hw/m48t59.c

   1 /*
   2  * QEMU M48T59 NVRAM emulation for PPC PREP platform
   3  *
   4  * Copyright (c) 2003-2004 Jocelyn Mayer
   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 "vl.h"
  25 #include "m48t59.h"
  26
  27 //#define DEBUG_NVRAM
  28
  29 #if defined(DEBUG_NVRAM)
  30 #define NVRAM_PRINTF(fmt, args...) do { printf(fmt , ##args); } while (0)
  31 #else
  32 #define NVRAM_PRINTF(fmt, args...) do { } while (0)
  33 #endif
  34
  35 struct m48t59_t {
  36     /* Hardware parameters */
  37     int      IRQ;
  38     uint32_t io_base;
  39     uint16_t size;
  40     /* RTC management */
  41     time_t   time_offset;
  42     time_t   stop_time;
  43     /* Alarm & watchdog */
  44     time_t   alarm;
  45     struct QEMUTimer *alrm_timer;
  46     struct QEMUTimer *wd_timer;
  47     /* NVRAM storage */
  48     uint8_t  lock;
  49     uint16_t addr;
  50     uint8_t *buffer;
  51 };
  52
  53 /* Fake timer functions */
  54 /* Generic helpers for BCD */
  55 static inline uint8_t toBCD (uint8_t value)
  56 {
  57     return (((value / 10) % 10) << 4) | (value % 10);
  58 }
  59
  60 static inline uint8_t fromBCD (uint8_t BCD)
  61 {
  62     return ((BCD >> 4) * 10) + (BCD & 0x0F);
  63 }
  64
  65 /* RTC management helpers */
  66 static void get_time (m48t59_t *NVRAM, struct tm *tm)
  67 {
  68     time_t t;
  69
  70     t = time(NULL) + NVRAM->time_offset;
  71 #ifdef _WIN32
  72     memcpy(tm,localtime(&t),sizeof(*tm));
  73 #else
  74     localtime_r (&t, tm) ;
  75 #endif
  76 }
  77
  78 static void set_time (m48t59_t *NVRAM, struct tm *tm)
  79 {
  80     time_t now, new_time;
  81
  82     new_time = mktime(tm);
  83     now = time(NULL);
  84     NVRAM->time_offset = new_time - now;
  85 }
  86
  87 /* Alarm management */
  88 static void alarm_cb (void *opaque)
  89 {
  90     struct tm tm, tm_now;
  91     uint64_t next_time;
  92     m48t59_t *NVRAM = opaque;
  93
  94     pic_set_irq(NVRAM->IRQ, 1);
  95     if ((NVRAM->buffer[0x1FF5] & 0x80) == 0 &&
  96         (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
  97         (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
  98         (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
  99         /* Repeat once a month */
 100         get_time(NVRAM, &tm_now);
 101         memcpy(&tm, &tm_now, sizeof(struct tm));
 102         tm.tm_mon++;
 103         if (tm.tm_mon == 13) {
 104             tm.tm_mon = 1;
 105             tm.tm_year++;
 106         }
 107         next_time = mktime(&tm);
 108     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
 109                (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
 110                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
 111                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 112         /* Repeat once a day */
 113         next_time = 24 * 60 * 60 + mktime(&tm_now);
 114     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
 115                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
 116                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
 117                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 118         /* Repeat once an hour */
 119         next_time = 60 * 60 + mktime(&tm_now);
 120     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
 121                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
 122                (NVRAM->buffer[0x1FF3] & 0x80) != 0 &&
 123                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
 124         /* Repeat once a minute */
 125         next_time = 60 + mktime(&tm_now);
 126     } else {
 127         /* Repeat once a second */
 128         next_time = 1 + mktime(&tm_now);
 129     }
 130     qemu_mod_timer(NVRAM->alrm_timer, next_time * 1000);
 131     pic_set_irq(NVRAM->IRQ, 0);
 132 }
