acpi: fix acpi_os_read_pci_configuration() misuse of raw_pci_read()
[deliverable/linux.git] / arch / frv / kernel / time.c
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1/* time.c: FRV arch-specific time handling
2 *
3 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * - Derived from arch/m68k/kernel/time.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
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13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/param.h>
18#include <linux/string.h>
19#include <linux/interrupt.h>
20#include <linux/profile.h>
21#include <linux/irq.h>
22#include <linux/mm.h>
23
24#include <asm/io.h>
25#include <asm/timer-regs.h>
26#include <asm/mb-regs.h>
27#include <asm/mb86943a.h>
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28
29#include <linux/timex.h>
30
31#define TICK_SIZE (tick_nsec / 1000)
32
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33unsigned long __nongprelbss __clkin_clock_speed_HZ;
34unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
35unsigned long __nongprelbss __res_bus_clock_speed_HZ;
36unsigned long __nongprelbss __sdram_clock_speed_HZ;
37unsigned long __nongprelbss __core_bus_clock_speed_HZ;
38unsigned long __nongprelbss __core_clock_speed_HZ;
39unsigned long __nongprelbss __dsu_clock_speed_HZ;
40unsigned long __nongprelbss __serial_clock_speed_HZ;
41unsigned long __delay_loops_MHz;
42
7d12e780 43static irqreturn_t timer_interrupt(int irq, void *dummy);
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44
45static struct irqaction timer_irq = {
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46 .handler = timer_interrupt,
47 .flags = IRQF_DISABLED,
48 .mask = CPU_MASK_NONE,
49 .name = "timer",
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50};
51
52static inline int set_rtc_mmss(unsigned long nowtime)
53{
54 return -1;
55}
56
57/*
58 * timer_interrupt() needs to keep up the real-time clock,
59 * as well as call the "do_timer()" routine every clocktick
60 */
7d12e780 61static irqreturn_t timer_interrupt(int irq, void *dummy)
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62{
63 /* last time the cmos clock got updated */
64 static long last_rtc_update = 0;
65
66 /*
67 * Here we are in the timer irq handler. We just have irqs locally
68 * disabled but we don't know if the timer_bh is running on the other
761a7e35 69 * CPU. We need to avoid to SMP race with it. NOTE: we don't need
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70 * the irq version of write_lock because as just said we have irq
71 * locally disabled. -arca
72 */
73 write_seqlock(&xtime_lock);
74
3171a030 75 do_timer(1);
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76 update_process_times(user_mode(get_irq_regs()));
77 profile_tick(CPU_PROFILING);
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78
79 /*
80 * If we have an externally synchronized Linux clock, then update
81 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
82 * called as close as possible to 500 ms before the new second starts.
83 */
b149ee22 84 if (ntp_synced() &&
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85 xtime.tv_sec > last_rtc_update + 660 &&
86 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
87 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2
88 ) {
89 if (set_rtc_mmss(xtime.tv_sec) == 0)
90 last_rtc_update = xtime.tv_sec;
91 else
92 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
93 }
94
95#ifdef CONFIG_HEARTBEAT
96 static unsigned short n;
97 n++;
98 __set_LEDS(n);
99#endif /* CONFIG_HEARTBEAT */
100
101 write_sequnlock(&xtime_lock);
102 return IRQ_HANDLED;
103}
104
105void time_divisor_init(void)
106{
107 unsigned short base, pre, prediv;
108
109 /* set the scheduling timer going */
110 pre = 1;
111 prediv = 4;
112 base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
113
114 __set_TPRV(pre);
115 __set_TxCKSL_DATA(0, prediv);
116 __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
117 __set_TCSR_DATA(0, base & 0xff);
118 __set_TCSR_DATA(0, base >> 8);
119}
120
121void time_init(void)
122{
123 unsigned int year, mon, day, hour, min, sec;
124
125 extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec);
126
127 /* FIX by dqg : Set to zero for platforms that don't have tod */
128 /* without this time is undefined and can overflow time_t, causing */
761a7e35 129 /* very strange errors */
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130 year = 1980;
131 mon = day = 1;
132 hour = min = sec = 0;
133 arch_gettod (&year, &mon, &day, &hour, &min, &sec);
134
135 if ((year += 1900) < 1970)
136 year += 100;
137 xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
138 xtime.tv_nsec = 0;
139
140 /* install scheduling interrupt handler */
141 setup_irq(IRQ_CPU_TIMER0, &timer_irq);
142
143 time_divisor_init();
144}
145
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146/*
147 * Scheduler clock - returns current time in nanosec units.
148 */
149unsigned long long sched_clock(void)
150{
151 return jiffies_64 * (1000000000 / HZ);
152}
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