xref: /linux/rust/kernel/net/phy.rs (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 
9 use crate::{device_id::RawDeviceId, error::*, prelude::*, types::Opaque};
10 use core::{marker::PhantomData, ptr::addr_of_mut};
11 
12 pub 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)]
22 pub 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.
44 pub 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)]
74 pub struct Device(Opaque<bindings::phy_device>);
75 
76 impl 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) == u64::from(bindings::AUTONEG_ENABLE)
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 c_int };
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,
174             DuplexMode::Half => bindings::DUPLEX_HALF,
175             DuplexMode::Unknown => bindings::DUPLEX_UNKNOWN,
176         };
177         // SAFETY: The struct invariant ensures that we may access
178         // this field without additional synchronization.
179         unsafe { (*phydev).duplex = v as c_int };
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 
200         to_result(ret).map(|()| ret as u16)
201     }
202 
203     /// Resolves the advertisements into PHY settings.
204     pub fn resolve_aneg_linkmode(&mut self) {
205         let phydev = self.0.get();
206         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
207         // So it's just an FFI call.
208         unsafe { bindings::phy_resolve_aneg_linkmode(phydev) };
209     }
210 
211     /// Executes software reset the PHY via `BMCR_RESET` bit.
212     pub fn genphy_soft_reset(&mut self) -> Result {
213         let phydev = self.0.get();
214         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
215         // So it's just an FFI call.
216         to_result(unsafe { bindings::genphy_soft_reset(phydev) })
217     }
218 
219     /// Initializes the PHY.
220     pub fn init_hw(&mut self) -> Result {
221         let phydev = self.0.get();
222         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
223         // So it's just an FFI call.
224         to_result(unsafe { bindings::phy_init_hw(phydev) })
225     }
226 
227     /// Starts auto-negotiation.
228     pub fn start_aneg(&mut self) -> Result {
229         let phydev = self.0.get();
230         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
231         // So it's just an FFI call.
232         to_result(unsafe { bindings::_phy_start_aneg(phydev) })
233     }
234 
235     /// Resumes the PHY via `BMCR_PDOWN` bit.
236     pub fn genphy_resume(&mut self) -> Result {
237         let phydev = self.0.get();
238         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
239         // So it's just an FFI call.
240         to_result(unsafe { bindings::genphy_resume(phydev) })
241     }
242 
243     /// Suspends the PHY via `BMCR_PDOWN` bit.
244     pub fn genphy_suspend(&mut self) -> Result {
245         let phydev = self.0.get();
246         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
247         // So it's just an FFI call.
248         to_result(unsafe { bindings::genphy_suspend(phydev) })
249     }
250 
251     /// Checks the link status and updates current link state.
252     pub fn genphy_read_status<R: reg::Register>(&mut self) -> Result<u16> {
253         R::read_status(self)
254     }
255 
256     /// Updates the link status.
257     pub fn genphy_update_link(&mut self) -> Result {
258         let phydev = self.0.get();
259         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
260         // So it's just an FFI call.
261         to_result(unsafe { bindings::genphy_update_link(phydev) })
262     }
263 
264     /// Reads link partner ability.
265     pub fn genphy_read_lpa(&mut self) -> Result {
266         let phydev = self.0.get();
267         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
268         // So it's just an FFI call.
269         to_result(unsafe { bindings::genphy_read_lpa(phydev) })
270     }
271 
272     /// Reads PHY abilities.
273     pub fn genphy_read_abilities(&mut self) -> Result {
274         let phydev = self.0.get();
275         // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
276         // So it's just an FFI call.
277         to_result(unsafe { bindings::genphy_read_abilities(phydev) })
278     }
279 }
280 
281 impl AsRef<kernel::device::Device> for Device {
282     fn as_ref(&self) -> &kernel::device::Device {
283         let phydev = self.0.get();
284         // SAFETY: The struct invariant ensures that `mdio.dev` is valid.
285         unsafe { kernel::device::Device::from_raw(addr_of_mut!((*phydev).mdio.dev)) }
286     }
287 }
288 
289 /// Defines certain other features this PHY supports (like interrupts).
290 ///
291 /// These flag values are used in [`Driver::FLAGS`].
292 pub mod flags {
293     /// PHY is internal.
294     pub const IS_INTERNAL: u32 = bindings::PHY_IS_INTERNAL;
295     /// PHY needs to be reset after the refclk is enabled.
