Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
| 50 | */ |
| 51 | |
| 52 | #define RTC_VERSION "1.12" |
| 53 | |
| 54 | #define RTC_IO_EXTENT 0x8 |
| 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/config.h> |
| 65 | #include <linux/interrupt.h> |
| 66 | #include <linux/module.h> |
| 67 | #include <linux/kernel.h> |
| 68 | #include <linux/types.h> |
| 69 | #include <linux/miscdevice.h> |
| 70 | #include <linux/ioport.h> |
| 71 | #include <linux/fcntl.h> |
| 72 | #include <linux/mc146818rtc.h> |
| 73 | #include <linux/init.h> |
| 74 | #include <linux/poll.h> |
| 75 | #include <linux/proc_fs.h> |
| 76 | #include <linux/seq_file.h> |
| 77 | #include <linux/spinlock.h> |
| 78 | #include <linux/sysctl.h> |
| 79 | #include <linux/wait.h> |
| 80 | #include <linux/bcd.h> |
Luca Falavigna | 47f176f | 2005-06-28 20:44:42 -0700 | [diff] [blame] | 81 | #include <linux/delay.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
| 83 | #include <asm/current.h> |
| 84 | #include <asm/uaccess.h> |
| 85 | #include <asm/system.h> |
| 86 | |
| 87 | #if defined(__i386__) |
| 88 | #include <asm/hpet.h> |
| 89 | #endif |
| 90 | |
| 91 | #ifdef __sparc__ |
| 92 | #include <linux/pci.h> |
| 93 | #include <asm/ebus.h> |
| 94 | #ifdef __sparc_v9__ |
| 95 | #include <asm/isa.h> |
| 96 | #endif |
| 97 | |
| 98 | static unsigned long rtc_port; |
| 99 | static int rtc_irq = PCI_IRQ_NONE; |
| 100 | #endif |
| 101 | |
| 102 | #ifdef CONFIG_HPET_RTC_IRQ |
| 103 | #undef RTC_IRQ |
| 104 | #endif |
| 105 | |
| 106 | #ifdef RTC_IRQ |
| 107 | static int rtc_has_irq = 1; |
| 108 | #endif |
| 109 | |
| 110 | #ifndef CONFIG_HPET_EMULATE_RTC |
| 111 | #define is_hpet_enabled() 0 |
| 112 | #define hpet_set_alarm_time(hrs, min, sec) 0 |
| 113 | #define hpet_set_periodic_freq(arg) 0 |
| 114 | #define hpet_mask_rtc_irq_bit(arg) 0 |
| 115 | #define hpet_set_rtc_irq_bit(arg) 0 |
| 116 | #define hpet_rtc_timer_init() do { } while (0) |
| 117 | #define hpet_rtc_dropped_irq() 0 |
| 118 | static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) {return 0;} |
| 119 | #else |
| 120 | extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs); |
| 121 | #endif |
| 122 | |
| 123 | /* |
| 124 | * We sponge a minor off of the misc major. No need slurping |
| 125 | * up another valuable major dev number for this. If you add |
| 126 | * an ioctl, make sure you don't conflict with SPARC's RTC |
| 127 | * ioctls. |
| 128 | */ |
| 129 | |
| 130 | static struct fasync_struct *rtc_async_queue; |
| 131 | |
| 132 | static DECLARE_WAIT_QUEUE_HEAD(rtc_wait); |
| 133 | |
| 134 | #ifdef RTC_IRQ |
| 135 | static struct timer_list rtc_irq_timer; |
| 136 | #endif |
| 137 | |
| 138 | static ssize_t rtc_read(struct file *file, char __user *buf, |
| 139 | size_t count, loff_t *ppos); |
| 140 | |
| 141 | static int rtc_ioctl(struct inode *inode, struct file *file, |
| 142 | unsigned int cmd, unsigned long arg); |
| 143 | |
| 144 | #ifdef RTC_IRQ |
| 145 | static unsigned int rtc_poll(struct file *file, poll_table *wait); |
| 146 | #endif |
| 147 | |
| 148 | static void get_rtc_alm_time (struct rtc_time *alm_tm); |
| 149 | #ifdef RTC_IRQ |
| 150 | static void rtc_dropped_irq(unsigned long data); |
| 151 | |
| 152 | static void set_rtc_irq_bit(unsigned char bit); |
| 153 | static void mask_rtc_irq_bit(unsigned char bit); |
| 154 | #endif |
| 155 | |
| 156 | static int rtc_proc_open(struct inode *inode, struct file *file); |
| 157 | |
| 158 | /* |
| 159 | * Bits in rtc_status. (6 bits of room for future expansion) |
| 160 | */ |
| 161 | |
| 162 | #define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */ |
| 163 | #define RTC_TIMER_ON 0x02 /* missed irq timer active */ |
| 164 | |
| 165 | /* |
| 166 | * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is |
| 167 | * protected by the big kernel lock. However, ioctl can still disable the timer |
| 168 | * in rtc_status and then with del_timer after the interrupt has read |
| 169 | * rtc_status but before mod_timer is called, which would then reenable the |
| 170 | * timer (but you would need to have an awful timing before you'd trip on it) |
| 171 | */ |
| 172 | static unsigned long rtc_status = 0; /* bitmapped status byte. */ |
| 173 | static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */ |
| 174 | static unsigned long rtc_irq_data = 0; /* our output to the world */ |
| 175 | static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */ |
| 176 | |
| 177 | #ifdef RTC_IRQ |
| 178 | /* |
| 179 | * rtc_task_lock nests inside rtc_lock. |
| 180 | */ |
| 181 | static DEFINE_SPINLOCK(rtc_task_lock); |
| 182 | static rtc_task_t *rtc_callback = NULL; |
| 183 | #endif |
| 184 | |
| 185 | /* |
| 186 | * If this driver ever becomes modularised, it will be really nice |
| 187 | * to make the epoch retain its value across module reload... |
| 188 | */ |
| 189 | |
| 190 | static unsigned long epoch = 1900; /* year corresponding to 0x00 */ |
| 191 | |
| 192 | static const unsigned char days_in_mo[] = |
| 193 | {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; |
| 194 | |
| 195 | /* |
| 196 | * Returns true if a clock update is in progress |
| 197 | */ |
| 198 | static inline unsigned char rtc_is_updating(void) |
| 199 | { |
| 200 | unsigned char uip; |
