rtc.c revision 048cd5888f81713af4597bde5815f32d58fdf5b0
1/* 2 * Real Time Clock interface for Linux 3 * 4 * Copyright (C) 1996 Paul Gortmaker 5 * 6 * This driver allows use of the real time clock (built into 7 * nearly all computers) from user space. It exports the /dev/rtc 8 * interface supporting various ioctl() and also the 9 * /proc/driver/rtc pseudo-file for status information. 10 * 11 * The ioctls can be used to set the interrupt behaviour and 12 * generation rate from the RTC via IRQ 8. Then the /dev/rtc 13 * interface can be used to make use of these timer interrupts, 14 * be they interval or alarm based. 15 * 16 * The /dev/rtc interface will block on reads until an interrupt 17 * has been received. If a RTC interrupt has already happened, 18 * it will output an unsigned long and then block. The output value 19 * contains the interrupt status in the low byte and the number of 20 * interrupts since the last read in the remaining high bytes. The 21 * /dev/rtc interface can also be used with the select(2) call. 22 * 23 * This program is free software; you can redistribute it and/or 24 * modify it under the terms of the GNU General Public License 25 * as published by the Free Software Foundation; either version 26 * 2 of the License, or (at your option) any later version. 27 * 28 * Based on other minimal char device drivers, like Alan's 29 * watchdog, Ted's random, etc. etc. 30 * 31 * 1.07 Paul Gortmaker. 32 * 1.08 Miquel van Smoorenburg: disallow certain things on the 33 * DEC Alpha as the CMOS clock is also used for other things. 34 * 1.09 Nikita Schmidt: epoch support and some Alpha cleanup. 35 * 1.09a Pete Zaitcev: Sun SPARC 36 * 1.09b Jeff Garzik: Modularize, init cleanup 37 * 1.09c Jeff Garzik: SMP cleanup 38 * 1.10 Paul Barton-Davis: add support for async I/O 39 * 1.10a Andrea Arcangeli: Alpha updates 40 * 1.10b Andrew Morton: SMP lock fix 41 * 1.10c Cesar Barros: SMP locking fixes and cleanup 42 * 1.10d Paul Gortmaker: delete paranoia check in rtc_exit 43 * 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness. 44 * 1.11 Takashi Iwai: Kernel access functions 45 * rtc_register/rtc_unregister/rtc_control 46 * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init 47 * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer 48 * CONFIG_HPET_EMULATE_RTC 49 * 1.12a Maciej W. Rozycki: Handle memory-mapped chips properly. 50 * 1.12ac Alan Cox: Allow read access to the day of week register 51 * 1.12b David John: Remove calls to the BKL. 52 */ 53 54#define RTC_VERSION "1.12b" 55 56/* 57 * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with 58 * interrupts disabled. Due to the index-port/data-port (0x70/0x71) 59 * design of the RTC, we don't want two different things trying to 60 * get to it at once. (e.g. the periodic 11 min sync from time.c vs. 61 * this driver.) 62 */ 63 64#include <linux/interrupt.h> 65#include <linux/module.h> 66#include <linux/kernel.h> 67#include <linux/types.h> 68#include <linux/miscdevice.h> 69#include <linux/ioport.h> 70#include <linux/fcntl.h> 71#include <linux/mc146818rtc.h> 72#include <linux/init.h> 73#include <linux/poll.h> 74#include <linux/proc_fs.h> 75#include <linux/seq_file.h> 76#include <linux/spinlock.h> 77#include <linux/sysctl.h> 78#include <linux/wait.h> 79#include <linux/bcd.h> 80#include <linux/delay.h> 81#include <linux/uaccess.h> 82 83#include <asm/current.h> 84#include <asm/system.h> 85 86#ifdef CONFIG_X86 87#include <asm/hpet.h> 88#endif 89 90#ifdef CONFIG_SPARC32 91#include <linux/of.h> 92#include <linux/of_device.h> 93#include <asm/io.h> 94 95static unsigned long rtc_port; 96static int rtc_irq; 97#endif 98 99#ifdef CONFIG_HPET_EMULATE_RTC 100#undef RTC_IRQ 101#endif 102 103#ifdef RTC_IRQ 104static int rtc_has_irq = 1; 105#endif 106 107#ifndef CONFIG_HPET_EMULATE_RTC 108#define is_hpet_enabled() 0 109#define hpet_set_alarm_time(hrs, min, sec) 0 110#define hpet_set_periodic_freq(arg) 0 111#define hpet_mask_rtc_irq_bit(arg) 0 112#define hpet_set_rtc_irq_bit(arg) 0 113#define hpet_rtc_timer_init() do { } while (0) 114#define hpet_rtc_dropped_irq() 0 115#define hpet_register_irq_handler(h) ({ 0; }) 116#define hpet_unregister_irq_handler(h) ({ 0; }) 117#ifdef RTC_IRQ 118static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) 119{ 120 return 0; 121} 122#endif 123#endif 124 125/* 126 * We sponge a minor off of the misc major. No need slurping 127 * up another valuable major dev number for this. If you add 128 * an ioctl, make sure you don't conflict with SPARC's RTC 129 * ioctls. 