hw/mc146818rtc.c

   1 /*
   2  * QEMU MC146818 RTC emulation
   3  *
   4  * Copyright (c) 2003-2004 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "hw.h"
  25 #include "qemu-timer.h"
  26 #include "sysemu.h"
  27 #include "pc.h"
  28 #include "isa.h"
  29 #include "hpet_emul.h"
  30
  31 //#define DEBUG_CMOS
  32
  33 #define RTC_REINJECT_ON_ACK_COUNT 20
  34
  35 #define RTC_SECONDS             0
  36 #define RTC_SECONDS_ALARM       1
  37 #define RTC_MINUTES             2
  38 #define RTC_MINUTES_ALARM       3
  39 #define RTC_HOURS               4
  40 #define RTC_HOURS_ALARM         5
  41 #define RTC_ALARM_DONT_CARE    0xC0
  42
  43 #define RTC_DAY_OF_WEEK         6
  44 #define RTC_DAY_OF_MONTH        7
  45 #define RTC_MONTH               8
  46 #define RTC_YEAR                9
  47
  48 #define RTC_REG_A               10
  49 #define RTC_REG_B               11
  50 #define RTC_REG_C               12
  51 #define RTC_REG_D               13
  52
  53 #define REG_A_UIP 0x80
  54
  55 #define REG_B_SET  0x80
  56 #define REG_B_PIE  0x40
  57 #define REG_B_AIE  0x20
  58 #define REG_B_UIE  0x10
  59 #define REG_B_SQWE 0x08
  60 #define REG_B_DM   0x04
  61
  62 #define REG_C_UF   0x10
  63 #define REG_C_IRQF 0x80
  64 #define REG_C_PF   0x40
  65 #define REG_C_AF   0x20
  66
  67 struct RTCState {
  68     ISADevice dev;
  69     uint8_t cmos_data[128];
  70     uint8_t cmos_index;
  71     struct tm current_tm;
  72     int32_t base_year;
  73     qemu_irq irq;
  74     qemu_irq sqw_irq;
  75     int it_shift;
  76     /* periodic timer */
  77     QEMUTimer *periodic_timer;
  78     int64_t next_periodic_time;
  79     /* second update */
  80     int64_t next_second_time;
  81     uint16_t irq_reinject_on_ack_count;
  82     uint32_t irq_coalesced;
  83     uint32_t period;
  84     QEMUTimer *coalesced_timer;
  85     QEMUTimer *second_timer;
  86     QEMUTimer *second_timer2;
  87 };
  88
  89 static void rtc_irq_raise(qemu_irq irq)
  90 {
  91     /* When HPET is operating in legacy mode, RTC interrupts are disabled
  92      * We block qemu_irq_raise, but not qemu_irq_lower, in case legacy
  93      * mode is established while interrupt is raised. We want it to
  94      * be lowered in any case
  95      */
  96 #if defined TARGET_I386
  97     if (!hpet_in_legacy_mode())
  98 #endif
  99         qemu_irq_raise(irq);
 100 }
 101
 102 static void rtc_set_time(RTCState *s);
 103 static void rtc_copy_date(RTCState *s);
 104
 105 #ifdef TARGET_I386
 106 static void rtc_coalesced_timer_update(RTCState *s)
 107 {
 108     if (s->irq_coalesced == 0) {
 109         qemu_del_timer(s->coalesced_timer);
 110     } else {
 111         /* divide each RTC interval to 2 - 8 smaller intervals */
 112         int c = MIN(s->irq_coalesced, 7) + 1;
 113         int64_t next_clock = qemu_get_clock(rtc_clock) +
 114             muldiv64(s->period / c, get_ticks_per_sec(), 32768);
 115         qemu_mod_timer(s->coalesced_timer, next_clock);
 116     }
 117 }
 118
 119 static void rtc_coalesced_timer(void *opaque)
 120 {
 121     RTCState *s = opaque;
 122
 123     if (s->irq_coalesced != 0) {
 124         apic_reset_irq_delivered();
 125         s->cmos_data[RTC_REG_C] |= 0xc0;
 126         rtc_irq_raise(s->irq);
 127         if (apic_get_irq_delivered()) {
 128             s->irq_coalesced--;
 129         }
 130     }
 131
 132     rtc_coalesced_timer_update(s);
 133 }
 134 #endif
 135
 136 static void rtc_timer_update(RTCState *s, int64_t current_time)
 137 {
 138     int period_code, period;
 139     int64_t cur_clock, next_irq_clock;
 140     int enable_pie;
 141
 142     period_code = s->cmos_data[RTC_REG_A] & 0x0f;
 143 #if defined TARGET_I386
 144     /* disable periodic timer if hpet is in legacy mode, since interrupts are
 145      * disabled anyway.
