Commit 7a718a1f authored by Danilo Krummrich's avatar Danilo Krummrich Committed by Greg Kroah-Hartman
Browse files

rust: driver: implement `Adapter` 



In order to not duplicate code in bus specific implementations (e.g.
platform), implement a generic `driver::Adapter` to represent the
connection of matched drivers and devices.

Bus specific `Adapter` implementations can simply implement this trait
to inherit generic functionality, such as matching OF or ACPI device IDs
and ID table entries.

Suggested-by: default avatarRob Herring (Arm) <robh@kernel.org>
Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
Tested-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20241219170425.12036-14-dakr@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bbe3b4d1

rust/bindings/bindings_helper.h

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/jump_label.h>

#include <linux/mdio.h>

#include <linux/miscdevice.h>

#include <linux/of_device.h>

#include <linux/pci.h>

#include <linux/phy.h>

#include <linux/pid_namespace.h>

rust/kernel/driver.rs

+57 −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::{init::PinInit, str::CStr, try_pin_init, types::Opaque, ThisModule};

use crate::{device, init::PinInit, of, str::CStr, try_pin_init, types::Opaque, ThisModule};

use core::pin::Pin;

use macros::{pin_data, pinned_drop};
@@ -115,3 +115,59 @@ fn init( 
        }

    }

}



/// The bus independent adapter to match a drivers and a devices.

///

/// This trait should be implemented by the bus specific adapter, which represents the connection

/// of a device and a driver.

///

/// It provides bus independent functions for device / driver interactions.

pub trait Adapter {

    /// The type holding driver private data about each device id supported by the driver.

    type IdInfo: 'static;



    /// The [`of::IdTable`] of the corresponding driver.

    fn of_id_table() -> Option<of::IdTable<Self::IdInfo>>;



    /// 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()?;



        // 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()) };



        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>() };



            Some(table.info(<of::DeviceId as crate::device_id::RawDeviceId>::index(id)))

        }

    }



    #[cfg(not(CONFIG_OF))]

    #[allow(missing_docs)]

    fn of_id_info(_dev: &device::Device) -> Option<&'static Self::IdInfo> {

        None

    }



    /// Returns the driver's private data from the matching entry of any of the ID tables, if any.

    ///

    /// 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::of_id_info(dev);

        if id.is_some() {

            return id;

        }



        None

    }

}