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_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 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 263
 264 static int
 265 cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 266 {
 267         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 268         unsigned char   rtc_control, rtc_intr;
 269         unsigned long   flags;
 270
 271         switch (cmd) {
 272         case RTC_AIE_OFF:
 273         case RTC_AIE_ON:
 274         case RTC_UIE_OFF:
 275         case RTC_UIE_ON:
 276         case RTC_PIE_OFF:
 277         case RTC_PIE_ON:
 278                 if (!is_valid_irq(cmos->irq))
 279                         return -EINVAL;
 280                 break;
 281         default:
 282                 return -ENOIOCTLCMD;
 283         }
 284
 285         spin_lock_irqsave(&rtc_lock, flags);
 286         rtc_control = CMOS_READ(RTC_CONTROL);
 287         switch (cmd) {
 288         case RTC_AIE_OFF:       /* alarm off */
 289                 rtc_control &= ~RTC_AIE;
 290                 break;
 291         case RTC_AIE_ON:        /* alarm on */
 292                 rtc_control |= RTC_AIE;
 293                 break;
 294         case RTC_UIE_OFF:       /* update off */
 295                 rtc_control &= ~RTC_UIE;
 296                 break;
 297         case RTC_UIE_ON:        /* update on */
 298                 rtc_control |= RTC_UIE;
 299                 break;
 300         case RTC_PIE_OFF:       /* periodic off */
 301                 rtc_control &= ~RTC_PIE;
 302                 break;
 303         case RTC_PIE_ON:        /* periodic on */
 304                 rtc_control |= RTC_PIE;
 305                 break;
 306         }
 307         CMOS_WRITE(rtc_control, RTC_CONTROL);
 308         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 309         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 310         if (is_intr(rtc_intr))
 311                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 312         spin_unlock_irqrestore(&rtc_lock, flags);
 313         return 0;
 314 }
 315
 316 #else
 317 #define cmos_rtc_ioctl  NULL
 318 #endif
 319
 320 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 321
 322 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 323 {
 324         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 325         unsigned char   rtc_control, valid;
 326
 327         spin_lock_irq(&rtc_lock);
 328         rtc_control = CMOS_READ(RTC_CONTROL);
 329         valid = CMOS_READ(RTC_VALID);
 330         spin_unlock_irq(&rtc_lock);
 331
 332         /* NOTE:  at least ICH6 reports battery status using a different
 333          * (non-RTC) bit; and SQWE is ignored on many current systems.
 334          */
 335         return seq_printf(seq,
 336                         "periodic_IRQ\t: %s\n"
 337                         "update_IRQ\t: %s\n"
 338                         // "square_wave\t: %s\n"
 339                         // "BCD\t\t: %s\n"
 340                         "DST_enable\t: %s\n"
 341                         "periodic_freq\t: %d\n"
 342                         "batt_status\t: %s\n",
 343                         (rtc_control & RTC_PIE) ? "yes" : "no",
 344                         (rtc_control & RTC_UIE) ? "yes" : "no",
 345                         // (rtc_control & RTC_SQWE) ? "yes" : "no",
 346                         // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 347                         (rtc_control & RTC_DST_EN) ? "yes" : "no",
 348                         cmos->rtc->irq_freq,
 349                         (valid & RTC_VRT) ? "okay" : "dead");
 350 }
 351
 352 #else
 353 #define cmos_procfs     NULL
 354 #endif
 355
 356 static const struct rtc_class_ops cmos_rtc_ops = {
 357         .ioctl          = cmos_rtc_ioctl,
 358         .read_time      = cmos_read_time,
 359         .set_time       = cmos_set_time,
 360         .read_alarm     = cmos_read_alarm,
 361         .set_alarm      = cmos_set_alarm,
 362         .proc           = cmos_procfs,
 363         .irq_set_freq   = cmos_set_freq,
 364 };
 365
 366 /*----------------------------------------------------------------*/
 367
 368 static struct cmos_rtc  cmos_rtc;
 369
 370 static irqreturn_t cmos_interrupt(int irq, void *p)
 371 {
 372         u8              irqstat;
 373
 374         spin_lock(&rtc_lock);
 375         irqstat = CMOS_READ(RTC_INTR_FLAGS);
 376         irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
 377         spin_unlock(&rtc_lock);
 378
 379         if (is_intr(irqstat)) {
 380                 rtc_update_irq(p, 1, irqstat);
 381                 return IRQ_HANDLED;
 382         } else
 383                 return IRQ_NONE;
 384 }
 385
 386 #ifdef  CONFIG_PNP
 387 #define is_pnp()        1
 388 #define INITSECTION
 389
 390 #else
 391 #define is_pnp()        0
 392 #define INITSECTION     __init
 393 #endif
 394
 395 static int INITSECTION
 396 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 397 {
 398         struct cmos_rtc_board_info      *info = dev->platform_data;
 399         int                             retval = 0;
 400         unsigned char                   rtc_control;
 401
 402         /* there can be only one ... */
 403         if (cmos_rtc.dev)
 404                 return -EBUSY;
 405
 406         if (!ports)
 407                 return -ENODEV;
 408
 409         cmos_rtc.irq = rtc_irq;
 410         cmos_rtc.iomem = ports;
 411
 412         /* For ACPI systems extension info comes from the FADT.  On others,
 413          * board specific setup provides it as appropriate.  Systems where
 414          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
 415          * some almost-clones) can provide hooks to make that behave.
