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 * $FreeBSD$ 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_isa.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/bus.h> 38 #include <sys/clock.h> 39 #include <sys/lock.h> 40 #include <sys/mutex.h> 41 #include <sys/kdb.h> 42 #include <sys/kernel.h> 43 #include <sys/module.h> 44 #include <sys/proc.h> 45 #include <sys/rman.h> 46 #include <sys/timeet.h> 47 48 #include <isa/rtc.h> 49 #ifdef DEV_ISA 50 #include <isa/isareg.h> 51 #include <isa/isavar.h> 52 #endif 53 #include <machine/intr_machdep.h> 54 #include "clock_if.h" 55 56 /* 57 * clock_lock protects low-level access to individual hardware registers. 58 * atrtc_time_lock protects the entire sequence of accessing multiple registers 59 * to read or write the date and time. 60 */ 61 #define RTC_LOCK do { if (!kdb_active) mtx_lock_spin(&clock_lock); } while (0) 62 #define RTC_UNLOCK do { if (!kdb_active) mtx_unlock_spin(&clock_lock); } while (0) 63 64 struct mtx atrtc_time_lock; 65 MTX_SYSINIT(atrtc_lock_init, &atrtc_time_lock, "atrtc", MTX_DEF); 66 67 int atrtcclock_disable = 0; 68 69 static int rtc_reg = -1; 70 static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 71 static u_char rtc_statusb = RTCSB_24HR; 72 73 /* 74 * RTC support routines 75 */ 76 77 int 78 rtcin(int reg) 79 { 80 u_char val; 81 82 RTC_LOCK; 83 if (rtc_reg != reg) { 84 inb(0x84); 85 outb(IO_RTC, reg); 86 rtc_reg = reg; 87 inb(0x84); 88 } 89 val = inb(IO_RTC + 1); 90 RTC_UNLOCK; 91 return (val); 92 } 93 94 void 95 writertc(int reg, u_char val) 96 { 97 98 RTC_LOCK; 99 if (rtc_reg != reg) { 100 inb(0x84); 101 outb(IO_RTC, reg); 102 rtc_reg = reg; 103 inb(0x84); 104 } 105 outb(IO_RTC + 1, val); 106 inb(0x84); 107 RTC_UNLOCK; 108 } 109 110 static __inline int 111 readrtc(int port) 112 { 113 int readval; 114 115 readval = rtcin(port); 116 if (readval >= 0 && (readval & 0xf) < 0xa && (readval & 0xf0) < 0xa0) 117 return (bcd2bin(readval)); 118 return (0); 119 } 120 121 static void 122 atrtc_start(void) 123 { 124 125 writertc(RTC_STATUSA, rtc_statusa); 126 writertc(RTC_STATUSB, RTCSB_24HR); 127 } 128 129 static void 130 atrtc_rate(unsigned rate) 131 { 132 133 rtc_statusa = RTCSA_DIVIDER | rate; 134 writertc(RTC_STATUSA, rtc_statusa); 135 } 136 137 static void 138 atrtc_enable_intr(void) 139 { 140 141 rtc_statusb |= RTCSB_PINTR; 142 writertc(RTC_STATUSB, rtc_statusb); 143 rtcin(RTC_INTR); 144 } 145 146 static void 147 atrtc_disable_intr(void) 148 { 149 150 rtc_statusb &= ~RTCSB_PINTR; 151 writertc(RTC_STATUSB, rtc_statusb); 152 rtcin(RTC_INTR); 153 } 154 155 void 156 atrtc_restore(void) 157 { 158 159 /* Restore all of the RTC's "status" (actually, control) registers. */ 160 rtcin(RTC_STATUSA); /* dummy to get rtc_reg set */ 161 writertc(RTC_STATUSB, RTCSB_24HR); 162 writertc(RTC_STATUSA, rtc_statusa); 163 writertc(RTC_STATUSB, rtc_statusb); 164 rtcin(RTC_INTR); 165 } 166 167 void 168 atrtc_set(struct timespec *ts) 169 { 170 struct clocktime ct; 171 172 clock_ts_to_ct(ts, &ct); 173 174 mtx_lock(&atrtc_time_lock); 175 176 /* Disable RTC updates and interrupts. */ 177 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 178 179 writertc(RTC_SEC, bin2bcd(ct.sec)); /* Write back Seconds */ 180 writertc(RTC_MIN, bin2bcd(ct.min)); /* Write back Minutes */ 181 writertc(RTC_HRS, bin2bcd(ct.hour)); /* Write back Hours */ 182 183 writertc(RTC_WDAY, ct.dow + 1); /* Write back Weekday */ 184 writertc(RTC_DAY, bin2bcd(ct.day)); /* Write back Day */ 185 writertc(RTC_MONTH, bin2bcd(ct.mon)); /* Write back Month */ 186 writertc(RTC_YEAR, bin2bcd(ct.year % 100)); /* Write back Year */ 187 #ifdef USE_RTC_CENTURY 