drivers/rtc/rtc-cmos.c

   1 /*
   2  * RTC class driver for "CMOS RTC":  PCs, ACPI, etc
   3  *
   4  * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
   5  * Copyright (C) 2006 David Brownell (convert to new framework)
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 /*
  14  * The original "cmos clock" chip was an MC146818 chip, now obsolete.
  15  * That defined the register interface now provided by all PCs, some
  16  * non-PC systems, and incorporated into ACPI.  Modern PC chipsets
  17  * integrate an MC146818 clone in their southbridge, and boards use
  18  * that instead of discrete clones like the DS12887 or M48T86.  There
  19  * are also clones that connect using the LPC bus.
  20  *
  21  * That register API is also used directly by various other drivers
  22  * (notably for integrated NVRAM), infrastructure (x86 has code to
  23  * bypass the RTC framework, directly reading the RTC during boot
  24  * and updating minutes/seconds for systems using NTP synch) and
  25  * utilities (like userspace 'hwclock', if no /dev node exists).
  26  *
  27  * So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
  28  * interrupts disabled, holding the global rtc_lock, to exclude those
  29  * other drivers and utilities on correctly configured systems.
  30  */
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/mod_devicetable.h>
  38
  39 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
  40 #include <asm-generic/rtc.h>
  41
  42
  43 struct cmos_rtc {
  44         struct rtc_device       *rtc;
  45         struct device           *dev;
  46         int                     irq;
  47         struct resource         *iomem;
  48
  49         void                    (*wake_on)(struct device *);
  50         void                    (*wake_off)(struct device *);
  51
  52         u8                      enabled_wake;
  53         u8                      suspend_ctrl;
  54
  55         /* newer hardware extends the original register set */
  56         u8                      day_alrm;
  57         u8                      mon_alrm;
  58         u8                      century;
  59 };
  60
  61 /* both platform and pnp busses use negative numbers for invalid irqs */
  62 #define is_valid_irq(n)         ((n) >= 0)
  63
  64 static const char driver_name[] = "rtc_cmos";
  65
  66 /* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
  67  * always mask it against the irq enable bits in RTC_CONTROL.  Bit values
  68  * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
  69  */
  70 #define RTC_IRQMASK     (RTC_PF | RTC_AF | RTC_UF)
  71
  72 static inline int is_intr(u8 rtc_intr)
  73 {
  74         if (!(rtc_intr & RTC_IRQF))
  75                 return 0;
  76         return rtc_intr & RTC_IRQMASK;
  77 }
  78
  79 /*----------------------------------------------------------------*/
  80
  81 static int cmos_read_time(struct device *dev, struct rtc_time *t)
  82 {
  83         /* REVISIT:  if the clock has a "century" register, use
  84          * that instead of the heuristic in get_rtc_time().
  85          * That'll make Y3K compatility (year > 2070) easy!
  86          */
  87         get_rtc_time(t);
  88         return 0;
  89 }
  90
  91 static int cmos_set_time(struct device *dev, struct rtc_time *t)
  92 {
  93         /* REVISIT:  set the "century" register if available
  94          *
  95          * NOTE: this ignores the issue whereby updating the seconds
  96          * takes effect exactly 500ms after we write the register.
  97          * (Also queueing and other delays before we get this far.)
  98          */
  99         return set_rtc_time(t);
 100 }
 101
 102 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 103 {
 104         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 105         unsigned char   rtc_control;
 106
 107         if (!is_valid_irq(cmos->irq))
 108                 return -EIO;
 109
 110         /* Basic alarms only support hour, minute, and seconds fields.
 111          * Some also support day and month, for alarms up to a year in
 112          * the future.
