pub fn set_input_mode(&self, neg_edge: EdgeMode, pos_edge: EdgeMode) {
        let pcnt = PCNT::regs();
        let conf0 = pcnt.unit(UNIT).conf0();

        conf0.modify(|_, w| {
            w.ch_neg_mode(NUM as u8).variant(neg_edge);
            w.ch_pos_mode(NUM as u8).variant(pos_edge)
        });
    }
Configures how the channel affects the counter based on the transition
made by the input signal.

* `neg_edge` - The effect on the counter when the input signal goes 1 ->
0.
* `pos_edge` - The effect on the counter when the input signal goes 0 ->
1.
esp-hal/src/pcnt/channel.rs