arch/sparc64/kernel/time.c

   1 /* $Id: time.c,v 1.42 2002/01/23 14:33:55 davem Exp $
   2  * time.c: UltraSparc timer and TOD clock support.
   3  *
   4  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
   5  * Copyright (C) 1998 Eddie C. Dost   (ecd@skynet.be)
   6  *
   7  * Based largely on code which is:
   8  *
   9  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/errno.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/param.h>
  18 #include <linux/string.h>
  19 #include <linux/mm.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/time.h>
  22 #include <linux/timex.h>
  23 #include <linux/init.h>
  24 #include <linux/ioport.h>
  25 #include <linux/mc146818rtc.h>
  26 #include <linux/delay.h>
  27 #include <linux/profile.h>
  28 #include <linux/bcd.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/cpufreq.h>
  31 #include <linux/percpu.h>
  32 #include <linux/profile.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/rtc.h>
  35
  36 #include <asm/oplib.h>
  37 #include <asm/mostek.h>
  38 #include <asm/timer.h>
  39 #include <asm/irq.h>
  40 #include <asm/io.h>
  41 #include <asm/sbus.h>
  42 #include <asm/fhc.h>
  43 #include <asm/pbm.h>
  44 #include <asm/ebus.h>
  45 #include <asm/isa.h>
  46 #include <asm/starfire.h>
  47 #include <asm/smp.h>
  48 #include <asm/sections.h>
  49 #include <asm/cpudata.h>
  50 #include <asm/uaccess.h>
  51
  52 DEFINE_SPINLOCK(mostek_lock);
  53 DEFINE_SPINLOCK(rtc_lock);
  54 void __iomem *mstk48t02_regs = NULL;
  55 #ifdef CONFIG_PCI
  56 unsigned long ds1287_regs = 0UL;
  57 #endif
  58
  59 extern unsigned long wall_jiffies;
  60
  61 static void __iomem *mstk48t08_regs;
  62 static void __iomem *mstk48t59_regs;
  63
  64 static int set_rtc_mmss(unsigned long);
  65
  66 #define TICK_PRIV_BIT   (1UL << 63)
  67
  68 #ifdef CONFIG_SMP
  69 unsigned long profile_pc(struct pt_regs *regs)
  70 {
  71         unsigned long pc = instruction_pointer(regs);
  72
  73         if (in_lock_functions(pc))
  74                 return regs->u_regs[UREG_RETPC];
  75         return pc;
  76 }
  77 EXPORT_SYMBOL(profile_pc);
  78 #endif
  79
  80 static void tick_disable_protection(void)
  81 {
  82         /* Set things up so user can access tick register for profiling
  83          * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
  84          * read back of %tick after writing it.
  85          */
  86         __asm__ __volatile__(
  87         "       ba,pt   %%xcc, 1f\n"
  88         "        nop\n"
  89         "       .align  64\n"
  90         "1:     rd      %%tick, %%g2\n"
  91         "       add     %%g2, 6, %%g2\n"
  92         "       andn    %%g2, %0, %%g2\n"
  93         "       wrpr    %%g2, 0, %%tick\n"
  94         "       rdpr    %%tick, %%g0"
  95         : /* no outputs */
  96         : "r" (TICK_PRIV_BIT)
  97         : "g2");
  98 }
  99
 100 static void tick_init_tick(unsigned long offset)
 101 {
 102         tick_disable_protection();
 103
 104         __asm__ __volatile__(
 105         "       rd      %%tick, %%g1\n"
 106         "       andn    %%g1, %1, %%g1\n"
 107         "       ba,pt   %%xcc, 1f\n"
 108         "        add    %%g1, %0, %%g1\n"
 109         "       .align  64\n"
 110         "1:     wr      %%g1, 0x0, %%tick_cmpr\n"
 111         "       rd      %%tick_cmpr, %%g0"
 112         : /* no outputs */
 113         : "r" (offset), "r" (TICK_PRIV_BIT)
 114         : "g1");
 115 }
 116
 117 static unsigned long tick_get_tick(void)
 118 {
 119         unsigned long ret;
 120
 121         __asm__ __volatile__("rd        %%tick, %0\n\t"
 122                              "mov       %0, %0"
 123                              : "=r" (ret));
 124
 125         return ret & ~TICK_PRIV_BIT;
 126 }
 127
 128 static unsigned long tick_get_compare(void)
 129 {
 130         unsigned long ret;
 131
 132         __asm__ __volatile__("rd        %%tick_cmpr, %0\n\t"
 133                              "mov       %0, %0"
 134                              : "=r" (ret));
 135
 136         return ret;
 137 }
 138
 139 static unsigned long tick_add_compare(unsigned long adj)
 140 {
 141         unsigned long new_compare;
 142
 143         /* Workaround for Spitfire Errata (#54 I think??), I discovered
 144          * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
 145          * number 103640.
 146          *
 147          * On Blackbird writes to %tick_cmpr can fail, the
 148          * workaround seems to be to execute the wr instruction
 149          * at the start of an I-cache line, and perform a dummy
 150          * read back from %tick_cmpr right after writing to it. -DaveM
 151          */
 152         __asm__ __volatile__("rd        %%tick_cmpr, %0\n\t"
 153                              "ba,pt     %%xcc, 1f\n\t"
 154                              " add      %0, %1, %0\n\t"
 155                              ".align    64\n"
 156                              "1:\n\t"
 157                              "wr        %0, 0, %%tick_cmpr\n\t"
 158                              "rd        %%tick_cmpr, %%g0"
 159                              : "=&r" (new_compare)
 160                              : "r" (adj));
 161
 162         return new_compare;
 163 }
 164
 165 static unsigned long tick_add_tick(unsigned long adj, unsigned long offset)
 166 {
 167         unsigned long new_tick, tmp;
 168
 169         /* Also need to handle Blackbird bug here too. */
 170         __asm__ __volatile__("rd        %%tick, %0\n\t"
 171                              "add       %0, %2, %0\n\t"
 172                              "wrpr      %0, 0, %%tick\n\t"
 173                              "andn      %0, %4, %1\n\t"
 174                              "ba,pt     %%xcc, 1f\n\t"
 175                              " add      %1, %3, %1\n\t"
 176                              ".align    64\n"
 177                              "1:\n\t"
 178                              "wr        %1, 0, %%tick_cmpr\n\t"
 179                              "rd        %%tick_cmpr, %%g0"
 180                              : "=&r" (new_tick), "=&r" (tmp)
 181                              : "r" (adj), "r" (offset), "r" (TICK_PRIV_BIT));
 182
 183         return new_tick;
 184 }
 185
 186 static struct sparc64_tick_ops tick_operations __read_mostly = {
 187         .init_tick      =       tick_init_tick,
 188         .get_tick       =       tick_get_tick,
 189         .get_compare    =       tick_get_compare,
 190         .add_tick       =       tick_add_tick,
 191         .add_compare    =       tick_add_compare,
 192         .softint_mask   =       1UL << 0,
 193 };
 194
 195 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
 196
 197 static void stick_init_tick(unsigned long offset)
 198 {
 199         /* Writes to the %tick and %stick register are not
 200          * allowed on sun4v.  The Hypervisor controls that
 201          * bit, per-strand.
