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/*

 *  linux/arch/m68k/hp300/time.c

 *

 *  Copyright (C) 1998 Philip Blundell <philb@gnu.org>

 *

 *  This file contains the HP300-specific time handling code.

 */

#include <asm/ptrace.h>

#include <linux/types.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/kernel_stat.h>

#include <linux/interrupt.h>

#include <asm/machdep.h>

#include <asm/irq.h>

#include <asm/io.h>

#include <asm/system.h>

#include <asm/traps.h>

#include "ints.h"

/* Clock hardware definitions */

#define CLOCKBASE       0xf05f8000

#define CLKCR1          0x1

#define CLKCR2          0x3

#define CLKCR3          CLKCR1

#define CLKSR           CLKCR2

#define CLKMSB1         0x5

#define CLKMSB2         0x9

#define CLKMSB3         0xD

/* This is for machines which generate the exact clock. */

#define USECS_PER_JIFFY (1000000/HZ)

#define INTVAL ((10000 / 4) - 1)

static void hp300_tick(int irq, void *dev_id, struct pt_regs *regs)

{

  unsigned long tmp;

  void (*vector)(int, void *, struct pt_regs *) = dev_id;

  in_8(CLOCKBASE + CLKSR);

  asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));

  vector(irq, NULL, regs);

}

unsigned long hp300_gettimeoffset(void)

{

  /* Read current timer 1 value */

  unsigned char lsb, msb1, msb2;

  unsigned short ticks;

  msb1 = in_8(CLOCKBASE + 5);

  lsb = in_8(CLOCKBASE + 7);

  msb2 = in_8(CLOCKBASE + 5);

  if (msb1 != msb2)

    /* A carry happened while we were reading.  Read it again */

    lsb = in_8(CLOCKBASE + 7);

  ticks = INTVAL - ((msb2 << 8) | lsb);

  return (USECS_PER_JIFFY * ticks) / INTVAL;

}

void __init hp300_sched_init(void (*vector)(int, void *, struct pt_regs *))

{

  out_8(CLOCKBASE + CLKCR2, 0x1);               /* select CR1 */

  out_8(CLOCKBASE + CLKCR1, 0x1);               /* reset */

  asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));

  sys_request_irq(6, hp300_tick, IRQ_FLG_STD, "timer tick", vector);

  out_8(CLOCKBASE + CLKCR2, 0x1);               /* select CR1 */

  out_8(CLOCKBASE + CLKCR1, 0x40);              /* enable irq */

}