rtc.c revision 0f74964627e0ece4ac8da0e2cd01906ec322b4fe
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 */ 52 53#define RTC_VERSION "1.12ac" 54 55/* 56 * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with 57 * interrupts disabled. Due to the index-port/data-port (0x70/0x71) 58 * design of the RTC, we don't want two different things trying to 59 * get to it at once. (e.g. the periodic 11 min sync from time.c vs. 60 * this driver.) 61 */ 62 63#include <linux/interrupt.h> 64#include <linux/module.h> 65#include <linux/kernel.h> 66#include <linux/types.h> 67#include <linux/miscdevice.h> 68#include <linux/ioport.h> 69#include <linux/fcntl.h> 70#include <linux/mc146818rtc.h> 71#include <linux/init.h> 72#include <linux/poll.h> 73#include <linux/proc_fs.h> 74#include <linux/seq_file.h> 75#include <linux/spinlock.h> 76#include <linux/sysctl.h> 77#include <linux/wait.h> 78#include <linux/bcd.h> 79#include <linux/delay.h> 80 81#include <asm/current.h> 82#include <asm/uaccess.h> 83#include <asm/system.h> 84 85#if defined(__i386__) 86#include <asm/hpet.h> 87#endif 88 89#ifdef __sparc__ 90#include <linux/pci.h> 91#include <asm/ebus.h> 92#ifdef __sparc_v9__ 93#include <asm/isa.h> 94#endif 95 96static unsigned long rtc_port; 97static int rtc_irq = PCI_IRQ_NONE; 98#endif 99 100#ifdef CONFIG_HPET_RTC_IRQ 101#undef RTC_IRQ 102#endif 103 104#ifdef RTC_IRQ 105static int rtc_has_irq = 1; 106#endif 107 108#ifndef CONFIG_HPET_EMULATE_RTC 109#define is_hpet_enabled() 0 110#define hpet_set_alarm_time(hrs, min, sec) 0 111#define hpet_set_periodic_freq(arg) 0 112#define hpet_mask_rtc_irq_bit(arg) 0 113#define hpet_set_rtc_irq_bit(arg) 0 114#define hpet_rtc_timer_init() do { } while (0) 115#define hpet_rtc_dropped_irq() 0 116static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) {return 0;} 117#else 118extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs); 119#endif 120 121/* 122 * We sponge a minor off of the misc major. No need slurping 123 * up another valuable major dev number for this. If you add 124 * an ioctl, make sure you don't conflict with SPARC's RTC 125 * ioctls. 126 */ 127 128static struct fasync_struct *rtc_async_queue; 129 130static DECLARE_WAIT_QUEUE_HEAD(rtc_wait); 131 132#ifdef RTC_IRQ 133static struct timer_list rtc_irq_timer; 134#endif 135 136static ssize_t rtc_read(struct file *file, char __user *buf, 137 size_t count, loff_t *ppos); 138 139static int rtc_ioctl(struct inode *inode, struct file *file, 140 unsigned int cmd, unsigned long arg); 141 142#ifdef RTC_IRQ 143static unsigned int rtc_poll(struct file *file, poll_table *wait); 144#endif 145 146static void get_rtc_alm_time (struct rtc_time *alm_tm); 147#ifdef RTC_IRQ 148static void rtc_dropped_irq(unsigned long data); 149 150static void set_rtc_irq_bit_locked(unsigned char bit); 151static void mask_rtc_irq_bit_locked(unsigned char bit); 152 153static inline void set_rtc_irq_bit(unsigned char bit) 154{ 155 spin_lock_irq(&rtc_lock); 156 set_rtc_irq_bit_locked(bit); 157 spin_unlock_irq(&rtc_lock); 158} 159 160static void mask_rtc_irq_bit(unsigned char bit) 161{ 162 spin_lock_irq(&rtc_lock); 163 mask_rtc_irq_bit_locked(bit); 164 spin_unlock_irq(&rtc_lock); 165} 166#endif 167 168static int rtc_proc_open(struct inode *inode, struct file *file); 169 170/* 171 * Bits in rtc_status. (6 bits of room for future expansion) 172 */ 173 174#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */ 175#define RTC_TIMER_ON 0x02 /* missed irq timer active */ 176 177/* 178 * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is 179 * protected by the big kernel lock. However, ioctl can still disable the timer 180 * in rtc_status and then with del_timer after the interrupt has read 181 * rtc_status but before mod_timer is called, which would then reenable the 182 * timer (but you would need to have an awful timing before you'd trip on it) 183 */ 184static unsigned long rtc_status = 0; /* bitmapped status byte. */ 185static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */ 186static unsigned long rtc_irq_data = 0; /* our output to the world */ 187static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */ 188 189#ifdef RTC_IRQ 190/* 191 * rtc_task_lock nests inside rtc_lock. 192 */ 193static DEFINE_SPINLOCK(rtc_task_lock); 194static rtc_task_t *rtc_callback = NULL; 195#endif 196 197/* 198 * If this driver ever becomes modularised, it will be really nice 199 * to make the epoch retain its value across module reload... 