Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Real Time Clock interface for |
| 3 | * - q40 and other m68k machines, |
| 4 | * - HP PARISC machines |
| 5 | * - PowerPC machines |
| 6 | * emulate some RTC irq capabilities in software |
| 7 | * |
| 8 | * Copyright (C) 1999 Richard Zidlicky |
| 9 | * |
| 10 | * based on Paul Gortmaker's rtc.c device and |
| 11 | * Sam Creasey Generic rtc driver |
| 12 | * |
| 13 | * This driver allows use of the real time clock (built into |
| 14 | * nearly all computers) from user space. It exports the /dev/rtc |
| 15 | * interface supporting various ioctl() and also the /proc/dev/rtc |
| 16 | * pseudo-file for status information. |
| 17 | * |
| 18 | * The ioctls can be used to set the interrupt behaviour where |
| 19 | * supported. |
| 20 | * |
| 21 | * The /dev/rtc interface will block on reads until an interrupt |
| 22 | * has been received. If a RTC interrupt has already happened, |
| 23 | * it will output an unsigned long and then block. The output value |
| 24 | * contains the interrupt status in the low byte and the number of |
| 25 | * interrupts since the last read in the remaining high bytes. The |
| 26 | * /dev/rtc interface can also be used with the select(2) call. |
| 27 | * |
| 28 | * This program is free software; you can redistribute it and/or |
| 29 | * modify it under the terms of the GNU General Public License |
| 30 | * as published by the Free Software Foundation; either version |
| 31 | * 2 of the License, or (at your option) any later version. |
| 32 | * |
| 33 | |
| 34 | * 1.01 fix for 2.3.X rz@linux-m68k.org |
| 35 | * 1.02 merged with code from genrtc.c rz@linux-m68k.org |
| 36 | * 1.03 make it more portable zippel@linux-m68k.org |
| 37 | * 1.04 removed useless timer code rz@linux-m68k.org |
| 38 | * 1.05 portable RTC_UIE emulation rz@linux-m68k.org |
| 39 | * 1.06 set_rtc_time can return an error trini@kernel.crashing.org |
| 40 | * 1.07 ported to HP PARISC (hppa) Helge Deller <deller@gmx.de> |
| 41 | */ |
| 42 | |
| 43 | #define RTC_VERSION "1.07" |
| 44 | |
| 45 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/errno.h> |
| 47 | #include <linux/miscdevice.h> |
| 48 | #include <linux/fcntl.h> |
| 49 | |
| 50 | #include <linux/rtc.h> |
| 51 | #include <linux/init.h> |
| 52 | #include <linux/poll.h> |
| 53 | #include <linux/proc_fs.h> |
| 54 | #include <linux/workqueue.h> |
| 55 | |
| 56 | #include <asm/uaccess.h> |
| 57 | #include <asm/system.h> |
| 58 | #include <asm/rtc.h> |
| 59 | |
| 60 | /* |
| 61 | * We sponge a minor off of the misc major. No need slurping |
| 62 | * up another valuable major dev number for this. If you add |
| 63 | * an ioctl, make sure you don't conflict with SPARC's RTC |
| 64 | * ioctls. |
| 65 | */ |
| 66 | |
| 67 | static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait); |
| 68 | |
| 69 | /* |
| 70 | * Bits in gen_rtc_status. |
| 71 | */ |
| 72 | |
| 73 | #define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */ |
| 74 | |
| 75 | static unsigned char gen_rtc_status; /* bitmapped status byte. */ |
| 76 | static unsigned long gen_rtc_irq_data; /* our output to the world */ |
| 77 | |
| 78 | /* months start at 0 now */ |
| 79 | static unsigned char days_in_mo[] = |
| 80 | {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; |
| 81 | |
| 82 | static int irq_active; |
| 83 | |
| 84 | #ifdef CONFIG_GEN_RTC_X |
| 85 | static struct work_struct genrtc_task; |
| 86 | static struct timer_list timer_task; |
| 87 | |
| 88 | static unsigned int oldsecs; |
| 89 | static int lostint; |
| 90 | static unsigned long tt_exp; |
