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| 2 | |
| 3 | * linux/arch/arm/kernel/time.c
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| 4 | *
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| 5 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds
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| 6 | * Modifications for ARM (C) 1994-2001 Russell King
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| 7 | *
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| 8 | * This file contains the ARM-specific time handling details:
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| 9 | * reading the RTC at bootup, etc...
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| 10 |
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| 11 | #include <linux/clockchips.h>
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| 12 | #include <linux/clocksource.h>
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| 13 | #include <linux/errno.h>
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| 14 | #include <linux/export.h>
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| 15 | #include <linux/init.h>
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| 16 | #include <linux/interrupt.h>
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| 17 | #include <linux/irq.h>
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| 18 | #include <linux/kernel.h>
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| 19 | #include <linux/of_clk.h>
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| 20 | #include <linux/profile.h>
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| 21 | #include <linux/sched.h>
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| 22 | #include <linux/sched_clock.h>
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| 23 | #include <linux/smp.h>
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| 24 | #include <linux/time.h>
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| 25 | #include <linux/timex.h>
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| 26 | #include <linux/timer.h>
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| 27 |
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| 28 | #include <asm/mach/arch.h>
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| 29 | #include <asm/mach/time.h>
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| 30 | #include <asm/stacktrace.h>
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| 31 | #include <asm/thread_info.h>
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| 32 |
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| 33 | #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
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| 34 | defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
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| 35 |
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| 36 | DEFINE_SPINLOCK(rtc_lock);
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| 37 | EXPORT_SYMBOL(rtc_lock);
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| 38 | #endif
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| 39 |
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| 40 |
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| 41 | #define USECS_PER_JIFFY (1000000/HZ)
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| 42 |
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| 43 | #ifdef CONFIG_SMP
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| 44 | unsigned long profile_pc(struct pt_regs *regs)
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| 45 | {
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| 46 | struct stackframe frame;
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| 47 |
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| 48 | if (!in_lock_functions(regs->ARM_pc))
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| 49 | return regs->ARM_pc;
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| 50 |
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| 51 | arm_get_current_stackframe(regs, &frame);
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| 52 | do {
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| 53 | int ret = unwind_frame(&frame);
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| 54 | if (ret < 0)
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| 55 | return 0;
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| 56 | } while (in_lock_functions(frame.pc));
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| 57 |
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| 58 | return frame.pc;
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| 59 | }
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| 60 | EXPORT_SYMBOL(profile_pc);
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| 61 | #endif
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| 62 |
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| 63 | static void dummy_clock_access(struct timespec64 *ts)
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| 64 | {
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| 65 | ts->tv_sec = 0;
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| 66 | ts->tv_nsec = 0;
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| 67 | }
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| 68 |
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| 69 | static clock_access_fn __read_persistent_clock = dummy_clock_access;
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| 70 |
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| 71 | void read_persistent_clock64(struct timespec64 *ts)
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| 72 | {
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| 73 | __read_persistent_clock(ts);
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| 74 | }
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| 75 |
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| 76 | int __init register_persistent_clock(clock_access_fn read_persistent)
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| 77 | {
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| 78 |
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| 79 | if (__read_persistent_clock == dummy_clock_access) {
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| 80 | if (read_persistent)
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| 81 | __read_persistent_clock = read_persistent;
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| 82 | return 0;
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| 83 | }
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| 84 |
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| 85 | return -EINVAL;
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| 86 | }
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| 87 |
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| 88 | void __init time_init(void)
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| 89 | {
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| 90 | if (machine_desc->init_time) {
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| 91 | machine_desc->init_time();
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| 92 | } else {
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| 93 | #ifdef CONFIG_COMMON_CLK
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| 94 | of_clk_init(NULL);
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| 95 | #endif
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| 96 | timer_probe();
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| 97 | tick_setup_hrtimer_broadcast();
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| 98 | }
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| 99 | }
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