Merge tag 'char-misc-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscHEADmaster

Pull Char/Misc/IIO/Binder updates from Greg KH:
 "Here is the big set of char/misc/iio and other driver subsystem
  changes for 6.18-rc1.

  Loads of different stuff in here, it was a busy development cycle in
  lots of different subsystems, with over 27k new lines added to the
  tree.

  Included in here are:

   - IIO updates including new drivers, reworking of existing apis, and
     other goodness in the sensor subsystems

   - MEI driver updates and additions

   - NVMEM driver updates

   - slimbus removal for an unused driver and some other minor updates

   - coresight driver updates and additions

   - MHI driver updates

   - comedi driver updates and fixes

   - extcon driver updates

   - interconnect driver additions

   - eeprom driver updates and fixes

   - minor UIO driver updates

   - tiny W1 driver updates

  But the majority of new code is in the rust bindings and additions,
  which includes:

   - misc driver rust binding updates for read/write support, we can now
     write "normal" misc drivers in rust fully, and the sample driver
     shows how this can be done.

   - Initial framework for USB driver rust bindings, which are disabled
     for now in the build, due to limited support, but coming in through
     this tree due to dependencies on other rust binding changes that
     were in here. I'll be enabling these back on in the build in the
     usb.git tree after -rc1 is out so that developers can continue to
     work on these in linux-next over the next development cycle.

   - Android Binder driver implemented in Rust.

     This is the big one, and was driving a huge majority of the rust
     binding work over the past years. Right now there are two binder
     drivers in the kernel, selected only at build time as to which one
     to use as binder wants to be included in the system at boot time.

     The binder C maintainers all agreed on this, as eventually, they
     want the C code to be removed from the tree, but it will take a few
     releases to get there while both are maintained to ensure that the
     rust implementation is fully stable and compliant with the existing
     userspace apis.

  All of these have been in linux-next for a while"

* tag 'char-misc-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (320 commits)
  rust: usb: keep usb::Device private for now
  rust: usb: don't retain device context for the interface parent
  USB: disable rust bindings from the build for now
  samples: rust: add a USB driver sample
  rust: usb: add basic USB abstractions
  coresight: Add label sysfs node support
  dt-bindings: arm: Add label in the coresight components
  coresight: tnoc: add new AMBA ID to support Trace Noc V2
  coresight: Fix incorrect handling for return value of devm_kzalloc
  coresight: tpda: fix the logic to setup the element size
  coresight: trbe: Return NULL pointer for allocation failures
  coresight: Refactor runtime PM
  coresight: Make clock sequence consistent
  coresight: Refactor driver data allocation
  coresight: Consolidate clock enabling
  coresight: Avoid enable programming clock duplicately
  coresight: Appropriately disable trace bus clocks
  coresight: Appropriately disable programming clocks
  coresight: etm4x: Support atclk
  coresight: catu: Support atclk
  ...

