linux/drivers/rtc/rtc-s3c.c
<<
>>
Prefs
   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 <mach/hardware.h>
  26#include <asm/uaccess.h>
  27#include <asm/io.h>
  28#include <asm/irq.h>
  29#include <plat/regs-rtc.h>
  30
  31/* I have yet to find an S3C implementation with more than one
  32 * of these rtc blocks in */
  33
  34static struct resource *s3c_rtc_mem;
  35
  36static void __iomem *s3c_rtc_base;
  37static int s3c_rtc_alarmno = NO_IRQ;
  38static int s3c_rtc_tickno  = NO_IRQ;
  39
  40static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
  41
  42/* IRQ Handlers */
  43
  44static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
  45{
  46        struct rtc_device *rdev = id;
  47
  48        rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
  49        return IRQ_HANDLED;
  50}
  51
  52static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
  53{
  54        struct rtc_device *rdev = id;
  55
  56        rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
  57        return IRQ_HANDLED;
  58}
  59
  60/* Update control registers */
  61static void s3c_rtc_setaie(int to)
  62{
  63        unsigned int tmp;
  64
  65        pr_debug("%s: aie=%d\n", __func__, to);
  66
  67        tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
  68
  69        if (to)
  70                tmp |= S3C2410_RTCALM_ALMEN;
  71
  72        writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
  73}
  74
  75static int s3c_rtc_setpie(struct device *dev, int enabled)
  76{
  77        unsigned int tmp;
  78
  79        pr_debug("%s: pie=%d\n", __func__, enabled);
  80
  81        spin_lock_irq(&s3c_rtc_pie_lock);
  82        tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
  83
  84        if (enabled)
  85                tmp |= S3C2410_TICNT_ENABLE;
  86
  87        writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
  88        spin_unlock_irq(&s3c_rtc_pie_lock);
  89
  90        return 0;
  91}
  92
  93static int s3c_rtc_setfreq(struct device *dev, int freq)
  94{
  95        unsigned int tmp;
  96
  97        if (!is_power_of_2(freq))
  98                return -EINVAL;
  99
 100        spin_lock_irq(&s3c_rtc_pie_lock);
 101
 102        tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
 103        tmp |= (128 / freq)-1;
 104
 105        writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
 106        spin_unlock_irq(&s3c_rtc_pie_lock);
 107
 108        return 0;
 109}
 110
 111/* Time read/write */
 112
 113static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
 114{
 115        unsigned int have_retried = 0;
 116        void __iomem *base = s3c_rtc_base;
 117
 118 retry_get_time:
 119        rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
 120        rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
 121        rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
 122        rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
 123        rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
 124        rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
 125
 126        /* the only way to work out wether the system was mid-update
 127         * when we read it is to check the second counter, and if it
 128         * is zero, then we re-try the entire read
 129         */
 130
 131        if (rtc_tm->tm_sec == 0 && !have_retried) {
 132                have_retried = 1;
 133                goto retry_get_time;
 134        }
 135
 136        pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
 137                 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
 138                 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
 139
 140        rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
 141        rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
 142        rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
 143        rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
 144        rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
 145        rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
 146
 147        rtc_tm->tm_year += 100;
 148        rtc_tm->tm_mon -= 1;
 149
 150        return 0;
 151}
 152
 153static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
 154{
 155        void __iomem *base = s3c_rtc_base;
 156        int year = tm->tm_year - 100;
 157
 158        pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
 159                 tm->tm_year, tm->tm_mon, tm->tm_mday,
 160                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 161
 162        /* we get around y2k by simply not supporting it */
 163
 164        if (year < 0 || year >= 100) {
 165                dev_err(dev, "rtc only supports 100 years\n");
 166                return -EINVAL;
 167        }
 168
 169        writeb(bin2bcd(tm->tm_sec),  base + S3C2410_RTCSEC);
 170        writeb(bin2bcd(tm->tm_min),  base + S3C2410_RTCMIN);
 171        writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
 172        writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
 173        writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
 174        writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
 175
 176        return 0;
 177}
 178
 179static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
 180{
 181        struct rtc_time *alm_tm = &alrm->time;
 182        void __iomem *base = s3c_rtc_base;
 183        unsigned int alm_en;
 184
 185        alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
 186        alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
 187        alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
 188        alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
