linux/arch/sparc/kernel/time.c
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   1/* linux/arch/sparc/kernel/time.c
   2 *
   3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
   4 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
   5 *
   6 * Chris Davis (cdavis@cois.on.ca) 03/27/1998
   7 * Added support for the intersil on the sun4/4200
   8 *
   9 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
  10 * Support for MicroSPARC-IIep, PCI CPU.
  11 *
  12 * This file handles the Sparc specific time handling details.
  13 *
  14 * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  15 *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  16 */
  17#include <linux/errno.h>
  18#include <linux/module.h>
  19#include <linux/sched.h>
  20#include <linux/kernel.h>
  21#include <linux/param.h>
  22#include <linux/string.h>
  23#include <linux/mm.h>
  24#include <linux/interrupt.h>
  25#include <linux/time.h>
  26#include <linux/timex.h>
  27#include <linux/init.h>
  28#include <linux/pci.h>
  29#include <linux/ioport.h>
  30#include <linux/profile.h>
  31#include <linux/of_device.h>
  32
  33#include <asm/oplib.h>
  34#include <asm/timer.h>
  35#include <asm/mostek.h>
  36#include <asm/system.h>
  37#include <asm/irq.h>
  38#include <asm/io.h>
  39#include <asm/idprom.h>
  40#include <asm/machines.h>
  41#include <asm/sun4paddr.h>
  42#include <asm/page.h>
  43#include <asm/pcic.h>
  44#include <asm/irq_regs.h>
  45
  46#include "irq.h"
  47
  48DEFINE_SPINLOCK(rtc_lock);
  49static enum sparc_clock_type sp_clock_typ;
  50DEFINE_SPINLOCK(mostek_lock);
  51void __iomem *mstk48t02_regs = NULL;
  52static struct mostek48t08 __iomem *mstk48t08_regs = NULL;
  53static int set_rtc_mmss(unsigned long);
  54static int sbus_do_settimeofday(struct timespec *tv);
  55
  56#ifdef CONFIG_SUN4
  57struct intersil *intersil_clock;
  58#define intersil_cmd(intersil_reg, intsil_cmd) intersil_reg->int_cmd_reg = \
  59        (intsil_cmd)
  60
  61#define intersil_intr(intersil_reg, intsil_cmd) intersil_reg->int_intr_reg = \
  62        (intsil_cmd)
  63
  64#define intersil_start(intersil_reg) intersil_cmd(intersil_reg, \
  65        ( INTERSIL_START | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
  66          INTERSIL_INTR_ENABLE))
  67
  68#define intersil_stop(intersil_reg) intersil_cmd(intersil_reg, \
  69        ( INTERSIL_STOP | INTERSIL_32K | INTERSIL_NORMAL | INTERSIL_24H |\
  70          INTERSIL_INTR_ENABLE))
  71
  72#define intersil_read_intr(intersil_reg, towhere) towhere = \
  73        intersil_reg->int_intr_reg
  74
  75#endif
  76
  77unsigned long profile_pc(struct pt_regs *regs)
  78{
  79        extern char __copy_user_begin[], __copy_user_end[];
  80        extern char __atomic_begin[], __atomic_end[];
  81        extern char __bzero_begin[], __bzero_end[];
  82
  83        unsigned long pc = regs->pc;
  84
  85        if (in_lock_functions(pc) ||
  86            (pc >= (unsigned long) __copy_user_begin &&
  87             pc < (unsigned long) __copy_user_end) ||
  88            (pc >= (unsigned long) __atomic_begin &&
  89             pc < (unsigned long) __atomic_end) ||
  90            (pc >= (unsigned long) __bzero_begin &&
  91             pc < (unsigned long) __bzero_end))
  92                pc = regs->u_regs[UREG_RETPC];
  93        return pc;
  94}
  95
  96EXPORT_SYMBOL(profile_pc);
  97
  98__volatile__ unsigned int *master_l10_counter;
  99__volatile__ unsigned int *master_l10_limit;
 100
 101/*
 102 * timer_interrupt() needs to keep up the real-time clock,
 103 * as well as call the "do_timer()" routine every clocktick
 104 */
 105
 106#define TICK_SIZE (tick_nsec / 1000)
 107
 108static irqreturn_t timer_interrupt(int dummy, void *dev_id)
 109{
 110        /* last time the cmos clock got updated */
 111        static long last_rtc_update;
 112
 113#ifndef CONFIG_SMP
 114        profile_tick(CPU_PROFILING);
 115#endif
 116
 117        /* Protect counter clear so that do_gettimeoffset works */
 118        write_seqlock(&xtime_lock);
 119#ifdef CONFIG_SUN4
 120        if((idprom->id_machtype == (SM_SUN4 | SM_4_260)) ||
 121           (idprom->id_machtype == (SM_SUN4 | SM_4_110))) {
 122                int temp;
 123                intersil_read_intr(intersil_clock, temp);
 124                /* re-enable the irq */
 125                enable_pil_irq(10);
 126        }
 127#endif
 128        clear_clock_irq();
 129
 130        do_timer(1);
 131
 132        /* Determine when to update the Mostek clock. */
