arc_emac: add clock handling

This adds ability for the arc_emac to really handle its supplying clock.
To get the needed clock-frequency either a real clock or the previous
clock-frequency property must be provided.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Max Schwarz <max.schwarz@online.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/net/arc_emac.txt b/Documentation/devicetree/bindings/net/arc_emac.txt
index 7fbb027218a1..a1d71eb43b20 100644
--- a/Documentation/devicetree/bindings/net/arc_emac.txt
+++ b/Documentation/devicetree/bindings/net/arc_emac.txt
@@ -4,11 +4,15 @@ Required properties:
 - compatible: Should be "snps,arc-emac"
 - reg: Address and length of the register set for the device
 - interrupts: Should contain the EMAC interrupts
-- clock-frequency: CPU frequency. It is needed to calculate and set polling
-period of EMAC.
 - max-speed: see ethernet.txt file in the same directory.
 - phy: see ethernet.txt file in the same directory.
 
+Clock handling:
+The clock frequency is needed to calculate and set polling period of EMAC.
+It must be provided by one of:
+- clock-frequency: CPU frequency.
+- clocks: reference to the clock supplying the EMAC.
+
 Child nodes of the driver are the individual PHY devices connected to the
 MDIO bus. They must have a "reg" property given the PHY address on the MDIO bus.
 
@@ -19,7 +23,11 @@ Examples:
 		reg = <0xc0fc2000 0x3c>;
 		interrupts = <6>;
 		mac-address = [ 00 11 22 33 44 55 ];
+
 		clock-frequency = <80000000>;
+		/* or */
+		clocks = <&emac_clock>;
+
 		max-speed = <100>;
 		phy = <&phy0>;