clock.c revision 1.39
1 /* $NetBSD: clock.c,v 1.39 2008/01/03 01:02:04 joerg Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department. 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: Utah $Hdr: clock.c 1.18 91/01/21$ 36 * 37 * @(#)clock.c 7.6 (Berkeley) 5/7/91 38 */ 39 /* 40 * Copyright (c) 1988 University of Utah. 41 * 42 * This code is derived from software contributed to Berkeley by 43 * the Systems Programming Group of the University of Utah Computer 44 * Science Department. 45 * 46 * Redistribution and use in source and binary forms, with or without 47 * modification, are permitted provided that the following conditions 48 * are met: 49 * 1. Redistributions of source code must retain the above copyright 50 * notice, this list of conditions and the following disclaimer. 51 * 2. Redistributions in binary form must reproduce the above copyright 52 * notice, this list of conditions and the following disclaimer in the 53 * documentation and/or other materials provided with the distribution. 54 * 3. All advertising materials mentioning features or use of this software 55 * must display the following acknowledgement: 56 * This product includes software developed by the University of 57 * California, Berkeley and its contributors. 58 * 4. Neither the name of the University nor the names of its contributors 59 * may be used to endorse or promote products derived from this software 60 * without specific prior written permission. 61 * 62 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 63 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 64 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 65 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 66 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 67 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 68 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 69 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 70 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 71 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 72 * SUCH DAMAGE. 73 * 74 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 75 * 76 * @(#)clock.c 7.6 (Berkeley) 5/7/91 77 */ 78 79 #include <sys/cdefs.h> 80 __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.39 2008/01/03 01:02:04 joerg Exp $"); 81 82 #include <sys/param.h> 83 #include <sys/kernel.h> 84 #include <sys/systm.h> 85 #include <sys/device.h> 86 #include <sys/uio.h> 87 #include <sys/conf.h> 88 #include <sys/proc.h> 89 #include <sys/event.h> 90 91 #include <dev/clock_subr.h> 92 93 #include <machine/psl.h> 94 #include <machine/cpu.h> 95 #include <machine/iomap.h> 96 #include <machine/mfp.h> 97 #include <atari/dev/clockreg.h> 98 #include <atari/atari/device.h> 99 100 #if defined(GPROF) && defined(PROFTIMER) 101 #include <machine/profile.h> 102 #endif 103 104 /* 105 * The MFP clock runs at 2457600Hz. We use a {system,stat,prof}clock divider 106 * of 200. Therefore the timer runs at an effective rate of: 107 * 2457600/200 = 12288Hz. 108 */ 109 #define CLOCK_HZ 12288 110 111 /* 112 * Machine-dependent clock routines. 113 * 114 * Inittodr initializes the time of day hardware which provides 115 * date functions. 116 * 117 * Resettodr restores the time of day hardware after a time change. 