arch/i386-pc/timer/ticks.c

   1 //#include DEBUG 1
   2
   3 //#include <aros/debug.h>
   4 #include <exec/types.h>
   5 #include <proto/exec.h>
   6 #include <asm/io.h>
   7
   8 #include <proto/timer.h>
   9
  10 #include "ticks.h"
  11
  12 const ULONG TIMER_RPROK = 3599597124UL;
  13
  14 ULONG tick2usec(ULONG tick)
  15 {
  16     ULONG ret, rest;
  17     asm volatile("mull %3":"=d"(ret),"=a"(rest):"a"(TIMER_RPROK),"m"(tick));
  18     ret+=rest>>31;
  19     return ret;
  20 }
  21
  22 ULONG usec2tick(ULONG usec)
  23 {
  24     ULONG ret;
  25     asm volatile("movl $0,%%eax; divl %2":"=a"(ret):"d"(usec),"m"(TIMER_RPROK));
  26     return ret;
  27 }
  28
  29 void EClockUpdate(struct TimerBase *TimerBase)
  30 {
  31     ULONG time, diff;
  32
  33     Disable();
  34
  35     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
  36     /* Latch the current time value */
  37
  38     outb(0x80, 0x43);
  39     /* Read out current 16-bit time */
  40     time = inb(0x42) >> 1;
  41     time += inb(0x42) << 7;
  42
  43     diff = (TimerBase->tb_prev_tick - time);
  44
  45     if (time > TimerBase->tb_prev_tick)
  46         diff += 0x8000;
  47
  48     TimerBase->tb_prev_tick = time;
  49
  50     TimerBase->tb_ticks_total += diff;
  51     TimerBase->tb_ticks_sec += diff;
  52     TimerBase->tb_ticks_elapsed += diff;
  53
  54     if (TimerBase->tb_ticks_sec >= 1193180) {
  55         TimerBase->tb_ticks_sec -= 1193180;
  56         TimerBase->tb_CurrentTime.tv_secs++;
  57     }
  58
  59     if (TimerBase->tb_ticks_elapsed >= 1193180) {
  60         TimerBase->tb_ticks_elapsed -= 1193180;
  61         TimerBase->tb_Elapsed.tv_secs++;
  62     }
  63
  64     TimerBase->tb_Elapsed.tv_micro = tick2usec(TimerBase->tb_ticks_elapsed);
  65     TimerBase->tb_CurrentTime.tv_micro = tick2usec(TimerBase->tb_ticks_sec);
  66
  67     Enable();
  68 }
  69
  70 void EClockSet(struct TimerBase *TimerBase)
  71 {
  72     ULONG time;
  73
  74     TimerBase->tb_ticks_sec = usec2tick(TimerBase->tb_CurrentTime.tv_micro);
  75     TimerBase->tb_ticks_total = TimerBase->tb_ticks_sec
  76                                 + (UQUAD)TimerBase->tb_CurrentTime.tv_secs * 1193180;
  77
  78     /* Latch the current time value */
  79     outb(0x80, 0x43);
  80     /* Read out current 16-bit time */
  81     time = inb(0x42) >> 1;
  82     time += inb(0x42) << 7;
  83     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
  84
  85     TimerBase->tb_prev_tick = time;
  86 }
  87
  88 void Timer0Setup(struct TimerBase *TimerBase)
  89 {
  90     struct timeval time;
  91     ULONG delay = 23864;
  92     struct timerequest *tr;
  93
  94     tr = (struct timerequest *)GetHead(&TimerBase->tb_Lists[TL_WAITVBL]);
  95
  96     if (tr)
  97     {
  98         time.tv_micro = tr->tr_time.tv_micro;
  99         time.tv_secs  = tr->tr_time.tv_secs;
 100
 101         EClockUpdate(TimerBase);
 102         SubTime(&time, &TimerBase->tb_CurrentTime);
 103
 104         if ((LONG)time.tv_secs < 0)
 105         {
 106             delay = 0;
 107         }
 108         else if (time.tv_secs == 0)
 109         {
 110             if (time.tv_micro < 20000)
 111             {
 112                 delay = usec2tick(time.tv_micro);
 113             }
 114         }
 115     }
 116
 117     tr = (struct timerequest *)GetHead(&TimerBase->tb_Lists[TL_VBLANK]);
 118
 119     if (tr)
 120     {
 121         time.tv_micro = tr->tr_time.tv_micro;
 122         time.tv_secs  = tr->tr_time.tv_secs;
 123
 124         EClockUpdate(TimerBase);
 125         SubTime(&time, &TimerBase->tb_Elapsed);
 126
 127         if ((LONG)time.tv_secs < 0)
 128         {
 129             delay = 0;
 130         }
 131         else if (time.tv_secs == 0)
 132         {
 133             if (time.tv_micro < 20000)
 134             {
 135                 if (delay > usec2tick(time.tv_micro))
 136                     delay = usec2tick(time.tv_micro);
 137             }
 138         }
 139     }
 140
 141     if (delay < 2) delay = 2;
 142
 143     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
 144     outb(0x38, 0x43);   /* Binary, mode 4, LSB&MSB */
 145     outb(delay & 0xff, 0x40);
 146     outb(delay >> 8, 0x40);
 147 }
 148