1 files changed, 456 insertions, 0 deletions

diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
new file mode 100644
index 000000000000..14ddb711bab3
--- /dev/null
+++ b/rust/kernel/usb.rs
@@ -0,0 +1,456 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPDX-FileCopyrightText: Copyright (C) 2025 Collabora Ltd.
+
+//! Abstractions for the USB bus.
+//!
+//! C header: [`include/linux/usb.h`](srctree/include/linux/usb.h)
+
+use crate::{
+    bindings, device,
+    device_id::{RawDeviceId, RawDeviceIdIndex},
+    driver,
+    error::{from_result, to_result, Result},
+    prelude::*,
+    str::CStr,
+    types::{AlwaysRefCounted, Opaque},
+    ThisModule,
+};
+use core::{marker::PhantomData, mem::MaybeUninit, ptr::NonNull};
+
+/// An adapter for the registration of USB drivers.
+pub struct Adapter<T: Driver>(T);
+
+// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
+// a preceding call to `register` has been successful.
+unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
+    type RegType = bindings::usb_driver;
+
+    unsafe fn register(
+        udrv: &Opaque<Self::RegType>,
+        name: &'static CStr,
+        module: &'static ThisModule,
+    ) -> Result {
+        // SAFETY: It's safe to set the fields of `struct usb_driver` on initialization.
+        unsafe {
+            (*udrv.get()).name = name.as_char_ptr();
+            (*udrv.get()).probe = Some(Self::probe_callback);
+            (*udrv.get()).disconnect = Some(Self::disconnect_callback);
+            (*udrv.get()).id_table = T::ID_TABLE.as_ptr();
+        }
+
+        // SAFETY: `udrv` is guaranteed to be a valid `RegType`.
+        to_result(unsafe {
+            bindings::usb_register_driver(udrv.get(), module.0, name.as_char_ptr())
+        })
+    }
+
+    unsafe fn unregister(udrv: &Opaque<Self::RegType>) {
+        // SAFETY: `udrv` is guaranteed to be a valid `RegType`.
+        unsafe { bindings::usb_deregister(udrv.get()) };
+    }
+}
+
+impl<T: Driver + 'static> Adapter<T> {
+    extern "C" fn probe_callback(
+        intf: *mut bindings::usb_interface,
+        id: *const bindings::usb_device_id,
+    ) -> kernel::ffi::c_int {
+        // SAFETY: The USB core only ever calls the probe callback with a valid pointer to a
+        // `struct usb_interface` and `struct usb_device_id`.
+        //
+        // INVARIANT: `intf` is valid for the duration of `probe_callback()`.
+        let intf = unsafe { &*intf.cast::<Interface<device::CoreInternal>>() };
+
+        from_result(|| {
+            // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `struct usb_device_id` and
+            // does not add additional invariants, so it's safe to transmute.
+            let id = unsafe { &*id.cast::<DeviceId>() };
+
+            let info = T::ID_TABLE.info(id.index());
+            let data = T::probe(intf, id, info)?;
+
+            let dev: &device::Device<device::CoreInternal> = intf.as_ref();
+            dev.set_drvdata(data);
+            Ok(0)
+        })
+    }
+
+    extern "C" fn disconnect_callback(intf: *mut bindings::usb_interface) {
+        // SAFETY: The USB core only ever calls the disconnect callback with a valid pointer to a
+        // `struct usb_interface`.
+        //
+        // INVARIANT: `intf` is valid for the duration of `disconnect_callback()`.
+        let intf = unsafe { &*intf.cast::<Interface<device::CoreInternal>>() };
+
+        let dev: &device::Device<device::CoreInternal> = intf.as_ref();
+
+        // SAFETY: `disconnect_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>>`.
+        let data = unsafe { dev.drvdata_obtain::<Pin<KBox<T>>>() };
+
+        T::disconnect(intf, data.as_ref());
+    }
+}
+
+/// Abstraction for the USB device ID structure, i.e. [`struct usb_device_id`].
+///
+/// [`struct usb_device_id`]: https://docs.kernel.org/driver-api/basics.html#c.usb_device_id
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct DeviceId(bindings::usb_device_id);
+
+impl DeviceId {
+    /// Equivalent to C's `USB_DEVICE` macro.
+    pub const fn from_id(vendor: u16, product: u16) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: bindings::USB_DEVICE_ID_MATCH_DEVICE as u16,
+            idVendor: vendor,
+            idProduct: product,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_VER` macro.
+    pub const fn from_device_ver(vendor: u16, product: u16, bcd_lo: u16, bcd_hi: u16) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: bindings::USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION as u16,
+            idVendor: vendor,
+            idProduct: product,
+            bcdDevice_lo: bcd_lo,
+            bcdDevice_hi: bcd_hi,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_INFO` macro.
+    pub const fn from_device_info(class: u8, subclass: u8, protocol: u8) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: bindings::USB_DEVICE_ID_MATCH_DEV_INFO as u16,
+            bDeviceClass: class,
+            bDeviceSubClass: subclass,
+            bDeviceProtocol: protocol,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_INTERFACE_INFO` macro.
