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

[Gupta, Suraj]

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@xxxxxxxxx>
>
> Lets see what the AI reviewer says about this, but it looks O.K. to me:
>
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
>
>      Andrew

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

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

Thanks,
Suraj