 202          */
 203         if (tlb_type != hypervisor) {
 204                 tick_disable_protection();
 205
 206                 /* Let the user get at STICK too. */
 207                 __asm__ __volatile__(
 208                 "       rd      %%asr24, %%g2\n"
 209                 "       andn    %%g2, %0, %%g2\n"
 210                 "       wr      %%g2, 0, %%asr24"
 211                 : /* no outputs */
 212                 : "r" (TICK_PRIV_BIT)
 213                 : "g1", "g2");
 214         }
 215
 216         __asm__ __volatile__(
 217         "       rd      %%asr24, %%g1\n"
 218         "       andn    %%g1, %1, %%g1\n"
 219         "       add     %%g1, %0, %%g1\n"
 220         "       wr      %%g1, 0x0, %%asr25"
 221         : /* no outputs */
 222         : "r" (offset), "r" (TICK_PRIV_BIT)
 223         : "g1");
 224 }
 225
 226 static unsigned long stick_get_tick(void)
 227 {
 228         unsigned long ret;
 229
 230         __asm__ __volatile__("rd        %%asr24, %0"
 231                              : "=r" (ret));
 232
 233         return ret & ~TICK_PRIV_BIT;
 234 }
 235
 236 static unsigned long stick_get_compare(void)
 237 {
 238         unsigned long ret;
 239
 240         __asm__ __volatile__("rd        %%asr25, %0"
 241                              : "=r" (ret));
 242
 243         return ret;
 244 }
 245
 246 static unsigned long stick_add_tick(unsigned long adj, unsigned long offset)
 247 {
 248         unsigned long new_tick, tmp;
 249
 250         __asm__ __volatile__("rd        %%asr24, %0\n\t"
 251                              "add       %0, %2, %0\n\t"
 252                              "wr        %0, 0, %%asr24\n\t"
 253                              "andn      %0, %4, %1\n\t"
 254                              "add       %1, %3, %1\n\t"
 255                              "wr        %1, 0, %%asr25"
 256                              : "=&r" (new_tick), "=&r" (tmp)
 257                              : "r" (adj), "r" (offset), "r" (TICK_PRIV_BIT));
 258
 259         return new_tick;
 260 }
 261
 262 static unsigned long stick_add_compare(unsigned long adj)
 263 {
 264         unsigned long new_compare;
 265
 266         __asm__ __volatile__("rd        %%asr25, %0\n\t"
 267                              "add       %0, %1, %0\n\t"
 268                              "wr        %0, 0, %%asr25"
 269                              : "=&r" (new_compare)
 270                              : "r" (adj));
 271
 272         return new_compare;
 273 }
 274
 275 static struct sparc64_tick_ops stick_operations __read_mostly = {
 276         .init_tick      =       stick_init_tick,
 277         .get_tick       =       stick_get_tick,
 278         .get_compare    =       stick_get_compare,
 279         .add_tick       =       stick_add_tick,
 280         .add_compare    =       stick_add_compare,
 281         .softint_mask   =       1UL << 16,
 282 };
 283
 284 /* On Hummingbird the STICK/STICK_CMPR register is implemented
 285  * in I/O space.  There are two 64-bit registers each, the
 286  * first holds the low 32-bits of the value and the second holds
 287  * the high 32-bits.
 288  *
 289  * Since STICK is constantly updating, we have to access it carefully.
 290  *
 291  * The sequence we use to read is:
 292  * 1) read high
 293  * 2) read low
 294  * 3) read high again, if it rolled re-read both low and high again.
 295  *
 296  * Writing STICK safely is also tricky:
 297  * 1) write low to zero
 298  * 2) write high
 299  * 3) write low
 300  */
 301 #define HBIRD_STICKCMP_ADDR     0x1fe0000f060UL
 302 #define HBIRD_STICK_ADDR        0x1fe0000f070UL
 303
 304 static unsigned long __hbird_read_stick(void)
 305 {
 306         unsigned long ret, tmp1, tmp2, tmp3;
 307         unsigned long addr = HBIRD_STICK_ADDR+8;
 308
 309         __asm__ __volatile__("ldxa      [%1] %5, %2\n"
 310                              "1:\n\t"
 311                              "sub       %1, 0x8, %1\n\t"
 312                              "ldxa      [%1] %5, %3\n\t"
 313                              "add       %1, 0x8, %1\n\t"
 314                              "ldxa      [%1] %5, %4\n\t"
 315                              "cmp       %4, %2\n\t"
 316                              "bne,a,pn  %%xcc, 1b\n\t"
 317                              " mov      %4, %2\n\t"
 318                              "sllx      %4, 32, %4\n\t"
 319                              "or        %3, %4, %0\n\t"
 320                              : "=&r" (ret), "=&r" (addr),
 321                                "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
 322                              : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
 323
 324         return ret;
 325 }
 326
 327 static unsigned long __hbird_read_compare(void)
 328 {
 329         unsigned long low, high;
 330         unsigned long addr = HBIRD_STICKCMP_ADDR;
 331
 332         __asm__ __volatile__("ldxa      [%2] %3, %0\n\t"
 333                              "add       %2, 0x8, %2\n\t"
 334                              "ldxa      [%2] %3, %1"
 335                              : "=&r" (low), "=&r" (high), "=&r" (addr)
 336                              : "i" (ASI_PHYS_BYPASS_EC_E), "2" (addr));
 337
 338         return (high << 32UL) | low;
 339 }
 340
 341 static void __hbird_write_stick(unsigned long val)
 342 {
 343         unsigned long low = (val & 0xffffffffUL);
 344         unsigned long high = (val >> 32UL);
 345         unsigned long addr = HBIRD_STICK_ADDR;
 346
 347         __asm__ __volatile__("stxa      %%g0, [%0] %4\n\t"
 348                              "add       %0, 0x8, %0\n\t"
 349                              "stxa      %3, [%0] %4\n\t"
 350                              "sub       %0, 0x8, %0\n\t"
 351                              "stxa      %2, [%0] %4"
 352                              : "=&r" (addr)
 353                              : "0" (addr), "r" (low), "r" (high),
 354                                "i" (ASI_PHYS_BYPASS_EC_E));
 355 }
 356
 357 static void __hbird_write_compare(unsigned long val)
 358 {
 359         unsigned long low = (val & 0xffffffffUL);
 360         unsigned long high = (val >> 32UL);
 361         unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
 362
 363         __asm__ __volatile__("stxa      %3, [%0] %4\n\t"
 364                              "sub       %0, 0x8, %0\n\t"
 365                              "stxa      %2, [%0] %4"
