diff mbox

[net-next,v3,1/2] net: dt-bindings: add RGMII TX delay configuration to meson8b-dwmac

Message ID 20161202233238.17561-2-martin.blumenstingl@googlemail.com
State Not Applicable, archived
Delegated to: David Miller
Headers show

Commit Message

Martin Blumenstingl Dec. 2, 2016, 11:32 p.m. UTC
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@googlemail.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
---
 Documentation/devicetree/bindings/net/meson-dwmac.txt | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Rob Herring (Arm) Dec. 9, 2016, 9:31 p.m. UTC | #1
On Sat, Dec 03, 2016 at 12:32:37AM +0100, Martin Blumenstingl wrote:
> 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@googlemail.com>
> Tested-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  Documentation/devicetree/bindings/net/meson-dwmac.txt | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>
diff mbox

Patch

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: