Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
402
arch/arm/kernel/time.c
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402
arch/arm/kernel/time.c
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/*
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* linux/arch/arm/kernel/time.c
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*
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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* Modifications for ARM (C) 1994-2001 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This file contains the ARM-specific time handling details:
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* reading the RTC at bootup, etc...
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*
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* 1994-07-02 Alan Modra
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* fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
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* 1998-12-20 Updated NTP code according to technical memorandum Jan '96
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* "A Kernel Model for Precision Timekeeping" by Dave Mills
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/init.h>
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#include <linux/smp.h>
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#include <linux/timex.h>
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#include <linux/errno.h>
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#include <linux/profile.h>
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#include <linux/sysdev.h>
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#include <linux/timer.h>
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#include <asm/hardware.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#include <asm/leds.h>
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#include <asm/thread_info.h>
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#include <asm/mach/time.h>
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u64 jiffies_64 = INITIAL_JIFFIES;
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EXPORT_SYMBOL(jiffies_64);
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/*
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* Our system timer.
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*/
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struct sys_timer *system_timer;
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extern unsigned long wall_jiffies;
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/* this needs a better home */
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DEFINE_SPINLOCK(rtc_lock);
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#ifdef CONFIG_SA1100_RTC_MODULE
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EXPORT_SYMBOL(rtc_lock);
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#endif
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/* change this if you have some constant time drift */
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#define USECS_PER_JIFFY (1000000/HZ)
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#ifdef CONFIG_SMP
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unsigned long profile_pc(struct pt_regs *regs)
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{
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unsigned long fp, pc = instruction_pointer(regs);
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if (in_lock_functions(pc)) {
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fp = regs->ARM_fp;
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pc = pc_pointer(((unsigned long *)fp)[-1]);
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}
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return pc;
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}
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EXPORT_SYMBOL(profile_pc);
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#endif
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/*
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* hook for setting the RTC's idea of the current time.
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*/
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int (*set_rtc)(void);
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static unsigned long dummy_gettimeoffset(void)
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{
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return 0;
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}
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/*
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* Scheduler clock - returns current time in nanosec units.
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* This is the default implementation. Sub-architecture
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* implementations can override this.
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*/
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unsigned long long __attribute__((weak)) sched_clock(void)
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{
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return (unsigned long long)jiffies * (1000000000 / HZ);
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}
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static unsigned long next_rtc_update;
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/*
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* If we have an externally synchronized linux clock, then update
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* CMOS clock accordingly every ~11 minutes. set_rtc() has to be
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* called as close as possible to 500 ms before the new second
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* starts.
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*/
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static inline void do_set_rtc(void)
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{
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if (time_status & STA_UNSYNC || set_rtc == NULL)
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return;
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if (next_rtc_update &&
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time_before((unsigned long)xtime.tv_sec, next_rtc_update))
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return;
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if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
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xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
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return;
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if (set_rtc())
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/*
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* rtc update failed. Try again in 60s
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*/
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next_rtc_update = xtime.tv_sec + 60;
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else
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next_rtc_update = xtime.tv_sec + 660;
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}
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#ifdef CONFIG_LEDS
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static void dummy_leds_event(led_event_t evt)
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{
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}
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void (*leds_event)(led_event_t) = dummy_leds_event;
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struct leds_evt_name {
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const char name[8];
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int on;
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int off;
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};
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static const struct leds_evt_name evt_names[] = {
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{ "amber", led_amber_on, led_amber_off },
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{ "blue", led_blue_on, led_blue_off },
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{ "green", led_green_on, led_green_off },
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{ "red", led_red_on, led_red_off },
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};
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static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size)
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{
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int ret = -EINVAL, len = strcspn(buf, " ");
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if (len > 0 && buf[len] == '\0')
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len--;
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if (strncmp(buf, "claim", len) == 0) {
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leds_event(led_claim);
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ret = size;
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} else if (strncmp(buf, "release", len) == 0) {
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leds_event(led_release);
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ret = size;
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} else {
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int i;
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for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
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if (strlen(evt_names[i].name) != len ||
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strncmp(buf, evt_names[i].name, len) != 0)
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continue;
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if (strncmp(buf+len, " on", 3) == 0) {
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leds_event(evt_names[i].on);
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ret = size;
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} else if (strncmp(buf+len, " off", 4) == 0) {
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leds_event(evt_names[i].off);
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ret = size;
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}
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break;
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}
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}
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return ret;
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}
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static SYSDEV_ATTR(event, 0200, NULL, leds_store);
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static int leds_suspend(struct sys_device *dev, pm_message_t state)
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{
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leds_event(led_stop);
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return 0;
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}
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static int leds_resume(struct sys_device *dev)
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{
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leds_event(led_start);
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return 0;
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}
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static int leds_shutdown(struct sys_device *dev)
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{
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leds_event(led_halted);
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return 0;
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}
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static struct sysdev_class leds_sysclass = {
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set_kset_name("leds"),
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.shutdown = leds_shutdown,
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.suspend = leds_suspend,
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.resume = leds_resume,
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};
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static struct sys_device leds_device = {
