LXR linux/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
  38static DECLARE_COMPLETION(at91_rtc_updated);
  39static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  40
  41/*
  42 * Decode time/date into rtc_time structure
  43 */
  44static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  45                                struct rtc_time *tm)
  46{
  47        unsigned int time, date;
  48
  49        /* must read twice in case it changes */
  50        do {
  51                time = at91_sys_read(timereg);
  52                date = at91_sys_read(calreg);
  53        } while ((time != at91_sys_read(timereg)) ||
  54                        (date != at91_sys_read(calreg)));
  55
  56        tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  57        tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  58        tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  59
  60        /*
  61         * The Calendar Alarm register does not have a field for
  62         * the year - so these will return an invalid value.  When an
  63         * alarm is set, at91_alarm_year wille store the current year.
  64         */
  65        tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  66        tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  67
  68        tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  69        tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  70        tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  71}
  72
  73/*
  74 * Read current time and date in RTC
  75 */
  76static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  77{
  78        at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  79        tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  80        tm->tm_year = tm->tm_year - 1900;
  81
  82        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  83                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  84                tm->tm_hour, tm->tm_min, tm->tm_sec);
  85
  86        return 0;
  87}
  88
  89/*
  90 * Set current time and date in RTC
  91 */
  92static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  93{
  94        unsigned long cr;
  95
  96        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  97                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  98                tm->tm_hour, tm->tm_min, tm->tm_sec);
  99
 100        /* Stop Time/Calendar from counting */
 101        cr = at91_sys_read(AT91_RTC_CR);
 102        at91_sys_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 103
 104        at91_sys_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 105        wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 106        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 107
 108        at91_sys_write(AT91_RTC_TIMR,
 109                          bin2bcd(tm->tm_sec) << 0
 110                        | bin2bcd(tm->tm_min) << 8
 111                        | bin2bcd(tm->tm_hour) << 16);
 112
 113        at91_sys_write(AT91_RTC_CALR,
 114                          bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 115                        | bin2bcd(tm->tm_year % 100) << 8       /* year */
 116                        | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 117                        | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 118                        | bin2bcd(tm->tm_mday) << 24);
 119
 120        /* Restart Time/Calendar */
 121        cr = at91_sys_read(AT91_RTC_CR);
 122        at91_sys_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 123
 124        return 0;
 125}
 126
 127/*
 128 * Read alarm time and date in RTC
 129 */
 130static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 131{
 132        struct rtc_time *tm = &alrm->time;
 133
 134        at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 135        tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 136        tm->tm_year = at91_alarm_year - 1900;
 137
 138        alrm->enabled = (at91_sys_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 139                        ? 1 : 0;
 140
 141        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 142                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 143                tm->tm_hour, tm->tm_min, tm->tm_sec);
 144
 145        return 0;
 146}
 147
 148/*
 149 * Set alarm time and date in RTC
 150 */
 151static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 152{
 153        struct rtc_time tm;
 154
 155        at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 156
 157        at91_alarm_year = tm.tm_year;
 158
 159        tm.tm_hour = alrm->time.tm_hour;
 160        tm.tm_min = alrm->time.tm_min;
 161        tm.tm_sec = alrm->time.tm_sec;
 162
 163        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 164        at91_sys_write(AT91_RTC_TIMALR,
 165                  bin2bcd(tm.tm_sec) << 0
 166                | bin2bcd(tm.tm_min) << 8
 167                | bin2bcd(tm.tm_hour) << 16
 168                | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 169        at91_sys_write(AT91_RTC_CALALR,
 170                  bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 171                | bin2bcd(tm.tm_mday) << 24
 172                | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 173
 174        if (alrm->enabled) {
 175                at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 176                at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 177        }
 178
 179        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 180                at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 181                tm.tm_min, tm.tm_sec);
 182
 183        return 0;
 184}
 185
 186/*
 187 * Handle commands from user-space
 188 */
 189static int at91_rtc_ioctl(struct device *dev, unsigned int cmd,
 190                        unsigned long arg)
 191{
 192        int ret = 0;
 193
 194        pr_debug("%s(): cmd=%08x, arg=%08lx.\n", __func__, cmd, arg);
 195
 196        /* important:  scrub old status before enabling IRQs */
 197        switch (cmd) {
 198        case RTC_UIE_OFF:       /* update off */
 199                at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
 200                break;
 201        case RTC_UIE_ON:        /* update on */
 202                at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
 203                at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 204                break;
 205        default:
 206                ret = -ENOIOCTLCMD;
 207                break;
 208        }
 209
 210        return ret;
 211}
 212
