forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
rtc-cmos.c
1480 lines (1218 loc) · 36.3 KB
/
rtc-cmos.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* RTC class driver for "CMOS RTC": PCs, ACPI, etc
*
* Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
* Copyright (C) 2006 David Brownell (convert to new framework)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
/*
* The original "cmos clock" chip was an MC146818 chip, now obsolete.
* That defined the register interface now provided by all PCs, some
* non-PC systems, and incorporated into ACPI. Modern PC chipsets
* integrate an MC146818 clone in their southbridge, and boards use
* that instead of discrete clones like the DS12887 or M48T86. There
* are also clones that connect using the LPC bus.
*
* That register API is also used directly by various other drivers
* (notably for integrated NVRAM), infrastructure (x86 has code to
* bypass the RTC framework, directly reading the RTC during boot
* and updating minutes/seconds for systems using NTP synch) and
* utilities (like userspace 'hwclock', if no /dev node exists).
*
* So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
* interrupts disabled, holding the global rtc_lock, to exclude those
* other drivers and utilities on correctly configured systems.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/log2.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#ifdef CONFIG_X86
#include <asm/i8259.h>
#include <asm/processor.h>
#include <linux/dmi.h>
#endif
/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
#include <linux/mc146818rtc.h>
/*
* Use ACPI SCI to replace HPET interrupt for RTC Alarm event
*
* If cleared, ACPI SCI is only used to wake up the system from suspend
*
* If set, ACPI SCI is used to handle UIE/AIE and system wakeup
*/
static bool use_acpi_alarm;
module_param(use_acpi_alarm, bool, 0444);
struct cmos_rtc {
struct rtc_device *rtc;
struct device *dev;
int irq;
struct resource *iomem;
time64_t alarm_expires;
void (*wake_on)(struct device *);
void (*wake_off)(struct device *);
u8 enabled_wake;
u8 suspend_ctrl;
/* newer hardware extends the original register set */
u8 day_alrm;
u8 mon_alrm;
u8 century;
struct rtc_wkalrm saved_wkalrm;
};
/* both platform and pnp busses use negative numbers for invalid irqs */
#define is_valid_irq(n) ((n) > 0)
static const char driver_name[] = "rtc_cmos";
/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
* always mask it against the irq enable bits in RTC_CONTROL. Bit values
* are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
*/
#define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
static inline int is_intr(u8 rtc_intr)
{
if (!(rtc_intr & RTC_IRQF))
return 0;
return rtc_intr & RTC_IRQMASK;
}
/*----------------------------------------------------------------*/
/* Much modern x86 hardware has HPETs (10+ MHz timers) which, because
* many BIOS programmers don't set up "sane mode" IRQ routing, are mostly
* used in a broken "legacy replacement" mode. The breakage includes
* HPET #1 hijacking the IRQ for this RTC, and being unavailable for
* other (better) use.
*
* When that broken mode is in use, platform glue provides a partial
* emulation of hardware RTC IRQ facilities using HPET #1. We don't
* want to use HPET for anything except those IRQs though...
*/
#ifdef CONFIG_HPET_EMULATE_RTC
#include <asm/hpet.h>
#else
static inline int is_hpet_enabled(void)
{
return 0;
}
static inline int hpet_mask_rtc_irq_bit(unsigned long mask)
{
return 0;
}
static inline int hpet_set_rtc_irq_bit(unsigned long mask)
{
return 0;
}
static inline int
hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
{
return 0;
}
static inline int hpet_set_periodic_freq(unsigned long freq)
{
return 0;
}
static inline int hpet_rtc_dropped_irq(void)
{
return 0;
}
static inline int hpet_rtc_timer_init(void)
{
return 0;
}
extern irq_handler_t hpet_rtc_interrupt;
static inline int hpet_register_irq_handler(irq_handler_t handler)
{
return 0;
}
static inline int hpet_unregister_irq_handler(irq_handler_t handler)
{
return 0;
}
#endif
/* Don't use HPET for RTC Alarm event if ACPI Fixed event is used */
static int use_hpet_alarm(void)
{
return is_hpet_enabled() && !use_acpi_alarm;
}
/*----------------------------------------------------------------*/
#ifdef RTC_PORT
/* Most newer x86 systems have two register banks, the first used
* for RTC and NVRAM and the second only for NVRAM. Caller must
* own rtc_lock ... and we won't worry about access during NMI.