130 */ 131 132static struct fasync_struct *rtc_async_queue; 133 134static DECLARE_WAIT_QUEUE_HEAD(rtc_wait); 135 136#ifdef RTC_IRQ 137static void rtc_dropped_irq(unsigned long data); 138 139static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0); 140#endif 141 142static ssize_t rtc_read(struct file *file, char __user *buf, 143 size_t count, loff_t *ppos); 144 145static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 146static void rtc_get_rtc_time(struct rtc_time *rtc_tm); 147 148#ifdef RTC_IRQ 149static unsigned int rtc_poll(struct file *file, poll_table *wait); 150#endif 151 152static void get_rtc_alm_time(struct rtc_time *alm_tm); 153#ifdef RTC_IRQ 154static void set_rtc_irq_bit_locked(unsigned char bit); 155static void mask_rtc_irq_bit_locked(unsigned char bit); 156 157static inline void set_rtc_irq_bit(unsigned char bit) 158{ 159 spin_lock_irq(&rtc_lock); 160 set_rtc_irq_bit_locked(bit); 161 spin_unlock_irq(&rtc_lock); 162} 163 164static void mask_rtc_irq_bit(unsigned char bit) 165{ 166 spin_lock_irq(&rtc_lock); 167 mask_rtc_irq_bit_locked(bit); 168 spin_unlock_irq(&rtc_lock); 169} 170#endif 171 172#ifdef CONFIG_PROC_FS 173static int rtc_proc_open(struct inode *inode, struct file *file); 174#endif 175 176/* 177 * Bits in rtc_status. (6 bits of room for future expansion) 178 */ 179 180#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */ 181#define RTC_TIMER_ON 0x02 /* missed irq timer active */ 182 183/* 184 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is 185 * protected by the spin lock rtc_lock. However, ioctl can still disable the 186 * timer in rtc_status and then with del_timer after the interrupt has read 187 * rtc_status but before mod_timer is called, which would then reenable the 188 * timer (but you would need to have an awful timing before you'd trip on it) 189 */ 190static unsigned long rtc_status; /* bitmapped status byte. */ 191static unsigned long rtc_freq; /* Current periodic IRQ rate */ 192static unsigned long rtc_irq_data; /* our output to the world */ 193static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */ 194 195#ifdef RTC_IRQ 196/* 197 * rtc_task_lock nests inside rtc_lock. 198 */ 199static DEFINE_SPINLOCK(rtc_task_lock); 200static rtc_task_t *rtc_callback; 201#endif 202 203/* 204 * If this driver ever becomes modularised, it will be really nice 205 * to make the epoch retain its value across module reload... 206 */ 207 208static unsigned long epoch = 1900; /* year corresponding to 0x00 */ 209 210static const unsigned char days_in_mo[] = 211{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 212 213/* 214 * Returns true if a clock update is in progress 215 */ 216static inline unsigned char rtc_is_updating(void) 217{ 218 unsigned long flags; 219 unsigned char uip; 220 221 spin_lock_irqsave(&rtc_lock, flags); 222 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); 223 spin_unlock_irqrestore(&rtc_lock, flags); 224 return uip; 225} 226 227#ifdef RTC_IRQ 228/* 229 * A very tiny interrupt handler. It runs with IRQF_DISABLED set, 230 * but there is possibility of conflicting with the set_rtc_mmss() 231 * call (the rtc irq and the timer irq can easily run at the same 232 * time in two different CPUs). So we need to serialize 233 * accesses to the chip with the rtc_lock spinlock that each 234 * architecture should implement in the timer code. 235 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.) 236 */ 237 238static irqreturn_t rtc_interrupt(int irq, void *dev_id) 239{ 240 /* 241 * Can be an alarm interrupt, update complete interrupt, 242 * or a periodic interrupt. We store the status in the 243 * low byte and the number of interrupts received since 244 * the last read in the remainder of rtc_irq_data. 245 */ 246 247 spin_lock(&rtc_lock); 248 rtc_irq_data += 0x100; 249 rtc_irq_data &= ~0xff; 250 if (is_hpet_enabled()) { 251 /* 252 * In this case it is HPET RTC interrupt handler 253 * calling us, with the interrupt information 254 * passed as arg1, instead of irq. 255 */ 256 rtc_irq_data |= (unsigned long)irq & 0xF0; 257 } else { 258 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); 259 } 260 261 if (rtc_status & RTC_TIMER_ON) 262 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); 263 264 spin_unlock(&rtc_lock); 265 266 /* Now do the rest of the actions */ 267 spin_lock(&rtc_task_lock); 268 if (rtc_callback) 269 rtc_callback->func(rtc_callback->private_data); 270 spin_unlock(&rtc_task_lock); 271 wake_up_interruptible(&rtc_wait); 272 273 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); 274 275 return IRQ_HANDLED; 276} 277#endif 278 279/* 280 * sysctl-tuning infrastructure. 