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[V6,06/15] rust: Add bare minimal bindings for clk framework

Message ID d5c8f6f8d16ce9d95ea1715641597f78e7c0e845.1736248242.git.viresh.kumar@linaro.org
State New
Headers show
Series Rust bindings for cpufreq and OPP core + sample driver | expand

Commit Message

Viresh Kumar Jan. 7, 2025, 11:21 a.m. UTC
This adds very basic bindings for the clk framework, implements only
clk_get() and clk_put(). These are the bare minimum bindings required
for many users and are simple enough to add in the first attempt.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 rust/bindings/bindings_helper.h |  1 +
 rust/kernel/clk.rs              | 48 +++++++++++++++++++++++++++++++++
 rust/kernel/lib.rs              |  1 +
 3 files changed, 50 insertions(+)
 create mode 100644 rust/kernel/clk.rs
diff mbox series

Patch

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 3225379abd2b..7a95d999ead8 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -15,6 +15,7 @@ 
 #include <linux/blk-mq.h>
 #include <linux/blk_types.h>
 #include <linux/blkdev.h>
+#include <linux/clk.h>
 #include <linux/cpumask.h>
 #include <linux/cred.h>
 #include <linux/errname.h>
diff --git a/rust/kernel/clk.rs b/rust/kernel/clk.rs
new file mode 100644
index 000000000000..123cdb43b115
--- /dev/null
+++ b/rust/kernel/clk.rs
@@ -0,0 +1,48 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+//! Clock abstractions.
+//!
+//! C header: [`include/linux/clk.h`](srctree/include/linux/clk.h)
+
+use crate::{
+    bindings,
+    device::Device,
+    error::{from_err_ptr, Result},
+    prelude::*,
+};
+
+use core::ptr;
+
+/// A simple implementation of `struct clk` from the C code.
+#[repr(transparent)]
+pub struct Clk(*mut bindings::clk);
+
+impl Clk {
+    /// Creates `Clk` instance for a device and a connection id.
+    pub fn new(dev: &Device, name: Option<&CStr>) -> Result<Self> {
+        let con_id = if let Some(name) = name {
+            name.as_ptr() as *const _
+        } else {
+            ptr::null()
+        };
+
+        // SAFETY: It is safe to call `clk_get()`, on a device pointer earlier received from the C
+        // code.
+        Ok(Self(from_err_ptr(unsafe {
+            bindings::clk_get(dev.as_raw(), con_id)
+        })?))
+    }
+
+    /// Obtain the raw `struct clk *`.
+    pub fn as_raw(&self) -> *mut bindings::clk {
+        self.0
+    }
+}
+
+impl Drop for Clk {
+    fn drop(&mut self) {
+        // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to
+        // relinquish it now.
+        unsafe { bindings::clk_put(self.0) };
+    }
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 8a0cd60eb6cc..70694becc9ff 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -38,6 +38,7 @@ 
 #[cfg(CONFIG_BLOCK)]
 pub mod block;
 mod build_assert;
+pub mod clk;
 pub mod cpumask;
 pub mod cred;
 pub mod device;