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#define at91_rtc_read(field) \
  36        __raw_readl(at91_rtc_regs + field)
  37#define at91_rtc_write(field, val) \
  38        __raw_writel((val), at91_rtc_regs + field)
  39
  40#define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
  41
  42static DECLARE_COMPLETION(at91_rtc_updated);
  43static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
  44static void __iomem *at91_rtc_regs;
  45static int irq;
  46
  47/*
  48 * Decode time/date into rtc_time structure
  49 */
  50static void at91_rtc_decodetime(unsigned int timereg, unsigned int calreg,
  51                                struct rtc_time *tm)
  52{
  53        unsigned int time, date;
  54
  55        /* must read twice in case it changes */
  56        do {
  57                time = at91_rtc_read(timereg);
  58                date = at91_rtc_read(calreg);
  59        } while ((time != at91_rtc_read(timereg)) ||
  60                        (date != at91_rtc_read(calreg)));
  61
  62        tm->tm_sec  = bcd2bin((time & AT91_RTC_SEC) >> 0);
  63        tm->tm_min  = bcd2bin((time & AT91_RTC_MIN) >> 8);
  64        tm->tm_hour = bcd2bin((time & AT91_RTC_HOUR) >> 16);
  65
  66        /*
  67         * The Calendar Alarm register does not have a field for
  68         * the year - so these will return an invalid value.  When an
  69         * alarm is set, at91_alarm_year will store the current year.
  70         */
  71        tm->tm_year  = bcd2bin(date & AT91_RTC_CENT) * 100;     /* century */
  72        tm->tm_year += bcd2bin((date & AT91_RTC_YEAR) >> 8);    /* year */
  73
  74        tm->tm_wday = bcd2bin((date & AT91_RTC_DAY) >> 21) - 1; /* day of the week [0-6], Sunday=0 */
  75        tm->tm_mon  = bcd2bin((date & AT91_RTC_MONTH) >> 16) - 1;
  76        tm->tm_mday = bcd2bin((date & AT91_RTC_DATE) >> 24);
  77}
  78
  79/*
  80 * Read current time and date in RTC
  81 */
  82static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
  83{
  84        at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, tm);
  85        tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
  86        tm->tm_year = tm->tm_year - 1900;
  87
  88        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
  89                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
  90                tm->tm_hour, tm->tm_min, tm->tm_sec);
  91
  92        return 0;
  93}
  94
  95/*
  96 * Set current time and date in RTC
  97 */
  98static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
  99{
 100        unsigned long cr;
 101
 102        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 103                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 104                tm->tm_hour, tm->tm_min, tm->tm_sec);
 105
 106        /* Stop Time/Calendar from counting */
 107        cr = at91_rtc_read(AT91_RTC_CR);
 108        at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
 109
 110        at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
 111        wait_for_completion(&at91_rtc_updated); /* wait for ACKUPD interrupt */
 112        at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
 113
 114        at91_rtc_write(AT91_RTC_TIMR,
 115                          bin2bcd(tm->tm_sec) << 0
 116                        | bin2bcd(tm->tm_min) << 8
 117                        | bin2bcd(tm->tm_hour) << 16);
 118
 119        at91_rtc_write(AT91_RTC_CALR,
 120                          bin2bcd((tm->tm_year + 1900) / 100)   /* century */
 121                        | bin2bcd(tm->tm_year % 100) << 8       /* year */
 122                        | bin2bcd(tm->tm_mon + 1) << 16         /* tm_mon starts at zero */
 123                        | bin2bcd(tm->tm_wday + 1) << 21        /* day of the week [0-6], Sunday=0 */
 124                        | bin2bcd(tm->tm_mday) << 24);
 125
 126        /* Restart Time/Calendar */
 127        cr = at91_rtc_read(AT91_RTC_CR);
 128        at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM));
 129
 130        return 0;
 131}
 132
 133/*
 134 * Read alarm time and date in RTC
 135 */
 136static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 137{
 138        struct rtc_time *tm = &alrm->time;
 139
 140        at91_rtc_decodetime(AT91_RTC_TIMALR, AT91_RTC_CALALR, tm);
 141        tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
 142        tm->tm_year = at91_alarm_year - 1900;
 143
 144        alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
 145                        ? 1 : 0;
 146
 147        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 148                1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
 149                tm->tm_hour, tm->tm_min, tm->tm_sec);
 150
 151        return 0;
 152}
 153
 154/*
 155 * Set alarm time and date in RTC
 156 */
 157static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 158{
 159        struct rtc_time tm;
 160
 161        at91_rtc_decodetime(AT91_RTC_TIMR, AT91_RTC_CALR, &tm);
 162
 163        at91_alarm_year = tm.tm_year;
 164
 165        tm.tm_hour = alrm->time.tm_hour;
 166        tm.tm_min = alrm->time.tm_min;
 167        tm.tm_sec = alrm->time.tm_sec;
 168
