11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/arch/arm/kernel/time.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 1991, 1992, 1995 Linus Torvalds 51da177e4SLinus Torvalds * Modifications for ARM (C) 1994-2001 Russell King 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4SLinus Torvalds * it under the terms of the GNU General Public License version 2 as 91da177e4SLinus Torvalds * published by the Free Software Foundation. 101da177e4SLinus Torvalds * 111da177e4SLinus Torvalds * This file contains the ARM-specific time handling details: 121da177e4SLinus Torvalds * reading the RTC at bootup, etc... 131da177e4SLinus Torvalds */ 141da177e4SLinus Torvalds #include <linux/module.h> 151da177e4SLinus Torvalds #include <linux/kernel.h> 161da177e4SLinus Torvalds #include <linux/interrupt.h> 171da177e4SLinus Torvalds #include <linux/time.h> 181da177e4SLinus Torvalds #include <linux/init.h> 19d43c36dcSAlexey Dobriyan #include <linux/sched.h> 201da177e4SLinus Torvalds #include <linux/smp.h> 211da177e4SLinus Torvalds #include <linux/timex.h> 221da177e4SLinus Torvalds #include <linux/errno.h> 231da177e4SLinus Torvalds #include <linux/profile.h> 241da177e4SLinus Torvalds #include <linux/sysdev.h> 251da177e4SLinus Torvalds #include <linux/timer.h> 26e317c8ccSFrederik Deweerdt #include <linux/irq.h> 271da177e4SLinus Torvalds 289ca3f07bSBen Dooks #include <linux/mc146818rtc.h> 299ca3f07bSBen Dooks 301da177e4SLinus Torvalds #include <asm/leds.h> 311da177e4SLinus Torvalds #include <asm/thread_info.h> 322d7c11bfSCatalin Marinas #include <asm/stacktrace.h> 338ff1443cSRussell King #include <asm/mach/arch.h> 341da177e4SLinus Torvalds #include <asm/mach/time.h> 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds /* 371da177e4SLinus Torvalds * Our system timer. 381da177e4SLinus Torvalds */ 398ff1443cSRussell King static struct sys_timer *system_timer; 401da177e4SLinus Torvalds 419dd34948SDavid Brownell #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) 421da177e4SLinus Torvalds /* this needs a better home */ 431da177e4SLinus Torvalds DEFINE_SPINLOCK(rtc_lock); 441da177e4SLinus Torvalds 459dd34948SDavid Brownell #ifdef CONFIG_RTC_DRV_CMOS_MODULE 461da177e4SLinus Torvalds EXPORT_SYMBOL(rtc_lock); 471da177e4SLinus Torvalds #endif 489dd34948SDavid Brownell #endif /* pc-style 'CMOS' RTC support */ 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds /* change this if you have some constant time drift */ 511da177e4SLinus Torvalds #define USECS_PER_JIFFY (1000000/HZ) 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds #ifdef CONFIG_SMP 541da177e4SLinus Torvalds unsigned long profile_pc(struct pt_regs *regs) 551da177e4SLinus Torvalds { 562d7c11bfSCatalin Marinas struct stackframe frame; 571da177e4SLinus Torvalds 582d7c11bfSCatalin Marinas if (!in_lock_functions(regs->ARM_pc)) 592d7c11bfSCatalin Marinas return regs->ARM_pc; 601da177e4SLinus Torvalds 612d7c11bfSCatalin Marinas frame.fp = regs->ARM_fp; 622d7c11bfSCatalin Marinas frame.sp = regs->ARM_sp; 632d7c11bfSCatalin Marinas frame.lr = regs->ARM_lr; 642d7c11bfSCatalin Marinas frame.pc = regs->ARM_pc; 652d7c11bfSCatalin Marinas do { 662d7c11bfSCatalin Marinas int ret = unwind_frame(&frame); 672d7c11bfSCatalin Marinas if (ret < 0) 682d7c11bfSCatalin Marinas return 0; 692d7c11bfSCatalin Marinas } while (in_lock_functions(frame.pc)); 702d7c11bfSCatalin Marinas 712d7c11bfSCatalin Marinas return frame.pc; 721da177e4SLinus Torvalds } 731da177e4SLinus Torvalds EXPORT_SYMBOL(profile_pc); 741da177e4SLinus Torvalds #endif 751da177e4SLinus Torvalds 765cfc8ee0SJohn Stultz #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET 775cfc8ee0SJohn Stultz u32 arch_gettimeoffset(void) 781da177e4SLinus Torvalds { 795cfc8ee0SJohn Stultz if (system_timer->offset != NULL) 805cfc8ee0SJohn Stultz return system_timer->offset() * 1000; 