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 <mach/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
  40 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
  41
  42 /* IRQ Handlers */
  43
  44 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
  45 {
  46         struct rtc_device *rdev = id;
  47
  48         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  49         return IRQ_HANDLED;
  50 }
  51
  52 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
  53 {
  54         struct rtc_device *rdev = id;
  55
  56         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  57         return IRQ_HANDLED;
  58 }
  59
  60 /* Update control registers */
  61 static void s3c_rtc_setaie(int to)
  62 {
  63         unsigned int tmp;
  64
  65         pr_debug("%s: aie=%d\n", __func__, to);
  66
  67         tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
  68
  69         if (to)
  70                 tmp |= S3C2410_RTCALM_ALMEN;
  71
  72         writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
  73 }
  74
  75 static int s3c_rtc_setpie(struct device *dev, int enabled)
  76 {
  77         unsigned int tmp;
  78
  79         pr_debug("%s: pie=%d\n", __func__, enabled);
  80
  81         spin_lock_irq(&s3c_rtc_pie_lock);
  82         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  83
  84         if (enabled)
  85                 tmp |= S3C2410_TICNT_ENABLE;
  86
  87         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
  88         spin_unlock_irq(&s3c_rtc_pie_lock);
  89
  90         return 0;
  91 }
  92
  93 static int s3c_rtc_setfreq(struct device *dev, int freq)
  94 {
  95         unsigned int tmp;
  96
  97         spin_lock_irq(&s3c_rtc_pie_lock);
  98
  99         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 100         tmp |= (128 / freq)-1;
 101
 102         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 103         spin_unlock_irq(&s3c_rtc_pie_lock);
 104
 105         return 0;
 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         rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
 138         rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
 139         rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
 140         rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
 141         rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
 142         rtc_tm->tm_year = bcd2bin(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                 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
 203         else
 204                 alm_tm->tm_sec = 0xff;
 205
 206         if (alm_en & S3C2410_RTCALM_MINEN)
 207                 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
 208         else
 209                 alm_tm->tm_min = 0xff;
 210
 211         if (alm_en & S3C2410_RTCALM_HOUREN)
 212                 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
 213         else
 214                 alm_tm->tm_hour = 0xff;
 215
 216         if (alm_en & S3C2410_RTCALM_DAYEN)
 217                 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
 218         else
 219                 alm_tm->tm_mday = 0xff;
 220
 221         if (alm_en & S3C2410_RTCALM_MONEN) {
 222                 alm_tm->tm_mon = bcd2bin(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                 alm_tm->tm_year = bcd2bin(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         s3c_rtc_setaie(alrm->enabled);
 271
 272         if (alrm->enabled)
 273                 enable_irq_wake(s3c_rtc_alarmno);
 274         else
 275                 disable_irq_wake(s3c_rtc_alarmno);
 276
 277         return 0;
 278 }
 279
 280 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 281 {
 282         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 283
 284         seq_printf(seq, "periodic_IRQ\t: %s\n",
 285                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 286         return 0;
 287 }
 288
 289 static int s3c_rtc_open(struct device *dev)
 290 {
 291         struct platform_device *pdev = to_platform_device(dev);
 292         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 293         int ret;
 294
 295         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 296                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 297
 298         if (ret) {
 299                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 300                 return ret;
 301         }
 302
 303         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 304                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 305
 306         if (ret) {
 307                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 308                 goto tick_err;
 309         }
 310
 311         return ret;
 312
 313  tick_err:
 314         free_irq(s3c_rtc_alarmno, rtc_dev);
 315         return ret;
 316 }
 317
 318 static void s3c_rtc_release(struct device *dev)
 319 {
 320         struct platform_device *pdev = to_platform_device(dev);
 321         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 322
 323         /* do not clear AIE here, it may be needed for wake */
 324
 325         s3c_rtc_setpie(dev, 0);
 326         free_irq(s3c_rtc_alarmno, rtc_dev);
 327         free_irq(s3c_rtc_tickno, rtc_dev);
 328 }
 329
 330 static const struct rtc_class_ops s3c_rtcops = {
 331         .open           = s3c_rtc_open,
 332         .release        = s3c_rtc_release,
 333         .read_time      = s3c_rtc_gettime,
 334         .set_time       = s3c_rtc_settime,
 335         .read_alarm     = s3c_rtc_getalarm,
 336         .set_alarm      = s3c_rtc_setalarm,
 337         .irq_set_freq   = s3c_rtc_setfreq,
 338         .irq_set_state  = s3c_rtc_setpie,
 339         .proc           = s3c_rtc_proc,
 340 };
 341
 342 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 343 {
 344         void __iomem *base = s3c_rtc_base;
 345         unsigned int tmp;
 346
 347         if (s3c_rtc_base == NULL)
 348                 return;
 349
 350         if (!en) {
 351                 tmp = readb(base + S3C2410_RTCCON);
 352                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 353