| 91 | |
| 92 | static void gen_rtc_timer(unsigned long data); |
| 93 | |
| 94 | static volatile int stask_active; /* schedule_work */ |
| 95 | static volatile int ttask_active; /* timer_task */ |
| 96 | static int stop_rtc_timers; /* don't requeue tasks */ |
| 97 | static DEFINE_SPINLOCK(gen_rtc_lock); |
| 98 | |
| 99 | static void gen_rtc_interrupt(unsigned long arg); |
| 100 | |
| 101 | /* |
| 102 | * Routine to poll RTC seconds field for change as often as possible, |
| 103 | * after first RTC_UIE use timer to reduce polling |
| 104 | */ |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 105 | static void genrtc_troutine(struct work_struct *work) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | { |
| 107 | unsigned int tmp = get_rtc_ss(); |
| 108 | |
| 109 | if (stop_rtc_timers) { |
| 110 | stask_active = 0; |
| 111 | return; |
| 112 | } |
| 113 | |
| 114 | if (oldsecs != tmp){ |
| 115 | oldsecs = tmp; |
| 116 | |
| 117 | timer_task.function = gen_rtc_timer; |
| 118 | timer_task.expires = jiffies + HZ - (HZ/10); |
| 119 | tt_exp=timer_task.expires; |
| 120 | ttask_active=1; |
| 121 | stask_active=0; |
| 122 | add_timer(&timer_task); |
| 123 | |
| 124 | gen_rtc_interrupt(0); |
| 125 | } else if (schedule_work(&genrtc_task) == 0) |
| 126 | stask_active = 0; |
| 127 | } |
| 128 | |
| 129 | static void gen_rtc_timer(unsigned long data) |
| 130 | { |
| 131 | lostint = get_rtc_ss() - oldsecs ; |
| 132 | if (lostint<0) |
| 133 | lostint = 60 - lostint; |
| 134 | if (time_after(jiffies, tt_exp)) |
| 135 | printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n", |
| 136 | jiffies-tt_exp); |
| 137 | ttask_active=0; |
| 138 | stask_active=1; |
| 139 | if ((schedule_work(&genrtc_task) == 0)) |
| 140 | stask_active = 0; |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * call gen_rtc_interrupt function to signal an RTC_UIE, |
| 145 | * arg is unused. |
| 146 | * Could be invoked either from a real interrupt handler or |
| 147 | * from some routine that periodically (eg 100HZ) monitors |
| 148 | * whether RTC_SECS changed |
| 149 | */ |
| 150 | static void gen_rtc_interrupt(unsigned long arg) |
| 151 | { |
| 152 | /* We store the status in the low byte and the number of |
| 153 | * interrupts received since the last read in the remainder |
| 154 | * of rtc_irq_data. */ |
| 155 | |
| 156 | gen_rtc_irq_data += 0x100; |
| 157 | gen_rtc_irq_data &= ~0xff; |
| 158 | gen_rtc_irq_data |= RTC_UIE; |
| 159 | |
| 160 | if (lostint){ |
| 161 | printk("genrtc: system delaying clock ticks?\n"); |
| 162 | /* increment count so that userspace knows something is wrong */ |
| 163 | gen_rtc_irq_data += ((lostint-1)<<8); |
| 164 | lostint = 0; |
| 165 | } |
| 166 | |
| 167 | wake_up_interruptible(&gen_rtc_wait); |
| 168 | } |
| 169 | |
| 170 | /* |
| 171 | * Now all the various file operations that we export. |
| 172 | */ |
| 173 | static ssize_t gen_rtc_read(struct file *file, char __user *buf, |
| 174 | size_t count, loff_t *ppos) |
| 175 | { |
| 176 | DECLARE_WAITQUEUE(wait, current); |
| 177 | unsigned long data; |
| 178 | ssize_t retval; |
| 179 | |
| 180 | if (count != sizeof (unsigned int) && count != sizeof (unsigned long)) |
| 181 | return -EINVAL; |
| 182 | |
| 183 | if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data) |
| 184 | return -EAGAIN; |
| 185 | |
| 186 | add_wait_queue(&gen_rtc_wait, &wait); |
| 187 | retval = -ERESTARTSYS; |
| 188 | |
| 189 | while (1) { |
| 190 | set_current_state(TASK_INTERRUPTIBLE); |
| 191 | data = xchg(&gen_rtc_irq_data, 0); |
| 192 | if (data) |
| 193 | break; |
