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
  31 #include <asm/uaccess.h>
  32
  33 #include <mach/at91_rtc.h>
  34
  35 #define at91_rtc_read(field) \
  36         __raw_readl(at91_rtc_regs + field)
  37 #define at91_rtc_write(field, val) \
  38         __raw_writel((val), at91_rtc_regs + field)
  39
  40 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  41
  42 static DECLARE_COMPLETION(at91_rtc_updated);
  43 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  44 static void __iomem *at91_rtc_regs;
  45 static int irq;
  46
  47 /*
  48  * Decode time/date into rtc_time structure
  49  */
  50 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  51                                 struct rtc_time *tm)
  52 {
  53         unsigned int time, date;
  54
  55         /* must read twice in case it changes */
  56         do {
  57                 time = at91_rtc_read(timereg);
  58                 date = at91_rtc_read(calreg);
  59         } while ((time != at91_rtc_read(timereg)) ||
  60                         (date != at91_rtc_read(calreg)));
  61
  62         tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  63         tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  64         tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  65
  66         /*
  67          * The Calendar Alarm register does not have a field for
  68          * the year - so these will return an invalid value.  When an
  69          * alarm is set, at91_alarm_year will store the current year.
  70          */
  71         tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  72         tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  73
  74         tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  75         tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  76         tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  77 }
  78
  79 /*
  80  * Read current time and date in RTC
  81  */
  82 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  83 {
  84         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  85         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  86         tm->tm_year = tm->tm_year - 1900;
  87
  88         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  89                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  90                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  91
  92         return 0;
  93 }
  94
  95 /*
  96  * Set current time and date in RTC
  97  */
  98 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  99 {
 100         unsigned long cr;
 101
 102         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 103                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 104                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 105
 106         /* Stop Time/Calendar from counting */
 107         cr = at91_rtc_read(AT91_RTC_CR);
 108         at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 109
 110         at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 111         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 112         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 113
 114         at91_rtc_write(AT91_RTC_TIMR,
 115                           bin2bcd(tm->tm_sec) << 0
 116                         | bin2bcd(tm->tm_min) << 8
 117                         | bin2bcd(tm->tm_hour) << 16);
 118
 119         at91_rtc_write(AT91_RTC_CALR,
 120                           bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 121                         | bin2bcd(tm->tm_year % 100) << 8       /* year */
 122                         | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 123                         | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 124                         | bin2bcd(tm->tm_mday) << 24);
 125
 126         /* Restart Time/Calendar */
 127         cr = at91_rtc_read(AT91_RTC_CR);
 128         at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 129
 130         return 0;
 131 }
 132
 133 /*
 134  * Read alarm time and date in RTC
 135  */
 136 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 137 {
 138         struct rtc_time *tm = &alrm->time;
 139
 140         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 141         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 142         tm->tm_year = at91_alarm_year - 1900;
 143
 144         alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 145                         ? 1 : 0;
 146
 147         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 148                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 149                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 150
 151         return 0;
 152 }
 153
 154 /*
 155  * Set alarm time and date in RTC
 156  */
 157 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 158 {
 159         struct rtc_time tm;
 160
 161         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 162
 163         at91_alarm_year = tm.tm_year;
 164
 165         tm.tm_hour = alrm->time.tm_hour;
 166         tm.tm_min = alrm->time.tm_min;
 167         tm.tm_sec = alrm->time.tm_sec;
 168
 169         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 170         at91_rtc_write(AT91_RTC_TIMALR,
 171                   bin2bcd(tm.tm_sec) << 0
 172                 | bin2bcd(tm.tm_min) << 8
 173                 | bin2bcd(tm.tm_hour) << 16
 174                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 175         at91_rtc_write(AT91_RTC_CALALR,
 176                   bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 177                 | bin2bcd(tm.tm_mday) << 24
 178                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 179
 180         if (alrm->enabled) {
 181                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 182                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 183         }
 184
 185         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 186                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 187                 tm.tm_min, tm.tm_sec);
 188
 189         return 0;
 190 }
 191
 192 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 193 {
 194         pr_debug("%s(): cmd=%08x\n", __func__, enabled);
 195
 196         if (enabled) {
 197                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 198                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 199         } else
 200                 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 201
 202         return 0;
 203 }
 204 /*
 205  * Provide additional RTC information in /proc/driver/rtc
 206  */
 207 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 208 {
 209         unsigned long imr = at91_rtc_read(AT91_RTC_IMR);
 210
 211         seq_printf(seq, "update_IRQ\t: %s\n",