188 writertc(RTC_CENTURY, bin2bcd(ct.year / 100)); /* ... and Century */ 189 #endif 190 191 /* Re-enable RTC updates and interrupts. */ 192 writertc(RTC_STATUSB, rtc_statusb); 193 rtcin(RTC_INTR); 194 195 mtx_unlock(&atrtc_time_lock); 196 } 197 198 /********************************************************************** 199 * RTC driver for subr_rtc 200 */ 201 202 struct atrtc_softc { 203 int port_rid, intr_rid; 204 struct resource *port_res; 205 struct resource *intr_res; 206 void *intr_handler; 207 struct eventtimer et; 208 }; 209 210 static int 211 rtc_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 212 { 213 214 atrtc_rate(max(fls(period + (period >> 1)) - 17, 1)); 215 atrtc_enable_intr(); 216 return (0); 217 } 218 219 static int 220 rtc_stop(struct eventtimer *et) 221 { 222 223 atrtc_disable_intr(); 224 return (0); 225 } 226 227 /* 228 * This routine receives statistical clock interrupts from the RTC. 229 * As explained above, these occur at 128 interrupts per second. 230 * When profiling, we receive interrupts at a rate of 1024 Hz. 231 * 232 * This does not actually add as much overhead as it sounds, because 233 * when the statistical clock is active, the hardclock driver no longer 234 * needs to keep (inaccurate) statistics on its own. This decouples 235 * statistics gathering from scheduling interrupts. 236 * 237 * The RTC chip requires that we read status register C (RTC_INTR) 238 * to acknowledge an interrupt, before it will generate the next one. 239 * Under high interrupt load, rtcintr() can be indefinitely delayed and 240 * the clock can tick immediately after the read from RTC_INTR. In this 241 * case, the mc146818A interrupt signal will not drop for long enough 242 * to register with the 8259 PIC. If an interrupt is missed, the stat 243 * clock will halt, considerably degrading system performance. This is 244 * why we use 'while' rather than a more straightforward 'if' below. 245 * Stat clock ticks can still be lost, causing minor loss of accuracy 246 * in the statistics, but the stat clock will no longer stop. 247 */ 248 static int 249 rtc_intr(void *arg) 250 { 251 struct atrtc_softc *sc = (struct atrtc_softc *)arg; 252 int flag = 0; 253 254 while (rtcin(RTC_INTR) & RTCIR_PERIOD) { 255 flag = 1; 256 if (sc->et.et_active) 257 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 258 } 259 return(flag ? FILTER_HANDLED : FILTER_STRAY); 260 } 261 262 /* 263 * Attach to the ISA PnP descriptors for the timer and realtime clock. 264 */ 265 static struct isa_pnp_id atrtc_ids[] = { 266 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 267 { 0 } 268 }; 269 270 static int 271 atrtc_probe(device_t dev) 272 { 273 int result; 274 275 result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids); 276 /* ENOENT means no PnP-ID, device is hinted. */ 277 if (result == ENOENT) { 278 device_set_desc(dev, "AT realtime clock"); 279 return (BUS_PROBE_LOW_PRIORITY); 280 } 281 return (result); 282 } 283 284 static int 285 atrtc_attach(device_t dev) 286 { 287 struct atrtc_softc *sc; 288 rman_res_t s; 289 int i; 290 291 sc = device_get_softc(dev); 292 sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid, 293 IO_RTC, IO_RTC + 1, 2, RF_ACTIVE); 294 if (sc->port_res == NULL) 295 device_printf(dev, "Warning: Couldn't map I/O.\n"); 296 atrtc_start(); 297 clock_register(dev, 1000000); 298 bzero(&sc->et, sizeof(struct eventtimer)); 299 if (!atrtcclock_disable && 300 (resource_int_value(device_get_name(dev), device_get_unit(dev), 301 "clock", &i) != 0 || i != 0)) { 302 sc->intr_rid = 0; 303 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 304 &s, NULL) == 0 && s != 8) 305 sc->intr_rid++; 306 sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 307 &sc->intr_rid, 8, 8, 1, RF_ACTIVE); 308 if (sc->intr_res == NULL) { 309 device_printf(dev, "Can't map interrupt.