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