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                 /* ignore upper bits on readback per ACPI spec */
 124                 t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
 125                 if (!t->time.tm_mday)
 126                         t->time.tm_mday = -1;
 127
 128                 if (cmos->mon_alrm) {
 129                         t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
 130                         if (!t->time.tm_mon)
 131                                 t->time.tm_mon = -1;
 132                 }
 133         }
 134
 135         rtc_control = CMOS_READ(RTC_CONTROL);
 136         spin_unlock_irq(&rtc_lock);
 137
 138         /* REVISIT this assumes PC style usage:  always BCD */
 139
 140         if (((unsigned)t->time.tm_sec) < 0x60)
 141                 t->time.tm_sec = BCD2BIN(t->time.tm_sec);
 142         else
 143                 t->time.tm_sec = -1;
 144         if (((unsigned)t->time.tm_min) < 0x60)
 145                 t->time.tm_min = BCD2BIN(t->time.tm_min);
 146         else
 147                 t->time.tm_min = -1;
 148         if (((unsigned)t->time.tm_hour) < 0x24)
 149                 t->time.tm_hour = BCD2BIN(t->time.tm_hour);
 150         else
 151                 t->time.tm_hour = -1;
 152
 153         if (cmos->day_alrm) {
 154                 if (((unsigned)t->time.tm_mday) <= 0x31)
 155                         t->time.tm_mday = BCD2BIN(t->time.tm_mday);
 156                 else
 157                         t->time.tm_mday = -1;
 158                 if (cmos->mon_alrm) {
 159                         if (((unsigned)t->time.tm_mon) <= 0x12)
 160                                 t->time.tm_mon = BCD2BIN(t->time.tm_mon) - 1;
 161                         else
 162                                 t->time.tm_mon = -1;
 163                 }
 164         }
 165         t->time.tm_year = -1;
 166
 167         t->enabled = !!(rtc_control & RTC_AIE);
 168         t->pending = 0;
 169
 170         return 0;
 171 }
 172
 173 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 174 {
 175         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 176         unsigned char   mon, mday, hrs, min, sec;
 177         unsigned char   rtc_control, rtc_intr;
 178
 179         if (!is_valid_irq(cmos->irq))
 180                 return -EIO;
 181
 182         /* REVISIT this assumes PC style usage:  always BCD */
 183
 184         /* Writing 0xff means "don't care" or "match all".  */
 185
 186         mon = t->time.tm_mon;
 187         mon = (mon < 12) ? BIN2BCD(mon) : 0xff;
 188         mon++;
 189
 190         mday = t->time.tm_mday;
 191         mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
 192
 193         hrs = t->time.tm_hour;
 194         hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;
 195
 196         min = t->time.tm_min;
 197         min = (min < 60) ? BIN2BCD(min) : 0xff;
 198
 199         sec = t->time.tm_sec;
 200         sec = (sec < 60) ? BIN2BCD(sec) : 0xff;
 201
 202         spin_lock_irq(&rtc_lock);
 203
 204         /* next rtc irq must not be from previous alarm setting */
 205         rtc_control = CMOS_READ(RTC_CONTROL);
 206         rtc_control &= ~RTC_AIE;
 207         CMOS_WRITE(rtc_control, RTC_CONTROL);
 208         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 209         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 210         if (is_intr(rtc_intr))
 211                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 212
 213         /* update alarm */
 214         CMOS_WRITE(hrs, RTC_HOURS_ALARM);
 215         CMOS_WRITE(min, RTC_MINUTES_ALARM);
 216         CMOS_WRITE(sec, RTC_SECONDS_ALARM);
 217
 218         /* the system may support an "enhanced" alarm */
 219         if (cmos->day_alrm) {
 220                 CMOS_WRITE(mday, cmos->day_alrm);
 221                 if (cmos->mon_alrm)
 222                         CMOS_WRITE(mon, cmos->mon_alrm);
 223         }
 224
 225         if (t->enabled) {
 226                 rtc_control |= RTC_AIE;
 227                 CMOS_WRITE(rtc_control, RTC_CONTROL);
 228                 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 229                 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 230                 if (is_intr(rtc_intr))
 231                         rtc_update_irq(cmos->rtc, 1, rtc_intr);
 232         }
 233
