ANDROID: rtc: class: support hctosys from modular RTC drivers

In order to support setting the system time from modular RTC drivers
via the hctosys mechanism, check at the end of RTC device registration
for whether the time should be synced, rather than once at late init.

Bug: 144103362
Bug: 143046457
Change-Id: I65d2fd14e075a65f2a23e1268b02c907c5245fb8
Signed-off-by: Steve Muckle <smuckle@google.com>

drivers/rtc/class.c

@@ -527,6 +527,11 @@ int __rtc_register_device(struct module *owner, struct rtc_device *rtc)
 	dev_info(rtc->dev.parent, "registered as %s\n",
 		 dev_name(&rtc->dev));
 
+#ifdef CONFIG_RTC_HCTOSYS_DEVICE
+	if (!strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE))
+		rtc_hctosys();
+#endif
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(__rtc_register_device);

drivers/rtc/hctosys.c

@@ -24,7 +24,7 @@
  * the best guess is to add 0.5s.
  */
 
-static int __init rtc_hctosys(void)
+int rtc_hctosys(void)
 {
 	int err = -ENODEV;
 	struct rtc_time tm;
@@ -73,5 +73,3 @@ static int __init rtc_hctosys(void)
 
 	return err;
 }
-
-late_initcall(rtc_hctosys);

drivers/rtc/rtc-core.h

@@ -60,3 +60,7 @@ int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
 	return 0;
 }
 #endif
+
+#ifdef CONFIG_RTC_HCTOSYS
+extern int rtc_hctosys(void);
+#endif