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 #include <asm/processor.h>
47 #include <linux/dmi.h>
48 #endif
49
50 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
51 #include <linux/mc146818rtc.h>
52
53 #ifdef CONFIG_ACPI
54 /*
55 * Use ACPI SCI to replace HPET interrupt for RTC Alarm event
56 *
57 * If cleared, ACPI SCI is only used to wake up the system from suspend
58 *
59 * If set, ACPI SCI is used to handle UIE/AIE and system wakeup
60 */
61
62 static bool use_acpi_alarm;
63 module_param(use_acpi_alarm, bool, 0444);
64
cmos_use_acpi_alarm(void)65 static inline int cmos_use_acpi_alarm(void)
66 {
67 return use_acpi_alarm;
68 }
69 #else /* !CONFIG_ACPI */
70
cmos_use_acpi_alarm(void)71 static inline int cmos_use_acpi_alarm(void)
72 {
73 return 0;
74 }
75 #endif
76
77 struct cmos_rtc {
78 struct rtc_device *rtc;
79 struct device *dev;
80 int irq;
81 struct resource *iomem;
82 time64_t alarm_expires;
83
84 void (*wake_on)(struct device *);
85 void (*wake_off)(struct device *);
86
87 u8 enabled_wake;
88 u8 suspend_ctrl;
89
90 /* newer hardware extends the original register set */
91 u8 day_alrm;
92 u8 mon_alrm;
93 u8 century;
94
95 struct rtc_wkalrm saved_wkalrm;
96 };
97
98 /* both platform and pnp busses use negative numbers for invalid irqs */
99 #define is_valid_irq(n) ((n) > 0)
100
101 static const char driver_name[] = "rtc_cmos";
102
103 /* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
104 * always mask it against the irq enable bits in RTC_CONTROL. Bit values
105 * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
106 */
107 #define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
108
is_intr(u8 rtc_intr)109 static inline int is_intr(u8 rtc_intr)
110 {
111 if (!(rtc_intr & RTC_IRQF))
112 return 0;
113 return rtc_intr & RTC_IRQMASK;
114 }
115
116 /*----------------------------------------------------------------*/
117
118 /* Much modern x86 hardware has HPETs (10+ MHz timers) which, because
119 * many BIOS programmers don't set up "sane mode" IRQ routing, are mostly
120 * used in a broken "legacy replacement" mode. The breakage includes
121 * HPET #1 hijacking the IRQ for this RTC, and being unavailable for
122 * other (better) use.
123 *
124 * When that broken mode is in use, platform glue provides a partial
125 * emulation of hardware RTC IRQ facilities using HPET #1. We don't
126 * want to use HPET for anything except those IRQs though...
127 */
128 #ifdef CONFIG_HPET_EMULATE_RTC
129 #include <asm/hpet.h>
130 #else
131
is_hpet_enabled(void)132 static inline int is_hpet_enabled(void)
133 {
134 return 0;
135 }
136
hpet_mask_rtc_irq_bit(unsigned long mask)137 static inline int hpet_mask_rtc_irq_bit(unsigned long mask)
138 {
139 return 0;
140 }
141
hpet_set_rtc_irq_bit(unsigned long mask)142 static inline int hpet_set_rtc_irq_bit(unsigned long mask)
143 {
144 return 0;
145 }
146
147 static inline int
hpet_set_alarm_time(unsigned char hrs,unsigned char min,unsigned char sec)148 hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
149 {
150 return 0;
151 }
152
hpet_set_periodic_freq(unsigned long freq)153 static inline int hpet_set_periodic_freq(unsigned long freq)
154 {
155 return 0;
156 }
157
hpet_rtc_dropped_irq(void)158 static inline int hpet_rtc_dropped_irq(void)
159 {
160 return 0;
161 }
162
hpet_rtc_timer_init(void)163 static inline int hpet_rtc_timer_init(void)
164 {
165 return 0;
166 }
167
168 extern irq_handler_t hpet_rtc_interrupt;
169
hpet_register_irq_handler(irq_handler_t handler)170 static inline int hpet_register_irq_handler(irq_handler_t handler)
171 {
172 return 0;
173 }
174
hpet_unregister_irq_handler(irq_handler_t handler)175 static inline int hpet_unregister_irq_handler(irq_handler_t handler)
176 {
177 return 0;
178 }
179
180 #endif
181
182 /* Don't use HPET for RTC Alarm event if ACPI Fixed event is used */
use_hpet_alarm(void)183 static inline int use_hpet_alarm(void)
184 {
185 return is_hpet_enabled() && !cmos_use_acpi_alarm();
186 }
187
188 /*----------------------------------------------------------------*/
189
190 #ifdef RTC_PORT
191
192 /* Most newer x86 systems have two register banks, the first used
193 * for RTC and NVRAM and the second only for NVRAM. Caller must
194 * own rtc_lock ... and we won't worry about access during NMI.
195 */
196 #define can_bank2 true
197
cmos_read_bank2(unsigned char addr)198 static inline unsigned char cmos_read_bank2(unsigned char addr)
199 {
200 outb(addr, RTC_PORT(2));
201 return inb(RTC_PORT(3));
202 }
203
cmos_write_bank2(unsigned char val,unsigned char addr)204 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
205 {
206 outb(addr, RTC_PORT(2));
207 outb(val, RTC_PORT(3));
208 }
209
210 #else
211
212 #define can_bank2 false
213
cmos_read_bank2(unsigned char addr)214 static inline unsigned char cmos_read_bank2(unsigned char addr)
215 {
216 return 0;
217 }
218
cmos_write_bank2(unsigned char val,unsigned char addr)219 static inline void cmos_write_bank2(unsigned char val, unsigned char addr)
220 {
221 }
222
223 #endif
224
225 /*----------------------------------------------------------------*/
226
cmos_read_time(struct device * dev,struct rtc_time * t)227 static int cmos_read_time(struct device *dev, struct rtc_time *t)
228 {
229 /*
230 * If pm_trace abused the RTC for storage, set the timespec to 0,
231 * which tells the caller that this RTC value is unusable.
232 */
233 if (!pm_trace_rtc_valid())
234 return -EIO;
235
236 /* REVISIT: if the clock has a "century" register, use
237 * that instead of the heuristic in mc146818_get_time().
238 * That'll make Y3K compatility (year > 2070) easy!
239 */
240 mc146818_get_time(t);
241 return 0;
242 }
243
cmos_set_time(struct device * dev,struct rtc_time * t)244 static int cmos_set_time(struct device *dev, struct rtc_time *t)
245 {
246 /* REVISIT: set the "century" register if available
247 *
248 * NOTE: this ignores the issue whereby updating the seconds
249 * takes effect exactly 500ms after we write the register.
