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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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//! Abstractions for the platform bus.//!//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
use crate::{ acpi, bindings, container_of, device::{ self, Bound, // }, driver, error::{ from_result, to_result, // }, io::{ mem::IoRequest, Resource, // }, irq::{ self, IrqRequest, // }, of, prelude::*, types::Opaque, ThisModule, //};
use core::{ marker::PhantomData, mem::offset_of, ptr::{ addr_of_mut, NonNull, // },};
/// An adapter for the registration of platform drivers.pub struct Adapter<T: Driver>(T);
// SAFETY:// - `bindings::platform_driver` is a C type declared as `repr(C)`.// - `T::Data` is the type of the driver's device private data.// - `struct platform_driver` embeds a `struct device_driver`.// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.unsafe impl<T: Driver> driver::DriverLayout for Adapter<T> { type DriverType = bindings::platform_driver; type DriverData<'bound> = T::Data<'bound>; const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);}
// SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if// a preceding call to `register` has been successful.unsafe impl<T: Driver> driver::RegistrationOps for Adapter<T> { unsafe fn register( pdrv: &Opaque<Self::DriverType>, name: &'static CStr, module: &'static ThisModule, ) -> Result { let of_table = match T::OF_ID_TABLE { Some(table) => table.as_ptr(), 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 `DriverType`. to_result(unsafe { bindings::__platform_driver_register(pdrv.get(), module.0, name.as_char_ptr()) }) }
unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) { // SAFETY: `pdrv` is guaranteed to be a valid `DriverType`. unsafe { bindings::platform_driver_unregister(pdrv.get()) }; }}
impl<T: Driver> Adapter<T> { extern "C" fn probe_callback(pdev: *mut bindings::platform_device) -> kernel::ffi::c_int { // SAFETY: The platform bus only ever calls the probe callback with a valid pointer to a // `struct platform_device`. // // INVARIANT: `pdev` is valid for the duration of `probe_callback()`. let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() }; let info = <Self as driver::Adapter>::id_info(pdev.as_ref());
from_result(|| { let data = T::probe(pdev, info);
pdev.as_ref().set_drvdata(data)?; Ok(0) }) }
extern "C" fn remove_callback(pdev: *mut bindings::platform_device) { // SAFETY: The platform bus only ever calls the remove callback with a valid pointer to a // `struct platform_device`. // // INVARIANT: `pdev` is valid for the duration of `remove_callback()`. let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() };
// SAFETY: `remove_callback` is only ever called after a successful call to // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called // and stored a `Pin<KBox<T::Data<'_>>>`. let data = unsafe { pdev.as_ref().drvdata_borrow::<T::Data<'_>>() };
T::unbind(pdev, data); }}
impl<T: Driver> driver::Adapter for Adapter<T> { type IdInfo = T::IdInfo;
fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> { T::OF_ID_TABLE }
fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> { T::ACPI_ID_TABLE }}
/// Declares a kernel module that exposes a single platform driver.////// # Examples////// ```ignore/// kernel::module_platform_driver! {/// type: MyDriver,/// name: "Module name",/// authors: ["Author name"],/// description: "Description",/// license: "GPL v2",/// }/// ```#[macro_export]macro_rules! module_platform_driver { ($($f:tt)*) => { $crate::module_driver!(<T>, $crate::platform::Adapter<T>, { $($f)* }); };}
/// The platform driver trait.////// Drivers must implement this trait in order to get a platform driver registered.////// # Examples//////```/// # use kernel::{/// # acpi,/// # bindings,/// # device::Core,/// # of,/// # platform,/// # };/// struct MyDriver;////// kernel::of_device_table!(/// OF_TABLE,/// MODULE_OF_TABLE,/// <MyDriver as platform::Driver>::IdInfo,/// [/// (of::DeviceId::new(c"test,device"), ())/// ]/// );////// kernel::acpi_device_table!(/// ACPI_TABLE,/// MODULE_ACPI_TABLE,/// <MyDriver as platform::Driver>::IdInfo,/// [/// (acpi::DeviceId::new(c"LNUXBEEF"), ())/// ]/// );////// impl platform::Driver for MyDriver {/// type IdInfo = ();/// type Data<'bound> = Self;/// 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<'bound>(/// _pdev: &'bound platform::Device<Core<'_>>,/// _id_info: Option<&'bound Self::IdInfo>,/// ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {/// Err(ENODEV)/// }/// }///```pub trait Driver { /// The type holding driver private data about each device id supported by the driver. // TODO: Use associated_type_defaults once stabilized: // // ``` // type IdInfo: 'static = (); // ``` type IdInfo: 'static;
/// The type of the driver's bus device private data. type Data<'bound>: Send + 'bound;
/// 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. /// Implementers should attempt to initialize the device here. fn probe<'bound>( dev: &'bound Device<device::Core<'_>>, id_info: Option<&'bound Self::IdInfo>, ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound;
