[3c7ed6b] | 1 | /** |
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| 2 | * @file clockdrv.c |
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| 3 | * |
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| 4 | * Game Boy Advance Clock driver. |
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| 5 | */ |
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| 6 | /* |
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| 7 | * RTEMS GBA BSP |
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| 8 | * |
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| 9 | * Copyright (c) 2004 Markku Puro <markku.puro@kopteri.net> |
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| 10 | * |
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| 11 | * The license and distribution terms for this file may be |
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| 12 | * found in found in the file LICENSE in this distribution or at |
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| 13 | * http://www.rtems.com/license/LICENSE. |
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| 14 | * |
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| 15 | * $Id$ |
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| 16 | */ |
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| 17 | |
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| 18 | #include <rtems.h> |
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| 19 | #include <bsp.h> |
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| 20 | #include <irq.h> |
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| 21 | #include <gba.h> |
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| 22 | |
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| 23 | |
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| 24 | /*-------------------------------------------------------------------------+ |
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| 25 | | Clock isr variables |
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| 26 | +--------------------------------------------------------------------------*/ |
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| 27 | rtems_isr Clock_isr(rtems_vector_number vector); |
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| 28 | static void clock_isr_on(const rtems_irq_connect_data *unused); |
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| 29 | static void clock_isr_off(const rtems_irq_connect_data *unused); |
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| 30 | static int clock_isr_is_on(const rtems_irq_connect_data *irq); |
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| 31 | |
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| 32 | rtems_irq_connect_data clock_isr_data = {BSP_IRQ_TIMER3, |
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| 33 | (rtems_irq_hdl)Clock_isr, |
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| 34 | clock_isr_on, |
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| 35 | clock_isr_off, |
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| 36 | clock_isr_is_on, |
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| 37 | 0, |
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| 38 | 0 }; |
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| 39 | |
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| 40 | #define CLOCK_VECTOR 0 |
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| 41 | |
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| 42 | #define Clock_driver_support_at_tick() |
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| 43 | |
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| 44 | #define Clock_driver_support_install_isr( _new, _old ) \ |
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| 45 | do { \ |
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| 46 | BSP_install_rtems_irq_handler(&clock_isr_data); \ |
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| 47 | } while(0) |
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| 48 | |
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| 49 | #define Clock_driver_support_shutdown_hardware() \ |
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| 50 | do { \ |
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| 51 | BSP_remove_rtems_irq_handler(&clock_isr_data); \ |
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| 52 | } while (0) |
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| 53 | |
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| 54 | |
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| 55 | /*-------------------------------------------------------------------------+ |
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| 56 | | Calculate Tick Times |
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| 57 | | 1 / 16.78Mhz => 59.595 ns |
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| 58 | | 64 / 16.78Mhz => 3.814 us |
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| 59 | | 256 / 16.78Mhz => 15.256 us |
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| 60 | | 1024 / 16.78Mhz => 61.025 us |
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| 61 | +--------------------------------------------------------------------------*/ |
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| 62 | #define __TimTickTime_us ((1000000L/__ClockFrequency)*__TimPreScaler) |
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| 63 | #define __TimTickTime_ns ((1000000000L/__ClockFrequency)*__TimPreScaler) |
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| 64 | |
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| 65 | #if (__TimPreScaler==1) |
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| 66 | #define GBA_TMCNT_PS 0x0000 |
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| 67 | #elif (__TimPreScaler==64) |
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| 68 | #define GBA_TMCNT_PS 0x0001 |
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| 69 | #elif (__TimPreScaler==256) |
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| 70 | #define GBA_TMCNT_PS 0x0002 |
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| 71 | #elif (__TimPreScaler==1024) |
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| 72 | #define GBA_TMCNT_PS 0x0003 |
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| 73 | #else |
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| 74 | #define GBA_TMCNT_PS 0x0003 |
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| 75 | #endif |
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| 76 | |
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| 77 | |
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| 78 | extern rtems_configuration_table BSP_Configuration; |
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| 79 | |
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| 80 | /** |
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| 81 | * @brief This function set up the clock hardware |
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| 82 | * |
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| 83 | * @param None |
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| 84 | * @return None |
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| 85 | */ |
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| 86 | void Clock_driver_support_initialize_hardware() |
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| 87 | { |
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| 88 | int tmreload = ((BSP_Configuration.microseconds_per_tick*1000)/__TimTickTime_ns); |
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| 89 | |
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| 90 | if (tmreload>0xFFFF) tmreload = 0xFFFF; |
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| 91 | GBA_REG_TM3CNT = (GBA_TMCNT_PS); |
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| 92 | GBA_REG_TM3D = (0x0000-tmreload); |
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| 93 | GBA_REG_TM3CNT = (0x00c0|GBA_TMCNT_PS); |
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| 94 | } |
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| 95 | |
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| 96 | /** |
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| 97 | * @brief This function is empty |
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| 98 | * |
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| 99 | * @param unused an unused parameter |
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| 100 | * @return None |
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| 101 | */ |
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| 102 | static void clock_isr_on(const rtems_irq_connect_data *unused) |
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| 103 | { |
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| 104 | return; |
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| 105 | } |
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| 106 | |
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| 107 | /** |
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| 108 | * @brief This function is empty |
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| 109 | * |
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| 110 | * @param unused an unused parameter |
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| 111 | * @return None |
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| 112 | */ |
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| 113 | static void clock_isr_off(const rtems_irq_connect_data *unused) |
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| 114 | { |
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| 115 | return; |
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| 116 | } |
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| 117 | |
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| 118 | /** |
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| 119 | * @brief This function is empty |
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| 120 | * |
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| 121 | * @param irq unused |
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| 122 | * @return constant 1 |
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| 123 | */ |
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| 124 | static int clock_isr_is_on(const rtems_irq_connect_data *irq) |
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| 125 | { |
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| 126 | return 1; |
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| 127 | } |
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| 128 | |
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| 129 | |
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| 130 | #include "../../../shared/clockdrv_shell.c" |
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