 113          */
 114         t->time.tm_mday = -1;
 115         t->time.tm_mon = -1;
 116
 117         spin_lock_irq(&rtc_lock);
 118         t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
 119         t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
 120         t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
 121
 122         if (cmos->day_alrm) {
 123                 t->time.tm_mday = CMOS_READ(cmos->day_alrm);
 124                 if (!t->time.tm_mday)
 125                         t->time.tm_mday = -1;
 126
 127                 if (cmos->mon_alrm) {
 128                         t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
 129                         if (!t->time.tm_mon)
 130                                 t->time.tm_mon = -1;
 131                 }
 132         }
 133
 134         rtc_control = CMOS_READ(RTC_CONTROL);
 135         spin_unlock_irq(&rtc_lock);
 136
 137         /* REVISIT this assumes PC style usage:  always BCD */
 138
 139         if (((unsigned)t->time.tm_sec) < 0x60)
 140                 t->time.tm_sec = BCD2BIN(t->time.tm_sec);
 141         else
 142                 t->time.tm_sec = -1;
 143         if (((unsigned)t->time.tm_min) < 0x60)
 144                 t->time.tm_min = BCD2BIN(t->time.tm_min);
 145         else
 146                 t->time.tm_min = -1;
 147         if (((unsigned)t->time.tm_hour) < 0x24)
 148                 t->time.tm_hour = BCD2BIN(t->time.tm_hour);
 149         else
 150                 t->time.tm_hour = -1;
 151
 152         if (cmos->day_alrm) {
 153                 if (((unsigned)t->time.tm_mday) <= 0x31)
 154                         t->time.tm_mday = BCD2BIN(t->time.tm_mday);
 155                 else
 156                         t->time.tm_mday = -1;
 157                 if (cmos->mon_alrm) {
 158                         if (((unsigned)t->time.tm_mon) <= 0x12)
 159                                 t->time.tm_mon = BCD2BIN(t->time.tm_mon) - 1;
 160                         else
 161                                 t->time.tm_mon = -1;
 162                 }
 163         }
 164         t->time.tm_year = -1;
 165
 166         t->enabled = !!(rtc_control & RTC_AIE);
 167         t->pending = 0;
 168
 169         return 0;
 170 }
 171
 172 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 173 {
 174         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 175         unsigned char   mon, mday, hrs, min, sec;
 176         unsigned char   rtc_control, rtc_intr;
 177
 178         if (!is_valid_irq(cmos->irq))
 179                 return -EIO;
 180
 181         /* REVISIT this assumes PC style usage:  always BCD */
 182
 183         /* Writing 0xff means "don't care" or "match all".  */
 184
 185         mon = t->time.tm_mon;
 186         mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
 187         mon++;
 188
 189         mday = t->time.tm_mday;
 190         mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
 191
 192         hrs = t->time.tm_hour;
 193         hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;
 194
 195         min = t->time.tm_min;
 196         min = (min < 60) ? BIN2BCD(min) : 0xff;
 197
 198         sec = t->time.tm_sec;
 199         sec = (sec < 60) ? BIN2BCD(sec) : 0xff;
 200
 201         spin_lock_irq(&rtc_lock);
 202
 203         /* next rtc irq must not be from previous alarm setting */
 204         rtc_control = CMOS_READ(RTC_CONTROL);
 205         rtc_control &= ~RTC_AIE;
 206         CMOS_WRITE(rtc_control, RTC_CONTROL);
 207         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 208         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 209         if (is_intr(rtc_intr))
 210                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 211
 212         /* update alarm */
 213         CMOS_WRITE(hrs, RTC_HOURS_ALARM);
 214         CMOS_WRITE(min, RTC_MINUTES_ALARM);
 215         CMOS_WRITE(sec, RTC_SECONDS_ALARM);
 216
 217         /* the system may support an "enhanced" alarm */
 218         if (cmos->day_alrm) {
 219                 CMOS_WRITE(mday, cmos->day_alrm);
 220                 if (cmos->mon_alrm)
 221                         CMOS_WRITE(mon, cmos->mon_alrm);
 222         }
 223
 224         if (t->enabled) {
 225                 rtc_control |= RTC_AIE;
 226                 CMOS_WRITE(rtc_control, RTC_CONTROL);
 227                 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 228                 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 229                 if (is_intr(rtc_intr))
