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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 | */ |
1da177e4 LT |
14 | #include <linux/module.h> |
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> | |
24 | #include <linux/sysdev.h> | |
25 | #include <linux/timer.h> | |
e317c8cc | 26 | #include <linux/irq.h> |
1da177e4 | 27 | |
9ca3f07b BD |
28 | #include <linux/mc146818rtc.h> |
29 | ||
1da177e4 LT |
30 | #include <asm/leds.h> |
31 | #include <asm/thread_info.h> | |
2d7c11bf | 32 | #include <asm/stacktrace.h> |
1da177e4 LT |
33 | #include <asm/mach/time.h> |
34 | ||
1da177e4 LT |
35 | /* |
36 | * Our system timer. | |
37 | */ | |
38 | struct sys_timer *system_timer; | |
39 | ||
9dd34948 | 40 | #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) |
1da177e4 LT |
41 | /* this needs a better home */ |
42 | DEFINE_SPINLOCK(rtc_lock); | |
43 | ||
9dd34948 | 44 | #ifdef CONFIG_RTC_DRV_CMOS_MODULE |
1da177e4 LT |
45 | EXPORT_SYMBOL(rtc_lock); |
46 | #endif | |
9dd34948 | 47 | #endif /* pc-style 'CMOS' RTC support */ |
1da177e4 LT |
48 | |
49 | /* change this if you have some constant time drift */ | |
50 | #define USECS_PER_JIFFY (1000000/HZ) | |
51 | ||
52 | #ifdef CONFIG_SMP | |
53 | unsigned long profile_pc(struct pt_regs *regs) | |
54 | { | |
2d7c11bf | 55 | struct stackframe frame; |
1da177e4 | 56 | |
2d7c11bf CM |
57 | if (!in_lock_functions(regs->ARM_pc)) |
58 | return regs->ARM_pc; | |
1da177e4 | 59 | |
2d7c11bf CM |
60 | frame.fp = regs->ARM_fp; |
61 | frame.sp = regs->ARM_sp; | |
62 | frame.lr = regs->ARM_lr; | |
63 | frame.pc = regs->ARM_pc; | |
64 | do { | |
65 | int ret = unwind_frame(&frame); | |
66 | if (ret < 0) | |
67 | return 0; | |
68 | } while (in_lock_functions(frame.pc)); | |
69 | ||
70 | return frame.pc; | |
1da177e4 LT |
71 | } |
72 | EXPORT_SYMBOL(profile_pc); | |
73 | #endif | |
74 | ||
746140c7 | 75 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
76 | static unsigned long dummy_gettimeoffset(void) |
77 | { | |
78 | return 0; | |
79 | } | |
746140c7 | 80 | #endif |
1da177e4 | 81 | |
1da177e4 LT |
82 | #ifdef CONFIG_LEDS_TIMER |
83 | static inline void do_leds(void) | |
84 | { | |
6d15cb42 | 85 | static unsigned int count = HZ/2; |
1da177e4 LT |
86 | |
87 | if (--count == 0) { | |
6d15cb42 | 88 | count = HZ/2; |
1da177e4 LT |
89 | leds_event(led_timer); |
90 | } | |
91 | } | |
92 | #else | |
93 | #define do_leds() | |
94 | #endif | |
95 | ||
746140c7 | 96 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
97 | void do_gettimeofday(struct timeval *tv) |
98 | { | |
99 | unsigned long flags; | |
100 | unsigned long seq; | |
8ef38609 | 101 | unsigned long usec, sec; |
1da177e4 LT |
102 | |
103 | do { | |
104 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | |
105 | usec = system_timer->offset(); | |
1da177e4 LT |
106 | sec = xtime.tv_sec; |
107 | usec += xtime.tv_nsec / 1000; | |
108 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | |
109 | ||
110 | /* usec may have gone up a lot: be safe */ | |
111 | while (usec >= 1000000) { | |
112 | usec -= 1000000; | |
113 | sec++; | |
114 | } | |
115 | ||
116 | tv->tv_sec = sec; | |
117 | tv->tv_usec = usec; | |
118 | } | |
119 | ||
120 | EXPORT_SYMBOL(do_gettimeofday); | |
121 | ||
122 | int do_settimeofday(struct timespec *tv) | |
123 | { | |
