[PATCH net-next v7 1/5] rust: core abstractions for network PHY drivers

FUJITA Tomonori
2023-10-26T00:16:56Z

This patch adds abstractions to implement network PHY drivers; the
driver registration and bindings for some of callback functions in
struct phy_driver and many genphy_ functions.

This feature is enabled with CONFIG_RUST_PHYLIB_ABSTRACTIONS=y.

This patch enables unstable const_maybe_uninit_zeroed feature for
kernel crate to enable unsafe code to handle a constant value with
uninitialized data. With the feature, the abstractions can initialize
a phy_driver structure with zero easily; instead of initializing all
the members by hand. It's supposed to be stable in the not so distant
future.

Link: https://github.com/rust-lang/rust/pull/116218

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
---
drivers/net/phy/Kconfig | 8 +
rust/bindings/bindings_helper.h | 3 +
rust/kernel/lib.rs | 3 +
rust/kernel/net.rs | 6 +
rust/kernel/net/phy.rs | 725 ++++++++++++++++++++++++++++++++
5 files changed, 745 insertions(+)
create mode 100644 rust/kernel/net.rs
create mode 100644 rust/kernel/net/phy.rs

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 421d2b62918f..0faebdb184ca 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -60,6 +60,14 @@ config FIXED_PHY

Currently tested with mpc866ads and mpc8349e-mitx.

+config RUST_PHYLIB_ABSTRACTIONS
+ bool "PHYLIB abstractions support"
+ depends on RUST
+ depends on PHYLIB=y
+ help
+ Adds support needed for PHY drivers written in Rust. It provides
+ a wrapper around the C phylib core.
+
config SFP
tristate "SFP cage support"
depends on I2C && PHYLINK
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index c91a3c24f607..ec4ee09a34ad 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -8,6 +8,9 @@