| 201 | |
| 202 | spin_lock_irq(&rtc_lock); |
| 203 | uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP); |
| 204 | spin_unlock_irq(&rtc_lock); |
| 205 | return uip; |
| 206 | } |
| 207 | |
| 208 | #ifdef RTC_IRQ |
| 209 | /* |
| 210 | * A very tiny interrupt handler. It runs with SA_INTERRUPT set, |
| 211 | * but there is possibility of conflicting with the set_rtc_mmss() |
| 212 | * call (the rtc irq and the timer irq can easily run at the same |
| 213 | * time in two different CPUs). So we need to serialize |
| 214 | * accesses to the chip with the rtc_lock spinlock that each |
| 215 | * architecture should implement in the timer code. |
| 216 | * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.) |
| 217 | */ |
| 218 | |
| 219 | irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 220 | { |
| 221 | /* |
| 222 | * Can be an alarm interrupt, update complete interrupt, |
| 223 | * or a periodic interrupt. We store the status in the |
| 224 | * low byte and the number of interrupts received since |
| 225 | * the last read in the remainder of rtc_irq_data. |
| 226 | */ |
| 227 | |
| 228 | spin_lock (&rtc_lock); |
| 229 | rtc_irq_data += 0x100; |
| 230 | rtc_irq_data &= ~0xff; |
| 231 | if (is_hpet_enabled()) { |
| 232 | /* |
| 233 | * In this case it is HPET RTC interrupt handler |
| 234 | * calling us, with the interrupt information |
| 235 | * passed as arg1, instead of irq. |
| 236 | */ |
| 237 | rtc_irq_data |= (unsigned long)irq & 0xF0; |
| 238 | } else { |
| 239 | rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); |
| 240 | } |
| 241 | |
| 242 | if (rtc_status & RTC_TIMER_ON) |
| 243 | mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); |
| 244 | |
| 245 | spin_unlock (&rtc_lock); |
| 246 | |
| 247 | /* Now do the rest of the actions */ |
| 248 | spin_lock(&rtc_task_lock); |
| 249 | if (rtc_callback) |
| 250 | rtc_callback->func(rtc_callback->private_data); |
| 251 | spin_unlock(&rtc_task_lock); |
| 252 | wake_up_interruptible(&rtc_wait); |
| 253 | |
| 254 | kill_fasync (&rtc_async_queue, SIGIO, POLL_IN); |
| 255 | |
| 256 | return IRQ_HANDLED; |
| 257 | } |
| 258 | #endif |
| 259 | |
| 260 | /* |
| 261 | * sysctl-tuning infrastructure. |
| 262 | */ |
| 263 | static ctl_table rtc_table[] = { |
| 264 | { |
| 265 | .ctl_name = 1, |
| 266 | .procname = "max-user-freq", |
| 267 | .data = &rtc_max_user_freq, |
| 268 | .maxlen = sizeof(int), |
| 269 | .mode = 0644, |
| 270 | .proc_handler = &proc_dointvec, |
| 271 | }, |
| 272 | { .ctl_name = 0 } |
| 273 | }; |
| 274 | |
| 275 | static ctl_table rtc_root[] = { |
| 276 | { |
| 277 | .ctl_name = 1, |
| 278 | .procname = "rtc", |
| 279 | .maxlen = 0, |
| 280 | .mode = 0555, |
| 281 | .child = rtc_table, |
| 282 | }, |
| 283 | { .ctl_name = 0 } |
| 284 | }; |
| 285 | |
| 286 | static ctl_table dev_root[] = { |
| 287 | { |
| 288 | .ctl_name = CTL_DEV, |
| 289 | .procname = "dev", |
| 290 | .maxlen = 0, |
| 291 | .mode = 0555, |
| 292 | .child = rtc_root, |
| 293 | }, |
| 294 | { .ctl_name = 0 } |
| 295 | }; |
| 296 | |
| 297 | static struct ctl_table_header *sysctl_header; |
| 298 | |
| 299 | static int __init init_sysctl(void) |
| 300 | { |
| 301 | sysctl_header = register_sysctl_table(dev_root, 0); |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | static void __exit cleanup_sysctl(void) |
| 306 | { |
| 307 | unregister_sysctl_table(sysctl_header); |
| 308 | } |
| 309 | |
| 310 | /* |
| 311 | * Now all the various file operations that we export. |
| 312 | */ |
| 313 | |
| 314 | static ssize_t rtc_read(struct file *file, char __user *buf, |
| 315 | size_t count, loff_t *ppos) |
| 316 | { |
| 317 | #ifndef RTC_IRQ |
| 318 | return -EIO; |
| 319 | #else |
| 320 | DECLARE_WAITQUEUE(wait, current); |
| 321 | unsigned long data; |
| 322 | ssize_t retval; |
| 323 | |
| 324 | if (rtc_has_irq == 0) |
| 325 | return -EIO; |
| 326 | |
| 327 | if (count < sizeof(unsigned)) |
| 328 | return -EINVAL; |
| 329 | |
| 330 | add_wait_queue(&rtc_wait, &wait); |
| 331 | |
| 332 | do { |
| 333 | /* First make it right. Then make it fast. Putting this whole |
| 334 | * block within the parentheses of a while would be too |
| 335 | * confusing. And no, xchg() is not the answer. */ |
| 336 | |
| 337 | __set_current_state(TASK_INTERRUPTIBLE); |
| 338 | |
| 339 | spin_lock_irq (&rtc_lock); |
| 340 | data = rtc_irq_data; |
| 341 | rtc_irq_data = 0; |
| 342 | spin_unlock_irq (&rtc_lock); |
| 343 | |
| 344 | if (data != 0) |
| 345 | break; |
| 346 | |
| 347 | if (file->f_flags & O_NONBLOCK) { |
| 348 | retval = -EAGAIN; |
| 349 | goto out; |
| 350 | } |
| 351 | if (signal_pending(current)) { |
| 352 | retval = -ERESTARTSYS; |
| 353 | goto out; |
| 354 | } |
| 355 | schedule(); |
| 356 | } while (1); |
| 357 | |
| 358 | if (count < sizeof(unsigned long)) |
| 359 | retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int); |
| 360 | else |
| 361 | retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long); |
| 362 | out: |
| 363 | current->state = TASK_RUNNING; |
| 364 | remove_wait_queue(&rtc_wait, &wait); |
| 365 | |
| 366 | return retval; |
| 367 | #endif |
| 368 | } |
| 369 | |
| 370 | static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel) |
| 371 | { |
| 372 | struct rtc_time wtime; |
| 373 | |
