On 30/09/15 14:27, Tim Harvey wrote: > On Wed, Sep 30, 2015 at 2:12 PM, Andrew Lunn <and...@lunn.ch> wrote: >> 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? > > It is possible to represent PCI devices in device-tree however not in > a dynamic or plug-able fashion - they have to be nested per bus/slot > which defeats the purpose of dynamic enumeration.
Even though a bus is completely auto-discoverable, if there is additional information needed to supplement that topology, having things be represented in Device Tree is typically accepted. > >> >>> 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. > > I was thinking of this as well, but then I would still need that shim > to know the netdevice that the driver I'm shimming creates so I can't > figure a way to do it without touching the PCI driver. You can register a network device notifier, and try to extract that information about this network device you need once you see that device being registered. As an example, there is a loopback/fake DSA switch driver here which uses the loopback interface as a parent network device (NB: this is using the network device name, which is pretty lame, but that does the job): https://github.com/ffainelli/linux/commit/67d1db45d17f8cc3b32d7a46c49d5df736cee56c -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
