pub fn into_async(self) -> OneShotTimer<'d, Async> {
        let handler = self.inner.async_interrupt_handler();
        self.inner.set_interrupt_handler(handler);
        OneShotTimer {
            inner: self.inner,
            _ph: PhantomData,
        }
    }
Converts the driver to [`Async`] mode.
esp-hal/src/timer/mod.rs