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  1// SPDX-License-Identifier: GPL-2.0
  2
  3// Copyright (C) 2023 FUJITA Tomonori <fujita.tomonori@gmail.com>
  4
  5//! Network PHY device.
  6//!
  7//! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
  8
  9use crate::{error::*, prelude::*, types::Opaque};
 10use core::{marker::PhantomData, ptr::addr_of_mut};
 11
 12pub mod reg;
 13
 14/// PHY state machine states.
 15///
 16/// Corresponds to the kernel's [`enum phy_state`].
 17///
 18/// Some of PHY drivers access to the state of PHY's software state machine.
 19///
 20/// [`enum phy_state`]: srctree/include/linux/phy.h
 21#[derive(PartialEq, Eq)]
 22pub enum DeviceState {
 23    /// PHY device and driver are not ready for anything.
 24    Down,
 25    /// PHY is ready to send and receive packets.
 26    Ready,
 27    /// PHY is up, but no polling or interrupts are done.
 28    Halted,
 29    /// PHY is up, but is in an error state.
 30    Error,
 31    /// PHY and attached device are ready to do work.
 32    Up,
 33    /// PHY is currently running.
 34    Running,
 35    /// PHY is up, but not currently plugged in.
 36    NoLink,
 37    /// PHY is performing a cable test.
 38    CableTest,
 39}
 40
 41/// A mode of Ethernet communication.
 42///
 43/// PHY drivers get duplex information from hardware and update the current state.
 44pub enum DuplexMode {
 45    /// PHY is in full-duplex mode.
 46    Full,
 47    /// PHY is in half-duplex mode.
 48    Half,
 49    /// PHY is in unknown duplex mode.
 50    Unknown,
 51}
 52
 53/// An instance of a PHY device.
 54///
 55/// Wraps the kernel's [`struct phy_device`].
 56///
 57/// A [`Device`] instance is created when a callback in [`Driver`] is executed. A PHY driver
 58/// executes [`Driver`]'s methods during the callback.
 59///
 60/// # Invariants
 61///
 62/// - Referencing a `phy_device` using this struct asserts that you are in
 63///   a context where all methods defined on this struct are safe to call.
 64/// - This struct always has a valid `self.0.mdio.dev`.
 65///
 66/// [`struct phy_device`]: srctree/include/linux/phy.h
 67// During the calls to most functions in [`Driver`], the C side (`PHYLIB`) holds a lock that is
 68// unique for every instance of [`Device`]. `PHYLIB` uses a different serialization technique for
 69// [`Driver::resume`] and [`Driver::suspend`]: `PHYLIB` updates `phy_device`'s state with
 70// the lock held, thus guaranteeing that [`Driver::resume`] has exclusive access to the instance.
 71// [`Driver::resume`] and [`Driver::suspend`] also are called where only one thread can access
 72// to the instance.
 73#[repr(transparent)]
 74pub struct Device(Opaque<bindings::phy_device>);
 75
 76impl Device {
 77    /// Creates a new [`Device`] instance from a raw pointer.
 78    ///
 79    /// # Safety
 80    ///
 81    /// For the duration of `'a`,
 82    /// - the pointer must point at a valid `phy_device`, and the caller
 83    ///   must be in a context where all methods defined on this struct
 84    ///   are safe to call.
 85    /// - `(*ptr).mdio.dev` must be a valid.
 86    unsafe fn from_raw<'a>(ptr: *mut bindings::phy_device) -> &'a mut Self {
 87        // CAST: `Self` is a `repr(transparent)` wrapper around `bindings::phy_device`.
 88        let ptr = ptr.cast::<Self>();
 89        // SAFETY: by the function requirements the pointer is valid and we have unique access for
 90        // the duration of `'a`.
 91        unsafe { &mut *ptr }
 92    }
 93
 94    /// Gets the id of the PHY.
 95    pub fn phy_id(&self) -> u32 {
 96        let phydev = self.0.get();
 97        // SAFETY: The struct invariant ensures that we may access
 98        // this field without additional synchronization.
 99        unsafe { (*phydev).phy_id }
100    }
101
102    /// Gets the state of PHY state machine states.
