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