Re: [PATCH 08/21] dt-bindings: mfd: x-powers: add AC200

On Tue, Aug 4, 2026 at 12:45 AM James Hilliard
[off-list ref] wrote:

On Mon, Aug 3, 2026 at 7:18 AM Andrew Lunn [off-list ref] wrote:

quoted

quoted

+            ethernet-phy-control {
+                compatible = "x-powers,ac200-ephy-ctl";
+                nvmem-cells = <&ephy_calibration>;
+                nvmem-cell-names = "calibration";
+                phy-mode = "rmii";
+            };

What do you mean by an ethernet PHY control?

I assume this is not an actual Ethernet PHY, but some control logic
around it? Where is the ethernet PHY itself?

Correct, this is not the Ethernet PHY itself. It is the package-specific
sideband control block that must be configured before the normal Clause 22
PHY registers become usable. For AC200, this control block is accessed
through the parent AC200 I2C regmap. For AC300, the equivalent control block
is accessed through a separate non-PHY Clause 22 address.

Basically, all the PHY behavior that is normally configured using strapping
pins on a discrete PHY is done over this I2C channel.

The actual Ethernet PHY is a separate device on the MAC's MDIO bus. The
shared PHY driver for that device is added in patch 16:

https://lore.kernel.org/linux-sunxi/20260802-submit-acx00-of-dynamic-v1-v1-16-0a53cd9e21cc@gmail.com/ (local)

The later board DTS patches instantiate it as an ethernet-phy node beneath
the MAC's MDIO bus and reference the appropriate sideband control provider.

quoted

       Andrew