git.oblomov.eu Git - linux-2.6/blob - 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/plat-s3c/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, 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, 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         alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
 195
 196         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 197                  alm_en,
 198                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 199                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 200
 201
 202         /* decode the alarm enable field */
 203
 204         if (alm_en & S3C2410_RTCALM_SECEN)
 205                 BCD_TO_BIN(alm_tm->tm_sec);
 206         else
 207                 alm_tm->tm_sec = 0xff;
 208
 209         if (alm_en & S3C2410_RTCALM_MINEN)
 210                 BCD_TO_BIN(alm_tm->tm_min);
 211         else
 212                 alm_tm->tm_min = 0xff;
 213
 214         if (alm_en & S3C2410_RTCALM_HOUREN)
 215                 BCD_TO_BIN(alm_tm->tm_hour);
 216         else
 217                 alm_tm->tm_hour = 0xff;
 218
 219         if (alm_en & S3C2410_RTCALM_DAYEN)
 220                 BCD_TO_BIN(alm_tm->tm_mday);
 221         else
 222                 alm_tm->tm_mday = 0xff;
 223
 224         if (alm_en & S3C2410_RTCALM_MONEN) {
 225                 BCD_TO_BIN(alm_tm->tm_mon);
 226                 alm_tm->tm_mon -= 1;
 227         } else {
 228                 alm_tm->tm_mon = 0xff;
 229         }
 230
 231         if (alm_en & S3C2410_RTCALM_YEAREN)
 232                 BCD_TO_BIN(alm_tm->tm_year);
 233         else
 234                 alm_tm->tm_year = 0xffff;
 235
 236         return 0;
 237 }
 238
 239 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 240 {
 241         struct rtc_time *tm = &alrm->time;
 242         void __iomem *base = s3c_rtc_base;
 243         unsigned int alrm_en;
 244
 245         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 246                  alrm->enabled,
 247                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 248                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 249
 250
 251         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 252         writeb(0x00, base + S3C2410_RTCALM);
 253
 254         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
 255                 alrm_en |= S3C2410_RTCALM_SECEN;
 256                 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
 257         }
 258
 259         if (tm->tm_min < 60 && tm->tm_min >= 0) {
 260                 alrm_en |= S3C2410_RTCALM_MINEN;
 261                 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
 262         }
 263
 264         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
 265                 alrm_en |= S3C2410_RTCALM_HOUREN;
 266                 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
 267         }
 268
 269         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 270
 271         writeb(alrm_en, base + S3C2410_RTCALM);
 272
 273         if (0) {
 274                 alrm_en = readb(base + S3C2410_RTCALM);
 275                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
 276                 writeb(alrm_en, base + S3C2410_RTCALM);
 277                 disable_irq_wake(s3c_rtc_alarmno);
 278         }
 279
 280         if (alrm->enabled)
 281                 enable_irq_wake(s3c_rtc_alarmno);
 282         else
 283                 disable_irq_wake(s3c_rtc_alarmno);
 284
 285         return 0;
 286 }
 287
 288 static int s3c_rtc_ioctl(struct device *dev,
 289                          unsigned int cmd, unsigned long arg)
 290 {
 291         unsigned int ret = -ENOIOCTLCMD;
 292
 293         switch (cmd) {
 294         case RTC_AIE_OFF:
 295         case RTC_AIE_ON:
 296                 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
 297                 ret = 0;
 298                 break;
 299
 300         case RTC_PIE_OFF:
 301         case RTC_PIE_ON:
 302                 tick_count = 0;
 303                 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
 304                 ret = 0;
 305                 break;
 306
 307         case RTC_IRQP_READ:
 308                 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
 309                 break;
 310
 311         case RTC_IRQP_SET:
 312                 /* check for power of 2 */
 313
 314                 if ((arg & (arg-1)) != 0 || arg < 1) {
 315                         ret = -EINVAL;
 316                         goto exit;
 317                 }
 318
 319                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
 320
 321                 s3c_rtc_setfreq(arg);
 322                 ret = 0;
 323                 break;
 324
 325         case RTC_UIE_ON:
 326         case RTC_UIE_OFF:
 327                 ret = -EINVAL;
 328         }
 329
 330  exit:
 331         return ret;
 332 }
 333
 334 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 335 {
 336         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 337
 338         seq_printf(seq, "periodic_IRQ\t: %s\n",
 339                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 340
 341         seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
 342
 343         return 0;
 344 }
 345
 346 static int s3c_rtc_open(struct device *dev)
 347 {
 348         struct platform_device *pdev = to_platform_device(dev);
 349         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 350         int ret;
 351
 352         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 353                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 354
 355         if (ret) {
 356                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 357                 return ret;
 358         }
 359
 360         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 361                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 362
 363         if (ret) {
 364                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 365                 goto tick_err;
 366         }
 367
 368         return ret;
 369
 370  tick_err:
 371         free_irq(s3c_rtc_alarmno, rtc_dev);
 372         return ret;
 373 }
 374
 375 static void s3c_rtc_release(struct device *dev)
 376 {
 377         struct platform_device *pdev = to_platform_device(dev);
 378         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 379
 380         /* do not clear AIE here, it may be needed for wake */
 381
 382         s3c_rtc_setpie(0);
 383         free_irq(s3c_rtc_alarmno, rtc_dev);
 384         free_irq(s3c_rtc_tickno, rtc_dev);
 385 }
 386
 387 static const struct rtc_class_ops s3c_rtcops = {
 388         .open           = s3c_rtc_open,
