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
  32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  33
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/spinlock.h>
  39 #include <linux/platform_device.h>
  40 #include <linux/log2.h>
  41 #include <linux/pm.h>
  42 #include <linux/of.h>
  43 #include <linux/of_platform.h>
  44
  45 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
  46 #include <linux/mc146818rtc.h>
  47
  48 struct cmos_rtc {
  49         struct rtc_device       *rtc;
  50         struct device           *dev;
  51         int                     irq;
  52         struct resource         *iomem;
  53         time64_t                alarm_expires;
  54
  55         void                    (*wake_on)(struct device *);
  56         void                    (*wake_off)(struct device *);
  57
  58         u8                      enabled_wake;
  59         u8                      suspend_ctrl;
  60
  61         /* newer hardware extends the original register set */
  62         u8                      day_alrm;
  63         u8                      mon_alrm;
  64         u8                      century;
  65
  66         struct rtc_wkalrm       saved_wkalrm;
  67 };
  68
  69 /* both platform and pnp busses use negative numbers for invalid irqs */
  70 #define is_valid_irq(n)         ((n) > 0)
  71
  72 static const char driver_name[] = "rtc_cmos";
  73
  74 /* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
  75  * always mask it against the irq enable bits in RTC_CONTROL.  Bit values
  76  * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
  77  */
  78 #define RTC_IRQMASK     (RTC_PF | RTC_AF | RTC_UF)
  79
  80 static inline int is_intr(u8 rtc_intr)
  81 {
  82         if (!(rtc_intr & RTC_IRQF))
  83                 return 0;
  84         return rtc_intr & RTC_IRQMASK;
  85 }
  86
  87 /*----------------------------------------------------------------*/
  88
  89 /* Much modern x86 hardware has HPETs (10+ MHz timers) which, because
  90  * many BIOS programmers don't set up "sane mode" IRQ routing, are mostly
  91  * used in a broken "legacy replacement" mode.  The breakage includes
  92  * HPET #1 hijacking the IRQ for this RTC, and being unavailable for
  93  * other (better) use.
  94  *
  95  * When that broken mode is in use, platform glue provides a partial
  96  * emulation of hardware RTC IRQ facilities using HPET #1.  We don't
  97  * want to use HPET for anything except those IRQs though...
  98  */
  99 #ifdef CONFIG_HPET_EMULATE_RTC
 100 #include <asm/hpet.h>
 101 #else
 102
 103 static inline int is_hpet_enabled(void)
 104 {
 105         return 0;
 106 }
 107
 108 static inline int hpet_mask_rtc_irq_bit(unsigned long mask)
 109 {
 110         return 0;
 111 }
 112
 113 static inline int hpet_set_rtc_irq_bit(unsigned long mask)
 114 {
 115         return 0;
 116 }
 117
 118 static inline int
 119 hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
 120 {
 121         return 0;
 122 }
 123
 124 static inline int hpet_set_periodic_freq(unsigned long freq)
 125 {
 126         return 0;
 127 }
 128
 129 static inline int hpet_rtc_dropped_irq(void)
 130 {
 131         return 0;
 132 }
 133
 134 static inline int hpet_rtc_timer_init(void)
 135 {
 136         return 0;
 137 }
 138
 139 extern irq_handler_t hpet_rtc_interrupt;
 140
 141 static inline int hpet_register_irq_handler(irq_handler_t handler)
 142 {
 143         return 0;
 144 }
 145
 146 static inline int hpet_unregister_irq_handler(irq_handler_t handler)
 147 {
 148         return 0;
 149 }
 150
 151 #endif
 152
 153 /*----------------------------------------------------------------*/
 154
 155 #ifdef RTC_PORT
 156
 157 /* Most newer x86 systems have two register banks, the first used
 158  * for RTC and NVRAM and the second only for NVRAM.  Caller must
 159  * own rtc_lock ... and we won't worry about access during NMI.
 160  */
 161 #define can_bank2       true
 162
 163 static inline unsigned char cmos_read_bank2(unsigned char addr)
 164 {
 165         outb(addr, RTC_PORT(2));
 166         return inb(RTC_PORT(3));
 167 }
 168
 169 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
 170 {
 171         outb(addr, RTC_PORT(2));
 172         outb(val, RTC_PORT(3));
 173 }
 174
 175 #else
 176
 177 #define can_bank2       false
 178
 179 static inline unsigned char cmos_read_bank2(unsigned char addr)
 180 {
 181         return 0;
 182 }
 183
 184 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
 185 {
 186 }
 187
 188 #endif
 189
 190 /*----------------------------------------------------------------*/
 191
 192 static int cmos_read_time(struct device *dev, struct rtc_time *t)
 193 {
 194         /*
 195          * If pm_trace abused the RTC for storage, set the timespec to 0,
 196          * which tells the caller that this RTC value is unusable.
 197          */
 198         if (!pm_trace_rtc_valid())
 199                 return -EIO;
 200
 201         /* REVISIT:  if the clock has a "century" register, use
 202          * that instead of the heuristic in mc146818_get_time().
 203          * That'll make Y3K compatility (year > 2070) easy!
 204          */
 205         mc146818_get_time(t);
 206         return 0;
 207 }
 208
 209 static int cmos_set_time(struct device *dev, struct rtc_time *t)
 210 {
 211         /* REVISIT:  set the "century" register if available
 212          *
 213          * NOTE: this ignores the issue whereby updating the seconds
 214          * takes effect exactly 500ms after we write the register.
 215          * (Also queueing and other delays before we get this far.)
