drivers/rtc/rtc-at91rm9200.c

   1 /*
   2  *      Real Time Clock interface for Linux on Atmel AT91RM9200
   3  *
   4  *      Copyright (C) 2002 Rick Bronson
   5  *
   6  *      Converted to RTC class model by Andrew Victor
   7  *
   8  *      Ported to Linux 2.6 by Steven Scholz
   9  *      Based on s3c2410-rtc.c Simtec Electronics
  10  *
  11  *      Based on sa1100-rtc.c by Nils Faerber
  12  *      Based on rtc.c by Paul Gortmaker
  13  *
  14  *      This program is free software; you can redistribute it and/or
  15  *      modify it under the terms of the GNU General Public License
  16  *      as published by the Free Software Foundation; either version
  17  *      2 of the License, or (at your option) any later version.
  18  *
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/time.h>
  25 #include <linux/rtc.h>
  26 #include <linux/bcd.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/ioctl.h>
  29 #include <linux/completion.h>
  30 #include <linux/io.h>
  31
  32 #include <asm/uaccess.h>
  33
  34 #include "rtc-at91rm9200.h"
  35
  36 #define at91_rtc_read(field) \
  37         __raw_readl(at91_rtc_regs + field)
  38 #define at91_rtc_write(field, val) \
  39         __raw_writel((val), at91_rtc_regs + field)
  40
  41 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  42
  43 static DECLARE_COMPLETION(at91_rtc_updated);
  44 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  45 static void __iomem *at91_rtc_regs;
  46 static int irq;
  47 static u32 at91_rtc_imr;
  48
  49 /*
  50  * Decode time/date into rtc_time structure
  51  */
  52 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  53                                 struct rtc_time *tm)
  54 {
  55         unsigned int time, date;
  56
  57         /* must read twice in case it changes */
  58         do {
  59                 time = at91_rtc_read(timereg);
  60                 date = at91_rtc_read(calreg);
  61         } while ((time != at91_rtc_read(timereg)) ||
  62                         (date != at91_rtc_read(calreg)));
  63
  64         tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  65         tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  66         tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  67
  68         /*
  69          * The Calendar Alarm register does not have a field for
  70          * the year - so these will return an invalid value.  When an
  71          * alarm is set, at91_alarm_year will store the current year.
  72          */
  73         tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  74         tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  75
  76         tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  77         tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  78         tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  79 }
  80
  81 /*
  82  * Read current time and date in RTC
  83  */
  84 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  85 {
  86         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  87         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  88         tm->tm_year = tm->tm_year - 1900;
  89
  90         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  91                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  92                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  93
  94         return 0;
  95 }
  96
  97 /*
  98  * Set current time and date in RTC
  99  */
 100 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
 101 {
 102         unsigned long cr;
 103
 104         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 105                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 106                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 107
 108         /* Stop Time/Calendar from counting */
 109         cr = at91_rtc_read(AT91_RTC_CR);
 110         at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 111
 112         at91_rtc_imr |= AT91_RTC_ACKUPD;
 113         at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 114         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 115         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 116         at91_rtc_imr &= ~AT91_RTC_ACKUPD;
 117
 118         at91_rtc_write(AT91_RTC_TIMR,
 119                           bin2bcd(tm->tm_sec) << 0
 120                         | bin2bcd(tm->tm_min) << 8
 121                         | bin2bcd(tm->tm_hour) << 16);
 122
 123         at91_rtc_write(AT91_RTC_CALR,
 124                           bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 125                         | bin2bcd(tm->tm_year % 100) << 8       /* year */
 126                         | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 127                         | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 128                         | bin2bcd(tm->tm_mday) << 24);
 129
 130         /* Restart Time/Calendar */
 131         cr = at91_rtc_read(AT91_RTC_CR);
 132         at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 133
 134         return 0;
 135 }
 136
 137 /*
 138  * Read alarm time and date in RTC
 139  */
 140 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 141 {
 142         struct rtc_time *tm = &alrm->time;
 143
 144         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 145         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 146         tm->tm_year = at91_alarm_year - 1900;
 147
 148         alrm->enabled = (at91_rtc_imr & AT91_RTC_ALARM)
 149                         ? 1 : 0;
 150
 151         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 152                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 153                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 154
 155         return 0;
 156 }
 157
 158 /*
