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 #ifdef CONFIG_X86
  45 #include <asm/i8259.h>
  46 #endif
  47
  48 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
  49 #include <linux/mc146818rtc.h>
  50
  51 struct cmos_rtc {
  52         struct rtc_device       *rtc;
  53         struct device           *dev;
  54         int                     irq;
  55         struct resource         *iomem;
  56         time64_t                alarm_expires;
  57
  58         void                    (*wake_on)(struct device *);
  59         void                    (*wake_off)(struct device *);
  60
  61         u8                      enabled_wake;
  62         u8                      suspend_ctrl;
  63
  64         /* newer hardware extends the original register set */
  65         u8                      day_alrm;
  66         u8                      mon_alrm;
  67         u8                      century;
  68
  69         struct rtc_wkalrm       saved_wkalrm;
  70 };
  71
  72 /* both platform and pnp busses use negative numbers for invalid irqs */
  73 #define is_valid_irq(n)         ((n) > 0)
  74
  75 static const char driver_name[] = "rtc_cmos";
  76
  77 /* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
  78  * always mask it against the irq enable bits in RTC_CONTROL.  Bit values
  79  * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
  80  */
  81 #define RTC_IRQMASK     (RTC_PF | RTC_AF | RTC_UF)
  82
  83 static inline int is_intr(u8 rtc_intr)
  84 {
  85         if (!(rtc_intr & RTC_IRQF))
  86                 return 0;
  87         return rtc_intr & RTC_IRQMASK;
  88 }
  89
  90 /*----------------------------------------------------------------*/
  91
  92 /* Much modern x86 hardware has HPETs (10+ MHz timers) which, because
  93  * many BIOS programmers don't set up "sane mode" IRQ routing, are mostly
  94  * used in a broken "legacy replacement" mode.  The breakage includes
  95  * HPET #1 hijacking the IRQ for this RTC, and being unavailable for
  96  * other (better) use.
  97  *
  98  * When that broken mode is in use, platform glue provides a partial
  99  * emulation of hardware RTC IRQ facilities using HPET #1.  We don't
 100  * want to use HPET for anything except those IRQs though...
 101  */
 102 #ifdef CONFIG_HPET_EMULATE_RTC
 103 #include <asm/hpet.h>
 104 #else
 105
 106 static inline int is_hpet_enabled(void)
 107 {
 108         return 0;
 109 }
 110
 111 static inline int hpet_mask_rtc_irq_bit(unsigned long mask)
 112 {
 113         return 0;
 114 }
 115
 116 static inline int hpet_set_rtc_irq_bit(unsigned long mask)
 117 {
 118         return 0;
 119 }
 120
 121 static inline int
 122 hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
 123 {
 124         return 0;
 125 }
 126
 127 static inline int hpet_set_periodic_freq(unsigned long freq)
 128 {
 129         return 0;
 130 }
 131
 132 static inline int hpet_rtc_dropped_irq(void)
 133 {
 134         return 0;
 135 }
 136
 137 static inline int hpet_rtc_timer_init(void)
 138 {
 139         return 0;
 140 }
 141
 142 extern irq_handler_t hpet_rtc_interrupt;
 143
 144 static inline int hpet_register_irq_handler(irq_handler_t handler)
 145 {
 146         return 0;
 147 }
 148
 149 static inline int hpet_unregister_irq_handler(irq_handler_t handler)
 150 {
 151         return 0;
 152 }
 153
 154 #endif
 155
 156 /*----------------------------------------------------------------*/
 157
 158 #ifdef RTC_PORT
 159
 160 /* Most newer x86 systems have two register banks, the first used
 161  * for RTC and NVRAM and the second only for NVRAM.  Caller must
 162  * own rtc_lock ... and we won't worry about access during NMI.
 163  */
 164 #define can_bank2       true
 165
 166 static inline unsigned char cmos_read_bank2(unsigned char addr)
 167 {
 168         outb(addr, RTC_PORT(2));
 169         return inb(RTC_PORT(3));
 170 }
 171
 172 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
 173 {
 174         outb(addr, RTC_PORT(2));
 175         outb(val, RTC_PORT(3));
 176 }
 177
 178 #else
 179
 180 #define can_bank2       false
 181
 182 static inline unsigned char cmos_read_bank2(unsigned char addr)
 183 {
 184         return 0;
 185 }
 186
 187 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
 188 {
 189 }
 190
 191 #endif
 192
 193 /*----------------------------------------------------------------*/
 194
 195 static int cmos_read_time(struct device *dev, struct rtc_time *t)
 196 {
 197         /*
 198          * If pm_trace abused the RTC for storage, set the timespec to 0,
 199          * which tells the caller that this RTC value is unusable.
 200          */
 201         if (!pm_trace_rtc_valid())
 202                 return -EIO;
 203
 204         /* REVISIT:  if the clock has a "century" register, use
 205          * that instead of the heuristic in mc146818_get_time().
 206          * That'll make Y3K compatility (year > 2070) easy!
 207          */
 208         mc146818_get_time(t);
 209         return 0;
 210 }
 211
 212 static int cmos_set_time(struct device *dev, struct rtc_time *t)
 213 {
 214         /* REVISIT:  set the "century" register if available
 215          *
 216          * NOTE: this ignores the issue whereby updating the seconds
 217          * takes effect exactly 500ms after we write the register.
 218          * (Also queueing and other delays before we get this far.)
 219          */
 220         return mc146818_set_time(t);
 221 }
 222
 223 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 224 {
 225         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 226         unsigned char   rtc_control;
 227
 228         if (!is_valid_irq(cmos->irq))
 229                 return -EIO;
 230
 231         /* Basic alarms only support hour, minute, and seconds fields.
 232          * Some also support day and month, for alarms up to a year in
 233          * the future.
