diff --git a/Documentation/devicetree/bindings/arm/arm-boards b/Documentation/devicetree/bindings/arm/arm-boards
new file mode 100644
index 0000000..91f2614
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm-boards
@@ -0,0 +1,20 @@
+ARM Versatile Application and Platform Baseboards
+-------------------------------------------------
+ARM's development hardware platform with connectors for customizable
+core tiles.  The hardware configuration of the Versatile boards is
+highly customizable.
+
+Required properties (in root node):
+	compatible = "arm,versatile-ab";  /* Application baseboard */
+	compatible = "arm,versatile-pb";  /* Platform baseboard */
+
+Interrupt controllers:
+- VIC required properties:
+	compatible = "arm,versatile-vic";
+	interrupt-controller;
+	#interrupt-cells = <1>;
+
+- SIC required properties:
+	compatible = "arm,versatile-sic";
+	interrupt-controller;
+	#interrupt-cells = <1>;
diff --git a/Documentation/devicetree/bindings/i2c/arm-versatile.txt b/Documentation/devicetree/bindings/i2c/arm-versatile.txt
new file mode 100644
index 0000000..361d31c
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/arm-versatile.txt
@@ -0,0 +1,10 @@
+i2c Controller on ARM Versatile platform:
+
+Required properties:
+- compatible : Must be "arm,versatile-i2c";
+- reg
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties:
+- Child nodes conforming to i2c bus binding
diff --git a/Documentation/devicetree/bindings/mtd/arm-versatile.txt b/Documentation/devicetree/bindings/mtd/arm-versatile.txt
new file mode 100644
index 0000000..476845d
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/arm-versatile.txt
@@ -0,0 +1,8 @@
+Flash device on ARM Versatile board
+
+Required properties:
+- compatible : must be "arm,versatile-flash";
+- bank-width : width in bytes of flash interface.
+
+Optional properties:
+- Subnode partition map from mtd flash binding
diff --git a/Documentation/devicetree/bindings/net/smsc-lan91c111.txt b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt
new file mode 100644
index 0000000..953049b
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt
@@ -0,0 +1,10 @@
+SMSC LAN91c111 Ethernet mac
+
+Required properties:
+- compatible = "smsc,lan91c111";
+- reg : physical address and size of registers
+- interrupts : interrupt connection
+
+Optional properties:
+- phy-device : phandle to Ethernet phy
+- local-mac-address : Ethernet mac address to use
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 09ebf0b..2c71a8f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1716,6 +1716,7 @@
 	bool "Flattened Device Tree support"
 	select OF
 	select OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
 	help
 	  Include support for flattened device tree machine descriptions.
 
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 3a4a04b..70c424e 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -282,6 +282,12 @@
 zinstall uinstall install: vmlinux
 	$(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $@
 
+%.dtb:
+	$(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $(boot)/$@
+
+dtbs:
+	$(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $(boot)/$@
+
 # We use MRPROPER_FILES and CLEAN_FILES now
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
@@ -298,6 +304,7 @@
   echo  '  uImage        - U-Boot wrapped zImage'
   echo  '  bootpImage    - Combined zImage and initial RAM disk' 
   echo  '                  (supply initrd image via make variable INITRD=<path>)'
+  echo  '  dtbs          - Build device tree blobs for enabled boards'
   echo  '  install       - Install uncompressed kernel'
   echo  '  zinstall      - Install compressed kernel'
   echo  '  uinstall      - Install U-Boot wrapped compressed kernel'
diff --git a/arch/arm/boot/Makefile b/arch/arm/boot/Makefile
index 9128fdd..a1edfd5 100644
--- a/arch/arm/boot/Makefile
+++ b/arch/arm/boot/Makefile
@@ -59,6 +59,12 @@
 
