ARM: at91/gpio: add irqdomain and DT support

Add "legacy" type of irqdomain to preserve old-style numbering
and allow smooth transition for both DT and non-DT cases.

Original idea and code by Jean-Christophe Plagniol-Villard.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi
index 67f94d3..a9dbbb5 100644
--- a/arch/arm/boot/dts/at91sam9g45.dtsi
+++ b/arch/arm/boot/dts/at91sam9g45.dtsi
@@ -22,6 +22,11 @@
 		serial2 = &usart1;
 		serial3 = &usart2;
 		serial4 = &usart3;
+		gpio0 = &pioA;
+		gpio1 = &pioB;
+		gpio2 = &pioC;
+		gpio3 = &pioD;
+		gpio4 = &pioE;
 	};
 	cpus {
 		cpu@0 {
@@ -59,6 +64,51 @@
 				interrupts = <21 4>;
 			};
 
+			pioA: gpio@fffff200 {
+				compatible = "atmel,at91rm9200-gpio";
+				reg = <0xfffff200 0x100>;
+				interrupts = <2 4>;
+				#gpio-cells = <2>;
+				gpio-controller;
+				interrupt-controller;
+			};
+
+			pioB: gpio@fffff400 {
+				compatible = "atmel,at91rm9200-gpio";
+				reg = <0xfffff400 0x100>;
+				interrupts = <3 4>;
+				#gpio-cells = <2>;
+				gpio-controller;
+				interrupt-controller;
+			};
+
+			pioC: gpio@fffff600 {
+				compatible = "atmel,at91rm9200-gpio";
+				reg = <0xfffff600 0x100>;
+				interrupts = <4 4>;
+				#gpio-cells = <2>;
+				gpio-controller;
+				interrupt-controller;
+			};
+
+			pioD: gpio@fffff800 {
+				compatible = "atmel,at91rm9200-gpio";
+				reg = <0xfffff800 0x100>;
+				interrupts = <5 4>;
+				#gpio-cells = <2>;
+				gpio-controller;
+				interrupt-controller;
+			};
+
+			pioE: gpio@fffffa00 {
+				compatible = "atmel,at91rm9200-gpio";
+				reg = <0xfffffa00 0x100>;
+				interrupts = <5 4>;
+				#gpio-cells = <2>;
+				gpio-controller;
+				interrupt-controller;
+			};
+
 			dbgu: serial@ffffee00 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xffffee00 0x200>;