 159  * Set alarm time and date in RTC
 160  */
 161 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 162 {
 163         struct rtc_time tm;
 164
 165         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 166
 167         at91_alarm_year = tm.tm_year;
 168
 169         tm.tm_hour = alrm->time.tm_hour;
 170         tm.tm_min = alrm->time.tm_min;
 171         tm.tm_sec = alrm->time.tm_sec;
 172
 173         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 174         at91_rtc_imr &= ~AT91_RTC_ALARM;
 175         at91_rtc_write(AT91_RTC_TIMALR,
 176                   bin2bcd(tm.tm_sec) << 0
 177                 | bin2bcd(tm.tm_min) << 8
 178                 | bin2bcd(tm.tm_hour) << 16
 179                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 180         at91_rtc_write(AT91_RTC_CALALR,
 181                   bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 182                 | bin2bcd(tm.tm_mday) << 24
 183                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 184
 185         if (alrm->enabled) {
 186                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 187                 at91_rtc_imr |= AT91_RTC_ALARM;
 188                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 189         }
 190
 191         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 192                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 193                 tm.tm_min, tm.tm_sec);
 194
 195         return 0;
 196 }
 197
 198 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 199 {
 200         dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
 201
 202         if (enabled) {
 203                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 204                 at91_rtc_imr |= AT91_RTC_ALARM;
 205                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 206         } else {
 207                 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 208                 at91_rtc_imr &= ~AT91_RTC_ALARM;
 209         }
 210
 211         return 0;
 212 }
 213 /*
 214  * Provide additional RTC information in /proc/driver/rtc
 215  */
 216 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 217 {
 218         seq_printf(seq, "update_IRQ\t: %s\n",
 219                         (at91_rtc_imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 220         seq_printf(seq, "periodic_IRQ\t: %s\n",
 221                         (at91_rtc_imr & AT91_RTC_SECEV) ? "yes" : "no");
 222
 223         return 0;
 224 }
 225
 226 /*
 227  * IRQ handler for the RTC
 228  */
 229 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 230 {
 231         struct platform_device *pdev = dev_id;
 232         struct rtc_device *rtc = platform_get_drvdata(pdev);
 233         unsigned int rtsr;
 234         unsigned long events = 0;
 235
 236         rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_imr;
 237         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 238                 if (rtsr & AT91_RTC_ALARM)
 239                         events |= (RTC_AF | RTC_IRQF);
 240                 if (rtsr & AT91_RTC_SECEV)
 241                         events |= (RTC_UF | RTC_IRQF);
 242                 if (rtsr & AT91_RTC_ACKUPD)
 243                         complete(&at91_rtc_updated);
 244
 245                 at91_rtc_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 246
 247                 rtc_update_irq(rtc, 1, events);
 248
 249                 dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__,
 250                         events >> 8, events & 0x000000FF);
 251
 252                 return IRQ_HANDLED;
 253         }
 254         return IRQ_NONE;                /* not handled */
 255 }
 256
 257 static const struct rtc_class_ops at91_rtc_ops = {
 258         .read_time      = at91_rtc_readtime,
 259         .set_time       = at91_rtc_settime,
 260         .read_alarm     = at91_rtc_readalarm,
 261         .set_alarm      = at91_rtc_setalarm,
 262         .proc           = at91_rtc_proc,
 263         .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 264 };
 265
 266 /*
 267  * Initialize and install RTC driver
 268  */
 269 static int __init at91_rtc_probe(struct platform_device *pdev)
 270 {
 271         struct rtc_device *rtc;
 272         struct resource *regs;
 273         int ret = 0;
 274
 275         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 276         if (!regs) {
 277                 dev_err(&pdev->dev, "no mmio resource defined\n");
 278                 return -ENXIO;
 279         }
 280
 281         irq = platform_get_irq(pdev, 0);
 282         if (irq < 0) {
 283                 dev_err(&pdev->dev, "no irq resource defined\n");
 284                 return -ENXIO;
 285         }
 286
 287         at91_rtc_regs = ioremap(regs->start, resource_size(regs));
 288         if (!at91_rtc_regs) {
 289                 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
 290                 return -ENOMEM;
 291         }
 292
 293         at91_rtc_write(AT91_RTC_CR, 0);
 294         at91_rtc_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 295
 296         /* Disable all interrupts */
 297         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 298                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 299                                         AT91_RTC_CALEV);
 300         at91_rtc_imr = 0;
 301
 302         ret = request_irq(irq, at91_rtc_interrupt,
 303                                 IRQF_SHARED,
 304                                 "at91_rtc", pdev);
 305         if (ret) {
 306                 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
 307                 return ret;
 308         }
 309
 310         /* cpu init code should really have flagged this device as
 311          * being wake-capable; if it didn't, do that here.
