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 #include <asm/rtc.h>
  33
  34 #include <asm/mach/time.h>
  35
  36 #include <asm/arch/at91_rtc.h>
  37
  38
  39 #define AT91_RTC_FREQ           1
  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
  45 /*
  46  * Decode time/date into rtc_time structure
  47  */
  48 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  49                                 struct rtc_time *tm)
  50 {
  51         unsigned int time, date;
  52
  53         /* must read twice in case it changes */
  54         do {
  55                 time = at91_sys_read(timereg);
  56                 date = at91_sys_read(calreg);
  57         } while ((time != at91_sys_read(timereg)) ||
  58                         (date != at91_sys_read(calreg)));
  59
  60         tm->tm_sec  = BCD2BIN((time & AT91_RTC_SEC) >> 0);
  61         tm->tm_min  = BCD2BIN((time & AT91_RTC_MIN) >> 8);
  62         tm->tm_hour = BCD2BIN((time & AT91_RTC_HOUR) >> 16);
  63
  64         /*
  65          * The Calendar Alarm register does not have a field for
  66          * the year - so these will return an invalid value.  When an
  67          * alarm is set, at91_alarm_year wille store the current year.
  68          */
  69         tm->tm_year  = BCD2BIN(date & AT91_RTC_CENT) * 100;     /* century */
  70         tm->tm_year += BCD2BIN((date & AT91_RTC_YEAR) >> 8);    /* year */
  71
  72         tm->tm_wday = BCD2BIN((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  73         tm->tm_mon  = BCD2BIN((date & AT91_RTC_MONTH) >> 16) - 1;
  74         tm->tm_mday = BCD2BIN((date & AT91_RTC_DATE) >> 24);
  75 }
  76
  77 /*
  78  * Read current time and date in RTC
  79  */
  80 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  81 {
  82         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  83         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  84         tm->tm_year = tm->tm_year - 1900;
  85
  86         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
  87                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  88                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  89
  90         return 0;
  91 }
  92
  93 /*
  94  * Set current time and date in RTC
  95  */
  96 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  97 {
  98         unsigned long cr;
  99
 100         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 101                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 102                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 103
 104         /* Stop Time/Calendar from counting */
 105         cr = at91_sys_read(AT91_RTC_CR);
 106         at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 107
 108         at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 109         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 110         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 111
 112         at91_sys_write(AT91_RTC_TIMR,
 113                           BIN2BCD(tm->tm_sec) << 0
 114                         | BIN2BCD(tm->tm_min) << 8
 115                         | BIN2BCD(tm->tm_hour) << 16);
 116
 117         at91_sys_write(AT91_RTC_CALR,
 118                           BIN2BCD((tm->tm_year + 1900) / 100)   /* century */
 119                         | BIN2BCD(tm->tm_year % 100) << 8       /* year */
 120                         | BIN2BCD(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 121                         | BIN2BCD(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 122                         | BIN2BCD(tm->tm_mday) << 24);
 123
 124         /* Restart Time/Calendar */
 125         cr = at91_sys_read(AT91_RTC_CR);
 126         at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 127
 128         return 0;
 129 }
 130
 131 /*
 132  * Read alarm time and date in RTC
 133  */
 134 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 135 {
 136         struct rtc_time *tm = &alrm->time;
 137
 138         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 139         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 140         tm->tm_year = at91_alarm_year - 1900;
 141
 142         alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 143                         ? 1 : 0;
 144
 145         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 146                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 147                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 148
 149         return 0;
 150 }
 151
 152 /*
 153  * Set alarm time and date in RTC
 154  */
 155 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 156 {
 157         struct rtc_time tm;
 158
 159         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 160
 161         at91_alarm_year = tm.tm_year;
 162
 163         tm.tm_hour = alrm->time.tm_hour;
 164         tm.tm_min = alrm->time.tm_min;
 165         tm.tm_sec = alrm->time.tm_sec;
 166
 167         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 168         at91_sys_write(AT91_RTC_TIMALR,
 169                   BIN2BCD(tm.tm_sec) << 0
 170                 | BIN2BCD(tm.tm_min) << 8
 171                 | BIN2BCD(tm.tm_hour) << 16
 172                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 173         at91_sys_write(AT91_RTC_CALALR,
 174                   BIN2BCD(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 175                 | BIN2BCD(tm.tm_mday) << 24
 176                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 177
 178         if (alrm->enabled)
 179                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 180
 181         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __FUNCTION__,
 182                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 183                 tm.tm_min, tm.tm_sec);
 184
 185         return 0;
 186 }
 187
 188 /*
 189  * Handle commands from user-space
 190  */
 191 static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
 192                         unsigned long arg)
 193 {
 194         int ret = 0;
 195
 196         pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __FUNCTION__, cmd, arg);
 197
 198         switch (cmd) {
 199         case RTC_AIE_OFF:       /* alarm off */
 200                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 201                 break;
 202         case RTC_AIE_ON:        /* alarm on */
 203                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 204                 break;
 205         case RTC_UIE_OFF:       /* update off */
 206         case RTC_PIE_OFF:       /* periodic off */
 207                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
 208                 break;
 209         case RTC_UIE_ON:        /* update on */
 210         case RTC_PIE_ON:        /* periodic on */
 211                 at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 212                 break;
 213         case RTC_IRQP_READ:     /* read periodic alarm frequency */
 214                 ret = put_user(AT91_RTC_FREQ, (unsigned long *) arg);
 215                 break;
 216         case RTC_IRQP_SET:      /* set periodic alarm frequency */
 217                 if (arg != AT91_RTC_FREQ)
 218                         ret = -EINVAL;
 219                 break;
 220         default:
 221                 ret = -ENOIOCTLCMD;
 222                 break;
 223         }
 224
 225         return ret;
 226 }
 227
 228 /*
 229  * Provide additional RTC information in /proc/driver/rtc
 230  */
 231 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 232 {
 233         unsigned long imr = at91_sys_read(AT91_RTC_IMR);
 234
 235         seq_printf(seq, "update_IRQ\t: %s\n",
 236                         (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 237         seq_printf(seq, "periodic_IRQ\t: %s\n",
 238                         (imr & AT91_RTC_SECEV) ? "yes" : "no");
 239         seq_printf(seq, "periodic_freq\t: %ld\n",
 240                         (unsigned long) AT91_RTC_FREQ);
 241
 242         return 0;
 243 }
 244
 245 /*
 246  * IRQ handler for the RTC
 247  */
 248 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 249 {
 250         struct platform_device *pdev = dev_id;
 251         struct rtc_device *rtc = platform_get_drvdata(pdev);
 252         unsigned int rtsr;
 253         unsigned long events = 0;
 254
 255         rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
 256         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 257                 if (rtsr & AT91_RTC_ALARM)
 258                         events |= (RTC_AF | RTC_IRQF);
 259                 if (rtsr & AT91_RTC_SECEV)
 260                         events |= (RTC_UF | RTC_IRQF);
 261                 if (rtsr & AT91_RTC_ACKUPD)
 262                         complete(&at91_rtc_updated);
 263
 264                 at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 265
 266                 rtc_update_irq(rtc, 1, events);
 267
 268                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __FUNCTION__,
 269                         events >> 8, events & 0x000000FF);
 270
 271                 return IRQ_HANDLED;
 272         }
 273         return IRQ_NONE;                /* not handled */
 274 }
 275
 276 static const struct rtc_class_ops at91_rtc_ops = {
 277         .ioctl          = at91_rtc_ioctl,
 278         .read_time      = at91_rtc_readtime,
 279         .set_time       = at91_rtc_settime,
 280         .read_alarm     = at91_rtc_readalarm,
 281         .set_alarm      = at91_rtc_setalarm,
 282         .proc           = at91_rtc_proc,
 283 };
 284
 285 /*
 286  * Initialize and install RTC driver
 287  */
 288 static int __init at91_rtc_probe(struct platform_device *pdev)
 289 {
 290         struct rtc_device *rtc;
 291         int ret;
 292
 293         at91_sys_write(AT91_RTC_CR, 0);
 294         at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 295
 296         /* Disable all interrupts */
 297         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 298                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 299                                         AT91_RTC_CALEV);
 300
 301         ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
 302                                 IRQF_DISABLED | IRQF_SHARED,
 303                                 "at91_rtc", pdev);
 304         if (ret) {
 305                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 306                                 AT91_ID_SYS);
 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(AT91_ID_SYS, pdev);
 320                 return PTR_ERR(rtc);
 321         }
 322         platform_set_drvdata(pdev, rtc);
 323
 324         printk(KERN_INFO "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_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 337                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 338                                         AT91_RTC_CALEV);
 339         free_irq(AT91_ID_SYS, pdev);
 340
 341         rtc_device_unregister(rtc);
 342         platform_set_drvdata(pdev, NULL);
 343
 344         return 0;
 345 }
 346
 347 #ifdef CONFIG_PM
 348
 349 /* AT91RM9200 RTC Power management control */
 350
 351 static u32 at91_rtc_imr;
 352
 353 static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 354 {
 355         /* this IRQ is shared with DBGU and other hardware which isn't
 356          * necessarily doing PM like we are...
 357          */
 358         at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
 359                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 360         if (at91_rtc_imr) {
 361                 if (device_may_wakeup(&pdev->dev))
 362                         enable_irq_wake(AT91_ID_SYS);
 363                 else
 364                         at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
 365         }
 366         return 0;
 367 }
 368
 369 static int at91_rtc_resume(struct platform_device *pdev)
 370 {
 371         if (at91_rtc_imr) {
 372                 if (device_may_wakeup(&pdev->dev))
 373                         disable_irq_wake(AT91_ID_SYS);
 374                 else
 375                         at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
 376         }
 377         return 0;
 378 }
 379 #else
 380 #define at91_rtc_suspend NULL
 381 #define at91_rtc_resume  NULL
 382 #endif
 383
 384 static struct platform_driver at91_rtc_driver = {
 385         .remove         = __exit_p(at91_rtc_remove),
 386         .suspend        = at91_rtc_suspend,
 387         .resume         = at91_rtc_resume,
 388         .driver         = {
 389                 .name   = "at91_rtc",
 390                 .owner  = THIS_MODULE,
 391         },
 392 };
 393
 394 static int __init at91_rtc_init(void)
 395 {
 396         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 397 }
 398
 399 static void __exit at91_rtc_exit(void)
 400 {
 401         platform_driver_unregister(&at91_rtc_driver);
 402 }
 403
 404 module_init(at91_rtc_init);
 405 module_exit(at91_rtc_exit);
 406
 407 MODULE_AUTHOR("Rick Bronson");
 408 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 409 MODULE_LICENSE("GPL");