#include <kunit/test.h>
#include <linux/errname.h>
+#include <linux/ethtool.h>
+#include <linux/mdio.h>
+#include <linux/phy.h>
#include <linux/slab.h>
#include <linux/refcount.h>
#include <linux/wait.h>
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index e8811700239a..0588422e273c 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -14,6 +14,7 @@
#![no_std]
#![feature(allocator_api)]
#![feature(coerce_unsized)]
+#![feature(const_maybe_uninit_zeroed)]
#![feature(dispatch_from_dyn)]
#![feature(new_uninit)]
#![feature(receiver_trait)]
@@ -36,6 +37,8 @@
pub mod ioctl;
#[cfg(CONFIG_KUNIT)]
pub mod kunit;
+#[cfg(CONFIG_NET)]
+pub mod net;
pub mod prelude;
pub mod print;
mod static_assert;
diff --git a/rust/kernel/net.rs b/rust/kernel/net.rs
new file mode 100644
index 000000000000..fe415cb369d3
--- /dev/null
+++ b/rust/kernel/net.rs
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Networking.
+
+#[cfg(CONFIG_RUST_PHYLIB_ABSTRACTIONS)]
+pub mod phy;
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
new file mode 100644
index 000000000000..61223f638bc6
--- /dev/null
+++ b/rust/kernel/net/phy.rs
@@ -0,0 +1,725 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2023 FUJITA Tomonori <fujita.tomonori@gmail.com>
+
+//! Network PHY device.
+//!
+//! C headers: [`include/linux/phy.h`](../../../../../../../include/linux/phy.h).
+
+use crate::{
+ bindings,
+ error::*,
+ prelude::{vtable, Pin},
+ str::CStr,
+ types::Opaque,
+};
+use core::marker::PhantomData;
+
+/// PHY state machine states.
+///
+/// Corresponds to the kernel's [`enum phy_state`].
+///
+/// Some of PHY drivers access to the state of PHY's software state machine.
+///
+/// [`enum phy_state`]: ../../../../../../../include/linux/phy.h
+#[derive(PartialEq)]
+pub enum DeviceState {
+ /// PHY device and driver are not ready for anything.
+ Down,
+ /// PHY is ready to send and receive packets.
+ Ready,
+ /// PHY is up, but no polling or interrupts are done.
+ Halted,
+ /// PHY is up, but is in an error state.
+ Error,
+ /// PHY and attached device are ready to do work.
+ Up,
+ /// PHY is currently running.
+ Running,
+ /// PHY is up, but not currently plugged in.
+ NoLink,
+ /// PHY is performing a cable test.
+ CableTest,
+}
+
+/// A mode of Ethernet communication.
+///
+/// PHY drivers get duplex information from hardware and update the current state.
+pub enum DuplexMode {
+ /// PHY is in full-duplex mode.
+ Full,
+ /// PHY is in half-duplex mode.
+ Half,
+ /// PHY is in unknown duplex mode.
+ Unknown,
+}
+
+/// An instance of a PHY device.
+///
+/// Wraps the kernel's [`struct phy_device`].
+///
+/// A [`Device`] instance is created when a callback in [`Driver`] is executed. A PHY driver
+/// executes [`Driver`]'s methods during the callback.
+///
+/// # Invariants
+///
+/// `self.0` is always in a valid state.
+///
+/// [`struct phy_device`]: ../../../../../../../include/linux/phy.h
+// During the calls to most functions in [`Driver`], the C side (`PHYLIB`) holds a lock that is
+// unique for every instance of [`Device`]. `PHYLIB` uses a different serialization technique for
+// [`Driver::resume`] and [`Driver::suspend`]: `PHYLIB` updates `phy_device`'s state with
+// the lock held, thus guaranteeing that [`Driver::resume`] has exclusive access to the instance.
+// [`Driver::resume`] and [`Driver::suspend`] also are called where only one thread can access
+// to the instance.
+#[repr(transparent)]
+pub struct Device(Opaque<bindings::phy_device>);
+
+impl Device {
+ /// Creates a new [`Device`] instance from a raw pointer.
+ ///
+ /// # Safety
+ ///
+ /// This function must only be called from the callbacks in `phy_driver`.
+ unsafe fn from_raw<'a>(ptr: *mut bindings::phy_device) -> &'a mut Self {
+ // CAST: `Self` is a `repr(transparent)` wrapper around `bindings::phy_device`.
+ let ptr = ptr.cast::<Self>();
+ // SAFETY: by the function requirements the pointer is valid and we have unique access for
+ // the duration of `'a`.
+ unsafe { &mut *ptr }
+ }
+
+ /// Gets the id of the PHY.
+ pub fn phy_id(&self) -> u32 {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ unsafe { (*phydev).phy_id }
+ }
+
+ /// Gets the state of PHY state machine states.
+ pub fn state(&self) -> DeviceState {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ let state = unsafe { (*phydev).state };
+ // TODO: this conversion code will be replaced with automatically generated code by bindgen
+ // when it becomes possible.
+ // better to call WARN_ONCE() when the state is out-of-range.
+ match state {
+ bindings::phy_state_PHY_DOWN => DeviceState::Down,
+ bindings::phy_state_PHY_READY => DeviceState::Ready,
+ bindings::phy_state_PHY_HALTED => DeviceState::Halted,
