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 #define RTC_LOCK do { if (!kdb_active) mtx_lock_spin(&clock_lock); } while (0) 57 #define RTC_UNLOCK do { if (!kdb_active) mtx_unlock_spin(&clock_lock); } while (0) 58 59 int atrtcclock_disable = 0; 60 61 static int rtc_reg = -1; 62 static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF; 63 static u_char rtc_statusb = RTCSB_24HR; 64 65 /* 66 * RTC support routines 67 */ 68 69 int 70 rtcin(int reg) 71 { 72 u_char val; 73 74 RTC_LOCK; 75 if (rtc_reg != reg) { 76 inb(0x84); 77 outb(IO_RTC, reg); 78 rtc_reg = reg; 79 inb(0x84); 80 } 81 val = inb(IO_RTC + 1); 82 RTC_UNLOCK; 83 return (val); 84 } 85 86 void 87 writertc(int reg, u_char val) 88 { 89 90 RTC_LOCK; 91 if (rtc_reg != reg) { 92 inb(0x84); 93 outb(IO_RTC, reg); 94 rtc_reg = reg; 95 inb(0x84); 96 } 97 outb(IO_RTC + 1, val); 98 inb(0x84); 99 RTC_UNLOCK; 100 } 101 102 static __inline int 103 readrtc(int port) 104 { 105 return(bcd2bin(rtcin(port))); 106 } 107 108 static void 109 atrtc_start(void) 110 { 111 112 writertc(RTC_STATUSA, rtc_statusa); 113 writertc(RTC_STATUSB, RTCSB_24HR); 114 } 115 116 static void 117 atrtc_rate(unsigned rate) 118 { 119 120 rtc_statusa = RTCSA_DIVIDER | rate; 121 writertc(RTC_STATUSA, rtc_statusa); 122 } 123 124 static void 125 atrtc_enable_intr(void) 126 { 127 128 rtc_statusb |= RTCSB_PINTR; 129 writertc(RTC_STATUSB, rtc_statusb); 130 rtcin(RTC_INTR); 131 } 132 133 static void 134 atrtc_disable_intr(void) 135 { 136 137 rtc_statusb &= ~RTCSB_PINTR; 138 writertc(RTC_STATUSB, rtc_statusb); 139 rtcin(RTC_INTR); 140 } 141 142 void 143 atrtc_restore(void) 144 { 145 146 /* Restore all of the RTC's "status" (actually, control) registers. */ 147 rtcin(RTC_STATUSA); /* dummy to get rtc_reg set */ 148 writertc(RTC_STATUSB, RTCSB_24HR); 149 writertc(RTC_STATUSA, rtc_statusa); 150 writertc(RTC_STATUSB, rtc_statusb); 151 rtcin(RTC_INTR); 152 } 153 154 /********************************************************************** 155 * RTC driver for subr_rtc 156 */ 157 158 struct atrtc_softc { 159 int port_rid, intr_rid; 160 struct resource *port_res; 161 struct resource *intr_res; 162 void *intr_handler; 163 struct eventtimer et; 164 }; 165 166 static int 167 rtc_start(struct eventtimer *et, 168 struct bintime *first, struct bintime *period) 169 { 170 171 atrtc_rate(max(fls((period->frac + (period->frac >> 1)) >> 32) - 17, 1)); 172 atrtc_enable_intr(); 173 return (0); 174 } 175 176 static int 177 rtc_stop(struct eventtimer *et) 178 { 179 180 atrtc_disable_intr(); 181 return (0); 182 } 183 184 /* 185 * This routine receives statistical clock interrupts from the RTC. 186 * As explained above, these occur at 128 interrupts per second. 187 * When profiling, we receive interrupts at a rate of 1024 Hz. 188 * 189 * This does not actually add as much overhead as it sounds, because 190 * when the statistical clock is active, the hardclock driver no longer 191 * needs to keep (inaccurate) statistics on its own. This decouples 192 * statistics gathering from scheduling interrupts. 