Block Diagram

The following image shows the block diagram of the RTC driver.
Figure 1. Block Diagram
Besides the general user space layer, the following layers are specific to the RTC module.
  • RTC subsystem: The RTC driver framework provided by the Linux kernel.
    • rtc-core: Provide API for RTC drivers to register the RTC devices and drivers.
    • interface: Provide interface to interact with the RTC devices (by calling ops functions). So ioctrl/proc/sysfs can either be used to set or read RTC time and alarm using API interface.
  • StarFive(AT8563) RTC driver: Define all underlying operations (read/write register) and register RTC devices to rtc-core.