bsps: Move benchmark timer to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

1 files changed, 80 insertions, 0 deletions

diff --git a/bsps/arm/edb7312/btimer/btimer.c b/bsps/arm/edb7312/btimer/btimer.c
new file mode 100644
index 0000000000..b795122ff3
--- /dev/null
+++ b/bsps/arm/edb7312/btimer/btimer.c
@@ -0,0 +1,80 @@
+/*
+ * Cirrus EP7312 Timer driver
+ *
+ * Copyright (c) 2002 by Jay Monkman <jtm@smoothsmoothie.com>
+ *
+ *  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.
+ *
+ * Notes:
+ *  This file manages the benchmark timer used by the RTEMS Timing Test
+ *  Suite.  Each measured time period is demarcated by calls to
+ *  benchmark_timer_initialize() and benchmark_timer_read().  benchmark_timer_read() usually returns
+ *  the number of microseconds since benchmark_timer_initialize() exitted.
+ *
+ *  It is important that the timer start/stop overhead be determined
+ *  when porting or modifying this code.
+*/
+
+#include <rtems.h>
+#include <bsp.h>
+#include <rtems/btimer.h>
+#include <ep7312.h>
+
+uint16_t         tstart;
+bool benchmark_timer_find_average_overhead;
+
+void benchmark_timer_initialize( void )
+{
+    *EP7312_SYSCON1 |= EP7312_SYSCON1_TC2_512KHZ;
+    *EP7312_TC2D = 0xffff;
+}
+
+/*
+ *  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      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 */
+
+benchmark_timer_t benchmark_timer_read( void )
+{
+  uint16_t         t;
+  uint32_t         total;
+  t = *EP7312_TC2D;
+
+  /*
+   *  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 = (uint32_t)0x0000ffff - t;  /* result is 1/512000 = ~2 uS */
+  total = (total * 1953) / 1000;   /* convert to uS */
+  if ( benchmark_timer_find_average_overhead == true )
+    return total;          /* in XXX microsecond units */
+  else {
+    if ( total < LEAST_VALID )
+      return 0;            /* below timer resolution */
+  /*
+   *  Somehow convert total into microseconds
+   */
+      return (total - AVG_OVERHEAD);
+    }
+}
+
+void benchmark_timer_disable_subtracting_average_overhead(
+  bool find_flag
+)
+{
+  benchmark_timer_find_average_overhead = find_flag;
+}