1/*- 2 * Copyright (c) 2008 Poul-Henning Kamp 3 * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: stable/11/sys/x86/isa/atrtc.c 345590 2019-03-27 19:17:42Z wulf $ 28 */ 29 30#include <sys/cdefs.h> 31__FBSDID("$FreeBSD: stable/11/sys/x86/isa/atrtc.c 345590 2019-03-27 19:17:42Z wulf $"); 32 33#include "opt_acpi.h" 34#include "opt_isa.h" 35 36#include <sys/param.h> 37#include <sys/systm.h> 38#include <sys/bus.h> 39#include <sys/clock.h> 40#include <sys/lock.h> 41#include <sys/mutex.h> 42#include <sys/kdb.h> 43#include <sys/kernel.h> 44#include <sys/module.h> 45#include <sys/proc.h> 46#include <sys/rman.h> 47#include <sys/timeet.h> 48 49#include <isa/rtc.h> 50#ifdef DEV_ISA 51#include <isa/isareg.h> 52#include <isa/isavar.h> 53#endif 54#include <machine/intr_machdep.h> 55#include "clock_if.h" 56#ifdef DEV_ACPI 57#include <contrib/dev/acpica/include/acpi.h> 58#include <contrib/dev/acpica/include/accommon.h> 59#include <dev/acpica/acpivar.h> 60#include <machine/md_var.h> 61#endif 62 63/* 64 * atrtc_lock protects low-level access to individual hardware registers. 65 * atrtc_time_lock protects the entire sequence of accessing multiple registers 66 * to read or write the date and time. 67 */ 68static struct mtx atrtc_lock; 69MTX_SYSINIT(atrtc_lock_init, &atrtc_lock, "atrtc", MTX_SPIN); 70 71struct mtx atrtc_time_lock; 72MTX_SYSINIT(atrtc_time_lock_init, &atrtc_time_lock, "atrtc_time", MTX_DEF); 73 74int atrtcclock_disable = 0; 75 76static int rtc_reg = -1; 77static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 78static u_char rtc_statusb = RTCSB_24HR; 79 80#ifdef DEV_ACPI 81#define _COMPONENT ACPI_TIMER 82ACPI_MODULE_NAME("ATRTC") 83#endif 84 85/* 86 * RTC support routines 87 */ 88 89static inline u_char 90rtcin_locked(int reg) 91{ 92 93 if (rtc_reg != reg) { 94 inb(0x84); 95 outb(IO_RTC, reg); 96 rtc_reg = reg; 97 inb(0x84); 98 } 99 return (inb(IO_RTC + 1)); 100} 101 102static inline void 103rtcout_locked(int reg, u_char val) 104{ 105 106 if (rtc_reg != reg) { 107 inb(0x84); 108 outb(IO_RTC, reg); 109 rtc_reg = reg; 110 inb(0x84); 111 } 112 outb(IO_RTC + 1, val); 113 inb(0x84); 114} 115 116int 117rtcin(int reg) 118{ 119 u_char val; 120 121 mtx_lock_spin(&atrtc_lock); 122 val = rtcin_locked(reg); 123 mtx_unlock_spin(&atrtc_lock); 124 return (val); 125} 126 127void 128writertc(int reg, u_char val) 129{ 130 131 mtx_lock_spin(&atrtc_lock); 132 rtcout_locked(reg, val); 133 mtx_unlock_spin(&atrtc_lock); 134} 135 136static void 137atrtc_start(void) 138{ 139 140 mtx_lock_spin(&atrtc_lock); 141 rtcout_locked(RTC_STATUSA, rtc_statusa); 142 rtcout_locked(RTC_STATUSB, RTCSB_24HR); 143 mtx_unlock_spin(&atrtc_lock); 144} 145 146static void 147atrtc_rate(unsigned rate) 148{ 149 150 rtc_statusa = RTCSA_DIVIDER | rate; 151 writertc(RTC_STATUSA, rtc_statusa); 152} 153 154static void 155atrtc_enable_intr(void) 156{ 157 158 rtc_statusb |= RTCSB_PINTR; 159 mtx_lock_spin(&atrtc_lock); 160 rtcout_locked(RTC_STATUSB, rtc_statusb); 161 rtcin_locked(RTC_INTR); 162 mtx_unlock_spin(&atrtc_lock); 163} 164 165static void 166atrtc_disable_intr(void) 167{ 168 169 rtc_statusb &= ~RTCSB_PINTR; 170 mtx_lock_spin(&atrtc_lock); 171 rtcout_locked(RTC_STATUSB, rtc_statusb); 172 rtcin_locked(RTC_INTR); 173 