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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/kernel/time.c
3 *
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
5 * Modifications for ARM (C) 1994-2001 Russell King
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This file contains the ARM-specific time handling details:
12 * reading the RTC at bootup, etc...
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/interrupt.h>
17#include <linux/time.h>
18#include <linux/init.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040019#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/smp.h>
21#include <linux/timex.h>
22#include <linux/errno.h>
23#include <linux/profile.h>
24#include <linux/sysdev.h>
25#include <linux/timer.h>
Frederik Deweerdte317c8c2006-10-06 18:58:24 +000026#include <linux/irq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Ben Dooks9ca3f072006-12-24 01:36:35 +010028#include <linux/mc146818rtc.h>
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/leds.h>
31#include <asm/thread_info.h>
Russell King211baa702011-01-11 16:23:04 +000032#include <asm/sched_clock.h>
Catalin Marinas2d7c11b2009-02-11 13:07:53 +010033#include <asm/stacktrace.h>
Russell King8ff14432010-12-20 10:18:36 +000034#include <asm/mach/arch.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <asm/mach/time.h>
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037/*
38 * Our system timer.
39 */
Russell King8ff14432010-12-20 10:18:36 +000040static struct sys_timer *system_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
David Brownell9dd34942007-01-17 22:11:27 +010042#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070043/* this needs a better home */
44DEFINE_SPINLOCK(rtc_lock);
45
David Brownell9dd34942007-01-17 22:11:27 +010046#ifdef CONFIG_RTC_DRV_CMOS_MODULE
Linus Torvalds1da177e2005-04-16 15:20:36 -070047EXPORT_SYMBOL(rtc_lock);
48#endif
David Brownell9dd34942007-01-17 22:11:27 +010049#endif /* pc-style 'CMOS' RTC support */
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51/* change this if you have some constant time drift */
52#define USECS_PER_JIFFY (1000000/HZ)
53
54#ifdef CONFIG_SMP
55unsigned long profile_pc(struct pt_regs *regs)
56{
Catalin Marinas2d7c11b2009-02-11 13:07:53 +010057 struct stackframe frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Catalin Marinas2d7c11b2009-02-11 13:07:53 +010059 if (!in_lock_functions(regs->ARM_pc))
60 return regs->ARM_pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Catalin Marinas2d7c11b2009-02-11 13:07:53 +010062 frame.fp = regs->ARM_fp;
63 frame.sp = regs->ARM_sp;
64 frame.lr = regs->ARM_lr;
65 frame.pc = regs->ARM_pc;
66 do {
67 int ret = unwind_frame(&frame);
68 if (ret < 0)
69 return 0;
70 } while (in_lock_functions(frame.pc));
71
72 return frame.pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073}
74EXPORT_SYMBOL(profile_pc);
75#endif
76
John Stultz5cfc8ee2010-03-24 00:22:36 +000077#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
78u32 arch_gettimeoffset(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
John Stultz5cfc8ee2010-03-24 00:22:36 +000080 if (system_timer->offset != NULL)
81 return system_timer->offset() * 1000;
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 return 0;
84}
John Stultz5cfc8ee2010-03-24 00:22:36 +000085#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#ifdef CONFIG_LEDS_TIMER
88static inline void do_leds(void)
89{
David Brownell6d15cb42006-11-06 19:29:16 +010090 static unsigned int count = HZ/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92 if (--count == 0) {
David Brownell6d15cb42006-11-06 19:29:16 +010093 count = HZ/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 leds_event(led_timer);
95 }
96}
97#else
98#define do_leds()
99#endif
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
Kevin Hilman9e4559d2007-03-14 17:33:24 +0100102#ifndef CONFIG_GENERIC_CLOCKEVENTS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103/*
104 * Kernel system timer support.
105 */
Linus Torvalds0cd61b62006-10-06 10:53:39 -0700106void timer_tick(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Frederik Deweerdte317c8c2006-10-06 18:58:24 +0000108 profile_tick(CPU_PROFILING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 do_leds();
Russell King193c3cc2008-01-28 10:16:37 +0000110 write_seqlock(&xtime_lock);
Atsushi Nemoto3171a032006-09-29 02:00:32 -0700111 do_timer(1);
Russell King193c3cc2008-01-28 10:16:37 +0000112 write_sequnlock(&xtime_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113#ifndef CONFIG_SMP
Russell Kingc97d4862006-10-25 13:59:16 +0100114 update_process_times(user_mode(get_irq_regs()));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115#endif
116}
Kevin Hilman9e4559d2007-03-14 17:33:24 +0100117#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
Kevin Hilman9e4559d2007-03-14 17:33:24 +0100119#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120static int timer_suspend(struct sys_device *dev, pm_message_t state)
121{
122 struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
123
124 if (timer->suspend != NULL)
125 timer->suspend();
126
127 return 0;
128}
129
130static int timer_resume(struct sys_device *dev)
131{
132 struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
133
134 if (timer->resume != NULL)
135 timer->resume();
136
137 return 0;
138}
139#else
140#define timer_suspend NULL
141#define timer_resume NULL
142#endif
143
144static struct sysdev_class timer_sysclass = {
Kay Sieversaf5ca3f2007-12-20 02:09:39 +0100145 .name = "timer",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 .suspend = timer_suspend,
147 .resume = timer_resume,
148};
149
150static int __init timer_init_sysfs(void)
151{
152 int ret = sysdev_class_register(&timer_sysclass);
153 if (ret == 0) {
154 system_timer->dev.cls = &timer_sysclass;
155 ret = sysdev_register(&system_timer->dev);
156 }
Russell King8749af62005-06-25 19:39:45 +0100157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 return ret;
159}
160
161device_initcall(timer_init_sysfs);
162
163void __init time_init(void)
164{
Russell King8ff14432010-12-20 10:18:36 +0000165 system_timer = machine_desc->timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 system_timer->init();
Russell King211baa702011-01-11 16:23:04 +0000167#ifdef CONFIG_HAVE_SCHED_CLOCK
168 sched_clock_postinit();
169#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170}
171