1 // SPDX-License-Identifier: GPL-2.0-only
3  * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
9  * Copyright (C) 2006-2007 Freescale Semiconductor
14  * recommended in .../Documentation/i2c/writing-clients.rst section
15  * "Sending and receiving", using SMBus level communication is preferred.
93 		return -EINVAL;  in ds1374_read_rtc()
100 		return -EIO;  in ds1374_read_rtc()
102 	for (i = nbytes - 1, *time = 0; i >= 0; i--)  in ds1374_read_rtc()
116 		return -EINVAL;  in ds1374_write_rtc()
137 		dev_warn(&client->dev,  in ds1374_check_rtc_status()
193 	if (client->irq <= 0)  in ds1374_read_alarm()
194 		return -EINVAL;  in ds1374_read_alarm()
196 	mutex_lock(&ds1374->mutex);  in ds1374_read_alarm()
214 	rtc_time64_to_tm(now + cur_alarm, &alarm->time);  in ds1374_read_alarm()
215 	alarm->enabled = !!(cr & DS1374_REG_CR_WACE);  in ds1374_read_alarm()
216 	alarm->pending = !!(sr & DS1374_REG_SR_AF);  in ds1374_read_alarm()
219 	mutex_unlock(&ds1374->mutex);  in ds1374_read_alarm()
232 	if (client->irq <= 0)  in ds1374_set_alarm()
233 		return -EINVAL;  in ds1374_set_alarm()
239 	new_alarm = rtc_tm_to_time64(&alarm->time);  in ds1374_set_alarm()
251 		new_alarm -= itime;  in ds1374_set_alarm()
253 	mutex_lock(&ds1374->mutex);  in ds1374_set_alarm()
259 	/* Disable any existing alarm before setting the new one  in ds1374_set_alarm()
271 	if (alarm->enabled) {  in ds1374_set_alarm()
279 	mutex_unlock(&ds1374->mutex);  in ds1374_set_alarm()
290 	schedule_work(&ds1374->work);  in ds1374_irq()
297 	struct i2c_client *client = ds1374->client;  in ds1374_work()
300 	mutex_lock(&ds1374->mutex);  in ds1374_work()
317 		rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);  in ds1374_work()
321 	if (!ds1374->exiting)  in ds1374_work()
322 		enable_irq(client->irq);  in ds1374_work()
324 	mutex_unlock(&ds1374->mutex);  in ds1374_work()
334 	mutex_lock(&ds1374->mutex);  in ds1374_alarm_irq_enable()
349 	mutex_unlock(&ds1374->mutex);  in ds1374_alarm_irq_enable()
375 #define TIMER_MARGIN_MAX	4095 /* 24-bit value */
379 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
392 static int ds1374_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)  in ds1374_wdt_settimeout()  argument
395 	struct i2c_client *client = ds1374->client;  in ds1374_wdt_settimeout()
398 	wdt->timeout = timeout;  in ds1374_wdt_settimeout()
404 	/* Disable any existing watchdog/alarm before setting the new one */  in ds1374_wdt_settimeout()
412 	timeout = timeout * 4096;  in ds1374_wdt_settimeout()
413 	ret = ds1374_write_rtc(client, timeout, DS1374_REG_WDALM0, 3);  in ds1374_wdt_settimeout()
437 	return ds1374_read_rtc(ds1374->client, &val, DS1374_REG_WDALM0, 3);  in ds1374_wdt_start()
443 	struct i2c_client *client = ds1374->client;  in ds1374_wdt_stop()
450 	/* Disable watchdog timer */  in ds1374_wdt_stop()
475 	ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);  in ds1374_probe()
477 		return -ENOMEM;  in ds1374_probe()
479 	ds1374->rtc = devm_rtc_allocate_device(&client->dev);  in ds1374_probe()
480 	if (IS_ERR(ds1374->rtc))  in ds1374_probe()
481 		return PTR_ERR(ds1374->rtc);  in ds1374_probe()
483 	ds1374->client = client;  in ds1374_probe()
486 	INIT_WORK(&ds1374->work, ds1374_work);  in ds1374_probe()
487 	mutex_init(&ds1374->mutex);  in ds1374_probe()
493 	if (client->irq > 0) {  in ds1374_probe()
494 		ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,  in ds1374_probe()
497 			dev_err(&client->dev, "unable to request IRQ\n");  in ds1374_probe()
501 		device_set_wakeup_capable(&client->dev, 1);  in ds1374_probe()
504 	ds1374->rtc->ops = &ds1374_rtc_ops;  in ds1374_probe()
505 	ds1374->rtc->range_max = U32_MAX;  in ds1374_probe()
507 	ret = devm_rtc_register_device(ds1374->rtc);  in ds1374_probe()
512 	ds1374->wdt.info = &ds1374_wdt_info;  in ds1374_probe()
513 	ds1374->wdt.ops = &ds1374_wdt_ops;  in ds1374_probe()
514 	ds1374->wdt.timeout = TIMER_MARGIN_DEFAULT;  in ds1374_probe()
515 	ds1374->wdt.min_timeout = TIMER_MARGIN_MIN;  in ds1374_probe()
516 	ds1374->wdt.max_timeout = TIMER_MARGIN_MAX;  in ds1374_probe()
518 	watchdog_init_timeout(&ds1374->wdt, wdt_margin, &client->dev);  in ds1374_probe()
519 	watchdog_set_nowayout(&ds1374->wdt, nowayout);  in ds1374_probe()
520 	watchdog_stop_on_reboot(&ds1374->wdt);  in ds1374_probe()
521 	watchdog_stop_on_unregister(&ds1374->wdt);  in ds1374_probe()
522 	watchdog_set_drvdata(&ds1374->wdt, ds1374);  in ds1374_probe()
523 	ds1374_wdt_settimeout(&ds1374->wdt, ds1374->wdt.timeout);  in ds1374_probe()
525 	ret = devm_watchdog_register_device(&client->dev, &ds1374->wdt);  in ds1374_probe()
537 	if (client->irq > 0) {  in ds1374_remove()
538 		mutex_lock(&ds1374->mutex);  in ds1374_remove()
539 		ds1374->exiting = 1;  in ds1374_remove()
540 		mutex_unlock(&ds1374->mutex);  in ds1374_remove()
542 		devm_free_irq(&client->dev, client->irq, client);  in ds1374_remove()
543 		cancel_work_sync(&ds1374->work);  in ds1374_remove()
552 	if (client->irq > 0 && device_may_wakeup(&client->dev))  in ds1374_suspend()
553 		enable_irq_wake(client->irq);  in ds1374_suspend()
561 	if (client->irq > 0 && device_may_wakeup(&client->dev))  in ds1374_resume()
562 		disable_irq_wake(client->irq);  in ds1374_resume()
571 		.name = "rtc-ds1374",