 146      */
 147     enable_pie = !hpet_in_legacy_mode();
 148 #else
 149     enable_pie = 1;
 150 #endif
 151     if (period_code != 0
 152         && (((s->cmos_data[RTC_REG_B] & REG_B_PIE) && enable_pie)
 153             || ((s->cmos_data[RTC_REG_B] & REG_B_SQWE) && s->sqw_irq))) {
 154         if (period_code <= 2)
 155             period_code += 7;
 156         /* period in 32 Khz cycles */
 157         period = 1 << (period_code - 1);
 158 #ifdef TARGET_I386
 159         if(period != s->period)
 160             s->irq_coalesced = (s->irq_coalesced * s->period) / period;
 161         s->period = period;
 162 #endif
 163         /* compute 32 khz clock */
 164         cur_clock = muldiv64(current_time, 32768, get_ticks_per_sec());
 165         next_irq_clock = (cur_clock & ~(period - 1)) + period;
 166         s->next_periodic_time =
 167             muldiv64(next_irq_clock, get_ticks_per_sec(), 32768) + 1;
 168         qemu_mod_timer(s->periodic_timer, s->next_periodic_time);
 169     } else {
 170 #ifdef TARGET_I386
 171         s->irq_coalesced = 0;
 172 #endif
 173         qemu_del_timer(s->periodic_timer);
 174     }
 175 }
 176
 177 static void rtc_periodic_timer(void *opaque)
 178 {
 179     RTCState *s = opaque;
 180
 181     rtc_timer_update(s, s->next_periodic_time);
 182     if (s->cmos_data[RTC_REG_B] & REG_B_PIE) {
 183         s->cmos_data[RTC_REG_C] |= 0xc0;
 184 #ifdef TARGET_I386
 185         if(rtc_td_hack) {
 186             if (s->irq_reinject_on_ack_count >= RTC_REINJECT_ON_ACK_COUNT)
 187                 s->irq_reinject_on_ack_count = 0;
 188             apic_reset_irq_delivered();
 189             rtc_irq_raise(s->irq);
 190             if (!apic_get_irq_delivered()) {
 191                 s->irq_coalesced++;
 192                 rtc_coalesced_timer_update(s);
 193             }
 194         } else
 195 #endif
 196         rtc_irq_raise(s->irq);
 197     }
 198     if (s->cmos_data[RTC_REG_B] & REG_B_SQWE) {
 199         /* Not square wave at all but we don't want 2048Hz interrupts!
