thejpster by the way, I also have another feature request (that I could also look at): For this peripheral, there is only one valid address. So I it was possible to do somehting like

```rust
#[derive(derive_mmio::Mmio, fixed=0xE000A000)]
#[repr(C)]
pub struct Gpio {
}
```

which in turn generates a new_mmio with 0 input arguments at the given address, that would be useful I think.