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 #include <linux/log2.h>
  24
  25 #include <asm/hardware.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/io.h>
  28 #include <asm/irq.h>
  29 #include <asm/rtc.h>
  30
  31 #include <asm/mach/time.h>
  32
  33 #include <asm/plat-s3c/regs-rtc.h>
  34
  35 /* I have yet to find an S3C implementation with more than one
  36  * of these rtc blocks in */
  37
  38 static struct resource *s3c_rtc_mem;
  39
  40 static void __iomem *s3c_rtc_base;
  41 static int s3c_rtc_alarmno = NO_IRQ;
  42 static int s3c_rtc_tickno  = NO_IRQ;
  43 static int s3c_rtc_freq    = 1;
  44
  45 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
  46 static unsigned int tick_count;
  47
  48 /* IRQ Handlers */
  49
  50 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
  51 {
  52         struct rtc_device *rdev = id;
  53
  54         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  55         return IRQ_HANDLED;
  56 }
  57
  58 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
  59 {
  60         struct rtc_device *rdev = id;
  61
  62         rtc_update_irq(rdev, tick_count++, RTC_PF | RTC_IRQF);
  63         return IRQ_HANDLED;
  64 }
  65
  66 /* Update control registers */
  67 static void s3c_rtc_setaie(int to)
  68 {
  69         unsigned int tmp;
  70
  71         pr_debug("%s: aie=%d\n", __FUNCTION__, to);
  72
  73         tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
  74
  75         if (to)
  76                 tmp |= S3C2410_RTCALM_ALMEN;
  77
  78         writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
  79 }
  80
  81 static void s3c_rtc_setpie(int to)
  82 {
  83         unsigned int tmp;
  84
  85         pr_debug("%s: pie=%d\n", __FUNCTION__, to);
  86
  87         spin_lock_irq(&s3c_rtc_pie_lock);
  88         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  89
  90         if (to)
  91                 tmp |= S3C2410_TICNT_ENABLE;
  92
  93         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
  94         spin_unlock_irq(&s3c_rtc_pie_lock);
  95 }
  96
  97 static void s3c_rtc_setfreq(int freq)
  98 {
  99         unsigned int tmp;
 100
 101         spin_lock_irq(&s3c_rtc_pie_lock);
 102         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 103
 104         s3c_rtc_freq = freq;
 105
 106         tmp |= (128 / freq)-1;
 107
 108         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 109         spin_unlock_irq(&s3c_rtc_pie_lock);
 110 }
 111
 112 /* Time read/write */
 113
 114 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 115 {
 116         unsigned int have_retried = 0;
 117         void __iomem *base = s3c_rtc_base;
 118
 119  retry_get_time:
 120         rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
 121         rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
 122         rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
 123         rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
 124         rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
 125         rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
 126
 127         /* the only way to work out wether the system was mid-update
 128          * when we read it is to check the second counter, and if it
 129          * is zero, then we re-try the entire read
 130          */
 131
 132         if (rtc_tm->tm_sec == 0 && !have_retried) {
 133                 have_retried = 1;
 134                 goto retry_get_time;
 135         }
 136
 137         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 138                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 139                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 140
 141         BCD_TO_BIN(rtc_tm->tm_sec);
 142         BCD_TO_BIN(rtc_tm->tm_min);
 143         BCD_TO_BIN(rtc_tm->tm_hour);
 144         BCD_TO_BIN(rtc_tm->tm_mday);
 145         BCD_TO_BIN(rtc_tm->tm_mon);
 146         BCD_TO_BIN(rtc_tm->tm_year);
 147
 148         rtc_tm->tm_year += 100;
 149         rtc_tm->tm_mon -= 1;
 150
 151         return 0;
 152 }
 153
 154 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 155 {
 156         void __iomem *base = s3c_rtc_base;
 157         int year = tm->tm_year - 100;
 158
 159         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 160                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 161                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 162
 163         /* we get around y2k by simply not supporting it */
 164
 165         if (year < 0 || year >= 100) {
 166                 dev_err(dev, "rtc only supports 100 years\n");
 167                 return -EINVAL;
 168         }
 169
 170         writeb(BIN2BCD(tm->tm_sec),  base + S3C2410_RTCSEC);
 171         writeb(BIN2BCD(tm->tm_min),  base + S3C2410_RTCMIN);
 172         writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
 173         writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
 174         writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
 175         writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
 176
 177         return 0;
 178 }
 179
 180 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 181 {
 182         struct rtc_time *alm_tm = &alrm->time;
 183         void __iomem *base = s3c_rtc_base;
 184         unsigned int alm_en;
 185
 186         alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
 187         alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
 188         alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
 189         alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
 190         alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
 191         alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
 192
 193         alm_en = readb(base + S3C2410_RTCALM);
 194
 195         alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
 196
 197         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 198                  alm_en,
 199                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 200                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 201
 202
 203         /* decode the alarm enable field */
 204
 205         if (alm_en & S3C2410_RTCALM_SECEN)
 206                 BCD_TO_BIN(alm_tm->tm_sec);
 207         else
 208                 alm_tm->tm_sec = 0xff;
 209
 210         if (alm_en & S3C2410_RTCALM_MINEN)
 211                 BCD_TO_BIN(alm_tm->tm_min);
 212         else
 213                 alm_tm->tm_min = 0xff;
 214
 215         if (alm_en & S3C2410_RTCALM_HOUREN)
 216                 BCD_TO_BIN(alm_tm->tm_hour);
 217         else
 218                 alm_tm->tm_hour = 0xff;
 219
 220         if (alm_en & S3C2410_RTCALM_DAYEN)
 221                 BCD_TO_BIN(alm_tm->tm_mday);
 222         else
 223                 alm_tm->tm_mday = 0xff;
 224
 225         if (alm_en & S3C2410_RTCALM_MONEN) {
 226                 BCD_TO_BIN(alm_tm->tm_mon);
 227                 alm_tm->tm_mon -= 1;
 228         } else {
 229                 alm_tm->tm_mon = 0xff;
 230         }
 231
 232         if (alm_en & S3C2410_RTCALM_YEAREN)
 233                 BCD_TO_BIN(alm_tm->tm_year);
 234         else
 235                 alm_tm->tm_year = 0xffff;
 236
 237         return 0;
 238 }
 239
 240 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 241 {
 242         struct rtc_time *tm = &alrm->time;
 243         void __iomem *base = s3c_rtc_base;
 244         unsigned int alrm_en;
 245
 246         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 247                  alrm->enabled,
 248                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 249                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 250
 251
 252         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 253         writeb(0x00, base + S3C2410_RTCALM);
 254
 255         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
 256                 alrm_en |= S3C2410_RTCALM_SECEN;
 257                 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
 258         }
 259
 260         if (tm->tm_min < 60 && tm->tm_min >= 0) {
 261                 alrm_en |= S3C2410_RTCALM_MINEN;
 262                 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
 263         }
 264
 265         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
 266                 alrm_en |= S3C2410_RTCALM_HOUREN;
 267                 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
 268         }
 269
 270         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 271
 272         writeb(alrm_en, base + S3C2410_RTCALM);
 273
 274         if (0) {
 275                 alrm_en = readb(base + S3C2410_RTCALM);
 276                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
 277                 writeb(alrm_en, base + S3C2410_RTCALM);
 278                 disable_irq_wake(s3c_rtc_alarmno);
 279         }
 280
 281         if (alrm->enabled)
 282                 enable_irq_wake(s3c_rtc_alarmno);
 283         else
 284                 disable_irq_wake(s3c_rtc_alarmno);
 285
 286         return 0;
 287 }
 288
 289 static int s3c_rtc_ioctl(struct device *dev,
 290                          unsigned int cmd, unsigned long arg)
 291 {
 292         unsigned int ret = -ENOIOCTLCMD;
 293
 294         switch (cmd) {
 295         case RTC_AIE_OFF:
 296         case RTC_AIE_ON:
 297                 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
 298                 ret = 0;
 299                 break;
