hw/rtc/ls7a_rtc.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Loongarch LS7A Real Time Clock emulation
   4  *
   5  * Copyright (C) 2021 Loongson Technology Corporation Limited
   6  */
   7
   8 #include "qemu/osdep.h"
   9 #include "hw/sysbus.h"
  10 #include "hw/irq.h"
  11 #include "include/hw/register.h"
  12 #include "qemu/timer.h"
  13 #include "sysemu/sysemu.h"
  14 #include "qemu/cutils.h"
  15 #include "qemu/log.h"
  16 #include "migration/vmstate.h"
  17 #include "hw/misc/unimp.h"
  18 #include "sysemu/rtc.h"
  19 #include "hw/registerfields.h"
  20
  21 #define SYS_TOYTRIM        0x20
  22 #define SYS_TOYWRITE0      0x24
  23 #define SYS_TOYWRITE1      0x28
  24 #define SYS_TOYREAD0       0x2C
  25 #define SYS_TOYREAD1       0x30
  26 #define SYS_TOYMATCH0      0x34
  27 #define SYS_TOYMATCH1      0x38
  28 #define SYS_TOYMATCH2      0x3C
  29 #define SYS_RTCCTRL        0x40
  30 #define SYS_RTCTRIM        0x60
  31 #define SYS_RTCWRTIE0      0x64
  32 #define SYS_RTCREAD0       0x68
  33 #define SYS_RTCMATCH0      0x6C
  34 #define SYS_RTCMATCH1      0x70
  35 #define SYS_RTCMATCH2      0x74
  36
  37 #define LS7A_RTC_FREQ     32768
  38 #define TIMER_NUMS        3
  39 /*
  40  * Shift bits and filed mask
  41  */
  42
  43 FIELD(TOY, MON, 26, 6)
  44 FIELD(TOY, DAY, 21, 5)
  45 FIELD(TOY, HOUR, 16, 5)
  46 FIELD(TOY, MIN, 10, 6)
  47 FIELD(TOY, SEC, 4, 6)
  48 FIELD(TOY, MSEC, 0, 4)
  49
  50 FIELD(TOY_MATCH, YEAR, 26, 6)
  51 FIELD(TOY_MATCH, MON, 22, 4)
  52 FIELD(TOY_MATCH, DAY, 17, 5)
  53 FIELD(TOY_MATCH, HOUR, 12, 5)
  54 FIELD(TOY_MATCH, MIN, 6, 6)
  55 FIELD(TOY_MATCH, SEC, 0, 6)
  56
  57 FIELD(RTC_CTRL, RTCEN, 13, 1)
  58 FIELD(RTC_CTRL, TOYEN, 11, 1)
  59 FIELD(RTC_CTRL, EO, 8, 1)
  60
  61 #define TYPE_LS7A_RTC "ls7a_rtc"
  62 OBJECT_DECLARE_SIMPLE_TYPE(LS7ARtcState, LS7A_RTC)
  63
  64 struct LS7ARtcState {
  65     SysBusDevice parent_obj;
  66
  67     MemoryRegion iomem;
  68     /*
  69      * Needed to preserve the tick_count across migration, even if the
  70      * absolute value of the rtc_clock is different on the source and
  71      * destination.