 230                         rtc_update_irq(cmos->rtc, 1, rtc_intr);
 231         }
 232
 233         spin_unlock_irq(&rtc_lock);
 234
 235         return 0;
 236 }
 237
 238 static int cmos_irq_set_freq(struct device *dev, int freq)
 239 {
 240         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 241         int             f;
 242         unsigned long   flags;
 243
 244         if (!is_valid_irq(cmos->irq))
 245                 return -ENXIO;
 246
 247         /* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
 248         f = ffs(freq);
 249         if (f != 0) {
 250                 if (f-- > 16 || freq != (1 << f))
 251                         return -EINVAL;
 252                 f = 16 - f;
 253         }
 254
 255         spin_lock_irqsave(&rtc_lock, flags);
 256         CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
 257         spin_unlock_irqrestore(&rtc_lock, flags);
 258
 259         return 0;
 260 }
 261
 262 static int cmos_irq_set_state(struct device *dev, int enabled)
 263 {
 264         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 265         unsigned char   rtc_control, rtc_intr;
 266         unsigned long   flags;
 267
 268         if (!is_valid_irq(cmos->irq))
 269                 return -ENXIO;
 270
 271         spin_lock_irqsave(&rtc_lock, flags);
 272         rtc_control = CMOS_READ(RTC_CONTROL);
 273
 274         if (enabled)
 275                 rtc_control |= RTC_PIE;
 276         else
 277                 rtc_control &= ~RTC_PIE;
 278
 279         CMOS_WRITE(rtc_control, RTC_CONTROL);
 280
 281         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 282         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 283         if (is_intr(rtc_intr))
 284                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 285
 286         spin_unlock_irqrestore(&rtc_lock, flags);
 287         return 0;
 288 }
 289
 290 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 291
 292 static int
 293 cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 294 {
 295         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 296         unsigned char   rtc_control, rtc_intr;
 297         unsigned long   flags;
 298
 299         switch (cmd) {
 300         case RTC_AIE_OFF:
 301         case RTC_AIE_ON:
 302         case RTC_UIE_OFF:
 303         case RTC_UIE_ON:
 304         case RTC_PIE_OFF:
 305         case RTC_PIE_ON:
 306                 if (!is_valid_irq(cmos->irq))
 307                         return -EINVAL;
 308                 break;
 309         default:
 310                 return -ENOIOCTLCMD;
 311         }
 312
 313         spin_lock_irqsave(&rtc_lock, flags);
 314         rtc_control = CMOS_READ(RTC_CONTROL);
 315         switch (cmd) {
 316         case RTC_AIE_OFF:       /* alarm off */
 317                 rtc_control &= ~RTC_AIE;
 318                 break;
 319         case RTC_AIE_ON:        /* alarm on */
 320                 rtc_control |= RTC_AIE;
 321                 break;
 322         case RTC_UIE_OFF:       /* update off */
 323                 rtc_control &= ~RTC_UIE;
 324                 break;
 325         case RTC_UIE_ON:        /* update on */
 326                 rtc_control |= RTC_UIE;
 327                 break;
 328         case RTC_PIE_OFF:       /* periodic off */
 329                 rtc_control &= ~RTC_PIE;
 330                 break;
 331         case RTC_PIE_ON:        /* periodic on */
 332                 rtc_control |= RTC_PIE;
 333                 break;
 334         }
 335         CMOS_WRITE(rtc_control, RTC_CONTROL);
 336         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 337         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 338         if (is_intr(rtc_intr))
 339                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 340         spin_unlock_irqrestore(&rtc_lock, flags);
 341         return 0;
 342 }
 343
 344 #else
 345 #define cmos_rtc_ioctl  NULL
 346 #endif
 347
 348 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 349
 350 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 351 {
 352         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 353         unsigned char   rtc_control, valid;
 354
 355         spin_lock_irq(&rtc_lock);
 356         rtc_control = CMOS_READ(RTC_CONTROL);
 357         valid = CMOS_READ(RTC_VALID);
 358         spin_unlock_irq(&rtc_lock);
 359
 360         /* NOTE:  at least ICH6 reports battery status using a different
 361          * (non-RTC) bit; and SQWE is ignored on many current systems.
