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                 /* Dallas 12887 RTC chip. */
 645
 646                 do {
 647                         sec  = CMOS_READ(RTC_SECONDS);
 648                         min  = CMOS_READ(RTC_MINUTES);
 649                         hour = CMOS_READ(RTC_HOURS);
 650                         day  = CMOS_READ(RTC_DAY_OF_MONTH);
 651                         mon  = CMOS_READ(RTC_MONTH);
 652                         year = CMOS_READ(RTC_YEAR);
 653                 } while (sec != CMOS_READ(RTC_SECONDS));
 654
 655                 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 656                         BCD_TO_BIN(sec);
 657                         BCD_TO_BIN(min);
 658                         BCD_TO_BIN(hour);
 659                         BCD_TO_BIN(day);
 660                         BCD_TO_BIN(mon);
 661                         BCD_TO_BIN(year);
 662                 }
 663                 if ((year += 1900) < 1970)
 664                         year += 100;
 665         }
 666
 667         xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
 668         xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 669         set_normalized_timespec(&wall_to_monotonic,
 670                                 -xtime.tv_sec, -xtime.tv_nsec);
 671
 672         if (mregs) {
 673                 tmp = mostek_read(mregs + MOSTEK_CREG);
 674                 tmp &= ~MSTK_CREG_READ;
 675                 mostek_write(mregs + MOSTEK_CREG, tmp);
 676
 677                 spin_unlock_irq(&mostek_lock);
 678         }
 679 }
 680
 681 /* davem suggests we keep this within the 4M locked kernel image */
 682 static u32 starfire_get_time(void)
 683 {
 684         static char obp_gettod[32];
 685         static u32 unix_tod;
 686
 687         sprintf(obp_gettod, "h# %08x unix-gettod",
 688                 (unsigned int) (long) &unix_tod);
 689         prom_feval(obp_gettod);
 690
 691         return unix_tod;
 692 }
 693
 694 static int starfire_set_time(u32 val)
 695 {
 696         /* Do nothing, time is set using the service processor
 697          * console on this platform.
 698          */
 699         return 0;
 700 }
 701
 702 static u32 hypervisor_get_time(void)
 703 {
 704         register unsigned long func asm("%o5");
 705         register unsigned long arg0 asm("%o0");
 706         register unsigned long arg1 asm("%o1");
 707         int retries = 10000;
 708
 709 retry:
 710         func = HV_FAST_TOD_GET;
 711         arg0 = 0;
 712         arg1 = 0;
 713         __asm__ __volatile__("ta        %6"
 714                              : "=&r" (func), "=&r" (arg0), "=&r" (arg1)
 715                              : "0" (func), "1" (arg0), "2" (arg1),
 716                                "i" (HV_FAST_TRAP));
 717         if (arg0 == HV_EOK)
 718                 return arg1;
 719         if (arg0 == HV_EWOULDBLOCK) {
 720                 if (--retries > 0) {
 721                         udelay(100);
 722                         goto retry;
 723                 }
 724                 printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
 725                 return 0;
 726         }
 727         printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
 728         return 0;
 729 }
 730
 731 static int hypervisor_set_time(u32 secs)
 732 {
 733         register unsigned long func asm("%o5");
 734         register unsigned long arg0 asm("%o0");
 735         int retries = 10000;
 736
 737 retry:
 738         func = HV_FAST_TOD_SET;
 739         arg0 = secs;
 740         __asm__ __volatile__("ta        %4"
 741                              : "=&r" (func), "=&r" (arg0)
 742                              : "0" (func), "1" (arg0),
 743                                "i" (HV_FAST_TRAP));
 744         if (arg0 == HV_EOK)
 745                 return 0;
 746         if (arg0 == HV_EWOULDBLOCK) {
 747                 if (--retries > 0) {
 748                         udelay(100);
 749                         goto retry;
 750                 }
 751                 printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
 752                 return -EAGAIN;
 753         }
 754         printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
 755         return -EOPNOTSUPP;
 756 }
 757
 758 void __init clock_probe(void)
 759 {
 760         struct linux_prom_registers clk_reg[2];
 761         char model[128];
 762         int node, busnd = -1, err;
 763         unsigned long flags;
 764         struct linux_central *cbus;
 765 #ifdef CONFIG_PCI
 766         struct linux_ebus *ebus = NULL;
 767         struct sparc_isa_bridge *isa_br = NULL;
 768 #endif
 769         static int invoked;
 770
 771         if (invoked)
 772                 return;
 773         invoked = 1;
 774
 775
 776         if (this_is_starfire) {
 777                 xtime.tv_sec = starfire_get_time();
 778                 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 779                 set_normalized_timespec(&wall_to_monotonic,
 780                                         -xtime.tv_sec, -xtime.tv_nsec);
 781                 return;
 782         }
 783         if (tlb_type == hypervisor) {
 784                 xtime.tv_sec = hypervisor_get_time();
 785                 xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 786                 set_normalized_timespec(&wall_to_monotonic,
 787                                         -xtime.tv_sec, -xtime.tv_nsec);
 788                 return;
 789         }
 790
 791         local_irq_save(flags);
 792
 793         cbus = central_bus;
 794         if (cbus != NULL)
 795                 busnd = central_bus->child->prom_node;
 796
 797         /* Check FHC Central then EBUSs then ISA bridges then SBUSs.
