• Maxime Ripard's avatar
    rtc: sun6i: Expose the 32kHz oscillator · 3855c2c3
    Maxime Ripard authored
    The RTC controls the input source of the main 32kHz oscillator in the
    system, feeding it to the clock unit too.
    By default, this is using an internal, very inaccurate (+/- 30%)
    oscillator with a divider to make it roughly around 32kHz. This is however
    quite impractical for the RTC, since our time will not be tracked properly.
    Since this oscillator is an input of the main clock unit, and since that
    clock unit will be probed using CLK_OF_DECLARE, we have to use it as well,
    leading to a two stage probe: one to enable the clock, the other one to
    enable the RTC.
    There is also a slight change in the binding that is required (and should
    have been from the beginning), since we'll need a phandle to the external
    oscillator used on that board. We support the old binding by not allowing
    to switch to the external oscillator and only using the internal one (which
    was the previous behaviour) in the case where we're missing that phandle.
    Signed-off-by: default avatarMaxime Ripard <[email protected]>
    Acked-by: Rob Herring's avatarRob Herring <[email protected]>
    Signed-off-by: default avatarAlexandre Belloni <[email protected]>
rtc-sun6i.c 14.7 KB