1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2008 Poul-Henning Kamp 5 * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_acpi.h" 36 #include "opt_isa.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/bus.h> 41 #include <sys/clock.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/kdb.h> 45 #include <sys/kernel.h> 46 #include <sys/module.h> 47 #include <sys/proc.h> 48 #include <sys/rman.h> 49 #include <sys/timeet.h> 50 51 #include <isa/rtc.h> 52 #ifdef DEV_ISA 53 #include <isa/isareg.h> 54 #include <isa/isavar.h> 55 #endif 56 #include <machine/intr_machdep.h> 57 #include "clock_if.h" 58 #ifdef DEV_ACPI 59 #include <contrib/dev/acpica/include/acpi.h> 60 #include <contrib/dev/acpica/include/accommon.h> 61 #include <dev/acpica/acpivar.h> 62 #include <machine/md_var.h> 63 #endif 64 65 /* 66 * atrtc_lock protects low-level access to individual hardware registers. 67 * atrtc_time_lock protects the entire sequence of accessing multiple registers 68 * to read or write the date and time. 69 */ 70 static struct mtx atrtc_lock; 71 MTX_SYSINIT(atrtc_lock_init, &atrtc_lock, "atrtc", MTX_SPIN); 72 73 /* Force RTC enabled/disabled. */ 74 static int atrtc_enabled = -1; 75 TUNABLE_INT("hw.atrtc.enabled", &atrtc_enabled); 76 77 struct mtx atrtc_time_lock; 78 MTX_SYSINIT(atrtc_time_lock_init, &atrtc_time_lock, "atrtc_time", MTX_DEF); 79 80 int atrtcclock_disable = 0; 81 82 static int rtc_reg = -1; 83 static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 84 static u_char rtc_statusb = RTCSB_24HR; 85 86 #ifdef DEV_ACPI 87 #define _COMPONENT ACPI_TIMER 88 ACPI_MODULE_NAME("ATRTC") 89 #endif 90 91 /* 92 * RTC support routines 93 */ 94 95 static inline u_char 96 rtcin_locked(int reg) 97 { 98 99 if (rtc_reg != reg) { 100 inb(0x84); 101 outb(IO_RTC, reg); 102 rtc_reg = reg; 103 inb(0x84); 104 } 105 return (inb(IO_RTC + 1)); 106 } 107 108 static inline void 109 rtcout_locked(int reg, u_char val) 110 { 111 112 if (rtc_reg != reg) { 113 inb(0x84); 114 outb(IO_RTC, reg); 115 rtc_reg = reg; 116 inb(0x84); 117 } 118 outb(IO_RTC + 1, val); 119 inb(0x84); 120 } 121 122 int 123 rtcin(int reg) 124 { 125 u_char val; 126 127 mtx_lock_spin(&atrtc_lock); 128 val = rtcin_locked(reg); 129 mtx_unlock_spin(&atrtc_lock); 130 return (val); 131 } 132 133 void 134 writertc(int reg, u_char val) 135 { 136 137 mtx_lock_spin(&atrtc_lock); 138 rtcout_locked(reg, val); 139 mtx_unlock_spin(&atrtc_lock); 140 } 141 142 static void 143 atrtc_start(void) 144 { 145 146 mtx_lock_spin(&atrtc_lock); 147 rtcout_locked(RTC_STATUSA, rtc_statusa); 148 rtcout_locked(RTC_STATUSB, RTCSB_24HR); 149 mtx_unlock_spin(&atrtc_lock); 150 } 151 152 static void 153 atrtc_rate(unsigned rate) 154 { 155 156 rtc_statusa = RTCSA_DIVIDER | rate; 157 writertc(RTC_STATUSA, rtc_statusa); 158 } 159 160 static void 161 atrtc_enable_intr(void) 162 { 163 164 rtc_statusb |= RTCSB_PINTR; 165 mtx_lock_spin(&atrtc_lock); 166 rtcout_locked(RTC_STATUSB, rtc_statusb); 167 rtcin_locked(RTC_INTR); 168 mtx_unlock_spin(&atrtc_lock); 169 } 170 171 static void 172 atrtc_disable_intr(void) 173 { 174 175 rtc_statusb &= ~RTCSB_PINTR; 176 mtx_lock_spin(&atrtc_lock); 177 rtcout_locked(RTC_STATUSB, rtc_statusb); 178 rtcin_locked(RTC_INTR); 179 mtx_unlock_spin(&atrtc_lock); 180 } 181 182 void 183 atrtc_restore(void) 184 { 185 186 /* Restore all of the RTC's "status" (actually, control) registers. */ 187 mtx_lock_spin(&atrtc_lock); 188 rtcin_locked(RTC_STATUSA); /* dummy to get rtc_reg set */ 189 rtcout_locked(RTC_STATUSB, RTCSB_24HR); 190 rtcout_locked(RTC_STATUSA, rtc_statusa); 191 rtcout_locked(RTC_STATUSB, rtc_statusb); 192 rtcin_locked(RTC_INTR); 193 mtx_unlock_spin(&atrtc_lock); 194 } 195 196 /********************************************************************** 197 * RTC driver for subr_rtc 198 */ 199 200 struct atrtc_softc { 201 int port_rid, intr_rid; 202 struct resource *port_res; 203 struct resource *intr_res; 204 void *intr_handler; 205 struct eventtimer et; 206 #ifdef DEV_ACPI 207 ACPI_HANDLE acpi_handle; 208 #endif 209 }; 210 211 static int 212 rtc_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 213 { 214 215 atrtc_rate(max(fls(period + (period >> 1)) - 17, 1)); 216 atrtc_enable_intr(); 217 return (0); 218 } 219 220 static int 221 rtc_stop(struct eventtimer *et) 222 { 223 224 atrtc_disable_intr(); 225 return (0); 226 } 227 228 /* 229 * This routine receives statistical clock interrupts from the RTC. 230 * As explained above, these occur at 128 interrupts per second. 231 * When profiling, we receive interrupts at a rate of 1024 Hz. 232 * 233 * This does not actually add as much overhead as it sounds, because 234 * when the statistical clock is active, the hardclock driver no longer 235 * needs to keep (inaccurate) statistics on its own. This decouples 236 * statistics gathering from scheduling interrupts. 237 * 238 * The RTC chip requires that we read status register C (RTC_INTR) 239 * to acknowledge an interrupt, before it will generate the next one. 240 * Under high interrupt load, rtcintr() can be indefinitely delayed and 241 * the clock can tick immediately after the read from RTC_INTR. In this 242 * case, the mc146818A interrupt signal will not drop for long enough 243 * to register with the 8259 PIC. If an interrupt is missed, the stat 244 * clock will halt, considerably degrading system performance. This is 245 * why we use 'while' rather than a more straightforward 'if' below. 246 * Stat clock ticks can still be lost, causing minor loss of accuracy 247 * in the statistics, but the stat clock will no longer stop. 248 */ 249 static int 250 rtc_intr(void *arg) 251 { 252 struct atrtc_softc *sc = (struct atrtc_softc *)arg; 253 int flag = 0; 254 255 while (rtcin(RTC_INTR) & RTCIR_PERIOD) { 256 flag = 1; 257 if (sc->et.et_active) 258 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 259 } 260 return(flag ? FILTER_HANDLED : FILTER_STRAY); 261 } 262 263 #ifdef DEV_ACPI 264 /* 265 * ACPI RTC CMOS address space handler 266 */ 267 #define ATRTC_LAST_REG 0x40 268 269 static void 270 rtcin_region(int reg, void *buf, int len) 271 { 272 u_char *ptr = buf; 273 274 /* Drop lock after each IO as intr and settime have greater priority */ 275 while (len-- > 0) 276 *ptr++ = rtcin(reg++) & 0xff; 277 } 278 279 static void 280 rtcout_region(int reg, const void *buf, int len) 281 { 282 const u_char *ptr = buf; 283 284 while (len-- > 0) 285 writertc(reg++, *ptr++); 286 } 287 288 static bool 289 atrtc_check_cmos_access(bool is_read, ACPI_PHYSICAL_ADDRESS addr, UINT32 len) 290 { 291 292 /* Block address space wrapping on out-of-bound access */ 293 if (addr >= ATRTC_LAST_REG || addr + len > ATRTC_LAST_REG) 294 return (false); 295 296 if (is_read) { 297 /* Reading 0x0C will muck with interrupts */ 298 if (addr <= RTC_INTR && addr + len > RTC_INTR) 299 return (false); 300 } else { 301 /* 302 * Allow single-byte writes to alarm registers and 303 * multi-byte writes to addr >= 0x30, else deny. 304 */ 305 if (!