This allows configuring the RGMII TX clock delay. The RGMII clock is generated by underlying hardware of the the Meson 8b / GXBB DWMAC glue. The configuration depends on the actual hardware (no delay may be needed due to the design of the actual circuit, the PHY might add this delay, etc.). Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> Tested-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> --- Documentation/devicetree/bindings/net/meson-dwmac.txt | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/devicetree/bindings/net/meson-dwmac.txt b/Documentation/devicetree/bindings/net/meson-dwmac.txt index 89e62dd..f8bc540 100644 --- a/Documentation/devicetree/bindings/net/meson-dwmac.txt +++ b/Documentation/devicetree/bindings/net/meson-dwmac.txt @@ -25,6 +25,20 @@ Required properties on Meson8b and newer: - "clkin0" - first parent clock of the internal mux - "clkin1" - second parent clock of the internal mux +Optional properties on Meson8b and newer: +- amlogic,tx-delay-ns: The internal RGMII TX clock delay (provided + by this driver) in nanoseconds. Allowed values + are: 0ns, 2ns, 4ns, 6ns. + This must be configured when the phy-mode is + "rgmii" (typically a value of 2ns is used in + this case). + When phy-mode is set to "rgmii-id" or + "rgmii-txid" the TX clock delay is already + provided by the PHY. In that case this + property should be set to 0ns (which disables + the TX clock delay in the MAC to prevent the + clock from going off because both PHY and MAC + are adding a delay). Example for Meson6: -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
