drivers/rtc/rtc-s3c.c

   1 /* drivers/rtc/rtc-s3c.c
   2  *
   3  * Copyright (c) 2004,2006 Simtec Electronics
   4  *      Ben Dooks, <ben@simtec.co.uk>
   5  *      http://armlinux.simtec.co.uk/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * S3C2410/S3C2440/S3C24XX Internal RTC Driver
  12 */
  13
  14 #include <linux/module.h>
  15 #include <linux/fs.h>
  16 #include <linux/string.h>
  17 #include <linux/init.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/rtc.h>
  21 #include <linux/bcd.h>
  22 #include <linux/clk.h>
  23
  24 #include <asm/hardware.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/io.h>
  27 #include <asm/irq.h>
  28 #include <asm/rtc.h>
  29
  30 #include <asm/mach/time.h>
  31
  32 #include <asm/arch/regs-rtc.h>
  33
  34 /* I have yet to find an S3C implementation with more than one
  35  * of these rtc blocks in */
  36
  37 static struct resource *s3c_rtc_mem;
  38
  39 static void __iomem *s3c_rtc_base;
  40 static int s3c_rtc_alarmno = NO_IRQ;
  41 static int s3c_rtc_tickno  = NO_IRQ;
  42 static int s3c_rtc_freq    = 1;
  43
  44 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
  45 static unsigned int tick_count;
  46
  47 /* IRQ Handlers */
  48
  49 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
  50 {
  51         struct rtc_device *rdev = id;
  52
  53         rtc_update_irq(&rdev->class_dev, 1, RTC_AF | RTC_IRQF);
  54         return IRQ_HANDLED;
  55 }
  56
  57 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
  58 {
  59         struct rtc_device *rdev = id;
  60
  61         rtc_update_irq(&rdev->class_dev, tick_count++, RTC_PF | RTC_IRQF);
  62         return IRQ_HANDLED;
  63 }
  64
  65 /* Update control registers */
  66 static void s3c_rtc_setaie(int to)
  67 {
  68         unsigned int tmp;
  69
  70         pr_debug("%s: aie=%d\n", __FUNCTION__, to);
  71
  72         tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
  73
  74         if (to)
  75                 tmp |= S3C2410_RTCALM_ALMEN;
  76
  77         writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
  78 }
  79
  80 static void s3c_rtc_setpie(int to)
  81 {
  82         unsigned int tmp;
  83
  84         pr_debug("%s: pie=%d\n", __FUNCTION__, to);
  85
  86         spin_lock_irq(&s3c_rtc_pie_lock);
  87         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  88
  89         if (to)
  90                 tmp |= S3C2410_TICNT_ENABLE;
  91
  92         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
  93         spin_unlock_irq(&s3c_rtc_pie_lock);
  94 }
  95
  96 static void s3c_rtc_setfreq(int freq)
  97 {
  98         unsigned int tmp;
  99
 100         spin_lock_irq(&s3c_rtc_pie_lock);
 101         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 102
 103         s3c_rtc_freq = freq;
 104
 105         tmp |= (128 / freq)-1;
 106
 107         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 108         spin_unlock_irq(&s3c_rtc_pie_lock);
 109 }
 110
 111 /* Time read/write */
 112
 113 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 114 {
 115         unsigned int have_retried = 0;
 116         void __iomem *base = s3c_rtc_base;
 117
 118  retry_get_time:
 119         rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
 120         rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
 121         rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
 122         rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
 123         rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
 124         rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
 125
 126         /* the only way to work out wether the system was mid-update
 127          * when we read it is to check the second counter, and if it
 128          * is zero, then we re-try the entire read
 129          */
 130
 131         if (rtc_tm->tm_sec == 0 && !have_retried) {
 132                 have_retried = 1;
 133                 goto retry_get_time;
 134         }
 135
 136         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 137                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 138                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 139
 140         BCD_TO_BIN(rtc_tm->tm_sec);
 141         BCD_TO_BIN(rtc_tm->tm_min);
 142         BCD_TO_BIN(rtc_tm->tm_hour);
 143         BCD_TO_BIN(rtc_tm->tm_mday);
 144         BCD_TO_BIN(rtc_tm->tm_mon);
 145         BCD_TO_BIN(rtc_tm->tm_year);
 146
 147         rtc_tm->tm_year += 100;
 148         rtc_tm->tm_mon -= 1;
 149
 150         return 0;
 151 }
 152
 153 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 154 {
 155         void __iomem *base = s3c_rtc_base;
 156         int year = tm->tm_year - 100;
 157
 158         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 159                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 160                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 161
 162         /* we get around y2k by simply not supporting it */
 163
 164         if (year < 0 || year >= 100) {
 165                 dev_err(dev, "rtc only supports 100 years\n");