 234         spin_unlock_irq(&rtc_lock);
 235
 236         return 0;
 237 }
 238
 239 static int cmos_irq_set_freq(struct device *dev, int freq)
 240 {
 241         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 242         int             f;
 243         unsigned long   flags;
 244
 245         if (!is_valid_irq(cmos->irq))
 246                 return -ENXIO;
 247
 248         /* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
 249         f = ffs(freq);
 250         if (f-- > 16)
 251                 return -EINVAL;
 252         f = 16 - f;
 253
 254         spin_lock_irqsave(&rtc_lock, flags);
 255         CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
 256         spin_unlock_irqrestore(&rtc_lock, flags);
 257
 258         return 0;
 259 }
 260
 261 static int cmos_irq_set_state(struct device *dev, int enabled)
 262 {
 263         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 264         unsigned char   rtc_control, rtc_intr;
 265         unsigned long   flags;
 266
 267         if (!is_valid_irq(cmos->irq))
 268                 return -ENXIO;
 269
 270         spin_lock_irqsave(&rtc_lock, flags);
 271         rtc_control = CMOS_READ(RTC_CONTROL);
 272
 273         if (enabled)
 274                 rtc_control |= RTC_PIE;
 275         else
 276                 rtc_control &= ~RTC_PIE;
 277
 278         CMOS_WRITE(rtc_control, RTC_CONTROL);
 279
 280         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 281         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 282         if (is_intr(rtc_intr))
 283                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 284
 285         spin_unlock_irqrestore(&rtc_lock, flags);
 286         return 0;
 287 }
 288
 289 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 290
 291 static int
 292 cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 293 {
 294         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 295         unsigned char   rtc_control, rtc_intr;
 296         unsigned long   flags;
 297
 298         switch (cmd) {
 299         case RTC_AIE_OFF:
 300         case RTC_AIE_ON:
 301         case RTC_UIE_OFF:
 302         case RTC_UIE_ON:
 303         case RTC_PIE_OFF:
 304         case RTC_PIE_ON:
 305                 if (!is_valid_irq(cmos->irq))
 306                         return -EINVAL;
 307                 break;
 308         default:
 309                 return -ENOIOCTLCMD;
 310         }
 311
 312         spin_lock_irqsave(&rtc_lock, flags);
 313         rtc_control = CMOS_READ(RTC_CONTROL);
 314         switch (cmd) {
 315         case RTC_AIE_OFF:       /* alarm off */
 316                 rtc_control &= ~RTC_AIE;
 317                 break;
 318         case RTC_AIE_ON:        /* alarm on */
 319                 rtc_control |= RTC_AIE;
 320                 break;
 321         case RTC_UIE_OFF:       /* update off */
 322                 rtc_control &= ~RTC_UIE;
 323                 break;
 324         case RTC_UIE_ON:        /* update on */
 325                 rtc_control |= RTC_UIE;
 326                 break;
 327         case RTC_PIE_OFF:       /* periodic off */
 328                 rtc_control &= ~RTC_PIE;
 329                 break;
 330         case RTC_PIE_ON:        /* periodic on */
 331                 rtc_control |= RTC_PIE;
 332                 break;
 333         }
 334         CMOS_WRITE(rtc_control, RTC_CONTROL);
 335         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 336         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 337         if (is_intr(rtc_intr))
 338                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 339         spin_unlock_irqrestore(&rtc_lock, flags);
 340         return 0;
 341 }
 342
 343 #else
 344 #define cmos_rtc_ioctl  NULL
 345 #endif
 346
 347 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 348
 349 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 350 {
 351         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 352         unsigned char   rtc_control, valid;
 353
 354         spin_lock_irq(&rtc_lock);
 355         rtc_control = CMOS_READ(RTC_CONTROL);
 356         valid = CMOS_READ(RTC_VALID);
 357         spin_unlock_irq(&rtc_lock);
 358
 359         /* NOTE:  at least ICH6 reports battery status using a different
 360          * (non-RTC) bit; and SQWE is ignored on many current systems.