 798          * That way we handle the presence of multiple properly.
 799          *
 800          * As a special case, machines with Central must provide the
 801          * timer chip there.
 802          */
 803 #ifdef CONFIG_PCI
 804         if (ebus_chain != NULL) {
 805                 ebus = ebus_chain;
 806                 if (busnd == -1)
 807                         busnd = ebus->prom_node;
 808         }
 809         if (isa_chain != NULL) {
 810                 isa_br = isa_chain;
 811                 if (busnd == -1)
 812                         busnd = isa_br->prom_node;
 813         }
 814 #endif
 815         if (sbus_root != NULL && busnd == -1)
 816                 busnd = sbus_root->prom_node;
 817
 818         if (busnd == -1) {
 819                 prom_printf("clock_probe: problem, cannot find bus to search.\n");
 820                 prom_halt();
 821         }
 822
 823         node = prom_getchild(busnd);
 824
 825         while (1) {
 826                 if (!node)
 827                         model[0] = 0;
 828                 else
 829                         prom_getstring(node, "model", model, sizeof(model));
 830                 if (strcmp(model, "mk48t02") &&
 831                     strcmp(model, "mk48t08") &&
 832                     strcmp(model, "mk48t59") &&
 833                     strcmp(model, "m5819") &&
 834                     strcmp(model, "m5819p") &&
 835                     strcmp(model, "m5823") &&
 836                     strcmp(model, "ds1287")) {
 837                         if (cbus != NULL) {
 838                                 prom_printf("clock_probe: Central bus lacks timer chip.\n");
 839                                 prom_halt();
 840                         }
 841
 842                         if (node != 0)
 843                                 node = prom_getsibling(node);
 844 #ifdef CONFIG_PCI
 845                         while ((node == 0) && ebus != NULL) {
 846                                 ebus = ebus->next;
 847                                 if (ebus != NULL) {
 848                                         busnd = ebus->prom_node;
 849                                         node = prom_getchild(busnd);
 850                                 }
 851                         }
 852                         while ((node == 0) && isa_br != NULL) {
 853                                 isa_br = isa_br->next;
 854                                 if (isa_br != NULL) {
 855                                         busnd = isa_br->prom_node;
 856                                         node = prom_getchild(busnd);
 857                                 }
 858                         }
 859 #endif
 860                         if (node == 0) {
 861                                 prom_printf("clock_probe: Cannot find timer chip\n");
 862                                 prom_halt();
 863                         }
 864                         continue;
 865                 }
 866
 867                 err = prom_getproperty(node, "reg", (char *)clk_reg,
 868                                        sizeof(clk_reg));
 869                 if(err == -1) {
 870                         prom_printf("clock_probe: Cannot get Mostek reg property\n");
 871                         prom_halt();
 872                 }
 873
 874                 if (cbus != NULL) {
 875                         apply_fhc_ranges(central_bus->child, clk_reg, 1);
 876                         apply_central_ranges(central_bus, clk_reg, 1);
 877                 }
 878 #ifdef CONFIG_PCI
 879                 else if (ebus != NULL) {
 880                         struct linux_ebus_device *edev;
 881
 882                         for_each_ebusdev(edev, ebus)
 883                                 if (edev->prom_node == node)
 884                                         break;
 885                         if (edev == NULL) {
 886                                 if (isa_chain != NULL)
 887                                         goto try_isa_clock;
 888                                 prom_printf("%s: Mostek not probed by EBUS\n",
 889                                             __FUNCTION__);
 890                                 prom_halt();
 891                         }
 892
 893                         if (!strcmp(model, "ds1287") ||
 894                             !strcmp(model, "m5819") ||
 895                             !strcmp(model, "m5819p") ||
 896                             !strcmp(model, "m5823")) {
 897                                 ds1287_regs = edev->resource[0].start;
 898                         } else {