+    pub const fn from_interface_info(class: u8, subclass: u8, protocol: u8) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: bindings::USB_DEVICE_ID_MATCH_INT_INFO as u16,
+            bInterfaceClass: class,
+            bInterfaceSubClass: subclass,
+            bInterfaceProtocol: protocol,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_INTERFACE_CLASS` macro.
+    pub const fn from_device_interface_class(vendor: u16, product: u16, class: u8) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: (bindings::USB_DEVICE_ID_MATCH_DEVICE
+                | bindings::USB_DEVICE_ID_MATCH_INT_CLASS) as u16,
+            idVendor: vendor,
+            idProduct: product,
+            bInterfaceClass: class,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_INTERFACE_PROTOCOL` macro.
+    pub const fn from_device_interface_protocol(vendor: u16, product: u16, protocol: u8) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: (bindings::USB_DEVICE_ID_MATCH_DEVICE
+                | bindings::USB_DEVICE_ID_MATCH_INT_PROTOCOL) as u16,
+            idVendor: vendor,
+            idProduct: product,
+            bInterfaceProtocol: protocol,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_INTERFACE_NUMBER` macro.
+    pub const fn from_device_interface_number(vendor: u16, product: u16, number: u8) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: (bindings::USB_DEVICE_ID_MATCH_DEVICE
+                | bindings::USB_DEVICE_ID_MATCH_INT_NUMBER) as u16,
+            idVendor: vendor,
+            idProduct: product,
+            bInterfaceNumber: number,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+
+    /// Equivalent to C's `USB_DEVICE_AND_INTERFACE_INFO` macro.
+    pub const fn from_device_and_interface_info(
+        vendor: u16,
+        product: u16,
+        class: u8,
+        subclass: u8,
+        protocol: u8,
+    ) -> Self {
+        Self(bindings::usb_device_id {
+            match_flags: (bindings::USB_DEVICE_ID_MATCH_INT_INFO
+                | bindings::USB_DEVICE_ID_MATCH_DEVICE) as u16,
+            idVendor: vendor,
+            idProduct: product,
+            bInterfaceClass: class,
+            bInterfaceSubClass: subclass,
+            bInterfaceProtocol: protocol,
+            // SAFETY: It is safe to use all zeroes for the other fields of `usb_device_id`.
+            ..unsafe { MaybeUninit::zeroed().assume_init() }
+        })
+    }
+}
+
+// SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `usb_device_id` and does not add
+// additional invariants, so it's safe to transmute to `RawType`.
+unsafe impl RawDeviceId for DeviceId {
+    type RawType = bindings::usb_device_id;
+}
+
+// SAFETY: `DRIVER_DATA_OFFSET` is the offset to the `driver_info` field.
+unsafe impl RawDeviceIdIndex for DeviceId {
+    const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::usb_device_id, driver_info);
+
+    fn index(&self) -> usize {
+        self.0.driver_info
+    }
+}
+
+/// [`IdTable`](kernel::device_id::IdTable) type for USB.
+pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
+
+/// Create a USB `IdTable` with its alias for modpost.
+#[macro_export]
+macro_rules! usb_device_table {
+    ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {
+        const $table_name: $crate::device_id::IdArray<
+            $crate::usb::DeviceId,
+            $id_info_type,
+            { $table_data.len() },
+        > = $crate::device_id::IdArray::new($table_data);
+
+        $crate::module_device_table!("usb", $module_table_name, $table_name);
+    };
+}
+
+/// The USB driver trait.
+///
+/// # Examples
+///
+///```
+/// # use kernel::{bindings, device::Core, usb};
+/// use kernel::prelude::*;
+///
+/// struct MyDriver;
+///
+/// kernel::usb_device_table!(
+///     USB_TABLE,
+///     MODULE_USB_TABLE,
+///     <MyDriver as usb::Driver>::IdInfo,
+///     [
+///         (usb::DeviceId::from_id(0x1234, 0x5678), ()),
+///         (usb::DeviceId::from_id(0xabcd, 0xef01), ()),
+///     ]
+/// );
+///
+/// impl usb::Driver for MyDriver {
+///     type IdInfo = ();
+///     const ID_TABLE: usb::IdTable<Self::IdInfo> = &USB_TABLE;
+///
+///     fn probe(
+///         _interface: &usb::Interface<Core>,
+///         _id: &usb::DeviceId,
+///         _info: &Self::IdInfo,
+///     ) -> Result<Pin<KBox<Self>>> {
+///         Err(ENODEV)
+///     }
+///
+///     fn disconnect(_interface: &usb::Interface<Core>, _data: Pin<&Self>) {}
+/// }
+///```
+pub trait Driver {
+    /// The type holding information about each one of the device ids supported by the driver.
+    type IdInfo: 'static;
+
+    /// The table of device ids supported by the driver.
+    const ID_TABLE: IdTable<Self::IdInfo>;
+
+    /// USB driver probe.
+    ///
+    /// Called when a new USB interface is bound to this driver.
+    /// Implementers should attempt to initialize the interface here.
+    fn probe(
+        interface: &Interface<device::Core>,
+        id: &DeviceId,
+        id_info: &Self::IdInfo,
+    ) -> Result<Pin<KBox<Self>>>;
+
+    /// USB driver disconnect.
+    ///
+    /// Called when the USB interface is about to be unbound from this driver.
