3  * RTC subsystem, base class
15 #include <linux/rtc.h>
21 #include "rtc-core.h"
28 	struct rtc_device *rtc = to_rtc_device(dev);  in rtc_device_release()  local
29 	struct timerqueue_head *head = &rtc->timerqueue;  in rtc_device_release()
32 	mutex_lock(&rtc->ops_lock);  in rtc_device_release()
35 	mutex_unlock(&rtc->ops_lock);  in rtc_device_release()
37 	cancel_work_sync(&rtc->irqwork);  in rtc_device_release()
39 	ida_free(&rtc_ida, rtc->id);  in rtc_device_release()
40 	mutex_destroy(&rtc->ops_lock);  in rtc_device_release()
41 	kfree(rtc);  in rtc_device_release()
45 /* Result of the last RTC to system clock attempt. */
48 /* IMPORTANT: the RTC only stores whole seconds. It is arbitrary
52  * in an rtc sync function, to read both xtime.tv_sec and
59 static void rtc_hctosys(struct rtc_device *rtc)  in rtc_hctosys()  argument
67 	err = rtc_read_time(rtc, &tm);  in rtc_hctosys()
69 		dev_err(rtc->dev.parent,  in rtc_hctosys()
85 	dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n",  in rtc_hctosys()
95  * On suspend(), measure the delta between one RTC and the
103 	struct rtc_device	*rtc = to_rtc_device(dev);  in rtc_suspend()  local
111 	if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)  in rtc_suspend()
114 	/* snapshot the current RTC and system time at suspend*/  in rtc_suspend()
115 	err = rtc_read_time(rtc, &tm);  in rtc_suspend()
117 		pr_debug("%s:  fail to read rtc time\n", dev_name(&rtc->dev));  in rtc_suspend()
128 	 * and rtc time stays close to constant.  in rtc_suspend()
148 	struct rtc_device	*rtc = to_rtc_device(dev);  in rtc_resume()  local
158 	if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)  in rtc_resume()
161 	/* snapshot the current rtc and system time at resume */  in rtc_resume()
163 	err = rtc_read_time(rtc, &tm);  in rtc_resume()
165 		pr_debug("%s:  fail to read rtc time\n", dev_name(&rtc->dev));  in rtc_resume()
173 		pr_debug("%s:  time travel!\n", dev_name(&rtc->dev));  in rtc_resume()
177 	/* calculate the RTC time delta (sleep time)*/  in rtc_resume()
181 	 * Since these RTC suspend/resume handlers are not called  in rtc_resume()
205 	struct rtc_device *rtc;  in rtc_allocate_device()  local
207 	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);  in rtc_allocate_device()
208 	if (!rtc)  in rtc_allocate_device()
211 	device_initialize(&rtc->dev);  in rtc_allocate_device()
219 	rtc->set_offset_nsec = NSEC_PER_SEC + 5 * NSEC_PER_MSEC;  in rtc_allocate_device()
221 	rtc->irq_freq = 1;  in rtc_allocate_device()
222 	rtc->max_user_freq = 64;  in rtc_allocate_device()
223 	rtc->dev.class = rtc_class;  in rtc_allocate_device()
224 	rtc->dev.groups = rtc_get_dev_attribute_groups();  in rtc_allocate_device()
225 	rtc->dev.release = rtc_device_release;  in rtc_allocate_device()
227 	mutex_init(&rtc->ops_lock);  in rtc_allocate_device()
228 	spin_lock_init(&rtc->irq_lock);  in rtc_allocate_device()
229 	init_waitqueue_head(&rtc->irq_queue);  in rtc_allocate_device()
232 	timerqueue_init_head(&rtc->timerqueue);  in rtc_allocate_device()
233 	INIT_WORK(&rtc->irqwork, rtc_timer_do_work);  in rtc_allocate_device()
235 	rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, rtc);  in rtc_allocate_device()
237 	rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, rtc);  in rtc_allocate_device()
239 	hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);  in rtc_allocate_device()
240 	rtc->pie_timer.function = rtc_pie_update_irq;  in rtc_allocate_device()
241 	rtc->pie_enabled = 0;  in rtc_allocate_device()
243 	set_bit(RTC_FEATURE_ALARM, rtc->features);  in rtc_allocate_device()
