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

Jiaxing Hu gahing at gahingwoo.com
Thu Jul 16 23:59:32 PDT 2026


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 at gahingwoo.com>
---
 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




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