drivers/char/s3c2410-rtc.c

   1 /* drivers/char/s3c2410_rtc.c
   2  *
   3  * Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk>
   4  *                    http://www.simtec.co.uk/products/SWLINUX/
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * S3C2410 Internal RTC Driver
  11  *
  12  *  Changelog:
  13  *      08-Nov-2004     BJD     Initial creation
  14  *      12-Nov-2004     BJD     Added periodic IRQ and PM code
  15  *      22-Nov-2004     BJD     Sign-test on alarm code to check for <0
  16  *      10-Mar-2005     LCVR    Changed S3C2410_VA_RTC to S3C24XX_VA_RTC
  17 */
  18
  19 #include <linux/module.h>
  20 #include <linux/fs.h>
  21 #include <linux/string.h>
  22 #include <linux/init.h>
  23 #include <linux/device.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/rtc.h>
  26 #include <linux/bcd.h>
  27
  28 #include <asm/hardware.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/io.h>
  31 #include <asm/irq.h>
  32 #include <asm/rtc.h>
  33
  34 #include <asm/mach/time.h>
  35
  36 #include <asm/hardware/clock.h>
  37 #include <asm/arch/regs-rtc.h>
  38
  39 /* need this for the RTC_AF definitions */
  40 #include <linux/mc146818rtc.h>
  41
  42 #undef S3C24XX_VA_RTC
  43 #define S3C24XX_VA_RTC s3c2410_rtc_base
  44
  45 static struct resource *s3c2410_rtc_mem;
  46
  47 static void __iomem *s3c2410_rtc_base;
  48 static int s3c2410_rtc_alarmno = NO_IRQ;
  49 static int s3c2410_rtc_tickno  = NO_IRQ;
  50 static int s3c2410_rtc_freq    = 1;
  51
  52 static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock);
  53
  54 /* IRQ Handlers */
  55
  56 static irqreturn_t s3c2410_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
  57 {
  58         rtc_update(1, RTC_AF | RTC_IRQF);
  59         return IRQ_HANDLED;
  60 }
  61
  62 static irqreturn_t s3c2410_rtc_tickirq(int irq, void *id, struct pt_regs *r)
  63 {
  64         rtc_update(1, RTC_PF | RTC_IRQF);
  65         return IRQ_HANDLED;
  66 }
  67
  68 /* Update control registers */
  69 static void s3c2410_rtc_setaie(int to)
  70 {
  71         unsigned int tmp;
  72
  73         pr_debug("%s: aie=%d\n", __FUNCTION__, to);
  74
  75         tmp = readb(S3C2410_RTCALM);
  76
  77         if (to)
  78                 tmp |= S3C2410_RTCALM_ALMEN;
  79         else
  80                 tmp &= ~S3C2410_RTCALM_ALMEN;
  81
  82
  83         writeb(tmp, S3C2410_RTCALM);
  84 }
  85
  86 static void s3c2410_rtc_setpie(int to)
  87 {
  88         unsigned int tmp;
  89
  90         pr_debug("%s: pie=%d\n", __FUNCTION__, to);
  91
  92         spin_lock_irq(&s3c2410_rtc_pie_lock);
  93         tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  94
  95         if (to)
  96                 tmp |= S3C2410_TICNT_ENABLE;
  97
  98         writeb(tmp, S3C2410_TICNT);
  99         spin_unlock_irq(&s3c2410_rtc_pie_lock);
 100 }
 101
 102 static void s3c2410_rtc_setfreq(int freq)
 103 {
 104         unsigned int tmp;
 105
 106         spin_lock_irq(&s3c2410_rtc_pie_lock);
 107         tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 108
 109         s3c2410_rtc_freq = freq;
 110
 111         tmp |= (128 / freq)-1;
 112
 113         writeb(tmp, S3C2410_TICNT);
 114         spin_unlock_irq(&s3c2410_rtc_pie_lock);
 115 }
 116
 117 /* Time read/write */
 118
 119 static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
 120 {
 121         unsigned int have_retried = 0;
 122
 123  retry_get_time:
 124         rtc_tm->tm_min  = readb(S3C2410_RTCMIN);
 125         rtc_tm->tm_hour = readb(S3C2410_RTCHOUR);
 126         rtc_tm->tm_mday = readb(S3C2410_RTCDATE);
 127         rtc_tm->tm_mon  = readb(S3C2410_RTCMON);
 128         rtc_tm->tm_year = readb(S3C2410_RTCYEAR);
 129         rtc_tm->tm_sec  = readb(S3C2410_RTCSEC);
 130
 131         /* the only way to work out wether the system was mid-update
 132          * when we read it is to check the second counter, and if it
 133          * is zero, then we re-try the entire read
 134          */
 135
 136         if (rtc_tm->tm_sec == 0 && !have_retried) {
 137                 have_retried = 1;
 138                 goto retry_get_time;
 139         }
 140
 141         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 142                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 143                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 144
 145         BCD_TO_BIN(rtc_tm->tm_sec);
 146         BCD_TO_BIN(rtc_tm->tm_min);
 147         BCD_TO_BIN(rtc_tm->tm_hour);
 148         BCD_TO_BIN(rtc_tm->tm_mday);
 149         BCD_TO_BIN(rtc_tm->tm_mon);
 150         BCD_TO_BIN(rtc_tm->tm_year);
 151
 152         rtc_tm->tm_year += 100;
 153         rtc_tm->tm_mon -= 1;
 154 }
 155
 156
 157 static int s3c2410_rtc_settime(struct rtc_time *tm)
 158 {
 159         /* the rtc gets round the y2k problem by just not supporting it */
 160
