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/arch/m68k/hp300/time.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 78 lines | 53 code | 13 blank | 12 comment | 3 complexity | 1a8b0af54e4e67eb027238983abea29e MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
 1/*
 2 *  linux/arch/m68k/hp300/time.c
 3 *
 4 *  Copyright (C) 1998 Philip Blundell <philb@gnu.org>
 5 *
 6 *  This file contains the HP300-specific time handling code.
 7 */
 8
 9#include <asm/ptrace.h>
10#include <linux/types.h>
11#include <linux/init.h>
12#include <linux/sched.h>
13#include <linux/kernel_stat.h>
14#include <linux/interrupt.h>
15#include <asm/machdep.h>
16#include <asm/irq.h>
17#include <asm/io.h>
18#include <asm/system.h>
19#include <asm/traps.h>
20#include <asm/blinken.h>
21
22/* Clock hardware definitions */
23
24#define CLOCKBASE	0xf05f8000
25
26#define	CLKCR1		0x1
27#define	CLKCR2		0x3
28#define	CLKCR3		CLKCR1
29#define	CLKSR		CLKCR2
30#define	CLKMSB1		0x5
31#define	CLKMSB2		0x9
32#define	CLKMSB3		0xD
33
34/* This is for machines which generate the exact clock. */
35#define USECS_PER_JIFFY (1000000/HZ)
36
37#define INTVAL ((10000 / 4) - 1)
38
39static irqreturn_t hp300_tick(int irq, void *dev_id)
40{
41	unsigned long tmp;
42	irq_handler_t vector = dev_id;
43	in_8(CLOCKBASE + CLKSR);
44	asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));
45	/* Turn off the network and SCSI leds */
46	blinken_leds(0, 0xe0);
47	return vector(irq, NULL);
48}
49
50unsigned long hp300_gettimeoffset(void)
51{
52  /* Read current timer 1 value */
53  unsigned char lsb, msb1, msb2;
54  unsigned short ticks;
55
56  msb1 = in_8(CLOCKBASE + 5);
57  lsb = in_8(CLOCKBASE + 7);
58  msb2 = in_8(CLOCKBASE + 5);
59  if (msb1 != msb2)
60    /* A carry happened while we were reading.  Read it again */
61    lsb = in_8(CLOCKBASE + 7);
62  ticks = INTVAL - ((msb2 << 8) | lsb);
63  return (USECS_PER_JIFFY * ticks) / INTVAL;
64}
65
66void __init hp300_sched_init(irq_handler_t vector)
67{
68  out_8(CLOCKBASE + CLKCR2, 0x1);		/* select CR1 */
69  out_8(CLOCKBASE + CLKCR1, 0x1);		/* reset */
70
71  asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
72
73  if (request_irq(IRQ_AUTO_6, hp300_tick, IRQ_FLG_STD, "timer tick", vector))
74    pr_err("Couldn't register timer interrupt\n");
75
76  out_8(CLOCKBASE + CLKCR2, 0x1);		/* select CR1 */
77  out_8(CLOCKBASE + CLKCR1, 0x40);		/* enable irq */
78}