[572484f] | 1 | /* |
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| 2 | * Use the last periodic interval timer (PIT3) as the system clock. |
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| 3 | * |
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[12b36efe] | 4 | * Author: W. Eric Norum <norume@aps.anl.gov> |
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| 5 | * |
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| 6 | * COPYRIGHT (c) 2005. |
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| 7 | * On-Line Applications Research Corporation (OAR). |
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| 8 | * |
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| 9 | * The license and distribution terms for this file may be |
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| 10 | * found in the file LICENSE in this distribution or at |
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[c499856] | 11 | * http://www.rtems.org/license/LICENSE. |
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[572484f] | 12 | */ |
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| 13 | |
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| 14 | #include <rtems.h> |
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[75acd9e] | 15 | #include <rtems/timecounter.h> |
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[572484f] | 16 | #include <bsp.h> |
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| 17 | #include <mcf5282/mcf5282.h> |
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| 18 | |
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[76ac1ee3] | 19 | /* |
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| 20 | * CPU load counters |
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| 21 | * Place in static RAM so updates don't hit the SDRAM |
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| 22 | */ |
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| 23 | #define IDLE_COUNTER __SRAMBASE.idle_counter |
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| 24 | #define FILTERED_IDLE __SRAMBASE.filtered_idle |
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| 25 | #define MAX_IDLE_COUNT __SRAMBASE.max_idle_count |
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| 26 | #define PITC_PER_TICK __SRAMBASE.pitc_per_tick |
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| 27 | #define NSEC_PER_PITC __SRAMBASE.nsec_per_pitc |
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| 28 | #define FILTER_SHIFT 6 |
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| 29 | |
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[572484f] | 30 | /* |
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| 31 | * Use INTC0 base |
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| 32 | */ |
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| 33 | #define CLOCK_VECTOR (64+58) |
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| 34 | |
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[75acd9e] | 35 | static rtems_timecounter_simple uC5282_tc; |
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| 36 | |
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| 37 | static uint32_t uC5282_tc_get(rtems_timecounter_simple *tc) |
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| 38 | { |
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| 39 | return MCF5282_PIT3_PCNTR; |
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| 40 | } |
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| 41 | |
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| 42 | static bool uC5282_tc_is_pending(rtems_timecounter_simple *tc) |
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| 43 | { |
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| 44 | return (MCF5282_PIT3_PCSR & MCF5282_PIT_PCSR_PIF) != 0; |
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| 45 | } |
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| 46 | |
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| 47 | static uint32_t uC5282_tc_get_timecount(struct timecounter *tc) |
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| 48 | { |
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| 49 | return rtems_timecounter_simple_downcounter_get( |
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| 50 | tc, |
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| 51 | uC5282_tc_get, |
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| 52 | uC5282_tc_is_pending |
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| 53 | ); |
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| 54 | } |
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| 55 | |
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[76ac1ee3] | 56 | static void uC5282_tc_at_tick(rtems_timecounter_simple *tc) |
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[75acd9e] | 57 | { |
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[76ac1ee3] | 58 | unsigned idle = IDLE_COUNTER; |
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| 59 | IDLE_COUNTER = 0; |
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| 60 | if (idle > MAX_IDLE_COUNT) |
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| 61 | MAX_IDLE_COUNT = idle; |
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| 62 | FILTERED_IDLE = idle + FILTERED_IDLE - (FILTERED_IDLE>>FILTER_SHIFT); |
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| 63 | MCF5282_PIT3_PCSR |= MCF5282_PIT_PCSR_PIF; |
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[75acd9e] | 64 | } |
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| 65 | |
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[76ac1ee3] | 66 | static void uC5282_tc_tick(void) |
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| 67 | { |
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| 68 | rtems_timecounter_simple_downcounter_tick( |
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| 69 | &uC5282_tc, |
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| 70 | uC5282_tc_get, |
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| 71 | uC5282_tc_at_tick |
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| 72 | ); |
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| 73 | } |
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[572484f] | 74 | |
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| 75 | /* |
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| 76 | * Attach clock interrupt handler |
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| 77 | */ |
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[f3b29236] | 78 | #define Clock_driver_support_install_isr( _new ) \ |
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| 79 | set_vector(_new, CLOCK_VECTOR, 1) |
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[572484f] | 80 | |
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| 81 | /* |
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| 82 | * Turn off the clock |
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| 83 | */ |
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| 84 | #define Clock_driver_support_shutdown_hardware() \ |