200 */ 201 202static unsigned long epoch = 1900; /* year corresponding to 0x00 */ 203 204static const unsigned char days_in_mo[] = 205{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; 206 207/* 208 * Returns true if a clock update is in progress 209 */ 210static inline unsigned char rtc_is_updating(void) 211{ 212 unsigned char uip; 213 214 spin_lock_irq(&rtc_lock); 215 uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); 216 spin_unlock_irq(&rtc_lock); 217 return uip; 218} 219 220#ifdef RTC_IRQ 221/* 222 * A very tiny interrupt handler. It runs with IRQF_DISABLED set, 223 * but there is possibility of conflicting with the set_rtc_mmss() 224 * call (the rtc irq and the timer irq can easily run at the same 225 * time in two different CPUs). So we need to serialize 226 * accesses to the chip with the rtc_lock spinlock that each 227 * architecture should implement in the timer code. 228 * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.) 229 */ 230 231irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) 232{ 233 /* 234 * Can be an alarm interrupt, update complete interrupt, 235 * or a periodic interrupt. We store the status in the 236 * low byte and the number of interrupts received since 237 * the last read in the remainder of rtc_irq_data. 238 */ 239 240 spin_lock (&rtc_lock); 241 rtc_irq_data += 0x100; 242 rtc_irq_data &= ~0xff; 243 if (is_hpet_enabled()) { 244 /* 245 * In this case it is HPET RTC interrupt handler 246 * calling us, with the interrupt information 247 * passed as arg1, instead of irq. 248 */ 249 rtc_irq_data |= (unsigned long)irq & 0xF0; 250 } else { 251 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); 252 } 253 254 if (rtc_status & RTC_TIMER_ON) 255 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); 256 257 spin_unlock (&rtc_lock); 258 259 /* Now do the rest of the actions */ 260 spin_lock(&rtc_task_lock); 261 if (rtc_callback) 262 rtc_callback->func(rtc_callback->private_data); 263 spin_unlock(&rtc_task_lock); 264 wake_up_interruptible(&rtc_wait); 265 266 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN); 267 268 return IRQ_HANDLED; 269} 270#endif 271 272/* 273 * sysctl-tuning infrastructure. 274 */ 275static ctl_table rtc_table[] = { 276 { 277 .ctl_name = 1, 278 .procname = "max-user-freq", 279 .data = &rtc_max_user_freq, 280 .maxlen = sizeof(int), 281 .mode = 0644, 282 .proc_handler = &proc_dointvec, 283 }, 284 { .ctl_name = 0 } 285}; 286 287static ctl_table rtc_root[] = { 288 { 289 .ctl_name = 1, 290 .procname = "rtc", 291 .maxlen = 0, 292 .mode = 0555, 293 .child = rtc_table, 294 }, 295 { .ctl_name = 0 } 296}; 297 298static ctl_table dev_root[] = { 299 { 300 .ctl_name = CTL_DEV, 301 .procname = "dev", 302 .maxlen = 0, 303 .mode = 0555, 304 .child = rtc_root, 305 }, 306 { .ctl_name = 0 } 307}; 308 309static struct ctl_table_header *sysctl_header; 310 311static int __init init_sysctl(void) 312{ 313 sysctl_header = register_sysctl_table(dev_root, 0); 314 return 0; 315} 316 317static void __exit cleanup_sysctl(void) 318{ 319 unregister_sysctl_table(sysctl_header); 320} 321 322/* 323 * Now all the various file operations that we export. 324 */ 325 326static ssize_t rtc_read(struct file *file, char __user *buf, 327 size_t count, loff_t *ppos) 328{ 329#ifndef RTC_IRQ 330 return -EIO; 331#else 332 DECLARE_WAITQUEUE(wait, current); 333 unsigned long data; 334 ssize_t retval; 335 336 if (rtc_has_irq == 0) 337 return -EIO; 338 339 /* 340 * Historically this function used to assume that sizeof(unsigned long) 341 * is the same in userspace and kernelspace. This lead to problems 342 * for configurations with multiple ABIs such a the MIPS o32 and 64 343 * ABIs supported on the same kernel. So now we support read of both 344 * 4 and 8 bytes and assume that's the sizeof(unsigned long) in the 345 * userspace ABI. 346 */ 347 if (count != sizeof(unsigned int) && count != sizeof(unsigned long)) 348 return -EINVAL; 349 350 add_wait_queue(&rtc_wait, &wait); 351 352 do { 353 /* First make it right. Then make it fast. Putting this whole 354 * block within the parentheses of a while would be too 355 * confusing. And no, xchg() is not the answer. */ 356 357 __set_current_state(TASK_INTERRUPTIBLE); 358 359 spin_lock_irq (&rtc_lock); 360 data = rtc_irq_data; 361 rtc_irq_data = 0; 362 spin_unlock_irq (&rtc_lock); 363 