clock.c revision 1.27.6.4
1 /* $NetBSD: clock.c,v 1.27.6.4 2002/07/12 01:39:26 nathanw Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1990 The Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 41 * 42 * @(#)clock.c 7.6 (Berkeley) 5/7/91 43 */ 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/systm.h> 48 #include <sys/device.h> 49 #include <sys/uio.h> 50 #include <sys/conf.h> 51 #include <sys/proc.h> 52 53 #include <dev/clock_subr.h> 54 55 #include <machine/psl.h> 56 #include <machine/cpu.h> 57 #include <machine/iomap.h> 58 #include <machine/mfp.h> 59 #include <atari/dev/clockreg.h> 60 #include <atari/atari/device.h> 61 62 #if defined(GPROF) && defined(PROFTIMER) 63 #include <machine/profile.h> 64 #endif 65 66 /* 67 * The MFP clock runs at 2457600Hz. We use a {system,stat,prof}clock divider 68 * of 200. Therefore the timer runs at an effective rate of: 69 * 2457600/200 = 12288Hz. 70 */ 71 #define CLOCK_HZ 12288 72 73 /* 74 * Machine-dependent clock routines. 75 * 76 * Inittodr initializes the time of day hardware which provides 77 * date functions. 78 * 79 * Resettodr restores the time of day hardware after a time change. 80 */ 81 82 struct clock_softc { 83 struct device sc_dev; 84 int sc_flags; 85 }; 86 87 /* 88 * 'sc_flags' state info. Only used by the rtc-device functions. 89 */ 90 #define RTC_OPEN 1 91 92 /* {b,c}devsw[] function prototypes for rtc functions */ 93 dev_type_open(rtcopen); 94 dev_type_close(rtcclose); 95 dev_type_read(rtcread); 96 dev_type_write(rtcwrite); 97 98 static void clockattach __P((struct device *, struct device *, void *)); 99 static int clockmatch __P((struct device *, struct cfdata *, void *)); 100 101 struct cfattach clock_ca = { 102 sizeof(struct clock_softc), clockmatch, clockattach 103 }; 104 105 extern struct cfdriver clock_cd; 106 107 void statintr __P((struct clockframe)); 108 109 static u_long gettod __P((void)); 110 static int twodigits __P((char *, int)); 111 112 static int divisor; /* Systemclock divisor */ 113 114 /* 115 * Statistics and profile clock intervals and variances. Variance must 116 * be a power of 2. Since this gives us an even number, not an odd number, 117 * we discard one case and compensate. That is, a variance of 64 would 118 * give us offsets in [0..63]. Instead, we take offsets in [1..63]. 119 * This is symmetric around the point 32, or statvar/2, and thus averages 120 * to that value (assuming uniform random numbers). 121 */ 122 #ifdef STATCLOCK 123 static int statvar = 32; /* {stat,prof}clock variance */ 124 static int statmin; /* statclock divisor - variance/2 */ 125 static int profmin; /* profclock divisor - variance/2 */ 126 static int clk2min; /* current, from above choices */ 127 #endif 128 129 int 130 clockmatch(pdp, cfp, auxp) 131 struct device *pdp; 132 struct cfdata *cfp; 133 void *auxp; 134 { 135 if (!atari_realconfig) { 136 /* 137 * Initialize Timer-B in the ST-MFP. This timer is used by 138 * the 'delay' function below. This timer is setup to be 139 * continueously counting from 255 back to zero at a 140 * frequency of 614400Hz. We do this *early* in the 141 * initialisation process. 142 */ 143 MFP->mf_tbcr = 0; /* Stop timer */ 144 MFP->mf_iera &= ~IA_TIMB; /* Disable timer interrupts */ 145 MFP->mf_tbdr = 0; 146 MFP->mf_tbcr = T_Q004; /* Start timer */ 147 148 /* 149 * Initialize the time structure 150 */ 151 time.tv_sec = 0; 152 time.tv_usec = 0; 153 154 return 0; 155 } 156 if(!strcmp("clock", auxp)) 157 return(1); 158 return(0); 159 } 160 161 /* 162 * Start the real-time clock. 