mtx_unlock_spin(&atrtc_lock); 174} 175 176void 177atrtc_restore(void) 178{ 179 180 /* Restore all of the RTC's "status" (actually, control) registers. */ 181 mtx_lock_spin(&atrtc_lock); 182 rtcin_locked(RTC_STATUSA); /* dummy to get rtc_reg set */ 183 rtcout_locked(RTC_STATUSB, RTCSB_24HR); 184 rtcout_locked(RTC_STATUSA, rtc_statusa); 185 rtcout_locked(RTC_STATUSB, rtc_statusb); 186 rtcin_locked(RTC_INTR); 187 mtx_unlock_spin(&atrtc_lock); 188} 189 190/********************************************************************** 191 * RTC driver for subr_rtc 192 */ 193 194struct atrtc_softc { 195 int port_rid, intr_rid; 196 struct resource *port_res; 197 struct resource *intr_res; 198 void *intr_handler; 199 struct eventtimer et; 200#ifdef DEV_ACPI 201 ACPI_HANDLE acpi_handle; 202#endif 203}; 204 205static int 206rtc_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 207{ 208 209 atrtc_rate(max(fls(period + (period >> 1)) - 17, 1)); 210 atrtc_enable_intr(); 211 return (0); 212} 213 214static int 215rtc_stop(struct eventtimer *et) 216{ 217 218 atrtc_disable_intr(); 219 return (0); 220} 221 222/* 223 * This routine receives statistical clock interrupts from the RTC. 224 * As explained above, these occur at 128 interrupts per second. 225 * When profiling, we receive interrupts at a rate of 1024 Hz. 226 * 227 * This does not actually add as much overhead as it sounds, because 228 * when the statistical clock is active, the hardclock driver no longer 229 * needs to keep (inaccurate) statistics on its own. This decouples 230 * statistics gathering from scheduling interrupts. 231 * 232 * The RTC chip requires that we read status register C (RTC_INTR) 233 * to acknowledge an interrupt, before it will generate the next one. 234 * Under high interrupt load, rtcintr() can be indefinitely delayed and 235 * the clock can tick immediately after the read from RTC_INTR. In this 236 * case, the mc146818A interrupt signal will not drop for long enough 237 * to register with the 8259 PIC. If an interrupt is missed, the stat 238 * clock will halt, considerably degrading system performance. This is 239 * why we use 'while' rather than a more straightforward 'if' below. 240 * Stat clock ticks can still be lost, causing minor loss of accuracy 241 * in the statistics, but the stat clock will no longer stop. 242 */ 243static int 244rtc_intr(void *arg) 245{ 246 struct atrtc_softc *sc = (struct atrtc_softc *)arg; 247 int flag = 0; 248 249 while (rtcin(RTC_INTR) & RTCIR_PERIOD) { 250 flag = 1; 251 if (sc->et.et_active) 252 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 253 } 254 return(flag ? FILTER_HANDLED : FILTER_STRAY); 255} 256 257#ifdef DEV_ACPI 258/* 259 * ACPI RTC CMOS address space handler 260 */ 261#define ATRTC_LAST_REG 0x40 262 263static void 264rtcin_region(int reg, void *buf, int len) 265{ 266 u_char *ptr = buf; 267 268 /* Drop lock after each IO as intr and settime have greater priority */ 269 while (len-- > 0) 270 *ptr++ = rtcin(reg++) & 0xff; 271} 272 273static void 274rtcout_region(int reg, const void *buf, int len) 275{ 276 const u_char *ptr = buf; 277 278 while (len-- > 0) 279 writertc(reg++, *ptr++); 280} 281 282static bool 283atrtc_check_cmos_access(bool is_read, ACPI_PHYSICAL_ADDRESS addr, UINT32 len) 284{ 285 286 /* Block address space wrapping on out-of-bound access */ 287 if (addr >= ATRTC_LAST_REG || addr + len > ATRTC_LAST_REG) 288 return (false); 289 290 if (is_read) { 291 /* Reading 0x0C will muck with interrupts */ 292 if (addr <= RTC_INTR && addr + len > RTC_INTR) 293 return (false); 294 } else { 295 /* 296 * Allow single-byte writes to alarm registers and 297 * multi-byte writes to addr >= 0x30, else deny. 298 */ 299 if (!