 362          */
 363         return seq_printf(seq,
 364                         "periodic_IRQ\t: %s\n"
 365                         "update_IRQ\t: %s\n"
 366                         // "square_wave\t: %s\n"
 367                         // "BCD\t\t: %s\n"
 368                         "DST_enable\t: %s\n"
 369                         "periodic_freq\t: %d\n"
 370                         "batt_status\t: %s\n",
 371                         (rtc_control & RTC_PIE) ? "yes" : "no",
 372                         (rtc_control & RTC_UIE) ? "yes" : "no",
 373                         // (rtc_control & RTC_SQWE) ? "yes" : "no",
 374                         // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 375                         (rtc_control & RTC_DST_EN) ? "yes" : "no",
 376                         cmos->rtc->irq_freq,
 377                         (valid & RTC_VRT) ? "okay" : "dead");
 378 }
 379
 380 #else
 381 #define cmos_procfs     NULL
 382 #endif
 383
 384 static const struct rtc_class_ops cmos_rtc_ops = {
 385         .ioctl          = cmos_rtc_ioctl,
 386         .read_time      = cmos_read_time,
 387         .set_time       = cmos_set_time,
 388         .read_alarm     = cmos_read_alarm,
 389         .set_alarm      = cmos_set_alarm,
 390         .proc           = cmos_procfs,
 391         .irq_set_freq   = cmos_irq_set_freq,
 392         .irq_set_state  = cmos_irq_set_state,
 393 };
 394
 395 /*----------------------------------------------------------------*/
 396
 397 static struct cmos_rtc  cmos_rtc;
 398
 399 static irqreturn_t cmos_interrupt(int irq, void *p)
 400 {
 401         u8              irqstat;
 402
 403         spin_lock(&rtc_lock);
 404         irqstat = CMOS_READ(RTC_INTR_FLAGS);
 405         irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
 406         spin_unlock(&rtc_lock);
 407
 408         if (is_intr(irqstat)) {
 409                 rtc_update_irq(p, 1, irqstat);
 410                 return IRQ_HANDLED;
 411         } else
 412                 return IRQ_NONE;
 413 }
 414
 415 #ifdef  CONFIG_PNP
 416 #define is_pnp()        1
 417 #define INITSECTION
 418
 419 #else
 420 #define is_pnp()        0
 421 #define INITSECTION     __init
 422 #endif
 423
 424 static int INITSECTION
 425 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 426 {
 427         struct cmos_rtc_board_info      *info = dev->platform_data;
 428         int                             retval = 0;
 429         unsigned char                   rtc_control;
 430
 431         /* there can be only one ... */
 432         if (cmos_rtc.dev)
 433                 return -EBUSY;
 434
 435         if (!ports)
 436                 return -ENODEV;
 437
 438         cmos_rtc.irq = rtc_irq;
 439         cmos_rtc.iomem = ports;
 440
 441         /* For ACPI systems extension info comes from the FADT.  On others,
 442          * board specific setup provides it as appropriate.  Systems where
 443          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
 444          * some almost-clones) can provide hooks to make that behave.
