[PATCH v6 0/6] rust: Add ACPI match table support for Rust drivers

[PATCH v6 0/6] rust: Add ACPI match table support for Rust drivers

[Igor Korotin]

This patch series introduces support for ACPI match tables in Rust 
drivers.

Currently, Rust abstractions support only Open Firmware (OF) device 
matching. This series extends the driver model to support ACPI-based 
matching, enabling Rust drivers to bind to ACPI-described devices.

Changes include:
  - A new `acpi::DeviceId` abstraction for working with 
   `struct acpi_device_id`.
  - Updates to the core `Adapter` trait and `platform::Driver` to support
    optional ACPI ID tables.
  - A sample implementation in the Rust platform driver, demonstrating 
    multi-bus matching.

This is especially useful for writing drivers that work across platforms 
using both OF and ACPI.

Tested using QEMU with a custom SSDT that creates an ACPI device matching
the sample Rust platform driver.

Igor Korotin (6):
  rust: acpi: add `acpi::DeviceId` abstraction
  rust: driver: Consolidate `Adapter::of_id_info` methods using `#[cfg]`
  rust: driver: Add ACPI id table support to Adapter trait
  rust: platform: Set `OF_ID_TABLE` default to `None` in `Driver` trait
  rust: platform: Add ACPI match table support to `Driver` trait
  samples: rust: add ACPI match table example to platform driver

Changelog
---------
v6:
 - Moved set `Driver::OF_ID_TABLE` default to `None` to a separate commit 
 - Removed out of scope change related to cpufreq driver.
 - Link to v5: https://lore.kernel.org/rust-for-linux/20250611174034.801460-1-igor.korotin.linux@gmail.com/
v5:
 - Got rid of unnecessary consolidation of `Adapter::acpi_id_info` methods.
   Instead, firstly made consolidation of `Adapter::of_id_info`, then
   `Adapter::acpi_id_info` is added using the same pattern. 
 - Set `Adapter::OF_ID_TABLE` and `Adapter::ACPI_ID_TABLE` as None by 
   default. 
 - Removed `Adapter::OF_ID_TABLE`/`Adapter::ACPI_ID_TABLE` initialization
   example due to irrelevance.
 - Removed extra `of` dependency and `Adapter::OF_ID_TABLE` initialization 
   in cpufreq driver.
 - Link to v4: https://lore.kernel.org/rust-for-linux/20250610145234.235005-1-igor.korotin.linux@gmail.com/
v4:
 - Fixed code example for `trait Adapter` in platform.rs 
 - Fixed driver implementation example in rust_driver_platform.rs and moved
   it to `trait Adapter` in platform.rs per Danilo Krummrich's suggestion.
 - Consolidated `Adapter::of_id_info` and `Adapter::acpi_id_info` methods using
   `#[cfg]` per Benno Lossin's suggestion.
 - Link to v3: https://lore.kernel.org/rust-for-linux/20250606170341.3880941-1-igor.korotin.linux@gmail.com/
v3:
 - Removed fwnode type check in `Adapter::id_info` per Greg's and Danilo's
   comments
 - Removed `is_of_node` rust helper, due to unnecessity. 
 - Fixed example code in `rust_driver_platform.rs` per Danilo's comment
 - Added an instruction of testing ACPI using QEMU with a custom SSDT
 - Fixed minor code formatting issues.
 - Link to v2: https://lore.kernel.org/rust-for-linux/20250605161956.3658374-1-igor.korotin.linux@gmail.com/
v2:
 - Removed misleading comment in `acpi::DeviceID` implementation. 
 - Removed unnecessary casting in `acpi::DeviceID::new`.
 - Moved `pub mod acpi` to correct alphabetical position in `rust/kernel/lib.rs`.
 - Link to v1: https://lore.kernel.org/rust-for-linux/20250530123815.1766726-1-igor.korotin.linux@gmail.com/

 MAINTAINERS                          |  1 +
 rust/bindings/bindings_helper.h      |  1 +
 rust/kernel/acpi.rs                  | 61 +++++++++++++++++++++
 rust/kernel/driver.rs                | 81 +++++++++++++++++++++-------
 rust/kernel/lib.rs                   |  1 +
 rust/kernel/platform.rs              | 29 ++++++++--
 samples/rust/rust_driver_platform.rs | 71 +++++++++++++++++++++++-
 7 files changed, 221 insertions(+), 24 deletions(-)
 create mode 100644 rust/kernel/acpi.rs


base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
-- 
2.43.0

[PATCH v6 1/6] rust: acpi: add `acpi::DeviceId` abstraction

[Igor Korotin]

`acpi::DeviceId` is an abstraction around `struct acpi_device_id`.

