bsps: Move benchmark timer to bsps

This patch is a part of the BSP source reorganization.

Update #3285.

1 files changed, 111 insertions, 0 deletions

diff --git a/bsps/lm32/shared/btimer/btimer.c b/bsps/lm32/shared/btimer/btimer.c
new file mode 100644
index 0000000000..e1980a7077
--- /dev/null
+++ b/bsps/lm32/shared/btimer/btimer.c
@@ -0,0 +1,111 @@
+/*  timer.c
+ *
+ *  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.
+ *
+ *  NOTE: It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  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.
+ *
+ *  Jukka Pietarinen <jukka.pietarinen@mrf.fi>, 2008,
+ *  Micro-Research Finland Oy
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <rtems/btimer.h>
+#include <rtems/bspIo.h>
+#include "../include/system_conf.h"
+#include "../../shared/clock/clock.h"
+
+static inline int timerread(unsigned int reg)
+{
+#if ON_SIMULATOR && defined(TIMER0_BASE_ADDRESS)
+  return *((int*)(TIMER0_BASE_ADDRESS + reg));
+#elif defined(TIMER1_BASE_ADDRESS)
+  return *((int*)(TIMER1_BASE_ADDRESS + reg));
+#else
+#warning "Benchmarking timer not available!"
+  return 0;
+#endif
+}
+
+static inline void timerwrite(unsigned int reg, int value)
+{
+#if ON_SIMULATOR && defined(TIMER0_BASE_ADDRESS)
+  *((int*)(TIMER0_BASE_ADDRESS + reg)) = value;
+#elif defined(TIMER1_BASE_ADDRESS)
+  *((int*)(TIMER1_BASE_ADDRESS + reg)) = value;
+#endif
+}
+
+bool benchmark_timer_find_average_overhead;
+
+void benchmark_timer_initialize( void )
+{
+  /* Set timer period */
+  timerwrite(LM32_CLOCK_PERIOD, 0xffffffff);
+  /* Stop timer */
+  timerwrite(LM32_CLOCK_CR, LM32_CLOCK_CR_STOP);
+  /* Clear status register */
+  timerwrite(LM32_CLOCK_SR, 0);
+  /* Start timer */
+  timerwrite(LM32_CLOCK_CR, LM32_CLOCK_CR_START);
+}
+
+/*
+ *  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      4  /* It typically takes X.X microseconds */
+                             /* (Y countdowns) to start/stop the timer. */
+                             /* This value is in microseconds. */
+#define LEAST_VALID       4  /* Don't trust a clicks value lower than this */
+
+benchmark_timer_t benchmark_timer_read( void )
+{
+  uint32_t ticks;
+  uint32_t total;
+  uint32_t status;
+
+  ticks = 0xffffffff - timerread(LM32_CLOCK_SNAPSHOT);
+  status = timerread(LM32_CLOCK_SR);
+  if (status & LM32_CLOCK_SR_TO)
+    printk("Timer overflow!\n");
+
+  total = ticks / (CPU_FREQUENCY / 1000000);
+
+  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;
+}