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 #include <linux/of.h>
  32 #include <linux/of_device.h>
  33
  34 #include <asm/uaccess.h>
  35
  36 #include "rtc-at91rm9200.h"
  37
  38 #define at91_rtc_read(field) \
  39         __raw_readl(at91_rtc_regs + field)
  40 #define at91_rtc_write(field, val) \
  41         __raw_writel((val), at91_rtc_regs + field)
  42
  43 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  44
  45 static DECLARE_COMPLETION(at91_rtc_updated);
  46 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  47 static void __iomem *at91_rtc_regs;
  48 static int irq;
  49
  50 /*
  51  * Decode time/date into rtc_time structure
  52  */
  53 static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  54                                 struct rtc_time *tm)
  55 {
  56         unsigned int time, date;
  57
  58         /* must read twice in case it changes */
  59         do {
  60                 time = at91_rtc_read(timereg);
  61                 date = at91_rtc_read(calreg);
  62         } while ((time != at91_rtc_read(timereg)) ||
  63                         (date != at91_rtc_read(calreg)));
  64
  65         tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  66         tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  67         tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  68
  69         /*
  70          * The Calendar Alarm register does not have a field for
  71          * the year - so these will return an invalid value.  When an
  72          * alarm is set, at91_alarm_year will store the current year.
  73          */
  74         tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  75         tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  76
  77         tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  78         tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  79         tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  80 }
  81
  82 /*
  83  * Read current time and date in RTC
  84  */
  85 static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  86 {
  87         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  88         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  89         tm->tm_year = tm->tm_year - 1900;
  90
  91         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  92                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  93                 tm->tm_hour, tm->tm_min, tm->tm_sec);
  94
  95         return 0;
  96 }
  97
  98 /*
  99  * Set current time and date in RTC
 100  */
 101 static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
 102 {
 103         unsigned long cr;
 104
 105         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 106                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 107                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 108
 109         /* Stop Time/Calendar from counting */
 110         cr = at91_rtc_read(AT91_RTC_CR);
 111         at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 112
 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
 117         at91_rtc_write(AT91_RTC_TIMR,
 118                           bin2bcd(tm->tm_sec) << 0
 119                         | bin2bcd(tm->tm_min) << 8
 120                         | bin2bcd(tm->tm_hour) << 16);
 121
 122         at91_rtc_write(AT91_RTC_CALR,
 123                           bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 124                         | bin2bcd(tm->tm_year % 100) << 8       /* year */
 125                         | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 126                         | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 127                         | bin2bcd(tm->tm_mday) << 24);
 128
 129         /* Restart Time/Calendar */
 130         cr = at91_rtc_read(AT91_RTC_CR);
 131         at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 132
 133         return 0;
 134 }
 135
 136 /*
 137  * Read alarm time and date in RTC
 138  */
 139 static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 140 {
 141         struct rtc_time *tm = &alrm->time;
 142
 143         at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 144         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 145         tm->tm_year = at91_alarm_year - 1900;
 146
 147         alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 148                         ? 1 : 0;
 149
 150         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 151                 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 152                 tm->tm_hour, tm->tm_min, tm->tm_sec);
 153
 154         return 0;
 155 }
 156
 157 /*
 158  * Set alarm time and date in RTC
 159  */
 160 static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 161 {
 162         struct rtc_time tm;
 163
 164         at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 165
 166         at91_alarm_year = tm.tm_year;
 167
 168         tm.tm_hour = alrm->time.tm_hour;
 169         tm.tm_min = alrm->time.tm_min;
 170         tm.tm_sec = alrm->time.tm_sec;
 171
 172         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 173         at91_rtc_write(AT91_RTC_TIMALR,
 174                   bin2bcd(tm.tm_sec) << 0
 175                 | bin2bcd(tm.tm_min) << 8
 176                 | bin2bcd(tm.tm_hour) << 16
 177                 | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 178         at91_rtc_write(AT91_RTC_CALALR,
 179                   bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 180                 | bin2bcd(tm.tm_mday) << 24
 181                 | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 182
 183         if (alrm->enabled) {
 184                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 185                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 186         }
 187
 188         dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 189                 at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 190                 tm.tm_min, tm.tm_sec);
 191
 192         return 0;
 193 }
 194
 195 static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 196 {
 197         dev_dbg(dev, "%s(): cmd=%08x\n", __func__, enabled);
 198
 199         if (enabled) {
 200                 at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 201                 at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 202         } else
 203                 at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 204
