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 void 155 atrtc_set(struct timespec *ts) 156 { 157 struct clocktime ct; 158 159 clock_ts_to_ct(ts, &ct); 160 161 /* Disable RTC updates and interrupts. */ 162 writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR); 163 164 writertc(RTC_SEC, bin2bcd(ct.sec)); /* Write back Seconds */ 165 writertc(RTC_MIN, bin2bcd(ct.min)); /* Write back Minutes */ 166 writertc(RTC_HRS, bin2bcd(ct.hour)); /* Write back Hours */ 167 168 writertc(RTC_WDAY, ct.dow + 1); /* Write back Weekday */ 169 writertc(RTC_DAY, bin2bcd(ct.day)); /* Write back Day */ 170 writertc(RTC_MONTH, bin2bcd(ct.mon)); /* Write back Month */ 171 writertc(RTC_YEAR, bin2bcd(ct.year % 100)); /* Write back Year */ 172 #ifdef USE_RTC_CENTURY 173 writertc(RTC_CENTURY, bin2bcd(ct.year / 100)); /* ... and Century */ 174 #endif 175 176 /* Re-enable RTC updates and interrupts. */ 177 writertc(RTC_STATUSB, rtc_statusb); 178 rtcin(RTC_INTR); 179 } 180 181 /********************************************************************** 182 * RTC driver for subr_rtc 183 */ 184 185 struct atrtc_softc { 186 int port_rid, intr_rid; 187 struct resource *port_res; 188 struct resource *intr_res; 189 void *intr_handler; 190 struct eventtimer et; 191 }; 192 193 static int 194 rtc_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 195 { 196 197 atrtc_rate(max(fls(period + (period >> 1)) - 17, 1)); 198 atrtc_enable_intr(); 199 return (0); 200 } 201 202 static int 203 rtc_stop(struct eventtimer *et) 204 { 205 206 atrtc_disable_intr(); 207 return (0); 208 } 209 210 /* 211 * This routine receives statistical clock interrupts from the RTC. 212 * As explained above, these occur at 128 interrupts per second. 213 * When profiling, we receive interrupts at a rate of 1024 Hz. 214 * 215 * This does not actually add as much overhead as it sounds, because 216 * when the statistical clock is active, the hardclock driver no longer 217 * needs to keep (inaccurate) statistics on its own. This decouples 218 * statistics gathering from scheduling interrupts. 219 * 220 * The RTC chip requires that we read status register C (RTC_INTR) 221 * to acknowledge an interrupt, before it will generate the next one. 222 * Under high interrupt load, rtcintr() can be indefinitely delayed and 223 * the clock can tick immediately after the read from RTC_INTR. In this 224 * case, the mc146818A interrupt signal will not drop for long enough 225 * to register with the 8259 PIC. If an interrupt is missed, the stat 226 * clock will halt, considerably degrading system performance. This is 227 * why we use 'while' rather than a more straightforward 'if' below. 228 * Stat clock ticks can still be lost, causing minor loss of accuracy 229 * in the statistics, but the stat clock will no longer stop. 230 */ 231 static int 232 rtc_intr(void *arg) 233 { 234 struct atrtc_softc *sc = (struct atrtc_softc *)arg; 235 int flag = 0; 236 237 while (rtcin(RTC_INTR) & RTCIR_PERIOD) { 238 flag = 1; 239 if (sc->et.et_active) 240 sc->et.et_event_cb(&sc->et, sc->et.et_arg); 241 } 242 return(flag ? FILTER_HANDLED : FILTER_STRAY); 243 } 244 245 /* 246 * Attach to the ISA PnP descriptors for the timer and realtime clock. 247 */ 248 static struct isa_pnp_id atrtc_ids[] = { 249 { 0x000bd041 /* PNP0B00 */, "AT realtime clock" }, 250 { 0 } 251 }; 252 253 static int 254 atrtc_probe(device_t dev) 255 { 256 int result; 257 258 result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids); 259 /* ENOENT means no PnP-ID, device is hinted. */ 260 if (result == ENOENT) { 261 device_set_desc(dev, "AT realtime clock"); 262 return (BUS_PROBE_LOW_PRIORITY); 263 } 264 return (result); 265 } 266 267 static int 268 atrtc_attach(device_t dev) 269 { 270 struct atrtc_softc *sc; 271 rman_res_t s; 272 int i; 273 274 sc = device_get_softc(dev); 275 sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->port_rid, 276 IO_RTC, IO_RTC + 1, 2, RF_ACTIVE); 277 if (sc->port_res == NULL) 278 device_printf(dev, "Warning: Couldn't map I/O.