*/
#define can_bank2 true
static inline unsigned char cmos_read_bank2(unsigned char addr)
{
outb(addr, RTC_PORT(2));
return inb(RTC_PORT(3));
}
static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
{
outb(addr, RTC_PORT(2));
outb(val, RTC_PORT(3));
}
#else
#define can_bank2 false
static inline unsigned char cmos_read_bank2(unsigned char addr)
{
return 0;
}
static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
{
}
#endif
/*----------------------------------------------------------------*/
static int cmos_read_time(struct device *dev, struct rtc_time *t)
{
/*
* If pm_trace abused the RTC for storage, set the timespec to 0,
* which tells the caller that this RTC value is unusable.
*/
if (!pm_trace_rtc_valid())
return -EIO;
/* REVISIT: if the clock has a "century" register, use
* that instead of the heuristic in mc146818_get_time().
* That'll make Y3K compatility (year > 2070) easy!
*/
mc146818_get_time(t);
return 0;
}
static int cmos_set_time(struct device *dev, struct rtc_time *t)
{
/* REVISIT: set the "century" register if available
*
* NOTE: this ignores the issue whereby updating the seconds
* takes effect exactly 500ms after we write the register.
* (Also queueing and other delays before we get this far.)
*/
return mc146818_set_time(t);
}
static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char rtc_control;
if (!is_valid_irq(cmos->irq))
return -EIO;
/* Basic alarms only support hour, minute, and seconds fields.
* Some also support day and month, for alarms up to a year in
* the future.
*/
spin_lock_irq(&rtc_lock);
t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
if (cmos->day_alrm) {
/* ignore upper bits on readback per ACPI spec */
t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
if (!t->time.tm_mday)
t->time.tm_mday = -1;
if (cmos->mon_alrm) {
t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
if (!t->time.tm_mon)
t->time.tm_mon = -1;
}
}
rtc_control = CMOS_READ(RTC_CONTROL);
spin_unlock_irq(&rtc_lock);
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
if (((unsigned)t->time.tm_sec) < 0x60)
t->time.tm_sec = bcd2bin(t->time.tm_sec);
else
t->time.tm_sec = -1;
if (((unsigned)t->time.tm_min) < 0x60)
t->time.tm_min = bcd2bin(t->time.tm_min);
else
t->time.tm_min = -1;
if (((unsigned)t->time.tm_hour) < 0x24)
t->time.tm_hour = bcd2bin(t->time.tm_hour);
else
t->time.tm_hour = -1;
if (cmos->day_alrm) {
if (((unsigned)t->time.tm_mday) <= 0x31)
t->time.tm_mday = bcd2bin(t->time.tm_mday);
else
t->time.tm_mday = -1;
if (cmos->mon_alrm) {
if (((unsigned)t->time.tm_mon) <= 0x12)
t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;
else
t->time.tm_mon = -1;
}
}
}
t->enabled = !!(rtc_control & RTC_AIE);
t->pending = 0;
return 0;
}
static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control)
{
unsigned char rtc_intr;
/* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
* allegedly some older rtcs need that to handle irqs properly
*/
rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
if (use_hpet_alarm())
return;
rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
if (is_intr(rtc_intr))
rtc_update_irq(cmos->rtc, 1, rtc_intr);
}
static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask)
{
unsigned char rtc_control;
/* flush any pending IRQ status, notably for update irqs,
* before we enable new IRQs
*/
rtc_control = CMOS_READ(RTC_CONTROL);
cmos_checkintr(cmos, rtc_control);
rtc_control |= mask;
CMOS_WRITE(rtc_control, RTC_CONTROL);
if (use_hpet_alarm())
hpet_set_rtc_irq_bit(mask);
if ((mask & RTC_AIE) && use_acpi_alarm) {
if (cmos->wake_on)
cmos->wake_on(cmos->dev);
}
cmos_checkintr(cmos, rtc_control);
}
static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)
{
unsigned char rtc_control;
