1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990 The Regents of the University of California. 5 * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org> 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * William Jolitz and Don Ahn. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: @(#)clock.c 7.2 (Berkeley) 5/12/91 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 /* 42 * Routines to handle clock hardware. 43 */ 44 45 #include "opt_clock.h" 46 #include "opt_isa.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/bus.h> 51 #include <sys/lock.h> 52 #include <sys/kdb.h> 53 #include <sys/mutex.h> 54 #include <sys/proc.h> 55 #include <sys/kernel.h> 56 #include <sys/module.h> 57 #include <sys/rman.h> 58 #include <sys/sched.h> 59 #include <sys/smp.h> 60 #include <sys/sysctl.h> 61 #include <sys/timeet.h> 62 #include <sys/timetc.h> 63 64 #include <machine/clock.h> 65 #include <machine/cpu.h> 66 #include <machine/intr_machdep.h> 67 #include <machine/ppireg.h> 68 #include <machine/timerreg.h> 69 #include <x86/init.h> 70 71 #include <isa/rtc.h> 72 #ifdef DEV_ISA 73 #include <isa/isareg.h> 74 #include <isa/isavar.h> 75 #endif 76 77 int clkintr_pending; 78 #ifndef TIMER_FREQ 79 #define TIMER_FREQ 1193182 80 #endif 81 u_int i8254_freq = TIMER_FREQ; 82 TUNABLE_INT("hw.i8254.freq", &i8254_freq); 83 int i8254_max_count; 84 static int i8254_timecounter = 1; 85 86 static struct mtx clock_lock; 87 static struct intsrc *i8254_intsrc; 88 static uint16_t i8254_lastcount; 89 static uint16_t i8254_offset; 90 static int (*i8254_pending)(struct intsrc *); 91 static int i8254_ticked; 92 93 struct attimer_softc { 94 int intr_en; 95 int port_rid, intr_rid; 96 struct resource *port_res; 97 struct resource *intr_res; 98 void *intr_handler; 99 struct timecounter tc; 100 struct eventtimer et; 101 int mode; 102 #define MODE_STOP 0 103 #define MODE_PERIODIC 1 104 #define MODE_ONESHOT 2 105 uint32_t period; 106 }; 107 static struct attimer_softc *attimer_sc = NULL; 108 109 static int timer0_period = -2; 110 static int timer0_mode = 0xffff; 111 static int timer0_last = 0xffff; 112 113 /* Values for timerX_state: */ 114 #define RELEASED 0 115 #define RELEASE_PENDING 1 116 #define ACQUIRED 2 117 #define ACQUIRE_PENDING 3 118 119 static u_char timer2_state; 120 121 static unsigned i8254_get_timecount(struct timecounter *tc); 122 static void set_i8254_freq(int mode, uint32_t period); 123 124 void 125 clock_init(void) 126 { 127 /* Init the clock lock */ 128 mtx_init(&clock_lock, "clk", NULL, MTX_SPIN | MTX_NOPROFILE); 129 /* Init the clock in order to use DELAY */ 130 init_ops.early_clock_source_init(); 131 } 132 133 static int 134 clkintr(void *arg) 135 { 136 struct attimer_softc *sc = (struct attimer_softc *)arg; 137 138 if (i8254_timecounter && sc->period != 0) { 139 mtx_lock_spin(&clock_lock); 140 if (i8254_ticked) 141 i8254_ticked = 0; 142 else { 143 i8254_offset += i8254_max_count; 144 i8254_lastcount = 0; 145 } 146 clkintr_pending = 0; 147 mtx_unlock_spin(&clock_lock); 148 } 149 150 if (sc->et.et_active && sc->mode != MODE_STOP) 151 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 152 153 return (FILTER_HANDLED); 154 } 155 156 int 157 timer_spkr_acquire(void) 158 { 159 int mode; 160 161 mode = TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT; 162 163 if (timer2_state != RELEASED) 164 return (-1); 165 timer2_state = ACQUIRED; 166 167 /* 168 * This access to the timer registers is as atomic as possible 169 * because it is a single instruction. We could do better if we 170 * knew the rate. Use of splclock() limits glitches to 10-100us, 171 * and this is probably good enough for timer2, so we aren't as 172 * careful with it as with timer0. 