         */
-        rtems_interrupt_disable(Irql);
-        Console_Port_Data[minor].bActive = TRUE;
-        mc68681_process(minor);
-        rtems_interrupt_enable(Irql);
-      } else {
-        /*
-         * Yield
-         */
-        rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
-      }
-
-      /*
-       * Wait for ring buffer to empty
-       */
-      continue;
-    }
-    else {
-      Ring_buffer_Add_character( &Console_Port_Data[minor].TxBuffer, buf[i]);
-      i++;
-    }
-  }
+  unsigned32      Irql;
+  unsigned32      pMC68681_port;
+  setRegister_f   setReg;
+
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
+  setReg        = Console_Port_Tbl[minor].setRegister;
 
   /*
-   * Ensure that characters are on the way
+   *  We are using interrupt driven output and termios only sends us one character
+   *  at a time.
    */
 
-  if(!Console_Port_Data[minor].bActive) {
-    /*
-     * Wake up the device
-     */
-    rtems_interrupt_disable(Irql);
-    Console_Port_Data[minor].bActive = TRUE;
-    mc68681_process(minor);
-    rtems_interrupt_enable(Irql);
-  }
+  if ( !len )
+    return 0;
 
-  return (len);
+  /*
+   * Wake up the device
+   */
+  rtems_interrupt_disable(Irql);
+    Console_Port_Data[minor].bActive = TRUE;
+    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, *buf);
+    mc68681_enable_interrupts(minor, MC68681_IMR_ENABLE_ALL);
+  rtems_interrupt_enable(Irql);
+  return 1;
 }
 
 /* 
@@ -807,29 +765,13 @@ MC68681_STATIC void mc68681_process(
    *  Deal with the transmitter
    */
 
-  while(TRUE) {
-    if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
-      Console_Port_Data[minor].bActive = FALSE;
-
-      /*
-       * There is no data to transmit
-       */
-      break;
-    }
+  ucLineStatus = (*getReg)(pMC68681, MC68681_INTERRUPT_STATUS_REG);
+  if (pMC68681 != pMC68681_port)
+    ucLineStatus >>= 4;
 
-    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
-    if(!(ucLineStatus & (MC68681_TX_EMPTY|MC68681_TX_READY))) {
-      /*
-       *  We'll get another interrupt when the TX can take another character.
-       */
-      break;
-    }
-
-    Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
-    /*
-     * transmit character
-     */
-    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, cChar);
+  if(ucLineStatus & MC68681_IR_TX_READY) {
+    mc68681_enable_interrupts(minor, MC68681_IMR_ENABLE_ALL_EXCEPT_TX);
+    rtems_termios_dequeue_characters(Console_Port_Data[minor].termios_data, 1);
   }
 
 }
@@ -848,49 +790,79 @@ MC68681_STATIC unsigned int mc68681_build_imr(
 )
 {
   int              mate;
+  int              is_a;
   unsigned int     mask;
   unsigned int     mate_mask;
   unsigned int     pMC68681;
   unsigned int     pMC68681_port;
   mc68681_context *pmc68681Context;
+  mc68681_context *mateContext;
   
   pMC68681        = Console_Port_Tbl[minor].ulCtrlPort1;
   pMC68681_port   = Console_Port_Tbl[minor].ulCtrlPort2;
   pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
   mate            = pmc68681Context->mate;
 
+  mask = 0;
   mate_mask = 0;
 
+  is_a = (pMC68681 == pMC68681_port);
+ 
   /*
-   *  Decide if the other port on this DUART is using interrupts
+   *  If there is a mate for this port, get its IMR mask.
    */
 
   if ( mate != -1 ) {
-    if ( Console_Port_Tbl[mate].pDeviceFns->deviceOutputUsesInterrupts )
-      mate_mask = 0x03;
+    mateContext = Console_Port_Data[mate].pDeviceContext;
+    
+    if (mateContext)
+      mate_mask = mateContext->imr;
+  }
 
-    /*
-     *  If equal, then minor is A so the mate must be B
-     */
+  /*
+   *  Calculate this port's IMR mask and save it in the context area.
+   */
 
