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     int64_t data;
  76     int tidx;
  77     uint32_t toymatch[3];
  78     uint32_t toytrim;
  79     uint32_t cntrctl;
  80     uint32_t rtctrim;
  81     uint32_t rtccount;
  82     uint32_t rtcmatch[3];
  83     QEMUTimer *toy_timer[TIMER_NUMS];
  84     QEMUTimer *rtc_timer[TIMER_NUMS];
  85     qemu_irq irq;
  86 };
  87
  88 /* switch nanoseconds time to rtc ticks */
  89 static uint64_t ls7a_rtc_ticks(void)
  90 {
  91     return qemu_clock_get_ns(rtc_clock) * LS7A_RTC_FREQ / NANOSECONDS_PER_SECOND;
  92 }
  93
  94 /* switch rtc ticks to nanoseconds */
  95 static uint64_t ticks_to_ns(uint64_t ticks)
  96 {
  97     return ticks * NANOSECONDS_PER_SECOND / LS7A_RTC_FREQ;
  98 }
  99
 100 static bool toy_enabled(LS7ARtcState *s)
 101 {
 102     return FIELD_EX32(s->cntrctl, RTC_CTRL, TOYEN) &&
 103            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 104 }
 105
 106 static bool rtc_enabled(LS7ARtcState *s)
 107 {
 108     return FIELD_EX32(s->cntrctl, RTC_CTRL, RTCEN) &&
 109            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 110 }
 111
 112 /* parse struct tm to toy value */
 113 static uint64_t toy_time_to_val_mon(const struct tm *tm)
 114 {
 115     uint64_t val = 0;
 116
 117     val = FIELD_DP32(val, TOY, MON, tm->tm_mon + 1);
 118     val = FIELD_DP32(val, TOY, DAY, tm->tm_mday);
 119     val = FIELD_DP32(val, TOY, HOUR, tm->tm_hour);
 120     val = FIELD_DP32(val, TOY, MIN, tm->tm_min);
 121     val = FIELD_DP32(val, TOY, SEC, tm->tm_sec);
 122     return val;
 123 }
 124
 125 static void toymatch_val_to_time(LS7ARtcState *s, uint64_t val, struct tm *tm)
 126 {
 127     qemu_get_timedate(tm, s->offset_toy);
 128     tm->tm_sec = FIELD_EX32(val, TOY_MATCH, SEC);
 129     tm->tm_min = FIELD_EX32(val, TOY_MATCH, MIN);
 130     tm->tm_hour = FIELD_EX32(val, TOY_MATCH, HOUR);
 131     tm->tm_mday = FIELD_EX32(val, TOY_MATCH, DAY);
 132     tm->tm_mon = FIELD_EX32(val, TOY_MATCH, MON) - 1;
 133     tm->tm_year += (FIELD_EX32(val, TOY_MATCH, YEAR) - (tm->tm_year & 0x3f));
 134 }
 135
 136 static void toymatch_write(LS7ARtcState *s, uint64_t val, int num)
 137 {
 138     int64_t now, expire_time;
 139     struct tm tm = {};
 140
 141     /* it do not support write when toy disabled */
 142     if (toy_enabled(s)) {
 143         s->toymatch[num] = val;
 144         /* calculate expire time */
 145         now = qemu_clock_get_ms(rtc_clock);
 146         toymatch_val_to_time(s, val, &tm);
 147         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
 148         timer_mod(s->toy_timer[num], expire_time);
 149     }
 150 }
 151
 152 static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)
 153 {
 154     uint64_t expire_ns;
 155
 156     /* it do not support write when toy disabled */
 157     if (rtc_enabled(s)) {
 158         s->rtcmatch[num] = val;
 159         /* calculate expire time */
 160         expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
 161         timer_mod_ns(s->rtc_timer[num], expire_ns);
 162     }
 163 }
 164
 165 static void ls7a_toy_stop(LS7ARtcState *s)
 166 {
 167     int i;
 168
