Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/config.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/sched.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/param.h> |
| 27 | #include <linux/string.h> |
| 28 | #include <linux/mm.h> |
| 29 | #include <linux/interrupt.h> |
| 30 | #include <linux/profile.h> |
| 31 | |
| 32 | #include <asm/io.h> |
| 33 | #include <asm/m32r.h> |
| 34 | |
| 35 | #include <asm/hw_irq.h> |
| 36 | |
| 37 | #ifdef CONFIG_SMP |
| 38 | extern void send_IPI_allbutself(int, int); |
| 39 | extern void smp_local_timer_interrupt(struct pt_regs *); |
| 40 | #endif |
| 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | extern unsigned long wall_jiffies; |
| 43 | #define TICK_SIZE (tick_nsec / 1000) |
| 44 | |
| 45 | /* |
| 46 | * Change this if you have some constant time drift |
| 47 | */ |
| 48 | |
| 49 | /* This is for machines which generate the exact clock. */ |
| 50 | #define USECS_PER_JIFFY (1000000/HZ) |
| 51 | |
| 52 | static unsigned long latch; |
| 53 | |
| 54 | static unsigned long do_gettimeoffset(void) |
| 55 | { |
| 56 | unsigned long elapsed_time = 0; /* [us] */ |
| 57 | |
| 58 | #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \ |
| 59 | || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \ |
Hirokazu Takata | 9287d95 | 2006-01-06 00:18:41 -0800 | [diff] [blame] | 60 | || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | #ifndef CONFIG_SMP |
| 62 | |
| 63 | unsigned long count; |
| 64 | |
| 65 | /* timer count may underflow right here */ |
| 66 | count = inl(M32R_MFT2CUT_PORTL); |
| 67 | |
| 68 | if (inl(M32R_ICU_CR18_PORTL) & 0x00000100) /* underflow check */ |
| 69 | count = 0; |
| 70 | |
| 71 | count = (latch - count) * TICK_SIZE; |
| 72 | elapsed_time = (count + latch / 2) / latch; |
| 73 | /* NOTE: LATCH is equal to the "interval" value (= reload count). */ |
| 74 | |
| 75 | #else /* CONFIG_SMP */ |
| 76 | unsigned long count; |
| 77 | static unsigned long p_jiffies = -1; |
| 78 | static unsigned long p_count = 0; |
| 79 | |
| 80 | /* timer count may underflow right here */ |
| 81 | count = inl(M32R_MFT2CUT_PORTL); |
| 82 | |
| 83 | if (jiffies == p_jiffies && count > p_count) |
| 84 | count = 0; |
| 85 | |
| 86 | p_jiffies = jiffies; |
| 87 | p_count = count; |
| 88 | |
| 89 | count = (latch - count) * TICK_SIZE; |
| 90 | elapsed_time = (count + latch / 2) / latch; |
| 91 | /* NOTE: LATCH is equal to the "interval" value (= reload count). */ |
| 92 | #endif /* CONFIG_SMP */ |
| 93 | #elif defined(CONFIG_CHIP_M32310) |
| 94 | #warning do_gettimeoffse not implemented |
| 95 | #else |
| 96 | #error no chip configuration |
| 97 | #endif |
| 98 | |
| 99 | return elapsed_time; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * This version of gettimeofday has near microsecond resolution. |
| 104 | */ |
| 105 | void do_gettimeofday(struct timeval *tv) |
| 106 | { |
| 107 | unsigned long seq; |
| 108 | unsigned long usec, sec; |
| 109 | unsigned long max_ntp_tick = tick_usec - tickadj; |
| 110 | |
| 111 | do { |
| 112 | unsigned long lost; |
| 113 | |
| 114 | seq = read_seqbegin(&xtime_lock); |
| 115 | |
| 116 | usec = do_gettimeoffset(); |
| 117 | lost = jiffies - wall_jiffies; |
| 118 | |
| 119 | /* |
| 120 | * If time_adjust is negative then NTP is slowing the clock |
| 121 | * so make sure not to go into next possible interval. |
| 122 | * Better to lose some accuracy than have time go backwards.. |
| 123 | */ |
| 124 | if (unlikely(time_adjust < 0)) { |
| 125 | usec = min(usec, max_ntp_tick); |
| 126 | if (lost) |