 200            Must be seen as a pulse.  */
 201         qemu_irq_raise(s->sqw_irq);
 202     }
 203 }
 204
 205 static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data)
 206 {
 207     RTCState *s = opaque;
 208
 209     if ((addr & 1) == 0) {
 210         s->cmos_index = data & 0x7f;
 211     } else {
 212 #ifdef DEBUG_CMOS
 213         printf("cmos: write index=0x%02x val=0x%02x\n",
 214                s->cmos_index, data);
 215 #endif
 216         switch(s->cmos_index) {
 217         case RTC_SECONDS_ALARM:
 218         case RTC_MINUTES_ALARM:
 219         case RTC_HOURS_ALARM:
 220             /* XXX: not supported */
 221             s->cmos_data[s->cmos_index] = data;
 222             break;
 223         case RTC_SECONDS:
 224         case RTC_MINUTES:
 225         case RTC_HOURS:
 226         case RTC_DAY_OF_WEEK:
 227         case RTC_DAY_OF_MONTH:
 228         case RTC_MONTH:
 229         case RTC_YEAR:
 230             s->cmos_data[s->cmos_index] = data;
 231             /* if in set mode, do not update the time */
 232             if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
 233                 rtc_set_time(s);
 234             }
 235             break;
 236         case RTC_REG_A:
 237             /* UIP bit is read only */
 238             s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) |
 239                 (s->cmos_data[RTC_REG_A] & REG_A_UIP);
 240             rtc_timer_update(s, qemu_get_clock(rtc_clock));
 241             break;
 242         case RTC_REG_B:
 243             if (data & REG_B_SET) {
 244                 /* set mode: reset UIP mode */
 245                 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
 246                 data &= ~REG_B_UIE;
 247             } else {
 248                 /* if disabling set mode, update the time */
 249                 if (s->cmos_data[RTC_REG_B] & REG_B_SET) {
 250                     rtc_set_time(s);
 251                 }
 252             }
 253             s->cmos_data[RTC_REG_B] = data;
 254             rtc_timer_update(s, qemu_get_clock(rtc_clock));
 255             break;
 256         case RTC_REG_C:
 257         case RTC_REG_D:
 258             /* cannot write to them */
 259             break;
 260         default:
 261             s->cmos_data[s->cmos_index] = data;
 262             break;
 263         }
 264     }
 265 }
 266
 267 static inline int rtc_to_bcd(RTCState *s, int a)
 268 {
 269     if (s->cmos_data[RTC_REG_B] & REG_B_DM) {
 270         return a;
 271     } else {
 272         return ((a / 10) << 4) | (a % 10);
 273     }
 274 }
 275
 276 static inline int rtc_from_bcd(RTCState *s, int a)
 277 {
 278     if (s->cmos_data[RTC_REG_B] & REG_B_DM) {
 279         return a;
 280     } else {
 281         return ((a >> 4) * 10) + (a & 0x0f);
 282     }
 283 }
 284
 285 static void rtc_set_time(RTCState *s)
 286 {
 287     struct tm *tm = &s->current_tm;
 288
 289     tm->tm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]);
 290     tm->tm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]);
 291     tm->tm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
 292     if (!(s->cmos_data[RTC_REG_B] & 0x02) &&
 293         (s->cmos_data[RTC_HOURS] & 0x80)) {
 294         tm->tm_hour += 12;
 295     }
 296     tm->tm_wday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]) - 1;
 297     tm->tm_mday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
 298     tm->tm_mon = rtc_from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
 299     tm->tm_year = rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year - 1900;
 300 }
 301
 302 static void rtc_copy_date(RTCState *s)
 303 {
 304     const struct tm *tm = &s->current_tm;
 305     int year;
 306
 307     s->cmos_data[RTC_SECONDS] = rtc_to_bcd(s, tm->tm_sec);
