rust: Add ACPI match table support for Rust drivers

61 lines not on this page · raw message

index 6b4774b2b1c3..5bbf3627212f 100644
@@ -51,6 +51,7 @@
 
 pub use ffi;
 
+pub mod acpi;
 pub mod alloc;
 #[cfg(CONFIG_AUXILIARY_BUS)]
 pub mod auxiliary;

index ec9166cedfa7..cb62b75a0c0e 100644
@@ -147,30 +147,32 @@ pub trait Adapter {
     /// Returns the driver's private data from the matching entry in the [`of::IdTable`], if any.
     ///
     /// If this returns `None`, it means there is no match with an entry in the [`of::IdTable`].
-    #[cfg(CONFIG_OF)]
     fn of_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
-        let table = Self::of_id_table()?;
+        #[cfg(not(CONFIG_OF))]
+        {
+            let _ = dev;
+            return None;
+        }
 
-        // SAFETY:
-        // - `table` has static lifetime, hence it's valid for read,
-        // - `dev` is guaranteed to be valid while it's alive, and so is `pdev.as_ref().as_raw()`.
-        let raw_id = unsafe { bindings::of_match_device(table.as_ptr(), dev.as_raw()) };
+        #[cfg(CONFIG_OF)]
+        {
+            let table = Self::of_id_table()?;
 
-        if raw_id.is_null() {
-            None
-        } else {
-            // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and
-            // does not add additional invariants, so it's safe to transmute.
-            let id = unsafe { &*raw_id.cast::<of::DeviceId>() };
+            // SAFETY:
+            // - `table` has static lifetime, hence it's valid for read,
+            // - `dev` is guaranteed to be valid while it's alive, and so is `pdev.as_ref().as_raw()`.
+            let raw_id = unsafe { bindings::of_match_device(table.as_ptr(), dev.as_raw()) };
 
-            Some(table.info(<of::DeviceId as crate::device_id::RawDeviceId>::index(id)))
-        }
-    }
+            if raw_id.is_null() {
+                None
+            } else {
+                // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and
+                // does not add additional invariants, so it's safe to transmute.
+                let id = unsafe { &*raw_id.cast::<of::DeviceId>() };
 
-    #[cfg(not(CONFIG_OF))]
-    #[allow(missing_docs)]
-    fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {
-        None
+                Some(table.info(<of::DeviceId as crate::device_id::RawDeviceId>::index(id)))
+            }
+        }
     }
 
     /// Returns the driver's private data from the matching entry of any of the ID tables, if any.

index bc494745f67b..dfb2dd500ef6 100644
@@ -28,6 +28,7 @@
  */
 #include <linux/hrtimer_types.h>
 
+#include <linux/acpi.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>

59 lines not on this page · raw message

index 5b21fa517e55..5923d29a0511 100644
@@ -5,7 +5,7 @@
 //! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
 
 use crate::{
-    bindings, container_of, device, driver,
+    acpi, bindings, container_of, device, driver,
     error::{to_result, Result},
     of,
     prelude::*,

@@ -94,6 +94,10 @@ impl<T: Driver + 'static> driver::Adapter for Adapter<T> {
     fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> {
         T::OF_ID_TABLE
     }
+
+    fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> {
+        None
+    }
 }
 
 /// Declares a kernel module that exposes a single platform driver.

index 5923d29a0511..2436f55b579b 100644
@@ -162,7 +162,7 @@ pub trait Driver: Send {
     type IdInfo: 'static;
 
     /// The table of OF device ids supported by the driver.
-    const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>>;
+    const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
 
     /// Platform driver probe.
     ///

index 2436f55b579b..62a9e4ec5c19 100644
@@ -37,12 +37,18 @@ unsafe fn register(
             None => core::ptr::null(),
         };
 
+        let acpi_table = match T::ACPI_ID_TABLE {
+            Some(table) => table.as_ptr(),
+            None => core::ptr::null(),
+        };
+
         // SAFETY: It's safe to set the fields of `struct platform_driver` on initialization.
         unsafe {
             (*pdrv.get()).driver.name = name.as_char_ptr();
             (*pdrv.get()).probe = Some(Self::probe_callback);
             (*pdrv.get()).remove = Some(Self::remove_callback);
             (*pdrv.get()).driver.of_match_table = of_table;
+            (*pdrv.get()).driver.acpi_match_table = acpi_table;
         }
 
         // SAFETY: `pdrv` is guaranteed to be a valid `RegType`.