 366                              : "=&r" (addr)
 367                              : "0" (addr), "r" (low), "r" (high),
 368                                "i" (ASI_PHYS_BYPASS_EC_E));
 369 }
 370
 371 static void hbtick_init_tick(unsigned long offset)
 372 {
 373         unsigned long val;
 374
 375         tick_disable_protection();
 376
 377         /* XXX This seems to be necessary to 'jumpstart' Hummingbird
 378          * XXX into actually sending STICK interrupts.  I think because
 379          * XXX of how we store %tick_cmpr in head.S this somehow resets the
 380          * XXX {TICK + STICK} interrupt mux.  -DaveM
 381          */
 382         __hbird_write_stick(__hbird_read_stick());
 383
 384         val = __hbird_read_stick() & ~TICK_PRIV_BIT;
 385         __hbird_write_compare(val + offset);
 386 }
 387
 388 static unsigned long hbtick_get_tick(void)
 389 {
 390         return __hbird_read_stick() & ~TICK_PRIV_BIT;
 391 }
 392
 393 static unsigned long hbtick_get_compare(void)
 394 {
 395         return __hbird_read_compare();
 396 }
 397
 398 static unsigned long hbtick_add_tick(unsigned long adj, unsigned long offset)
 399 {
 400         unsigned long val;
 401
 402         val = __hbird_read_stick() + adj;
 403         __hbird_write_stick(val);
 404
 405         val &= ~TICK_PRIV_BIT;
 406         __hbird_write_compare(val + offset);
 407
 408         return val;
 409 }
 410
 411 static unsigned long hbtick_add_compare(unsigned long adj)
 412 {
 413         unsigned long val = __hbird_read_compare() + adj;
 414
 415         val &= ~TICK_PRIV_BIT;
 416         __hbird_write_compare(val);
 417
 418         return val;
 419 }
 420
 421 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
 422         .init_tick      =       hbtick_init_tick,
 423         .get_tick       =       hbtick_get_tick,
 424         .get_compare    =       hbtick_get_compare,
 425         .add_tick       =       hbtick_add_tick,
 426         .add_compare    =       hbtick_add_compare,
 427         .softint_mask   =       1UL << 0,
 428 };
 429
 430 /* timer_interrupt() needs to keep up the real-time clock,
 431  * as well as call the "do_timer()" routine every clocktick
 432  *
 433  * NOTE: On SUN5 systems the ticker interrupt comes in using 2
 434  *       interrupts, one at level14 and one with softint bit 0.
 435  */
 436 unsigned long timer_tick_offset __read_mostly;
 437
 438 static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
 439
 440 #define TICK_SIZE (tick_nsec / 1000)
 441
 442 static inline void timer_check_rtc(void)
 443 {
 444         /* last time the cmos clock got updated */
 445         static long last_rtc_update;
 446
 447         /* Determine when to update the Mostek clock. */
 448         if (ntp_synced() &&
 449             xtime.tv_sec > last_rtc_update + 660 &&
 450             (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
 451             (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
 452                 if (set_rtc_mmss(xtime.tv_sec) == 0)
 453                         last_rtc_update = xtime.tv_sec;
 454                 else
 455                         last_rtc_update = xtime.tv_sec - 600;
 456                         /* do it again in 60 s */
 457         }
 458 }
 459
 460 static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 461 {
 462         unsigned long ticks, compare, pstate;
 463
 464         write_seqlock(&xtime_lock);
 465
 466         do {
 467 #ifndef CONFIG_SMP
 468                 profile_tick(CPU_PROFILING, regs);
 469                 update_process_times(user_mode(regs));
 470 #endif
 471                 do_timer(regs);
 472
 473                 /* Guarantee that the following sequences execute
 474                  * uninterrupted.
 475                  */
 476                 __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 477                                      "wrpr      %0, %1, %%pstate"
 478                                      : "=r" (pstate)
 479                                      : "i" (PSTATE_IE));
 480
 481                 compare = tick_ops->add_compare(timer_tick_offset);
 482                 ticks = tick_ops->get_tick();
 483
 484                 /* Restore PSTATE_IE. */
 485                 __asm__ __volatile__("wrpr      %0, 0x0, %%pstate"
 486                                      : /* no outputs */
 487                                      : "r" (pstate));
 488         } while (time_after_eq(ticks, compare));
 489
 490         timer_check_rtc();
 491
 492         write_sequnlock(&xtime_lock);
 493
 494         return IRQ_HANDLED;
 495 }
 496
 497 #ifdef CONFIG_SMP
 498 void timer_tick_interrupt(struct pt_regs *regs)
 499 {
 500         write_seqlock(&xtime_lock);
 501
 502         do_timer(regs);
 503
 504         timer_check_rtc();
 505
 506         write_sequnlock(&xtime_lock);
 507 }
 508 #endif
 509
 510 /* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
 511 static void __init kick_start_clock(void)
 512 {
 513         void __iomem *regs = mstk48t02_regs;
 514         u8 sec, tmp;
 515         int i, count;
 516
 517         prom_printf("CLOCK: Clock was stopped. Kick start ");
 518
 519         spin_lock_irq(&mostek_lock);
 520
 521         /* Turn on the kick start bit to start the oscillator. */
 522         tmp = mostek_read(regs + MOSTEK_CREG);
 523         tmp |= MSTK_CREG_WRITE;
 524         mostek_write(regs + MOSTEK_CREG, tmp);
 525         tmp = mostek_read(regs + MOSTEK_SEC);
 526         tmp &= ~MSTK_STOP;
 527         mostek_write(regs + MOSTEK_SEC, tmp);
 528         tmp = mostek_read(regs + MOSTEK_HOUR);
 529         tmp |= MSTK_KICK_START;
 530         mostek_write(regs + MOSTEK_HOUR, tmp);
 531         tmp = mostek_read(regs + MOSTEK_CREG);
 532         tmp &= ~MSTK_CREG_WRITE;
 533         mostek_write(regs + MOSTEK_CREG, tmp);
 534
 535         spin_unlock_irq(&mostek_lock);
 536
 537         /* Delay to allow the clock oscillator to start. */
 538         sec = MSTK_REG_SEC(regs);
 539         for (i = 0; i < 3; i++) {
 540                 while (sec == MSTK_REG_SEC(regs))
 541                         for (count = 0; count < 100000; count++)
 542                                 /* nothing */ ;
 543                 prom_printf(".");
 544                 sec = MSTK_REG_SEC(regs);
 545         }
 546         prom_printf("\n");
 547
 548         spin_lock_irq(&mostek_lock);
 549
 550         /* Turn off kick start and set a "valid" time and date. */