 133
 134
 135 static void get_alarm (m48t59_t *NVRAM, struct tm *tm)
 136 {
 137 #ifdef _WIN32
 138     memcpy(tm,localtime(&NVRAM->alarm),sizeof(*tm));
 139 #else
 140     localtime_r (&NVRAM->alarm, tm);
 141 #endif
 142 }
 143
 144 static void set_alarm (m48t59_t *NVRAM, struct tm *tm)
 145 {
 146     NVRAM->alarm = mktime(tm);
 147     if (NVRAM->alrm_timer != NULL) {
 148         qemu_del_timer(NVRAM->alrm_timer);
 149         NVRAM->alrm_timer = NULL;
 150     }
 151     if (NVRAM->alarm - time(NULL) > 0)
 152         qemu_mod_timer(NVRAM->alrm_timer, NVRAM->alarm * 1000);
 153 }
 154
 155 /* Watchdog management */
 156 static void watchdog_cb (void *opaque)
 157 {
 158     m48t59_t *NVRAM = opaque;
 159
 160     NVRAM->buffer[0x1FF0] |= 0x80;
 161     if (NVRAM->buffer[0x1FF7] & 0x80) {
 162         NVRAM->buffer[0x1FF7] = 0x00;
 163         NVRAM->buffer[0x1FFC] &= ~0x40;
 164         /* May it be a hw CPU Reset instead ? */
 165         reset_requested = 1;
 166         printf("Watchdog reset...\n");
 167         cpu_interrupt(cpu_single_env, CPU_INTERRUPT_EXIT);
 168     } else {
 169         pic_set_irq(NVRAM->IRQ, 1);
 170         pic_set_irq(NVRAM->IRQ, 0);
 171     }
 172 }
 173
 174 static void set_up_watchdog (m48t59_t *NVRAM, uint8_t value)
 175 {
 176     uint64_t interval; /* in 1/16 seconds */
 177
 178     if (NVRAM->wd_timer != NULL) {
 179         qemu_del_timer(NVRAM->wd_timer);
 180         NVRAM->wd_timer = NULL;
 181     }
 182     NVRAM->buffer[0x1FF0] &= ~0x80;
 183     if (value != 0) {
 184         interval = (1 << (2 * (value & 0x03))) * ((value >> 2) & 0x1F);
 185         qemu_mod_timer(NVRAM->wd_timer, ((uint64_t)time(NULL) * 1000) +
 186                        ((interval * 1000) >> 4));
 187     }
 188 }
 189
 190 /* Direct access to NVRAM */
 191 void m48t59_write (m48t59_t *NVRAM, uint32_t val)
 192 {
 193     struct tm tm;
 194     int tmp;
 195
 196     if (NVRAM->addr > 0x1FF8 && NVRAM->addr < 0x2000)
 197         NVRAM_PRINTF("%s: 0x%08x => 0x%08x\n", __func__, NVRAM->addr, val);
 198     switch (NVRAM->addr) {
 199     case 0x1FF0:
 200         /* flags register : read-only */
 201         break;
 202     case 0x1FF1:
 203         /* unused */
 204         break;
 205     case 0x1FF2:
 206         /* alarm seconds */
 207         tmp = fromBCD(val & 0x7F);
 208         if (tmp >= 0 && tmp <= 59) {
 209             get_alarm(NVRAM, &tm);
 210             tm.tm_sec = tmp;
 211             NVRAM->buffer[0x1FF2] = val;
 212             set_alarm(NVRAM, &tm);
 213         }
 214         break;
 215     case 0x1FF3:
 216         /* alarm minutes */
 217         tmp = fromBCD(val & 0x7F);
 218         if (tmp >= 0 && tmp <= 59) {
 219             get_alarm(NVRAM, &tm);
 220             tm.tm_min = tmp;
 221             NVRAM->buffer[0x1FF3] = val;
 222             set_alarm(NVRAM, &tm);
 223         }
 224         break;
 225     case 0x1FF4:
 226         /* alarm hours */
 227         tmp = fromBCD(val & 0x3F);
 228         if (tmp >= 0 && tmp <= 23) {
 229             get_alarm(NVRAM, &tm);
 230             tm.tm_hour = tmp;
 231             NVRAM->buffer[0x1FF4] = val;
 232             set_alarm(NVRAM, &tm);
 233         }
 234         break;
 235     case 0x1FF5:
 236         /* alarm date */
 237         tmp = fromBCD(val & 0x1F);
 238         if (tmp != 0) {
 239             get_alarm(NVRAM, &tm);
 240             tm.tm_mday = tmp;
 241             NVRAM->buffer[0x1FF5] = val;
 242             set_alarm(NVRAM, &tm);
 243         }
 244         break;
 245     case 0x1FF6:
 246         /* interrupts */
 247         NVRAM->buffer[0x1FF6] = val;
 248         break;
 249     case 0x1FF7:
 250         /* watchdog */
 251         NVRAM->buffer[0x1FF7] = val;
 252         set_up_watchdog(NVRAM, val);
 253         break;
 254     case 0x1FF8:
 255         /* control */