 361          */
 362         return seq_printf(seq,
 363                         "periodic_IRQ\t: %s\n"
 364                         "update_IRQ\t: %s\n"
 365                         // "square_wave\t: %s\n"
 366                         // "BCD\t\t: %s\n"
 367                         "DST_enable\t: %s\n"
 368                         "periodic_freq\t: %d\n"
 369                         "batt_status\t: %s\n",
 370                         (rtc_control & RTC_PIE) ? "yes" : "no",
 371                         (rtc_control & RTC_UIE) ? "yes" : "no",
 372                         // (rtc_control & RTC_SQWE) ? "yes" : "no",
 373                         // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 374                         (rtc_control & RTC_DST_EN) ? "yes" : "no",
 375                         cmos->rtc->irq_freq,
 376                         (valid & RTC_VRT) ? "okay" : "dead");
 377 }
 378
 379 #else
 380 #define cmos_procfs     NULL
 381 #endif
 382
 383 static const struct rtc_class_ops cmos_rtc_ops = {
 384         .ioctl          = cmos_rtc_ioctl,
 385         .read_time      = cmos_read_time,
 386         .set_time       = cmos_set_time,
 387         .read_alarm     = cmos_read_alarm,
 388         .set_alarm      = cmos_set_alarm,
 389         .proc           = cmos_procfs,
 390         .irq_set_freq   = cmos_irq_set_freq,
 391         .irq_set_state  = cmos_irq_set_state,
 392 };
 393
 394 /*----------------------------------------------------------------*/
 395
 396 static struct cmos_rtc  cmos_rtc;
 397
 398 static irqreturn_t cmos_interrupt(int irq, void *p)
 399 {
 400         u8              irqstat;
 401
 402         spin_lock(&rtc_lock);
 403         irqstat = CMOS_READ(RTC_INTR_FLAGS);
 404         irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
 405         spin_unlock(&rtc_lock);
 406
 407         if (is_intr(irqstat)) {
 408                 rtc_update_irq(p, 1, irqstat);
 409                 return IRQ_HANDLED;
 410         } else
 411                 return IRQ_NONE;
 412 }
 413
 414 #ifdef  CONFIG_PNP
 415 #define is_pnp()        1
 416 #define INITSECTION
 417
 418 #else
 419 #define is_pnp()        0
 420 #define INITSECTION     __init
 421 #endif
 422
 423 static int INITSECTION
 424 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 425 {
 426         struct cmos_rtc_board_info      *info = dev->platform_data;
 427         int                             retval = 0;
 428         unsigned char                   rtc_control;
 429
 430         /* there can be only one ... */
 431         if (cmos_rtc.dev)
 432                 return -EBUSY;
 433
 434         if (!ports)
 435                 return -ENODEV;
 436
 437         /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
 438          *
 439          * REVISIT non-x86 systems may instead use memory space resources
 440          * (needing ioremap etc), not i/o space resources like this ...
 441          */
 442         ports = request_region(ports->start,
 443                         ports->end + 1 - ports->start,
 444                         driver_name);
 445         if (!ports) {
 446                 dev_dbg(dev, "i/o registers already in use\n");
 447                 return -EBUSY;
 448         }
 449
 450         cmos_rtc.irq = rtc_irq;
 451         cmos_rtc.iomem = ports;
 452
 453         /* For ACPI systems extension info comes from the FADT.  On others,
 454          * board specific setup provides it as appropriate.  Systems where
 455          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
 456          * some almost-clones) can provide hooks to make that behave.