364 if (data != 0) 365 break; 366 367 if (file->f_flags & O_NONBLOCK) { 368 retval = -EAGAIN; 369 goto out; 370 } 371 if (signal_pending(current)) { 372 retval = -ERESTARTSYS; 373 goto out; 374 } 375 schedule(); 376 } while (1); 377 378 if (count == sizeof(unsigned int)) 379 retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int); 380 else 381 retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long); 382 if (!retval) 383 retval = count; 384 out: 385 current->state = TASK_RUNNING; 386 remove_wait_queue(&rtc_wait, &wait); 387 388 return retval; 389#endif 390} 391 392static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) 393{ 394 struct rtc_time wtime; 395 396#ifdef RTC_IRQ 397 if (rtc_has_irq == 0) { 398 switch (cmd) { 399 case RTC_AIE_OFF: 400 case RTC_AIE_ON: 401 case RTC_PIE_OFF: 402 case RTC_PIE_ON: 403 case RTC_UIE_OFF: 404 case RTC_UIE_ON: 405 case RTC_IRQP_READ: 406 case RTC_IRQP_SET: 407 return -EINVAL; 408 }; 409 } 410#endif 411 412 switch (cmd) { 413#ifdef RTC_IRQ 414 case RTC_AIE_OFF: /* Mask alarm int. enab. bit */ 415 { 416 mask_rtc_irq_bit(RTC_AIE); 417 return 0; 418 } 419 case RTC_AIE_ON: /* Allow alarm interrupts. */ 420 { 421 set_rtc_irq_bit(RTC_AIE); 422 return 0; 423 } 424 case RTC_PIE_OFF: /* Mask periodic int. enab. bit */ 425 { 426 unsigned long flags; /* can be called from isr via rtc_control() */ 427 spin_lock_irqsave (&rtc_lock, flags); 428 mask_rtc_irq_bit_locked(RTC_PIE); 429 if (rtc_status & RTC_TIMER_ON) { 430 rtc_status &= ~RTC_TIMER_ON; 431 del_timer(&rtc_irq_timer); 432 } 433 spin_unlock_irqrestore (&rtc_lock, flags); 434 return 0; 435 } 436 case RTC_PIE_ON: /* Allow periodic ints */ 437 { 438 unsigned long flags; /* can be called from isr via rtc_control() */ 439 /* 440 * We don't really want Joe User enabling more 441 * than 64Hz of interrupts on a multi-user machine. 442 */ 443 if (!kernel && (rtc_freq > rtc_max_user_freq) && 444 (!capable(CAP_SYS_RESOURCE))) 445 return -EACCES; 446 447 spin_lock_irqsave (&rtc_lock, flags); 448 if (!(rtc_status & RTC_TIMER_ON)) { 449 rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100; 450 add_timer(&rtc_irq_timer); 451 rtc_status |= RTC_TIMER_ON; 452 } 453 set_rtc_irq_bit_locked(RTC_PIE); 454 spin_unlock_irqrestore (&rtc_lock, flags); 455 return 0; 456 } 457 case RTC_UIE_OFF: /* Mask ints from RTC updates. */ 458 { 459 mask_rtc_irq_bit(RTC_UIE); 460 return 0; 461 } 462 case RTC_UIE_ON: /* Allow ints for RTC updates. */ 463 { 464 set_rtc_irq_bit(RTC_UIE); 465 return 0; 466 } 467#endif 468 case RTC_ALM_READ: /* Read the present alarm time */ 469 { 470 /* 471 * This returns a struct rtc_time. Reading >= 0xc0 472 * means "don't care" or "match all". Only the tm_hour, 473 * tm_min, and tm_sec values are filled in. 474 */ 475 memset(&wtime, 0, sizeof(struct rtc_time)); 476 get_rtc_alm_time(&wtime); 477 break; 478 } 479 case RTC_ALM_SET: /* Store a time into the alarm */ 480 { 481 /* 482 * This expects a struct rtc_time. Writing 0xff means 483 * "don't care" or "match all". Only the tm_hour, 484 * tm_min and tm_sec are used. 485 */ 486 unsigned char hrs, min, sec; 487 struct rtc_time alm_tm; 488 489 if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg, 490 sizeof(struct rtc_time))) 491 return -EFAULT; 492 493 hrs = alm_tm.tm_hour; 494 min = alm_tm.tm_min; 495 sec = alm_tm.tm_sec; 496 497 spin_lock_irq(&rtc_lock); 498 if (hpet_set_alarm_time(hrs, min, sec)) { 499 /* 500 * Fallthru and set alarm time in CMOS too, 501 * so that we will get proper value in RTC_ALM_READ 502 */ 503 } 504 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || 505 RTC_ALWAYS_BCD) 506 { 507 if (sec < 60) BIN_TO_BCD(sec); 508 else sec = 0xff; 509 510 if (min < 60) BIN_TO_BCD(min); 511 else min = 0xff; 512 513 if (hrs < 24) BIN_TO_BCD(hrs); 514 else hrs = 0xff; 515 } 516 CMOS_WRITE(hrs, RTC_HOURS_ALARM); 517 CMOS_WRITE(min, RTC_MINUTES_ALARM); 518 CMOS_WRITE(sec, RTC_SECONDS_ALARM); 519 spin_unlock_irq(&rtc_lock); 520 521 return 0; 522 } 523 case RTC_RD_TIME: /* Read the time/date from RTC */ 524 { 525 memset(&wtime, 0, sizeof(struct rtc_time)); 526 rtc_get_rtc_time(&wtime); 527 break; 528 } 529 case RTC_SET_TIME: /* Set the RTC */ 530 { 531 struct rtc_time rtc_tm; 532 unsigned char mon, day, hrs, min, sec, leap_yr; 533 unsigned char save_control, save_freq_select; 534 unsigned int yrs; 535#ifdef CONFIG_MACH_DECSTATION 536 unsigned int real_yrs; 