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Diffstat (limited to 'c/src/lib/libcpu/m68k/mcf5206/timer/timer.c')
| -rw-r--r-- | c/src/lib/libcpu/m68k/mcf5206/timer/timer.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/m68k/mcf5206/timer/timer.c b/c/src/lib/libcpu/m68k/mcf5206/timer/timer.c new file mode 100644 index 0000000000..82464753be --- /dev/null +++ b/c/src/lib/libcpu/m68k/mcf5206/timer/timer.c @@ -0,0 +1,175 @@ +/* + * Timer Init + * + * This module initializes TIMER 2 for on the MCF5206E for benchmarks. + * + * Copyright (C) 2000 OKTET Ltd., St.-Petersburg, Russia + * Author: Victor V. Vengerov <vvv@oktet.ru> + * + * Based on work: + * Author: + * David Fiddes, D.J@fiddes.surfaid.org + * http://www.calm.hw.ac.uk/davidf/coldfire/ + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * + * http://www.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + +#include <rtems.h> +#include <bsp.h> +#include "mcf5206/mcf5206e.h" + +#define TRR2_VAL 65530 + +rtems_unsigned32 Timer_interrupts; + +rtems_boolean Timer_driver_Find_average_overhead; + +/* External assembler interrupt handler routine */ +extern rtems_isr timerisr(rtems_vector_number vector); + + +/* Timer_initialize -- + * Initialize timer 2 for accurate time measurement. + * + * PARAMETERS: + * none + * + * RETURNS: + * none + */ +void +Timer_initialize(void) +{ + /* Catch timer2 interrupts */ + set_vector(timerisr, BSP_INTVEC_TIMER2, 0); + + /* Initialize interrupts for timer2 */ + *MCF5206E_ICR(MBAR, MCF5206E_INTR_TIMER_2) = + MCF5206E_ICR_AVEC | + ((BSP_INTLVL_TIMER2 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) | + ((BSP_INTPRIO_TIMER2 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP); + + /* Enable interrupts from timer2 */ + *MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_2); + + /* Reset Timer */ + *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_RST; + *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_ICLK_STOP; + *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_RST; + *MCF5206E_TCN(MBAR, 2) = 0; /* Zero timer counter */ + Timer_interrupts = 0; /* Clear timer ISR counter */ + *MCF5206E_TER(MBAR, 2) = MCF5206E_TER_REF | MCF5206E_TER_CAP; /*clr pend*/ + *MCF5206E_TRR(MBAR, 2) = TRR2_VAL - 1; + *MCF5206E_TMR(MBAR, 2) = + (((BSP_SYSTEM_FREQUENCY / 1000000) << MCF5206E_TMR_PS_S) & + MCF5206E_TMR_PS) | + MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR | + MCF5206E_TMR_RST; + *MCF5206E_TMR(MBAR, 2) |= MCF5206E_TMR_ICLK_MSCLK; +} + +/* + * 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 2.0 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 */ + +/* Read_timer -- + * Read timer value in microsecond units since timer start. + * + * PARAMETERS: + * none + * + * RETURNS: + * number of microseconds since timer has been started + */ +int +Read_timer( void ) +{ + rtems_unsigned16 clicks; + rtems_unsigned32 total; + + /* + * Read the timer and see how many clicks it has been since counter + * rolled over. + */ + clicks = *MCF5206E_TCN(MBAR, 2); + + /* Stop Timer... */ + *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_ICLK_STOP | + MCF5206E_TMR_RST; + + /* + * Total is calculated by taking into account the number of timer + * overflow interrupts since the timer was initialized and clicks + * since the last interrupts. + */ + + total = (Timer_interrupts * TRR2_VAL) + clicks; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in XXX microsecond units */ + + if ( total < LEAST_VALID ) + return 0; /* below timer resolution */ + + /* + * Return the count in microseconds + */ + return (total - AVG_OVERHEAD); +} + + +/* Empty_function -- + * Empty function call used in loops to measure basic cost of looping + * in Timing Test Suite. + * + * PARAMETERS: + * none + * + * RETURNS: + * RTEMS_SUCCESSFUL + */ +rtems_status_code +Empty_function(void) +{ + return RTEMS_SUCCESSFUL; +} + +/* Set_find_average_overhead -- + * This routine is invoked by the "Check Timer" (tmck) test in the + * RTEMS Timing Test Suite. It makes the Read_timer routine not + * subtract the overhead required to initialize and read the benchmark + * timer. + * + * PARAMETERS: + * find_flag - boolean flag, TRUE if overhead must not be subtracted. + * + * RETURNS: + * none + */ +void +Set_find_average_overhead(rtems_boolean find_flag) +{ + Timer_driver_Find_average_overhead = find_flag; +} |