296     pub const RST_AFTER_CLK_EN: u32 = bindings::PHY_RST_AFTER_CLK_EN;
297     /// Polling is used to detect PHY status changes.
298     pub const POLL_CABLE_TEST: u32 = bindings::PHY_POLL_CABLE_TEST;
299     /// Don't suspend.
300     pub const ALWAYS_CALL_SUSPEND: u32 = bindings::PHY_ALWAYS_CALL_SUSPEND;
301 }
302 
303 /// An adapter for the registration of a PHY driver.
304 struct Adapter<T: Driver> {
305     _p: PhantomData<T>,
306 }
307 
308 impl<T: Driver> Adapter<T> {
309     /// # Safety
310     ///
311     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
312     unsafe extern "C" fn soft_reset_callback(phydev: *mut bindings::phy_device) -> c_int {
313         from_result(|| {
314             // SAFETY: This callback is called only in contexts
315             // where we hold `phy_device->lock`, so the accessors on
316             // `Device` are okay to call.
317             let dev = unsafe { Device::from_raw(phydev) };
318             T::soft_reset(dev)?;
319             Ok(0)
320         })
321     }
322 
323     /// # Safety
324     ///
325     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
326     unsafe extern "C" fn probe_callback(phydev: *mut bindings::phy_device) -> c_int {
327         from_result(|| {
328             // SAFETY: This callback is called only in contexts
329             // where we can exclusively access `phy_device` because
330             // it's not published yet, so the accessors on `Device` are okay
331             // to call.
332             let dev = unsafe { Device::from_raw(phydev) };
333             T::probe(dev)?;
334             Ok(0)
335         })
336     }
337 
338     /// # Safety
339     ///
340     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
341     unsafe extern "C" fn get_features_callback(phydev: *mut bindings::phy_device) -> c_int {
342         from_result(|| {
343             // SAFETY: This callback is called only in contexts
344             // where we hold `phy_device->lock`, so the accessors on
345             // `Device` are okay to call.
346             let dev = unsafe { Device::from_raw(phydev) };
347             T::get_features(dev)?;
348             Ok(0)
349         })
350     }
351 
352     /// # Safety
353     ///
354     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
355     unsafe extern "C" fn suspend_callback(phydev: *mut bindings::phy_device) -> c_int {
356         from_result(|| {
357             // SAFETY: The C core code ensures that the accessors on
358             // `Device` are okay to call even though `phy_device->lock`
359             // might not be held.
360             let dev = unsafe { Device::from_raw(phydev) };
361             T::suspend(dev)?;
362             Ok(0)
363         })
364     }
365 
366     /// # Safety
367     ///
368     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
369     unsafe extern "C" fn resume_callback(phydev: *mut bindings::phy_device) -> c_int {
370         from_result(|| {
371             // SAFETY: The C core code ensures that the accessors on
372             // `Device` are okay to call even though `phy_device->lock`
373             // might not be held.
374             let dev = unsafe { Device::from_raw(phydev) };
375             T::resume(dev)?;
376             Ok(0)
377         })
378     }
379 
380     /// # Safety
381     ///
382     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
383     unsafe extern "C" fn config_aneg_callback(phydev: *mut bindings::phy_device) -> c_int {
384         from_result(|| {
385             // SAFETY: This callback is called only in contexts
386             // where we hold `phy_device->lock`, so the accessors on
387             // `Device` are okay to call.
388             let dev = unsafe { Device::from_raw(phydev) };
389             T::config_aneg(dev)?;
390             Ok(0)
391         })
392     }
393 
394     /// # Safety
395     ///
396     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
397     unsafe extern "C" fn read_status_callback(phydev: *mut bindings::phy_device) -> c_int {
398         from_result(|| {
399             // SAFETY: This callback is called only in contexts
400             // where we hold `phy_device->lock`, so the accessors on
401             // `Device` are okay to call.
402             let dev = unsafe { Device::from_raw(phydev) };
403             T::read_status(dev)?;
404             Ok(0)
405         })
406     }
407 
408     /// # Safety
409     ///
410     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
411     unsafe extern "C" fn match_phy_device_callback(
412         phydev: *mut bindings::phy_device,
413         _phydrv: *const bindings::phy_driver,
414     ) -> c_int {
415         // SAFETY: This callback is called only in contexts
416         // where we hold `phy_device->lock`, so the accessors on
417         // `Device` are okay to call.