118 */ 119 120 struct clock_softc { 121 struct device sc_dev; 122 int sc_flags; 123 }; 124 125 /* 126 * 'sc_flags' state info. Only used by the rtc-device functions. 127 */ 128 #define RTC_OPEN 1 129 130 dev_type_open(rtcopen); 131 dev_type_close(rtcclose); 132 dev_type_read(rtcread); 133 dev_type_write(rtcwrite); 134 135 static void clockattach __P((struct device *, struct device *, void *)); 136 static int clockmatch __P((struct device *, struct cfdata *, void *)); 137 138 CFATTACH_DECL(clock, sizeof(struct clock_softc), 139 clockmatch, clockattach, NULL, NULL); 140 141 extern struct cfdriver clock_cd; 142 143 const struct cdevsw rtc_cdevsw = { 144 rtcopen, rtcclose, rtcread, rtcwrite, noioctl, 145 nostop, notty, nopoll, nommap, nokqfilter, 146 }; 147 148 void statintr __P((struct clockframe)); 149 150 static u_long gettod __P((void)); 151 static int twodigits __P((char *, int)); 152 153 static int divisor; /* Systemclock divisor */ 154 155 /* 156 * Statistics and profile clock intervals and variances. Variance must 157 * be a power of 2. Since this gives us an even number, not an odd number, 158 * we discard one case and compensate. That is, a variance of 64 would 159 * give us offsets in [0..63]. Instead, we take offsets in [1..63]. 160 * This is symmetric around the point 32, or statvar/2, and thus averages 161 * to that value (assuming uniform random numbers). 162 */ 163 #ifdef STATCLOCK 164 static int statvar = 32; /* {stat,prof}clock variance */ 165 static int statmin; /* statclock divisor - variance/2 */ 166 static int profmin; /* profclock divisor - variance/2 */ 167 static int clk2min; /* current, from above choices */ 168 #endif 169 170 int 171 clockmatch(pdp, cfp, auxp) 172 struct device *pdp; 173 struct cfdata *cfp; 174 void *auxp; 175 { 176 if (!atari_realconfig) { 177 /* 178 * Initialize Timer-B in the ST-MFP. This timer is used by 179 * the 'delay' function below. This timer is setup to be 180 * continueously counting from 255 back to zero at a 181 * frequency of 614400Hz. We do this *early* in the 182 * initialisation process. 183 */ 184 MFP->mf_tbcr = 0; /* Stop timer */ 185 MFP->mf_iera &= ~IA_TIMB; /* Disable timer interrupts */ 186 MFP->mf_tbdr = 0; 187 MFP->mf_tbcr = T_Q004; /* Start timer */ 188 189 /* 190 * Initialize the time structure 191 */ 192 time.tv_sec = 0; 193 time.tv_usec = 0; 194 195 return 0; 196 } 197 if(!strcmp("clock", auxp)) 198 return(1); 199 return(0); 200 } 201 202 /* 203 * Start the real-time clock. 204 */ 205 void clockattach(pdp, dp, auxp) 206 struct device *pdp, *dp; 207 void *auxp; 208 { 209 struct clock_softc *sc = (void *)dp; 210 211 sc->sc_flags = 0; 212 213 /* 214 * Initialize Timer-A in the ST-MFP. We use a divisor of 200. 215 * The MFP clock runs at 2457600Hz. Therefore the timer runs 216 * at an effective rate of: 2457600/200 = 12288Hz. The 217 * following expression works for 48, 64 or 96 hz. 218 */ 219 divisor = CLOCK_HZ/hz; 220 MFP->mf_tacr = 0; /* Stop timer */ 221 MFP->mf_iera &= ~IA_TIMA; /* Disable timer interrupts */ 222 MFP->mf_tadr = divisor; /* Set divisor */ 223 224 if (hz != 48 && hz != 64 && hz != 96) { /* XXX */ 225 printf (": illegal value %d for systemclock, reset to %d\n\t", 226 hz, 64); 227 hz = 64; 228 } 229 printf(": system hz %d timer-A divisor 200/%d\n", hz, divisor); 230 231 #ifdef STATCLOCK 232 if ((stathz == 0) || (stathz > hz) || (CLOCK_HZ % stathz)) 233 stathz = hz; 234 if ((profhz == 0) || (profhz > (hz << 1)) || (CLOCK_HZ % profhz)) 235 profhz = hz << 1; 236 237 MFP->mf_tcdcr &= 0x7; /* Stop timer */ 238 MFP->mf_ierb &= ~IB_TIMC; /* Disable timer inter. */ 239 MFP->mf_tcdr = CLOCK_HZ/stathz; /* Set divisor */ 240 241 statmin = (CLOCK_HZ/stathz) - (statvar >> 1); 242 profmin = (CLOCK_HZ/profhz) - (statvar >> 1); 243 clk2min = statmin; 244 #endif /* STATCLOCK */ 245 246 } 247 248 void cpu_initclocks() 249 { 250 MFP->mf_tacr = T_Q200; /* Start timer */ 251 MFP->mf_ipra = (u_int8_t)~IA_TIMA;/* Clear pending interrupts */ 252 MFP->mf_iera |= IA_TIMA; /* Enable timer interrupts */ 253 MFP->mf_imra |= IA_TIMA; /* ..... */ 254 255 #ifdef STATCLOCK 256 MFP->mf_tcdcr = (MFP->mf_tcdcr & 0x7) | (T_Q200<<4); /* Start */ 257 MFP->mf_iprb = (u_int8_t)~IB_TIMC;/* Clear pending interrupts */ 258 MFP->mf_ierb |= IB_TIMC; /* Enable timer interrupts */ 259 MFP->mf_imrb |= IB_TIMC; /* ..... */ 260 #endif /* STATCLOCK */ 261 } 262 263 void 264 setstatclockrate(newhz) 265 int newhz; 266 { 267 #ifdef STATCLOCK 268 if (newhz == stathz) 269 clk2min = statmin; 270 else clk2min = profmin; 271 #endif /* STATCLOCK */ 272 } 273 274 #ifdef STATCLOCK 275 void 276 statintr(frame) 277 struct clockframe frame; 278 { 279 register int var, r; 280 281 var = statvar - 1; 282 do { 283 r = random() & var; 284 } while(r == 0); 285 286 /* 287 * Note that we are always lagging behind as the new divisor 288 * value will not be loaded until the next interrupt. This 289 * shouldn't disturb the median frequency (I think ;-) ) as 290 * only the value used when switching frequencies is used 291 * twice. This shouldn't happen very often. 292 */ 293 MFP->mf_tcdr = clk2min + r; 294 295 statclock(&frame); 296 } 297 #endif /* STATCLOCK */ 298 299 /* 300 * Returns number of usec since last recorded clock "tick" 301 * (i.e. clock interrupt). 302 */ 303 long 304 clkread() 305 { 306 u_int delta; 307 u_char ipra, tadr; 308 309 /* 310 * Note: Order is important! 311 * By reading 'ipra' before 'tadr' and caching the data, I try to avoid 312 * the situation that very low value in 'tadr' is read (== a big delta) 313 * while also acccounting for a full 'tick' because the counter went 314 * through zero during the calculations. 315 */ 316 ipra = MFP->mf_ipra; tadr = MFP->mf_tadr; 317 318 delta = ((divisor - tadr) * tick) / divisor; 319 /* 320 * Account for pending clock interrupts 321 */ 322 if(ipra & IA_TIMA) 323 return(delta + tick); 324 return(delta); 325 } 326 327 #define TIMB_FREQ 614400 328 #define TIMB_LIMIT 256 329 330 /* 331 * Wait "n" microseconds. 332 * Relies on MFP-Timer B counting down from TIMB_LIMIT at TIMB_FREQ Hz. 333 * Note: timer had better have been programmed before this is first used! 334 */ 335 void 336 delay(unsigned int n) 337 { 338 int ticks, otick, remaining; 339 340 /* 341 * Read the counter first, so that the rest of the setup overhead is 342 * counted. 343 */ 344 otick = MFP->mf_tbdr; 345 346 if (n <= UINT_MAX / TIMB_FREQ) { 347 /* 348 * For unsigned arithmetic, division can be replaced with 349 * multiplication with the inverse and a shift. 350 */ 351 remaining = n * TIMB_FREQ / 1000000; 352 } else { 353 /* This is a very long delay. 354 * Being slow here doesn't matter. 