+    fn disconnect(interface: &Interface<device::Core>, data: Pin<&Self>);
+}
+
+/// A USB interface.
+///
+/// This structure represents the Rust abstraction for a C [`struct usb_interface`].
+/// The implementation abstracts the usage of a C [`struct usb_interface`] passed
+/// in from the C side.
+///
+/// # Invariants
+///
+/// An [`Interface`] instance represents a valid [`struct usb_interface`] created
+/// by the C portion of the kernel.
+///
+/// [`struct usb_interface`]: https://www.kernel.org/doc/html/latest/driver-api/usb/usb.html#c.usb_interface
+#[repr(transparent)]
+pub struct Interface<Ctx: device::DeviceContext = device::Normal>(
+    Opaque<bindings::usb_interface>,
+    PhantomData<Ctx>,
+);
+
+impl<Ctx: device::DeviceContext> Interface<Ctx> {
+    fn as_raw(&self) -> *mut bindings::usb_interface {
+        self.0.get()
+    }
+}
+
+// SAFETY: `Interface` is a transparent wrapper of a type that doesn't depend on
+// `Interface`'s generic argument.
+kernel::impl_device_context_deref!(unsafe { Interface });
+kernel::impl_device_context_into_aref!(Interface);
+
+impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Interface<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 usb_interface`.
+        let dev = unsafe { &raw mut ((*self.as_raw()).dev) };
+
+        // SAFETY: `dev` points to a valid `struct device`.
+        unsafe { device::Device::from_raw(dev) }
+    }
+}
+
+impl<Ctx: device::DeviceContext> AsRef<Device> for Interface<Ctx> {
+    fn as_ref(&self) -> &Device {
+        // SAFETY: `self.as_raw()` is valid by the type invariants.
+        let usb_dev = unsafe { bindings::interface_to_usbdev(self.as_raw()) };
+
+        // SAFETY: For a valid `struct usb_interface` pointer, the above call to
+        // `interface_to_usbdev()` guarantees to return a valid pointer to a `struct usb_device`.
+        unsafe { &*(usb_dev.cast()) }
+    }
+}
+
+// SAFETY: Instances of `Interface` are always reference-counted.
+unsafe impl AlwaysRefCounted for Interface {
+    fn inc_ref(&self) {
+        // SAFETY: The invariants of `Interface` guarantee that `self.as_raw()`
+        // returns a valid `struct usb_interface` pointer, for which we will
+        // acquire a new refcount.
+        unsafe { bindings::usb_get_intf(self.as_raw()) };
+    }
+
+    unsafe fn dec_ref(obj: NonNull<Self>) {
+        // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+        unsafe { bindings::usb_put_intf(obj.cast().as_ptr()) }
+    }
+}
+
+// SAFETY: A `Interface` is always reference-counted and can be released from any thread.
+unsafe impl Send for Interface {}
+
+// SAFETY: It is safe to send a &Interface to another thread because we do not
+// allow any mutation through a shared reference.
+unsafe impl Sync for Interface {}
+
+/// A USB device.
+///
+/// This structure represents the Rust abstraction for a C [`struct usb_device`].
+/// The implementation abstracts the usage of a C [`struct usb_device`] passed in
+/// from the C side.
+///
+/// # Invariants
+///
+/// A [`Device`] instance represents a valid [`struct usb_device`] created by the C portion of the
+/// kernel.
+///
+/// [`struct usb_device`]: https://www.kernel.org/doc/html/latest/driver-api/usb/usb.html#c.usb_device
+#[repr(transparent)]
+struct Device<Ctx: device::DeviceContext = device::Normal>(
+    Opaque<bindings::usb_device>,
+    PhantomData<Ctx>,
+);
+
+impl<Ctx: device::DeviceContext> Device<Ctx> {
+    fn as_raw(&self) -> *mut bindings::usb_device {
+        self.0.get()
+    }
+}
+
+// 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);
+
+// SAFETY: Instances of `Device` are always reference-counted.
+unsafe impl AlwaysRefCounted for Device {
+    fn inc_ref(&self) {
+        // SAFETY: The invariants of `Device` guarantee that `self.as_raw()`
+        // returns a valid `struct usb_device` pointer, for which we will
+        // acquire a new refcount.
+        unsafe { bindings::usb_get_dev(self.as_raw()) };
+    }
+
+    unsafe fn dec_ref(obj: NonNull<Self>) {
+        // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+        unsafe { bindings::usb_put_dev(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 usb_device`.
+        let dev = unsafe { &raw mut ((*self.as_raw()).dev) };
+
+        // SAFETY: `dev` points to a valid `struct device`.
+        unsafe { device::Device::from_raw(dev) }
+    }
+}
+
+// SAFETY: A `Device` is always reference-counted and can be released from any thread.
+unsafe impl Send for Device {}
+
+// SAFETY: It is safe to send a &Device to another thread because we do not
+// allow any mutation through a shared reference.
+unsafe impl Sync for Device {}
+
+/// Declares a kernel module that exposes a single USB driver.
+///
+/// # Examples
+///
+/// ```ignore
+/// module_usb_driver! {
+///     type: MyDriver,
+///     name: "Module name",
+///     author: ["Author name"],
+///     description: "Description",
+///     license: "GPL v2",
+/// }
+/// ```
+#[macro_export]
+macro_rules! module_usb_driver {
+    ($($f:tt)*) => {
+        $crate::module_driver!(<T>, $crate::usb::Adapter<T>, { $($f)* });
+    }
+}