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rust: net::phy unified read/write API for C22 and C45 registers

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Add the unified read/write API for C22 and C45 registers. The
abstractions support access to only C22 registers now. Instead of
adding read/write_c45 methods specifically for C45, a new reg module
supports the unified API to access C22 and C45 registers with trait,
by calling an appropriate phylib functions.

Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
FUJITA Tomonori 2024-08-28 07:35:14 +00:00 committed by David S. Miller
parent 7909892a9f
commit b2e47002b2
5 changed files with 209 additions and 27 deletions
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1
MAINTAINERS
View File

@ -8357,6 +8357,7 @@ L: netdev@vger.kernel.org
L: rust-for-linux@vger.kernel.org
S: Maintained
F: rust/kernel/net/phy.rs
F: rust/kernel/net/phy/reg.rs
EXEC & BINFMT API, ELF
R: Eric Biederman <ebiederm@xmission.com>

7
drivers/net/phy/ax88796b_rust.rs
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@ -6,7 +6,7 @@
//! C version of this driver: [`drivers/net/phy/ax88796b.c`](./ax88796b.c)
use kernel::{
c_str,
net::phy::{self, DeviceId, Driver},
net::phy::{self, reg::C22, DeviceId, Driver},
prelude::*,
uapi,
};
@ -24,7 +24,6 @@ kernel::module_phy_driver! {
license: "GPL",
}
const MII_BMCR: u16 = uapi::MII_BMCR as u16;
const BMCR_SPEED100: u16 = uapi::BMCR_SPEED100 as u16;
const BMCR_FULLDPLX: u16 = uapi::BMCR_FULLDPLX as u16;
@ -33,7 +32,7 @@ const BMCR_FULLDPLX: u16 = uapi::BMCR_FULLDPLX as u16;
// Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
// such as used on the Individual Computers' X-Surf 100 Zorro card.
fn asix_soft_reset(dev: &mut phy::Device) -> Result {
dev.write(uapi::MII_BMCR as u16, 0)?;
dev.write(C22::BMCR, 0)?;
dev.genphy_soft_reset()
}
@ -55,7 +54,7 @@ impl Driver for PhyAX88772A {
}
// If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve
// linkmode so use MII_BMCR as default values.
let ret = dev.read(MII_BMCR)?;
let ret = dev.read(C22::BMCR)?;
if ret & BMCR_SPEED100 != 0 {
dev.set_speed(uapi::SPEED_100);

31
rust/kernel/net/phy.rs
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@ -9,6 +9,8 @@
use crate::{error::*, prelude::*, types::Opaque};
use core::{marker::PhantomData, ptr::addr_of_mut};
pub mod reg;
/// PHY state machine states.
///
/// Corresponds to the kernel's [`enum phy_state`].
@ -177,32 +179,15 @@ impl Device {
unsafe { (*phydev).duplex = v };
}
/// Reads a given C22 PHY register.
/// Reads a PHY register.
// This function reads a hardware register and updates the stats so takes `&mut self`.
pub fn read(&mut self, regnum: u16) -> Result<u16> {
let phydev = self.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
// So it's just an FFI call, open code of `phy_read()` with a valid `phy_device` pointer
// `phydev`.
let ret = unsafe {
bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into())
};
if ret < 0 {
Err(Error::from_errno(ret))
} else {
Ok(ret as u16)
}
pub fn read<R: reg::Register>(&mut self, reg: R) -> Result<u16> {
reg.read(self)
}
/// Writes a given C22 PHY register.
pub fn write(&mut self, regnum: u16, val: u16) -> Result {
let phydev = self.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
// So it's just an FFI call, open code of `phy_write()` with a valid `phy_device` pointer
// `phydev`.
to_result(unsafe {
bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into(), val)
})
/// Writes a PHY register.
pub fn write<R: reg::Register>(&mut self, reg: R, val: u16) -> Result {
reg.write(self, val)
}
/// Reads a paged register.