124 | time_t wtm_sec, sec = tv->tv_sec; | |
125 | long wtm_nsec, nsec = tv->tv_nsec; | |
126 | ||
127 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
128 | return -EINVAL; | |
129 | ||
130 | write_seqlock_irq(&xtime_lock); | |
131 | /* | |
132 | * This is revolting. We need to set "xtime" correctly. However, the | |
133 | * value in this location is the value at the most recent update of | |
134 | * wall time. Discover what correction gettimeofday() would have | |
135 | * done, and then undo it! | |
136 | */ | |
137 | nsec -= system_timer->offset() * NSEC_PER_USEC; | |
1da177e4 LT |
138 | |
139 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | |
140 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
141 | ||
142 | set_normalized_timespec(&xtime, sec, nsec); | |
143 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
144 | ||
b149ee22 | 145 | ntp_clear(); |
1da177e4 LT |
146 | write_sequnlock_irq(&xtime_lock); |
147 | clock_was_set(); | |
148 | return 0; | |
149 | } | |
150 | ||
151 | EXPORT_SYMBOL(do_settimeofday); | |
746140c7 | 152 | #endif /* !CONFIG_GENERIC_TIME */ |
1da177e4 | 153 | |
9e4559dd | 154 | #ifndef CONFIG_GENERIC_CLOCKEVENTS |
1da177e4 LT |
155 | /* |
156 | * Kernel system timer support. | |
157 | */ | |
0cd61b68 | 158 | void timer_tick(void) |
1da177e4 | 159 | { |
e317c8cc | 160 | profile_tick(CPU_PROFILING); |
1da177e4 | 161 | do_leds(); |
193c3cc1 | 162 | write_seqlock(&xtime_lock); |
3171a030 | 163 | do_timer(1); |
193c3cc1 | 164 | write_sequnlock(&xtime_lock); |
1da177e4 | 165 | #ifndef CONFIG_SMP |
c97d4869 | 166 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
167 | #endif |
168 | } | |
9e4559dd | 169 | #endif |
1da177e4 | 170 | |
9e4559dd | 171 | #if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) |
1da177e4 LT |
172 | static int timer_suspend(struct sys_device *dev, pm_message_t state) |
173 | { | |
174 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
175 | ||
176 | if (timer->suspend != NULL) | |
177 | timer->suspend(); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | static int timer_resume(struct sys_device *dev) | |
183 | { | |
184 | struct sys_timer *timer = container_of(dev, struct sys_timer, dev); | |
185 | ||
186 | if (timer->resume != NULL) | |
187 | timer->resume(); | |
188 | ||
189 | return 0; | |
190 | } | |
191 | #else | |
192 | #define timer_suspend NULL | |
193 | #define timer_resume NULL | |
194 | #endif | |
195 | ||
196 | static struct sysdev_class timer_sysclass = { | |
af5ca3f4 | 197 | .name = "timer", |
1da177e4 LT |
198 | .suspend = timer_suspend, |
199 | .resume = timer_resume, | |
200 | }; | |
201 | ||
202 | static int __init timer_init_sysfs(void) | |
203 | { | |
204 | int ret = sysdev_class_register(&timer_sysclass); | |
205 | if (ret == 0) { | |
206 | system_timer->dev.cls = &timer_sysclass; | |
207 | ret = sysdev_register(&system_timer->dev); | |
208 | } | |
8749af68 | 209 | |
1da177e4 LT |
210 | return ret; |
211 | } | |
212 | ||
213 | device_initcall(timer_init_sysfs); | |
214 | ||
215 | void __init time_init(void) | |
216 | { | |
746140c7 | 217 | #ifndef CONFIG_GENERIC_TIME |
1da177e4 LT |
218 | if (system_timer->offset == NULL) |
219 | system_timer->offset = dummy_gettimeoffset; | |
746140c7 | 220 | #endif |
1da177e4 LT |
221 | system_timer->init(); |
222 | } | |
223 |