arch/all-pc/timer/timer_init.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Timer startup and device commands
   6 */
   7
   8 /****************************************************************************************/
   9
  10 #include <exec/devices.h>
  11 #include <exec/interrupts.h>
  12 #include <devices/timer.h>
  13 #include <hardware/intbits.h>
  14 #include <proto/exec.h>
  15 #include <proto/kernel.h>
  16 #include <aros/symbolsets.h>
  17 #include <asm/io.h>
  18 #include <aros/debug.h>
  19
  20 #include "ticks.h"
  21
  22 #define KernelBase LIBBASE->tb_KernelBase
  23
  24 /****************************************************************************************/
  25
  26 static void TimerInt(struct TimerBase *TimerBase, struct ExecBase *SysBase)
  27 {
  28     /*
  29      * Sync up with the hardware, we need the proper time value in order to
  30      * process our requests correctly.
  31      */
  32     EClockUpdate(TimerBase);
  33     /*
  34      * Process MICROHZ requests.
  35      * VBLANK is emulated by us, so we don't check it here. We always
  36      * have one active request in this list, which will cause VBLANK checking.
  37      */
  38     handleMicroHZ(TimerBase, SysBase);
  39     /* Request next interrupt from the hardware */
  40     Timer0Setup(TimerBase);
  41 }
  42
  43 /****************************************************************************************/
  44
  45 static int hw_Init(struct TimerBase *LIBBASE)
  46 {
  47     /* We must have kernel.resource */
  48     D(bug("[Timer] KernelBase = 0x%p\n", KernelBase));
  49     if (!KernelBase)
  50         return FALSE;
  51
  52     /* Start up the interrupt server. We know that our HW timer is at IRQ 0 */
  53     LIBBASE->tb_TimerIRQHandle = KrnAddIRQHandler(0, TimerInt, LIBBASE, SysBase);
  54     D(bug("[Timer] IRQ handle = 0x%p\n", LIBBASE->tb_TimerIRQHandle));
  55     if (!LIBBASE->tb_TimerIRQHandle)
  56         return FALSE;
  57
  58     D(bug("[Timer] Initializing hardware...\n"));
  59
  60     /* We have fixed EClock rate. VBlank will be emulated at 50Hz, can be changed at runtime. */
  61     SysBase->VBlankFrequency    = 50;
  62     SysBase->ex_EClockFrequency = 1193180;
  63     LIBBASE->tb_eclock_rate     = 1193180;
  64     LIBBASE->tb_prev_tick       = 0xFFFF;
  65
  66     /* Start up the timer. Count the whole range for now. */
  67     outb(CH0|ACCESS_FULL|MODE_SW_STROBE, PIT_CONTROL);  /* Software strobe mode, 16-bit access */
  68     ch_write(0xFFFF, PIT_CH0);
  69
  70     /*
  71      * Start the timer2.
  72      * FIXME: This is not used by timer.device any more and must be removed.
  73      * However PS/2 port driver uses polled microsecond delays via channel 2,
  74      * and it relies on it being activated by us. This urgently needs to
  75      * be fixed!
  76      */
  77     outb((inb(0x61) & 0xfd) | 1, 0x61); /* Enable the timer (set GATE on) */
  78     outb(0xb4, 0x43);                   /* Binary mode on Timer2, count mode 2 */
  79     outb(0x00, 0x42);                   /* We're counting whole range */
  80     outb(0x00, 0x42);
  81
  82     /* Own VBlank EMU */
  83     D(bug("[Timer] Starting VBlank emulation (%u Hz)...\n", SysBase->VBlankFrequency));
  84
  85     LIBBASE->tb_vblank_timerequest.tr_node.io_Command = TR_ADDREQUEST;
  86     LIBBASE->tb_vblank_timerequest.tr_node.io_Device = &LIBBASE->tb_Device;
  87     LIBBASE->tb_vblank_timerequest.tr_node.io_Unit   = (struct Unit *)UNIT_MICROHZ;
  88     LIBBASE->tb_vblank_timerequest.tr_time.tv_secs   = 0;
  89     LIBBASE->tb_vblank_timerequest.tr_time.tv_micro  = 1000000 / SysBase->VBlankFrequency;
  90
  91     SendIO(&LIBBASE->tb_vblank_timerequest.tr_node);
  92
  93     D(bug("[Timer] Done\n"));
  94
  95     return TRUE;
  96 }
  97
  98 /****************************************************************************************/
  99
 100 static int hw_Expunge(struct TimerBase *LIBBASE)
 101 {
 102     KrnRemIRQHandler(LIBBASE->tb_TimerIRQHandle);
 103
 104     return TRUE;
 105 }
 106
 107 /****************************************************************************************/
 108
 109 ADD2INITLIB(hw_Init, 0)
 110 ADD2EXPUNGELIB(hw_Expunge, 0)