173 */ 174 outb(TIMER_MODE, TIMER_SEL2 | (mode & 0x3f)); 175 176 ppi_spkr_on(); /* enable counter2 output to speaker */ 177 return (0); 178 } 179 180 int 181 timer_spkr_release(void) 182 { 183 184 if (timer2_state != ACQUIRED) 185 return (-1); 186 timer2_state = RELEASED; 187 outb(TIMER_MODE, TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT); 188 189 ppi_spkr_off(); /* disable counter2 output to speaker */ 190 return (0); 191 } 192 193 void 194 timer_spkr_setfreq(int freq) 195 { 196 197 freq = i8254_freq / freq; 198 mtx_lock_spin(&clock_lock); 199 outb(TIMER_CNTR2, freq & 0xff); 200 outb(TIMER_CNTR2, freq >> 8); 201 mtx_unlock_spin(&clock_lock); 202 } 203 204 static int 205 getit(void) 206 { 207 int high, low; 208 209 mtx_lock_spin(&clock_lock); 210 211 /* Select timer0 and latch counter value. */ 212 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 213 214 low = inb(TIMER_CNTR0); 215 high = inb(TIMER_CNTR0); 216 217 mtx_unlock_spin(&clock_lock); 218 return ((high << 8) | low); 219 } 220 221 /* 222 * Wait "n" microseconds. 223 * Relies on timer 1 counting down from (i8254_freq / hz) 224 * Note: timer had better have been programmed before this is first used! 225 */ 226 void 227 i8254_delay(int n) 228 { 229 int delta, prev_tick, tick, ticks_left; 230 #ifdef DELAYDEBUG 231 int getit_calls = 1; 232 int n1; 233 static int state = 0; 234 235 if (state == 0) { 236 state = 1; 237 for (n1 = 1; n1 <= 10000000; n1 *= 10) 238 DELAY(n1); 239 state = 2; 240 } 241 if (state == 1) 242 printf("DELAY(%d)...", n); 243 #endif 244 /* 245 * Read the counter first, so that the rest of the setup overhead is 246 * counted. Guess the initial overhead is 20 usec (on most systems it 247 * takes about 1.5 usec for each of the i/o's in getit(). The loop 248 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The 249 * multiplications and divisions to scale the count take a while). 250 * 251 * However, if ddb is active then use a fake counter since reading 252 * the i8254 counter involves acquiring a lock. ddb must not do 253 * locking for many reasons, but it calls here for at least atkbd 254 * input. 255 */ 256 #ifdef KDB 257 if (kdb_active) 258 prev_tick = 1; 259 else 260 #endif 261 prev_tick = getit(); 262 n -= 0; /* XXX actually guess no initial overhead */ 263 /* 264 * Calculate (n * (i8254_freq / 1e6)) without using floating point 265 * and without any avoidable overflows. 266 */ 267 if (n <= 0) 268 ticks_left = 0; 269 else if (n < 256) 270 /* 271 * Use fixed point to avoid a slow division by 1000000. 272 * 39099 = 1193182 * 2^15 / 10^6 rounded to nearest. 273 * 2^15 is the first power of 2 that gives exact results 274 * for n between 0 and 256. 275 */ 276 ticks_left = ((u_int)n * 39099 + (1 << 15) - 1) >> 15; 277 else 278 /* 279 * Don't bother using fixed point, although gcc-2.7.2 280 * generates particularly poor code for the long long 281 * division, since even the slow way will complete long 282 * before the delay is up (unless we're interrupted). 