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

[Remo Senekowitsch <remo@buenzli.dev>]

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