[PATCH net-next v2 1/2] dt-bindings: net: rockchip-dwmac: allow output clock_in_out for RGMII

From: Jiaxing Hu

Date: Fri Jul 17 2026 - 03:02:32 EST


The clock_in_out description said RGMII must use "input". That is no
longer true: an RGMII PHY with no crystal can take its 25 MHz reference
from the SoC, in which case clock_in_out is "output". Document it.

Signed-off-by: Jiaxing Hu <gahing@xxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/net/rockchip-dwmac.yaml | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/rockchip-dwmac.yaml b/Documentation/devicetree/bindings/net/rockchip-dwmac.yaml
index 80c252845..d5816d6dc 100644
--- a/Documentation/devicetree/bindings/net/rockchip-dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/rockchip-dwmac.yaml
@@ -89,8 +89,9 @@ properties:

clock_in_out:
description:
- For RGMII, it must be "input", means main clock(125MHz)
- is not sourced from SoC's PLL, but input from PHY.
+ For RGMII, "input" means the 125MHz main clock is input from the
+ PHY, not sourced from the SoC PLL; "output" means the SoC provides
+ a 25MHz reference clock out to a crystal-less PHY.
For RMII, "input" means PHY provides the reference clock(50MHz),
"output" means GMAC provides the reference clock.
$ref: /schemas/types.yaml#/definitions/string
--
2.43.0