 161         if (tm->tm_year < 100)
 162                 return -EINVAL;
 163
 164         writeb(BIN2BCD(tm->tm_sec),  S3C2410_RTCSEC);
 165         writeb(BIN2BCD(tm->tm_min),  S3C2410_RTCMIN);
 166         writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
 167         writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
 168         writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
 169         writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
 170
 171         return 0;
 172 }
 173
 174 static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
 175 {
 176         struct rtc_time *alm_tm = &alrm->time;
 177         unsigned int alm_en;
 178
 179         alm_tm->tm_sec  = readb(S3C2410_ALMSEC);
 180         alm_tm->tm_min  = readb(S3C2410_ALMMIN);
 181         alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
 182         alm_tm->tm_mon  = readb(S3C2410_ALMMON);
 183         alm_tm->tm_mday = readb(S3C2410_ALMDATE);
 184         alm_tm->tm_year = readb(S3C2410_ALMYEAR);
 185
 186         alm_en = readb(S3C2410_RTCALM);
 187
 188         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 189                  alm_en,
 190                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 191                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 192
 193
 194         /* decode the alarm enable field */
 195
 196         if (alm_en & S3C2410_RTCALM_SECEN) {
 197                 BCD_TO_BIN(alm_tm->tm_sec);
 198         } else {
 199                 alm_tm->tm_sec = 0xff;
 200         }
 201
 202         if (alm_en & S3C2410_RTCALM_MINEN) {
 203                 BCD_TO_BIN(alm_tm->tm_min);
 204         } else {
 205                 alm_tm->tm_min = 0xff;
 206         }
 207
 208         if (alm_en & S3C2410_RTCALM_HOUREN) {
 209                 BCD_TO_BIN(alm_tm->tm_hour);
 210         } else {
 211                 alm_tm->tm_hour = 0xff;
 212         }
 213
 214         if (alm_en & S3C2410_RTCALM_DAYEN) {
 215                 BCD_TO_BIN(alm_tm->tm_mday);
 216         } else {
 217                 alm_tm->tm_mday = 0xff;
 218         }
 219
 220         if (alm_en & S3C2410_RTCALM_MONEN) {
 221                 BCD_TO_BIN(alm_tm->tm_mon);
 222                 alm_tm->tm_mon -= 1;
 223         } else {
 224                 alm_tm->tm_mon = 0xff;
 225         }
 226
 227         if (alm_en & S3C2410_RTCALM_YEAREN) {
 228                 BCD_TO_BIN(alm_tm->tm_year);
 229         } else {
 230                 alm_tm->tm_year = 0xffff;
 231         }
 232
 233         /* todo - set alrm->enabled ? */
 234 }
 235
 236 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
 237 {
 238         struct rtc_time *tm = &alrm->time;
 239         unsigned int alrm_en;
 240
 241         pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 242                  alrm->enabled,
 243                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 244                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 245
 246         if (alrm->enabled || 1) {
 247                 alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 248                 writeb(0x00, S3C2410_RTCALM);
 249
 250                 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
 251                         alrm_en |= S3C2410_RTCALM_SECEN;
 252                         writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
 253                 }
 254
 255                 if (tm->tm_min < 60 && tm->tm_min >= 0) {
 256                         alrm_en |= S3C2410_RTCALM_MINEN;
 257                         writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
 258                 }
 259
 260                 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
 261                         alrm_en |= S3C2410_RTCALM_HOUREN;
 262                         writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
 263                 }
 264
 265                 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 266
 267                 writeb(alrm_en, S3C2410_RTCALM);
 268                 enable_irq_wake(s3c2410_rtc_alarmno);
 269         } else {
 270                 alrm_en = readb(S3C2410_RTCALM);
 271                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
 272                 writeb(alrm_en, S3C2410_RTCALM);
 273                 disable_irq_wake(s3c2410_rtc_alarmno);
 274         }
 275
 276         return 0;
 277 }
 278
 279 static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
 280 {
 281         switch (cmd) {
 282         case RTC_AIE_OFF:
 283         case RTC_AIE_ON:
 284                 s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
 285                 return 0;
 286
 287         case RTC_PIE_OFF:
 288         case RTC_PIE_ON:
 289                 s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
 290                 return 0;
 291
