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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 56 | pj | 1 | /* |
| 2 | * PC/HW routine collection v1.0 for DOS/DJGPP |
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| 3 | * |
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| 4 | * Copyright (C) 2002 - Borca Daniel |
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| 5 | * Email : dborca@yahoo.com |
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| 6 | * Web : http://www.geocities.com/dborca |
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| 7 | */ |
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| 8 | |||
| 9 | |||
| 10 | #include <pc.h> |
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| 11 | |||
| 12 | #include "pc_hw.h" |
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| 13 | |||
| 14 | #define TIMER_IRQ 0 |
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| 15 | |||
| 16 | #define MAX_TIMERS 8 |
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| 17 | |||
| 18 | #define PIT_FREQ 0x1234DD |
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| 19 | |||
| 20 | #define unvolatile(__v, __t) __extension__ ({union { volatile __t __cp; __t __p; } __q; __q.__cp = __v; __q.__p;}) |
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| 21 | |||
| 22 | static int timer_installed; |
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| 23 | |||
| 24 | typedef struct { |
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| 25 | volatile unsigned int counter, clock_ticks, freq; |
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| 26 | volatile PFUNC func; |
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| 27 | volatile void *parm; |
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| 28 | } TIMER; |
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| 29 | |||
| 30 | TIMER timer_main, timer_func[MAX_TIMERS]; |
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| 31 | |||
| 32 | static int timer () |
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| 33 | { |
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| 34 | int i; |
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| 35 | |||
| 36 | for (i=0;i<MAX_TIMERS;i++) { |
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| 37 | TIMER *t = &timer_func[i]; |
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| 38 | if (t->func) { |
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| 39 | t->clock_ticks += t->counter; |
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| 40 | if (t->clock_ticks>=timer_main.counter) { |
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| 41 | t->clock_ticks -= timer_main.counter; |
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| 42 | t->func(unvolatile(t->parm, void *)); |
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| 43 | } |
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| 44 | } |
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| 45 | } |
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| 46 | |||
| 47 | timer_main.clock_ticks += timer_main.counter; |
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| 48 | if (timer_main.clock_ticks>=0x10000) { |
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| 49 | timer_main.clock_ticks -= 0x10000; |
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| 50 | return 1; |
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| 51 | } else { |
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| 52 | outportb(0x20, 0x20); |
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| 53 | return 0; |
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| 54 | } |
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| 55 | } ENDOFUNC(timer) |
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| 56 | |||
| 57 | void pc_remove_timer (void) |
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| 58 | { |
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| 59 | if (timer_installed) { |
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| 60 | timer_installed = FALSE; |
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| 61 | pc_clexit(pc_remove_timer); |
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| 62 | |||
| 63 | DISABLE(); |
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| 64 | outportb(0x43, 0x34); |
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| 65 | outportb(0x40, 0); |
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| 66 | outportb(0x40, 0); |
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| 67 | ENABLE(); |
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| 68 | |||
| 69 | pc_remove_irq(TIMER_IRQ); |
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| 70 | } |
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| 71 | } |
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| 72 | |||
| 73 | static int install_timer (void) |
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| 74 | { |
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| 75 | if (timer_installed||pc_install_irq(TIMER_IRQ, timer)) { |
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| 76 | return -1; |
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| 77 | } else { |
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| 78 | LOCKDATA(timer_func); |
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| 79 | LOCKDATA(timer_main); |
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| 80 | LOCKFUNC(timer); |
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| 81 | |||
| 82 | timer_main.counter = 0x10000; |
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| 83 | |||
| 84 | DISABLE(); |
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| 85 | outportb(0x43, 0x34); |
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| 86 | outportb(0x40, 0); |
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| 87 | outportb(0x40, 0); |
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| 88 | timer_main.clock_ticks = 0; |
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| 89 | ENABLE(); |
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| 90 | |||
| 91 | pc_atexit(pc_remove_timer); |
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| 92 | timer_installed = TRUE; |
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| 93 | return 0; |
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| 94 | } |
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| 95 | } |
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| 96 | |||
| 97 | static TIMER *find_slot (PFUNC func) |
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| 98 | { |
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| 99 | int i; |
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| 100 | |||
| 101 | for (i=0;i<MAX_TIMERS;i++) { |
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| 102 | if (timer_func[i].func==func) { |
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| 103 | return &timer_func[i]; |
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| 104 | } |
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| 105 | } |
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| 106 | for (i=0;i<MAX_TIMERS;i++) { |
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| 107 | if (!timer_func[i].func) { |
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| 108 | return &timer_func[i]; |
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| 109 | } |
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| 110 | } |
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| 111 | |||
| 112 | return NULL; |
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| 113 | } |
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| 114 | |||
| 115 | int pc_install_int (PFUNC func, void *parm, unsigned int freq) |
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| 116 | { |
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| 117 | int i; |
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| 118 | TIMER *t; |
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| 119 | |||
| 120 | if (!timer_installed) { |
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| 121 | if (install_timer()) { |
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| 122 | return -1; |
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| 123 | } |
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| 124 | } |
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| 125 | |||
| 126 | if ((t=find_slot(func))!=NULL) { |
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| 127 | unsigned int new_counter = PIT_FREQ / freq; |
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| 128 | |||
| 129 | DISABLE(); |
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| 130 | |||
| 131 | t->func = func; |
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| 132 | t->parm = parm; |
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| 133 | t->freq = freq; |
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| 134 | t->clock_ticks = 0; |
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| 135 | |||
| 136 | if (new_counter < timer_main.counter) { |
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| 137 | for (i=0;i<MAX_TIMERS;i++) { |
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| 138 | if (timer_func[i].func) { |
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| 139 | timer_func[i].counter = new_counter * timer_func[i].freq / freq; |
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| 140 | } |
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| 141 | } |
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| 142 | outportb(0x43, 0x34); |
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| 143 | outportb(0x40, (unsigned char)new_counter); |
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| 144 | outportb(0x40, (unsigned char)(new_counter>>8)); |
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| 145 | timer_main.clock_ticks = 0; |
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| 146 | timer_main.counter = new_counter; |
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| 147 | timer_main.freq = freq; |
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| 148 | } else { |
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| 149 | t->counter = PIT_FREQ * freq / (timer_main.freq * timer_main.freq); |
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| 150 | } |
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| 151 | |||
| 152 | ENABLE(); |
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| 153 | |||
| 154 | return 0; |
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| 155 | } |
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| 156 | |||
| 157 | return -1; |
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| 158 | } |