rtc_control = CMOS_READ(RTC_CONTROL);
rtc_control &= ~mask;
CMOS_WRITE(rtc_control, RTC_CONTROL);
if (use_hpet_alarm())
hpet_mask_rtc_irq_bit(mask);
if ((mask & RTC_AIE) && use_acpi_alarm) {
if (cmos->wake_off)
cmos->wake_off(cmos->dev);
}
cmos_checkintr(cmos, rtc_control);
}
static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
struct rtc_time now;
cmos_read_time(dev, &now);
if (!cmos->day_alrm) {
time64_t t_max_date;
time64_t t_alrm;
t_max_date = rtc_tm_to_time64(&now);
t_max_date += 24 * 60 * 60 - 1;
t_alrm = rtc_tm_to_time64(&t->time);
if (t_alrm > t_max_date) {
dev_err(dev,
"Alarms can be up to one day in the future\n");
return -EINVAL;
}
} else if (!cmos->mon_alrm) {
struct rtc_time max_date = now;
time64_t t_max_date;
time64_t t_alrm;
int max_mday;
if (max_date.tm_mon == 11) {
max_date.tm_mon = 0;
max_date.tm_year += 1;
} else {
max_date.tm_mon += 1;
}
max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
if (max_date.tm_mday > max_mday)
max_date.tm_mday = max_mday;
t_max_date = rtc_tm_to_time64(&max_date);
t_max_date -= 1;
t_alrm = rtc_tm_to_time64(&t->time);
if (t_alrm > t_max_date) {
dev_err(dev,
"Alarms can be up to one month in the future\n");
return -EINVAL;
}
} else {
struct rtc_time max_date = now;
time64_t t_max_date;
time64_t t_alrm;
int max_mday;
max_date.tm_year += 1;
max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
if (max_date.tm_mday > max_mday)
max_date.tm_mday = max_mday;
t_max_date = rtc_tm_to_time64(&max_date);
t_max_date -= 1;
t_alrm = rtc_tm_to_time64(&t->time);
if (t_alrm > t_max_date) {
dev_err(dev,
"Alarms can be up to one year in the future\n");
return -EINVAL;
}
}
return 0;
}
static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char mon, mday, hrs, min, sec, rtc_control;
int ret;
if (!is_valid_irq(cmos->irq))
return -EIO;
ret = cmos_validate_alarm(dev, t);
if (ret < 0)
return ret;
mon = t->time.tm_mon + 1;
mday = t->time.tm_mday;
hrs = t->time.tm_hour;
min = t->time.tm_min;
sec = t->time.tm_sec;
rtc_control = CMOS_READ(RTC_CONTROL);
if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
/* Writing 0xff means "don't care" or "match all". */
mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
min = (min < 60) ? bin2bcd(min) : 0xff;
sec = (sec < 60) ? bin2bcd(sec) : 0xff;
}
spin_lock_irq(&rtc_lock);
/* next rtc irq must not be from previous alarm setting */
cmos_irq_disable(cmos, RTC_AIE);
/* update alarm */
CMOS_WRITE(hrs, RTC_HOURS_ALARM);
CMOS_WRITE(min, RTC_MINUTES_ALARM);
CMOS_WRITE(sec, RTC_SECONDS_ALARM);
/* the system may support an "enhanced" alarm */
if (cmos->day_alrm) {
CMOS_WRITE(mday, cmos->day_alrm);
if (cmos->mon_alrm)
CMOS_WRITE(mon, cmos->mon_alrm);
}
if (use_hpet_alarm()) {
/*
* FIXME the HPET alarm glue currently ignores day_alrm
* and mon_alrm ...
*/
hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min,
t->time.tm_sec);
}
if (t->enabled)
cmos_irq_enable(cmos, RTC_AIE);
spin_unlock_irq(&rtc_lock);
cmos->alarm_expires = rtc_tm_to_time64(&t->time);
return 0;
}
static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned long flags;
if (!is_valid_irq(cmos->irq))
return -EINVAL;
spin_lock_irqsave(&rtc_lock, flags);
if (enabled)
cmos_irq_enable(cmos, RTC_AIE);
else
cmos_irq_disable(cmos, RTC_AIE);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
}
#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
static int cmos_procfs(struct device *dev, struct seq_file *seq)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char rtc_control, valid;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
valid = CMOS_READ(RTC_VALID);
spin_unlock_irq(&rtc_lock);
/* NOTE: at least ICH6 reports battery status using a different
* (non-RTC) bit; and SQWE is ignored on many current systems.
