National Semi DP83865 Phy on custom hardware with PPC 8540 CPU

Ed Henderson ednh at
Fri Jun 27 12:45:24 EST 2008



I am a hardware engineer and I designed a board based on a Power PC MPC8540
CPU. The hardware was patterned after another board with a Marvel driver. I
had some difficulty locating the Marvel Chips, so I used a National
Semiconductor DP83865 Phy instead, available at Digikey. We looked at this
and felt it would not be too difficult to adapt the current Kernel code to
this phy. In practice, now that we have hardware built, it is proving to be
a bit more difficult to bring up. It is very interesting that u-boot
contains code for this Phy, and we are able to get to the u-boot command
line, setup and Ethernet address, ping and even do a tftpboot kernel
transfer. Unfortunately, in the Kernel, we do not have the same success.
This seems to indicate that the hardware is working, at least to some


We did some modifications on the Marvel driver in order to 'attempt' to
adapt it to the National Phy. To be honest, we are not that familiar with
this aspect of Kernel development, so we could really use some
pointers/tips/assistance.  There are some file geared toward the DP83865,
but they are "PCI" drivers. Our Phy is directly connected to the PPC. I do
not  know if it make sense to start with the natsemi.c file (which is geared
toward PCI), or to make our changes to the Marvel phy.


 I would appreciate any help in resolving this issue.




Ed Henderson


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