((len == 1 && (addr == RTC_SECALRM || 300 addr == RTC_MINALRM || 301 addr == RTC_HRSALRM)) || 302 addr >= 0x30)) 303 return (false); 304 } 305 return (true); 306} 307 308static ACPI_STATUS 309atrtc_acpi_cmos_handler(UINT32 func, ACPI_PHYSICAL_ADDRESS addr, 310 UINT32 bitwidth, UINT64 *value, void *context, void *region_context) 311{ 312 device_t dev = context; 313 UINT32 bytewidth = howmany(bitwidth, 8); 314 bool is_read = func == ACPI_READ; 315 316 /* ACPICA is very verbose on CMOS handler failures, so we, too */ 317#define CMOS_HANDLER_ERR(fmt, ...) \ 318 device_printf(dev, "ACPI [SystemCMOS] handler: " fmt, ##__VA_ARGS__) 319 320 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 321 322 if (value == NULL) { 323 CMOS_HANDLER_ERR("NULL parameter\n"); 324 return (AE_BAD_PARAMETER); 325 } 326 if (bitwidth == 0 || (bitwidth & 0x07) != 0) { 327 CMOS_HANDLER_ERR("Invalid bitwidth: %u\n", bitwidth); 328 return (AE_BAD_PARAMETER); 329 } 330 if (!atrtc_check_cmos_access(is_read, addr, bytewidth)) { 331 CMOS_HANDLER_ERR("%s access rejected: addr=%#04jx, len=%u\n", 332 is_read ? "Read" : "Write", (uintmax_t)addr, bytewidth); 333 return (AE_BAD_PARAMETER); 334 } 335 336 switch (func) { 337 case ACPI_READ: 338 rtcin_region(addr, value, bytewidth); 339 break; 340 case ACPI_WRITE: 341 rtcout_region(addr, value, bytewidth); 342 break; 343 default: 344 CMOS_HANDLER_ERR("Invalid function: %u\n", func); 345 return (AE_BAD_PARAMETER); 346 } 347 348 ACPI_VPRINT(dev, acpi_device_get_parent_softc(dev), 349 "ACPI RTC CMOS %s access: addr=%#04x, len=%u, val=%*D\n", 350 is_read ? "read" : "write", (unsigned)addr, bytewidth, 351 bytewidth, value, " "); 352 353 return (AE_OK); 354} 355 356static int 357atrtc_reg_acpi_cmos_handler(device_t dev) 358{ 359 struct atrtc_softc *sc = device_get_softc(dev); 360 361 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__); 362 363 /* Don't handle address space events if driver is disabled. */ 364 if (acpi_disabled("atrtc")) 365 return (ENXIO); 366 367 sc->acpi_handle = acpi_get_handle(dev); 368 if (sc->acpi_handle == NULL || 369 ACPI_FAILURE(AcpiInstallAddressSpaceHandler(sc->acpi_handle, 370 ACPI_ADR_SPACE_CMOS, atrtc_acpi_cmos_handler, NULL, dev))) { 371 sc->acpi_handle = NULL; 372 device_printf(dev, 373 "Can't register ACPI CMOS address space handler\n"); 374 return (ENXIO); 375 } 376 377 return (0); 378} 379 380static int 381atrtc_unreg_acpi_cmos_handler(device_t dev) 382{ 383 struct atrtc_softc *sc = device_get_softc(dev); 384 385 ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__); 386 387 if (sc->acpi_handle != NULL) 388 AcpiRemoveAddressSpaceHandler(sc->acpi_handle, 389 ACPI_ADR_SPACE_CMOS, atrtc_acpi_cmos_handler); 390 391 return (0); 392} 393#endif /* DEV_ACPI */ 394 395/* 396 * Attach to the ISA PnP descriptors for the timer and realtime clock. 