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 #include <linux/slab.h>
  25
  26 #include <mach/hardware.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/io.h>
  29 #include <asm/irq.h>
  30 #include <plat/regs-rtc.h>
  31
  32 /* I have yet to find an S3C implementation with more than one
  33  * of these rtc blocks in */
  34
  35 static struct resource *s3c_rtc_mem;
  36
  37 static void __iomem *s3c_rtc_base;
  38 static int s3c_rtc_alarmno = NO_IRQ;
  39 static int s3c_rtc_tickno  = NO_IRQ;
  40
  41 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
  42
  43 /* IRQ Handlers */
  44
  45 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
  46 {
  47         struct rtc_device *rdev = id;
  48
  49         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  50         return IRQ_HANDLED;
  51 }
  52
  53 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
  54 {
  55         struct rtc_device *rdev = id;
  56
  57         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  58         return IRQ_HANDLED;
  59 }
  60
  61 /* Update control registers */
  62 static void s3c_rtc_setaie(int to)
  63 {
  64         unsigned int tmp;
  65
  66         pr_debug("%s: aie=%d\n", __func__, to);
  67
  68         tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
  69
  70         if (to)
  71                 tmp |= S3C2410_RTCALM_ALMEN;
  72
  73         writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
  74 }
  75
  76 static int s3c_rtc_setpie(struct device *dev, int enabled)
  77 {
  78         unsigned int tmp;
  79
  80         pr_debug("%s: pie=%d\n", __func__, enabled);
  81
  82         spin_lock_irq(&s3c_rtc_pie_lock);
  83         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  84
  85         if (enabled)
  86                 tmp |= S3C2410_TICNT_ENABLE;
  87
  88         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
  89         spin_unlock_irq(&s3c_rtc_pie_lock);
  90
  91         return 0;
  92 }
  93
  94 static int s3c_rtc_setfreq(struct device *dev, int freq)
  95 {
  96         unsigned int tmp;
  97
  98         if (!is_power_of_2(freq))
  99                 return -EINVAL;
 100
 101         spin_lock_irq(&s3c_rtc_pie_lock);
 102
 103         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 104         tmp |= (128 / freq)-1;
 105
 106         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 107         spin_unlock_irq(&s3c_rtc_pie_lock);
 108
 109         return 0;
 110 }
 111
 112 /* Time read/write */
 113
 114 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 115 {
 116         unsigned int have_retried = 0;
 117         void __iomem *base = s3c_rtc_base;
 118
 119  retry_get_time:
 120         rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
 121         rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
 122         rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
 123         rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
 124         rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
 125         rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
 126
 127         /* the only way to work out wether the system was mid-update
 128          * when we read it is to check the second counter, and if it
 129          * is zero, then we re-try the entire read
 130          */
 131
 132         if (rtc_tm->tm_sec == 0 && !have_retried) {
 133                 have_retried = 1;
 134                 goto retry_get_time;
 135         }
 136
 137         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 138                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 139                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 140
 141         rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
 142         rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
 143         rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
 144         rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
 145         rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
 146         rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
 147
 148         rtc_tm->tm_year += 100;
 149         rtc_tm->tm_mon -= 1;
 150
 151         return 0;
 152 }
 153
 154 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 155 {
 156         void __iomem *base = s3c_rtc_base;
 157         int year = tm->tm_year - 100;
 158
 159         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 160                  tm->tm_year, tm->tm_mon, tm->tm_mday,
 161                  tm->tm_hour, tm->tm_min, tm->tm_sec);
 162
 163         /* we get around y2k by simply not supporting it */
 164
 165         if (year < 0 || year >= 100) {
 166                 dev_err(dev, "rtc only supports 100 years\n");
 167                 return -EINVAL;
 168         }
 169
 170         writeb(bin2bcd(tm->tm_sec),  base + S3C2410_RTCSEC);
 171         writeb(bin2bcd(tm->tm_min),  base + S3C2410_RTCMIN);
 172         writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
 173         writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
 174         writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
 175         writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
 176
 177         return 0;
 178 }
 179
 180 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 181 {
 182         struct rtc_time *alm_tm = &alrm->time;
 183         void __iomem *base = s3c_rtc_base;
 184         unsigned int alm_en;
 185
 186         alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
 187         alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
 188         alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
 189         alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
 190         alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
 191         alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
 192
 193         alm_en = readb(base + S3C2410_RTCALM);
 194