 899                                 mstk48t59_regs = (void __iomem *)
 900                                         edev->resource[0].start;
 901                                 mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 902                         }
 903                         break;
 904                 }
 905                 else if (isa_br != NULL) {
 906                         struct sparc_isa_device *isadev;
 907
 908 try_isa_clock:
 909                         for_each_isadev(isadev, isa_br)
 910                                 if (isadev->prom_node == node)
 911                                         break;
 912                         if (isadev == NULL) {
 913                                 prom_printf("%s: Mostek not probed by ISA\n");
 914                                 prom_halt();
 915                         }
 916                         if (!strcmp(model, "ds1287") ||
 917                             !strcmp(model, "m5819") ||
 918                             !strcmp(model, "m5819p") ||
 919                             !strcmp(model, "m5823")) {
 920                                 ds1287_regs = isadev->resource.start;
 921                         } else {
 922                                 mstk48t59_regs = (void __iomem *)
 923                                         isadev->resource.start;
 924                                 mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 925                         }
 926                         break;
 927                 }
 928 #endif
 929                 else {
 930                         if (sbus_root->num_sbus_ranges) {
 931                                 int nranges = sbus_root->num_sbus_ranges;
 932                                 int rngc;
 933
 934                                 for (rngc = 0; rngc < nranges; rngc++)
 935                                         if (clk_reg[0].which_io ==
 936                                             sbus_root->sbus_ranges[rngc].ot_child_space)
 937                                                 break;
 938                                 if (rngc == nranges) {
 939                                         prom_printf("clock_probe: Cannot find ranges for "
 940                                                     "clock regs.\n");
 941                                         prom_halt();
 942                                 }
 943                                 clk_reg[0].which_io =
 944                                         sbus_root->sbus_ranges[rngc].ot_parent_space;
 945                                 clk_reg[0].phys_addr +=
 946                                         sbus_root->sbus_ranges[rngc].ot_parent_base;
 947                         }
 948                 }
 949
 950                 if(model[5] == '0' && model[6] == '2') {
 951                         mstk48t02_regs = (void __iomem *)
 952                                 (((u64)clk_reg[0].phys_addr) |
 953                                  (((u64)clk_reg[0].which_io)<<32UL));
 954                 } else if(model[5] == '0' && model[6] == '8') {
 955                         mstk48t08_regs = (void __iomem *)
 956                                 (((u64)clk_reg[0].phys_addr) |
 957                                  (((u64)clk_reg[0].which_io)<<32UL));
 958                         mstk48t02_regs = mstk48t08_regs + MOSTEK_48T08_48T02;
 959                 } else {
 960                         mstk48t59_regs = (void __iomem *)
 961                                 (((u64)clk_reg[0].phys_addr) |
 962                                  (((u64)clk_reg[0].which_io)<<32UL));
 963                         mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
 964                 }
 965                 break;
 966         }
 967
 968         if (mstk48t02_regs != NULL) {
 969                 /* Report a low battery voltage condition. */
 970                 if (has_low_battery())
 971                         prom_printf("NVRAM: Low battery voltage!\n");
 972
 973                 /* Kick start the clock if it is completely stopped. */
 974                 if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
 975                         kick_start_clock();
 976         }
 977
 978         set_system_time();
 979
 980         local_irq_restore(flags);
 981 }
 982
 983 /* This is gets the master TICK_INT timer going. */
 984 static unsigned long sparc64_init_timers(void)
 985 {
 986         unsigned long clock;
 987         int node;
 988 #ifdef CONFIG_SMP
 989         extern void smp_tick_init(void);
 990 #endif
 991
 992         if (tlb_type == spitfire) {