 300
 301         case RTC_PIE_OFF:
 302         case RTC_PIE_ON:
 303                 tick_count = 0;
 304                 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
 305                 ret = 0;
 306                 break;
 307
 308         case RTC_IRQP_READ:
 309                 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
 310                 break;
 311
 312         case RTC_IRQP_SET:
 313                 if (!is_power_of_2(arg)) {
 314                         ret = -EINVAL;
 315                         goto exit;
 316                 }
 317
 318                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
 319
 320                 s3c_rtc_setfreq(arg);
 321                 ret = 0;
 322                 break;
 323
 324         case RTC_UIE_ON:
 325         case RTC_UIE_OFF:
 326                 ret = -EINVAL;
 327         }
 328
 329  exit:
 330         return ret;
 331 }
 332
 333 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 334 {
 335         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 336
 337         seq_printf(seq, "periodic_IRQ\t: %s\n",
 338                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 339
 340         seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
 341
 342         return 0;
 343 }
 344
 345 static int s3c_rtc_open(struct device *dev)
 346 {
 347         struct platform_device *pdev = to_platform_device(dev);
 348         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 349         int ret;
 350
 351         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 352                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 353
 354         if (ret) {
 355                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 356                 return ret;
 357         }
 358
 359         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 360                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 361
 362         if (ret) {
 363                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 364                 goto tick_err;
 365         }
 366
 367         return ret;
 368
 369  tick_err:
 370         free_irq(s3c_rtc_alarmno, rtc_dev);
 371         return ret;
 372 }
 373
 374 static void s3c_rtc_release(struct device *dev)
 375 {
 376         struct platform_device *pdev = to_platform_device(dev);
 377         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 378
 379         /* do not clear AIE here, it may be needed for wake */
 380
 381         s3c_rtc_setpie(0);
 382         free_irq(s3c_rtc_alarmno, rtc_dev);
 383         free_irq(s3c_rtc_tickno, rtc_dev);
 384 }
 385
 386 static const struct rtc_class_ops s3c_rtcops = {
 387         .open           = s3c_rtc_open,
 388         .release        = s3c_rtc_release,
 389         .ioctl          = s3c_rtc_ioctl,
 390         .read_time      = s3c_rtc_gettime,
 391         .set_time       = s3c_rtc_settime,
 392         .read_alarm     = s3c_rtc_getalarm,
 393         .set_alarm      = s3c_rtc_setalarm,
 394         .proc           = s3c_rtc_proc,
 395 };
 396
 397 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 398 {
 399         void __iomem *base = s3c_rtc_base;
 400         unsigned int tmp;
 401
 402         if (s3c_rtc_base == NULL)
 403                 return;
 404
 405         if (!en) {
 406                 tmp = readb(base + S3C2410_RTCCON);
 407                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 408
 409                 tmp = readb(base + S3C2410_TICNT);
 410                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 411         } else {
 412                 /* re-enable the device, and check it is ok */
 413
 414                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 415                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 416
 417                         tmp = readb(base + S3C2410_RTCCON);
 418                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 419                 }
 420
 421                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 422                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 423
 424                         tmp = readb(base + S3C2410_RTCCON);
 425                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 426                 }
 427
 428                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 429                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 430
 431                         tmp = readb(base + S3C2410_RTCCON);
 432                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 433                 }
 434         }
 435 }
 436
 437 static int s3c_rtc_remove(struct platform_device *dev)
 438 {