 234          */
 235
 236         spin_lock_irq(&rtc_lock);
 237         t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
 238         t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
 239         t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
 240
 241         if (cmos->day_alrm) {
 242                 /* ignore upper bits on readback per ACPI spec */
 243                 t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
 244                 if (!t->time.tm_mday)
 245                         t->time.tm_mday = -1;
 246
 247                 if (cmos->mon_alrm) {
 248                         t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
 249                         if (!t->time.tm_mon)
 250                                 t->time.tm_mon = -1;
 251                 }
 252         }
 253
 254         rtc_control = CMOS_READ(RTC_CONTROL);
 255         spin_unlock_irq(&rtc_lock);
 256
 257         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 258                 if (((unsigned)t->time.tm_sec) < 0x60)
 259                         t->time.tm_sec = bcd2bin(t->time.tm_sec);
 260                 else
 261                         t->time.tm_sec = -1;
 262                 if (((unsigned)t->time.tm_min) < 0x60)
 263                         t->time.tm_min = bcd2bin(t->time.tm_min);
 264                 else
 265                         t->time.tm_min = -1;
 266                 if (((unsigned)t->time.tm_hour) < 0x24)
 267                         t->time.tm_hour = bcd2bin(t->time.tm_hour);
 268                 else
 269                         t->time.tm_hour = -1;
 270
 271                 if (cmos->day_alrm) {
 272                         if (((unsigned)t->time.tm_mday) <= 0x31)
 273                                 t->time.tm_mday = bcd2bin(t->time.tm_mday);
 274                         else
 275                                 t->time.tm_mday = -1;
 276
 277                         if (cmos->mon_alrm) {
 278                                 if (((unsigned)t->time.tm_mon) <= 0x12)
 279                                         t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;
 280                                 else
 281                                         t->time.tm_mon = -1;
 282                         }
 283                 }
 284         }
 285
 286         t->enabled = !!(rtc_control & RTC_AIE);
 287         t->pending = 0;
 288
 289         return 0;
 290 }
 291
 292 static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control)
 293 {
 294         unsigned char   rtc_intr;
 295
 296         /* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
 297          * allegedly some older rtcs need that to handle irqs properly
 298          */
 299         rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
 300
 301         if (is_hpet_enabled())
 302                 return;
 303
 304         rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 305         if (is_intr(rtc_intr))
 306                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
 307 }
 308
 309 static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask)
 310 {
 311         unsigned char   rtc_control;
 312
 313         /* flush any pending IRQ status, notably for update irqs,
 314          * before we enable new IRQs
 315          */
 316         rtc_control = CMOS_READ(RTC_CONTROL);
 317         cmos_checkintr(cmos, rtc_control);
 318
 319         rtc_control |= mask;
 320         CMOS_WRITE(rtc_control, RTC_CONTROL);
 321         hpet_set_rtc_irq_bit(mask);
 322
 323         cmos_checkintr(cmos, rtc_control);
 324 }
 325
 326 static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)
 327 {
 328         unsigned char   rtc_control;
 329
 330         rtc_control = CMOS_READ(RTC_CONTROL);
 331         rtc_control &= ~mask;
 332         CMOS_WRITE(rtc_control, RTC_CONTROL);
 333         hpet_mask_rtc_irq_bit(mask);
 334
 335         cmos_checkintr(cmos, rtc_control);
 336 }
 337
 338 static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t)
 339 {
 340         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 341         struct rtc_time now;
 342
 343         cmos_read_time(dev, &now);
 344
 345         if (!cmos->day_alrm) {
 346                 time64_t t_max_date;
 347                 time64_t t_alrm;
 348
 349                 t_max_date = rtc_tm_to_time64(&now);
 350                 t_max_date += 24 * 60 * 60 - 1;
 351                 t_alrm = rtc_tm_to_time64(&t->time);
 352                 if (t_alrm > t_max_date) {
 353                         dev_err(dev,
 354                                 "Alarms can be up to one day in the future\n");
 355                         return -EINVAL;
 356                 }
 357         } else if (!cmos->mon_alrm) {
 358                 struct rtc_time max_date = now;
 359                 time64_t t_max_date;
 360                 time64_t t_alrm;
 361                 int max_mday;
 362
 363                 if (max_date.tm_mon == 11) {
 364                         max_date.tm_mon = 0;
 365                         max_date.tm_year += 1;
 366                 } else {
 367                         max_date.tm_mon += 1;
 368                 }
 369                 max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
 370                 if (max_date.tm_mday > max_mday)
 371                         max_date.tm_mday = max_mday;
 372
 373                 t_max_date = rtc_tm_to_time64(&max_date);
 374                 t_max_date -= 1;
 375                 t_alrm = rtc_tm_to_time64(&t->time);
 376                 if (t_alrm > t_max_date) {
 377                         dev_err(dev,
 378                                 "Alarms can be up to one month in the future\n");
 379                         return -EINVAL;
 380                 }
 381         } else {
 382                 struct rtc_time max_date = now;
 383                 time64_t t_max_date;
 384                 time64_t t_alrm;
 385                 int max_mday;
 386
 387                 max_date.tm_year += 1;
 388                 max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
 389                 if (max_date.tm_mday > max_mday)
 390                         max_date.tm_mday = max_mday;
 391
 392                 t_max_date = rtc_tm_to_time64(&max_date);
 393                 t_max_date -= 1;
 394                 t_alrm = rtc_tm_to_time64(&t->time);
 395                 if (t_alrm > t_max_date) {
 396                         dev_err(dev,
 397                                 "Alarms can be up to one year in the future\n");
 398                         return -EINVAL;
 399                 }
 400         }
 401
 402         return 0;
 403 }
 404
 405 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 406 {
 407         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 408         unsigned char mon, mday, hrs, min, sec, rtc_control;
 409         int ret;
 410
 411         if (!is_valid_irq(cmos->irq))
 412                 return -EIO;
 413
 414         ret = cmos_validate_alarm(dev, t);
 415         if (ret < 0)
 416                 return ret;
 417
 418         mon = t->time.tm_mon + 1;
 419         mday = t->time.tm_mday;
 420         hrs = t->time.tm_hour;
 421         min = t->time.tm_min;
 422         sec = t->time.tm_sec;
 423
 424         spin_lock_irq(&rtc_lock);
 425         rtc_control = CMOS_READ(RTC_CONTROL);
 426         spin_unlock_irq(&rtc_lock);
 427
 428         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
 429                 /* Writing 0xff means "don't care" or "match all".  */
 430                 mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
 431                 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
 432                 hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
 433                 min = (min < 60) ? bin2bcd(min) : 0xff;
 434                 sec = (sec < 60) ? bin2bcd(sec) : 0xff;
 435         }
 436
 437         spin_lock_irq(&rtc_lock);
 438
 439         /* next rtc irq must not be from previous alarm setting */
 440         cmos_irq_disable(cmos, RTC_AIE);
 441
 442         /* update alarm */
 443         CMOS_WRITE(hrs, RTC_HOURS_ALARM);
 444         CMOS_WRITE(min, RTC_MINUTES_ALARM);
 445         CMOS_WRITE(sec, RTC_SECONDS_ALARM);
 446
 447         /* the system may support an "enhanced" alarm */
 448         if (cmos->day_alrm) {
 449                 CMOS_WRITE(mday, cmos->day_alrm);
 450                 if (cmos->mon_alrm)
 451                         CMOS_WRITE(mon, cmos->mon_alrm);
 452         }
 453
 454         /* FIXME the HPET alarm glue currently ignores day_alrm
 455          * and mon_alrm ...
