bsps: Move benchmark timer to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

bsps/arm/csb337/btimer/btimer.c

@@ -0,0 +1,91 @@
+/**
+ * @file
+ * @brief Cogent CSB337 Timer driver
+ *
+ * This uses timer 0 for timing measurments.
+ */
+
+/*
+ *  Copyright (c) 2004 by Jay Monkman <jtm@lopingdog.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.
+ */
+
+#include <bsp.h>
+#include <rtems.h>
+#include <rtems/btimer.h>
+#include <at91rm9200.h>
+#include <at91rm9200_pmc.h>
+
+uint16_t tstart;
+bool benchmark_timer_find_average_overhead;
+uint32_t tick_time;
+/*
+ * Set up TC0 -
+ *   timer_clock2 (MCK/8)
+ *   capture mode - this shouldn't matter
+ */
+void benchmark_timer_initialize( void )
+{
+    uint32_t tmr_freq;
+
+    /* since we are using timer_clock2, divide mck by 8 */
+    tmr_freq = at91rm9200_get_mck() / 8;
+
+    TC_TC0_REG(TC_CMR) = TC_CMR_TCCLKS(1);   /* timer_clock2 */
+    TC_TC0_REG(TC_CCR) = (TC_CCR_CLKEN       /* enable the counter */
+                          | TC_CCR_SWTRG);   /* start it up */
+
+    /* tick time in nanoseconds */
+    tick_time = 1000000000/tmr_freq;
+
+}
+
+/*
+ *  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 = TC_TC0_REG(TC_CV);
+
+  /*
+   *  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 = t * tick_time;
+
+  if ( benchmark_timer_find_average_overhead == 1 )
+    return total;          /* in nanosecond 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;
+}
+