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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/clockchips.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/of_clk.h>
20#include <linux/profile.h>
21#include <linux/sched.h>
22#include <linux/sched_clock.h>
23#include <linux/smp.h>
24#include <linux/time.h>
25#include <linux/timex.h>
26#include <linux/timer.h>
27
28#include <asm/mach/arch.h>
29#include <asm/mach/time.h>
30#include <asm/stacktrace.h>
31#include <asm/thread_info.h>
32
33#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
34 defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
35/* this needs a better home */
36DEFINE_SPINLOCK(rtc_lock);
37EXPORT_SYMBOL(rtc_lock);
38#endif /* pc-style 'CMOS' RTC support */
39
40/* change this if you have some constant time drift */
41#define USECS_PER_JIFFY (1000000/HZ)
42
43#ifdef CONFIG_SMP
44unsigned long profile_pc(struct pt_regs *regs)
45{
46 struct stackframe frame;
47
48 if (!in_lock_functions(regs->ARM_pc))
49 return regs->ARM_pc;
50
51 arm_get_current_stackframe(regs, &frame);
52 do {
53 int ret = unwind_frame(&frame);
54 if (ret < 0)
55 return 0;
56 } while (in_lock_functions(frame.pc));
57
58 return frame.pc;
59}
60EXPORT_SYMBOL(profile_pc);
61#endif
62
63#ifndef CONFIG_GENERIC_CLOCKEVENTS
64/*
65 * Kernel system timer support.
66 */
67void timer_tick(void)
68{
69 profile_tick(CPU_PROFILING);
70 xtime_update(1);
71#ifndef CONFIG_SMP
72 update_process_times(user_mode(get_irq_regs()));
73#endif
74}
75#endif
76
77static void dummy_clock_access(struct timespec64 *ts)
78{
79 ts->tv_sec = 0;
80 ts->tv_nsec = 0;
81}
82
83static clock_access_fn __read_persistent_clock = dummy_clock_access;
84
85void read_persistent_clock64(struct timespec64 *ts)
86{
87 __read_persistent_clock(ts);
88}
89
90int __init register_persistent_clock(clock_access_fn read_persistent)
91{
92 /* Only allow the clockaccess functions to be registered once */
93 if (__read_persistent_clock == dummy_clock_access) {
94 if (read_persistent)
95 __read_persistent_clock = read_persistent;
96 return 0;
97 }
98
99 return -EINVAL;
100}
101
102void __init time_init(void)
103{
104 if (machine_desc->init_time) {
105 machine_desc->init_time();
106 } else {
107#ifdef CONFIG_COMMON_CLK
108 of_clk_init(NULL);
109#endif
110 timer_probe();
111 tick_setup_hrtimer_broadcast();
112 }
113}
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/module.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 <linux/mc146818rtc.h>
29
30#include <asm/leds.h>
31#include <asm/thread_info.h>
32#include <asm/sched_clock.h>
33#include <asm/stacktrace.h>
34#include <asm/mach/arch.h>
35#include <asm/mach/time.h>
36
37/*
38 * Our system timer.
39 */
40static struct sys_timer *system_timer;
41
42#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
43/* this needs a better home */
44DEFINE_SPINLOCK(rtc_lock);
45
46#ifdef CONFIG_RTC_DRV_CMOS_MODULE
47EXPORT_SYMBOL(rtc_lock);
48#endif
49#endif /* pc-style 'CMOS' RTC support */
50
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{
57 struct stackframe frame;
58
59 if (!in_lock_functions(regs->ARM_pc))
60 return regs->ARM_pc;
61
62 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;
73}
74EXPORT_SYMBOL(profile_pc);
75#endif
76
77#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
78u32 arch_gettimeoffset(void)
79{
80 if (system_timer->offset != NULL)
81 return system_timer->offset() * 1000;
82
83 return 0;
84}
85#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
86
87#ifdef CONFIG_LEDS_TIMER
88static inline void do_leds(void)
89{
90 static unsigned int count = HZ/2;
91
92 if (--count == 0) {
93 count = HZ/2;
94 leds_event(led_timer);
95 }
96}
97#else
98#define do_leds()
99#endif
100
101
102#ifndef CONFIG_GENERIC_CLOCKEVENTS
103/*
104 * Kernel system timer support.
105 */
106void timer_tick(void)
107{
108 profile_tick(CPU_PROFILING);
109 do_leds();
110 xtime_update(1);
111#ifndef CONFIG_SMP
112 update_process_times(user_mode(get_irq_regs()));
113#endif
114}
115#endif
116
117#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS)
118static int timer_suspend(void)
119{
120 if (system_timer->suspend)
121 system_timer->suspend();
122
123 return 0;
124}
125
126static void timer_resume(void)
127{
128 if (system_timer->resume)
129 system_timer->resume();
130}
131#else
132#define timer_suspend NULL
133#define timer_resume NULL
134#endif
135
136static struct syscore_ops timer_syscore_ops = {
137 .suspend = timer_suspend,
138 .resume = timer_resume,
139};
140
141static int __init timer_init_syscore_ops(void)
142{
143 register_syscore_ops(&timer_syscore_ops);
144
145 return 0;
146}
147
148device_initcall(timer_init_syscore_ops);
149
150void __init time_init(void)
151{
152 system_timer = machine_desc->timer;
153 system_timer->init();
154#ifdef CONFIG_HAVE_SCHED_CLOCK
155 sched_clock_postinit();
156#endif
157}
158