537#endif 538 539 if (!capable(CAP_SYS_TIME)) 540 return -EACCES; 541 542 if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg, 543 sizeof(struct rtc_time))) 544 return -EFAULT; 545 546 yrs = rtc_tm.tm_year + 1900; 547 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ 548 day = rtc_tm.tm_mday; 549 hrs = rtc_tm.tm_hour; 550 min = rtc_tm.tm_min; 551 sec = rtc_tm.tm_sec; 552 553 if (yrs < 1970) 554 return -EINVAL; 555 556 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); 557 558 if ((mon > 12) || (day == 0)) 559 return -EINVAL; 560 561 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) 562 return -EINVAL; 563 564 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) 565 return -EINVAL; 566 567 if ((yrs -= epoch) > 255) /* They are unsigned */ 568 return -EINVAL; 569 570 spin_lock_irq(&rtc_lock); 571#ifdef CONFIG_MACH_DECSTATION 572 real_yrs = yrs; 573 yrs = 72; 574 575 /* 576 * We want to keep the year set to 73 until March 577 * for non-leap years, so that Feb, 29th is handled 578 * correctly. 579 */ 580 if (!leap_yr && mon < 3) { 581 real_yrs--; 582 yrs = 73; 583 } 584#endif 585 /* These limits and adjustments are independent of 586 * whether the chip is in binary mode or not. 587 */ 588 if (yrs > 169) { 589 spin_unlock_irq(&rtc_lock); 590 return -EINVAL; 591 } 592 if (yrs >= 100) 593 yrs -= 100; 594 595 if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) 596 || RTC_ALWAYS_BCD) { 597 BIN_TO_BCD(sec); 598 BIN_TO_BCD(min); 599 BIN_TO_BCD(hrs); 600 BIN_TO_BCD(day); 601 BIN_TO_BCD(mon); 602 BIN_TO_BCD(yrs); 603 } 604 605 save_control = CMOS_READ(RTC_CONTROL); 606 CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); 607 save_freq_select = CMOS_READ(RTC_FREQ_SELECT); 608 CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); 609 610#ifdef CONFIG_MACH_DECSTATION 611 CMOS_WRITE(real_yrs, RTC_DEC_YEAR); 612#endif 613 CMOS_WRITE(yrs, RTC_YEAR); 614 CMOS_WRITE(mon, RTC_MONTH); 615 CMOS_WRITE(day, RTC_DAY_OF_MONTH); 616 CMOS_WRITE(hrs, RTC_HOURS); 617 CMOS_WRITE(min, RTC_MINUTES); 618 CMOS_WRITE(sec, RTC_SECONDS); 619 620 CMOS_WRITE(save_control, RTC_CONTROL); 621 CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); 622 623 spin_unlock_irq(&rtc_lock); 624 return 0; 625 } 626#ifdef RTC_IRQ 627 case RTC_IRQP_READ: /* Read the periodic IRQ rate. */ 628 { 629 return put_user(rtc_freq, (unsigned long __user *)arg); 630 } 631 case RTC_IRQP_SET: /* Set periodic IRQ rate. */ 632 { 633 int tmp = 0; 634 unsigned char val; 635 unsigned long flags; /* can be called from isr via rtc_control() */ 636 637 /* 638 * The max we can do is 8192Hz. 639 */ 640 if ((arg < 2) || (arg > 8192)) 641 return -EINVAL; 642 /* 643 * We don't really want Joe User generating more 644 * than 64Hz of interrupts on a multi-user machine. 645 */ 646 if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE))) 647 return -EACCES; 648 649 while (arg > (1<<tmp)) 650 tmp++; 651 652 /* 653 * Check that the input was really a power of 2. 654 */ 655 if (arg != (1<<tmp)) 656 return -EINVAL; 657 658 spin_lock_irqsave(&rtc_lock, flags); 659 if (hpet_set_periodic_freq(arg)) { 660 spin_unlock_irqrestore(&rtc_lock, flags); 661 return 0; 662 } 663 rtc_freq = arg; 664 665 val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0; 666 val |= (16 - tmp); 667 CMOS_WRITE(val, RTC_FREQ_SELECT); 668 spin_unlock_irqrestore(&rtc_lock, flags); 669 return 0; 670 } 671#endif 672 case RTC_EPOCH_READ: /* Read the epoch. */ 673 { 674 return put_user (epoch, (unsigned long __user *)arg); 675 } 676 case RTC_EPOCH_SET: /* Set the epoch. */ 677 { 678 /* 679 * There were no RTC clocks before 1900. 680 */ 681 if (arg < 1900) 682 return -EINVAL; 683 684 if (!capable(CAP_SYS_TIME)) 685 return -EACCES; 686 687 epoch = arg; 688 return 0; 689 } 690 default: 691 return -ENOTTY; 692 } 693 return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0; 694} 695 696static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 697 unsigned long arg) 698{ 699 return rtc_do_ioctl(cmd, arg, 0); 700} 701 702/* 703 * We enforce only one user at a time here with the open/close. 704 * Also clear the previous interrupt data on an open, and clean 705 * up things on a close. 