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

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