Add support for the maxlinear,rmii-refclk-out boolean property on port
nodes to configure the RMII reference clock to be an output rather than
an input.

This property is only applicable for ports in RMII mode and allows the
switch to provide the reference clock for RMII-connected PHYs instead
of requiring an external clock source.

This corresponds to the driver changes that read this Device Tree
property to configure the RMII clock direction.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
---
 Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml b/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
index 8ccbc8942eb3..ab3ee4ecd938 100644
--- a/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/lantiq,gswip.yaml
@@ -31,6 +31,11 @@ patternProperties:
               The delay lines adjust the MII clock vs. data timing.
               If this property is not present the delay is determined by
               the interface mode.
+          maxlinear,rmii-refclk-out:
+            type: boolean
+            description:
+              Configure the RMII reference clock to be a clock output
+              rather than an input. Only applicable for RMII mode.
 
 maintainers:
   - Hauke Mehrtens <hauke@hauke-m.de>
-- 
2.51.2