 216          */
 217         return mc146818_set_time(t);
 218 }
 219
 220 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 221 {
 222         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 223         unsigned char   rtc_control;
 224
 225         if (!is_valid_irq(cmos->irq))
 226                 return -EIO;
 227
 228         /* Basic alarms only support hour, minute, and seconds fields.
 229          * Some also support day and month, for alarms up to a year in
 230          * the future.
 231          */
 232
 233         spin_lock_irq(&rtc_lock);
 234         t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
 235         t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
 236         t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
 237
 238         if (cmos->day_alrm) {
 239                 /* ignore upper bits on readback per ACPI spec */
 240                 t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
 241                 if (!t->time.tm_mday)
 242                         t->time.tm_mday = -1;
 243
 244                 if (cmos->mon_alrm) {
 245                         t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
 246                         if (!t->time.tm_mon)
 247                                 t->time.tm_mon = -1;
 248                 }
 249         }
 250
 251         rtc_control = CMOS_READ(RTC_CONTROL);
 252         spin_unlock_irq(&rtc_lock);
 253
 254         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 255                 if (((unsigned)t->time.tm_sec) < 0x60)
 256                         t->time.tm_sec = bcd2bin(t->time.tm_sec);
 257                 else
 258                         t->time.tm_sec = -1;
 259                 if (((unsigned)t->time.tm_min) < 0x60)
 260                         t->time.tm_min = bcd2bin(t->time.tm_min);
 261                 else
 262                         t->time.tm_min = -1;
 263                 if (((unsigned)t->time.tm_hour) < 0x24)
 264                         t->time.tm_hour = bcd2bin(t->time.tm_hour);
 265                 else
 266                         t->time.tm_hour = -1;
 267
 268                 if (cmos->day_alrm) {
 269                         if (((unsigned)t->time.tm_mday) <= 0x31)
 270                                 t->time.tm_mday = bcd2bin(t->time.tm_mday);
 271                         else
 272                                 t->time.tm_mday = -1;
 273
 274                         if (cmos->mon_alrm) {
 275                                 if (((unsigned)t->time.tm_mon) <= 0x12)
 276                                         t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;
 277                                 else
 278                                         t->time.tm_mon = -1;
 279                         }
 280                 }
 281         }
 282
 283         t->enabled = !!(rtc_control & RTC_AIE);
 284         t->pending = 0;
 285
 286         return 0;
 287 }
 288
 289 static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control)
 290 {
 291         unsigned char   rtc_intr;
 292
 293         /* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
 294          * allegedly some older rtcs need that to handle irqs properly
 295          */
 296         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 297
 298         if (is_hpet_enabled())
 299                 return;
 300
 301         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 302         if (is_intr(rtc_intr))
 303                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 304 }
 305
 306 static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask)
 307 {
 308         unsigned char   rtc_control;
 309
 310         /* flush any pending IRQ status, notably for update irqs,
 311          * before we enable new IRQs
 312          */
 313         rtc_control = CMOS_READ(RTC_CONTROL);
 314         cmos_checkintr(cmos, rtc_control);
 315
 316         rtc_control |= mask;
 317         CMOS_WRITE(rtc_control, RTC_CONTROL);
 318         hpet_set_rtc_irq_bit(mask);
 319
 320         cmos_checkintr(cmos, rtc_control);
 321 }
 322
 323 static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)
 324 {
 325         unsigned char   rtc_control;
 326
 327         rtc_control = CMOS_READ(RTC_CONTROL);
 328         rtc_control &= ~mask;
 329         CMOS_WRITE(rtc_control, RTC_CONTROL);
 330         hpet_mask_rtc_irq_bit(mask);
 331
 332         cmos_checkintr(cmos, rtc_control);
 333 }
 334
 335 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 336 {
 337         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 338         unsigned char mon, mday, hrs, min, sec, rtc_control;
 339
 340         if (!is_valid_irq(cmos->irq))
 341                 return -EIO;
 342
 343         mon = t->time.tm_mon + 1;
 344         mday = t->time.tm_mday;
 345         hrs = t->time.tm_hour;
 346         min = t->time.tm_min;
 347         sec = t->time.tm_sec;
 348
 349         rtc_control = CMOS_READ(RTC_CONTROL);
 350         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 351                 /* Writing 0xff means "don't care" or "match all".  */
 352                 mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
 353                 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
 354                 hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
 355                 min = (min < 60) ? bin2bcd(min) : 0xff;
 356                 sec = (sec < 60) ? bin2bcd(sec) : 0xff;
 357         }
 358
 359         spin_lock_irq(&rtc_lock);
 360
 361         /* next rtc irq must not be from previous alarm setting */
 362         cmos_irq_disable(cmos, RTC_AIE);
 363
 364         /* update alarm */
 365         CMOS_WRITE(hrs, RTC_HOURS_ALARM);
 366         CMOS_WRITE(min, RTC_MINUTES_ALARM);
 367         CMOS_WRITE(sec, RTC_SECONDS_ALARM);
 368
 369         /* the system may support an "enhanced" alarm */
 370         if (cmos->day_alrm) {
 371                 CMOS_WRITE(mday, cmos->day_alrm);
 372                 if (cmos->mon_alrm)
 373                         CMOS_WRITE(mon, cmos->mon_alrm);
 374         }
 375
 376         /* FIXME the HPET alarm glue currently ignores day_alrm
 377          * and mon_alrm ...
