xref: /linux/rust/kernel/net/phy.rs (revision 9a8682f0875b8cedad42bdfe601e6ab204fad06d)
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) == 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 
284 impl 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::from_raw(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`].
295 pub 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.
307 struct Adapter<T: Driver> {
308     _p: PhantomData<T>,
309 }
310 
311 impl<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         _phydrv: *const bindings::phy_driver,
425     ) -> crate::ffi::c_int {
426         // SAFETY: This callback is called only in contexts
427         // where we hold `phy_device->lock`, so the accessors on
428         // `Device` are okay to call.
429         let dev = unsafe { Device::from_raw(phydev) };
430         T::match_phy_device(dev) as i32
431     }
432 
433     /// # Safety
434     ///
435     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
436     unsafe extern "C" fn read_mmd_callback(
437         phydev: *mut bindings::phy_device,
438         devnum: i32,
439         regnum: u16,
440     ) -> i32 {
441         from_result(|| {
442             // SAFETY: This callback is called only in contexts
443             // where we hold `phy_device->lock`, so the accessors on
444             // `Device` are okay to call.
445             let dev = unsafe { Device::from_raw(phydev) };
446             // CAST: the C side verifies devnum < 32.
447             let ret = T::read_mmd(dev, devnum as u8, regnum)?;
448             Ok(ret.into())
449         })
450     }
451 
452     /// # Safety
453     ///
454     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
455     unsafe extern "C" fn write_mmd_callback(
456         phydev: *mut bindings::phy_device,
457         devnum: i32,
458         regnum: u16,
459         val: u16,
460     ) -> i32 {
461         from_result(|| {
462             // SAFETY: This callback is called only in contexts
463             // where we hold `phy_device->lock`, so the accessors on
464             // `Device` are okay to call.
465             let dev = unsafe { Device::from_raw(phydev) };
466             T::write_mmd(dev, devnum as u8, regnum, val)?;
467             Ok(0)
468         })
469     }
470 
471     /// # Safety
472     ///
473     /// `phydev` must be passed by the corresponding callback in `phy_driver`.
474     unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) {
475         // SAFETY: This callback is called only in contexts
476         // where we hold `phy_device->lock`, so the accessors on
477         // `Device` are okay to call.
478         let dev = unsafe { Device::from_raw(phydev) };
479         T::link_change_notify(dev);
480     }
481 }
482 
483 /// Driver structure for a particular PHY type.
484 ///
485 /// Wraps the kernel's [`struct phy_driver`].
486 /// This is used to register a driver for a particular PHY type with the kernel.
487 ///
488 /// # Invariants
489 ///
490 /// `self.0` is always in a valid state.
491 ///
492 /// [`struct phy_driver`]: srctree/include/linux/phy.h
493 #[repr(transparent)]
494 pub struct DriverVTable(Opaque<bindings::phy_driver>);
495 
496 // SAFETY: `DriverVTable` doesn't expose any &self method to access internal data, so it's safe to
497 // share `&DriverVTable` across execution context boundaries.
498 unsafe impl Sync for DriverVTable {}
499 
500 /// Creates a [`DriverVTable`] instance from [`Driver`].
501 ///
502 /// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`.
503 ///
504 /// [`module_phy_driver`]: crate::module_phy_driver
505 pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
506     // INVARIANT: All the fields of `struct phy_driver` are initialized properly.