| 374 | #ifdef RTC_IRQ |
| 375 | if (rtc_has_irq == 0) { |
| 376 | switch (cmd) { |
| 377 | case RTC_AIE_OFF: |
| 378 | case RTC_AIE_ON: |
| 379 | case RTC_PIE_OFF: |
| 380 | case RTC_PIE_ON: |
| 381 | case RTC_UIE_OFF: |
| 382 | case RTC_UIE_ON: |
| 383 | case RTC_IRQP_READ: |
| 384 | case RTC_IRQP_SET: |
| 385 | return -EINVAL; |
| 386 | }; |
| 387 | } |
| 388 | #endif |
| 389 | |
| 390 | switch (cmd) { |
| 391 | #ifdef RTC_IRQ |
| 392 | case RTC_AIE_OFF: /* Mask alarm int. enab. bit */ |
| 393 | { |
| 394 | mask_rtc_irq_bit(RTC_AIE); |
| 395 | return 0; |
| 396 | } |
| 397 | case RTC_AIE_ON: /* Allow alarm interrupts. */ |
| 398 | { |
| 399 | set_rtc_irq_bit(RTC_AIE); |
| 400 | return 0; |
| 401 | } |
| 402 | case RTC_PIE_OFF: /* Mask periodic int. enab. bit */ |
| 403 | { |
| 404 | mask_rtc_irq_bit(RTC_PIE); |
| 405 | if (rtc_status & RTC_TIMER_ON) { |
| 406 | spin_lock_irq (&rtc_lock); |
| 407 | rtc_status &= ~RTC_TIMER_ON; |
| 408 | del_timer(&rtc_irq_timer); |
| 409 | spin_unlock_irq (&rtc_lock); |
| 410 | } |
| 411 | return 0; |
| 412 | } |
| 413 | case RTC_PIE_ON: /* Allow periodic ints */ |
| 414 | { |
| 415 | |
| 416 | /* |
| 417 | * We don't really want Joe User enabling more |
| 418 | * than 64Hz of interrupts on a multi-user machine. |
| 419 | */ |
| 420 | if (!kernel && (rtc_freq > rtc_max_user_freq) && |
| 421 | (!capable(CAP_SYS_RESOURCE))) |
| 422 | return -EACCES; |
| 423 | |
| 424 | if (!(rtc_status & RTC_TIMER_ON)) { |
| 425 | spin_lock_irq (&rtc_lock); |
| 426 | rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100; |
| 427 | add_timer(&rtc_irq_timer); |
| 428 | rtc_status |= RTC_TIMER_ON; |
| 429 | spin_unlock_irq (&rtc_lock); |
| 430 | } |
| 431 | set_rtc_irq_bit(RTC_PIE); |
| 432 | return 0; |
| 433 | } |
| 434 | case RTC_UIE_OFF: /* Mask ints from RTC updates. */ |
| 435 | { |
| 436 | mask_rtc_irq_bit(RTC_UIE); |
| 437 | return 0; |
| 438 | } |
| 439 | case RTC_UIE_ON: /* Allow ints for RTC updates. */ |
| 440 | { |
| 441 | set_rtc_irq_bit(RTC_UIE); |
| 442 | return 0; |
| 443 | } |
| 444 | #endif |
| 445 | case RTC_ALM_READ: /* Read the present alarm time */ |
| 446 | { |
| 447 | /* |
| 448 | * This returns a struct rtc_time. Reading >= 0xc0 |
| 449 | * means "don't care" or "match all". Only the tm_hour, |
| 450 | * tm_min, and tm_sec values are filled in. |
| 451 | */ |
| 452 | memset(&wtime, 0, sizeof(struct rtc_time)); |
| 453 | get_rtc_alm_time(&wtime); |
| 454 | break; |
| 455 | } |
| 456 | case RTC_ALM_SET: /* Store a time into the alarm */ |
| 457 | { |
| 458 | /* |
| 459 | * This expects a struct rtc_time. Writing 0xff means |
| 460 | * "don't care" or "match all". Only the tm_hour, |
| 461 | * tm_min and tm_sec are used. |
| 462 | */ |
| 463 | unsigned char hrs, min, sec; |
| 464 | struct rtc_time alm_tm; |
| 465 | |
| 466 | if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg, |
| 467 | sizeof(struct rtc_time))) |
| 468 | return -EFAULT; |
| 469 | |
| 470 | hrs = alm_tm.tm_hour; |
| 471 | min = alm_tm.tm_min; |
| 472 | sec = alm_tm.tm_sec; |
| 473 | |
| 474 | spin_lock_irq(&rtc_lock); |
| 475 | if (hpet_set_alarm_time(hrs, min, sec)) { |
| 476 | /* |
| 477 | * Fallthru and set alarm time in CMOS too, |
| 478 | * so that we will get proper value in RTC_ALM_READ |
| 479 | */ |
| 480 | } |
| 481 | if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || |
| 482 | RTC_ALWAYS_BCD) |
| 483 | { |
| 484 | if (sec < 60) BIN_TO_BCD(sec); |
| 485 | else sec = 0xff; |
| 486 | |
| 487 | if (min < 60) BIN_TO_BCD(min); |
| 488 | else min = 0xff; |
| 489 | |
| 490 | if (hrs < 24) BIN_TO_BCD(hrs); |
| 491 | else hrs = 0xff; |
| 492 | } |
| 493 | CMOS_WRITE(hrs, RTC_HOURS_ALARM); |
| 494 | CMOS_WRITE(min, RTC_MINUTES_ALARM); |
| 495 | CMOS_WRITE(sec, RTC_SECONDS_ALARM); |
| 496 | spin_unlock_irq(&rtc_lock); |
| 497 | |
| 498 | return 0; |
| 499 | } |
| 500 | case RTC_RD_TIME: /* Read the time/date from RTC */ |
| 501 | { |
| 502 | memset(&wtime, 0, sizeof(struct rtc_time)); |
| 503 | rtc_get_rtc_time(&wtime); |
| 504 | break; |
| 505 | } |
| 506 | case RTC_SET_TIME: /* Set the RTC */ |
| 507 | { |
| 508 | struct rtc_time rtc_tm; |
| 509 | unsigned char mon, day, hrs, min, sec, leap_yr; |
| 510 | unsigned char save_control, save_freq_select; |
| 511 | unsigned int yrs; |
| 512 | #ifdef CONFIG_MACH_DECSTATION |
| 513 | unsigned int real_yrs; |
| 514 | #endif |
| 515 | |
| 516 | if (!capable(CAP_SYS_TIME)) |
| 517 | return -EACCES; |
| 518 | |
| 519 | if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg, |
| 520 | sizeof(struct rtc_time))) |
| 521 | return -EFAULT; |
| 522 | |
| 523 | yrs = rtc_tm.tm_year + 1900; |
| 524 | mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */ |
| 525 | day = rtc_tm.tm_mday; |
| 526 | hrs = rtc_tm.tm_hour; |
| 527 | min = rtc_tm.tm_min; |
| 528 | sec = rtc_tm.tm_sec; |
| 529 | |
| 530 | if (yrs < 1970) |
| 531 | return -EINVAL; |
| 532 | |
| 533 | leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400)); |
| 534 | |
| 535 | if ((mon > 12) || (day == 0)) |
| 536 | return -EINVAL; |
| 537 | |
| 538 | if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr))) |
| 539 | return -EINVAL; |
| 540 | |
| 541 | if ((hrs >= 24) || (min >= 60) || (sec >= 60)) |
| 542 | return -EINVAL; |