281 */ 282static ctl_table rtc_table[] = { 283 { 284 .ctl_name = CTL_UNNUMBERED, 285 .procname = "max-user-freq", 286 .data = &rtc_max_user_freq, 287 .maxlen = sizeof(int), 288 .mode = 0644, 289 .proc_handler = &proc_dointvec, 290 }, 291 { .ctl_name = 0 } 292}; 293 294static ctl_table rtc_root[] = { 295 { 296 .ctl_name = CTL_UNNUMBERED, 297 .procname = "rtc", 298 .mode = 0555, 299 .child = rtc_table, 300 }, 301 { .ctl_name = 0 } 302}; 303 304static ctl_table dev_root[] = { 305 { 306 .ctl_name = CTL_DEV, 307 .procname = "dev", 308 .mode = 0555, 309 .child = rtc_root, 310 }, 311 { .ctl_name = 0 } 312}; 313 314static struct ctl_table_header *sysctl_header; 315 316static int __init init_sysctl(void) 317{ 318 sysctl_header = register_sysctl_table(dev_root); 319 return 0; 320} 321 322static void __exit cleanup_sysctl(void) 323{ 324 unregister_sysctl_table(sysctl_header); 325} 326 327/* 328 * Now all the various file operations that we export. 329 */ 330 331static ssize_t rtc_read(struct file *file, char __user *buf, 332 size_t count, loff_t *ppos) 333{ 334#ifndef RTC_IRQ 335 return -EIO; 336#else 337 DECLARE_WAITQUEUE(wait, current); 338 unsigned long data; 339 ssize_t retval; 340 341 if (rtc_has_irq == 0) 342 return -EIO; 343 344 /* 345 * Historically this function used to assume that sizeof(unsigned long) 346 * is the same in userspace and kernelspace. This lead to problems 347 * for configurations with multiple ABIs such a the MIPS o32 and 64 348 * ABIs supported on the same kernel. So now we support read of both 349 * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the 350 * userspace ABI. 351 */ 352 if (count != sizeof(unsigned int) && count != sizeof(unsigned long)) 353 return -EINVAL; 354 355 add_wait_queue(&rtc_wait, &wait); 356 357 do { 358 /* First make it right. Then make it fast. Putting this whole 359 * block within the parentheses of a while would be too 360 * confusing. And no, xchg() is not the answer. */ 361 362 __set_current_state(TASK_INTERRUPTIBLE); 363 364 spin_lock_irq(&rtc_lock); 365 data = rtc_irq_data; 366 rtc_irq_data = 0; 367 spin_unlock_irq(&rtc_lock); 368 369 if (data != 0) 370 break; 371 372 if (file->f_flags & O_NONBLOCK) { 373 retval = -EAGAIN; 374 goto out; 375 } 376 if (signal_pending(current)) { 377 retval = -ERESTARTSYS; 378 goto out; 379 } 380 schedule(); 381 } while (1); 382 383 if (count == sizeof(unsigned int)) { 384 retval = put_user(data, 385 (unsigned int __user *)buf) ?: sizeof(int); 386 } else { 387 retval = put_user(data, 388 (unsigned long __user *)buf) ?: sizeof(long); 389 } 390 if (!retval) 391 retval = count; 392 out: 393 __set_current_state(TASK_RUNNING); 394 remove_wait_queue(&rtc_wait, &wait); 395 396 return retval; 397#endif 398} 399 400static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) 401{ 402 struct rtc_time wtime; 403 404#ifdef RTC_IRQ 405 if (rtc_has_irq == 0) { 406 switch (cmd) { 407 case RTC_AIE_OFF: 408 case RTC_AIE_ON: 409 case RTC_PIE_OFF: 410 case RTC_PIE_ON: 411 case RTC_UIE_OFF: 412 case RTC_UIE_ON: 413 case RTC_IRQP_READ: 414 case RTC_IRQP_SET: 415 return -EINVAL; 416 }; 417 } 418#endif 419 420 switch (cmd) { 421#ifdef RTC_IRQ 422 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */ 423 { 424 mask_rtc_irq_bit(RTC_AIE); 425 return 0; 426 } 427 case RTC_AIE_ON: /* Allow alarm interrupts. */ 428 { 429 set_rtc_irq_bit(RTC_AIE); 430 return 0; 431 } 432 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */ 433 { 434 /* can be called from isr via rtc_control() */ 435 unsigned long flags; 436 437 spin_lock_irqsave(&rtc_lock, flags); 438 mask_rtc_irq_bit_locked(RTC_PIE); 439 if (rtc_status & RTC_TIMER_ON) { 440 rtc_status &= ~RTC_TIMER_ON; 441 del_timer(&rtc_irq_timer); 442 } 443 spin_unlock_irqrestore(&rtc_lock, flags); 444 445 return 0; 446 } 447 case RTC_PIE_ON: /* Allow periodic ints */ 448 { 449 /* can be called from isr via rtc_control() */ 450 unsigned long flags; 451 452 /* 453 * We don't really want Joe User enabling more 454 * than 64Hz of interrupts on a multi-user machine. 455 */ 456 if (!kernel && (rtc_freq > rtc_max_user_freq) && 457 (!capable(CAP_SYS_RESOURCE))) 458 return -EACCES; 459 460 spin_lock_irqsave(&rtc_lock, flags); 461 if (!(rtc_status & RTC_TIMER_ON)) { 462 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 463 2*HZ/100); 464 rtc_status |= RTC_TIMER_ON; 465 } 466 set_rtc_irq_bit_locked(RTC_PIE); 467 spin_unlock_irqrestore(&rtc_lock, flags); 468 469 return 0; 470 } 471 case RTC_UIE_OFF: /* Mask ints from RTC updates. */ 472 { 473 mask_rtc_irq_bit(RTC_UIE); 474 return 0; 475 } 476 case RTC_UIE_ON: /* Allow ints for RTC updates. */ 477 { 478 set_rtc_irq_bit(RTC_UIE); 479 return 0; 480 } 481#endif 482 case RTC_ALM_READ: /* Read the present alarm time */ 483 { 484 /* 485 * This returns a struct rtc_time. Reading >= 0xc0 486 * means "don't care" or "match all". Only the tm_hour, 487 * tm_min, and tm_sec values are filled in. 488 */ 489 memset(&wtime, 0, sizeof(struct rtc_time)); 490 get_rtc_alm_time(&wtime); 491 break; 492 } 493 case RTC_ALM_SET: /* Store a time into the alarm */ 494 { 495 /* 496 * This expects a struct rtc_time. Writing 0xff means 497 * "don't care" or "match all". Only the tm_hour, 498 * tm_min and tm_sec are used. 499 */ 500 unsigned