arch/all-mingw32/timer/timer_init.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 /*
   7  * Windows-hosted timer driver.
   8  *
   9  * In Windows kernel we have two statically allocated timers.
  10  * Timer 0 is used by kernel for VBlank interrupts, timer 1 is our one.
  11  *
  12  * Our VBlank unit is driven by exec interrupt.
  13  *
  14  * TODO: Rewrite this implementation to use variable time intervals.
  15  */
  16
  17 #include <aros/bootloader.h>
  18 #include <aros/debug.h>
  19 #include <aros/symbolsets.h>
  20 #include <exec/execbase.h>
  21 #include <exec/interrupts.h>
  22 #include <hardware/intbits.h>
  23 #include <proto/arossupport.h>
  24 #include <proto/bootloader.h>
  25 #include <proto/exec.h>
  26 #include <proto/hostlib.h>
  27 #include <proto/kernel.h>
  28
  29 #include "timer_intern.h"
  30 #include "timer_macros.h"
  31 #include "timervblank.h"
  32
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 /* Timer 1 (EClock) interrupt handler */
  37 static void TimerTick(struct TimerBase *TimerBase, struct ExecBase *SysBase)
  38 {
  39     /* Increment EClock value and process microhz requests */
  40     ADDTIME(&TimerBase->tb_CurrentTime, &TimerBase->tb_Platform.tb_VBlankTime);
  41     ADDTIME(&TimerBase->tb_Elapsed, &TimerBase->tb_Platform.tb_VBlankTime);
  42     TimerBase->tb_ticks_total++;
  43
  44     handleMicroHZ(TimerBase, SysBase);
  45 }
  46
  47 /****************************************************************************************/
  48
  49 #define KernelBase TimerBase->tb_KernelBase
  50
  51 static int Timer_Init(struct TimerBase *TimerBase)
  52 {
  53     APTR BootLoaderBase;
  54     int ret;
  55
  56     HostLibBase = OpenResource("hostlib.resource");
  57     if (!HostLibBase)
  58         return FALSE;
  59
  60     TimerBase->tb_Platform.kernelHandle = HostLib_Open("Libs\\Host\\kernel.dll", NULL);
  61     if (!TimerBase->tb_Platform.kernelHandle)
  62         return FALSE;
  63
  64     TimerBase->tb_Platform.StartClock = HostLib_GetPointer(TimerBase->tb_Platform.kernelHandle, "StartClock", NULL);
  65     if (!TimerBase->tb_Platform.StartClock)
  66         return FALSE;
  67
  68     /* Install timer IRQ handler */
  69     TimerBase->tb_TimerIRQHandle = KrnAddIRQHandler(1, TimerTick, TimerBase, SysBase);
  70     if (!TimerBase->tb_TimerIRQHandle)
  71         return FALSE;
  72
  73     /* Set up VBlank handler */
  74     vblank_Init(TimerBase);
  75
  76     /* By default we want 100 Hz EClock */
  77     TimerBase->tb_eclock_rate = 100;
  78
  79     /*
  80      * Since we are software-driven, we can just ask the user which
  81      * frequencies he wishes to use.
  82      */
  83     BootLoaderBase = OpenResource("bootloader.resource");
  84     if (BootLoaderBase)
  85     {
  86         struct List *args = GetBootInfo(BL_Args);
  87
  88         if (args)
  89         {
  90             struct Node *node;
  91
  92             for (node = args->lh_Head; node->ln_Succ; node = node->ln_Succ)
  93             {
  94                 if (strncasecmp(node->ln_Name, "eclock=", 7) == 0)
  95                 {
  96                     TimerBase->tb_eclock_rate = atoi(&node->ln_Name[7]);
  97                     break;
  98                 }
  99             }
 100         }
 101     }
 102
 103     /* Set ExecBase public field. */
 104     SysBase->ex_EClockFrequency = TimerBase->tb_eclock_rate;
 105     D(bug("[Timer_Init] Timer frequency is %d\n", TimerBase->tb_eclock_rate));
 106
 107     /* Calculate timer period in us */
 108     TimerBase->tb_Platform.tb_VBlankTime.tv_secs  = 0;
 109     TimerBase->tb_Platform.tb_VBlankTime.tv_micro = 1000000 / TimerBase->tb_eclock_rate;
 110
 111     /* Start up timer 1 */
 112     Forbid();
 113     ret = TimerBase->tb_Platform.StartClock(1, TimerBase->tb_eclock_rate);
 114     Permit();
 115
 116     D(bug("[Timer_Init] StartClock() returned %d\n", ret));
 117     return ret;
 118 }
 119
 120 static int Timer_Expunge(struct TimerBase *TimerBase)
 121 {
 122     if (!HostLibBase)
 123         return TRUE;
 124
 125     if (TimerBase->tb_TimerIRQHandle)
 126         KrnRemIRQHandler(TimerBase->tb_TimerIRQHandle);
 127
 128     if (TimerBase->tb_Platform.kernelHandle)
 129         HostLib_Close(TimerBase->tb_Platform.kernelHandle, NULL);
 130
 131     return TRUE;
 132 }
 133
 134 ADD2INITLIB(Timer_Init, 0)
 135 ADD2EXPUNGELIB(Timer_Expunge, 0)