 551         tmp = mostek_read(regs + MOSTEK_CREG);
 552         tmp |= MSTK_CREG_WRITE;
 553         mostek_write(regs + MOSTEK_CREG, tmp);
 554         tmp = mostek_read(regs + MOSTEK_HOUR);
 555         tmp &= ~MSTK_KICK_START;
 556         mostek_write(regs + MOSTEK_HOUR, tmp);
 557         MSTK_SET_REG_SEC(regs,0);
 558         MSTK_SET_REG_MIN(regs,0);
 559         MSTK_SET_REG_HOUR(regs,0);
 560         MSTK_SET_REG_DOW(regs,5);
 561         MSTK_SET_REG_DOM(regs,1);
 562         MSTK_SET_REG_MONTH(regs,8);
 563         MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
 564         tmp = mostek_read(regs + MOSTEK_CREG);
 565         tmp &= ~MSTK_CREG_WRITE;
 566         mostek_write(regs + MOSTEK_CREG, tmp);
 567
 568         spin_unlock_irq(&mostek_lock);
 569
 570         /* Ensure the kick start bit is off. If it isn't, turn it off. */
 571         while (mostek_read(regs + MOSTEK_HOUR) & MSTK_KICK_START) {
 572                 prom_printf("CLOCK: Kick start still on!\n");
 573
 574                 spin_lock_irq(&mostek_lock);
 575
 576                 tmp = mostek_read(regs + MOSTEK_CREG);
 577                 tmp |= MSTK_CREG_WRITE;
 578                 mostek_write(regs + MOSTEK_CREG, tmp);
 579
 580                 tmp = mostek_read(regs + MOSTEK_HOUR);
 581                 tmp &= ~MSTK_KICK_START;
 582                 mostek_write(regs + MOSTEK_HOUR, tmp);
 583
 584                 tmp = mostek_read(regs + MOSTEK_CREG);
 585                 tmp &= ~MSTK_CREG_WRITE;
 586                 mostek_write(regs + MOSTEK_CREG, tmp);
 587
 588                 spin_unlock_irq(&mostek_lock);
 589         }
 590
 591         prom_printf("CLOCK: Kick start procedure successful.\n");
 592 }
 593
 594 /* Return nonzero if the clock chip battery is low. */
 595 static int __init has_low_battery(void)
 596 {
 597         void __iomem *regs = mstk48t02_regs;
 598         u8 data1, data2;
 599
 600         spin_lock_irq(&mostek_lock);
 601
 602         data1 = mostek_read(regs + MOSTEK_EEPROM);      /* Read some data. */
 603         mostek_write(regs + MOSTEK_EEPROM, ~data1);     /* Write back the complement. */
 604         data2 = mostek_read(regs + MOSTEK_EEPROM);      /* Read back the complement. */
 605         mostek_write(regs + MOSTEK_EEPROM, data1);      /* Restore original value. */
 606
 607         spin_unlock_irq(&mostek_lock);
 608
 609         return (data1 == data2);        /* Was the write blocked? */
 610 }
 611
 612 /* Probe for the real time clock chip. */
 613 static void __init set_system_time(void)
 614 {
 615         unsigned int year, mon, day, hour, min, sec;
 616         void __iomem *mregs = mstk48t02_regs;
 617 #ifdef CONFIG_PCI
 618         unsigned long dregs = ds1287_regs;
 619 #else
 620         unsigned long dregs = 0UL;
 621 #endif
 622         u8 tmp;
 623
 624         if (!mregs && !dregs) {
 625                 prom_printf("Something wrong, clock regs not mapped yet.\n");
 626                 prom_halt();
 627         }
 628
 629         if (mregs) {
 630                 spin_lock_irq(&mostek_lock);
 631
 632                 /* Traditional Mostek chip. */
 633                 tmp = mostek_read(mregs + MOSTEK_CREG);
 634                 tmp |= MSTK_CREG_READ;
 635                 mostek_write(mregs + MOSTEK_CREG, tmp);
 636
 637                 sec = MSTK_REG_SEC(mregs);
 638                 min = MSTK_REG_MIN(mregs);
 639                 hour = MSTK_REG_HOUR(mregs);
 640                 day = MSTK_REG_DOM(mregs);
 641                 mon = MSTK_REG_MONTH(mregs);
 642                 year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
 643         } else {
 644                 int i;
 645
 646                 /* Dallas 12887 RTC chip. */
 647
 648                 /* Stolen from arch/i386/kernel/time.c, see there for
 649                  * credits and descriptive comments.
 650                  */
 651                 for (i = 0; i < 1000000; i++) {
 652                         if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
 653                                 break;
 654                         udelay(10);
 655                 }
 656                 for (i = 0; i < 1000000; i++) {
 657                         if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
 658                                 break;
 659                         udelay(10);
 660                 }
 661                 do {
 662                         sec  = CMOS_READ(RTC_SECONDS);
 663                         min  = CMOS_READ(RTC_MINUTES);
 664                         hour = CMOS_READ(RTC_HOURS);
 665                         day  = CMOS_READ(RTC_DAY_OF_MONTH);
 666                         mon  = CMOS_READ(RTC_MONTH);
 667                         year = CMOS_READ(RTC_YEAR);
 668                 } while (sec != CMOS_READ(RTC_SECONDS));
 669                 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 670                         BCD_TO_BIN(sec);
 671                         BCD_TO_BIN(min);
 672                         BCD_TO_BIN(hour);
 673                         BCD_TO_BIN(day);
 674                         BCD_TO_BIN(mon);
 675                         BCD_TO_BIN(year);
 676                 }
 677                 if ((year += 1900) < 1970)
 678                         year += 100;
 679         }
 680
 681         xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
 682         xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 683         set_normalized_timespec(&wall_to_monotonic,
 684                                 -xtime.tv_sec, -xtime.tv_nsec);
 685
 686         if (mregs) {
 687                 tmp = mostek_read(mregs + MOSTEK_CREG);
 688                 tmp &= ~MSTK_CREG_READ;
 689                 mostek_write(mregs + MOSTEK_CREG, tmp);
 690
 691                 spin_unlock_irq(&mostek_lock);
 692         }
 693 }
 694
 695 /* davem suggests we keep this within the 4M locked kernel image */
 696 static u32 starfire_get_time(void)
 697 {
 698         static char obp_gettod[32];
 699         static u32 unix_tod;
 700
 701         sprintf(obp_gettod, "h# %08x unix-gettod",
 702                 (unsigned int) (long) &unix_tod);
 703         prom_feval(obp_gettod);
 704
 705         return unix_tod;
 706 }
 707
 708 static int starfire_set_time(u32 val)
 709 {
 710         /* Do nothing, time is set using the service processor
 711          * console on this platform.