This is used by subsequent patches, in particular the i2c driver
abstractions, to create ACPI device ID tables.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 MAINTAINERS         |  1 +
 rust/kernel/acpi.rs | 61 +++++++++++++++++++++++++++++++++++++++++++++
 rust/kernel/lib.rs  |  1 +
 3 files changed, 63 insertions(+)
 create mode 100644 rust/kernel/acpi.rs

diff --git a/MAINTAINERS b/MAINTAINERS
index a92290fffa16..6c809ea30e6a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -302,6 +302,7 @@ F:	include/linux/acpi.h
 F:	include/linux/fwnode.h
 F:	include/linux/fw_table.h
 F:	lib/fw_table.c
+F:	rust/kernel/acpi.rs
 F:	tools/power/acpi/
 
 ACPI APEI
diff --git a/rust/kernel/acpi.rs b/rust/kernel/acpi.rs
new file mode 100644
index 000000000000..f9a98dc4eb8a
--- /dev/null
+++ b/rust/kernel/acpi.rs
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Advanced Configuration and Power Interface abstractions.
+
+use crate::{bindings, device_id::RawDeviceId, prelude::*};
+
+/// IdTable type for ACPI drivers.
+pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
+
+/// An ACPI device id.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct DeviceId(bindings::acpi_device_id);
+
+// SAFETY:
+// * `DeviceId` is a `#[repr(transparent)` wrapper of `struct acpi_device_id` and does not add
+//   additional invariants, so it's safe to transmute to `RawType`.
+// * `DRIVER_DATA_OFFSET` is the offset to the `data` field.
+unsafe impl RawDeviceId for DeviceId {
+    type RawType = bindings::acpi_device_id;
+
+    const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::acpi_device_id, driver_data);
+
+    fn index(&self) -> usize {
+        self.0.driver_data as _
+    }
+}
+
+impl DeviceId {
+    const ACPI_ID_LEN: usize = 16;
+
+    /// Create a new device id from an ACPI 'id' string.
+    pub const fn new(id: &'static CStr) -> Self {
+        assert!(id.len() <= Self::ACPI_ID_LEN, "ID exceeds 16 bytes");
+        let src = id.as_bytes_with_nul();
+        // Replace with `bindings::acpi_device_id::default()` once stabilized for `const`.
+        // SAFETY: FFI type is valid to be zero-initialized.
+        let mut acpi: bindings::acpi_device_id = unsafe { core::mem::zeroed() };
+        let mut i = 0;
+        while i < src.len() {
+            acpi.id[i] = src[i];
+            i += 1;
+        }
+
+        Self(acpi)
+    }
+}
+
+/// Create an ACPI `IdTable` with an "alias" for modpost.
+#[macro_export]
+macro_rules! acpi_device_table {
+    ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {
+        const $table_name: $crate::device_id::IdArray<
+            $crate::acpi::DeviceId,
+            $id_info_type,
+            { $table_data.len() },
+        > = $crate::device_id::IdArray::new($table_data);
+
+        $crate::module_device_table!("acpi", $module_table_name, $table_name);
+    };
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 6b4774b2b1c3..5bbf3627212f 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -51,6 +51,7 @@
 
 pub use ffi;
 
+pub mod acpi;
 pub mod alloc;
 #[cfg(CONFIG_AUXILIARY_BUS)]
 pub mod auxiliary;
-- 
2.43.0

[PATCH v6 2/6] rust: driver: Consolidate `Adapter::of_id_info` methods using `#[cfg]`

[Igor Korotin]

Refactor the `of_id_info` methods in the `Adapter` trait to reduce
duplication. Previously, the method had two versions selected
via `#[cfg(...)]` and `#[cfg(not(...))]`. This change merges them into a
single method by using `#[cfg]` blocks within the method body.