815cfc8ee0SJohn Stultz 821da177e4SLinus Torvalds return 0; 831da177e4SLinus Torvalds } 845cfc8ee0SJohn Stultz #endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */ 851da177e4SLinus Torvalds 861da177e4SLinus Torvalds #ifdef CONFIG_LEDS_TIMER 871da177e4SLinus Torvalds static inline void do_leds(void) 881da177e4SLinus Torvalds { 896d15cb42SDavid Brownell static unsigned int count = HZ/2; 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds if (--count == 0) { 926d15cb42SDavid Brownell count = HZ/2; 931da177e4SLinus Torvalds leds_event(led_timer); 941da177e4SLinus Torvalds } 951da177e4SLinus Torvalds } 961da177e4SLinus Torvalds #else 971da177e4SLinus Torvalds #define do_leds() 981da177e4SLinus Torvalds #endif 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds 1019e4559ddSKevin Hilman #ifndef CONFIG_GENERIC_CLOCKEVENTS 1021da177e4SLinus Torvalds /* 1031da177e4SLinus Torvalds * Kernel system timer support. 1041da177e4SLinus Torvalds */ 1050cd61b68SLinus Torvalds void timer_tick(void) 1061da177e4SLinus Torvalds { 107e317c8ccSFrederik Deweerdt profile_tick(CPU_PROFILING); 1081da177e4SLinus Torvalds do_leds(); 109193c3cc1SRussell King write_seqlock(&xtime_lock); 1103171a030SAtsushi Nemoto do_timer(1); 111193c3cc1SRussell King write_sequnlock(&xtime_lock); 1121da177e4SLinus Torvalds #ifndef CONFIG_SMP 113c97d4869SRussell King update_process_times(user_mode(get_irq_regs())); 1141da177e4SLinus Torvalds #endif 1151da177e4SLinus Torvalds } 1169e4559ddSKevin Hilman #endif 1171da177e4SLinus Torvalds 1189e4559ddSKevin Hilman #if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS) 1191da177e4SLinus Torvalds static int timer_suspend(struct sys_device *dev, pm_message_t state) 1201da177e4SLinus Torvalds { 1211da177e4SLinus Torvalds struct sys_timer *timer = container_of(dev, struct sys_timer, dev); 1221da177e4SLinus Torvalds 1231da177e4SLinus Torvalds if (timer->suspend != NULL) 1241da177e4SLinus Torvalds timer->suspend(); 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds return 0; 1271da177e4SLinus Torvalds } 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvalds static int timer_resume(struct sys_device *dev) 1301da177e4SLinus Torvalds { 1311da177e4SLinus Torvalds struct sys_timer *timer = container_of(dev, struct sys_timer, dev); 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds if (timer->resume != NULL) 1341da177e4SLinus Torvalds timer->resume(); 1351da177e4SLinus Torvalds 1361da177e4SLinus Torvalds return 0; 1371da177e4SLinus Torvalds } 1381da177e4SLinus Torvalds #else 1391da177e4SLinus Torvalds #define timer_suspend NULL 1401da177e4SLinus Torvalds #define timer_resume NULL 1411da177e4SLinus Torvalds #endif 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds static struct sysdev_class timer_sysclass = { 144af5ca3f4SKay Sievers .name = "timer", 1451da177e4SLinus Torvalds .suspend = timer_suspend, 1461da177e4SLinus Torvalds .resume = timer_resume, 1471da177e4SLinus Torvalds }; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds static int __init timer_init_sysfs(void) 1501da177e4SLinus Torvalds { 1511da177e4SLinus Torvalds int ret = sysdev_class_register(&timer_sysclass); 1521da177e4SLinus Torvalds if (ret == 0) { 1531da177e4SLinus Torvalds system_timer->dev.cls = &timer_sysclass; 1541da177e4SLinus Torvalds ret = sysdev_register(&system_timer->dev); 1551da177e4SLinus Torvalds } 1568749af68SRussell King 1571da177e4SLinus Torvalds return ret; 1581da177e4SLinus Torvalds } 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds device_initcall(timer_init_sysfs); 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds void __init time_init(void) 1631da177e4SLinus Torvalds { 1648ff1443cSRussell King system_timer = machine_desc->timer; 1651da177e4SLinus Torvalds system_timer->init(); 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds 168