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
  26 //  gcc 4.3.1 with -O2: Following doesn't work properly, probably because it
  27 //                      doesn't tell about edx trashing.
  28 //
  29 //    asm volatile("movl $0,%%eax; divl %2":"=a"(ret):"d"(usec),"m"(TIMER_RPROK));
  30 //
  31     asm volatile("movl $0,%%eax; divl %2":"=a"(ret),"+d"(usec):"m"(TIMER_RPROK));
  32     return ret;
  33 }
  34
  35 void EClockUpdate(struct TimerBase *TimerBase)
  36 {
  37     ULONG time, diff;
  38
  39     Disable();
  40
  41     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
  42     /* Latch the current time value */
  43
  44     outb(0x80, 0x43);
  45     /* Read out current 16-bit time */
  46     time = inb(0x42) >> 1;
  47     time += inb(0x42) << 7;
  48
  49     diff = (TimerBase->tb_prev_tick - time);
  50
  51     if (time > TimerBase->tb_prev_tick)
  52         diff += 0x8000;
  53
  54     TimerBase->tb_prev_tick = time;
  55
  56     TimerBase->tb_ticks_total += diff;
  57     TimerBase->tb_ticks_sec += diff;
  58     TimerBase->tb_ticks_elapsed += diff;
  59
  60     if (TimerBase->tb_ticks_sec >= 1193180) {
  61         TimerBase->tb_ticks_sec -= 1193180;
  62         TimerBase->tb_CurrentTime.tv_secs++;
  63     }
  64
  65     if (TimerBase->tb_ticks_elapsed >= 1193180) {
  66         TimerBase->tb_ticks_elapsed -= 1193180;
  67         TimerBase->tb_Elapsed.tv_secs++;
  68     }
  69
  70     TimerBase->tb_Elapsed.tv_micro = tick2usec(TimerBase->tb_ticks_elapsed);
  71     TimerBase->tb_CurrentTime.tv_micro = tick2usec(TimerBase->tb_ticks_sec);
  72
  73     Enable();
  74 }
  75
  76 void EClockSet(struct TimerBase *TimerBase)
  77 {
  78     ULONG time;
  79
  80     TimerBase->tb_ticks_sec = usec2tick(TimerBase->tb_CurrentTime.tv_micro);
  81     TimerBase->tb_ticks_total = TimerBase->tb_ticks_sec
  82                                 + (UQUAD)TimerBase->tb_CurrentTime.tv_secs * 1193180;
  83
  84     /* Latch the current time value */
  85     outb(0x80, 0x43);
  86     /* Read out current 16-bit time */
  87     time = inb(0x42) >> 1;
  88     time += inb(0x42) << 7;
  89     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
  90
  91     TimerBase->tb_prev_tick = time;
  92 }
  93
  94 void Timer0Setup(struct TimerBase *TimerBase)
  95 {
  96     struct timeval time;
  97     ULONG delay = 23864;
  98     struct timerequest *tr;
  99
 100     tr = (struct timerequest *)GetHead(&TimerBase->tb_Lists[TL_WAITVBL]);
 101
 102     if (tr)
 103     {
 104         time.tv_micro = tr->tr_time.tv_micro;
 105         time.tv_secs  = tr->tr_time.tv_secs;
 106
 107         EClockUpdate(TimerBase);
 108         SubTime(&time, &TimerBase->tb_CurrentTime);
 109
 110         if ((LONG)time.tv_secs < 0)
 111         {
 112             delay = 0;
 113         }
 114         else if (time.tv_secs == 0)
 115         {
 116             if (time.tv_micro < 20000)
 117             {
 118                 delay = usec2tick(time.tv_micro);
 119             }
 120         }
 121     }
 122
 123     tr = (struct timerequest *)GetHead(&TimerBase->tb_Lists[TL_VBLANK]);
 124
 125     if (tr)
 126     {
 127         time.tv_micro = tr->tr_time.tv_micro;
 128         time.tv_secs  = tr->tr_time.tv_secs;
 129
 130         EClockUpdate(TimerBase);
 131         SubTime(&time, &TimerBase->tb_Elapsed);
 132
 133         if ((LONG)time.tv_secs < 0)
 134         {
 135             delay = 0;
 136         }
 137         else if (time.tv_secs == 0)
 138         {
 139             if (time.tv_micro < 20000)
 140             {
 141                 if (delay > usec2tick(time.tv_micro))
 142                     delay = usec2tick(time.tv_micro);
 143             }
 144         }
 145     }
 146
 147     if (delay < 2) delay = 2;
 148
 149     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
 150     outb(0x30, 0x43);   /* Binary, mode 0, LSB&MSB */
 151     outb(delay & 0xff, 0x40);
 152     outb(delay >> 8, 0x40);
 153 }
 154