Suggested-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 rust/kernel/driver.rs | 40 +++++++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 19 deletions(-)

diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs
index ec9166cedfa7..cb62b75a0c0e 100644
--- a/rust/kernel/driver.rs
+++ b/rust/kernel/driver.rs
@@ -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.
-- 
2.43.0

[PATCH v6 3/6] rust: driver: Add ACPI id table support to Adapter trait

[Igor Korotin]

Extend the `Adapter` trait to support ACPI device identification.

This mirrors the existing Open Firmware (OF) support (`of_id_table`) and
enables Rust drivers to match and retrieve ACPI-specific device data
when `CONFIG_ACPI` is enabled.

To avoid breaking compilation, a stub implementation of `acpi_id_table()`
is added to the Platform adapter; the full implementation will be provided
in a subsequent patch.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 rust/bindings/bindings_helper.h |  1 +
 rust/kernel/driver.rs           | 41 ++++++++++++++++++++++++++++++++-
 rust/kernel/platform.rs         |  6 ++++-
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index bc494745f67b..dfb2dd500ef6 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -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>
diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs
index cb62b75a0c0e..8389c122a047 100644
--- a/rust/kernel/driver.rs
+++ b/rust/kernel/driver.rs
@@ -6,7 +6,7 @@
 //! register using the [`Registration`] class.
 
 use crate::error::{Error, Result};
-use crate::{device, of, str::CStr, try_pin_init, types::Opaque, ThisModule};
+use crate::{acpi, device, of, str::CStr, try_pin_init, types::Opaque, ThisModule};
 use core::pin::Pin;
 use pin_init::{pin_data, pinned_drop, PinInit};
 
@@ -141,6 +141,40 @@ pub trait Adapter {
     /// The type holding driver private data about each device id supported by the driver.
     type IdInfo: 'static;
 
+    /// The [`acpi::IdTable`] of the corresponding driver
+    fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>>;
+
+    /// Returns the driver's private data from the matching entry in the [`acpi::IdTable`], if any.
+    ///
+    /// If this returns `None`, it means there is no match with an entry in the [`acpi::IdTable`].
+    fn acpi_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
+        #[cfg(not(CONFIG_ACPI))]
+        {
+            let _ = dev;
+            return None;
+        }
+
+        #[cfg(CONFIG_ACPI)]
+        {
+            let table = Self::acpi_id_table()?;
+
+            // 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::acpi_match_device(table.as_ptr(), dev.as_raw()) };
+
+            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::<acpi::DeviceId>() };
+
+                Some(table.info(<acpi::DeviceId as crate::device_id::RawDeviceId>::index(id)))
+            }
+        }
+    }
+
     /// The [`of::IdTable`] of the corresponding driver.
     fn of_id_table() -> Option<of::IdTable<Self::IdInfo>>;
 
@@ -180,6 +214,11 @@ fn of_id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
     /// If this returns `None`, it means that there is no match in any of the ID tables directly
     /// associated with a [`device::Device`].
     fn id_info(dev: &device::Device) -> Option<&'static Self::IdInfo> {
+        let id = Self::acpi_id_info(dev);
+        if id.is_some() {
+            return id;
+        }
+
         let id = Self::of_id_info(dev);
         if id.is_some() {
             return id;
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 5b21fa517e55..5923d29a0511 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -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.
-- 
2.43.0

[PATCH v6 4/6] rust: platform: Set `OF_ID_TABLE` default to `None` in `Driver` trait

[Igor Korotin]

Provide a default value of `None` for `Driver::OF_ID_TABLE` to simplify
driver implementations.

Drivers that do not require OpenFirmware matching no longer need to
import the `of` module or define the constant explicitly.

This reduces unnecessary boilerplate and avoids pulling in unused
dependencies.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 rust/kernel/platform.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 5923d29a0511..2436f55b579b 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -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.
     ///
-- 
2.43.0

[PATCH v6 5/6] rust: platform: Add ACPI match table support to `Driver` trait

[Igor Korotin]

Extend the `platform::Driver` trait to support ACPI device matching by
adding the `ACPI_ID_TABLE` constant.