 133        if (ntp_synced() &&
 134            xtime.tv_sec > last_rtc_update + 660 &&
 135            (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
 136            (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
 137          if (set_rtc_mmss(xtime.tv_sec) == 0)
 138            last_rtc_update = xtime.tv_sec;
 139          else
 140            last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
 141        }
 142        write_sequnlock(&xtime_lock);
 143
 144#ifndef CONFIG_SMP
 145        update_process_times(user_mode(get_irq_regs()));
 146#endif
 147        return IRQ_HANDLED;
 148}
 149
 150/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
 151static void __devinit kick_start_clock(void)
 152{
 153        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
 154        unsigned char sec;
 155        int i, count;
 156
 157        prom_printf("CLOCK: Clock was stopped. Kick start ");
 158
 159        spin_lock_irq(&mostek_lock);
 160
 161        /* Turn on the kick start bit to start the oscillator. */
 162        regs->creg |= MSTK_CREG_WRITE;
 163        regs->sec &= ~MSTK_STOP;
 164        regs->hour |= MSTK_KICK_START;
 165        regs->creg &= ~MSTK_CREG_WRITE;
 166
 167        spin_unlock_irq(&mostek_lock);
 168
 169        /* Delay to allow the clock oscillator to start. */
 170        sec = MSTK_REG_SEC(regs);
 171        for (i = 0; i < 3; i++) {
 172                while (sec == MSTK_REG_SEC(regs))
 173                        for (count = 0; count < 100000; count++)
 174                                /* nothing */ ;
 175                prom_printf(".");
 176                sec = regs->sec;
 177        }
 178        prom_printf("\n");
 179
 180        spin_lock_irq(&mostek_lock);
 181
 182        /* Turn off kick start and set a "valid" time and date. */
 183        regs->creg |= MSTK_CREG_WRITE;
 184        regs->hour &= ~MSTK_KICK_START;
 185        MSTK_SET_REG_SEC(regs,0);
 186        MSTK_SET_REG_MIN(regs,0);
 187        MSTK_SET_REG_HOUR(regs,0);
 188        MSTK_SET_REG_DOW(regs,5);
 189        MSTK_SET_REG_DOM(regs,1);
 190        MSTK_SET_REG_MONTH(regs,8);
 191        MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
 192        regs->creg &= ~MSTK_CREG_WRITE;
 193
 194        spin_unlock_irq(&mostek_lock);
 195
 196        /* Ensure the kick start bit is off. If it isn't, turn it off. */
 197        while (regs->hour & MSTK_KICK_START) {
 198                prom_printf("CLOCK: Kick start still on!\n");
 199
 200                spin_lock_irq(&mostek_lock);
 201                regs->creg |= MSTK_CREG_WRITE;
 202                regs->hour &= ~MSTK_KICK_START;
 203                regs->creg &= ~MSTK_CREG_WRITE;
 204                spin_unlock_irq(&mostek_lock);
 205        }
 206
 207        prom_printf("CLOCK: Kick start procedure successful.\n");
 208}
 209
 210/* Return nonzero if the clock chip battery is low. */
 211static inline int has_low_battery(void)
 212{
 213        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
 214        unsigned char data1, data2;
 215
 216        spin_lock_irq(&mostek_lock);
 217        data1 = regs->eeprom[0];        /* Read some data. */
 218        regs->eeprom[0] = ~data1;       /* Write back the complement. */
 219        data2 = regs->eeprom[0];        /* Read back the complement. */
 220        regs->eeprom[0] = data1;        /* Restore the original value. */
 221        spin_unlock_irq(&mostek_lock);
 222
 223        return (data1 == data2);        /* Was the write blocked? */
 224}
 225
 226static void __devinit mostek_set_system_time(void)
 227{
 228        unsigned int year, mon, day, hour, min, sec;
 229        struct mostek48t02 *mregs;
 230
 231        mregs = (struct mostek48t02 *)mstk48t02_regs;
 232        if(!mregs) {
 233                prom_printf("Something wrong, clock regs not mapped yet.\n");
 234                prom_halt();
 235        }               
 236        spin_lock_irq(&mostek_lock);
 237        mregs->creg |= MSTK_CREG_READ;
 238        sec = MSTK_REG_SEC(mregs);
 239        min = MSTK_REG_MIN(mregs);
 240        hour = MSTK_REG_HOUR(mregs);
 241        day = MSTK_REG_DOM(mregs);
 242        mon = MSTK_REG_MONTH(mregs);
 243        year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
 244        xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
 245        xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 246        set_normalized_timespec(&wall_to_monotonic,