-    if ( pMC68681 == pMC68681_port )
-      mate_mask <<= 4;
-  }
+  if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts )
+    mask = enable_flag;
+
+  pmc68681Context->imr = mask;
 
   /*
-   *  Add in minor's mask
+   *  Now return the full IMR value
    */
 
-  mask = 0;
-  if ( enable_flag ) {
-    if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
-      if ( pMC68681 == pMC68681_port )
-         mask = 0x03;
-      else
-         mask = 0x30;
-    }
-  }
+  if (is_a)
+    return (mate_mask << 4) | mask;
+
+  return (mask << 4) | mate_mask;
+}
+
+/*
+ *  mc68681_enable_interrupts
+ *
+ *  This function initializes the hardware for this port to use interrupts.
+ */
+
+MC68681_STATIC void mc68681_enable_interrupts(
+  int minor,
+  int imr_mask
+)
+{
+  unsigned32            pMC68681;
+  setRegister_f         setReg;
+
+  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
+  setReg   = Console_Port_Tbl[minor].setRegister;
+
+  /*
+   *  Enable interrupts on RX and TX -- not break
+   */
 
-  return mask | mate_mask;
+  (*setReg)(
+     pMC68681,
+     MC68681_INTERRUPT_MASK_REG,
+     mc68681_build_imr(minor, imr_mask)
+  );
 }
 
diff --git a/c/src/libchip/serial/mc68681.c b/c/src/libchip/serial/mc68681.c
index 9793015c6d..19e9509a79 100644
--- a/c/src/libchip/serial/mc68681.c
+++ b/c/src/libchip/serial/mc68681.c
@@ -35,7 +35,7 @@ console_fns mc68681_fns =
 {
   libchip_serial_default_probe,   /* deviceProbe */
   mc68681_open,                   /* deviceFirstOpen */
-  mc68681_flush,                  /* deviceLastClose */
+  NULL,                           /* deviceLastClose */
   NULL,                           /* deviceRead */
   mc68681_write_support_int,      /* deviceWrite */
   mc68681_initialize_interrupts,  /* deviceInitialize */
@@ -293,6 +293,7 @@ MC68681_STATIC void mc68681_initialize_context(
     if ( Console_Port_Tbl[port].ulCtrlPort1 == pMC68681 && 
          Console_Port_Tbl[port].ulCtrlPort2 != pMC68681_port ) {
       pmc68681Context->mate = port;
+      pmc68681Context->imr  = 0;
       break;
     }
   }
@@ -328,23 +329,23 @@ MC68681_STATIC void mc68681_init(int minor)
    *  Reset everything and leave this port disabled.
    */
 
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_RX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_TX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_ERROR );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_RESET_BREAK );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_STOP_BREAK );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
-  (*setReg)( pMC68681, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_RX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_TX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_ERROR );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_RESET_BREAK );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_STOP_BREAK );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_TX );
+  (*setReg)( pMC68681_port, MC68681_COMMAND, MC68681_MODE_REG_DISABLE_RX );
 
 
-  (*setReg)( pMC68681, MC68681_MODE_REG_1A, 0x00 );
-  (*setReg)( pMC68681, MC68681_MODE_REG_2A, 0x02 );
+  (*setReg)( pMC68681_port, MC68681_MODE_REG_1A, 0x00 );
+  (*setReg)( pMC68681_port, 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));
+  mc68681_enable_interrupts( minor, MC68681_IMR_DISABLE_ALL );
 }
 
 /*
@@ -498,7 +499,8 @@ MC68681_STATIC rtems_isr mc68681_isr(
   int     minor;
 
   for(minor=0 ; minor<Console_Port_Count ; minor++) {
-    if(vector == Console_Port_Tbl[minor].ulIntVector) {
+    if(Console_Port_Tbl[minor].ulIntVector == vector && 
+       Console_Port_Tbl[minor].deviceType == SERIAL_MC68681 ) {
       mc68681_process(minor);
     }
   }
@@ -513,8 +515,10 @@ MC68681_STATIC rtems_isr mc68681_isr(
  *  NOTE:  This is the "interrupt mode" close entry point.
  */
 