 169     /* delete timers, and when re-enabled, recalculate expire time */
 170     for (i = 0; i < TIMER_NUMS; i++) {
 171         timer_del(s->toy_timer[i]);
 172     }
 173 }
 174
 175 static void ls7a_rtc_stop(LS7ARtcState *s)
 176 {
 177     int i;
 178
 179     /* delete timers, and when re-enabled, recalculate expire time */
 180     for (i = 0; i < TIMER_NUMS; i++) {
 181         timer_del(s->rtc_timer[i]);
 182     }
 183 }
 184
 185 static void ls7a_toy_start(LS7ARtcState *s)
 186 {
 187     int i;
 188     uint64_t expire_time, now;
 189     struct tm tm = {};
 190
 191     now = qemu_clock_get_ms(rtc_clock);
 192
 193     /* recalculate expire time and enable timer */
 194     for (i = 0; i < TIMER_NUMS; i++) {
 195         toymatch_val_to_time(s, s->toymatch[i], &tm);
 196         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
 197         timer_mod(s->toy_timer[i], expire_time);
 198     }
 199 }
 200
 201 static void ls7a_rtc_start(LS7ARtcState *s)
 202 {
 203     int i;
 204     uint64_t expire_time;
 205
 206     /* recalculate expire time and enable timer */
 207     for (i = 0; i < TIMER_NUMS; i++) {
 208         expire_time = ticks_to_ns(s->rtcmatch[i]) - ticks_to_ns(s->offset_rtc);
 209         timer_mod_ns(s->rtc_timer[i], expire_time);
 210     }
 211 }
 212
 213 static uint64_t ls7a_rtc_read(void *opaque, hwaddr addr, unsigned size)
 214 {
 215     LS7ARtcState *s = LS7A_RTC(opaque);
 216     struct tm tm;
 217     int val = 0;
 218
 219     switch (addr) {
 220     case SYS_TOYREAD0:
 221         if (toy_enabled(s)) {
 222             qemu_get_timedate(&tm, s->offset_toy);
 223             val = toy_time_to_val_mon(&tm);
 224         } else {
 225             /* return 0 when toy disabled */
 226             val = 0;
 227         }
 228         break;
 229     case SYS_TOYREAD1:
 230         if (toy_enabled(s)) {
 231             qemu_get_timedate(&tm, s->offset_toy);
 232             val = tm.tm_year;
 233         } else {
 234             /* return 0 when toy disabled */
 235             val = 0;
 236         }
 237         break;
 238     case SYS_TOYMATCH0:
 239         val = s->toymatch[0];
 240         break;
 241     case SYS_TOYMATCH1:
 242         val = s->toymatch[1];
 243         break;
 244     case SYS_TOYMATCH2:
 245         val = s->toymatch[2];
 246         break;
 247     case SYS_RTCCTRL:
 248         val = s->cntrctl;
 249         break;
 250     case SYS_RTCREAD0:
 251         if (rtc_enabled(s)) {
 252             val = ls7a_rtc_ticks() + s->offset_rtc;
 253         } else {
 254             /* return 0 when rtc disabled */
 255             val = 0;
 256         }
 257         break;
 258     case SYS_RTCMATCH0:
 259         val = s->rtcmatch[0];
 260         break;
 261     case SYS_RTCMATCH1:
 262         val = s->rtcmatch[1];
 263         break;
 264     case SYS_RTCMATCH2:
 265         val = s->rtcmatch[2];
 266         break;
 267     default:
 268         val = 0;
 269         break;
 270     }
 271     return val;
 272 }
 273
 274 static void ls7a_rtc_write(void *opaque, hwaddr addr,
 275                            uint64_t val, unsigned size)
 276 {
 277     int old_toyen, old_rtcen, new_toyen, new_rtcen;