 166                 return -EINVAL;
 167         }
 168
 169         writeb(BIN2BCD(tm->tm_sec),  base + S3C2410_RTCSEC);
 170         writeb(BIN2BCD(tm->tm_min),  base + S3C2410_RTCMIN);
 171         writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
 172         writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
 173         writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
 174         writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
 175
 176         return 0;
 177 }
 178
 179 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 180 {
 181         struct rtc_time *alm_tm = &alrm->time;
 182         void __iomem *base = s3c_rtc_base;
 183         unsigned int alm_en;
 184
 185         alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
 186         alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
 187         alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
 188         alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
 189         alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
 190         alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
 191
 192         alm_en = readb(base + S3C2410_RTCALM);
 193
 194         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 195                  alm_en,
 196                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 197                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 198
 199
 200         /* decode the alarm enable field */
 201
 202         if (alm_en & S3C2410_RTCALM_SECEN)
 203                 BCD_TO_BIN(alm_tm->tm_sec);
 204         else
 205                 alm_tm->tm_sec = 0xff;
 206
 207         if (alm_en & S3C2410_RTCALM_MINEN)
 208                 BCD_TO_BIN(alm_tm->tm_min);
 209         else
 210                 alm_tm->tm_min = 0xff;
 211
 212         if (alm_en & S3C2410_RTCALM_HOUREN)
 213                 BCD_TO_BIN(alm_tm->tm_hour);
 214         else
 215                 alm_tm->tm_hour = 0xff;
 216
 217         if (alm_en & S3C2410_RTCALM_DAYEN)
 218                 BCD_TO_BIN(alm_tm->tm_mday);
 219         else
 220                 alm_tm->tm_mday = 0xff;
 221
 222         if (alm_en & S3C2410_RTCALM_MONEN) {
 223                 BCD_TO_BIN(alm_tm->tm_mon);
 224                 alm_tm->tm_mon -= 1;
 225         } else {
 226                 alm_tm->tm_mon = 0xff;
 227         }
 228
 229         if (alm_en & S3C2410_RTCALM_YEAREN)
 230                 BCD_TO_BIN(alm_tm->tm_year);
 231         else
 232                 alm_tm->tm_year = 0xffff;
 233
 234         return 0;
 235 }
 236
 237 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 238 {
 239         struct rtc_time *tm = &alrm->time;
 240         void __iomem *base = s3c_rtc_base;
 241         unsigned int alrm_en;
 242
 243         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 244                  alrm->enabled,
 245                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 246                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 247
 248
 249         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 250         writeb(0x00, base + S3C2410_RTCALM);
 251
 252         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
 253                 alrm_en |= S3C2410_RTCALM_SECEN;
 254                 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
 255         }
 256
 257         if (tm->tm_min < 60 && tm->tm_min >= 0) {
 258                 alrm_en |= S3C2410_RTCALM_MINEN;
 259                 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
 260         }
 261
 262         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
 263                 alrm_en |= S3C2410_RTCALM_HOUREN;
 264                 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
 265         }
 266
 267         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 268
 269         writeb(alrm_en, base + S3C2410_RTCALM);
 270
 271         if (0) {
 272                 alrm_en = readb(base + S3C2410_RTCALM);
 273                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
 274                 writeb(alrm_en, base + S3C2410_RTCALM);
 275                 disable_irq_wake(s3c_rtc_alarmno);
 276         }
 277
 278         if (alrm->enabled)
 279                 enable_irq_wake(s3c_rtc_alarmno);
 280         else
 281                 disable_irq_wake(s3c_rtc_alarmno);
 282
 283         return 0;
 284 }
 285
 286 static int s3c_rtc_ioctl(struct device *dev,
 287                          unsigned int cmd, unsigned long arg)
 288 {
 289         unsigned int ret = -ENOIOCTLCMD;
 290
 291         switch (cmd) {
 292         case RTC_AIE_OFF:
 293         case RTC_AIE_ON:
 294                 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
 295                 ret = 0;
 296                 break;
 297
 298         case RTC_PIE_OFF:
 299         case RTC_PIE_ON:
 300                 tick_count = 0;
 301                 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
 302                 ret = 0;
 303                 break;
 304