 445          */
 446         if (info) {
 447                 cmos_rtc.day_alrm = info->rtc_day_alarm;
 448                 cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 449                 cmos_rtc.century = info->rtc_century;
 450
 451                 if (info->wake_on && info->wake_off) {
 452                         cmos_rtc.wake_on = info->wake_on;
 453                         cmos_rtc.wake_off = info->wake_off;
 454                 }
 455         }
 456
 457         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
 458                                 &cmos_rtc_ops, THIS_MODULE);
 459         if (IS_ERR(cmos_rtc.rtc))
 460                 return PTR_ERR(cmos_rtc.rtc);
 461
 462         cmos_rtc.dev = dev;
 463         dev_set_drvdata(dev, &cmos_rtc);
 464
 465         /* platform and pnp busses handle resources incompatibly.
 466          *
 467          * REVISIT for non-x86 systems we may need to handle io memory
 468          * resources: ioremap them, and request_mem_region().
 469          */
 470         if (is_pnp()) {
 471                 retval = request_resource(&ioport_resource, ports);
 472                 if (retval < 0) {
 473                         dev_dbg(dev, "i/o registers already in use\n");
 474                         goto cleanup0;
 475                 }
 476         }
 477         rename_region(ports, cmos_rtc.rtc->dev.bus_id);
 478
 479         spin_lock_irq(&rtc_lock);
 480
 481         /* force periodic irq to CMOS reset default of 1024Hz;
 482          *
 483          * REVISIT it's been reported that at least one x86_64 ALI mobo
 484          * doesn't use 32KHz here ... for portability we might need to
 485          * do something about other clock frequencies.
 486          */
 487         CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
 488         cmos_rtc.rtc->irq_freq = 1024;
 489
 490         /* disable irqs.
 491          *
 492          * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
 493          * allegedly some older rtcs need that to handle irqs properly
 494          */
 495         rtc_control = CMOS_READ(RTC_CONTROL);
 496         rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
 497         CMOS_WRITE(rtc_control, RTC_CONTROL);
 498         CMOS_READ(RTC_INTR_FLAGS);
 499
 500         spin_unlock_irq(&rtc_lock);
 501
 502         /* FIXME teach the alarm code how to handle binary mode;
 503          * <asm-generic/rtc.h> doesn't know 12-hour mode either.
 504          */
 505         if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
 506                 dev_dbg(dev, "only 24-hr BCD mode supported\n");
 507                 retval = -ENXIO;
 508                 goto cleanup1;
 509         }
 510
 511         if (is_valid_irq(rtc_irq))
 512                 retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
 513                                 cmos_rtc.rtc->dev.bus_id,
 514                                 cmos_rtc.rtc);
 515         if (retval < 0) {
 516                 dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 517                 goto cleanup1;
 518         }
 519
 520         /* REVISIT optionally make 50 or 114 bytes NVRAM available,
 521          * like rtc-ds1553, rtc-ds1742 ... this will often include
 522          * registers for century, and day/month alarm.
 523          */
 524
 525         pr_info("%s: alarms up to one %s%s\n",
 526                         cmos_rtc.rtc->dev.bus_id,
 527                         is_valid_irq(rtc_irq)
 528                                 ?  (cmos_rtc.mon_alrm
 529                                         ? "year"
 530                                         : (cmos_rtc.day_alrm
 531                                                 ? "month" : "day"))
 532                                 : "no",
 533                         cmos_rtc.century ? ", y3k" : ""
 534                         );
 535
 536         return 0;
 537
 538 cleanup1:
 539         rename_region(ports, NULL);
 540 cleanup0:
 541         rtc_device_unregister(cmos_rtc.rtc);
 542         return retval;
 543 }
 544
 545 static void cmos_do_shutdown(void)
 546 {
 547         unsigned char   rtc_control;
 548
 549         spin_lock_irq(&rtc_lock);
 550         rtc_control = CMOS_READ(RTC_CONTROL);
