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/platform_device.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/rtc.h>
  26 #include <linux/bcd.h>
  27 #include <linux/clk.h>
  28
  29 #include <asm/hardware.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/io.h>
  32 #include <asm/irq.h>
  33 #include <asm/rtc.h>
  34
  35 #include <asm/mach/time.h>
  36
  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 int 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         return 0;
 156 }
 157
 158
 159 static int s3c2410_rtc_settime(struct rtc_time *tm)
 160 {
 161         /* the rtc gets round the y2k problem by just not supporting it */
 162
 163         if (tm->tm_year < 100)
 164                 return -EINVAL;
 165
 166         writeb(BIN2BCD(tm->tm_sec),  S3C2410_RTCSEC);
 167         writeb(BIN2BCD(tm->tm_min),  S3C2410_RTCMIN);
 168         writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
 169         writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
 170         writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
 171         writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
 172
 173         return 0;
 174 }
 175
 176 static int s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
 177 {
 178         struct rtc_time *alm_tm = &alrm->time;
 179         unsigned int alm_en;
 180
 181         alm_tm->tm_sec  = readb(S3C2410_ALMSEC);
 182         alm_tm->tm_min  = readb(S3C2410_ALMMIN);
 183         alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
 184         alm_tm->tm_mon  = readb(S3C2410_ALMMON);
 185         alm_tm->tm_mday = readb(S3C2410_ALMDATE);
 186         alm_tm->tm_year = readb(S3C2410_ALMYEAR);
 187
 188         alm_en = readb(S3C2410_RTCALM);
 189
 190         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 191                  alm_en,
 192                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 193                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 194
 195
 196         /* decode the alarm enable field */
 197
 198         if (alm_en & S3C2410_RTCALM_SECEN) {
 199                 BCD_TO_BIN(alm_tm->tm_sec);
 200         } else {
 201                 alm_tm->tm_sec = 0xff;
 202         }
 203
 204         if (alm_en & S3C2410_RTCALM_MINEN) {
 205                 BCD_TO_BIN(alm_tm->tm_min);
 206         } else {
 207                 alm_tm->tm_min = 0xff;
 208         }
 209
 210         if (alm_en & S3C2410_RTCALM_HOUREN) {
 211                 BCD_TO_BIN(alm_tm->tm_hour);
 212         } else {
 213                 alm_tm->tm_hour = 0xff;
 214         }
 215
 216         if (alm_en & S3C2410_RTCALM_DAYEN) {
 217                 BCD_TO_BIN(alm_tm->tm_mday);
 218         } else {
 219                 alm_tm->tm_mday = 0xff;
 220         }
 221
 222         if (alm_en & S3C2410_RTCALM_MONEN) {
 223                 BCD_TO_BIN(alm_tm->tm_mon);
 224                 alm_tm->tm_mon -= 1;
 225         } else {
 226                 alm_tm->tm_mon = 0xff;
 227         }
 228
 229         if (alm_en & S3C2410_RTCALM_YEAREN) {
 230                 BCD_TO_BIN(alm_tm->tm_year);
 231         } else {
 232                 alm_tm->tm_year = 0xffff;
 233         }
 234
 235         /* todo - set alrm->enabled ? */
 236
 237         return 0;
 238 }
 239
 240 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
 241 {
 242         struct rtc_time *tm = &alrm->time;
 243         unsigned int alrm_en;
 244
 245         pr_debug("s3c2410_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         if (alrm->enabled || 1) {
 251                 alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 252                 writeb(0x00, 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), 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), 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), S3C2410_ALMHOUR);
 267                 }
 268
 269                 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 270
 271                 writeb(alrm_en, S3C2410_RTCALM);
 272                 enable_irq_wake(s3c2410_rtc_alarmno);
 273         } else {
 274                 alrm_en = readb(S3C2410_RTCALM);
 275                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
 276                 writeb(alrm_en, S3C2410_RTCALM);
 277                 disable_irq_wake(s3c2410_rtc_alarmno);
 278         }
 279
 280         return 0;
 281 }
 282
 283 static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
 284 {
 285         switch (cmd) {
 286         case RTC_AIE_OFF:
 287         case RTC_AIE_ON:
 288                 s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
 289                 return 0;
 290
 291         case RTC_PIE_OFF:
 292         case RTC_PIE_ON:
 293                 s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
 294                 return 0;