397 */ 398static struct isa_pnp_id atrtc_ids[] = { 399 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 400 { 0 } 401}; 402 403static int 404atrtc_probe(device_t dev) 405{ 406 int result; 407 408 result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids); 409 /* ENOENT means no PnP-ID, device is hinted. */ 410 if (result == ENOENT) { 411 device_set_desc(dev, "AT realtime clock"); 412 return (BUS_PROBE_LOW_PRIORITY); 413 } 414 return (result); 415} 416 417static int 418atrtc_attach(device_t dev) 419{ 420 struct atrtc_softc *sc; 421 rman_res_t s; 422 int i; 423 424 sc = device_get_softc(dev); 425 sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid, 426 IO_RTC, IO_RTC + 1, 2, RF_ACTIVE); 427 if (sc->port_res == NULL) 428 device_printf(dev, "Warning: Couldn't map I/O.\n"); 429 atrtc_start(); 430 clock_register(dev, 1000000); 431 bzero(&sc->et, sizeof(struct eventtimer)); 432 if (!atrtcclock_disable && 433 (resource_int_value(device_get_name(dev), device_get_unit(dev), 434 "clock", &i) != 0 || i != 0)) { 435 sc->intr_rid = 0; 436 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 437 &s, NULL) == 0 && s != 8) 438 sc->intr_rid++; 439 sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 440 &sc->intr_rid, 8, 8, 1, RF_ACTIVE); 441 if (sc->intr_res == NULL) { 442 device_printf(dev, "Can't map interrupt.\n"); 443 return (0); 444 } else if ((bus_setup_intr(dev, sc->intr_res, INTR_TYPE_CLK, 445 rtc_intr, NULL, sc, &sc->intr_handler))) { 446 device_printf(dev, "Can't setup interrupt.\n"); 447 return (0); 448 } else { 449 /* Bind IRQ to BSP to avoid live migration. */ 450 bus_bind_intr(dev, sc->intr_res, 0); 451 } 452 sc->et.et_name = "RTC"; 453 sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_POW2DIV; 454 sc->et.et_quality = 0; 455 sc->et.et_frequency = 32768; 456 sc->et.et_min_period = 0x00080000; 457 sc->et.et_max_period = 0x80000000; 458 sc->et.et_start = rtc_start; 459 sc->et.et_stop = rtc_stop; 460 sc->et.et_priv = dev; 461 et_register(&sc->et); 462 } 463 return(0); 464} 465 466static int 467atrtc_isa_attach(device_t dev) 468{ 469 470 return (atrtc_attach(dev)); 471} 472 473#ifdef DEV_ACPI 474static int 475atrtc_acpi_attach(device_t dev) 476{ 477 int ret; 478 479 ret = atrtc_attach(dev); 480 if (ret) 481 return (ret); 482 483 (void)atrtc_reg_acpi_cmos_handler(dev); 484 485 return (0); 486} 487 488static int 489atrtc_acpi_detach(device_t dev) 490{ 491 492 (void)atrtc_unreg_acpi_cmos_handler(dev); 493 return (0); 494} 495#endif /* DEV_ACPI */ 496 497static int 498atrtc_resume(device_t dev) 499{ 500 501 atrtc_restore(); 502 return(0); 503} 504 505static int 506atrtc_settime(device_t dev __unused, struct timespec *ts) 507{ 508 struct bcd_clocktime bct; 509 510 clock_ts_to_bcd(ts, &bct, false); 511 clock_dbgprint_bcd(dev, CLOCK_DBG_WRITE, &bct); 512 513 mtx_lock(&atrtc_time_lock); 514 mtx_lock_spin(&atrtc_lock); 515 516 /* Disable RTC updates and interrupts. */ 517 rtcout_locked(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 518 519 /* Write all the time registers. */ 520 rtcout_locked(RTC_SEC, bct.sec); 521 rtcout_locked(RTC_MIN, bct.min); 522 rtcout_locked(RTC_HRS, bct.hour); 523 rtcout_locked(RTC_WDAY, bct.dow + 1); 524 rtcout_locked(RTC_DAY, bct.day); 525 rtcout_locked(RTC_MONTH, bct.mon); 526 rtcout_locked(RTC_YEAR, bct.year & 0xff); 527#ifdef USE_RTC_CENTURY 528 rtcout_locked(RTC_CENTURY, bct.year >> 8); 529#endif 530 531 /* 532 * Re-enable RTC updates and interrupts. 