283 */ 284 ticks_left = ((u_int)n * (long long)i8254_freq + 999999) 285 / 1000000; 286 287 while (ticks_left > 0) { 288 #ifdef KDB 289 if (kdb_active) { 290 inb(0x84); 291 tick = prev_tick - 1; 292 if (tick <= 0) 293 tick = i8254_max_count; 294 } else 295 #endif 296 tick = getit(); 297 #ifdef DELAYDEBUG 298 ++getit_calls; 299 #endif 300 delta = prev_tick - tick; 301 prev_tick = tick; 302 if (delta < 0) { 303 delta += i8254_max_count; 304 /* 305 * Guard against i8254_max_count being wrong. 306 * This shouldn't happen in normal operation, 307 * but it may happen if set_i8254_freq() is 308 * traced. 309 */ 310 if (delta < 0) 311 delta = 0; 312 } 313 ticks_left -= delta; 314 } 315 #ifdef DELAYDEBUG 316 if (state == 1) 317 printf(" %d calls to getit() at %d usec each\n", 318 getit_calls, (n + 5) / getit_calls); 319 #endif 320 } 321 322 static void 323 set_i8254_freq(int mode, uint32_t period) 324 { 325 int new_count, new_mode; 326 327 mtx_lock_spin(&clock_lock); 328 if (mode == MODE_STOP) { 329 if (i8254_timecounter) { 330 mode = MODE_PERIODIC; 331 new_count = 0x10000; 332 } else 333 new_count = -1; 334 } else { 335 new_count = min(((uint64_t)i8254_freq * period + 336 0x80000000LLU) >> 32, 0x10000); 337 } 338 if (new_count == timer0_period) 339 goto out; 340 i8254_max_count = ((new_count & ~0xffff) != 0) ? 0xffff : new_count; 341 timer0_period = (mode == MODE_PERIODIC) ? new_count : -1; 342 switch (mode) { 343 case MODE_STOP: 344 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT; 345 outb(TIMER_MODE, new_mode); 346 outb(TIMER_CNTR0, 0); 347 outb(TIMER_CNTR0, 0); 348 break; 349 case MODE_PERIODIC: 350 new_mode = TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT; 351 outb(TIMER_MODE, new_mode); 352 outb(TIMER_CNTR0, new_count & 0xff); 353 outb(TIMER_CNTR0, new_count >> 8); 354 break; 355 case MODE_ONESHOT: 356 if (new_count < 256 && timer0_last < 256) { 357 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_LSB; 358 if (new_mode != timer0_mode) 359 outb(TIMER_MODE, new_mode); 360 outb(TIMER_CNTR0, new_count & 0xff); 361 break; 362 } 363 new_mode = TIMER_SEL0 | TIMER_INTTC | TIMER_16BIT; 364 if (new_mode != timer0_mode) 365 outb(TIMER_MODE, new_mode); 366 outb(TIMER_CNTR0, new_count & 0xff); 367 outb(TIMER_CNTR0, new_count >> 8); 368 break; 369 default: 370 panic("set_i8254_freq: unknown operational mode"); 371 } 372 timer0_mode = new_mode; 373 timer0_last = new_count; 374 out: 375 mtx_unlock_spin(&clock_lock); 376 } 377 378 static void 379 i8254_restore(void) 380 { 381 382 timer0_period = -2; 383 timer0_mode = 0xffff; 384 timer0_last = 0xffff; 385 if (attimer_sc != NULL) 386 set_i8254_freq(attimer_sc->mode, attimer_sc->period); 387 else 388 set_i8254_freq(MODE_STOP, 0); 389 } 390 391 #ifndef __amd64__ 392 /* 393 * Restore all the timers non-atomically (XXX: should be atomically). 394 * 395 * This function is called from pmtimer_resume() to restore all the timers. 396 * This should not be necessary, but there are broken laptops that do not 397 * restore all the timers on resume. The APM spec was at best vague on the 398 * subject. 