103    pub fn state(&self) -> DeviceState {
104        let phydev = self.0.get();
105        // SAFETY: The struct invariant ensures that we may access
106        // this field without additional synchronization.
107        let state = unsafe { (*phydev).state };
108        // TODO: this conversion code will be replaced with automatically generated code by bindgen
109        // when it becomes possible.
110        match state {
111            bindings::phy_state_PHY_DOWN => DeviceState::Down,
112            bindings::phy_state_PHY_READY => DeviceState::Ready,
113            bindings::phy_state_PHY_HALTED => DeviceState::Halted,
114            bindings::phy_state_PHY_ERROR => DeviceState::Error,
115            bindings::phy_state_PHY_UP => DeviceState::Up,
116            bindings::phy_state_PHY_RUNNING => DeviceState::Running,
117            bindings::phy_state_PHY_NOLINK => DeviceState::NoLink,
118            bindings::phy_state_PHY_CABLETEST => DeviceState::CableTest,
119            _ => DeviceState::Error,
120        }
121    }
122
123    /// Gets the current link state.
124    ///
125    /// It returns true if the link is up.
126    pub fn is_link_up(&self) -> bool {
127        const LINK_IS_UP: u64 = 1;
128        // TODO: the code to access to the bit field will be replaced with automatically
129        // generated code by bindgen when it becomes possible.
130        // SAFETY: The struct invariant ensures that we may access
131        // this field without additional synchronization.
132        let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
133        bit_field.get(14, 1) == LINK_IS_UP
134    }
135
136    /// Gets the current auto-negotiation configuration.
137    ///
138    /// It returns true if auto-negotiation is enabled.
139    pub fn is_autoneg_enabled(&self) -> bool {
140        // TODO: the code to access to the bit field will be replaced with automatically
141        // generated code by bindgen when it becomes possible.
142        // SAFETY: The struct invariant ensures that we may access
143        // this field without additional synchronization.
144        let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
145        bit_field.get(13, 1) == bindings::AUTONEG_ENABLE as u64
146    }
147
148    /// Gets the current auto-negotiation state.
149    ///
150    /// It returns true if auto-negotiation is completed.
151    pub fn is_autoneg_completed(&self) -> bool {
152        const AUTONEG_COMPLETED: u64 = 1;
153        // TODO: the code to access to the bit field will be replaced with automatically
154        // generated code by bindgen when it becomes possible.
155        // SAFETY: The struct invariant ensures that we may access
156        // this field without additional synchronization.
157        let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
158        bit_field.get(15, 1) == AUTONEG_COMPLETED
159    }
160
161    /// Sets the speed of the PHY.
162    pub fn set_speed(&mut self, speed: u32) {
163        let phydev = self.0.get();
164        // SAFETY: The struct invariant ensures that we may access
165        // this field without additional synchronization.
166        unsafe { (*phydev).speed = speed as i32 };
167    }
168
169    /// Sets duplex mode.
170    pub fn set_duplex(&mut self, mode: DuplexMode) {
171        let phydev = self.0.get();
172        let v = match mode {
173            DuplexMode::Full => bindings::DUPLEX_FULL as i32,
174            DuplexMode::Half => bindings::DUPLEX_HALF as i32,
175            DuplexMode::Unknown => bindings::DUPLEX_UNKNOWN as i32,
176        };
177        // SAFETY: The struct invariant ensures that we may access
178        // this field without additional synchronization.
179        unsafe { (*phydev).duplex = v };
180    }
181
182    /// Reads a PHY register.
183    // This function reads a hardware register and updates the stats so takes `&mut self`.
184    pub fn read<R: reg::Register>(&mut self, reg: R) -> Result<u16> {
185        reg.read(self)
186    }
187
188    /// Writes a PHY register.
189    pub fn write<R: reg::Register>(&mut self, reg: R, val: u16) -> Result {
190        reg.write(self, val)
191    }
192
193    /// Reads a paged register.
194    pub fn read_paged(&mut self, page: u16, regnum: u16) -> Result<u16> {
195        let phydev = self.0.get();
196        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
197        // So it's just an FFI call.
