Merge branches 'pm-sleep' and 'powercap'
[muen/linux.git] / 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         rtc_control = CMOS_READ(RTC_CONTROL);
425         if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
426                 /* Writing 0xff means "don't care" or "match all".  */
427                 mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
428                 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
429                 hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
430                 min = (min < 60) ? bin2bcd(min) : 0xff;
431                 sec = (sec < 60) ? bin2bcd(sec) : 0xff;
432         }
433
434         spin_lock_irq(&rtc_lock);
435
436         /* next rtc irq must not be from previous alarm setting */
437         cmos_irq_disable(cmos, RTC_AIE);
438
439         /* update alarm */
440         CMOS_WRITE(hrs, RTC_HOURS_ALARM);
441         CMOS_WRITE(min, RTC_MINUTES_ALARM);
442         CMOS_WRITE(sec, RTC_SECONDS_ALARM);
443
444         /* the system may support an "enhanced" alarm */
445         if (cmos->day_alrm) {
446                 CMOS_WRITE(mday, cmos->day_alrm);
447                 if (cmos->mon_alrm)
448                         CMOS_WRITE(mon, cmos->mon_alrm);
449         }
450
451         /* FIXME the HPET alarm glue currently ignores day_alrm
452          * and mon_alrm ...
453          */
454         hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);
455
456         if (t->enabled)
457                 cmos_irq_enable(cmos, RTC_AIE);
458
459         spin_unlock_irq(&rtc_lock);
460
461         cmos->alarm_expires = rtc_tm_to_time64(&t->time);
462
463         return 0;
464 }
465
466 static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
467 {
468         struct cmos_rtc *cmos = dev_get_drvdata(dev);
469         unsigned long   flags;
470
471         if (!is_valid_irq(cmos->irq))
472                 return -EINVAL;
473
474         spin_lock_irqsave(&rtc_lock, flags);
475
476         if (enabled)
477                 cmos_irq_enable(cmos, RTC_AIE);
478         else
479                 cmos_irq_disable(cmos, RTC_AIE);
480
481         spin_unlock_irqrestore(&rtc_lock, flags);
482         return 0;
483 }
484
485 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
486
487 static int cmos_procfs(struct device *dev, struct seq_file *seq)
488 {
489         struct cmos_rtc *cmos = dev_get_drvdata(dev);
490         unsigned char   rtc_control, valid;
491
492         spin_lock_irq(&rtc_lock);
493         rtc_control = CMOS_READ(RTC_CONTROL);
494         valid = CMOS_READ(RTC_VALID);
495         spin_unlock_irq(&rtc_lock);
496
497         /* NOTE:  at least ICH6 reports battery status using a different
498          * (non-RTC) bit; and SQWE is ignored on many current systems.
499          */
500         seq_printf(seq,
501                    "periodic_IRQ\t: %s\n"
502                    "update_IRQ\t: %s\n"
503                    "HPET_emulated\t: %s\n"
504                    // "square_wave\t: %s\n"
505                    "BCD\t\t: %s\n"
506                    "DST_enable\t: %s\n"
507                    "periodic_freq\t: %d\n"
508                    "batt_status\t: %s\n",
509                    (rtc_control & RTC_PIE) ? "yes" : "no",
510                    (rtc_control & RTC_UIE) ? "yes" : "no",
511                    is_hpet_enabled() ? "yes" : "no",
512                    // (rtc_control & RTC_SQWE) ? "yes" : "no",
513                    (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
514                    (rtc_control & RTC_DST_EN) ? "yes" : "no",
515                    cmos->rtc->irq_freq,
516                    (valid & RTC_VRT) ? "okay" : "dead");
517
518         return 0;
519 }
520
521 #else
522 #define cmos_procfs     NULL
523 #endif
524
525 static const struct rtc_class_ops cmos_rtc_ops = {
526         .read_time              = cmos_read_time,
527         .set_time               = cmos_set_time,
528         .read_alarm             = cmos_read_alarm,
529         .set_alarm              = cmos_set_alarm,
530         .proc                   = cmos_procfs,
531         .alarm_irq_enable       = cmos_alarm_irq_enable,
532 };
533
534 /*----------------------------------------------------------------*/
535
536 /*
537  * All these chips have at least 64 bytes of address space, shared by
538  * RTC registers and NVRAM.  Most of those bytes of NVRAM are used
539  * by boot firmware.  Modern chips have 128 or 256 bytes.