 378          */
 379         hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);
 380
 381         if (t->enabled)
 382                 cmos_irq_enable(cmos, RTC_AIE);
 383
 384         spin_unlock_irq(&rtc_lock);
 385
 386         cmos->alarm_expires = rtc_tm_to_time64(&t->time);
 387
 388         return 0;
 389 }
 390
 391 static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
 392 {
 393         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 394         unsigned long   flags;
 395
 396         if (!is_valid_irq(cmos->irq))
 397                 return -EINVAL;
 398
 399         spin_lock_irqsave(&rtc_lock, flags);
 400
 401         if (enabled)
 402                 cmos_irq_enable(cmos, RTC_AIE);
 403         else
 404                 cmos_irq_disable(cmos, RTC_AIE);
 405
 406         spin_unlock_irqrestore(&rtc_lock, flags);
 407         return 0;
 408 }
 409
 410 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
 411
 412 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 413 {
 414         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 415         unsigned char   rtc_control, valid;
 416
 417         spin_lock_irq(&rtc_lock);
 418         rtc_control = CMOS_READ(RTC_CONTROL);
 419         valid = CMOS_READ(RTC_VALID);
 420         spin_unlock_irq(&rtc_lock);
 421
 422         /* NOTE:  at least ICH6 reports battery status using a different
 423          * (non-RTC) bit; and SQWE is ignored on many current systems.
 424          */
 425         seq_printf(seq,
 426                    "periodic_IRQ\t: %s\n"
 427                    "update_IRQ\t: %s\n"
 428                    "HPET_emulated\t: %s\n"
 429                    // "square_wave\t: %s\n"
 430                    "BCD\t\t: %s\n"
 431                    "DST_enable\t: %s\n"
 432                    "periodic_freq\t: %d\n"
 433                    "batt_status\t: %s\n",
 434                    (rtc_control & RTC_PIE) ? "yes" : "no",
 435                    (rtc_control & RTC_UIE) ? "yes" : "no",
 436                    is_hpet_enabled() ? "yes" : "no",
 437                    // (rtc_control & RTC_SQWE) ? "yes" : "no",
 438                    (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 439                    (rtc_control & RTC_DST_EN) ? "yes" : "no",
 440                    cmos->rtc->irq_freq,
 441                    (valid & RTC_VRT) ? "okay" : "dead");
 442
 443         return 0;
 444 }
 445
 446 #else
 447 #define cmos_procfs     NULL
 448 #endif
 449
 450 static const struct rtc_class_ops cmos_rtc_ops = {
 451         .read_time              = cmos_read_time,
 452         .set_time               = cmos_set_time,
 453         .read_alarm             = cmos_read_alarm,
 454         .set_alarm              = cmos_set_alarm,
 455         .proc                   = cmos_procfs,
 456         .alarm_irq_enable       = cmos_alarm_irq_enable,
 457 };
 458
 459 /*----------------------------------------------------------------*/
 460
 461 /*
 462  * All these chips have at least 64 bytes of address space, shared by
 463  * RTC registers and NVRAM.  Most of those bytes of NVRAM are used
 464  * by boot firmware.  Modern chips have 128 or 256 bytes.
 465  */
 466
 467 #define NVRAM_OFFSET    (RTC_REG_D + 1)
 468
 469 static ssize_t
 470 cmos_nvram_read(struct file *filp, struct kobject *kobj,
 471                 struct bin_attribute *attr,
 472                 char *buf, loff_t off, size_t count)
 473 {
 474         int     retval;
 475
 476         off += NVRAM_OFFSET;
 477         spin_lock_irq(&rtc_lock);
 478         for (retval = 0; count; count--, off++, retval++) {
 479                 if (off < 128)
 480                         *buf++ = CMOS_READ(off);
 481                 else if (can_bank2)
 482                         *buf++ = cmos_read_bank2(off);
 483                 else
 484                         break;
 485         }
 486         spin_unlock_irq(&rtc_lock);
 487
 488         return retval;
 489 }
 490
 491 static ssize_t
 492 cmos_nvram_write(struct file *filp, struct kobject *kobj,
 493                 struct bin_attribute *attr,
 494                 char *buf, loff_t off, size_t count)
 495 {
 496         struct cmos_rtc *cmos;
 497         int             retval;
 498
 499         cmos = dev_get_drvdata(container_of(kobj, struct device, kobj));
 500
 501         /* NOTE:  on at least PCs and Ataris, the boot firmware uses a
 502          * checksum on part of the NVRAM data.  That's currently ignored
 503          * here.  If userspace is smart enough to know what fields of
 504          * NVRAM to update, updating checksums is also part of its job.
 505          */
 506         off += NVRAM_OFFSET;
 507         spin_lock_irq(&rtc_lock);
 508         for (retval = 0; count; count--, off++, retval++) {
 509                 /* don't trash RTC registers */
 510                 if (off == cmos->day_alrm
 511                                 || off == cmos->mon_alrm
 512                                 || off == cmos->century)
 513                         buf++;
 514                 else if (off < 128)
 515                         CMOS_WRITE(*buf++, off);
 516                 else if (can_bank2)
 517                         cmos_write_bank2(*buf++, off);
 518                 else
 519                         break;
 520         }
 521         spin_unlock_irq(&rtc_lock);
 522
 523         return retval;
 524 }
 525
 526 static struct bin_attribute nvram = {
 527         .attr = {
 528                 .name   = "nvram",
 529                 .mode   = S_IRUGO | S_IWUSR,
 530         },
 531
 532         .read   = cmos_nvram_read,
 533         .write  = cmos_nvram_write,
 534         /* size gets set up later */
 535 };
 536
 537 /*----------------------------------------------------------------*/
 538
 539 static struct cmos_rtc  cmos_rtc;
 540
 541 static irqreturn_t cmos_interrupt(int irq, void *p)
 542 {
 543         u8              irqstat;
 544         u8              rtc_control;
 545
 546         spin_lock(&rtc_lock);
 547
 548         /* When the HPET interrupt handler calls us, the interrupt
 549          * status is passed as arg1 instead of the irq number.  But
 550          * always clear irq status, even when HPET is in the way.