198        let ret = unsafe { bindings::phy_read_paged(phydev, page.into(), regnum.into()) };
199        if ret < 0 {
200            Err(Error::from_errno(ret))
201        } else {
202            Ok(ret as u16)
203        }
204    }
205
206    /// Resolves the advertisements into PHY settings.
207    pub fn resolve_aneg_linkmode(&mut self) {
208        let phydev = self.0.get();
209        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
210        // So it's just an FFI call.
211        unsafe { bindings::phy_resolve_aneg_linkmode(phydev) };
212    }
213
214    /// Executes software reset the PHY via `BMCR_RESET` bit.
215    pub fn genphy_soft_reset(&mut self) -> Result {
216        let phydev = self.0.get();
217        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
218        // So it's just an FFI call.
219        to_result(unsafe { bindings::genphy_soft_reset(phydev) })
220    }
221
222    /// Initializes the PHY.
223    pub fn init_hw(&mut self) -> Result {
224        let phydev = self.0.get();
225        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
226        // So it's just an FFI call.
227        to_result(unsafe { bindings::phy_init_hw(phydev) })
228    }
229
230    /// Starts auto-negotiation.
231    pub fn start_aneg(&mut self) -> Result {
232        let phydev = self.0.get();
233        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
234        // So it's just an FFI call.
235        to_result(unsafe { bindings::_phy_start_aneg(phydev) })
236    }
237
238    /// Resumes the PHY via `BMCR_PDOWN` bit.
239    pub fn genphy_resume(&mut self) -> Result {
240        let phydev = self.0.get();
241        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
242        // So it's just an FFI call.
243        to_result(unsafe { bindings::genphy_resume(phydev) })
244    }
245
246    /// Suspends the PHY via `BMCR_PDOWN` bit.
247    pub fn genphy_suspend(&mut self) -> Result {
248        let phydev = self.0.get();
249        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
250        // So it's just an FFI call.
251        to_result(unsafe { bindings::genphy_suspend(phydev) })
252    }
253
254    /// Checks the link status and updates current link state.
255    pub fn genphy_read_status<R: reg::Register>(&mut self) -> Result<u16> {
256        R::read_status(self)
257    }
258
259    /// Updates the link status.
260    pub fn genphy_update_link(&mut self) -> Result {
261        let phydev = self.0.get();
262        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
263        // So it's just an FFI call.
264        to_result(unsafe { bindings::genphy_update_link(phydev) })
265    }
266
267    /// Reads link partner ability.
268    pub fn genphy_read_lpa(&mut self) -> Result {
269        let phydev = self.0.get();
270        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
271        // So it's just an FFI call.
272        to_result(unsafe { bindings::genphy_read_lpa(phydev) })
273    }
274
275    /// Reads PHY abilities.
276    pub fn genphy_read_abilities(&mut self) -> Result {
277        let phydev = self.0.get();
278        // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
279        // So it's just an FFI call.
280        to_result(unsafe { bindings::genphy_read_abilities(phydev) })
281    }
282}
283
284impl AsRef<kernel::device::Device> for Device {
285    fn as_ref(&self) -> &kernel::device::Device {
286        let phydev = self.0.get();
287        // SAFETY: The struct invariant ensures that `mdio.dev` is valid.
288        unsafe { kernel::device::Device::as_ref(addr_of_mut!((*phydev).mdio.dev)) }
289    }
290}
291
292/// Defines certain other features this PHY supports (like interrupts).
293///
294/// These flag values are used in [`Driver::FLAGS`].
295pub mod flags {
296    /// PHY is internal.
297    pub const IS_INTERNAL: u32 = bindings::PHY_IS_INTERNAL;
298    /// PHY needs to be reset after the refclk is enabled.
299    pub const RST_AFTER_CLK_EN: u32 = bindings::PHY_RST_AFTER_CLK_EN;
300    /// Polling is used to detect PHY status changes.
301    pub const POLL_CABLE_TEST: u32 = bindings::PHY_POLL_CABLE_TEST;
302    /// Don't suspend.
303    pub const ALWAYS_CALL_SUSPEND: u32 = bindings::PHY_ALWAYS_CALL_SUSPEND;
304}
305
306/// An adapter for the registration of a PHY driver.
