1 // SPDX-License-Identifier: GPL-2.0
13 #include "rtc-core.h"
19  * ideally UTC.  However, PCs that also boot to MS-Windows normally use
27 	return sysfs_emit(buf, "%s %s\n", dev_driver_string(dev->parent),  in name_show()
28 			  dev_name(dev->parent));  in name_show()
77 	return sysfs_emit(buf, "%d\n", to_rtc_device(dev)->max_user_freq);  in max_user_freq_show()
93 		return -EINVAL;  in max_user_freq_store()
95 	rtc->max_user_freq = (int)val;  in max_user_freq_store()
102  * hctosys_show - indicate if the given RTC set the system time
115 	    strcmp(dev_name(&to_rtc_device(dev)->dev),  in hctosys_show()
130 	 * conceptually one-shot, even though some common RTCs (on PCs)  in wakealarm_show()
133 	 * NOTE: RTC implementations where the alarm doesn't match an  in wakealarm_show()
134 	 * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC  in wakealarm_show()
135 	 * alarms after they trigger, to ensure one-shot semantics.  in wakealarm_show()
152 	time64_t now, alarm;  in wakealarm_store()  local
177 	retval = kstrtos64(buf_ptr, 0, &alarm);  in wakealarm_store()
181 		alarm += now;  in wakealarm_store()
182 	if (alarm > now || push) {  in wakealarm_store()
193 				alarm += push;  in wakealarm_store()
195 				return -EBUSY;  in wakealarm_store()
197 			return -EINVAL;  in wakealarm_store()
202 		/* Provide a valid future alarm time.  Linux isn't EFI,  in wakealarm_store()
203 		 * this time won't be ignored when disabling the alarm.  in wakealarm_store()
205 		alarm = now + 300;  in wakealarm_store()
207 	rtc_time64_to_tm(alarm, &alm.time);  in wakealarm_store()
245 	return sysfs_emit(buf, "[%lld,%llu]\n", to_rtc_device(dev)->range_min,  in range_show()
246 			  to_rtc_device(dev)->range_max);  in range_show()
263 /* The reason to trigger an alarm with no process watching it (via sysfs)
264  * is its side effect:  waking from a system state like suspend-to-RAM or
265  * suspend-to-disk.  So: no attribute unless that side effect is possible.
270 	if (!device_can_wakeup(rtc->dev.parent))  in rtc_does_wakealarm()
273 	return !!test_bit(RTC_FEATURE_ALARM, rtc->features);  in rtc_does_wakealarm()
281 	umode_t mode = attr->mode;  in rtc_attr_is_visible()
287 		if (!rtc->ops->set_offset)  in rtc_attr_is_visible()
290 		if (!(rtc->range_max - rtc->range_min))  in rtc_attr_is_visible()
316 		/* No need to modify current groups if nothing new is provided */  in rtc_add_groups()
320 		return -EINVAL;  in rtc_add_groups()
323 	groups = rtc->dev.groups;  in rtc_add_groups()
329 	groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);  in rtc_add_groups()
331 		return -ENOMEM;  in rtc_add_groups()
332 	memcpy(groups, rtc->dev.groups, old_cnt * sizeof(*groups));  in rtc_add_groups()
336 	old = rtc->dev.groups;  in rtc_add_groups()
337 	rtc->dev.groups = groups;  in rtc_add_groups()
339 		devm_kfree(&rtc->dev, old);  in rtc_add_groups()