 278     LS7ARtcState *s = LS7A_RTC(opaque);
 279     struct tm tm;
 280
 281     switch (addr) {
 282     case SYS_TOYWRITE0:
 283         /* it do not support write when toy disabled */
 284         if (toy_enabled(s)) {
 285             qemu_get_timedate(&tm, s->offset_toy);
 286             tm.tm_sec = FIELD_EX32(val, TOY, SEC);
 287             tm.tm_min = FIELD_EX32(val, TOY, MIN);
 288             tm.tm_hour = FIELD_EX32(val, TOY, HOUR);
 289             tm.tm_mday = FIELD_EX32(val, TOY, DAY);
 290             tm.tm_mon = FIELD_EX32(val, TOY, MON) - 1;
 291             s->offset_toy = qemu_timedate_diff(&tm);
 292         }
 293     break;
 294     case SYS_TOYWRITE1:
 295         if (toy_enabled(s)) {
 296             qemu_get_timedate(&tm, s->offset_toy);
 297             tm.tm_year = val;
 298             s->offset_toy = qemu_timedate_diff(&tm);
 299         }
 300         break;
 301     case SYS_TOYMATCH0:
 302         toymatch_write(s, val, 0);
 303         break;
 304     case SYS_TOYMATCH1:
 305         toymatch_write(s, val, 1);
 306         break;
 307     case SYS_TOYMATCH2:
 308         toymatch_write(s, val, 2);
 309         break;
 310     case SYS_RTCCTRL:
 311         /* get old ctrl */
 312         old_toyen = toy_enabled(s);
 313         old_rtcen = rtc_enabled(s);
 314
 315         s->cntrctl = val;
 316         /* get new ctrl */
 317         new_toyen = toy_enabled(s);
 318         new_rtcen = rtc_enabled(s);
 319
 320         /*
 321          * we do not consider if EO changed, as it always set at most time.
 322          * toy or rtc enabled should start timer. otherwise, stop timer
 323          */
 324         if (old_toyen != new_toyen) {
 325             if (new_toyen) {
 326                 ls7a_toy_start(s);
 327             } else {
 328                 ls7a_toy_stop(s);
 329             }
 330         }
 331         if (old_rtcen != new_rtcen) {
 332             if (new_rtcen) {
 333                 ls7a_rtc_start(s);
 334             } else {
 335                 ls7a_rtc_stop(s);
 336             }
 337         }
 338         break;
 339     case SYS_RTCWRTIE0:
 340         if (rtc_enabled(s)) {
 341             s->offset_rtc = val - ls7a_rtc_ticks();
 342         }
 343         break;
 344     case SYS_RTCMATCH0:
 345         rtcmatch_write(s, val, 0);
 346         break;
 347     case SYS_RTCMATCH1:
 348         rtcmatch_write(s, val, 1);
 349         break;
 350     case SYS_RTCMATCH2:
 351         rtcmatch_write(s, val, 2);
 352         break;
 353     default:
 354         break;
 355     }
 356 }
 357
 358 static const MemoryRegionOps ls7a_rtc_ops = {
 359     .read = ls7a_rtc_read,
 360     .write = ls7a_rtc_write,
 361     .endianness = DEVICE_LITTLE_ENDIAN,
 362     .valid = {
 363         .min_access_size = 4,
 364         .max_access_size = 4,
 365     },
 366 };
 367
 368 static void toy_timer_cb(void *opaque)
 369 {
 370     LS7ARtcState *s = opaque;
 371
 372     if (toy_enabled(s)) {
 373         qemu_irq_raise(s->irq);
 374     }
 375 }
 376
 377 static void rtc_timer_cb(void *opaque)
 378 {
 379     LS7ARtcState *s = opaque;
 380
 381     if (rtc_enabled(s)) {