307struct Adapter<T: Driver> {
308    _p: PhantomData<T>,
309}
310
311impl<T: Driver> Adapter<T> {
312    /// # Safety
313    ///
314    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
315    unsafe extern "C" fn soft_reset_callback(
316        phydev: *mut bindings::phy_device,
317    ) -> crate::ffi::c_int {
318        from_result(|| {
319            // SAFETY: This callback is called only in contexts
320            // where we hold `phy_device->lock`, so the accessors on
321            // `Device` are okay to call.
322            let dev = unsafe { Device::from_raw(phydev) };
323            T::soft_reset(dev)?;
324            Ok(0)
325        })
326    }
327
328    /// # Safety
329    ///
330    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
331    unsafe extern "C" fn probe_callback(phydev: *mut bindings::phy_device) -> crate::ffi::c_int {
332        from_result(|| {
333            // SAFETY: This callback is called only in contexts
334            // where we can exclusively access `phy_device` because
335            // it's not published yet, so the accessors on `Device` are okay
336            // to call.
337            let dev = unsafe { Device::from_raw(phydev) };
338            T::probe(dev)?;
339            Ok(0)
340        })
341    }
342
343    /// # Safety
344    ///
345    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
346    unsafe extern "C" fn get_features_callback(
347        phydev: *mut bindings::phy_device,
348    ) -> crate::ffi::c_int {
349        from_result(|| {
350            // SAFETY: This callback is called only in contexts
351            // where we hold `phy_device->lock`, so the accessors on
352            // `Device` are okay to call.
353            let dev = unsafe { Device::from_raw(phydev) };
354            T::get_features(dev)?;
355            Ok(0)
356        })
357    }
358
359    /// # Safety
360    ///
361    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
362    unsafe extern "C" fn suspend_callback(phydev: *mut bindings::phy_device) -> crate::ffi::c_int {
363        from_result(|| {
364            // SAFETY: The C core code ensures that the accessors on
365            // `Device` are okay to call even though `phy_device->lock`
366            // might not be held.
367            let dev = unsafe { Device::from_raw(phydev) };
368            T::suspend(dev)?;
369            Ok(0)
370        })
371    }
372
373    /// # Safety
374    ///
375    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
376    unsafe extern "C" fn resume_callback(phydev: *mut bindings::phy_device) -> crate::ffi::c_int {
377        from_result(|| {
378            // SAFETY: The C core code ensures that the accessors on
379            // `Device` are okay to call even though `phy_device->lock`
380            // might not be held.
381            let dev = unsafe { Device::from_raw(phydev) };
382            T::resume(dev)?;
383            Ok(0)
384        })
385    }
386
387    /// # Safety
388    ///
389    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
390    unsafe extern "C" fn config_aneg_callback(
391        phydev: *mut bindings::phy_device,
392    ) -> crate::ffi::c_int {
393        from_result(|| {
394            // SAFETY: This callback is called only in contexts
395            // where we hold `phy_device->lock`, so the accessors on
396            // `Device` are okay to call.
397            let dev = unsafe { Device::from_raw(phydev) };
398            T::config_aneg(dev)?;
399            Ok(0)
400        })
401    }
402
403    /// # Safety
404    ///
405    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
406    unsafe extern "C" fn read_status_callback(
407        phydev: *mut bindings::phy_device,
408    ) -> crate::ffi::c_int {
409        from_result(|| {
410            // SAFETY: This callback is called only in contexts
411            // where we hold `phy_device->lock`, so the accessors on
412            // `Device` are okay to call.
413            let dev = unsafe { Device::from_raw(phydev) };
414            T::read_status(dev)?;
415            Ok(0)
416        })
417    }
418
419    /// # Safety
420    ///
421    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
422    unsafe extern "C" fn match_phy_device_callback(
423        phydev: *mut bindings::phy_device,
424    ) -> crate::ffi::c_int {
425        // SAFETY: This callback is called only in contexts
426        // where we hold `phy_device->lock`, so the accessors on
427        // `Device` are okay to call.
