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

From: Viresh Kumar
Date: Mon Jan 13 2025 - 06:24:50 EST


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@xxxxxxxxxx>
---
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