| 543 | |
| 544 | if ((yrs -= epoch) > 255) /* They are unsigned */ |
| 545 | return -EINVAL; |
| 546 | |
| 547 | spin_lock_irq(&rtc_lock); |
| 548 | #ifdef CONFIG_MACH_DECSTATION |
| 549 | real_yrs = yrs; |
| 550 | yrs = 72; |
| 551 | |
| 552 | /* |
| 553 | * We want to keep the year set to 73 until March |
| 554 | * for non-leap years, so that Feb, 29th is handled |
| 555 | * correctly. |
| 556 | */ |
| 557 | if (!leap_yr && mon < 3) { |
| 558 | real_yrs--; |
| 559 | yrs = 73; |
| 560 | } |
| 561 | #endif |
| 562 | /* These limits and adjustments are independent of |
| 563 | * whether the chip is in binary mode or not. |
| 564 | */ |
| 565 | if (yrs > 169) { |
| 566 | spin_unlock_irq(&rtc_lock); |
| 567 | return -EINVAL; |
| 568 | } |
| 569 | if (yrs >= 100) |
| 570 | yrs -= 100; |
| 571 | |
| 572 | if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) |
| 573 | || RTC_ALWAYS_BCD) { |
| 574 | BIN_TO_BCD(sec); |
| 575 | BIN_TO_BCD(min); |
| 576 | BIN_TO_BCD(hrs); |
| 577 | BIN_TO_BCD(day); |
| 578 | BIN_TO_BCD(mon); |
| 579 | BIN_TO_BCD(yrs); |
| 580 | } |
| 581 | |
| 582 | save_control = CMOS_READ(RTC_CONTROL); |
| 583 | CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); |
| 584 | save_freq_select = CMOS_READ(RTC_FREQ_SELECT); |
| 585 | CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); |
| 586 | |
| 587 | #ifdef CONFIG_MACH_DECSTATION |
| 588 | CMOS_WRITE(real_yrs, RTC_DEC_YEAR); |
| 589 | #endif |
| 590 | CMOS_WRITE(yrs, RTC_YEAR); |
| 591 | CMOS_WRITE(mon, RTC_MONTH); |
| 592 | CMOS_WRITE(day, RTC_DAY_OF_MONTH); |
| 593 | CMOS_WRITE(hrs, RTC_HOURS); |
| 594 | CMOS_WRITE(min, RTC_MINUTES); |
| 595 | CMOS_WRITE(sec, RTC_SECONDS); |
| 596 | |
| 597 | CMOS_WRITE(save_control, RTC_CONTROL); |
| 598 | CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); |
| 599 | |
| 600 | spin_unlock_irq(&rtc_lock); |
| 601 | return 0; |
| 602 | } |
| 603 | #ifdef RTC_IRQ |
| 604 | case RTC_IRQP_READ: /* Read the periodic IRQ rate. */ |
| 605 | { |
| 606 | return put_user(rtc_freq, (unsigned long __user *)arg); |
| 607 | } |
| 608 | case RTC_IRQP_SET: /* Set periodic IRQ rate. */ |
| 609 | { |
| 610 | int tmp = 0; |
| 611 | unsigned char val; |
| 612 | |
| 613 | /* |
| 614 | * The max we can do is 8192Hz. |
| 615 | */ |
| 616 | if ((arg < 2) || (arg > 8192)) |
| 617 | return -EINVAL; |
| 618 | /* |
| 619 | * We don't really want Joe User generating more |
| 620 | * than 64Hz of interrupts on a multi-user machine. |
| 621 | */ |
| 622 | if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE))) |
| 623 | return -EACCES; |
| 624 | |
| 625 | while (arg > (1<<tmp)) |
| 626 | tmp++; |
| 627 | |
| 628 | /* |
| 629 | * Check that the input was really a power of 2. |
| 630 | */ |
| 631 | if (arg != (1<<tmp)) |
| 632 | return -EINVAL; |
| 633 | |
| 634 | spin_lock_irq(&rtc_lock); |
| 635 | if (hpet_set_periodic_freq(arg)) { |
| 636 | spin_unlock_irq(&rtc_lock); |
| 637 | return 0; |
| 638 | } |
| 639 | rtc_freq = arg; |
| 640 | |
| 641 | val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0; |
| 642 | val |= (16 - tmp); |
| 643 | CMOS_WRITE(val, RTC_FREQ_SELECT); |
| 644 | spin_unlock_irq(&rtc_lock); |
| 645 | return 0; |
| 646 | } |
| 647 | #endif |
| 648 | case RTC_EPOCH_READ: /* Read the epoch. */ |
| 649 | { |
| 650 | return put_user (epoch, (unsigned long __user *)arg); |
| 651 | } |
| 652 | case RTC_EPOCH_SET: /* Set the epoch. */ |
| 653 | { |
| 654 | /* |
| 655 | * There were no RTC clocks before 1900. |
| 656 | */ |
| 657 | if (arg < 1900) |
| 658 | return -EINVAL; |
| 659 | |
| 660 | if (!capable(CAP_SYS_TIME)) |
| 661 | return -EACCES; |
| 662 | |
| 663 | epoch = arg; |
| 664 | return 0; |
| 665 | } |
| 666 | default: |
| 667 | return -ENOTTY; |
| 668 | } |
| 669 | return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0; |
| 670 | } |
| 671 | |
| 672 | static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, |
| 673 | unsigned long arg) |
| 674 | { |
| 675 | return rtc_do_ioctl(cmd, arg, 0); |
| 676 | } |
| 677 | |
| 678 | /* |
| 679 | * We enforce only one user at a time here with the open/close. |
| 680 | * Also clear the previous interrupt data on an open, and clean |
| 681 | * up things on a close. |
| 682 | */ |
| 683 | |
| 684 | /* We use rtc_lock to protect against concurrent opens. So the BKL is not |
| 685 | * needed here. Or anywhere else in this driver. */ |
| 686 | static int rtc_open(struct inode *inode, struct file *file) |
| 687 | { |
| 688 | spin_lock_irq (&rtc_lock); |
| 689 | |
| 690 | if(rtc_status & RTC_IS_OPEN) |
| 691 | goto out_busy; |
| 692 | |
| 693 | rtc_status |= RTC_IS_OPEN; |
| 694 | |
| 695 | rtc_irq_data = 0; |
| 696 | spin_unlock_irq (&rtc_lock); |
| 697 | return 0; |
| 698 | |
| 699 | out_busy: |
| 700 | spin_unlock_irq (&rtc_lock); |
| 701 | return -EBUSY; |
| 702 | } |
| 703 | |
| 704 | static int rtc_fasync (int fd, struct file *filp, int on) |
| 705 | |
| 706 | { |
| 707 | return fasync_helper (fd, filp, on, &rtc_async_queue); |
| 708 | } |
| 709 | |
| 710 | static int rtc_release(struct inode *inode, struct file *file) |
| 711 | { |
| 712 | #ifdef RTC_IRQ |
| 713 | unsigned char tmp; |
| 714 | |
| 715 | if (rtc_has_irq == 0) |
| 716 | goto no_irq; |
| 717 | |
| 718 | /* |