 551          *
 552          * Note that HPET and RTC are almost certainly out of phase,
 553          * giving different IRQ status ...
 554          */
 555         irqstat = CMOS_READ(RTC_INTR_FLAGS);
 556         rtc_control = CMOS_READ(RTC_CONTROL);
 557         if (is_hpet_enabled())
 558                 irqstat = (unsigned long)irq & 0xF0;
 559
 560         /* If we were suspended, RTC_CONTROL may not be accurate since the
 561          * bios may have cleared it.
 562          */
 563         if (!cmos_rtc.suspend_ctrl)
 564                 irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 565         else
 566                 irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
 567
 568         /* All Linux RTC alarms should be treated as if they were oneshot.
 569          * Similar code may be needed in system wakeup paths, in case the
 570          * alarm woke the system.
 571          */
 572         if (irqstat & RTC_AIE) {
 573                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
 574                 rtc_control &= ~RTC_AIE;
 575                 CMOS_WRITE(rtc_control, RTC_CONTROL);
 576                 hpet_mask_rtc_irq_bit(RTC_AIE);
 577                 CMOS_READ(RTC_INTR_FLAGS);
 578         }
 579         spin_unlock(&rtc_lock);
 580
 581         if (is_intr(irqstat)) {
 582                 rtc_update_irq(p, 1, irqstat);
 583                 return IRQ_HANDLED;
 584         } else
 585                 return IRQ_NONE;
 586 }
 587
 588 #ifdef  CONFIG_PNP
 589 #define INITSECTION
 590
 591 #else
 592 #define INITSECTION     __init
 593 #endif
 594
 595 static int INITSECTION
 596 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 597 {
 598         struct cmos_rtc_board_info      *info = dev_get_platdata(dev);
 599         int                             retval = 0;
 600         unsigned char                   rtc_control;
 601         unsigned                        address_space;
 602         u32                             flags = 0;
 603
 604         /* there can be only one ... */
 605         if (cmos_rtc.dev)
 606                 return -EBUSY;
 607
 608         if (!ports)
 609                 return -ENODEV;
 610
 611         /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
 612          *
 613          * REVISIT non-x86 systems may instead use memory space resources
 614          * (needing ioremap etc), not i/o space resources like this ...
 615          */
 616         if (RTC_IOMAPPED)
 617                 ports = request_region(ports->start, resource_size(ports),
 618                                        driver_name);
 619         else
 620                 ports = request_mem_region(ports->start, resource_size(ports),
 621                                            driver_name);
 622         if (!ports) {
 623                 dev_dbg(dev, "i/o registers already in use\n");
 624                 return -EBUSY;
 625         }
 626
 627         cmos_rtc.irq = rtc_irq;
 628         cmos_rtc.iomem = ports;
 629
 630         /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
 631          * driver did, but don't reject unknown configs.   Old hardware
 632          * won't address 128 bytes.  Newer chips have multiple banks,
 633          * though they may not be listed in one I/O resource.
 634          */
 635 #if     defined(CONFIG_ATARI)
 636         address_space = 64;
 637 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
 638                         || defined(__sparc__) || defined(__mips__) \
 639                         || defined(__powerpc__) || defined(CONFIG_MN10300)
 640         address_space = 128;
 641 #else
 642 #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
 643         address_space = 128;
 644 #endif
 645         if (can_bank2 && ports->end > (ports->start + 1))
 646                 address_space = 256;
 647
 648         /* For ACPI systems extension info comes from the FADT.  On others,
 649          * board specific setup provides it as appropriate.  Systems where
 650          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
 651          * some almost-clones) can provide hooks to make that behave.
 652          *
 653          * Note that ACPI doesn't preclude putting these registers into
 654          * "extended" areas of the chip, including some that we won't yet
 655          * expect CMOS_READ and friends to handle.
 656          */
 657         if (info) {
 658                 if (info->flags)
 659                         flags = info->flags;
 660                 if (info->address_space)
 661                         address_space = info->address_space;
 662
 663                 if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
 664                         cmos_rtc.day_alrm = info->rtc_day_alarm;
 665                 if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
 666                         cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 667                 if (info->rtc_century && info->rtc_century < 128)
 668                         cmos_rtc.century = info->rtc_century;
 669
 670                 if (info->wake_on && info->wake_off) {
 671                         cmos_rtc.wake_on = info->wake_on;
 672                         cmos_rtc.wake_off = info->wake_off;
 673                 }
 674         }
 675
 676         cmos_rtc.dev = dev;
 677         dev_set_drvdata(dev, &cmos_rtc);
 678
 679         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
 680                                 &cmos_rtc_ops, THIS_MODULE);
 681         if (IS_ERR(cmos_rtc.rtc)) {
 682                 retval = PTR_ERR(cmos_rtc.rtc);
 683                 goto cleanup0;
 684         }
 685
 686         rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
 687
 688         spin_lock_irq(&rtc_lock);
 689
 690         if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
 691                 /* force periodic irq to CMOS reset default of 1024Hz;
 692                  *
 693                  * REVISIT it's been reported that at least one x86_64 ALI
 694                  * mobo doesn't use 32KHz here ... for portability we might
 695                  * need to do something about other clock frequencies.