 993                 unsigned long ver, manuf, impl;
 994
 995                 __asm__ __volatile__ ("rdpr %%ver, %0"
 996                                       : "=&r" (ver));
 997                 manuf = ((ver >> 48) & 0xffff);
 998                 impl = ((ver >> 32) & 0xffff);
 999                 if (manuf == 0x17 && impl == 0x13) {
1000                         /* Hummingbird, aka Ultra-IIe */
1001                         tick_ops = &hbtick_operations;
1002                         node = prom_root_node;
1003                         clock = prom_getint(node, "stick-frequency");
1004                 } else {
1005                         tick_ops = &tick_operations;
1006                         cpu_find_by_instance(0, &node, NULL);
1007                         clock = prom_getint(node, "clock-frequency");
1008                 }
1009         } else {
1010                 tick_ops = &stick_operations;
1011                 node = prom_root_node;
1012                 clock = prom_getint(node, "stick-frequency");
1013         }
1014         timer_tick_offset = clock / HZ;
1015
1016 #ifdef CONFIG_SMP
1017         smp_tick_init();
1018 #endif
1019
1020         return clock;
1021 }
1022
1023 static void sparc64_start_timers(irqreturn_t (*cfunc)(int, void *, struct pt_regs *))
1024 {
1025         unsigned long pstate;
1026         int err;
1027
1028         /* Register IRQ handler. */
1029         err = request_irq(build_irq(0, 0, 0UL, 0UL), cfunc, 0,
1030                           "timer", NULL);
1031
1032         if (err) {
1033                 prom_printf("Serious problem, cannot register TICK_INT\n");
1034                 prom_halt();
1035         }
1036
1037         /* Guarantee that the following sequences execute
1038          * uninterrupted.
1039          */
1040         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
1041                              "wrpr      %0, %1, %%pstate"
1042                              : "=r" (pstate)
1043                              : "i" (PSTATE_IE));
1044
1045         tick_ops->init_tick(timer_tick_offset);
1046
1047         /* Restore PSTATE_IE. */
1048         __asm__ __volatile__("wrpr      %0, 0x0, %%pstate"
1049                              : /* no outputs */
1050                              : "r" (pstate));
1051
1052         local_irq_enable();
1053 }
1054
1055 struct freq_table {
1056         unsigned long clock_tick_ref;
1057         unsigned int ref_freq;
1058 };
1059 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
1060
1061 unsigned long sparc64_get_clock_tick(unsigned int cpu)
1062 {
1063         struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
1064
1065         if (ft->clock_tick_ref)
1066                 return ft->clock_tick_ref;
1067         return cpu_data(cpu).clock_tick;
1068 }
1069
1070 #ifdef CONFIG_CPU_FREQ
1071
1072 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
1073                                     void *data)
1074 {
1075         struct cpufreq_freqs *freq = data;
1076         unsigned int cpu = freq->cpu;
1077         struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
1078
1079         if (!ft->ref_freq) {
1080                 ft->ref_freq = freq->old;
1081                 ft->clock_tick_ref = cpu_data(cpu).clock_tick;
1082         }
1083         if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
1084             (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
1085             (val == CPUFREQ_RESUMECHANGE)) {
1086                 cpu_data(cpu).clock_tick =
1087                         cpufreq_scale(ft->clock_tick_ref,
1088                                       ft->ref_freq,
1089                                       freq->new);
1090         }
1091
1092         return 0;
1093 }
1094
1095 static struct notifier_block sparc64_cpufreq_notifier_block = {
1096         .notifier_call  = sparc64_cpufreq_notifier
1097 };
1098
1099 #endif /* CONFIG_CPU_FREQ */
1100
1101 static struct time_interpolator sparc64_cpu_interpolator = {
1102         .source         =       TIME_SOURCE_CPU,
1103         .shift          =       16,
1104         .mask           =       0xffffffffffffffffLL
1105 };
1106
1107 /* The quotient formula is taken from the IA64 port. */
1108 #define SPARC64_NSEC_PER_CYC_SHIFT      30UL
1109 void __init time_init(void)
1110 {
1111         unsigned long clock = sparc64_init_timers();
1112
1113         sparc64_cpu_interpolator.frequency = clock;
1114         register_time_interpolator(&sparc64_cpu_interpolator);
1115
1116         /* Now that the interpolator is registered, it is
1117          * safe to start the timer ticking.