| 719 | * Turn off all interrupts once the device is no longer |
| 720 | * in use, and clear the data. |
| 721 | */ |
| 722 | |
| 723 | spin_lock_irq(&rtc_lock); |
| 724 | if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { |
| 725 | tmp = CMOS_READ(RTC_CONTROL); |
| 726 | tmp &= ~RTC_PIE; |
| 727 | tmp &= ~RTC_AIE; |
| 728 | tmp &= ~RTC_UIE; |
| 729 | CMOS_WRITE(tmp, RTC_CONTROL); |
| 730 | CMOS_READ(RTC_INTR_FLAGS); |
| 731 | } |
| 732 | if (rtc_status & RTC_TIMER_ON) { |
| 733 | rtc_status &= ~RTC_TIMER_ON; |
| 734 | del_timer(&rtc_irq_timer); |
| 735 | } |
| 736 | spin_unlock_irq(&rtc_lock); |
| 737 | |
| 738 | if (file->f_flags & FASYNC) { |
| 739 | rtc_fasync (-1, file, 0); |
| 740 | } |
| 741 | no_irq: |
| 742 | #endif |
| 743 | |
| 744 | spin_lock_irq (&rtc_lock); |
| 745 | rtc_irq_data = 0; |
| 746 | rtc_status &= ~RTC_IS_OPEN; |
| 747 | spin_unlock_irq (&rtc_lock); |
| 748 | return 0; |
| 749 | } |
| 750 | |
| 751 | #ifdef RTC_IRQ |
| 752 | /* Called without the kernel lock - fine */ |
| 753 | static unsigned int rtc_poll(struct file *file, poll_table *wait) |
| 754 | { |
| 755 | unsigned long l; |
| 756 | |
| 757 | if (rtc_has_irq == 0) |
| 758 | return 0; |
| 759 | |
| 760 | poll_wait(file, &rtc_wait, wait); |
| 761 | |
| 762 | spin_lock_irq (&rtc_lock); |
| 763 | l = rtc_irq_data; |
| 764 | spin_unlock_irq (&rtc_lock); |
| 765 | |
| 766 | if (l != 0) |
| 767 | return POLLIN | POLLRDNORM; |
| 768 | return 0; |
| 769 | } |
| 770 | #endif |
| 771 | |
| 772 | /* |
| 773 | * exported stuffs |
| 774 | */ |
| 775 | |
| 776 | EXPORT_SYMBOL(rtc_register); |
| 777 | EXPORT_SYMBOL(rtc_unregister); |
| 778 | EXPORT_SYMBOL(rtc_control); |
| 779 | |
| 780 | int rtc_register(rtc_task_t *task) |
| 781 | { |
| 782 | #ifndef RTC_IRQ |
| 783 | return -EIO; |
| 784 | #else |
| 785 | if (task == NULL || task->func == NULL) |
| 786 | return -EINVAL; |
| 787 | spin_lock_irq(&rtc_lock); |
| 788 | if (rtc_status & RTC_IS_OPEN) { |
| 789 | spin_unlock_irq(&rtc_lock); |
| 790 | return -EBUSY; |
| 791 | } |
| 792 | spin_lock(&rtc_task_lock); |
| 793 | if (rtc_callback) { |
| 794 | spin_unlock(&rtc_task_lock); |
| 795 | spin_unlock_irq(&rtc_lock); |
| 796 | return -EBUSY; |
| 797 | } |
| 798 | rtc_status |= RTC_IS_OPEN; |
| 799 | rtc_callback = task; |
| 800 | spin_unlock(&rtc_task_lock); |
| 801 | spin_unlock_irq(&rtc_lock); |
| 802 | return 0; |
| 803 | #endif |
| 804 | } |
| 805 | |
| 806 | int rtc_unregister(rtc_task_t *task) |
| 807 | { |
| 808 | #ifndef RTC_IRQ |
| 809 | return -EIO; |
| 810 | #else |
| 811 | unsigned char tmp; |
| 812 | |
| 813 | spin_lock_irq(&rtc_lock); |
| 814 | spin_lock(&rtc_task_lock); |
| 815 | if (rtc_callback != task) { |
| 816 | spin_unlock(&rtc_task_lock); |
| 817 | spin_unlock_irq(&rtc_lock); |
| 818 | return -ENXIO; |
| 819 | } |
| 820 | rtc_callback = NULL; |
| 821 | |
| 822 | /* disable controls */ |
| 823 | if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) { |
| 824 | tmp = CMOS_READ(RTC_CONTROL); |
| 825 | tmp &= ~RTC_PIE; |
| 826 | tmp &= ~RTC_AIE; |
| 827 | tmp &= ~RTC_UIE; |
| 828 | CMOS_WRITE(tmp, RTC_CONTROL); |
| 829 | CMOS_READ(RTC_INTR_FLAGS); |
| 830 | } |
| 831 | if (rtc_status & RTC_TIMER_ON) { |
| 832 | rtc_status &= ~RTC_TIMER_ON; |
| 833 | del_timer(&rtc_irq_timer); |
| 834 | } |
| 835 | rtc_status &= ~RTC_IS_OPEN; |
| 836 | spin_unlock(&rtc_task_lock); |
| 837 | spin_unlock_irq(&rtc_lock); |
| 838 | return 0; |
| 839 | #endif |
| 840 | } |
| 841 | |
| 842 | int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg) |
| 843 | { |
| 844 | #ifndef RTC_IRQ |
| 845 | return -EIO; |
| 846 | #else |
| 847 | spin_lock_irq(&rtc_task_lock); |
| 848 | if (rtc_callback != task) { |
| 849 | spin_unlock_irq(&rtc_task_lock); |
| 850 | return -ENXIO; |
| 851 | } |
| 852 | spin_unlock_irq(&rtc_task_lock); |
| 853 | return rtc_do_ioctl(cmd, arg, 1); |
| 854 | #endif |
| 855 | } |
| 856 | |
| 857 | |
| 858 | /* |
| 859 | * The various file operations we support. |
| 860 | */ |
| 861 | |
| 862 | static struct file_operations rtc_fops = { |
| 863 | .owner = THIS_MODULE, |
| 864 | .llseek = no_llseek, |
| 865 | .read = rtc_read, |
| 866 | #ifdef RTC_IRQ |
| 867 | .poll = rtc_poll, |
| 868 | #endif |
| 869 | .ioctl = rtc_ioctl, |
| 870 | .open = rtc_open, |
| 871 | .release = rtc_release, |
| 872 | .fasync = rtc_fasync, |
| 873 | }; |
| 874 | |
| 875 | static struct miscdevice rtc_dev = { |
| 876 | .minor = RTC_MINOR, |
| 877 | .name = "rtc", |
| 878 | .fops = &rtc_fops, |
| 879 | }; |
| 880 | |
| 881 | static struct file_operations rtc_proc_fops = { |
| 882 | .owner = THIS_MODULE, |
| 883 | .open = rtc_proc_open, |
| 884 | .read = seq_read, |
| 885 | .llseek = seq_lseek, |
| 886 | .release = single_release, |
| 887 | }; |
| 888 | |
| 889 | #if defined(RTC_IRQ) && !defined(__sparc__) |
| 890 | static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs); |
| 891 | #endif |
| 892 | |
| 893 | static int __init rtc_init(void) |
| 894 | { |
| 895 | struct proc_dir_entry *ent; |
| 896 | #if defined(__alpha__) || defined(__mips__) |
| 897 | unsigned int year, ctrl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | char *guess = NULL; |
| 899 | #endif |
| 900 | #ifdef __sparc__ |
| 901 | struct linux_ebus *ebus; |
| 902 | struct linux_ebus_device *edev; |