 696                  */
 697                 cmos_rtc.rtc->irq_freq = 1024;
 698                 hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);
 699                 CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
 700         }
 701
 702         /* disable irqs */
 703         if (is_valid_irq(rtc_irq))
 704                 cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE);
 705
 706         rtc_control = CMOS_READ(RTC_CONTROL);
 707
 708         spin_unlock_irq(&rtc_lock);
 709
 710         /* FIXME:
 711          * <asm-generic/rtc.h> doesn't know 12-hour mode either.
 712          */
 713         if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
 714                 dev_warn(dev, "only 24-hr supported\n");
 715                 retval = -ENXIO;
 716                 goto cleanup1;
 717         }
 718
 719         hpet_rtc_timer_init();
 720
 721         if (is_valid_irq(rtc_irq)) {
 722                 irq_handler_t rtc_cmos_int_handler;
 723
 724                 if (is_hpet_enabled()) {
 725                         rtc_cmos_int_handler = hpet_rtc_interrupt;
 726                         retval = hpet_register_irq_handler(cmos_interrupt);
 727                         if (retval) {
 728                                 hpet_mask_rtc_irq_bit(RTC_IRQMASK);
 729                                 dev_warn(dev, "hpet_register_irq_handler "
 730                                                 " failed in rtc_init().");
 731                                 goto cleanup1;
 732                         }
 733                 } else
 734                         rtc_cmos_int_handler = cmos_interrupt;
 735
 736                 retval = request_irq(rtc_irq, rtc_cmos_int_handler,
 737                                 IRQF_SHARED, dev_name(&cmos_rtc.rtc->dev),
 738                                 cmos_rtc.rtc);
 739                 if (retval < 0) {
 740                         dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 741                         goto cleanup1;
 742                 }
 743         }
 744
 745         /* export at least the first block of NVRAM */
 746         nvram.size = address_space - NVRAM_OFFSET;
 747         retval = sysfs_create_bin_file(&dev->kobj, &nvram);
 748         if (retval < 0) {
 749                 dev_dbg(dev, "can't create nvram file? %d\n", retval);
 750                 goto cleanup2;
 751         }
 752
 753         dev_info(dev, "%s%s, %zd bytes nvram%s\n",
 754                 !is_valid_irq(rtc_irq) ? "no alarms" :
 755                         cmos_rtc.mon_alrm ? "alarms up to one year" :
 756                         cmos_rtc.day_alrm ? "alarms up to one month" :
 757                         "alarms up to one day",
 758                 cmos_rtc.century ? ", y3k" : "",
 759                 nvram.size,
 760                 is_hpet_enabled() ? ", hpet irqs" : "");
 761
 762         return 0;
 763
 764 cleanup2:
 765         if (is_valid_irq(rtc_irq))
 766                 free_irq(rtc_irq, cmos_rtc.rtc);
 767 cleanup1:
 768         cmos_rtc.dev = NULL;
 769         rtc_device_unregister(cmos_rtc.rtc);
 770 cleanup0:
 771         if (RTC_IOMAPPED)
 772                 release_region(ports->start, resource_size(ports));
 773         else
 774                 release_mem_region(ports->start, resource_size(ports));
 775         return retval;
 776 }
 777
 778 static void cmos_do_shutdown(int rtc_irq)
 779 {
 780         spin_lock_irq(&rtc_lock);
 781         if (is_valid_irq(rtc_irq))
 782                 cmos_irq_disable(&cmos_rtc, RTC_IRQMASK);
 783         spin_unlock_irq(&rtc_lock);
 784 }
 785
 786 static void cmos_do_remove(struct device *dev)
 787 {
 788         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 789         struct resource *ports;
 790
 791         cmos_do_shutdown(cmos->irq);
 792
 793         sysfs_remove_bin_file(&dev->kobj, &nvram);
 794
 795         if (is_valid_irq(cmos->irq)) {
 796                 free_irq(cmos->irq, cmos->rtc);
 797                 hpet_unregister_irq_handler(cmos_interrupt);
 798         }
 799
 800         rtc_device_unregister(cmos->rtc);
 801         cmos->rtc = NULL;
 802
 803         ports = cmos->iomem;
 804         if (RTC_IOMAPPED)
 805                 release_region(ports->start, resource_size(ports));
 806         else
 807                 release_mem_region(ports->start, resource_size(ports));
 808         cmos->iomem = NULL;
 809
 810         cmos->dev = NULL;
 811 }
 812
 813 static int cmos_aie_poweroff(struct device *dev)
 814 {
 815         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 816         struct rtc_time now;
 817         time64_t t_now;
 818         int retval = 0;
 819         unsigned char rtc_control;
 820
 821         if (!cmos->alarm_expires)
 822                 return -EINVAL;
 823
 824         spin_lock_irq(&rtc_lock);
 825         rtc_control = CMOS_READ(RTC_CONTROL);
 826         spin_unlock_irq(&rtc_lock);
 827
 828         /* We only care about the situation where AIE is disabled. */
 829         if (rtc_control & RTC_AIE)
 830                 return -EBUSY;
 831
 832         cmos_read_time(dev, &now);
 833         t_now = rtc_tm_to_time64(&now);
 834
 835         /*
 836          * When enabling "RTC wake-up" in BIOS setup, the machine reboots
 837          * automatically right after shutdown on some buggy boxes.
 838          * This automatic rebooting issue won't happen when the alarm
 839          * time is larger than now+1 seconds.