| 127 | usec += lost * max_ntp_tick; |
| 128 | } else if (unlikely(lost)) |
| 129 | usec += lost * tick_usec; |
| 130 | |
| 131 | sec = xtime.tv_sec; |
| 132 | usec += (xtime.tv_nsec / 1000); |
| 133 | } while (read_seqretry(&xtime_lock, seq)); |
| 134 | |
| 135 | while (usec >= 1000000) { |
| 136 | usec -= 1000000; |
| 137 | sec++; |
| 138 | } |
| 139 | |
| 140 | tv->tv_sec = sec; |
| 141 | tv->tv_usec = usec; |
| 142 | } |
| 143 | |
| 144 | EXPORT_SYMBOL(do_gettimeofday); |
| 145 | |
| 146 | int do_settimeofday(struct timespec *tv) |
| 147 | { |
| 148 | time_t wtm_sec, sec = tv->tv_sec; |
| 149 | long wtm_nsec, nsec = tv->tv_nsec; |
| 150 | |
| 151 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) |
| 152 | return -EINVAL; |
| 153 | |
| 154 | write_seqlock_irq(&xtime_lock); |
| 155 | /* |
| 156 | * This is revolting. We need to set "xtime" correctly. However, the |
| 157 | * value in this location is the value at the most recent update of |
| 158 | * wall time. Discover what correction gettimeofday() would have |
| 159 | * made, and then undo it! |
| 160 | */ |
| 161 | nsec -= do_gettimeoffset() * NSEC_PER_USEC; |
| 162 | nsec -= (jiffies - wall_jiffies) * TICK_NSEC; |
| 163 | |
| 164 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); |
| 165 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); |
| 166 | |
| 167 | set_normalized_timespec(&xtime, sec, nsec); |
| 168 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); |
| 169 | |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 170 | ntp_clear(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | write_sequnlock_irq(&xtime_lock); |
| 172 | clock_was_set(); |
| 173 | |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | EXPORT_SYMBOL(do_settimeofday); |
| 178 | |
| 179 | /* |
| 180 | * In order to set the CMOS clock precisely, set_rtc_mmss has to be |
| 181 | * called 500 ms after the second nowtime has started, because when |
| 182 | * nowtime is written into the registers of the CMOS clock, it will |
| 183 | * jump to the next second precisely 500 ms later. Check the Motorola |
| 184 | * MC146818A or Dallas DS12887 data sheet for details. |
| 185 | * |
| 186 | * BUG: This routine does not handle hour overflow properly; it just |
| 187 | * sets the minutes. Usually you won't notice until after reboot! |
| 188 | */ |
| 189 | static inline int set_rtc_mmss(unsigned long nowtime) |
| 190 | { |
| 191 | return 0; |
| 192 | } |
| 193 | |
| 194 | /* last time the cmos clock got updated */ |
| 195 | static long last_rtc_update = 0; |
| 196 | |
| 197 | /* |
| 198 | * timer_interrupt() needs to keep up the real-time clock, |
| 199 | * as well as call the "do_timer()" routine every clocktick |
| 200 | */ |
Hirokazu Takata | 2757a71 | 2005-08-01 21:11:35 -0700 | [diff] [blame] | 201 | irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
| 203 | #ifndef CONFIG_SMP |
| 204 | profile_tick(CPU_PROFILING, regs); |
| 205 | #endif |
| 206 | do_timer(regs); |
| 207 | |
| 208 | #ifndef CONFIG_SMP |
| 209 | update_process_times(user_mode(regs)); |
| 210 | #endif |
| 211 | /* |
| 212 | * If we have an externally synchronized Linux clock, then update |
| 213 | * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be |
| 214 | * called as close as possible to 500 ms before the new second starts. |
| 215 | */ |
Hirokazu Takata | 2757a71 | 2005-08-01 21:11:35 -0700 | [diff] [blame] | 216 | write_seqlock(&xtime_lock); |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 217 | if (ntp_synced() |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | && xtime.tv_sec > last_rtc_update + 660 |