| 903 | #ifdef __sparc_v9__ |
| 904 | struct sparc_isa_bridge *isa_br; |
| 905 | struct sparc_isa_device *isa_dev; |
| 906 | #endif |
| 907 | #endif |
| 908 | |
| 909 | #ifdef __sparc__ |
| 910 | for_each_ebus(ebus) { |
| 911 | for_each_ebusdev(edev, ebus) { |
| 912 | if(strcmp(edev->prom_name, "rtc") == 0) { |
| 913 | rtc_port = edev->resource[0].start; |
| 914 | rtc_irq = edev->irqs[0]; |
| 915 | goto found; |
| 916 | } |
| 917 | } |
| 918 | } |
| 919 | #ifdef __sparc_v9__ |
| 920 | for_each_isa(isa_br) { |
| 921 | for_each_isadev(isa_dev, isa_br) { |
| 922 | if (strcmp(isa_dev->prom_name, "rtc") == 0) { |
| 923 | rtc_port = isa_dev->resource.start; |
| 924 | rtc_irq = isa_dev->irq; |
| 925 | goto found; |
| 926 | } |
| 927 | } |
| 928 | } |
| 929 | #endif |
| 930 | printk(KERN_ERR "rtc_init: no PC rtc found\n"); |
| 931 | return -EIO; |
| 932 | |
| 933 | found: |
| 934 | if (rtc_irq == PCI_IRQ_NONE) { |
| 935 | rtc_has_irq = 0; |
| 936 | goto no_irq; |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * XXX Interrupt pin #7 in Espresso is shared between RTC and |
| 941 | * PCI Slot 2 INTA# (and some INTx# in Slot 1). SA_INTERRUPT here |
| 942 | * is asking for trouble with add-on boards. Change to SA_SHIRQ. |
| 943 | */ |
| 944 | if (request_irq(rtc_irq, rtc_interrupt, SA_INTERRUPT, "rtc", (void *)&rtc_port)) { |
| 945 | /* |
| 946 | * Standard way for sparc to print irq's is to use |
| 947 | * __irq_itoa(). I think for EBus it's ok to use %d. |
| 948 | */ |
| 949 | printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq); |
| 950 | return -EIO; |
| 951 | } |
| 952 | no_irq: |
| 953 | #else |
| 954 | if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) { |
| 955 | printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0)); |
| 956 | return -EIO; |
| 957 | } |
| 958 | |
| 959 | #ifdef RTC_IRQ |
| 960 | if (is_hpet_enabled()) { |
| 961 | rtc_int_handler_ptr = hpet_rtc_interrupt; |
| 962 | } else { |
| 963 | rtc_int_handler_ptr = rtc_interrupt; |
| 964 | } |
| 965 | |
| 966 | if(request_irq(RTC_IRQ, rtc_int_handler_ptr, SA_INTERRUPT, "rtc", NULL)) { |
| 967 | /* Yeah right, seeing as irq 8 doesn't even hit the bus. */ |
| 968 | printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ); |
| 969 | release_region(RTC_PORT(0), RTC_IO_EXTENT); |
| 970 | return -EIO; |
| 971 | } |
| 972 | hpet_rtc_timer_init(); |
| 973 | |
| 974 | #endif |
| 975 | |
| 976 | #endif /* __sparc__ vs. others */ |
| 977 | |
| 978 | if (misc_register(&rtc_dev)) { |
| 979 | #ifdef RTC_IRQ |
| 980 | free_irq(RTC_IRQ, NULL); |
| 981 | #endif |
| 982 | release_region(RTC_PORT(0), RTC_IO_EXTENT); |
| 983 | return -ENODEV; |
| 984 | } |
| 985 | |
| 986 | ent = create_proc_entry("driver/rtc", 0, NULL); |
| 987 | if (!ent) { |
| 988 | #ifdef RTC_IRQ |
| 989 | free_irq(RTC_IRQ, NULL); |
| 990 | #endif |
| 991 | release_region(RTC_PORT(0), RTC_IO_EXTENT); |
| 992 | misc_deregister(&rtc_dev); |
| 993 | return -ENOMEM; |
| 994 | } |
| 995 | ent->proc_fops = &rtc_proc_fops; |
| 996 | |
| 997 | #if defined(__alpha__) || defined(__mips__) |
| 998 | rtc_freq = HZ; |
| 999 | |
| 1000 | /* Each operating system on an Alpha uses its own epoch. |
| 1001 | Let's try to guess which one we are using now. */ |
| 1002 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | if (rtc_is_updating() != 0) |
Luca Falavigna | 47f176f | 2005-06-28 20:44:42 -0700 | [diff] [blame] | 1004 | msleep(20); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | |
| 1006 | spin_lock_irq(&rtc_lock); |
| 1007 | year = CMOS_READ(RTC_YEAR); |
| 1008 | ctrl = CMOS_READ(RTC_CONTROL); |
| 1009 | spin_unlock_irq(&rtc_lock); |
| 1010 | |
| 1011 | if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
| 1012 | BCD_TO_BIN(year); /* This should never happen... */ |
| 1013 | |
| 1014 | if (year < 20) { |
| 1015 | epoch = 2000; |
| 1016 | guess = "SRM (post-2000)"; |
| 1017 | } else if (year >= 20 && year < 48) { |
| 1018 | epoch = 1980; |
| 1019 | guess = "ARC console"; |
| 1020 | } else if (year >= 48 && year < 72) { |
| 1021 | epoch = 1952; |
| 1022 | guess = "Digital UNIX"; |
| 1023 | #if defined(__mips__) |
| 1024 | } else if (year >= 72 && year < 74) { |
| 1025 | epoch = 2000; |
| 1026 | guess = "Digital DECstation"; |
| 1027 | #else |
| 1028 | } else if (year >= 70) { |
| 1029 | epoch = 1900; |
| 1030 | guess = "Standard PC (1900)"; |
| 1031 | #endif |
| 1032 | } |
| 1033 | if (guess) |
| 1034 | printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch); |
| 1035 | #endif |
| 1036 | #ifdef RTC_IRQ |
| 1037 | if (rtc_has_irq == 0) |
| 1038 | goto no_irq2; |
| 1039 | |
| 1040 | init_timer(&rtc_irq_timer); |
| 1041 | rtc_irq_timer.function = rtc_dropped_irq; |
| 1042 | spin_lock_irq(&rtc_lock); |
| 1043 | rtc_freq = 1024; |
| 1044 | if (!hpet_set_periodic_freq(rtc_freq)) { |
| 1045 | /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */ |
| 1046 | CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT); |
| 1047 | } |
| 1048 | spin_unlock_irq(&rtc_lock); |
| 1049 | no_irq2: |
| 1050 | #endif |
| 1051 | |
| 1052 | (void) init_sysctl(); |
| 1053 | |
| 1054 | printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n"); |
| 1055 | |
| 1056 | return 0; |
| 1057 | } |
| 1058 | |