 712          */
 713         return 0;
 714 }
 715
 716 static u32 hypervisor_get_time(void)
 717 {
 718         register unsigned long func asm("%o5");
 719         register unsigned long arg0 asm("%o0");
 720         register unsigned long arg1 asm("%o1");
 721         int retries = 10000;
 722
 723 retry:
 724         func = HV_FAST_TOD_GET;
 725         arg0 = 0;
 726         arg1 = 0;
 727         __asm__ __volatile__("ta        %6"
 728                              : "=&r" (func), "=&r" (arg0), "=&r" (arg1)
 729                              : "0" (func), "1" (arg0), "2" (arg1),
 730                                "i" (HV_FAST_TRAP));
 731         if (arg0 == HV_EOK)
 732                 return arg1;
 733         if (arg0 == HV_EWOULDBLOCK) {
 734                 if (--retries > 0) {
 735                         udelay(100);
 736                         goto retry;
 737                 }
 738                 printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
 739                 return 0;
 740         }
 741         printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
 742         return 0;
 743 }
 744
 745 static int hypervisor_set_time(u32 secs)
 746 {
 747         register unsigned long func asm("%o5");
 748         register unsigned long arg0 asm("%o0");
 749         int retries = 10000;
 750
 751 retry:
 752         func = HV_FAST_TOD_SET;
 753         arg0 = secs;
 754         __asm__ __volatile__("ta        %4"
 755                              : "=&r" (func), "=&r" (arg0)
 756                              : "0" (func), "1" (arg0),
 757                                "i" (HV_FAST_TRAP));
 758         if (arg0 == HV_EOK)
 759                 return 0;
 760         if (arg0 == HV_EWOULDBLOCK) {
 761                 if (--retries > 0) {
 762                         udelay(100);
 763                         goto retry;
 764                 }
 765                 printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
 766                 return -EAGAIN;
 767         }
 768         printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
 769         return -EOPNOTSUPP;
 770 }
 771
 772 void __init clock_probe(void)
 773 {
 774         struct linux_prom_registers clk_reg[2];
 775         char model[128];
 776         int node, busnd = -1, err;
 777         unsigned long flags;
 778         struct linux_central *cbus;
 779 #ifdef CONFIG_PCI
 780         struct linux_ebus *ebus = NULL;
 781         struct sparc_isa_bridge *isa_br = NULL;
 782 #endif
 783         static int invoked;
 784
 785         if (invoked)
 786                 return;
 787         invoked = 1;
 788
 789
 790         if (this_is_starfire) {
 791                 xtime.tv_sec = starfire_get_time();
 792                 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 793                 set_normalized_timespec(&wall_to_monotonic,
 794                                         -xtime.tv_sec, -xtime.tv_nsec);
 795                 return;
 796         }
 797         if (tlb_type == hypervisor) {
 798                 xtime.tv_sec = hypervisor_get_time();
 799                 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 800                 set_normalized_timespec(&wall_to_monotonic,
 801                                         -xtime.tv_sec, -xtime.tv_nsec);
 802                 return;
 803         }
 804
 805         local_irq_save(flags);
 806
 807         cbus = central_bus;
 808         if (cbus != NULL)
 809                 busnd = central_bus->child->prom_node;
 810
 811         /* Check FHC Central then EBUSs then ISA bridges then SBUSs.
 812          * That way we handle the presence of multiple properly.
 813          *
 814          * As a special case, machines with Central must provide the
 815          * timer chip there.
 816          */
 817 #ifdef CONFIG_PCI
 818         if (ebus_chain != NULL) {
 819                 ebus = ebus_chain;
 820                 if (busnd == -1)
 821                         busnd = ebus->prom_node;
 822         }
 823         if (isa_chain != NULL) {
 824                 isa_br = isa_chain;
 825                 if (busnd == -1)
 826                         busnd = isa_br->prom_node;
 827         }
 828 #endif
 829         if (sbus_root != NULL && busnd == -1)
 830                 busnd = sbus_root->prom_node;
 831
 832         if (busnd == -1) {
 833                 prom_printf("clock_probe: problem, cannot find bus to search.\n");
 834                 prom_halt();
 835         }
 836
 837         node = prom_getchild(busnd);
 838
 839         while (1) {
 840                 if (!node)
 841                         model[0] = 0;
 842                 else
 843                         prom_getstring(node, "model", model, sizeof(model));
 844                 if (strcmp(model, "mk48t02") &&
 845                     strcmp(model, "mk48t08") &&
 846                     strcmp(model, "mk48t59") &&
 847                     strcmp(model, "m5819") &&
 848                     strcmp(model, "m5819p") &&
 849                     strcmp(model, "m5823") &&
 850                     strcmp(model, "ds1287")) {
 851                         if (cbus != NULL) {
 852                                 prom_printf("clock_probe: Central bus lacks timer chip.\n");
 853                                 prom_halt();
 854                         }
 855
 856                         if (node != 0)
 857                                 node = prom_getsibling(node);
 858 #ifdef CONFIG_PCI
 859                         while ((node == 0) && ebus != NULL) {
 860                                 ebus = ebus->next;
 861                                 if (ebus != NULL) {
 862                                         busnd = ebus->prom_node;
 863                                         node = prom_getchild(busnd);
 864                                 }
 865                         }
 866                         while ((node == 0) && isa_br != NULL) {
 867                                 isa_br = isa_br->next;
 868                                 if (isa_br != NULL) {
 869                                         busnd = isa_br->prom_node;
 870                                         node = prom_getchild(busnd);
 871                                 }
 872                         }
 873 #endif
 874                         if (node == 0) {
 875                                 prom_printf("clock_probe: Cannot find timer chip\n");
 876                                 prom_halt();
 877                         }
 878                         continue;
 879                 }
 880
 881                 err = prom_getproperty(node, "reg", (char *)clk_reg,
 882                                        sizeof(clk_reg));
 883                 if(err == -1) {
 884                         prom_printf("clock_probe: Cannot get Mostek reg property\n");
 885                         prom_halt();
 886                 }
 887
 888                 if (cbus != NULL) {
 889                         apply_fhc_ranges(central_bus->child, clk_reg, 1);
 890                         apply_central_ranges(central_bus, clk_reg, 1);
 891                 }
 892 #ifdef CONFIG_PCI
 893                 else if (ebus != NULL) {
 894                         struct linux_ebus_device *edev;
 895
 896                         for_each_ebusdev(edev, ebus)
 897                                 if (edev->prom_node == node)
 898                                         break;
 899                         if (edev == NULL) {
 900                                 if (isa_chain != NULL)
 901                                         goto try_isa_clock;
 902                                 prom_printf("%s: Mostek not probed by EBUS\n",
 903                                             __FUNCTION__);
 904                                 prom_halt();
 905                         }
 906
 907                         if (!strcmp(model, "ds1287") ||
 908                             !strcmp(model, "m5819") ||
 909                             !strcmp(model, "m5819p") ||
 910                             !strcmp(model, "m5823")) {
 911                                 ds1287_regs = edev->resource[0].start;
 912                         } else {
 913                                 mstk48t59_regs = (void __iomem *)
 914                                         edev->resource[0].start;
 915                                 mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 916                         }
 917                         break;
 918                 }
 919                 else if (isa_br != NULL) {
 920                         struct sparc_isa_device *isadev;
 921
 922 try_isa_clock:
 923                         for_each_isadev(isadev, isa_br)
