+Note that many of these ioctls need not actually be implemented by your
+driver. The common rtc-dev interface handles many of these nicely if your
+driver returns ENOIOCTLCMD. Some common examples:
+
+ * RTC_RD_TIME, RTC_SET_TIME: the read_time/set_time functions will be
+ called with appropriate values.
+
+ * RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: the
+ set_alarm/read_alarm functions will be called.
+
+ * RTC_IRQP_SET, RTC_IRQP_READ: the irq_set_freq function will be called
+ to set the frequency while the framework will handle the read for you
+ since the frequency is stored in the irq_freq member of the rtc_device
+ structure. Also make sure you set the max_user_freq member in your
+ initialization routines so the framework can sanity check the user
+ input for you.
+
+If all else fails, check out the rtc-test.c driver!
+