*/
seq_printf(seq,
"periodic_IRQ\t: %s\n"
"update_IRQ\t: %s\n"
"HPET_emulated\t: %s\n"
// "square_wave\t: %s\n"
"BCD\t\t: %s\n"
"DST_enable\t: %s\n"
"periodic_freq\t: %d\n"
"batt_status\t: %s\n",
(rtc_control & RTC_PIE) ? "yes" : "no",
(rtc_control & RTC_UIE) ? "yes" : "no",
use_hpet_alarm() ? "yes" : "no",
// (rtc_control & RTC_SQWE) ? "yes" : "no",
(rtc_control & RTC_DM_BINARY) ? "no" : "yes",
(rtc_control & RTC_DST_EN) ? "yes" : "no",
cmos->rtc->irq_freq,
(valid & RTC_VRT) ? "okay" : "dead");
return 0;
}
#else
#define cmos_procfs NULL
#endif
static const struct rtc_class_ops cmos_rtc_ops = {
.read_time = cmos_read_time,
.set_time = cmos_set_time,
.read_alarm = cmos_read_alarm,
.set_alarm = cmos_set_alarm,
.proc = cmos_procfs,
.alarm_irq_enable = cmos_alarm_irq_enable,
};
/*----------------------------------------------------------------*/
/*
* All these chips have at least 64 bytes of address space, shared by
* RTC registers and NVRAM. Most of those bytes of NVRAM are used
* by boot firmware. Modern chips have 128 or 256 bytes.
*/
#define NVRAM_OFFSET (RTC_REG_D + 1)
static int cmos_nvram_read(void *priv, unsigned int off, void *val,
size_t count)
{
unsigned char *buf = val;
int retval;
off += NVRAM_OFFSET;
spin_lock_irq(&rtc_lock);
for (retval = 0; count; count--, off++, retval++) {
if (off < 128)
*buf++ = CMOS_READ(off);
else if (can_bank2)
*buf++ = cmos_read_bank2(off);
else
break;
}
spin_unlock_irq(&rtc_lock);
return retval;
}
static int cmos_nvram_write(void *priv, unsigned int off, void *val,
size_t count)
{
struct cmos_rtc *cmos = priv;
unsigned char *buf = val;
int retval;
/* NOTE: on at least PCs and Ataris, the boot firmware uses a
* checksum on part of the NVRAM data. That's currently ignored
* here. If userspace is smart enough to know what fields of
* NVRAM to update, updating checksums is also part of its job.
*/
off += NVRAM_OFFSET;
spin_lock_irq(&rtc_lock);
for (retval = 0; count; count--, off++, retval++) {
/* don't trash RTC registers */
if (off == cmos->day_alrm
|| off == cmos->mon_alrm
|| off == cmos->century)
buf++;
else if (off < 128)
CMOS_WRITE(*buf++, off);
else if (can_bank2)
cmos_write_bank2(*buf++, off);
else
break;
}
spin_unlock_irq(&rtc_lock);
return retval;
}
/*----------------------------------------------------------------*/
static struct cmos_rtc cmos_rtc;
static irqreturn_t cmos_interrupt(int irq, void *p)
{
u8 irqstat;
u8 rtc_control;
spin_lock(&rtc_lock);
/* When the HPET interrupt handler calls us, the interrupt
* status is passed as arg1 instead of the irq number. But
* always clear irq status, even when HPET is in the way.
*
* Note that HPET and RTC are almost certainly out of phase,
* giving different IRQ status ...
*/
irqstat = CMOS_READ(RTC_INTR_FLAGS);
rtc_control = CMOS_READ(RTC_CONTROL);
if (use_hpet_alarm())
irqstat = (unsigned long)irq & 0xF0;
/* If we were suspended, RTC_CONTROL may not be accurate since the
* bios may have cleared it.
*/
if (!cmos_rtc.suspend_ctrl)
irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
else
irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
/* All Linux RTC alarms should be treated as if they were oneshot.
* Similar code may be needed in system wakeup paths, in case the
* alarm woke the system.
*/
if (irqstat & RTC_AIE) {
cmos_rtc.suspend_ctrl &= ~RTC_AIE;
rtc_control &= ~RTC_AIE;
CMOS_WRITE(rtc_control, RTC_CONTROL);
if (use_hpet_alarm())
hpet_mask_rtc_irq_bit(RTC_AIE);
CMOS_READ(RTC_INTR_FLAGS);
}
spin_unlock(&rtc_lock);
if (is_intr(irqstat)) {
rtc_update_irq(p, 1, irqstat);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
#ifdef CONFIG_PNP
#define INITSECTION
#else
#define INITSECTION __init
#endif
static int INITSECTION
cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
{
struct cmos_rtc_board_info *info = dev_get_platdata(dev);
int retval = 0;
unsigned char rtc_control;
unsigned address_space;
u32 flags = 0;
struct nvmem_config nvmem_cfg = {
.name = "cmos_nvram",
.word_size = 1,
.stride = 1,
.reg_read = cmos_nvram_read,
.reg_write = cmos_nvram_write,
.priv = &cmos_rtc,
};
/* there can be only one ... */
if (cmos_rtc.dev)
return -EBUSY;
if (!ports)
return -ENODEV;
/* Claim I/O ports ASAP, minimizing conflict with legacy driver.