| 1059 | static void __exit rtc_exit (void) |
| 1060 | { |
| 1061 | cleanup_sysctl(); |
| 1062 | remove_proc_entry ("driver/rtc", NULL); |
| 1063 | misc_deregister(&rtc_dev); |
| 1064 | |
| 1065 | #ifdef __sparc__ |
| 1066 | if (rtc_has_irq) |
| 1067 | free_irq (rtc_irq, &rtc_port); |
| 1068 | #else |
| 1069 | release_region (RTC_PORT (0), RTC_IO_EXTENT); |
| 1070 | #ifdef RTC_IRQ |
| 1071 | if (rtc_has_irq) |
| 1072 | free_irq (RTC_IRQ, NULL); |
| 1073 | #endif |
| 1074 | #endif /* __sparc__ */ |
| 1075 | } |
| 1076 | |
| 1077 | module_init(rtc_init); |
| 1078 | module_exit(rtc_exit); |
| 1079 | |
| 1080 | #ifdef RTC_IRQ |
| 1081 | /* |
| 1082 | * At IRQ rates >= 4096Hz, an interrupt may get lost altogether. |
| 1083 | * (usually during an IDE disk interrupt, with IRQ unmasking off) |
| 1084 | * Since the interrupt handler doesn't get called, the IRQ status |
| 1085 | * byte doesn't get read, and the RTC stops generating interrupts. |
| 1086 | * A timer is set, and will call this function if/when that happens. |
| 1087 | * To get it out of this stalled state, we just read the status. |
| 1088 | * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost. |
| 1089 | * (You *really* shouldn't be trying to use a non-realtime system |
| 1090 | * for something that requires a steady > 1KHz signal anyways.) |
| 1091 | */ |
| 1092 | |
| 1093 | static void rtc_dropped_irq(unsigned long data) |
| 1094 | { |
| 1095 | unsigned long freq; |
| 1096 | |
| 1097 | spin_lock_irq (&rtc_lock); |
| 1098 | |
| 1099 | if (hpet_rtc_dropped_irq()) { |
| 1100 | spin_unlock_irq(&rtc_lock); |
| 1101 | return; |
| 1102 | } |
| 1103 | |
| 1104 | /* Just in case someone disabled the timer from behind our back... */ |
| 1105 | if (rtc_status & RTC_TIMER_ON) |
| 1106 | mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100); |
| 1107 | |
| 1108 | rtc_irq_data += ((rtc_freq/HZ)<<8); |
| 1109 | rtc_irq_data &= ~0xff; |
| 1110 | rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */ |
| 1111 | |
| 1112 | freq = rtc_freq; |
| 1113 | |
| 1114 | spin_unlock_irq(&rtc_lock); |
| 1115 | |
| 1116 | printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq); |
| 1117 | |
| 1118 | /* Now we have new data */ |
| 1119 | wake_up_interruptible(&rtc_wait); |
| 1120 | |
| 1121 | kill_fasync (&rtc_async_queue, SIGIO, POLL_IN); |
| 1122 | } |
| 1123 | #endif |
| 1124 | |
| 1125 | /* |
| 1126 | * Info exported via "/proc/driver/rtc". |
| 1127 | */ |
| 1128 | |
| 1129 | static int rtc_proc_show(struct seq_file *seq, void *v) |
| 1130 | { |
| 1131 | #define YN(bit) ((ctrl & bit) ? "yes" : "no") |
| 1132 | #define NY(bit) ((ctrl & bit) ? "no" : "yes") |
| 1133 | struct rtc_time tm; |
| 1134 | unsigned char batt, ctrl; |
| 1135 | unsigned long freq; |
| 1136 | |
| 1137 | spin_lock_irq(&rtc_lock); |
| 1138 | batt = CMOS_READ(RTC_VALID) & RTC_VRT; |
| 1139 | ctrl = CMOS_READ(RTC_CONTROL); |
| 1140 | freq = rtc_freq; |
| 1141 | spin_unlock_irq(&rtc_lock); |
| 1142 | |
| 1143 | |
| 1144 | rtc_get_rtc_time(&tm); |
| 1145 | |
| 1146 | /* |
| 1147 | * There is no way to tell if the luser has the RTC set for local |
| 1148 | * time or for Universal Standard Time (GMT). Probably local though. |
| 1149 | */ |
| 1150 | seq_printf(seq, |
| 1151 | "rtc_time\t: %02d:%02d:%02d\n" |
| 1152 | "rtc_date\t: %04d-%02d-%02d\n" |
| 1153 | "rtc_epoch\t: %04lu\n", |
| 1154 | tm.tm_hour, tm.tm_min, tm.tm_sec, |
| 1155 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch); |
| 1156 | |
| 1157 | get_rtc_alm_time(&tm); |
| 1158 | |
| 1159 | /* |
| 1160 | * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will |
| 1161 | * match any value for that particular field. Values that are |
| 1162 | * greater than a valid time, but less than 0xc0 shouldn't appear. |
| 1163 | */ |
| 1164 | seq_puts(seq, "alarm\t\t: "); |
| 1165 | if (tm.tm_hour <= 24) |
| 1166 | seq_printf(seq, "%02d:", tm.tm_hour); |
| 1167 | else |
| 1168 | seq_puts(seq, "**:"); |
| 1169 | |
| 1170 | if (tm.tm_min <= 59) |
| 1171 | seq_printf(seq, "%02d:", tm.tm_min); |
| 1172 | else |
| 1173 | seq_puts(seq, "**:"); |
| 1174 | |
| 1175 | if (tm.tm_sec <= 59) |
| 1176 | seq_printf(seq, "%02d\n", tm.tm_sec); |
| 1177 | else |
| 1178 | seq_puts(seq, "**\n"); |
| 1179 | |
| 1180 | seq_printf(seq, |
| 1181 | "DST_enable\t: %s\n" |
| 1182 | "BCD\t\t: %s\n" |
| 1183 | "24hr\t\t: %s\n" |
| 1184 | "square_wave\t: %s\n" |
| 1185 | "alarm_IRQ\t: %s\n" |
| 1186 | "update_IRQ\t: %s\n" |
| 1187 | "periodic_IRQ\t: %s\n" |
| 1188 | "periodic_freq\t: %ld\n" |
| 1189 | "batt_status\t: %s\n", |
| 1190 | YN(RTC_DST_EN), |
| 1191 | NY(RTC_DM_BINARY), |
| 1192 | YN(RTC_24H), |
| 1193 | YN(RTC_SQWE), |
| 1194 | YN(RTC_AIE), |
| 1195 | YN(RTC_UIE), |
| 1196 | YN(RTC_PIE), |
| 1197 | freq, |
| 1198 | batt ? "okay" : "dead"); |
| 1199 | |
| 1200 | return 0; |
| 1201 | #undef YN |
| 1202 | #undef NY |
| 1203 | } |
| 1204 | |
| 1205 | static int rtc_proc_open(struct inode *inode, struct file *file) |
| 1206 | { |
| 1207 | return single_open(file, rtc_proc_show, NULL); |
| 1208 | } |
| 1209 | |
| 1210 | void rtc_get_rtc_time(struct rtc_time *rtc_tm) |
| 1211 | { |
Petr Vandrovec | 403fe5a | 2005-08-05 15:50:07 +0200 | [diff] [blame^] | 1212 | unsigned long uip_watchdog = jiffies; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1213 | unsigned char ctrl; |