706 */ 707 708/* We use rtc_lock to protect against concurrent opens. So the BKL is not 709 * needed here. Or anywhere else in this driver. */ 710static int rtc_open(struct inode *inode, struct file *file) 711{ 712 spin_lock_irq (&rtc_lock); 713 714 if(rtc_status & RTC_IS_OPEN) 715 goto out_busy; 716 717 rtc_status |= RTC_IS_OPEN; 718 719 rtc_irq_data = 0; 720 spin_unlock_irq (&rtc_lock); 721 return 0; 722 723out_busy: 724 spin_unlock_irq (&rtc_lock); 725 return -EBUSY; 726} 727 728static int rtc_fasync (int fd, struct file *filp, int on) 729 730{ 731 return fasync_helper (fd, filp, on, &rtc_async_queue); 732} 733 734static int rtc_release(struct inode *inode, struct file *file) 735{ 736#ifdef RTC_IRQ 737 unsigned char tmp; 738 739 if (rtc_has_irq == 0) 740 goto no_irq; 741 742 /* 743 * Turn off all interrupts once the device is no longer 744 * in use, and clear the data. 745 */ 746 747 spin_lock_irq(&rtc_lock); 748 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { 749 tmp = CMOS_READ(RTC_CONTROL); 750 tmp &= ~RTC_PIE; 751 tmp &= ~RTC_AIE; 752 tmp &= ~RTC_UIE; 753 CMOS_WRITE(tmp, RTC_CONTROL); 754 CMOS_READ(RTC_INTR_FLAGS); 755 } 756 if (rtc_status & RTC_TIMER_ON) { 757 rtc_status &= ~RTC_TIMER_ON; 758 del_timer(&rtc_irq_timer); 759 } 760 spin_unlock_irq(&rtc_lock); 761 762 if (file->f_flags & FASYNC) { 763 rtc_fasync (-1, file, 0); 764 } 765no_irq: 766#endif 767 768 spin_lock_irq (&rtc_lock); 769 rtc_irq_data = 0; 770 rtc_status &= ~RTC_IS_OPEN; 771 spin_unlock_irq (&rtc_lock); 772 return 0; 773} 774 775#ifdef RTC_IRQ 776/* Called without the kernel lock - fine */ 777static unsigned int rtc_poll(struct file *file, poll_table *wait) 778{ 779 unsigned long l; 780 781 if (rtc_has_irq == 0) 782 return 0; 783 784 poll_wait(file, &rtc_wait, wait); 785 786 spin_lock_irq (&rtc_lock); 787 l = rtc_irq_data; 788 spin_unlock_irq (&rtc_lock); 789 790 if (l != 0) 791 return POLLIN | POLLRDNORM; 792 return 0; 793} 794#endif 795 796/* 797 * exported stuffs 798 */ 799 800EXPORT_SYMBOL(rtc_register); 801EXPORT_SYMBOL(rtc_unregister); 802EXPORT_SYMBOL(rtc_control); 803 804int rtc_register(rtc_task_t *task) 805{ 806#ifndef RTC_IRQ 807 return -EIO; 808#else 809 if (task == NULL || task->func == NULL) 810 return -EINVAL; 811 spin_lock_irq(&rtc_lock); 812 if (rtc_status & RTC_IS_OPEN) { 813 spin_unlock_irq(&rtc_lock); 814 return -EBUSY; 815 } 816 spin_lock(&rtc_task_lock); 817 if (rtc_callback) { 818 spin_unlock(&rtc_task_lock); 819 spin_unlock_irq(&rtc_lock); 820 return -EBUSY; 821 } 822 rtc_status |= RTC_IS_OPEN; 823 rtc_callback = task; 824 spin_unlock(&rtc_task_lock); 825 spin_unlock_irq(&rtc_lock); 826 return 0; 827#endif 828} 829 830int rtc_unregister(rtc_task_t *task) 831{ 832#ifndef RTC_IRQ 833 return -EIO; 834#else 835 unsigned char tmp; 836 837 spin_lock_irq(&rtc_lock); 838 spin_lock(&rtc_task_lock); 839 if (rtc_callback != task) { 840 spin_unlock(&rtc_task_lock); 841 spin_unlock_irq(&rtc_lock); 842 return -ENXIO; 843 } 844 rtc_callback = NULL; 845 846 /* disable controls */ 847 if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { 848 tmp = CMOS_READ(RTC_CONTROL); 849 tmp &= ~RTC_PIE; 850 tmp &= ~RTC_AIE; 851 tmp &= ~RTC_UIE; 852 CMOS_WRITE(tmp, RTC_CONTROL); 853 CMOS_READ(RTC_INTR_FLAGS); 854 } 855 if (rtc_status & RTC_TIMER_ON) { 856 rtc_status &= ~RTC_TIMER_ON; 857 del_timer(&rtc_irq_timer); 858 } 859 rtc_status &= ~RTC_IS_OPEN; 860 spin_unlock(&rtc_task_lock); 861 spin_unlock_irq(&rtc_lock); 862 return 0; 863#endif 864} 865 866int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg) 867{ 868#ifndef RTC_IRQ 869 return -EIO; 870#else 871 unsigned long flags; 872 if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET) 873 return -EINVAL; 874 spin_lock_irqsave(&rtc_task_lock, flags); 875 if (rtc_callback != task) { 876 spin_unlock_irqrestore(&rtc_task_lock, flags); 877 return -ENXIO; 878 } 879 spin_unlock_irqrestore(&rtc_task_lock, flags); 880 return rtc_do_ioctl(cmd, arg, 1); 881#endif 882} 883 884 885/* 886 * The various file operations we support. 