char hrs, min, sec; 501 struct rtc_time alm_tm; 502 503 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg, 504 sizeof(struct rtc_time))) 505 return -EFAULT; 506 507 hrs = alm_tm.tm_hour; 508 min = alm_tm.tm_min; 509 sec = alm_tm.tm_sec; 510 511 spin_lock_irq(&rtc_lock); 512 if (hpet_set_alarm_time(hrs, min, sec)) { 513 /* 514 * Fallthru and set alarm time in CMOS too, 515 * so that we will get proper value in RTC_ALM_READ 516 */ 517 } 518 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || 519 RTC_ALWAYS_BCD) { 520 if (sec < 60) 521 sec = bin2bcd(sec); 522 else 523 sec = 0xff; 524 525 if (min < 60) 526 min = bin2bcd(min); 527 else 528 min = 0xff; 529 530 if (hrs < 24) 531 hrs = bin2bcd(hrs); 532 else 533 hrs = 0xff; 534 } 535 CMOS_WRITE(hrs, RTC_HOURS_ALARM); 536 CMOS_WRITE(min, RTC_MINUTES_ALARM); 537 CMOS_WRITE(sec, RTC_SECONDS_ALARM); 538 spin_unlock_irq(&rtc_lock); 539 540 return 0; 541 } 542 case RTC_RD_TIME: /* Read the time/date from RTC */ 543 { 544 memset(&wtime, 0, sizeof(struct rtc_time)); 545 rtc_get_rtc_time(&wtime); 546 break; 547 } 548 case RTC_SET_TIME: /* Set the RTC */ 549 { 550 struct rtc_time rtc_tm; 551 unsigned char mon, day, hrs, min, sec, leap_yr; 552 unsigned char save_control, save_freq_select; 553 unsigned int yrs; 554#ifdef CONFIG_MACH_DECSTATION 555 unsigned int real_yrs; 556#endif 557 558 if (!capable(CAP_SYS_TIME)) 559 return -EACCES; 560 561 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg, 562 sizeof(struct rtc_time))) 563 return -EFAULT; 564 565 yrs = rtc_tm.tm_year + 1900; 566 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 567 day = rtc_tm.tm_mday; 568 hrs = rtc_tm.tm_hour; 569 min = rtc_tm.tm_min; 570 sec = rtc_tm.tm_sec; 571 572 if (yrs < 1970) 573 return -EINVAL; 574 575 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 576 577 if ((mon > 12) || (day == 0)) 578 return -EINVAL; 579 580 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 581 return -EINVAL; 582 583 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 584 return -EINVAL; 585 586 yrs -= epoch; 587 if (yrs > 255) /* They are unsigned */ 588 return -EINVAL; 589 590 spin_lock_irq(&rtc_lock); 591#ifdef CONFIG_MACH_DECSTATION 592 real_yrs = yrs; 593 yrs = 72; 594 595 /* 596 * We want to keep the year set to 73 until March 597 * for non-leap years, so that Feb, 29th is handled 598 * correctly. 599 */ 600 if (!leap_yr && mon < 3) { 601 real_yrs--; 602 yrs = 73; 603 } 604#endif 605 /* These limits and adjustments are independent of 606 * whether the chip is in binary mode or not. 607 */ 608 if (yrs > 169) { 609 spin_unlock_irq(&rtc_lock); 610 return -EINVAL; 611 } 612 if (yrs >= 100) 613 yrs -= 100; 614 615 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 616 || RTC_ALWAYS_BCD) { 617 sec = bin2bcd(sec); 618 min = bin2bcd(min); 619 hrs = bin2bcd(hrs); 620 day = bin2bcd(day); 621 mon = bin2bcd(mon); 622 yrs = bin2bcd(yrs); 623 } 624 625 save_control = CMOS_READ(RTC_CONTROL); 626 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); 627 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); 628 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 629 630#ifdef CONFIG_MACH_DECSTATION 631 CMOS_WRITE(real_yrs, RTC_DEC_YEAR); 632#endif 633 CMOS_WRITE(yrs, RTC_YEAR); 634 CMOS_WRITE(mon, RTC_MONTH); 635 CMOS_WRITE(day, RTC_DAY_OF_MONTH); 636 CMOS_WRITE(hrs, RTC_HOURS); 637 CMOS_WRITE(min, RTC_MINUTES); 638 CMOS_WRITE(sec, RTC_SECONDS); 639 640 CMOS_WRITE(save_control, RTC_CONTROL); 641 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); 642 643 spin_unlock_irq(&rtc_lock); 644 return 0; 645 } 646#ifdef RTC_IRQ 647 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */ 648 { 649 return put_user(rtc_freq, (unsigned long __user *)arg); 650 } 651 case RTC_IRQP_SET: /* Set periodic IRQ rate. */ 652 { 653 int tmp = 0; 654 unsigned char val; 655 /* can be called from isr via rtc_control() */ 656 unsigned long flags; 657 658 /* 659 * The max we can do is 8192Hz. 660 */ 661 if ((arg < 2) || (arg > 8192)) 662 return -EINVAL; 663 /* 664 * We don't really want Joe User generating more 665 * than 64Hz of interrupts on a multi-user machine. 666 */ 667 if (!kernel && (arg > rtc_max_user_freq) && 668 !capable(CAP_SYS_RESOURCE)) 669 return -EACCES; 670 671 while (arg > (1<<tmp)) 672 tmp++; 673 674 /* 675 * Check that the input was really a power of 2. 676 */ 677 if (arg != (1<<tmp)) 678 return -EINVAL; 679 680 rtc_freq = arg; 681 682 spin_lock_irqsave(&rtc_lock, flags); 683 if (hpet_set_periodic_freq(arg)) { 684 spin_unlock_irqrestore(&rtc_lock, flags); 685 return 0; 686 } 687 688 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0; 689 val |= (16 - tmp); 690 CMOS_WRITE(val, RTC_FREQ_SELECT); 691 spin_unlock_irqrestore(&rtc_lock, flags); 692 return 0; 693 } 694#endif 695 case RTC_EPOCH_READ: /* Read the epoch. */ 696 { 697 return put_user(epoch, (unsigned long __user *)arg); 698 } 699 case RTC_EPOCH_SET: /* Set the epoch. */ 700 { 701 /* 702 * There were no RTC clocks before 1900. 