507     DriverVTable(Opaque::new(bindings::phy_driver {
508         name: T::NAME.as_char_ptr().cast_mut(),
509         flags: T::FLAGS,
510         phy_id: T::PHY_DEVICE_ID.id(),
511         phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
512         soft_reset: if T::HAS_SOFT_RESET {
513             Some(Adapter::<T>::soft_reset_callback)
514         } else {
515             None
516         },
517         probe: if T::HAS_PROBE {
518             Some(Adapter::<T>::probe_callback)
519         } else {
520             None
521         },
522         get_features: if T::HAS_GET_FEATURES {
523             Some(Adapter::<T>::get_features_callback)
524         } else {
525             None
526         },
527         match_phy_device: if T::HAS_MATCH_PHY_DEVICE {
528             Some(Adapter::<T>::match_phy_device_callback)
529         } else {
530             None
531         },
532         suspend: if T::HAS_SUSPEND {
533             Some(Adapter::<T>::suspend_callback)
534         } else {
535             None
536         },
537         resume: if T::HAS_RESUME {
538             Some(Adapter::<T>::resume_callback)
539         } else {
540             None
541         },
542         config_aneg: if T::HAS_CONFIG_ANEG {
543             Some(Adapter::<T>::config_aneg_callback)
544         } else {
545             None
546         },
547         read_status: if T::HAS_READ_STATUS {
548             Some(Adapter::<T>::read_status_callback)
549         } else {
550             None
551         },
552         read_mmd: if T::HAS_READ_MMD {
553             Some(Adapter::<T>::read_mmd_callback)
554         } else {
555             None
556         },
557         write_mmd: if T::HAS_WRITE_MMD {
558             Some(Adapter::<T>::write_mmd_callback)
559         } else {
560             None
561         },
562         link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY {
563             Some(Adapter::<T>::link_change_notify_callback)
564         } else {
565             None
566         },
567         // SAFETY: The rest is zeroed out to initialize `struct phy_driver`,
568         // sets `Option<&F>` to be `None`.
569         ..unsafe { core::mem::MaybeUninit::<bindings::phy_driver>::zeroed().assume_init() }
570     }))
571 }
572 
573 /// Driver implementation for a particular PHY type.
574 ///
575 /// This trait is used to create a [`DriverVTable`].
576 #[vtable]
577 pub trait Driver {
578     /// Defines certain other features this PHY supports.
579     /// It is a combination of the flags in the [`flags`] module.
580     const FLAGS: u32 = 0;
581 
582     /// The friendly name of this PHY type.
583     const NAME: &'static CStr;
584 
585     /// This driver only works for PHYs with IDs which match this field.
586     /// The default id and mask are zero.
587     const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0);
588 
589     /// Issues a PHY software reset.
590     fn soft_reset(_dev: &mut Device) -> Result {
591         build_error!(VTABLE_DEFAULT_ERROR)
592     }
593 
594     /// Sets up device-specific structures during discovery.
595     fn probe(_dev: &mut Device) -> Result {
596         build_error!(VTABLE_DEFAULT_ERROR)
597     }
598 
599     /// Probes the hardware to determine what abilities it has.
600     fn get_features(_dev: &mut Device) -> Result {
601         build_error!(VTABLE_DEFAULT_ERROR)
602     }
603 
604     /// Returns true if this is a suitable driver for the given phydev.
605     /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`].
606     fn match_phy_device(_dev: &Device) -> bool {
607         false
608     }
609 
610     /// Configures the advertisement and resets auto-negotiation
611     /// if auto-negotiation is enabled.
612     fn config_aneg(_dev: &mut Device) -> Result {
613         build_error!(VTABLE_DEFAULT_ERROR)
614     }
615 
616     /// Determines the negotiated speed and duplex.
617     fn read_status(_dev: &mut Device) -> Result<u16> {
618         build_error!(VTABLE_DEFAULT_ERROR)
619     }
620 
621     /// Suspends the hardware, saving state if needed.
622     fn suspend(_dev: &mut Device) -> Result {
623         build_error!(VTABLE_DEFAULT_ERROR)
624     }
625 
626     /// Resumes the hardware, restoring state if needed.
627     fn resume(_dev: &mut Device) -> Result {
628         build_error!(VTABLE_DEFAULT_ERROR)
629     }
630 
631     /// Overrides the default MMD read function for reading a MMD register.
632     fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
633         build_error!(VTABLE_DEFAULT_ERROR)
634     }
635 
636     /// Overrides the default MMD write function for writing a MMD register.
637     fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
638         build_error!(VTABLE_DEFAULT_ERROR)
639     }
640 
641     /// Callback for notification of link change.
642     fn link_change_notify(_dev: &mut Device) {}
643 }
644 
645 /// Registration structure for PHY drivers.
646 ///
647 /// Registers [`DriverVTable`] instances with the kernel. They will be unregistered when dropped.
648 ///
649 /// # Invariants
650 ///
651 /// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
652 pub struct Registration {
653     drivers: Pin<&'static mut [DriverVTable]>,
654 }
655 
656 // SAFETY: The only action allowed in a `Registration` instance is dropping it, which is safe to do
657 // from any thread because `phy_drivers_unregister` can be called from any thread context.
658 unsafe impl Send for Registration {}
659 
660 impl Registration {
661     /// Registers a PHY driver.