 840          *
 841          * If the alarm time is equal to now+1 seconds, the issue can be
 842          * prevented by cancelling the alarm.
 843          */
 844         if (cmos->alarm_expires == t_now + 1) {
 845                 struct rtc_wkalrm alarm;
 846
 847                 /* Cancel the AIE timer by configuring the past time. */
 848                 rtc_time64_to_tm(t_now - 1, &alarm.time);
 849                 alarm.enabled = 0;
 850                 retval = cmos_set_alarm(dev, &alarm);
 851         } else if (cmos->alarm_expires > t_now + 1) {
 852                 retval = -EBUSY;
 853         }
 854
 855         return retval;
 856 }
 857
 858 static int cmos_suspend(struct device *dev)
 859 {
 860         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 861         unsigned char   tmp;
 862
 863         /* only the alarm might be a wakeup event source */
 864         spin_lock_irq(&rtc_lock);
 865         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 866         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 867                 unsigned char   mask;
 868
 869                 if (device_may_wakeup(dev))
 870                         mask = RTC_IRQMASK & ~RTC_AIE;
 871                 else
 872                         mask = RTC_IRQMASK;
 873                 tmp &= ~mask;
 874                 CMOS_WRITE(tmp, RTC_CONTROL);
 875                 hpet_mask_rtc_irq_bit(mask);
 876
 877                 cmos_checkintr(cmos, tmp);
 878         }
 879         spin_unlock_irq(&rtc_lock);
 880
 881         if (tmp & RTC_AIE) {
 882                 cmos->enabled_wake = 1;
 883                 if (cmos->wake_on)
 884                         cmos->wake_on(dev);
 885                 else
 886                         enable_irq_wake(cmos->irq);
 887         }
 888
 889         cmos_read_alarm(dev, &cmos->saved_wkalrm);
 890
 891         dev_dbg(dev, "suspend%s, ctrl %02x\n",
 892                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
 893                         tmp);
 894
 895         return 0;
 896 }
 897
 898 /* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even
 899  * after a detour through G3 "mechanical off", although the ACPI spec
 900  * says wakeup should only work from G1/S4 "hibernate".  To most users,
 901  * distinctions between S4 and S5 are pointless.  So when the hardware
 902  * allows, don't draw that distinction.
 903  */
 904 static inline int cmos_poweroff(struct device *dev)
 905 {
 906         if (!IS_ENABLED(CONFIG_PM))
 907                 return -ENOSYS;
 908
 909         return cmos_suspend(dev);
 910 }
 911
 912 static void cmos_check_wkalrm(struct device *dev)
 913 {
 914         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 915         struct rtc_wkalrm current_alarm;
 916         time64_t t_current_expires;
 917         time64_t t_saved_expires;
 918
 919         cmos_read_alarm(dev, &current_alarm);
 920         t_current_expires = rtc_tm_to_time64(&current_alarm.time);
 921         t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
 922         if (t_current_expires != t_saved_expires ||
 923             cmos->saved_wkalrm.enabled != current_alarm.enabled) {
 924                 cmos_set_alarm(dev, &cmos->saved_wkalrm);
 925         }
 926 }
 927
 928 static void cmos_check_acpi_rtc_status(struct device *dev,
 929                                        unsigned char *rtc_control);
 930
 931 static int __maybe_unused cmos_resume(struct device *dev)
 932 {
 933         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 934         unsigned char tmp;
 935
 936         if (cmos->enabled_wake) {
 937                 if (cmos->wake_off)
 938                         cmos->wake_off(dev);
 939                 else
 940                         disable_irq_wake(cmos->irq);
 941                 cmos->enabled_wake = 0;
 942         }
 943
 944         /* The BIOS might have changed the alarm, restore it */
 945         cmos_check_wkalrm(dev);
 946
 947         spin_lock_irq(&rtc_lock);
 948         tmp = cmos->suspend_ctrl;
 949         cmos->suspend_ctrl = 0;
 950         /* re-enable any irqs previously active */
 951         if (tmp & RTC_IRQMASK) {
 952                 unsigned char   mask;
 953
 954                 if (device_may_wakeup(dev))
 955                         hpet_rtc_timer_init();
 956
 957                 do {
 958                         CMOS_WRITE(tmp, RTC_CONTROL);
 959                         hpet_set_rtc_irq_bit(tmp & RTC_IRQMASK);
 960
 961                         mask = CMOS_READ(RTC_INTR_FLAGS);
 962                         mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
 963                         if (!is_hpet_enabled() || !is_intr(mask))
 964                                 break;
 965
 966                         /* force one-shot behavior if HPET blocked
 967                          * the wake alarm's irq
 968                          */
 969                         rtc_update_irq(cmos->rtc, 1, mask);
 970                         tmp &= ~RTC_AIE;
 971                         hpet_mask_rtc_irq_bit(RTC_AIE);
 972                 } while (mask & RTC_AIE);
 973
 974                 if (tmp & RTC_AIE)
 975                         cmos_check_acpi_rtc_status(dev, &tmp);
 976         }
 977         spin_unlock_irq(&rtc_lock);
 978
 979         dev_dbg(dev, "resume, ctrl %02x\n", tmp);
 980
 981         return 0;
 982 }
 983
 984 static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
 985
 986 /*----------------------------------------------------------------*/
 987
 988 /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
 989  * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
 990  * probably list them in similar PNPBIOS tables; so PNP is more common.
 991  *
 992  * We don't use legacy "poke at the hardware" probing.  Ancient PCs that
 993  * predate even PNPBIOS should set up platform_bus devices.