 382         qemu_irq_raise(s->irq);
 383     }
 384 }
 385
 386 static void ls7a_rtc_realize(DeviceState *dev, Error **errp)
 387 {
 388     int i;
 389     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 390     LS7ARtcState *d = LS7A_RTC(sbd);
 391     memory_region_init_io(&d->iomem, NULL, &ls7a_rtc_ops,
 392                          (void *)d, "ls7a_rtc", 0x100);
 393
 394     sysbus_init_irq(sbd, &d->irq);
 395
 396     sysbus_init_mmio(sbd, &d->iomem);
 397     for (i = 0; i < TIMER_NUMS; i++) {
 398         d->toymatch[i] = 0;
 399         d->rtcmatch[i] = 0;
 400         d->toy_timer[i] = timer_new_ms(rtc_clock, toy_timer_cb, d);
 401         d->rtc_timer[i] = timer_new_ms(rtc_clock, rtc_timer_cb, d);
 402     }
 403     d->offset_toy = 0;
 404     d->offset_rtc = 0;
 405
 406 }
 407
 408 /* delete timer and clear reg when reset */
 409 static void ls7a_rtc_reset(DeviceState *dev)
 410 {
 411     int i;
 412     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 413     LS7ARtcState *d = LS7A_RTC(sbd);
 414     for (i = 0; i < TIMER_NUMS; i++) {
 415         if (toy_enabled(d)) {
 416             timer_del(d->toy_timer[i]);
 417         }
 418         if (rtc_enabled(d)) {
 419             timer_del(d->rtc_timer[i]);
 420         }
 421         d->toymatch[i] = 0;
 422         d->rtcmatch[i] = 0;
 423     }
 424     d->cntrctl = 0;
 425 }
 426
 427 static int ls7a_rtc_pre_save(void *opaque)
 428 {
 429     LS7ARtcState *s = LS7A_RTC(opaque);
 430
 431     ls7a_toy_stop(s);
 432     ls7a_rtc_stop(s);
 433
 434     return 0;
 435 }
 436
 437 static int ls7a_rtc_post_load(void *opaque, int version_id)
 438 {
 439     LS7ARtcState *s = LS7A_RTC(opaque);
 440     if (toy_enabled(s)) {
 441         ls7a_toy_start(s);
 442     }
 443
 444     if (rtc_enabled(s)) {
 445         ls7a_rtc_start(s);
 446     }
 447
 448     return 0;
 449 }
 450
 451 static const VMStateDescription vmstate_ls7a_rtc = {
 452     .name = "ls7a_rtc",
 453     .version_id = 1,
 454     .minimum_version_id = 1,
 455     .pre_save = ls7a_rtc_pre_save,
 456     .post_load = ls7a_rtc_post_load,
 457     .fields = (VMStateField[]) {
 458         VMSTATE_INT64(offset_toy, LS7ARtcState),
 459         VMSTATE_INT64(offset_rtc, LS7ARtcState),
 460         VMSTATE_UINT32_ARRAY(toymatch, LS7ARtcState, TIMER_NUMS),
 461         VMSTATE_UINT32_ARRAY(rtcmatch, LS7ARtcState, TIMER_NUMS),
 462         VMSTATE_UINT32(cntrctl, LS7ARtcState),
 463         VMSTATE_END_OF_LIST()
 464     }
 465 };
 466
 467 static void ls7a_rtc_class_init(ObjectClass *klass, void *data)
 468 {
 469     DeviceClass *dc = DEVICE_CLASS(klass);
 470     dc->vmsd = &vmstate_ls7a_rtc;
 471     dc->realize = ls7a_rtc_realize;
 472     dc->reset = ls7a_rtc_reset;
 473     dc->desc = "ls7a rtc";
 474 }
 475
 476 static const TypeInfo ls7a_rtc_info = {
 477     .name          = TYPE_LS7A_RTC,
 478     .parent        = TYPE_SYS_BUS_DEVICE,
 479     .instance_size = sizeof(LS7ARtcState),
 480     .class_init    = ls7a_rtc_class_init,
 481 };
 482
 483 static void ls7a_rtc_register_types(void)
 484 {
 485     type_register_static(&ls7a_rtc_info);
 486 }
 487
 488 type_init(ls7a_rtc_register_types)