540  */
541
542 #define NVRAM_OFFSET    (RTC_REG_D + 1)
543
544 static ssize_t
545 cmos_nvram_read(struct file *filp, struct kobject *kobj,
546                 struct bin_attribute *attr,
547                 char *buf, loff_t off, size_t count)
548 {
549         int     retval;
550
551         off += NVRAM_OFFSET;
552         spin_lock_irq(&rtc_lock);
553         for (retval = 0; count; count--, off++, retval++) {
554                 if (off < 128)
555                         *buf++ = CMOS_READ(off);
556                 else if (can_bank2)
557                         *buf++ = cmos_read_bank2(off);
558                 else
559                         break;
560         }
561         spin_unlock_irq(&rtc_lock);
562
563         return retval;
564 }
565
566 static ssize_t
567 cmos_nvram_write(struct file *filp, struct kobject *kobj,
568                 struct bin_attribute *attr,
569                 char *buf, loff_t off, size_t count)
570 {
571         struct cmos_rtc *cmos;
572         int             retval;
573
574         cmos = dev_get_drvdata(container_of(kobj, struct device, kobj));
575
576         /* NOTE:  on at least PCs and Ataris, the boot firmware uses a
577          * checksum on part of the NVRAM data.  That's currently ignored
578          * here.  If userspace is smart enough to know what fields of
579          * NVRAM to update, updating checksums is also part of its job.
580          */
581         off += NVRAM_OFFSET;
582         spin_lock_irq(&rtc_lock);
583         for (retval = 0; count; count--, off++, retval++) {
584                 /* don't trash RTC registers */
585                 if (off == cmos->day_alrm
586                                 || off == cmos->mon_alrm
587                                 || off == cmos->century)
588                         buf++;
589                 else if (off < 128)
590                         CMOS_WRITE(*buf++, off);
591                 else if (can_bank2)
592                         cmos_write_bank2(*buf++, off);
593                 else
594                         break;
595         }
596         spin_unlock_irq(&rtc_lock);
597
598         return retval;
599 }
600
601 static struct bin_attribute nvram = {
602         .attr = {
603                 .name   = "nvram",
604                 .mode   = S_IRUGO | S_IWUSR,
605         },
606
607         .read   = cmos_nvram_read,
608         .write  = cmos_nvram_write,
609         /* size gets set up later */
610 };
611
612 /*----------------------------------------------------------------*/
613
614 static struct cmos_rtc  cmos_rtc;
615
616 static irqreturn_t cmos_interrupt(int irq, void *p)
617 {
618         u8              irqstat;
619         u8              rtc_control;
620
621         spin_lock(&rtc_lock);
622
623         /* When the HPET interrupt handler calls us, the interrupt
624          * status is passed as arg1 instead of the irq number.  But
625          * always clear irq status, even when HPET is in the way.
626          *
627          * Note that HPET and RTC are almost certainly out of phase,
628          * giving different IRQ status ...
629          */
630         irqstat = CMOS_READ(RTC_INTR_FLAGS);
631         rtc_control = CMOS_READ(RTC_CONTROL);
632         if (is_hpet_enabled())
633                 irqstat = (unsigned long)irq & 0xF0;
634
635         /* If we were suspended, RTC_CONTROL may not be accurate since the
636          * bios may have cleared it.
637          */
638         if (!cmos_rtc.suspend_ctrl)
639                 irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
640         else
641                 irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
642
643         /* All Linux RTC alarms should be treated as if they were oneshot.
644          * Similar code may be needed in system wakeup paths, in case the
645          * alarm woke the system.