703 */ 704 if (arg < 1900) 705 return -EINVAL; 706 707 if (!capable(CAP_SYS_TIME)) 708 return -EACCES; 709 710 epoch = arg; 711 return 0; 712 } 713 default: 714 return -ENOTTY; 715 } 716 return copy_to_user((void __user *)arg, 717 &wtime, sizeof wtime) ? -EFAULT : 0; 718} 719 720static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 721{ 722 long ret; 723 ret = rtc_do_ioctl(cmd, arg, 0); 724 return ret; 725} 726 727/* 728 * We enforce only one user at a time here with the open/close. 729 * Also clear the previous interrupt data on an open, and clean 730 * up things on a close. 731 */ 732static int rtc_open(struct inode *inode, struct file *file) 733{ 734 spin_lock_irq(&rtc_lock); 735 736 if (rtc_status & RTC_IS_OPEN) 737 goto out_busy; 738 739 rtc_status |= RTC_IS_OPEN; 740 741 rtc_irq_data = 0; 742 spin_unlock_irq(&rtc_lock); 743 return 0; 744 745out_busy: 746 spin_unlock_irq(&rtc_lock); 747 return -EBUSY; 748} 749 750static int rtc_fasync(int fd, struct file *filp, int on) 751{ 752 return fasync_helper(fd, filp, on, &rtc_async_queue); 753} 754 755static int rtc_release(struct inode *inode, struct file *file) 756{ 757#ifdef RTC_IRQ 758 unsigned char tmp; 759 760 if (rtc_has_irq == 0) 761 goto no_irq; 762 763 /* 764 * Turn off all interrupts once the device is no longer 765 * in use, and clear the data. 766 */ 767 768 spin_lock_irq(&rtc_lock); 769 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { 770 tmp = CMOS_READ(RTC_CONTROL); 771 tmp &= ~RTC_PIE; 772 tmp &= ~RTC_AIE; 773 tmp &= ~RTC_UIE; 774 CMOS_WRITE(tmp, RTC_CONTROL); 775 CMOS_READ(RTC_INTR_FLAGS); 776 } 777 if (rtc_status & RTC_TIMER_ON) { 778 rtc_status &= ~RTC_TIMER_ON; 779 del_timer(&rtc_irq_timer); 780 } 781 spin_unlock_irq(&rtc_lock); 782 783no_irq: 784#endif 785 786 spin_lock_irq(&rtc_lock); 787 rtc_irq_data = 0; 788 rtc_status &= ~RTC_IS_OPEN; 789 spin_unlock_irq(&rtc_lock); 790 791 return 0; 792} 793 794#ifdef RTC_IRQ 795static unsigned int rtc_poll(struct file *file, poll_table *wait) 796{ 797 unsigned long l; 798 799 if (rtc_has_irq == 0) 800 return 0; 801 802 poll_wait(file, &rtc_wait, wait); 803 804 spin_lock_irq(&rtc_lock); 805 l = rtc_irq_data; 806 spin_unlock_irq(&rtc_lock); 807 808 if (l != 0) 809 return POLLIN | POLLRDNORM; 810 return 0; 811} 812#endif 813 814int rtc_register(rtc_task_t *task) 815{ 816#ifndef RTC_IRQ 817 return -EIO; 818#else 819 if (task == NULL || task->func == NULL) 820 return -EINVAL; 821 spin_lock_irq(&rtc_lock); 822 if (rtc_status & RTC_IS_OPEN) { 823 spin_unlock_irq(&rtc_lock); 824 return -EBUSY; 825 } 826 spin_lock(&rtc_task_lock); 827 if (rtc_callback) { 828 spin_unlock(&rtc_task_lock); 829 spin_unlock_irq(&rtc_lock); 830 return -EBUSY; 831 } 832 rtc_status |= RTC_IS_OPEN; 833 rtc_callback = task; 834 spin_unlock(&rtc_task_lock); 835 spin_unlock_irq(&rtc_lock); 836 return 0; 837#endif 838} 839EXPORT_SYMBOL(rtc_register); 840 841int rtc_unregister(rtc_task_t *task) 842{ 843#ifndef RTC_IRQ 844 return -EIO; 845#else 846 unsigned char tmp; 847 848 spin_lock_irq(&rtc_lock); 849 spin_lock(&rtc_task_lock); 850 if (rtc_callback != task) { 851 spin_unlock(&rtc_task_lock); 852 spin_unlock_irq(&rtc_lock); 853 return -ENXIO; 854 } 855 rtc_callback = NULL; 856 857 /* disable controls */ 858 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { 859 tmp = CMOS_READ(RTC_CONTROL); 860 tmp &= ~RTC_PIE; 861 tmp &= ~RTC_AIE; 862 tmp &= ~RTC_UIE; 863 CMOS_WRITE(tmp, RTC_CONTROL); 864 CMOS_READ(RTC_INTR_FLAGS); 865 } 866 if (rtc_status & RTC_TIMER_ON) { 867 rtc_status &= ~RTC_TIMER_ON; 868 del_timer(&rtc_irq_timer); 869 } 870 rtc_status &= ~RTC_IS_OPEN; 871 spin_unlock(&rtc_task_lock); 872 spin_unlock_irq(&rtc_lock); 873 return 0; 874#endif 875} 876EXPORT_SYMBOL(rtc_unregister); 877 878int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg) 879{ 880#ifndef RTC_IRQ 881 return -EIO; 882#else 883 unsigned long flags; 884 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET) 885 return -EINVAL; 886 spin_lock_irqsave(&rtc_task_lock, flags); 887 if (rtc_callback != task) { 888 spin_unlock_irqrestore(&rtc_task_lock, flags); 889 return -ENXIO; 890 } 891 spin_unlock_irqrestore(&rtc_task_lock, flags); 892 return rtc_do_ioctl(cmd, arg, 1); 893#endif 894} 895EXPORT_SYMBOL(rtc_control); 896 897/* 898 * The various file operations we support. 