 205         return 0;
 206 }
 207 /*
 208  * Provide additional RTC information in /proc/driver/rtc
 209  */
 210 static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 211 {
 212         unsigned long imr = at91_rtc_read(AT91_RTC_IMR);
 213
 214         seq_printf(seq, "update_IRQ\t: %s\n",
 215                         (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 216         seq_printf(seq, "periodic_IRQ\t: %s\n",
 217                         (imr & AT91_RTC_SECEV) ? "yes" : "no");
 218
 219         return 0;
 220 }
 221
 222 /*
 223  * IRQ handler for the RTC
 224  */
 225 static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 226 {
 227         struct platform_device *pdev = dev_id;
 228         struct rtc_device *rtc = platform_get_drvdata(pdev);
 229         unsigned int rtsr;
 230         unsigned long events = 0;
 231
 232         rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
 233         if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 234                 if (rtsr & AT91_RTC_ALARM)
 235                         events |= (RTC_AF | RTC_IRQF);
 236                 if (rtsr & AT91_RTC_SECEV)
 237                         events |= (RTC_UF | RTC_IRQF);
 238                 if (rtsr & AT91_RTC_ACKUPD)
 239                         complete(&at91_rtc_updated);
 240
 241                 at91_rtc_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 242
 243                 rtc_update_irq(rtc, 1, events);
 244
 245                 dev_dbg(&pdev->dev, "%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         struct resource *regs;
 269         int ret = 0;
 270
 271         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 272         if (!regs) {
 273                 dev_err(&pdev->dev, "no mmio resource defined\n");
 274                 return -ENXIO;
 275         }
 276
 277         irq = platform_get_irq(pdev, 0);
 278         if (irq < 0) {
 279                 dev_err(&pdev->dev, "no irq resource defined\n");
 280                 return -ENXIO;
 281         }
 282
 283         at91_rtc_regs = ioremap(regs->start, resource_size(regs));
 284         if (!at91_rtc_regs) {
 285                 dev_err(&pdev->dev, "failed to map registers, aborting.\n");
 286                 return -ENOMEM;
 287         }
 288
 289         at91_rtc_write(AT91_RTC_CR, 0);
 290         at91_rtc_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 291
 292         /* Disable all interrupts */
 293         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 294                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 295                                         AT91_RTC_CALEV);
 296
 297         ret = request_irq(irq, at91_rtc_interrupt,
 298                                 IRQF_SHARED,
 299                                 "at91_rtc", pdev);
 300         if (ret) {
 301                 dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
 302                 goto err_unmap;
 303         }
 304
 305         /* cpu init code should really have flagged this device as
 306          * being wake-capable; if it didn't, do that here.
 307          */
 308         if (!device_can_wakeup(&pdev->dev))
 309                 device_init_wakeup(&pdev->dev, 1);
 310
 311         rtc = rtc_device_register(pdev->name, &pdev->dev,
 312                                 &at91_rtc_ops, THIS_MODULE);
 313         if (IS_ERR(rtc)) {
 314                 ret = PTR_ERR(rtc);
 315                 goto err_free_irq;
 316         }
 317         platform_set_drvdata(pdev, rtc);
 318
 319         dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
 320         return 0;
 321
 322 err_free_irq:
 323         free_irq(irq, pdev);
 324 err_unmap:
 325         iounmap(at91_rtc_regs);
 326
 327         return ret;
 328 }
 329
 330 /*
 331  * Disable and remove the RTC driver
 332  */
 333 static int __exit at91_rtc_remove(struct platform_device *pdev)
 334 {
 335         struct rtc_device *rtc = platform_get_drvdata(pdev);
 336
 337         /* Disable all interrupts */
 338         at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 339                                         AT91_RTC_SECEV | AT91_RTC_TIMEV |
 340                                         AT91_RTC_CALEV);
 341         free_irq(irq, pdev);
 342
 343         rtc_device_unregister(rtc);
 344         iounmap(at91_rtc_regs);
 345         platform_set_drvdata(pdev, NULL);
 346
 347         return 0;
 348 }
 349
 350 #ifdef CONFIG_PM_SLEEP
 351
 352 /* AT91RM9200 RTC Power management control */
 353
 354 static u32 at91_rtc_imr;
 355
 356 static int at91_rtc_suspend(struct device *dev)
 357 {
 358         /* this IRQ is shared with DBGU and other hardware which isn't
 359          * necessarily doing PM like we are...
 360          */
 361         at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
 362                         & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 363         if (at91_rtc_imr) {
 364                 if (device_may_wakeup(dev))
 365                         enable_irq_wake(irq);
 366                 else
 367                         at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
 368         }
 369         return 0;
 370 }
 371
 372 static int at91_rtc_resume(struct device *dev)
 373 {
 374         if (at91_rtc_imr) {
 375                 if (device_may_wakeup(dev))
 376                         disable_irq_wake(irq);
 377                 else
 378                         at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
 379         }
 380         return 0;
 381 }
 382 #endif
 383
 384 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
 385
 386 static const struct of_device_id at91_rtc_dt_ids[] = {
 387         { .compatible = "atmel,at91rm9200-rtc" },
 388         { /* sentinel */ }
 389 };
 390 MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
 391
 392 static struct platform_driver at91_rtc_driver = {
 393         .remove         = __exit_p(at91_rtc_remove),
 394         .driver         = {
 395                 .name   = "at91_rtc",
 396                 .owner  = THIS_MODULE,
 397                 .pm     = &at91_rtc_pm_ops,
 398                 .of_match_table = of_match_ptr(at91_rtc_dt_ids),
 399         },
 400 };
 401
 402 module_platform_driver_probe(at91_rtc_driver, at91_rtc_probe);
 403
 404 MODULE_AUTHOR("Rick Bronson");
 405 MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 406 MODULE_LICENSE("GPL");
 407 MODULE_ALIAS("platform:at91_rtc");