646          */
647         if (irqstat & RTC_AIE) {
648                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
649                 rtc_control &= ~RTC_AIE;
650                 CMOS_WRITE(rtc_control, RTC_CONTROL);
651                 hpet_mask_rtc_irq_bit(RTC_AIE);
652                 CMOS_READ(RTC_INTR_FLAGS);
653         }
654         spin_unlock(&rtc_lock);
655
656         if (is_intr(irqstat)) {
657                 rtc_update_irq(p, 1, irqstat);
658                 return IRQ_HANDLED;
659         } else
660                 return IRQ_NONE;
661 }
662
663 #ifdef  CONFIG_PNP
664 #define INITSECTION
665
666 #else
667 #define INITSECTION     __init
668 #endif
669
670 static int INITSECTION
671 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
672 {
673         struct cmos_rtc_board_info      *info = dev_get_platdata(dev);
674         int                             retval = 0;
675         unsigned char                   rtc_control;
676         unsigned                        address_space;
677         u32                             flags = 0;
678
679         /* there can be only one ... */
680         if (cmos_rtc.dev)
681                 return -EBUSY;
682
683         if (!ports)
684                 return -ENODEV;
685
686         /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
687          *
688          * REVISIT non-x86 systems may instead use memory space resources
689          * (needing ioremap etc), not i/o space resources like this ...
690          */
691         if (RTC_IOMAPPED)
692                 ports = request_region(ports->start, resource_size(ports),
693                                        driver_name);
694         else
695                 ports = request_mem_region(ports->start, resource_size(ports),
696                                            driver_name);
697         if (!ports) {
698                 dev_dbg(dev, "i/o registers already in use\n");
699                 return -EBUSY;
700         }
701
702         cmos_rtc.irq = rtc_irq;
703         cmos_rtc.iomem = ports;
704
705         /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
706          * driver did, but don't reject unknown configs.   Old hardware
707          * won't address 128 bytes.  Newer chips have multiple banks,
708          * though they may not be listed in one I/O resource.
709          */
710 #if     defined(CONFIG_ATARI)
711         address_space = 64;
712 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
713                         || defined(__sparc__) || defined(__mips__) \
714                         || defined(__powerpc__) || defined(CONFIG_MN10300)
715         address_space = 128;
716 #else
717 #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
718         address_space = 128;
719 #endif
720         if (can_bank2 && ports->end > (ports->start + 1))
721                 address_space = 256;
722
723         /* For ACPI systems extension info comes from the FADT.  On others,
724          * board specific setup provides it as appropriate.  Systems where
725          * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
726          * some almost-clones) can provide hooks to make that behave.
727          *
728          * Note that ACPI doesn't preclude putting these registers into
729          * "extended" areas of the chip, including some that we won't yet
730          * expect CMOS_READ and friends to handle.
731          */
732         if (info) {
733                 if (info->flags)
734                         flags = info->flags;
735                 if (info->address_space)
736                         address_space = info->address_space;
737
738                 if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
739                         cmos_rtc.day_alrm = info->rtc_day_alarm;
740                 if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
741                         cmos_rtc.mon_alrm = info->rtc_mon_alarm;
742                 if (info->rtc_century && info->rtc_century < 128)
743                         cmos_rtc.century = info->rtc_century;
744
745                 if (info->wake_on && info->wake_off) {
746                         cmos_rtc.wake_on = info->wake_on;
747                         cmos_rtc.wake_off = info->wake_off;
748                 }
749         }
750
751         cmos_rtc.dev = dev;
752         dev_set_drvdata(dev, &cmos_rtc);
753
754         cmos_rtc.rtc = rtc_device_register(driver_name, dev,
755                                 &cmos_rtc_ops, THIS_MODULE);
756         if (IS_ERR(cmos_rtc.rtc)) {
757                 retval = PTR_ERR(cmos_rtc.rtc);
758                 goto cleanup0;
759         }
760
761         rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
762
763         spin_lock_irq(&rtc_lock);
764
765         if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
766                 /* force periodic irq to CMOS reset default of 1024Hz;
767                  *
768                  * REVISIT it's been reported that at least one x86_64 ALI
769                  * mobo doesn't use 32KHz here ... for portability we might
770                  * need to do something about other clock frequencies.
