arm64: dts: uniphier: stabilize ethernet of LD20 reference board

Currently, the ethernet RGMII mode on the LD20 reference board is
unstable.

The default drive-strength of ethernet TX pins is too strong because
there is no dumping resistor on the TX lines on the board.

Weaken the drive-strength to make the ethernet more stable.

Signed-off-by: Masahiro Yamada <[email protected]>

diff --git a/arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dts b/arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dts
index 2c1a92fafbfbe053808b00e4b8b66804f6744e4d..440c2e6a638b998c163b3f8aea91f94e115f516b 100644 (file)
--- a/arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dts
+++ b/arch/arm64/boot/dts/socionext/uniphier-ld20-ref.dts
@@ -67,3 +67,11 @@
                reg = <0>;
        };
 };
+
+&pinctrl_ether_rgmii {
+       tx {
+               pins = "RGMII_TXCLK", "RGMII_TXD0", "RGMII_TXD1",
+                      "RGMII_TXD2", "RGMII_TXD3", "RGMII_TXCTL";
+               drive-strength = <9>;
+       };
+};