 416          */
 417         if (info) {
 418                 cmos_rtc.day_alrm = info->rtc_day_alarm;
 419                 cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 420                 cmos_rtc.century = info->rtc_century;
 421
 422                 if (info->wake_on && info->wake_off) {
 423                         cmos_rtc.wake_on = info->wake_on;
 424                         cmos_rtc.wake_off = info->wake_off;
 425                 }
 426         }
 427
 428         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
 429                                 &cmos_rtc_ops, THIS_MODULE);
 430         if (IS_ERR(cmos_rtc.rtc))
 431                 return PTR_ERR(cmos_rtc.rtc);
 432
 433         cmos_rtc.dev = dev;
 434         dev_set_drvdata(dev, &cmos_rtc);
 435
 436         /* platform and pnp busses handle resources incompatibly.
 437          *
 438          * REVISIT for non-x86 systems we may need to handle io memory
 439          * resources: ioremap them, and request_mem_region().
 440          */
 441         if (is_pnp()) {
 442                 retval = request_resource(&ioport_resource, ports);
 443                 if (retval < 0) {
 444                         dev_dbg(dev, "i/o registers already in use\n");
 445                         goto cleanup0;
 446                 }
 447         }
 448         rename_region(ports, cmos_rtc.rtc->dev.bus_id);
 449
 450         spin_lock_irq(&rtc_lock);
 451
 452         /* force periodic irq to CMOS reset default of 1024Hz;
 453          *
 454          * REVISIT it's been reported that at least one x86_64 ALI mobo
 455          * doesn't use 32KHz here ... for portability we might need to
 456          * do something about other clock frequencies.
 457          */
 458         CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
 459         cmos_rtc.rtc->irq_freq = 1024;
 460
 461         /* disable irqs.
 462          *
 463          * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
 464          * allegedly some older rtcs need that to handle irqs properly
 465          */
 466         rtc_control = CMOS_READ(RTC_CONTROL);
 467         rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
 468         CMOS_WRITE(rtc_control, RTC_CONTROL);
 469         CMOS_READ(RTC_INTR_FLAGS);
 470
 471         spin_unlock_irq(&rtc_lock);
 472
 473         /* FIXME teach the alarm code how to handle binary mode;
 474          * <asm-generic/rtc.h> doesn't know 12-hour mode either.
 475          */
 476         if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
 477                 dev_dbg(dev, "only 24-hr BCD mode supported\n");
 478                 retval = -ENXIO;
 479                 goto cleanup1;
 480         }
 481
 482         if (is_valid_irq(rtc_irq))
 483                 retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,
 484                                 cmos_rtc.rtc->dev.bus_id,
 485                                 cmos_rtc.rtc);
 486         if (retval < 0) {
 487                 dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 488                 goto cleanup1;
 489         }
 490
 491         /* REVISIT optionally make 50 or 114 bytes NVRAM available,
 492          * like rtc-ds1553, rtc-ds1742 ... this will often include
 493          * registers for century, and day/month alarm.
