[PATCH 3/3] net: stmmac: dwmac-socfpga: Add mac-mode DT property support

[Nazle Asmade, Muhammad Nazim Amirul]

On 1/7/2026 10:43 pm, Andrew Lunn wrote:
> On Tue, Jun 30, 2026 at 06:31:08AM -0700, muhammad.nazim.amirul.nazle.asmade at altera.com wrote:
>> From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade at altera.com>
>>
>> Russell King's commit de696c63c1dc ("net: stmmac: socfpga: convert to
>> use phy_interface") replaced mac_interface with phy_interface in
>> socfpga_get_plat_phymode(), noting that no upstream DTS files set the
>> "mac-mode" property, making the two values identical.
>>
>> The Agilex5 SoCDK TSN Config2 board is an exception: its gmac1 TSN
>> port uses GMII internally in the MAC while the PHY-side interface is
>> RGMII, so mac-mode and phy-mode differ. Without restoring mac_interface
>> support, the MAC is configured with RGMII instead of GMII, causing
>> connectivity failures on this board.
>>
>> Add socfpga_of_get_mac_mode() to read the optional "mac-mode" DT
>> property and store it in a new mac_interface field. When the property
>> is absent, mac_interface falls back to phy_interface, preserving
>> the existing behaviour for all other boards.
> 
> I don't actually see a need for mac-mode. From what you are saying,
> there is no choice. The MAC is hard wired to the converter block. So
> you can just look at the compatible. You are going to need to use the
> compatible anyway, to mask the phy-mode to handle the "MAC" doing the
> RGMII delays.
> 
>        Andrew
> 
Hi Maxime, Andrew

Thanks for the reviews!

Hi Andrew,

The challenge with using compatible is that the TSN Config2 board has 
two ports — only gmac1 uses the GMII-to-RGMII converter, while gmac2 
connects directly to its PHY. A board-level compatible check would need 
additional logic to know which port to apply the GMII override to.

With mac-mode, the configuration is per-port in the DTS — consistent 
with how altr,emac-splitter works today. I also addressing Maxime's 
feedback in v2 by unifying the splitter and mac-mode code paths.

BR,
Nazim