193 * 194 * The RTC chip requires that we read status register C (RTC_INTR) 195 * to acknowledge an interrupt, before it will generate the next one. 196 * Under high interrupt load, rtcintr() can be indefinitely delayed and 197 * the clock can tick immediately after the read from RTC_INTR. In this 198 * case, the mc146818A interrupt signal will not drop for long enough 199 * to register with the 8259 PIC. If an interrupt is missed, the stat 200 * clock will halt, considerably degrading system performance. This is 201 * why we use 'while' rather than a more straightforward 'if' below. 202 * Stat clock ticks can still be lost, causing minor loss of accuracy 203 * in the statistics, but the stat clock will no longer stop. 204 */ 205 static int 206 rtc_intr(void *arg) 207 { 208 struct atrtc_softc *sc = (struct atrtc_softc *)arg; 209 int flag = 0; 210 211 while (rtcin(RTC_INTR) & RTCIR_PERIOD) { 212 flag = 1; 213 if (sc->et.et_active) 214 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 215 } 216 return(flag ? FILTER_HANDLED : FILTER_STRAY); 217 } 218 219 /* 220 * Attach to the ISA PnP descriptors for the timer and realtime clock. 221 */ 222 static struct isa_pnp_id atrtc_ids[] = { 223 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 224 { 0 } 225 }; 226 227 static int 228 atrtc_probe(device_t dev) 229 { 230 int result; 231 232 result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids); 233 /* ENOENT means no PnP-ID, device is hinted. */ 234 if (result == ENOENT) { 235 device_set_desc(dev, "AT realtime clock"); 236 return (BUS_PROBE_LOW_PRIORITY); 237 } 238 return (result); 239 } 240 241 static int 242 atrtc_attach(device_t dev) 243 { 244 struct atrtc_softc *sc; 245 u_long s; 246 int i; 247 248 sc = device_get_softc(dev); 249 sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid, 250 IO_RTC, IO_RTC + 1, 2, RF_ACTIVE); 251 if (sc->port_res == NULL) 252 device_printf(dev, "Warning: Couldn't map I/O.\n"); 253 atrtc_start(); 254 clock_register(dev, 1000000); 255 bzero(&sc->et, sizeof(struct eventtimer)); 256 if (!atrtcclock_disable && 257 (resource_int_value(device_get_name(dev), device_get_unit(dev), 258 "clock", &i) != 0 || i != 0)) { 259 sc->intr_rid = 0; 260 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 261 &s, NULL) == 0 && s != 8) 262 sc->intr_rid++; 263 sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 264 &sc->intr_rid, 8, 8, 1, RF_ACTIVE); 265 if (sc->intr_res == NULL) { 266 device_printf(dev, "Can't map interrupt.\n"); 267 return (0); 268 } else if ((bus_setup_intr(dev, sc->intr_res, INTR_TYPE_CLK, 269 rtc_intr, NULL, sc, &sc->intr_handler))) { 270 device_printf(dev, "Can't setup interrupt.\n"); 271 return (0); 272 } else { 273 /* Bind IRQ to BSP to avoid live migration. */ 274 bus_bind_intr(dev, sc->intr_res, 0); 275 } 276 sc->et.et_name = "RTC"; 277 sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_POW2DIV; 278 sc->et.et_quality = 0; 279 sc->et.et_frequency = 32768; 280 sc->et.et_min_period.sec = 0; 281 sc->et.et_min_period.frac = 0x0008LLU << 48; 282 sc->et.et_max_period.sec = 0; 283 sc->et.et_max_period.frac = 0x8000LLU << 48; 284 sc->et.et_start = rtc_start; 285 sc->et.et_stop = rtc_stop; 286 sc->et.et_priv = dev; 287 et_register(&sc->et); 288 } 289 return(0); 290 } 291 292 static int 293 atrtc_resume(device_t dev) 294 { 295 296 atrtc_restore(); 297 return(0); 298 } 299 300 static int 301 atrtc_settime(device_t dev __unused, struct timespec *ts) 302 { 303 struct clocktime ct; 