[PATCH v3 2/2] rust: platform: add irq accessors

[Daniel Almeida <daniel.almeida@collabora.com>]

These accessors can be used to retrieve an IRQ from a platform device by
index or name. The IRQ can then be used to request the line using
irq::request::Registration::register() and
irq::request::ThreadedRegistration::register().

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
---
 rust/kernel/platform.rs | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 4917cb34e2fe8027d3d861e90de51de85f006735..1acaebf38d99d06f93fa13b0b356671ea77ed97a 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -188,6 +188,58 @@ impl Device {
     fn as_raw(&self) -> *mut bindings::platform_device {
         self.0.get()
     }
+
+    /// Returns an IRQ for the device by index.
+    pub fn irq_by_index(&self, index: u32) -> Result<u32> {
+        // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+        let res = unsafe { bindings::platform_get_irq(self.as_raw(), index) };
+
+        if res < 0 {
+            return Err(Error::from_errno(res));
+        }
+
+        Ok(res as u32)
+    }
+
+    /// Same as [`Self::irq_by_index`] but does not print an error message if an IRQ
+    /// cannot be obtained.
+    pub fn optional_irq_by_index(&self, index: u32) -> Result<u32> {
+        // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+        let res = unsafe { bindings::platform_get_irq_optional(self.as_raw(), index) };
+
+        if res < 0 {
+            return Err(Error::from_errno(res));
+        }
+
+        Ok(res as u32)
+    }
+
+    /// Returns an IRQ for the device by name.
+    pub fn irq_by_name(&self, name: &CStr) -> Result<u32> {
+        // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+        let res = unsafe { bindings::platform_get_irq_byname(self.as_raw(), name.as_char_ptr()) };
+
+        if res < 0 {
+            return Err(Error::from_errno(res));
+        }
+
+        Ok(res as u32)
+    }
+
+    /// Same as [`Self::irq_by_name`] but does not print an error message if an IRQ
+    /// cannot be obtained.
+    pub fn optional_irq_by_name(&self, name: &CStr) -> Result<u32> {
+        // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+        let res = unsafe {
+            bindings::platform_get_irq_byname_optional(self.as_raw(), name.as_char_ptr())
+        };
+
+        if res < 0 {
+            return Err(Error::from_errno(res));
+        }
+
+        Ok(res as u32)
+    }
 }
 
 impl Deref for Device<device::Core> {

-- 
2.49.0