/// Platform driver unbind. /// /// Called when a [`Device`] is unbound from its bound [`Driver`]. Implementing this callback /// is optional. /// /// This callback serves as a place for drivers to perform teardown operations that require a /// `&Device<Core>` or `&Device<Bound>` reference. For instance, drivers may try to perform I/O /// operations to gracefully tear down the device. /// /// Otherwise, release operations for driver resources should be performed in `Drop`. fn unbind<'bound>(dev: &'bound Device<device::Core<'_>>, this: Pin<&Self::Data<'bound>>) { let _ = (dev, this); }}
/// The platform device representation.////// This structure represents the Rust abstraction for a C `struct platform_device`. The/// implementation abstracts the usage of an already existing C `struct platform_device` within Rust/// code that we get passed from the C side.////// # Invariants////// A [`Device`] instance represents a valid `struct platform_device` created by the C portion of/// the kernel.#[repr(transparent)]pub struct Device<Ctx: device::DeviceContext = device::Normal>( Opaque<bindings::platform_device>, PhantomData<Ctx>,);
impl<Ctx: device::DeviceContext> Device<Ctx> { fn as_raw(&self) -> *mut bindings::platform_device { self.0.get() }
/// Returns the resource at `index`, if any. pub fn resource_by_index(&self, index: u32) -> Option<&Resource> { // SAFETY: `self.as_raw()` returns a valid pointer to a `struct platform_device`. let resource = unsafe { bindings::platform_get_resource(self.as_raw(), bindings::IORESOURCE_MEM, index) };
if resource.is_null() { return None; }
// SAFETY: `resource` is a valid pointer to a `struct resource` as // returned by `platform_get_resource`. Some(unsafe { Resource::from_raw(resource) }) }
/// Returns the resource with a given `name`, if any. pub fn resource_by_name(&self, name: &CStr) -> Option<&Resource> { // SAFETY: `self.as_raw()` returns a valid pointer to a `struct // platform_device` and `name` points to a valid C string. let resource = unsafe { bindings::platform_get_resource_byname( self.as_raw(), bindings::IORESOURCE_MEM, name.as_char_ptr(), ) };
if resource.is_null() { return None; }
// SAFETY: `resource` is a valid pointer to a `struct resource` as // returned by `platform_get_resource`. Some(unsafe { Resource::from_raw(resource) }) }}
impl Device<Bound> { /// Returns an `IoRequest` for the resource at `index`, if any. pub fn io_request_by_index(&self, index: u32) -> Option<IoRequest<'_>> { self.resource_by_index(index) // SAFETY: `resource` is a valid resource for `&self` during the // lifetime of the `IoRequest`. .map(|resource| unsafe { IoRequest::new(self.as_ref(), resource) }) }
/// Returns an `IoRequest` for the resource with a given `name`, if any. pub fn io_request_by_name(&self, name: &CStr) -> Option<IoRequest<'_>> { self.resource_by_name(name) // SAFETY: `resource` is a valid resource for `&self` during the // lifetime of the `IoRequest`. .map(|resource| unsafe { IoRequest::new(self.as_ref(), resource) }) }}
// SAFETY: `platform::Device` is a transparent wrapper of `struct platform_device`.// The offset is guaranteed to point to a valid device field inside `platform::Device`.unsafe impl<Ctx: device::DeviceContext> device::AsBusDevice<Ctx> for Device<Ctx> { const OFFSET: usize = offset_of!(bindings::platform_device, dev);}
macro_rules! define_irq_accessor_by_index { ( $(#[$meta:meta])* $fn_name:ident, $request_fn:ident, $reg_type:ident, $handler_trait:ident ) => { $(#[$meta])* pub fn $fn_name<'a, T: irq::$handler_trait + 'static>( &'a self, flags: irq::Flags, index: u32, name: &'static CStr, handler: impl PinInit<T, Error> + 'a, ) -> impl PinInit<irq::$reg_type<T>, Error> + 'a { pin_init::pin_init_scope(move || { let request = self.$request_fn(index)?;
Ok(irq::$reg_type::<T>::new( request, flags, name, handler, )) }) } };}
macro_rules! define_irq_accessor_by_name { ( $(#[$meta:meta])* $fn_name:ident, $request_fn:ident, $reg_type:ident, $handler_trait:ident ) => { $(#[$meta])* pub fn $fn_name<'a, T: irq::$handler_trait + 'static>( &'a self, flags: irq::Flags, irq_name: &'a CStr, name: &'static CStr, handler: impl PinInit<T, Error> + 'a, ) -> impl PinInit<irq::$reg_type<T>, Error> + 'a { pin_init::pin_init_scope(move || { let request = self.$request_fn(irq_name)?;
Ok(irq::$reg_type::<T>::new( request, flags, name, handler, )) }) } };}
impl Device<Bound> { /// Returns an [`IrqRequest`] for the IRQ at the given index, if any. pub fn irq_by_index(&self, index: u32) -> Result<IrqRequest<'_>> { // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`. let irq = unsafe { bindings::platform_get_irq(self.as_raw(), index) };
if irq < 0 { return Err(Error::from_errno(irq)); }
// SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`. Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) }) }
/// Returns an [`IrqRequest`] for the IRQ at the given index, but does not /// print an error if the IRQ cannot be obtained. pub fn optional_irq_by_index(&self, index: u32) -> Result<IrqRequest<'_>> { // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`. let irq = unsafe { bindings::platform_get_irq_optional(self.as_raw(), index) };
