Struct FwNode

pub struct FwNode(/* private fields */);

A reference-counted fwnode_handle.

This structure represents the Rust abstraction for a C struct fwnode_handle. This implementation abstracts the usage of an already existing C struct fwnode_handle within Rust code that we get passed from the C side.

Invariants

A FwNode instance represents a valid struct fwnode_handle created by the C portion of the kernel.

Instances of this type are always reference-counted, that is, a call to fwnode_handle_get ensures that the allocation remains valid at least until the matching call to fwnode_handle_put.

Implementations

impl FwNode

pub fn display_name(&self) -> impl Display + '_

Returns an object that implements Display for printing the name of a node.

This is an alternative to the default Display implementation, which prints the full path.

pub fn property_present(&self, name: &CStr) -> bool

Checks if property is present or not.

pub fn property_read_bool(&self, name: &CStr) -> bool

Returns firmware property name boolean value.

pub fn property_match_string( &self, name: &CStr, match_str: &CStr, ) -> Result<usize>

Returns the index of matching string match_str for firmware string property name.

pub fn property_read_array_vec<'fwnode, 'name, T: PropertyInt>( &'fwnode self, name: &'name CStr, len: usize, ) -> Result<PropertyGuard<'fwnode, 'name, KVec<T>>>

Returns firmware property name integer array values in a KVec.

pub fn property_count_elem<T: PropertyInt>(&self, name: &CStr) -> Result<usize>

Returns integer array length for firmware property name.

pub fn property_read<'fwnode, 'name, T: Property>( &'fwnode self, name: &'name CStr, ) -> PropertyGuard<'fwnode, 'name, T>

Returns the value of firmware property name.

This method is generic over the type of value to read. The types that can be read are strings, integers and arrays of integers.

Reading a KVec of integers is done with the separate method Self::property_read_array_vec, because it takes an additional len argument.

Reading a boolean is done with the separate method Self::property_read_bool, because this operation is infallible.

For more precise documentation about what types can be read, see the implementors of Property and its implementations on foreign types.

Examples

fn examples(dev: &Device) -> Result {
    let fwnode = dev.fwnode().ok_or(ENOENT)?;
    let b: u32 = fwnode.property_read(c_str!("some-number")).required_by(dev)?;
    if let Some(s) = fwnode.property_read::<CString>(c_str!("some-str")).optional() {
        // ...
    }
    Ok(())
}

Trait Implementations

impl AlwaysRefCounted for FwNode

fn inc_ref(&self)

Increments the reference count on the object.

unsafe fn dec_ref(obj: NonNull<Self>)

Decrements the reference count on the object.

impl Display for FwNode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.