@@ -96,7 +102,7 @@ fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> {
     }
 
     fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> {
-        None
+        T::ACPI_ID_TABLE
     }
 }
 

@@ -127,7 +133,7 @@ macro_rules! module_platform_driver {
 /// # Example
 ///
 ///```
-/// # use kernel::{bindings, c_str, device::Core, of, platform};
+/// # use kernel::{acpi, bindings, c_str, device::Core, of, platform};
 ///
 /// struct MyDriver;
 ///

@@ -140,9 +146,19 @@ macro_rules! module_platform_driver {
 ///     ]
 /// );
 ///
+/// kernel::acpi_device_table!(
+///     ACPI_TABLE,
+///     MODULE_ACPI_TABLE,
+///     <MyDriver as platform::Driver>::IdInfo,
+///     [
+///         (acpi::DeviceId::new(c_str!("TEST4321")), ())
+///     ]
+/// );
+///
 /// impl platform::Driver for MyDriver {
 ///     type IdInfo = ();
 ///     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+///     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 ///
 ///     fn probe(
 ///         _pdev: &platform::Device<Core>,

@@ -164,6 +180,9 @@ pub trait Driver: Send {
     /// The table of OF device ids supported by the driver.
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
 
+    /// The table of ACPI device ids supported by the driver.
+    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = None;
+
     /// Platform driver probe.
     ///
     /// Called when a new platform device is added or discovered.

index 8b42b3cfb363..35d5067aa023 100644
@@ -2,7 +2,7 @@
 
 //! Rust Platform driver sample.
 
-use kernel::{c_str, device::Core, of, platform, prelude::*, types::ARef};
+use kernel::{acpi, c_str, device::Core, of, platform, prelude::*, types::ARef};
 
 struct SampleDriver {
     pdev: ARef<platform::Device>,

@@ -17,9 +17,78 @@ struct SampleDriver {
     [(of::DeviceId::new(c_str!("test,rust-device")), Info(42))]
 );
 
+// ACPI match table test
+//
+// This demonstrates how to test an ACPI-based Rust platform driver using QEMU
+// with a custom SSDT.
+//
+// Steps:
+//
+// 1. **Create an SSDT source file** (`ssdt.dsl`) with the following content:
+//
+//     ```asl
+//     DefinitionBlock ("", "SSDT", 2, "TEST", "VIRTACPI", 0x00000001)
+//     {
+//         Scope (\_SB)
+//         {
+//             Device (T432)
+//             {
+//                 Name (_HID, "TEST4321")  // ACPI hardware ID to match
+//                 Name (_UID, 1)
+//                 Name (_STA, 0x0F)        // Device present, enabled
+//                 Name (_CRS, ResourceTemplate ()
+//                 {
+//                     Memory32Fixed (ReadWrite, 0xFED00000, 0x1000)
+//                 })
+//             }
+//         }
+//     }
+//     ```
+//
+// 2. **Compile the table**:
+//
+//     ```sh
+//     iasl -tc ssdt.dsl
+//     ```
+//
+//     This generates `ssdt.aml`
+//
+// 3. **Run QEMU** with the compiled AML file:
+//
+//     ```sh
+//     qemu-system-x86_64 -m 512M \
+//         -enable-kvm \
+//         -kernel path/to/bzImage \
+//         -append "root=/dev/sda console=ttyS0" \
+//         -hda rootfs.img \
+//         -serial stdio \
+//         -acpitable file=ssdt.aml
+//     ```
+//
+//     Requirements:
+//     - The `rust_driver_platform` must be present either:
+//         - built directly into the kernel (`bzImage`), or
+//         - available as a `.ko` file and loadable from `rootfs.img`
+//
+// 4. **Verify it worked** by checking `dmesg`:
+//
+//     ```
+//     rust_driver_platform TEST4321:00: Probed with info: '0'.
+//     ```
+//
+// This demonstrates ACPI table matching using a custom ID in QEMU with a minimal SSDT
+
+kernel::acpi_device_table!(
+    ACPI_TABLE,
+    MODULE_ACPI_TABLE,
+    <SampleDriver as platform::Driver>::IdInfo,
+    [(acpi::DeviceId::new(c_str!("TEST4321")), Info(0))]
+);
+
 impl platform::Driver for SampleDriver {
     type IdInfo = Info;
     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
 
     fn probe(
         pdev: &platform::Device<Core>,

index 08f68e2dac4a..177b9ffd7ba4 100644
@@ -6,3 +6,9 @@ void rust_helper_fwnode_handle_put(struct fwnode_handle *fwnode)
 {
 	fwnode_handle_put(fwnode);
 }
+
+bool rust_helper_fwnode_device_is_compatible(const struct fwnode_handle *fwnode,
+					     const char *match)
+{
+	return fwnode_device_is_compatible(fwnode, match);
+}

index 838509111e57..a946bf8d5571 100644
@@ -93,6 +93,15 @@ pub fn property_present(&self, name: &CStr) -> bool {
         unsafe { bindings::fwnode_property_present(self.as_raw().cast_const(), name.as_char_ptr()) }
     }
 
+    /// Return `true` if this [`FwNode`] is compatible with `match_str`, `false` otherwise.
+    pub fn is_compatible(&self, match_str: &CStr) -> bool {
+        // SAFETY:
+        // - By the invariant of `CStr`, `name.as_char_ptr()` is valid and null-terminated.
+        // - The type invariant of `Self` guarantees that `self.as_raw() is a pointer to a valid
+        //   `struct fwnode_handle`.
+        unsafe { bindings::fwnode_device_is_compatible(self.as_raw(), match_str.as_char_ptr()) }
+    }
+
     /// Returns firmware property `name` boolean value.
     pub fn property_read_bool(&self, name: &CStr) -> bool {
         // SAFETY:

index c0abf78d0683..000bb915af60 100644
@@ -32,13 +32,15 @@ fn probe(
         pdev: &platform::Device<Core>,
         info: Option<&Self::IdInfo>,
     ) -> Result<Pin<KBox<Self>>> {
-        dev_dbg!(pdev.as_ref(), "Probe Rust Platform driver sample.\n");
+        let dev = pdev.as_ref();
+
+        dev_dbg!(dev, "Probe Rust Platform driver sample.\n");
 
         if let Some(info) = info {
-            dev_info!(pdev.as_ref(), "Probed with info: '{}'.\n", info.0);
+            dev_info!(dev, "Probed with info: '{}'.\n", info.0);
         }
 
-        Self::properties_parse(pdev.as_ref())?;
+        Self::properties_parse(dev)?;
 
         let drvdata = KBox::new(Self { pdev: pdev.into() }, GFP_KERNEL)?;
 

index 000bb915af60..036dd0b899b0 100644
@@ -40,7 +40,12 @@ fn probe(
             dev_info!(dev, "Probed with info: '{}'.\n", info.0);
         }
 
-        Self::properties_parse(dev)?;
+        if dev
+            .fwnode()
+            .is_some_and(|node| node.is_compatible(c_str!("test,rust-device")))
+        {
+            Self::properties_parse(dev)?;
+        }
 
         let drvdata = KBox::new(Self { pdev: pdev.into() }, GFP_KERNEL)?;