1/* 2 * linux/arch/m32r/kernel/time.c 3 * 4 * Copyright (c) 2001, 2002 Hiroyuki Kondo, Hirokazu Takata, 5 * Hitoshi Yamamoto 6 * Taken from i386 version. 7 * Copyright (C) 1991, 1992, 1995 Linus Torvalds 8 * Copyright (C) 1996, 1997, 1998 Ralf Baechle 9 * 10 * This file contains the time handling details for PC-style clocks as 11 * found in some MIPS systems. 12 * 13 * Some code taken from sh version. 14 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka 15 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> 16 */ 17 18#undef DEBUG_TIMER 19 20#include <linux/errno.h> 21#include <linux/init.h> 22#include <linux/module.h> 23#include <linux/sched.h> 24#include <linux/kernel.h> 25#include <linux/param.h> 26#include <linux/string.h> 27#include <linux/mm.h> 28#include <linux/interrupt.h> 29#include <linux/profile.h> 30 31#include <asm/io.h> 32#include <asm/m32r.h> 33 34#include <asm/hw_irq.h> 35 36#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) 37/* this needs a better home */ 38DEFINE_SPINLOCK(rtc_lock); 39 40#ifdef CONFIG_RTC_DRV_CMOS_MODULE 41EXPORT_SYMBOL(rtc_lock); 42#endif 43#endif /* pc-style 'CMOS' RTC support */ 44 45#ifdef CONFIG_SMP 46extern void smp_local_timer_interrupt(void); 47#endif 48 49#define TICK_SIZE (tick_nsec / 1000) 50 51/* 52 * Change this if you have some constant time drift 53 */ 54 55/* This is for machines which generate the exact clock. */ 56#define USECS_PER_JIFFY (1000000/HZ) 57 58static unsigned long latch; 59 60u32 arch_gettimeoffset(void) 61{ 62 unsigned long elapsed_time = 0; /* [us] */ 63 64#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) || \ 65 defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP) \ 66 || defined(CONFIG_CHIP_M32104) 67#ifndef CONFIG_SMP 68 69 unsigned long count; 70 71 /* timer count may underflow right here */ 72 count = inl(M32R_MFT2CUT_PORTL); 73 74 if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */ 75 count = 0; 76 77 count = (latch - count) * TICK_SIZE; 78 elapsed_time = DIV_ROUND_CLOSEST(count, latch); 79 /* NOTE: LATCH is equal to the "interval" value (= reload count). */ 80 81#else /* CONFIG_SMP */ 82 unsigned long count; 83 static unsigned long p_jiffies = -1; 84 static unsigned long p_count = 0; 85 86 /* timer count may underflow right here */ 87 count = inl(M32R_MFT2CUT_PORTL); 88 89 if (jiffies == p_jiffies && count > p_count) 90 count = 0; 91 92 p_jiffies = jiffies; 93 p_count = count; 94 95 count = (latch - count) * TICK_SIZE; 96 elapsed_time = DIV_ROUND_CLOSEST(count, latch); 97 /* NOTE: LATCH is equal to the "interval" value (= reload count). */ 98#endif /* CONFIG_SMP */ 99#elif defined(CONFIG_CHIP_M32310) 100#warning do_gettimeoffse not implemented 101#else 102#error no chip configuration 103#endif 104 105 return elapsed_time * 1000; 106} 107 108/* 109 * timer_interrupt() needs to keep up the real-time clock, 110 * as well as call the "do_timer()" routine every clocktick 111 */ 112static irqreturn_t timer_interrupt(int irq, void *dev_id) 113{ 114#ifndef CONFIG_SMP 115 profile_tick(CPU_PROFILING); 116#endif 117 do_timer(1); 118 119#ifndef CONFIG_SMP 120 update_process_times(user_mode(get_irq_regs())); 121#endif 122 /* As we return to user mode fire off the other CPU schedulers.. 123 this is basically because we don't yet share IRQ's around. 124 This message is rigged to be safe on the 386 - basically it's 125 a hack, so don't look closely for now.. */ 126 127#ifdef CONFIG_SMP 128 smp_local_timer_interrupt(); 129 smp_send_timer(); 130#endif 131 132 return IRQ_HANDLED; 133} 134 135static struct irqaction irq0 = { 136 .handler = timer_interrupt, 137 .flags = IRQF_DISABLED, 138 .name = "MFT2", 139}; 140 141void read_persistent_clock(struct timespec *ts) 142{ 143 unsigned int epoch, year, mon, day, hour, min, sec; 144 145 sec = min = hour = day = mon = year = 0; 146 epoch = 0; 147 148 year = 23; 149 mon = 4; 150 day = 17; 151 152 /* Attempt to guess the epoch. This is the same heuristic as in rtc.c 153 so no stupid things will happen to timekeeping. Who knows, maybe 154 Ultrix also uses 1952 as epoch ... */ 155 if (year > 10 && year < 44) 156 epoch = 1980; 157 else if (year < 96) 158 epoch = 1952; 159 year += epoch; 160 161 ts->tv_sec = mktime(year, mon, day, hour, min, sec); 162 ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); 163} 164 165 166void __init time_init(void) 167{ 168#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) || \ 169 defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP) \ 170 || defined(CONFIG_CHIP_M32104) 171 172 /* M32102 MFT setup */ 173 setup_irq(M32R_IRQ_MFT2, &irq0); 174 { 175 unsigned long bus_clock; 176 unsigned short divide; 177 178 bus_clock = boot_cpu_data.bus_clock; 179 divide = boot_cpu_data.timer_divide; 180 latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ); 181 182 printk("Timer start : latch = %ld\n", latch); 183 184 outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \ 185 |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL); 186 outl(latch, M32R_MFT2RLD_PORTL); 187 outl(latch, M32R_MFT2CUT_PORTL); 188 outl(0, M32R_MFT2CMPRLD_PORTL); 189 outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL); 190 } 191 192#elif defined(CONFIG_CHIP_M32310) 193#warning time_init not implemented 194#else 195#error no chip configuration 196#endif 197} 198