 312          */
 313         if (!device_can_wakeup(&pdev->dev))
 314                 device_init_wakeup(&pdev->dev, 1);
 315
 316         rtc = rtc_device_register(pdev->name, &pdev->dev,
 317                                 &at91_rtc_ops, THIS_MODULE);
 318         if (IS_ERR(rtc)) {
 319                 free_irq(irq, pdev);
 320                 return PTR_ERR(rtc);
 321         }
 322         platform_set_drvdata(pdev, rtc);
 323
 324         dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
 325         return 0;
 326 }
 327
 328 /*
 329  * Disable and remove the RTC driver
 330  */
 331 static int __exit at91_rtc_remove(struct platform_device *pdev)
 332 {
 333         struct rtc_device *rtc = platform_get_drvdata(pdev);
 334
 335         /* Disable all interrupts */
 336         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 337                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 338                                         AT91_RTC_CALEV);
 339         at91_rtc_imr = 0;
 340         free_irq(irq, pdev);
 341
 342         rtc_device_unregister(rtc);
 343         platform_set_drvdata(pdev, NULL);
 344
 345         return 0;
 346 }
 347
 348 #ifdef CONFIG_PM
 349
 350 /* AT91RM9200 RTC Power management control */
 351
 352 static u32 at91_rtc_bkpimr;
 353
 354
 355 static int at91_rtc_suspend(struct device *dev)
 356 {
 357         /* this IRQ is shared with DBGU and other hardware which isn't
 358          * necessarily doing PM like we are...
 359          */
 360         at91_rtc_bkpimr = at91_rtc_imr & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 361         if (at91_rtc_bkpimr) {
 362                 if (device_may_wakeup(dev)) {
 363                         enable_irq_wake(irq);
 364                 } else {
 365                         at91_rtc_write(AT91_RTC_IDR, at91_rtc_bkpimr);
 366                         at91_rtc_imr &= ~at91_rtc_bkpimr;
 367                 }
 368 }
 369         return 0;
 370 }
 371
 372 static int at91_rtc_resume(struct device *dev)
 373 {
 374         if (at91_rtc_bkpimr) {
 375                 if (device_may_wakeup(dev)) {
 376                         disable_irq_wake(irq);
 377                 } else {
 378                         at91_rtc_imr |= at91_rtc_bkpimr;
 379                         at91_rtc_write(AT91_RTC_IER, at91_rtc_bkpimr);
 380                 }
 381         }
 382         return 0;
 383 }
 384
 385 static const struct dev_pm_ops at91_rtc_pm = {
 386         .suspend =      at91_rtc_suspend,
 387         .resume =       at91_rtc_resume,
 388 };
 389
 390 #define at91_rtc_pm_ptr &at91_rtc_pm
 391
 392 #else
 393 #define at91_rtc_pm_ptr NULL
 394 #endif
 395
 396 static struct platform_driver at91_rtc_driver = {
 397         .remove         = __exit_p(at91_rtc_remove),
 398         .driver         = {
 399                 .name   = "at91_rtc",
 400                 .owner  = THIS_MODULE,
 401                 .pm     = at91_rtc_pm_ptr,
 402         },
 403 };
 404
 405 static int __init at91_rtc_init(void)
 406 {
 407         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 408 }
 409
 410 static void __exit at91_rtc_exit(void)
 411 {
 412         platform_driver_unregister(&at91_rtc_driver);
 413 }
 414
 415 module_init(at91_rtc_init);
 416 module_exit(at91_rtc_exit);
 417
 418 MODULE_AUTHOR("Rick Bronson");
 419 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 420 MODULE_LICENSE("GPL");
 421 MODULE_ALIAS("platform:at91_rtc");