771                  */
772                 cmos_rtc.rtc->irq_freq = 1024;
773                 hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);
774                 CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
775         }
776
777         /* disable irqs */
778         if (is_valid_irq(rtc_irq))
779                 cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE);
780
781         rtc_control = CMOS_READ(RTC_CONTROL);
782
783         spin_unlock_irq(&rtc_lock);
784
785         if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
786                 dev_warn(dev, "only 24-hr supported\n");
787                 retval = -ENXIO;
788                 goto cleanup1;
789         }
790
791         hpet_rtc_timer_init();
792
793         if (is_valid_irq(rtc_irq)) {
794                 irq_handler_t rtc_cmos_int_handler;
795
796                 if (is_hpet_enabled()) {
797                         rtc_cmos_int_handler = hpet_rtc_interrupt;
798                         retval = hpet_register_irq_handler(cmos_interrupt);
799                         if (retval) {
800                                 hpet_mask_rtc_irq_bit(RTC_IRQMASK);
801                                 dev_warn(dev, "hpet_register_irq_handler "
802                                                 " failed in rtc_init().");
803                                 goto cleanup1;
804                         }
805                 } else
806                         rtc_cmos_int_handler = cmos_interrupt;
807
808                 retval = request_irq(rtc_irq, rtc_cmos_int_handler,
809                                 IRQF_SHARED, dev_name(&cmos_rtc.rtc->dev),
810                                 cmos_rtc.rtc);
811                 if (retval < 0) {
812                         dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
813                         goto cleanup1;
814                 }
815         }
816
817         /* export at least the first block of NVRAM */
818         nvram.size = address_space - NVRAM_OFFSET;
819         retval = sysfs_create_bin_file(&dev->kobj, &nvram);
820         if (retval < 0) {
821                 dev_dbg(dev, "can't create nvram file? %d\n", retval);
822                 goto cleanup2;
823         }
824
825         dev_info(dev, "%s%s, %zd bytes nvram%s\n",
826                 !is_valid_irq(rtc_irq) ? "no alarms" :
827                         cmos_rtc.mon_alrm ? "alarms up to one year" :
828                         cmos_rtc.day_alrm ? "alarms up to one month" :
829                         "alarms up to one day",
830                 cmos_rtc.century ? ", y3k" : "",
831                 nvram.size,
832                 is_hpet_enabled() ? ", hpet irqs" : "");
833
834         return 0;
835
836 cleanup2:
837         if (is_valid_irq(rtc_irq))
838                 free_irq(rtc_irq, cmos_rtc.rtc);
839 cleanup1:
840         cmos_rtc.dev = NULL;
841         rtc_device_unregister(cmos_rtc.rtc);
842 cleanup0:
843         if (RTC_IOMAPPED)
844                 release_region(ports->start, resource_size(ports));
845         else
846                 release_mem_region(ports->start, resource_size(ports));
847         return retval;
848 }
849
850 static void cmos_do_shutdown(int rtc_irq)
851 {
852         spin_lock_irq(&rtc_lock);
853         if (is_valid_irq(rtc_irq))
854                 cmos_irq_disable(&cmos_rtc, RTC_IRQMASK);
855         spin_unlock_irq(&rtc_lock);
856 }
857
858 static void cmos_do_remove(struct device *dev)
859 {
860         struct cmos_rtc *cmos = dev_get_drvdata(dev);
861         struct resource *ports;
862
863         cmos_do_shutdown(cmos->irq);
864
865         sysfs_remove_bin_file(&dev->kobj, &nvram);
866
867         if (is_valid_irq(cmos->irq)) {
868                 free_irq(cmos->irq, cmos->rtc);
869                 hpet_unregister_irq_handler(cmos_interrupt);
870         }
871
872         rtc_device_unregister(cmos->rtc);
873         cmos->rtc = NULL;
874
875         ports = cmos->iomem;
876         if (RTC_IOMAPPED)
877                 release_region(ports->start, resource_size(ports));
878         else
879                 release_mem_region(ports->start, resource_size(ports));
880         cmos->iomem = NULL;
881
882         cmos->dev = NULL;
883 }
884
885 static int cmos_aie_poweroff(struct device *dev)
886 {
887         struct cmos_rtc *cmos = dev_get_drvdata(dev);
888         struct rtc_time now;
889         time64_t t_now;
890         int retval = 0;
891         unsigned char rtc_control;
892
893         if (!cmos->alarm_expires)
894                 return -EINVAL;
895
896         spin_lock_irq(&rtc_lock);
897         rtc_control = CMOS_READ(RTC_CONTROL);
898         spin_unlock_irq(&rtc_lock);
899
900         /* We only care about the situation where AIE is disabled. */
901         if (rtc_control & RTC_AIE)
902                 return -EBUSY;
903
904         cmos_read_time(dev, &now);
905         t_now = rtc_tm_to_time64(&now);
906
907         /*
908          * When enabling "RTC wake-up" in BIOS setup, the machine reboots
909          * automatically right after shutdown on some buggy boxes.