 195         alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
 196
 197         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 198                  alm_en,
 199                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 200                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 201
 202
 203         /* decode the alarm enable field */
 204
 205         if (alm_en & S3C2410_RTCALM_SECEN)
 206                 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
 207         else
 208                 alm_tm->tm_sec = 0xff;
 209
 210         if (alm_en & S3C2410_RTCALM_MINEN)
 211                 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
 212         else
 213                 alm_tm->tm_min = 0xff;
 214
 215         if (alm_en & S3C2410_RTCALM_HOUREN)
 216                 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
 217         else
 218                 alm_tm->tm_hour = 0xff;
 219
 220         if (alm_en & S3C2410_RTCALM_DAYEN)
 221                 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
 222         else
 223                 alm_tm->tm_mday = 0xff;
 224
 225         if (alm_en & S3C2410_RTCALM_MONEN) {
 226                 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
 227                 alm_tm->tm_mon -= 1;
 228         } else {
 229                 alm_tm->tm_mon = 0xff;
 230         }
 231
 232         if (alm_en & S3C2410_RTCALM_YEAREN)
 233                 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
 234         else
 235                 alm_tm->tm_year = 0xffff;
 236
 237         return 0;
 238 }
 239
 240 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 241 {
 242         struct rtc_time *tm = &alrm->time;
 243         void __iomem *base = s3c_rtc_base;
 244         unsigned int alrm_en;
 245
 246         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
 247                  alrm->enabled,
 248                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
 249                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
 250
 251
 252         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 253         writeb(0x00, base + S3C2410_RTCALM);
 254
 255         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
 256                 alrm_en |= S3C2410_RTCALM_SECEN;
 257                 writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC);
 258         }
 259
 260         if (tm->tm_min < 60 && tm->tm_min >= 0) {
 261                 alrm_en |= S3C2410_RTCALM_MINEN;
 262                 writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN);
 263         }
 264
 265         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
 266                 alrm_en |= S3C2410_RTCALM_HOUREN;
 267                 writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR);
 268         }
 269
 270         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 271
 272         writeb(alrm_en, base + S3C2410_RTCALM);
 273
 274         s3c_rtc_setaie(alrm->enabled);
 275
 276         if (alrm->enabled)
 277                 enable_irq_wake(s3c_rtc_alarmno);
 278         else
 279                 disable_irq_wake(s3c_rtc_alarmno);
 280
 281         return 0;
 282 }
 283
 284 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 285 {
 286         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 287
 288         seq_printf(seq, "periodic_IRQ\t: %s\n",
 289                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 290         return 0;
 291 }
 292
 293 static int s3c_rtc_open(struct device *dev)
 294 {
 295         struct platform_device *pdev = to_platform_device(dev);
 296         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 297         int ret;
 298
 299         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 300                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 301
 302         if (ret) {
 303                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 304                 return ret;
 305         }
 306
 307         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 308                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 309
 310         if (ret) {
 311                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 312                 goto tick_err;
 313         }
 314
 315         return ret;
 316
 317  tick_err:
 318         free_irq(s3c_rtc_alarmno, rtc_dev);
 319         return ret;
 320 }
 321
 322 static void s3c_rtc_release(struct device *dev)
 323 {
 324         struct platform_device *pdev = to_platform_device(dev);
 325         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 326
 327         /* do not clear AIE here, it may be needed for wake */
 328
 329         s3c_rtc_setpie(dev, 0);
 330         free_irq(s3c_rtc_alarmno, rtc_dev);
 331         free_irq(s3c_rtc_tickno, rtc_dev);
 332 }
 333
 334 static const struct rtc_class_ops s3c_rtcops = {
 335         .open           = s3c_rtc_open,
 336         .release        = s3c_rtc_release,
 337         .read_time      = s3c_rtc_gettime,
 338         .set_time       = s3c_rtc_settime,
 339         .read_alarm     = s3c_rtc_getalarm,
 340         .set_alarm      = s3c_rtc_setalarm,
 341         .irq_set_freq   = s3c_rtc_setfreq,
 342         .irq_set_state  = s3c_rtc_setpie,
 343         .proc           = s3c_rtc_proc,
 344 };
 345
 346 static void s3c_rtc_enable(struct platform_device *pdev, int en)
 347 {
 348         void __iomem *base = s3c_rtc_base;
 349         unsigned int tmp;
 350
 351         if (s3c_rtc_base == NULL)
 352                 return;
 353
 354         if (!en) {
 355                 tmp = readb(base + S3C2410_RTCCON);
 356                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 357
 358                 tmp = readb(base + S3C2410_TICNT);
 359                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 360         } else {
 361                 /* re-enable the device, and check it is ok */