 456          */
 457         hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);
 458
 459         if (t->enabled)
 460                 cmos_irq_enable(cmos, RTC_AIE);
 461
 462         spin_unlock_irq(&rtc_lock);
 463
 464         cmos->alarm_expires = rtc_tm_to_time64(&t->time);
 465
 466         return 0;
 467 }
 468
 469 static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
 470 {
 471         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 472         unsigned long   flags;
 473
 474         if (!is_valid_irq(cmos->irq))
 475                 return -EINVAL;
 476
 477         spin_lock_irqsave(&rtc_lock, flags);
 478
 479         if (enabled)
 480                 cmos_irq_enable(cmos, RTC_AIE);
 481         else
 482                 cmos_irq_disable(cmos, RTC_AIE);
 483
 484         spin_unlock_irqrestore(&rtc_lock, flags);
 485         return 0;
 486 }
 487
 488 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
 489
 490 static int cmos_procfs(struct device *dev, struct seq_file *seq)
 491 {
 492         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 493         unsigned char   rtc_control, valid;
 494
 495         spin_lock_irq(&rtc_lock);
 496         rtc_control = CMOS_READ(RTC_CONTROL);
 497         valid = CMOS_READ(RTC_VALID);
 498         spin_unlock_irq(&rtc_lock);
 499
 500         /* NOTE:  at least ICH6 reports battery status using a different
 501          * (non-RTC) bit; and SQWE is ignored on many current systems.
 502          */
 503         seq_printf(seq,
 504                    "periodic_IRQ\t: %s\n"
 505                    "update_IRQ\t: %s\n"
 506                    "HPET_emulated\t: %s\n"
 507                    // "square_wave\t: %s\n"
 508                    "BCD\t\t: %s\n"
 509                    "DST_enable\t: %s\n"
 510                    "periodic_freq\t: %d\n"
 511                    "batt_status\t: %s\n",
 512                    (rtc_control & RTC_PIE) ? "yes" : "no",
 513                    (rtc_control & RTC_UIE) ? "yes" : "no",
 514                    is_hpet_enabled() ? "yes" : "no",
 515                    // (rtc_control & RTC_SQWE) ? "yes" : "no",
 516                    (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
 517                    (rtc_control & RTC_DST_EN) ? "yes" : "no",
 518                    cmos->rtc->irq_freq,
 519                    (valid & RTC_VRT) ? "okay" : "dead");
 520
 521         return 0;
 522 }
 523
 524 #else
 525 #define cmos_procfs     NULL
 526 #endif
 527
 528 static const struct rtc_class_ops cmos_rtc_ops = {
 529         .read_time              = cmos_read_time,
 530         .set_time               = cmos_set_time,
 531         .read_alarm             = cmos_read_alarm,
 532         .set_alarm              = cmos_set_alarm,
 533         .proc                   = cmos_procfs,
 534         .alarm_irq_enable       = cmos_alarm_irq_enable,
 535 };
 536
 537 /*----------------------------------------------------------------*/
 538
 539 /*
 540  * All these chips have at least 64 bytes of address space, shared by
 541  * RTC registers and NVRAM.  Most of those bytes of NVRAM are used
 542  * by boot firmware.  Modern chips have 128 or 256 bytes.
 543  */
 544
 545 #define NVRAM_OFFSET    (RTC_REG_D + 1)
 546
 547 static ssize_t
 548 cmos_nvram_read(struct file *filp, struct kobject *kobj,
 549                 struct bin_attribute *attr,
 550                 char *buf, loff_t off, size_t count)
 551 {
 552         int     retval;
 553
 554         off += NVRAM_OFFSET;
 555         spin_lock_irq(&rtc_lock);
 556         for (retval = 0; count; count--, off++, retval++) {
 557                 if (off < 128)
 558                         *buf++ = CMOS_READ(off);
 559                 else if (can_bank2)
 560                         *buf++ = cmos_read_bank2(off);
 561                 else
 562                         break;
 563         }
 564         spin_unlock_irq(&rtc_lock);
 565
 566         return retval;
 567 }
 568
 569 static ssize_t
 570 cmos_nvram_write(struct file *filp, struct kobject *kobj,
 571                 struct bin_attribute *attr,
 572                 char *buf, loff_t off, size_t count)
 573 {
 574         struct cmos_rtc *cmos;
 575         int             retval;
 576
 577         cmos = dev_get_drvdata(container_of(kobj, struct device, kobj));
 578
 579         /* NOTE:  on at least PCs and Ataris, the boot firmware uses a
 580          * checksum on part of the NVRAM data.  That's currently ignored
 581          * here.  If userspace is smart enough to know what fields of
 582          * NVRAM to update, updating checksums is also part of its job.