 994  */
 995
 996 #ifdef  CONFIG_ACPI
 997
 998 #include <linux/acpi.h>
 999
1000 static u32 rtc_handler(void *context)
1001 {
1002         struct device *dev = context;
1003         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1004         unsigned char rtc_control = 0;
1005         unsigned char rtc_intr;
1006         unsigned long flags;
1007
1008         spin_lock_irqsave(&rtc_lock, flags);
1009         if (cmos_rtc.suspend_ctrl)
1010                 rtc_control = CMOS_READ(RTC_CONTROL);
1011         if (rtc_control & RTC_AIE) {
1012                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
1013                 CMOS_WRITE(rtc_control, RTC_CONTROL);
1014                 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
1015                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
1016         }
1017         spin_unlock_irqrestore(&rtc_lock, flags);
1018
1019         pm_wakeup_event(dev, 0);
1020         acpi_clear_event(ACPI_EVENT_RTC);
1021         acpi_disable_event(ACPI_EVENT_RTC, 0);
1022         return ACPI_INTERRUPT_HANDLED;
1023 }
1024
1025 static inline void rtc_wake_setup(struct device *dev)
1026 {
1027         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
1028         /*
1029          * After the RTC handler is installed, the Fixed_RTC event should
1030          * be disabled. Only when the RTC alarm is set will it be enabled.
1031          */
1032         acpi_clear_event(ACPI_EVENT_RTC);
1033         acpi_disable_event(ACPI_EVENT_RTC, 0);
1034 }
1035
1036 static void rtc_wake_on(struct device *dev)
1037 {
1038         acpi_clear_event(ACPI_EVENT_RTC);
1039         acpi_enable_event(ACPI_EVENT_RTC, 0);
1040 }
1041
1042 static void rtc_wake_off(struct device *dev)
1043 {
1044         acpi_disable_event(ACPI_EVENT_RTC, 0);
1045 }
1046
1047 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
1048  * its device node and pass extra config data.  This helps its driver use
1049  * capabilities that the now-obsolete mc146818 didn't have, and informs it
1050  * that this board's RTC is wakeup-capable (per ACPI spec).
1051  */
1052 static struct cmos_rtc_board_info acpi_rtc_info;
1053
1054 static void cmos_wake_setup(struct device *dev)
1055 {
1056         if (acpi_disabled)
1057                 return;
1058
1059         rtc_wake_setup(dev);
1060         acpi_rtc_info.wake_on = rtc_wake_on;
1061         acpi_rtc_info.wake_off = rtc_wake_off;
1062
1063         /* workaround bug in some ACPI tables */
1064         if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
1065                 dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
1066                         acpi_gbl_FADT.month_alarm);
1067                 acpi_gbl_FADT.month_alarm = 0;
1068         }
1069
1070         acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
1071         acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
1072         acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
1073
1074         /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
1075         if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
1076                 dev_info(dev, "RTC can wake from S4\n");
1077
1078         dev->platform_data = &acpi_rtc_info;
1079
1080         /* RTC always wakes from S1/S2/S3, and often S4/STD */
1081         device_init_wakeup(dev, 1);
1082 }
1083
1084 static void cmos_check_acpi_rtc_status(struct device *dev,
1085                                        unsigned char *rtc_control)
1086 {
1087         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1088         acpi_event_status rtc_status;
1089         acpi_status status;
1090
1091         if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
1092                 return;
1093
1094         status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
1095         if (ACPI_FAILURE(status)) {
1096                 dev_err(dev, "Could not get RTC status\n");
1097         } else if (rtc_status & ACPI_EVENT_FLAG_SET) {
1098                 unsigned char mask;
1099                 *rtc_control &= ~RTC_AIE;
1100                 CMOS_WRITE(*rtc_control, RTC_CONTROL);
1101                 mask = CMOS_READ(RTC_INTR_FLAGS);
1102                 rtc_update_irq(cmos->rtc, 1, mask);
1103         }
1104 }
1105
1106 #else
1107
1108 static void cmos_wake_setup(struct device *dev)
1109 {
1110 }
1111
1112 static void cmos_check_acpi_rtc_status(struct device *dev,
1113                                        unsigned char *rtc_control)
1114 {
1115 }
1116
1117 #endif
1118
1119 #ifdef  CONFIG_PNP
1120
1121 #include <linux/pnp.h>
1122
1123 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
1124 {
1125         cmos_wake_setup(&pnp->dev);
1126
1127         if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0))
1128                 /* Some machines contain a PNP entry for the RTC, but
1129                  * don't define the IRQ. It should always be safe to
1130                  * hardcode it in these cases
1131                  */
1132                 return cmos_do_probe(&pnp->dev,
1133                                 pnp_get_resource(pnp, IORESOURCE_IO, 0), 8);
1134         else
1135                 return cmos_do_probe(&pnp->dev,
1136                                 pnp_get_resource(pnp, IORESOURCE_IO, 0),
1137                                 pnp_irq(pnp, 0));
1138 }
1139
1140 static void cmos_pnp_remove(struct pnp_dev *pnp)
1141 {
1142         cmos_do_remove(&pnp->dev);
1143 }
1144
1145 static void cmos_pnp_shutdown(struct pnp_dev *pnp)
1146 {
1147         struct device *dev = &pnp->dev;
1148         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1149
1150         if (system_state == SYSTEM_POWER_OFF) {