1118          */
1119         sparc64_start_timers(timer_interrupt);
1120
1121         timer_ticks_per_nsec_quotient =
1122                 (((NSEC_PER_SEC << SPARC64_NSEC_PER_CYC_SHIFT) +
1123                   (clock / 2)) / clock);
1124
1125 #ifdef CONFIG_CPU_FREQ
1126         cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
1127                                   CPUFREQ_TRANSITION_NOTIFIER);
1128 #endif
1129 }
1130
1131 unsigned long long sched_clock(void)
1132 {
1133         unsigned long ticks = tick_ops->get_tick();
1134
1135         return (ticks * timer_ticks_per_nsec_quotient)
1136                 >> SPARC64_NSEC_PER_CYC_SHIFT;
1137 }
1138
1139 static int set_rtc_mmss(unsigned long nowtime)
1140 {
1141         int real_seconds, real_minutes, chip_minutes;
1142         void __iomem *mregs = mstk48t02_regs;
1143 #ifdef CONFIG_PCI
1144         unsigned long dregs = ds1287_regs;
1145 #else
1146         unsigned long dregs = 0UL;
1147 #endif
1148         unsigned long flags;
1149         u8 tmp;
1150
1151         /*
1152          * Not having a register set can lead to trouble.
1153          * Also starfire doesn't have a tod clock.
1154          */
1155         if (!mregs && !dregs)
1156                 return -1;
1157
1158         if (mregs) {
1159                 spin_lock_irqsave(&mostek_lock, flags);
1160
1161                 /* Read the current RTC minutes. */
1162                 tmp = mostek_read(mregs + MOSTEK_CREG);
1163                 tmp |= MSTK_CREG_READ;
1164                 mostek_write(mregs + MOSTEK_CREG, tmp);
1165
1166                 chip_minutes = MSTK_REG_MIN(mregs);
1167
1168                 tmp = mostek_read(mregs + MOSTEK_CREG);
1169                 tmp &= ~MSTK_CREG_READ;
1170                 mostek_write(mregs + MOSTEK_CREG, tmp);
1171
1172                 /*
1173                  * since we're only adjusting minutes and seconds,
1174                  * don't interfere with hour overflow. This avoids
1175                  * messing with unknown time zones but requires your
1176                  * RTC not to be off by more than 15 minutes
1177                  */
1178                 real_seconds = nowtime % 60;
1179                 real_minutes = nowtime / 60;
1180                 if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
1181                         real_minutes += 30;     /* correct for half hour time zone */
1182                 real_minutes %= 60;
1183
1184                 if (abs(real_minutes - chip_minutes) < 30) {
1185                         tmp = mostek_read(mregs + MOSTEK_CREG);
1186                         tmp |= MSTK_CREG_WRITE;
1187                         mostek_write(mregs + MOSTEK_CREG, tmp);
1188
1189                         MSTK_SET_REG_SEC(mregs,real_seconds);
1190                         MSTK_SET_REG_MIN(mregs,real_minutes);
1191
1192                         tmp = mostek_read(mregs + MOSTEK_CREG);
1193                         tmp &= ~MSTK_CREG_WRITE;
1194                         mostek_write(mregs + MOSTEK_CREG, tmp);
1195
1196                         spin_unlock_irqrestore(&mostek_lock, flags);
1197
1198                         return 0;
1199                 } else {
1200                         spin_unlock_irqrestore(&mostek_lock, flags);
1201
1202                         return -1;
1203                 }
1204         } else {
1205                 int retval = 0;
1206                 unsigned char save_control, save_freq_select;
1207
1208                 /* Stolen from arch/i386/kernel/time.c, see there for
1209                  * credits and descriptive comments.