 292         case RTC_IRQP_READ:
 293                 return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
 294
 295         case RTC_IRQP_SET:
 296                 if (arg < 1 || arg > 64)
 297                         return -EINVAL;
 298
 299                 if (!capable(CAP_SYS_RESOURCE))
 300                         return -EACCES;
 301
 302                 /* check for power of 2 */
 303
 304                 if ((arg & (arg-1)) != 0)
 305                         return -EINVAL;
 306
 307                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
 308
 309                 s3c2410_rtc_setfreq(arg);
 310                 return 0;
 311
 312         case RTC_UIE_ON:
 313         case RTC_UIE_OFF:
 314                 return -EINVAL;
 315         }
 316
 317         return -EINVAL;
 318 }
 319
 320 static int s3c2410_rtc_proc(char *buf)
 321 {
 322         unsigned int rtcalm = readb(S3C2410_RTCALM);
 323         unsigned int ticnt = readb (S3C2410_TICNT);
 324         char *p = buf;
 325
 326         p += sprintf(p, "alarm_IRQ\t: %s\n",
 327                      (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
 328         p += sprintf(p, "periodic_IRQ\t: %s\n",
 329                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 330         p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
 331
 332         return p - buf;
 333 }
 334
 335 static int s3c2410_rtc_open(void)
 336 {
 337         int ret;
 338
 339         ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
 340                           SA_INTERRUPT,  "s3c2410-rtc alarm", NULL);
 341
 342         if (ret)
 343                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
 344
 345         ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
 346                           SA_INTERRUPT,  "s3c2410-rtc tick", NULL);
 347
 348         if (ret) {
 349                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
 350                 goto tick_err;
 351         }
 352
 353         return ret;
 354
 355  tick_err:
 356         free_irq(s3c2410_rtc_alarmno, NULL);
 357         return ret;
 358 }
 359
 360 static void s3c2410_rtc_release(void)
 361 {
 362         /* do not clear AIE here, it may be needed for wake */
 363
 364         s3c2410_rtc_setpie(0);
 365         free_irq(s3c2410_rtc_alarmno, NULL);
 366         free_irq(s3c2410_rtc_tickno, NULL);
 367 }
 368
 369 static struct rtc_ops s3c2410_rtcops = {
 370         .owner          = THIS_MODULE,
 371         .open           = s3c2410_rtc_open,
 372         .release        = s3c2410_rtc_release,
 373         .ioctl          = s3c2410_rtc_ioctl,
 374         .read_time      = s3c2410_rtc_gettime,
 375         .set_time       = s3c2410_rtc_settime,
 376         .read_alarm     = s3c2410_rtc_getalarm,
 377         .set_alarm      = s3c2410_rtc_setalarm,
 378         .proc           = s3c2410_rtc_proc,
 379 };
 380
 381 static void s3c2410_rtc_enable(struct device *dev, int en)
 382 {
 383         unsigned int tmp;
 384
 385         if (s3c2410_rtc_base == NULL)
 386                 return;
 387
 388         if (!en) {
 389                 tmp = readb(S3C2410_RTCCON);
 390                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
 391
 392                 tmp = readb(S3C2410_TICNT);
 393                 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
 394         } else {
 395                 /* re-enable the device, and check it is ok */
 396
 397                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 398                         dev_info(dev, "rtc disabled, re-enabling\n");
 399
 400                         tmp = readb(S3C2410_RTCCON);
 401                         writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
 402                 }
 403
 404                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 405                         dev_info(dev, "removing S3C2410_RTCCON_CNTSEL\n");
 406
 407                         tmp = readb(S3C2410_RTCCON);
 408                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
 409                 }
 410
 411                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 412                         dev_info(dev, "removing S3C2410_RTCCON_CLKRST\n");
 413
 414                         tmp = readb(S3C2410_RTCCON);
 415                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
 416                 }
 417         }
 418 }
 419
 420 static int s3c2410_rtc_remove(struct device *dev)
 421 {
 422         unregister_rtc(&s3c2410_rtcops);
 423
 424         s3c2410_rtc_setpie(0);
 425         s3c2410_rtc_setaie(0);
 426
 427         if (s3c2410_rtc_mem != NULL) {
 428                 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
 429                 iounmap(s3c2410_rtc_base);
 430                 release_resource(s3c2410_rtc_mem);
