From d5490f1f67116419ddf3b4c7b9f3d5a0fb2fd407 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sun, 22 Jan 2017 23:02:45 +0100 Subject: [PATCH] net: dt-bindings: add RGMII TX delay configuration to meson8b-dwmac 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 Tested-by: Neil Armstrong Acked-by: Rob Herring Signed-off-by: David S. Miller --- Documentation/devicetree/bindings/net/meson-dwmac.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/net/meson-dwmac.txt b/Documentation/devicetree/bindings/net/meson-dwmac.txt index 89e62dd..0703ad3 100644 --- a/Documentation/devicetree/bindings/net/meson-dwmac.txt +++ b/Documentation/devicetree/bindings/net/meson-dwmac.txt @@ -25,6 +25,22 @@ 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. + When phy-mode is set to "rgmii" then the TX + delay should be explicitly configured. When + not configured a fallback of 2ns is used. + When the phy-mode is set to either "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). + Any configuration is ignored when the phy-mode + is set to "rmii". Example for Meson6: -- 2.7.4