 endif
 
+# Rule to build device tree blobs
+$(obj)/%.dtb: $(src)/dts/%.dts
+	$(call cmd,dtc)
+
+$(obj)/dtbs: $(addprefix $(obj)/, $(dtb-y))
+
 quiet_cmd_uimage = UIMAGE  $@
       cmd_uimage = $(CONFIG_SHELL) $(MKIMAGE) -A arm -O linux -T kernel \
 		   -C none -a $(LOADADDR) -e $(STARTADDR) \
diff --git a/arch/arm/boot/dts/skeleton.dtsi b/arch/arm/boot/dts/skeleton.dtsi
new file mode 100644
index 0000000..b41d241
--- /dev/null
+++ b/arch/arm/boot/dts/skeleton.dtsi
@@ -0,0 +1,13 @@
+/*
+ * Skeleton device tree; the bare minimum needed to boot; just include and
+ * add a compatible value.  The bootloader will typically populate the memory
+ * node.
+ */
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	chosen { };
+	aliases { };
+	memory { device_type = "memory"; reg = <0 0>; };
+};
diff --git a/arch/arm/boot/dts/tegra-harmony.dts b/arch/arm/boot/dts/tegra-harmony.dts
new file mode 100644
index 0000000..4c05334
--- /dev/null
+++ b/arch/arm/boot/dts/tegra-harmony.dts
@@ -0,0 +1,70 @@
+/dts-v1/;
+
+/memreserve/ 0x1c000000 0x04000000;
+/include/ "tegra20.dtsi"
+
+/ {
+	model = "NVIDIA Tegra2 Harmony evaluation board";
+	compatible = "nvidia,harmony", "nvidia,tegra20";
+
+	chosen {
+		bootargs = "vmalloc=192M video=tegrafb console=ttyS0,115200n8 root=/dev/mmcblk0p2 rw rootwait";
+	};
+
+	memory@0 {
+		reg = < 0x00000000 0x40000000 >;
+	};
+
+	i2c@7000c000 {
+		clock-frequency = <400000>;
+
+		codec: wm8903@1a {
+			compatible = "wlf,wm8903";
+			reg = <0x1a>;
+			interrupts = < 347 >;
+
+			gpio-controller;
+			#gpio-cells = <2>;
+
+			/* 0x8000 = Not configured */
+			gpio-cfg = < 0x8000 0x8000 0 0x8000 0x8000 >;
+		};
+	};
+
+	i2c@7000c400 {
+		clock-frequency = <400000>;
+	};
+
+	i2c@7000c500 {
+		clock-frequency = <400000>;
+	};
+
+	i2c@7000d000 {
+		clock-frequency = <400000>;
+	};
+
+	sound {
+		compatible = "nvidia,harmony-sound", "nvidia,tegra-wm8903";
+
+		spkr-en-gpios = <&codec 2 0>;
+		hp-det-gpios = <&gpio 178 0>;
+		int-mic-en-gpios = <&gpio 184 0>;
+		ext-mic-en-gpios = <&gpio 185 0>;
+	};
+
+	serial@70006300 {
+		clock-frequency = < 216000000 >;
+	};
+
+	sdhci@c8000200 {
+		gpios = <&gpio 69 0>, /* cd, gpio PI5 */
+			<&gpio 57 0>, /* wp, gpio PH1 */
+			<&gpio 155 0>; /* power, gpio PT3 */
+	};
+
+	sdhci@c8000600 {
+		gpios = <&gpio 58 0>, /* cd, gpio PH2 */
+			<&gpio 59 0>, /* wp, gpio PH3 */
+			<&gpio 70 0>; /* power, gpio PI6 */
+	};
+};
diff --git a/arch/arm/boot/dts/tegra-seaboard.dts b/arch/arm/boot/dts/tegra-seaboard.dts
new file mode 100644
index 0000000..1940cae0
--- /dev/null
+++ b/arch/arm/boot/dts/tegra-seaboard.dts
@@ -0,0 +1,28 @@
+/dts-v1/;
+
+/memreserve/ 0x1c000000 0x04000000;
+/include/ "tegra20.dtsi"
+
+/ {
+	model = "NVIDIA Seaboard";
+	compatible = "nvidia,seaboard", "nvidia,tegra20";
+
+	chosen {
+		bootargs = "vmalloc=192M video=tegrafb console=ttyS0,115200n8 root=/dev/mmcblk1p3 rw rootwait";
+	};
+
+	memory {
+		device_type = "memory";
+		reg = < 0x00000000 0x40000000 >;
+	};
+
+	serial@70006300 {
+		clock-frequency = < 216000000 >;
+	};
+
+	sdhci@c8000400 {
+		gpios = <&gpio 69 0>, /* cd, gpio PI5 */
+			<&gpio 57 0>, /* wp, gpio PH1 */
+			<&gpio 70 0>; /* power, gpio PI6 */
+	};
+};
diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
new file mode 100644
index 0000000..5727595
--- /dev/null
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -0,0 +1,139 @@
+/include/ "skeleton.dtsi"
+
+/ {
+	compatible = "nvidia,tegra20";
+	interrupt-parent = <&intc>;
+
+	intc: interrupt-controller@50041000 {
+		compatible = "nvidia,tegra20-gic";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		reg = < 0x50041000 0x1000 >,
+		      < 0x50040100 0x0100 >;
+	};
+
+	i2c@7000c000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2c";
+		reg = <0x7000C000 0x100>;
+		interrupts = < 70 >;
+	};
+
+	i2c@7000c400 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2c";
+		reg = <0x7000C400 0x100>;
+		interrupts = < 116 >;
+	};
+
+	i2c@7000c500 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2c";
+		reg = <0x7000C500 0x100>;
+		interrupts = < 124 >;
+	};
+
+	i2c@7000d000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2c";
+		reg = <0x7000D000 0x200>;
+		interrupts = < 85 >;
+	};
+
+	i2s@70002800 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2s";
+		reg = <0x70002800 0x200>;
+		interrupts = < 45 >;
+		dma-channel = < 2 >;
+	};
+
+	i2s@70002a00 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-i2s";
+		reg = <0x70002a00 0x200>;
+		interrupts = < 35 >;
+		dma-channel = < 1 >;
+	};
+
+	das@70000c00 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "nvidia,tegra20-das";
+		reg = <0x70000c00 0x80>;
+	};
+
+	gpio: gpio@6000d000 {
+		compatible = "nvidia,tegra20-gpio";
+		reg = < 0x6000d000 0x1000 >;
+		interrupts = < 64 65 66 67 87 119 121 >;
+		#gpio-cells = <2>;
+		gpio-controller;
+	};
+
+	serial@70006000 {
+		compatible = "nvidia,tegra20-uart";
+		reg = <0x70006000 0x40>;
+		reg-shift = <2>;
+		interrupts = < 68 >;
+	};
+
+	serial@70006040 {
+		compatible = "nvidia,tegra20-uart";
+		reg = <0x70006040 0x40>;
+		reg-shift = <2>;
+		interrupts = < 69 >;
+	};
+
+	serial@70006200 {
+		compatible = "nvidia,tegra20-uart";
+		reg = <0x70006200 0x100>;
+		reg-shift = <2>;
+		interrupts = < 78 >;
+	};
+
+	serial@70006300 {
+		compatible = "nvidia,tegra20-uart";
+		reg = <0x70006300 0x100>;
+		reg-shift = <2>;
+		interrupts = < 122 >;
+	};
+
+	serial@70006400 {
+		compatible = "nvidia,tegra20-uart";
+		reg = <0x70006400 0x100>;
+		reg-shift = <2>;
+		interrupts = < 123 >;
+	};
+
+	sdhci@c8000000 {
+		compatible = "nvidia,tegra20-sdhci";
+		reg = <0xc8000000 0x200>;
+		interrupts = < 46 >;
+	};
+
+	sdhci@c8000200 {
+		compatible = "nvidia,tegra20-sdhci";
+		reg = <0xc8000200 0x200>;
+		interrupts = < 47 >;
+	};
+
+	sdhci@c8000400 {
+		compatible = "nvidia,tegra20-sdhci";
+		reg = <0xc8000400 0x200>;
+		interrupts = < 51 >;
+	};
+
+	sdhci@c8000600 {
+		compatible = "nvidia,tegra20-sdhci";
+		reg = <0xc8000600 0x200>;
+		interrupts = < 63 >;
+	};
+};
+
diff --git a/arch/arm/boot/dts/versatile-ab.dts b/arch/arm/boot/dts/versatile-ab.dts
new file mode 100644
index 0000000..0b32925
--- /dev/null
+++ b/arch/arm/boot/dts/versatile-ab.dts
@@ -0,0 +1,192 @@
+/dts-v1/;
+/include/ "skeleton.dtsi"
+
+/ {
+	model = "ARM Versatile AB";
+	compatible = "arm,versatile-ab";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	interrupt-parent = <&vic>;
+
+	aliases {
+		serial0 = &uart0;
+		serial1 = &uart1;
+		serial2 = &uart2;
+		i2c0 = &i2c0;
+	};
+
+	memory {
+		reg = <0x0 0x08000000>;
+	};
+
+	flash@34000000 {
+		compatible = "arm,versatile-flash";
+		reg = <0x34000000 0x4000000>;
+		bank-width = <4>;
+	};
+
+	i2c0: i2c@10002000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "arm,versatile-i2c";
+		reg = <0x10002000 0x1000>;
+
+		rtc@68 {
+			compatible = "dallas,ds1338";
+			reg = <0x68>;
+		};
+	};
+
+	net@10010000 {
+		compatible = "smsc,lan91c111";
+		reg = <0x10010000 0x10000>;
+		interrupts = <25>;
+	};
+
+	lcd@10008000 {
+		compatible = "arm,versatile-lcd";
+		reg = <0x10008000 0x1000>;
+	};
+
+	amba {
+		compatible = "arm,amba-bus";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		vic: intc@10140000 {
+			compatible = "arm,versatile-vic";
+			interrupt-controller;
+			#interrupt-cells = <1>;
+			reg = <0x10140000 0x1000>;
+		};
+
+		sic: intc@10003000 {
+			compatible = "arm,versatile-sic";
+			interrupt-controller;
+			#interrupt-cells = <1>;
+			reg = <0x10003000 0x1000>;
+			interrupt-parent = <&vic>;
+			interrupts = <31>; /* Cascaded to vic */
+		};
+
+		dma@10130000 {
+			compatible = "arm,pl081", "arm,primecell";
+			reg = <0x10130000 0x1000>;
+			interrupts = <17>;
+		};
+
+		uart0: uart@101f1000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x101f1000 0x1000>;
+			interrupts = <12>;
+		};
+
+		uart1: uart@101f2000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x101f2000 0x1000>;
+			interrupts = <13>;
+		};
+
+		uart2: uart@101f3000 {
+			compatible = "arm,pl011", "arm,primecell";
+			reg = <0x101f3000 0x1000>;
+			interrupts = <14>;
+		};
+
+		smc@10100000 {
+			compatible = "arm,primecell";
+			reg = <0x10100000 0x1000>;
+		};
+
+		mpmc@10110000 {
+			compatible = "arm,primecell";
+			reg = <0x10110000 0x1000>;
+		};
+
+		display@10120000 {
+			compatible = "arm,pl110", "arm,primecell";
+			reg = <0x10120000 0x1000>;
+			interrupts = <16>;
+		};
+
+		sctl@101e0000 {
+			compatible = "arm,primecell";
+			reg = <0x101e0000 0x1000>;
+		};
+
+		watchdog@101e1000 {
+			compatible = "arm,primecell";
+			reg = <0x101e1000 0x1000>;
+			interrupts = <0>;
+		};
+
+		gpio0: gpio@101e4000 {
+			compatible = "arm,pl061", "arm,primecell";
+			reg = <0x101e4000 0x1000>;
+			gpio-controller;
+			interrupts = <6>;
+			#gpio-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+		};
+
+		gpio1: gpio@101e5000 {
+			compatible = "arm,pl061", "arm,primecell";
+			reg = <0x101e5000 0x1000>;
+			interrupts = <7>;
+			gpio-controller;
+			#gpio-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+		};
+
+		rtc@101e8000 {
+			compatible = "arm,pl030", "arm,primecell";
+			reg = <0x101e8000 0x1000>;
+			interrupts = <10>;
+		};
+
+		sci@101f0000 {
+			compatible = "arm,primecell";
+			reg = <0x101f0000 0x1000>;
+			interrupts = <15>;
+		};
+
+		ssp@101f4000 {
+			compatible = "arm,pl022", "arm,primecell";
+			reg = <0x101f4000 0x1000>;
+			interrupts = <11>;
+		};
+
+		fpga {
+			compatible = "arm,versatile-fpga", "simple-bus";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0x10000000 0x10000>;
+
+			aaci@4000 {
+				compatible = "arm,primecell";
+				reg = <0x4000 0x1000>;
+				interrupts = <24>;
+			};
+			mmc@5000 {
+				compatible = "arm,primecell";
+				reg = < 0x5000 0x1000>;
+				interrupts = <22>;
+			};
+			kmi@6000 {
+				compatible = "arm,pl050", "arm,primecell";
+				reg = <0x6000 0x1000>;
+				interrupt-parent = <&sic>;
+				interrupts = <3>;
+			};
+			kmi@7000 {
+				compatible = "arm,pl050", "arm,primecell";
+				reg = <0x7000 0x1000>;
+				interrupt-parent = <&sic>;
+				interrupts = <4>;
+			};
+		};
+	};
+};
diff --git a/arch/arm/boot/dts/versatile-pb.dts b/arch/arm/boot/dts/versatile-pb.dts
new file mode 100644
index 0000000..8a614e3
--- /dev/null
+++ b/arch/arm/boot/dts/versatile-pb.dts
@@ -0,0 +1,48 @@
+/include/ "versatile-ab.dts"
+
+/ {
+	model = "ARM Versatile PB";
+	compatible = "arm,versatile-pb";
+
+	amba {
+		gpio2: gpio@101e6000 {
+			compatible = "arm,pl061", "arm,primecell";
+			reg = <0x101e6000 0x1000>;
+			interrupts = <8>;
+			gpio-controller;
+			#gpio-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+		};
+
+		gpio3: gpio@101e7000 {
+			compatible = "arm,pl061", "arm,primecell";
+			reg = <0x101e7000 0x1000>;
+			interrupts = <9>;
+			gpio-controller;
+			#gpio-cells = <2>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+		};
+
+		fpga {
+			uart@9000 {
+				compatible = "arm,pl011", "arm,primecell";
+				reg = <0x9000 0x1000>;
+				interrupt-parent = <&sic>;
+				interrupts = <6>;
+			};
+			sci@a000 {
+				compatible = "arm,primecell";
+				reg = <0xa000 0x1000>;
+				interrupt-parent = <&sic>;
+				interrupts = <5>;
+			};
+			mmc@b000 {
+				compatible = "arm,primecell";
+				reg = <0xb000 0x1000>;
+				interrupts = <23>;
+			};
+		};
+	};
+};
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index 3281fb4..217aa191 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -74,4 +74,11 @@
 #define MACHINE_END				\
 };
 