 924                                 if (isadev->prom_node == node)
 925                                         break;
 926                         if (isadev == NULL) {
 927                                 prom_printf("%s: Mostek not probed by ISA\n");
 928                                 prom_halt();
 929                         }
 930                         if (!strcmp(model, "ds1287") ||
 931                             !strcmp(model, "m5819") ||
 932                             !strcmp(model, "m5819p") ||
 933                             !strcmp(model, "m5823")) {
 934                                 ds1287_regs = isadev->resource.start;
 935                         } else {
 936                                 mstk48t59_regs = (void __iomem *)
 937                                         isadev->resource.start;
 938                                 mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 939                         }
 940                         break;
 941                 }
 942 #endif
 943                 else {
 944                         if (sbus_root->num_sbus_ranges) {
 945                                 int nranges = sbus_root->num_sbus_ranges;
 946                                 int rngc;
 947
 948                                 for (rngc = 0; rngc < nranges; rngc++)
 949                                         if (clk_reg[0].which_io ==
 950                                             sbus_root->sbus_ranges[rngc].ot_child_space)
 951                                                 break;
 952                                 if (rngc == nranges) {
 953                                         prom_printf("clock_probe: Cannot find ranges for "
 954                                                     "clock regs.\n");
 955                                         prom_halt();
 956                                 }
 957                                 clk_reg[0].which_io =
 958                                         sbus_root->sbus_ranges[rngc].ot_parent_space;
 959                                 clk_reg[0].phys_addr +=
 960                                         sbus_root->sbus_ranges[rngc].ot_parent_base;
 961                         }
 962                 }
 963
 964                 if(model[5] == '0' && model[6] == '2') {
 965                         mstk48t02_regs = (void __iomem *)
 966                                 (((u64)clk_reg[0].phys_addr) |
 967                                  (((u64)clk_reg[0].which_io)<<32UL));
 968                 } else if(model[5] == '0' && model[6] == '8') {
 969                         mstk48t08_regs = (void __iomem *)
 970                                 (((u64)clk_reg[0].phys_addr) |
 971                                  (((u64)clk_reg[0].which_io)<<32UL));
 972                         mstk48t02_regs = mstk48t08_regs + MOSTEK_48T08_48T02;
 973                 } else {
 974                         mstk48t59_regs = (void __iomem *)
 975                                 (((u64)clk_reg[0].phys_addr) |
 976                                  (((u64)clk_reg[0].which_io)<<32UL));
 977                         mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 978                 }
 979                 break;
 980         }
 981
 982         if (mstk48t02_regs != NULL) {
 983                 /* Report a low battery voltage condition. */
 984                 if (has_low_battery())
 985                         prom_printf("NVRAM: Low battery voltage!\n");
 986
 987                 /* Kick start the clock if it is completely stopped. */
 988                 if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
 989                         kick_start_clock();
 990         }
 991
 992         set_system_time();
 993
 994         local_irq_restore(flags);
 995 }
 996
 997 /* This is gets the master TICK_INT timer going. */
 998 static unsigned long sparc64_init_timers(void)
 999 {
1000         unsigned long clock;
1001         int node;
1002 #ifdef CONFIG_SMP
1003         extern void smp_tick_init(void);
1004 #endif
1005
1006         if (tlb_type == spitfire) {
1007                 unsigned long ver, manuf, impl;
1008
1009                 __asm__ __volatile__ ("rdpr %%ver, %0"
1010                                       : "=&r" (ver));
1011                 manuf = ((ver >> 48) & 0xffff);
1012                 impl = ((ver >> 32) & 0xffff);
1013                 if (manuf == 0x17 && impl == 0x13) {
1014                         /* Hummingbird, aka Ultra-IIe */
1015                         tick_ops = &hbtick_operations;
1016                         node = prom_root_node;
1017                         clock = prom_getint(node, "stick-frequency");
1018                 } else {
1019                         tick_ops = &tick_operations;
1020                         cpu_find_by_instance(0, &node, NULL);
1021                         clock = prom_getint(node, "clock-frequency");
1022                 }
1023         } else {
1024                 tick_ops = &stick_operations;
1025                 node = prom_root_node;
1026                 clock = prom_getint(node, "stick-frequency");
1027         }
1028         timer_tick_offset = clock / HZ;
1029
1030 #ifdef CONFIG_SMP
1031         smp_tick_init();
1032 #endif
1033
1034         return clock;
1035 }
1036
1037 static void sparc64_start_timers(irqreturn_t (*cfunc)(int, void *, struct pt_regs *))
1038 {
1039         unsigned long pstate;
1040         int err;
1041
1042         /* Register IRQ handler. */
1043         err = request_irq(build_irq(0, 0, 0UL, 0UL), cfunc, 0,
1044                           "timer", NULL);
1045
1046         if (err) {
1047                 prom_printf("Serious problem, cannot register TICK_INT\n");
1048                 prom_halt();
1049         }
1050
1051         /* Guarantee that the following sequences execute
1052          * uninterrupted.
1053          */
1054         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
1055                              "wrpr      %0, %1, %%pstate"
1056                              : "=r" (pstate)
1057                              : "i" (PSTATE_IE));
1058
1059         tick_ops->init_tick(timer_tick_offset);
1060
1061         /* Restore PSTATE_IE. */
1062         __asm__ __volatile__("wrpr      %0, 0x0, %%pstate"
1063                              : /* no outputs */
1064                              : "r" (pstate));
1065
1066         local_irq_enable();
1067 }
1068
1069 struct freq_table {
1070         unsigned long clock_tick_ref;
1071         unsigned int ref_freq;
1072 };
1073 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
1074
1075 unsigned long sparc64_get_clock_tick(unsigned int cpu)
1076 {
1077         struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
1078
1079         if (ft->clock_tick_ref)
1080                 return ft->clock_tick_ref;
1081         return cpu_data(cpu).clock_tick;
1082 }
1083
1084 #ifdef CONFIG_CPU_FREQ
1085
1086 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
1087                                     void *data)
1088 {
1089         struct cpufreq_freqs *freq = data;
1090         unsigned int cpu = freq->cpu;
1091         struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
1092
1093         if (!ft->ref_freq) {
1094                 ft->ref_freq = freq->old;
1095                 ft->clock_tick_ref = cpu_data(cpu).clock_tick;
1096         }
1097         if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
1098             (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
1099             (val == CPUFREQ_RESUMECHANGE)) {
1100                 cpu_data(cpu).clock_tick =
1101                         cpufreq_scale(ft->clock_tick_ref,
1102                                       ft->ref_freq,
1103                                       freq->new);
1104         }
1105
1106         return 0;
1107 }
1108
1109 static struct notifier_block sparc64_cpufreq_notifier_block = {
1110         .notifier_call  = sparc64_cpufreq_notifier
1111 };
1112
1113 #endif /* CONFIG_CPU_FREQ */
1114
1115 static struct time_interpolator sparc64_cpu_interpolator = {
1116         .source         =       TIME_SOURCE_CPU,
1117         .shift          =       16,
1118         .mask           =       0xffffffffffffffffLL
1119 };
1120
1121 /* The quotient formula is taken from the IA64 port. */
1122 #define SPARC64_NSEC_PER_CYC_SHIFT      30UL
1123 void __init time_init(void)
1124 {
1125         unsigned long clock = sparc64_init_timers();
1126
1127         sparc64_cpu_interpolator.frequency = clock;
1128         register_time_interpolator(&sparc64_cpu_interpolator);
1129
1130         /* Now that the interpolator is registered, it is
1131          * safe to start the timer ticking.