887 */ 888 889static const struct file_operations rtc_fops = { 890 .owner = THIS_MODULE, 891 .llseek = no_llseek, 892 .read = rtc_read, 893#ifdef RTC_IRQ 894 .poll = rtc_poll, 895#endif 896 .ioctl = rtc_ioctl, 897 .open = rtc_open, 898 .release = rtc_release, 899 .fasync = rtc_fasync, 900}; 901 902static struct miscdevice rtc_dev = { 903 .minor = RTC_MINOR, 904 .name = "rtc", 905 .fops = &rtc_fops, 906}; 907 908static const struct file_operations rtc_proc_fops = { 909 .owner = THIS_MODULE, 910 .open = rtc_proc_open, 911 .read = seq_read, 912 .llseek = seq_lseek, 913 .release = single_release, 914}; 915 916#if defined(RTC_IRQ) && !defined(__sparc__) 917static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs); 918#endif 919 920static int __init rtc_init(void) 921{ 922 struct proc_dir_entry *ent; 923#if defined(__alpha__) || defined(__mips__) 924 unsigned int year, ctrl; 925 char *guess = NULL; 926#endif 927#ifdef __sparc__ 928 struct linux_ebus *ebus; 929 struct linux_ebus_device *edev; 930#ifdef __sparc_v9__ 931 struct sparc_isa_bridge *isa_br; 932 struct sparc_isa_device *isa_dev; 933#endif 934#endif 935#ifndef __sparc__ 936 void *r; 937#endif 938 939#ifdef __sparc__ 940 for_each_ebus(ebus) { 941 for_each_ebusdev(edev, ebus) { 942 if(strcmp(edev->prom_node->name, "rtc") == 0) { 943 rtc_port = edev->resource[0].start; 944 rtc_irq = edev->irqs[0]; 945 goto found; 946 } 947 } 948 } 949#ifdef __sparc_v9__ 950 for_each_isa(isa_br) { 951 for_each_isadev(isa_dev, isa_br) { 952 if (strcmp(isa_dev->prom_node->name, "rtc") == 0) { 953 rtc_port = isa_dev->resource.start; 954 rtc_irq = isa_dev->irq; 955 goto found; 956 } 957 } 958 } 959#endif 960 printk(KERN_ERR "rtc_init: no PC rtc found\n"); 961 return -EIO; 962 963found: 964 if (rtc_irq == PCI_IRQ_NONE) { 965 rtc_has_irq = 0; 966 goto no_irq; 967 } 968 969 /* 970 * XXX Interrupt pin #7 in Espresso is shared between RTC and 971 * PCI Slot 2 INTA# (and some INTx# in Slot 1). 972 */ 973 if (request_irq(rtc_irq, rtc_interrupt, IRQF_SHARED, "rtc", (void *)&rtc_port)) { 974 printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq); 975 return -EIO; 976 } 977no_irq: 978#else 979 if (RTC_IOMAPPED) 980 r = request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); 981 else 982 r = request_mem_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc"); 983 if (!r) { 984 printk(KERN_ERR "rtc: I/O resource %lx is not free.\n", 985 (long)(RTC_PORT(0))); 986 return -EIO; 987 } 988 989#ifdef RTC_IRQ 990 if (is_hpet_enabled()) { 991 rtc_int_handler_ptr = hpet_rtc_interrupt; 992 } else { 993 rtc_int_handler_ptr = rtc_interrupt; 994 } 995 996 if(request_irq(RTC_IRQ, rtc_int_handler_ptr, IRQF_DISABLED, "rtc", NULL)) { 997 /* Yeah right, seeing as irq 8 doesn't even hit the bus. */ 998 printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ); 999 if (RTC_IOMAPPED) 1000 release_region(RTC_PORT(0), RTC_IO_EXTENT); 1001 else 1002 release_mem_region(RTC_PORT(0), RTC_IO_EXTENT); 1003 return -EIO; 1004 } 1005 hpet_rtc_timer_init(); 1006 1007#endif 1008 1009#endif /* __sparc__ vs. others */ 1010 1011 if (misc_register(&rtc_dev)) { 1012#ifdef RTC_IRQ 1013 free_irq(RTC_IRQ, NULL); 1014#endif 1015 release_region(RTC_PORT(0), RTC_IO_EXTENT); 1016 return -ENODEV; 1017 } 1018 1019 ent = create_proc_entry("driver/rtc", 0, NULL); 1020 if (!ent) { 1021#ifdef RTC_IRQ 1022 free_irq(RTC_IRQ, NULL); 1023#endif 1024 release_region(RTC_PORT(0), RTC_IO_EXTENT); 1025 misc_deregister(&rtc_dev); 1026 return -ENOMEM; 1027 } 1028 ent->proc_fops = &rtc_proc_fops; 1029 1030#if defined(__alpha__) || defined(__mips__) 1031 rtc_freq = HZ; 1032 1033 /* Each operating system on an Alpha uses its own epoch. 1034 Let's try to guess which one we are using now. */ 1035 1036 if (rtc_is_updating() != 0) 1037 msleep(20); 1038 1039 spin_lock_irq(&rtc_lock); 1040 year = CMOS_READ(RTC_YEAR); 1041 ctrl = CMOS_READ(RTC_CONTROL); 1042 spin_unlock_irq(&rtc_lock); 1043 1044 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) 1045 BCD_TO_BIN(year); /* This should never happen... */ 1046 1047 if (year < 20) { 1048 epoch = 2000; 1049 guess = "SRM (post-2000)"; 1050 } else if (year >= 20 && year < 48) { 1051 epoch = 1980; 1052 guess = "ARC console"; 1053 } else if (year >= 48 && year < 72) { 1054 epoch = 1952; 1055 guess = "Digital UNIX"; 1056#if defined(__mips__) 1057 } else if (year >= 72 && year < 74) { 1058 epoch = 2000; 1059 guess = "Digital DECstation"; 1060#else 1061 } else if (year >= 70) { 1062 epoch = 1900; 1063 guess = "Standard PC (1900)"; 1064#endif 1065 } 1066 if (guess) 1067 printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch); 1068#endif 1069#ifdef RTC_IRQ 1070 if (rtc_has_irq == 0) 1071 goto no_irq2; 1072 1073 init_timer(&rtc_irq_timer); 1074 rtc_irq_timer.function = rtc_dropped_irq; 1075 spin_lock_irq(&rtc_lock); 1076 rtc_freq = 1024; 1077 if (!hpet_set_periodic_freq(rtc_freq)) { 1078 /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */ 1079 CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT); 1080 } 1081 spin_unlock_irq(&rtc_lock); 1082no_irq2: 1083#endif 1084 1085 (void) init_sysctl(); 1086 1087 printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n"); 1088 1089 return 0; 1090} 1091 1092static void __exit rtc_exit (void) 1093{ 1094 cleanup_sysctl(); 1095 remove_proc_entry ("driver/rtc", NULL); 1096 misc_deregister(&rtc_dev); 1097 1098#ifdef __sparc__ 1099 if (rtc_has_irq) 1100 free_irq (rtc_irq, &rtc_port); 1101#else 1102 if (RTC_IOMAPPED) 1103 release_region(RTC_PORT(0), RTC_IO_EXTENT); 1104 else 1105 release_mem_region(RTC_PORT(0), RTC_IO_EXTENT); 1106#ifdef RTC_IRQ 1107 if (rtc_has_irq) 1108 free_irq (RTC_IRQ, NULL); 1109#endif 1110#endif /* __sparc__ */ 1111} 1112 1113module_init(rtc_init); 1114module_exit(rtc_exit); 1115 1116#ifdef RTC_IRQ 1117/* 1118 * At IRQ rates >= 4096Hz, an interrupt may get lost altogether. 1119 * (usually during an IDE disk interrupt, with IRQ unmasking off) 1120 * Since the interrupt handler doesn't get called, the IRQ status 1121 * byte doesn't get read, and the RTC stops generating interrupts. 1122 * A timer is set, and will call this function if/when that happens. 1123 * To get it out of this stalled state, we just read the status. 1124 * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost. 1125 * (You *really* shouldn't be trying to use a non-realtime system 1126 * for something that requires a steady > 1KHz signal anyways.) 1127 */ 1128 1129static void rtc_dropped_irq(unsigned long data) 1130{ 1131 unsigned long freq; 1132 1133 spin_lock_irq (&rtc_lock); 1134 1135 if (hpet_rtc_dropped_irq()) { 1136 spin_unlock_irq(&rtc_lock); 1137 return; 1138 } 1139 1140 /* Just in case someone disabled the timer from behind our back... */ 1141 if (rtc_status & RTC_TIMER_ON) 1142 mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); 1143 1144 rtc_irq_data += ((rtc_freq/HZ)<<8); 1145 rtc_irq_data &= ~0xff; 1146 rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */ 1147 1148 freq = rtc_freq; 1149 1150 spin_unlock_irq(&rtc_lock); 1151 1152 printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq); 1153 1154 /* Now we have new data */ 1155 wake_up_interruptible(&rtc_wait); 1156 1157 kill_fasync (&rtc_async_queue, SIGIO, POLL_IN); 1158} 1159#endif 1160 1161/* 1162 * Info exported via "/proc/driver/rtc". 1163 */ 1164 1165static int rtc_proc_show(struct seq_file *seq, void *v) 1166{ 1167#define YN(bit) ((ctrl & bit) ? "yes" : "no") 1168#define NY(bit) ((ctrl & bit) ? "no" : "yes") 1169 struct rtc_time tm; 1170 unsigned char batt, ctrl; 1171 unsigned long freq; 1172 1173 spin_lock_irq(&rtc_lock); 1174 batt = CMOS_READ(RTC_VALID) & RTC_VRT; 1175 ctrl = CMOS_READ(RTC_CONTROL); 1176 freq = rtc_freq; 1177 spin_unlock_irq(&rtc_lock); 1178 1179 1180 rtc_get_rtc_time(&tm); 1181 1182 /* 1183 * There is no way to tell if the luser has the RTC set for local 1184 * time or for Universal Standard Time (GMT). Probably local though. 1185 */ 1186 seq_printf(seq, 1187 "rtc_time\t: %02d:%02d:%02d\n" 1188 "rtc_date\t: %04d-%02d-%02d\n" 1189 "rtc_epoch\t: %04lu\n", 1190 tm.tm_hour, tm.tm_min, tm.tm_sec, 1191 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch); 1192 1193 get_rtc_alm_time(&tm); 1194 1195 /* 1196 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will 1197 * match any value for that particular field. Values that are 1198 * greater than a valid time, but less than 0xc0 shouldn't appear. 1199 */ 1200 seq_puts(seq, "alarm\t\t: "); 1201 if (tm.tm_hour <= 24) 1202 seq_printf(seq, "%02d:", tm.tm_hour); 1203 else 1204 seq_puts(seq, "**:"); 1205 1206 if (tm.tm_min <= 59) 1207 seq_printf(seq, "%02d:", tm.tm_min); 1208 else 1209 seq_puts(seq, "**:"); 1210 1211 if (tm.tm_sec <= 59) 1212 seq_printf(seq, "%02d\n", tm.tm_sec); 1213 else 1214 seq_puts(seq, "**\n"); 1215 1216 seq_printf(seq, 1217 "DST_enable\t: %s\n" 1218 "BCD\t\t: %s\n" 1219 "24hr\t\t: %s\n" 1220 "square_wave\t: %s\n" 1221 "alarm_IRQ\t: %s\n" 1222 "update_IRQ\t: %s\n" 1223 "periodic_IRQ\t: %s\n" 1224 "periodic_freq\t: %ld\n" 1225 "batt_status\t: %s\n", 1226 YN(RTC_DST_EN), 1227 NY(RTC_DM_BINARY), 1228 YN(RTC_24H), 1229 YN(RTC_SQWE), 1230 YN(RTC_AIE), 1231 YN(RTC_UIE), 1232 YN(RTC_PIE), 1233 freq, 1234 batt ? "okay" : "dead"); 1235 1236 return 0; 1237#undef YN 1238#undef NY 1239} 1240 1241static int rtc_proc_open(struct inode *inode, struct file *file) 1242{ 1243 return single_open(file, rtc_proc_show, NULL); 1244} 1245 1246void rtc_get_rtc_time(struct rtc_time *rtc_tm) 1247{ 1248 unsigned long uip_watchdog = jiffies, flags; 1249 unsigned char ctrl; 1250#ifdef CONFIG_MACH_DECSTATION 1251 unsigned int real_year; 1252#endif 1253 1254 /* 1255 * read RTC once any update in progress is done. The update 1256 * can take just over 2ms. We wait 20ms. There is no need to 1257 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. 