 189        alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
 190        alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
 191
 192        alm_en = readb(base + S3C2410_RTCALM);
 193
 194        alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
 195
 196        pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
 197                 alm_en,
 198                 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
 199                 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
 200
 201
 202        /* decode the alarm enable field */
 203
 204        if (alm_en & S3C2410_RTCALM_SECEN)
 205                alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
 206        else
 207                alm_tm->tm_sec = 0xff;
 208
 209        if (alm_en & S3C2410_RTCALM_MINEN)
 210                alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
 211        else
 212                alm_tm->tm_min = 0xff;
 213
 214        if (alm_en & S3C2410_RTCALM_HOUREN)
 215                alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
 216        else
 217                alm_tm->tm_hour = 0xff;
 218
 219        if (alm_en & S3C2410_RTCALM_DAYEN)
 220                alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
 221        else
 222                alm_tm->tm_mday = 0xff;
 223
 224        if (alm_en & S3C2410_RTCALM_MONEN) {
 225                alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
 226                alm_tm->tm_mon -= 1;
 227        } else {
 228                alm_tm->tm_mon = 0xff;
 229        }
 230
 231        if (alm_en & S3C2410_RTCALM_YEAREN)
 232                alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
 233        else
 234                alm_tm->tm_year = 0xffff;
 235
 236        return 0;
 237}
 238
 239static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 240{
 241        struct rtc_time *tm = &alrm->time;
 242        void __iomem *base = s3c_rtc_base;
 243        unsigned int alrm_en;
 244
 245        pr_debug("s3c_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
 251        alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
 252        writeb(0x00, base + 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), base + 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), base + 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), base + S3C2410_ALMHOUR);
 267        }
 268
 269        pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
 270
 271        writeb(alrm_en, base + S3C2410_RTCALM);
 272
 273        s3c_rtc_setaie(alrm->enabled);
 274
 275        if (alrm->enabled)
 276                enable_irq_wake(s3c_rtc_alarmno);
 277        else
 278                disable_irq_wake(s3c_rtc_alarmno);
 279
 280        return 0;
 281}
 282
 283static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 284{
 285        unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
 286
 287        seq_printf(seq, "periodic_IRQ\t: %s\n",
 288                     (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
 289        return 0;
 290}
 291
 292static int s3c_rtc_open(struct device *dev)
 293{
 294        struct platform_device *pdev = to_platform_device(dev);
 295        struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 296        int ret;
 297
 298        ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
 299                          IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
 300
 301        if (ret) {
 302                dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
 303                return ret;
 304        }
 305
 306        ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
 307                          IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
 308
 309        if (ret) {
 310                dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
 311                goto tick_err;
 312        }
 313
 314        return ret;
 315
 316 tick_err:
 317        free_irq(s3c_rtc_alarmno, rtc_dev);
 318        return ret;
 319}
 320
 321static void s3c_rtc_release(struct device *dev)
 322{
 323        struct platform_device *pdev = to_platform_device(dev);
 324        struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
 325
 326        /* do not clear AIE here, it may be needed for wake */
 327
 328        s3c_rtc_setpie(dev, 0);
 329        free_irq(s3c_rtc_alarmno, rtc_dev);
 330        free_irq(s3c_rtc_tickno, rtc_dev);
 331}
 332
 333static const struct rtc_class_ops s3c_rtcops = {
 334        .open           = s3c_rtc_open,
 335        .release        = s3c_rtc_release,
 336        .read_time      = s3c_rtc_gettime,
 337        .set_time       = s3c_rtc_settime,
 338        .read_alarm     = s3c_rtc_getalarm,
 339        .set_alarm      = s3c_rtc_setalarm,
 340        .irq_set_freq   = s3c_rtc_setfreq,
 341        .irq_set_state  = s3c_rtc_setpie,
 342        .proc           = s3c_rtc_proc,
 343};
 344
 345static void s3c_rtc_enable(struct platform_device *pdev, int en)
 346{
 347        void __iomem *base = s3c_rtc_base;
 348        unsigned int tmp;
 349
 350        if (s3c_rtc_base == NULL)
 351                return;
 352
 353        if (!en) {
 354                tmp = readb(base + S3C2410_RTCCON);
 355                writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
 356
 357                tmp = readb(base + S3C2410_TICNT);
 358                writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
 359        } else {
 360                /* re-enable the device, and check it is ok */
 361
 362                if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
 363                        dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
 364
