On Wed, Sep 30, 2015 at 01:44:52PM -0700, Tim Harvey wrote:

Greetings,

I'm working on adding DSA support for a PCIe expansion card (designed
by us) that has common PCIe NIC connected via its mii-bus to a Marvell
MV88E6171. Because the NIC is a PCIe device, it has no device-tree
representation of its NIC or its mdio bus, but does register its mdio
bus with Linux.

It is possible to represent PCIe devices in device tree. Take a look
at ePAPR. Is the PCIe host in DT?

Perhaps the right approach is to program the NIC's EEPROM on our board
with a PCI_ID/DEVICE_ID of ours, add support for those ID's to the
NIC's driver, and within the NIC's driver create and register dsa
platform device when our ID is encountered?

This sounds sensible. But i doubt you can add your DSA platform
information to the NIC's device driver. Better would be to have a
small shim driver which is loaded on your PCI_ID/DEVICE_ID. That would
instantiate the NIC driver, and insert a DSA platform device.

    Andrew