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 #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 <plat/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         if (!is_power_of_2(freq))
  98                 return -EINVAL;
  99
 100         spin_lock_irq(&s3c_rtc_pie_lock);
 101
 102         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 103         tmp |= (128 / freq)-1;
 104
 105         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 106         spin_unlock_irq(&s3c_rtc_pie_lock);
 107
 108         return 0;
 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         rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
 141         rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
 142         rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
 143         rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
 144         rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
 145         rtc_tm->tm_year = bcd2bin(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                 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
 206         else
 207                 alm_tm->tm_sec = 0xff;
 208
 209         if (alm_en & S3C2410_RTCALM_MINEN)
 210                 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
 211         else
 212                 alm_tm->tm_min = 0xff;
 213
 214         if (alm_en & S3C2410_RTCALM_HOUREN)
 215                 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
 216         else
 217                 alm_tm->tm_hour = 0xff;
 218
 219         if (alm_en & S3C2410_RTCALM_DAYEN)
 220                 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
 221         else
 222                 alm_tm->tm_mday = 0xff;
 223
 224         if (alm_en & S3C2410_RTCALM_MONEN) {
 225                 alm_tm->tm_mon = bcd2bin(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                 alm_tm->tm_year = bcd2bin(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         s3c_rtc_setaie(alrm->enabled);
 274
 275         if (alrm->enabled)
 276                 enable_irq_wake(s3c_rtc_alarmno);
 277         else
 278                 disable_irq_wake(s3c_rtc_alarmno);
 279
 280         return 0;
 281 }
 282
 283 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 284 {
 285         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 286
 287         seq_printf(seq, "periodic_IRQ\t: %s\n",
 288                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 289         return 0;
 290 }
 291
 292 static int s3c_rtc_open(struct device *dev)
 293 {
 294         struct platform_device *pdev = to_platform_device(dev);
 295         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 296         int ret;
 297
 298         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 299                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 300
 301         if (ret) {
 302                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 303                 return ret;
 304         }
 305
 306         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 307                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 308
 309         if (ret) {
 310                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 311                 goto tick_err;
 312         }
 313
 314         return ret;
 315
 316  tick_err:
 317         free_irq(s3c_rtc_alarmno, rtc_dev);
 318         return ret;
 319 }
 320
 321 static void s3c_rtc_release(struct device *dev)
 322 {
 323         struct platform_device *pdev = to_platform_device(dev);
 324         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 325
 326         /* do not clear AIE here, it may be needed for wake */
 327
 328         s3c_rtc_setpie(dev, 0);
 329         free_irq(s3c_rtc_alarmno, rtc_dev);
 330         free_irq(s3c_rtc_tickno, rtc_dev);
 331 }
 332
 333 static const struct rtc_class_ops s3c_rtcops = {
 334         .open           = s3c_rtc_open,
 335         .release        = s3c_rtc_release,
 336         .read_time      = s3c_rtc_gettime,
 337         .set_time       = s3c_rtc_settime,
 338         .read_alarm     = s3c_rtc_getalarm,
 339         .set_alarm      = s3c_rtc_setalarm,
 340         .irq_set_freq   = s3c_rtc_setfreq,
 341         .irq_set_state  = s3c_rtc_setpie,
 342         .proc           = s3c_rtc_proc,
 343 };
 344
 345 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 346 {
 347         void __iomem *base = s3c_rtc_base;
 348         unsigned int tmp;
 349
 350         if (s3c_rtc_base == NULL)
 351                 return;
 352
 353         if (!en) {
 354                 tmp = readb(base + S3C2410_RTCCON);
 355                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 356
 357                 tmp = readb(base + S3C2410_TICNT);
 358                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 359         } else {
 360                 /* re-enable the device, and check it is ok */
 361
 362                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 363                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 364
 365                         tmp = readb(base + S3C2410_RTCCON);
 366                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 367                 }
 368
 369                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 370                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 371