\n"); 279 atrtc_start(); 280 clock_register(dev, 1000000); 281 bzero(&sc->et, sizeof(struct eventtimer)); 282 if (!atrtcclock_disable && 283 (resource_int_value(device_get_name(dev), device_get_unit(dev), 284 "clock", &i) != 0 || i != 0)) { 285 sc->intr_rid = 0; 286 while (bus_get_resource(dev, SYS_RES_IRQ, sc->intr_rid, 287 &s, NULL) == 0 && s != 8) 288 sc->intr_rid++; 289 sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ, 290 &sc->intr_rid, 8, 8, 1, RF_ACTIVE); 291 if (sc->intr_res == NULL) { 292 device_printf(dev, "Can't map interrupt.\n"); 293 return (0); 294 } else if ((bus_setup_intr(dev, sc->intr_res, INTR_TYPE_CLK, 295 rtc_intr, NULL, sc, &sc->intr_handler))) { 296 device_printf(dev, "Can't setup interrupt.\n"); 297 return (0); 298 } else { 299 /* Bind IRQ to BSP to avoid live migration. */ 300 bus_bind_intr(dev, sc->intr_res, 0); 301 } 302 sc->et.et_name = "RTC"; 303 sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_POW2DIV; 304 sc->et.et_quality = 0; 305 sc->et.et_frequency = 32768; 306 sc->et.et_min_period = 0x00080000; 307 sc->et.et_max_period = 0x80000000; 308 sc->et.et_start = rtc_start; 309 sc->et.et_stop = rtc_stop; 310 sc->et.et_priv = dev; 311 et_register(&sc->et); 312 } 313 return(0); 314 } 315 316 static int 317 atrtc_resume(device_t dev) 318 { 319 320 atrtc_restore(); 321 return(0); 322 } 323 324 static int 325 atrtc_settime(device_t dev __unused, struct timespec *ts) 326 { 327 328 atrtc_set(ts); 329 return (0); 330 } 331 332 static int 333 atrtc_gettime(device_t dev, struct timespec *ts) 334 { 335 struct clocktime ct; 336 337 /* Look if we have a RTC present and the time is valid */ 338 if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) { 339 device_printf(dev, "WARNING: Battery failure indication\n"); 340 return (EINVAL); 341 } 342 343 /* 344 * wait for time update to complete 345 * If RTCSA_TUP is zero, we have at least 244us before next update. 346 * This is fast enough on most hardware, but a refinement would be 347 * to make sure that no more than 240us pass after we start reading, 348 * and try again if so. 349 */ 350 while (rtcin(RTC_STATUSA) & RTCSA_TUP) 351 continue; 352 critical_enter(); 353 ct.nsec = 0; 354 ct.sec = readrtc(RTC_SEC); 355 ct.min = readrtc(RTC_MIN); 356 ct.hour = readrtc(RTC_HRS); 357 ct.day = readrtc(RTC_DAY); 358 ct.dow = readrtc(RTC_WDAY) - 1; 359 ct.mon = readrtc(RTC_MONTH); 360 ct.year = readrtc(RTC_YEAR); 361 #ifdef USE_RTC_CENTURY 362 ct.year += readrtc(RTC_CENTURY) * 100; 363 #else 364 ct.year += (ct.year < 80 ? 2000 : 1900); 365 #endif 366 critical_exit(); 367 /* Set dow = -1 because some clocks don't set it correctly. */ 368 ct.dow = -1; 369 return (clock_ct_to_ts(&ct, ts)); 370 } 371 372 static device_method_t atrtc_methods[] = { 373 /* Device interface */ 374 DEVMETHOD(device_probe, atrtc_probe), 375 DEVMETHOD(device_attach, atrtc_attach), 376 DEVMETHOD(device_detach, bus_generic_detach), 377 DEVMETHOD(device_shutdown, bus_generic_shutdown), 378 DEVMETHOD(device_suspend, bus_generic_suspend), 379 /* XXX stop statclock? */ 380 DEVMETHOD(device_resume, atrtc_resume), 381 382 /* clock interface */ 383 DEVMETHOD(clock_gettime, atrtc_gettime), 384 DEVMETHOD(clock_settime, atrtc_settime), 385 386 { 0, 0 } 387 }; 388 389 static driver_t atrtc_driver = { 390 "atrtc", 391 atrtc_methods, 392 sizeof(struct atrtc_softc), 393 }; 394 395 static devclass_t atrtc_devclass; 396 397 DRIVER_MODULE(atrtc, isa, atrtc_driver, atrtc_devclass, 0, 0); 398 DRIVER_MODULE(atrtc, acpi, atrtc_driver, atrtc_devclass, 0, 0); 399 400 #include "opt_ddb.h" 401 #ifdef DDB 402 #include <ddb/ddb.h> 403 404 DB_SHOW_COMMAND(rtc, rtc) 405 { 406 printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n", 407 rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY), 408 rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC), 409 rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR)); 410 } 411 #endif /* DDB */ 412