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| 85 | do { \ |
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| 86 | MCF5282_PIT3_PCSR &= ~MCF5282_PIT_PCSR_EN; \ |
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| 87 | } while(0) |
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| 88 | |
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| 89 | /* |
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| 90 | * Set up the clock hardware |
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| 91 | * |
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[3f60fb4f] | 92 | * f_pit = f_clk / 2^(preScaleCode+1) / N = 1/(us_per_tick/us_per_s) |
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| 93 | * |
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| 94 | * N = f_clk / 2^(preScaleCode+1) * us_per_tick / us_per_s |
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| 95 | * |
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| 96 | * ns_per_pit_clk = ns_per_s / (f_clk / 2^(preScaleCode+1)) |
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| 97 | * = ns_per_s * 2^(preScaleCode+1) / f_clk; |
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[572484f] | 98 | */ |
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| 99 | #define Clock_driver_support_initialize_hardware() \ |
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| 100 | do { \ |
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[75acd9e] | 101 | unsigned long long N; \ |
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[572484f] | 102 | int level; \ |
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[3f60fb4f] | 103 | int preScaleCode = 0; \ |
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| 104 | N = bsp_get_CPU_clock_speed(); \ |
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| 105 | N *= rtems_configuration_get_microseconds_per_tick(); \ |
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| 106 | N /= 2*1000000; /* min_prescale * us_per_s */ \ |
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| 107 | while ( N > 0x10000 ) { \ |
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| 108 | preScaleCode++; \ |
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| 109 | N >>= 1; \ |
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| 110 | } \ |
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| 111 | PITC_PER_TICK = N; \ |
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| 112 | N = 2000000000ULL << preScaleCode; \ |
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| 113 | N /= bsp_get_CPU_clock_speed(); \ |
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| 114 | NSEC_PER_PITC = N; \ |
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| 115 | IDLE_COUNTER = 0; \ |
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| 116 | FILTERED_IDLE = 0; \ |
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[be5b08a] | 117 | MAX_IDLE_COUNT = 0; \ |
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[5b6111b] | 118 | bsp_allocate_interrupt(PIT3_IRQ_LEVEL, PIT3_IRQ_PRIORITY); \ |
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[572484f] | 119 | MCF5282_INTC0_ICR58 = MCF5282_INTC_ICR_IL(PIT3_IRQ_LEVEL) | \ |
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| 120 | MCF5282_INTC_ICR_IP(PIT3_IRQ_PRIORITY); \ |
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| 121 | rtems_interrupt_disable( level ); \ |
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| 122 | MCF5282_INTC0_IMRH &= ~MCF5282_INTC_IMRH_INT58; \ |
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[d8302856] | 123 | MCF5282_PIT3_PCSR &= ~MCF5282_PIT_PCSR_EN; \ |
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[572484f] | 124 | rtems_interrupt_enable( level ); \ |
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[d8302856] | 125 | MCF5282_PIT3_PCSR = MCF5282_PIT_PCSR_PRE(preScaleCode) | \ |
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[be5b08a] | 126 | MCF5282_PIT_PCSR_OVW | \ |
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| 127 | MCF5282_PIT_PCSR_PIE | \ |
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| 128 | MCF5282_PIT_PCSR_RLD; \ |
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[3f60fb4f] | 129 | MCF5282_PIT3_PMR = PITC_PER_TICK - 1; \ |
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[d8302856] | 130 | MCF5282_PIT3_PCSR = MCF5282_PIT_PCSR_PRE(preScaleCode) | \ |
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[572484f] | 131 | MCF5282_PIT_PCSR_PIE | \ |
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| 132 | MCF5282_PIT_PCSR_RLD | \ |
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| 133 | MCF5282_PIT_PCSR_EN; \ |
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[75acd9e] | 134 | rtems_timecounter_simple_install( \ |
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| 135 | &uC5282_tc, \ |
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| 136 | bsp_get_CPU_clock_speed() >> (preScaleCode + 1), \ |
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| 137 | PITC_PER_TICK, \ |
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| 138 | uC5282_tc_get_timecount \ |
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| 139 | ); \ |
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[572484f] | 140 | } while (0) |
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| 141 | |
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[be5b08a] | 142 | /* |
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| 143 | * Provide our own version of the idle task |
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| 144 | */ |
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[d4df6ea3] | 145 | void * bsp_idle_thread(uint32_t ignored) |
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[be5b08a] | 146 | { |
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[3f60fb4f] | 147 | /* Atomic increment */ |
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| 148 | for(;;) |
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| 149 | __asm__ volatile ("addq.l #1,%0"::"m"(IDLE_COUNTER)); |
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[be5b08a] | 150 | } |
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| 151 | |
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[0f9dd74] | 152 | int bsp_cpu_load_percentage(void) |
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[be5b08a] | 153 | { |
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[b468898] | 154 | return MAX_IDLE_COUNT ? |
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| 155 | (100 - ((100 * (FILTERED_IDLE >> FILTER_SHIFT)) / MAX_IDLE_COUNT)) : |
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| 156 | 0; |
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[be5b08a] | 157 | } |
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| 158 | |
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[75acd9e] | 159 | #define Clock_driver_timecounter_tick() uC5282_tc_tick() |
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| 160 | |
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[7632906] | 161 | #include "../../../shared/dev/clock/clockimpl.h" |
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