Commit 7a5cb145 authored by Igor Korotin's avatar Igor Korotin Committed by Danilo Krummrich
Browse files

rust: driver: Add ACPI id table support to Adapter trait 



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: default avatarIgor Korotin <igor.korotin.linux@gmail.com>
Link: https://lore.kernel.org/r/20250620153914.295679-1-igor.korotin.linux@gmail.com


[ Fix clippy warning if #[cfg(not(CONFIG_OF))]; fix checkpatch.pl line
  length warnings. - Danilo ]
Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 0f549d25

rust/bindings/bindings_helper.h

+1 −0
Original line number Diff line number Diff line
@@ -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>

rust/kernel/driver.rs

+40 −1
Original line number Diff line number Diff line
@@ -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;

            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 `dev.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 acpi_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;

rust/kernel/platform.rs

+5 −1
Original line number Diff line number Diff line
@@ -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.