 295
 296         case RTC_IRQP_READ:
 297                 return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
 298
 299         case RTC_IRQP_SET:
 300                 if (arg < 1 || arg > 64)
 301                         return -EINVAL;
 302
 303                 if (!capable(CAP_SYS_RESOURCE))
 304                         return -EACCES;
 305
 306                 /* check for power of 2 */
 307
 308                 if ((arg & (arg-1)) != 0)
 309                         return -EINVAL;
 310
 311                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
 312
 313                 s3c2410_rtc_setfreq(arg);
 314                 return 0;
 315
 316         case RTC_UIE_ON:
 317         case RTC_UIE_OFF:
 318                 return -EINVAL;
 319         }
 320
 321         return -EINVAL;
 322 }
 323
 324 static int s3c2410_rtc_proc(char *buf)
 325 {
 326         unsigned int rtcalm = readb(S3C2410_RTCALM);
 327         unsigned int ticnt = readb (S3C2410_TICNT);
 328         char *p = buf;
 329
 330         p += sprintf(p, "alarm_IRQ\t: %s\n",
 331                      (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
 332         p += sprintf(p, "periodic_IRQ\t: %s\n",
 333                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 334         p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
 335
 336         return p - buf;
 337 }
 338
 339 static int s3c2410_rtc_open(void)
 340 {
 341         int ret;
 342
 343         ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
 344                           IRQF_DISABLED,  "s3c2410-rtc alarm", NULL);
 345
 346         if (ret)
 347                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
 348
 349         ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
 350                           IRQF_DISABLED,  "s3c2410-rtc tick", NULL);
 351
 352         if (ret) {
 353                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
 354                 goto tick_err;
 355         }
 356
 357         return ret;
 358
 359  tick_err:
 360         free_irq(s3c2410_rtc_alarmno, NULL);
 361         return ret;
 362 }
 363
 364 static void s3c2410_rtc_release(void)
 365 {
 366         /* do not clear AIE here, it may be needed for wake */
 367
 368         s3c2410_rtc_setpie(0);
 369         free_irq(s3c2410_rtc_alarmno, NULL);
 370         free_irq(s3c2410_rtc_tickno, NULL);
 371 }
 372
 373 static struct rtc_ops s3c2410_rtcops = {
 374         .owner          = THIS_MODULE,
 375         .open           = s3c2410_rtc_open,
 376         .release        = s3c2410_rtc_release,
 377         .ioctl          = s3c2410_rtc_ioctl,
 378         .read_time      = s3c2410_rtc_gettime,
 379         .set_time       = s3c2410_rtc_settime,
 380         .read_alarm     = s3c2410_rtc_getalarm,
 381         .set_alarm      = s3c2410_rtc_setalarm,
 382         .proc           = s3c2410_rtc_proc,
 383 };
 384
 385 static void s3c2410_rtc_enable(struct platform_device *pdev, int en)
 386 {
 387         unsigned int tmp;
 388
 389         if (s3c2410_rtc_base == NULL)
 390                 return;
 391
 392         if (!en) {
 393                 tmp = readb(S3C2410_RTCCON);
 394                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
 395
 396                 tmp = readb(S3C2410_TICNT);
 397                 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
 398         } else {
 399                 /* re-enable the device, and check it is ok */
 400
 401                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 402                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 403
 404                         tmp = readb(S3C2410_RTCCON);
 405                         writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
 406                 }
 407
 408                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 409                         dev_info(&pdev->dev, "removing S3C2410_RTCCON_CNTSEL\n");
 410
 411                         tmp = readb(S3C2410_RTCCON);
 412                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
 413                 }
 414
 415                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 416                         dev_info(&pdev->dev, "removing S3C2410_RTCCON_CLKRST\n");
 417
 418                         tmp = readb(S3C2410_RTCCON);
 419                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
 420                 }
 421         }
 422 }
 423
 424 static int s3c2410_rtc_remove(struct platform_device *dev)
 425 {
 426         unregister_rtc(&s3c2410_rtcops);
 427
 428         s3c2410_rtc_setpie(0);
 429         s3c2410_rtc_setaie(0);
 430
 431         if (s3c2410_rtc_mem != NULL) {
 432                 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
 433                 iounmap(s3c2410_rtc_base);