 389         .release        = s3c_rtc_release,
 390         .ioctl          = s3c_rtc_ioctl,
 391         .read_time      = s3c_rtc_gettime,
 392         .set_time       = s3c_rtc_settime,
 393         .read_alarm     = s3c_rtc_getalarm,
 394         .set_alarm      = s3c_rtc_setalarm,
 395         .proc           = s3c_rtc_proc,
 396 };
 397
 398 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 399 {
 400         void __iomem *base = s3c_rtc_base;
 401         unsigned int tmp;
 402
 403         if (s3c_rtc_base == NULL)
 404                 return;
 405
 406         if (!en) {
 407                 tmp = readb(base + S3C2410_RTCCON);
 408                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 409
 410                 tmp = readb(base + S3C2410_TICNT);
 411                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 412         } else {
 413                 /* re-enable the device, and check it is ok */
 414
 415                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 416                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 417
 418                         tmp = readb(base + S3C2410_RTCCON);
 419                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 420                 }
 421
 422                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 423                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 424
 425                         tmp = readb(base + S3C2410_RTCCON);
 426                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 427                 }
 428
 429                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 430                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 431
 432                         tmp = readb(base + S3C2410_RTCCON);
 433                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 434                 }
 435         }
 436 }
 437
 438 static int s3c_rtc_remove(struct platform_device *dev)
 439 {
 440         struct rtc_device *rtc = platform_get_drvdata(dev);
 441
 442         platform_set_drvdata(dev, NULL);
 443         rtc_device_unregister(rtc);
 444
 445         s3c_rtc_setpie(0);
 446         s3c_rtc_setaie(0);
 447
 448         iounmap(s3c_rtc_base);
 449         release_resource(s3c_rtc_mem);
 450         kfree(s3c_rtc_mem);
 451
 452         return 0;
 453 }
 454
 455 static int s3c_rtc_probe(struct platform_device *pdev)
 456 {
 457         struct rtc_device *rtc;
 458         struct resource *res;
 459         int ret;
 460
 461         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
 462
 463         /* find the IRQs */
 464
 465         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 466         if (s3c_rtc_tickno < 0) {
 467                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 468                 return -ENOENT;
 469         }
 470
 471         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 472         if (s3c_rtc_alarmno < 0) {
 473                 dev_err(&pdev->dev, "no irq for alarm\n");
 474                 return -ENOENT;
 475         }
 476
 477         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 478                  s3c_rtc_tickno, s3c_rtc_alarmno);
 479
 480         /* get the memory region */
 481
 482         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 483         if (res == NULL) {
 484                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 485                 return -ENOENT;
 486         }
 487
 488         s3c_rtc_mem = request_mem_region(res->start,
 489                                          res->end-res->start+1,
 490                                          pdev->name);
 491
 492         if (s3c_rtc_mem == NULL) {
 493                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 494                 ret = -ENOENT;
 495                 goto err_nores;
 496         }
 497
 498         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 499         if (s3c_rtc_base == NULL) {
 500                 dev_err(&pdev->dev, "failed ioremap()\n");
 501                 ret = -EINVAL;
 502                 goto err_nomap;
 503         }
 504
 505         /* check to see if everything is setup correctly */
 506
 507         s3c_rtc_enable(pdev, 1);
 508
 509         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 510                  readb(s3c_rtc_base + S3C2410_RTCCON));
 511
 512         s3c_rtc_setfreq(s3c_rtc_freq);
 513
 514         /* register RTC and exit */
 515
 516         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 517                                   THIS_MODULE);
 518
 519         if (IS_ERR(rtc)) {
 520                 dev_err(&pdev->dev, "cannot attach rtc\n");
 521                 ret = PTR_ERR(rtc);
 522                 goto err_nortc;
 523         }
 524
 525         rtc->max_user_freq = 128;
 526
 527         platform_set_drvdata(pdev, rtc);
 528         return 0;
 529
 530  err_nortc:
 531         s3c_rtc_enable(pdev, 0);
 532         iounmap(s3c_rtc_base);
 533
 534  err_nomap:
 535         release_resource(s3c_rtc_mem);
 536
 537  err_nores:
 538         return ret;
 539 }
 540
 541 #ifdef CONFIG_PM
 542
 543 /* RTC Power management control */
 544
 545 static int ticnt_save;
 546
 547 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 548 {
 549         /* save TICNT for anyone using periodic interrupts */
 550         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 551         s3c_rtc_enable(pdev, 0);
 552         return 0;
 553 }
 554
 555 static int s3c_rtc_resume(struct platform_device *pdev)
 556 {
 557         s3c_rtc_enable(pdev, 1);
 558         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 559         return 0;
 560 }
 561 #else
 562 #define s3c_rtc_suspend NULL
 563 #define s3c_rtc_resume  NULL
 564 #endif
 565
 566 static struct platform_driver s3c2410_rtcdrv = {
 567         .probe          = s3c_rtc_probe,
 568         .remove         = s3c_rtc_remove,
 569         .suspend        = s3c_rtc_suspend,
 570         .resume         = s3c_rtc_resume,
 571         .driver         = {
 572                 .name   = "s3c2410-rtc",
 573                 .owner  = THIS_MODULE,
 574         },
 575 };
 576
 577 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 578
 579 static int __init s3c_rtc_init(void)
 580 {
 581         printk(banner);
 582         return platform_driver_register(&s3c2410_rtcdrv);
 583 }
 584
 585 static void __exit s3c_rtc_exit(void)
 586 {
 587         platform_driver_unregister(&s3c2410_rtcdrv);
 588 }
 589
 590 module_init(s3c_rtc_init);
 591 module_exit(s3c_rtc_exit);
 592
 593 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 594 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 595 MODULE_LICENSE("GPL");