1258 * If you need to know *exactly* when a second has started, enable 1259 * periodic update complete interrupts, (via ioctl) and then 1260 * immediately read /dev/rtc which will block until you get the IRQ. 1261 * Once the read clears, read the RTC time (again via ioctl). Easy. 1262 */ 1263 1264 while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100) { 1265 barrier(); 1266 cpu_relax(); 1267 } 1268 1269 /* 1270 * Only the values that we read from the RTC are set. We leave 1271 * tm_wday, tm_yday and tm_isdst untouched. Note that while the 1272 * RTC has RTC_DAY_OF_WEEK, we should usually ignore it, as it is 1273 * only updated by the RTC when initially set to a non-zero value. 1274 */ 1275 spin_lock_irqsave(&rtc_lock, flags); 1276 rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); 1277 rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); 1278 rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); 1279 rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); 1280 rtc_tm->tm_mon = CMOS_READ(RTC_MONTH); 1281 rtc_tm->tm_year = CMOS_READ(RTC_YEAR); 1282 /* Only set from 2.6.16 onwards */ 1283 rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK); 1284 1285#ifdef CONFIG_MACH_DECSTATION 1286 real_year = CMOS_READ(RTC_DEC_YEAR); 1287#endif 1288 ctrl = CMOS_READ(RTC_CONTROL); 1289 spin_unlock_irqrestore(&rtc_lock, flags); 1290 1291 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) 1292 { 1293 BCD_TO_BIN(rtc_tm->tm_sec); 1294 BCD_TO_BIN(rtc_tm->tm_min); 1295 BCD_TO_BIN(rtc_tm->tm_hour); 1296 BCD_TO_BIN(rtc_tm->tm_mday); 1297 BCD_TO_BIN(rtc_tm->tm_mon); 1298 BCD_TO_BIN(rtc_tm->tm_year); 1299 BCD_TO_BIN(rtc_tm->tm_wday); 1300 } 1301 1302#ifdef CONFIG_MACH_DECSTATION 1303 rtc_tm->tm_year += real_year - 72; 1304#endif 1305 1306 /* 1307 * Account for differences between how the RTC uses the values 1308 * and how they are defined in a struct rtc_time; 1309 */ 1310 if ((rtc_tm->tm_year += (epoch - 1900)) <= 69) 1311 rtc_tm->tm_year += 100; 1312 1313 rtc_tm->tm_mon--; 1314} 1315 1316static void get_rtc_alm_time(struct rtc_time *alm_tm) 1317{ 1318 unsigned char ctrl; 1319 1320 /* 1321 * Only the values that we read from the RTC are set. That 1322 * means only tm_hour, tm_min, and tm_sec. 1323 */ 1324 spin_lock_irq(&rtc_lock); 1325 alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM); 1326 alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM); 1327 alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM); 1328 ctrl = CMOS_READ(RTC_CONTROL); 1329 spin_unlock_irq(&rtc_lock); 1330 1331 if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) 1332 { 1333 BCD_TO_BIN(alm_tm->tm_sec); 1334 BCD_TO_BIN(alm_tm->tm_min); 1335 BCD_TO_BIN(alm_tm->tm_hour); 1336 } 1337} 1338 1339#ifdef RTC_IRQ 1340/* 1341 * Used to disable/enable interrupts for any one of UIE, AIE, PIE. 1342 * Rumour has it that if you frob the interrupt enable/disable 1343 * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to 1344 * ensure you actually start getting interrupts. Probably for 1345 * compatibility with older/broken chipset RTC implementations. 1346 * We also clear out any old irq data after an ioctl() that 1347 * meddles with the interrupt enable/disable bits. 1348 */ 1349 1350static void mask_rtc_irq_bit_locked(unsigned char bit) 1351{ 1352 unsigned char val; 1353 1354 if (hpet_mask_rtc_irq_bit(bit)) 1355 return; 1356 val = CMOS_READ(RTC_CONTROL); 1357 val &= ~bit; 1358 CMOS_WRITE(val, RTC_CONTROL); 1359 CMOS_READ(RTC_INTR_FLAGS); 1360 1361 rtc_irq_data = 0; 1362} 1363 1364static void set_rtc_irq_bit_locked(unsigned char bit) 1365{ 1366 unsigned char val; 1367 1368 if (hpet_set_rtc_irq_bit(bit)) 1369 return; 1370 val = CMOS_READ(RTC_CONTROL); 1371 val |= bit; 1372 CMOS_WRITE(val, RTC_CONTROL); 1373 CMOS_READ(RTC_INTR_FLAGS); 1374 1375 rtc_irq_data = 0; 1376} 1377#endif 1378 1379MODULE_AUTHOR("Paul Gortmaker"); 1380MODULE_LICENSE("GPL"); 1381MODULE_ALIAS_MISCDEV(RTC_MINOR); 1382