((len == 1 && (addr == RTC_SECALRM || 306 addr == RTC_MINALRM || 307 addr == RTC_HRSALRM)) || 308 addr >= 0x30)) 309 return (false); 310 } 311 return (true); 312 } 313 314 static ACPI_STATUS 315 atrtc_acpi_cmos_handler(UINT32 func, ACPI_PHYSICAL_ADDRESS addr, 316 UINT32 bitwidth, UINT64 *value, void *context, void *region_context) 317 { 318 device_t dev = context; 319 UINT32 bytewidth = howmany(bitwidth, 8); 320 bool is_read = func == ACPI_READ; 321 322 /* ACPICA is very verbose on CMOS handler failures, so we, too */ 323 #define CMOS_HANDLER_ERR(fmt, ...) \ 324 device_printf(dev, "ACPI [SystemCMOS] handler: " fmt, ##__VA_ARGS__) 325 326 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 327 328 if (value == NULL) { 329 CMOS_HANDLER_ERR("NULL parameter\n"); 330 return (AE_BAD_PARAMETER); 331 } 332 if (bitwidth == 0 || (bitwidth & 0x07) != 0) { 333 CMOS_HANDLER_ERR("Invalid bitwidth: %u\n", bitwidth); 334 return (AE_BAD_PARAMETER); 335 } 336 if (!atrtc_check_cmos_access(is_read, addr, bytewidth)) { 337 CMOS_HANDLER_ERR("%s access rejected: addr=%#04jx, len=%u\n", 338 is_read ? "Read" : "Write", (uintmax_t)addr, bytewidth); 339 return (AE_BAD_PARAMETER); 340 } 341 342 switch (func) { 343 case ACPI_READ: 344 rtcin_region(addr, value, bytewidth); 345 break; 346 case ACPI_WRITE: 347 rtcout_region(addr, value, bytewidth); 348 break; 349 default: 350 CMOS_HANDLER_ERR("Invalid function: %u\n", func); 351 return (AE_BAD_PARAMETER); 352 } 353 354 ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev), 355 "ACPI RTC CMOS %s access: addr=%#04x, len=%u, val=%*D\n", 356 is_read ? "read" : "write", (unsigned)addr, bytewidth, 357 bytewidth, value, " "); 358 359 return (AE_OK); 360 } 361 362 static int 363 atrtc_reg_acpi_cmos_handler(device_t dev) 364 { 365 struct atrtc_softc *sc = device_get_softc(dev); 366 367 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__); 368 369 /* Don't handle address space events if driver is disabled. */ 370 if (acpi_disabled("atrtc")) 371 return (ENXIO); 372 373 sc->acpi_handle = acpi_get_handle(dev); 374 if (sc->acpi_handle == NULL || 375 ACPI_FAILURE(AcpiInstallAddressSpaceHandler(sc->acpi_handle, 376 ACPI_ADR_SPACE_CMOS, atrtc_acpi_cmos_handler, NULL, dev))) { 377 sc->acpi_handle = NULL; 378 device_printf(dev, 379 "Can't register ACPI CMOS address space handler\n"); 380 return (ENXIO); 381 } 382 383 return (0); 384 } 385 386 static int 387 atrtc_unreg_acpi_cmos_handler(device_t dev) 388 { 389 struct atrtc_softc *sc = device_get_softc(dev); 390 391 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__); 392 393 if (sc->acpi_handle != NULL) 394 AcpiRemoveAddressSpaceHandler(sc->acpi_handle, 395 ACPI_ADR_SPACE_CMOS, atrtc_acpi_cmos_handler); 396 397 return (0); 398 } 399 #endif /* DEV_ACPI */ 400 401 /* 402 * Attach to the ISA PnP descriptors for the timer and realtime clock. 