662     pub fn register(
663         module: &'static crate::ThisModule,
664         drivers: Pin<&'static mut [DriverVTable]>,
665     ) -> Result<Self> {
666         if drivers.is_empty() {
667             return Err(code::EINVAL);
668         }
669         // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of
670         // the `drivers` slice are initialized properly. `drivers` will not be moved.
671         // So it's just an FFI call.
672         to_result(unsafe {
673             bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
674         })?;
675         // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
676         Ok(Registration { drivers })
677     }
678 }
679 
680 impl Drop for Registration {
681     fn drop(&mut self) {
682         // SAFETY: The type invariants guarantee that `self.drivers` is valid.
683         // So it's just an FFI call.
684         unsafe {
685             bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32)
686         };
687     }
688 }
689 
690 /// An identifier for PHY devices on an MDIO/MII bus.
691 ///
692 /// Represents the kernel's `struct mdio_device_id`. This is used to find an appropriate
693 /// PHY driver.
694 #[repr(transparent)]
695 #[derive(Clone, Copy)]
696 pub struct DeviceId(bindings::mdio_device_id);
697 
698 impl DeviceId {
699     /// Creates a new instance with the exact match mask.
700     pub const fn new_with_exact_mask(id: u32) -> Self {
701         Self(bindings::mdio_device_id {
702             phy_id: id,
703             phy_id_mask: DeviceMask::Exact.as_int(),
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         Self(bindings::mdio_device_id {
710             phy_id: id,
711             phy_id_mask: DeviceMask::Model.as_int(),
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         Self(bindings::mdio_device_id {
718             phy_id: id,
719             phy_id_mask: DeviceMask::Vendor.as_int(),
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         Self(bindings::mdio_device_id {
726             phy_id: id,
727             phy_id_mask: DeviceMask::Custom(mask).as_int(),
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 the MDIO device's PHY ID.
737     pub const fn id(&self) -> u32 {
738         self.0.phy_id
739     }
740 
741     /// Get the MDIO device's match mask.
742     pub const fn mask_as_int(&self) -> u32 {
743         self.0.phy_id_mask
744     }
745 
746     // macro use only
747     #[doc(hidden)]
748     pub const fn mdio_device_id(&self) -> bindings::mdio_device_id {
749         self.0
750     }
751 }
752 
753 // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `struct mdio_device_id`
754 // and does not add additional invariants, so it's safe to transmute to `RawType`.
755 unsafe impl RawDeviceId for DeviceId {
756     type RawType = bindings::mdio_device_id;
757 }
758 
759 enum DeviceMask {
760     Exact,
761     Model,
762     Vendor,
763     Custom(u32),
764 }
765 
766 impl DeviceMask {
767     const MASK_EXACT: u32 = !0;
768     const MASK_MODEL: u32 = !0 << 4;
769     const MASK_VENDOR: u32 = !0 << 10;
770 
771     const fn as_int(&self) -> u32 {
772         match self {
773             DeviceMask::Exact => Self::MASK_EXACT,
774             DeviceMask::Model => Self::MASK_MODEL,
775             DeviceMask::Vendor => Self::MASK_VENDOR,
776             DeviceMask::Custom(mask) => *mask,
777         }
778     }
779 }
780 
781 /// Declares a kernel module for PHYs drivers.
782 ///
783 /// This creates a static array of kernel's `struct phy_driver` and registers it.
784 /// This also corresponds to the kernel's `MODULE_DEVICE_TABLE` macro, which embeds the information
785 /// for module loading into the module binary file. Every driver needs an entry in `device_table`.