+/* XXX remove me */
 MC68681_STATIC int mc68681_flush(int major, int minor, void *arg)
 {
+#if 0
   while(!Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
     /*
      * Yield while we wait
@@ -526,33 +530,11 @@ MC68681_STATIC int mc68681_flush(int major, int minor, void *arg)
 
   mc68681_close(major, minor, arg);
 
+#endif
   return(RTEMS_SUCCESSFUL);
 }
 
 /*
- *  mc68681_enable_interrupts
- *
- *  This function initializes the hardware for this port to use interrupts.
- */
-
-MC68681_STATIC void mc68681_enable_interrupts(
-  int minor
-)
-{
-  unsigned32            pMC68681;
-  setRegister_f         setReg;
-
-  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
-  setReg   = Console_Port_Tbl[minor].setRegister;
-
-  /*
-   *  Enable interrupts on RX and TX -- not break
-   */
-
-  (*setReg)( pMC68681, MC68681_INTERRUPT_MASK_REG, mc68681_build_imr(minor, 1));
-}
-
-/*
  *  mc68681_initialize_interrupts
  *
  *  This routine initializes the console's receive and transmit
@@ -563,13 +545,11 @@ MC68681_STATIC void mc68681_initialize_interrupts(int minor)
 {
   mc68681_init(minor);
 
-  Ring_buffer_Initialize(&Console_Port_Data[minor].TxBuffer);
-
   Console_Port_Data[minor].bActive = FALSE;
 
   set_vector(mc68681_isr, Console_Port_Tbl[minor].ulIntVector, 1);
 
-  mc68681_enable_interrupts(minor);
+  mc68681_enable_interrupts(minor,MC68681_IMR_ENABLE_ALL_EXCEPT_TX);
 }
 
 /* 
@@ -584,52 +564,30 @@ MC68681_STATIC int mc68681_write_support_int(
   int         len
 )
 {
-  int i;
-  unsigned32 Irql;
-
-  for(i=0 ; i<len ;) {
-    if(Ring_buffer_Is_full(&Console_Port_Data[minor].TxBuffer)) {
-      if(!Console_Port_Data[minor].bActive) {
-        /*
-         * Wake up the device
-         */
-        rtems_interrupt_disable(Irql);
-        Console_Port_Data[minor].bActive = TRUE;
-        mc68681_process(minor);
-        rtems_interrupt_enable(Irql);
-      } else {
-        /*
-         * Yield
-         */
-        rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
-      }
-
-      /*
-       * Wait for ring buffer to empty
-       */
-      continue;
-    }
-    else {
-      Ring_buffer_Add_character( &Console_Port_Data[minor].TxBuffer, buf[i]);
-      i++;
-    }
-  }
+  unsigned32      Irql;
+  unsigned32      pMC68681_port;
+  setRegister_f   setReg;
+
+  pMC68681_port = Console_Port_Tbl[minor].ulCtrlPort2;
+  setReg        = Console_Port_Tbl[minor].setRegister;
 
   /*
-   * Ensure that characters are on the way
+   *  We are using interrupt driven output and termios only sends us one character
+   *  at a time.
    */
 
-  if(!Console_Port_Data[minor].bActive) {
-    /*
-     * Wake up the device
-     */
-    rtems_interrupt_disable(Irql);
-    Console_Port_Data[minor].bActive = TRUE;
-    mc68681_process(minor);
-    rtems_interrupt_enable(Irql);
-  }
+  if ( !len )
+    return 0;
 
-  return (len);
+  /*
+   * Wake up the device
+   */
+  rtems_interrupt_disable(Irql);
+    Console_Port_Data[minor].bActive = TRUE;
+    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, *buf);
+    mc68681_enable_interrupts(minor, MC68681_IMR_ENABLE_ALL);
+  rtems_interrupt_enable(Irql);
+  return 1;
 }
 
 /* 
@@ -807,29 +765,13 @@ MC68681_STATIC void mc68681_process(
    *  Deal with the transmitter
    */
 