244 	set_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);  in rtc_allocate_device()
246 	return rtc;  in rtc_allocate_device()
254 		of_id = of_alias_get_id(dev->of_node, "rtc");  in rtc_device_get_id()
256 		of_id = of_alias_get_id(dev->parent->of_node, "rtc");  in rtc_device_get_id()
270 static void rtc_device_get_offset(struct rtc_device *rtc)  in rtc_device_get_offset()  argument
277 	 * If RTC driver did not implement the range of RTC hardware device,  in rtc_device_get_offset()
278 	 * then we can not expand the RTC range by adding or subtracting one  in rtc_device_get_offset()
281 	if (rtc->range_min == rtc->range_max)  in rtc_device_get_offset()
284 	ret = device_property_read_u32(rtc->dev.parent, "start-year",  in rtc_device_get_offset()
287 		rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0);  in rtc_device_get_offset()
288 		rtc->set_start_time = true;  in rtc_device_get_offset()
292 	 * If user did not implement the start time for RTC driver, then no  in rtc_device_get_offset()
293 	 * need to expand the RTC range.  in rtc_device_get_offset()
295 	if (!rtc->set_start_time)  in rtc_device_get_offset()
298 	range_secs = rtc->range_max - rtc->range_min + 1;  in rtc_device_get_offset()
301 	 * If the start_secs is larger than the maximum seconds (rtc->range_max)  in rtc_device_get_offset()
302 	 * supported by RTC hardware or the maximum seconds of new expanded  in rtc_device_get_offset()
303 	 * range (start_secs + rtc->range_max - rtc->range_min) is less than  in rtc_device_get_offset()
304 	 * rtc->range_min, which means the minimum seconds (rtc->range_min) of  in rtc_device_get_offset()
305 	 * RTC hardware will be mapped to start_secs by adding one offset, so  in rtc_device_get_offset()
307 	 * rtc->offset_secs = rtc->start_secs - rtc->range_min;  in rtc_device_get_offset()
309 	 * If the start_secs is larger than the minimum seconds (rtc->range_min)  in rtc_device_get_offset()
310 	 * supported by RTC hardware, then there is one region is overlapped  in rtc_device_get_offset()
311 	 * between the original RTC hardware range and the new expanded range,  in rtc_device_get_offset()
313 	 * expanded range due to it is valid for RTC device. So the minimum  in rtc_device_get_offset()
314 	 * seconds of RTC hardware (rtc->range_min) should be mapped to  in rtc_device_get_offset()
315 	 * rtc->range_max + 1, then the offset seconds formula should be:  in rtc_device_get_offset()
316 	 * rtc->offset_secs = rtc->range_max - rtc->range_min + 1;  in rtc_device_get_offset()
318 	 * If the start_secs is less than the minimum seconds (rtc->range_min),  in rtc_device_get_offset()
320 	 * start_secs + rtc->range_max - rtc->range_min + 1, then the  in rtc_device_get_offset()
322 	 * rtc->offset_secs = -(rtc->range_max - rtc->range_min + 1);  in rtc_device_get_offset()
326 	if (rtc->start_secs > rtc->range_max ||  in rtc_device_get_offset()
327 	    rtc->start_secs + range_secs - 1 < rtc->range_min)  in rtc_device_get_offset()
328 		rtc->offset_secs = rtc->start_secs - rtc->range_min;  in rtc_device_get_offset()
329 	else if (rtc->start_secs > rtc->range_min)  in rtc_device_get_offset()
330 		rtc->offset_secs = range_secs;  in rtc_device_get_offset()
331 	else if (rtc->start_secs < rtc->range_min)  in rtc_device_get_offset()
332 		rtc->offset_secs = -range_secs;  in rtc_device_get_offset()
334 		rtc->offset_secs = 0;  in rtc_device_get_offset()
339 	struct rtc_device *rtc = data;  in devm_rtc_unregister_device()  local
341 	mutex_lock(&rtc->ops_lock);  in devm_rtc_unregister_device()