304 305 clock_ts_to_ct(ts, &ct); 306 307 /* Disable RTC updates and interrupts. */ 308 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 309 310 writertc(RTC_SEC, bin2bcd(ct.sec)); /* Write back Seconds */ 311 writertc(RTC_MIN, bin2bcd(ct.min)); /* Write back Minutes */ 312 writertc(RTC_HRS, bin2bcd(ct.hour)); /* Write back Hours */ 313 314 writertc(RTC_WDAY, ct.dow + 1); /* Write back Weekday */ 315 writertc(RTC_DAY, bin2bcd(ct.day)); /* Write back Day */ 316 writertc(RTC_MONTH, bin2bcd(ct.mon)); /* Write back Month */ 317 writertc(RTC_YEAR, bin2bcd(ct.year % 100)); /* Write back Year */ 318 #ifdef USE_RTC_CENTURY 319 writertc(RTC_CENTURY, bin2bcd(ct.year / 100)); /* ... and Century */ 320 #endif 321 322 /* Reenable RTC updates and interrupts. */ 323 writertc(RTC_STATUSB, rtc_statusb); 324 rtcin(RTC_INTR); 325 return (0); 326 } 327 328 static int 329 atrtc_gettime(device_t dev, struct timespec *ts) 330 { 331 struct clocktime ct; 332 333 /* Look if we have a RTC present and the time is valid */ 334 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) { 335 device_printf(dev, "WARNING: Battery failure indication\n"); 336 return (EINVAL); 337 } 338 339 /* 340 * wait for time update to complete 341 * If RTCSA_TUP is zero, we have at least 244us before next update. 342 * This is fast enough on most hardware, but a refinement would be 343 * to make sure that no more than 240us pass after we start reading, 344 * and try again if so. 345 */ 346 while (rtcin(RTC_STATUSA) & RTCSA_TUP) 347 continue; 348 critical_enter(); 349 ct.nsec = 0; 350 ct.sec = readrtc(RTC_SEC); 351 ct.min = readrtc(RTC_MIN); 352 ct.hour = readrtc(RTC_HRS); 353 ct.day = readrtc(RTC_DAY); 354 ct.dow = readrtc(RTC_WDAY) - 1; 355 ct.mon = readrtc(RTC_MONTH); 356 ct.year = readrtc(RTC_YEAR); 357 #ifdef USE_RTC_CENTURY 358 ct.year += readrtc(RTC_CENTURY) * 100; 359 #else 360 ct.year += 2000; 361 #endif 362 critical_exit(); 363 /* Set dow = -1 because some clocks don't set it correctly. */ 364 ct.dow = -1; 365 return (clock_ct_to_ts(&ct, ts)); 366 } 367 368 static device_method_t atrtc_methods[] = { 369 /* Device interface */ 370 DEVMETHOD(device_probe, atrtc_probe), 371 DEVMETHOD(device_attach, atrtc_attach), 372 DEVMETHOD(device_detach, bus_generic_detach), 373 DEVMETHOD(device_shutdown, bus_generic_shutdown), 374 DEVMETHOD(device_suspend, bus_generic_suspend), 375 /* XXX stop statclock? */ 376 DEVMETHOD(device_resume, atrtc_resume), 377 378 /* clock interface */ 379 DEVMETHOD(clock_gettime, atrtc_gettime), 380 DEVMETHOD(clock_settime, atrtc_settime), 381 382 { 0, 0 } 383 }; 384 385 static driver_t atrtc_driver = { 386 "atrtc", 387 atrtc_methods, 388 sizeof(struct atrtc_softc), 389 }; 390 391 static devclass_t atrtc_devclass; 392 393 DRIVER_MODULE(atrtc, isa, atrtc_driver, atrtc_devclass, 0, 0); 394 DRIVER_MODULE(atrtc, acpi, atrtc_driver, atrtc_devclass, 0, 0); 395 396 #include "opt_ddb.h" 397 #ifdef DDB 398 #include <ddb/ddb.h> 399 400 DB_SHOW_COMMAND(rtc, rtc) 401 { 402 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n", 403 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY), 404 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC), 405 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR)); 406 } 407 #endif /* DDB */ 408