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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...
13 */
14#include <linux/export.h>
15#include <linux/kernel.h>
16#include <linux/interrupt.h>
17#include <linux/time.h>
18#include <linux/init.h>
19#include <linux/sched.h>
20#include <linux/smp.h>
21#include <linux/timex.h>
22#include <linux/errno.h>
23#include <linux/profile.h>
24#include <linux/syscore_ops.h>
25#include <linux/timer.h>
26#include <linux/irq.h>
27
28#include <asm/leds.h>
29#include <asm/thread_info.h>
30#include <asm/sched_clock.h>
31#include <asm/stacktrace.h>
32#include <asm/mach/arch.h>
33#include <asm/mach/time.h>
34
35/*
36 * Our system timer.
37 */
38static struct sys_timer *system_timer;
39
40#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
41 defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
42/* this needs a better home */
43DEFINE_SPINLOCK(rtc_lock);
44EXPORT_SYMBOL(rtc_lock);
45#endif /* pc-style 'CMOS' RTC support */
46
47/* change this if you have some constant time drift */
48#define USECS_PER_JIFFY (1000000/HZ)
49
50#ifdef CONFIG_SMP
51unsigned long profile_pc(struct pt_regs *regs)
52{
53 struct stackframe frame;
54
55 if (!in_lock_functions(regs->ARM_pc))
56 return regs->ARM_pc;
57
58 frame.fp = regs->ARM_fp;
59 frame.sp = regs->ARM_sp;
60 frame.lr = regs->ARM_lr;
61 frame.pc = regs->ARM_pc;
62 do {
63 int ret = unwind_frame(&frame);
64 if (ret < 0)
65 return 0;
66 } while (in_lock_functions(frame.pc));
67
68 return frame.pc;
69}
70EXPORT_SYMBOL(profile_pc);
71#endif
72
73#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
74u32 arch_gettimeoffset(void)
75{
76 if (system_timer->offset != NULL)
77 return system_timer->offset() * 1000;
78
79 return 0;
80}
81#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
82
83#ifdef CONFIG_LEDS_TIMER
84static inline void do_leds(void)
85{
86 static unsigned int count = HZ/2;
87
88 if (--count == 0) {
89 count = HZ/2;
90 leds_event(led_timer);
91 }
92}
93#else
94#define do_leds()
95#endif
96
97
98#ifndef CONFIG_GENERIC_CLOCKEVENTS
99/*
100 * Kernel system timer support.
101 */
102void timer_tick(void)
103{
104 profile_tick(CPU_PROFILING);
105 do_leds();
106 xtime_update(1);
107#ifndef CONFIG_SMP
108 update_process_times(user_mode(get_irq_regs()));
109#endif
110}
111#endif
112
113static void dummy_clock_access(struct timespec *ts)
114{
115 ts->tv_sec = 0;
116 ts->tv_nsec = 0;
117}
118
119static clock_access_fn __read_persistent_clock = dummy_clock_access;
120static clock_access_fn __read_boot_clock = dummy_clock_access;;
121
122void read_persistent_clock(struct timespec *ts)
123{
124 __read_persistent_clock(ts);
125}
126
127void read_boot_clock(struct timespec *ts)
128{
129 __read_boot_clock(ts);
130}
131
132int __init register_persistent_clock(clock_access_fn read_boot,
133 clock_access_fn read_persistent)
134{
135 /* Only allow the clockaccess functions to be registered once */
136 if (__read_persistent_clock == dummy_clock_access &&
137 __read_boot_clock == dummy_clock_access) {
138 if (read_boot)
139 __read_boot_clock = read_boot;
140 if (read_persistent)
141 __read_persistent_clock = read_persistent;
142
143 return 0;
144 }
145
146 return -EINVAL;
147}
148
149#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS)
150static int timer_suspend(void)
151{
152 if (system_timer->suspend)
153 system_timer->suspend();
154
155 return 0;
156}
157
158static void timer_resume(void)
159{
160 if (system_timer->resume)
161 system_timer->resume();
162}
163#else
164#define timer_suspend NULL
165#define timer_resume NULL
166#endif
167
168static struct syscore_ops timer_syscore_ops = {
169 .suspend = timer_suspend,
170 .resume = timer_resume,
171};
172
173static int __init timer_init_syscore_ops(void)
174{
175 register_syscore_ops(&timer_syscore_ops);
176
177 return 0;
178}
179
180device_initcall(timer_init_syscore_ops);
181
182void __init time_init(void)
183{
184 system_timer = machine_desc->timer;
185 system_timer->init();
186 sched_clock_postinit();
187}
188
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/arm/kernel/time.c
4 *
5 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
6 * Modifications for ARM (C) 1994-2001 Russell King
7 *
8 * This file contains the ARM-specific time handling details:
9 * reading the RTC at bootup, etc...
10 */
11#include <linux/clk-provider.h>
12#include <linux/clocksource.h>
13#include <linux/errno.h>
14#include <linux/export.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/kernel.h>
19#include <linux/profile.h>
20#include <linux/sched.h>
21#include <linux/sched_clock.h>
22#include <linux/smp.h>
23#include <linux/time.h>
24#include <linux/timex.h>
25#include <linux/timer.h>
26
27#include <asm/mach/arch.h>
28#include <asm/mach/time.h>
29#include <asm/stacktrace.h>
30#include <asm/thread_info.h>
31
32#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
33 defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
34/* this needs a better home */
35DEFINE_SPINLOCK(rtc_lock);
36EXPORT_SYMBOL(rtc_lock);
37#endif /* pc-style 'CMOS' RTC support */
38
39/* change this if you have some constant time drift */
40#define USECS_PER_JIFFY (1000000/HZ)
41
42#ifdef CONFIG_SMP
43unsigned long profile_pc(struct pt_regs *regs)
44{
45 struct stackframe frame;
46
47 if (!in_lock_functions(regs->ARM_pc))
48 return regs->ARM_pc;
49
50 arm_get_current_stackframe(regs, &frame);
51 do {
52 int ret = unwind_frame(&frame);
53 if (ret < 0)
54 return 0;
55 } while (in_lock_functions(frame.pc));
56
57 return frame.pc;
58}
59EXPORT_SYMBOL(profile_pc);
60#endif
61
62#ifndef CONFIG_GENERIC_CLOCKEVENTS
63/*
64 * Kernel system timer support.
65 */
66void timer_tick(void)
67{
68 profile_tick(CPU_PROFILING);
69 xtime_update(1);
70#ifndef CONFIG_SMP
71 update_process_times(user_mode(get_irq_regs()));
72#endif
73}
74#endif
75
76static void dummy_clock_access(struct timespec64 *ts)
77{
78 ts->tv_sec = 0;
79 ts->tv_nsec = 0;
80}
81
82static clock_access_fn __read_persistent_clock = dummy_clock_access;
83
84void read_persistent_clock64(struct timespec64 *ts)
85{
86 __read_persistent_clock(ts);
87}
88
89int __init register_persistent_clock(clock_access_fn read_persistent)
90{
91 /* Only allow the clockaccess functions to be registered once */
92 if (__read_persistent_clock == dummy_clock_access) {
93 if (read_persistent)
94 __read_persistent_clock = read_persistent;
95 return 0;
96 }
97
98 return -EINVAL;
99}
100
101void __init time_init(void)
102{
103 if (machine_desc->init_time) {
104 machine_desc->init_time();
105 } else {
106#ifdef CONFIG_COMMON_CLK
107 of_clk_init(NULL);
108#endif
109 timer_probe();
110 }
111}