1151                 int retval = cmos_poweroff(dev);
1152
1153                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1154                         return;
1155         }
1156
1157         cmos_do_shutdown(cmos->irq);
1158 }
1159
1160 static const struct pnp_device_id rtc_ids[] = {
1161         { .id = "PNP0b00", },
1162         { .id = "PNP0b01", },
1163         { .id = "PNP0b02", },
1164         { },
1165 };
1166 MODULE_DEVICE_TABLE(pnp, rtc_ids);
1167
1168 static struct pnp_driver cmos_pnp_driver = {
1169         .name           = (char *) driver_name,
1170         .id_table       = rtc_ids,
1171         .probe          = cmos_pnp_probe,
1172         .remove         = cmos_pnp_remove,
1173         .shutdown       = cmos_pnp_shutdown,
1174
1175         /* flag ensures resume() gets called, and stops syslog spam */
1176         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
1177         .driver         = {
1178                         .pm = &cmos_pm_ops,
1179         },
1180 };
1181
1182 #endif  /* CONFIG_PNP */
1183
1184 #ifdef CONFIG_OF
1185 static const struct of_device_id of_cmos_match[] = {
1186         {
1187                 .compatible = "motorola,mc146818",
1188         },
1189         { },
1190 };
1191 MODULE_DEVICE_TABLE(of, of_cmos_match);
1192
1193 static __init void cmos_of_init(struct platform_device *pdev)
1194 {
1195         struct device_node *node = pdev->dev.of_node;
1196         struct rtc_time time;
1197         int ret;
1198         const __be32 *val;
1199
1200         if (!node)
1201                 return;
1202
1203         val = of_get_property(node, "ctrl-reg", NULL);
1204         if (val)
1205                 CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
1206
1207         val = of_get_property(node, "freq-reg", NULL);
1208         if (val)
1209                 CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
1210
1211         cmos_read_time(&pdev->dev, &time);
1212         ret = rtc_valid_tm(&time);
1213         if (ret) {
1214                 struct rtc_time def_time = {
1215                         .tm_year = 1,
1216                         .tm_mday = 1,
1217                 };
1218                 cmos_set_time(&pdev->dev, &def_time);
1219         }
1220 }
1221 #else
1222 static inline void cmos_of_init(struct platform_device *pdev) {}
1223 #endif
1224 /*----------------------------------------------------------------*/
1225
1226 /* Platform setup should have set up an RTC device, when PNP is
1227  * unavailable ... this could happen even on (older) PCs.
1228  */
1229
1230 static int __init cmos_platform_probe(struct platform_device *pdev)
1231 {
1232         struct resource *resource;
1233         int irq;
1234
1235         cmos_of_init(pdev);
1236         cmos_wake_setup(&pdev->dev);
1237
1238         if (RTC_IOMAPPED)
1239                 resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
1240         else
1241                 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1242         irq = platform_get_irq(pdev, 0);
1243         if (irq < 0)
1244                 irq = -1;
1245
1246         return cmos_do_probe(&pdev->dev, resource, irq);
1247 }
1248
1249 static int cmos_platform_remove(struct platform_device *pdev)
1250 {
1251         cmos_do_remove(&pdev->dev);
1252         return 0;
1253 }
1254
1255 static void cmos_platform_shutdown(struct platform_device *pdev)
1256 {
1257         struct device *dev = &pdev->dev;
1258         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1259
1260         if (system_state == SYSTEM_POWER_OFF) {
1261                 int retval = cmos_poweroff(dev);
1262
1263                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1264                         return;
1265         }
1266
1267         cmos_do_shutdown(cmos->irq);
1268 }
1269
1270 /* work with hotplug and coldplug */
1271 MODULE_ALIAS("platform:rtc_cmos");
1272
1273 static struct platform_driver cmos_platform_driver = {
1274         .remove         = cmos_platform_remove,
1275         .shutdown       = cmos_platform_shutdown,
1276         .driver = {
1277                 .name           = driver_name,
1278                 .pm             = &cmos_pm_ops,
1279                 .of_match_table = of_match_ptr(of_cmos_match),
1280         }
1281 };
1282
1283 #ifdef CONFIG_PNP
1284 static bool pnp_driver_registered;
1285 #endif
1286 static bool platform_driver_registered;
1287
1288 static int __init cmos_init(void)
1289 {
1290         int retval = 0;
1291
1292 #ifdef  CONFIG_PNP
1293         retval = pnp_register_driver(&cmos_pnp_driver);
1294         if (retval == 0)
1295                 pnp_driver_registered = true;
1296 #endif
1297
1298         if (!cmos_rtc.dev) {
1299                 retval = platform_driver_probe(&cmos_platform_driver,
1300                                                cmos_platform_probe);
1301                 if (retval == 0)
1302                         platform_driver_registered = true;
1303         }
1304
1305         if (retval == 0)
1306                 return 0;
1307
1308 #ifdef  CONFIG_PNP
1309         if (pnp_driver_registered)
1310                 pnp_unregister_driver(&cmos_pnp_driver);
1311 #endif
1312         return retval;
1313 }
1314 module_init(cmos_init);
1315
1316 static void __exit cmos_exit(void)
1317 {
1318 #ifdef  CONFIG_PNP
1319         if (pnp_driver_registered)
1320                 pnp_unregister_driver(&cmos_pnp_driver);
1321 #endif
1322         if (platform_driver_registered)
1323                 platform_driver_unregister(&cmos_platform_driver);
1324 }
1325 module_exit(cmos_exit);
1326
1327
1328 MODULE_AUTHOR("David Brownell");
1329 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
1330 MODULE_LICENSE("GPL");