 256         NVRAM->buffer[0x1FF8] = (val & ~0xA0) | 0x90;
 257         break;
 258     case 0x1FF9:
 259         /* seconds (BCD) */
 260         tmp = fromBCD(val & 0x7F);
 261         if (tmp >= 0 && tmp <= 59) {
 262             get_time(NVRAM, &tm);
 263             tm.tm_sec = tmp;
 264             set_time(NVRAM, &tm);
 265         }
 266         if ((val & 0x80) ^ (NVRAM->buffer[0x1FF9] & 0x80)) {
 267             if (val & 0x80) {
 268                 NVRAM->stop_time = time(NULL);
 269             } else {
 270                 NVRAM->time_offset += NVRAM->stop_time - time(NULL);
 271                 NVRAM->stop_time = 0;
 272             }
 273         }
 274         NVRAM->buffer[0x1FF9] = val & 0x80;
 275         break;
 276     case 0x1FFA:
 277         /* minutes (BCD) */
 278         tmp = fromBCD(val & 0x7F);
 279         if (tmp >= 0 && tmp <= 59) {
 280             get_time(NVRAM, &tm);
 281             tm.tm_min = tmp;
 282             set_time(NVRAM, &tm);
 283         }
 284         break;
 285     case 0x1FFB:
 286         /* hours (BCD) */
 287         tmp = fromBCD(val & 0x3F);
 288         if (tmp >= 0 && tmp <= 23) {
 289             get_time(NVRAM, &tm);
 290             tm.tm_hour = tmp;
 291             set_time(NVRAM, &tm);
 292         }
 293         break;
 294     case 0x1FFC:
 295         /* day of the week / century */
 296         tmp = fromBCD(val & 0x07);
 297         get_time(NVRAM, &tm);
 298         tm.tm_wday = tmp;
 299         set_time(NVRAM, &tm);
 300         NVRAM->buffer[0x1FFC] = val & 0x40;
 301         break;
 302     case 0x1FFD:
 303         /* date */
 304         tmp = fromBCD(val & 0x1F);
 305         if (tmp != 0) {
 306             get_time(NVRAM, &tm);
 307             tm.tm_mday = tmp;
 308             set_time(NVRAM, &tm);
 309         }
 310         break;
 311     case 0x1FFE:
 312         /* month */
 313         tmp = fromBCD(val & 0x1F);
 314         if (tmp >= 1 && tmp <= 12) {
 315             get_time(NVRAM, &tm);
 316             tm.tm_mon = tmp - 1;
 317             set_time(NVRAM, &tm);
 318         }
 319         break;
 320     case 0x1FFF:
 321         /* year */
 322         tmp = fromBCD(val);
 323         if (tmp >= 0 && tmp <= 99) {
 324             get_time(NVRAM, &tm);
 325             tm.tm_year = fromBCD(val);
 326             set_time(NVRAM, &tm);
 327         }
 328         break;
 329     default:
 330         /* Check lock registers state */
 331         if (NVRAM->addr >= 0x20 && NVRAM->addr <= 0x2F && (NVRAM->lock & 1))
 332             break;
 333         if (NVRAM->addr >= 0x30 && NVRAM->addr <= 0x3F && (NVRAM->lock & 2))
 334             break;
 335         if (NVRAM->addr < 0x1FF0 ||
 336             (NVRAM->addr > 0x1FFF && NVRAM->addr < NVRAM->size)) {
 337             NVRAM->buffer[NVRAM->addr] = val & 0xFF;
 338         }
 339         break;
 340     }
 341 }
 342
 343 uint32_t m48t59_read (m48t59_t *NVRAM)
 344 {
 345     struct tm tm;
 346     uint32_t retval = 0xFF;
 347
 348     switch (NVRAM->addr) {
 349     case 0x1FF0:
 350         /* flags register */
 351         goto do_read;
 352     case 0x1FF1:
 353         /* unused */
 354         retval = 0;
 355         break;
 356     case 0x1FF2:
 357         /* alarm seconds */
 358         goto do_read;
 359     case 0x1FF3:
 360         /* alarm minutes */
 361         goto do_read;
 362     case 0x1FF4:
 363         /* alarm hours */
 364         goto do_read;
 365     case 0x1FF5:
 366         /* alarm date */
 367         goto do_read;
 368     case 0x1FF6:
 369         /* interrupts */
 370         goto do_read;
 371     case 0x1FF7:
 372         /* A read resets the watchdog */
 373         set_up_watchdog(NVRAM, NVRAM->buffer[0x1FF7]);
 374         goto do_read;
 375     case 0x1FF8:
 376         /* control */
 377         goto do_read;
