1 files changed, 130 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/gen68302/timer/timer.c b/c/src/lib/libbsp/m68k/gen68302/timer/timer.c
new file mode 100644
index 0000000000..4d60b6a82b
--- /dev/null
+++ b/c/src/lib/libbsp/m68k/gen68302/timer/timer.c
@@ -0,0 +1,130 @@
+/*  Timer_init()
+ *
+ *  This routine initializes TIMER 2 for an MC68302.
+ *
+ *  Input parameters:  NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  NOTE: It is important that the timer start/stop overhead be 
+ *        determined when porting or modifying this code.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+
+#include <rtems.h>
+#include <bsp.h>
+#include "m68302.h"
+
+
+#define TMR2_VAL 0x071b	/* Timer mode register
+			 * (section 3.5.2.1 in 68302 manual)
+			 * 15-8: "7"	prescaler divide by 8 (x+1)
+			 *  7-6: 00	dis. intr. on capture event
+			 *    5:  0	active-low pulse
+			 *    4:  1	intr. on reaching reference
+			 *    3:  1	restart counter on reference
+			 *  2-1: 01	master clock input source
+			 *    0:  1	enable timer
+			 */
+#define TRR2_VAL 2000	/* Timer reference register
+			 * (section 3.5.2.2 in 68302 manual)
+			 * 2000 ticks @ (16MHz/1)/8 = 1-ms count
+			 */
+
+rtems_unsigned32 Timer_interrupts;
+
+rtems_boolean Timer_driver_Find_average_overhead;
+
+rtems_isr timerisr();
+
+void Timer_initialize( void )
+{
+    m302.reg.tmr2 = 0;			/* disable timer */
+
+    Timer_interrupts = 0;		/* clear timer ISR count */
+
+    m302.reg.trr2 = TRR2_VAL;		/* set timer reference register */
+    m302.reg.tmr2 = TMR2_VAL;		/* set timer mode register */
+    m302.reg.imr |= RBIT_IMR_TIMER2;	/* set 68302 int-mask to allow ints */
+}
+
+/*
+ *  The following controls the behavior of Read_timer().
+ *
+ *  FIND_AVG_OVERHEAD *  instructs the routine to return the "raw" count.
+ *
+ *  AVG_OVEREHAD is the overhead for starting and stopping the timer.  It
+ *  is usually deducted from the number returned.
+ *
+ *  LEAST_VALID is the lowest number this routine should trust.  Numbers
+ *  below this are "noise" and zero is returned.
+ */
+
+#define AVG_OVERHEAD      0  /* It typically takes X.X microseconds */
+                             /* (Y countdowns) to start/stop the timer. */
+                             /* This value is in microseconds. */
+#define LEAST_VALID       1  /* Don't trust a clicks value lower than this */
+
+/*
+ * Return timer value in 1/2-microsecond units
+ */
+int Read_timer( void )
+{
+  rtems_unsigned16 clicks;
+  rtems_unsigned32 total;
+
+  /*
+   *  Read the timer and see how many clicks it has been since counter
+   *  rolled over.
+   */
+
+  clicks = m302.reg.tcn2;
+
+  /*
+   *  Total is calculated by taking into account the number of timer overflow
+   *  interrupts since the timer was initialized and clicks since the last
+   *  interrupts.
+   */
+
+  total = (Timer_interrupts * TRR2_VAL) + clicks;
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in XXX microsecond units */
+
+  if ( total < LEAST_VALID )
+    return 0;            /* below timer resolution */
+
+  /*
+   *  Convert 1/2-microsecond count into microseconds
+   */
+
+  return (total - AVG_OVERHEAD) >> 1;
+}
+
+
+/*
+ *  Empty function call used in loops to measure basic cost of looping
+ *  in Timing Test Suite.
+ */
+
+rtems_status_code Empty_function(void)
+{
+    return RTEMS_SUCCESSFUL;
+}
+
+void Set_find_average_overhead(
+  rtems_boolean find_flag
+)
+{
+  Timer_driver_Find_average_overhead = find_flag;
+}