1 files changed, 149 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/gba/timer/timer.c b/c/src/lib/libbsp/arm/gba/timer/timer.c
new file mode 100644
index 0000000000..ee61df823d
--- /dev/null
+++ b/c/src/lib/libbsp/arm/gba/timer/timer.c
@@ -0,0 +1,149 @@
+/**
+ *  @file timer.c
+ *
+ *  GBA Timer driver.
+ */
+/*
+ *  RTEMS GBA BSP
+ *
+ *  Copyright (c) 2002 by Jay Monkman <jtm@smoothsmoothie.com>
+ *
+ *  Copyright (c) 2004  Markku Puro <markku.puro@kopteri.net>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/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
+ *  Timer_initialize() and Read_timer().  Read_timer() usually returns
+ *  the number of microseconds since Timer_initialize() exitted.
+ *
+ *  It is important that the timer start/stop overhead be determined
+ *  when porting or modifying this code.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+#include <bsp.h>
+#include <irq.h>
+#include <gba.h>
+
+/*
+ * Set up the timer hardware
+ *    1 / 16.78Mhz  => 59.595 ns
+ *   64 / 16.78Mhz  =>  3.814 us
+ *  256 / 16.78Mhz  => 15.256 us
+ * 1024 / 16.78Mhz  => 61.025 us
+ */
+#define  __TimePreScaler      1
+#define  __TickTime_ns        ((1000000000L/__ClockFrequency)*__TimePreScaler)
+#define  __TickTime_us        ((1000000L/__ClockFrequency)*__TimePreScaler)
+
+#if (__TimePreScaler==1)
+ #define GBA_TM0CNT_PS    0x0000
+#elif (__TimePreScaler==64)
+ #define GBA_TM0CNT_PS    0x0001
+#elif (__TimePreScaler==256)
+ #define GBA_TM0CNT_PS    0x0002
+#elif (__TimePreScaler==1024)
+ #define GBA_TM0CNT_PS    0x0003
+#else
+ #define GBA_TM0CNT_PS    0x0003
+#endif
+
+rtems_boolean  Timer_driver_Find_average_overhead;
+
+/**
+ *  @brief Timer_initialize start TM0 and TM1
+ *
+ *  @param  None
+ *  @return None
+ */
+void Timer_initialize( void )
+{
+  GBA_REG_TM1CNT =  0x0000;                /* Stop Counters         */
+  GBA_REG_TM0CNT =  0x0000;
+  GBA_REG_TM1D   =  0x0000;                /* Reset Counters        */
+  GBA_REG_TM0D   =  0x0000;
+  /* Start Counters */
+  GBA_REG_TM1CNT =  0x0084;                /* Start Count Up timing */
+  GBA_REG_TM0CNT = (0x0080|GBA_TM0CNT_PS); /* Start Count           */
+}
+
+/*
+ *  The following controls the behavior of Read_timer().
+ *
+ *  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    3  /**< It typically takes 3 microseconds          */
+#define LEAST_VALID     1  /**< Don't trust a clicks value lower than this */
+
+/**
+ *  @brief Read_timer return timer countervalue in microseconds.
+ *
+ *  Used in Timing Test Suite.
+ *
+ *  @param  None
+ *  @return Timer value in microseconds
+ */
+uint32_t Read_timer( void )
+{
+  uint32_t  ticks;
+  uint32_t  total;
+
+  /* Stop Counters */
+  GBA_REG_TM0CNT =  0x0000;
+  GBA_REG_TM1CNT =  0x0000;
+  /* Read Counters */
+  ticks = (GBA_REG_TM1D<<16) | GBA_REG_TM0D;
+  if ( ticks < LEAST_VALID ) {
+      return 0;  /* below timer resolution */
+  }
+  /* convert to uS */
+  total = ((ticks * __TickTime_ns) / 1000);
+  if ( Timer_driver_Find_average_overhead == 1 ) {
+      return total;          /* in microseconds */
+  }
+  else {
+    if ( total < AVG_OVERHEAD ) {
+        return 0;
+    }
+    return (total - AVG_OVERHEAD);
+  }
+}
+
+/**
+ *  @brief Empty function
+ *
+ *  Empty function call used in loops to measure basic cost of looping
+ *  in Timing Test Suite.
+ *
+ *  @param  None
+ *  @return RTEMS_SUCCESSFUL
+*/
+rtems_status_code Empty_function( void )
+{
+   return RTEMS_SUCCESSFUL;
+}
+
+/**
+ *  @brief Set Timer_driver_Find_average_overhead flag.
+ *
+ *  Used in Timing Test Suite.
+ *
+ *  @param  find_flag boolean find_flag
+ *  @return None
+*/
+void Set_find_average_overhead(rtems_boolean find_flag)
+{
+   Timer_driver_Find_average_overhead = find_flag;
+}