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.id = 0,
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.cls = &leds_sysclass,
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};
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static int __init leds_init(void)
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{
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int ret;
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ret = sysdev_class_register(&leds_sysclass);
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if (ret == 0)
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ret = sysdev_register(&leds_device);
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if (ret == 0)
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ret = sysdev_create_file(&leds_device, &attr_event);
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return ret;
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}
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device_initcall(leds_init);
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EXPORT_SYMBOL(leds_event);
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#endif
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#ifdef CONFIG_LEDS_TIMER
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static inline void do_leds(void)
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{
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static unsigned int count = 50;
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if (--count == 0) {
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count = 50;
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leds_event(led_timer);
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}
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}
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#else
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#define do_leds()
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#endif
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void do_gettimeofday(struct timeval *tv)
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{
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unsigned long flags;
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unsigned long seq;
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unsigned long usec, sec, lost;
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do {
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seq = read_seqbegin_irqsave(&xtime_lock, flags);
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usec = system_timer->offset();
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lost = jiffies - wall_jiffies;
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if (lost)
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usec += lost * USECS_PER_JIFFY;
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sec = xtime.tv_sec;
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usec += xtime.tv_nsec / 1000;
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} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
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/* usec may have gone up a lot: be safe */
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while (usec >= 1000000) {
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usec -= 1000000;
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sec++;
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}
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tv->tv_sec = sec;
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tv->tv_usec = usec;
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}
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EXPORT_SYMBOL(do_gettimeofday);
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int do_settimeofday(struct timespec *tv)
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{
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time_t wtm_sec, sec = tv->tv_sec;
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long wtm_nsec, nsec = tv->tv_nsec;
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if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
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return -EINVAL;
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write_seqlock_irq(&xtime_lock);
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/*
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* This is revolting. We need to set "xtime" correctly. However, the
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* value in this location is the value at the most recent update of
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* wall time. Discover what correction gettimeofday() would have
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* done, and then undo it!
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*/
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nsec -= system_timer->offset() * NSEC_PER_USEC;
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nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
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wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
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wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
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set_normalized_timespec(&xtime, sec, nsec);
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set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
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time_adjust = 0; /* stop active adjtime() */
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time_status |= STA_UNSYNC;
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time_maxerror = NTP_PHASE_LIMIT;
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time_esterror = NTP_PHASE_LIMIT;
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write_sequnlock_irq(&xtime_lock);
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clock_was_set();
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return 0;
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}
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EXPORT_SYMBOL(do_settimeofday);
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/**
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* save_time_delta - Save the offset between system time and RTC time
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* @delta: pointer to timespec to store delta
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* @rtc: pointer to timespec for current RTC time
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*
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* Return a delta between the system time and the RTC time, such
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* that system time can be restored later with restore_time_delta()
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*/
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void save_time_delta(struct timespec *delta, struct timespec *rtc)
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{
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set_normalized_timespec(delta,
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xtime.tv_sec - rtc->tv_sec,
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xtime.tv_nsec - rtc->tv_nsec);
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}
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EXPORT_SYMBOL(save_time_delta);
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/**
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* restore_time_delta - Restore the current system time
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* @delta: delta returned by save_time_delta()
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* @rtc: pointer to timespec for current RTC time
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*/
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void restore_time_delta(struct timespec *delta, struct timespec *rtc)
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{
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struct timespec ts;
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set_normalized_timespec(&ts,
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delta->tv_sec + rtc->tv_sec,
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delta->tv_nsec + rtc->tv_nsec);
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do_settimeofday(&ts);
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}
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EXPORT_SYMBOL(restore_time_delta);
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/*
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* Kernel system timer support.
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*/
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void timer_tick(struct pt_regs *regs)
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{
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profile_tick(CPU_PROFILING, regs);
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do_leds();
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do_set_rtc();
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do_timer(regs);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(regs));
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#endif
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}
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#ifdef CONFIG_PM
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static int timer_suspend(struct sys_device *dev, pm_message_t state)
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{
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struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
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if (timer->suspend != NULL)
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timer->suspend();
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return 0;
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}
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static int timer_resume(struct sys_device *dev)
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{
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struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
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if (timer->resume != NULL)
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timer->resume();
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return 0;
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}
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#else
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#define timer_suspend NULL
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#define timer_resume NULL
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#endif
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static struct sysdev_class timer_sysclass = {
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set_kset_name("timer"),
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.suspend = timer_suspend,
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.resume = timer_resume,
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};
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static int __init timer_init_sysfs(void)
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{
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int ret = sysdev_class_register(&timer_sysclass);
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if (ret == 0) {
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system_timer->dev.cls = &timer_sysclass;
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ret = sysdev_register(&system_timer->dev);
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}
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return ret;
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}
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device_initcall(timer_init_sysfs);
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void __init time_init(void)
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{
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if (system_timer->offset == NULL)
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system_timer->offset = dummy_gettimeoffset;
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system_timer->init();
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}
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Block a user