 494          */
 495
 496         pr_info("%s: alarms up to one %s%s\n",
 497                         cmos_rtc.rtc->dev.bus_id,
 498                         is_valid_irq(rtc_irq)
 499                                 ?  (cmos_rtc.mon_alrm
 500                                         ? "year"
 501                                         : (cmos_rtc.day_alrm
 502                                                 ? "month" : "day"))
 503                                 : "no",
 504                         cmos_rtc.century ? ", y3k" : ""
 505                         );
 506
 507         return 0;
 508
 509 cleanup1:
 510         rename_region(ports, NULL);
 511 cleanup0:
 512         rtc_device_unregister(cmos_rtc.rtc);
 513         return retval;
 514 }
 515
 516 static void cmos_do_shutdown(void)
 517 {
 518         unsigned char   rtc_control;
 519
 520         spin_lock_irq(&rtc_lock);
 521         rtc_control = CMOS_READ(RTC_CONTROL);
 522         rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 523         CMOS_WRITE(rtc_control, RTC_CONTROL);
 524         CMOS_READ(RTC_INTR_FLAGS);
 525         spin_unlock_irq(&rtc_lock);
 526 }
 527
 528 static void __exit cmos_do_remove(struct device *dev)
 529 {
 530         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 531
 532         cmos_do_shutdown();
 533
 534         if (is_pnp())
 535                 release_resource(cmos->iomem);
 536         rename_region(cmos->iomem, NULL);
 537
 538         if (is_valid_irq(cmos->irq))
 539                 free_irq(cmos->irq, cmos_rtc.rtc);
 540
 541         rtc_device_unregister(cmos_rtc.rtc);
 542
 543         cmos_rtc.dev = NULL;
 544         dev_set_drvdata(dev, NULL);
 545 }
 546
 547 #ifdef  CONFIG_PM
 548
 549 static int cmos_suspend(struct device *dev, pm_message_t mesg)
 550 {
 551         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 552         int             do_wake = device_may_wakeup(dev);
 553         unsigned char   tmp;
 554
 555         /* only the alarm might be a wakeup event source */
 556         spin_lock_irq(&rtc_lock);
 557         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 558         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 559                 unsigned char   irqstat;
 560
 561                 if (do_wake)
 562                         tmp &= ~(RTC_PIE|RTC_UIE);
 563                 else
 564                         tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
 565                 CMOS_WRITE(tmp, RTC_CONTROL);
 566                 irqstat = CMOS_READ(RTC_INTR_FLAGS);
 567                 irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
 568                 if (is_intr(irqstat))
 569                         rtc_update_irq(cmos->rtc, 1, irqstat);
 570         }
 571         spin_unlock_irq(&rtc_lock);
 572
 573         if (tmp & RTC_AIE) {
 574                 cmos->enabled_wake = 1;
 575                 if (cmos->wake_on)
 576                         cmos->wake_on(dev);
 577                 else
 578                         enable_irq_wake(cmos->irq);
 579         }
 580
 581         pr_debug("%s: suspend%s, ctrl %02x\n",
 582                         cmos_rtc.rtc->dev.bus_id,
 583                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
 584                         tmp);
 585
 586         return 0;
 587 }
 588
 589 static int cmos_resume(struct device *dev)
 590 {
 591         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 592         unsigned char   tmp = cmos->suspend_ctrl;
 593
 594         /* re-enable any irqs previously active */
 595         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 596
 597                 if (cmos->enabled_wake) {
 598                         if (cmos->wake_off)
 599                                 cmos->wake_off(dev);
 600                         else
 601                                 disable_irq_wake(cmos->irq);
 602                         cmos->enabled_wake = 0;
 603                 }
 604
 605                 spin_lock_irq(&rtc_lock);
 606                 CMOS_WRITE(tmp, RTC_CONTROL);
 607                 tmp = CMOS_READ(RTC_INTR_FLAGS);
 608                 tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
 609                 if (is_intr(tmp))
 610                         rtc_update_irq(cmos->rtc, 1, tmp);
 611                 spin_unlock_irq(&rtc_lock);
 612         }
 613
 614         pr_debug("%s: resume, ctrl %02x\n",
 615                         cmos_rtc.rtc->dev.bus_id,
 616                         cmos->suspend_ctrl);
 617
 618
 619         return 0;
 620 }
 621
 622 #else
 623 #define cmos_suspend    NULL
 624 #define cmos_resume     NULL
 625 #endif
 626
 627 /*----------------------------------------------------------------*/
 628
 629 /* The "CMOS" RTC normally lives on the platform_bus.  On ACPI systems,
 630  * the device node will always be created as a PNPACPI device.
