1 files changed, 152 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/powerpc/dmv177/timer/timer.c b/c/src/lib/libbsp/powerpc/dmv177/timer/timer.c
new file mode 100644
index 0000000000..72d1bb79a3
--- /dev/null
+++ b/c/src/lib/libbsp/powerpc/dmv177/timer/timer.c
@@ -0,0 +1,152 @@
+/*  timer.c
+ *
+ *  This file implements a benchmark timer using the General Purpose Timer on
+ *  the MEC.
+ *
+ *  The license and distribution terms for this file are in
+ *  the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#include <assert.h>
+
+#include <bsp.h>
+
+rtems_unsigned64 Timer_driver_Start_time;
+
+rtems_boolean Timer_driver_Find_average_overhead;
+
+static inline rtems_unsigned64 PPC_Get_timebase_register( void )
+{
+  rtems_unsigned32 tbr_low;
+  rtems_unsigned32 tbr_high;
+  rtems_unsigned32 tbr_high_old;
+  rtems_unsigned64 tbr;
+
+  do {
+    asm volatile( "mftbu %0" : "=r" (tbr_high_old));
+    asm volatile( "mftb  %0" : "=r" (tbr_low));
+    asm volatile( "mftbu %0" : "=r" (tbr_high));
+  } while ( tbr_high_old != tbr_high );
+
+  tbr = tbr_high;
+  tbr <<= 32;
+  tbr |= tbr_low;
+  return tbr;
+}
+
+/*  PAGE
+ *
+ *  Timer_initialize
+ *  
+ *  This routine initializes the timer.  
+ *
+ *  Input parameters:   NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  Return values:      NONE
+ *
+ */
+
+void Timer_initialize()
+{
+  /*
+   *  Timer runs long and accurate enough not to require an interrupt.
+   */
+
+
+  Timer_driver_Start_time = PPC_Get_timebase_register();
+  
+
+}
+
+#define AVG_OVERHEAD     24  /* It typically takes 24 instructions */
+                             /*     to start/stop the timer. */
+#define LEAST_VALID       1  /* Don't trust a value lower than this */
+                             /* psim can count instructions. :) */
+
+/*  PAGE
+ *
+ *  Read_timer
+ *
+ *  This routine reads the timer.
+ *
+ *  Input parameters:   NONE
+ *
+ *  Output parameters:  NONE
+ *
+ *  Return values:      timer in ms units
+ *
+ */
+
+int Read_timer()
+{
+  rtems_unsigned64  clicks;
+  rtems_unsigned64  total64;
+  rtems_unsigned32  total;
+
+  /* approximately CLOCK_SPEED clicks per microsecond */
+
+  clicks = PPC_Get_timebase_register();
+
+  assert( clicks > Timer_driver_Start_time );
+
+  total64 = clicks - Timer_driver_Start_time;
+
+  assert( total64 <= 0xffffffff );  /* fits into a unsigned32 */
+
+  total = (rtems_unsigned32) total64;
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in one microsecond units */
+
+  if ( total < LEAST_VALID )
+    return 0;            /* below timer resolution */
+
+  return total - AVG_OVERHEAD;
+}
+
+/*  PAGE
+ *
+ *  Empty_function
+ *
+ *  This routine is called during the idle loop.
+ *
+ *  Input parameters:   NONE
+ *
+ *  Output parameters:  
+ *    status code of successful
+ *
+ *  Return values:      NONE
+ *
+ */
+
+rtems_status_code Empty_function( void )
+{
+  return RTEMS_SUCCESSFUL;
+}
+
+/*  PAGE
+ *
+ *  Set_find_average_overhead
+ *
+ *  This routine sets a global boolean to the value passed in.
+ *
+ *  Input parameters: 
+ *    find_flag  - flag to indicate to find the average overhead.
+ *
+ *  Output parameters:  NONE
+ *
+ *  Return values:      NONE
+ *
+ */
+
+void Set_find_average_overhead(
+  rtems_boolean find_flag
+)
+{
+  Timer_driver_Find_average_overhead = find_flag;
+}