dt-bindings: describe the support of "clock-frequency" in mdio

mdio bus frequency is going to be configurable at boottime by a property
in DT now, so add a description to it.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/devicetree/bindings/net/xilinx_axienet.txt b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
index 1aa4c6006cd07c50419ef8d2e0d016a3c09436f2..80e505a2fda162055b6f9cfd6749b5ac855836f1 100644 (file)
--- a/Documentation/devicetree/bindings/net/xilinx_axienet.txt
+++ b/Documentation/devicetree/bindings/net/xilinx_axienet.txt
@@ -68,6 +68,8 @@ Optional properties:
  - mdio                : Child node for MDIO bus. Must be defined if PHY access is
                  required through the core's MDIO interface (i.e. always,
                  unless the PHY is accessed through a different bus).
+                 Non-standard MDIO bus frequency is supported via
+                 "clock-frequency", see mdio.yaml.
 
  - pcs-handle:           Phandle to the internal PCS/PMA PHY in SGMII or 1000Base-X
                  modes, where "pcs-handle" should be used to point