418         let dev = unsafe { Device::from_raw(phydev) };
419         T::match_phy_device(dev).into()
420     }
421 
422     /// # Safety
423     ///
424     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
425     unsafe extern "C" fn read_mmd_callback(
426         phydev: *mut bindings::phy_device,
427         devnum: i32,
428         regnum: u16,
429     ) -> i32 {
430         from_result(|| {
431             // SAFETY: This callback is called only in contexts
432             // where we hold `phy_device->lock`, so the accessors on
433             // `Device` are okay to call.
434             let dev = unsafe { Device::from_raw(phydev) };
435             // CAST: the C side verifies devnum < 32.
436             let ret = T::read_mmd(dev, devnum as u8, regnum)?;
437             Ok(ret.into())
438         })
439     }
440 
441     /// # Safety
442     ///
443     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
444     unsafe extern "C" fn write_mmd_callback(
445         phydev: *mut bindings::phy_device,
446         devnum: i32,
447         regnum: u16,
448         val: u16,
449     ) -> i32 {
450         from_result(|| {
451             // SAFETY: This callback is called only in contexts
452             // where we hold `phy_device->lock`, so the accessors on
453             // `Device` are okay to call.
454             let dev = unsafe { Device::from_raw(phydev) };
455             T::write_mmd(dev, devnum as u8, regnum, val)?;
456             Ok(0)
457         })
458     }
459 
460     /// # Safety
461     ///
462     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
463     unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) {
464         // SAFETY: This callback is called only in contexts
465         // where we hold `phy_device->lock`, so the accessors on
466         // `Device` are okay to call.
467         let dev = unsafe { Device::from_raw(phydev) };
468         T::link_change_notify(dev);
469     }
470 }
471 
472 /// Driver structure for a particular PHY type.
473 ///
474 /// Wraps the kernel's [`struct phy_driver`].
475 /// This is used to register a driver for a particular PHY type with the kernel.
476 ///
477 /// # Invariants
478 ///
479 /// `self.0` is always in a valid state.
480 ///
481 /// [`struct phy_driver`]: srctree/include/linux/phy.h
482 #[repr(transparent)]
483 pub struct DriverVTable(Opaque<bindings::phy_driver>);
484 
485 // SAFETY: `DriverVTable` doesn't expose any &self method to access internal data, so it's safe to
486 // share `&DriverVTable` across execution context boundaries.
487 unsafe impl Sync for DriverVTable {}
488 
489 /// Creates a [`DriverVTable`] instance from [`Driver`].
490 ///
491 /// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`.
492 ///
493 /// [`module_phy_driver`]: crate::module_phy_driver
494 pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
495     // INVARIANT: All the fields of `struct phy_driver` are initialized properly.
496     DriverVTable(Opaque::new(bindings::phy_driver {
497         name: crate::str::as_char_ptr_in_const_context(T::NAME).cast_mut(),
498         flags: T::FLAGS,
499         phy_id: T::PHY_DEVICE_ID.id(),
500         phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
501         soft_reset: if T::HAS_SOFT_RESET {
502             Some(Adapter::<T>::soft_reset_callback)
503         } else {
504             None
505         },
506         probe: if T::HAS_PROBE {
507             Some(Adapter::<T>::probe_callback)
508         } else {
509             None
510         },
511         get_features: if T::HAS_GET_FEATURES {
512             Some(Adapter::<T>::get_features_callback)
513         } else {
514             None
515         },
516         match_phy_device: if T::HAS_MATCH_PHY_DEVICE {
517             Some(Adapter::<T>::match_phy_device_callback)
518         } else {
519             None
520         },
521         suspend: if T::HAS_SUSPEND {
522             Some(Adapter::<T>::suspend_callback)
523         } else {
524             None
525         },
526         resume: if T::HAS_RESUME {
527             Some(Adapter::<T>::resume_callback)
528         } else {
529             None
530         },
531         config_aneg: if T::HAS_CONFIG_ANEG {
532             Some(Adapter::<T>::config_aneg_callback)
533         } else {
534             None
535         },
536         read_status: if T::HAS_READ_STATUS {
537             Some(Adapter::<T>::read_status_callback)
538         } else {
539             None
540         },
541         read_mmd: if T::HAS_READ_MMD {
542             Some(Adapter::<T>::read_mmd_callback)
543         } else {
544             None
545         },
546         write_mmd: if T::HAS_WRITE_MMD {
547             Some(Adapter::<T>::write_mmd_callback)
548         } else {
549             None
550         },
551         link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY {
552             Some(Adapter::<T>::link_change_notify_callback)
553         } else {
554             None
555         },
556         // SAFETY: The rest is zeroed out to initialize `struct phy_driver`,
557         // sets `Option<&F>` to be `None`.
