diff options
author | Joel Sherrill <joel.sherrill@OARcorp.com> | 1995-09-20 15:05:19 +0000 |
---|---|---|
committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 1995-09-20 15:05:19 +0000 |
commit | 486c329f2b4f95dbfefdcbefbe6b25adf7895a94 (patch) | |
tree | e98ee376985db23cf7f6f7da3ba5fe5e63327dbb /c/src/lib/libbsp/m68k/efi332/timer/timer.c | |
parent | Heap changes required some changes in this screen. (diff) | |
download | rtems-486c329f2b4f95dbfefdcbefbe6b25adf7895a94.tar.bz2 |
Actually adding efi bsp's from John Gwynne after forgetting to
commit them.
Diffstat (limited to '')
-rw-r--r-- | c/src/lib/libbsp/m68k/efi332/timer/timer.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/efi332/timer/timer.c b/c/src/lib/libbsp/m68k/efi332/timer/timer.c new file mode 100644 index 0000000000..7a9b1b6267 --- /dev/null +++ b/c/src/lib/libbsp/m68k/efi332/timer/timer.c @@ -0,0 +1,84 @@ +/* Timer_init() + * + * This routine initializes a timer in efi68k's DP8570A TCP + * + * Input parameters: NONE + * + * Output parameters: NONE + * + * NOTE: It is important that the timer start/stop overhead be + * determined when porting or modifying this code. + * + * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. + * On-Line Applications Research Corporation (OAR). + * All rights assigned to U.S. Government, 1994. + * + * This material may be reproduced by or for the U.S. Government pursuant + * to the copyright license under the clause at DFARS 252.227-7013. This + * notice must appear in all copies of this file and its derivatives. + * + * $Id$ + */ + + +#include <bsp.h> + +rtems_boolean Timer_driver_Find_average_overhead; + +extern rtems_isr Clock_isr(); + +void Timer_initialize( void ) +{ +} + +/* + * The following controls the behavior of Read_timer(). + * + * FIND_AVG_OVERHEAD * instructs the routine to return the "raw" count. + * + * 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 */ + +/* + * Return timer value in 1/2-microsecond units + */ +int Read_timer( void ) +{ + rtems_unsigned32 total; + total = 0; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in XXX microsecond units */ + + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + + return (total - AVG_OVERHEAD); +} + + +/* + * Empty function call used in loops to measure basic cost of looping + * in Timing Test Suite. + */ + +rtems_status_code Empty_function(void) +{ + return RTEMS_SUCCESSFUL; +} + +void Set_find_average_overhead( + rtems_boolean find_flag +) +{ + Timer_driver_Find_average_overhead = find_flag; +} |