if irq < 0 { return Err(Error::from_errno(irq)); }
// SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`. Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) }) }
/// Returns an [`IrqRequest`] for the IRQ with the given name, if any. pub fn irq_by_name(&self, name: &CStr) -> Result<IrqRequest<'_>> { // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`. let irq = unsafe { bindings::platform_get_irq_byname(self.as_raw(), name.as_char_ptr()) };
if irq < 0 { return Err(Error::from_errno(irq)); }
// SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`. Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) }) }
/// Returns an [`IrqRequest`] for the IRQ with the given name, but does not /// print an error if the IRQ cannot be obtained. pub fn optional_irq_by_name(&self, name: &CStr) -> Result<IrqRequest<'_>> { // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`. let irq = unsafe { bindings::platform_get_irq_byname_optional(self.as_raw(), name.as_char_ptr()) };
if irq < 0 { return Err(Error::from_errno(irq)); }
// SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`. Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) }) }
define_irq_accessor_by_index!( /// Returns a [`irq::Registration`] for the IRQ at the given index. request_irq_by_index, irq_by_index, Registration, Handler ); define_irq_accessor_by_name!( /// Returns a [`irq::Registration`] for the IRQ with the given name. request_irq_by_name, irq_by_name, Registration, Handler ); define_irq_accessor_by_index!( /// Does the same as [`Self::request_irq_by_index`], except that it does /// not print an error message if the IRQ cannot be obtained. request_optional_irq_by_index, optional_irq_by_index, Registration, Handler ); define_irq_accessor_by_name!( /// Does the same as [`Self::request_irq_by_name`], except that it does /// not print an error message if the IRQ cannot be obtained. request_optional_irq_by_name, optional_irq_by_name, Registration, Handler );
define_irq_accessor_by_index!( /// Returns a [`irq::ThreadedRegistration`] for the IRQ at the given index. request_threaded_irq_by_index, irq_by_index, ThreadedRegistration, ThreadedHandler ); define_irq_accessor_by_name!( /// Returns a [`irq::ThreadedRegistration`] for the IRQ with the given name. request_threaded_irq_by_name, irq_by_name, ThreadedRegistration, ThreadedHandler ); define_irq_accessor_by_index!( /// Does the same as [`Self::request_threaded_irq_by_index`], except /// that it does not print an error message if the IRQ cannot be /// obtained. request_optional_threaded_irq_by_index, optional_irq_by_index, ThreadedRegistration, ThreadedHandler ); define_irq_accessor_by_name!( /// Does the same as [`Self::request_threaded_irq_by_name`], except that /// it does not print an error message if the IRQ cannot be obtained. request_optional_threaded_irq_by_name, optional_irq_by_name, ThreadedRegistration, ThreadedHandler );}
// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic// argument.kernel::impl_device_context_deref!(unsafe { Device });kernel::impl_device_context_into_aref!(Device);
impl<'a> crate::dma::Device<'a> for Device<device::Core<'a>> {}
// SAFETY: Instances of `Device` are always reference-counted.unsafe impl crate::sync::aref::AlwaysRefCounted for Device { fn inc_ref(&self) { // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero. unsafe { bindings::get_device(self.as_ref().as_raw()) }; }
unsafe fn dec_ref(obj: NonNull<Self>) { // SAFETY: The safety requirements guarantee that the refcount is non-zero. unsafe { bindings::platform_device_put(obj.cast().as_ptr()) } }}
impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> { fn as_ref(&self) -> &device::Device<Ctx> { // SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid // `struct platform_device`. let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };
// SAFETY: `dev` points to a valid `struct device`. unsafe { device::Device::from_raw(dev) } }}
impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> { type Error = kernel::error::Error;
fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> { // SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a // `struct device`. if !unsafe { bindings::dev_is_platform(dev.as_raw()) } { return Err(EINVAL); }
// SAFETY: We've just verified that the bus type of `dev` equals // `bindings::platform_bus_type`, hence `dev` must be embedded in a valid // `struct platform_device` as guaranteed by the corresponding C code. let pdev = unsafe { container_of!(dev.as_raw(), bindings::platform_device, dev) };
// SAFETY: `pdev` is a valid pointer to a `struct platform_device`. Ok(unsafe { &*pdev.cast() }) }}
// SAFETY: A `Device` is always reference-counted and can be released from any thread.unsafe impl Send for Device {}
// SAFETY: `Device` can be shared among threads because all methods of `Device`// (i.e. `Device<Normal>) are thread safe.unsafe impl Sync for Device {}
// SAFETY: Same as `Device<Normal>` -- the underlying `struct platform_device` is the same;// `Bound` is a zero-sized type-state marker that does not affect thread safety.unsafe impl Sync for Device<device::Bound> {}