910          * This automatic rebooting issue won't happen when the alarm
911          * time is larger than now+1 seconds.
912          *
913          * If the alarm time is equal to now+1 seconds, the issue can be
914          * prevented by cancelling the alarm.
915          */
916         if (cmos->alarm_expires == t_now + 1) {
917                 struct rtc_wkalrm alarm;
918
919                 /* Cancel the AIE timer by configuring the past time. */
920                 rtc_time64_to_tm(t_now - 1, &alarm.time);
921                 alarm.enabled = 0;
922                 retval = cmos_set_alarm(dev, &alarm);
923         } else if (cmos->alarm_expires > t_now + 1) {
924                 retval = -EBUSY;
925         }
926
927         return retval;
928 }
929
930 static int cmos_suspend(struct device *dev)
931 {
932         struct cmos_rtc *cmos = dev_get_drvdata(dev);
933         unsigned char   tmp;
934
935         /* only the alarm might be a wakeup event source */
936         spin_lock_irq(&rtc_lock);
937         cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
938         if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
939                 unsigned char   mask;
940
941                 if (device_may_wakeup(dev))
942                         mask = RTC_IRQMASK & ~RTC_AIE;
943                 else
944                         mask = RTC_IRQMASK;
945                 tmp &= ~mask;
946                 CMOS_WRITE(tmp, RTC_CONTROL);
947                 hpet_mask_rtc_irq_bit(mask);
948
949                 cmos_checkintr(cmos, tmp);
950         }
951         spin_unlock_irq(&rtc_lock);
952
953         if (tmp & RTC_AIE) {
954                 cmos->enabled_wake = 1;
955                 if (cmos->wake_on)
956                         cmos->wake_on(dev);
957                 else
958                         enable_irq_wake(cmos->irq);
959         }
960
961         cmos_read_alarm(dev, &cmos->saved_wkalrm);
962
963         dev_dbg(dev, "suspend%s, ctrl %02x\n",
964                         (tmp & RTC_AIE) ? ", alarm may wake" : "",
965                         tmp);
966
967         return 0;
968 }
969
970 /* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even
971  * after a detour through G3 "mechanical off", although the ACPI spec
972  * says wakeup should only work from G1/S4 "hibernate".  To most users,
973  * distinctions between S4 and S5 are pointless.  So when the hardware
974  * allows, don't draw that distinction.
975  */
976 static inline int cmos_poweroff(struct device *dev)
977 {
978         if (!IS_ENABLED(CONFIG_PM))
979                 return -ENOSYS;
980
981         return cmos_suspend(dev);
982 }
983
984 static void cmos_check_wkalrm(struct device *dev)
985 {
986         struct cmos_rtc *cmos = dev_get_drvdata(dev);
987         struct rtc_wkalrm current_alarm;
988         time64_t t_current_expires;
989         time64_t t_saved_expires;
990
991         cmos_read_alarm(dev, &current_alarm);
992         t_current_expires = rtc_tm_to_time64(&current_alarm.time);
993         t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
994         if (t_current_expires != t_saved_expires ||
995             cmos->saved_wkalrm.enabled != current_alarm.enabled) {
996                 cmos_set_alarm(dev, &cmos->saved_wkalrm);
997         }
998 }
999
1000 static void cmos_check_acpi_rtc_status(struct device *dev,
1001                                        unsigned char *rtc_control);
1002
1003 static int __maybe_unused cmos_resume(struct device *dev)
1004 {
1005         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1006         unsigned char tmp;
1007
1008         if (cmos->enabled_wake) {
1009                 if (cmos->wake_off)
1010                         cmos->wake_off(dev);
1011                 else
1012                         disable_irq_wake(cmos->irq);
1013                 cmos->enabled_wake = 0;
1014         }
1015
1016         /* The BIOS might have changed the alarm, restore it */
1017         cmos_check_wkalrm(dev);
1018
1019         spin_lock_irq(&rtc_lock);
1020         tmp = cmos->suspend_ctrl;
1021         cmos->suspend_ctrl = 0;
1022         /* re-enable any irqs previously active */
1023         if (tmp & RTC_IRQMASK) {
1024                 unsigned char   mask;
1025
1026                 if (device_may_wakeup(dev))
1027                         hpet_rtc_timer_init();
1028
1029                 do {
1030                         CMOS_WRITE(tmp, RTC_CONTROL);
1031                         hpet_set_rtc_irq_bit(tmp & RTC_IRQMASK);
1032
1033                         mask = CMOS_READ(RTC_INTR_FLAGS);
1034                         mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
1035                         if (!is_hpet_enabled() || !is_intr(mask))
1036                                 break;
1037
1038                         /* force one-shot behavior if HPET blocked
1039                          * the wake alarm's irq
1040                          */
1041                         rtc_update_irq(cmos->rtc, 1, mask);
1042                         tmp &= ~RTC_AIE;
1043                         hpet_mask_rtc_irq_bit(RTC_AIE);
1044                 } while (mask & RTC_AIE);
1045
1046                 if (tmp & RTC_AIE)
1047                         cmos_check_acpi_rtc_status(dev, &tmp);
1048         }
1049         spin_unlock_irq(&rtc_lock);
1050
1051         dev_dbg(dev, "resume, ctrl %02x\n", tmp);
1052
1053         return 0;
1054 }
1055
1056 static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
1057
1058 /*----------------------------------------------------------------*/
1059
1060 /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
1061  * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
1062  * probably list them in similar PNPBIOS tables; so PNP is more common.