| 219 | && (xtime.tv_nsec / 1000) >= 500000 - ((unsigned)TICK_SIZE) / 2 |
| 220 | && (xtime.tv_nsec / 1000) <= 500000 + ((unsigned)TICK_SIZE) / 2) |
| 221 | { |
| 222 | if (set_rtc_mmss(xtime.tv_sec) == 0) |
| 223 | last_rtc_update = xtime.tv_sec; |
| 224 | else /* do it again in 60 s */ |
| 225 | last_rtc_update = xtime.tv_sec - 600; |
| 226 | } |
Hirokazu Takata | 2757a71 | 2005-08-01 21:11:35 -0700 | [diff] [blame] | 227 | write_sequnlock(&xtime_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | /* As we return to user mode fire off the other CPU schedulers.. |
| 229 | this is basically because we don't yet share IRQ's around. |
| 230 | This message is rigged to be safe on the 386 - basically it's |
| 231 | a hack, so don't look closely for now.. */ |
| 232 | |
| 233 | #ifdef CONFIG_SMP |
| 234 | smp_local_timer_interrupt(regs); |
Hirokazu Takata | 2757a71 | 2005-08-01 21:11:35 -0700 | [diff] [blame] | 235 | smp_send_timer(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | |
| 238 | return IRQ_HANDLED; |
| 239 | } |
| 240 | |
| 241 | struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, |
| 242 | "MFT2", NULL, NULL }; |
| 243 | |
| 244 | void __init time_init(void) |
| 245 | { |
| 246 | unsigned int epoch, year, mon, day, hour, min, sec; |
| 247 | |
| 248 | sec = min = hour = day = mon = year = 0; |
| 249 | epoch = 0; |
| 250 | |
| 251 | year = 23; |
| 252 | mon = 4; |
| 253 | day = 17; |
| 254 | |
| 255 | /* Attempt to guess the epoch. This is the same heuristic as in rtc.c |
| 256 | so no stupid things will happen to timekeeping. Who knows, maybe |
| 257 | Ultrix also uses 1952 as epoch ... */ |
| 258 | if (year > 10 && year < 44) |
| 259 | epoch = 1980; |
| 260 | else if (year < 96) |
| 261 | epoch = 1952; |
| 262 | year += epoch; |
| 263 | |
| 264 | xtime.tv_sec = mktime(year, mon, day, hour, min, sec); |
| 265 | xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); |
| 266 | set_normalized_timespec(&wall_to_monotonic, |
| 267 | -xtime.tv_sec, -xtime.tv_nsec); |
| 268 | |
| 269 | #if defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_XNUX2) \ |
| 270 | || defined(CONFIG_CHIP_VDEC2) || defined(CONFIG_CHIP_M32700) \ |
Hirokazu Takata | 9287d95 | 2006-01-06 00:18:41 -0800 | [diff] [blame] | 271 | || defined(CONFIG_CHIP_OPSP) || defined(CONFIG_CHIP_M32104) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | |
| 273 | /* M32102 MFT setup */ |
| 274 | setup_irq(M32R_IRQ_MFT2, &irq0); |
| 275 | { |
| 276 | unsigned long bus_clock; |
| 277 | unsigned short divide; |
| 278 | |
| 279 | bus_clock = boot_cpu_data.bus_clock; |
| 280 | divide = boot_cpu_data.timer_divide; |
| 281 | latch = (bus_clock/divide + HZ / 2) / HZ; |
| 282 | |
| 283 | printk("Timer start : latch = %ld\n", latch); |
| 284 | |
| 285 | outl((M32R_MFTMOD_CC_MASK | M32R_MFTMOD_TCCR \ |
| 286 | |M32R_MFTMOD_CSSEL011), M32R_MFT2MOD_PORTL); |
| 287 | outl(latch, M32R_MFT2RLD_PORTL); |
| 288 | outl(latch, M32R_MFT2CUT_PORTL); |
| 289 | outl(0, M32R_MFT2CMPRLD_PORTL); |
| 290 | outl((M32R_MFTCR_MFT2MSK|M32R_MFTCR_MFT2EN), M32R_MFTCR_PORTL); |
| 291 | } |
| 292 | |
| 293 | #elif defined(CONFIG_CHIP_M32310) |
| 294 | #warning time_init not implemented |
| 295 | #else |
| 296 | #error no chip configuration |
| 297 | #endif |
| 298 | } |
| 299 | |
| 300 | /* |
| 301 | * Scheduler clock - returns current time in nanosec units. |
| 302 | */ |
| 303 | unsigned long long sched_clock(void) |
| 304 | { |
| 305 | return (unsigned long long)jiffies * (1000000000 / HZ); |
| 306 | } |