163 */ 164 void clockattach(pdp, dp, auxp) 165 struct device *pdp, *dp; 166 void *auxp; 167 { 168 struct clock_softc *sc = (void *)dp; 169 170 sc->sc_flags = 0; 171 172 /* 173 * Initialize Timer-A in the ST-MFP. We use a divisor of 200. 174 * The MFP clock runs at 2457600Hz. Therefore the timer runs 175 * at an effective rate of: 2457600/200 = 12288Hz. The 176 * following expression works for 48, 64 or 96 hz. 177 */ 178 divisor = CLOCK_HZ/hz; 179 MFP->mf_tacr = 0; /* Stop timer */ 180 MFP->mf_iera &= ~IA_TIMA; /* Disable timer interrupts */ 181 MFP->mf_tadr = divisor; /* Set divisor */ 182 183 if (hz != 48 && hz != 64 && hz != 96) { /* XXX */ 184 printf (": illegal value %d for systemclock, reset to %d\n\t", 185 hz, 64); 186 hz = 64; 187 } 188 printf(": system hz %d timer-A divisor 200/%d\n", hz, divisor); 189 190 #ifdef STATCLOCK 191 if ((stathz == 0) || (stathz > hz) || (CLOCK_HZ % stathz)) 192 stathz = hz; 193 if ((profhz == 0) || (profhz > (hz << 1)) || (CLOCK_HZ % profhz)) 194 profhz = hz << 1; 195 196 MFP->mf_tcdcr &= 0x7; /* Stop timer */ 197 MFP->mf_ierb &= ~IB_TIMC; /* Disable timer inter. */ 198 MFP->mf_tcdr = CLOCK_HZ/stathz; /* Set divisor */ 199 200 statmin = (CLOCK_HZ/stathz) - (statvar >> 1); 201 profmin = (CLOCK_HZ/profhz) - (statvar >> 1); 202 clk2min = statmin; 203 #endif /* STATCLOCK */ 204 205 } 206 207 void cpu_initclocks() 208 { 209 MFP->mf_tacr = T_Q200; /* Start timer */ 210 MFP->mf_ipra = (u_int8_t)~IA_TIMA;/* Clear pending interrupts */ 211 MFP->mf_iera |= IA_TIMA; /* Enable timer interrupts */ 212 MFP->mf_imra |= IA_TIMA; /* ..... */ 213 214 #ifdef STATCLOCK 215 MFP->mf_tcdcr = (MFP->mf_tcdcr & 0x7) | (T_Q200<<4); /* Start */ 216 MFP->mf_iprb = (u_int8_t)~IB_TIMC;/* Clear pending interrupts */ 217 MFP->mf_ierb |= IB_TIMC; /* Enable timer interrupts */ 218 MFP->mf_imrb |= IB_TIMC; /* ..... */ 219 #endif /* STATCLOCK */ 220 } 221 222 void 223 setstatclockrate(newhz) 224 int newhz; 225 { 226 #ifdef STATCLOCK 227 if (newhz == stathz) 228 clk2min = statmin; 229 else clk2min = profmin; 230 #endif /* STATCLOCK */ 231 } 232 233 #ifdef STATCLOCK 234 void 235 statintr(frame) 236 struct clockframe frame; 237 { 238 register int var, r; 239 240 var = statvar - 1; 241 do { 242 r = random() & var; 243 } while(r == 0); 244 245 /* 246 * Note that we are always lagging behind as the new divisor 247 * value will not be loaded until the next interrupt. This 248 * shouldn't disturb the median frequency (I think ;-) ) as 249 * only the value used when switching frequencies is used 250 * twice. This shouldn't happen very often. 251 */ 252 MFP->mf_tcdr = clk2min + r; 253 254 statclock(&frame); 255 } 256 #endif /* STATCLOCK */ 257 258 /* 259 * Returns number of usec since last recorded clock "tick" 260 * (i.e. clock interrupt). 261 */ 262 long 263 clkread() 264 { 265 u_int delta; 266 u_char ipra, tadr; 267 268 /* 269 * Note: Order is important! 270 * By reading 'ipra' before 'tadr' and caching the data, I try to avoid 271 * the situation that very low value in 'tadr' is read (== a big delta) 272 * while also acccounting for a full 'tick' because the counter went 273 * through zero during the calculations. 274 */ 275 ipra = MFP->mf_ipra; tadr = MFP->mf_tadr; 276 277 delta = ((divisor - tadr) * tick) / divisor; 278 /* 279 * Account for pending clock interrupts 280 */ 281 if(ipra & IA_TIMA) 282 return(delta + tick); 283 return(delta); 284 } 285 286 #define TIMB_FREQ 614400 287 #define TIMB_LIMIT 256 288 289 /* 290 * Wait "n" microseconds. 