This allows Rust platform drivers to define ACPI match tables alongside
their existing OF match tables. These changes mirror the existing OF
support and allow Rust platform drivers to match devices based on ACPI
identifiers.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 rust/kernel/platform.rs | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 2436f55b579b..62a9e4ec5c19 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -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.
-- 
2.43.0

[PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Igor Korotin]

Extend the Rust sample platform driver to probe using device/driver name
matching, OF ID table matching, or ACPI ID table matching.

Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
---
 samples/rust/rust_driver_platform.rs | 71 +++++++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 1 deletion(-)

diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index 8b42b3cfb363..35d5067aa023 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -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>,
-- 
2.43.0

[PATCH 1/3] rust: device: implement FwNode::is_compatible()

[Danilo Krummrich]

Implement FwNode::is_compatible() to check whether a given match string
is compatible with a FwNode.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/helpers/property.c        | 6 ++++++
 rust/kernel/device/property.rs | 9 +++++++++
 2 files changed, 15 insertions(+)

diff --git a/rust/helpers/property.c b/rust/helpers/property.c
index 08f68e2dac4a..177b9ffd7ba4 100644
--- a/rust/helpers/property.c
+++ b/rust/helpers/property.c
@@ -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);
+}
diff --git a/rust/kernel/device/property.rs b/rust/kernel/device/property.rs
index 838509111e57..a946bf8d5571 100644
--- a/rust/kernel/device/property.rs
+++ b/rust/kernel/device/property.rs
@@ -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:

base-commit: 2a1ea59de83bf367215e2a4dd9bf8bbd061349b3
-- 
2.49.0

[PATCH 2/3] samples: rust: platform: don't call as_ref() repeatedly

[Danilo Krummrich]

In SampleDriver::probe() don't call pdev.as_ref() repeatedly, instead
introduce a dedicated &Device.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 samples/rust/rust_driver_platform.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index c0abf78d0683..000bb915af60 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -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)?;
 
-- 
2.49.0

[PATCH 3/3] samples: rust: platform: conditionally call Self::properties_parse()

[Danilo Krummrich]

Only call Self::properties_parse() when the device is compatible with
"test,rust-device".

Once we add ACPI support, we don't want the ACPI device to fail probing
in Self::properties_parse().

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 samples/rust/rust_driver_platform.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index 000bb915af60..036dd0b899b0 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -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)?;
 
-- 
2.49.0

Re: [PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Danilo Krummrich]

On Fri, Jun 13, 2025 at 02:54:07PM +0100, Igor Korotin wrote:
> Extend the Rust sample platform driver to probe using device/driver name
> matching, OF ID table matching, or ACPI ID table matching.

Can you please rebase onto driver-core-next? You may also want to add the three
patches I sent as a reply to this one to your series.

> Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
> ---
>  samples/rust/rust_driver_platform.rs | 71 +++++++++++++++++++++++++++-
>  1 file changed, 70 insertions(+), 1 deletion(-)
> 
> diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
> index 8b42b3cfb363..35d5067aa023 100644
> --- a/samples/rust/rust_driver_platform.rs
> +++ b/samples/rust/rust_driver_platform.rs
> @@ -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

Can you please move this up into the module-level documentation?

> +kernel::acpi_device_table!(
> +    ACPI_TABLE,
> +    MODULE_ACPI_TABLE,
> +    <SampleDriver as platform::Driver>::IdInfo,
> +    [(acpi::DeviceId::new(c_str!("TEST4321")), Info(0))]

Let's use something like "SAMPLE_DRV0" instead.

> +);
> +
>  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>,
> -- 
> 2.43.0
> 

Re: [PATCH v6 1/6] rust: acpi: add `acpi::DeviceId` abstraction

[Danilo Krummrich]

On Fri, Jun 13, 2025 at 02:38:42PM +0100, Igor Korotin wrote:
> +impl DeviceId {
> +    const ACPI_ID_LEN: usize = 16;
> +
> +    /// Create a new device id from an ACPI 'id' string.
> +    pub const fn new(id: &'static CStr) -> Self {
> +        assert!(id.len() <= Self::ACPI_ID_LEN, "ID exceeds 16 bytes");

Please use build_assert!() for this check.

