drivers/rtc/rtc-at91.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 #include <asm/rtc.h>
  33
  34 #include <asm/mach/time.h>
  35
  36
  37 #define AT91_RTC_FREQ           1
  38 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  39
  40 static DECLARE_COMPLETION(at91_rtc_updated);
  41 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  42
  43 /*
  44  * Decode time/date into rtc_time structure
  45  */
  46 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  47                                 struct rtc_time *tm)
  48 {
  49         unsigned int time, date;
  50
  51         /* must read twice in case it changes */
  52         do {
  53                 time = at91_sys_read(timereg);
  54                 date = at91_sys_read(calreg);
  55         } while ((time != at91_sys_read(timereg)) ||
  56                         (date != at91_sys_read(calreg)));
  57
  58         tm->tm_sec  = BCD2BIN((time & AT91_RTC_SEC) >> 0);
  59         tm->tm_min  = BCD2BIN((time & AT91_RTC_MIN) >> 8);
  60         tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
  61
  62         /*
  63          * The Calendar Alarm register does not have a field for
  64          * the year - so these will return an invalid value.  When an
  65          * alarm is set, at91_alarm_year wille store the current year.
  66          */
  67         tm->tm_year  = BCD2BIN(date & AT91_RTC_CENT) * 100;     /* century */
  68         tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8);    /* year */
  69
  70         tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  71         tm->tm_mon  = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
  72         tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
  73 }
  74
  75 /*
  76  * Read current time and date in RTC
  77  */
  78 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  79 {
  80         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  81         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  82         tm->tm_year = tm->tm_year - 1900;
  83
  84         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
  85                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  86                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  87
  88         return 0;
  89 }
  90
  91 /*
  92  * Set current time and date in RTC
  93  */
  94 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  95 {
  96         unsigned long cr;
  97
  98         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
  99                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 100                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 101
 102         /* Stop Time/Calendar from counting */
 103         cr = at91_sys_read(AT91_RTC_CR);
 104         at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 105
 106         at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 107         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 108         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 109
 110         at91_sys_write(AT91_RTC_TIMR,
 111                           BIN2BCD(tm->tm_sec) << 0
 112                         | BIN2BCD(tm->tm_min) << 8
 113                         | BIN2BCD(tm->tm_hour) << 16);
 114
 115         at91_sys_write(AT91_RTC_CALR,
 116                           BIN2BCD((tm->tm_year + 1900) / 100)   /* century */
 117                         | BIN2BCD(tm->tm_year % 100) << 8       /* year */
 118                         | BIN2BCD(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 119                         | BIN2BCD(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 120                         | BIN2BCD(tm->tm_mday) << 24);
 121
 122         /* Restart Time/Calendar */
 123         cr = at91_sys_read(AT91_RTC_CR);
 124         at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 125
 126         return 0;
 127 }
 128
 129 /*
 130  * Read alarm time and date in RTC
 131  */
 132 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 133 {
 134         struct rtc_time *tm = &alrm->time;
 135
 136         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 137         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 138         tm->tm_year = at91_alarm_year - 1900;
 139
 140         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 141                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 142                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 143
 144         return 0;
 145 }
 146
 147 /*
 148  * Set alarm time and date in RTC
 149  */
 150 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 151 {
 152         struct rtc_time tm;
 153
 154         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 155
 156         at91_alarm_year = tm.tm_year;
 157
 158         tm.tm_hour = alrm->time.tm_hour;
 159         tm.tm_min = alrm->time.tm_min;
 160         tm.tm_sec = alrm->time.tm_sec;
 161
 162         at91_sys_write(AT91_RTC_TIMALR,
 163                   BIN2BCD(tm.tm_sec) << 0
 164                 | BIN2BCD(tm.tm_min) << 8
 165                 | BIN2BCD(tm.tm_hour) << 16
 166                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 167         at91_sys_write(AT91_RTC_CALALR,
 168                   BIN2BCD(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 169                 | BIN2BCD(tm.tm_mday) << 24
 170                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 171
 172         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 173                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 174                 tm.tm_min, tm.tm_sec);
 175
 176         return 0;
 177 }
 178
 179 /*
 180  * Handle commands from user-space
 181  */
 182 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
 183                         unsigned long arg)
 184 {
 185         int ret = 0;
 186
 187         pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
 188
 189         switch (cmd) {
 190         case RTC_AIE_OFF:       /* alarm off */
 191                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 192                 break;
 193         case RTC_AIE_ON:        /* alarm on */
 194                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 195                 break;
 196         case RTC_UIE_OFF:       /* update off */
 197         case RTC_PIE_OFF:       /* periodic off */
 198                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
 199                 break;
 200         case RTC_UIE_ON:        /* update on */
 201         case RTC_PIE_ON:        /* periodic on */
 202                 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 203                 break;
 204         case RTC_IRQP_READ:     /* read periodic alarm frequency */
 205                 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
 206                 break;
 207         case RTC_IRQP_SET:      /* set periodic alarm frequency */
 208                 if (arg != AT91_RTC_FREQ)
 209                         ret = -EINVAL;
 210                 break;
 211         default:
 212                 ret = -ENOIOCTLCMD;
 213                 break;
 214         }
 215
 216         return ret;
 217 }
 218
 219 /*
 220  * Provide additional RTC information in /proc/driver/rtc
 221  */
 222 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 223 {
 224         unsigned long imr = at91_sys_read(AT91_RTC_IMR);
 225
 226         seq_printf(seq, "alarm_IRQ\t: %s\n",
 227                         (imr & AT91_RTC_ALARM) ? "yes" : "no");
 228         seq_printf(seq, "update_IRQ\t: %s\n",
 229                         (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 230         seq_printf(seq, "periodic_IRQ\t: %s\n",
 231                         (imr & AT91_RTC_SECEV) ? "yes" : "no");
 232         seq_printf(seq, "periodic_freq\t: %ld\n",
 233                         (unsigned long) AT91_RTC_FREQ);
 234
 235         return 0;
 236 }
 237
 238 /*
 239  * IRQ handler for the RTC
 240  */
 241 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 242 {
 243         struct platform_device *pdev = dev_id;
 244         struct rtc_device *rtc = platform_get_drvdata(pdev);
 245         unsigned int rtsr;
 246         unsigned long events = 0;
 247
 248         rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
 249         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 250                 if (rtsr & AT91_RTC_ALARM)
 251                         events |= (RTC_AF | RTC_IRQF);
 252                 if (rtsr & AT91_RTC_SECEV)
 253                         events |= (RTC_UF | RTC_IRQF);
 254                 if (rtsr & AT91_RTC_ACKUPD)
 255                         complete(&at91_rtc_updated);
 256
 257                 at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 258
 259                 rtc_update_irq(&rtc->class_dev, 1, events);
 260
 261                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
 262                         events >> 8, events & 0x000000FF);
 263
 264                 return IRQ_HANDLED;
 265         }
 266         return IRQ_NONE;                /* not handled */
 267 }
 268
 269 static const struct rtc_class_ops at91_rtc_ops = {
 270         .ioctl          = at91_rtc_ioctl,
 271         .read_time      = at91_rtc_readtime,
 272         .set_time       = at91_rtc_settime,
 273         .read_alarm     = at91_rtc_readalarm,
 274         .set_alarm      = at91_rtc_setalarm,
 275         .proc           = at91_rtc_proc,
 276 };
 277
 278 /*
 279  * Initialize and install RTC driver
 280  */
 281 static int __init at91_rtc_probe(struct platform_device *pdev)
 282 {
 283         struct rtc_device *rtc;
 284         int ret;
 285
 286         at91_sys_write(AT91_RTC_CR, 0);
 287         at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 288
 289         /* Disable all interrupts */
 290         at91_sys_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(AT91_ID_SYS, at91_rtc_interrupt,
 295                                 IRQF_SHARED, "at91_rtc", pdev);
 296         if (ret) {
 297                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 298                                 AT91_ID_SYS);
 299                 return ret;
 300         }
 301
 302         rtc = rtc_device_register(pdev->name, &pdev->dev,
 303                                 &at91_rtc_ops, THIS_MODULE);
 304         if (IS_ERR(rtc)) {
 305                 free_irq(AT91_ID_SYS, pdev);
 306                 return PTR_ERR(rtc);
 307         }
 308         platform_set_drvdata(pdev, rtc);
 309         device_init_wakeup(&pdev->dev, 1);
 310
 311         printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 312         return 0;
 313 }
 314
 315 /*
 316  * Disable and remove the RTC driver
 317  */
 318 static int __devexit at91_rtc_remove(struct platform_device *pdev)
 319 {
 320         struct rtc_device *rtc = platform_get_drvdata(pdev);
 321
 322         /* Disable all interrupts */
 323         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 324                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 325                                         AT91_RTC_CALEV);
 326         free_irq(AT91_ID_SYS, pdev);
 327
 328         rtc_device_unregister(rtc);
 329         platform_set_drvdata(pdev, NULL);
 330         device_init_wakeup(&pdev->dev, 0);
 331
 332         return 0;
 333 }
 334
 335 #ifdef CONFIG_PM
 336
 337 /* AT91RM9200 RTC Power management control */
 338
 339 static struct timespec at91_rtc_delta;
 340 static u32 at91_rtc_imr;
 341
 342 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 343 {
 344         struct rtc_time tm;
 345         struct timespec time;
 346
 347         time.tv_nsec = 0;
 348
 349         /* calculate time delta for suspend */
 350         at91_rtc_readtime(&pdev->dev, &tm);
 351         rtc_tm_to_time(&tm, &time.tv_sec);
 352         save_time_delta(&at91_rtc_delta, &time);
 353
 354         /* this IRQ is shared with DBGU and other hardware which isn't
 355          * necessarily doing PM like we are...
 356          */
 357         at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
 358                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 359         if (at91_rtc_imr) {
 360                 if (device_may_wakeup(&pdev->dev))
 361                         enable_irq_wake(AT91_ID_SYS);
 362                 else
 363                         at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
 364         }
 365
 366         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 367                 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
 368                 tm.tm_hour, tm.tm_min, tm.tm_sec);
 369
 370         return 0;
 371 }
 372
 373 static int at91_rtc_resume(struct platform_device *pdev)
 374 {
 375         struct rtc_time tm;
 376         struct timespec time;
 377
 378         time.tv_nsec = 0;
 379
 380         at91_rtc_readtime(&pdev->dev, &tm);
 381         rtc_tm_to_time(&tm, &time.tv_sec);
 382         restore_time_delta(&at91_rtc_delta, &time);
 383
 384         if (at91_rtc_imr) {
 385                 if (device_may_wakeup(&pdev->dev))
 386                         disable_irq_wake(AT91_ID_SYS);
 387                 else
 388                         at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
 389         }
 390
 391         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 392                 1900 + tm.tm_year, tm.tm_mon, tm.tm_mday,
 393                 tm.tm_hour, tm.tm_min, tm.tm_sec);
 394
 395         return 0;
 396 }
 397 #else
 398 #define at91_rtc_suspend NULL
 399 #define at91_rtc_resume  NULL
 400 #endif
 401
 402 static struct platform_driver at91_rtc_driver = {
 403         .probe          = at91_rtc_probe,
 404         .remove         = at91_rtc_remove,
 405         .suspend        = at91_rtc_suspend,
 406         .resume         = at91_rtc_resume,
 407         .driver         = {
 408                 .name   = "at91_rtc",
 409                 .owner  = THIS_MODULE,
 410         },
 411 };
 412
 413 static int __init at91_rtc_init(void)
 414 {
 415         return platform_driver_register(&at91_rtc_driver);
 416 }
 417
 418 static void __exit at91_rtc_exit(void)
 419 {
 420         platform_driver_unregister(&at91_rtc_driver);
 421 }
 422
 423 module_init(at91_rtc_init);
 424 module_exit(at91_rtc_exit);
 425
 426 MODULE_AUTHOR("Rick Bronson");
 427 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 428 MODULE_LICENSE("GPL");