 362
 363                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 364                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 365
 366                         tmp = readb(base + S3C2410_RTCCON);
 367                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 368                 }
 369
 370                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 371                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 372
 373                         tmp = readb(base + S3C2410_RTCCON);
 374                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 375                 }
 376
 377                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 378                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 379
 380                         tmp = readb(base + S3C2410_RTCCON);
 381                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 382                 }
 383         }
 384 }
 385
 386 static int __devexit s3c_rtc_remove(struct platform_device *dev)
 387 {
 388         struct rtc_device *rtc = platform_get_drvdata(dev);
 389
 390         platform_set_drvdata(dev, NULL);
 391         rtc_device_unregister(rtc);
 392
 393         s3c_rtc_setpie(&dev->dev, 0);
 394         s3c_rtc_setaie(0);
 395
 396         iounmap(s3c_rtc_base);
 397         release_resource(s3c_rtc_mem);
 398         kfree(s3c_rtc_mem);
 399
 400         return 0;
 401 }
 402
 403 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 404 {
 405         struct rtc_device *rtc;
 406         struct resource *res;
 407         int ret;
 408
 409         pr_debug("%s: probe=%p\n", __func__, pdev);
 410
 411         /* find the IRQs */
 412
 413         s3c_rtc_tickno = platform_get_irq(pdev, 1);
 414         if (s3c_rtc_tickno < 0) {
 415                 dev_err(&pdev->dev, "no irq for rtc tick\n");
 416                 return -ENOENT;
 417         }
 418
 419         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 420         if (s3c_rtc_alarmno < 0) {
 421                 dev_err(&pdev->dev, "no irq for alarm\n");
 422                 return -ENOENT;
 423         }
 424
 425         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 426                  s3c_rtc_tickno, s3c_rtc_alarmno);
 427
 428         /* get the memory region */
 429
 430         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 431         if (res == NULL) {
 432                 dev_err(&pdev->dev, "failed to get memory region resource\n");
 433                 return -ENOENT;
 434         }
 435
 436         s3c_rtc_mem = request_mem_region(res->start,
 437                                          res->end-res->start+1,
 438                                          pdev->name);
 439
 440         if (s3c_rtc_mem == NULL) {
 441                 dev_err(&pdev->dev, "failed to reserve memory region\n");
 442                 ret = -ENOENT;
 443                 goto err_nores;
 444         }
 445
 446         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 447         if (s3c_rtc_base == NULL) {
 448                 dev_err(&pdev->dev, "failed ioremap()\n");
 449                 ret = -EINVAL;
 450                 goto err_nomap;
 451         }
 452
 453         /* check to see if everything is setup correctly */
 454
 455         s3c_rtc_enable(pdev, 1);
 456
 457         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 458                  readb(s3c_rtc_base + S3C2410_RTCCON));
 459
 460         s3c_rtc_setfreq(&pdev->dev, 1);
 461
 462         device_init_wakeup(&pdev->dev, 1);
 463
 464         /* register RTC and exit */
 465
 466         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 467                                   THIS_MODULE);
 468
 469         if (IS_ERR(rtc)) {
 470                 dev_err(&pdev->dev, "cannot attach rtc\n");
 471                 ret = PTR_ERR(rtc);
 472                 goto err_nortc;
 473         }
 474
 475         rtc->max_user_freq = 128;
 476
 477         platform_set_drvdata(pdev, rtc);
 478         return 0;
 479
 480  err_nortc:
 481         s3c_rtc_enable(pdev, 0);
 482         iounmap(s3c_rtc_base);
 483
 484  err_nomap:
 485         release_resource(s3c_rtc_mem);
 486
 487  err_nores:
 488         return ret;
 489 }
 490
 491 #ifdef CONFIG_PM
 492
 493 /* RTC Power management control */
 494
 495 static int ticnt_save;
 496
 497 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 498 {
 499         /* save TICNT for anyone using periodic interrupts */
 500         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 501         s3c_rtc_enable(pdev, 0);
 502         return 0;
 503 }
 504
 505 static int s3c_rtc_resume(struct platform_device *pdev)
 506 {
 507         s3c_rtc_enable(pdev, 1);
 508         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 509         return 0;
 510 }
 511 #else
 512 #define s3c_rtc_suspend NULL
 513 #define s3c_rtc_resume  NULL
 514 #endif
 515
 516 static struct platform_driver s3c2410_rtc_driver = {
 517         .probe          = s3c_rtc_probe,
 518         .remove         = __devexit_p(s3c_rtc_remove),
 519         .suspend        = s3c_rtc_suspend,
 520         .resume         = s3c_rtc_resume,
 521         .driver         = {
 522                 .name   = "s3c2410-rtc",
 523                 .owner  = THIS_MODULE,
 524         },
 525 };
 526
 527 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 528
 529 static int __init s3c_rtc_init(void)
 530 {
 531         printk(banner);
 532         return platform_driver_register(&s3c2410_rtc_driver);
 533 }
 534
 535 static void __exit s3c_rtc_exit(void)
 536 {
 537         platform_driver_unregister(&s3c2410_rtc_driver);
 538 }
 539
 540 module_init(s3c_rtc_init);
 541 module_exit(s3c_rtc_exit);
 542
 543 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 544 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 545 MODULE_LICENSE("GPL");
 546 MODULE_ALIAS("platform:s3c2410-rtc");