1 files changed, 141 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/efi68k/timer/timer.c b/c/src/lib/libbsp/m68k/efi68k/timer/timer.c
new file mode 100644
index 0000000000..b53e31ec0d
--- /dev/null
+++ b/c/src/lib/libbsp/m68k/efi68k/timer/timer.c
@@ -0,0 +1,141 @@
+/*  Timer_init()
+ *
+ *  This routine initializes a timer in efi68k's DP8570A TCP
+ *
+ *  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 <bsp.h>
+
+rtems_boolean Timer_driver_Find_average_overhead;
+
+extern rtems_isr Clock_isr();
+
+void Timer_initialize( void )
+{
+  /* stop counter */
+  *MSR = 0;
+  *T0CR = 0;
+
+  /*
+   * Make sure isr is installed
+   */
+
+  set_vector( Clock_isr, TCP_ISR_LEVEL+24, 1);
+
+  /* clear timer ISR count */
+  Timer_interrupts = 0;
+
+  /* load count (count down timer) */
+  *MSR = 0;
+  *T0_MSB = 0xff;
+  *T0_LSB = 0xff;
+
+  /* clear old interrupts */
+  *MSR = T0;
+
+  /* enable timer 0 interrupt */
+  *MSR = RS;
+  *ICR0 |= T0E;
+
+  /* 
+     TSS = 1        starts the timer (timer resets on start)
+     M1/0 = 0/1     rate generator
+     C2/1/0 = 0/0/0 external clock (8MHz) (1/8 usec resolution)
+     RD = 0         read data (latchs count)
+     CHG = 0        hold
+   */
+  *MSR = 0;
+  *T0CR = (TSS | M0);
+}
+
+/*
+ *  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;
+  rtems_unsigned32 msb, lsb;
+
+
+  /*
+   *  Read the timer and see how many clicks it has been since counter
+   *  rolled over.
+   */
+
+  *MSR = 0;
+  *T0CR |= RD;
+  /* must read MSB first */  
+  msb = *T0_MSB;
+  lsb = *T0_LSB;
+  clicks = 0xffff - ((msb << 8) | lsb);
+
+  /*
+   *  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 * 0x10000 + clicks + 4)/8; /* in micoseconds */
+  /*                                            ^^^ round to nearest int */
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in XXX microsecond units */
+
+  if ( total < LEAST_VALID )
+    return 0;            /* below timer resolution */
+
+  return (total - AVG_OVERHEAD);
+}
+
+
+/*
+ *  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;
+}