\n"); 310 return (0); 311 } else if ((bus_setup_intr(dev, sc->intr_res, INTR_TYPE_CLK, 312 rtc_intr, NULL, sc, &sc->intr_handler))) { 313 device_printf(dev, "Can't setup interrupt.\n"); 314 return (0); 315 } else { 316 /* Bind IRQ to BSP to avoid live migration. */ 317 bus_bind_intr(dev, sc->intr_res, 0); 318 } 319 sc->et.et_name = "RTC"; 320 sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_POW2DIV; 321 sc->et.et_quality = 0; 322 sc->et.et_frequency = 32768; 323 sc->et.et_min_period = 0x00080000; 324 sc->et.et_max_period = 0x80000000; 325 sc->et.et_start = rtc_start; 326 sc->et.et_stop = rtc_stop; 327 sc->et.et_priv = dev; 328 et_register(&sc->et); 329 } 330 return(0); 331 } 332 333 static int 334 atrtc_resume(device_t dev) 335 { 336 337 atrtc_restore(); 338 return(0); 339 } 340 341 static int 342 atrtc_settime(device_t dev __unused, struct timespec *ts) 343 { 344 345 atrtc_set(ts); 346 return (0); 347 } 348 349 static int 350 atrtc_gettime(device_t dev, struct timespec *ts) 351 { 352 struct clocktime ct; 353 354 /* Look if we have a RTC present and the time is valid */ 355 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) { 356 device_printf(dev, "WARNING: Battery failure indication\n"); 357 return (EINVAL); 358 } 359 360 /* 361 * wait for time update to complete 362 * If RTCSA_TUP is zero, we have at least 244us before next update. 363 * This is fast enough on most hardware, but a refinement would be 364 * to make sure that no more than 240us pass after we start reading, 365 * and try again if so. 366 */ 367 mtx_lock(&atrtc_time_lock); 368 while (rtcin(RTC_STATUSA) & RTCSA_TUP) 369 continue; 370 critical_enter(); 371 ct.nsec = 0; 372 ct.sec = readrtc(RTC_SEC); 373 ct.min = readrtc(RTC_MIN); 374 ct.hour = readrtc(RTC_HRS); 375 ct.day = readrtc(RTC_DAY); 376 ct.dow = readrtc(RTC_WDAY) - 1; 377 ct.mon = readrtc(RTC_MONTH); 378 ct.year = readrtc(RTC_YEAR); 379 #ifdef USE_RTC_CENTURY 380 ct.year += readrtc(RTC_CENTURY) * 100; 381 #else 382 ct.year += (ct.year < 80 ? 2000 : 1900); 383 #endif 384 critical_exit(); 385 mtx_unlock(&atrtc_time_lock); 386 /* Set dow = -1 because some clocks don't set it correctly. */ 387 ct.dow = -1; 388 return (clock_ct_to_ts(&ct, ts)); 389 } 390 391 static device_method_t atrtc_methods[] = { 392 /* Device interface */ 393 DEVMETHOD(device_probe, atrtc_probe), 394 DEVMETHOD(device_attach, atrtc_attach), 395 DEVMETHOD(device_detach, bus_generic_detach), 396 DEVMETHOD(device_shutdown, bus_generic_shutdown), 397 DEVMETHOD(device_suspend, bus_generic_suspend), 398 /* XXX stop statclock? */ 399 DEVMETHOD(device_resume, atrtc_resume), 400 401 /* clock interface */ 402 DEVMETHOD(clock_gettime, atrtc_gettime), 403 DEVMETHOD(clock_settime, atrtc_settime), 404 405 { 0, 0 } 406 }; 407 408 static driver_t atrtc_driver = { 409 "atrtc", 410 atrtc_methods, 411 sizeof(struct atrtc_softc), 412 }; 413 414 static devclass_t atrtc_devclass; 415 416 DRIVER_MODULE(atrtc, isa, atrtc_driver, atrtc_devclass, 0, 0); 417 DRIVER_MODULE(atrtc, acpi, atrtc_driver, atrtc_devclass, 0, 0); 418 419 #include "opt_ddb.h" 420 #ifdef DDB 421 #include <ddb/ddb.h> 422 423 DB_SHOW_COMMAND(rtc, rtc) 424 { 425 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n", 426 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY), 427 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC), 428 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR)); 429 } 430 #endif /* DDB */ 431