 169        at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 170        at91_rtc_write(AT91_RTC_TIMALR,
 171                  bin2bcd(tm.tm_sec) << 0
 172                | bin2bcd(tm.tm_min) << 8
 173                | bin2bcd(tm.tm_hour) << 16
 174                | AT91_RTC_HOUREN | AT91_RTC_MINEN | AT91_RTC_SECEN);
 175        at91_rtc_write(AT91_RTC_CALALR,
 176                  bin2bcd(tm.tm_mon + 1) << 16          /* tm_mon starts at zero */
 177                | bin2bcd(tm.tm_mday) << 24
 178                | AT91_RTC_DATEEN | AT91_RTC_MTHEN);
 179
 180        if (alrm->enabled) {
 181                at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 182                at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 183        }
 184
 185        pr_debug("%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
 186                at91_alarm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
 187                tm.tm_min, tm.tm_sec);
 188
 189        return 0;
 190}
 191
 192static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 193{
 194        pr_debug("%s(): cmd=%08x\n", __func__, enabled);
 195
 196        if (enabled) {
 197                at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
 198                at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
 199        } else
 200                at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
 201
 202        return 0;
 203}
 204/*
 205 * Provide additional RTC information in /proc/driver/rtc
 206 */
 207static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
 208{
 209        unsigned long imr = at91_rtc_read(AT91_RTC_IMR);
 210
 211        seq_printf(seq, "update_IRQ\t: %s\n",
 212                        (imr & AT91_RTC_ACKUPD) ? "yes" : "no");
 213        seq_printf(seq, "periodic_IRQ\t: %s\n",
 214                        (imr & AT91_RTC_SECEV) ? "yes" : "no");
 215
 216        return 0;
 217}
 218
 219/*
 220 * IRQ handler for the RTC
 221 */
 222static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
 223{
 224        struct platform_device *pdev = dev_id;
 225        struct rtc_device *rtc = platform_get_drvdata(pdev);
 226        unsigned int rtsr;
 227        unsigned long events = 0;
 228
 229        rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
 230        if (rtsr) {             /* this interrupt is shared!  Is it ours? */
 231                if (rtsr & AT91_RTC_ALARM)
 232                        events |= (RTC_AF | RTC_IRQF);
 233                if (rtsr & AT91_RTC_SECEV)
 234                        events |= (RTC_UF | RTC_IRQF);
 235                if (rtsr & AT91_RTC_ACKUPD)
 236                        complete(&at91_rtc_updated);
 237
 238                at91_rtc_write(AT91_RTC_SCCR, rtsr);    /* clear status reg */
 239
 240                rtc_update_irq(rtc, 1, events);
 241
 242                pr_debug("%s(): num=%ld, events=0x%02lx\n", __func__,
 243                        events >> 8, events & 0x000000FF);
 244
 245                return IRQ_HANDLED;
 246        }
 247        return IRQ_NONE;                /* not handled */
 248}
 249
 250static const struct rtc_class_ops at91_rtc_ops = {
 251        .read_time      = at91_rtc_readtime,
 252        .set_time       = at91_rtc_settime,
 253        .read_alarm     = at91_rtc_readalarm,
 254        .set_alarm      = at91_rtc_setalarm,
 255        .proc           = at91_rtc_proc,
 256        .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 257};
 258
 259/*
 260 * Initialize and install RTC driver
 261 */
 262static int __init at91_rtc_probe(struct platform_device *pdev)
 263{
 264        struct rtc_device *rtc;
 265        struct resource *regs;
 266        int ret = 0;
 267
 268        regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 269        if (!regs) {
 270                dev_err(&pdev->dev, "no mmio resource defined\n");
 271                return -ENXIO;
 272        }
 273
 274        irq = platform_get_irq(pdev, 0);
 275        if (irq < 0) {
 276                dev_err(&pdev->dev, "no irq resource defined\n");
 277                return -ENXIO;
 278        }
 279
 280        at91_rtc_regs = ioremap(regs->start, resource_size(regs));
 281        if (!at91_rtc_regs) {
 282                dev_err(&pdev->dev, "failed to map registers, aborting.\n");
 283                return -ENOMEM;
 284        }
 285
 286        at91_rtc_write(AT91_RTC_CR, 0);
 287        at91_rtc_write(AT91_RTC_MR, 0);         /* 24 hour mode */
 288
 289        /* Disable all interrupts */
 290        at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 291                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
 292                                        AT91_RTC_CALEV);
 293
 294        ret = request_irq(irq, at91_rtc_interrupt,
 295                                IRQF_SHARED,
 296                                "at91_rtc", pdev);
 297        if (ret) {
 298                printk(KERN_ERR "at91_rtc: IRQ %d already in use.\n",
 299                                irq);
 300                return ret;
 301        }
 302
 303        /* cpu init code should really have flagged this device as
 304         * being wake-capable; if it didn't, do that here.