1063  *
1064  * We don't use legacy "poke at the hardware" probing.  Ancient PCs that
1065  * predate even PNPBIOS should set up platform_bus devices.
1066  */
1067
1068 #ifdef  CONFIG_ACPI
1069
1070 #include <linux/acpi.h>
1071
1072 static u32 rtc_handler(void *context)
1073 {
1074         struct device *dev = context;
1075         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1076         unsigned char rtc_control = 0;
1077         unsigned char rtc_intr;
1078         unsigned long flags;
1079
1080         spin_lock_irqsave(&rtc_lock, flags);
1081         if (cmos_rtc.suspend_ctrl)
1082                 rtc_control = CMOS_READ(RTC_CONTROL);
1083         if (rtc_control & RTC_AIE) {
1084                 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
1085                 CMOS_WRITE(rtc_control, RTC_CONTROL);
1086                 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
1087                 rtc_update_irq(cmos->rtc, 1, rtc_intr);
1088         }
1089         spin_unlock_irqrestore(&rtc_lock, flags);
1090
1091         pm_wakeup_hard_event(dev);
1092         acpi_clear_event(ACPI_EVENT_RTC);
1093         acpi_disable_event(ACPI_EVENT_RTC, 0);
1094         return ACPI_INTERRUPT_HANDLED;
1095 }
1096
1097 static inline void rtc_wake_setup(struct device *dev)
1098 {
1099         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
1100         /*
1101          * After the RTC handler is installed, the Fixed_RTC event should
1102          * be disabled. Only when the RTC alarm is set will it be enabled.
1103          */
1104         acpi_clear_event(ACPI_EVENT_RTC);
1105         acpi_disable_event(ACPI_EVENT_RTC, 0);
1106 }
1107
1108 static void rtc_wake_on(struct device *dev)
1109 {
1110         acpi_clear_event(ACPI_EVENT_RTC);
1111         acpi_enable_event(ACPI_EVENT_RTC, 0);
1112 }
1113
1114 static void rtc_wake_off(struct device *dev)
1115 {
1116         acpi_disable_event(ACPI_EVENT_RTC, 0);
1117 }
1118
1119 /* Every ACPI platform has a mc146818 compatible "cmos rtc".  Here we find
1120  * its device node and pass extra config data.  This helps its driver use
1121  * capabilities that the now-obsolete mc146818 didn't have, and informs it
1122  * that this board's RTC is wakeup-capable (per ACPI spec).