 308     s->cmos_data[RTC_MINUTES] = rtc_to_bcd(s, tm->tm_min);
 309     if (s->cmos_data[RTC_REG_B] & 0x02) {
 310         /* 24 hour format */
 311         s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, tm->tm_hour);
 312     } else {
 313         /* 12 hour format */
 314         s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, tm->tm_hour % 12);
 315         if (tm->tm_hour >= 12)
 316             s->cmos_data[RTC_HOURS] |= 0x80;
 317     }
 318     s->cmos_data[RTC_DAY_OF_WEEK] = rtc_to_bcd(s, tm->tm_wday + 1);
 319     s->cmos_data[RTC_DAY_OF_MONTH] = rtc_to_bcd(s, tm->tm_mday);
 320     s->cmos_data[RTC_MONTH] = rtc_to_bcd(s, tm->tm_mon + 1);
 321     year = (tm->tm_year - s->base_year) % 100;
 322     if (year < 0)
 323         year += 100;
 324     s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year);
 325 }
 326
 327 /* month is between 0 and 11. */
 328 static int get_days_in_month(int month, int year)
 329 {
 330     static const int days_tab[12] = {
 331         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 332     };
 333     int d;
 334     if ((unsigned )month >= 12)
 335         return 31;
 336     d = days_tab[month];
 337     if (month == 1) {
 338         if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0))
 339             d++;
 340     }
 341     return d;
 342 }
 343
 344 /* update 'tm' to the next second */
 345 static void rtc_next_second(struct tm *tm)
 346 {
 347     int days_in_month;
 348
 349     tm->tm_sec++;
 350     if ((unsigned)tm->tm_sec >= 60) {
 351         tm->tm_sec = 0;
 352         tm->tm_min++;
 353         if ((unsigned)tm->tm_min >= 60) {
 354             tm->tm_min = 0;
 355             tm->tm_hour++;
 356             if ((unsigned)tm->tm_hour >= 24) {
 357                 tm->tm_hour = 0;
 358                 /* next day */
 359                 tm->tm_wday++;
 360                 if ((unsigned)tm->tm_wday >= 7)
 361                     tm->tm_wday = 0;
 362                 days_in_month = get_days_in_month(tm->tm_mon,
 363                                                   tm->tm_year + 1900);
 364                 tm->tm_mday++;
 365                 if (tm->tm_mday < 1) {
 366                     tm->tm_mday = 1;
 367                 } else if (tm->tm_mday > days_in_month) {
 368                     tm->tm_mday = 1;
 369                     tm->tm_mon++;
 370                     if (tm->tm_mon >= 12) {
 371                         tm->tm_mon = 0;
 372                         tm->tm_year++;
 373                     }
 374                 }
 375             }
 376         }
 377     }
 378 }
 379
 380
 381 static void rtc_update_second(void *opaque)
 382 {
 383     RTCState *s = opaque;
 384     int64_t delay;
 385
 386     /* if the oscillator is not in normal operation, we do not update */
 387     if ((s->cmos_data[RTC_REG_A] & 0x70) != 0x20) {
 388         s->next_second_time += get_ticks_per_sec();
 389         qemu_mod_timer(s->second_timer, s->next_second_time);
 390     } else {
 391         rtc_next_second(&s->current_tm);
 392
 393         if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
 394             /* update in progress bit */
 395             s->cmos_data[RTC_REG_A] |= REG_A_UIP;
 396         }
 397         /* should be 244 us = 8 / 32768 seconds, but currently the
 398            timers do not have the necessary resolution. */
 399         delay = (get_ticks_per_sec() * 1) / 100;
 400         if (delay < 1)
 401             delay = 1;
 402         qemu_mod_timer(s->second_timer2,
 403                        s->next_second_time + delay);
 404     }
 405 }
 406
 407 static void rtc_update_second2(void *opaque)
 408 {
 409     RTCState *s = opaque;
 410
 411     if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