355 */ 356 remaining = (unsigned long long) n * TIMB_FREQ / 1000000; 357 } 358 359 while(remaining > 0) { 360 ticks = MFP->mf_tbdr; 361 if(ticks > otick) 362 remaining -= TIMB_LIMIT - (ticks - otick); 363 else 364 remaining -= otick - ticks; 365 otick = ticks; 366 } 367 } 368 369 #ifdef GPROF 370 /* 371 * profclock() is expanded in line in lev6intr() unless profiling kernel. 372 * Assumes it is called with clock interrupts blocked. 373 */ 374 profclock(pc, ps) 375 void *pc; 376 int ps; 377 { 378 /* 379 * Came from user mode. 380 * If this process is being profiled record the tick. 381 */ 382 if (USERMODE(ps)) { 383 if (p->p_stats.p_prof.pr_scale) 384 addupc(pc, &curproc->p_stats.p_prof, 1); 385 } 386 /* 387 * Came from kernel (supervisor) mode. 388 * If we are profiling the kernel, record the tick. 389 */ 390 else if (profiling < 2) { 391 register int s = pc - s_lowpc; 392 393 if (s < s_textsize) 394 kcount[s / (HISTFRACTION * sizeof (*kcount))]++; 395 } 396 /* 397 * Kernel profiling was on but has been disabled. 398 * Mark as no longer profiling kernel and if all profiling done, 399 * disable the clock. 400 */ 401 if (profiling && (profon & PRF_KERNEL)) { 402 profon &= ~PRF_KERNEL; 403 if (profon == PRF_NONE) 404 stopprofclock(); 405 } 406 } 407 #endif 408 409 /*********************************************************************** 410 * Real Time Clock support * 411 ***********************************************************************/ 412 413 u_int mc146818_read(rtc, regno) 414 void *rtc; 415 u_int regno; 416 { 417 ((struct rtc *)rtc)->rtc_regno = regno; 418 return(((struct rtc *)rtc)->rtc_data & 0377); 419 } 420 421 void mc146818_write(rtc, regno, value) 422 void *rtc; 423 u_int regno, value; 424 { 425 ((struct rtc *)rtc)->rtc_regno = regno; 426 ((struct rtc *)rtc)->rtc_data = value; 427 } 428 429 /* 430 * Initialize the time of day register, assuming the RTC runs in UTC. 431 * Since we've got the 'rtc' device, this functionality should be removed 432 * from the kernel. The only problem to be solved before that can happen 433 * is the possibility of init(1) providing a way (rc.boot?) to set 434 * the RTC before single-user mode is entered. 435 */ 436 void 437 inittodr(base) 438 time_t base; 439 { 440 /* Battery clock does not store usec's, so forget about it. */ 441 time.tv_sec = gettod(); 442 time.tv_usec = 0; 443 } 444 445 /* 446 * Function turned into a No-op. Use /dev/rtc to update the RTC. 447 */ 448 void 449 resettodr() 450 { 451 return; 452 } 453 454 static u_long 455 gettod() 456 { 457 int sps; 458 mc_todregs clkregs; 459 u_int regb; 460 struct clock_ymdhms dt; 461 462 sps = splhigh(); 463 regb = mc146818_read(RTC, MC_REGB); 464 MC146818_GETTOD(RTC, &clkregs); 465 splx(sps); 466 467 regb &= MC_REGB_24HR|MC_REGB_BINARY; 468 if (regb != (MC_REGB_24HR|MC_REGB_BINARY)) { 469 printf("Error: Nonstandard RealTimeClock Configuration -" 470 " value ignored\n" 471 " A write to /dev/rtc will correct this.