-  while(TRUE) {
-    if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
-      Console_Port_Data[minor].bActive = FALSE;
-
-      /*
-       * There is no data to transmit
-       */
-      break;
-    }
+  ucLineStatus = (*getReg)(pMC68681, MC68681_INTERRUPT_STATUS_REG);
+  if (pMC68681 != pMC68681_port)
+    ucLineStatus >>= 4;
 
-    ucLineStatus = (*getReg)(pMC68681_port, MC68681_STATUS);
-    if(!(ucLineStatus & (MC68681_TX_EMPTY|MC68681_TX_READY))) {
-      /*
-       *  We'll get another interrupt when the TX can take another character.
-       */
-      break;
-    }
-
-    Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
-    /*
-     * transmit character
-     */
-    (*setReg)(pMC68681_port, MC68681_TX_BUFFER, cChar);
+  if(ucLineStatus & MC68681_IR_TX_READY) {
+    mc68681_enable_interrupts(minor, MC68681_IMR_ENABLE_ALL_EXCEPT_TX);
+    rtems_termios_dequeue_characters(Console_Port_Data[minor].termios_data, 1);
   }
 
 }
@@ -848,49 +790,79 @@ MC68681_STATIC unsigned int mc68681_build_imr(
 )
 {
   int              mate;
+  int              is_a;
   unsigned int     mask;
   unsigned int     mate_mask;
   unsigned int     pMC68681;
   unsigned int     pMC68681_port;
   mc68681_context *pmc68681Context;
+  mc68681_context *mateContext;
   
   pMC68681        = Console_Port_Tbl[minor].ulCtrlPort1;
   pMC68681_port   = Console_Port_Tbl[minor].ulCtrlPort2;
   pmc68681Context = (mc68681_context *) Console_Port_Data[minor].pDeviceContext;
   mate            = pmc68681Context->mate;
 
+  mask = 0;
   mate_mask = 0;
 
+  is_a = (pMC68681 == pMC68681_port);
+ 
   /*
-   *  Decide if the other port on this DUART is using interrupts
+   *  If there is a mate for this port, get its IMR mask.
    */
 
   if ( mate != -1 ) {
-    if ( Console_Port_Tbl[mate].pDeviceFns->deviceOutputUsesInterrupts )
-      mate_mask = 0x03;
+    mateContext = Console_Port_Data[mate].pDeviceContext;
+    
+    if (mateContext)
+      mate_mask = mateContext->imr;
+  }
 
-    /*
-     *  If equal, then minor is A so the mate must be B
-     */
+  /*
+   *  Calculate this port's IMR mask and save it in the context area.
+   */
 
-    if ( pMC68681 == pMC68681_port )
-      mate_mask <<= 4;
-  }
+  if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts )
+    mask = enable_flag;
+
+  pmc68681Context->imr = mask;
 
   /*
-   *  Add in minor's mask
+   *  Now return the full IMR value
    */
 
-  mask = 0;
-  if ( enable_flag ) {
-    if ( Console_Port_Tbl[minor].pDeviceFns->deviceOutputUsesInterrupts ) {
-      if ( pMC68681 == pMC68681_port )
-         mask = 0x03;
-      else
-         mask = 0x30;
-    }
-  }
+  if (is_a)
+    return (mate_mask << 4) | mask;
+
+  return (mask << 4) | mate_mask;
+}
+
+/*
+ *  mc68681_enable_interrupts
+ *
+ *  This function initializes the hardware for this port to use interrupts.
+ */
+
+MC68681_STATIC void mc68681_enable_interrupts(
+  int minor,
+  int imr_mask
+)
+{
+  unsigned32            pMC68681;
+  setRegister_f         setReg;
+
+  pMC68681 = Console_Port_Tbl[minor].ulCtrlPort1;
+  setReg   = Console_Port_Tbl[minor].setRegister;
+
+  /*
+   *  Enable interrupts on RX and TX -- not break
+   */
 
-  return mask | mate_mask;
+  (*setReg)(
+     pMC68681,
+     MC68681_INTERRUPT_MASK_REG,
+     mc68681_build_imr(minor, imr_mask)
+  );
 }