196
rust/kernel/net/phy/reg.rs Normal file
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@ -0,0 +1,196 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2024 FUJITA Tomonori <fujita.tomonori@gmail.com>
//! PHY register interfaces.
//!
//! This module provides support for accessing PHY registers in the
//! Ethernet management interface clauses 22 and 45 register namespaces, as
//! defined in IEEE 802.3.
use super::Device;
use crate::build_assert;
use crate::error::*;
use crate::uapi;
mod private {
/// Marker that a trait cannot be implemented outside of this crate
pub trait Sealed {}
}
/// Accesses PHY registers.
///
/// This trait is used to implement the unified interface to access
/// C22 and C45 PHY registers.
///
/// # Examples
///
/// ```ignore
/// fn link_change_notify(dev: &mut Device) {
/// // read C22 BMCR register
/// dev.read(C22::BMCR);
/// // read C45 PMA/PMD control 1 register
/// dev.read(C45::new(Mmd::PMAPMD, 0));
/// }
/// ```
pub trait Register: private::Sealed {
/// Reads a PHY register.
fn read(&self, dev: &mut Device) -> Result<u16>;
/// Writes a PHY register.
fn write(&self, dev: &mut Device, val: u16) -> Result;
}
/// A single MDIO clause 22 register address (5 bits).
#[derive(Copy, Clone, Debug)]
pub struct C22(u8);
impl C22 {
/// Basic mode control.
pub const BMCR: Self = C22(0x00);
/// Basic mode status.
pub const BMSR: Self = C22(0x01);
/// PHY identifier 1.
pub const PHYSID1: Self = C22(0x02);
/// PHY identifier 2.
pub const PHYSID2: Self = C22(0x03);
/// Auto-negotiation advertisement.
pub const ADVERTISE: Self = C22(0x04);
/// Auto-negotiation link partner base page ability.
pub const LPA: Self = C22(0x05);
/// Auto-negotiation expansion.
pub const EXPANSION: Self = C22(0x06);
/// Auto-negotiation next page transmit.
pub const NEXT_PAGE_TRANSMIT: Self = C22(0x07);
/// Auto-negotiation link partner received next page.
pub const LP_RECEIVED_NEXT_PAGE: Self = C22(0x08);
/// Master-slave control.
pub const MASTER_SLAVE_CONTROL: Self = C22(0x09);
/// Master-slave status.
pub const MASTER_SLAVE_STATUS: Self = C22(0x0a);
/// PSE Control.
pub const PSE_CONTROL: Self = C22(0x0b);
/// PSE Status.
pub const PSE_STATUS: Self = C22(0x0c);
/// MMD Register control.
pub const MMD_CONTROL: Self = C22(0x0d);
/// MMD Register address data.
pub const MMD_DATA: Self = C22(0x0e);
/// Extended status.
pub const EXTENDED_STATUS: Self = C22(0x0f);
/// Creates a new instance of `C22` with a vendor specific register.
pub const fn vendor_specific<const N: u8>() -> Self {
build_assert!(
N > 0x0f && N < 0x20,
"Vendor-specific register address must be between 16 and 31"
);
C22(N)
}
}
impl private::Sealed for C22 {}
impl Register for C22 {
fn read(&self, dev: &mut Device) -> Result<u16> {
let phydev = dev.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Device`.
// So it's just an FFI call, open code of `phy_read()` with a valid `phy_device` pointer
// `phydev`.
let ret = unsafe {
bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, self.0.into())
};
to_result(ret)?;
Ok(ret as u16)
}
fn write(&self, dev: &mut Device, val: u16) -> Result {
let phydev = dev.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Device`.
// So it's just an FFI call, open code of `phy_write()` with a valid `phy_device` pointer
// `phydev`.
to_result(unsafe {
bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, self.0.into(), val)
})
}
}
/// A single MDIO clause 45 register device and address.
#[derive(Copy, Clone, Debug)]
pub struct Mmd(u8);
impl Mmd {
/// Physical Medium Attachment/Dependent.
pub const PMAPMD: Self = Mmd(uapi::MDIO_MMD_PMAPMD as u8);
/// WAN interface sublayer.
pub const WIS: Self = Mmd(uapi::MDIO_MMD_WIS as u8);
/// Physical coding sublayer.
pub const PCS: Self = Mmd(uapi::MDIO_MMD_PCS as u8);
/// PHY Extender sublayer.
pub const PHYXS: Self = Mmd(uapi::MDIO_MMD_PHYXS as u8);
/// DTE Extender sublayer.
pub const DTEXS: Self = Mmd(uapi::MDIO_MMD_DTEXS as u8);
/// Transmission convergence.
pub const TC: Self = Mmd(uapi::MDIO_MMD_TC as u8);
/// Auto negotiation.
pub const AN: Self = Mmd(uapi::MDIO_MMD_AN as u8);
/// Separated PMA (1).
pub const SEPARATED_PMA1: Self = Mmd(8);
/// Separated PMA (2).
pub const SEPARATED_PMA2: Self = Mmd(9);
/// Separated PMA (3).
pub const SEPARATED_PMA3: Self = Mmd(10);
/// Separated PMA (4).
pub const SEPARATED_PMA4: Self = Mmd(11);
/// OFDM PMA/PMD.
pub const OFDM_PMAPMD: Self = Mmd(12);
/// Power unit.
pub const POWER_UNIT: Self = Mmd(13);
/// Clause 22 extension.
pub const C22_EXT: Self = Mmd(uapi::MDIO_MMD_C22EXT as u8);
/// Vendor specific 1.
pub const VEND1: Self = Mmd(uapi::MDIO_MMD_VEND1 as u8);
/// Vendor specific 2.
pub const VEND2: Self = Mmd(uapi::MDIO_MMD_VEND2 as u8);
}
/// A single MDIO clause 45 register device and address.
///
/// Clause 45 uses a 5-bit device address to access a specific MMD within
/// a port, then a 16-bit register address to access a location within
/// that device. `C45` represents this by storing a [`Mmd`] and
/// a register number.
pub struct C45 {
devad: Mmd,
regnum: u16,
}
impl C45 {
/// Creates a new instance of `C45`.
pub fn new(devad: Mmd, regnum: u16) -> Self {
Self { devad, regnum }
}
}
impl private::Sealed for C45 {}
impl Register for C45 {
fn read(&self, dev: &mut Device) -> Result<u16> {
let phydev = dev.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Device`.
// So it's just an FFI call.
let ret =
unsafe { bindings::phy_read_mmd(phydev, self.devad.0.into(), self.regnum.into()) };
to_result(ret)?;
Ok(ret as u16)
}
fn write(&self, dev: &mut Device, val: u16) -> Result {
let phydev = dev.0.get();
// SAFETY: `phydev` is pointing to a valid object by the type invariant of `Device`.
// So it's just an FFI call.
to_result(unsafe {
bindings::phy_write_mmd(phydev, self.devad.0.into(), self.regnum.into(), val)
})
}
}

1
rust/uapi/uapi_helper.h
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@ -7,5 +7,6 @@
*/
#include <uapi/asm-generic/ioctl.h>
#include <uapi/linux/mdio.h>
#include <uapi/linux/mii.h>
#include <uapi/linux/ethtool.h>