rust: of: Add wrapper for of_property_present()

Used by aop_audio which can't use device::Device::property_present()
since it is not a fully populated device.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

rust/helpers/of.c

@@ -14,6 +14,11 @@ bool rust_helper_of_node_is_root(const struct device_node *np)
 {
 	return of_node_is_root(np);
 }
+
+bool rust_helper_of_property_present(const struct device_node *np, const char *propname)
+{
+	return of_property_present(np, propname);
+}
 #endif
 
 struct device_node *rust_helper_of_parse_phandle(const struct device_node *np,

rust/kernel/of.rs

@@ -274,6 +274,23 @@ impl Node {
         }
     }
 
+    #[allow(unused_variables)]
+    /// Check whether node property exists.
+    pub fn property_present(&self, propname: &CStr) -> bool {
+        #[cfg(not(CONFIG_OF))]
+        {
+            false
+        }
+        #[cfg(CONFIG_OF)]
+        // SAFETY: `raw_node` is valid per the type invariant.
+        unsafe {
+            bool::from(bindings::of_property_present(
+                self.raw_node,
+                propname.as_char_ptr(),
+            ))
+        }
+    }
+
     #[allow(unused_variables)]
     /// Look up a node property by name, returning a `Property` object if found.
     pub fn find_property(&self, propname: &CStr) -> Option<Property<'_>> {