 439         struct rtc_device *rtc = platform_get_drvdata(dev);
 440
 441         platform_set_drvdata(dev, NULL);
 442         rtc_device_unregister(rtc);
 443
 444         s3c_rtc_setpie(0);
 445         s3c_rtc_setaie(0);
 446
 447         iounmap(s3c_rtc_base);
 448         release_resource(s3c_rtc_mem);
 449         kfree(s3c_rtc_mem);
 450
 451         return 0;
 452 }
 453
 454 static int s3c_rtc_probe(struct platform_device *pdev)
 455 {
 456         struct rtc_device *rtc;
 457         struct resource *res;
 458         int ret;
 459
 460         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
 461
 462         /* find the IRQs */
 463
 464         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 465         if (s3c_rtc_tickno < 0) {
 466                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 467                 return -ENOENT;
 468         }
 469
 470         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 471         if (s3c_rtc_alarmno < 0) {
 472                 dev_err(&pdev->dev, "no irq for alarm\n");
 473                 return -ENOENT;
 474         }
 475
 476         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 477                  s3c_rtc_tickno, s3c_rtc_alarmno);
 478
 479         /* get the memory region */
 480
 481         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 482         if (res == NULL) {
 483                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 484                 return -ENOENT;
 485         }
 486
 487         s3c_rtc_mem = request_mem_region(res->start,
 488                                          res->end-res->start+1,
 489                                          pdev->name);
 490
 491         if (s3c_rtc_mem == NULL) {
 492                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 493                 ret = -ENOENT;
 494                 goto err_nores;
 495         }
 496
 497         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 498         if (s3c_rtc_base == NULL) {
 499                 dev_err(&pdev->dev, "failed ioremap()\n");
 500                 ret = -EINVAL;
 501                 goto err_nomap;
 502         }
 503
 504         /* check to see if everything is setup correctly */
 505
 506         s3c_rtc_enable(pdev, 1);
 507
 508         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 509                  readb(s3c_rtc_base + S3C2410_RTCCON));
 510
 511         s3c_rtc_setfreq(s3c_rtc_freq);
 512
 513         /* register RTC and exit */
 514
 515         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 516                                   THIS_MODULE);
 517
 518         if (IS_ERR(rtc)) {
 519                 dev_err(&pdev->dev, "cannot attach rtc\n");
 520                 ret = PTR_ERR(rtc);
 521                 goto err_nortc;
 522         }
 523
 524         rtc->max_user_freq = 128;
 525
 526         platform_set_drvdata(pdev, rtc);
 527         return 0;
 528
 529  err_nortc:
 530         s3c_rtc_enable(pdev, 0);
 531         iounmap(s3c_rtc_base);
 532
 533  err_nomap:
 534         release_resource(s3c_rtc_mem);
 535
 536  err_nores:
 537         return ret;
 538 }
 539
 540 #ifdef CONFIG_PM
 541
 542 /* RTC Power management control */
 543
 544 static int ticnt_save;
 545
 546 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 547 {
 548         /* save TICNT for anyone using periodic interrupts */
 549         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 550         s3c_rtc_enable(pdev, 0);
 551         return 0;
 552 }
 553
 554 static int s3c_rtc_resume(struct platform_device *pdev)
 555 {
 556         s3c_rtc_enable(pdev, 1);
 557         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 558         return 0;
 559 }
 560 #else
 561 #define s3c_rtc_suspend NULL
 562 #define s3c_rtc_resume  NULL
 563 #endif
 564
 565 static struct platform_driver s3c2410_rtcdrv = {
 566         .probe          = s3c_rtc_probe,
 567         .remove         = s3c_rtc_remove,
 568         .suspend        = s3c_rtc_suspend,
 569         .resume         = s3c_rtc_resume,
 570         .driver         = {
 571                 .name   = "s3c2410-rtc",
 572                 .owner  = THIS_MODULE,
 573         },
 574 };
 575
 576 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 577
 578 static int __init s3c_rtc_init(void)
 579 {
 580         printk(banner);
 581         return platform_driver_register(&s3c2410_rtcdrv);
 582 }
 583
 584 static void __exit s3c_rtc_exit(void)
 585 {
 586         platform_driver_unregister(&s3c2410_rtcdrv);
 587 }
 588
 589 module_init(s3c_rtc_init);
 590 module_exit(s3c_rtc_exit);
 591
 592 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 593 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 594 MODULE_LICENSE("GPL");