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 60static u32 m32r_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) \ 66 || defined(CONFIG_CHIP_OPSP) || 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 "xtime_update()" 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 xtime_update(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 .name = "MFT2", 138}; 139 140void read_persistent_clock(struct timespec *ts) 141{ 142 unsigned int epoch, year, mon, day, hour, min, sec; 143 144 sec = min = hour = day = mon = year = 0; 145 epoch = 0; 146 147 year = 23; 148 mon = 4; 149 day = 17; 150 151 /* Attempt to guess the epoch. This is the same heuristic as in rtc.c 152 so no stupid things will happen to timekeeping. Who knows, maybe 153 Ultrix also uses 1952 as epoch ... */ 154 if (year > 10 && year < 44) 155 epoch = 1980; 156 else if (year < 96) 157 epoch = 1952; 158 year += epoch; 159 160 ts->tv_sec = mktime(year, mon, day, hour, min, sec); 161 ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); 162} 163 164 165void __init time_init(void) 166{ 167 arch_gettimeoffset = m32r_gettimeoffset; 168 169#if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \ 170 || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \ 171 || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104) 172 173 /* M32102 MFT setup */ 174 setup_irq(M32R_IRQ_MFT2, &irq0); 175 { 176 unsigned long bus_clock; 177 unsigned short divide; 178 179 bus_clock = boot_cpu_data.bus_clock; 180 divide = boot_cpu_data.timer_divide; 181 latch = DIV_ROUND_CLOSEST(bus_clock/divide, HZ); 182 183 printk("Timer start : latch = %ld\n", latch); 184 185 outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \ 186 |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL); 187 outl(latch, M32R_MFT2RLD_PORTL); 188 outl(latch, M32R_MFT2CUT_PORTL); 189 outl(0, M32R_MFT2CMPRLD_PORTL); 190 outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL); 191 } 192 193#elif defined(CONFIG_CHIP_M32310) 194#warning time_init not implemented 195#else 196#error no chip configuration 197#endif 198} 199