 457          */
 458         if (info) {
 459                 cmos_rtc.day_alrm = info->rtc_day_alarm;
 460                 cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 461                 cmos_rtc.century = info->rtc_century;
 462
 463                 if (info->wake_on && info->wake_off) {
 464                         cmos_rtc.wake_on = info->wake_on;
 465                         cmos_rtc.wake_off = info->wake_off;
 466                 }
 467         }
 468
 469         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
 470                                 &cmos_rtc_ops, THIS_MODULE);
 471         if (IS_ERR(cmos_rtc.rtc)) {
 472                 retval = PTR_ERR(cmos_rtc.rtc);
 473                 goto cleanup0;
 474         }
 475
 476         cmos_rtc.dev = dev;
 477         dev_set_drvdata(dev, &cmos_rtc);
 478         rename_region(ports, cmos_rtc.rtc->dev.bus_id);
 479
 480         spin_lock_irq(&rtc_lock);
 481
 482         /* force periodic irq to CMOS reset default of 1024Hz;
 483          *
 484          * REVISIT it's been reported that at least one x86_64 ALI mobo
 485          * doesn't use 32KHz here ... for portability we might need to
 486          * do something about other clock frequencies.
 487          */
 488         CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
 489         cmos_rtc.rtc->irq_freq = 1024;
 490
 491         /* disable irqs.
 492          *
 493          * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
 494          * allegedly some older rtcs need that to handle irqs properly
 495          */
 496         rtc_control = CMOS_READ(RTC_CONTROL);
 497         rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
 498         CMOS_WRITE(rtc_control, RTC_CONTROL);
 499         CMOS_READ(RTC_INTR_FLAGS);
 500
 501         spin_unlock_irq(&rtc_lock);
 502
 503         /* FIXME teach the alarm code how to handle binary mode;
 504          * <asm-generic/rtc.h> doesn't know 12-hour mode either.
 505          */
 506         if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
 507                 dev_dbg(dev, "only 24-hr BCD mode supported\n");
 508                 retval = -ENXIO;
 509                 goto cleanup1;
 510         }
 511
 512         if (is_valid_irq(rtc_irq))
 513                 retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
 514                                 cmos_rtc.rtc->dev.bus_id,
 515                                 cmos_rtc.rtc);
 516         if (retval < 0) {
 517                 dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 518                 goto cleanup1;
 519         }
 520
 521         /* REVISIT optionally make 50 or 114 bytes NVRAM available,
 522          * like rtc-ds1553, rtc-ds1742 ... this will often include
 523          * registers for century, and day/month alarm.
 524          */
 525
 526         pr_info("%s: alarms up to one %s%s\n",
 527                         cmos_rtc.rtc->dev.bus_id,
 528                         is_valid_irq(rtc_irq)
 529                                 ?  (cmos_rtc.mon_alrm
 530                                         ? "year"
 531                                         : (cmos_rtc.day_alrm
 532                                                 ? "month" : "day"))
 533                                 : "no",
 534                         cmos_rtc.century ? ", y3k" : ""
 535                         );
 536
 537         return 0;
 538
 539 cleanup1:
 540         cmos_rtc.dev = NULL;
 541         rtc_device_unregister(cmos_rtc.rtc);
 542 cleanup0:
 543         release_region(ports->start, ports->end + 1 - ports->start);
 544         return retval;
 545 }
 546
 547 static void cmos_do_shutdown(void)
 548 {
 549         unsigned char   rtc_control;
 550
 551         spin_lock_irq(&rtc_lock);
 552         rtc_control = CMOS_READ(RTC_CONTROL);
 553         rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 554         CMOS_WRITE(rtc_control, RTC_CONTROL);
 555         CMOS_READ(RTC_INTR_FLAGS);
 556         spin_unlock_irq(&rtc_lock);
 557 }
 558
 559 static void __exit cmos_do_remove(struct device *dev)
 560 {
