1 files changed, 67 insertions, 0 deletions
diff --git a/bsps/mips/jmr3904/btimer/btimer.c b/bsps/mips/jmr3904/btimer/btimer.c
new file mode 100644
index 0000000000..ca97cd3a0b
--- /dev/null
+++ b/bsps/mips/jmr3904/btimer/btimer.c
@@ -0,0 +1,67 @@
+/*
+ *  This file implements a benchmark timer using a TX39 timer.
+ *
+ *  NOTE: On the simulator, the count directly reflects instructions.
+ *
+ *  COPYRIGHT (c) 1989-2000.
+ *  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 <assert.h>
+
+#include <bsp.h>
+#include <rtems/btimer.h>
+
+bool benchmark_timer_find_average_overhead;
+
+void benchmark_timer_initialize(void)
+{
+  /*
+   *  Programming the compare register as the maximum value should let
+   *  it run long enough and accurate enough not to require an interrupt.
+   *  but if it ever does generate an interrupt, we will simply fault.
+   *
+   *  NOTE:  This is similar to the clock driver initialization
+   *         with the exception that the divider is disabled and
+   *         the compare register is set to the maximum value.
+   */
+
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TCR,   0x20 );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_CCDR, 0x3 );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TRR, 0x0 );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_CPRA, 0xFFFFFFFF );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TISR, 0x00 );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_ITMR, 0x0001 );
+  TX3904_TIMER_WRITE( TX3904_TIMER1_BASE, TX3904_TIMER_TCR,   0xe0 );
+}
+
+#define AVG_OVERHEAD      0  /* It typically takes N instructions */
+                             /*     to start/stop the timer. */
+#define LEAST_VALID       1  /* Don't trust a value lower than this */
+                             /* tx39 simulator can count instructions. :) */
+
+benchmark_timer_t benchmark_timer_read(void)
+{
+  uint32_t          total;
+
+  total = TX3904_TIMER_READ( TX3904_TIMER1_BASE, TX3904_TIMER_TRR );
+
+  if ( benchmark_timer_find_average_overhead == true )
+    return total;          /* in one microsecond units */
+
+  if ( total < LEAST_VALID )
+    return 0;            /* below timer resolution */
+
+  return total - AVG_OVERHEAD;
+}
+
+void benchmark_timer_disable_subtracting_average_overhead(
+  bool find_flag
+)
+{
+  benchmark_timer_find_average_overhead = find_flag;
+}