 213static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 214{
 215        pr_debug("%s(): cmd=%08x\n", __func__, enabled);
 216
 217        if (enabled) {
 218                at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 219                at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 220        } else
 221                at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 222
 223        return 0;
 224}
 225/*
 226 * Provide additional RTC information in /proc/driver/rtc
 227 */
 228static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 229{
 230        unsigned long imr = at91_sys_read(AT91_RTC_IMR);
 231
 232        seq_printf(seq, "update_IRQ\t: %s\n",
 233                        (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 234        seq_printf(seq, "periodic_IRQ\t: %s\n",
 235                        (imr & AT91_RTC_SECEV) ? "yes" : "no");
 236
 237        return 0;
 238}
 239
 240/*
 241 * IRQ handler for the RTC
 242 */
 243static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 244{
 245        struct platform_device *pdev = dev_id;
 246        struct rtc_device *rtc = platform_get_drvdata(pdev);
 247        unsigned int rtsr;
 248        unsigned long events = 0;
 249
 250        rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
 251        if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 252                if (rtsr & AT91_RTC_ALARM)
 253                        events |= (RTC_AF | RTC_IRQF);
 254                if (rtsr & AT91_RTC_SECEV)
 255                        events |= (RTC_UF | RTC_IRQF);
 256                if (rtsr & AT91_RTC_ACKUPD)
 257                        complete(&at91_rtc_updated);
 258
 259                at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 260
 261                rtc_update_irq(rtc, 1, events);
 262
 263                pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
 264                        events >> 8, events & 0x000000FF);
 265
 266                return IRQ_HANDLED;
 267        }
 268        return IRQ_NONE;                /* not handled */
 269}
 270
 271static const struct rtc_class_ops at91_rtc_ops = {
 272        .ioctl          = at91_rtc_ioctl,
 273        .read_time      = at91_rtc_readtime,
 274        .set_time       = at91_rtc_settime,
 275        .read_alarm     = at91_rtc_readalarm,
 276        .set_alarm      = at91_rtc_setalarm,
 277        .proc           = at91_rtc_proc,
 278        .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 279};
 280
 281/*
 282 * Initialize and install RTC driver
 283 */
 284static int __init at91_rtc_probe(struct platform_device *pdev)
 285{
 286        struct rtc_device *rtc;
 287        int ret;
 288
 289        at91_sys_write(AT91_RTC_CR, 0);
 290        at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 291
 292        /* Disable all interrupts */
 293        at91_sys_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(AT91_ID_SYS, at91_rtc_interrupt,
 298                                IRQF_SHARED,
 299                                "at91_rtc", pdev);
 300        if (ret) {
 301                printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 302                                AT91_ID_SYS);
 303                return ret;
 304        }
 305
 306        /* cpu init code should really have flagged this device as
 307         * being wake-capable; if it didn't, do that here.
 308         */
 309        if (!device_can_wakeup(&pdev->dev))
 310                device_init_wakeup(&pdev->dev, 1);
 311
 312        rtc = rtc_device_register(pdev->name, &pdev->dev,
 313                                &at91_rtc_ops, THIS_MODULE);
 314        if (IS_ERR(rtc)) {
 315                free_irq(AT91_ID_SYS, pdev);
 316                return PTR_ERR(rtc);
 317        }
 318        platform_set_drvdata(pdev, rtc);
 319
 320        printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 321        return 0;
 322}
 323
 324/*
 325 * Disable and remove the RTC driver
 326 */
 327static int __exit at91_rtc_remove(struct platform_device *pdev)
 328{
 329        struct rtc_device *rtc = platform_get_drvdata(pdev);
 330
 331        /* Disable all interrupts */
 332        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 333                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
 334                                        AT91_RTC_CALEV);
 335        free_irq(AT91_ID_SYS, pdev);
 336
 337        rtc_device_unregister(rtc);
 338        platform_set_drvdata(pdev, NULL);
 339
 340        return 0;
 341}
 342
 343#ifdef CONFIG_PM
 344
 345/* AT91RM9200 RTC Power management control */
 346
 347static u32 at91_rtc_imr;
 348
 349static int at91_rtc_suspend(struct device *dev)
 350{
 351        /* this IRQ is shared with DBGU and other hardware which isn't
 352         * necessarily doing PM like we are...
 353         */
 354        at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
 355                        & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 356        if (at91_rtc_imr) {
 357                if (device_may_wakeup(dev))
 358                        enable_irq_wake(AT91_ID_SYS);
 359                else
 360                        at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
 361        }
 362        return 0;
 363}
 364
 365static int at91_rtc_resume(struct device *dev)
 366{
 367        if (at91_rtc_imr) {
 368                if (device_may_wakeup(dev))
 369                        disable_irq_wake(AT91_ID_SYS);
 370                else
 371                        at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
 372        }
 373        return 0;
 374}
 375
 376static const struct dev_pm_ops at91_rtc_pm = {
 377        .suspend =      at91_rtc_suspend,
 378        .resume =       at91_rtc_resume,
 379};
 380
 381#define at91_rtc_pm_ptr &at91_rtc_pm
 382
 383#else
 384#define at91_rtc_pm_ptr NULL
 385#endif
 386
 387static struct platform_driver at91_rtc_driver = {
 388        .remove         = __exit_p(at91_rtc_remove),
 389        .driver         = {
 390                .name   = "at91_rtc",
 391                .owner  = THIS_MODULE,
 392                .pm     = at91_rtc_pm_ptr,
 393        },
 394};
 395
 396static int __init at91_rtc_init(void)
 397{
 398        return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 399}
 400
 401static void __exit at91_rtc_exit(void)
 402{
 403        platform_driver_unregister(&at91_rtc_driver);
 404}
 405
 406module_init(at91_rtc_init);
 407module_exit(at91_rtc_exit);
 408
 409MODULE_AUTHOR("Rick Bronson");
 410MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 411MODULE_LICENSE("GPL");
 412MODULE_ALIAS("platform:at91_rtc");
 413