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_AIE_OFF:       /* alarm off */
 199                at91_sys_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 200                break;
 201        case RTC_AIE_ON:        /* alarm on */
 202                at91_sys_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 203                at91_sys_write(AT91_RTC_IER, AT91_RTC_ALARM);
 204                break;
 205        case RTC_UIE_OFF:       /* update off */
 206                at91_sys_write(AT91_RTC_IDR, AT91_RTC_SECEV);
 207                break;
 208        case RTC_UIE_ON:        /* update on */
 209                at91_sys_write(AT91_RTC_SCCR, AT91_RTC_SECEV);
 210                at91_sys_write(AT91_RTC_IER, AT91_RTC_SECEV);
 211                break;
 212        default:
 213                ret = -ENOIOCTLCMD;
 214                break;
 215        }
 216
 217        return ret;
 218}
 219
 220/*
 221 * Provide additional RTC information in /proc/driver/rtc
 222 */
 223static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 224{
 225        unsigned long imr = at91_sys_read(AT91_RTC_IMR);
 226
 227        seq_printf(seq, "update_IRQ\t: %s\n",
 228                        (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 229        seq_printf(seq, "periodic_IRQ\t: %s\n",
 230                        (imr & AT91_RTC_SECEV) ? "yes" : "no");
 231
 232        return 0;
 233}
 234
 235/*
 236 * IRQ handler for the RTC
 237 */
 238static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 239{
 240        struct platform_device *pdev = dev_id;
 241        struct rtc_device *rtc = platform_get_drvdata(pdev);
 242        unsigned int rtsr;
 243        unsigned long events = 0;
 244
 245        rtsr = at91_sys_read(AT91_RTC_SR) & at91_sys_read(AT91_RTC_IMR);
 246        if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 247                if (rtsr & AT91_RTC_ALARM)
 248                        events |= (RTC_AF | RTC_IRQF);
 249                if (rtsr & AT91_RTC_SECEV)
 250                        events |= (RTC_UF | RTC_IRQF);
 251                if (rtsr & AT91_RTC_ACKUPD)
 252                        complete(&at91_rtc_updated);
 253
 254                at91_sys_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 255
 256                rtc_update_irq(rtc, 1, events);
 257
 258                pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
 259                        events >> 8, events & 0x000000FF);
 260
 261                return IRQ_HANDLED;
 262        }
 263        return IRQ_NONE;                /* not handled */
 264}
 265
 266static const struct rtc_class_ops at91_rtc_ops = {
 267        .ioctl          = at91_rtc_ioctl,
 268        .read_time      = at91_rtc_readtime,
 269        .set_time       = at91_rtc_settime,
 270        .read_alarm     = at91_rtc_readalarm,
 271        .set_alarm      = at91_rtc_setalarm,
 272        .proc           = at91_rtc_proc,
 273};
 274
 275/*
 276 * Initialize and install RTC driver
 277 */
 278static int __init at91_rtc_probe(struct platform_device *pdev)
 279{
 280        struct rtc_device *rtc;
 281        int ret;
 282
 283        at91_sys_write(AT91_RTC_CR, 0);
 284        at91_sys_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 285
 286        /* Disable all interrupts */
 287        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 288                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
 289                                        AT91_RTC_CALEV);
 290
 291        ret = request_irq(AT91_ID_SYS, at91_rtc_interrupt,
 292                                IRQF_DISABLED | IRQF_SHARED,
 293                                "at91_rtc", pdev);
 294        if (ret) {
 295                printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 296                                AT91_ID_SYS);
 297                return ret;
 298        }
 299
 300        /* cpu init code should really have flagged this device as
 301         * being wake-capable; if it didn't, do that here.
 302         */
 303        if (!device_can_wakeup(&pdev->dev))
 304                device_init_wakeup(&pdev->dev, 1);
 305
 306        rtc = rtc_device_register(pdev->name, &pdev->dev,
 307                                &at91_rtc_ops, THIS_MODULE);
 308        if (IS_ERR(rtc)) {
 309                free_irq(AT91_ID_SYS, pdev);
 310                return PTR_ERR(rtc);
 311        }
 312        platform_set_drvdata(pdev, rtc);
 313
 314        printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 315        return 0;
 316}
 317
 318/*
 319 * Disable and remove the RTC driver
 320 */
 321static int __exit at91_rtc_remove(struct platform_device *pdev)
 322{
 323        struct rtc_device *rtc = platform_get_drvdata(pdev);
 324
 325        /* Disable all interrupts */
 326        at91_sys_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 327                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
 328                                        AT91_RTC_CALEV);
 329        free_irq(AT91_ID_SYS, pdev);
 330
 331        rtc_device_unregister(rtc);
 332        platform_set_drvdata(pdev, NULL);
 333
 334        return 0;
 335}
 336
 337#ifdef CONFIG_PM
 338
 339/* AT91RM9200 RTC Power management control */
 340
 341static u32 at91_rtc_imr;
 342
 343static int at91_rtc_suspend(struct platform_device *pdev, pm_message_t state)
 344{
 345        /* this IRQ is shared with DBGU and other hardware which isn't
 346         * necessarily doing PM like we are...
 347         */
 348        at91_rtc_imr = at91_sys_read(AT91_RTC_IMR)
 349                        & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 350        if (at91_rtc_imr) {
 351                if (device_may_wakeup(&pdev->dev))
 352                        enable_irq_wake(AT91_ID_SYS);
 353                else
 354                        at91_sys_write(AT91_RTC_IDR, at91_rtc_imr);
 355        }
 356        return 0;
 357}
 358
 359static int at91_rtc_resume(struct platform_device *pdev)
 360{
 361        if (at91_rtc_imr) {
 362                if (device_may_wakeup(&pdev->dev))
 363                        disable_irq_wake(AT91_ID_SYS);
 364                else
 365                        at91_sys_write(AT91_RTC_IER, at91_rtc_imr);
 366        }
 367        return 0;
 368}
 369#else
 370#define at91_rtc_suspend NULL
 371#define at91_rtc_resume  NULL
 372#endif
 373
 374static struct platform_driver at91_rtc_driver = {
 375        .remove         = __exit_p(at91_rtc_remove),
 376        .suspend        = at91_rtc_suspend,
 377        .resume         = at91_rtc_resume,
 378        .driver         = {
 379                .name   = "at91_rtc",
 380                .owner  = THIS_MODULE,
 381        },
 382};
 383
 384static int __init at91_rtc_init(void)
 385{
 386        return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 387}
 388
 389static void __exit at91_rtc_exit(void)
 390{
 391        platform_driver_unregister(&at91_rtc_driver);
 392}
 393
 394module_init(at91_rtc_init);
 395module_exit(at91_rtc_exit);
 396
 397MODULE_AUTHOR("Rick Bronson");
 398MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 399MODULE_LICENSE("GPL");
 400MODULE_ALIAS("platform:at91_rtc");
 401