 583          */
 584         off += NVRAM_OFFSET;
 585         spin_lock_irq(&rtc_lock);
 586         for (retval = 0; count; count--, off++, retval++) {
 587                 /* don't trash RTC registers */
 588                 if (off == cmos->day_alrm
 589                                 || off == cmos->mon_alrm
 590                                 || off == cmos->century)
 591                         buf++;
 592                 else if (off < 128)
 593                         CMOS_WRITE(*buf++, off);
 594                 else if (can_bank2)
 595                         cmos_write_bank2(*buf++, off);
 596                 else
 597                         break;
 598         }
 599         spin_unlock_irq(&rtc_lock);
 600
 601         return retval;
 602 }
 603
 604 static struct bin_attribute nvram = {
 605         .attr = {
 606                 .name   = "nvram",
 607                 .mode   = S_IRUGO | S_IWUSR,
 608         },
 609
 610         .read   = cmos_nvram_read,
 611         .write  = cmos_nvram_write,
 612         /* size gets set up later */
 613 };
 614
 615 /*----------------------------------------------------------------*/
 616
 617 static struct cmos_rtc  cmos_rtc;
 618
 619 static irqreturn_t cmos_interrupt(int irq, void *p)
 620 {
 621         u8              irqstat;
 622         u8              rtc_control;
 623
 624         spin_lock(&rtc_lock);
 625
 626         /* When the HPET interrupt handler calls us, the interrupt
 627          * status is passed as arg1 instead of the irq number.  But
 628          * always clear irq status, even when HPET is in the way.
 629          *
 630          * Note that HPET and RTC are almost certainly out of phase,
 631          * giving different IRQ status ...
 632          */
 633         irqstat = CMOS_READ(RTC_INTR_FLAGS);
 634         rtc_control = CMOS_READ(RTC_CONTROL);
 635         if (is_hpet_enabled())
 636                 irqstat = (unsigned long)irq & 0xF0;
 637
 638         /* If we were suspended, RTC_CONTROL may not be accurate since the
 639          * bios may have cleared it.
 640          */
 641         if (!cmos_rtc.suspend_ctrl)
 642                 irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
 643         else
 644                 irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
 645
 646         /* All Linux RTC alarms should be treated as if they were oneshot.
 647          * Similar code may be needed in system wakeup paths, in case the
 648          * alarm woke the system.
 649          */
 650         if (irqstat & RTC_AIE) {
 651                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
 652                 rtc_control &= ~RTC_AIE;
 653                 CMOS_WRITE(rtc_control, RTC_CONTROL);
 654                 hpet_mask_rtc_irq_bit(RTC_AIE);
 655                 CMOS_READ(RTC_INTR_FLAGS);
 656         }
 657         spin_unlock(&rtc_lock);
 658
 659         if (is_intr(irqstat)) {
 660                 rtc_update_irq(p, 1, irqstat);
 661                 return IRQ_HANDLED;
 662         } else
 663                 return IRQ_NONE;
 664 }
 665
 666 #ifdef  CONFIG_PNP
 667 #define INITSECTION
 668
 669 #else
 670 #define INITSECTION     __init
 671 #endif
 672
 673 static int INITSECTION
 674 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 675 {
 676         struct cmos_rtc_board_info      *info = dev_get_platdata(dev);
 677         int                             retval = 0;
 678         unsigned char                   rtc_control;
 679         unsigned                        address_space;
 680         u32                             flags = 0;
 681
 682         /* there can be only one ... */
 683         if (cmos_rtc.dev)
 684                 return -EBUSY;
 685
 686         if (!ports)
 687                 return -ENODEV;
 688
 689         /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
 690          *
 691          * REVISIT non-x86 systems may instead use memory space resources
 692          * (needing ioremap etc), not i/o space resources like this ...
 693          */
 694         if (RTC_IOMAPPED)
 695                 ports = request_region(ports->start, resource_size(ports),
 696                                        driver_name);
 697         else
 698                 ports = request_mem_region(ports->start, resource_size(ports),
 699                                            driver_name);
 700         if (!ports) {
 701                 dev_dbg(dev, "i/o registers already in use\n");
 702                 return -EBUSY;
 703         }
 704
 705         cmos_rtc.irq = rtc_irq;
 706         cmos_rtc.iomem = ports;
 707
 708         /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
 709          * driver did, but don't reject unknown configs.   Old hardware
 710          * won't address 128 bytes.  Newer chips have multiple banks,
 711          * though they may not be listed in one I/O resource.
 712          */
 713 #if     defined(CONFIG_ATARI)
 714         address_space = 64;
 715 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
 716                         || defined(__sparc__) || defined(__mips__) \
 717                         || defined(__powerpc__) || defined(CONFIG_MN10300)
 718         address_space = 128;
 719 #else
 720 #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
 721         address_space = 128;
 722 #endif
 723         if (can_bank2 && ports->end > (ports->start + 1))
 724                 address_space = 256;
 725
 726         /* For ACPI systems extension info comes from the FADT.  On others,
 727          * board specific setup provides it as appropriate.  Systems where
 728          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
 729          * some almost-clones) can provide hooks to make that behave.
 730          *
 731          * Note that ACPI doesn't preclude putting these registers into
 732          * "extended" areas of the chip, including some that we won't yet
 733          * expect CMOS_READ and friends to handle.
