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(LS7ARtcState *s, uint64_t val, struct tm *tm)
 152 {
 153     qemu_get_timedate(tm, s->offset_toy);
 154     tm->tm_sec = FIELD_EX32(val, TOY_MATCH, SEC);
 155     tm->tm_min = FIELD_EX32(val, TOY_MATCH, MIN);
 156     tm->tm_hour = FIELD_EX32(val, TOY_MATCH, HOUR);
 157     tm->tm_mday = FIELD_EX32(val, TOY_MATCH, DAY);
 158     tm->tm_mon = FIELD_EX32(val, TOY_MATCH, MON) - 1;
 159     tm->tm_year += (FIELD_EX32(val, TOY_MATCH, YEAR) - (tm->tm_year & 0x3f));
 160 }
 161
 162 static void toymatch_write(LS7ARtcState *s, uint64_t val, int num)
 163 {
 164     int64_t now, expire_time;
 165     struct tm tm = {};
 166
 167     /* it do not support write when toy disabled */
 168     if (toy_enabled(s)) {
 169         s->toymatch[num] = val;
 170         /* caculate expire time */
 171         now = qemu_clock_get_ms(rtc_clock);
 172         toymatch_val_to_time(s, val, &tm);
 173         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
 174         timer_mod(s->toy_timer[num], expire_time);
 175     }
 176 }
 177
 178 static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)
 179 {
 180     uint64_t expire_ns;
 181
 182     /* it do not support write when toy disabled */
 183     if (rtc_enabled(s)) {
 184         s->rtcmatch[num] = val;
 185         /* caculate expire time */
 186         expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
 187         timer_mod_ns(s->rtc_timer[num], expire_ns);
 188     }
 189 }
 190
 191 static void ls7a_toy_stop(LS7ARtcState *s)
 192 {
 193     int i;
 194     struct tm tm;
 195     /*
 196      * save time when disabled toy,
 197      * because toy time not add counters.
 198      */
 199     qemu_get_timedate(&tm, s->offset_toy);
 200     s->save_toy_mon = toy_time_to_val_mon(tm);
 201     s->save_toy_year = toy_time_to_val_year(tm);
 202
 203     /* delete timers, and when re-enabled, recaculate expire time */
 204     for (i = 0; i < TIMER_NUMS; i++) {
 205         timer_del(s->toy_timer[i]);
 206     }
 207 }
 208
 209 static void ls7a_rtc_stop(LS7ARtcState *s)
 210 {
 211     int i;
 212     uint64_t time;
 213
 214     /* save rtc time */
 215     time = ls7a_rtc_ticks() + s->offset_rtc;
 216     s->save_rtc = time;
 217
 218     /* delete timers, and when re-enabled, recaculate expire time */
 219     for (i = 0; i < TIMER_NUMS; i++) {
 220         timer_del(s->rtc_timer[i]);
 221     }
 222 }
 223
 224 static void ls7a_toy_start(LS7ARtcState *s)
 225 {
 226     int i;
 227     uint64_t expire_time, now;
 228     struct tm tm = {};
 229     /*
 230      * need to recaculate toy offset
 231      * and expire time when enable it.
 232      */
 233     toy_val_to_time_mon(s->save_toy_mon, &tm);
 234     toy_val_to_time_year(s->save_toy_year, &tm);
 235
 236     s->offset_toy = qemu_timedate_diff(&tm);
 237     now = qemu_clock_get_ms(rtc_clock);
 238
 239     /* recaculate expire time and enable timer */
 240     for (i = 0; i < TIMER_NUMS; i++) {
 241         toymatch_val_to_time(s, s->toymatch[i], &tm);
 242         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
 243         timer_mod(s->toy_timer[i], expire_time);
 244     }
 245 }
 246
 247 static void ls7a_rtc_start(LS7ARtcState *s)
 248 {
 249     int i;
 250     uint64_t expire_time, now;
 251
 252     /*
 253      * need to recaculate rtc offset
 254      * and expire time when enable it.