533 */ 534 rtcout_locked(RTC_STATUSB, rtc_statusb); 535 rtcin_locked(RTC_INTR); 536 537 mtx_unlock_spin(&atrtc_lock); 538 mtx_unlock(&atrtc_time_lock); 539 540 return (0); 541} 542 543static int 544atrtc_gettime(device_t dev, struct timespec *ts) 545{ 546 struct bcd_clocktime bct; 547 548 /* Look if we have a RTC present and the time is valid */ 549 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) { 550 device_printf(dev, "WARNING: Battery failure indication\n"); 551 return (EINVAL); 552 } 553 554 /* 555 * wait for time update to complete 556 * If RTCSA_TUP is zero, we have at least 244us before next update. 557 * This is fast enough on most hardware, but a refinement would be 558 * to make sure that no more than 240us pass after we start reading, 559 * and try again if so. 560 */ 561 mtx_lock(&atrtc_time_lock); 562 while (rtcin(RTC_STATUSA) & RTCSA_TUP) 563 continue; 564 mtx_lock_spin(&atrtc_lock); 565 bct.sec = rtcin_locked(RTC_SEC); 566 bct.min = rtcin_locked(RTC_MIN); 567 bct.hour = rtcin_locked(RTC_HRS); 568 bct.day = rtcin_locked(RTC_DAY); 569 bct.mon = rtcin_locked(RTC_MONTH); 570 bct.year = rtcin_locked(RTC_YEAR); 571#ifdef USE_RTC_CENTURY 572 bct.year |= rtcin_locked(RTC_CENTURY) << 8; 573#endif 574 mtx_unlock_spin(&atrtc_lock); 575 mtx_unlock(&atrtc_time_lock); 576 /* dow is unused in timespec conversion and we have no nsec info. */ 577 bct.dow = 0; 578 bct.nsec = 0; 579 clock_dbgprint_bcd(dev, CLOCK_DBG_READ, &bct); 580 return (clock_bcd_to_ts(&bct, ts, false)); 581} 582 583static device_method_t atrtc_isa_methods[] = { 584 /* Device interface */ 585 DEVMETHOD(device_probe, atrtc_probe), 586 DEVMETHOD(device_attach, atrtc_isa_attach), 587 DEVMETHOD(device_detach, bus_generic_detach), 588 DEVMETHOD(device_shutdown, bus_generic_shutdown), 589 DEVMETHOD(device_suspend, bus_generic_suspend), 590 /* XXX stop statclock? */ 591 DEVMETHOD(device_resume, atrtc_resume), 592 593 /* clock interface */ 594 DEVMETHOD(clock_gettime, atrtc_gettime), 595 DEVMETHOD(clock_settime, atrtc_settime), 596 597 { 0, 0 } 598}; 599 600static driver_t atrtc_isa_driver = { 601 "atrtc", 602 atrtc_isa_methods, 603 sizeof(struct atrtc_softc), 604}; 605 606#ifdef DEV_ACPI 607static device_method_t atrtc_acpi_methods[] = { 608 /* Device interface */ 609 DEVMETHOD(device_probe, atrtc_probe), 610 DEVMETHOD(device_attach, atrtc_acpi_attach), 611 DEVMETHOD(device_detach, atrtc_acpi_detach), 612 /* XXX stop statclock? */ 613 DEVMETHOD(device_resume, atrtc_resume), 614 615 /* clock interface */ 616 DEVMETHOD(clock_gettime, atrtc_gettime), 617 DEVMETHOD(clock_settime, atrtc_settime), 618 619 { 0, 0 } 620}; 621 622static driver_t atrtc_acpi_driver = { 623 "atrtc", 624 atrtc_acpi_methods, 625 sizeof(struct atrtc_softc), 626}; 627#endif /* DEV_ACPI */ 628 629static devclass_t atrtc_devclass; 630 631DRIVER_MODULE(atrtc, isa, atrtc_isa_driver, atrtc_devclass, 0, 0); 632#ifdef DEV_ACPI 633DRIVER_MODULE(atrtc, acpi, atrtc_acpi_driver, atrtc_devclass, 0, 0); 634#endif 635