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

["Gupta, Suraj" <suraj.gupta2@amd.com>]

On 9/28/2026 10:49 PM, Andrew Lunn wrote:
> 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@gmail.com>
> 
> Lets see what the AI reviewer says about this, but it looks O.K. to me:
> 
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> 
>      Andrew

Validated on zynqmp DT based board, probe works fine as before.

Tested-by: Suraj Gupta <suraj.gupta2@amd.com>
Reviewed-by: Suraj Gupta <suraj.gupta2@amd.com>

Thanks,
Suraj