1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * RTC class driver for "CMOS RTC":  PCs, ACPI, etc
10  * The original "cmos clock" chip was an MC146818 chip, now obsolete.
12  * non-PC systems, and incorporated into ACPI.  Modern PC chipsets
46 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
112 /*----------------------------------------------------------------*/
184 /*----------------------------------------------------------------*/
221 /*----------------------------------------------------------------*/
232 		return -EIO;  in cmos_read_time()
253 	struct cmos_rtc *cmos;  member
263 	struct rtc_time *time = p->time;  in cmos_read_alarm_callback()
265 	time->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);  in cmos_read_alarm_callback()
266 	time->tm_min = CMOS_READ(RTC_MINUTES_ALARM);  in cmos_read_alarm_callback()
267 	time->tm_hour = CMOS_READ(RTC_HOURS_ALARM);  in cmos_read_alarm_callback()
269 	if (p->cmos->day_alrm) {  in cmos_read_alarm_callback()
271 		time->tm_mday = CMOS_READ(p->cmos->day_alrm) & 0x3f;  in cmos_read_alarm_callback()
272 		if (!time->tm_mday)  in cmos_read_alarm_callback()
273 			time->tm_mday = -1;  in cmos_read_alarm_callback()
275 		if (p->cmos->mon_alrm) {  in cmos_read_alarm_callback()
276 			time->tm_mon = CMOS_READ(p->cmos->mon_alrm);  in cmos_read_alarm_callback()
277 			if (!time->tm_mon)  in cmos_read_alarm_callback()
278 				time->tm_mon = -1;  in cmos_read_alarm_callback()
282 	p->rtc_control = CMOS_READ(RTC_CONTROL);  in cmos_read_alarm_callback()
287 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_read_alarm()  local
289 		.cmos = cmos,  in cmos_read_alarm()
290 		.time = &t->time,  in cmos_read_alarm()
294 	if (!is_valid_irq(cmos->irq))  in cmos_read_alarm()
295 		return -ETIMEDOUT;  in cmos_read_alarm()
303 	 * update is in progress - during this time reads return bogus values  in cmos_read_alarm()
311 		return -EIO;  in cmos_read_alarm()
314 		if (((unsigned)t->time.tm_sec) < 0x60)  in cmos_read_alarm()
315 			t->time.tm_sec = bcd2bin(t->time.tm_sec);  in cmos_read_alarm()
317 			t->time.tm_sec = -1;  in cmos_read_alarm()
318 		if (((unsigned)t->time.tm_min) < 0x60)  in cmos_read_alarm()
319 			t->time.tm_min = bcd2bin(t->time.tm_min);  in cmos_read_alarm()
321 			t->time.tm_min = -1;  in cmos_read_alarm()
322 		if (((unsigned)t->time.tm_hour) < 0x24)  in cmos_read_alarm()
323 			t->time.tm_hour = bcd2bin(t->time.tm_hour);  in cmos_read_alarm()
325 			t->time.tm_hour = -1;  in cmos_read_alarm()
327 		if (cmos->day_alrm) {  in cmos_read_alarm()
328 			if (((unsigned)t->time.tm_mday) <= 0x31)  in cmos_read_alarm()
329 				t->time.tm_mday = bcd2bin(t->time.tm_mday);  in cmos_read_alarm()
331 				t->time.tm_mday = -1;  in cmos_read_alarm()
333 			if (cmos->mon_alrm) {  in cmos_read_alarm()
334 				if (((unsigned)t->time.tm_mon) <= 0x12)  in cmos_read_alarm()
335 					t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;  in cmos_read_alarm()
337 					t->time.tm_mon = -1;  in cmos_read_alarm()
342 	t->enabled = !!(p.rtc_control & RTC_AIE);  in cmos_read_alarm()
343 	t->pending = 0;  in cmos_read_alarm()
348 static void cmos_checkintr(struct cmos_rtc *cmos, unsigned char rtc_control)  in cmos_checkintr()  argument
362 		rtc_update_irq(cmos->rtc, 1, rtc_intr);  in cmos_checkintr()
365 static void cmos_irq_enable(struct cmos_rtc *cmos, unsigned char mask)  in cmos_irq_enable()  argument
373 	cmos_checkintr(cmos, rtc_control);  in cmos_irq_enable()
381 		if (cmos->wake_on)  in cmos_irq_enable()
382 			cmos->wake_on(cmos->dev);  in cmos_irq_enable()
385 	cmos_checkintr(cmos, rtc_control);  in cmos_irq_enable()
388 static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)  in cmos_irq_disable()  argument
399 		if (cmos->wake_off)  in cmos_irq_disable()
400 			cmos->wake_off(cmos->dev);  in cmos_irq_disable()
403 	cmos_checkintr(cmos, rtc_control);  in cmos_irq_disable()
408 	struct cmos_rtc *cmos = dev_get_drvdata(dev);  in cmos_validate_alarm()  local
413 	if (!cmos->day_alrm) {  in cmos_validate_alarm()
418 		t_max_date += 24 * 60 * 60 - 1;  in cmos_validate_alarm()
419 		t_alrm = rtc_tm_to_time64(&t->time);  in cmos_validate_alarm()
423 			return -EINVAL;  in cmos_validate_alarm()
425 	} else if (!cmos->mon_alrm) {  in cmos_validate_alarm()
442 		t_max_date -= 1;  in cmos_validate_alarm()
443 		t_alrm = rtc_tm_to_time64(&t->time);  in cmos_validate_alarm()
447 			return -EINVAL;  in cmos_validate_alarm()
461 		t_max_date -= 1;  in cmos_validate_alarm()
462 		t_alrm = rtc_tm_to_time64(&t->time);  in cmos_validate_alarm()
466 			return -EINVAL;  in cmos_validate_alarm()
474 	struct cmos_rtc *cmos;  member
489 	cmos_irq_disable(p->cmos, RTC_AIE);  in cmos_set_alarm_callback()
492 	CMOS_WRITE(p->hrs, RTC_HOURS_ALARM);  in cmos_set_alarm_callback()
493 	CMOS_WRITE(p->min, RTC_MINUTES_ALARM);  in cmos_set_alarm_callback()
494 	CMOS_WRITE(p->sec, RTC_SECONDS_ALARM);  in cmos_set_alarm_callback()
497 	if (p->cmos->day_alrm) {  in cmos_set_alarm_callback()
498 		CMOS_WRITE(p->mday, p->cmos->day_alrm);  in cmos_set_alarm_callback()
499 		if (p->cmos->mon_alrm)  in cmos_set_alarm_callback()
500 			CMOS_WRITE(p->mon, p->cmos->mon_alrm);  in cmos_set_alarm_callback()
508 		hpet_set_alarm_time(p->t->time.tm_hour, p->t->time.tm_min,  in cmos_set_alarm_callback()
509 				    p->t->time.tm_sec);  in cmos_set_alarm_callback()
512 	if (p->t->enabled)  in cmos_set_alarm_callback()
513 		cmos_irq_enable(p->cmos, RTC_AIE);  in cmos_set_alarm_callback()
518 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_set_alarm()  local
520 		.cmos = cmos,  in cmos_set_alarm()
527 	if (!is_valid_irq(cmos->irq))  in cmos_set_alarm()
528 		return -EIO;  in cmos_set_alarm()
534 	p.mon = t->time.tm_mon + 1;  in cmos_set_alarm()
535 	p.mday = t->time.tm_mday;  in cmos_set_alarm()
536 	p.hrs = t->time.tm_hour;  in cmos_set_alarm()
537 	p.min = t->time.tm_min;  in cmos_set_alarm()
538 	p.sec = t->time.tm_sec;  in cmos_set_alarm()
555 	 * update is in progress - during this time writes fail silently.  in cmos_set_alarm()
560 		return -ETIMEDOUT;  in cmos_set_alarm()
562 	cmos->alarm_expires = rtc_tm_to_time64(&t->time);  in cmos_set_alarm()
569 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_alarm_irq_enable()  local
575 		cmos_irq_enable(cmos, RTC_AIE);  in cmos_alarm_irq_enable()
577 		cmos_irq_disable(cmos, RTC_AIE);  in cmos_alarm_irq_enable()
587 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_procfs()  local
596 	 * (non-RTC) bit; and SQWE is ignored on many current systems.  in cmos_procfs()
613 		   cmos->rtc->irq_freq,  in cmos_procfs()
632 /*----------------------------------------------------------------*/
649 	for (; count; count--, off++) {  in cmos_nvram_read()
659 	return count ? -EIO : 0;  in cmos_nvram_read()
665 	struct cmos_rtc	*cmos = priv;  in cmos_nvram_write()  local
675 	for (; count; count--, off++) {  in cmos_nvram_write()
677 		if (off == cmos->day_alrm  in cmos_nvram_write()
678 				|| off == cmos->mon_alrm  in cmos_nvram_write()
679 				|| off == cmos->century)  in cmos_nvram_write()
690 	return count ? -EIO : 0;  in cmos_nvram_write()
693 /*----------------------------------------------------------------*/
752 	struct cmos_rtc *cmos = dev_get_drvdata(dev);  in rtc_handler()  local
764 		cmos_interrupt(0, (void *)cmos->rtc);  in rtc_handler()
774 			rtc_update_irq(cmos->rtc, 1, rtc_intr);  in rtc_handler()
874 	struct cmos_rtc *cmos = dev_get_drvdata(dev);  in cmos_check_acpi_rtc_status()  local
889 		rtc_update_irq(cmos->rtc, 1, mask);  in cmos_check_acpi_rtc_status()
943 		return -EBUSY;  in cmos_do_probe()
946 		return -ENODEV;  in cmos_do_probe()
950 	 * REVISIT non-x86 systems may instead use memory space resources  in cmos_do_probe()
954 		ports = request_region(ports->start, resource_size(ports),  in cmos_do_probe()
957 		ports = request_mem_region(ports->start, resource_size(ports),  in cmos_do_probe()
961 		return -EBUSY;  in cmos_do_probe()
982 	if (can_bank2 && ports->end > (ports->start + 1))  in cmos_do_probe()
988 	 * some almost-clones) can provide hooks to make that behave.  in cmos_do_probe()
995 		if (info->flags)  in cmos_do_probe()
996 			flags = info->flags;  in cmos_do_probe()
997 		if (info->address_space)  in cmos_do_probe()
998 			address_space = info->address_space;  in cmos_do_probe()
1000 		cmos_rtc.day_alrm = info->rtc_day_alarm;  in cmos_do_probe()
1001 		cmos_rtc.mon_alrm = info->rtc_mon_alarm;  in cmos_do_probe()
1002 		cmos_rtc.century = info->rtc_century;  in cmos_do_probe()
1004 		if (info->wake_on && info->wake_off) {  in cmos_do_probe()
1005 			cmos_rtc.wake_on = info->wake_on;  in cmos_do_probe()
1006 			cmos_rtc.wake_off = info->wake_off;  in cmos_do_probe()
1031 		cmos_rtc.rtc->alarm_offset_max = SECS_PER_YEAR - 1;  in cmos_do_probe()
1033 		cmos_rtc.rtc->alarm_offset_max = SECS_PER_MONTH - 1;  in cmos_do_probe()
1035 		cmos_rtc.rtc->alarm_offset_max = SECS_PER_DAY - 1;  in cmos_do_probe()
1037 	rename_region(ports, dev_name(&cmos_rtc.rtc->dev));  in cmos_do_probe()
1041 		retval = -ENXIO;  in cmos_do_probe()
1048 		/* force periodic irq to CMOS reset default of 1024Hz;  in cmos_do_probe()
1054 		cmos_rtc.rtc->irq_freq = 1024;  in cmos_do_probe()
1056 			hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq);  in cmos_do_probe()
1069 		dev_warn(dev, "only 24-hr supported\n");  in cmos_do_probe()
1070 		retval = -ENXIO;  in cmos_do_probe()
1093 				0, dev_name(&cmos_rtc.rtc->dev),  in cmos_do_probe()
1100 		clear_bit(RTC_FEATURE_ALARM, cmos_rtc.rtc->features);  in cmos_do_probe()
1103 	cmos_rtc.rtc->ops = &cmos_rtc_ops;  in cmos_do_probe()
1110 	cmos_rtc.rtc->set_offset_nsec = NSEC_PER_SEC / 2;  in cmos_do_probe()
1113 	nvmem_cfg.size = address_space - NVRAM_OFFSET;  in cmos_do_probe()
1141 		release_region(ports->start, resource_size(ports));  in cmos_do_probe()
1143 		release_mem_region(ports->start, resource_size(ports));  in cmos_do_probe()
1157 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_do_remove()  local
1160 	cmos_do_shutdown(cmos->irq);  in cmos_do_remove()
1162 	if (is_valid_irq(cmos->irq)) {  in cmos_do_remove()
1163 		free_irq(cmos->irq, cmos->rtc);  in cmos_do_remove()
1171 	cmos->rtc = NULL;  in cmos_do_remove()
1173 	ports = cmos->iomem;  in cmos_do_remove()
1175 		release_region(ports->start, resource_size(ports));  in cmos_do_remove()
1177 		release_mem_region(ports->start, resource_size(ports));  in cmos_do_remove()
1178 	cmos->iomem = NULL;  in cmos_do_remove()
1180 	cmos->dev = NULL;  in cmos_do_remove()
1185 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_aie_poweroff()  local
1191 	if (!cmos->alarm_expires)  in cmos_aie_poweroff()
1192 		return -EINVAL;  in cmos_aie_poweroff()
1200 		return -EBUSY;  in cmos_aie_poweroff()
1206 	 * When enabling "RTC wake-up" in BIOS setup, the machine reboots  in cmos_aie_poweroff()
1214 	if (cmos->alarm_expires == t_now + 1) {  in cmos_aie_poweroff()
1218 		rtc_time64_to_tm(t_now - 1, &alarm.time);  in cmos_aie_poweroff()
1221 	} else if (cmos->alarm_expires > t_now + 1) {  in cmos_aie_poweroff()
1222 		retval = -EBUSY;  in cmos_aie_poweroff()
1230 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_suspend()  local
1235 	cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);  in cmos_suspend()
1247 		cmos_checkintr(cmos, tmp);  in cmos_suspend()
1252 		cmos->enabled_wake = 1;  in cmos_suspend()
1253 		if (cmos->wake_on)  in cmos_suspend()
1254 			cmos->wake_on(dev);  in cmos_suspend()
1256 			enable_irq_wake(cmos->irq);  in cmos_suspend()
1259 	memset(&cmos->saved_wkalrm, 0, sizeof(struct rtc_wkalrm));  in cmos_suspend()
1260 	cmos_read_alarm(dev, &cmos->saved_wkalrm);  in cmos_suspend()
1278 		return -ENOSYS;  in cmos_poweroff()
1285 	struct cmos_rtc *cmos = dev_get_drvdata(dev);  in cmos_check_wkalrm()  local
1293 	if (!(cmos->suspend_ctrl & RTC_AIE))  in cmos_check_wkalrm()
1303 	if (t_now >= cmos->alarm_expires && cmos_use_acpi_alarm()) {  in cmos_check_wkalrm()
1305 		cmos_interrupt(0, (void *)cmos->rtc);  in cmos_check_wkalrm()
1313 	t_saved_expires = rtc_tm_to_time64(&cmos->saved_wkalrm.time);  in cmos_check_wkalrm()
1315 	    cmos->saved_wkalrm.enabled != current_alarm.enabled) {  in cmos_check_wkalrm()
1316 		cmos_set_alarm(dev, &cmos->saved_wkalrm);  in cmos_check_wkalrm()
1322 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_resume()  local
1325 	if (cmos->enabled_wake && !cmos_use_acpi_alarm()) {  in cmos_resume()
1326 		if (cmos->wake_off)  in cmos_resume()
1327 			cmos->wake_off(dev);  in cmos_resume()
1329 			disable_irq_wake(cmos->irq);  in cmos_resume()
1330 		cmos->enabled_wake = 0;  in cmos_resume()
1337 	tmp = cmos->suspend_ctrl;  in cmos_resume()
1338 	cmos->suspend_ctrl = 0;  in cmos_resume()
1339 	/* re-enable any irqs previously active */  in cmos_resume()
1356 			/* force one-shot behavior if HPET blocked  in cmos_resume()
1359 			rtc_update_irq(cmos->rtc, 1, mask);  in cmos_resume()
1376 /*----------------------------------------------------------------*/
1378 /* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
1379  * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
1408 	return cmos_do_probe(&pnp->dev, pnp_get_resource(pnp, IORESOURCE_IO, 0), irq);  in cmos_pnp_probe()
1413 	cmos_do_remove(&pnp->dev);  in cmos_pnp_remove()
1418 	struct device *dev = &pnp->dev;  in cmos_pnp_shutdown()
1419 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_pnp_shutdown()  local
1428 	cmos_do_shutdown(cmos->irq);  in cmos_pnp_shutdown()
1458 		.compatible = "motorola,mc146818",
1466 	struct device_node *node = pdev->dev.of_node;  in cmos_of_init()
1472 	val = of_get_property(node, "ctrl-reg", NULL);  in cmos_of_init()
1476 	val = of_get_property(node, "freq-reg", NULL);  in cmos_of_init()
1483 /*----------------------------------------------------------------*/
1502 		irq = -1;  in cmos_platform_probe()
1504 	return cmos_do_probe(&pdev->dev, resource, irq);  in cmos_platform_probe()
1509 	cmos_do_remove(&pdev->dev);  in cmos_platform_remove()
1514 	struct device *dev = &pdev->dev;  in cmos_platform_shutdown()
1515 	struct cmos_rtc	*cmos = dev_get_drvdata(dev);  in cmos_platform_shutdown()  local
1524 	cmos_do_shutdown(cmos->irq);  in cmos_platform_shutdown()
1586 MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");