250 * (Also queueing and other delays before we get this far.)
251 */
252 return mc146818_set_time(t);
253 }
254
cmos_read_alarm(struct device * dev,struct rtc_wkalrm * t)255 static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
256 {
257 struct cmos_rtc *cmos = dev_get_drvdata(dev);
258 unsigned char rtc_control;
259
260 /* This not only a rtc_op, but also called directly */
261 if (!is_valid_irq(cmos->irq))
262 return -EIO;
263
264 /* Basic alarms only support hour, minute, and seconds fields.
265 * Some also support day and month, for alarms up to a year in
266 * the future.
267 */
268
269 spin_lock_irq(&rtc_lock);
270 t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
271 t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
272 t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
273
274 if (cmos->day_alrm) {
275 /* ignore upper bits on readback per ACPI spec */
276 t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
277 if (!t->time.tm_mday)
278 t->time.tm_mday = -1;
279
280 if (cmos->mon_alrm) {
281 t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
282 if (!t->time.tm_mon)
283 t->time.tm_mon = -1;
284 }
285 }
286
287 rtc_control = CMOS_READ(RTC_CONTROL);
288 spin_unlock_irq(&rtc_lock);
289
290 if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
291 if (((unsigned)t->time.tm_sec) < 0x60)
292 t->time.tm_sec = bcd2bin(t->time.tm_sec);
293 else
294 t->time.tm_sec = -1;
295 if (((unsigned)t->time.tm_min) < 0x60)
296 t->time.tm_min = bcd2bin(t->time.tm_min);
297 else
298 t->time.tm_min = -1;
299 if (((unsigned)t->time.tm_hour) < 0x24)
300 t->time.tm_hour = bcd2bin(t->time.tm_hour);
301 else
302 t->time.tm_hour = -1;
303
304 if (cmos->day_alrm) {
305 if (((unsigned)t->time.tm_mday) <= 0x31)
306 t->time.tm_mday = bcd2bin(t->time.tm_mday);
307 else
308 t->time.tm_mday = -1;
309
310 if (cmos->mon_alrm) {
311 if (((unsigned)t->time.tm_mon) <= 0x12)
312 t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;
313 else
314 t->time.tm_mon = -1;
315 }
316 }
317 }
318
319 t->enabled = !!(rtc_control & RTC_AIE);
320 t->pending = 0;
321
322 return 0;
323 }
324
cmos_checkintr(struct cmos_rtc * cmos,unsigned char rtc_control)325 static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control)
326 {
327 unsigned char rtc_intr;
328
329 /* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
330 * allegedly some older rtcs need that to handle irqs properly
331 */
332 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
333
334 if (use_hpet_alarm())
335 return;
336
337 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
338 if (is_intr(rtc_intr))
339 rtc_update_irq(cmos->rtc, 1, rtc_intr);
340 }
341
cmos_irq_enable(struct cmos_rtc * cmos,unsigned char mask)342 static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask)
343 {
344 unsigned char rtc_control;
345
346 /* flush any pending IRQ status, notably for update irqs,
347 * before we enable new IRQs
348 */
349 rtc_control = CMOS_READ(RTC_CONTROL);
350 cmos_checkintr(cmos, rtc_control);
351
352 rtc_control |= mask;
353 CMOS_WRITE(rtc_control, RTC_CONTROL);
354 if (use_hpet_alarm())
355 hpet_set_rtc_irq_bit(mask);
356
357 if ((mask & RTC_AIE) && cmos_use_acpi_alarm()) {
358 if (cmos->wake_on)
359 cmos->wake_on(cmos->dev);
360 }
361
362 cmos_checkintr(cmos, rtc_control);
363 }
364
cmos_irq_disable(struct cmos_rtc * cmos,unsigned char mask)365 static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)
366 {
367 unsigned char rtc_control;
368
369 rtc_control = CMOS_READ(RTC_CONTROL);
370 rtc_control &= ~mask;
371 CMOS_WRITE(rtc_control, RTC_CONTROL);
372 if (use_hpet_alarm())
373 hpet_mask_rtc_irq_bit(mask);
374
375 if ((mask & RTC_AIE) && cmos_use_acpi_alarm()) {
376 if (cmos->wake_off)
377 cmos->wake_off(cmos->dev);
378 }
379
380 cmos_checkintr(cmos, rtc_control);
381 }
382
cmos_validate_alarm(struct device * dev,struct rtc_wkalrm * t)383 static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t)
384 {
385 struct cmos_rtc *cmos = dev_get_drvdata(dev);
386 struct rtc_time now;
387
388 cmos_read_time(dev, &now);
389
390 if (!cmos->day_alrm) {
391 time64_t t_max_date;
392 time64_t t_alrm;
393
394 t_max_date = rtc_tm_to_time64(&now);
395 t_max_date += 24 * 60 * 60 - 1;
396 t_alrm = rtc_tm_to_time64(&t->time);
397 if (t_alrm > t_max_date) {
398 dev_err(dev,
399 "Alarms can be up to one day in the future\n");
400 return -EINVAL;
401 }
402 } else if (!cmos->mon_alrm) {
403 struct rtc_time max_date = now;
404 time64_t t_max_date;
405 time64_t t_alrm;
406 int max_mday;
407
408 if (max_date.tm_mon == 11) {
409 max_date.tm_mon = 0;
410 max_date.tm_year += 1;
411 } else {
412 max_date.tm_mon += 1;
413 }
414 max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
415 if (max_date.tm_mday > max_mday)
416 max_date.tm_mday = max_mday;
417
418 t_max_date = rtc_tm_to_time64(&max_date);
419 t_max_date -= 1;
420 t_alrm = rtc_tm_to_time64(&t->time);
421 if (t_alrm > t_max_date) {
422 dev_err(dev,
423 "Alarms can be up to one month in the future\n");
424 return -EINVAL;
425 }
426 } else {
427 struct rtc_time max_date = now;
428 time64_t t_max_date;
429 time64_t t_alrm;
430 int max_mday;
431
432 max_date.tm_year += 1;
433 max_mday = rtc_month_days(max_date.tm_mon, max_date.tm_year);
434 if (max_date.tm_mday > max_mday)
435 max_date.tm_mday = max_mday;
436
437 t_max_date = rtc_tm_to_time64(&max_date);
438 t_max_date -= 1;
439 t_alrm = rtc_tm_to_time64(&t->time);
440 if (t_alrm > t_max_date) {
441 dev_err(dev,
442 "Alarms can be up to one year in the future\n");
