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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;
readb(CLOCKBASE + CLKSR);
asm volatile ("movpw %1@(5),%0" : "=r" (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 = readb(CLOCKBASE + 5);
lsb = readb(CLOCKBASE + 7);
msb2 = readb(CLOCKBASE + 5);
if (msb1 != msb2)
/* A carry happened while we were reading. Read it again */
lsb = readb(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 *))
{
writeb(0x1, CLOCKBASE + CLKCR2); /* select CR1 */
writeb(0x1, CLOCKBASE + CLKCR1); /* reset */
asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
sys_request_irq(6, hp300_tick, IRQ_FLG_STD, "timer tick", vector);
writeb(0x1, CLOCKBASE + CLKCR2); /* select CR1 */
writeb(0x40, CLOCKBASE + CLKCR1); /* enable irq */
}
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