 305         case RTC_IRQP_READ:
 306                 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
 307                 break;
 308
 309         case RTC_IRQP_SET:
 310                 /* check for power of 2 */
 311
 312                 if ((arg & (arg-1)) != 0 || arg < 1) {
 313                         ret = -EINVAL;
 314                         goto exit;
 315                 }
 316
 317                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
 318
 319                 s3c_rtc_setfreq(arg);
 320                 ret = 0;
 321                 break;
 322
 323         case RTC_UIE_ON:
 324         case RTC_UIE_OFF:
 325                 ret = -EINVAL;
 326         }
 327
 328  exit:
 329         return ret;
 330 }
 331
 332 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 333 {
 334         unsigned int rtcalm = readb(s3c_rtc_base + S3C2410_RTCALM);
 335         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 336
 337         seq_printf(seq, "alarm_IRQ\t: %s\n",
 338                    (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
 339
 340         seq_printf(seq, "periodic_IRQ\t: %s\n",
 341                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 342
 343         seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
 344
 345         return 0;
 346 }
 347
 348 static int s3c_rtc_open(struct device *dev)
 349 {
 350         struct platform_device *pdev = to_platform_device(dev);
 351         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 352         int ret;
 353
 354         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 355                           SA_INTERRUPT,  "s3c2410-rtc alarm", rtc_dev);
 356
 357         if (ret) {
 358                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 359                 return ret;
 360         }
 361
 362         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 363                           SA_INTERRUPT,  "s3c2410-rtc tick", rtc_dev);
 364
 365         if (ret) {
 366                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 367                 goto tick_err;
 368         }
 369
 370         return ret;
 371
 372  tick_err:
 373         free_irq(s3c_rtc_alarmno, rtc_dev);
 374         return ret;
 375 }
 376
 377 static void s3c_rtc_release(struct device *dev)
 378 {
 379         struct platform_device *pdev = to_platform_device(dev);
 380         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 381
 382         /* do not clear AIE here, it may be needed for wake */
 383
 384         s3c_rtc_setpie(0);
 385         free_irq(s3c_rtc_alarmno, rtc_dev);
 386         free_irq(s3c_rtc_tickno, rtc_dev);
 387 }
 388
 389 static const struct rtc_class_ops s3c_rtcops = {
 390         .open           = s3c_rtc_open,
 391         .release        = s3c_rtc_release,
 392         .ioctl          = s3c_rtc_ioctl,
 393         .read_time      = s3c_rtc_gettime,
 394         .set_time       = s3c_rtc_settime,
 395         .read_alarm     = s3c_rtc_getalarm,
 396         .set_alarm      = s3c_rtc_setalarm,
 397         .proc           = s3c_rtc_proc,
 398 };
 399
 400 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 401 {
 402         void __iomem *base = s3c_rtc_base;
 403         unsigned int tmp;
 404
 405         if (s3c_rtc_base == NULL)
 406                 return;
 407
 408         if (!en) {
 409                 tmp = readb(base + S3C2410_RTCCON);
 410                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 411
 412                 tmp = readb(base + S3C2410_TICNT);
 413                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 414         } else {
 415                 /* re-enable the device, and check it is ok */
 416
 417                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 418                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 419
 420                         tmp = readb(base + S3C2410_RTCCON);
 421                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 422                 }
 423
 424                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 425                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 426
 427                         tmp = readb(base + S3C2410_RTCCON);
 428                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 429                 }
 430
 431                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 432                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 433
 434                         tmp = readb(base + S3C2410_RTCCON);
 435                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 436                 }
 437         }
 438 }
 439
 440 static int s3c_rtc_remove(struct platform_device *dev)
 441 {
 442         struct rtc_device *rtc = platform_get_drvdata(dev);
 443
 444         platform_set_drvdata(dev, NULL);
 445         rtc_device_unregister(rtc);
 446
 447         s3c_rtc_setpie(0);
 448         s3c_rtc_setaie(0);
 449
 450         iounmap(s3c_rtc_base);
 451         release_resource(s3c_rtc_mem);
 452         kfree(s3c_rtc_mem);