*
* REVISIT non-x86 systems may instead use memory space resources
* (needing ioremap etc), not i/o space resources like this ...
*/
if (RTC_IOMAPPED)
ports = request_region(ports->start, resource_size(ports),
driver_name);
else
ports = request_mem_region(ports->start, resource_size(ports),
driver_name);
if (!ports) {
dev_dbg(dev, "i/o registers already in use\n");
return -EBUSY;
}
cmos_rtc.irq = rtc_irq;
cmos_rtc.iomem = ports;
/* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
* driver did, but don't reject unknown configs. Old hardware
* won't address 128 bytes. Newer chips have multiple banks,
* though they may not be listed in one I/O resource.
*/
#if defined(CONFIG_ATARI)
address_space = 64;
#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
|| defined(__sparc__) || defined(__mips__) \
|| defined(__powerpc__)
address_space = 128;
#else
#warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
address_space = 128;
#endif
if (can_bank2 && ports->end > (ports->start + 1))
address_space = 256;
/* For ACPI systems extension info comes from the FADT. On others,
* board specific setup provides it as appropriate. Systems where
* the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
* some almost-clones) can provide hooks to make that behave.
*
* Note that ACPI doesn't preclude putting these registers into
* "extended" areas of the chip, including some that we won't yet
* expect CMOS_READ and friends to handle.
*/
if (info) {
if (info->flags)
flags = info->flags;
if (info->address_space)
address_space = info->address_space;
if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
cmos_rtc.day_alrm = info->rtc_day_alarm;
if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
cmos_rtc.mon_alrm = info->rtc_mon_alarm;
if (info->rtc_century && info->rtc_century < 128)
cmos_rtc.century = info->rtc_century;
if (info->wake_on && info->wake_off) {
cmos_rtc.wake_on = info->wake_on;
cmos_rtc.wake_off = info->wake_off;
}
}
cmos_rtc.dev = dev;
dev_set_drvdata(dev, &cmos_rtc);
cmos_rtc.rtc = devm_rtc_allocate_device(dev);
if (IS_ERR(cmos_rtc.rtc)) {
retval = PTR_ERR(cmos_rtc.rtc);
goto cleanup0;
}
rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
spin_lock_irq(&rtc_lock);
if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
/* force periodic irq to CMOS reset default of 1024Hz;
*
* REVISIT it's been reported that at least one x86_64 ALI
* mobo doesn't use 32KHz here ... for portability we might
* need to do something about other clock frequencies.
*/
cmos_rtc.rtc->irq_freq = 1024;
if (use_hpet_alarm())
hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);
CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
}
/* disable irqs */
if (is_valid_irq(rtc_irq))
cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE);
rtc_control = CMOS_READ(RTC_CONTROL);
spin_unlock_irq(&rtc_lock);
if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
dev_warn(dev, "only 24-hr supported\n");
retval = -ENXIO;
goto cleanup1;
}
if (use_hpet_alarm())
hpet_rtc_timer_init();
if (is_valid_irq(rtc_irq)) {
irq_handler_t rtc_cmos_int_handler;
if (use_hpet_alarm()) {
rtc_cmos_int_handler = hpet_rtc_interrupt;
retval = hpet_register_irq_handler(cmos_interrupt);
if (retval) {
hpet_mask_rtc_irq_bit(RTC_IRQMASK);
dev_warn(dev, "hpet_register_irq_handler "
" failed in rtc_init().");
goto cleanup1;
}
} else
rtc_cmos_int_handler = cmos_interrupt;
retval = request_irq(rtc_irq, rtc_cmos_int_handler,
IRQF_SHARED, dev_name(&cmos_rtc.rtc->dev),
cmos_rtc.rtc);
if (retval < 0) {
dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
goto cleanup1;
}
}
cmos_rtc.rtc->ops = &cmos_rtc_ops;
cmos_rtc.rtc->nvram_old_abi = true;
retval = rtc_register_device(cmos_rtc.rtc);
if (retval)
goto cleanup2;
/* export at least the first block of NVRAM */
nvmem_cfg.size = address_space - NVRAM_OFFSET;
if (rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg))
dev_err(dev, "nvmem registration failed\n");
dev_info(dev, "%s%s, %d bytes nvram%s\n",
!is_valid_irq(rtc_irq) ? "no alarms" :
cmos_rtc.mon_alrm ? "alarms up to one year" :
cmos_rtc.day_alrm ? "alarms up to one month" :
"alarms up to one day",
cmos_rtc.century ? ", y3k" : "",
nvmem_cfg.size,
use_hpet_alarm() ? ", hpet irqs" : "");
return 0;
cleanup2:
if (is_valid_irq(rtc_irq))
free_irq(rtc_irq, cmos_rtc.rtc);
cleanup1:
cmos_rtc.dev = NULL;
cleanup0:
if (RTC_IOMAPPED)
release_region(ports->start, resource_size(ports));
else
release_mem_region(ports->start, resource_size(ports));
return retval;
}
static void cmos_do_shutdown(int rtc_irq)
{
spin_lock_irq(&rtc_lock);
if (is_valid_irq(rtc_irq))
cmos_irq_disable(&cmos_rtc, RTC_IRQMASK);
spin_unlock_irq(&rtc_lock);
}
static void cmos_do_remove(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
struct resource *ports;
cmos_do_shutdown(cmos->irq);
if (is_valid_irq(cmos->irq)) {
free_irq(cmos->irq, cmos->rtc);
if (use_hpet_alarm())
hpet_unregister_irq_handler(cmos_interrupt);
}
cmos->rtc = NULL;
ports = cmos->iomem;
if (RTC_IOMAPPED)
release_region(ports->start, resource_size(ports));
else
release_mem_region(ports->start, resource_size(ports));
cmos->iomem = NULL;
cmos->dev = NULL;
}
static int cmos_aie_poweroff(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
struct rtc_time now;
time64_t t_now;
int retval = 0;
unsigned char rtc_control;
if (!cmos->alarm_expires)
return -EINVAL;
spin_lock_irq(&rtc_lock);
rtc_control = CMOS_READ(RTC_CONTROL);
spin_unlock_irq(&rtc_lock);
/* We only care about the situation where AIE is disabled. */
if (rtc_control & RTC_AIE)
return -EBUSY;
cmos_read_time(dev, &now);
t_now = rtc_tm_to_time64(&now);
/*
* When enabling "RTC wake-up" in BIOS setup, the machine reboots
* automatically right after shutdown on some buggy boxes.
* This automatic rebooting issue won't happen when the alarm
* time is larger than now+1 seconds.
*
* If the alarm time is equal to now+1 seconds, the issue can be
* prevented by cancelling the alarm.
*/
if (cmos->alarm_expires == t_now + 1) {
struct rtc_wkalrm alarm;
/* Cancel the AIE timer by configuring the past time. */
rtc_time64_to_tm(t_now - 1, &alarm.time);
alarm.enabled = 0;
retval = cmos_set_alarm(dev, &alarm);
} else if (cmos->alarm_expires > t_now + 1) {
retval = -EBUSY;
}
return retval;
}
static int cmos_suspend(struct device *dev)
{
struct cmos_rtc *cmos = dev_get_drvdata(dev);
unsigned char tmp;
/* only the alarm might be a wakeup event source */
spin_lock_irq(&rtc_lock);
cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
unsigned char mask;
if (device_may_wakeup(dev))
mask = RTC_IRQMASK & ~RTC_AIE;
else
mask = RTC_IRQMASK;
tmp &= ~mask;
CMOS_WRITE(tmp, RTC_CONTROL);
if (use_hpet_alarm())
hpet_mask_rtc_irq_bit(mask);
cmos_checkintr(cmos, tmp);
}
spin_unlock_irq(&rtc_lock);
if ((tmp & RTC_AIE) && !use_acpi_alarm) {
cmos->enabled_wake = 1;
if (cmos->wake_on)
cmos->wake_on(dev);
else
enable_irq_wake(cmos->irq);
}
cmos_read_alarm(dev, &cmos->saved_wkalrm);
dev_dbg(dev, "suspend%s, ctrl %02x\n",
(tmp & RTC_AIE) ? ", alarm may wake" : "",
tmp);
return 0;
}
/* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even