 372                         tmp = readb(base + S3C2410_RTCCON);
 373                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 374                 }
 375
 376                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 377                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 378
 379                         tmp = readb(base + S3C2410_RTCCON);
 380                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 381                 }
 382         }
 383 }
 384
 385 static int __devexit s3c_rtc_remove(struct platform_device *dev)
 386 {
 387         struct rtc_device *rtc = platform_get_drvdata(dev);
 388
 389         platform_set_drvdata(dev, NULL);
 390         rtc_device_unregister(rtc);
 391
 392         s3c_rtc_setpie(&dev->dev, 0);
 393         s3c_rtc_setaie(0);
 394
 395         iounmap(s3c_rtc_base);
 396         release_resource(s3c_rtc_mem);
 397         kfree(s3c_rtc_mem);
 398
 399         return 0;
 400 }
 401
 402 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 403 {
 404         struct rtc_device *rtc;
 405         struct resource *res;
 406         int ret;
 407
 408         pr_debug("%s: probe=%p\n", __func__, pdev);
 409
 410         /* find the IRQs */
 411
 412         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 413         if (s3c_rtc_tickno < 0) {
 414                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 415                 return -ENOENT;
 416         }
 417
 418         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 419         if (s3c_rtc_alarmno < 0) {
 420                 dev_err(&pdev->dev, "no irq for alarm\n");
 421                 return -ENOENT;
 422         }
 423
 424         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 425                  s3c_rtc_tickno, s3c_rtc_alarmno);
 426
 427         /* get the memory region */
 428
 429         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 430         if (res == NULL) {
 431                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 432                 return -ENOENT;
 433         }
 434
 435         s3c_rtc_mem = request_mem_region(res->start,
 436                                          res->end-res->start+1,
 437                                          pdev->name);
 438
 439         if (s3c_rtc_mem == NULL) {
 440                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 441                 ret = -ENOENT;
 442                 goto err_nores;
 443         }
 444
 445         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 446         if (s3c_rtc_base == NULL) {
 447                 dev_err(&pdev->dev, "failed ioremap()\n");
 448                 ret = -EINVAL;
 449                 goto err_nomap;
 450         }
 451
 452         /* check to see if everything is setup correctly */
 453
 454         s3c_rtc_enable(pdev, 1);
 455
 456         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 457                  readb(s3c_rtc_base + S3C2410_RTCCON));
 458
 459         s3c_rtc_setfreq(&pdev->dev, 1);
 460
 461         device_init_wakeup(&pdev->dev, 1);
 462
 463         /* register RTC and exit */
 464
 465         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 466                                   THIS_MODULE);
 467
 468         if (IS_ERR(rtc)) {
 469                 dev_err(&pdev->dev, "cannot attach rtc\n");
 470                 ret = PTR_ERR(rtc);
 471                 goto err_nortc;
 472         }
 473
 474         rtc->max_user_freq = 128;
 475
 476         platform_set_drvdata(pdev, rtc);
 477         return 0;
 478
 479  err_nortc:
 480         s3c_rtc_enable(pdev, 0);
 481         iounmap(s3c_rtc_base);
 482
 483  err_nomap:
 484         release_resource(s3c_rtc_mem);
 485
 486  err_nores:
 487         return ret;
 488 }
 489
 490 #ifdef CONFIG_PM
 491
 492 /* RTC Power management control */
 493
 494 static int ticnt_save;
 495
 496 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 497 {
 498         /* save TICNT for anyone using periodic interrupts */
 499         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 500         s3c_rtc_enable(pdev, 0);
 501         return 0;
 502 }
 503
 504 static int s3c_rtc_resume(struct platform_device *pdev)
 505 {
 506         s3c_rtc_enable(pdev, 1);
 507         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 508         return 0;
 509 }
 510 #else
 511 #define s3c_rtc_suspend NULL
 512 #define s3c_rtc_resume  NULL
 513 #endif
 514
 515 static struct platform_driver s3c2410_rtc_driver = {
 516         .probe          = s3c_rtc_probe,
 517         .remove         = __devexit_p(s3c_rtc_remove),
 518         .suspend        = s3c_rtc_suspend,
 519         .resume         = s3c_rtc_resume,
 520         .driver         = {
 521                 .name   = "s3c2410-rtc",
 522                 .owner  = THIS_MODULE,
 523         },
 524 };
 525
 526 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 527
 528 static int __init s3c_rtc_init(void)
 529 {
 530         printk(banner);
 531         return platform_driver_register(&s3c2410_rtc_driver);
 532 }
 533
 534 static void __exit s3c_rtc_exit(void)
 535 {
 536         platform_driver_unregister(&s3c2410_rtc_driver);
 537 }
 538
 539 module_init(s3c_rtc_init);
 540 module_exit(s3c_rtc_exit);
 541
 542 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 543 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 544 MODULE_LICENSE("GPL");
 545 MODULE_ALIAS("platform:s3c2410-rtc");