 354                 tmp = readb(base + S3C2410_TICNT);
 355                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 356         } else {
 357                 /* re-enable the device, and check it is ok */
 358
 359                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 360                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 361
 362                         tmp = readb(base + S3C2410_RTCCON);
 363                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 364                 }
 365
 366                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 367                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 368
 369                         tmp = readb(base + S3C2410_RTCCON);
 370                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 371                 }
 372
 373                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 374                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 375
 376                         tmp = readb(base + S3C2410_RTCCON);
 377                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 378                 }
 379         }
 380 }
 381
 382 static int __devexit s3c_rtc_remove(struct platform_device *dev)
 383 {
 384         struct rtc_device *rtc = platform_get_drvdata(dev);
 385
 386         platform_set_drvdata(dev, NULL);
 387         rtc_device_unregister(rtc);
 388
 389         s3c_rtc_setpie(&dev->dev, 0);
 390         s3c_rtc_setaie(0);
 391
 392         iounmap(s3c_rtc_base);
 393         release_resource(s3c_rtc_mem);
 394         kfree(s3c_rtc_mem);
 395
 396         return 0;
 397 }
 398
 399 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 400 {
 401         struct rtc_device *rtc;
 402         struct resource *res;
 403         int ret;
 404
 405         pr_debug("%s: probe=%p\n", __func__, pdev);
 406
 407         /* find the IRQs */
 408
 409         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 410         if (s3c_rtc_tickno < 0) {
 411                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 412                 return -ENOENT;
 413         }
 414
 415         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 416         if (s3c_rtc_alarmno < 0) {
 417                 dev_err(&pdev->dev, "no irq for alarm\n");
 418                 return -ENOENT;
 419         }
 420
 421         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 422                  s3c_rtc_tickno, s3c_rtc_alarmno);
 423
 424         /* get the memory region */
 425
 426         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 427         if (res == NULL) {
 428                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 429                 return -ENOENT;
 430         }
 431
 432         s3c_rtc_mem = request_mem_region(res->start,
 433                                          res->end-res->start+1,
 434                                          pdev->name);
 435
 436         if (s3c_rtc_mem == NULL) {
 437                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 438                 ret = -ENOENT;
 439                 goto err_nores;
 440         }
 441
 442         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 443         if (s3c_rtc_base == NULL) {
 444                 dev_err(&pdev->dev, "failed ioremap()\n");
 445                 ret = -EINVAL;
 446                 goto err_nomap;
 447         }
 448
 449         /* check to see if everything is setup correctly */
 450
 451         s3c_rtc_enable(pdev, 1);
 452
 453         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 454                  readb(s3c_rtc_base + S3C2410_RTCCON));
 455
 456         s3c_rtc_setfreq(&pdev->dev, 1);
 457
 458         device_init_wakeup(&pdev->dev, 1);
 459
 460         /* register RTC and exit */
 461
 462         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 463                                   THIS_MODULE);
 464
 465         if (IS_ERR(rtc)) {
 466                 dev_err(&pdev->dev, "cannot attach rtc\n");
 467                 ret = PTR_ERR(rtc);
 468                 goto err_nortc;
 469         }
 470
 471         rtc->max_user_freq = 128;
 472
 473         platform_set_drvdata(pdev, rtc);
 474         return 0;
 475
 476  err_nortc:
 477         s3c_rtc_enable(pdev, 0);
 478         iounmap(s3c_rtc_base);
 479
 480  err_nomap:
 481         release_resource(s3c_rtc_mem);
 482
 483  err_nores:
 484         return ret;
 485 }
 486
 487 #ifdef CONFIG_PM
 488
 489 /* RTC Power management control */
 490
 491 static int ticnt_save;
 492
 493 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 494 {
 495         /* save TICNT for anyone using periodic interrupts */
 496         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 497         s3c_rtc_enable(pdev, 0);
 498         return 0;
 499 }
 500
 501 static int s3c_rtc_resume(struct platform_device *pdev)
 502 {
 503         s3c_rtc_enable(pdev, 1);
 504         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 505         return 0;
 506 }
 507 #else
 508 #define s3c_rtc_suspend NULL
 509 #define s3c_rtc_resume  NULL
 510 #endif
 511
 512 static struct platform_driver s3c2410_rtc_driver = {
 513         .probe          = s3c_rtc_probe,
 514         .remove         = __devexit_p(s3c_rtc_remove),
 515         .suspend        = s3c_rtc_suspend,
 516         .resume         = s3c_rtc_resume,
 517         .driver         = {
 518                 .name   = "s3c2410-rtc",
 519                 .owner  = THIS_MODULE,
 520         },
 521 };
 522
 523 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 524
 525 static int __init s3c_rtc_init(void)
 526 {
 527         printk(banner);
 528         return platform_driver_register(&s3c2410_rtc_driver);
 529 }
 530
 531 static void __exit s3c_rtc_exit(void)
 532 {
 533         platform_driver_unregister(&s3c2410_rtc_driver);
 534 }
 535
 536 module_init(s3c_rtc_init);
 537 module_exit(s3c_rtc_exit);
 538
 539 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 540 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 541 MODULE_LICENSE("GPL");
 542 MODULE_ALIAS("platform:s3c2410-rtc");