 255      */
 256     now = ls7a_rtc_ticks();
 257     s->offset_rtc = s->save_rtc - now;
 258
 259     /* recaculate expire time and enable timer */
 260     for (i = 0; i < TIMER_NUMS; i++) {
 261         expire_time = ticks_to_ns(s->rtcmatch[i]) - ticks_to_ns(s->offset_rtc);
 262         timer_mod_ns(s->rtc_timer[i], expire_time);
 263     }
 264 }
 265
 266 static uint64_t ls7a_rtc_read(void *opaque, hwaddr addr, unsigned size)
 267 {
 268     LS7ARtcState *s = LS7A_RTC(opaque);
 269     struct tm tm;
 270     int val = 0;
 271
 272     switch (addr) {
 273     case SYS_TOYREAD0:
 274         /* if toy disabled, read save toy time */
 275         if (toy_enabled(s)) {
 276             qemu_get_timedate(&tm, s->offset_toy);
 277             val = toy_time_to_val_mon(tm);
 278         } else {
 279             /* read save mon val */
 280             val = s->save_toy_mon;
 281         }
 282         break;
 283     case SYS_TOYREAD1:
 284         /* if toy disabled, read save toy time */
 285         if (toy_enabled(s)) {
 286             qemu_get_timedate(&tm, s->offset_toy);
 287             val = tm.tm_year;
 288         } else {
 289             /* read save year val */
 290             val = s->save_toy_year;
 291         }
 292         break;
 293     case SYS_TOYMATCH0:
 294         val = s->toymatch[0];
 295         break;
 296     case SYS_TOYMATCH1:
 297         val = s->toymatch[1];
 298         break;
 299     case SYS_TOYMATCH2:
 300         val = s->toymatch[2];
 301         break;
 302     case SYS_RTCCTRL:
 303         val = s->cntrctl;
 304         break;
 305     case SYS_RTCREAD0:
 306         /* if rtc disabled, read save rtc time */
 307         if (rtc_enabled(s)) {
 308             val = ls7a_rtc_ticks() + s->offset_rtc;
 309         } else {
 310             val = s->save_rtc;
 311         }
 312         break;
 313     case SYS_RTCMATCH0:
 314         val = s->rtcmatch[0];
 315         break;
 316     case SYS_RTCMATCH1:
 317         val = s->rtcmatch[1];
 318         break;
 319     case SYS_RTCMATCH2:
 320         val = s->rtcmatch[2];
 321         break;
 322     default:
 323         val = 0;
 324         break;
 325     }
 326     return val;
 327 }
 328
 329 static void ls7a_rtc_write(void *opaque, hwaddr addr,
 330                            uint64_t val, unsigned size)
 331 {
 332     int old_toyen, old_rtcen, new_toyen, new_rtcen;
 333     LS7ARtcState *s = LS7A_RTC(opaque);
 334     struct tm tm;
 335
 336     switch (addr) {
 337     case SYS_TOYWRITE0:
 338         /* it do not support write when toy disabled */
 339         if (toy_enabled(s)) {
 340             qemu_get_timedate(&tm, s->offset_toy);
 341             tm.tm_sec = FIELD_EX32(val, TOY, SEC);
 342             tm.tm_min = FIELD_EX32(val, TOY, MIN);
 343             tm.tm_hour = FIELD_EX32(val, TOY, HOUR);
 344             tm.tm_mday = FIELD_EX32(val, TOY, DAY);
 345             tm.tm_mon = FIELD_EX32(val, TOY, MON) - 1;
 346             s->offset_toy = qemu_timedate_diff(&tm);
 347         }
 348     break;
 349     case SYS_TOYWRITE1:
 350         if (toy_enabled(s)) {
 351             qemu_get_timedate(&tm, s->offset_toy);
 352             tm.tm_year = val;
 353             s->offset_toy = qemu_timedate_diff(&tm);
 354         }
 355         break;
 356     case SYS_TOYMATCH0:
 357         toymatch_write(s, val, 0);
 358         break;
 359     case SYS_TOYMATCH1:
 360         toymatch_write(s, val, 1);
 361         break;
 362     case SYS_TOYMATCH2:
 363         toymatch_write(s, val, 2);
 364         break;
 365     case SYS_RTCCTRL:
 366         /* get old ctrl */
 367         old_toyen = toy_enabled(s);
 368         old_rtcen = rtc_enabled(s);
 369
 370         s->cntrctl = val;
 371         /* get new ctrl */
 372         new_toyen = toy_enabled(s);
 373         new_rtcen = rtc_enabled(s);
 374
 375         /*
 376          * we do not consider if EO changed, as it always set at most time.