1132          */
1133         sparc64_start_timers(timer_interrupt);
1134
1135         timer_ticks_per_nsec_quotient =
1136                 (((NSEC_PER_SEC << SPARC64_NSEC_PER_CYC_SHIFT) +
1137                   (clock / 2)) / clock);
1138
1139 #ifdef CONFIG_CPU_FREQ
1140         cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
1141                                   CPUFREQ_TRANSITION_NOTIFIER);
1142 #endif
1143 }
1144
1145 unsigned long long sched_clock(void)
1146 {
1147         unsigned long ticks = tick_ops->get_tick();
1148
1149         return (ticks * timer_ticks_per_nsec_quotient)
1150                 >> SPARC64_NSEC_PER_CYC_SHIFT;
1151 }
1152
1153 static int set_rtc_mmss(unsigned long nowtime)
1154 {
1155         int real_seconds, real_minutes, chip_minutes;
1156         void __iomem *mregs = mstk48t02_regs;
1157 #ifdef CONFIG_PCI
1158         unsigned long dregs = ds1287_regs;
1159 #else
1160         unsigned long dregs = 0UL;
1161 #endif
1162         unsigned long flags;
1163         u8 tmp;
1164
1165         /*
1166          * Not having a register set can lead to trouble.
1167          * Also starfire doesn't have a tod clock.
1168          */
1169         if (!mregs && !dregs)
1170                 return -1;
1171
1172         if (mregs) {
1173                 spin_lock_irqsave(&mostek_lock, flags);
1174
1175                 /* Read the current RTC minutes. */
1176                 tmp = mostek_read(mregs + MOSTEK_CREG);
1177                 tmp |= MSTK_CREG_READ;
1178                 mostek_write(mregs + MOSTEK_CREG, tmp);
1179
1180                 chip_minutes = MSTK_REG_MIN(mregs);
1181
1182                 tmp = mostek_read(mregs + MOSTEK_CREG);
1183                 tmp &= ~MSTK_CREG_READ;
1184                 mostek_write(mregs + MOSTEK_CREG, tmp);
1185
1186                 /*
1187                  * since we're only adjusting minutes and seconds,
1188                  * don't interfere with hour overflow. This avoids
1189                  * messing with unknown time zones but requires your
1190                  * RTC not to be off by more than 15 minutes
1191                  */
1192                 real_seconds = nowtime % 60;
1193                 real_minutes = nowtime / 60;
1194                 if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
1195                         real_minutes += 30;     /* correct for half hour time zone */
1196                 real_minutes %= 60;
1197
1198                 if (abs(real_minutes - chip_minutes) < 30) {
1199                         tmp = mostek_read(mregs + MOSTEK_CREG);
1200                         tmp |= MSTK_CREG_WRITE;
1201                         mostek_write(mregs + MOSTEK_CREG, tmp);
1202
1203                         MSTK_SET_REG_SEC(mregs,real_seconds);
1204                         MSTK_SET_REG_MIN(mregs,real_minutes);
1205
1206                         tmp = mostek_read(mregs + MOSTEK_CREG);
1207                         tmp &= ~MSTK_CREG_WRITE;
1208                         mostek_write(mregs + MOSTEK_CREG, tmp);
1209
1210                         spin_unlock_irqrestore(&mostek_lock, flags);
1211
1212                         return 0;
1213                 } else {
1214                         spin_unlock_irqrestore(&mostek_lock, flags);
1215
1216                         return -1;
1217                 }
1218         } else {
1219                 int retval = 0;
1220                 unsigned char save_control, save_freq_select;
1221
1222                 /* Stolen from arch/i386/kernel/time.c, see there for
1223                  * credits and descriptive comments.
1224                  */
1225                 spin_lock_irqsave(&rtc_lock, flags);
1226                 save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
1227                 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
1228
1229                 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
1230                 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
1231
1232                 chip_minutes = CMOS_READ(RTC_MINUTES);
1233                 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1234                         BCD_TO_BIN(chip_minutes);
1235                 real_seconds = nowtime % 60;
1236                 real_minutes = nowtime / 60;
1237                 if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
1238                         real_minutes += 30;
1239                 real_minutes %= 60;
1240
1241                 if (abs(real_minutes - chip_minutes) < 30) {
1242                         if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1243                                 BIN_TO_BCD(real_seconds);
1244                                 BIN_TO_BCD(real_minutes);
1245                         }
1246                         CMOS_WRITE(real_seconds,RTC_SECONDS);
1247                         CMOS_WRITE(real_minutes,RTC_MINUTES);
1248                 } else {
1249                         printk(KERN_WARNING
1250                                "set_rtc_mmss: can't update from %d to %d\n",
1251                                chip_minutes, real_minutes);
1252                         retval = -1;
1253                 }
1254
1255                 CMOS_WRITE(save_control, RTC_CONTROL);
1256                 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
1257                 spin_unlock_irqrestore(&rtc_lock, flags);
1258
1259                 return retval;
1260         }
1261 }
1262
1263 #define RTC_IS_OPEN             0x01    /* means /dev/rtc is in use     */
1264 static unsigned char mini_rtc_status;   /* bitmapped status byte.       */
1265
1266 /* months start at 0 now */
1267 static unsigned char days_in_mo[] =
1268 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
1269
1270 #define FEBRUARY        2
1271 #define STARTOFTIME     1970
1272 #define SECDAY          86400L
1273 #define SECYR           (SECDAY * 365)
1274 #define leapyear(year)          ((year) % 4 == 0 && \
1275                                  ((year) % 100 != 0 || (year) % 400 == 0))
1276 #define days_in_year(a)         (leapyear(a) ? 366 : 365)
1277 #define days_in_month(a)        (month_days[(a) - 1])
1278
1279 static int month_days[12] = {
1280         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1281 };
1282
1283 /*
1284  * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1285  */
1286 static void GregorianDay(struct rtc_time * tm)
1287 {
1288         int leapsToDate;
1289         int lastYear;
1290         int day;
1291         int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1292
1293         lastYear = tm->tm_year - 1;
1294
1295         /*
1296          * Number of leap corrections to apply up to end of last year
1297          */
1298         leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
1299
1300         /*
1301          * This year is a leap year if it is divisible by 4 except when it is
1302          * divisible by 100 unless it is divisible by 400
1303          *
1304          * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1305          */
1306         day = tm->tm_mon > 2 && leapyear(tm->tm_year);
1307
1308         day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
1309                    tm->tm_mday;
1310
1311         tm->tm_wday = day % 7;
1312 }
1313
1314 static void to_tm(int tim, struct rtc_time *tm)
1315 {
1316         register int    i;
1317         register long   hms, day;
1318
1319         day = tim / SECDAY;
1320         hms = tim % SECDAY;
1321
1322         /* Hours, minutes, seconds are easy */
1323         tm->tm_hour = hms / 3600;
1324         tm->tm_min = (hms % 3600) / 60;
1325         tm->tm_sec = (hms % 3600) % 60;
1326
1327         /* Number of years in days */
1328         for (i = STARTOFTIME; day >= days_in_year(i); i++)
1329                 day -= days_in_year(i);
1330         tm->tm_year = i;
1331
1332         /* Number of months in days left */
1333         if (leapyear(tm->tm_year))
1334                 days_in_month(FEBRUARY) = 29;
1335         for (i = 1; day >= days_in_month(i); i++)
1336                 day -= days_in_month(i);
1337         days_in_month(FEBRUARY) = 28;
1338         tm->tm_mon = i;
1339
1340         /* Days are what is left over (+1) from all that. */
1341         tm->tm_mday = day + 1;
1342
1343         /*
1344          * Determine the day of week
1345          */
1346         GregorianDay(tm);
1347 }
1348
1349 /* Both Starfire and SUN4V give us seconds since Jan 1st, 1970,
1350  * aka Unix time.  So we have to convert to/from rtc_time.