  72      */
  73     int64_t offset_toy;
  74     int64_t offset_rtc;
  75     uint64_t save_toy_mon;
  76     uint64_t save_toy_year;
  77     uint64_t save_rtc;
  78     int64_t data;
  79     int tidx;
  80     uint32_t toymatch[3];
  81     uint32_t toytrim;
  82     uint32_t cntrctl;
  83     uint32_t rtctrim;
  84     uint32_t rtccount;
  85     uint32_t rtcmatch[3];
  86     QEMUTimer *toy_timer[TIMER_NUMS];
  87     QEMUTimer *rtc_timer[TIMER_NUMS];
  88     qemu_irq irq;
  89 };
  90
  91 /* switch nanoseconds time to rtc ticks */
  92 static inline uint64_t ls7a_rtc_ticks(void)
  93 {
  94     return qemu_clock_get_ns(rtc_clock) * LS7A_RTC_FREQ / NANOSECONDS_PER_SECOND;
  95 }
  96
  97 /* switch rtc ticks to nanoseconds */
  98 static inline uint64_t ticks_to_ns(uint64_t ticks)
  99 {
 100     return ticks * NANOSECONDS_PER_SECOND / LS7A_RTC_FREQ;
 101 }
 102
 103 static inline bool toy_enabled(LS7ARtcState *s)
 104 {
 105     return FIELD_EX32(s->cntrctl, RTC_CTRL, TOYEN) &&
 106            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 107 }
 108
 109 static inline bool rtc_enabled(LS7ARtcState *s)
 110 {
 111     return FIELD_EX32(s->cntrctl, RTC_CTRL, RTCEN) &&
 112            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 113 }
 114
 115 /* parse toy value to struct tm */
 116 static inline void toy_val_to_time_mon(uint64_t toy_val, struct tm *tm)
 117 {
 118     tm->tm_sec = FIELD_EX32(toy_val, TOY, SEC);
 119     tm->tm_min = FIELD_EX32(toy_val, TOY, MIN);
 120     tm->tm_hour = FIELD_EX32(toy_val, TOY, HOUR);
 121     tm->tm_mday = FIELD_EX32(toy_val, TOY, DAY);
 122     tm->tm_mon = FIELD_EX32(toy_val, TOY, MON) - 1;
 123 }
 124
 125 static inline void toy_val_to_time_year(uint64_t toy_year, struct tm *tm)
 126 {
 127     tm->tm_year = toy_year;
 128 }
 129
 130 /* parse struct tm to toy value */
 131 static inline uint64_t toy_time_to_val_mon(struct tm tm)
 132 {
 133     uint64_t val = 0;
 134
 135     val = FIELD_DP32(val, TOY, MON, tm.tm_mon + 1);
 136     val = FIELD_DP32(val, TOY, DAY, tm.tm_mday);
 137     val = FIELD_DP32(val, TOY, HOUR, tm.tm_hour);
 138     val = FIELD_DP32(val, TOY, MIN, tm.tm_min);
 139     val = FIELD_DP32(val, TOY, SEC, tm.tm_sec);
 140     return val;
 141 }
 142
 143 static inline uint64_t toy_time_to_val_year(struct tm tm)
 144 {
 145     uint64_t year;
 146
 147     year = tm.tm_year;
 148     return year;
 149 }
 150
 151 static inline void toymatch_val_to_time(uint64_t val, struct tm *tm)
 152 {
 153     tm->tm_sec = FIELD_EX32(val, TOY_MATCH, SEC);
 154     tm->tm_min = FIELD_EX32(val, TOY_MATCH, MIN);
 155     tm->tm_hour = FIELD_EX32(val, TOY_MATCH, HOUR);
 156     tm->tm_mday = FIELD_EX32(val, TOY_MATCH, DAY);
 157     tm->tm_mon = FIELD_EX32(val, TOY_MATCH, MON) - 1;
 158     tm->tm_year += (FIELD_EX32(val, TOY_MATCH, YEAR) - (tm->tm_year & 0x3f));
 159 }
 160
 161 static void toymatch_write(LS7ARtcState *s, struct tm *tm, uint64_t val, int num)
 162 {
 163     int64_t now, expire_time;
 164
 165     /* it do not support write when toy disabled */
 166     if (toy_enabled(s)) {
 167         s->toymatch[num] = val;
 168         /* caculate expire time */
 169         now = qemu_clock_get_ms(rtc_clock);
 170         toymatch_val_to_time(val, tm);
 171         expire_time = now + (qemu_timedate_diff(tm) - s->offset_toy) * 1000;
 172         timer_mod(s->toy_timer[num], expire_time);
 173     }
 174 }
 175
 176 static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)
 177 {
 178     uint64_t expire_ns;
 179
 180     /* it do not support write when toy disabled */
 181     if (rtc_enabled(s)) {
 182         s->rtcmatch[num] = val;
 183         /* caculate expire time */
 184         expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
 185         timer_mod_ns(s->rtc_timer[num], expire_ns);
 186     }
 187 }
 188
 189 static void ls7a_toy_stop(LS7ARtcState *s)
 190 {
 191     int i;
 192     struct tm tm;
 193     /*
 194      * save time when disabled toy,
 195      * because toy time not add counters.