558         ..unsafe { core::mem::MaybeUninit::<bindings::phy_driver>::zeroed().assume_init() }
559     }))
560 }
561 
562 /// Driver implementation for a particular PHY type.
563 ///
564 /// This trait is used to create a [`DriverVTable`].
565 #[vtable]
566 pub trait Driver {
567     /// Defines certain other features this PHY supports.
568     /// It is a combination of the flags in the [`flags`] module.
569     const FLAGS: u32 = 0;
570 
571     /// The friendly name of this PHY type.
572     const NAME: &'static CStr;
573 
574     /// This driver only works for PHYs with IDs which match this field.
575     /// The default id and mask are zero.
576     const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0);
577 
578     /// Issues a PHY software reset.
579     fn soft_reset(_dev: &mut Device) -> Result {
580         build_error!(VTABLE_DEFAULT_ERROR)
581     }
582 
583     /// Sets up device-specific structures during discovery.
584     fn probe(_dev: &mut Device) -> Result {
585         build_error!(VTABLE_DEFAULT_ERROR)
586     }
587 
588     /// Probes the hardware to determine what abilities it has.
589     fn get_features(_dev: &mut Device) -> Result {
590         build_error!(VTABLE_DEFAULT_ERROR)
591     }
592 
593     /// Returns true if this is a suitable driver for the given phydev.
594     /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`].
595     fn match_phy_device(_dev: &Device) -> bool {
596         false
597     }
598 
599     /// Configures the advertisement and resets auto-negotiation
600     /// if auto-negotiation is enabled.
601     fn config_aneg(_dev: &mut Device) -> Result {
602         build_error!(VTABLE_DEFAULT_ERROR)
603     }
604 
605     /// Determines the negotiated speed and duplex.
606     fn read_status(_dev: &mut Device) -> Result<u16> {
607         build_error!(VTABLE_DEFAULT_ERROR)
608     }
609 
610     /// Suspends the hardware, saving state if needed.
611     fn suspend(_dev: &mut Device) -> Result {
612         build_error!(VTABLE_DEFAULT_ERROR)
613     }
614 
615     /// Resumes the hardware, restoring state if needed.
616     fn resume(_dev: &mut Device) -> Result {
617         build_error!(VTABLE_DEFAULT_ERROR)
618     }
619 
620     /// Overrides the default MMD read function for reading a MMD register.
621     fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
622         build_error!(VTABLE_DEFAULT_ERROR)
623     }
624 
625     /// Overrides the default MMD write function for writing a MMD register.
626     fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
627         build_error!(VTABLE_DEFAULT_ERROR)
628     }
629 
630     /// Callback for notification of link change.
631     fn link_change_notify(_dev: &mut Device) {}
632 }
633 
634 /// Registration structure for PHY drivers.
635 ///
636 /// Registers [`DriverVTable`] instances with the kernel. They will be unregistered when dropped.
637 ///
638 /// # Invariants
639 ///
640 /// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
641 pub struct Registration {
642     drivers: Pin<&'static mut [DriverVTable]>,
643 }
644 
645 // SAFETY: The only action allowed in a `Registration` instance is dropping it, which is safe to do
646 // from any thread because `phy_drivers_unregister` can be called from any thread context.
647 unsafe impl Send for Registration {}
648 
649 impl Registration {
650     /// Registers a PHY driver.
651     pub fn register(
652         module: &'static crate::ThisModule,
653         drivers: Pin<&'static mut [DriverVTable]>,
654     ) -> Result<Self> {
655         if drivers.is_empty() {
656             return Err(code::EINVAL);
657         }
658         // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of
659         // the `drivers` slice are initialized properly. `drivers` will not be moved.
660         // So it's just an FFI call.
661         to_result(unsafe {
662             bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
663         })?;
664         // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
665         Ok(Registration { drivers })
666     }
667 }
668 
669 impl Drop for Registration {
670     fn drop(&mut self) {
671         // SAFETY: The type invariants guarantee that `self.drivers` is valid.