1351  */
1352 static inline void mini_get_rtc_time(struct rtc_time *time)
1353 {
1354         unsigned long flags;
1355         u32 seconds;
1356
1357         spin_lock_irqsave(&rtc_lock, flags);
1358         seconds = 0;
1359         if (this_is_starfire)
1360                 seconds = starfire_get_time();
1361         else if (tlb_type == hypervisor)
1362                 seconds = hypervisor_get_time();
1363         spin_unlock_irqrestore(&rtc_lock, flags);
1364
1365         to_tm(seconds, time);
1366         time->tm_year -= 1900;
1367         time->tm_mon -= 1;
1368 }
1369
1370 static inline int mini_set_rtc_time(struct rtc_time *time)
1371 {
1372         u32 seconds = mktime(time->tm_year + 1900, time->tm_mon + 1,
1373                              time->tm_mday, time->tm_hour,
1374                              time->tm_min, time->tm_sec);
1375         unsigned long flags;
1376         int err;
1377
1378         spin_lock_irqsave(&rtc_lock, flags);
1379         err = -ENODEV;
1380         if (this_is_starfire)
1381                 err = starfire_set_time(seconds);
1382         else  if (tlb_type == hypervisor)
1383                 err = hypervisor_set_time(seconds);
1384         spin_unlock_irqrestore(&rtc_lock, flags);
1385
1386         return err;
1387 }
1388
1389 static int mini_rtc_ioctl(struct inode *inode, struct file *file,
1390                           unsigned int cmd, unsigned long arg)
1391 {
1392         struct rtc_time wtime;
1393         void __user *argp = (void __user *)arg;
1394
1395         switch (cmd) {
1396
1397         case RTC_PLL_GET:
1398                 return -EINVAL;
1399
1400         case RTC_PLL_SET:
1401                 return -EINVAL;
1402
1403         case RTC_UIE_OFF:       /* disable ints from RTC updates.       */
1404                 return 0;
1405
1406         case RTC_UIE_ON:        /* enable ints for RTC updates. */
1407                 return -EINVAL;
1408
1409         case RTC_RD_TIME:       /* Read the time/date from RTC  */
1410                 /* this doesn't get week-day, who cares */
1411                 memset(&wtime, 0, sizeof(wtime));
1412                 mini_get_rtc_time(&wtime);
1413
1414                 return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
1415
1416         case RTC_SET_TIME:      /* Set the RTC */
1417             {
1418                 int year;
1419                 unsigned char leap_yr;
1420
1421                 if (!capable(CAP_SYS_TIME))
1422                         return -EACCES;
1423
1424                 if (copy_from_user(&wtime, argp, sizeof(wtime)))
1425                         return -EFAULT;
1426
1427                 year = wtime.tm_year + 1900;
1428                 leap_yr = ((!(year % 4) && (year % 100)) ||
1429                            !(year % 400));
1430
1431                 if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
1432                         return -EINVAL;
1433
1434                 if (wtime.tm_mday < 0 || wtime.tm_mday >
1435                     (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
1436                         return -EINVAL;
1437
1438                 if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
1439                     wtime.tm_min < 0 || wtime.tm_min >= 60 ||
1440                     wtime.tm_sec < 0 || wtime.tm_sec >= 60)
1441                         return -EINVAL;
1442
1443                 return mini_set_rtc_time(&wtime);
1444             }
1445         }
1446
1447         return -EINVAL;
1448 }
1449
1450 static int mini_rtc_open(struct inode *inode, struct file *file)
1451 {
1452         if (mini_rtc_status & RTC_IS_OPEN)
1453                 return -EBUSY;
1454
1455         mini_rtc_status |= RTC_IS_OPEN;
1456
1457         return 0;
1458 }
1459
1460 static int mini_rtc_release(struct inode *inode, struct file *file)
1461 {
1462         mini_rtc_status &= ~RTC_IS_OPEN;
1463         return 0;
1464 }
1465
1466
1467 static struct file_operations mini_rtc_fops = {
1468         .owner          = THIS_MODULE,
1469         .ioctl          = mini_rtc_ioctl,
1470         .open           = mini_rtc_open,
1471         .release        = mini_rtc_release,
1472 };
1473
1474 static struct miscdevice rtc_mini_dev =
1475 {
1476         .minor          = RTC_MINOR,
1477         .name           = "rtc",
1478         .fops           = &mini_rtc_fops,
1479 };
1480
1481 static int __init rtc_mini_init(void)
1482 {
1483         int retval;
1484
1485         if (tlb_type != hypervisor && !this_is_starfire)
1486                 return -ENODEV;
1487
1488         printk(KERN_INFO "Mini RTC Driver\n");
1489
1490         retval = misc_register(&rtc_mini_dev);
1491         if (retval < 0)
1492                 return retval;
1493
1494         return 0;
1495 }
1496
1497 static void __exit rtc_mini_exit(void)
1498 {
1499         misc_deregister(&rtc_mini_dev);
1500 }
1501
1502
1503 module_init(rtc_mini_init);
1504 module_exit(rtc_mini_exit);