1123  */
1124 static struct cmos_rtc_board_info acpi_rtc_info;
1125
1126 static void cmos_wake_setup(struct device *dev)
1127 {
1128         if (acpi_disabled)
1129                 return;
1130
1131         rtc_wake_setup(dev);
1132         acpi_rtc_info.wake_on = rtc_wake_on;
1133         acpi_rtc_info.wake_off = rtc_wake_off;
1134
1135         /* workaround bug in some ACPI tables */
1136         if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
1137                 dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
1138                         acpi_gbl_FADT.month_alarm);
1139                 acpi_gbl_FADT.month_alarm = 0;
1140         }
1141
1142         acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
1143         acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
1144         acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
1145
1146         /* NOTE:  S4_RTC_WAKE is NOT currently useful to Linux */
1147         if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
1148                 dev_info(dev, "RTC can wake from S4\n");
1149
1150         dev->platform_data = &acpi_rtc_info;
1151
1152         /* RTC always wakes from S1/S2/S3, and often S4/STD */
1153         device_init_wakeup(dev, 1);
1154 }
1155
1156 static void cmos_check_acpi_rtc_status(struct device *dev,
1157                                        unsigned char *rtc_control)
1158 {
1159         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1160         acpi_event_status rtc_status;
1161         acpi_status status;
1162
1163         if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
1164                 return;
1165
1166         status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
1167         if (ACPI_FAILURE(status)) {
1168                 dev_err(dev, "Could not get RTC status\n");
1169         } else if (rtc_status & ACPI_EVENT_FLAG_SET) {
1170                 unsigned char mask;
1171                 *rtc_control &= ~RTC_AIE;
1172                 CMOS_WRITE(*rtc_control, RTC_CONTROL);
1173                 mask = CMOS_READ(RTC_INTR_FLAGS);
1174                 rtc_update_irq(cmos->rtc, 1, mask);
1175         }
1176 }
1177
1178 #else
1179
1180 static void cmos_wake_setup(struct device *dev)
1181 {
1182 }
1183
1184 static void cmos_check_acpi_rtc_status(struct device *dev,
1185                                        unsigned char *rtc_control)
1186 {
1187 }
1188
1189 #endif
1190
1191 #ifdef  CONFIG_PNP
1192
1193 #include <linux/pnp.h>
1194
1195 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
1196 {
1197         cmos_wake_setup(&pnp->dev);
1198
1199         if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
1200                 unsigned int irq = 0;
1201 #ifdef CONFIG_X86
1202                 /* Some machines contain a PNP entry for the RTC, but
1203                  * don't define the IRQ. It should always be safe to
1204                  * hardcode it on systems with a legacy PIC.
1205                  */
1206                 if (nr_legacy_irqs())
1207                         irq = 8;
1208 #endif
1209                 return cmos_do_probe(&pnp->dev,
1210                                 pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
1211         } else {
1212                 return cmos_do_probe(&pnp->dev,
1213                                 pnp_get_resource(pnp, IORESOURCE_IO, 0),
1214                                 pnp_irq(pnp, 0));
1215         }
1216 }
1217
1218 static void cmos_pnp_remove(struct pnp_dev *pnp)
1219 {
1220         cmos_do_remove(&pnp->dev);
1221 }
1222
1223 static void cmos_pnp_shutdown(struct pnp_dev *pnp)
1224 {
1225         struct device *dev = &pnp->dev;
1226         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1227
1228         if (system_state == SYSTEM_POWER_OFF) {
1229                 int retval = cmos_poweroff(dev);
1230
1231                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1232                         return;
1233         }
1234
1235         cmos_do_shutdown(cmos->irq);
1236 }
1237
1238 static const struct pnp_device_id rtc_ids[] = {
1239         { .id = "PNP0b00", },
1240         { .id = "PNP0b01", },
1241         { .id = "PNP0b02", },
1242         { },
1243 };
1244 MODULE_DEVICE_TABLE(pnp, rtc_ids);
1245
1246 static struct pnp_driver cmos_pnp_driver = {
1247         .name           = (char *) driver_name,
1248         .id_table       = rtc_ids,
1249         .probe          = cmos_pnp_probe,
1250         .remove         = cmos_pnp_remove,
1251         .shutdown       = cmos_pnp_shutdown,
1252
1253         /* flag ensures resume() gets called, and stops syslog spam */
1254         .flags          = PNP_DRIVER_RES_DO_NOT_CHANGE,
1255         .driver         = {
1256                         .pm = &cmos_pm_ops,
1257         },
1258 };
1259
1260 #endif  /* CONFIG_PNP */
1261
1262 #ifdef CONFIG_OF
1263 static const struct of_device_id of_cmos_match[] = {
1264         {
1265                 .compatible = "motorola,mc146818",
1266         },
1267         { },
1268 };
1269 MODULE_DEVICE_TABLE(of, of_cmos_match);
1270
1271 static __init void cmos_of_init(struct platform_device *pdev)
1272 {
1273         struct device_node *node = pdev->dev.of_node;
1274         struct rtc_time time;
1275         int ret;
1276         const __be32 *val;
1277
1278         if (!node)
1279                 return;
1280
1281         val = of_get_property(node, "ctrl-reg", NULL);
1282         if (val)
1283                 CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
1284
1285         val = of_get_property(node, "freq-reg", NULL);
1286         if (val)
1287                 CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
1288
1289         cmos_read_time(&pdev->dev, &time);
1290         ret = rtc_valid_tm(&time);
1291         if (ret) {
1292                 struct rtc_time def_time = {
1293                         .tm_year = 1,
1294                         .tm_mday = 1,
1295                 };
1296                 cmos_set_time(&pdev->dev, &def_time);
1297         }
1298 }
1299 #else
1300 static inline void cmos_of_init(struct platform_device *pdev) {}
1301 #endif
1302 /*----------------------------------------------------------------*/
1303
1304 /* Platform setup should have set up an RTC device, when PNP is
1305  * unavailable ... this could happen even on (older) PCs.