 305         */
 306        if (!device_can_wakeup(&pdev->dev))
 307                device_init_wakeup(&pdev->dev, 1);
 308
 309        rtc = rtc_device_register(pdev->name, &pdev->dev,
 310                                &at91_rtc_ops, THIS_MODULE);
 311        if (IS_ERR(rtc)) {
 312                free_irq(irq, pdev);
 313                return PTR_ERR(rtc);
 314        }
 315        platform_set_drvdata(pdev, rtc);
 316
 317        printk(KERN_INFO "AT91 Real Time Clock driver.\n");
 318        return 0;
 319}
 320
 321/*
 322 * Disable and remove the RTC driver
 323 */
 324static int __exit at91_rtc_remove(struct platform_device *pdev)
 325{
 326        struct rtc_device *rtc = platform_get_drvdata(pdev);
 327
 328        /* Disable all interrupts */
 329        at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
 330                                        AT91_RTC_SECEV | AT91_RTC_TIMEV |
 331                                        AT91_RTC_CALEV);
 332        free_irq(irq, pdev);
 333
 334        rtc_device_unregister(rtc);
 335        platform_set_drvdata(pdev, NULL);
 336
 337        return 0;
 338}
 339
 340#ifdef CONFIG_PM
 341
 342/* AT91RM9200 RTC Power management control */
 343
 344static u32 at91_rtc_imr;
 345
 346static int at91_rtc_suspend(struct device *dev)
 347{
 348        /* this IRQ is shared with DBGU and other hardware which isn't
 349         * necessarily doing PM like we are...
 350         */
 351        at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
 352                        & (AT91_RTC_ALARM|AT91_RTC_SECEV);
 353        if (at91_rtc_imr) {
 354                if (device_may_wakeup(dev))
 355                        enable_irq_wake(irq);
 356                else
 357                        at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
 358        }
 359        return 0;
 360}
 361
 362static int at91_rtc_resume(struct device *dev)
 363{
 364        if (at91_rtc_imr) {
 365                if (device_may_wakeup(dev))
 366                        disable_irq_wake(irq);
 367                else
 368                        at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
 369        }
 370        return 0;
 371}
 372
 373static const struct dev_pm_ops at91_rtc_pm = {
 374        .suspend =      at91_rtc_suspend,
 375        .resume =       at91_rtc_resume,
 376};
 377
 378#define at91_rtc_pm_ptr &at91_rtc_pm
 379
 380#else
 381#define at91_rtc_pm_ptr NULL
 382#endif
 383
 384static struct platform_driver at91_rtc_driver = {
 385        .remove         = __exit_p(at91_rtc_remove),
 386        .driver         = {
 387                .name   = "at91_rtc",
 388                .owner  = THIS_MODULE,
 389                .pm     = at91_rtc_pm_ptr,
 390        },
 391};
 392
 393static int __init at91_rtc_init(void)
 394{
 395        return platform_driver_probe(&at91_rtc_driver, at91_rtc_probe);
 396}
 397
 398static void __exit at91_rtc_exit(void)
 399{
 400        platform_driver_unregister(&at91_rtc_driver);
 401}
 402
 403module_init(at91_rtc_init);
 404module_exit(at91_rtc_exit);
 405
 406MODULE_AUTHOR("Rick Bronson");
 407MODULE_DESCRIPTION("RTC driver for Atmel AT91RM9200");
 408MODULE_LICENSE("GPL");
 409MODULE_ALIAS("platform:at91_rtc");
 410