net: dsa: mv88e6xxx: Implement interrupt support.

The switch can have up to two interrupt controllers. One of these
contains the interrupts from the integrated PHYs, so is useful to
export. The Marvell PHY driver can then be used in interrupt mode,
rather than polling, speeding up PHY handling and reducing load on the
MDIO bus.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/dsa/marvell.txt

@@ -20,16 +20,35 @@ Required properties:
 Optional properties:
 
 - reset-gpios		: Should be a gpio specifier for a reset line
-
+- interrupt-parent	: Parent interrupt controller
+- interrupts		: Interrupt from the switch
+- interrupt-controller	: Indicates the switch is itself an interrupt
+			  controller. This is used for the PHY interrupts.
+#interrupt-cells = <2>	: Controller uses two cells, number and flag
+- mdio			: container of PHY and devices on the switches MDIO
+			  bus
 Example:
 
        mdio {
                #address-cells = <1>;
                #size-cells = <0>;
+               interrupt-parent = <&gpio0>;
+               interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
+               interrupt-controller;
+               #interrupt-cells = <2>;
 
                switch0: switch@0 {
                        compatible = "marvell,mv88e6085";
                        reg = <0>;
 		       reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
                };
+               mdio {
+                       #address-cells = <1>;
+                       #size-cells = <0>;
+                       switch1phy0: switch1phy0@0 {
+                               reg = <0>;
+                               interrupt-parent = <&switch0>;
+                               interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+                       };
+               };
        };