 196      */
 197     qemu_get_timedate(&tm, s->offset_toy);
 198     s->save_toy_mon = toy_time_to_val_mon(tm);
 199     s->save_toy_year = toy_time_to_val_year(tm);
 200
 201     /* delete timers, and when re-enabled, recaculate expire time */
 202     for (i = 0; i < TIMER_NUMS; i++) {
 203         timer_del(s->toy_timer[i]);
 204     }
 205 }
 206
 207 static void ls7a_rtc_stop(LS7ARtcState *s)
 208 {
 209     int i;
 210     uint64_t time;
 211
 212     /* save rtc time */
 213     time = ls7a_rtc_ticks() + s->offset_rtc;
 214     s->save_rtc = time;
 215
 216     /* delete timers, and when re-enabled, recaculate expire time */
 217     for (i = 0; i < TIMER_NUMS; i++) {
 218         timer_del(s->rtc_timer[i]);
 219     }
 220 }
 221
 222 static void ls7a_toy_start(LS7ARtcState *s)
 223 {
 224     int i;
 225     uint64_t expire_time, now;
 226     struct tm tm;
 227     /*
 228      * need to recaculate toy offset
 229      * and expire time when enable it.
 230      */
 231     toy_val_to_time_mon(s->save_toy_mon, &tm);
 232     toy_val_to_time_year(s->save_toy_year, &tm);
 233
 234     s->offset_toy = qemu_timedate_diff(&tm);
 235     now = qemu_clock_get_ms(rtc_clock);
 236
 237     /* recaculate expire time and enable timer */
 238     for (i = 0; i < TIMER_NUMS; i++) {
 239         toymatch_val_to_time(s->toymatch[i], &tm);
 240         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
 241         timer_mod(s->toy_timer[i], expire_time);
 242     }
 243 }
 244
 245 static void ls7a_rtc_start(LS7ARtcState *s)
 246 {
 247     int i;
 248     uint64_t expire_time, now;
 249
 250     /*
 251      * need to recaculate rtc offset
 252      * and expire time when enable it.
 253      */
 254     now = ls7a_rtc_ticks();
 255     s->offset_rtc = s->save_rtc - now;
 256
 257     /* recaculate expire time and enable timer */
 258     for (i = 0; i < TIMER_NUMS; i++) {
 259         expire_time = ticks_to_ns(s->rtcmatch[i]) - ticks_to_ns(s->offset_rtc);
 260         timer_mod_ns(s->rtc_timer[i], expire_time);
 261     }
 262 }
 263
 264 static uint64_t ls7a_rtc_read(void *opaque, hwaddr addr, unsigned size)
 265 {
 266     LS7ARtcState *s = LS7A_RTC(opaque);
 267     struct tm tm;
 268     int val = 0;
 269
 270     switch (addr) {
 271     case SYS_TOYREAD0:
 272         /* if toy disabled, read save toy time */
 273         if (toy_enabled(s)) {
 274             qemu_get_timedate(&tm, s->offset_toy);
 275             val = toy_time_to_val_mon(tm);
 276         } else {
 277             /* read save mon val */
 278             val = s->save_toy_mon;
 279         }
 280         break;
 281     case SYS_TOYREAD1:
 282         /* if toy disabled, read save toy time */
 283         if (toy_enabled(s)) {
 284             qemu_get_timedate(&tm, s->offset_toy);
 285             val = tm.tm_year;
 286         } else {
 287             /* read save year val */
 288             val = s->save_toy_year;
 289         }
 290         break;
 291     case SYS_TOYMATCH0:
 292         val = s->toymatch[0];
 293         break;
 294     case SYS_TOYMATCH1:
 295         val = s->toymatch[1];
 296         break;
 297     case SYS_TOYMATCH2:
 298         val = s->toymatch[2];
 299         break;
 300     case SYS_RTCCTRL:
 301         val = s->cntrctl;
 302         break;
 303     case SYS_RTCREAD0:
 304         /* if rtc disabled, read save rtc time */