 551         rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 552         CMOS_WRITE(rtc_control, RTC_CONTROL);
 553         CMOS_READ(RTC_INTR_FLAGS);
 554         spin_unlock_irq(&rtc_lock);
 555 }
 556
 557 static void __exit cmos_do_remove(struct device *dev)
 558 {
 559         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 560
 561         cmos_do_shutdown();
 562
 563         if (is_pnp())
 564                 release_resource(cmos->iomem);
 565         rename_region(cmos->iomem, NULL);
 566
 567         if (is_valid_irq(cmos->irq))
 568                 free_irq(cmos->irq, cmos_rtc.rtc);
 569
 570         rtc_device_unregister(cmos_rtc.rtc);
 571
 572         cmos_rtc.dev = NULL;
 573         dev_set_drvdata(dev, NULL);
 574 }
 575
 576 #ifdef  CONFIG_PM
 577
 578 static int cmos_suspend(struct device *dev, pm_message_t mesg)
 579 {
 580         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 581         int             do_wake = device_may_wakeup(dev);
 582         unsigned char   tmp;
 583
 584         /* only the alarm might be a wakeup event source */
 585         spin_lock_irq(&rtc_lock);
 586         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 587         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 588                 unsigned char   irqstat;
 589
 590                 if (do_wake)
 591                         tmp &= ~(RTC_PIE|RTC_UIE);
 592                 else
 593                         tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 594                 CMOS_WRITE(tmp, RTC_CONTROL);
 595                 irqstat = CMOS_READ(RTC_INTR_FLAGS);
 596                 irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
 597                 if (is_intr(irqstat))
 598                         rtc_update_irq(cmos->rtc, 1, irqstat);
 599         }
 600         spin_unlock_irq(&rtc_lock);
 601
 602         if (tmp & RTC_AIE) {
 603                 cmos->enabled_wake = 1;
 604                 if (cmos->wake_on)
 605                         cmos->wake_on(dev);
 606                 else
 607                         enable_irq_wake(cmos->irq);
 608         }
 609
 610         pr_debug("%s: suspend%s, ctrl %02x\n",
 611                         cmos_rtc.rtc->dev.bus_id,
 612                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
 613                         tmp);
 614
 615         return 0;
 616 }
 617
 618 static int cmos_resume(struct device *dev)
 619 {
 620         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 621         unsigned char   tmp = cmos->suspend_ctrl;
 622
 623         /* re-enable any irqs previously active */
 624         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 625
 626                 if (cmos->enabled_wake) {
 627                         if (cmos->wake_off)
 628                                 cmos->wake_off(dev);
 629                         else
 630                                 disable_irq_wake(cmos->irq);
 631                         cmos->enabled_wake = 0;
 632                 }
 633
 634                 spin_lock_irq(&rtc_lock);
 635                 CMOS_WRITE(tmp, RTC_CONTROL);
 636                 tmp = CMOS_READ(RTC_INTR_FLAGS);
 637                 tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
 638                 if (is_intr(tmp))
 639                         rtc_update_irq(cmos->rtc, 1, tmp);
 640                 spin_unlock_irq(&rtc_lock);
 641         }
 642
 643         pr_debug("%s: resume, ctrl %02x\n",
 644                         cmos_rtc.rtc->dev.bus_id,
 645                         cmos->suspend_ctrl);
 646
 647
 648         return 0;
 649 }
 650
 651 #else
 652 #define cmos_suspend    NULL
 653 #define cmos_resume     NULL
 654 #endif
 655
 656 /*----------------------------------------------------------------*/
 657
 658 /* The "CMOS" RTC normally lives on the platform_bus.  On ACPI systems,
 659  * the device node will always be created as a PNPACPI device.
 660  */
 661
 662 #ifdef  CONFIG_PNP
 663
 664 #include <linux/pnp.h>
 665
 666 static int __devinit
 667 cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 668 {
 669         /* REVISIT paranoia argues for a shutdown notifier, since PNP
 670          * drivers can't provide shutdown() methods to disable IRQs.
 671          * Or better yet, fix PNP to allow those methods...