 453
 454         return 0;
 455 }
 456
 457 static int s3c_rtc_probe(struct platform_device *pdev)
 458 {
 459         struct rtc_device *rtc;
 460         struct resource *res;
 461         int ret;
 462
 463         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
 464
 465         /* find the IRQs */
 466
 467         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 468         if (s3c_rtc_tickno < 0) {
 469                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 470                 return -ENOENT;
 471         }
 472
 473         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 474         if (s3c_rtc_alarmno < 0) {
 475                 dev_err(&pdev->dev, "no irq for alarm\n");
 476                 return -ENOENT;
 477         }
 478
 479         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 480                  s3c_rtc_tickno, s3c_rtc_alarmno);
 481
 482         /* get the memory region */
 483
 484         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 485         if (res == NULL) {
 486                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 487                 return -ENOENT;
 488         }
 489
 490         s3c_rtc_mem = request_mem_region(res->start,
 491                                          res->end-res->start+1,
 492                                          pdev->name);
 493
 494         if (s3c_rtc_mem == NULL) {
 495                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 496                 ret = -ENOENT;
 497                 goto err_nores;
 498         }
 499
 500         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 501         if (s3c_rtc_base == NULL) {
 502                 dev_err(&pdev->dev, "failed ioremap()\n");
 503                 ret = -EINVAL;
 504                 goto err_nomap;
 505         }
 506
 507         /* check to see if everything is setup correctly */
 508
 509         s3c_rtc_enable(pdev, 1);
 510
 511         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 512                  readb(s3c_rtc_base + S3C2410_RTCCON));
 513
 514         s3c_rtc_setfreq(s3c_rtc_freq);
 515
 516         /* register RTC and exit */
 517
 518         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 519                                   THIS_MODULE);
 520
 521         if (IS_ERR(rtc)) {
 522                 dev_err(&pdev->dev, "cannot attach rtc\n");
 523                 ret = PTR_ERR(rtc);
 524                 goto err_nortc;
 525         }
 526
 527         rtc->max_user_freq = 128;
 528
 529         platform_set_drvdata(pdev, rtc);
 530         return 0;
 531
 532  err_nortc:
 533         s3c_rtc_enable(pdev, 0);
 534         iounmap(s3c_rtc_base);
 535
 536  err_nomap:
 537         release_resource(s3c_rtc_mem);
 538
 539  err_nores:
 540         return ret;
 541 }
 542
 543 #ifdef CONFIG_PM
 544
 545 /* RTC Power management control */
 546
 547 static struct timespec s3c_rtc_delta;
 548
 549 static int ticnt_save;
 550
 551 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 552 {
 553         struct rtc_time tm;
 554         struct timespec time;
 555
 556         time.tv_nsec = 0;
 557
 558         /* save TICNT for anyone using periodic interrupts */
 559
 560         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 561
 562         /* calculate time delta for suspend */
 563
 564         s3c_rtc_gettime(&pdev->dev, &tm);
 565         rtc_tm_to_time(&tm, &time.tv_sec);
 566         save_time_delta(&s3c_rtc_delta, &time);
 567         s3c_rtc_enable(pdev, 0);
 568
 569         return 0;
 570 }
 571
 572 static int s3c_rtc_resume(struct platform_device *pdev)
 573 {
 574         struct rtc_time tm;
 575         struct timespec time;
 576
 577         time.tv_nsec = 0;
 578
 579         s3c_rtc_enable(pdev, 1);
 580         s3c_rtc_gettime(&pdev->dev, &tm);
 581         rtc_tm_to_time(&tm, &time.tv_sec);
 582         restore_time_delta(&s3c_rtc_delta, &time);
 583
 584         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 585         return 0;
 586 }
 587 #else
 588 #define s3c_rtc_suspend NULL
 589 #define s3c_rtc_resume  NULL
 590 #endif
 591
 592 static struct platform_driver s3c2410_rtcdrv = {
 593         .probe          = s3c_rtc_probe,
 594         .remove         = s3c_rtc_remove,
 595         .suspend        = s3c_rtc_suspend,
 596         .resume         = s3c_rtc_resume,
 597         .driver         = {
 598                 .name   = "s3c2410-rtc",
 599                 .owner  = THIS_MODULE,
 600         },
 601 };
 602
 603 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 604
 605 static int __init s3c_rtc_init(void)
 606 {
 607         printk(banner);
 608         return platform_driver_register(&s3c2410_rtcdrv);
 609 }
 610
 611 static void __exit s3c_rtc_exit(void)
 612 {
 613         platform_driver_unregister(&s3c2410_rtcdrv);
 614 }
 615
 616 module_init(s3c_rtc_init);
 617 module_exit(s3c_rtc_exit);
 618
 619 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 620 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 621 MODULE_LICENSE("GPL");