Hi Danilo, > +/// ```no_run > +/// # use kernel::{bindings, io::{Io, IoRaw}}; > +/// # use core::ops::Deref; > +/// > +/// // See also [`pci::Bar`] for a real example. > +/// struct IoMem<const SIZE: usize>(IoRaw<SIZE>); > +/// > +/// impl<const SIZE: usize> IoMem<SIZE> { > +/// /// # Safety > +/// /// > +/// /// [`paddr`, `paddr` + `SIZE`) must be a valid MMIO region that is mappable into the CPUs > +/// /// virtual address space. > +/// unsafe fn new(paddr: usize) -> Result<Self>{ > +/// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is > +/// // valid for `ioremap`. > +/// let addr = unsafe { bindings::ioremap(paddr as _, SIZE.try_into().unwrap()) }; This line generates a warning when building the doctests on arm64: warning: useless conversion to the same type: usize --> rust/doctests_kernel_generated.rs:3601:59 | 3601 | let addr = unsafe { bindings::ioremap(paddr as _, SIZE.try_into().unwrap()) }; | ^^^^^^^^^^^^^^^ | = help: consider removing .try_into() = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion Same things happens as well in devres.rs > +/// if addr.is_null() { > +/// return Err(ENOMEM); > +/// } > +/// > +/// Ok(IoMem(IoRaw::new(addr as _, SIZE)?)) > +/// } > +/// } > +/// > +/// impl<const SIZE: usize> Drop for IoMem<SIZE> { > +/// fn drop(&mut self) { > +/// // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`. > +/// unsafe { bindings::iounmap(self.0.addr() as _); }; > +/// } > +/// } > +/// > +/// impl<const SIZE: usize> Deref for IoMem<SIZE> { > +/// type Target = Io<SIZE>; > +/// > +/// fn deref(&self) -> &Self::Target { > +/// // SAFETY: The memory range stored in `self` has been properly mapped in `Self::new`. > +/// unsafe { Io::from_raw(&self.0) } > +/// } > +/// } > +/// > +///# fn no_run() -> Result<(), Error> { > +/// // SAFETY: Invalid usage for example purposes. > +/// let iomem = unsafe { IoMem::<{ core::mem::size_of::<u32>() }>::new(0xBAAAAAAD)? }; > +/// iomem.writel(0x42, 0x0); > +/// assert!(iomem.try_writel(0x42, 0x0).is_ok()); > +/// assert!(iomem.try_writel(0x42, 0x4).is_err()); > +/// # Ok(()) > +/// # } > +/// ```