 247                                -xtime.tv_sec, -xtime.tv_nsec);
 248        mregs->creg &= ~MSTK_CREG_READ;
 249        spin_unlock_irq(&mostek_lock);
 250}
 251
 252/* Probe for the real time clock chip on Sun4 */
 253static inline void sun4_clock_probe(void)
 254{
 255#ifdef CONFIG_SUN4
 256        int temp;
 257        struct resource r;
 258
 259        memset(&r, 0, sizeof(r));
 260        if( idprom->id_machtype == (SM_SUN4 | SM_4_330) ) {
 261                sp_clock_typ = MSTK48T02;
 262                r.start = sun4_clock_physaddr;
 263                mstk48t02_regs = sbus_ioremap(&r, 0,
 264                                       sizeof(struct mostek48t02), NULL);
 265                mstk48t08_regs = NULL;  /* To catch weirdness */
 266                intersil_clock = NULL;  /* just in case */
 267
 268                /* Kick start the clock if it is completely stopped. */
 269                if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
 270                        kick_start_clock();
 271        } else if( idprom->id_machtype == (SM_SUN4 | SM_4_260)) {
 272                /* intersil setup code */
 273                printk("Clock: INTERSIL at %8x ",sun4_clock_physaddr);
 274                sp_clock_typ = INTERSIL;
 275                r.start = sun4_clock_physaddr;
 276                intersil_clock = (struct intersil *) 
 277                    sbus_ioremap(&r, 0, sizeof(*intersil_clock), "intersil");
 278                mstk48t02_regs = 0;  /* just be sure */
 279                mstk48t08_regs = NULL;  /* ditto */
 280                /* initialise the clock */
 281
 282                intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
 283
 284                intersil_start(intersil_clock);
 285
 286                intersil_read_intr(intersil_clock, temp);
 287                while (!(temp & 0x80))
 288                        intersil_read_intr(intersil_clock, temp);
 289
 290                intersil_read_intr(intersil_clock, temp);
 291                while (!(temp & 0x80))
 292                        intersil_read_intr(intersil_clock, temp);
 293
 294                intersil_stop(intersil_clock);
 295
 296        }
 297#endif
 298}
 299
 300#ifndef CONFIG_SUN4
 301static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
 302{
 303        struct device_node *dp = op->node;
 304        const char *model = of_get_property(dp, "model", NULL);
 305
 306        if (!model)
 307                return -ENODEV;
 308
 309        if (!strcmp(model, "mk48t02")) {
 310                sp_clock_typ = MSTK48T02;
 311
 312                /* Map the clock register io area read-only */
 313                mstk48t02_regs = of_ioremap(&op->resource[0], 0,
 314                                            sizeof(struct mostek48t02),
 315                                            "mk48t02");
 316                mstk48t08_regs = NULL;  /* To catch weirdness */
 317        } else if (!strcmp(model, "mk48t08")) {
 318                sp_clock_typ = MSTK48T08;
 319                mstk48t08_regs = of_ioremap(&op->resource[0], 0,
 320                                            sizeof(struct mostek48t08),
 321                                            "mk48t08");
 322
 323                mstk48t02_regs = &mstk48t08_regs->regs;
 324        } else
 325                return -ENODEV;
 326
 327        /* Report a low battery voltage condition. */
 328        if (has_low_battery())
 329                printk(KERN_CRIT "NVRAM: Low battery voltage!\n");
 330
 331        /* Kick start the clock if it is completely stopped. */
 332        if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
 333                kick_start_clock();
 334
 335        mostek_set_system_time();
 336
 337        return 0;
 338}
 339
 340static struct of_device_id clock_match[] = {
 341        {
 342                .name = "eeprom",
 343        },
 344        {},
 345};
 346
 347static struct of_platform_driver clock_driver = {
 348        .match_table    = clock_match,
 349        .probe          = clock_probe,
 350        .driver         = {
 351                .name   = "clock",
 352        },
 353};
 354
 355
 356/* Probe for the mostek real time clock chip. */
 357static int __init clock_init(void)
 358{
 359        return of_register_driver(&clock_driver, &of_platform_bus_type);
 360}
 361
 362/* Must be after subsys_initcall() so that busses are probed.  Must
 363 * be before device_initcall() because things like the RTC driver
 364 * need to see the clock registers.