899 */ 900 901static const struct file_operations rtc_fops = { 902 .owner = THIS_MODULE, 903 .llseek = no_llseek, 904 .read = rtc_read, 905#ifdef RTC_IRQ 906 .poll = rtc_poll, 907#endif 908 .unlocked_ioctl = rtc_ioctl, 909 .open = rtc_open, 910 .release = rtc_release, 911 .fasync = rtc_fasync, 912}; 913 914static struct miscdevice rtc_dev = { 915 .minor = RTC_MINOR, 916 .name = "rtc", 917 .fops = &rtc_fops, 918}; 919 920#ifdef CONFIG_PROC_FS 921static const struct file_operations rtc_proc_fops = { 922 .owner = THIS_MODULE, 923 .open = rtc_proc_open, 924 .read = seq_read, 925 .llseek = seq_lseek, 926 .release = single_release, 927}; 928#endif 929 930static resource_size_t rtc_size; 931 932static struct resource * __init rtc_request_region(resource_size_t size) 933{ 934 struct resource *r; 935 936 if (RTC_IOMAPPED) 937 r = request_region(RTC_PORT(0), size, "rtc"); 938 else 939 r = request_mem_region(RTC_PORT(0), size, "rtc"); 940 941 if (r) 942 rtc_size = size; 943 944 return r; 945} 946 947static void rtc_release_region(void) 948{ 949 if (RTC_IOMAPPED) 950 release_region(RTC_PORT(0), rtc_size); 951 else 952 release_mem_region(RTC_PORT(0), rtc_size); 953} 954 955static int __init rtc_init(void) 956{ 957#ifdef CONFIG_PROC_FS 958 struct proc_dir_entry *ent; 959#endif 960#if defined(__alpha__) || defined(__mips__) 961 unsigned int year, ctrl; 962 char *guess = NULL; 963#endif 964#ifdef CONFIG_SPARC32 965 struct device_node *ebus_dp; 966 struct of_device *op; 967#else 968 void *r; 969#ifdef RTC_IRQ 970 irq_handler_t rtc_int_handler_ptr; 971#endif 972#endif 973 974#ifdef CONFIG_SPARC32 975 for_each_node_by_name(ebus_dp, "ebus") { 976 struct device_node *dp; 977 for (dp = ebus_dp; dp; dp = dp->sibling) { 978 if (!strcmp(dp->name, "rtc")) { 979 op = of_find_device_by_node(dp); 980 if (op) { 981 rtc_port = op->resource[0].start; 982 rtc_irq = op->irqs[0]; 983 goto found; 984 } 985 } 986 } 987 } 988 rtc_has_irq = 0; 989 printk(KERN_ERR "rtc_init: no PC rtc found\n"); 990 return -EIO; 991 992found: 993 if (!rtc_irq) { 994 rtc_has_irq = 0; 995 goto no_irq; 996 } 997 998 /* 999 * XXX Interrupt pin #7 in Espresso is shared between RTC and 1000 * PCI Slot 2 INTA# (and some INTx# in Slot 1). 1001 */ 1002 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", 1003 (void *)&rtc_port)) { 1004 rtc_has_irq = 0; 1005 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq); 1006 return -EIO; 1007 } 1008no_irq: 1009#else 1010 r = rtc_request_region(RTC_IO_EXTENT); 1011 1012 /* 1013 * If we've already requested a smaller range (for example, because 1014 * PNPBIOS or ACPI told us how the device is configured), the request 1015 * above might fail because it's too big. 1016 * 1017 * If so, request just the range we actually use. 1018 */ 1019 if (!r) 1020 r = rtc_request_region(RTC_IO_EXTENT_USED); 1021 if (!r) { 1022#ifdef RTC_IRQ 1023 rtc_has_irq = 0; 1024#endif 1025 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n", 1026 (long)(RTC_PORT(0))); 1027 return -EIO; 1028 } 1029 1030#ifdef RTC_IRQ 1031 if (is_hpet_enabled()) { 1032 int err; 1033 1034 rtc_int_handler_ptr = hpet_rtc_interrupt; 1035 err = hpet_register_irq_handler(rtc_interrupt); 1036 if (err != 0) { 1037 printk(KERN_WARNING "hpet_register_irq_handler failed " 1038 "in rtc_init()."); 1039 return err; 1040 } 1041 } else { 1042 rtc_int_handler_ptr = rtc_interrupt; 1043 } 1044 1045 if (request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, 1046 "rtc", NULL)) { 1047 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */ 1048 rtc_has_irq = 0; 1049 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ); 1050 rtc_release_region(); 1051 1052 return -EIO; 1053 } 1054 hpet_rtc_timer_init(); 1055 1056#endif 1057 1058#endif /* CONFIG_SPARC32 vs. others */ 1059 1060 if (misc_register(&rtc_dev)) { 1061#ifdef RTC_IRQ 1062 free_irq(RTC_IRQ, NULL); 1063 hpet_unregister_irq_handler(rtc_interrupt); 1064 rtc_has_irq = 0; 1065#endif 1066 rtc_release_region(); 1067 return -ENODEV; 1068 } 1069 1070#ifdef CONFIG_PROC_FS 1071 ent = proc_create("driver/rtc", 0, NULL, &rtc_proc_fops); 1072 if (!ent) 1073 printk(KERN_WARNING "rtc: Failed to register with procfs.\n"); 1074#endif 1075 1076#if defined(__alpha__) || defined(__mips__) 1077 rtc_freq = HZ; 1078 1079 /* Each operating system on an Alpha uses its own epoch. 1080 Let's try to guess which one we are using now. */ 1081 1082 if (rtc_is_updating() != 0) 1083 msleep(20); 1084 1085 spin_lock_irq(&rtc_lock); 1086 year = CMOS_READ(RTC_YEAR); 1087 ctrl = CMOS_READ(RTC_CONTROL); 1088 spin_unlock_irq(&rtc_lock); 1089 1090 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) 1091 year = bcd2bin(year); /* This should never happen... */ 1092 1093 if (year < 20) { 1094 epoch = 2000; 1095 guess = "SRM (post-2000)"; 1096 } else if (year >= 20 && year < 48) { 1097 epoch = 1980; 1098 guess = "ARC console"; 1099 } else if (year >= 48 && year < 72) { 1100 epoch = 1952; 1101 guess = "Digital UNIX"; 1102#if defined(__mips__) 1103 } else if (year >= 72 && year < 74) { 1104 epoch = 2000; 1105 guess = "Digital DECstation"; 1106#else 1107 } else if (year >= 70) { 