443 return -EINVAL;
444 }
445 }
446
447 return 0;
448 }
449
cmos_set_alarm(struct device * dev,struct rtc_wkalrm * t)450 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
451 {
452 struct cmos_rtc *cmos = dev_get_drvdata(dev);
453 unsigned char mon, mday, hrs, min, sec, rtc_control;
454 int ret;
455
456 /* This not only a rtc_op, but also called directly */
457 if (!is_valid_irq(cmos->irq))
458 return -EIO;
459
460 ret = cmos_validate_alarm(dev, t);
461 if (ret < 0)
462 return ret;
463
464 mon = t->time.tm_mon + 1;
465 mday = t->time.tm_mday;
466 hrs = t->time.tm_hour;
467 min = t->time.tm_min;
468 sec = t->time.tm_sec;
469
470 spin_lock_irq(&rtc_lock);
471 rtc_control = CMOS_READ(RTC_CONTROL);
472 spin_unlock_irq(&rtc_lock);
473
474 if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
475 /* Writing 0xff means "don't care" or "match all". */
476 mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
477 mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
478 hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
479 min = (min < 60) ? bin2bcd(min) : 0xff;
480 sec = (sec < 60) ? bin2bcd(sec) : 0xff;
481 }
482
483 spin_lock_irq(&rtc_lock);
484
485 /* next rtc irq must not be from previous alarm setting */
486 cmos_irq_disable(cmos, RTC_AIE);
487
488 /* update alarm */
489 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
490 CMOS_WRITE(min, RTC_MINUTES_ALARM);
491 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
492
493 /* the system may support an "enhanced" alarm */
494 if (cmos->day_alrm) {
495 CMOS_WRITE(mday, cmos->day_alrm);
496 if (cmos->mon_alrm)
497 CMOS_WRITE(mon, cmos->mon_alrm);
498 }
499
500 if (use_hpet_alarm()) {
501 /*
502 * FIXME the HPET alarm glue currently ignores day_alrm
503 * and mon_alrm ...
504 */
505 hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min,
506 t->time.tm_sec);
507 }
508
509 if (t->enabled)
510 cmos_irq_enable(cmos, RTC_AIE);
511
512 spin_unlock_irq(&rtc_lock);
513
514 cmos->alarm_expires = rtc_tm_to_time64(&t->time);
515
516 return 0;
517 }
518
cmos_alarm_irq_enable(struct device * dev,unsigned int enabled)519 static int cmos_alarm_irq_enable(struct device *dev, unsigned int enabled)
520 {
521 struct cmos_rtc *cmos = dev_get_drvdata(dev);
522 unsigned long flags;
523
524 spin_lock_irqsave(&rtc_lock, flags);
525
526 if (enabled)
527 cmos_irq_enable(cmos, RTC_AIE);
528 else
529 cmos_irq_disable(cmos, RTC_AIE);
530
531 spin_unlock_irqrestore(&rtc_lock, flags);
532 return 0;
533 }
534
535 #if IS_ENABLED(CONFIG_RTC_INTF_PROC)
536
cmos_procfs(struct device * dev,struct seq_file * seq)537 static int cmos_procfs(struct device *dev, struct seq_file *seq)
538 {
539 struct cmos_rtc *cmos = dev_get_drvdata(dev);
540 unsigned char rtc_control, valid;
541
542 spin_lock_irq(&rtc_lock);
543 rtc_control = CMOS_READ(RTC_CONTROL);
544 valid = CMOS_READ(RTC_VALID);
545 spin_unlock_irq(&rtc_lock);
546
547 /* NOTE: at least ICH6 reports battery status using a different
548 * (non-RTC) bit; and SQWE is ignored on many current systems.
549 */
550 seq_printf(seq,
551 "periodic_IRQ\t: %s\n"
552 "update_IRQ\t: %s\n"
553 "HPET_emulated\t: %s\n"
554 // "square_wave\t: %s\n"
555 "BCD\t\t: %s\n"
556 "DST_enable\t: %s\n"
557 "periodic_freq\t: %d\n"
558 "batt_status\t: %s\n",
559 (rtc_control & RTC_PIE) ? "yes" : "no",
560 (rtc_control & RTC_UIE) ? "yes" : "no",
561 use_hpet_alarm() ? "yes" : "no",
562 // (rtc_control & RTC_SQWE) ? "yes" : "no",
563 (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
564 (rtc_control & RTC_DST_EN) ? "yes" : "no",
565 cmos->rtc->irq_freq,
566 (valid & RTC_VRT) ? "okay" : "dead");
567
568 return 0;
569 }
570
571 #else
572 #define cmos_procfs NULL
573 #endif
574
575 static const struct rtc_class_ops cmos_rtc_ops = {
576 .read_time = cmos_read_time,
577 .set_time = cmos_set_time,
578 .read_alarm = cmos_read_alarm,
579 .set_alarm = cmos_set_alarm,
580 .proc = cmos_procfs,
581 .alarm_irq_enable = cmos_alarm_irq_enable,
582 };
583
584 static const struct rtc_class_ops cmos_rtc_ops_no_alarm = {
585 .read_time = cmos_read_time,
586 .set_time = cmos_set_time,
587 .proc = cmos_procfs,
588 };
589
590 /*----------------------------------------------------------------*/
591
592 /*
593 * All these chips have at least 64 bytes of address space, shared by
594 * RTC registers and NVRAM. Most of those bytes of NVRAM are used
595 * by boot firmware. Modern chips have 128 or 256 bytes.
596 */
597
598 #define NVRAM_OFFSET (RTC_REG_D + 1)
599
cmos_nvram_read(void * priv,unsigned int off,void * val,size_t count)600 static int cmos_nvram_read(void *priv, unsigned int off, void *val,
601 size_t count)
602 {
603 unsigned char *buf = val;
604 int retval;
605
606 off += NVRAM_OFFSET;
607 spin_lock_irq(&rtc_lock);
608 for (retval = 0; count; count--, off++, retval++) {
609 if (off < 128)
610 *buf++ = CMOS_READ(off);
611 else if (can_bank2)
612 *buf++ = cmos_read_bank2(off);
613 else
614 break;
615 }
616 spin_unlock_irq(&rtc_lock);
617
618 return retval;
619 }
620
cmos_nvram_write(void * priv,unsigned int off,void * val,size_t count)621 static int cmos_nvram_write(void *priv, unsigned int off, void *val,
622 size_t count)
623 {
624 struct cmos_rtc *cmos = priv;
625 unsigned char *buf = val;
626 int retval;
627
628 /* NOTE: on at least PCs and Ataris, the boot firmware uses a
629 * checksum on part of the NVRAM data. That's currently ignored
630 * here. If userspace is smart enough to know what fields of
631 * NVRAM to update, updating checksums is also part of its job.