1210                  */
1211                 spin_lock_irqsave(&rtc_lock, flags);
1212                 save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
1213                 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
1214
1215                 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
1216                 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
1217
1218                 chip_minutes = CMOS_READ(RTC_MINUTES);
1219                 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
1220                         BCD_TO_BIN(chip_minutes);
1221                 real_seconds = nowtime % 60;
1222                 real_minutes = nowtime / 60;
1223                 if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
1224                         real_minutes += 30;
1225                 real_minutes %= 60;
1226
1227                 if (abs(real_minutes - chip_minutes) < 30) {
1228                         if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
1229                                 BIN_TO_BCD(real_seconds);
1230                                 BIN_TO_BCD(real_minutes);
1231                         }
1232                         CMOS_WRITE(real_seconds,RTC_SECONDS);
1233                         CMOS_WRITE(real_minutes,RTC_MINUTES);
1234                 } else {
1235                         printk(KERN_WARNING
1236                                "set_rtc_mmss: can't update from %d to %d\n",
1237                                chip_minutes, real_minutes);
1238                         retval = -1;
1239                 }
1240
1241                 CMOS_WRITE(save_control, RTC_CONTROL);
1242                 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
1243                 spin_unlock_irqrestore(&rtc_lock, flags);
1244
1245                 return retval;
1246         }
1247 }
1248
1249 #define RTC_IS_OPEN             0x01    /* means /dev/rtc is in use     */
1250 static unsigned char mini_rtc_status;   /* bitmapped status byte.       */
1251
1252 /* months start at 0 now */
1253 static unsigned char days_in_mo[] =
1254 {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
1255
1256 #define FEBRUARY        2
1257 #define STARTOFTIME     1970
1258 #define SECDAY          86400L
1259 #define SECYR           (SECDAY * 365)
1260 #define leapyear(year)          ((year) % 4 == 0 && \
1261                                  ((year) % 100 != 0 || (year) % 400 == 0))
1262 #define days_in_year(a)         (leapyear(a) ? 366 : 365)
1263 #define days_in_month(a)        (month_days[(a) - 1])
1264
1265 static int month_days[12] = {
1266         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1267 };
1268
1269 /*
1270  * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1271  */
1272 static void GregorianDay(struct rtc_time * tm)
1273 {
1274         int leapsToDate;
1275         int lastYear;
1276         int day;
1277         int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1278
1279         lastYear = tm->tm_year - 1;
1280
1281         /*
1282          * Number of leap corrections to apply up to end of last year
1283          */
1284         leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
1285
1286         /*
1287          * This year is a leap year if it is divisible by 4 except when it is
1288          * divisible by 100 unless it is divisible by 400
1289          *
1290          * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1291          */
1292         day = tm->tm_mon > 2 && leapyear(tm->tm_year);
1293
1294         day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
1295                    tm->tm_mday;
1296
1297         tm->tm_wday = day % 7;
1298 }
1299
1300 static void to_tm(int tim, struct rtc_time *tm)
1301 {
1302         register int    i;
1303         register long   hms, day;
1304
1305         day = tim / SECDAY;
1306         hms = tim % SECDAY;
1307
1308         /* Hours, minutes, seconds are easy */
1309         tm->tm_hour = hms / 3600;
1310         tm->tm_min = (hms % 3600) / 60;
1311         tm->tm_sec = (hms % 3600) % 60;
1312
1313         /* Number of years in days */
1314         for (i = STARTOFTIME; day >= days_in_year(i); i++)
1315                 day -= days_in_year(i);
1316         tm->tm_year = i;
1317
1318         /* Number of months in days left */
1319         if (leapyear(tm->tm_year))
1320                 days_in_month(FEBRUARY) = 29;
1321         for (i = 1; day >= days_in_month(i); i++)
1322                 day -= days_in_month(i);
1323         days_in_month(FEBRUARY) = 28;
1324         tm->tm_mon = i;
1325
1326         /* Days are what is left over (+1) from all that. */
1327         tm->tm_mday = day + 1;
1328
1329         /*
1330          * Determine the day of week
1331          */
1332         GregorianDay(tm);
1333 }
1334
1335 /* Both Starfire and SUN4V give us seconds since Jan 1st, 1970,
1336  * aka Unix time.  So we have to convert to/from rtc_time.