291 * Relies on MFP-Timer B counting down from TIMB_LIMIT at TIMB_FREQ Hz. 292 * Note: timer had better have been programmed before this is first used! 293 */ 294 void 295 delay(n) 296 int n; 297 { 298 int tick, otick; 299 300 /* 301 * Read the counter first, so that the rest of the setup overhead is 302 * counted. 303 */ 304 otick = MFP->mf_tbdr; 305 306 /* 307 * Calculate ((n * TIMER_FREQ) / 1e6) using explicit assembler code so 308 * we can take advantage of the intermediate 64-bit quantity to prevent 309 * loss of significance. 310 */ 311 n -= 5; 312 if(n < 0) 313 return; 314 { 315 u_int temp; 316 317 __asm __volatile ("mulul %2,%1:%0" : "=d" (n), "=d" (temp) 318 : "d" (TIMB_FREQ), "d" (n)); 319 __asm __volatile ("divul %1,%2:%0" : "=d" (n) 320 : "d"(1000000),"d"(temp),"0"(n)); 321 } 322 323 while(n > 0) { 324 tick = MFP->mf_tbdr; 325 if(tick > otick) 326 n -= TIMB_LIMIT - (tick - otick); 327 else n -= otick - tick; 328 otick = tick; 329 } 330 } 331 332 #ifdef GPROF 333 /* 334 * profclock() is expanded in line in lev6intr() unless profiling kernel. 335 * Assumes it is called with clock interrupts blocked. 336 */ 337 profclock(pc, ps) 338 caddr_t pc; 339 int ps; 340 { 341 /* 342 * Came from user mode. 343 * If this process is being profiled record the tick. 344 */ 345 if (USERMODE(ps)) { 346 if (p->p_stats.p_prof.pr_scale) 347 addupc(pc, &curproc->p_stats.p_prof, 1); 348 } 349 /* 350 * Came from kernel (supervisor) mode. 351 * If we are profiling the kernel, record the tick. 352 */ 353 else if (profiling < 2) { 354 register int s = pc - s_lowpc; 355 356 if (s < s_textsize) 357 kcount[s / (HISTFRACTION * sizeof (*kcount))]++; 358 } 359 /* 360 * Kernel profiling was on but has been disabled. 361 * Mark as no longer profiling kernel and if all profiling done, 362 * disable the clock. 363 */ 364 if (profiling && (profon & PRF_KERNEL)) { 365 profon &= ~PRF_KERNEL; 366 if (profon == PRF_NONE) 367 stopprofclock(); 368 } 369 } 370 #endif 371 372 /*********************************************************************** 373 * Real Time Clock support * 374 ***********************************************************************/ 375 376 u_int mc146818_read(rtc, regno) 377 void *rtc; 378 u_int regno; 379 { 380 ((struct rtc *)rtc)->rtc_regno = regno; 381 return(((struct rtc *)rtc)->rtc_data & 0377); 382 } 383 384 void mc146818_write(rtc, regno, value) 385 void *rtc; 386 u_int regno, value; 387 { 388 ((struct rtc *)rtc)->rtc_regno = regno; 389 ((struct rtc *)rtc)->rtc_data = value; 390 } 391 392 /* 393 * Initialize the time of day register, assuming the RTC runs in UTC. 394 * Since we've got the 'rtc' device, this functionality should be removed 395 * from the kernel. The only problem to be solved before that can happen 396 * is the possibility of init(1) providing a way (rc.boot?) to set 397 * the RTC before single-user mode is entered. 398 */ 399 void 400 inittodr(base) 401 time_t base; 402 { 403 /* Battery clock does not store usec's, so forget about it. */ 404 time.tv_sec = gettod(); 405 time.tv_usec = 0; 406 } 407 408 /* 409 * Function turned into a No-op. Use /dev/rtc to update the RTC. 410 */ 411 void 412 resettodr() 413 { 414 return; 415 } 416 417 static u_long 418 gettod() 419 { 420 int sps; 421 mc_todregs clkregs; 422 u_int regb; 423 struct clock_ymdhms dt; 424 425 sps = splhigh(); 426 regb = mc146818_read(RTC, MC_REGB); 427 MC146818_GETTOD(RTC, &clkregs); 428 splx(sps); 429 430 regb &= MC_REGB_24HR|MC_REGB_BINARY; 431 if (regb != (MC_REGB_24HR|MC_REGB_BINARY)) { 432 printf("Error: Nonstandard RealTimeClock Configuration -" 433 " value ignored\n" 434 " A write to /dev/rtc will correct this.