632 */
633 off += NVRAM_OFFSET;
634 spin_lock_irq(&rtc_lock);
635 for (retval = 0; count; count--, off++, retval++) {
636 /* don't trash RTC registers */
637 if (off == cmos->day_alrm
638 || off == cmos->mon_alrm
639 || off == cmos->century)
640 buf++;
641 else if (off < 128)
642 CMOS_WRITE(*buf++, off);
643 else if (can_bank2)
644 cmos_write_bank2(*buf++, off);
645 else
646 break;
647 }
648 spin_unlock_irq(&rtc_lock);
649
650 return retval;
651 }
652
653 /*----------------------------------------------------------------*/
654
655 static struct cmos_rtc cmos_rtc;
656
cmos_interrupt(int irq,void * p)657 static irqreturn_t cmos_interrupt(int irq, void *p)
658 {
659 u8 irqstat;
660 u8 rtc_control;
661
662 spin_lock(&rtc_lock);
663
664 /* When the HPET interrupt handler calls us, the interrupt
665 * status is passed as arg1 instead of the irq number. But
666 * always clear irq status, even when HPET is in the way.
667 *
668 * Note that HPET and RTC are almost certainly out of phase,
669 * giving different IRQ status ...
670 */
671 irqstat = CMOS_READ(RTC_INTR_FLAGS);
672 rtc_control = CMOS_READ(RTC_CONTROL);
673 if (use_hpet_alarm())
674 irqstat = (unsigned long)irq & 0xF0;
675
676 /* If we were suspended, RTC_CONTROL may not be accurate since the
677 * bios may have cleared it.
678 */
679 if (!cmos_rtc.suspend_ctrl)
680 irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
681 else
682 irqstat &= (cmos_rtc.suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
683
684 /* All Linux RTC alarms should be treated as if they were oneshot.
685 * Similar code may be needed in system wakeup paths, in case the
686 * alarm woke the system.
687 */
688 if (irqstat & RTC_AIE) {
689 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
690 rtc_control &= ~RTC_AIE;
691 CMOS_WRITE(rtc_control, RTC_CONTROL);
692 if (use_hpet_alarm())
693 hpet_mask_rtc_irq_bit(RTC_AIE);
694 CMOS_READ(RTC_INTR_FLAGS);
695 }
696 spin_unlock(&rtc_lock);
697
698 if (is_intr(irqstat)) {
699 rtc_update_irq(p, 1, irqstat);
700 return IRQ_HANDLED;
701 } else
702 return IRQ_NONE;
703 }
704
705 #ifdef CONFIG_PNP
706 #define INITSECTION
707
708 #else
709 #define INITSECTION __init
710 #endif
711
712 static int INITSECTION
cmos_do_probe(struct device * dev,struct resource * ports,int rtc_irq)713 cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
714 {
715 struct cmos_rtc_board_info *info = dev_get_platdata(dev);
716 int retval = 0;
717 unsigned char rtc_control;
718 unsigned address_space;
719 u32 flags = 0;
720 struct nvmem_config nvmem_cfg = {
721 .name = "cmos_nvram",
722 .word_size = 1,
723 .stride = 1,
724 .reg_read = cmos_nvram_read,
725 .reg_write = cmos_nvram_write,
726 .priv = &cmos_rtc,
727 };
728
729 /* there can be only one ... */
730 if (cmos_rtc.dev)
731 return -EBUSY;
732
733 if (!ports)
734 return -ENODEV;
735
736 /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
737 *
738 * REVISIT non-x86 systems may instead use memory space resources
739 * (needing ioremap etc), not i/o space resources like this ...
740 */
741 if (RTC_IOMAPPED)
742 ports = request_region(ports->start, resource_size(ports),
743 driver_name);
744 else
745 ports = request_mem_region(ports->start, resource_size(ports),
746 driver_name);
747 if (!ports) {
748 dev_dbg(dev, "i/o registers already in use\n");
749 return -EBUSY;
750 }
751
752 cmos_rtc.irq = rtc_irq;
753 cmos_rtc.iomem = ports;
754
755 /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
756 * driver did, but don't reject unknown configs. Old hardware
757 * won't address 128 bytes. Newer chips have multiple banks,
758 * though they may not be listed in one I/O resource.
759 */
760 #if defined(CONFIG_ATARI)
761 address_space = 64;
762 #elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
763 || defined(__sparc__) || defined(__mips__) \
764 || defined(__powerpc__)
765 address_space = 128;
766 #else
767 #warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
768 address_space = 128;
769 #endif
770 if (can_bank2 && ports->end > (ports->start + 1))
771 address_space = 256;
772
773 /* For ACPI systems extension info comes from the FADT. On others,
774 * board specific setup provides it as appropriate. Systems where
775 * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
776 * some almost-clones) can provide hooks to make that behave.
777 *
778 * Note that ACPI doesn't preclude putting these registers into
779 * "extended" areas of the chip, including some that we won't yet
780 * expect CMOS_READ and friends to handle.
781 */
782 if (info) {
783 if (info->flags)
784 flags = info->flags;
785 if (info->address_space)
786 address_space = info->address_space;
787
788 if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
789 cmos_rtc.day_alrm = info->rtc_day_alarm;
790 if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
791 cmos_rtc.mon_alrm = info->rtc_mon_alarm;
792 if (info->rtc_century && info->rtc_century < 128)
793 cmos_rtc.century = info->rtc_century;
794
795 if (info->wake_on && info->wake_off) {
796 cmos_rtc.wake_on = info->wake_on;
797 cmos_rtc.wake_off = info->wake_off;
798 }
799 }
800
801 cmos_rtc.dev = dev;
802 dev_set_drvdata(dev, &cmos_rtc);
803
804 cmos_rtc.rtc = devm_rtc_allocate_device(dev);
805 if (IS_ERR(cmos_rtc.rtc)) {
806 retval = PTR_ERR(cmos_rtc.rtc);
807 goto cleanup0;
808 }
809
810 rename_region(ports, dev_name(&cmos_rtc.rtc->dev));
811
812 spin_lock_irq(&rtc_lock);
813
814 if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) {
815 /* force periodic irq to CMOS reset default of 1024Hz;
816 *
817 * REVISIT it's been reported that at least one x86_64 ALI
818 * mobo doesn't use 32KHz here ... for portability we might
819 * need to do something about other clock frequencies.