1306  */
1307
1308 static int __init cmos_platform_probe(struct platform_device *pdev)
1309 {
1310         struct resource *resource;
1311         int irq;
1312
1313         cmos_of_init(pdev);
1314         cmos_wake_setup(&pdev->dev);
1315
1316         if (RTC_IOMAPPED)
1317                 resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
1318         else
1319                 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1320         irq = platform_get_irq(pdev, 0);
1321         if (irq < 0)
1322                 irq = -1;
1323
1324         return cmos_do_probe(&pdev->dev, resource, irq);
1325 }
1326
1327 static int cmos_platform_remove(struct platform_device *pdev)
1328 {
1329         cmos_do_remove(&pdev->dev);
1330         return 0;
1331 }
1332
1333 static void cmos_platform_shutdown(struct platform_device *pdev)
1334 {
1335         struct device *dev = &pdev->dev;
1336         struct cmos_rtc *cmos = dev_get_drvdata(dev);
1337
1338         if (system_state == SYSTEM_POWER_OFF) {
1339                 int retval = cmos_poweroff(dev);
1340
1341                 if (cmos_aie_poweroff(dev) < 0 && !retval)
1342                         return;
1343         }
1344
1345         cmos_do_shutdown(cmos->irq);
1346 }
1347
1348 /* work with hotplug and coldplug */
1349 MODULE_ALIAS("platform:rtc_cmos");
1350
1351 static struct platform_driver cmos_platform_driver = {
1352         .remove         = cmos_platform_remove,
1353         .shutdown       = cmos_platform_shutdown,
1354         .driver = {
1355                 .name           = driver_name,
1356                 .pm             = &cmos_pm_ops,
1357                 .of_match_table = of_match_ptr(of_cmos_match),
1358         }
1359 };
1360
1361 #ifdef CONFIG_PNP
1362 static bool pnp_driver_registered;
1363 #endif
1364 static bool platform_driver_registered;
1365
1366 static int __init cmos_init(void)
1367 {
1368         int retval = 0;
1369
1370 #ifdef  CONFIG_PNP
1371         retval = pnp_register_driver(&cmos_pnp_driver);
1372         if (retval == 0)
1373                 pnp_driver_registered = true;
1374 #endif
1375
1376         if (!cmos_rtc.dev) {
1377                 retval = platform_driver_probe(&cmos_platform_driver,
1378                                                cmos_platform_probe);
1379                 if (retval == 0)
1380                         platform_driver_registered = true;
1381         }
1382
1383         if (retval == 0)
1384                 return 0;
1385
1386 #ifdef  CONFIG_PNP
1387         if (pnp_driver_registered)
1388                 pnp_unregister_driver(&cmos_pnp_driver);
1389 #endif
1390         return retval;
1391 }
1392 module_init(cmos_init);
1393
1394 static void __exit cmos_exit(void)
1395 {
1396 #ifdef  CONFIG_PNP
1397         if (pnp_driver_registered)
1398                 pnp_unregister_driver(&cmos_pnp_driver);
1399 #endif
1400         if (platform_driver_registered)
1401                 platform_driver_unregister(&cmos_platform_driver);
1402 }
1403 module_exit(cmos_exit);
1404
1405
1406 MODULE_AUTHOR("David Brownell");
1407 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
1408 MODULE_LICENSE("GPL");