1108 epoch = 1900; 1109 guess = "Standard PC (1900)"; 1110#endif 1111 } 1112 if (guess) 1113 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", 1114 guess, epoch); 1115#endif 1116#ifdef RTC_IRQ 1117 if (rtc_has_irq == 0) 1118 goto no_irq2; 1119 1120 spin_lock_irq(&rtc_lock); 1121 rtc_freq = 1024; 1122 if (!hpet_set_periodic_freq(rtc_freq)) { 1123 /* 1124 * Initialize periodic frequency to CMOS reset default, 1125 * which is 1024Hz 1126 */ 1127 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), 1128 RTC_FREQ_SELECT); 1129 } 1130 spin_unlock_irq(&rtc_lock); 1131no_irq2: 1132#endif 1133 1134 (void) init_sysctl(); 1135 1136 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n"); 1137 1138 return 0; 1139} 1140 1141static void __exit rtc_exit(void) 1142{ 1143 cleanup_sysctl(); 1144 remove_proc_entry("driver/rtc", NULL); 1145 misc_deregister(&rtc_dev); 1146 1147#ifdef CONFIG_SPARC32 1148 if (rtc_has_irq) 1149 free_irq(rtc_irq, &rtc_port); 1150#else 1151 rtc_release_region(); 1152#ifdef RTC_IRQ 1153 if (rtc_has_irq) { 1154 free_irq(RTC_IRQ, NULL); 1155 hpet_unregister_irq_handler(hpet_rtc_interrupt); 1156 } 1157#endif 1158#endif /* CONFIG_SPARC32 */ 1159} 1160 1161module_init(rtc_init); 1162module_exit(rtc_exit); 1163 1164#ifdef RTC_IRQ 1165/* 1166 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether. 1167 * (usually during an IDE disk interrupt, with IRQ unmasking off) 1168 * Since the interrupt handler doesn't get called, the IRQ status 1169 * byte doesn't get read, and the RTC stops generating interrupts. 1170 * A timer is set, and will call this function if/when that happens. 1171 * To get it out of this stalled state, we just read the status. 1172 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost. 1173 * (You *really* shouldn't be trying to use a non-realtime system 1174 * for something that requires a steady > 1KHz signal anyways.) 1175 */ 1176 1177static void rtc_dropped_irq(unsigned long data) 1178{ 1179 unsigned long freq; 1180 1181 spin_lock_irq(&rtc_lock); 1182 1183 if (hpet_rtc_dropped_irq()) { 1184 spin_unlock_irq(&rtc_lock); 1185 return; 1186 } 1187 1188 /* Just in case someone disabled the timer from behind our back... */ 1189 if (rtc_status & RTC_TIMER_ON) 1190 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); 1191 1192 rtc_irq_data += ((rtc_freq/HZ)<<8); 1193 rtc_irq_data &= ~0xff; 1194 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */ 1195 1196 freq = rtc_freq; 1197 1198 spin_unlock_irq(&rtc_lock); 1199 1200 if (printk_ratelimit()) { 1201 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", 1202 freq); 1203 } 1204 1205 /* Now we have new data */ 1206 wake_up_interruptible(&rtc_wait); 1207 1208 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN); 1209} 1210#endif 1211 1212#ifdef CONFIG_PROC_FS 1213/* 1214 * Info exported via "/proc/driver/rtc". 1215 */ 1216 1217static int rtc_proc_show(struct seq_file *seq, void *v) 1218{ 1219#define YN(bit) ((ctrl & bit) ? "yes" : "no") 1220#define NY(bit) ((ctrl & bit) ? "no" : "yes") 1221 struct rtc_time tm; 1222 unsigned char batt, ctrl; 1223 unsigned long freq; 1224 1225 spin_lock_irq(&rtc_lock); 1226 batt = CMOS_READ(RTC_VALID) & RTC_VRT; 1227 ctrl = CMOS_READ(RTC_CONTROL); 1228 freq = rtc_freq; 1229 spin_unlock_irq(&rtc_lock); 1230 1231 1232 rtc_get_rtc_time(&tm); 1233 1234 /* 1235 * There is no way to tell if the luser has the RTC set for local 1236 * time or for Universal Standard Time (GMT). Probably local though. 1237 */ 1238 seq_printf(seq, 1239 "rtc_time\t: %02d:%02d:%02d\n" 1240 "rtc_date\t: %04d-%02d-%02d\n" 1241 "rtc_epoch\t: %04lu\n", 1242 tm.tm_hour, tm.tm_min, tm.tm_sec, 1243 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch); 1244 1245 get_rtc_alm_time(&tm); 1246 1247 /* 1248 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will 1249 * match any value for that particular field. Values that are 1250 * greater than a valid time, but less than 0xc0 shouldn't appear. 1251 */ 1252 seq_puts(seq, "alarm\t\t: "); 1253 if (tm.tm_hour <= 24) 1254 seq_printf(seq, "%02d:", tm.tm_hour); 1255 else 1256 seq_puts(seq, "**:"); 1257 1258 if (tm.tm_min <= 59) 1259 seq_printf(seq, "%02d:", tm.tm_min); 1260 else 1261 seq_puts(seq, "**:"); 1262 1263 if (tm.tm_sec <= 59) 1264 seq_printf(seq, "%02d\n", tm.tm_sec); 1265 else 1266 seq_puts(seq, "**\n"); 1267 1268 seq_printf(seq, 1269 "DST_enable\t: %s\n" 1270 "BCD\t\t: %s\n" 1271 "24hr\t\t: %s\n" 1272 "square_wave\t: %s\n" 1273 "alarm_IRQ\t: %s\n" 1274 "update_IRQ\t: %s\n" 1275 "periodic_IRQ\t: %s\n" 1276 "periodic_freq\t: %ld\n" 1277 "batt_status\t: %s\n", 1278 YN(RTC_DST_EN), 1279 NY(RTC_DM_BINARY), 1280 YN(RTC_24H), 1281 YN(RTC_SQWE), 1282 YN(RTC_AIE), 1283 YN(RTC_UIE), 1284 YN(RTC_PIE), 1285 freq, 1286 batt ? "okay" : "dead"); 1287 1288 return 0; 1289#undef YN 1290#undef NY 1291} 1292 1293static int rtc_proc_open(struct inode *inode, struct file *file) 1294{ 1295 return single_open(file, rtc_proc_show, NULL); 1296} 1297#endif 1298 1299static void rtc_get_rtc_time(struct rtc_time *rtc_tm) 1300{ 1301 unsigned long uip_watchdog = jiffies, flags; 1302 unsigned char ctrl; 1303#ifdef CONFIG_MACH_DECSTATION 1304 unsigned int real_year; 1305#endif 1306 1307 /* 1308 * read RTC once any update in progress is done. The update 1309 * can take just over 2ms. We wait 20ms. There is no need to 1310 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. 