\n"); 435 return(0); 436 } 437 if(clkregs[MC_SEC] > 59) 438 return(0); 439 if(clkregs[MC_MIN] > 59) 440 return(0); 441 if(clkregs[MC_HOUR] > 23) 442 return(0); 443 if(range_test(clkregs[MC_DOM], 1, 31)) 444 return(0); 445 if (range_test(clkregs[MC_MONTH], 1, 12)) 446 return(0); 447 if(clkregs[MC_YEAR] > 99) 448 return(0); 449 450 dt.dt_year = clkregs[MC_YEAR] + GEMSTARTOFTIME; 451 dt.dt_mon = clkregs[MC_MONTH]; 452 dt.dt_day = clkregs[MC_DOM]; 453 dt.dt_hour = clkregs[MC_HOUR]; 454 dt.dt_min = clkregs[MC_MIN]; 455 dt.dt_sec = clkregs[MC_SEC]; 456 457 return(clock_ymdhms_to_secs(&dt)); 458 } 459 /*********************************************************************** 460 * RTC-device support * 461 ***********************************************************************/ 462 int 463 rtcopen(dev, flag, mode, p) 464 dev_t dev; 465 int flag, mode; 466 struct proc *p; 467 { 468 int unit = minor(dev); 469 struct clock_softc *sc; 470 471 if (unit >= clock_cd.cd_ndevs) 472 return ENXIO; 473 sc = clock_cd.cd_devs[unit]; 474 if (!sc) 475 return ENXIO; 476 if (sc->sc_flags & RTC_OPEN) 477 return EBUSY; 478 479 sc->sc_flags = RTC_OPEN; 480 return 0; 481 } 482 483 int 484 rtcclose(dev, flag, mode, p) 485 dev_t dev; 486 int flag; 487 int mode; 488 struct proc *p; 489 { 490 int unit = minor(dev); 491 struct clock_softc *sc = clock_cd.cd_devs[unit]; 492 493 sc->sc_flags = 0; 494 return 0; 495 } 496 497 int 498 rtcread(dev, uio, flags) 499 dev_t dev; 500 struct uio *uio; 501 int flags; 502 { 503 struct clock_softc *sc; 504 mc_todregs clkregs; 505 int s, length; 506 char buffer[16]; 507 508 sc = clock_cd.cd_devs[minor(dev)]; 509 510 s = splhigh(); 511 MC146818_GETTOD(RTC, &clkregs); 512 splx(s); 513 514 sprintf(buffer, "%4d%02d%02d%02d%02d.%02d\n", 515 clkregs[MC_YEAR] + GEMSTARTOFTIME, 516 clkregs[MC_MONTH], clkregs[MC_DOM], 517 clkregs[MC_HOUR], clkregs[MC_MIN], clkregs[MC_SEC]); 518 519 if (uio->uio_offset > strlen(buffer)) 520 return 0; 521 522 length = strlen(buffer) - uio->uio_offset; 523 if (length > uio->uio_resid) 524 length = uio->uio_resid; 525 526 return(uiomove((caddr_t)buffer, length, uio)); 527 } 528 529 static int 530 twodigits(buffer, pos) 531 char *buffer; 532 int pos; 533 { 534 int result = 0; 535 536 if (buffer[pos] >= '0' && buffer[pos] <= '9') 537 result = (buffer[pos] - '0') * 10; 538 if (buffer[pos+1] >= '0' && buffer[pos+1] <= '9') 539 result += (buffer[pos+1] - '0'); 540 return(result); 541 } 542 543 int 544 rtcwrite(dev, uio, flags) 545 dev_t dev; 546 struct uio *uio; 547 int flags; 548 { 549 mc_todregs clkregs; 550 int s, length, error; 551 char buffer[16]; 552 553 /* 554 * We require atomic updates! 555 */ 556 length = uio->uio_resid; 557 if (uio->uio_offset || (length != sizeof(buffer) 558 && length != sizeof(buffer - 1))) 559 return(EINVAL); 560 561 if ((error = uiomove((caddr_t)buffer, sizeof(buffer), uio))) 562 return(error); 563 564 if (length == sizeof(buffer) && buffer[sizeof(buffer) - 1] != '\n') 565 return(EINVAL); 566 567 s = splclock(); 568 mc146818_write(RTC, MC_REGB, 569 mc146818_read(RTC, MC_REGB) | MC_REGB_24HR | MC_REGB_BINARY); 570 MC146818_GETTOD(RTC, &clkregs); 571 splx(s); 572 573 clkregs[MC_SEC] = twodigits(buffer, 13); 574 clkregs[MC_MIN] = twodigits(buffer, 10); 575 clkregs[MC_HOUR] = twodigits(buffer, 8); 576 clkregs[MC_DOM] = twodigits(buffer, 6); 577 clkregs[MC_MONTH] = twodigits(buffer, 4); 578 s = twodigits(buffer, 0) * 100 + twodigits(buffer, 2); 579 clkregs[MC_YEAR] = s - GEMSTARTOFTIME; 580 581 s = splclock(); 582 MC146818_PUTTOD(RTC, &clkregs); 583 splx(s); 584 585 return(0); 586 } 587
Indexes created Tue Sep 30 17:09:57 GMT 2025