| 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 | |
| 95 | static unsigned long rtc_port; |
| 96 | static int rtc_irq; |
| 97 | #endif |
| 98 | |
| 99 | #ifdef CONFIG_HPET_EMULATE_RTC |
| 100 | #undef RTC_IRQ |
| 101 | #endif |
| 102 | |
| 103 | #ifdef RTC_IRQ |
| 104 | static 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 |
| 118 | static 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 | |
| 132 | static struct fasync_struct *rtc_async_queue; |
| 133 | |
| 134 | static DECLARE_WAIT_QUEUE_HEAD(rtc_wait); |
| 135 | |
| 136 | #ifdef RTC_IRQ |
| 137 | static void rtc_dropped_irq(unsigned long data); |
| 138 | |
| 139 | static DEFINE_TIMER(rtc_irq_timer, rtc_dropped_irq, 0, 0); |
| 140 | #endif |
| 141 | |
| 142 | static ssize_t rtc_read(struct file *file, char __user *buf, |
| 143 | size_t count, loff_t *ppos); |
| 144 | |
| 145 | static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
| 146 | static void rtc_get_rtc_time(struct rtc_time *rtc_tm); |
| 147 | |
| 148 | #ifdef RTC_IRQ |
| 149 | static unsigned int rtc_poll(struct file *file, poll_table *wait); |
| 150 | #endif |
| 151 | |
| 152 | static void get_rtc_alm_time(struct rtc_time *alm_tm); |
| 153 | #ifdef RTC_IRQ |
| 154 | static void set_rtc_irq_bit_locked(unsigned char bit); |
| 155 | static void mask_rtc_irq_bit_locked(unsigned char bit); |
| 156 | |
| 157 | static 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 | |
| 164 | static 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 |
| 173 | static 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 | */ |
| 190 | static unsigned long rtc_status; /* bitmapped status byte. */ |
| 191 | static unsigned long rtc_freq; /* Current periodic IRQ rate */ |
| 192 | static unsigned long rtc_irq_data; /* our output to the world */ |
| 193 | static 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 | */ |
| 199 | static DEFINE_SPINLOCK(rtc_task_lock); |
| 200 | static 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 | |
| 208 | static unsigned long epoch = 1900; /* year corresponding to 0x00 */ |
| 209 | |
| 210 | static 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 | */ |
| 216 | static 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 | |
| 238 | static 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 | */ |
| 282 | static 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 | |
| 294 | static 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 | |
| 304 | static 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 | |
| 314 | static struct ctl_table_header *sysctl_header; |
| 315 | |
| 316 | static int __init init_sysctl(void) |
| 317 | { |
| 318 | sysctl_header = register_sysctl_table(dev_root); |
| 319 | return 0; |
| 320 | } |
| 321 | |
| 322 | static 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 | |
| 331 | static 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 | |
| 400 | static 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 | |
| 720 | static 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 | */ |
| 732 | static 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 | |
| 745 | out_busy: |
| 746 | spin_unlock_irq(&rtc_lock); |
| 747 | return -EBUSY; |
| 748 | } |
| 749 | |
| 750 | static int rtc_fasync(int fd, struct file *filp, int on) |
| 751 | { |
| 752 | return fasync_helper(fd, filp, on, &rtc_async_queue); |
| 753 | } |
| 754 | |
| 755 | static 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 | |
| 783 | no_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 |
| 795 | static 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 | |
| 814 | int 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 | } |
| 839 | EXPORT_SYMBOL(rtc_register); |
| 840 | |
| 841 | int 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 | } |
| 876 | EXPORT_SYMBOL(rtc_unregister); |
| 877 | |
| 878 | int 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 | } |
| 895 | EXPORT_SYMBOL(rtc_control); |
| 896 | |
| 897 | /* |
| 898 | * The various file operations we support. |
| 899 | */ |
| 900 | |
| 901 | static 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 | |
| 914 | static struct miscdevice rtc_dev = { |
| 915 | .minor = RTC_MINOR, |
| 916 | .name = "rtc", |
| 917 | .fops = &rtc_fops, |
| 918 | }; |
| 919 | |
| 920 | #ifdef CONFIG_PROC_FS |
| 921 | static 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 | |
| 930 | static resource_size_t rtc_size; |
| 931 | |
| 932 | static 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 | |
| 947 | static 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 | |
| 955 | static 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 | |
| 992 | found: |
| 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 | } |
| 1008 | no_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); |
| 1131 | no_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 | |
| 1141 | static 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 | |
| 1161 | module_init(rtc_init); |
| 1162 | module_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 | |
| 1177 | static 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 | |
| 1217 | static 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 | |
| 1293 | static int rtc_proc_open(struct inode *inode, struct file *file) |
| 1294 | { |
| 1295 | return single_open(file, rtc_proc_show, NULL); |
| 1296 | } |
| 1297 | #endif |
| 1298 | |
| 1299 | static 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 | |
| 1368 | static 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 | |
| 1401 | static 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 | |
| 1415 | static 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 | |
| 1430 | MODULE_AUTHOR("Paul Gortmaker"); |
| 1431 | MODULE_LICENSE("GPL"); |
| 1432 | MODULE_ALIAS_MISCDEV(RTC_MINOR); |