672         // So it's just an FFI call.
673         unsafe {
674             bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32)
675         };
676     }
677 }
678 
679 /// An identifier for PHY devices on an MDIO/MII bus.
680 ///
681 /// Represents the kernel's `struct mdio_device_id`. This is used to find an appropriate
682 /// PHY driver.
683 #[repr(transparent)]
684 #[derive(Clone, Copy)]
685 pub struct DeviceId(bindings::mdio_device_id);
686 
687 impl DeviceId {
688     /// Creates a new instance with the exact match mask.
689     pub const fn new_with_exact_mask(id: u32) -> Self {
690         Self(bindings::mdio_device_id {
691             phy_id: id,
692             phy_id_mask: DeviceMask::Exact.as_int(),
693         })
694     }
695 
696     /// Creates a new instance with the model match mask.
697     pub const fn new_with_model_mask(id: u32) -> Self {
698         Self(bindings::mdio_device_id {
699             phy_id: id,
700             phy_id_mask: DeviceMask::Model.as_int(),
701         })
702     }
703 
704     /// Creates a new instance with the vendor match mask.
705     pub const fn new_with_vendor_mask(id: u32) -> Self {
706         Self(bindings::mdio_device_id {
707             phy_id: id,
708             phy_id_mask: DeviceMask::Vendor.as_int(),
709         })
710     }
711 
712     /// Creates a new instance with a custom match mask.
713     pub const fn new_with_custom_mask(id: u32, mask: u32) -> Self {
714         Self(bindings::mdio_device_id {
715             phy_id: id,
716             phy_id_mask: DeviceMask::Custom(mask).as_int(),
717         })
718     }
719 
720     /// Creates a new instance from [`Driver`].
721     pub const fn new_with_driver<T: Driver>() -> Self {
722         T::PHY_DEVICE_ID
723     }
724 
725     /// Get the MDIO device's PHY ID.
726     pub const fn id(&self) -> u32 {
727         self.0.phy_id
728     }
729 
730     /// Get the MDIO device's match mask.
731     pub const fn mask_as_int(&self) -> u32 {
732         self.0.phy_id_mask
733     }
734 
735     // macro use only
736     #[doc(hidden)]
737     pub const fn mdio_device_id(&self) -> bindings::mdio_device_id {
738         self.0
739     }
740 }
741 
742 // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `struct mdio_device_id`
743 // and does not add additional invariants, so it's safe to transmute to `RawType`.
744 unsafe impl RawDeviceId for DeviceId {
745     type RawType = bindings::mdio_device_id;
746 }
747 
748 enum DeviceMask {
749     Exact,
750     Model,
751     Vendor,
752     Custom(u32),
753 }
754 
755 impl DeviceMask {
756     const MASK_EXACT: u32 = !0;
757     const MASK_MODEL: u32 = !0 << 4;
758     const MASK_VENDOR: u32 = !0 << 10;
759 
760     const fn as_int(&self) -> u32 {
761         match self {
762             DeviceMask::Exact => Self::MASK_EXACT,
763             DeviceMask::Model => Self::MASK_MODEL,
764             DeviceMask::Vendor => Self::MASK_VENDOR,
765             DeviceMask::Custom(mask) => *mask,
766         }
767     }
768 }
769 
770 /// Declares a kernel module for PHYs drivers.
771 ///
772 /// This creates a static array of kernel's `struct phy_driver` and registers it.
773 /// This also corresponds to the kernel's `MODULE_DEVICE_TABLE` macro, which embeds the information
774 /// for module loading into the module binary file. Every driver needs an entry in `device_table`.