 378     case 0x1FF9:
 379         /* seconds (BCD) */
 380         get_time(NVRAM, &tm);
 381         retval = (NVRAM->buffer[0x1FF9] & 0x80) | toBCD(tm.tm_sec);
 382         break;
 383     case 0x1FFA:
 384         /* minutes (BCD) */
 385         get_time(NVRAM, &tm);
 386         retval = toBCD(tm.tm_min);
 387         break;
 388     case 0x1FFB:
 389         /* hours (BCD) */
 390         get_time(NVRAM, &tm);
 391         retval = toBCD(tm.tm_hour);
 392         break;
 393     case 0x1FFC:
 394         /* day of the week / century */
 395         get_time(NVRAM, &tm);
 396         retval = NVRAM->buffer[0x1FFC] | tm.tm_wday;
 397         break;
 398     case 0x1FFD:
 399         /* date */
 400         get_time(NVRAM, &tm);
 401         retval = toBCD(tm.tm_mday);
 402         break;
 403     case 0x1FFE:
 404         /* month */
 405         get_time(NVRAM, &tm);
 406         retval = toBCD(tm.tm_mon + 1);
 407         break;
 408     case 0x1FFF:
 409         /* year */
 410         get_time(NVRAM, &tm);
 411         retval = toBCD(tm.tm_year);
 412         break;
 413     default:
 414         /* Check lock registers state */
 415         if (NVRAM->addr >= 0x20 && NVRAM->addr <= 0x2F && (NVRAM->lock & 1))
 416             break;
 417         if (NVRAM->addr >= 0x30 && NVRAM->addr <= 0x3F && (NVRAM->lock & 2))
 418             break;
 419         if (NVRAM->addr < 0x1FF0 ||
 420             (NVRAM->addr > 0x1FFF && NVRAM->addr < NVRAM->size)) {
 421         do_read:
 422             retval = NVRAM->buffer[NVRAM->addr];
 423         }
 424         break;
 425     }
 426     if (NVRAM->addr > 0x1FF9 && NVRAM->addr < 0x2000)
 427         NVRAM_PRINTF("0x%08x <= 0x%08x\n", NVRAM->addr, retval);
 428
 429     return retval;
 430 }
 431
 432 void m48t59_set_addr (m48t59_t *NVRAM, uint32_t addr)
 433 {
 434     NVRAM->addr = addr;
 435 }
 436
 437 void m48t59_toggle_lock (m48t59_t *NVRAM, int lock)
 438 {
 439     NVRAM->lock ^= 1 << lock;
 440 }
 441
 442 /* IO access to NVRAM */
 443 static void NVRAM_writeb (void *opaque, uint32_t addr, uint32_t val)
 444 {
 445     m48t59_t *NVRAM = opaque;
 446
 447     addr -= NVRAM->io_base;
 448     NVRAM_PRINTF("0x%08x => 0x%08x\n", addr, val);
 449     switch (addr) {
 450     case 0:
 451         NVRAM->addr &= ~0x00FF;
 452         NVRAM->addr |= val;
 453         break;
 454     case 1:
 455         NVRAM->addr &= ~0xFF00;
 456         NVRAM->addr |= val << 8;
 457         break;
 458     case 3:
 459         m48t59_write(NVRAM, val);
 460         NVRAM->addr = 0x0000;
 461         break;
 462     default:
 463         break;
 464     }
 465 }
 466
 467 static uint32_t NVRAM_readb (void *opaque, uint32_t addr)
 468 {
 469     m48t59_t *NVRAM = opaque;
 470     uint32_t retval;
 471
 472     addr -= NVRAM->io_base;
 473     switch (addr) {
 474     case 3:
 475         retval = m48t59_read(NVRAM);
 476         break;
 477     default:
 478         retval = -1;
 479         break;
 480     }
 481     NVRAM_PRINTF("0x%08x <= 0x%08x\n", addr, retval);
 482
 483     return retval;
 484 }
 485
 486 /* Initialisation routine */
 487 m48t59_t *m48t59_init (int IRQ, uint32_t io_base, uint16_t size)
 488 {
 489     m48t59_t *s;
 490
 491     s = qemu_mallocz(sizeof(m48t59_t));
 492     if (!s)
 493         return NULL;
 494     s->buffer = qemu_mallocz(size);
 495     if (!s->buffer) {
 496         qemu_free(s);
 497         return NULL;
 498     }
 499     s->IRQ = IRQ;
 500     s->size = size;
 501     s->io_base = io_base;
 502     s->addr = 0;
 503     register_ioport_read(io_base, 0x04, 1, NVRAM_readb, s);
 504     register_ioport_write(io_base, 0x04, 1, NVRAM_writeb, s);
 505     s->alrm_timer = qemu_new_timer(vm_clock, &alarm_cb, s);
 506     s->wd_timer = qemu_new_timer(vm_clock, &watchdog_cb, s);
 507     s->lock = 0;
 508
 509     return s;
 510 }