> +        let src = id.as_bytes_with_nul();
> +        // Replace with `bindings::acpi_device_id::default()` once stabilized for `const`.
> +        // SAFETY: FFI type is valid to be zero-initialized.
> +        let mut acpi: bindings::acpi_device_id = unsafe { core::mem::zeroed() };
> +        let mut i = 0;
> +        while i < src.len() {
> +            acpi.id[i] = src[i];
> +            i += 1;
> +        }
> +
> +        Self(acpi)
> +    }
> +}

Re: [PATCH 2/3] samples: rust: platform: don't call as_ref() repeatedly

[Dirk Behme]

On 16/06/2025 21:40, Danilo Krummrich wrote:
> In SampleDriver::probe() don't call pdev.as_ref() repeatedly, instead
> introduce a dedicated &Device.
> 
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
>  samples/rust/rust_driver_platform.rs | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
> index c0abf78d0683..000bb915af60 100644
> --- a/samples/rust/rust_driver_platform.rs
> +++ b/samples/rust/rust_driver_platform.rs
> @@ -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)?;

Yes!

Reviewed-by: Dirk Behme <dirk.behme@de.bosch.com>

Thanks,

Dirk

Re: [PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Igor Korotin]

On 6/16/25 20:52, Danilo Krummrich wrote:
>> +kernel::acpi_device_table!(
>> +    ACPI_TABLE,
>> +    MODULE_ACPI_TABLE,
>> +    <SampleDriver as platform::Driver>::IdInfo,
>> +    [(acpi::DeviceId::new(c_str!("TEST4321")), Info(0))]
> 
> Let's use something like "SAMPLE_DRV0" instead.

Nope, that's prohibited by ACPI HID naming rules. A brief description
can be found here:
https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html.
According to section 6.1.5, ACPI IDs must be 7 or 8 characters long and
follow the format "AAA####" or "AAAA####", where A is an uppercase
letter [A–Z] and # is an uppercase letter or digit [A–Z, 0–9]. No
underscores or special characters are allowed.

The `iasl` utility throws an error if an invalid HID string is used in a
dsl file.

I could suggest on of the following:
DRV0001
DRVR0001
PDRV0001
TEST0001
TST0001

Let me know which one you'd prefer for the code and documentation.

Best Regards
Igor

Re: [PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Danilo Krummrich]

On Tue, Jun 17, 2025 at 05:39:07PM +0100, Igor Korotin wrote:
> I could suggest on of the following:
> DRV0001
> DRVR0001
> PDRV0001

This one looks reasonable to me.

> TEST0001
> TST0001

Re: [PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Rafael J. Wysocki]

On Tue, Jun 17, 2025 at 7:15 PM Danilo Krummrich <dakr@kernel.org> wrote:
>
> On Tue, Jun 17, 2025 at 05:39:07PM +0100, Igor Korotin wrote:
> > I could suggest on of the following:
> > DRV0001
> > DRVR0001
> > PDRV0001
>
> This one looks reasonable to me.
>
> > TEST0001
> > TST0001

Can we please avoid using made up device IDs in the code, even if it
is just sample code?

It is way better to use a real one that's been reserved already as
"never use in real ACPI tables" for some reason.  I think I can find a
few of these for you if need be.

Thanks!

Re: [PATCH v6 6/6] samples: rust: add ACPI match table example to platform driver

[Danilo Krummrich]

On Wed, Jun 25, 2025 at 11:17:33AM +0200, Rafael J. Wysocki wrote:
> On Tue, Jun 17, 2025 at 7:15 PM Danilo Krummrich <dakr@kernel.org> wrote:
> >
> > On Tue, Jun 17, 2025 at 05:39:07PM +0100, Igor Korotin wrote:
> > > I could suggest on of the following:
> > > DRV0001
> > > DRVR0001
> > > PDRV0001
> >
> > This one looks reasonable to me.
> >
> > > TEST0001
> > > TST0001
> 
> Can we please avoid using made up device IDs in the code, even if it
> is just sample code?
> 
> It is way better to use a real one that's been reserved already as
> "never use in real ACPI tables" for some reason.  I think I can find a
> few of these for you if need be.
> 
> Thanks!

Sure! Please let me know which one you think fits best and I'll use it instead
of "TST0001" when I apply the series.

- Danilo