[00717a3] | 1 | /* |
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| 2 | * Timer Init |
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| 3 | * |
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| 4 | * This module initializes TIMER 2 for on the MCF5206E for benchmarks. |
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| 5 | * |
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| 6 | * Copyright (C) 2000 OKTET Ltd., St.-Petersburg, Russia |
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| 7 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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| 8 | * |
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| 9 | * Based on work: |
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| 10 | * Author: |
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| 11 | * David Fiddes, D.J@fiddes.surfaid.org |
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| 12 | * http://www.calm.hw.ac.uk/davidf/coldfire/ |
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| 13 | * |
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| 14 | * COPYRIGHT (c) 1989-1998. |
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| 15 | * On-Line Applications Research Corporation (OAR). |
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| 16 | * Copyright assigned to U.S. Government, 1994. |
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| 17 | * |
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| 18 | * The license and distribution terms for this file may be |
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| 19 | * found in the file LICENSE in this distribution or at |
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| 20 | * |
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| 21 | * http://www.OARcorp.com/rtems/license.html. |
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| 22 | * |
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| 23 | * $Id$ |
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| 24 | */ |
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| 25 | |
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| 26 | #include <rtems.h> |
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| 27 | #include <bsp.h> |
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| 28 | #include "mcf5206/mcf5206e.h" |
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| 29 | |
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| 30 | #define TRR2_VAL 65530 |
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| 31 | |
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| 32 | rtems_unsigned32 Timer_interrupts; |
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| 33 | |
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| 34 | rtems_boolean Timer_driver_Find_average_overhead; |
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| 35 | |
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| 36 | /* External assembler interrupt handler routine */ |
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| 37 | extern rtems_isr timerisr(rtems_vector_number vector); |
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| 38 | |
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| 39 | |
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| 40 | /* Timer_initialize -- |
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| 41 | * Initialize timer 2 for accurate time measurement. |
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| 42 | * |
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| 43 | * PARAMETERS: |
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| 44 | * none |
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| 45 | * |
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| 46 | * RETURNS: |
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| 47 | * none |
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| 48 | */ |
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| 49 | void |
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| 50 | Timer_initialize(void) |
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| 51 | { |
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| 52 | /* Catch timer2 interrupts */ |
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| 53 | set_vector(timerisr, BSP_INTVEC_TIMER2, 0); |
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| 54 | |
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| 55 | /* Initialize interrupts for timer2 */ |
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| 56 | *MCF5206E_ICR(MBAR, MCF5206E_INTR_TIMER_2) = |
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| 57 | MCF5206E_ICR_AVEC | |
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| 58 | ((BSP_INTLVL_TIMER2 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) | |
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| 59 | ((BSP_INTPRIO_TIMER2 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP); |
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| 60 | |
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| 61 | /* Enable interrupts from timer2 */ |
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| 62 | *MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_2); |
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| 63 | |
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| 64 | /* Reset Timer */ |
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| 65 | *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_RST; |
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| 66 | *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_ICLK_STOP; |
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| 67 | *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_RST; |
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| 68 | *MCF5206E_TCN(MBAR, 2) = 0; /* Zero timer counter */ |
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| 69 | Timer_interrupts = 0; /* Clear timer ISR counter */ |
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| 70 | *MCF5206E_TER(MBAR, 2) = MCF5206E_TER_REF | MCF5206E_TER_CAP; /*clr pend*/ |
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| 71 | *MCF5206E_TRR(MBAR, 2) = TRR2_VAL - 1; |
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| 72 | *MCF5206E_TMR(MBAR, 2) = |
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| 73 | (((BSP_SYSTEM_FREQUENCY / 1000000) << MCF5206E_TMR_PS_S) & |
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| 74 | MCF5206E_TMR_PS) | |
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| 75 | MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR | |
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| 76 | MCF5206E_TMR_RST; |
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| 77 | *MCF5206E_TMR(MBAR, 2) |= MCF5206E_TMR_ICLK_MSCLK; |
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| 78 | } |
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| 79 | |
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| 80 | /* |
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| 81 | * The following controls the behavior of Read_timer(). |
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| 82 | * |
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| 83 | * FIND_AVG_OVERHEAD * instructs the routine to return the "raw" count. |
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| 84 | * |
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| 85 | * AVG_OVEREHAD is the overhead for starting and stopping the timer. It |
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| 86 | * is usually deducted from the number returned. |