 631  */
 632
 633 #ifdef  CONFIG_PNP
 634
 635 #include <linux/pnp.h>
 636
 637 static int __devinit
 638 cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 639 {
 640         /* REVISIT paranoia argues for a shutdown notifier, since PNP
 641          * drivers can't provide shutdown() methods to disable IRQs.
 642          * Or better yet, fix PNP to allow those methods...
 643          */
 644         if (pnp_port_start(pnp,0) == 0x70 && !pnp_irq_valid(pnp,0))
 645                 /* Some machines contain a PNP entry for the RTC, but
 646                  * don't define the IRQ. It should always be safe to
 647                  * hardcode it in these cases
 648                  */
 649                 return cmos_do_probe(&pnp->dev, &pnp->res.port_resource[0], 8);
 650         else
 651                 return cmos_do_probe(&pnp->dev,
 652                                      &pnp->res.port_resource[0],
 653                                      pnp->res.irq_resource[0].start);
 654 }
 655
 656 static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
 657 {
 658         cmos_do_remove(&pnp->dev);
 659 }
 660
 661 #ifdef  CONFIG_PM
 662
 663 static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
 664 {
 665         return cmos_suspend(&pnp->dev, mesg);
 666 }
 667
 668 static int cmos_pnp_resume(struct pnp_dev *pnp)
 669 {
 670         return cmos_resume(&pnp->dev);
 671 }
 672
 673 #else
 674 #define cmos_pnp_suspend        NULL
 675 #define cmos_pnp_resume         NULL
 676 #endif
 677
 678
 679 static const struct pnp_device_id rtc_ids[] = {
 680         { .id = "PNP0b00", },
 681         { .id = "PNP0b01", },
 682         { .id = "PNP0b02", },
 683         { },
 684 };
 685 MODULE_DEVICE_TABLE(pnp, rtc_ids);
 686
 687 static struct pnp_driver cmos_pnp_driver = {
 688         .name           = (char *) driver_name,
 689         .id_table       = rtc_ids,
 690         .probe          = cmos_pnp_probe,
 691         .remove         = __exit_p(cmos_pnp_remove),
 692
 693         /* flag ensures resume() gets called, and stops syslog spam */
 694         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
 695         .suspend        = cmos_pnp_suspend,
 696         .resume         = cmos_pnp_resume,
 697 };
 698
 699 static int __init cmos_init(void)
 700 {
 701         return pnp_register_driver(&cmos_pnp_driver);
 702 }
 703 module_init(cmos_init);
 704
 705 static void __exit cmos_exit(void)
 706 {
 707         pnp_unregister_driver(&cmos_pnp_driver);
 708 }
 709 module_exit(cmos_exit);
 710
 711 #else   /* no PNP */
 712
 713 /*----------------------------------------------------------------*/
 714
 715 /* Platform setup should have set up an RTC device, when PNP is
 716  * unavailable ... this could happen even on (older) PCs.
 717  */
 718
 719 static int __init cmos_platform_probe(struct platform_device *pdev)
 720 {
 721         return cmos_do_probe(&pdev->dev,
 722                         platform_get_resource(pdev, IORESOURCE_IO, 0),
 723                         platform_get_irq(pdev, 0));
 724 }
 725
 726 static int __exit cmos_platform_remove(struct platform_device *pdev)
 727 {
 728         cmos_do_remove(&pdev->dev);
 729         return 0;
 730 }
 731
 732 static void cmos_platform_shutdown(struct platform_device *pdev)
 733 {
 734         cmos_do_shutdown();
 735 }
 736
 737 static struct platform_driver cmos_platform_driver = {
 738         .remove         = __exit_p(cmos_platform_remove),
 739         .shutdown       = cmos_platform_shutdown,
 740         .driver = {
 741                 .name           = (char *) driver_name,
 742                 .suspend        = cmos_suspend,
 743                 .resume         = cmos_resume,
 744         }
 745 };
 746
 747 static int __init cmos_init(void)
 748 {
 749         return platform_driver_probe(&cmos_platform_driver,
 750                         cmos_platform_probe);
 751 }
 752 module_init(cmos_init);
 753
 754 static void __exit cmos_exit(void)
 755 {
 756         platform_driver_unregister(&cmos_platform_driver);
 757 }
 758 module_exit(cmos_exit);
 759
 760
 761 #endif  /* !PNP */
 762
 763 MODULE_AUTHOR("David Brownell");
 764 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
 765 MODULE_LICENSE("GPL");