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