 734          */
 735         if (info) {
 736                 if (info->flags)
 737                         flags = info->flags;
 738                 if (info->address_space)
 739                         address_space = info->address_space;
 740
 741                 if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
 742                         cmos_rtc.day_alrm = info->rtc_day_alarm;
 743                 if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
 744                         cmos_rtc.mon_alrm = info->rtc_mon_alarm;
 745                 if (info->rtc_century && info->rtc_century < 128)
 746                         cmos_rtc.century = info->rtc_century;
 747
 748                 if (info->wake_on && info->wake_off) {
 749                         cmos_rtc.wake_on = info->wake_on;
 750                         cmos_rtc.wake_off = info->wake_off;
 751                 }
 752         }
 753
 754         cmos_rtc.dev = dev;
 755         dev_set_drvdata(dev, &cmos_rtc);
 756
 757         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
 758                                 &cmos_rtc_ops, THIS_MODULE);
 759         if (IS_ERR(cmos_rtc.rtc)) {
 760                 retval = PTR_ERR(cmos_rtc.rtc);
 761                 goto cleanup0;
 762         }
 763
 764         rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
 765
 766         spin_lock_irq(&rtc_lock);
 767
 768         if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
 769                 /* force periodic irq to CMOS reset default of 1024Hz;
 770                  *
 771                  * REVISIT it's been reported that at least one x86_64 ALI
 772                  * mobo doesn't use 32KHz here ... for portability we might
 773                  * need to do something about other clock frequencies.
 774                  */
 775                 cmos_rtc.rtc->irq_freq = 1024;
 776                 hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);
 777                 CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
 778         }
 779
 780         /* disable irqs */
 781         if (is_valid_irq(rtc_irq))
 782                 cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE);
 783
 784         rtc_control = CMOS_READ(RTC_CONTROL);
 785
 786         spin_unlock_irq(&rtc_lock);
 787
 788         if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
 789                 dev_warn(dev, "only 24-hr supported\n");
 790                 retval = -ENXIO;
 791                 goto cleanup1;
 792         }
 793
 794         hpet_rtc_timer_init();
 795
 796         if (is_valid_irq(rtc_irq)) {
 797                 irq_handler_t rtc_cmos_int_handler;
 798
 799                 if (is_hpet_enabled()) {
 800                         rtc_cmos_int_handler = hpet_rtc_interrupt;
 801                         retval = hpet_register_irq_handler(cmos_interrupt);
 802                         if (retval) {
 803                                 hpet_mask_rtc_irq_bit(RTC_IRQMASK);
 804                                 dev_warn(dev, "hpet_register_irq_handler "
 805                                                 " failed in rtc_init().");
 806                                 goto cleanup1;
 807                         }
 808                 } else
 809                         rtc_cmos_int_handler = cmos_interrupt;
 810
 811                 retval = request_irq(rtc_irq, rtc_cmos_int_handler,
 812                                 0, dev_name(&cmos_rtc.rtc->dev),
 813                                 cmos_rtc.rtc);
 814                 if (retval < 0) {
 815                         dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
 816                         goto cleanup1;
 817                 }
 818         }
 819
 820         /* export at least the first block of NVRAM */
 821         nvram.size = address_space - NVRAM_OFFSET;
 822         retval = sysfs_create_bin_file(&dev->kobj, &nvram);
 823         if (retval < 0) {
 824                 dev_dbg(dev, "can't create nvram file? %d\n", retval);
 825                 goto cleanup2;
 826         }
 827
 828         dev_info(dev, "%s%s, %zd bytes nvram%s\n",
 829                 !is_valid_irq(rtc_irq) ? "no alarms" :
 830                         cmos_rtc.mon_alrm ? "alarms up to one year" :
 831                         cmos_rtc.day_alrm ? "alarms up to one month" :
 832                         "alarms up to one day",
 833                 cmos_rtc.century ? ", y3k" : "",
 834                 nvram.size,
 835                 is_hpet_enabled() ? ", hpet irqs" : "");
 836
 837         return 0;
 838
 839 cleanup2:
 840         if (is_valid_irq(rtc_irq))
 841                 free_irq(rtc_irq, cmos_rtc.rtc);
 842 cleanup1:
 843         cmos_rtc.dev = NULL;
 844         rtc_device_unregister(cmos_rtc.rtc);
 845 cleanup0:
 846         if (RTC_IOMAPPED)
 847                 release_region(ports->start, resource_size(ports));
 848         else
 849                 release_mem_region(ports->start, resource_size(ports));
 850         return retval;
 851 }
 852
 853 static void cmos_do_shutdown(int rtc_irq)
 854 {
 855         spin_lock_irq(&rtc_lock);
 856         if (is_valid_irq(rtc_irq))
 857                 cmos_irq_disable(&cmos_rtc, RTC_IRQMASK);
 858         spin_unlock_irq(&rtc_lock);
 859 }
 860
 861 static void cmos_do_remove(struct device *dev)
 862 {
 863         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 864         struct resource *ports;
 865
 866         cmos_do_shutdown(cmos->irq);
 867
 868         sysfs_remove_bin_file(&dev->kobj, &nvram);
 869
 870         if (is_valid_irq(cmos->irq)) {
 871                 free_irq(cmos->irq, cmos->rtc);
 872                 hpet_unregister_irq_handler(cmos_interrupt);
 873         }
 874
 875         rtc_device_unregister(cmos->rtc);
 876         cmos->rtc = NULL;
 877
 878         ports = cmos->iomem;
 879         if (RTC_IOMAPPED)
 880                 release_region(ports->start, resource_size(ports));
 881         else
 882                 release_mem_region(ports->start, resource_size(ports));
 883         cmos->iomem = NULL;
 884
 885         cmos->dev = NULL;
 886 }
 887
 888 static int cmos_aie_poweroff(struct device *dev)
 889 {
 890         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 891         struct rtc_time now;
 892         time64_t t_now;
 893         int retval = 0;
 894         unsigned char rtc_control;
 895
 896         if (!cmos->alarm_expires)
 897                 return -EINVAL;
 898
 899         spin_lock_irq(&rtc_lock);
 900         rtc_control = CMOS_READ(RTC_CONTROL);
 901         spin_unlock_irq(&rtc_lock);
 902
 903         /* We only care about the situation where AIE is disabled. */
 904         if (rtc_control & RTC_AIE)
 905                 return -EBUSY;
 906
 907         cmos_read_time(dev, &now);
 908         t_now = rtc_tm_to_time64(&now);
 909
 910         /*
 911          * When enabling "RTC wake-up" in BIOS setup, the machine reboots
 912          * automatically right after shutdown on some buggy boxes.