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| 87 | * |
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| 88 | * LEAST_VALID is the lowest number this routine should trust. Numbers |
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| 89 | * below this are "noise" and zero is returned. |
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| 90 | */ |
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| 91 | |
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| 92 | #define AVG_OVERHEAD 0 /* It typically takes 2.0 microseconds */ |
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| 93 | /* (Y countdowns) to start/stop the timer. */ |
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| 94 | /* This value is in microseconds. */ |
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| 95 | #define LEAST_VALID 1 /* Don't trust a clicks value lower than this */ |
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| 96 | |
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| 97 | /* Read_timer -- |
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| 98 | * Read timer value in microsecond units since timer start. |
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| 99 | * |
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| 100 | * PARAMETERS: |
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| 101 | * none |
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| 102 | * |
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| 103 | * RETURNS: |
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| 104 | * number of microseconds since timer has been started |
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| 105 | */ |
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| 106 | int |
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| 107 | Read_timer( void ) |
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| 108 | { |
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| 109 | rtems_unsigned16 clicks; |
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| 110 | rtems_unsigned32 total; |
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| 111 | |
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| 112 | /* |
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| 113 | * Read the timer and see how many clicks it has been since counter |
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| 114 | * rolled over. |
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| 115 | */ |
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| 116 | clicks = *MCF5206E_TCN(MBAR, 2); |
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| 117 | |
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| 118 | /* Stop Timer... */ |
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| 119 | *MCF5206E_TMR(MBAR, 2) = MCF5206E_TMR_ICLK_STOP | |
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| 120 | MCF5206E_TMR_RST; |
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| 121 | |
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| 122 | /* |
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| 123 | * Total is calculated by taking into account the number of timer |
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| 124 | * overflow interrupts since the timer was initialized and clicks |
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| 125 | * since the last interrupts. |
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| 126 | */ |
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| 127 | |
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| 128 | total = (Timer_interrupts * TRR2_VAL) + clicks; |
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| 129 | |
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| 130 | if ( Timer_driver_Find_average_overhead == 1 ) |
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| 131 | return total; /* in XXX microsecond units */ |
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| 132 | |
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| 133 | if ( total < LEAST_VALID ) |
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| 134 | return 0; /* below timer resolution */ |
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| 135 | |
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| 136 | /* |
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| 137 | * Return the count in microseconds |
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| 138 | */ |
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| 139 | return (total - AVG_OVERHEAD); |
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| 140 | } |
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| 141 | |
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| 142 | |
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| 143 | /* Empty_function -- |
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| 144 | * Empty function call used in loops to measure basic cost of looping |
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| 145 | * in Timing Test Suite. |
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| 146 | * |
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| 147 | * PARAMETERS: |
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| 148 | * none |
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| 149 | * |
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| 150 | * RETURNS: |
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| 151 | * RTEMS_SUCCESSFUL |
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| 152 | */ |
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| 153 | rtems_status_code |
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| 154 | Empty_function(void) |
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| 155 | { |
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| 156 | return RTEMS_SUCCESSFUL; |
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| 157 | } |
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| 158 | |
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| 159 | /* Set_find_average_overhead -- |
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| 160 | * This routine is invoked by the "Check Timer" (tmck) test in the |
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| 161 | * RTEMS Timing Test Suite. It makes the Read_timer routine not |
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| 162 | * subtract the overhead required to initialize and read the benchmark |
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| 163 | * timer. |
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| 164 | * |
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| 165 | * PARAMETERS: |
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| 166 | * find_flag - boolean flag, TRUE if overhead must not be subtracted. |
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| 167 | * |
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| 168 | * RETURNS: |
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| 169 | * none |
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| 170 | */ |
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| 171 | void |
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| 172 | Set_find_average_overhead(rtems_boolean find_flag) |
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| 173 | { |
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| 174 | Timer_driver_Find_average_overhead = find_flag; |
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| 175 | } |
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