 365                        tmp = readb(base + S3C2410_RTCCON);
 366                        writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
 367                }
 368
 369                if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
 370                        dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
 371
 372                        tmp = readb(base + S3C2410_RTCCON);
 373                        writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
 374                }
 375
 376                if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
 377                        dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
 378
 379                        tmp = readb(base + S3C2410_RTCCON);
 380                        writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
 381                }
 382        }
 383}
 384
 385static int __devexit s3c_rtc_remove(struct platform_device *dev)
 386{
 387        struct rtc_device *rtc = platform_get_drvdata(dev);
 388
 389        platform_set_drvdata(dev, NULL);
 390        rtc_device_unregister(rtc);
 391
 392        s3c_rtc_setpie(&dev->dev, 0);
 393        s3c_rtc_setaie(0);
 394
 395        iounmap(s3c_rtc_base);
 396        release_resource(s3c_rtc_mem);
 397        kfree(s3c_rtc_mem);
 398
 399        return 0;
 400}
 401
 402static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 403{
 404        struct rtc_device *rtc;
 405        struct resource *res;
 406        int ret;
 407
 408        pr_debug("%s: probe=%p\n", __func__, pdev);
 409
 410        /* find the IRQs */
 411
 412        s3c_rtc_tickno = platform_get_irq(pdev, 1);
 413        if (s3c_rtc_tickno < 0) {
 414                dev_err(&pdev->dev, "no irq for rtc tick\n");
 415                return -ENOENT;
 416        }
 417
 418        s3c_rtc_alarmno = platform_get_irq(pdev, 0);
 419        if (s3c_rtc_alarmno < 0) {
 420                dev_err(&pdev->dev, "no irq for alarm\n");
 421                return -ENOENT;
 422        }
 423
 424        pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
 425                 s3c_rtc_tickno, s3c_rtc_alarmno);
 426
 427        /* get the memory region */
 428
 429        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 430        if (res == NULL) {
 431                dev_err(&pdev->dev, "failed to get memory region resource\n");
 432                return -ENOENT;
 433        }
 434
 435        s3c_rtc_mem = request_mem_region(res->start,
 436                                         res->end-res->start+1,
 437                                         pdev->name);
 438
 439        if (s3c_rtc_mem == NULL) {
 440                dev_err(&pdev->dev, "failed to reserve memory region\n");
 441                ret = -ENOENT;
 442                goto err_nores;
 443        }
 444
 445        s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
 446        if (s3c_rtc_base == NULL) {
 447                dev_err(&pdev->dev, "failed ioremap()\n");
 448                ret = -EINVAL;
 449                goto err_nomap;
 450        }
 451
 452        /* check to see if everything is setup correctly */
 453
 454        s3c_rtc_enable(pdev, 1);
 455
 456        pr_debug("s3c2410_rtc: RTCCON=%02x\n",
 457                 readb(s3c_rtc_base + S3C2410_RTCCON));
 458
 459        s3c_rtc_setfreq(&pdev->dev, 1);
 460
 461        device_init_wakeup(&pdev->dev, 1);
 462
 463        /* register RTC and exit */
 464
 465        rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
 466                                  THIS_MODULE);
 467
 468        if (IS_ERR(rtc)) {
 469                dev_err(&pdev->dev, "cannot attach rtc\n");
 470                ret = PTR_ERR(rtc);
 471                goto err_nortc;
 472        }
 473
 474        rtc->max_user_freq = 128;
 475
 476        platform_set_drvdata(pdev, rtc);
 477        return 0;
 478
 479 err_nortc:
 480        s3c_rtc_enable(pdev, 0);
 481        iounmap(s3c_rtc_base);
 482
 483 err_nomap:
 484        release_resource(s3c_rtc_mem);
 485
 486 err_nores:
 487        return ret;
 488}
 489
 490#ifdef CONFIG_PM
 491
 492/* RTC Power management control */
 493
 494static int ticnt_save;
 495
 496static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 497{
 498        /* save TICNT for anyone using periodic interrupts */
 499        ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
 500        s3c_rtc_enable(pdev, 0);
 501        return 0;
 502}
 503
 504static int s3c_rtc_resume(struct platform_device *pdev)
 505{
 506        s3c_rtc_enable(pdev, 1);
 507        writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
 508        return 0;
 509}
 510#else
 511#define s3c_rtc_suspend NULL
 512#define s3c_rtc_resume  NULL
 513#endif
 514
 515static struct platform_driver s3c2410_rtc_driver = {
 516        .probe          = s3c_rtc_probe,
 517        .remove         = __devexit_p(s3c_rtc_remove),
 518        .suspend        = s3c_rtc_suspend,
 519        .resume         = s3c_rtc_resume,
 520        .driver         = {
 521                .name   = "s3c2410-rtc",
 522                .owner  = THIS_MODULE,
 523        },
 524};
 525
 526static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
 527
 528static int __init s3c_rtc_init(void)
 529{
 530        printk(banner);
 531        return platform_driver_register(&s3c2410_rtc_driver);
 532}
 533
 534static void __exit s3c_rtc_exit(void)
 535{
 536        platform_driver_unregister(&s3c2410_rtc_driver);
 537}
 538
 539module_init(s3c_rtc_init);
 540module_exit(s3c_rtc_exit);
 541
 542MODULE_DESCRIPTION("Samsung S3C RTC Driver");
 543MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 544MODULE_LICENSE("GPL");
 545MODULE_ALIAS("platform:s3c2410-rtc");
 546