 431                 kfree(s3c2410_rtc_mem);
 432         }
 433
 434         return 0;
 435 }
 436
 437 static int s3c2410_rtc_probe(struct device *dev)
 438 {
 439         struct platform_device *pdev = to_platform_device(dev);
 440         struct resource *res;
 441         int ret;
 442
 443         pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev);
 444
 445         /* find the IRQs */
 446
 447         s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
 448         if (s3c2410_rtc_tickno <= 0) {
 449                 dev_err(dev, "no irq for rtc tick\n");
 450                 return -ENOENT;
 451         }
 452
 453         s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
 454         if (s3c2410_rtc_alarmno <= 0) {
 455                 dev_err(dev, "no irq for alarm\n");
 456                 return -ENOENT;
 457         }
 458
 459         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 460                  s3c2410_rtc_tickno, s3c2410_rtc_alarmno);
 461
 462         /* get the memory region */
 463
 464         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 465         if (res == NULL) {
 466                 dev_err(dev, "failed to get memory region resource\n");
 467                 return -ENOENT;
 468         }
 469
 470         s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
 471                                      pdev->name);
 472
 473         if (s3c2410_rtc_mem == NULL) {
 474                 dev_err(dev, "failed to reserve memory region\n");
 475                 ret = -ENOENT;
 476                 goto exit_err;
 477         }
 478
 479         s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
 480         if (s3c2410_rtc_base == NULL) {
 481                 dev_err(dev, "failed ioremap()\n");
 482                 ret = -EINVAL;
 483                 goto exit_err;
 484         }
 485
 486         s3c2410_rtc_mem = res;
 487         pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
 488
 489         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
 490
 491         /* check to see if everything is setup correctly */
 492
 493         s3c2410_rtc_enable(dev, 1);
 494
 495         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
 496
 497         s3c2410_rtc_setfreq(s3c2410_rtc_freq);
 498
 499         /* register RTC and exit */
 500
 501         register_rtc(&s3c2410_rtcops);
 502         return 0;
 503
 504  exit_err:
 505         dev_err(dev, "error %d during initialisation\n", ret);
 506
 507         return ret;
 508 }
 509
 510 #ifdef CONFIG_PM
 511
 512 /* S3C2410 RTC Power management control */
 513
 514 static struct timespec s3c2410_rtc_delta;
 515
 516 static int ticnt_save;
 517
 518 static int s3c2410_rtc_suspend(struct device *dev, u32 state, u32 level)
 519 {
 520         struct rtc_time tm;
 521         struct timespec time;
 522
 523         time.tv_nsec = 0;
 524
 525         if (level == SUSPEND_POWER_DOWN) {
 526                 /* save TICNT for anyone using periodic interrupts */
 527
 528                 ticnt_save = readb(S3C2410_TICNT);
 529
 530                 /* calculate time delta for suspend */
 531
 532                 s3c2410_rtc_gettime(&tm);
 533                 rtc_tm_to_time(&tm, &time.tv_sec);
 534                 save_time_delta(&s3c2410_rtc_delta, &time);
 535                 s3c2410_rtc_enable(dev, 0);
 536         }
 537
 538         return 0;
 539 }
 540
 541 static int s3c2410_rtc_resume(struct device *dev, u32 level)
 542 {
 543         struct rtc_time tm;
 544         struct timespec time;
 545
 546         time.tv_nsec = 0;
 547
 548         s3c2410_rtc_enable(dev, 1);
 549         s3c2410_rtc_gettime(&tm);
 550         rtc_tm_to_time(&tm, &time.tv_sec);
 551         restore_time_delta(&s3c2410_rtc_delta, &time);
 552
 553         writeb(ticnt_save, S3C2410_TICNT);
 554         return 0;
 555 }
 556 #else
 557 #define s3c2410_rtc_suspend NULL
 558 #define s3c2410_rtc_resume  NULL
 559 #endif
 560
 561 static struct device_driver s3c2410_rtcdrv = {
 562         .name           = "s3c2410-rtc",
 563         .bus            = &platform_bus_type,
 564         .probe          = s3c2410_rtc_probe,
 565         .remove         = s3c2410_rtc_remove,
 566         .suspend        = s3c2410_rtc_suspend,
 567         .resume         = s3c2410_rtc_resume,
 568 };
 569
 570 static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
 571
 572 static int __init s3c2410_rtc_init(void)
 573 {
 574         printk(banner);
 575         return driver_register(&s3c2410_rtcdrv);
 576 }
 577
 578 static void __exit s3c2410_rtc_exit(void)
 579 {
 580         driver_unregister(&s3c2410_rtcdrv);
 581 }
 582
 583 module_init(s3c2410_rtc_init);
 584 module_exit(s3c2410_rtc_exit);
 585
 586 MODULE_DESCRIPTION("S3C24XX RTC Driver");
 587 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 588 MODULE_LICENSE("GPL");