[PATCH V7 04/16] rust: device: Add property_present()

[Viresh Kumar <viresh.kumar@linaro.org>]

This implements Device::property_present(), which calls C APIs
device_property_present() helper.

The new helper will be used by Rust based cpufreq drivers.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 rust/bindings/bindings_helper.h | 1 +
 rust/kernel/device.rs           | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index d63e7f6d10ea..fda1e0d8f376 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -27,6 +27,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/platform_device.h>
 #include <linux/poll.h>
+#include <linux/property.h>
 #include <linux/refcount.h>
 #include <linux/sched.h>
 #include <linux/security.h>
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index d5e6a19ff6b7..e8c4cda5aacc 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -6,6 +6,7 @@
 
 use crate::{
     bindings,
+    str::CString,
     types::{ARef, Opaque},
 };
 use core::{fmt, ptr};
@@ -180,6 +181,12 @@ unsafe fn printk(&self, klevel: &[u8], msg: fmt::Arguments<'_>) {
             )
         };
     }
+
+    /// Checks if property is present or not.
+    pub fn property_present(&self, name: &CString) -> bool {
+        // SAFETY: By the invariant of `CString`, `name` is null-terminated.
+        unsafe { bindings::device_property_present(self.as_raw().cast_const(), name.as_ptr() as *const _) }
+    }
 }
 
 // SAFETY: Instances of `Device` are always reference-counted.
-- 
2.31.1.272.g89b43f80a514