| 194 | if (signal_pending(current)) |
| 195 | goto out; |
| 196 | schedule(); |
| 197 | } |
| 198 | |
| 199 | /* first test allows optimizer to nuke this case for 32-bit machines */ |
| 200 | if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) { |
| 201 | unsigned int uidata = data; |
Atsushi Nemoto | f3537ea | 2006-05-01 12:16:17 -0700 | [diff] [blame] | 202 | retval = put_user(uidata, (unsigned int __user *)buf) ?: |
| 203 | sizeof(unsigned int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | } |
| 205 | else { |
Atsushi Nemoto | f3537ea | 2006-05-01 12:16:17 -0700 | [diff] [blame] | 206 | retval = put_user(data, (unsigned long __user *)buf) ?: |
| 207 | sizeof(unsigned long); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | out: |
Milind Arun Choudhary | cc0a8fb | 2007-05-08 00:30:52 -0700 | [diff] [blame^] | 210 | __set_current_state(TASK_RUNNING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | remove_wait_queue(&gen_rtc_wait, &wait); |
| 212 | |
| 213 | return retval; |
| 214 | } |
| 215 | |
| 216 | static unsigned int gen_rtc_poll(struct file *file, |
| 217 | struct poll_table_struct *wait) |
| 218 | { |
| 219 | poll_wait(file, &gen_rtc_wait, wait); |
| 220 | if (gen_rtc_irq_data != 0) |
| 221 | return POLLIN | POLLRDNORM; |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | #endif |
| 226 | |
| 227 | /* |
| 228 | * Used to disable/enable interrupts, only RTC_UIE supported |
| 229 | * We also clear out any old irq data after an ioctl() that |
| 230 | * meddles with the interrupt enable/disable bits. |
| 231 | */ |
| 232 | |
| 233 | static inline void gen_clear_rtc_irq_bit(unsigned char bit) |
| 234 | { |
| 235 | #ifdef CONFIG_GEN_RTC_X |
| 236 | stop_rtc_timers = 1; |
| 237 | if (ttask_active){ |
| 238 | del_timer_sync(&timer_task); |
| 239 | ttask_active = 0; |
| 240 | } |
| 241 | while (stask_active) |
| 242 | schedule(); |
| 243 | |
| 244 | spin_lock(&gen_rtc_lock); |
| 245 | irq_active = 0; |
| 246 | spin_unlock(&gen_rtc_lock); |
| 247 | #endif |
| 248 | } |
| 249 | |
| 250 | static inline int gen_set_rtc_irq_bit(unsigned char bit) |
| 251 | { |
| 252 | #ifdef CONFIG_GEN_RTC_X |
| 253 | spin_lock(&gen_rtc_lock); |
| 254 | if ( !irq_active ) { |
| 255 | irq_active = 1; |
| 256 | stop_rtc_timers = 0; |
| 257 | lostint = 0; |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 258 | INIT_WORK(&genrtc_task, genrtc_troutine); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | oldsecs = get_rtc_ss(); |
| 260 | init_timer(&timer_task); |
| 261 | |
| 262 | stask_active = 1; |
| 263 | if (schedule_work(&genrtc_task) == 0){ |
| 264 | stask_active = 0; |
| 265 | } |
| 266 | } |
| 267 | spin_unlock(&gen_rtc_lock); |
| 268 | gen_rtc_irq_data = 0; |
| 269 | return 0; |
| 270 | #else |
| 271 | return -EINVAL; |
| 272 | #endif |
| 273 | } |
| 274 | |
| 275 | static int gen_rtc_ioctl(struct inode *inode, struct file *file, |
| 276 | unsigned int cmd, unsigned long arg) |
| 277 | { |
| 278 | struct rtc_time wtime; |
| 279 | struct rtc_pll_info pll; |
| 280 | void __user *argp = (void __user *)arg; |
| 281 | |
| 282 | switch (cmd) { |
| 283 | |
| 284 | case RTC_PLL_GET: |
| 285 | if (get_rtc_pll(&pll)) |
| 286 | return -EINVAL; |
| 287 | else |
| 288 | return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0; |
| 289 | |
| 290 | case RTC_PLL_SET: |
| 291 | if (!capable(CAP_SYS_TIME)) |
| 292 | return -EACCES; |
| 293 | if (copy_from_user(&pll, argp, sizeof(pll))) |
| 294 | return -EFAULT; |
| 295 | return set_rtc_pll(&pll); |
| 296 | |
| 297 | case RTC_UIE_OFF: /* disable ints from RTC updates. */ |