820 */
821 cmos_rtc.rtc->irq_freq = 1024;
822 if (use_hpet_alarm())
823 hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);
824 CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
825 }
826
827 /* disable irqs */
828 if (is_valid_irq(rtc_irq))
829 cmos_irq_disable(&cmos_rtc, RTC_PIE | RTC_AIE | RTC_UIE);
830
831 rtc_control = CMOS_READ(RTC_CONTROL);
832
833 spin_unlock_irq(&rtc_lock);
834
835 if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
836 dev_warn(dev, "only 24-hr supported\n");
837 retval = -ENXIO;
838 goto cleanup1;
839 }
840
841 if (use_hpet_alarm())
842 hpet_rtc_timer_init();
843
844 if (is_valid_irq(rtc_irq)) {
845 irq_handler_t rtc_cmos_int_handler;
846
847 if (use_hpet_alarm()) {
848 rtc_cmos_int_handler = hpet_rtc_interrupt;
849 retval = hpet_register_irq_handler(cmos_interrupt);
850 if (retval) {
851 hpet_mask_rtc_irq_bit(RTC_IRQMASK);
852 dev_warn(dev, "hpet_register_irq_handler "
853 " failed in rtc_init().");
854 goto cleanup1;
855 }
856 } else
857 rtc_cmos_int_handler = cmos_interrupt;
858
859 retval = request_irq(rtc_irq, rtc_cmos_int_handler,
860 0, dev_name(&cmos_rtc.rtc->dev),
861 cmos_rtc.rtc);
862 if (retval < 0) {
863 dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
864 goto cleanup1;
865 }
866
867 cmos_rtc.rtc->ops = &cmos_rtc_ops;
868 } else {
869 cmos_rtc.rtc->ops = &cmos_rtc_ops_no_alarm;
870 }
871
872 cmos_rtc.rtc->nvram_old_abi = true;
873 retval = rtc_register_device(cmos_rtc.rtc);
874 if (retval)
875 goto cleanup2;
876
877 /* export at least the first block of NVRAM */
878 nvmem_cfg.size = address_space - NVRAM_OFFSET;
879 if (rtc_nvmem_register(cmos_rtc.rtc, &nvmem_cfg))
880 dev_err(dev, "nvmem registration failed\n");
881
882 dev_info(dev, "%s%s, %d bytes nvram%s\n",
883 !is_valid_irq(rtc_irq) ? "no alarms" :
884 cmos_rtc.mon_alrm ? "alarms up to one year" :
885 cmos_rtc.day_alrm ? "alarms up to one month" :
886 "alarms up to one day",
887 cmos_rtc.century ? ", y3k" : "",
888 nvmem_cfg.size,
889 use_hpet_alarm() ? ", hpet irqs" : "");
890
891 return 0;
892
893 cleanup2:
894 if (is_valid_irq(rtc_irq))
895 free_irq(rtc_irq, cmos_rtc.rtc);
896 cleanup1:
897 cmos_rtc.dev = NULL;
898 cleanup0:
899 if (RTC_IOMAPPED)
900 release_region(ports->start, resource_size(ports));
901 else
902 release_mem_region(ports->start, resource_size(ports));
903 return retval;
904 }
905
cmos_do_shutdown(int rtc_irq)906 static void cmos_do_shutdown(int rtc_irq)
907 {
908 spin_lock_irq(&rtc_lock);
909 if (is_valid_irq(rtc_irq))
910 cmos_irq_disable(&cmos_rtc, RTC_IRQMASK);
911 spin_unlock_irq(&rtc_lock);
912 }
913
cmos_do_remove(struct device * dev)914 static void cmos_do_remove(struct device *dev)
915 {
916 struct cmos_rtc *cmos = dev_get_drvdata(dev);
917 struct resource *ports;
918
919 cmos_do_shutdown(cmos->irq);
920
921 if (is_valid_irq(cmos->irq)) {
922 free_irq(cmos->irq, cmos->rtc);
923 if (use_hpet_alarm())
924 hpet_unregister_irq_handler(cmos_interrupt);
925 }
926
927 cmos->rtc = NULL;
928
929 ports = cmos->iomem;
930 if (RTC_IOMAPPED)
931 release_region(ports->start, resource_size(ports));
932 else
933 release_mem_region(ports->start, resource_size(ports));
934 cmos->iomem = NULL;
935
936 cmos->dev = NULL;
937 }
938
cmos_aie_poweroff(struct device * dev)939 static int cmos_aie_poweroff(struct device *dev)
940 {
941 struct cmos_rtc *cmos = dev_get_drvdata(dev);
942 struct rtc_time now;
943 time64_t t_now;
944 int retval = 0;
945 unsigned char rtc_control;
946
947 if (!cmos->alarm_expires)
948 return -EINVAL;
949
950 spin_lock_irq(&rtc_lock);
951 rtc_control = CMOS_READ(RTC_CONTROL);
952 spin_unlock_irq(&rtc_lock);
953
954 /* We only care about the situation where AIE is disabled. */
955 if (rtc_control & RTC_AIE)
956 return -EBUSY;
957
958 cmos_read_time(dev, &now);
959 t_now = rtc_tm_to_time64(&now);
960
961 /*
962 * When enabling "RTC wake-up" in BIOS setup, the machine reboots
963 * automatically right after shutdown on some buggy boxes.
964 * This automatic rebooting issue won't happen when the alarm
965 * time is larger than now+1 seconds.
966 *
967 * If the alarm time is equal to now+1 seconds, the issue can be
968 * prevented by cancelling the alarm.