 365 */
 366fs_initcall(clock_init);
 367#endif /* !CONFIG_SUN4 */
 368
 369static void __init sbus_time_init(void)
 370{
 371
 372        BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
 373        btfixup();
 374
 375        if (ARCH_SUN4)
 376                sun4_clock_probe();
 377
 378        sparc_init_timers(timer_interrupt);
 379        
 380#ifdef CONFIG_SUN4
 381        if(idprom->id_machtype == (SM_SUN4 | SM_4_330)) {
 382                mostek_set_system_time();
 383        } else if(idprom->id_machtype == (SM_SUN4 | SM_4_260) ) {
 384                /* initialise the intersil on sun4 */
 385                unsigned int year, mon, day, hour, min, sec;
 386                int temp;
 387                struct intersil *iregs;
 388
 389                iregs=intersil_clock;
 390                if(!iregs) {
 391                        prom_printf("Something wrong, clock regs not mapped yet.\n");
 392                        prom_halt();
 393                }
 394
 395                intersil_intr(intersil_clock,INTERSIL_INT_100HZ);
 396                disable_pil_irq(10);
 397                intersil_stop(iregs);
 398                intersil_read_intr(intersil_clock, temp);
 399
 400                temp = iregs->clk.int_csec;
 401
 402                sec = iregs->clk.int_sec;
 403                min = iregs->clk.int_min;
 404                hour = iregs->clk.int_hour;
 405                day = iregs->clk.int_day;
 406                mon = iregs->clk.int_month;
 407                year = MSTK_CVT_YEAR(iregs->clk.int_year);
 408
 409                enable_pil_irq(10);
 410                intersil_start(iregs);
 411
 412                xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
 413                xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 414                set_normalized_timespec(&wall_to_monotonic,
 415                                       -xtime.tv_sec, -xtime.tv_nsec);
 416                printk("%u/%u/%u %u:%u:%u\n",day,mon,year,hour,min,sec);
 417        }
 418#endif
 419
 420        /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
 421        local_irq_enable();
 422}
 423
 424void __init time_init(void)
 425{
 426#ifdef CONFIG_PCI
 427        extern void pci_time_init(void);
 428        if (pcic_present()) {
 429                pci_time_init();
 430                return;
 431        }
 432#endif
 433        sbus_time_init();
 434}
 435
 436static inline unsigned long do_gettimeoffset(void)
 437{
 438        unsigned long val = *master_l10_counter;
 439        unsigned long usec = (val >> 10) & 0x1fffff;
 440
 441        /* Limit hit?  */
 442        if (val & 0x80000000)
 443                usec += 1000000 / HZ;
 444
 445        return usec;
 446}
 447
 448/* Ok, my cute asm atomicity trick doesn't work anymore.
 449 * There are just too many variables that need to be protected
 450 * now (both members of xtime, et al.)
 451 */
 452void do_gettimeofday(struct timeval *tv)
 453{
 454        unsigned long flags;
 455        unsigned long seq;
 456        unsigned long usec, sec;
 457        unsigned long max_ntp_tick = tick_usec - tickadj;
 458
 459        do {
 460                seq = read_seqbegin_irqsave(&xtime_lock, flags);
 461                usec = do_gettimeoffset();
 462
 463                /*
 464                 * If time_adjust is negative then NTP is slowing the clock
 465                 * so make sure not to go into next possible interval.
 466                 * Better to lose some accuracy than have time go backwards..
