1 files changed, 113 insertions, 0 deletions
diff --git a/bsps/mips/shared/timer/timer.c b/bsps/mips/shared/timer/timer.c
new file mode 100644
index 0000000000..da5291a48a
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+++ b/bsps/mips/shared/timer/timer.c
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+/**
+ *  @file
+ *  @brief IDT 4650 Timer Driver.
+ *
+ *  This file manages the benchmark timer used by the RTEMS Timing Test
+ *  Suite.
+ */
+
+/*
+ *  Author:     Craig Lebakken <craigl@transition.com>
+ *
+ *  COPYRIGHT (c) 1996 by Transition Networks Inc.
+ *
+ *  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 Transition Networks not be used in
+ *      advertising or publicity pertaining to distribution of the
+ *      software without specific, written prior permission.
+ *      Transition Networks makes no representations about the suitability
+ *      of this software for any purpose.
+ *
+ *  derived from src/lib/libbsp/no_cpu/no_bsp/timer/timer.c
+ *
+ *  COPYRIGHT (c) 1989-1999.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+
+#include <rtems.h>
+#include <rtems/btimer.h>
+
+#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ )
+#define TIMER_MAX_VALUE 0xffffffff
+
+extern uint32_t   mips_read_timer( void );
+
+static bool benchmark_timer_find_average_overhead;
+static uint32_t   benchmark_timer_initial_value = 0;
+
+void benchmark_timer_initialize( void )
+{
+   benchmark_timer_initial_value = mips_read_timer();
+  /*
+   *  Somehow start the timer
+   */
+
+  /* Timer on 4650 is always running */
+}
+
+/*
+ *  The following controls the behavior of benchmark_timer_read().
+ *
+ *  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      8  /* It typically takes X.X microseconds */
+                             /* (Y countdowns) to start/stop the timer. */
+                             /* This value is in cycles. */
+#define LEAST_VALID       1  /* Don't trust a clicks value lower than this */
+
+benchmark_timer_t benchmark_timer_read( void )
+{
+  uint64_t   clicks;
+  uint32_t   total;
+
+  /*
+   *  Read the timer and see how many clicks it has been since we started.
+   */
+
+  clicks = mips_read_timer();   /* XXX: read some HW here */
+  if (clicks < benchmark_timer_initial_value)
+  {
+      clicks += TIMER_MAX_VALUE;
+  }
+  clicks -= benchmark_timer_initial_value;
+
+  /*
+   *  Total is calculated by taking into account the number of timer overflow
+   *  interrupts since the timer was initialized and clicks since the last
+   *  interrupts.
+   */
+#if 0 /* leave total in number of cycles */
+   total = clicks / CLOCKS_PER_MICROSECOND;
+#else
+   total = clicks;
+#endif
+
+  if ( benchmark_timer_find_average_overhead == 1 )
+    return total;          /* in # cycles units */
+  else {
+    if ( total < LEAST_VALID )
+      return 0;            /* below timer resolution */
+  /*
+   *  leave total in cycles
+   */
+      return (total - AVG_OVERHEAD);
+    }
+}
+
+void benchmark_timer_disable_subtracting_average_overhead(bool find_flag)
+{
+  benchmark_timer_find_average_overhead = find_flag;
+}