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