 377          * toy or rtc enabled should start timer. otherwise, stop timer
 378          */
 379         if (old_toyen != new_toyen) {
 380             if (new_toyen) {
 381                 ls7a_toy_start(s);
 382             } else {
 383                 ls7a_toy_stop(s);
 384             }
 385         }
 386         if (old_rtcen != new_rtcen) {
 387             if (new_rtcen) {
 388                 ls7a_rtc_start(s);
 389             } else {
 390                 ls7a_rtc_stop(s);
 391             }
 392         }
 393         break;
 394     case SYS_RTCWRTIE0:
 395         if (rtc_enabled(s)) {
 396             s->offset_rtc = val - ls7a_rtc_ticks();
 397         }
 398         break;
 399     case SYS_RTCMATCH0:
 400         rtcmatch_write(s, val, 0);
 401         break;
 402     case SYS_RTCMATCH1:
 403         rtcmatch_write(s, val, 1);
 404         break;
 405     case SYS_RTCMATCH2:
 406         rtcmatch_write(s, val, 2);
 407         break;
 408     default:
 409         break;
 410     }
 411 }
 412
 413 static const MemoryRegionOps ls7a_rtc_ops = {
 414     .read = ls7a_rtc_read,
 415     .write = ls7a_rtc_write,
 416     .endianness = DEVICE_LITTLE_ENDIAN,
 417     .valid = {
 418         .min_access_size = 4,
 419         .max_access_size = 4,
 420     },
 421 };
 422
 423 static void toy_timer_cb(void *opaque)
 424 {
 425     LS7ARtcState *s = opaque;
 426
 427     if (toy_enabled(s)) {
 428         qemu_irq_pulse(s->irq);
 429     }
 430 }
 431
 432 static void rtc_timer_cb(void *opaque)
 433 {
 434     LS7ARtcState *s = opaque;
 435
 436     if (rtc_enabled(s)) {
 437         qemu_irq_pulse(s->irq);
 438     }
 439 }
 440
 441 static void ls7a_rtc_realize(DeviceState *dev, Error **errp)
 442 {
 443     int i;
 444     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 445     LS7ARtcState *d = LS7A_RTC(sbd);
 446     memory_region_init_io(&d->iomem, NULL, &ls7a_rtc_ops,
 447                          (void *)d, "ls7a_rtc", 0x100);
 448
 449     sysbus_init_irq(sbd, &d->irq);
 450
 451     sysbus_init_mmio(sbd, &d->iomem);
 452     for (i = 0; i < TIMER_NUMS; i++) {
 453         d->toymatch[i] = 0;
 454         d->rtcmatch[i] = 0;
 455         d->toy_timer[i] = timer_new_ms(rtc_clock, toy_timer_cb, d);
 456         d->rtc_timer[i] = timer_new_ms(rtc_clock, rtc_timer_cb, d);
 457     }
 458     d->offset_toy = 0;
 459     d->offset_rtc = 0;
 460     d->save_toy_mon = 0;
 461     d->save_toy_year = 0;
 462     d->save_rtc = 0;
 463
 464     create_unimplemented_device("mmio fallback 1", 0x10013ffc, 0x4);
 465 }
 466
 467 static int ls7a_rtc_pre_save(void *opaque)
 468 {
 469     LS7ARtcState *s = LS7A_RTC(opaque);
 470
 471     ls7a_toy_stop(s);
 472     ls7a_rtc_stop(s);
 473
 474     return 0;
 475 }
 476
 477 static int ls7a_rtc_post_load(void *opaque, int version_id)
 478 {
 479     LS7ARtcState *s = LS7A_RTC(opaque);
 480     if (toy_enabled(s)) {
 481         ls7a_toy_start(s);
 482     }
 483
 484     if (rtc_enabled(s)) {
 485         ls7a_rtc_start(s);
 486     }
 487
 488     return 0;
 489 }
 490
 491 static const VMStateDescription vmstate_ls7a_rtc = {
 492     .name = "ls7a_rtc",
 493     .version_id = 1,
 494     .minimum_version_id = 1,
 495     .pre_save = ls7a_rtc_pre_save,
 496     .post_load = ls7a_rtc_post_load,
 497     .fields = (VMStateField[]) {
 498         VMSTATE_INT64(offset_toy, LS7ARtcState),
 499         VMSTATE_INT64(offset_rtc, LS7ARtcState),
 500         VMSTATE_UINT64(save_toy_mon, LS7ARtcState),
 501         VMSTATE_UINT64(save_toy_year, LS7ARtcState),
 502         VMSTATE_UINT64(save_rtc, LS7ARtcState),
 503         VMSTATE_UINT32_ARRAY(toymatch, LS7ARtcState, TIMER_NUMS),
 504         VMSTATE_UINT32_ARRAY(rtcmatch, LS7ARtcState, TIMER_NUMS),
 505         VMSTATE_UINT32(cntrctl, LS7ARtcState),
 506         VMSTATE_END_OF_LIST()
 507     }
 508 };
 509
 510 static void ls7a_rtc_class_init(ObjectClass *klass, void *data)
 511 {
 512     DeviceClass *dc = DEVICE_CLASS(klass);
 513     dc->vmsd = &vmstate_ls7a_rtc;
 514     dc->realize = ls7a_rtc_realize;
 515     dc->desc = "ls7a rtc";
 516 }
 517
 518 static const TypeInfo ls7a_rtc_info = {
 519     .name          = TYPE_LS7A_RTC,
 520     .parent        = TYPE_SYS_BUS_DEVICE,
 521     .instance_size = sizeof(LS7ARtcState),
 522     .class_init    = ls7a_rtc_class_init,
 523 };
 524
 525 static void ls7a_rtc_register_types(void)
 526 {
 527     type_register_static(&ls7a_rtc_info);
 528 }
 529
 530 type_init(ls7a_rtc_register_types)