[PATCH v6 0/2] rust: input: add input/serio abstractions and port Gravis Stinger driver

[Vecheslav Filatov <harepro29@gmail.com>]

This patch series introduces safe Rust abstractions for Linux input
devices (struct input_dev) and the serio (Serial I/O) bus subsystem,
along with a port of the legacy Gravis Stinger serial gamepad driver
to safe Rust.

Changes in v6:
  - Developer identity: updated author and Signed-off-by to developer's
    real name (Vecheslav Filatov) across all commits to adhere to the
    Linux Kernel Developer's Certificate of Origin (DCO).
  - serio: eliminated constructor function-call syntax for
    bindings::irqreturn by directly pattern-matching Driver::interrupt()
    return values to canonical constants bindings::irqreturn::IRQ_NONE
    and bindings::irqreturn::IRQ_HANDLED, ensuring flawless compilation
    across all bindgen configurations (both type-alias and newtype).

Changes in v5:
  - serio: decoupled child device allocation and publication in Driver
    lifecycle (init -> start -> attach). Child input devices are
    allocated and configured before opening the port, but only registered
    via Driver::start() after serio_open() succeeds. This prevents
    premature registration and spurious uevents on probe failures.
  - serio: added C wrappers rust_helper_serio_pause_rx() and
    rust_helper_serio_continue_rx() to safely attach child devices in
    Driver::attach() under hardware RX pause, eliminating races with
    concurrent interrupts without sleeping.
  - serio: removed redundant Device::as_device() method and made
    Device::as_raw() crate-private (pub(crate)), relying on the standard
    AsRef<device::Device> implementation.

Changes in v4:
  - Makefile: restored analog.o and db9.o in joystick Makefile
    that were inadvertently removed during previous revisions.
  - serio: eliminated concurrent borrow_mut() and aliasing data races
    between connect_callback() and interrupt_callback() by initializing
    and registering the input device prior to serio_open().
  - serio: mapped interrupt return codes without missing constants.
  - serio & stinger: formatted all module imports in strict vertical
    style with trailing // comments.
  - serio: annotated Registration::drop() and Driver::disconnect() with
    #[inline].

Changes in v3:
  - input: added AllocatedDevice::set_phys_from_parent() to dynamically
    format the physical device path ("%s/input0") in an owned kernel
    heap buffer.
  - input: managed parent device reference counts in set_parent(), drop(),
    and register() using get_device()/put_device() to avoid dangling
    pointers and reference leaks.
  - input: eliminated manual cleanup duplication in register() by checking
    to_result() before mem::forget(self).
  - input: implemented Send and Sync for AllocatedDevice, added #[inline]
    on small methods, and formatted imports vertically.
  - serio: integrated serio::Device with kernel device abstractions via
    AsBusDevice, impl_device_context_deref!, and AsRef<device::Device>.
  - stinger: restored userspace-visible device name ("Gravis Stinger")
    and dynamic phys path, preserving udev and EVIOCGNAME compatibility.
  - stinger: maintained module name "stinger.ko" using Kbuild object
    aliasing under CONFIG_JOYSTICK_STINGER_RUST.

Changes in v2:
  - Combined serio subsystem abstractions and Gravis Stinger driver
    port into a single patch (2/2).
  - Retained original C driver (stinger.c) under CONFIG_JOYSTICK_STINGER
    and introduced CONFIG_JOYSTICK_STINGER_RUST to avoid regressions on
    architectures and configurations without Rust support.
  - Ensured IS_REACHABLE() guards for C helpers and #[cfg(CONFIG_* = "y")]
    for rust/kernel modules to prevent unresolved symbols.

Vecheslav Filatov (2):
  rust: input: add input device abstractions
  rust: serio: add serio bus abstractions and port Gravis Stinger driver

 drivers/input/joystick/Kconfig         |  14 ++
 drivers/input/joystick/Makefile        |   3 +
 drivers/input/joystick/stinger_rust.rs | 191 +++++++++++++++
 rust/bindings/bindings_helper.h        |   2 +
 rust/helpers/helpers.c                 |   2 +
 rust/helpers/input.c                   |  22 ++
 rust/helpers/serio.c                   |  27 ++
 rust/kernel/input.rs                   | 253 +++++++++++++++++++
 rust/kernel/lib.rs                     |   4 +
 rust/kernel/serio.rs                   | 328 +++++++++++++++++++++++++
 10 files changed, 846 insertions(+)
 create mode 100644 drivers/input/joystick/stinger_rust.rs
 create mode 100644 rust/helpers/input.c
 create mode 100644 rust/helpers/serio.c
 create mode 100644 rust/kernel/input.rs
 create mode 100644 rust/kernel/serio.rs

-- 
2.56.0