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1da177e4 LT |
1 | /* |
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... | |
1da177e4 | 13 | */ |
ecea4ab6 | 14 | #include <linux/export.h> |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/time.h> | |
18 | #include <linux/init.h> | |
d43c36dc | 19 | #include <linux/sched.h> |
1da177e4 LT |
20 | #include <linux/smp.h> |
21 | #include <linux/timex.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/profile.h> | |
328f5cc3 | 24 | #include <linux/syscore_ops.h> |
1da177e4 | 25 | #include <linux/timer.h> |
e317c8cc | 26 | #include <linux/irq.h> |
1da177e4 | 27 | |
1da177e4 | 28 | #include <asm/thread_info.h> |
211baa70 | 29 | #include <asm/sched_clock.h> |
2d7c11bf | 30 | #include <asm/stacktrace.h> |
8ff1443c | 31 | #include <asm/mach/arch.h> |
1da177e4 LT |
32 | #include <asm/mach/time.h> |
33 | ||
1da177e4 LT |
34 | /* |
35 | * Our system timer. | |
36 | */ | |
8ff1443c | 37 | static struct sys_timer *system_timer; |
1da177e4 | 38 | |
63216d3c AB |
39 | #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \ |
40 | defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE) | |
1da177e4 LT |
41 | /* this needs a better home */ |
42 | DEFINE_SPINLOCK(rtc_lock); | |
1da177e4 | 43 | EXPORT_SYMBOL(rtc_lock); |
9dd34948 | 44 | #endif /* pc-style 'CMOS' RTC support */ |
1da177e4 LT |
45 | |
46 | /* change this if you have some constant time drift */ | |
47 | #define USECS_PER_JIFFY (1000000/HZ) | |
48 | ||
49 | #ifdef CONFIG_SMP | |
50 | unsigned long profile_pc(struct pt_regs *regs) | |
51 | { | |
2d7c11bf | 52 | struct stackframe frame; |
1da177e4 | 53 | |
2d7c11bf CM |
54 | if (!in_lock_functions(regs->ARM_pc)) |
55 | return regs->ARM_pc; | |
1da177e4 | 56 | |
2d7c11bf CM |
57 | frame.fp = regs->ARM_fp; |
58 | frame.sp = regs->ARM_sp; | |
59 | frame.lr = regs->ARM_lr; | |
60 | frame.pc = regs->ARM_pc; | |
61 | do { | |
62 | int ret = unwind_frame(&frame); | |
63 | if (ret < 0) | |
64 | return 0; | |
65 | } while (in_lock_functions(frame.pc)); | |
66 | ||
67 | return frame.pc; | |
1da177e4 LT |
68 | } |
69 | EXPORT_SYMBOL(profile_pc); | |
70 | #endif | |
71 | ||
5cfc8ee0 JS |
72 | #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET |
73 | u32 arch_gettimeoffset(void) | |
1da177e4 | 74 | { |
5cfc8ee0 JS |
75 | if (system_timer->offset != NULL) |
76 | return system_timer->offset() * 1000; | |
77 | ||
1da177e4 LT |
78 | return 0; |
79 | } | |
5cfc8ee0 | 80 | #endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */ |
1da177e4 | 81 | |
9e4559dd | 82 | #ifndef CONFIG_GENERIC_CLOCKEVENTS |
1da177e4 LT |
83 | /* |
84 | * Kernel system timer support. | |
85 | */ | |
0cd61b68 | 86 | void timer_tick(void) |
1da177e4 | 87 | { |
e317c8cc | 88 | profile_tick(CPU_PROFILING); |
6906e33c | 89 | xtime_update(1); |
1da177e4 | 90 | #ifndef CONFIG_SMP |
c97d4869 | 91 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
92 | #endif |
93 | } | |
9e4559dd | 94 | #endif |
1da177e4 | 95 | |
bd0493ea MZ |
96 | static void dummy_clock_access(struct timespec *ts) |
97 | { | |
98 | ts->tv_sec = 0; | |
99 | ts->tv_nsec = 0; | |
100 | } | |
101 | ||
102 | static clock_access_fn __read_persistent_clock = dummy_clock_access; | |
103 | static clock_access_fn __read_boot_clock = dummy_clock_access;; | |
104 | ||
105 | void read_persistent_clock(struct timespec *ts) | |
106 | { | |
107 | __read_persistent_clock(ts); | |
108 | } | |
109 | ||
110 | void read_boot_clock(struct timespec *ts) | |
111 | { | |
112 | __read_boot_clock(ts); | |
113 | } | |
114 | ||
115 | int __init register_persistent_clock(clock_access_fn read_boot, | |
116 | clock_access_fn read_persistent) | |
117 | { | |
118 | /* Only allow the clockaccess functions to be registered once */ | |
119 | if (__read_persistent_clock == dummy_clock_access && | |
120 | __read_boot_clock == dummy_clock_access) { | |
121 | if (read_boot) | |
122 | __read_boot_clock = read_boot; | |
123 | if (read_persistent) | |
124 | __read_persistent_clock = read_persistent; | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | return -EINVAL; | |
130 | } | |
131 | ||
9e4559dd | 132 | #if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) |
328f5cc3 | 133 | static int timer_suspend(void) |
1da177e4 | 134 | { |
328f5cc3 RW |
135 | if (system_timer->suspend) |
136 | system_timer->suspend(); | |
1da177e4 LT |
137 | |
138 | return 0; | |
139 | } | |
140 | ||
328f5cc3 | 141 | static void timer_resume(void) |
1da177e4 | 142 | { |
328f5cc3 RW |
143 | if (system_timer->resume) |
144 | system_timer->resume(); | |
1da177e4 LT |
145 | } |
146 | #else | |
147 | #define timer_suspend NULL | |
148 | #define timer_resume NULL | |
149 | #endif | |
150 | ||
328f5cc3 | 151 | static struct syscore_ops timer_syscore_ops = { |
1da177e4 LT |
152 | .suspend = timer_suspend, |
153 | .resume = timer_resume, | |
154 | }; | |
155 | ||
328f5cc3 | 156 | static int __init timer_init_syscore_ops(void) |
1da177e4 | 157 | { |
328f5cc3 | 158 | register_syscore_ops(&timer_syscore_ops); |
8749af68 | 159 | |
328f5cc3 | 160 | return 0; |
1da177e4 LT |
161 | } |
162 | ||
328f5cc3 | 163 | device_initcall(timer_init_syscore_ops); |
1da177e4 LT |
164 | |
165 | void __init time_init(void) | |
166 | { | |
8ff1443c | 167 | system_timer = machine_desc->timer; |
1da177e4 | 168 | system_timer->init(); |
211baa70 | 169 | sched_clock_postinit(); |
1da177e4 LT |
170 | } |
171 |