| 298 | gen_clear_rtc_irq_bit(RTC_UIE); |
| 299 | return 0; |
| 300 | |
| 301 | case RTC_UIE_ON: /* enable ints for RTC updates. */ |
| 302 | return gen_set_rtc_irq_bit(RTC_UIE); |
| 303 | |
| 304 | case RTC_RD_TIME: /* Read the time/date from RTC */ |
| 305 | /* this doesn't get week-day, who cares */ |
| 306 | memset(&wtime, 0, sizeof(wtime)); |
| 307 | get_rtc_time(&wtime); |
| 308 | |
| 309 | return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0; |
| 310 | |
| 311 | case RTC_SET_TIME: /* Set the RTC */ |
| 312 | { |
| 313 | int year; |
| 314 | unsigned char leap_yr; |
| 315 | |
| 316 | if (!capable(CAP_SYS_TIME)) |
| 317 | return -EACCES; |
| 318 | |
| 319 | if (copy_from_user(&wtime, argp, sizeof(wtime))) |
| 320 | return -EFAULT; |
| 321 | |
| 322 | year = wtime.tm_year + 1900; |
| 323 | leap_yr = ((!(year % 4) && (year % 100)) || |
| 324 | !(year % 400)); |
| 325 | |
| 326 | if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1)) |
| 327 | return -EINVAL; |
| 328 | |
| 329 | if (wtime.tm_mday < 0 || wtime.tm_mday > |
| 330 | (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr))) |
| 331 | return -EINVAL; |
| 332 | |
| 333 | if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 || |
| 334 | wtime.tm_min < 0 || wtime.tm_min >= 60 || |
| 335 | wtime.tm_sec < 0 || wtime.tm_sec >= 60) |
| 336 | return -EINVAL; |
| 337 | |
| 338 | return set_rtc_time(&wtime); |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | return -EINVAL; |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * We enforce only one user at a time here with the open/close. |
| 347 | * Also clear the previous interrupt data on an open, and clean |
| 348 | * up things on a close. |
| 349 | */ |
| 350 | |
| 351 | static int gen_rtc_open(struct inode *inode, struct file *file) |
| 352 | { |
| 353 | if (gen_rtc_status & RTC_IS_OPEN) |
| 354 | return -EBUSY; |
| 355 | |
| 356 | gen_rtc_status |= RTC_IS_OPEN; |
| 357 | gen_rtc_irq_data = 0; |
| 358 | irq_active = 0; |
| 359 | |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | static int gen_rtc_release(struct inode *inode, struct file *file) |
| 364 | { |
| 365 | /* |
| 366 | * Turn off all interrupts once the device is no longer |
| 367 | * in use and clear the data. |
| 368 | */ |
| 369 | |
| 370 | gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE); |
| 371 | |
| 372 | gen_rtc_status &= ~RTC_IS_OPEN; |
| 373 | return 0; |
| 374 | } |
| 375 | |
| 376 | |
| 377 | #ifdef CONFIG_PROC_FS |
| 378 | |
| 379 | /* |
| 380 | * Info exported via "/proc/rtc". |
| 381 | */ |
| 382 | |
| 383 | static int gen_rtc_proc_output(char *buf) |
| 384 | { |
| 385 | char *p; |
| 386 | struct rtc_time tm; |
| 387 | unsigned int flags; |
| 388 | struct rtc_pll_info pll; |
| 389 | |
| 390 | p = buf; |
| 391 | |
| 392 | flags = get_rtc_time(&tm); |
| 393 | |
| 394 | p += sprintf(p, |
| 395 | "rtc_time\t: %02d:%02d:%02d\n" |
| 396 | "rtc_date\t: %04d-%02d-%02d\n" |
| 397 | "rtc_epoch\t: %04u\n", |
| 398 | tm.tm_hour, tm.tm_min, tm.tm_sec, |
| 399 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900); |
| 400 | |
| 401 | tm.tm_hour = tm.tm_min = tm.tm_sec = 0; |
| 402 | |
| 403 | p += sprintf(p, "alarm\t\t: "); |
| 404 | if (tm.tm_hour <= 24) |
| 405 | p += sprintf(p, "%02d:", tm.tm_hour); |
| 406 | else |
| 407 | p += sprintf(p, "**:"); |
| 408 | |
| 409 | if (tm.tm_min <= 59) |
| 410 | p += sprintf(p, "%02d:", tm.tm_min); |
| 411 | else |
| 412 | p += sprintf(p, "**:"); |
| 413 | |
| 414 | if (tm.tm_sec <= 59) |
| 415 | p += sprintf(p, "%02d\n", tm.tm_sec); |
| 416 | else |
