[U-Boot] Question: Information regarding MII and PHY

[Graeme Russ]

Hi Mike,

On Fri, Sep 23, 2011 at 8:21 AM, Mike Frysinger <vapier at gentoo.org> wrote:
> On Wednesday, September 21, 2011 23:12:44 Graeme Russ wrote:
>> On Thu, Sep 22, 2011 at 11:20 AM, Graeme Russ wrote:
>> I now see why there is no relationship between MII/PHY and PCI as they are
>> not connected to the PCI bus - Communication with the PHY is done through
>> the MAC. So is it the case that 'PHY Drivers' in U-Boot provide access
>> to the PHY (Transceiver) _through_ the MAC and in order to use the PHY
>> drivers, the MAC driver (i.e. the Ethernet driver) needs to provide hooks
>> to pass PHY requests from U-Boot over the (RG)MII interface?
>
> i believe this is correct.  the intention is to be like Linux where you've got
> a driver for the MAC, and you've got drivers for the PHYs, and the MAC driver
> provides the hooks for the PHY layer to access what it needs.
>
> not all drivers have been converted to the PHY abstraction, and we don't have
> a requirement atm for that.
>
> there's also a bit of a mess as we try to move to the Linux phylib code ...
> another area that needs a bit of TLC.

I tried to port the Intel PCH GBe driver last night without much luck.
Just trying to satisfy the data structure requirements (let alone the
support functions) brings in a rediculous amount of extraneous Linux
header files (pretty much the entire TCP/IP stack definitions). I think
I'll abandon the direct approach and try to pick out the init, Tx and Rx
functions piece by piece.

I'll have a look at phylib while I'm at it, but I doubt that I'll be able
to have time to properly figure it at atm

I suppose that is why Wolfgang would like a network custodian

Regards,

Graeme