diff options
Diffstat (limited to 'c/src/lib/libbsp/sparc/leon3/timer/timer.c')
-rw-r--r-- | c/src/lib/libbsp/sparc/leon3/timer/timer.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/sparc/leon3/timer/timer.c b/c/src/lib/libbsp/sparc/leon3/timer/timer.c new file mode 100644 index 0000000000..63a3cd2058 --- /dev/null +++ b/c/src/lib/libbsp/sparc/leon3/timer/timer.c @@ -0,0 +1,82 @@ +/* timer.c + * + * This file implements a benchmark timer using timer 2. + * + * COPYRIGHT (c) 1989-1998. + * 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.com/license/LICENSE. + * + * Ported to LEON implementation of the SPARC by On-Line Applications + * Research Corporation (OAR) under contract to the European Space + * Agency (ESA). + * + * LEON modifications of respective RTEMS file: COPYRIGHT (c) 1995. + * European Space Agency. + * + * $Id$ + */ + + +#include <bsp.h> + +rtems_boolean Timer_driver_Find_average_overhead; + +rtems_boolean Timer_driver_Is_initialized = FALSE; + +extern volatile LEON3_Timer_Regs_Map *LEON3_Timer_Regs; + +void Timer_initialize() +{ + /* + * Timer runs long and accurate enough not to require an interrupt. + */ + if (LEON3_Timer_Regs) { + if ( Timer_driver_Is_initialized == FALSE ) { + /* approximately 1 us per countdown */ + LEON3_Timer_Regs->reload_t1 = 0xffffff; + LEON3_Timer_Regs->value_t1 = 0xffffff; + } else { + Timer_driver_Is_initialized = TRUE; + } + LEON3_Timer_Regs->conf_t1 = LEON3_GPTIMER_EN | LEON3_GPTIMER_LD; + } +} + +#define AVG_OVERHEAD 3 /* It typically takes 3.0 microseconds */ + /* to start/stop the timer. */ +#define LEAST_VALID 2 /* Don't trust a value lower than this */ + +int Read_timer() +{ + uint32_t total; + + if (LEON3_Timer_Regs) { + total = LEON3_Timer_Regs->value_t1; + + total = 0xffffff - total; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in one microsecond units */ + + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + + return total - AVG_OVERHEAD; + } + return 0; +} + +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; +} |