 913          * This automatic rebooting issue won't happen when the alarm
 914          * time is larger than now+1 seconds.
 915          *
 916          * If the alarm time is equal to now+1 seconds, the issue can be
 917          * prevented by cancelling the alarm.
 918          */
 919         if (cmos->alarm_expires == t_now + 1) {
 920                 struct rtc_wkalrm alarm;
 921
 922                 /* Cancel the AIE timer by configuring the past time. */
 923                 rtc_time64_to_tm(t_now - 1, &alarm.time);
 924                 alarm.enabled = 0;
 925                 retval = cmos_set_alarm(dev, &alarm);
 926         } else if (cmos->alarm_expires > t_now + 1) {
 927                 retval = -EBUSY;
 928         }
 929
 930         return retval;
 931 }
 932
 933 static int cmos_suspend(struct device *dev)
 934 {
 935         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 936         unsigned char   tmp;
 937
 938         /* only the alarm might be a wakeup event source */
 939         spin_lock_irq(&rtc_lock);
 940         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
 941         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
 942                 unsigned char   mask;
 943
 944                 if (device_may_wakeup(dev))
 945                         mask = RTC_IRQMASK & ~RTC_AIE;
 946                 else
 947                         mask = RTC_IRQMASK;
 948                 tmp &= ~mask;
 949                 CMOS_WRITE(tmp, RTC_CONTROL);
 950                 hpet_mask_rtc_irq_bit(mask);
 951
 952                 cmos_checkintr(cmos, tmp);
 953         }
 954         spin_unlock_irq(&rtc_lock);
 955
 956         if (tmp & RTC_AIE) {
 957                 cmos->enabled_wake = 1;
 958                 if (cmos->wake_on)
 959                         cmos->wake_on(dev);
 960                 else
 961                         enable_irq_wake(cmos->irq);
 962         }
 963
 964         cmos_read_alarm(dev, &cmos->saved_wkalrm);
 965
 966         dev_dbg(dev, "suspend%s, ctrl %02x\n",
 967                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
 968                         tmp);
 969
 970         return 0;
 971 }
 972
 973 /* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even
 974  * after a detour through G3 "mechanical off", although the ACPI spec
 975  * says wakeup should only work from G1/S4 "hibernate".  To most users,
 976  * distinctions between S4 and S5 are pointless.  So when the hardware
 977  * allows, don't draw that distinction.
 978  */
 979 static inline int cmos_poweroff(struct device *dev)
 980 {
 981         if (!IS_ENABLED(CONFIG_PM))
 982                 return -ENOSYS;
 983
 984         return cmos_suspend(dev);
 985 }
 986
 987 static void cmos_check_wkalrm(struct device *dev)
 988 {
 989         struct cmos_rtc *cmos = dev_get_drvdata(dev);
 990         struct rtc_wkalrm current_alarm;
 991         time64_t t_current_expires;
 992         time64_t t_saved_expires;
 993
 994         cmos_read_alarm(dev, &current_alarm);
 995         t_current_expires = rtc_tm_to_time64(&current_alarm.time);
 996         t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
 997         if (t_current_expires != t_saved_expires ||
 998             cmos->saved_wkalrm.enabled != current_alarm.enabled) {
 999                 cmos_set_alarm(dev, &cmos->saved_wkalrm);
1000         }
1001 }
1002
1003 static void cmos_check_acpi_rtc_status(struct device *dev,
1004                                        unsigned char *rtc_control);
1005
1006 static int __maybe_unused cmos_resume(struct device *dev)
1007 {
1008         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1009         unsigned char tmp;
1010
1011         if (cmos->enabled_wake) {
1012                 if (cmos->wake_off)
1013                         cmos->wake_off(dev);
1014                 else
1015                         disable_irq_wake(cmos->irq);
1016                 cmos->enabled_wake = 0;
1017         }
1018
1019         /* The BIOS might have changed the alarm, restore it */
1020         cmos_check_wkalrm(dev);
1021
1022         spin_lock_irq(&rtc_lock);
1023         tmp = cmos->suspend_ctrl;
1024         cmos->suspend_ctrl = 0;
1025         /* re-enable any irqs previously active */
1026         if (tmp & RTC_IRQMASK) {
1027                 unsigned char   mask;
1028
1029                 if (device_may_wakeup(dev))
1030                         hpet_rtc_timer_init();
1031
1032                 do {
1033                         CMOS_WRITE(tmp, RTC_CONTROL);
1034                         hpet_set_rtc_irq_bit(tmp & RTC_IRQMASK);
1035
1036                         mask = CMOS_READ(RTC_INTR_FLAGS);
1037                         mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
1038                         if (!is_hpet_enabled() || !is_intr(mask))
1039                                 break;
1040
1041                         /* force one-shot behavior if HPET blocked
1042                          * the wake alarm's irq
1043                          */
1044                         rtc_update_irq(cmos->rtc, 1, mask);
1045                         tmp &= ~RTC_AIE;
1046                         hpet_mask_rtc_irq_bit(RTC_AIE);
1047                 } while (mask & RTC_AIE);
1048
1049                 if (tmp & RTC_AIE)
1050                         cmos_check_acpi_rtc_status(dev, &tmp);
1051         }
1052         spin_unlock_irq(&rtc_lock);
1053
1054         dev_dbg(dev, "resume, ctrl %02x\n", tmp);
1055
1056         return 0;
1057 }
1058
1059 static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
1060
1061 /*----------------------------------------------------------------*/
1062
1063 /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
1064  * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
1065  * probably list them in similar PNPBIOS tables; so PNP is more common.