969 */
970 if (cmos->alarm_expires == t_now + 1) {
971 struct rtc_wkalrm alarm;
972
973 /* Cancel the AIE timer by configuring the past time. */
974 rtc_time64_to_tm(t_now - 1, &alarm.time);
975 alarm.enabled = 0;
976 retval = cmos_set_alarm(dev, &alarm);
977 } else if (cmos->alarm_expires > t_now + 1) {
978 retval = -EBUSY;
979 }
980
981 return retval;
982 }
983
cmos_suspend(struct device * dev)984 static int cmos_suspend(struct device *dev)
985 {
986 struct cmos_rtc *cmos = dev_get_drvdata(dev);
987 unsigned char tmp;
988
989 /* only the alarm might be a wakeup event source */
990 spin_lock_irq(&rtc_lock);
991 cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
992 if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
993 unsigned char mask;
994
995 if (device_may_wakeup(dev))
996 mask = RTC_IRQMASK & ~RTC_AIE;
997 else
998 mask = RTC_IRQMASK;
999 tmp &= ~mask;
1000 CMOS_WRITE(tmp, RTC_CONTROL);
1001 if (use_hpet_alarm())
1002 hpet_mask_rtc_irq_bit(mask);
1003 cmos_checkintr(cmos, tmp);
1004 }
1005 spin_unlock_irq(&rtc_lock);
1006
1007 if ((tmp & RTC_AIE) && !cmos_use_acpi_alarm()) {
1008 cmos->enabled_wake = 1;
1009 if (cmos->wake_on)
1010 cmos->wake_on(dev);
1011 else
1012 enable_irq_wake(cmos->irq);
1013 }
1014
1015 cmos_read_alarm(dev, &cmos->saved_wkalrm);
1016
1017 dev_dbg(dev, "suspend%s, ctrl %02x\n",
1018 (tmp & RTC_AIE) ? ", alarm may wake" : "",
1019 tmp);
1020
1021 return 0;
1022 }
1023
1024 /* We want RTC alarms to wake us from e.g. ACPI G2/S5 "soft off", even
1025 * after a detour through G3 "mechanical off", although the ACPI spec
1026 * says wakeup should only work from G1/S4 "hibernate". To most users,
1027 * distinctions between S4 and S5 are pointless. So when the hardware
1028 * allows, don't draw that distinction.
1029 */
cmos_poweroff(struct device * dev)1030 static inline int cmos_poweroff(struct device *dev)
1031 {
1032 if (!IS_ENABLED(CONFIG_PM))
1033 return -ENOSYS;
1034
1035 return cmos_suspend(dev);
1036 }
1037
cmos_check_wkalrm(struct device * dev)1038 static void cmos_check_wkalrm(struct device *dev)
1039 {
1040 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1041 struct rtc_wkalrm current_alarm;
1042 time64_t t_now;
1043 time64_t t_current_expires;
1044 time64_t t_saved_expires;
1045 struct rtc_time now;
1046
1047 /* Check if we have RTC Alarm armed */
1048 if (!(cmos->suspend_ctrl & RTC_AIE))
1049 return;
1050
1051 cmos_read_time(dev, &now);
1052 t_now = rtc_tm_to_time64(&now);
1053
1054 /*
1055 * ACPI RTC wake event is cleared after resume from STR,
1056 * ACK the rtc irq here
1057 */
1058 if (t_now >= cmos->alarm_expires && cmos_use_acpi_alarm()) {
1059 cmos_interrupt(0, (void *)cmos->rtc);
1060 return;
1061 }
1062
1063 cmos_read_alarm(dev, ¤t_alarm);
1064 t_current_expires = rtc_tm_to_time64(¤t_alarm.time);
1065 t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);
1066 if (t_current_expires != t_saved_expires ||
1067 cmos->saved_wkalrm.enabled != current_alarm.enabled) {
1068 cmos_set_alarm(dev, &cmos->saved_wkalrm);
1069 }
1070 }
1071
1072 static void cmos_check_acpi_rtc_status(struct device *dev,
1073 unsigned char *rtc_control);
1074
cmos_resume(struct device * dev)1075 static int __maybe_unused cmos_resume(struct device *dev)
1076 {
1077 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1078 unsigned char tmp;
1079
1080 if (cmos->enabled_wake && !cmos_use_acpi_alarm()) {
1081 if (cmos->wake_off)
1082 cmos->wake_off(dev);
1083 else
1084 disable_irq_wake(cmos->irq);
1085 cmos->enabled_wake = 0;
1086 }
1087
1088 /* The BIOS might have changed the alarm, restore it */
1089 cmos_check_wkalrm(dev);
1090
1091 spin_lock_irq(&rtc_lock);
1092 tmp = cmos->suspend_ctrl;
1093 cmos->suspend_ctrl = 0;
1094 /* re-enable any irqs previously active */
1095 if (tmp & RTC_IRQMASK) {
1096 unsigned char mask;
1097
1098 if (device_may_wakeup(dev) && use_hpet_alarm())
1099 hpet_rtc_timer_init();
1100
1101 do {
1102 CMOS_WRITE(tmp, RTC_CONTROL);
1103 if (use_hpet_alarm())
1104 hpet_set_rtc_irq_bit(tmp & RTC_IRQMASK);
1105
1106 mask = CMOS_READ(RTC_INTR_FLAGS);
1107 mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
1108 if (!use_hpet_alarm() || !is_intr(mask))
1109 break;
1110
1111 /* force one-shot behavior if HPET blocked
1112 * the wake alarm's irq
1113 */
1114 rtc_update_irq(cmos->rtc, 1, mask);
1115 tmp &= ~RTC_AIE;
1116 hpet_mask_rtc_irq_bit(RTC_AIE);
1117 } while (mask & RTC_AIE);
1118
1119 if (tmp & RTC_AIE)
1120 cmos_check_acpi_rtc_status(dev, &tmp);
1121 }
1122 spin_unlock_irq(&rtc_lock);
1123
1124 dev_dbg(dev, "resume, ctrl %02x\n", tmp);
1125
1126 return 0;
1127 }
1128
1129 static SIMPLE_DEV_PM_OPS(cmos_pm_ops, cmos_suspend, cmos_resume);
1130
1131 /*----------------------------------------------------------------*/
1132
1133 /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
1134 * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
1135 * probably list them in similar PNPBIOS tables; so PNP is more common.
1136 *
1137 * We don't use legacy "poke at the hardware" probing. Ancient PCs that
1138 * predate even PNPBIOS should set up platform_bus devices.
1139 */
1140
1141 #ifdef CONFIG_ACPI
1142
1143 #include <linux/acpi.h>
1144
rtc_handler(void * context)1145 static u32 rtc_handler(void *context)
1146 {
1147 struct device *dev = context;
1148 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1149 unsigned char rtc_control = 0;
1150 unsigned char rtc_intr;
1151 unsigned long flags;
1152
1153
1154 /*
1155 * Always update rtc irq when ACPI is used as RTC Alarm.
1156 * Or else, ACPI SCI is enabled during suspend/resume only,
1157 * update rtc irq in that case.