 467                 */
 468                if (unlikely(time_adjust < 0))
 469                        usec = min(usec, max_ntp_tick);
 470
 471                sec = xtime.tv_sec;
 472                usec += (xtime.tv_nsec / 1000);
 473        } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 474
 475        while (usec >= 1000000) {
 476                usec -= 1000000;
 477                sec++;
 478        }
 479
 480        tv->tv_sec = sec;
 481        tv->tv_usec = usec;
 482}
 483
 484EXPORT_SYMBOL(do_gettimeofday);
 485
 486int do_settimeofday(struct timespec *tv)
 487{
 488        int ret;
 489
 490        write_seqlock_irq(&xtime_lock);
 491        ret = bus_do_settimeofday(tv);
 492        write_sequnlock_irq(&xtime_lock);
 493        clock_was_set();
 494        return ret;
 495}
 496
 497EXPORT_SYMBOL(do_settimeofday);
 498
 499static int sbus_do_settimeofday(struct timespec *tv)
 500{
 501        time_t wtm_sec, sec = tv->tv_sec;
 502        long wtm_nsec, nsec = tv->tv_nsec;
 503
 504        if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 505                return -EINVAL;
 506
 507        /*
 508         * This is revolting. We need to set "xtime" correctly. However, the
 509         * value in this location is the value at the most recent update of
 510         * wall time.  Discover what correction gettimeofday() would have
 511         * made, and then undo it!
 512         */
 513        nsec -= 1000 * do_gettimeoffset();
 514
 515        wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 516        wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 517
 518        set_normalized_timespec(&xtime, sec, nsec);
 519        set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 520
 521        ntp_clear();
 522        return 0;
 523}
 524
 525/*
 526 * BUG: This routine does not handle hour overflow properly; it just
 527 *      sets the minutes. Usually you won't notice until after reboot!
 528 */
 529static int set_rtc_mmss(unsigned long nowtime)
 530{
 531        int real_seconds, real_minutes, mostek_minutes;
 532        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
 533        unsigned long flags;
 534#ifdef CONFIG_SUN4
 535        struct intersil *iregs = intersil_clock;
 536        int temp;
 537#endif
 538
 539        /* Not having a register set can lead to trouble. */
 540        if (!regs) {
 541#ifdef CONFIG_SUN4
 542                if(!iregs)
 543                return -1;
 544                else {
 545                        temp = iregs->clk.int_csec;
 546
 547                        mostek_minutes = iregs->clk.int_min;
 548
 549                        real_seconds = nowtime % 60;
 550                        real_minutes = nowtime / 60;
 551                        if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
 552                                real_minutes += 30;     /* correct for half hour time zone */
 553                        real_minutes %= 60;
 554
 555                        if (abs(real_minutes - mostek_minutes) < 30) {
 556                                intersil_stop(iregs);
 557                                iregs->clk.int_sec=real_seconds;
 558                                iregs->clk.int_min=real_minutes;
 559                                intersil_start(iregs);
 560                        } else {
 561                                printk(KERN_WARNING
 562                               "set_rtc_mmss: can't update from %d to %d\n",
 563                                       mostek_minutes, real_minutes);
 564                                return -1;
 565                        }
 566                        
 567                        return 0;
 568                }
 569#endif
 570        }
 571
 572        spin_lock_irqsave(&mostek_lock, flags);
 573        /* Read the current RTC minutes. */
 574        regs->creg |= MSTK_CREG_READ;
 575        mostek_minutes = MSTK_REG_MIN(regs);
 576        regs->creg &= ~MSTK_CREG_READ;
 577
 578        /*
 579         * since we're only adjusting minutes and seconds,
 580         * don't interfere with hour overflow. This avoids
 581         * messing with unknown time zones but requires your
 582         * RTC not to be off by more than 15 minutes
 583         */
 584        real_seconds = nowtime % 60;
 585        real_minutes = nowtime / 60;
 586        if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
 587                real_minutes += 30;     /* correct for half hour time zone */
 588        real_minutes %= 60;
 589
 590        if (abs(real_minutes - mostek_minutes) < 30) {
 591                regs->creg |= MSTK_CREG_WRITE;
 592                MSTK_SET_REG_SEC(regs,real_seconds);
 593                MSTK_SET_REG_MIN(regs,real_minutes);
 594                regs->creg &= ~MSTK_CREG_WRITE;
 595                spin_unlock_irqrestore(&mostek_lock, flags);
 596                return 0;
 597        } else {
 598                spin_unlock_irqrestore(&mostek_lock, flags);
 599                return -1;
 600        }
 601}
 602