 434                 release_resource(s3c2410_rtc_mem);
 435                 kfree(s3c2410_rtc_mem);
 436         }
 437
 438         return 0;
 439 }
 440
 441 static int s3c2410_rtc_probe(struct platform_device *pdev)
 442 {
 443         struct resource *res;
 444         int ret;
 445
 446         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
 447
 448         /* find the IRQs */
 449
 450         s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
 451         if (s3c2410_rtc_tickno < 0) {
 452                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 453                 return -ENOENT;
 454         }
 455
 456         s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
 457         if (s3c2410_rtc_alarmno < 0) {
 458                 dev_err(&pdev->dev, "no irq for alarm\n");
 459                 return -ENOENT;
 460         }
 461
 462         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 463                  s3c2410_rtc_tickno, s3c2410_rtc_alarmno);
 464
 465         /* get the memory region */
 466
 467         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 468         if (res == NULL) {
 469                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 470                 return -ENOENT;
 471         }
 472
 473         s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
 474                                      pdev->name);
 475
 476         if (s3c2410_rtc_mem == NULL) {
 477                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 478                 ret = -ENOENT;
 479                 goto exit_err;
 480         }
 481
 482         s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
 483         if (s3c2410_rtc_base == NULL) {
 484                 dev_err(&pdev->dev, "failed ioremap()\n");
 485                 ret = -EINVAL;
 486                 goto exit_err;
 487         }
 488
 489         s3c2410_rtc_mem = res;
 490         pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
 491
 492         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
 493
 494         /* check to see if everything is setup correctly */
 495
 496         s3c2410_rtc_enable(pdev, 1);
 497
 498         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
 499
 500         s3c2410_rtc_setfreq(s3c2410_rtc_freq);
 501
 502         /* register RTC and exit */
 503
 504         register_rtc(&s3c2410_rtcops);
 505         return 0;
 506
 507  exit_err:
 508         dev_err(&pdev->dev, "error %d during initialisation\n", ret);
 509
 510         return ret;
 511 }
 512
 513 #ifdef CONFIG_PM
 514
 515 /* S3C2410 RTC Power management control */
 516
 517 static struct timespec s3c2410_rtc_delta;
 518
 519 static int ticnt_save;
 520
 521 static int s3c2410_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 522 {
 523         struct rtc_time tm;
 524         struct timespec time;
 525
 526         time.tv_nsec = 0;
 527
 528         /* save TICNT for anyone using periodic interrupts */
 529
 530         ticnt_save = readb(S3C2410_TICNT);
 531
 532         /* calculate time delta for suspend */
 533
 534         s3c2410_rtc_gettime(&tm);
 535         rtc_tm_to_time(&tm, &time.tv_sec);
 536         save_time_delta(&s3c2410_rtc_delta, &time);
 537         s3c2410_rtc_enable(pdev, 0);
 538
 539         return 0;
 540 }
 541
 542 static int s3c2410_rtc_resume(struct platform_device *pdev)
 543 {
 544         struct rtc_time tm;
 545         struct timespec time;
 546
 547         time.tv_nsec = 0;
 548
 549         s3c2410_rtc_enable(pdev, 1);
 550         s3c2410_rtc_gettime(&tm);
 551         rtc_tm_to_time(&tm, &time.tv_sec);
 552         restore_time_delta(&s3c2410_rtc_delta, &time);
 553
 554         writeb(ticnt_save, S3C2410_TICNT);
 555         return 0;
 556 }
 557 #else
 558 #define s3c2410_rtc_suspend NULL
 559 #define s3c2410_rtc_resume  NULL
 560 #endif
 561
 562 static struct platform_driver s3c2410_rtcdrv = {
 563         .probe          = s3c2410_rtc_probe,
 564         .remove         = s3c2410_rtc_remove,
 565         .suspend        = s3c2410_rtc_suspend,
 566         .resume         = s3c2410_rtc_resume,
 567         .driver         = {
 568                 .name   = "s3c2410-rtc",
 569                 .owner  = THIS_MODULE,
 570         },
 571 };
 572
 573 static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
 574
 575 static int __init s3c2410_rtc_init(void)
 576 {
 577         printk(banner);
 578         return platform_driver_register(&s3c2410_rtcdrv);
 579 }
 580
 581 static void __exit s3c2410_rtc_exit(void)
 582 {
 583         platform_driver_unregister(&s3c2410_rtcdrv);
 584 }
 585
 586 module_init(s3c2410_rtc_init);
 587 module_exit(s3c2410_rtc_exit);
 588
 589 MODULE_DESCRIPTION("S3C24XX RTC Driver");
 590 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 591 MODULE_LICENSE("GPL");