dt-bindings: Document microchip,downshift-after

Document the optional downshift-after property of the lan78xx's PHY.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>

diff --git a/Documentation/devicetree/bindings/net/microchip,lan78xx.txt b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
index 76786a0..ad1d013 100644 (file)
--- a/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
+++ b/Documentation/devicetree/bindings/net/microchip,lan78xx.txt
@@ -15,6 +15,9 @@ Optional properties of the embedded PHY:
 - microchip,led-modes: a 0..4 element vector, with each element configuring
   the operating mode of an LED. Omitted LEDs are turned off. Allowed values
   are defined in "include/dt-bindings/net/microchip-lan78xx.h".
+- microchip,downshift-after: sets the number of failed auto-negotiation
+  attempts after which the link is downgraded from 1000BASE-T. Should be one of
+  2, 3, 4, 5 or 0, where 0 means never downshift.
 
 Example: