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
  36 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  37
  38 static DECLARE_COMPLETION(at91_rtc_updated);
  39 static DECLARE_COMPLETION(at91_rtc_upd_rdy);
  40 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  41
  42 /*
  43  * Decode time/date into rtc_time structure
  44  */
  45 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  46                                 struct rtc_time *tm)
  47 {
  48         unsigned int time, date;
  49
  50         /* must read twice in case it changes */
  51         do {
  52                 time = at91_sys_read(timereg);
  53                 date = at91_sys_read(calreg);
  54         } while ((time != at91_sys_read(timereg)) ||
  55                         (date != at91_sys_read(calreg)));
  56
  57         tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  58         tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  59         tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  60
  61         /*
  62          * The Calendar Alarm register does not have a field for
  63          * the year - so these will return an invalid value.  When an
  64          * alarm is set, at91_alarm_year will store the current year.
  65          */
  66         tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  67         tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  68
  69         tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  70         tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  71         tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  72 }
  73
  74 /*
  75  * Read current time and date in RTC
  76  */
  77 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  78 {
  79         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  80         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  81         tm->tm_year = tm->tm_year - 1900;
  82
  83         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  84                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  85                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  86
  87         return 0;
  88 }
  89
  90 /*
  91  * Set current time and date in RTC
  92  */
  93 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  94 {
  95         unsigned long cr;
  96
  97         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  98                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  99                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 100
 101         wait_for_completion(&at91_rtc_upd_rdy);
 102
 103         /* Stop Time/Calendar from counting */
 104         cr = at91_sys_read(AT91_RTC_CR);
 105         at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 106
 107         at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 108         wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 109         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 110
 111         at91_sys_write(AT91_RTC_TIMR,
 112                           bin2bcd(tm->tm_sec) << 0
 113                         | bin2bcd(tm->tm_min) << 8
 114                         | bin2bcd(tm->tm_hour) << 16);
 115
 116         at91_sys_write(AT91_RTC_CALR,
 117                           bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 118                         | bin2bcd(tm->tm_year % 100) << 8       /* year */
 119                         | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 120                         | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 121                         | bin2bcd(tm->tm_mday) << 24);
 122
 123         /* Restart Time/Calendar */
 124         cr = at91_sys_read(AT91_RTC_CR);
 125         at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
 126         at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 127         at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 128
 129         return 0;
 130 }
 131
 132 /*
 133  * Read alarm time and date in RTC
 134  */
 135 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 136 {
 137         struct rtc_time *tm = &alrm->time;
 138
 139         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 140         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 141         tm->tm_year = at91_alarm_year - 1900;
 142
 143         alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 144                         ? 1 : 0;
 145
 146         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 147                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 148                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 149
 150         return 0;
 151 }
 152
 153 /*
 154  * Set alarm time and date in RTC
 155  */
 156 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 157 {
 158         struct rtc_time tm;
 159
 160         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 161
 162         at91_alarm_year = tm.tm_year;
 163
 164         tm.tm_mon = alrm->time.tm_mon;
 165         tm.tm_mday = alrm->time.tm_mday;
 166         tm.tm_hour = alrm->time.tm_hour;
 167         tm.tm_min = alrm->time.tm_min;
 168         tm.tm_sec = alrm->time.tm_sec;
 169
 170         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 171         at91_sys_write(AT91_RTC_TIMALR,
 172                   bin2bcd(tm.tm_sec) << 0
 173                 | bin2bcd(tm.tm_min) << 8
 174                 | bin2bcd(tm.tm_hour) << 16
 175                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 176         at91_sys_write(AT91_RTC_CALALR,
 177                   bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 178                 | bin2bcd(tm.tm_mday) << 24
 179                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 180
 181         if (alrm->enabled) {
 182                 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 183                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 184         }
 185
 186         pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 187                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 188                 tm.tm_min, tm.tm_sec);
 189
 190         return 0;
 191 }
 192
 193 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 194 {
 195         pr_debug("%s(): cmd=%08x\n", __func__, enabled);
 196
 197         if (enabled) {
 198                 at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 199                 at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 200         } else
 201                 at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 202
 203         return 0;
 204 }
 205 /*
 206  * Provide additional RTC information in /proc/driver/rtc
 207  */
 208 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 209 {
 210         unsigned long imr = at91_sys_read(AT91_RTC_IMR);
 211
 212         seq_printf(seq, "update_IRQ\t: %s\n",
 213                         (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 214         seq_printf(seq, "periodic_IRQ\t: %s\n",
 215                         (imr & AT91_RTC_SECEV) ? "yes" : "no");
 216
 217         return 0;
 218 }
 219
 220 /*
 221  * IRQ handler for the RTC
 222  */
 223 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 224 {
 225         struct platform_device *pdev = dev_id;
 226         struct rtc_device *rtc = platform_get_drvdata(pdev);
 227         unsigned int rtsr;
 228         unsigned long events = 0;
 229
 230         rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
 231         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 232                 if (rtsr & AT91_RTC_ALARM)
 233                         events |= (RTC_AF | RTC_IRQF);
 234                 if (rtsr & AT91_RTC_SECEV) {
 235                         complete(&at91_rtc_upd_rdy);
 236                         at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
 237                 }
 238                 if (rtsr & AT91_RTC_ACKUPD)
 239                         complete(&at91_rtc_updated);
 240
 241                 at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 242
 243                 rtc_update_irq(rtc, 1, events);
 244
 245                 pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
 246                         events >> 8, events & 0x000000FF);
 247
 248                 return IRQ_HANDLED;
 249         }
 250         return IRQ_NONE;                /* not handled */
 251 }
 252
 253 static const struct rtc_class_ops at91_rtc_ops = {
 254         .read_time      = at91_rtc_readtime,
 255         .set_time       = at91_rtc_settime,
 256         .read_alarm     = at91_rtc_readalarm,
 257         .set_alarm      = at91_rtc_setalarm,
 258         .proc           = at91_rtc_proc,
 259         .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 260 };
 261
 262 /*
 263  * Initialize and install RTC driver
 264  */
 265 static int __init at91_rtc_probe(struct platform_device *pdev)
 266 {
 267         struct rtc_device *rtc;
 268         int ret;
 269
 270         at91_sys_write(AT91_RTC_CR, 0);
 271         at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 272
 273         /* Disable all interrupts */
 274         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 275                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 276                                         AT91_RTC_CALEV);
 277
 278         ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
 279                                 IRQF_SHARED,
 280                                 "at91_rtc", pdev);
 281         if (ret) {
 282                 printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 283                                 AT91_ID_SYS);
 284                 return ret;
 285         }
 286
 287         /* cpu init code should really have flagged this device as
 288          * being wake-capable; if it didn't, do that here.
 289          */
 290         if (!device_can_wakeup(&pdev->dev))
 291                 device_init_wakeup(&pdev->dev, 1);
 292
 293         rtc = rtc_device_register(pdev->name, &pdev->dev,
 294                                 &at91_rtc_ops, THIS_MODULE);
 295         if (IS_ERR(rtc)) {
 296                 free_irq(AT91_ID_SYS, pdev);
 297                 return PTR_ERR(rtc);
 298         }
 299         platform_set_drvdata(pdev, rtc);
 300
 301         /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
 302          * completion.
 303          */
 304         at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 305
 306         printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 307         return 0;
 308 }
 309
 310 /*
 311  * Disable and remove the RTC driver
 312  */
 313 static int __exit at91_rtc_remove(struct platform_device *pdev)
 314 {
 315         struct rtc_device *rtc = platform_get_drvdata(pdev);
 316
 317         /* Disable all interrupts */
 318         at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 319                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 320                                         AT91_RTC_CALEV);
 321         free_irq(AT91_ID_SYS, pdev);
 322
 323         rtc_device_unregister(rtc);
 324         platform_set_drvdata(pdev, NULL);
 325
 326         return 0;
 327 }
 328
 329 #ifdef CONFIG_PM
 330
 331 /* AT91RM9200 RTC Power management control */
 332
 333 static u32 at91_rtc_imr;
 334
 335 static int at91_rtc_suspend(struct device *dev)
 336 {
 337         /* this IRQ is shared with DBGU and other hardware which isn't
 338          * necessarily doing PM like we are...
 339          */
 340         at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
 341                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 342         if (at91_rtc_imr) {
 343                 if (device_may_wakeup(dev))
 344                         enable_irq_wake(AT91_ID_SYS);
 345                 else
 346                         at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
 347         }
 348         return 0;
 349 }
 350
 351 static int at91_rtc_resume(struct device *dev)
 352 {
 353         if (at91_rtc_imr) {
 354                 if (device_may_wakeup(dev))
 355                         disable_irq_wake(AT91_ID_SYS);
 356                 else
 357                         at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
 358         }
 359         return 0;
 360 }
 361
 362 static const struct dev_pm_ops at91_rtc_pm = {
 363         .suspend =      at91_rtc_suspend,
 364         .resume =       at91_rtc_resume,
 365 };
 366
 367 #define at91_rtc_pm_ptr &at91_rtc_pm
 368
 369 #else
 370 #define at91_rtc_pm_ptr NULL
 371 #endif
 372
 373 static struct platform_driver at91_rtc_driver = {
 374         .remove         = __exit_p(at91_rtc_remove),
 375         .driver         = {
 376                 .name   = "at91_rtc",
 377                 .owner  = THIS_MODULE,
 378                 .pm     = at91_rtc_pm_ptr,
 379         },
 380 };
 381
 382 static int __init at91_rtc_init(void)
 383 {
 384         return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 385 }
 386
 387 static void __exit at91_rtc_exit(void)
 388 {
 389         platform_driver_unregister(&at91_rtc_driver);
 390 }
 391
 392 module_init(at91_rtc_init);
 393 module_exit(at91_rtc_exit);
 394
 395 MODULE_AUTHOR("Rick Bronson");
 396 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 397 MODULE_LICENSE("GPL");
 398 MODULE_ALIAS("platform:at91_rtc");