 561         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 562         struct resource *ports;
 563
 564         cmos_do_shutdown();
 565
 566         if (is_valid_irq(cmos->irq))
 567                 free_irq(cmos->irq, cmos->rtc);
 568
 569         rtc_device_unregister(cmos->rtc);
 570         cmos->rtc = NULL;
 571
 572         ports = cmos->iomem;
 573         release_region(ports->start, ports->end + 1 - ports->start);
 574         cmos->iomem = NULL;
 575
 576         cmos->dev = NULL;
 577         dev_set_drvdata(dev, NULL);
 578 }
 579
 580 #ifdef  CONFIG_PM
 581
 582 static int cmos_suspend(struct device *dev, pm_message_t mesg)
 583 {
 584         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 585         int             do_wake = device_may_wakeup(dev);
 586         unsigned char   tmp;
 587
 588         /* only the alarm might be a wakeup event source */
 589         spin_lock_irq(&rtc_lock);
 590         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 591         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 592                 unsigned char   irqstat;
 593
 594                 if (do_wake)
 595                         tmp &= ~(RTC_PIE|RTC_UIE);
 596                 else
 597                         tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 598                 CMOS_WRITE(tmp, RTC_CONTROL);
 599                 irqstat = CMOS_READ(RTC_INTR_FLAGS);
 600                 irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
 601                 if (is_intr(irqstat))
 602                         rtc_update_irq(cmos->rtc, 1, irqstat);
 603         }
 604         spin_unlock_irq(&rtc_lock);
 605
 606         if (tmp & RTC_AIE) {
 607                 cmos->enabled_wake = 1;
 608                 if (cmos->wake_on)
 609                         cmos->wake_on(dev);
 610                 else
 611                         enable_irq_wake(cmos->irq);
 612         }
 613
 614         pr_debug("%s: suspend%s, ctrl %02x\n",
 615                         cmos_rtc.rtc->dev.bus_id,
 616                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
 617                         tmp);
 618
 619         return 0;
 620 }
 621
 622 static int cmos_resume(struct device *dev)
 623 {
 624         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 625         unsigned char   tmp = cmos->suspend_ctrl;
 626
 627         /* re-enable any irqs previously active */
 628         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 629
 630                 if (cmos->enabled_wake) {
 631                         if (cmos->wake_off)
 632                                 cmos->wake_off(dev);
 633                         else
 634                                 disable_irq_wake(cmos->irq);
 635                         cmos->enabled_wake = 0;
 636                 }
 637
 638                 spin_lock_irq(&rtc_lock);
 639                 CMOS_WRITE(tmp, RTC_CONTROL);
 640                 tmp = CMOS_READ(RTC_INTR_FLAGS);
 641                 tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
 642                 if (is_intr(tmp))
 643                         rtc_update_irq(cmos->rtc, 1, tmp);
 644                 spin_unlock_irq(&rtc_lock);
 645         }
 646
 647         pr_debug("%s: resume, ctrl %02x\n",
 648                         cmos_rtc.rtc->dev.bus_id,
 649                         cmos->suspend_ctrl);
 650
 651
 652         return 0;
 653 }
 654
 655 #else
 656 #define cmos_suspend    NULL
 657 #define cmos_resume     NULL
 658 #endif
 659
 660 /*----------------------------------------------------------------*/
 661
 662 /* The "CMOS" RTC normally lives on the platform_bus.  On ACPI systems,
 663  * the device node will always be created as a PNPACPI device.  Plus
 664  * pre-ACPI PCs probably list it in the PNPBIOS tables.
 665  */
 666
 667 #ifdef  CONFIG_PNP
 668
 669 #include <linux/pnp.h>
 670
 671 static int __devinit
 672 cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 673 {
 674         /* REVISIT paranoia argues for a shutdown notifier, since PNP
 675          * drivers can't provide shutdown() methods to disable IRQs.
 676          * Or better yet, fix PNP to allow those methods...