343 	 * Remove innards of this RTC, then disable it, before  in devm_rtc_unregister_device()
346 	rtc_proc_del_device(rtc);  in devm_rtc_unregister_device()
347 	if (!test_bit(RTC_NO_CDEV, &rtc->flags))  in devm_rtc_unregister_device()
348 		cdev_device_del(&rtc->char_dev, &rtc->dev);  in devm_rtc_unregister_device()
349 	rtc->ops = NULL;  in devm_rtc_unregister_device()
350 	mutex_unlock(&rtc->ops_lock);  in devm_rtc_unregister_device()
355 	struct rtc_device *rtc = res;  in devm_rtc_release_device()  local
357 	put_device(&rtc->dev);  in devm_rtc_release_device()
362 	struct rtc_device *rtc;  in devm_rtc_allocate_device()  local
369 	rtc = rtc_allocate_device();  in devm_rtc_allocate_device()
370 	if (!rtc) {  in devm_rtc_allocate_device()
375 	rtc->id = id;  in devm_rtc_allocate_device()
376 	rtc->dev.parent = dev;  in devm_rtc_allocate_device()
377 	err = dev_set_name(&rtc->dev, "rtc%d", id);  in devm_rtc_allocate_device()
381 	err = devm_add_action_or_reset(dev, devm_rtc_release_device, rtc);  in devm_rtc_allocate_device()
385 	return rtc;  in devm_rtc_allocate_device()
389 int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc)  in __devm_rtc_register_device()  argument
394 	if (!rtc->ops) {  in __devm_rtc_register_device()
395 		dev_dbg(&rtc->dev, "no ops set\n");  in __devm_rtc_register_device()
399 	if (!rtc->ops->set_alarm)  in __devm_rtc_register_device()
400 		clear_bit(RTC_FEATURE_ALARM, rtc->features);  in __devm_rtc_register_device()
402 	if (rtc->ops->set_offset)  in __devm_rtc_register_device()
403 		set_bit(RTC_FEATURE_CORRECTION, rtc->features);  in __devm_rtc_register_device()
405 	rtc->owner = owner;  in __devm_rtc_register_device()
406 	rtc_device_get_offset(rtc);  in __devm_rtc_register_device()
409 	err = __rtc_read_alarm(rtc, &alrm);  in __devm_rtc_register_device()
411 		rtc_initialize_alarm(rtc, &alrm);  in __devm_rtc_register_device()
413 	rtc_dev_prepare(rtc);  in __devm_rtc_register_device()
415 	err = cdev_device_add(&rtc->char_dev, &rtc->dev);  in __devm_rtc_register_device()
417 		set_bit(RTC_NO_CDEV, &rtc->flags);  in __devm_rtc_register_device()
418 		dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n",  in __devm_rtc_register_device()
419 			 MAJOR(rtc->dev.devt), rtc->id);  in __devm_rtc_register_device()
421 		dev_dbg(rtc->dev.parent, "char device (%d:%d)\n",  in __devm_rtc_register_device()
422 			MAJOR(rtc->dev.devt), rtc->id);  in __devm_rtc_register_device()
425 	rtc_proc_add_device(rtc);  in __devm_rtc_register_device()
427 	dev_info(rtc->dev.parent, "registered as %s\n",  in __devm_rtc_register_device()
428 		 dev_name(&rtc->dev));  in __devm_rtc_register_device()
431 	if (!strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE))  in __devm_rtc_register_device()
432 		rtc_hctosys(rtc);  in __devm_rtc_register_device()
435 	return devm_add_action_or_reset(rtc->dev.parent,  in __devm_rtc_register_device()
436 					devm_rtc_unregister_device, rtc);  in __devm_rtc_register_device()
444  * @ops: the rtc operations structure
447  * @return a struct rtc on success, or an ERR_PTR on error
459 	struct rtc_device *rtc;  in devm_rtc_device_register()  local
462 	rtc = devm_rtc_allocate_device(dev);  in devm_rtc_device_register()
463 	if (IS_ERR(rtc))  in devm_rtc_device_register()
464 		return rtc;  in devm_rtc_device_register()
466 	rtc->ops = ops;  in devm_rtc_device_register()
468 	err = __devm_rtc_register_device(owner, rtc);  in devm_rtc_device_register()
472 	return rtc;  in devm_rtc_device_register()
478 	rtc_class = class_create(THIS_MODULE, "rtc");  in rtc_init()