775 ///
776 /// # Examples
777 ///
778 /// ```
779 /// # mod module_phy_driver_sample {
780 /// use kernel::c_str;
781 /// use kernel::net::phy::{self, DeviceId};
782 /// use kernel::prelude::*;
783 ///
784 /// kernel::module_phy_driver! {
785 ///     drivers: [PhySample],
786 ///     device_table: [
787 ///         DeviceId::new_with_driver::<PhySample>()
788 ///     ],
789 ///     name: "rust_sample_phy",
790 ///     authors: ["Rust for Linux Contributors"],
791 ///     description: "Rust sample PHYs driver",
792 ///     license: "GPL",
793 /// }
794 ///
795 /// struct PhySample;
796 ///
797 /// #[vtable]
798 /// impl phy::Driver for PhySample {
799 ///     const NAME: &'static CStr = c_str!("PhySample");
800 ///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
801 /// }
802 /// # }
803 /// ```
804 ///
805 /// This expands to the following code:
806 ///
807 /// ```ignore
808 /// use kernel::c_str;
809 /// use kernel::net::phy::{self, DeviceId};
810 /// use kernel::prelude::*;
811 ///
812 /// struct Module {
813 ///     _reg: ::kernel::net::phy::Registration,
814 /// }
815 ///
816 /// module! {
817 ///     type: Module,
818 ///     name: "rust_sample_phy",
819 ///     authors: ["Rust for Linux Contributors"],
820 ///     description: "Rust sample PHYs driver",
821 ///     license: "GPL",
822 /// }
823 ///
824 /// struct PhySample;
825 ///
826 /// #[vtable]
827 /// impl phy::Driver for PhySample {
828 ///     const NAME: &'static CStr = c_str!("PhySample");
829 ///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
830 /// }
831 ///
832 /// const _: () = {
833 ///     static mut DRIVERS: [::kernel::net::phy::DriverVTable; 1] =
834 ///         [::kernel::net::phy::create_phy_driver::<PhySample>()];
835 ///
836 ///     impl ::kernel::Module for Module {
837 ///         fn init(module: &'static ::kernel::ThisModule) -> Result<Self> {
838 ///             let drivers = unsafe { &mut DRIVERS };
839 ///             let mut reg = ::kernel::net::phy::Registration::register(
840 ///                 module,
841 ///                 ::core::pin::Pin::static_mut(drivers),
842 ///             )?;
843 ///             Ok(Module { _reg: reg })
844 ///         }
845 ///     }
846 /// };
847 ///
848 /// const N: usize = 1;
849 ///
850 /// const TABLE: ::kernel::device_id::IdArray<::kernel::net::phy::DeviceId, (), N> =
851 ///     ::kernel::device_id::IdArray::new_without_index([
852 ///         ::kernel::net::phy::DeviceId(
853 ///             ::kernel::bindings::mdio_device_id {
854 ///                 phy_id: 0x00000001,
855 ///                 phy_id_mask: 0xffffffff,
856 ///             }),
857 ///     ]);
858 ///
859 /// ::kernel::module_device_table!("mdio", phydev, TABLE);
860 /// ```
861 #[macro_export]
862 macro_rules! module_phy_driver {
863     (@replace_expr $_t:tt $sub:expr) => {$sub};
864 
865     (@count_devices $($x:expr),*) => {
866         0usize $(+ $crate::module_phy_driver!(@replace_expr $x 1usize))*
867     };
868 
869     (@device_table [$($dev:expr),+]) => {
870         const N: usize = $crate::module_phy_driver!(@count_devices $($dev),+);
871 
872         const TABLE: $crate::device_id::IdArray<$crate::net::phy::DeviceId, (), N> =
873             $crate::device_id::IdArray::new_without_index([ $(($dev,())),+, ]);
874 
875         $crate::module_device_table!("mdio", phydev, TABLE);
876     };
877 
878     (drivers: [$($driver:ident),+ $(,)?], device_table: [$($dev:expr),+ $(,)?], $($f:tt)*) => {
879         struct Module {
880             _reg: $crate::net::phy::Registration,
881         }
882 
883         $crate::prelude::module! {
884             type: Module,
885             $($f)*
886         }
887 
888         const _: () = {
889             static mut DRIVERS: [$crate::net::phy::DriverVTable;
890                 $crate::module_phy_driver!(@count_devices $($driver),+)] =
891                 [$($crate::net::phy::create_phy_driver::<$driver>()),+];
892 
893             impl $crate::Module for Module {
894                 fn init(module: &'static $crate::ThisModule) -> Result<Self> {
895                     // SAFETY: The anonymous constant guarantees that nobody else can access
896                     // the `DRIVERS` static. The array is used only in the C side.
897                     let drivers = unsafe { &mut DRIVERS };
898                     let mut reg = $crate::net::phy::Registration::register(
899                         module,
900                         ::core::pin::Pin::static_mut(drivers),
901                     )?;
902                     Ok(Module { _reg: reg })
903                 }
904             }
905         };
906 
907         $crate::module_phy_driver!(@device_table [$($dev),+]);
908     }
909 }
910