1337  */
1338 static inline void mini_get_rtc_time(struct rtc_time *time)
1339 {
1340         unsigned long flags;
1341         u32 seconds;
1342
1343         spin_lock_irqsave(&rtc_lock, flags);
1344         seconds = 0;
1345         if (this_is_starfire)
1346                 seconds = starfire_get_time();
1347         else if (tlb_type == hypervisor)
1348                 seconds = hypervisor_get_time();
1349         spin_unlock_irqrestore(&rtc_lock, flags);
1350
1351         to_tm(seconds, time);
1352         time->tm_year -= 1900;
1353         time->tm_mon -= 1;
1354 }
1355
1356 static inline int mini_set_rtc_time(struct rtc_time *time)
1357 {
1358         u32 seconds = mktime(time->tm_year + 1900, time->tm_mon + 1,
1359                              time->tm_mday, time->tm_hour,
1360                              time->tm_min, time->tm_sec);
1361         unsigned long flags;
1362         int err;
1363
1364         spin_lock_irqsave(&rtc_lock, flags);
1365         err = -ENODEV;
1366         if (this_is_starfire)
1367                 err = starfire_set_time(seconds);
1368         else  if (tlb_type == hypervisor)
1369                 err = hypervisor_set_time(seconds);
1370         spin_unlock_irqrestore(&rtc_lock, flags);
1371
1372         return err;
1373 }
1374
1375 static int mini_rtc_ioctl(struct inode *inode, struct file *file,
1376                           unsigned int cmd, unsigned long arg)
1377 {
1378         struct rtc_time wtime;
1379         void __user *argp = (void __user *)arg;
1380
1381         switch (cmd) {
1382
1383         case RTC_PLL_GET:
1384                 return -EINVAL;
1385
1386         case RTC_PLL_SET:
1387                 return -EINVAL;
1388
1389         case RTC_UIE_OFF:       /* disable ints from RTC updates.       */
1390                 return 0;
1391
1392         case RTC_UIE_ON:        /* enable ints for RTC updates. */
1393                 return -EINVAL;
1394
1395         case RTC_RD_TIME:       /* Read the time/date from RTC  */
1396                 /* this doesn't get week-day, who cares */
1397                 memset(&wtime, 0, sizeof(wtime));
1398                 mini_get_rtc_time(&wtime);
1399
1400                 return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
1401
1402         case RTC_SET_TIME:      /* Set the RTC */
1403             {
1404                 int year;
1405                 unsigned char leap_yr;
1406
1407                 if (!capable(CAP_SYS_TIME))
1408                         return -EACCES;
1409
1410                 if (copy_from_user(&wtime, argp, sizeof(wtime)))
1411                         return -EFAULT;
1412
1413                 year = wtime.tm_year + 1900;
1414                 leap_yr = ((!(year % 4) && (year % 100)) ||
1415                            !(year % 400));
1416
1417                 if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
1418                         return -EINVAL;
1419
1420                 if (wtime.tm_mday < 0 || wtime.tm_mday >
1421                     (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
1422                         return -EINVAL;
1423
1424                 if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
1425                     wtime.tm_min < 0 || wtime.tm_min >= 60 ||
1426                     wtime.tm_sec < 0 || wtime.tm_sec >= 60)
1427                         return -EINVAL;
1428
1429                 return mini_set_rtc_time(&wtime);
1430             }
1431         }
1432
1433         return -EINVAL;
1434 }
1435
1436 static int mini_rtc_open(struct inode *inode, struct file *file)
1437 {
1438         if (mini_rtc_status & RTC_IS_OPEN)
1439                 return -EBUSY;
1440
1441         mini_rtc_status |= RTC_IS_OPEN;
1442
1443         return 0;
1444 }
1445
1446 static int mini_rtc_release(struct inode *inode, struct file *file)
1447 {
1448         mini_rtc_status &= ~RTC_IS_OPEN;
1449         return 0;
1450 }
1451
1452
1453 static struct file_operations mini_rtc_fops = {
1454         .owner          = THIS_MODULE,
1455         .ioctl          = mini_rtc_ioctl,
1456         .open           = mini_rtc_open,
1457         .release        = mini_rtc_release,
1458 };
1459
1460 static struct miscdevice rtc_mini_dev =
1461 {
1462         .minor          = RTC_MINOR,
1463         .name           = "rtc",
1464         .fops           = &mini_rtc_fops,
1465 };
1466
1467 static int __init rtc_mini_init(void)
1468 {
1469         int retval;
1470
1471         if (tlb_type != hypervisor && !this_is_starfire)
1472                 return -ENODEV;
1473
1474         printk(KERN_INFO "Mini RTC Driver\n");
1475
1476         retval = misc_register(&rtc_mini_dev);
1477         if (retval < 0)
1478                 return retval;
1479
1480         return 0;
1481 }
1482
1483 static void __exit rtc_mini_exit(void)
1484 {
1485         misc_deregister(&rtc_mini_dev);
1486 }
1487
1488
1489 module_init(rtc_mini_init);
1490 module_exit(rtc_mini_exit);