rust: platdev: add platform_ioremap_resource function

Signed-off-by: Maciej Falkowski <[email protected]>

Author: Maciej Falkowski

rust/kernel/error.rs

@@ -488,17 +488,12 @@ pub(crate) use from_kernel_result;
 /// # use kernel::from_kernel_err_ptr;
 /// # use kernel::c_types;
 /// # use kernel::bindings;
-/// fn devm_platform_ioremap_resource(
+/// pub fn devm_platform_ioremap_resource(
 ///     pdev: &mut PlatformDevice,
 ///     index: u32,
 /// ) -> Result<*mut c_types::c_void> {
-///     // SAFETY: FFI call.
-///     unsafe {
-///         from_kernel_err_ptr(bindings::devm_platform_ioremap_resource(
-///             pdev.to_ptr(),
-///             index,
-///         ))
-///     }
+///     // SAFETY: `pdev` is valid by the type invariant.
+///     unsafe { from_kernel_err_ptr(bindings::devm_platform_ioremap_resource(pdev.0, index)) }
 /// }
 /// ```
 // TODO: remove `dead_code` marker once an in-kernel client is available.

rust/kernel/io_mem.rs

@@ -6,7 +6,11 @@
 
 #![allow(dead_code)]
 
-use crate::{bindings, Error, Result};
+use crate::{
+    bindings
+    platdev::{self, PlatformDevice},
+    Error, Result,
+};
 use core::convert::TryInto;
 
 /// Represents a memory resource.
@@ -164,6 +168,14 @@ impl<const SIZE: usize> IoMem<SIZE> {
         }
     }
 
+    // TODO: Handle Drop properly
+    pub fn try_platform_ioremap_resource(pdev: &mut PlatformDevice, index: u32) -> Result<Self> {
+        let raw_ptr = platdev::devm_platform_ioremap_resource(pdev, index)?;
+        Ok(Self {
+            ptr: raw_ptr as usize,
+        })
+    }
+
     const fn offset_ok<T>(offset: usize) -> bool {
         let type_size = core::mem::size_of::<T>();
         if let Some(end) = offset.checked_add(type_size) {

rust/kernel/platdev.rs

@@ -8,7 +8,7 @@
 
 use crate::{
     bindings, c_types, device,
-    error::{from_kernel_result, Error, Result},
+    error::{from_kernel_err_ptr, from_kernel_result, Error, Result},
     of::OfMatchTable,
     str::CStr,
     types::PointerWrapper,
@@ -32,6 +32,15 @@ unsafe impl device::RawDevice for PlatformDevice {
     }
 }
 
+/// Ioremaps resources of a platform device.
+pub fn devm_platform_ioremap_resource(
+    pdev: &mut PlatformDevice,
+    index: u32,
+) -> Result<*mut c_types::c_void> {
+    // SAFETY: `pdev` is valid by the type invariant.
+    unsafe { from_kernel_err_ptr(bindings::devm_platform_ioremap_resource(pdev.0, index)) }
+}
+
 /// A registration of a platform device.
 #[derive(Default)]
 pub struct Registration {