428        let dev = unsafe { Device::from_raw(phydev) };
429        T::match_phy_device(dev) as i32
430    }
431
432    /// # Safety
433    ///
434    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
435    unsafe extern "C" fn read_mmd_callback(
436        phydev: *mut bindings::phy_device,
437        devnum: i32,
438        regnum: u16,
439    ) -> i32 {
440        from_result(|| {
441            // SAFETY: This callback is called only in contexts
442            // where we hold `phy_device->lock`, so the accessors on
443            // `Device` are okay to call.
444            let dev = unsafe { Device::from_raw(phydev) };
445            // CAST: the C side verifies devnum < 32.
446            let ret = T::read_mmd(dev, devnum as u8, regnum)?;
447            Ok(ret.into())
448        })
449    }
450
451    /// # Safety
452    ///
453    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
454    unsafe extern "C" fn write_mmd_callback(
455        phydev: *mut bindings::phy_device,
456        devnum: i32,
457        regnum: u16,
458        val: u16,
459    ) -> i32 {
460        from_result(|| {
461            // SAFETY: This callback is called only in contexts
462            // where we hold `phy_device->lock`, so the accessors on
463            // `Device` are okay to call.
464            let dev = unsafe { Device::from_raw(phydev) };
465            T::write_mmd(dev, devnum as u8, regnum, val)?;
466            Ok(0)
467        })
468    }
469
470    /// # Safety
471    ///
472    /// `phydev` must be passed by the corresponding callback in `phy_driver`.
473    unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) {
474        // SAFETY: This callback is called only in contexts
475        // where we hold `phy_device->lock`, so the accessors on
476        // `Device` are okay to call.
477        let dev = unsafe { Device::from_raw(phydev) };
478        T::link_change_notify(dev);
479    }
480}
481
482/// Driver structure for a particular PHY type.
483///
484/// Wraps the kernel's [`struct phy_driver`].
485/// This is used to register a driver for a particular PHY type with the kernel.
486///
487/// # Invariants
488///
489/// `self.0` is always in a valid state.
490///
491/// [`struct phy_driver`]: srctree/include/linux/phy.h
492#[repr(transparent)]
493pub struct DriverVTable(Opaque<bindings::phy_driver>);
494
495// SAFETY: `DriverVTable` doesn't expose any &self method to access internal data, so it's safe to
496// share `&DriverVTable` across execution context boundaries.
497unsafe impl Sync for DriverVTable {}
498
499/// Creates a [`DriverVTable`] instance from [`Driver`].
500///
501/// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`.
502///
503/// [`module_phy_driver`]: crate::module_phy_driver
504pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
505    // INVARIANT: All the fields of `struct phy_driver` are initialized properly.
506    DriverVTable(Opaque::new(bindings::phy_driver {
507        name: T::NAME.as_char_ptr().cast_mut(),
508        flags: T::FLAGS,
509        phy_id: T::PHY_DEVICE_ID.id,
510        phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
511        soft_reset: if T::HAS_SOFT_RESET {
512            Some(Adapter::<T>::soft_reset_callback)
513        } else {
514            None
515        },
516        probe: if T::HAS_PROBE {
517            Some(Adapter::<T>::probe_callback)
518        } else {
519            None
520        },
521        get_features: if T::HAS_GET_FEATURES {
522            Some(Adapter::<T>::get_features_callback)
523        } else {
524            None
525        },
526        match_phy_device: if T::HAS_MATCH_PHY_DEVICE {
527            Some(Adapter::<T>::match_phy_device_callback)
528        } else {
529            None
530        },
531        suspend: if T::HAS_SUSPEND {
532            Some(Adapter::<T>::suspend_callback)
533        } else {
534            None
535        },
536        resume: if T::HAS_RESUME {
537            Some(Adapter::<T>::resume_callback)
538        } else {
539            None
540        },
541        config_aneg: if T::HAS_CONFIG_ANEG {
542            Some(Adapter::<T>::config_aneg_callback)
543        } else {
544            None
545        },
546        read_status: if T::HAS_READ_STATUS {
547            Some(Adapter::<T>::read_status_callback)
548        } else {
549            None
550        },
551        read_mmd: if T::HAS_READ_MMD {
552            Some(Adapter::<T>::read_mmd_callback)
553        } else {
554            None
555        },
556        write_mmd: if T::HAS_WRITE_MMD {
557            Some(Adapter::<T>::write_mmd_callback)
558        } else {
559            None
560        },
561        link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY {
562            Some(Adapter::<T>::link_change_notify_callback)
563        } else {
564            None
565        },
566        // SAFETY: The rest is zeroed out to initialize `struct phy_driver`,
567        // sets `Option<&F>` to be `None`.
568        ..unsafe { core::mem::MaybeUninit::<bindings::phy_driver>::zeroed().assume_init() }
569    }))
570}
571
572/// Driver implementation for a particular PHY type.
573///
574/// This trait is used to create a [`DriverVTable`].
575#[vtable]
576pub trait Driver {
577    /// Defines certain other features this PHY supports.
578    /// It is a combination of the flags in the [`flags`] module.
579    const FLAGS: u32 = 0;
580
581    /// The friendly name of this PHY type.
582    const NAME: &'static CStr;
583
584    /// This driver only works for PHYs with IDs which match this field.
585    /// The default id and mask are zero.
586    const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0);
587
588    /// Issues a PHY software reset.
589    fn soft_reset(_dev: &mut Device) -> Result {
590        kernel::build_error(VTABLE_DEFAULT_ERROR)
591    }
592
593    /// Sets up device-specific structures during discovery.
594    fn probe(_dev: &mut Device) -> Result {
595        kernel::build_error(VTABLE_DEFAULT_ERROR)
596    }
597
598    /// Probes the hardware to determine what abilities it has.
599    fn get_features(_dev: &mut Device) -> Result {
600        kernel::build_error(VTABLE_DEFAULT_ERROR)
601    }
602
603    /// Returns true if this is a suitable driver for the given phydev.
604    /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`].
605    fn match_phy_device(_dev: &Device) -> bool {
606        false
607    }
608
609    /// Configures the advertisement and resets auto-negotiation
610    /// if auto-negotiation is enabled.
611    fn config_aneg(_dev: &mut Device) -> Result {
612        kernel::build_error(VTABLE_DEFAULT_ERROR)
613    }
614
615    /// Determines the negotiated speed and duplex.
616    fn read_status(_dev: &mut Device) -> Result<u16> {
617        kernel::build_error(VTABLE_DEFAULT_ERROR)
618    }
619
620    /// Suspends the hardware, saving state if needed.
621    fn suspend(_dev: &mut Device) -> Result {
622        kernel::build_error(VTABLE_DEFAULT_ERROR)
623    }
624
625    /// Resumes the hardware, restoring state if needed.
626    fn resume(_dev: &mut Device) -> Result {
627        kernel::build_error(VTABLE_DEFAULT_ERROR)
628    }
629
630    /// Overrides the default MMD read function for reading a MMD register.
631    fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
632        kernel::build_error(VTABLE_DEFAULT_ERROR)
633    }
634
635    /// Overrides the default MMD write function for writing a MMD register.
636    fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
637        kernel::build_error(VTABLE_DEFAULT_ERROR)
638    }
639
640    /// Callback for notification of link change.
641    fn link_change_notify(_dev: &mut Device) {}
642}
643
644/// Registration structure for PHY drivers.
645///
646/// Registers [`DriverVTable`] instances with the kernel. They will be unregistered when dropped.
647///
648/// # Invariants
649///
650/// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
651pub struct Registration {
652    drivers: Pin<&'static mut [DriverVTable]>,
653}
654
655// SAFETY: The only action allowed in a `Registration` instance is dropping it, which is safe to do
656// from any thread because `phy_drivers_unregister` can be called from any thread context.
657unsafe impl Send for Registration {}
658
659impl Registration {
660    /// Registers a PHY driver.
661    pub fn register(
662        module: &'static crate::ThisModule,
663        drivers: Pin<&'static mut [DriverVTable]>,
664    ) -> Result<Self> {
665        if drivers.is_empty() {
666            return Err(code::EINVAL);
667        }
668        // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of
669        // the `drivers` slice are initialized properly. `drivers` will not be moved.
670        // So it's just an FFI call.
671        to_result(unsafe {
672            bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
673        })?;
674        // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
675        Ok(Registration { drivers })
676    }
677}
678
679impl Drop for Registration {
680    fn drop(&mut self) {
681        // SAFETY: The type invariants guarantee that `self.drivers` is valid.
682        // So it's just an FFI call.
683        unsafe {
684            bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32)
685        };
686    }
687}
688
689/// An identifier for PHY devices on an MDIO/MII bus.
690///
691/// Represents the kernel's `struct mdio_device_id`. This is used to find an appropriate
692/// PHY driver.
693pub struct DeviceId {
694    id: u32,
695    mask: DeviceMask,
696}
697
698impl DeviceId {
699    /// Creates a new instance with the exact match mask.
700    pub const fn new_with_exact_mask(id: u32) -> Self {
701        DeviceId {
702            id,
703            mask: DeviceMask::Exact,
704        }
705    }
706
707    /// Creates a new instance with the model match mask.
708    pub const fn new_with_model_mask(id: u32) -> Self {
709        DeviceId {
710            id,
711            mask: DeviceMask::Model,
712        }
713    }
714
715    /// Creates a new instance with the vendor match mask.
716    pub const fn new_with_vendor_mask(id: u32) -> Self {
717        DeviceId {
718            id,
719            mask: DeviceMask::Vendor,
720        }
721    }
722
723    /// Creates a new instance with a custom match mask.
724    pub const fn new_with_custom_mask(id: u32, mask: u32) -> Self {
725        DeviceId {
726            id,
727            mask: DeviceMask::Custom(mask),
728        }
729    }
730
731    /// Creates a new instance from [`Driver`].
732    pub const fn new_with_driver<T: Driver>() -> Self {
733        T::PHY_DEVICE_ID
734    }
735
736    /// Get a `mask` as u32.
737    pub const fn mask_as_int(&self) -> u32 {
738        self.mask.as_int()
739    }
740
741    // macro use only
742    #[doc(hidden)]
743    pub const fn mdio_device_id(&self) -> bindings::mdio_device_id {
744        bindings::mdio_device_id {
745            phy_id: self.id,
746            phy_id_mask: self.mask.as_int(),
747        }
748    }
749}
750
751enum DeviceMask {
752    Exact,
753    Model,
754    Vendor,
755    Custom(u32),
756}
757
758impl DeviceMask {
759    const MASK_EXACT: u32 = !0;
760    const MASK_MODEL: u32 = !0 << 4;
761    const MASK_VENDOR: u32 = !0 << 10;
762
763    const fn as_int(&self) -> u32 {
764        match self {
765            DeviceMask::Exact => Self::MASK_EXACT,
766            DeviceMask::Model => Self::MASK_MODEL,
767            DeviceMask::Vendor => Self::MASK_VENDOR,
768            DeviceMask::Custom(mask) => *mask,
769        }
770    }
771}
772
773/// Declares a kernel module for PHYs drivers.
774///
775/// This creates a static array of kernel's `struct phy_driver` and registers it.
776/// This also corresponds to the kernel's `MODULE_DEVICE_TABLE` macro, which embeds the information
777/// for module loading into the module binary file. Every driver needs an entry in `device_table`.
