[PATCH 08/10] rust: property: Add property_get_reference_args

Remo Senekowitsch
2025-03-26T17:15:19Z

Signed-off-by: Remo Senekowitsch <remo@buenzli.dev>
---
rust/kernel/property.rs | 63 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)

diff --git a/rust/kernel/property.rs b/rust/kernel/property.rs
index dc927ad93..f1d0a33ba 100644
--- a/rust/kernel/property.rs
+++ b/rust/kernel/property.rs
@@ -8,6 +8,7 @@

use crate::{
alloc::KVec,
+ arrayvec::ArrayVec,
bindings,
device::Device,
error::{to_result, Result},
@@ -64,6 +65,20 @@ pub fn get_child_by_name(&self, name: &CStr) -> Option<ARef<FwNode>> {
pub fn children<'a>(&'a self) -> impl Iterator<Item = ARef<FwNode>> + 'a {
self.fwnode().children()
}
+
+ /// Finds a reference with arguments.
+ pub fn property_get_reference_args(
+ &self,
+ prop: &CStr,
+ nargs: NArgs<'_>,
+ index: u32,
+ ) -> Result<(
+ ARef<FwNode>,
+ ArrayVec<{ bindings::NR_FWNODE_REFERENCE_ARGS as usize }, u64>,
+ )> {
+ self.fwnode()
+ .property_get_reference_args(prop, nargs, index)
+ }
}

/// A reference-counted fwnode_handle.
@@ -226,6 +241,45 @@ pub fn children<'a>(&'a self) -> impl Iterator<Item = ARef<FwNode>> + 'a {
Some(next)
})
}
+
+ /// Finds a reference with arguments.
+ pub fn property_get_reference_args(
+ &self,
+ prop: &CStr,
+ nargs: NArgs<'_>,
+ index: u32,
+ ) -> Result<(
+ ARef<Self>,
+ ArrayVec<{ bindings::NR_FWNODE_REFERENCE_ARGS as usize }, u64>,
+ )> {
+ let mut out_args = bindings::fwnode_reference_args::default();
+
+ let (nargs_prop, nargs) = match nargs {
+ NArgs::Prop(nargs_prop) => (nargs_prop.as_char_ptr(), 0),
+ NArgs::N(nargs) => (ptr::null(), nargs),
+ };
+
+ let ret = unsafe {
+ bindings::fwnode_property_get_reference_args(
+ self.0.get(),
+ prop.as_char_ptr(),
+ nargs_prop,
+ nargs,
+ index,
+ &mut out_args,
+ )
+ };
+ to_result(ret)?;
+
+ let node = unsafe { FwNode::from_raw(out_args.fwnode) };
+ let mut args = ArrayVec::default();
+
+ for i in 0..out_args.nargs {
+ args.push(out_args.args[i as usize]);
+ }
+
+ Ok((node, args))
+ }
}

// SAFETY: Instances of `FwNode` are always reference-counted.
@@ -302,3 +356,12 @@ fn read(fwnode: &FwNode, name: &CStr) -> Result<T> {
Ok(val[0])
}
}
+
+/// The number of arguments of a reference.
+pub enum NArgs<'a> {
+ /// The name of the property of the reference indicating the number of
+ /// arguments.
+ Prop(&'a CStr),
+ /// The known number of arguments.
+ N(u32),
+}
--
2.49.0