| 1214 | #ifdef CONFIG_MACH_DECSTATION |
| 1215 | unsigned int real_year; |
| 1216 | #endif |
| 1217 | |
| 1218 | /* |
| 1219 | * read RTC once any update in progress is done. The update |
Luca Falavigna | 47f176f | 2005-06-28 20:44:42 -0700 | [diff] [blame] | 1220 | * can take just over 2ms. We wait 20ms. There is no need to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP. |
| 1222 | * If you need to know *exactly* when a second has started, enable |
| 1223 | * periodic update complete interrupts, (via ioctl) and then |
| 1224 | * immediately read /dev/rtc which will block until you get the IRQ. |
| 1225 | * Once the read clears, read the RTC time (again via ioctl). Easy. |
| 1226 | */ |
| 1227 | |
Petr Vandrovec | 403fe5a | 2005-08-05 15:50:07 +0200 | [diff] [blame^] | 1228 | while (rtc_is_updating() != 0 && jiffies - uip_watchdog < 2*HZ/100) { |
| 1229 | barrier(); |
| 1230 | cpu_relax(); |
| 1231 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | |
| 1233 | /* |
| 1234 | * Only the values that we read from the RTC are set. We leave |
| 1235 | * tm_wday, tm_yday and tm_isdst untouched. Even though the |
| 1236 | * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated |
| 1237 | * by the RTC when initially set to a non-zero value. |
| 1238 | */ |
| 1239 | spin_lock_irq(&rtc_lock); |
| 1240 | rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS); |
| 1241 | rtc_tm->tm_min = CMOS_READ(RTC_MINUTES); |
| 1242 | rtc_tm->tm_hour = CMOS_READ(RTC_HOURS); |
| 1243 | rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH); |
| 1244 | rtc_tm->tm_mon = CMOS_READ(RTC_MONTH); |
| 1245 | rtc_tm->tm_year = CMOS_READ(RTC_YEAR); |
| 1246 | #ifdef CONFIG_MACH_DECSTATION |
| 1247 | real_year = CMOS_READ(RTC_DEC_YEAR); |
| 1248 | #endif |
| 1249 | ctrl = CMOS_READ(RTC_CONTROL); |
| 1250 | spin_unlock_irq(&rtc_lock); |
| 1251 | |
| 1252 | if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
| 1253 | { |
| 1254 | BCD_TO_BIN(rtc_tm->tm_sec); |
| 1255 | BCD_TO_BIN(rtc_tm->tm_min); |
| 1256 | BCD_TO_BIN(rtc_tm->tm_hour); |
| 1257 | BCD_TO_BIN(rtc_tm->tm_mday); |
| 1258 | BCD_TO_BIN(rtc_tm->tm_mon); |
| 1259 | BCD_TO_BIN(rtc_tm->tm_year); |
| 1260 | } |
| 1261 | |
| 1262 | #ifdef CONFIG_MACH_DECSTATION |
| 1263 | rtc_tm->tm_year += real_year - 72; |
| 1264 | #endif |
| 1265 | |
| 1266 | /* |
| 1267 | * Account for differences between how the RTC uses the values |
| 1268 | * and how they are defined in a struct rtc_time; |
| 1269 | */ |
| 1270 | if ((rtc_tm->tm_year += (epoch - 1900)) <= 69) |
| 1271 | rtc_tm->tm_year += 100; |
| 1272 | |
| 1273 | rtc_tm->tm_mon--; |
| 1274 | } |
| 1275 | |
| 1276 | static void get_rtc_alm_time(struct rtc_time *alm_tm) |
| 1277 | { |
| 1278 | unsigned char ctrl; |
| 1279 | |
| 1280 | /* |
| 1281 | * Only the values that we read from the RTC are set. That |
| 1282 | * means only tm_hour, tm_min, and tm_sec. |
| 1283 | */ |
| 1284 | spin_lock_irq(&rtc_lock); |
| 1285 | alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM); |
| 1286 | alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM); |
| 1287 | alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM); |
| 1288 | ctrl = CMOS_READ(RTC_CONTROL); |
| 1289 | spin_unlock_irq(&rtc_lock); |
| 1290 | |
| 1291 | if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) |
| 1292 | { |
| 1293 | BCD_TO_BIN(alm_tm->tm_sec); |
| 1294 | BCD_TO_BIN(alm_tm->tm_min); |
| 1295 | BCD_TO_BIN(alm_tm->tm_hour); |
| 1296 | } |
| 1297 | } |
| 1298 | |
| 1299 | #ifdef RTC_IRQ |
| 1300 | /* |
| 1301 | * Used to disable/enable interrupts for any one of UIE, AIE, PIE. |
| 1302 | * Rumour has it that if you frob the interrupt enable/disable |
| 1303 | * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to |
| 1304 | * ensure you actually start getting interrupts. Probably for |
| 1305 | * compatibility with older/broken chipset RTC implementations. |
| 1306 | * We also clear out any old irq data after an ioctl() that |
| 1307 | * meddles with the interrupt enable/disable bits. |
| 1308 | */ |
| 1309 | |
| 1310 | static void mask_rtc_irq_bit(unsigned char bit) |
| 1311 | { |
| 1312 | unsigned char val; |
| 1313 | |
| 1314 | spin_lock_irq(&rtc_lock); |
| 1315 | if (hpet_mask_rtc_irq_bit(bit)) { |
| 1316 | spin_unlock_irq(&rtc_lock); |
| 1317 | return; |
| 1318 | } |
| 1319 | val = CMOS_READ(RTC_CONTROL); |
| 1320 | val &= ~bit; |
| 1321 | CMOS_WRITE(val, RTC_CONTROL); |
| 1322 | CMOS_READ(RTC_INTR_FLAGS); |
| 1323 | |
| 1324 | rtc_irq_data = 0; |
| 1325 | spin_unlock_irq(&rtc_lock); |
| 1326 | } |
| 1327 | |
| 1328 | static void set_rtc_irq_bit(unsigned char bit) |
| 1329 | { |
| 1330 | unsigned char val; |
| 1331 | |
| 1332 | spin_lock_irq(&rtc_lock); |
| 1333 | if (hpet_set_rtc_irq_bit(bit)) { |
| 1334 | spin_unlock_irq(&rtc_lock); |
| 1335 | return; |
| 1336 | } |
| 1337 | val = CMOS_READ(RTC_CONTROL); |
| 1338 | val |= bit; |
| 1339 | CMOS_WRITE(val, RTC_CONTROL); |
| 1340 | CMOS_READ(RTC_INTR_FLAGS); |
| 1341 | |
| 1342 | rtc_irq_data = 0; |
| 1343 | spin_unlock_irq(&rtc_lock); |
| 1344 | } |
| 1345 | #endif |
| 1346 | |
| 1347 | MODULE_AUTHOR("Paul Gortmaker"); |
| 1348 | MODULE_LICENSE("GPL"); |
| 1349 | MODULE_ALIAS_MISCDEV(RTC_MINOR); |