+ bindings::phy_state_PHY_ERROR => DeviceState::Error,
+ bindings::phy_state_PHY_UP => DeviceState::Up,
+ bindings::phy_state_PHY_RUNNING => DeviceState::Running,
+ bindings::phy_state_PHY_NOLINK => DeviceState::NoLink,
+ bindings::phy_state_PHY_CABLETEST => DeviceState::CableTest,
+ _ => DeviceState::Error,
+ }
+ }
+
+ /// Gets the current link state.
+ ///
+ /// It returns true if the link is up.
+ pub fn is_link_up(&self) -> bool {
+ const LINK_IS_UP: u32 = 1;
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ let phydev = unsafe { *self.0.get() };
+ phydev.link() == LINK_IS_UP
+ }
+
+ /// Gets the current auto-negotiation configuration.
+ ///
+ /// It returns true if auto-negotiation is enabled.
+ pub fn is_autoneg_enabled(&self) -> bool {
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ let phydev = unsafe { *self.0.get() };
+ phydev.autoneg() == bindings::AUTONEG_ENABLE
+ }
+
+ /// Gets the current auto-negotiation state.
+ ///
+ /// It returns true if auto-negotiation is completed.
+ pub fn is_autoneg_completed(&self) -> bool {
+ const AUTONEG_COMPLETED: u32 = 1;
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ let phydev = unsafe { *self.0.get() };
+ phydev.autoneg_complete() == AUTONEG_COMPLETED
+ }
+
+ /// Sets the speed of the PHY.
+ pub fn set_speed(&mut self, speed: u32) {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ unsafe { (*phydev).speed = speed as i32 };
+ }
+
+ /// Sets duplex mode.
+ pub fn set_duplex(&mut self, mode: DuplexMode) {
+ let phydev = self.0.get();
+ let v = match mode {
+ DuplexMode::Full => bindings::DUPLEX_FULL as i32,
+ DuplexMode::Half => bindings::DUPLEX_HALF as i32,
+ DuplexMode::Unknown => bindings::DUPLEX_UNKNOWN as i32,
+ };
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ unsafe { (*phydev).duplex = v };
+ }
+
+ /// Reads a given C22 PHY register.
+ // This function reads a hardware register and updates the stats so takes `&mut self`.
+ pub fn read(&mut self, regnum: u16) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ let ret = unsafe {
+ bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into())
+ };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Writes a given C22 PHY register.
+ pub fn write(&mut self, regnum: u16, val: u16) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe {
+ bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into(), val)
+ })
+ }
+
+ /// Reads a paged register.
+ pub fn read_paged(&mut self, page: u16, regnum: u16) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ let ret = unsafe { bindings::phy_read_paged(phydev, page.into(), regnum.into()) };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Resolves the advertisements into PHY settings.
+ pub fn resolve_aneg_linkmode(&mut self) {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ unsafe { bindings::phy_resolve_aneg_linkmode(phydev) };
+ }
+
+ /// Executes software reset the PHY via `BMCR_RESET` bit.
+ pub fn genphy_soft_reset(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_soft_reset(phydev) })
+ }
+
+ /// Initializes the PHY.
+ pub fn init_hw(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // so an FFI call with a valid pointer.
+ to_result(unsafe { bindings::phy_init_hw(phydev) })
+ }
+
+ /// Starts auto-negotiation.
+ pub fn start_aneg(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::phy_start_aneg(phydev) })
+ }
+
+ /// Resumes the PHY via `BMCR_PDOWN` bit.
+ pub fn genphy_resume(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_resume(phydev) })
+ }
+
+ /// Suspends the PHY via `BMCR_PDOWN` bit.
+ pub fn genphy_suspend(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_suspend(phydev) })
+ }
+
+ /// Checks the link status and updates current link state.
+ pub fn genphy_read_status(&mut self) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ let ret = unsafe { bindings::genphy_read_status(phydev) };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Updates the link status.
+ pub fn genphy_update_link(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_update_link(phydev) })
+ }
+
+ /// Reads link partner ability.
+ pub fn genphy_read_lpa(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_read_lpa(phydev) })
+ }
+
+ /// Reads PHY abilities.
+ pub fn genphy_read_abilities(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe { bindings::genphy_read_abilities(phydev) })
+ }
+}
+
+/// Defines certain other features this PHY supports (like interrupts).
+///
+/// These flag values are used in [`Driver::FLAGS`].
+pub mod flags {
+ /// PHY is internal.
+ pub const IS_INTERNAL: u32 = bindings::PHY_IS_INTERNAL;
+ /// PHY needs to be reset after the refclk is enabled.
+ pub const RST_AFTER_CLK_EN: u32 = bindings::PHY_RST_AFTER_CLK_EN;
+ /// Polling is used to detect PHY status changes.
+ pub const POLL_CABLE_TEST: u32 = bindings::PHY_POLL_CABLE_TEST;
+ /// Don't suspend.
+ pub const ALWAYS_CALL_SUSPEND: u32 = bindings::PHY_ALWAYS_CALL_SUSPEND;
+}
+
+/// An adapter for the registration of a PHY driver.
+struct Adapter<T: Driver> {
+ _p: PhantomData<T>,
+}
+
+impl<T: Driver> Adapter<T> {
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn soft_reset_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::soft_reset(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn get_features_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::get_features(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn suspend_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::suspend(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn resume_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::resume(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn config_aneg_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::config_aneg(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn read_status_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::read_status(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn match_phy_device_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::match_phy_device(dev) as i32
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn read_mmd_callback(
+ phydev: *mut bindings::phy_device,
+ devnum: i32,
+ regnum: u16,
+ ) -> i32 {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ // CAST: the C side verifies devnum < 32.
+ let ret = T::read_mmd(dev, devnum as u8, regnum)?;
+ Ok(ret.into())
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn write_mmd_callback(
+ phydev: *mut bindings::phy_device,
+ devnum: i32,
+ regnum: u16,
+ val: u16,
+ ) -> i32 {
+ from_result(|| {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::write_mmd(dev, devnum as u8, regnum, val)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) {
+ // SAFETY: Preconditions ensure `phydev` is valid.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::link_change_notify(dev);
+ }
+}
+
+/// Driver structure for a particular PHY type.
+///
+/// Wraps the kernel's [`struct phy_driver`].
+/// This is used to register a driver for a particular PHY type with the kernel.
+///
+/// # Invariants
+///
+/// `self.0` is always in a valid state.
+///
+/// [`struct phy_driver`]: ../../../../../../../include/linux/phy.h
+#[repr(transparent)]
+pub struct DriverVTable(Opaque<bindings::phy_driver>);
+
+/// Creates a [`DriverVTable`] instance from [`Driver`].
+///
+/// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`.
+///
+/// [`module_phy_driver`]: crate::module_phy_driver
+pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
+ // INVARIANT: All the fields of `struct phy_driver` are initialized properly.
+ DriverVTable(Opaque::new(bindings::phy_driver {
+ name: T::NAME.as_char_ptr().cast_mut(),
+ flags: T::FLAGS,
+ phy_id: T::PHY_DEVICE_ID.id,
+ phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
+ soft_reset: if T::HAS_SOFT_RESET {
+ Some(Adapter::<T>::soft_reset_callback)
+ } else {
+ None
+ },
+ get_features: if T::HAS_GET_FEATURES {
+ Some(Adapter::<T>::get_features_callback)
+ } else {
+ None
+ },
+ match_phy_device: if T::HAS_MATCH_PHY_DEVICE {
+ Some(Adapter::<T>::match_phy_device_callback)
+ } else {
+ None
+ },
+ suspend: if T::HAS_SUSPEND {
+ Some(Adapter::<T>::suspend_callback)
+ } else {
+ None
+ },
+ resume: if T::HAS_RESUME {
+ Some(Adapter::<T>::resume_callback)
+ } else {
+ None
+ },
+ config_aneg: if T::HAS_CONFIG_ANEG {
+ Some(Adapter::<T>::config_aneg_callback)
+ } else {
+ None
+ },
+ read_status: if T::HAS_READ_STATUS {
+ Some(Adapter::<T>::read_status_callback)
+ } else {
+ None
+ },
+ read_mmd: if T::HAS_READ_MMD {
+ Some(Adapter::<T>::read_mmd_callback)
+ } else {
+ None
+ },
+ write_mmd: if T::HAS_WRITE_MMD {
+ Some(Adapter::<T>::write_mmd_callback)
+ } else {
+ None
+ },
+ link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY {
+ Some(Adapter::<T>::link_change_notify_callback)
+ } else {
+ None
+ },
+ // SAFETY: The rest is zeroed out to initialize `struct phy_driver`,
+ // sets `Option<&F>` to be `None`.
+ ..unsafe { core::mem::MaybeUninit::<bindings::phy_driver>::zeroed().assume_init() }
+ }))
+}
+
+/// Driver implementation for a particular PHY type.
+///
+/// This trait is used to create a [`DriverVTable`].
+#[vtable]
+pub trait Driver {
+ /// Defines certain other features this PHY supports.
+ /// It is a combination of the flags in the [`flags`] module.
+ const FLAGS: u32 = 0;
+
+ /// The friendly name of this PHY type.
+ const NAME: &'static CStr;
+
+ /// This driver only works for PHYs with IDs which match this field.