1066  *
1067  * We don't use legacy "poke at the hardware" probing.  Ancient PCs that
1068  * predate even PNPBIOS should set up platform_bus devices.
1069  */
1070
1071 #ifdef  CONFIG_ACPI
1072
1073 #include <linux/acpi.h>
1074
1075 static u32 rtc_handler(void *context)
1076 {
1077         struct device *dev = context;
1078         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1079         unsigned char rtc_control = 0;
1080         unsigned char rtc_intr;
1081         unsigned long flags;
1082
1083         spin_lock_irqsave(&rtc_lock, flags);
1084         if (cmos_rtc.suspend_ctrl)
1085                 rtc_control = CMOS_READ(RTC_CONTROL);
1086         if (rtc_control & RTC_AIE) {
1087                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
1088                 CMOS_WRITE(rtc_control, RTC_CONTROL);
1089                 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
1090                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
1091         }
1092         spin_unlock_irqrestore(&rtc_lock, flags);
1093
1094         pm_wakeup_hard_event(dev);
1095         acpi_clear_event(ACPI_EVENT_RTC);
1096         acpi_disable_event(ACPI_EVENT_RTC, 0);
1097         return ACPI_INTERRUPT_HANDLED;
1098 }
1099
1100 static inline void rtc_wake_setup(struct device *dev)
1101 {
1102         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
1103         /*
1104          * After the RTC handler is installed, the Fixed_RTC event should
1105          * be disabled. Only when the RTC alarm is set will it be enabled.
1106          */
1107         acpi_clear_event(ACPI_EVENT_RTC);
1108         acpi_disable_event(ACPI_EVENT_RTC, 0);
1109 }
1110
1111 static void rtc_wake_on(struct device *dev)
1112 {
1113         acpi_clear_event(ACPI_EVENT_RTC);
1114         acpi_enable_event(ACPI_EVENT_RTC, 0);
1115 }
1116
1117 static void rtc_wake_off(struct device *dev)
1118 {
1119         acpi_disable_event(ACPI_EVENT_RTC, 0);
1120 }
1121
1122 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
1123  * its device node and pass extra config data.  This helps its driver use
1124  * capabilities that the now-obsolete mc146818 didn't have, and informs it
1125  * that this board's RTC is wakeup-capable (per ACPI spec).
1126  */
1127 static struct cmos_rtc_board_info acpi_rtc_info;
1128
1129 static void cmos_wake_setup(struct device *dev)
1130 {
1131         if (acpi_disabled)
1132                 return;
1133
1134         rtc_wake_setup(dev);
1135         acpi_rtc_info.wake_on = rtc_wake_on;
1136         acpi_rtc_info.wake_off = rtc_wake_off;
1137
1138         /* workaround bug in some ACPI tables */
1139         if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
1140                 dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
1141                         acpi_gbl_FADT.month_alarm);
1142                 acpi_gbl_FADT.month_alarm = 0;
1143         }
1144
1145         acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
1146         acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
1147         acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
1148
1149         /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
1150         if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
1151                 dev_info(dev, "RTC can wake from S4\n");
1152
1153         dev->platform_data = &acpi_rtc_info;
1154
1155         /* RTC always wakes from S1/S2/S3, and often S4/STD */
1156         device_init_wakeup(dev, 1);
1157 }
1158
1159 static void cmos_check_acpi_rtc_status(struct device *dev,
1160                                        unsigned char *rtc_control)
1161 {
1162         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1163         acpi_event_status rtc_status;
1164         acpi_status status;
1165
1166         if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
1167                 return;
1168
1169         status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
1170         if (ACPI_FAILURE(status)) {
1171                 dev_err(dev, "Could not get RTC status\n");
1172         } else if (rtc_status & ACPI_EVENT_FLAG_SET) {
1173                 unsigned char mask;
1174                 *rtc_control &= ~RTC_AIE;
1175                 CMOS_WRITE(*rtc_control, RTC_CONTROL);
1176                 mask = CMOS_READ(RTC_INTR_FLAGS);
1177                 rtc_update_irq(cmos->rtc, 1, mask);
1178         }
1179 }
1180
1181 #else
1182
1183 static void cmos_wake_setup(struct device *dev)
1184 {
1185 }
1186
1187 static void cmos_check_acpi_rtc_status(struct device *dev,
1188                                        unsigned char *rtc_control)
1189 {
1190 }
1191
1192 #endif
1193
1194 #ifdef  CONFIG_PNP
1195
1196 #include <linux/pnp.h>
1197
1198 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
1199 {
1200         cmos_wake_setup(&pnp->dev);
1201
1202         if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
1203                 unsigned int irq = 0;
1204 #ifdef CONFIG_X86
1205                 /* Some machines contain a PNP entry for the RTC, but
1206                  * don't define the IRQ. It should always be safe to
1207                  * hardcode it on systems with a legacy PIC.