 305         if (rtc_enabled(s)) {
 306             val = ls7a_rtc_ticks() + s->offset_rtc;
 307         } else {
 308             val = s->save_rtc;
 309         }
 310         break;
 311     case SYS_RTCMATCH0:
 312         val = s->rtcmatch[0];
 313         break;
 314     case SYS_RTCMATCH1:
 315         val = s->rtcmatch[1];
 316         break;
 317     case SYS_RTCMATCH2:
 318         val = s->rtcmatch[2];
 319         break;
 320     default:
 321         val = 0;
 322         break;
 323     }
 324     return val;
 325 }
 326
 327 static void ls7a_rtc_write(void *opaque, hwaddr addr,
 328                            uint64_t val, unsigned size)
 329 {
 330     int old_toyen, old_rtcen, new_toyen, new_rtcen;
 331     LS7ARtcState *s = LS7A_RTC(opaque);
 332     struct tm tm;
 333
 334     switch (addr) {
 335     case SYS_TOYWRITE0:
 336         /* it do not support write when toy disabled */
 337         if (toy_enabled(s)) {
 338             qemu_get_timedate(&tm, s->offset_toy);
 339             tm.tm_sec = FIELD_EX32(val, TOY, SEC);
 340             tm.tm_min = FIELD_EX32(val, TOY, MIN);
 341             tm.tm_hour = FIELD_EX32(val, TOY, HOUR);
 342             tm.tm_mday = FIELD_EX32(val, TOY, DAY);
 343             tm.tm_mon = FIELD_EX32(val, TOY, MON) - 1;
 344             s->offset_toy = qemu_timedate_diff(&tm);
 345         }
 346     break;
 347     case SYS_TOYWRITE1:
 348         if (toy_enabled(s)) {
 349             qemu_get_timedate(&tm, s->offset_toy);
 350             tm.tm_year = val;
 351             s->offset_toy = qemu_timedate_diff(&tm);
 352         }
 353         break;
 354     case SYS_TOYMATCH0:
 355         toymatch_write(s, &tm, val, 0);
 356         break;
 357     case SYS_TOYMATCH1:
 358         toymatch_write(s, &tm, val, 1);
 359         break;
 360     case SYS_TOYMATCH2:
 361         toymatch_write(s, &tm, val, 2);
 362         break;
 363     case SYS_RTCCTRL:
 364         /* get old ctrl */
 365         old_toyen = toy_enabled(s);
 366         old_rtcen = rtc_enabled(s);
 367
 368         s->cntrctl = val;
 369         /* get new ctrl */
 370         new_toyen = toy_enabled(s);
 371         new_rtcen = rtc_enabled(s);
 372
 373         /*
 374          * we do not consider if EO changed, as it always set at most time.
 375          * toy or rtc enabled should start timer. otherwise, stop timer
 376          */
 377         if (old_toyen != new_toyen) {
 378             if (new_toyen) {
 379                 ls7a_toy_start(s);
 380             } else {
 381                 ls7a_toy_stop(s);
 382             }
 383         }
 384         if (old_rtcen != new_rtcen) {
 385             if (new_rtcen) {
 386                 ls7a_rtc_start(s);
 387             } else {
 388                 ls7a_rtc_stop(s);
 389             }
 390         }
 391         break;
 392     case SYS_RTCWRTIE0:
 393         if (rtc_enabled(s)) {
 394             s->offset_rtc = val - ls7a_rtc_ticks();
 395         }
 396         break;
 397     case SYS_RTCMATCH0:
 398         rtcmatch_write(s, val, 0);
 399         break;
 400     case SYS_RTCMATCH1:
 401         rtcmatch_write(s, val, 1);
 402         break;
 403     case SYS_RTCMATCH2:
 404         rtcmatch_write(s, val, 2);
 405         break;
 406     default:
 407         break;
 408     }
 409 }
 410
 411 static const MemoryRegionOps ls7a_rtc_ops = {
 412     .read = ls7a_rtc_read,
