1 files changed, 98 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/powerpc/ppc403/timer/timer.c b/c/src/lib/libcpu/powerpc/ppc403/timer/timer.c
new file mode 100644
index 0000000000..9f266e847d
--- /dev/null
+++ b/c/src/lib/libcpu/powerpc/ppc403/timer/timer.c
@@ -0,0 +1,98 @@
+/*  timer.c
+ *
+ *  This file manages the interval timer on the PowerPC 403*.
+ *  We shall use the bottom 32 bits of the timebase register,
+ *
+ *  NOTE: It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  Author:	Andrew Bray <andy@i-cubed.co.uk>
+ *
+ *  COPYRIGHT (c) 1995 by i-cubed ltd.
+ *
+ *  To anyone who acknowledges that this file is provided "AS IS"
+ *  without any express or implied warranty:
+ *      permission to use, copy, modify, and distribute this file
+ *      for any purpose is hereby granted without fee, provided that
+ *      the above copyright notice and this notice appears in all
+ *      copies, and that the name of i-cubed limited not be used in
+ *      advertising or publicity pertaining to distribution of the
+ *      software without specific, written prior permission.
+ *      i-cubed limited makes no representations about the suitability
+ *      of this software for any purpose.
+ *
+ *  Derived from c/src/lib/libcpu/hppa1_1/timer/timer.c:
+ *
+ *  COPYRIGHT (c) 1989-1997.
+ *  On-Line Applications Research Corporation (OAR).
+ *  Copyright assigned to U.S. Government, 1994.
+ *
+ *  The license and distribution terms for this file may in
+ *  the file LICENSE in this distribution or at
+ *  http://www.OARcorp.com/rtems/license.html.
+ *
+ *  $Id$
+ */
+
+#include <bsp.h>
+#include <rtems.h>
+
+extern rtems_cpu_table           Cpu_table;             /* owned by BSP */
+
+static volatile rtems_unsigned32 Timer_starting;
+static rtems_boolean Timer_driver_Find_average_overhead;
+
+/*
+ *  This is so small that this code will be reproduced where needed.
+ */
+static inline rtems_unsigned32 get_itimer(void)
+{
+   rtems_unsigned32 ret;
+
+   asm volatile ("mfspr %0, 0x3dd" : "=r" ((ret))); /* TBLO */
+
+   return ret;
+}
+
+void Timer_initialize()
+{
+  rtems_unsigned32 iocr;
+
+  asm volatile ("mfdcr %0, 0xa0" : "=r" (iocr)); /* IOCR */
+  iocr &= ~4;
+  iocr |= 4;  /* Select external timer clock */
+  asm volatile ("mtdcr 0xa0, %0" : "=r" (iocr) : "0" (iocr)); /* IOCR */
+
+  Timer_starting = get_itimer();
+}
+
+int Read_timer()
+{
+  rtems_unsigned32 clicks;
+  rtems_unsigned32 total;
+
+  clicks = get_itimer();
+
+  total = clicks - Timer_starting;
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+    return total;          /* in XXX microsecond units */
+
+  else {
+    if ( total < Cpu_table.timer_least_valid )
+      return 0;            /* below timer resolution */
+    return (total - Cpu_table.timer_average_overhead);
+  }
+}
+
+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;
+}