1208                  */
1209                 if (nr_legacy_irqs())
1210                         irq = 8;
1211 #endif
1212                 return cmos_do_probe(&pnp->dev,
1213                                 pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
1214         } else {
1215                 return cmos_do_probe(&pnp->dev,
1216                                 pnp_get_resource(pnp, IORESOURCE_IO, 0),
1217                                 pnp_irq(pnp, 0));
1218         }
1219 }
1220
1221 static void cmos_pnp_remove(struct pnp_dev *pnp)
1222 {
1223         cmos_do_remove(&pnp->dev);
1224 }
1225
1226 static void cmos_pnp_shutdown(struct pnp_dev *pnp)
1227 {
1228         struct device *dev = &pnp->dev;
1229         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1230
1231         if (system_state == SYSTEM_POWER_OFF) {
1232                 int retval = cmos_poweroff(dev);
1233
1234                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1235                         return;
1236         }
1237
1238         cmos_do_shutdown(cmos->irq);
1239 }
1240
1241 static const struct pnp_device_id rtc_ids[] = {
1242         { .id = "PNP0b00", },
1243         { .id = "PNP0b01", },
1244         { .id = "PNP0b02", },
1245         { },
1246 };
1247 MODULE_DEVICE_TABLE(pnp, rtc_ids);
1248
1249 static struct pnp_driver cmos_pnp_driver = {
1250         .name           = (char *) driver_name,
1251         .id_table       = rtc_ids,
1252         .probe          = cmos_pnp_probe,
1253         .remove         = cmos_pnp_remove,
1254         .shutdown       = cmos_pnp_shutdown,
1255
1256         /* flag ensures resume() gets called, and stops syslog spam */
1257         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
1258         .driver         = {
1259                         .pm = &cmos_pm_ops,
1260         },
1261 };
1262
1263 #endif  /* CONFIG_PNP */
1264
1265 #ifdef CONFIG_OF
1266 static const struct of_device_id of_cmos_match[] = {
1267         {
1268                 .compatible = "motorola,mc146818",
1269         },
1270         { },
1271 };
1272 MODULE_DEVICE_TABLE(of, of_cmos_match);
1273
1274 static __init void cmos_of_init(struct platform_device *pdev)
1275 {
1276         struct device_node *node = pdev->dev.of_node;
1277         struct rtc_time time;
1278         int ret;
1279         const __be32 *val;
1280
1281         if (!node)
1282                 return;
1283
1284         val = of_get_property(node, "ctrl-reg", NULL);
1285         if (val)
1286                 CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
1287
1288         val = of_get_property(node, "freq-reg", NULL);
1289         if (val)
1290                 CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
1291
1292         cmos_read_time(&pdev->dev, &time);
1293         ret = rtc_valid_tm(&time);
1294         if (ret) {
1295                 struct rtc_time def_time = {
1296                         .tm_year = 1,
1297                         .tm_mday = 1,
1298                 };
1299                 cmos_set_time(&pdev->dev, &def_time);
1300         }
1301 }
1302 #else
1303 static inline void cmos_of_init(struct platform_device *pdev) {}
1304 #endif
1305 /*----------------------------------------------------------------*/
1306
1307 /* Platform setup should have set up an RTC device, when PNP is
1308  * unavailable ... this could happen even on (older) PCs.
1309  */
1310
1311 static int __init cmos_platform_probe(struct platform_device *pdev)
1312 {
1313         struct resource *resource;
1314         int irq;
1315
1316         cmos_of_init(pdev);
1317         cmos_wake_setup(&pdev->dev);
1318
1319         if (RTC_IOMAPPED)
1320                 resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
1321         else
1322                 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1323         irq = platform_get_irq(pdev, 0);
1324         if (irq < 0)
1325                 irq = -1;
1326
1327         return cmos_do_probe(&pdev->dev, resource, irq);
1328 }
1329
1330 static int cmos_platform_remove(struct platform_device *pdev)
1331 {
1332         cmos_do_remove(&pdev->dev);
1333         return 0;
1334 }
1335
1336 static void cmos_platform_shutdown(struct platform_device *pdev)
1337 {
1338         struct device *dev = &pdev->dev;
1339         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1340
1341         if (system_state == SYSTEM_POWER_OFF) {
1342                 int retval = cmos_poweroff(dev);
1343
1344                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1345                         return;
1346         }
1347
1348         cmos_do_shutdown(cmos->irq);
1349 }
1350
1351 /* work with hotplug and coldplug */
1352 MODULE_ALIAS("platform:rtc_cmos");
1353
1354 static struct platform_driver cmos_platform_driver = {
1355         .remove         = cmos_platform_remove,
1356         .shutdown       = cmos_platform_shutdown,
1357         .driver = {
1358                 .name           = driver_name,
1359                 .pm             = &cmos_pm_ops,
1360                 .of_match_table = of_match_ptr(of_cmos_match),
1361         }
1362 };
1363
1364 #ifdef CONFIG_PNP
1365 static bool pnp_driver_registered;
1366 #endif
1367 static bool platform_driver_registered;
1368
1369 static int __init cmos_init(void)
1370 {
1371         int retval = 0;
1372
1373 #ifdef  CONFIG_PNP
1374         retval = pnp_register_driver(&cmos_pnp_driver);
1375         if (retval == 0)
1376                 pnp_driver_registered = true;
1377 #endif
1378
1379         if (!cmos_rtc.dev) {
1380                 retval = platform_driver_probe(&cmos_platform_driver,
1381                                                cmos_platform_probe);
1382                 if (retval == 0)
1383                         platform_driver_registered = true;
1384         }
1385
1386         if (retval == 0)
1387                 return 0;
1388
1389 #ifdef  CONFIG_PNP
1390         if (pnp_driver_registered)
1391                 pnp_unregister_driver(&cmos_pnp_driver);
1392 #endif
1393         return retval;
1394 }
1395 module_init(cmos_init);
1396
1397 static void __exit cmos_exit(void)
1398 {
1399 #ifdef  CONFIG_PNP
1400         if (pnp_driver_registered)
1401                 pnp_unregister_driver(&cmos_pnp_driver);
1402 #endif
1403         if (platform_driver_registered)
1404                 platform_driver_unregister(&cmos_platform_driver);
1405 }
1406 module_exit(cmos_exit);
1407
1408
1409 MODULE_AUTHOR("David Brownell");
1410 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
1411 MODULE_LICENSE("GPL");