InputPin not implemented for downgraded open_drain_output

[gray-heron]

Hello,
my project features two groups of six TM1637 displays, for whom I need to read a logical state of open-drain pins. Hence, I would like to group those pins in arrays, and I need them all to have the same type.

But I found out that InputPin trait is no longer satisfied after downgrade:

fn test<INPUT>(i: &mut INPUT) where INPUT: InputPin {}

[...]

        let mut p1 = gpioc.pc8.into_open_drain_output(&mut gpioc.crh);
        let mut p2 = gpioc.pc9.into_open_drain_output(&mut gpioc.crh).downgrade();

        test(&mut p1); //OK
        test(&mut p2); //Error

In gpio.rs I can see the implementation for generic OD pins and this would be enough for me (I can move all such pins to gpioc), but Generic is private:

impl InputPin for Generic<Output<OpenDrain>> {
    type Error = Infallible;
    fn is_high(&self) -> Result<bool, Self::Error> {
        self.is_low().map(|b| !b)
    }
        
    fn is_low(&self) -> Result<bool, Self::Error> {
        // NOTE(unsafe) atomic read with no side effects
        Ok(unsafe { (*$GPIOX::ptr()).idr.read().bits() & (1 << self.i) == 0 })
    }
}

Is there a technical reason behind loosing InputPin for downgraded OD pin? If so, how should I approach this? I don't want two functions doing the same thing, each taking 6 similar arguments.

Cheers,
~CS

[TeXitoi]

We just forgot this impl.