 212                         (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 213         seq_printf(seq, "periodic_IRQ\t: %s\n",
 214                         (imr & AT91_RTC_SECEV) ? "yes" : "no");
 215
 216         return 0;
 217 }
 218
 219 /*
 220  * IRQ handler for the RTC
 221  */
 222 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 223 {
 224         struct platform_device *pdev = dev_id;
 225         struct rtc_device *rtc = platform_get_drvdata(pdev);
 226         unsigned int rtsr;
 227         unsigned long events = 0;
 228
 229         rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
 230         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 231                 if (rtsr & AT91_RTC_ALARM)
 232                         events |= (RTC_AF | RTC_IRQF);
 233                 if (rtsr & AT91_RTC_SECEV)
 234                         events |= (RTC_UF | RTC_IRQF);
 235                 if (rtsr & AT91_RTC_ACKUPD)
 236                         complete(&at91_rtc_updated);
 237
 238                 at91_rtc_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 239
 240                 rtc_update_irq(rtc, 1, events);
 241
 242                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
 243                         events >> 8, events & 0x000000FF);
 244
 245                 return IRQ_HANDLED;
 246         }
 247         return IRQ_NONE;                /* not handled */
 248 }
 249
 250 static const struct rtc_class_ops at91_rtc_ops = {
 251         .read_time      = at91_rtc_readtime,
 252         .set_time       = at91_rtc_settime,
 253         .read_alarm     = at91_rtc_readalarm,
 254         .set_alarm      = at91_rtc_setalarm,
 255         .proc           = at91_rtc_proc,
 256         .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 257 };
 258
 259 /*
 260  * Initialize and install RTC driver
 261  */
 262 static int __init at91_rtc_probe(struct platform_device *pdev)
 263 {
 264         struct rtc_device *rtc;
 265         struct resource *regs;
 266         int ret = 0;
 267
 268         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 269         if (!regs) {
 270                 dev_err(&pdev->dev, "no mmio resource defined\n");
 271                 return -ENXIO;
 272         }
 273
 274         irq = platform_get_irq(pdev, 0);
 275         if (irq < 0) {
 276                 dev_err(&pdev->dev, "no irq resource defined\n");
 277                 return -ENXIO;
 278         }
 279
 280         at91_rtc_regs = ioremap(regs->start, resource_size(regs));
 281         if (!at91_rtc_regs) {
 282                 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
 283                 return -ENOMEM;
 284         }
 285
 286         at91_rtc_write(AT91_RTC_CR, 0);
 287         at91_rtc_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 288
 289         /* Disable all interrupts */
 290         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 291                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 292                                         AT91_RTC_CALEV);
 293
 294         ret = request_irq(irq, at91_rtc_interrupt,
 295                                 IRQF_SHARED,
 296                                 "at91_rtc", pdev);
 297         if (ret) {
 298                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 299                                 irq);
 300                 return ret;
 301         }
 302
 303         /* cpu init code should really have flagged this device as
 304          * being wake-capable; if it didn't, do that here.
 305          */
 306         if (!device_can_wakeup(&pdev->dev))
 307                 device_init_wakeup(&pdev->dev, 1);
 308
 309         rtc = rtc_device_register(pdev->name, &pdev->dev,
 310                                 &at91_rtc_ops, THIS_MODULE);
 311         if (IS_ERR(rtc)) {
 312                 free_irq(irq, pdev);
 313                 return PTR_ERR(rtc);
 314         }
 315         platform_set_drvdata(pdev, rtc);
 316
 317         printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 318         return 0;
 319 }
 320
 321 /*
 322  * Disable and remove the RTC driver
 323  */
 324 static int __exit at91_rtc_remove(struct platform_device *pdev)
 325 {
 326         struct rtc_device *rtc = platform_get_drvdata(pdev);
 327
 328         /* Disable all interrupts */
 329         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 330                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 331                                         AT91_RTC_CALEV);
 332         free_irq(irq, pdev);
 333
 334         rtc_device_unregister(rtc);
 335         platform_set_drvdata(pdev, NULL);
 336
 337         return 0;
 338 }
 339
 340 #ifdef CONFIG_PM
 341
 342 /* AT91RM9200 RTC Power management control */
 343
 344 static u32 at91_rtc_imr;
 345
 346 static int at91_rtc_suspend(struct device *dev)
 347 {
 348         /* this IRQ is shared with DBGU and other hardware which isn't
 349          * necessarily doing PM like we are...
 350          */
 351         at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
 352                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 353         if (at91_rtc_imr) {
 354                 if (device_may_wakeup(dev))
 355                         enable_irq_wake(irq);
 356                 else
 357                         at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
 358         }
 359         return 0;
 360 }
 361
 362 static int at91_rtc_resume(struct device *dev)
 363 {
 364         if (at91_rtc_imr) {
 365                 if (device_may_wakeup(dev))
 366                         disable_irq_wake(irq);
 367                 else
 368                         at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
 369         }
 370         return 0;
 371 }
 372
 373 static const struct dev_pm_ops at91_rtc_pm = {
 374         .suspend =      at91_rtc_suspend,
 375         .resume =       at91_rtc_resume,
 376 };
 377
 378 #define at91_rtc_pm_ptr &at91_rtc_pm
 379
 380 #else
 381 #define at91_rtc_pm_ptr NULL
 382 #endif
 383
 384 static struct platform_driver at91_rtc_driver = {
 385         .remove         = __exit_p(at91_rtc_remove),
 386         .driver         = {
 387                 .name   = "at91_rtc",
 388                 .owner  = THIS_MODULE,
 389                 .pm     = at91_rtc_pm_ptr,
 390         },
 391 };
 392
 393 static int __init at91_rtc_init(void)
 394 {
 395         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 396 }
 397
 398 static void __exit at91_rtc_exit(void)
 399 {
 400         platform_driver_unregister(&at91_rtc_driver);
 401 }
 402
 403 module_init(at91_rtc_init);
 404 module_exit(at91_rtc_exit);
 405
 406 MODULE_AUTHOR("Rick Bronson");
 407 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 408 MODULE_LICENSE("GPL");
 409 MODULE_ALIAS("platform:at91_rtc");