\n"); 472 return(0); 473 } 474 if(clkregs[MC_SEC] > 59) 475 return(0); 476 if(clkregs[MC_MIN] > 59) 477 return(0); 478 if(clkregs[MC_HOUR] > 23) 479 return(0); 480 if(range_test(clkregs[MC_DOM], 1, 31)) 481 return(0); 482 if (range_test(clkregs[MC_MONTH], 1, 12)) 483 return(0); 484 if(clkregs[MC_YEAR] > 99) 485 return(0); 486 487 dt.dt_year = clkregs[MC_YEAR] + GEMSTARTOFTIME; 488 dt.dt_mon = clkregs[MC_MONTH]; 489 dt.dt_day = clkregs[MC_DOM]; 490 dt.dt_hour = clkregs[MC_HOUR]; 491 dt.dt_min = clkregs[MC_MIN]; 492 dt.dt_sec = clkregs[MC_SEC]; 493 494 return(clock_ymdhms_to_secs(&dt)); 495 } 496 /*********************************************************************** 497 * RTC-device support * 498 ***********************************************************************/ 499 int 500 rtcopen(dev, flag, mode, l) 501 dev_t dev; 502 int flag, mode; 503 struct lwp *l; 504 { 505 int unit = minor(dev); 506 struct clock_softc *sc; 507 508 if (unit >= clock_cd.cd_ndevs) 509 return ENXIO; 510 sc = clock_cd.cd_devs[unit]; 511 if (!sc) 512 return ENXIO; 513 if (sc->sc_flags & RTC_OPEN) 514 return EBUSY; 515 516 sc->sc_flags = RTC_OPEN; 517 return 0; 518 } 519 520 int 521 rtcclose(dev, flag, mode, l) 522 dev_t dev; 523 int flag; 524 int mode; 525 struct lwp *l; 526 { 527 int unit = minor(dev); 528 struct clock_softc *sc = clock_cd.cd_devs[unit]; 529 530 sc->sc_flags = 0; 531 return 0; 532 } 533 534 int 535 rtcread(dev, uio, flags) 536 dev_t dev; 537 struct uio *uio; 538 int flags; 539 { 540 struct clock_softc *sc; 541 mc_todregs clkregs; 542 int s, length; 543 char buffer[16]; 544 545 sc = clock_cd.cd_devs[minor(dev)]; 546 547 s = splhigh(); 548 MC146818_GETTOD(RTC, &clkregs); 549 splx(s); 550 551 sprintf(buffer, "%4d%02d%02d%02d%02d.%02d\n", 552 clkregs[MC_YEAR] + GEMSTARTOFTIME, 553 clkregs[MC_MONTH], clkregs[MC_DOM], 554 clkregs[MC_HOUR], clkregs[MC_MIN], clkregs[MC_SEC]); 555 556 if (uio->uio_offset > strlen(buffer)) 557 return 0; 558 559 length = strlen(buffer) - uio->uio_offset; 560 if (length > uio->uio_resid) 561 length = uio->uio_resid; 562 563 return(uiomove((void *)buffer, length, uio)); 564 } 565 566 static int 567 twodigits(buffer, pos) 568 char *buffer; 569 int pos; 570 { 571 int result = 0; 572 573 if (buffer[pos] >= '0' && buffer[pos] <= '9') 574 result = (buffer[pos] - '0') * 10; 575 if (buffer[pos+1] >= '0' && buffer[pos+1] <= '9') 576 result += (buffer[pos+1] - '0'); 577 return(result); 578 } 579 580 int 581 rtcwrite(dev, uio, flags) 582 dev_t dev; 583 struct uio *uio; 584 int flags; 585 { 586 mc_todregs clkregs; 587 int s, length, error; 588 char buffer[16]; 589 590 /* 591 * We require atomic updates! 592 */ 593 length = uio->uio_resid; 594 if (uio->uio_offset || (length != sizeof(buffer) 595 && length != sizeof(buffer - 1))) 596 return(EINVAL); 597 598 if ((error = uiomove((void *)buffer, sizeof(buffer), uio))) 599 return(error); 600 601 if (length == sizeof(buffer) && buffer[sizeof(buffer) - 1] != '\n') 602 return(EINVAL); 603 604 s = splclock(); 605 mc146818_write(RTC, MC_REGB, 606 mc146818_read(RTC, MC_REGB) | MC_REGB_24HR | MC_REGB_BINARY); 607 MC146818_GETTOD(RTC, &clkregs); 608 splx(s); 609 610 clkregs[MC_SEC] = twodigits(buffer, 13); 611 clkregs[MC_MIN] = twodigits(buffer, 10); 612 clkregs[MC_HOUR] = twodigits(buffer, 8); 613 clkregs[MC_DOM] = twodigits(buffer, 6); 614 clkregs[MC_MONTH] = twodigits(buffer, 4); 615 s = twodigits(buffer, 0) * 100 + twodigits(buffer, 2); 616 clkregs[MC_YEAR] = s - GEMSTARTOFTIME; 617 618 s = splclock(); 619 MC146818_PUTTOD(RTC, &clkregs); 620 splx(s); 621 622 return(0); 623 } 624
Indexes created Tue Sep 23 07:09:52 GMT 2025