403 */ 404 static struct isa_pnp_id atrtc_ids[] = { 405 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 406 { 0 } 407 }; 408 409 static bool 410 atrtc_acpi_disabled(void) 411 { 412 #ifdef DEV_ACPI 413 uint16_t flags; 414 415 if (!acpi_get_fadt_bootflags(&flags)) 416 return (false); 417 return ((flags & ACPI_FADT_NO_CMOS_RTC) != 0); 418 #else 419 return (false); 420 #endif 421 } 422 423 static int 424 atrtc_probe(device_t dev) 425 { 426 int result; 427 428 if ((atrtc_enabled == -1 && atrtc_acpi_disabled()) || 429 (atrtc_enabled == 0)) 430 return (ENXIO); 431 432 result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids); 433 /* ENOENT means no PnP-ID, device is hinted. */ 434 if (result == ENOENT) { 435 device_set_desc(dev, "AT realtime clock"); 436 return (BUS_PROBE_LOW_PRIORITY); 437 } 438 return (result); 439 } 440 441 static int 442 atrtc_attach(device_t dev) 443 { 444 struct atrtc_softc *sc; 445 rman_res_t s; 446 int i; 447 448 sc = device_get_softc(dev); 449 sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid, 450 IO_RTC, IO_RTC + 1, 2, RF_ACTIVE); 451 if (sc->port_res == NULL) 452 device_printf(dev, "Warning: Couldn't map I/O.\n"); 453 atrtc_start(); 454 clock_register(dev, 1000000); 455 bzero(&sc->et, sizeof(struct eventtimer)); 456 if (!atrtcclock_disable && 457 (resource_int_value(device_get_name(dev), device_get_unit(dev), 458 "clock", &i) != 0 || i != 0)) { 459 sc->intr_rid = 0; 460 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 461 &s, NULL) == 0 && s != 8) 462 sc->intr_rid++; 463 sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 464 &sc->intr_rid, 8, 8, 1, RF_ACTIVE); 465 if (sc->intr_res == NULL) { 466 device_printf(dev, "Can't map interrupt.\n"); 467 return (0); 468 } else if ((bus_setup_intr(dev, sc->intr_res, INTR_TYPE_CLK, 469 rtc_intr, NULL, sc, &sc->intr_handler))) { 470 device_printf(dev, "Can't setup interrupt.\n"); 471 return (0); 472 } else { 473 /* Bind IRQ to BSP to avoid live migration. */ 474 bus_bind_intr(dev, sc->intr_res, 0); 475 } 476 sc->et.et_name = "RTC"; 477 sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_POW2DIV; 478 sc->et.et_quality = 0; 479 sc->et.et_frequency = 32768; 480 sc->et.et_min_period = 0x00080000; 481 sc->et.et_max_period = 0x80000000; 482 sc->et.et_start = rtc_start; 483 sc->et.et_stop = rtc_stop; 484 sc->et.et_priv = dev; 485 et_register(&sc->et); 486 } 487 return(0); 488 } 489 490 static int 491 atrtc_isa_attach(device_t dev) 492 { 493 494 return (atrtc_attach(dev)); 495 } 496 497 #ifdef DEV_ACPI 498 static int 499 atrtc_acpi_attach(device_t dev) 500 { 501 int ret; 502 503 ret = atrtc_attach(dev); 504 if (ret) 505 return (ret); 506 507 (void)atrtc_reg_acpi_cmos_handler(dev); 508 509 return (0); 510 } 511 512 static int 513 atrtc_acpi_detach(device_t dev) 514 { 515 516 (void)atrtc_unreg_acpi_cmos_handler(dev); 517 return (0); 518 } 519 #endif /* DEV_ACPI */ 520 521 static int 522 atrtc_resume(device_t dev) 523 { 524 525 atrtc_restore(); 526 return(0); 527 } 528 529 static int 530 atrtc_settime(device_t dev __unused, struct timespec *ts) 531 { 532 struct bcd_clocktime bct; 533 534 clock_ts_to_bcd(ts, &bct, false); 535 clock_dbgprint_bcd(dev, CLOCK_DBG_WRITE, &bct); 536 537 mtx_lock(&atrtc_time_lock); 538 mtx_lock_spin(&atrtc_lock); 539 540 /* Disable RTC updates and interrupts. */ 541 rtcout_locked(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 542 543 /* Write all the time registers. */ 544 rtcout_locked(RTC_SEC, bct.sec); 545 rtcout_locked(RTC_MIN, bct.min); 546 rtcout_locked(RTC_HRS, bct.hour); 547 rtcout_locked(RTC_WDAY, bct.dow + 1); 548 rtcout_locked(RTC_DAY, bct.day); 549 rtcout_locked(RTC_MONTH, bct.mon); 550 rtcout_locked(RTC_YEAR, bct.year & 0xff); 551 #ifdef USE_RTC_CENTURY 552 rtcout_locked(RTC_CENTURY, bct.year >> 8); 553 #endif 554 555 /* 556 * Re-enable RTC updates and interrupts. 