+ /// The default id and mask are zero.
+ const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0);
+
+ /// Issues a PHY software reset.
+ fn soft_reset(_dev: &mut Device) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Probes the hardware to determine what abilities it has.
+ fn get_features(_dev: &mut Device) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Returns true if this is a suitable driver for the given phydev.
+ /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`].
+ fn match_phy_device(_dev: &Device) -> bool {
+ false
+ }
+
+ /// Configures the advertisement and resets auto-negotiation
+ /// if auto-negotiation is enabled.
+ fn config_aneg(_dev: &mut Device) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Determines the negotiated speed and duplex.
+ fn read_status(_dev: &mut Device) -> Result<u16> {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Suspends the hardware, saving state if needed.
+ fn suspend(_dev: &mut Device) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Resumes the hardware, restoring state if needed.
+ fn resume(_dev: &mut Device) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Overrides the default MMD read function for reading a MMD register.
+ fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Overrides the default MMD write function for writing a MMD register.
+ fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
+ Err(code::ENOTSUPP)
+ }
+
+ /// Callback for notification of link change.
+ fn link_change_notify(_dev: &mut Device) {}
+}
+
+/// Registration structure for PHY drivers.
+///
+/// Registers [`DriverVTable`] instances with the kernel. They will be unregistered when dropped.
+///
+/// # Invariants
+///
+/// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
+pub struct Registration {
+ drivers: Pin<&'static mut [DriverVTable]>,
+}
+
+impl Registration {
+ /// Registers a PHY driver.
+ pub fn register(
+ module: &'static crate::ThisModule,
+ drivers: Pin<&'static mut [DriverVTable]>,
+ ) -> Result<Self> {
+ if drivers.is_empty() {
+ return Err(code::EINVAL);
+ }
+ // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of
+ // the `drivers` slice are initialized properly. `drivers` will not be moved.
+ // So an FFI call with a valid pointer.
+ to_result(unsafe {
+ bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
+ })?;
+ // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
+ Ok(Registration { drivers })
+ }
+}
+
+impl Drop for Registration {
+ fn drop(&mut self) {
+ // SAFETY: The type invariants guarantee that `self.drivers` is valid.
+ // So an FFI call with a valid pointer.
+ unsafe {
+ bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32)
+ };
+ }
+}
+
+// SAFETY: `Registration` does not expose any of its state across threads.
+unsafe impl Send for Registration {}
+
+// SAFETY: `Registration` does not expose any of its state across threads.
+unsafe impl Sync for Registration {}
+
+/// An identifier for PHY devices on an MDIO/MII bus.
+///
+/// Represents the kernel's `struct mdio_device_id`. This is used to find an appropriate
+/// PHY driver.
+pub struct DeviceId {
+ id: u32,
+ mask: DeviceMask,
+}
+
+impl DeviceId {
+ /// Creates a new instance with the exact match mask.
+ pub const fn new_with_exact_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Exact,
+ }
+ }
+
+ /// Creates a new instance with the model match mask.
+ pub const fn new_with_model_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Model,
+ }
+ }
+
+ /// Creates a new instance with the vendor match mask.
+ pub const fn new_with_vendor_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Vendor,
+ }
+ }
+
+ /// Creates a new instance with a custom match mask.
+ pub const fn new_with_custom_mask(id: u32, mask: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Custom(mask),
+ }
+ }
+
+ /// Creates a new instance from [`Driver`].
+ pub const fn new_with_driver<T: Driver>() -> Self {
+ T::PHY_DEVICE_ID
+ }
+
+ /// Get a `mask` as u32.
+ pub const fn mask_as_int(&self) -> u32 {
+ self.mask.as_int()
+ }
+
+ // macro use only
+ #[doc(hidden)]
+ pub const fn mdio_device_id(&self) -> bindings::mdio_device_id {
+ bindings::mdio_device_id {
+ phy_id: self.id,
+ phy_id_mask: self.mask.as_int(),
+ }
+ }
+}
+
+enum DeviceMask {
+ Exact,
+ Model,
+ Vendor,
+ Custom(u32),
+}
+
+impl DeviceMask {
+ const MASK_EXACT: u32 = !0;
+ const MASK_MODEL: u32 = !0 << 4;
+ const MASK_VENDOR: u32 = !0 << 10;
+
+ const fn as_int(&self) -> u32 {
+ match self {
+ DeviceMask::Exact => Self::MASK_EXACT,
+ DeviceMask::Model => Self::MASK_MODEL,
+ DeviceMask::Vendor => Self::MASK_VENDOR,
+ DeviceMask::Custom(mask) => *mask,
+ }
+ }
+}
--
2.34.1