 412         rtc_copy_date(s);
 413     }
 414
 415     /* check alarm */
 416     if (s->cmos_data[RTC_REG_B] & REG_B_AIE) {
 417         if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 ||
 418              s->cmos_data[RTC_SECONDS_ALARM] == s->current_tm.tm_sec) &&
 419             ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 ||
 420              s->cmos_data[RTC_MINUTES_ALARM] == s->current_tm.tm_mon) &&
 421             ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 ||
 422              s->cmos_data[RTC_HOURS_ALARM] == s->current_tm.tm_hour)) {
 423
 424             s->cmos_data[RTC_REG_C] |= 0xa0;
 425             rtc_irq_raise(s->irq);
 426         }
 427     }
 428
 429     /* update ended interrupt */
 430     s->cmos_data[RTC_REG_C] |= REG_C_UF;
 431     if (s->cmos_data[RTC_REG_B] & REG_B_UIE) {
 432       s->cmos_data[RTC_REG_C] |= REG_C_IRQF;
 433       rtc_irq_raise(s->irq);
 434     }
 435
 436     /* clear update in progress bit */
 437     s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
 438
 439     s->next_second_time += get_ticks_per_sec();
 440     qemu_mod_timer(s->second_timer, s->next_second_time);
 441 }
 442
 443 static uint32_t cmos_ioport_read(void *opaque, uint32_t addr)
 444 {
 445     RTCState *s = opaque;
 446     int ret;
 447     if ((addr & 1) == 0) {
 448         return 0xff;
 449     } else {
 450         switch(s->cmos_index) {
 451         case RTC_SECONDS:
 452         case RTC_MINUTES:
 453         case RTC_HOURS:
 454         case RTC_DAY_OF_WEEK:
 455         case RTC_DAY_OF_MONTH:
 456         case RTC_MONTH:
 457         case RTC_YEAR:
 458             ret = s->cmos_data[s->cmos_index];
 459             break;
 460         case RTC_REG_A:
 461             ret = s->cmos_data[s->cmos_index];
 462             break;
 463         case RTC_REG_C:
 464             ret = s->cmos_data[s->cmos_index];
 465             qemu_irq_lower(s->irq);
 466 #ifdef TARGET_I386
 467             if(s->irq_coalesced &&
 468                     s->irq_reinject_on_ack_count < RTC_REINJECT_ON_ACK_COUNT) {
 469                 s->irq_reinject_on_ack_count++;
 470                 apic_reset_irq_delivered();
 471                 qemu_irq_raise(s->irq);
 472                 if (apic_get_irq_delivered())
 473                     s->irq_coalesced--;
 474                 break;
 475             }
 476 #endif
 477
 478             s->cmos_data[RTC_REG_C] = 0x00;
 479             break;
 480         default:
 481             ret = s->cmos_data[s->cmos_index];
 482             break;
 483         }
 484 #ifdef DEBUG_CMOS
 485         printf("cmos: read index=0x%02x val=0x%02x\n",
 486                s->cmos_index, ret);
 487 #endif
 488         return ret;
 489     }
 490 }
 491
 492 void rtc_set_memory(RTCState *s, int addr, int val)
 493 {
 494     if (addr >= 0 && addr <= 127)
 495         s->cmos_data[addr] = val;
 496 }
 497
 498 void rtc_set_date(RTCState *s, const struct tm *tm)
 499 {
 500     s->current_tm = *tm;
 501     rtc_copy_date(s);
 502 }
 503
 504 /* PC cmos mappings */
 505 #define REG_IBM_CENTURY_BYTE        0x32
 506 #define REG_IBM_PS2_CENTURY_BYTE    0x37
 507
 508 static void rtc_set_date_from_host(RTCState *s)
 509 {
 510     struct tm tm;
 511     int val;
 512
 513     /* set the CMOS date */
 514     qemu_get_timedate(&tm, 0);
 515     rtc_set_date(s, &tm);
 516
 517     val = rtc_to_bcd(s, (tm.tm_year / 100) + 19);
 518     rtc_set_memory(s, REG_IBM_CENTURY_BYTE, val);
 519     rtc_set_memory(s, REG_IBM_PS2_CENTURY_BYTE, val);
 520 }
 521
 522 static int rtc_post_load(void *opaque, int version_id)
 523 {
 524 #ifdef TARGET_I386
 525     RTCState *s = opaque;
 526
 527     if (version_id >= 2) {
 528         if (rtc_td_hack) {