 677          */
 678         if (pnp_port_start(pnp,0) == 0x70 && !pnp_irq_valid(pnp,0))
 679                 /* Some machines contain a PNP entry for the RTC, but
 680                  * don't define the IRQ. It should always be safe to
 681                  * hardcode it in these cases
 682                  */
 683                 return cmos_do_probe(&pnp->dev, &pnp->res.port_resource[0], 8);
 684         else
 685                 return cmos_do_probe(&pnp->dev,
 686                                      &pnp->res.port_resource[0],
 687                                      pnp->res.irq_resource[0].start);
 688 }
 689
 690 static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
 691 {
 692         cmos_do_remove(&pnp->dev);
 693 }
 694
 695 #ifdef  CONFIG_PM
 696
 697 static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
 698 {
 699         return cmos_suspend(&pnp->dev, mesg);
 700 }
 701
 702 static int cmos_pnp_resume(struct pnp_dev *pnp)
 703 {
 704         return cmos_resume(&pnp->dev);
 705 }
 706
 707 #else
 708 #define cmos_pnp_suspend        NULL
 709 #define cmos_pnp_resume         NULL
 710 #endif
 711
 712
 713 static const struct pnp_device_id rtc_ids[] = {
 714         { .id = "PNP0b00", },
 715         { .id = "PNP0b01", },
 716         { .id = "PNP0b02", },
 717         { },
 718 };
 719 MODULE_DEVICE_TABLE(pnp, rtc_ids);
 720
 721 static struct pnp_driver cmos_pnp_driver = {
 722         .name           = (char *) driver_name,
 723         .id_table       = rtc_ids,
 724         .probe          = cmos_pnp_probe,
 725         .remove         = __exit_p(cmos_pnp_remove),
 726
 727         /* flag ensures resume() gets called, and stops syslog spam */
 728         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
 729         .suspend        = cmos_pnp_suspend,
 730         .resume         = cmos_pnp_resume,
 731 };
 732
 733 static int __init cmos_init(void)
 734 {
 735         return pnp_register_driver(&cmos_pnp_driver);
 736 }
 737 module_init(cmos_init);
 738
 739 static void __exit cmos_exit(void)
 740 {
 741         pnp_unregister_driver(&cmos_pnp_driver);
 742 }
 743 module_exit(cmos_exit);
 744
 745 #else   /* no PNP */
 746
 747 /*----------------------------------------------------------------*/
 748
 749 /* Platform setup should have set up an RTC device, when PNP is
 750  * unavailable ... this could happen even on (older) PCs.
 751  */
 752
 753 static int __init cmos_platform_probe(struct platform_device *pdev)
 754 {
 755         return cmos_do_probe(&pdev->dev,
 756                         platform_get_resource(pdev, IORESOURCE_IO, 0),
 757                         platform_get_irq(pdev, 0));
 758 }
 759
 760 static int __exit cmos_platform_remove(struct platform_device *pdev)
 761 {
 762         cmos_do_remove(&pdev->dev);
 763         return 0;
 764 }
 765
 766 static void cmos_platform_shutdown(struct platform_device *pdev)
 767 {
 768         cmos_do_shutdown();
 769 }
 770
 771 static struct platform_driver cmos_platform_driver = {
 772         .remove         = __exit_p(cmos_platform_remove),
 773         .shutdown       = cmos_platform_shutdown,
 774         .driver = {
 775                 .name           = (char *) driver_name,
 776                 .suspend        = cmos_suspend,
 777                 .resume         = cmos_resume,
 778         }
 779 };
 780
 781 static int __init cmos_init(void)
 782 {
 783         return platform_driver_probe(&cmos_platform_driver,
 784                         cmos_platform_probe);
 785 }
 786 module_init(cmos_init);
 787
 788 static void __exit cmos_exit(void)
 789 {
 790         platform_driver_unregister(&cmos_platform_driver);
 791 }
 792 module_exit(cmos_exit);
 793
 794
 795 #endif  /* !PNP */
 796
 797 MODULE_AUTHOR("David Brownell");
 798 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
 799 MODULE_LICENSE("GPL");