786 ///
787 /// # Examples
788 ///
789 /// ```
790 /// # mod module_phy_driver_sample {
791 /// use kernel::c_str;
792 /// use kernel::net::phy::{self, DeviceId};
793 /// use kernel::prelude::*;
794 ///
795 /// kernel::module_phy_driver! {
796 ///     drivers: [PhySample],
797 ///     device_table: [
798 ///         DeviceId::new_with_driver::<PhySample>()
799 ///     ],
800 ///     name: "rust_sample_phy",
801 ///     authors: ["Rust for Linux Contributors"],
802 ///     description: "Rust sample PHYs driver",
803 ///     license: "GPL",
804 /// }
805 ///
806 /// struct PhySample;
807 ///
808 /// #[vtable]
809 /// impl phy::Driver for PhySample {
810 ///     const NAME: &'static CStr = c_str!("PhySample");
811 ///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
812 /// }
813 /// # }
814 /// ```
815 ///
816 /// This expands to the following code:
817 ///
818 /// ```ignore
819 /// use kernel::c_str;
820 /// use kernel::net::phy::{self, DeviceId};
821 /// use kernel::prelude::*;
822 ///
823 /// struct Module {
824 ///     _reg: ::kernel::net::phy::Registration,
825 /// }
826 ///
827 /// module! {
828 ///     type: Module,
829 ///     name: "rust_sample_phy",
830 ///     authors: ["Rust for Linux Contributors"],
831 ///     description: "Rust sample PHYs driver",
832 ///     license: "GPL",
833 /// }
834 ///
835 /// struct PhySample;
836 ///
837 /// #[vtable]
838 /// impl phy::Driver for PhySample {
839 ///     const NAME: &'static CStr = c_str!("PhySample");
840 ///     const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
841 /// }
842 ///
843 /// const _: () = {
844 ///     static mut DRIVERS: [::kernel::net::phy::DriverVTable; 1] =
845 ///         [::kernel::net::phy::create_phy_driver::<PhySample>()];
846 ///
847 ///     impl ::kernel::Module for Module {
848 ///         fn init(module: &'static ::kernel::ThisModule) -> Result<Self> {
849 ///             let drivers = unsafe { &mut DRIVERS };
850 ///             let mut reg = ::kernel::net::phy::Registration::register(
851 ///                 module,
852 ///                 ::core::pin::Pin::static_mut(drivers),
853 ///             )?;
854 ///             Ok(Module { _reg: reg })
855 ///         }
856 ///     }
857 /// };
858 ///
859 /// const N: usize = 1;
860 ///
861 /// const TABLE: ::kernel::device_id::IdArray<::kernel::net::phy::DeviceId, (), N> =
862 ///     ::kernel::device_id::IdArray::new_without_index([
863 ///         ::kernel::net::phy::DeviceId(
864 ///             ::kernel::bindings::mdio_device_id {
865 ///                 phy_id: 0x00000001,
866 ///                 phy_id_mask: 0xffffffff,
867 ///             }),
868 ///     ]);
869 ///
870 /// ::kernel::module_device_table!("mdio", phydev, TABLE);
871 /// ```
872 #[macro_export]
873 macro_rules! module_phy_driver {
874     (@replace_expr $_t:tt $sub:expr) => {$sub};
875 
876     (@count_devices $($x:expr),*) => {
877         0usize $(+ $crate::module_phy_driver!(@replace_expr $x 1usize))*
878     };
879 
880     (@device_table [$($dev:expr),+]) => {
881         const N: usize = $crate::module_phy_driver!(@count_devices $($dev),+);
882 
883         const TABLE: $crate::device_id::IdArray<$crate::net::phy::DeviceId, (), N> =
884             $crate::device_id::IdArray::new_without_index([ $(($dev,())),+, ]);
885 
886         $crate::module_device_table!("mdio", phydev, TABLE);
887     };
888 
889     (drivers: [$($driver:ident),+ $(,)?], device_table: [$($dev:expr),+ $(,)?], $($f:tt)*) => {
890         struct Module {
891             _reg: $crate::net::phy::Registration,
892         }
893 
894         $crate::prelude::module! {
895             type: Module,
896             $($f)*
897         }
898 
899         const _: () = {
900             static mut DRIVERS: [$crate::net::phy::DriverVTable;
901                 $crate::module_phy_driver!(@count_devices $($driver),+)] =
902                 [$($crate::net::phy::create_phy_driver::<$driver>()),+];
903 
904             impl $crate::Module for Module {
905                 fn init(module: &'static $crate::ThisModule) -> Result<Self> {
906                     // SAFETY: The anonymous constant guarantees that nobody else can access
907                     // the `DRIVERS` static. The array is used only in the C side.
908                     let drivers = unsafe { &mut DRIVERS };
909                     let mut reg = $crate::net::phy::Registration::register(
910                         module,
911                         ::core::pin::Pin::static_mut(drivers),
912                     )?;
913                     Ok(Module { _reg: reg })
914                 }
915             }
916         };
917 
918         $crate::module_phy_driver!(@device_table [$($dev),+]);
919     }
920 }
921