 413     .write = ls7a_rtc_write,
 414     .endianness = DEVICE_LITTLE_ENDIAN,
 415     .valid = {
 416         .min_access_size = 4,
 417         .max_access_size = 4,
 418     },
 419 };
 420
 421 static void toy_timer_cb(void *opaque)
 422 {
 423     LS7ARtcState *s = opaque;
 424
 425     if (toy_enabled(s)) {
 426         qemu_irq_pulse(s->irq);
 427     }
 428 }
 429
 430 static void rtc_timer_cb(void *opaque)
 431 {
 432     LS7ARtcState *s = opaque;
 433
 434     if (rtc_enabled(s)) {
 435         qemu_irq_pulse(s->irq);
 436     }
 437 }
 438
 439 static void ls7a_rtc_realize(DeviceState *dev, Error **errp)
 440 {
 441     int i;
 442     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 443     LS7ARtcState *d = LS7A_RTC(sbd);
 444     memory_region_init_io(&d->iomem, NULL, &ls7a_rtc_ops,
 445                          (void *)d, "ls7a_rtc", 0x100);
 446
 447     sysbus_init_irq(sbd, &d->irq);
 448
 449     sysbus_init_mmio(sbd, &d->iomem);
 450     for (i = 0; i < TIMER_NUMS; i++) {
 451         d->toymatch[i] = 0;
 452         d->rtcmatch[i] = 0;
 453         d->toy_timer[i] = timer_new_ms(rtc_clock, toy_timer_cb, d);
 454         d->rtc_timer[i] = timer_new_ms(rtc_clock, rtc_timer_cb, d);
 455     }
 456     d->offset_toy = 0;
 457     d->offset_rtc = 0;
 458     d->save_toy_mon = 0;
 459     d->save_toy_year = 0;
 460     d->save_rtc = 0;
 461
 462     create_unimplemented_device("mmio fallback 1", 0x10013ffc, 0x4);
 463 }
 464
 465 static int ls7a_rtc_pre_save(void *opaque)
 466 {
 467     LS7ARtcState *s = LS7A_RTC(opaque);
 468
 469     ls7a_toy_stop(s);
 470     ls7a_rtc_stop(s);
 471
 472     return 0;
 473 }
 474
 475 static int ls7a_rtc_post_load(void *opaque, int version_id)
 476 {
 477     LS7ARtcState *s = LS7A_RTC(opaque);
 478     if (toy_enabled(s)) {
 479         ls7a_toy_start(s);
 480     }
 481
 482     if (rtc_enabled(s)) {
 483         ls7a_rtc_start(s);
 484     }
 485
 486     return 0;
 487 }
 488
 489 static const VMStateDescription vmstate_ls7a_rtc = {
 490     .name = "ls7a_rtc",
 491     .version_id = 1,
 492     .minimum_version_id = 1,
 493     .pre_save = ls7a_rtc_pre_save,
 494     .post_load = ls7a_rtc_post_load,
 495     .fields = (VMStateField[]) {
 496         VMSTATE_INT64(offset_toy, LS7ARtcState),
 497         VMSTATE_INT64(offset_rtc, LS7ARtcState),
 498         VMSTATE_UINT64(save_toy_mon, LS7ARtcState),
 499         VMSTATE_UINT64(save_toy_year, LS7ARtcState),
 500         VMSTATE_UINT64(save_rtc, LS7ARtcState),
 501         VMSTATE_UINT32_ARRAY(toymatch, LS7ARtcState, TIMER_NUMS),
 502         VMSTATE_UINT32_ARRAY(rtcmatch, LS7ARtcState, TIMER_NUMS),
 503         VMSTATE_UINT32(cntrctl, LS7ARtcState),
 504         VMSTATE_END_OF_LIST()
 505     }
 506 };
 507
 508 static void ls7a_rtc_class_init(ObjectClass *klass, void *data)
 509 {
 510     DeviceClass *dc = DEVICE_CLASS(klass);
 511     dc->vmsd = &vmstate_ls7a_rtc;
 512     dc->realize = ls7a_rtc_realize;
 513     dc->desc = "ls7a rtc";
 514 }
 515
 516 static const TypeInfo ls7a_rtc_info = {
 517     .name          = TYPE_LS7A_RTC,
 518     .parent        = TYPE_SYS_BUS_DEVICE,
 519     .instance_size = sizeof(LS7ARtcState),
 520     .class_init    = ls7a_rtc_class_init,
 521 };
 522
 523 static void ls7a_rtc_register_types(void)
 524 {
 525     type_register_static(&ls7a_rtc_info);
 526 }
 527
 528 type_init(ls7a_rtc_register_types)