| 417 | p += sprintf(p, "**\n"); |
| 418 | |
| 419 | p += sprintf(p, |
| 420 | "DST_enable\t: %s\n" |
| 421 | "BCD\t\t: %s\n" |
| 422 | "24hr\t\t: %s\n" |
| 423 | "square_wave\t: %s\n" |
| 424 | "alarm_IRQ\t: %s\n" |
| 425 | "update_IRQ\t: %s\n" |
| 426 | "periodic_IRQ\t: %s\n" |
| 427 | "periodic_freq\t: %ld\n" |
| 428 | "batt_status\t: %s\n", |
| 429 | (flags & RTC_DST_EN) ? "yes" : "no", |
| 430 | (flags & RTC_DM_BINARY) ? "no" : "yes", |
| 431 | (flags & RTC_24H) ? "yes" : "no", |
| 432 | (flags & RTC_SQWE) ? "yes" : "no", |
| 433 | (flags & RTC_AIE) ? "yes" : "no", |
| 434 | irq_active ? "yes" : "no", |
| 435 | (flags & RTC_PIE) ? "yes" : "no", |
| 436 | 0L /* freq */, |
| 437 | (flags & RTC_BATT_BAD) ? "bad" : "okay"); |
| 438 | if (!get_rtc_pll(&pll)) |
| 439 | p += sprintf(p, |
| 440 | "PLL adjustment\t: %d\n" |
| 441 | "PLL max +ve adjustment\t: %d\n" |
| 442 | "PLL max -ve adjustment\t: %d\n" |
| 443 | "PLL +ve adjustment factor\t: %d\n" |
| 444 | "PLL -ve adjustment factor\t: %d\n" |
| 445 | "PLL frequency\t: %ld\n", |
| 446 | pll.pll_value, |
| 447 | pll.pll_max, |
| 448 | pll.pll_min, |
| 449 | pll.pll_posmult, |
| 450 | pll.pll_negmult, |
| 451 | pll.pll_clock); |
| 452 | return p - buf; |
| 453 | } |
| 454 | |
| 455 | static int gen_rtc_read_proc(char *page, char **start, off_t off, |
| 456 | int count, int *eof, void *data) |
| 457 | { |
| 458 | int len = gen_rtc_proc_output (page); |
| 459 | if (len <= off+count) *eof = 1; |
| 460 | *start = page + off; |
| 461 | len -= off; |
| 462 | if (len>count) len = count; |
| 463 | if (len<0) len = 0; |
| 464 | return len; |
| 465 | } |
| 466 | |
| 467 | static int __init gen_rtc_proc_init(void) |
| 468 | { |
| 469 | struct proc_dir_entry *r; |
| 470 | |
| 471 | r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL); |
| 472 | if (!r) |
| 473 | return -ENOMEM; |
| 474 | return 0; |
| 475 | } |
| 476 | #else |
| 477 | static inline int gen_rtc_proc_init(void) { return 0; } |
| 478 | #endif /* CONFIG_PROC_FS */ |
| 479 | |
| 480 | |
| 481 | /* |
| 482 | * The various file operations we support. |
| 483 | */ |
| 484 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 485 | static const struct file_operations gen_rtc_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | .owner = THIS_MODULE, |
| 487 | #ifdef CONFIG_GEN_RTC_X |
| 488 | .read = gen_rtc_read, |
| 489 | .poll = gen_rtc_poll, |
| 490 | #endif |
| 491 | .ioctl = gen_rtc_ioctl, |
| 492 | .open = gen_rtc_open, |
| 493 | .release = gen_rtc_release, |
| 494 | }; |
| 495 | |
| 496 | static struct miscdevice rtc_gen_dev = |
| 497 | { |
| 498 | .minor = RTC_MINOR, |
| 499 | .name = "rtc", |
| 500 | .fops = &gen_rtc_fops, |
| 501 | }; |
| 502 | |
| 503 | static int __init rtc_generic_init(void) |
| 504 | { |
| 505 | int retval; |
| 506 | |
| 507 | printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION); |
| 508 | |
| 509 | retval = misc_register(&rtc_gen_dev); |
| 510 | if (retval < 0) |
| 511 | return retval; |
| 512 | |
| 513 | retval = gen_rtc_proc_init(); |
| 514 | if (retval) { |
| 515 | misc_deregister(&rtc_gen_dev); |
| 516 | return retval; |
| 517 | } |
| 518 | |
| 519 | return 0; |
| 520 | } |
| 521 | |
| 522 | static void __exit rtc_generic_exit(void) |
| 523 | { |
| 524 | remove_proc_entry ("driver/rtc", NULL); |
| 525 | misc_deregister(&rtc_gen_dev); |
| 526 | } |
| 527 | |
| 528 | |
| 529 | module_init(rtc_generic_init); |
| 530 | module_exit(rtc_generic_exit); |
| 531 | |
| 532 | MODULE_AUTHOR("Richard Zidlicky"); |
| 533 | MODULE_LICENSE("GPL"); |
| 534 | MODULE_ALIAS_MISCDEV(RTC_MINOR); |