778///
779/// # Examples
780///
781/// ```
782/// # mod module_phy_driver_sample {
783/// use kernel::c_str;
784/// use kernel::net::phy::{self, DeviceId};
785/// use kernel::prelude::*;
786///
787/// kernel::module_phy_driver! {
788///     drivers: [PhySample],
789///     device_table: [
790///         DeviceId::new_with_driver::<PhySample>()
791///     ],
792///     name: "rust_sample_phy",
793///     author: "Rust for Linux Contributors",
794///     description: "Rust sample PHYs driver",
795///     license: "GPL",
796/// }
797///
798/// struct PhySample;
799///
800/// #[vtable]
801/// impl phy::Driver for PhySample {
802///     const NAME: &'static CStr = c_str!("PhySample");
803///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
804/// }
805/// # }
806/// ```
807///
808/// This expands to the following code:
809///
810/// ```ignore
811/// use kernel::c_str;
812/// use kernel::net::phy::{self, DeviceId};
813/// use kernel::prelude::*;
814///
815/// struct Module {
816///     _reg: ::kernel::net::phy::Registration,
817/// }
818///
819/// module! {
820///     type: Module,
821///     name: "rust_sample_phy",
822///     author: "Rust for Linux Contributors",
823///     description: "Rust sample PHYs driver",
824///     license: "GPL",
825/// }
826///
827/// struct PhySample;
828///
829/// #[vtable]
830/// impl phy::Driver for PhySample {
831///     const NAME: &'static CStr = c_str!("PhySample");
832///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
833/// }
834///
835/// const _: () = {
836///     static mut DRIVERS: [::kernel::net::phy::DriverVTable; 1] =
837///         [::kernel::net::phy::create_phy_driver::<PhySample>()];
838///
839///     impl ::kernel::Module for Module {
840///         fn init(module: &'static ThisModule) -> Result<Self> {
841///             let drivers = unsafe { &mut DRIVERS };
842///             let mut reg = ::kernel::net::phy::Registration::register(
843///                 module,
844///                 ::core::pin::Pin::static_mut(drivers),
845///             )?;
846///             Ok(Module { _reg: reg })
847///         }
848///     }
849/// };
850///
851/// const _DEVICE_TABLE: [::kernel::bindings::mdio_device_id; 2] = [
852///     ::kernel::bindings::mdio_device_id {
853///         phy_id: 0x00000001,
854///         phy_id_mask: 0xffffffff,
855///     },
856///     ::kernel::bindings::mdio_device_id {
857///         phy_id: 0,
858///         phy_id_mask: 0,
859///     },
860/// ];
861/// #[cfg(MODULE)]
862/// #[no_mangle]
863/// static __mod_device_table__mdio__phydev: [::kernel::bindings::mdio_device_id; 2] = _DEVICE_TABLE;
864/// ```
865#[macro_export]
866macro_rules! module_phy_driver {
867    (@replace_expr $_t:tt $sub:expr) => {$sub};
868
869    (@count_devices $($x:expr),*) => {
870        0usize $(+ $crate::module_phy_driver!(@replace_expr $x 1usize))*
871    };
872
873    (@device_table [$($dev:expr),+]) => {
874        // SAFETY: C will not read off the end of this constant since the last element is zero.
875        const _DEVICE_TABLE: [$crate::bindings::mdio_device_id;
876            $crate::module_phy_driver!(@count_devices $($dev),+) + 1] = [
877            $($dev.mdio_device_id()),+,
878            $crate::bindings::mdio_device_id {
879                phy_id: 0,
880                phy_id_mask: 0
881            }
882        ];
883
884        #[cfg(MODULE)]
885        #[no_mangle]
886        static __mod_device_table__mdio__phydev: [$crate::bindings::mdio_device_id;
887            $crate::module_phy_driver!(@count_devices $($dev),+) + 1] = _DEVICE_TABLE;
888    };
889
890    (drivers: [$($driver:ident),+ $(,)?], device_table: [$($dev:expr),+ $(,)?], $($f:tt)*) => {
891        struct Module {
892            _reg: $crate::net::phy::Registration,
893        }
894
895        $crate::prelude::module! {
896            type: Module,
897            $($f)*
898        }
899
900        const _: () = {
901            static mut DRIVERS: [$crate::net::phy::DriverVTable;
902                $crate::module_phy_driver!(@count_devices $($driver),+)] =
903                [$($crate::net::phy::create_phy_driver::<$driver>()),+];
904
905            impl $crate::Module for Module {
906                fn init(module: &'static ThisModule) -> Result<Self> {
907                    // SAFETY: The anonymous constant guarantees that nobody else can access
908                    // the `DRIVERS` static. The array is used only in the C side.
909                    let drivers = unsafe { &mut DRIVERS };
910                    let mut reg = $crate::net::phy::Registration::register(
911                        module,
912                        ::core::pin::Pin::static_mut(drivers),
913                    )?;
914                    Ok(Module { _reg: reg })
915                }
916            }
917        };
918
919        $crate::module_phy_driver!(@device_table [$($dev),+]);
920    }
921}