 529             rtc_coalesced_timer_update(s);
 530         }
 531     }
 532 #endif
 533     return 0;
 534 }
 535
 536 static const VMStateDescription vmstate_rtc = {
 537     .name = "mc146818rtc",
 538     .version_id = 2,
 539     .minimum_version_id = 1,
 540     .minimum_version_id_old = 1,
 541     .post_load = rtc_post_load,
 542     .fields      = (VMStateField []) {
 543         VMSTATE_BUFFER(cmos_data, RTCState),
 544         VMSTATE_UINT8(cmos_index, RTCState),
 545         VMSTATE_INT32(current_tm.tm_sec, RTCState),
 546         VMSTATE_INT32(current_tm.tm_min, RTCState),
 547         VMSTATE_INT32(current_tm.tm_hour, RTCState),
 548         VMSTATE_INT32(current_tm.tm_wday, RTCState),
 549         VMSTATE_INT32(current_tm.tm_mday, RTCState),
 550         VMSTATE_INT32(current_tm.tm_mon, RTCState),
 551         VMSTATE_INT32(current_tm.tm_year, RTCState),
 552         VMSTATE_TIMER(periodic_timer, RTCState),
 553         VMSTATE_INT64(next_periodic_time, RTCState),
 554         VMSTATE_INT64(next_second_time, RTCState),
 555         VMSTATE_TIMER(second_timer, RTCState),
 556         VMSTATE_TIMER(second_timer2, RTCState),
 557         VMSTATE_UINT32_V(irq_coalesced, RTCState, 2),
 558         VMSTATE_UINT32_V(period, RTCState, 2),
 559         VMSTATE_END_OF_LIST()
 560     }
 561 };
 562
 563 static void rtc_reset(void *opaque)
 564 {
 565     RTCState *s = opaque;
 566
 567     s->cmos_data[RTC_REG_B] &= ~(REG_B_PIE | REG_B_AIE | REG_B_SQWE);
 568     s->cmos_data[RTC_REG_C] &= ~(REG_C_UF | REG_C_IRQF | REG_C_PF | REG_C_AF);
 569
 570     qemu_irq_lower(s->irq);
 571
 572 #ifdef TARGET_I386
 573     if (rtc_td_hack)
 574             s->irq_coalesced = 0;
 575 #endif
 576 }
 577
 578 static int rtc_initfn(ISADevice *dev)
 579 {
 580     RTCState *s = DO_UPCAST(RTCState, dev, dev);
 581     int base = 0x70;
 582     int isairq = 8;
 583
 584     isa_init_irq(dev, &s->irq, isairq);
 585
 586     s->cmos_data[RTC_REG_A] = 0x26;
 587     s->cmos_data[RTC_REG_B] = 0x02;
 588     s->cmos_data[RTC_REG_C] = 0x00;
 589     s->cmos_data[RTC_REG_D] = 0x80;
 590
 591     rtc_set_date_from_host(s);
 592
 593     s->periodic_timer = qemu_new_timer(rtc_clock, rtc_periodic_timer, s);
 594 #ifdef TARGET_I386
 595     if (rtc_td_hack)
 596         s->coalesced_timer =
 597             qemu_new_timer(rtc_clock, rtc_coalesced_timer, s);
 598 #endif
 599     s->second_timer = qemu_new_timer(rtc_clock, rtc_update_second, s);
 600     s->second_timer2 = qemu_new_timer(rtc_clock, rtc_update_second2, s);
 601
 602     s->next_second_time =
 603         qemu_get_clock(rtc_clock) + (get_ticks_per_sec() * 99) / 100;
 604     qemu_mod_timer(s->second_timer2, s->next_second_time);
 605
 606     register_ioport_write(base, 2, 1, cmos_ioport_write, s);
 607     register_ioport_read(base, 2, 1, cmos_ioport_read, s);
 608
 609     vmstate_register(base, &vmstate_rtc, s);
 610     qemu_register_reset(rtc_reset, s);
 611     return 0;
 612 }
 613
 614 RTCState *rtc_init(int base_year)
 615 {
 616     ISADevice *dev;
 617
 618     dev = isa_create("mc146818rtc");
 619     qdev_prop_set_int32(&dev->qdev, "base_year", base_year);
 620     qdev_init_nofail(&dev->qdev);
 621     return DO_UPCAST(RTCState, dev, dev);
 622 }
 623
 624 static ISADeviceInfo mc146818rtc_info = {
 625     .qdev.name     = "mc146818rtc",
 626     .qdev.size     = sizeof(RTCState),
 627     .qdev.no_user  = 1,
 628     .init          = rtc_initfn,
 629     .qdev.props    = (Property[]) {
 630         DEFINE_PROP_INT32("base_year", RTCState, base_year, 1980),
 631         DEFINE_PROP_END_OF_LIST(),
 632     }
 633 };
 634
 635 static void mc146818rtc_register(void)
 636 {
 637     isa_qdev_register(&mc146818rtc_info);
 638 }
 639 device_init(mc146818rtc_register)