rt-thread/components/drivers/rtc/Kconfig

menuconfig RT_USING_RTC
    bool "Using RTC device drivers"
    default n
    help
      Enable the RTC core so hardware real-time clocks can be registered via
      `rt_hw_rtc_register`, the kernel can keep wall clock time across suspend/
      resume, and applications can query or set calendar values through the
      `rtc` character device. Turn this on whenever you have a peripheral or
      PMIC that supplies timestamp/backup registers referenced from the device
      tree; disable it only on chips that genuinely lack RTC hardware.

    if RT_USING_RTC
        config RT_USING_ALARM
            bool "Using RTC alarm"
            default n
            help
              Spawn the alarm service defined in `dev_alarm.c`. The driver
              creates an RT-Thread worker thread that reconciles user-space
              alarms with the RTC wakeup registers, automatically reprograms
              oneshot/periodic alarms, and raises callbacks when the hardware
              interrupt fires. Enable this if your application needs wakeup at a
              given date/time; leave it disabled to save RAM/CPU when alarms are
              not used.

        if RT_USING_ALARM
            config RT_ALARM_STACK_SIZE
                int "stack size for alarm thread"
                default IDLE_THREAD_STACK_SIZE
                help
                  Specify the stack size (bytes) used by the internal alarm
                  management thread. Increase this when alarm callbacks perform
                  complex logic or use libc time conversions; shrink it on very
                  constrained MCUs when you are sure the callbacks stay shallow.

            config RT_ALARM_TIMESLICE
                int "timeslice for alarm thread"
                default 5
                help
                  Define the timeslice (OS ticks) granted to the alarm thread
                  when it runs at the same priority as other time-sensitive
                  tasks. Lower values make the system more responsive at the
                  cost of additional context switches; higher values slightly
                  delay alarm handling under load.

            config RT_ALARM_PRIORITY
                int "priority for alarm thread"
                default 10
                help
                  RT-Thread priority (smaller numbers are higher priority) of
                  the alarm management thread. Choose a priority above most
                  application threads if you require deterministic wakeups, or
                  below CPU-intensive tasks when alarm latency is less critical.

            config RT_ALARM_USING_LOCAL_TIME
                bool "Using local time for the alarm calculation"
                default n
                depends on RT_USING_ALARM
                help
                  Make the alarm service convert timestamps with `mktime()` so
                  alarms follow the configured local time zone instead of UTC.
                  Enable this when alarms must honor daylight saving or custom
                  offsets; otherwise keep it disabled to avoid the overhead of
                  repeatedly converting between UTC and local time.
        endif

        config RT_USING_SOFT_RTC
            bool "Using software simulation RTC device"
            default n
            help
              Build the tick-based software RTC implementation (`dev_soft_rtc`)
              for boards without dedicated RTC hardware. The driver keeps time
              by accumulating system ticks and stores values in RAM only, so it
              resets to the compile-time default after power loss. Enable it for
              simulations or low-cost MCUs that still need an `rtc` device node;
              disable it when real RTC registers are available to avoid two
              competing time sources.
    endif

config RT_RTC_DS1302
    bool "Dallas/Maxim DS1302"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_SPI
    default n

config RT_RTC_DS1307
    bool "Dallas/Maxim DS1307/37/38/39/40, ST M41T11"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_I2C
    default n

config RT_RTC_GOLDFISH
    bool "Goldfish Real Time Clock"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    default n

config RT_RTC_HYM8563
    bool "Haoyu Microelectronics HYM8563"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_I2C
    default n

config RT_RTC_PCF8523
    bool "NXP PCF8523"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_I2C
    default n

config RT_RTC_PCF8563
    bool "Philips PCF8563/Epson RTC8564"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_I2C
    default n

config RT_RTC_PL031
    bool "ARM PL031"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    default n

config RT_RTC_RX8010
    bool "Epson RX8010SJ"
    depends on RT_USING_DM
    depends on RT_USING_RTC
    depends on RT_USING_I2C
    default n

if RT_USING_DM && RT_USING_RTC
    osource "$(SOC_DM_RTC_DIR)/Kconfig"
endif