557 */ 558 rtcout_locked(RTC_STATUSB, rtc_statusb); 559 rtcin_locked(RTC_INTR); 560 561 mtx_unlock_spin(&atrtc_lock); 562 mtx_unlock(&atrtc_time_lock); 563 564 return (0); 565 } 566 567 static int 568 atrtc_gettime(device_t dev, struct timespec *ts) 569 { 570 struct bcd_clocktime bct; 571 572 /* Look if we have a RTC present and the time is valid */ 573 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) { 574 device_printf(dev, "WARNING: Battery failure indication\n"); 575 return (EINVAL); 576 } 577 578 /* 579 * wait for time update to complete 580 * If RTCSA_TUP is zero, we have at least 244us before next update. 581 * This is fast enough on most hardware, but a refinement would be 582 * to make sure that no more than 240us pass after we start reading, 583 * and try again if so. 584 */ 585 mtx_lock(&atrtc_time_lock); 586 while (rtcin(RTC_STATUSA) & RTCSA_TUP) 587 continue; 588 mtx_lock_spin(&atrtc_lock); 589 bct.sec = rtcin_locked(RTC_SEC); 590 bct.min = rtcin_locked(RTC_MIN); 591 bct.hour = rtcin_locked(RTC_HRS); 592 bct.day = rtcin_locked(RTC_DAY); 593 bct.mon = rtcin_locked(RTC_MONTH); 594 bct.year = rtcin_locked(RTC_YEAR); 595 #ifdef USE_RTC_CENTURY 596 bct.year |= rtcin_locked(RTC_CENTURY) << 8; 597 #endif 598 mtx_unlock_spin(&atrtc_lock); 599 mtx_unlock(&atrtc_time_lock); 600 /* dow is unused in timespec conversion and we have no nsec info. */ 601 bct.dow = 0; 602 bct.nsec = 0; 603 clock_dbgprint_bcd(dev, CLOCK_DBG_READ, &bct); 604 return (clock_bcd_to_ts(&bct, ts, false)); 605 } 606 607 static device_method_t atrtc_isa_methods[] = { 608 /* Device interface */ 609 DEVMETHOD(device_probe, atrtc_probe), 610 DEVMETHOD(device_attach, atrtc_isa_attach), 611 DEVMETHOD(device_detach, bus_generic_detach), 612 DEVMETHOD(device_shutdown, bus_generic_shutdown), 613 DEVMETHOD(device_suspend, bus_generic_suspend), 614 /* XXX stop statclock? */ 615 DEVMETHOD(device_resume, atrtc_resume), 616 617 /* clock interface */ 618 DEVMETHOD(clock_gettime, atrtc_gettime), 619 DEVMETHOD(clock_settime, atrtc_settime), 620 621 { 0, 0 } 622 }; 623 624 static driver_t atrtc_isa_driver = { 625 "atrtc", 626 atrtc_isa_methods, 627 sizeof(struct atrtc_softc), 628 }; 629 630 #ifdef DEV_ACPI 631 static device_method_t atrtc_acpi_methods[] = { 632 /* Device interface */ 633 DEVMETHOD(device_probe, atrtc_probe), 634 DEVMETHOD(device_attach, atrtc_acpi_attach), 635 DEVMETHOD(device_detach, atrtc_acpi_detach), 636 /* XXX stop statclock? */ 637 DEVMETHOD(device_resume, atrtc_resume), 638 639 /* clock interface */ 640 DEVMETHOD(clock_gettime, atrtc_gettime), 641 DEVMETHOD(clock_settime, atrtc_settime), 642 643 { 0, 0 } 644 }; 645 646 static driver_t atrtc_acpi_driver = { 647 "atrtc", 648 atrtc_acpi_methods, 649 sizeof(struct atrtc_softc), 650 }; 651 #endif /* DEV_ACPI */ 652 653 static devclass_t atrtc_devclass; 654 655 DRIVER_MODULE(atrtc, isa, atrtc_isa_driver, atrtc_devclass, 0, 0); 656 #ifdef DEV_ACPI 657 DRIVER_MODULE(atrtc, acpi, atrtc_acpi_driver, atrtc_devclass, 0, 0); 658 #endif 659 ISA_PNP_INFO(atrtc_ids); 660