Re: [RFC PATCH v1] rust: net::phy support to C45 registers access

[Benno Lossin <benno.lossin@proton.me>]

On 27.05.24 23:57, Andrew Lunn wrote:
>> +/// Accesses to C22 registers.
>> +#[derive(Clone, Copy)]
>> +pub enum RegC22 {
>> +    /// Basic mode control.
>> +    Bmcr = uapi::MII_BMCR as isize,
>> +    /// Basic mode status.
>> +    Bmsr = uapi::MII_BMSR as isize,
>> +    /// PHY identifier 1.
>> +    PhysId1 = uapi::MII_PHYSID1 as isize,
>> +    /// PHY identifier 2.
>> +    PhysId2 = uapi::MII_PHYSID2 as isize,
>> +    /// Auto-negotiation advertisement.
>> +    Advertise = uapi::MII_ADVERTISE as isize,
>> +    /// Auto-negotiation link partner base page ability.
>> +    Lpa = uapi::MII_LPA as isize,
>> +    /// Auto-negotiation expansion.
>> +    Expansion = uapi::MII_EXPANSION as isize,
>> +    /// 1000BASE-T control.
>> +    Ctrl1000 = uapi::MII_CTRL1000 as isize,
>> +    /// 1000BASE-T status.
>> +    Stat1000 = uapi::MII_STAT1000 as isize,
>> +    /// MMD access control.
>> +    MmdCtrl = uapi::MII_MMD_CTRL as isize,
>> +    /// MMD access data.
>> +    MmdData = uapi::MII_MMD_DATA as isize,
>> +    /// Extended status.
>> +    Estatus = uapi::MII_ESTATUS as isize,
>> +    /// Disconnect counter.
> 
>> +    Dcounter = uapi::MII_DCOUNTER as isize,
>> +    /// False carrier sense counter.
>> +    Fcscounter = uapi::MII_FCSCOUNTER as isize,
>> +    /// N-way auto-negotiation test.
>> +    Nwaytest = uapi::MII_NWAYTEST as isize,
>> +    /// Receive error counter.
>> +    Rerrcounter = uapi::MII_RERRCOUNTER as isize,
>> +    /// Silicon revision.
>> +    Srervision = uapi::MII_SREVISION as isize,
>> +    /// Reserved.
>> +    Resv1 = uapi::MII_RESV1 as isize,
>> +    /// Lpback, rx, bypass error.
>> +    Lbrerror = uapi::MII_LBRERROR as isize,
>> +    /// PHY address.
>> +    Phyaddr = uapi::MII_PHYADDR as isize,
>> +    /// Reserved.
>> +    Resv2 = uapi::MII_RESV2 as isize,
>> +    /// TPI status for 10Mbps.
>> +    TpiStatus = uapi::MII_TPISTATUS as isize,
>> +    /// Network interface configuration.
>> +    Nconfig = uapi::MII_NCONFIG as isize,
> 
> 802.3 C22 defines 16 through 31 as vendor specific. Most of the
> #defines appear to come from the S390 driver. We probably should not
> add them in the Rust API when there meaning is not clearly
> defined. However, a driver should be able to use them, e.g, by
> defining their own vendor specific name to a given value.

@Fujita, you could fix this by adding a `VendorSpecific(T)` enum variant
and add a generic parameter to `C22`. Then the user has the option to
declare their own variant. You will probably need another trait for the
`T` value to extract the correct register number (you can try to use
`build_assert!` to ensure that the custom registers are not in the 0..16
range).

---
Cheers,
Benno