1311 * If you need to know *exactly* when a second has started, enable 1312 * periodic update complete interrupts, (via ioctl) and then 1313 * immediately read /dev/rtc which will block until you get the IRQ. 1314 * Once the read clears, read the RTC time (again via ioctl). Easy. 1315 */ 1316 1317 while (rtc_is_updating() != 0 && 1318 time_before(jiffies, uip_watchdog + 2*HZ/100)) 1319 cpu_relax(); 1320 1321 /* 1322 * Only the values that we read from the RTC are set. We leave 1323 * tm_wday, tm_yday and tm_isdst untouched. Note that while the 1324 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is 1325 * only updated by the RTC when initially set to a non-zero value. 1326 */ 1327 spin_lock_irqsave(&rtc_lock, flags); 1328 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); 1329 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); 1330 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); 1331 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); 1332 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH); 1333 rtc_tm->tm_year = CMOS_READ(RTC_YEAR); 1334 /* Only set from 2.6.16 onwards */ 1335 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK); 1336 1337#ifdef CONFIG_MACH_DECSTATION 1338 real_year = CMOS_READ(RTC_DEC_YEAR); 1339#endif 1340 ctrl = CMOS_READ(RTC_CONTROL); 1341 spin_unlock_irqrestore(&rtc_lock, flags); 1342 1343 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 1344 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec); 1345 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min); 1346 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour); 1347 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday); 1348 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon); 1349 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year); 1350 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday); 1351 } 1352 1353#ifdef CONFIG_MACH_DECSTATION 1354 rtc_tm->tm_year += real_year - 72; 1355#endif 1356 1357 /* 1358 * Account for differences between how the RTC uses the values 1359 * and how they are defined in a struct rtc_time; 1360 */ 1361 rtc_tm->tm_year += epoch - 1900; 1362 if (rtc_tm->tm_year <= 69) 1363 rtc_tm->tm_year += 100; 1364 1365 rtc_tm->tm_mon--; 1366} 1367 1368static void get_rtc_alm_time(struct rtc_time *alm_tm) 1369{ 1370 unsigned char ctrl; 1371 1372 /* 1373 * Only the values that we read from the RTC are set. That 1374 * means only tm_hour, tm_min, and tm_sec. 1375 */ 1376 spin_lock_irq(&rtc_lock); 1377 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM); 1378 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM); 1379 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM); 1380 ctrl = CMOS_READ(RTC_CONTROL); 1381 spin_unlock_irq(&rtc_lock); 1382 1383 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { 1384 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec); 1385 alm_tm->tm_min = bcd2bin(alm_tm->tm_min); 1386 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour); 1387 } 1388} 1389 1390#ifdef RTC_IRQ 1391/* 1392 * Used to disable/enable interrupts for any one of UIE, AIE, PIE. 1393 * Rumour has it that if you frob the interrupt enable/disable 1394 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to 1395 * ensure you actually start getting interrupts. Probably for 1396 * compatibility with older/broken chipset RTC implementations. 1397 * We also clear out any old irq data after an ioctl() that 1398 * meddles with the interrupt enable/disable bits. 1399 */ 1400 1401static void mask_rtc_irq_bit_locked(unsigned char bit) 1402{ 1403 unsigned char val; 1404 1405 if (hpet_mask_rtc_irq_bit(bit)) 1406 return; 1407 val = CMOS_READ(RTC_CONTROL); 1408 val &= ~bit; 1409 CMOS_WRITE(val, RTC_CONTROL); 1410 CMOS_READ(RTC_INTR_FLAGS); 1411 1412 rtc_irq_data = 0; 1413} 1414 1415static void set_rtc_irq_bit_locked(unsigned char bit) 1416{ 1417 unsigned char val; 1418 1419 if (hpet_set_rtc_irq_bit(bit)) 1420 return; 1421 val = CMOS_READ(RTC_CONTROL); 1422 val |= bit; 1423 CMOS_WRITE(val, RTC_CONTROL); 1424 CMOS_READ(RTC_INTR_FLAGS); 1425 1426 rtc_irq_data = 0; 1427} 1428#endif 1429 1430MODULE_AUTHOR("Paul Gortmaker"); 1431MODULE_LICENSE("GPL"); 1432MODULE_ALIAS_MISCDEV(RTC_MINOR); 1433