 672          */
 673         if (pnp_port_start(pnp,0) == 0x70 && !pnp_irq_valid(pnp,0))
 674                 /* Some machines contain a PNP entry for the RTC, but
 675                  * don't define the IRQ. It should always be safe to
 676                  * hardcode it in these cases
 677                  */
 678                 return cmos_do_probe(&pnp->dev, &pnp->res.port_resource[0], 8);
 679         else
 680                 return cmos_do_probe(&pnp->dev,
 681                                      &pnp->res.port_resource[0],
 682                                      pnp->res.irq_resource[0].start);
 683 }
 684
 685 static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
 686 {
 687         cmos_do_remove(&pnp->dev);
 688 }
 689
 690 #ifdef  CONFIG_PM
 691
 692 static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
 693 {
 694         return cmos_suspend(&pnp->dev, mesg);
 695 }
 696
 697 static int cmos_pnp_resume(struct pnp_dev *pnp)
 698 {
 699         return cmos_resume(&pnp->dev);
 700 }
 701
 702 #else
 703 #define cmos_pnp_suspend        NULL
 704 #define cmos_pnp_resume         NULL
 705 #endif
 706
 707
 708 static const struct pnp_device_id rtc_ids[] = {
 709         { .id = "PNP0b00", },
 710         { .id = "PNP0b01", },
 711         { .id = "PNP0b02", },
 712         { },
 713 };
 714 MODULE_DEVICE_TABLE(pnp, rtc_ids);
 715
 716 static struct pnp_driver cmos_pnp_driver = {
 717         .name           = (char *) driver_name,
 718         .id_table       = rtc_ids,
 719         .probe          = cmos_pnp_probe,
 720         .remove         = __exit_p(cmos_pnp_remove),
 721
 722         /* flag ensures resume() gets called, and stops syslog spam */
 723         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
 724         .suspend        = cmos_pnp_suspend,
 725         .resume         = cmos_pnp_resume,
 726 };
 727
 728 static int __init cmos_init(void)
 729 {
 730         return pnp_register_driver(&cmos_pnp_driver);
 731 }
 732 module_init(cmos_init);
 733
 734 static void __exit cmos_exit(void)
 735 {
 736         pnp_unregister_driver(&cmos_pnp_driver);
 737 }
 738 module_exit(cmos_exit);
 739
 740 #else   /* no PNP */
 741
 742 /*----------------------------------------------------------------*/
 743
 744 /* Platform setup should have set up an RTC device, when PNP is
 745  * unavailable ... this could happen even on (older) PCs.
 746  */
 747
 748 static int __init cmos_platform_probe(struct platform_device *pdev)
 749 {
 750         return cmos_do_probe(&pdev->dev,
 751                         platform_get_resource(pdev, IORESOURCE_IO, 0),
 752                         platform_get_irq(pdev, 0));
 753 }
 754
 755 static int __exit cmos_platform_remove(struct platform_device *pdev)
 756 {
 757         cmos_do_remove(&pdev->dev);
 758         return 0;
 759 }
 760
 761 static void cmos_platform_shutdown(struct platform_device *pdev)
 762 {
 763         cmos_do_shutdown();
 764 }
 765
 766 static struct platform_driver cmos_platform_driver = {
 767         .remove         = __exit_p(cmos_platform_remove),
 768         .shutdown       = cmos_platform_shutdown,
 769         .driver = {
 770                 .name           = (char *) driver_name,
 771                 .suspend        = cmos_suspend,
 772                 .resume         = cmos_resume,
 773         }
 774 };
 775
 776 static int __init cmos_init(void)
 777 {
 778         return platform_driver_probe(&cmos_platform_driver,
 779                         cmos_platform_probe);
 780 }
 781 module_init(cmos_init);
 782
 783 static void __exit cmos_exit(void)
 784 {
 785         platform_driver_unregister(&cmos_platform_driver);
 786 }
 787 module_exit(cmos_exit);
 788
 789
 790 #endif  /* !PNP */
 791
 792 MODULE_AUTHOR("David Brownell");
 793 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
 794 MODULE_LICENSE("GPL");