399 * pmtimer is used only with the old APM power management, and not with 400 * acpi, which is required for amd64, so skip it in that case. 401 */ 402 void 403 timer_restore(void) 404 { 405 406 i8254_restore(); /* restore i8254_freq and hz */ 407 atrtc_restore(); /* reenable RTC interrupts */ 408 } 409 #endif 410 411 /* This is separate from startrtclock() so that it can be called early. */ 412 void 413 i8254_init(void) 414 { 415 416 set_i8254_freq(MODE_STOP, 0); 417 } 418 419 void 420 startrtclock() 421 { 422 423 init_TSC(); 424 } 425 426 void 427 cpu_initclocks(void) 428 { 429 #ifdef EARLY_AP_STARTUP 430 struct thread *td; 431 int i; 432 433 td = curthread; 434 cpu_initclocks_bsp(); 435 CPU_FOREACH(i) { 436 if (i == 0) 437 continue; 438 thread_lock(td); 439 sched_bind(td, i); 440 thread_unlock(td); 441 cpu_initclocks_ap(); 442 } 443 thread_lock(td); 444 if (sched_is_bound(td)) 445 sched_unbind(td); 446 thread_unlock(td); 447 #else 448 cpu_initclocks_bsp(); 449 #endif 450 } 451 452 static int 453 sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS) 454 { 455 int error; 456 u_int freq; 457 458 /* 459 * Use `i8254' instead of `timer' in external names because `timer' 460 * is too generic. Should use it everywhere. 461 */ 462 freq = i8254_freq; 463 error = sysctl_handle_int(oidp, &freq, 0, req); 464 if (error == 0 && req->newptr != NULL) { 465 i8254_freq = freq; 466 if (attimer_sc != NULL) { 467 set_i8254_freq(attimer_sc->mode, attimer_sc->period); 468 attimer_sc->tc.tc_frequency = freq; 469 } else { 470 set_i8254_freq(MODE_STOP, 0); 471 } 472 } 473 return (error); 474 } 475 476 SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW, 477 0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", 478 "i8254 timer frequency"); 479 480 static unsigned 481 i8254_get_timecount(struct timecounter *tc) 482 { 483 device_t dev = (device_t)tc->tc_priv; 484 struct attimer_softc *sc = device_get_softc(dev); 485 register_t flags; 486 uint16_t count; 487 u_int high, low; 488 489 if (sc->period == 0) 490 return (i8254_max_count - getit()); 491 492 #ifdef __amd64__ 493 flags = read_rflags(); 494 #else 495 flags = read_eflags(); 496 #endif 497 mtx_lock_spin(&clock_lock); 498 499 /* Select timer0 and latch counter value. */ 500 outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); 501 502 low = inb(TIMER_CNTR0); 503 high = inb(TIMER_CNTR0); 504 count = i8254_max_count - ((high << 8) | low); 505 if (count < i8254_lastcount || 506 (!i8254_ticked && (clkintr_pending || 507 ((count < 20 || (!(flags & PSL_I) && 508 count < i8254_max_count / 2u)) && 509 i8254_pending != NULL && i8254_pending(i8254_intsrc))))) { 510 i8254_ticked = 1; 511 i8254_offset += i8254_max_count; 512 } 513 i8254_lastcount = count; 514 count += i8254_offset; 515 mtx_unlock_spin(&clock_lock); 516 return (count); 517 } 518 519 static int 520 attimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 521 { 522 device_t dev = (device_t)et->et_priv; 523 struct attimer_softc *sc = device_get_softc(dev); 524 525 if (period != 0) { 526 sc->mode = MODE_PERIODIC; 527 sc->period = period; 528 } else { 529 sc->mode = MODE_ONESHOT; 530 sc->period = first; 531 } 532 if (!sc->intr_en) { 533 i8254_intsrc->is_pic->pic_enable_source(i8254_intsrc); 534 sc->intr_en = 1; 535 } 536 set_i8254_freq(sc->mode, sc->period); 537 return (0); 538 } 539 540 static int 541 attimer_stop(struct eventtimer *et) 542 { 543 device_t dev = (device_t)et->et_priv; 544 struct attimer_softc *sc = device_get_softc(dev); 545 546 sc->mode = MODE_STOP; 547 sc->period = 0; 548 set_i8254_freq(sc->mode, sc->period); 549 return (0); 550 } 551 552 #ifdef DEV_ISA 553 /* 554 * Attach to the ISA PnP descriptors for the timer 555 */ 556 static struct isa_pnp_id attimer_ids[] = { 557 { 0x0001d041 /* PNP0100 */, "AT timer" }, 558 { 0 } 559 }; 560 561 static int 562 attimer_probe(device_t dev) 563 { 564 int result; 565 566 result = ISA_PNP_PROBE(device_get_parent(dev), dev, attimer_ids); 567 /* ENOENT means no PnP-ID, device is hinted. */ 568 if (result == ENOENT) { 569 device_set_desc(dev, "AT timer"); 570 return (BUS_PROBE_LOW_PRIORITY); 571 } 572 return (result); 573 } 574 575 static int 576 attimer_attach(device_t dev) 577 { 578 struct attimer_softc *sc; 579 rman_res_t s; 580 int i; 581 582 attimer_sc = sc = device_get_softc(dev); 583 bzero(sc, sizeof(struct attimer_softc)); 584 if (!(sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, 585 &sc->port_rid, IO_TIMER1, IO_TIMER1 + 3, 4, RF_ACTIVE))) 586 device_printf(dev,"Warning: Couldn't map I/O.\n"); 587 i8254_intsrc = intr_lookup_source(0); 588 if (i8254_intsrc != NULL) 589 i8254_pending = i8254_intsrc->is_pic->pic_source_pending; 590 resource_int_value(device_get_name(dev), device_get_unit(dev), 591 "timecounter", &i8254_timecounter); 592 set_i8254_freq(MODE_STOP, 0); 593 if (i8254_timecounter) { 594 sc->tc.tc_get_timecount = i8254_get_timecount; 595 sc->tc.tc_counter_mask = 0xffff; 596 sc->tc.tc_frequency = i8254_freq; 597 sc->tc.tc_name = "i8254"; 598 sc->tc.tc_quality = 0; 599 sc->tc.tc_priv = dev; 600 tc_init(&sc->tc); 601 } 602 if (resource_int_value(device_get_name(dev), device_get_unit(dev), 603 "clock", &i) != 0 || i != 0) { 604 sc->intr_rid = 0; 605 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 606 &s, NULL) == 0 && s != 0) 607 sc->intr_rid++; 608 if (!(sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 609 &sc->intr_rid, 0, 0, 1, RF_ACTIVE))) { 610 device_printf(dev,"Can't map interrupt.\n"); 611 return (0); 612 } 613 /* Dirty hack, to make bus_setup_intr to not enable source. */ 614 i8254_intsrc->is_handlers++; 615 if ((bus_setup_intr(dev, sc->intr_res, 616 INTR_MPSAFE | INTR_TYPE_CLK, 617 (driver_filter_t *)clkintr, NULL, 618 sc, &sc->intr_handler))) { 619 device_printf(dev, "Can't setup interrupt.\n"); 620 i8254_intsrc->is_handlers--; 621 return (0); 622 } 623 i8254_intsrc->is_handlers--; 624 i8254_intsrc->is_pic->pic_enable_intr(i8254_intsrc); 625 sc->et.et_name = "i8254"; 626 sc->et.et_flags = ET_FLAGS_PERIODIC; 627 if (!i8254_timecounter) 628 sc->et.et_flags |= ET_FLAGS_ONESHOT; 629 sc->et.et_quality = 100; 630 sc->et.et_frequency = i8254_freq; 631 sc->et.et_min_period = (0x0002LLU << 32) / i8254_freq; 632 sc->et.et_max_period = (0xfffeLLU << 32) / i8254_freq; 633 sc->et.et_start = attimer_start; 634 sc->et.et_stop = attimer_stop; 635 sc->et.et_priv = dev; 636 et_register(&sc->et); 637 } 638 return(0); 639 } 640 641 static int 642 attimer_resume(device_t dev) 643 { 644 645 i8254_restore(); 646 return (0); 647 } 648 649 static device_method_t attimer_methods[] = { 650 /* Device interface */ 651 DEVMETHOD(device_probe, attimer_probe), 652 DEVMETHOD(device_attach, attimer_attach), 653 DEVMETHOD(device_detach, bus_generic_detach), 654 DEVMETHOD(device_shutdown, bus_generic_shutdown), 655 DEVMETHOD(device_suspend, bus_generic_suspend), 656 DEVMETHOD(device_resume, attimer_resume), 657 { 0, 0 } 658 }; 659 660 static driver_t attimer_driver = { 661 "attimer", 662 attimer_methods, 663 sizeof(struct attimer_softc), 664 }; 665 666 static devclass_t attimer_devclass; 667 668 DRIVER_MODULE(attimer, isa, attimer_driver, attimer_devclass, 0, 0); 669 DRIVER_MODULE(attimer, acpi, attimer_driver, attimer_devclass, 0, 0); 670 ISA_PNP_INFO(attimer_ids); 671 672 #endif /* DEV_ISA */ 673