Commit | Line | Data |
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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> | |
1da177e4 | 24 | #include <linux/timer.h> |
f414f13f | 25 | #include <linux/clocksource.h> |
e317c8cc | 26 | #include <linux/irq.h> |
38ff87f7 | 27 | #include <linux/sched_clock.h> |
1da177e4 | 28 | |
1da177e4 | 29 | #include <asm/thread_info.h> |
2d7c11bf | 30 | #include <asm/stacktrace.h> |
8ff1443c | 31 | #include <asm/mach/arch.h> |
1da177e4 LT |
32 | #include <asm/mach/time.h> |
33 | ||
63216d3c AB |
34 | #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \ |
35 | defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE) | |
1da177e4 LT |
36 | /* this needs a better home */ |
37 | DEFINE_SPINLOCK(rtc_lock); | |
1da177e4 | 38 | EXPORT_SYMBOL(rtc_lock); |
9dd34948 | 39 | #endif /* pc-style 'CMOS' RTC support */ |
1da177e4 LT |
40 | |
41 | /* change this if you have some constant time drift */ | |
42 | #define USECS_PER_JIFFY (1000000/HZ) | |
43 | ||
44 | #ifdef CONFIG_SMP | |
45 | unsigned long profile_pc(struct pt_regs *regs) | |
46 | { | |
2d7c11bf | 47 | struct stackframe frame; |
1da177e4 | 48 | |
2d7c11bf CM |
49 | if (!in_lock_functions(regs->ARM_pc)) |
50 | return regs->ARM_pc; | |
1da177e4 | 51 | |
2d7c11bf CM |
52 | frame.fp = regs->ARM_fp; |
53 | frame.sp = regs->ARM_sp; | |
54 | frame.lr = regs->ARM_lr; | |
55 | frame.pc = regs->ARM_pc; | |
56 | do { | |
57 | int ret = unwind_frame(&frame); | |
58 | if (ret < 0) | |
59 | return 0; | |
60 | } while (in_lock_functions(frame.pc)); | |
61 | ||
62 | return frame.pc; | |
1da177e4 LT |
63 | } |
64 | EXPORT_SYMBOL(profile_pc); | |
65 | #endif | |
66 | ||
9e4559dd | 67 | #ifndef CONFIG_GENERIC_CLOCKEVENTS |
1da177e4 LT |
68 | /* |
69 | * Kernel system timer support. | |
70 | */ | |
0cd61b68 | 71 | void timer_tick(void) |
1da177e4 | 72 | { |
e317c8cc | 73 | profile_tick(CPU_PROFILING); |
6906e33c | 74 | xtime_update(1); |
1da177e4 | 75 | #ifndef CONFIG_SMP |
c97d4869 | 76 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
77 | #endif |
78 | } | |
9e4559dd | 79 | #endif |
1da177e4 | 80 | |
bd0493ea MZ |
81 | static void dummy_clock_access(struct timespec *ts) |
82 | { | |
83 | ts->tv_sec = 0; | |
84 | ts->tv_nsec = 0; | |
85 | } | |
86 | ||
87 | static clock_access_fn __read_persistent_clock = dummy_clock_access; | |
88 | static clock_access_fn __read_boot_clock = dummy_clock_access;; | |
89 | ||
90 | void read_persistent_clock(struct timespec *ts) | |
91 | { | |
92 | __read_persistent_clock(ts); | |
93 | } | |
94 | ||
95 | void read_boot_clock(struct timespec *ts) | |
96 | { | |
97 | __read_boot_clock(ts); | |
98 | } | |
99 | ||
100 | int __init register_persistent_clock(clock_access_fn read_boot, | |
101 | clock_access_fn read_persistent) | |
102 | { | |
103 | /* Only allow the clockaccess functions to be registered once */ | |
104 | if (__read_persistent_clock == dummy_clock_access && | |
105 | __read_boot_clock == dummy_clock_access) { | |
106 | if (read_boot) | |
107 | __read_boot_clock = read_boot; | |
108 | if (read_persistent) | |
109 | __read_persistent_clock = read_persistent; | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | return -EINVAL; | |
115 | } | |
116 | ||
1da177e4 LT |
117 | void __init time_init(void) |
118 | { | |
f414f13f AB |
119 | if (machine_desc->init_time) |
120 | machine_desc->init_time(); | |
121 | else | |
122 | clocksource_of_init(); | |
1da177e4 | 123 | } |