1158 */
1159 if (cmos_use_acpi_alarm())
1160 cmos_interrupt(0, (void *)cmos->rtc);
1161 else {
1162 /* Fix me: can we use cmos_interrupt() here as well? */
1163 spin_lock_irqsave(&rtc_lock, flags);
1164 if (cmos_rtc.suspend_ctrl)
1165 rtc_control = CMOS_READ(RTC_CONTROL);
1166 if (rtc_control & RTC_AIE) {
1167 cmos_rtc.suspend_ctrl &= ~RTC_AIE;
1168 CMOS_WRITE(rtc_control, RTC_CONTROL);
1169 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
1170 rtc_update_irq(cmos->rtc, 1, rtc_intr);
1171 }
1172 spin_unlock_irqrestore(&rtc_lock, flags);
1173 }
1174
1175 pm_wakeup_hard_event(dev);
1176 acpi_clear_event(ACPI_EVENT_RTC);
1177 acpi_disable_event(ACPI_EVENT_RTC, 0);
1178 return ACPI_INTERRUPT_HANDLED;
1179 }
1180
rtc_wake_setup(struct device * dev)1181 static inline void rtc_wake_setup(struct device *dev)
1182 {
1183 acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, dev);
1184 /*
1185 * After the RTC handler is installed, the Fixed_RTC event should
1186 * be disabled. Only when the RTC alarm is set will it be enabled.
1187 */
1188 acpi_clear_event(ACPI_EVENT_RTC);
1189 acpi_disable_event(ACPI_EVENT_RTC, 0);
1190 }
1191
rtc_wake_on(struct device * dev)1192 static void rtc_wake_on(struct device *dev)
1193 {
1194 acpi_clear_event(ACPI_EVENT_RTC);
1195 acpi_enable_event(ACPI_EVENT_RTC, 0);
1196 }
1197
rtc_wake_off(struct device * dev)1198 static void rtc_wake_off(struct device *dev)
1199 {
1200 acpi_disable_event(ACPI_EVENT_RTC, 0);
1201 }
1202
1203 #ifdef CONFIG_X86
1204 /* Enable use_acpi_alarm mode for Intel platforms no earlier than 2015 */
use_acpi_alarm_quirks(void)1205 static void use_acpi_alarm_quirks(void)
1206 {
1207 int year;
1208
1209 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
1210 return;
1211
1212 if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
1213 return;
1214
1215 if (!is_hpet_enabled())
1216 return;
1217
1218 if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year >= 2015)
1219 use_acpi_alarm = true;
1220 }
1221 #else
use_acpi_alarm_quirks(void)1222 static inline void use_acpi_alarm_quirks(void) { }
1223 #endif
1224
1225 /* Every ACPI platform has a mc146818 compatible "cmos rtc". Here we find
1226 * its device node and pass extra config data. This helps its driver use
1227 * capabilities that the now-obsolete mc146818 didn't have, and informs it
1228 * that this board's RTC is wakeup-capable (per ACPI spec).
1229 */
1230 static struct cmos_rtc_board_info acpi_rtc_info;
1231
cmos_wake_setup(struct device * dev)1232 static void cmos_wake_setup(struct device *dev)
1233 {
1234 if (acpi_disabled)
1235 return;
1236
1237 use_acpi_alarm_quirks();
1238
1239 rtc_wake_setup(dev);
1240 acpi_rtc_info.wake_on = rtc_wake_on;
1241 acpi_rtc_info.wake_off = rtc_wake_off;
1242
1243 /* workaround bug in some ACPI tables */
1244 if (acpi_gbl_FADT.month_alarm && !acpi_gbl_FADT.day_alarm) {
1245 dev_dbg(dev, "bogus FADT month_alarm (%d)\n",
1246 acpi_gbl_FADT.month_alarm);
1247 acpi_gbl_FADT.month_alarm = 0;
1248 }
1249
1250 acpi_rtc_info.rtc_day_alarm = acpi_gbl_FADT.day_alarm;
1251 acpi_rtc_info.rtc_mon_alarm = acpi_gbl_FADT.month_alarm;
1252 acpi_rtc_info.rtc_century = acpi_gbl_FADT.century;
1253
1254 /* NOTE: S4_RTC_WAKE is NOT currently useful to Linux */
1255 if (acpi_gbl_FADT.flags & ACPI_FADT_S4_RTC_WAKE)
1256 dev_info(dev, "RTC can wake from S4\n");
1257
1258 dev->platform_data = &acpi_rtc_info;
1259
1260 /* RTC always wakes from S1/S2/S3, and often S4/STD */
1261 device_init_wakeup(dev, 1);
1262 }
1263
cmos_check_acpi_rtc_status(struct device * dev,unsigned char * rtc_control)1264 static void cmos_check_acpi_rtc_status(struct device *dev,
1265 unsigned char *rtc_control)
1266 {
1267 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1268 acpi_event_status rtc_status;
1269 acpi_status status;
1270
1271 if (acpi_gbl_FADT.flags & ACPI_FADT_FIXED_RTC)
1272 return;
1273
1274 status = acpi_get_event_status(ACPI_EVENT_RTC, &rtc_status);
1275 if (ACPI_FAILURE(status)) {
1276 dev_err(dev, "Could not get RTC status\n");
1277 } else if (rtc_status & ACPI_EVENT_FLAG_SET) {
1278 unsigned char mask;
1279 *rtc_control &= ~RTC_AIE;
1280 CMOS_WRITE(*rtc_control, RTC_CONTROL);
1281 mask = CMOS_READ(RTC_INTR_FLAGS);
1282 rtc_update_irq(cmos->rtc, 1, mask);
1283 }
1284 }
1285
1286 #else
1287
cmos_wake_setup(struct device * dev)1288 static void cmos_wake_setup(struct device *dev)
1289 {
1290 }
1291
cmos_check_acpi_rtc_status(struct device * dev,unsigned char * rtc_control)1292 static void cmos_check_acpi_rtc_status(struct device *dev,
1293 unsigned char *rtc_control)
1294 {
1295 }
1296
1297 #endif
1298
1299 #ifdef CONFIG_PNP
1300
1301 #include <linux/pnp.h>
1302
cmos_pnp_probe(struct pnp_dev * pnp,const struct pnp_device_id * id)1303 static int cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
1304 {
1305 cmos_wake_setup(&pnp->dev);
1306
1307 if (pnp_port_start(pnp, 0) == 0x70 && !pnp_irq_valid(pnp, 0)) {
1308 unsigned int irq = 0;
1309 #ifdef CONFIG_X86
1310 /* Some machines contain a PNP entry for the RTC, but
1311 * don't define the IRQ. It should always be safe to
1312 * hardcode it on systems with a legacy PIC.
