Re: [PATCH net-next v2 1/2] net: axienet: use device_property and fwnode APIs for probe-time config

[Andrew Lunn]

On Mon, Sep 28, 2026 at 10:42:55AM +0300, Sagi Maimon wrote:
> axienet_probe() reads its configuration exclusively through the of_*
> API, so the driver can only be instantiated from a device tree node.
> 
> The ADVA TimeCard X2 is a PCIe timing card, driven by ptp_ocp, whose
> FPGA contains an AXI Ethernet MAC with an AXI DMA engine.  ptp_ocp is
> going to register the MAC as a child platform device described by a
> software node, so that this driver runs it rather than a copy in
> ptp_ocp.  That needs the probe-time configuration to be readable from a
> software node.
> 
> Convert only the lookups such a caller needs: "xlnx,rxmem", which probe
> requires; "phy-mode"; the MAC address; and the PHY connection, which is
> where phylink finds a "fixed-link" child.  On a device tree this is a
> no-op: device_property_read_u32() dispatches to the of_* implementation
> when dev->fwnode is an OF node, phylink_of_phy_connect() is a wrapper
> around phylink_fwnode_phy_connect(), and device_get_phy_mode() and
> device_get_mac_address() are thin fwnode wrappers around the same
> lookups.  device_get_mac_address() also keeps the "mac-address" nvmem
> cell fallback that of_get_mac_address() has.
> 
> Note that device_get_phy_mode() returns the mode as a positive value
> rather than through an out parameter, so the error test changes from
> "if (ret)" to "if (ret < 0)".
> 
> Everything else stays on the OF API.  "xlnx,txcsum", "xlnx,rxcsum" and
> "xlnx,switch-x-sgmii" are optional, and "xlnx,phy-type" is deprecated in
> favour of "phy-mode".  Without an OF node each of those lookups finds
> nothing, exactly as for a device tree node that leaves them out: no
> checksum offload, no runtime SGMII/1000BASE-X switching and a
> fall-through to "phy-mode".  The "dmas" test likewise selects the
> built-in AXI DMA engine.  The "axistream-connected", "pcs-handle" and
> "phy-handle" phandle lookups stay too: a caller without an OF node takes
> neither branch, getting its DMA registers from its own platform
> resources, and it cannot use the SGMII and 1000BASE-X modes, which need
> a PCS.
> 
> No functional change intended.
> 
> Tested on the X2 with a local ptp_ocp change, with CONFIG_OF disabled
> and enabled: the interface probes with its configuration read from the
> software node and passes traffic.  No device tree board was available,
> so the claim that this is a no-op for device tree users rests on the
> dispatch described above.
> 
> Assisted-by: LLM sparse
> Signed-off-by: Sagi Maimon <maimon.sagi@xxxxxxxxx>

Lets see what the AI reviewer says about this, but it looks O.K. to me:

Reviewed-by: Andrew Lunn <andrew@xxxxxxx>

    Andrew