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