1313 */
1314 if (nr_legacy_irqs())
1315 irq = 8;
1316 #endif
1317 return cmos_do_probe(&pnp->dev,
1318 pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);
1319 } else {
1320 return cmos_do_probe(&pnp->dev,
1321 pnp_get_resource(pnp, IORESOURCE_IO, 0),
1322 pnp_irq(pnp, 0));
1323 }
1324 }
1325
cmos_pnp_remove(struct pnp_dev * pnp)1326 static void cmos_pnp_remove(struct pnp_dev *pnp)
1327 {
1328 cmos_do_remove(&pnp->dev);
1329 }
1330
cmos_pnp_shutdown(struct pnp_dev * pnp)1331 static void cmos_pnp_shutdown(struct pnp_dev *pnp)
1332 {
1333 struct device *dev = &pnp->dev;
1334 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1335
1336 if (system_state == SYSTEM_POWER_OFF) {
1337 int retval = cmos_poweroff(dev);
1338
1339 if (cmos_aie_poweroff(dev) < 0 && !retval)
1340 return;
1341 }
1342
1343 cmos_do_shutdown(cmos->irq);
1344 }
1345
1346 static const struct pnp_device_id rtc_ids[] = {
1347 { .id = "PNP0b00", },
1348 { .id = "PNP0b01", },
1349 { .id = "PNP0b02", },
1350 { },
1351 };
1352 MODULE_DEVICE_TABLE(pnp, rtc_ids);
1353
1354 static struct pnp_driver cmos_pnp_driver = {
1355 .name = (char *) driver_name,
1356 .id_table = rtc_ids,
1357 .probe = cmos_pnp_probe,
1358 .remove = cmos_pnp_remove,
1359 .shutdown = cmos_pnp_shutdown,
1360
1361 /* flag ensures resume() gets called, and stops syslog spam */
1362 .flags = PNP_DRIVER_RES_DO_NOT_CHANGE,
1363 .driver = {
1364 .pm = &cmos_pm_ops,
1365 },
1366 };
1367
1368 #endif /* CONFIG_PNP */
1369
1370 #ifdef CONFIG_OF
1371 static const struct of_device_id of_cmos_match[] = {
1372 {
1373 .compatible = "motorola,mc146818",
1374 },
1375 { },
1376 };
1377 MODULE_DEVICE_TABLE(of, of_cmos_match);
1378
cmos_of_init(struct platform_device * pdev)1379 static __init void cmos_of_init(struct platform_device *pdev)
1380 {
1381 struct device_node *node = pdev->dev.of_node;
1382 const __be32 *val;
1383
1384 if (!node)
1385 return;
1386
1387 val = of_get_property(node, "ctrl-reg", NULL);
1388 if (val)
1389 CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
1390
1391 val = of_get_property(node, "freq-reg", NULL);
1392 if (val)
1393 CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
1394 }
1395 #else
cmos_of_init(struct platform_device * pdev)1396 static inline void cmos_of_init(struct platform_device *pdev) {}
1397 #endif
1398 /*----------------------------------------------------------------*/
1399
1400 /* Platform setup should have set up an RTC device, when PNP is
1401 * unavailable ... this could happen even on (older) PCs.
1402 */
1403
cmos_platform_probe(struct platform_device * pdev)1404 static int __init cmos_platform_probe(struct platform_device *pdev)
1405 {
1406 struct resource *resource;
1407 int irq;
1408
1409 cmos_of_init(pdev);
1410 cmos_wake_setup(&pdev->dev);
1411
1412 if (RTC_IOMAPPED)
1413 resource = platform_get_resource(pdev, IORESOURCE_IO, 0);
1414 else
1415 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1416 irq = platform_get_irq(pdev, 0);
1417 if (irq < 0)
1418 irq = -1;
1419
1420 return cmos_do_probe(&pdev->dev, resource, irq);
1421 }
1422
cmos_platform_remove(struct platform_device * pdev)1423 static int cmos_platform_remove(struct platform_device *pdev)
1424 {
1425 cmos_do_remove(&pdev->dev);
1426 return 0;
1427 }
1428
cmos_platform_shutdown(struct platform_device * pdev)1429 static void cmos_platform_shutdown(struct platform_device *pdev)
1430 {
1431 struct device *dev = &pdev->dev;
1432 struct cmos_rtc *cmos = dev_get_drvdata(dev);
1433
1434 if (system_state == SYSTEM_POWER_OFF) {
1435 int retval = cmos_poweroff(dev);
1436
1437 if (cmos_aie_poweroff(dev) < 0 && !retval)
1438 return;
1439 }
1440
1441 cmos_do_shutdown(cmos->irq);
1442 }
1443
1444 /* work with hotplug and coldplug */
1445 MODULE_ALIAS("platform:rtc_cmos");
1446
1447 static struct platform_driver cmos_platform_driver = {
1448 .remove = cmos_platform_remove,
1449 .shutdown = cmos_platform_shutdown,
1450 .driver = {
1451 .name = driver_name,
1452 .pm = &cmos_pm_ops,
1453 .of_match_table = of_match_ptr(of_cmos_match),
1454 }
1455 };
1456
1457 #ifdef CONFIG_PNP
1458 static bool pnp_driver_registered;
1459 #endif
1460 static bool platform_driver_registered;
1461
cmos_init(void)1462 static int __init cmos_init(void)
1463 {
1464 int retval = 0;
1465
1466 #ifdef CONFIG_PNP
1467 retval = pnp_register_driver(&cmos_pnp_driver);
1468 if (retval == 0)
1469 pnp_driver_registered = true;
1470 #endif
1471
1472 if (!cmos_rtc.dev) {
1473 retval = platform_driver_probe(&cmos_platform_driver,
1474 cmos_platform_probe);
1475 if (retval == 0)
1476 platform_driver_registered = true;
1477 }
1478
1479 if (retval == 0)
1480 return 0;
1481
1482 #ifdef CONFIG_PNP
1483 if (pnp_driver_registered)
1484 pnp_unregister_driver(&cmos_pnp_driver);
1485 #endif
1486 return retval;
1487 }
1488 module_init(cmos_init);
1489
cmos_exit(void)1490 static void __exit cmos_exit(void)
1491 {
1492 #ifdef CONFIG_PNP
1493 if (pnp_driver_registered)
1494 pnp_unregister_driver(&cmos_pnp_driver);
1495 #endif
1496 if (platform_driver_registered)
1497 platform_driver_unregister(&cmos_platform_driver);
1498 }
1499 module_exit(cmos_exit);
1500
1501
1502 MODULE_AUTHOR("David Brownell");
1503 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
1504 MODULE_LICENSE("GPL");
1505