+#define DT_MACHINE_START(_name, _namestr)		\
+static const struct machine_desc __mach_desc_##_name	\
+ __used							\
+ __attribute__((__section__(".arch.info.init"))) = {	\
+	.nr		= ~0,				\
+	.name		= _namestr,
+
 #endif
diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
index 11b8708..6f65ca8 100644
--- a/arch/arm/include/asm/prom.h
+++ b/arch/arm/include/asm/prom.h
@@ -16,11 +16,6 @@
 #include <asm/setup.h>
 #include <asm/irq.h>
 
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-	return;
-}
-
 extern struct machine_desc *setup_machine_fdt(unsigned int dt_phys);
 extern void arm_dt_memblock_reserve(void);
 
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 0cdd7b4..1a33e9d 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -132,17 +132,3 @@
 
 	return mdesc_best;
 }
-
-/**
- * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
- *
- * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
- * mapped 1:1 onto Linux irq numbers.  Cascaded irq controllers are not
- * supported.
- */
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	return intspec[0];
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 5ec1846..4b8abf9 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -51,6 +51,12 @@
 	 also be included for some of the derivative boards that
 	 have large similarities with the seaboard design.
 
+config MACH_TEGRA_DT
+	bool "Generic Tegra board (FDT support)"
+	select USE_OF
+	help
+	  Support for generic nVidia Tegra boards using Flattened Device Tree
+
 config MACH_TRIMSLICE
        bool "TrimSlice board"
        select TEGRA_PCI
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index ed58ef9..f11b910 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -29,5 +29,8 @@
 obj-${CONFIG_MACH_SEABOARD}             += board-seaboard.o
 obj-${CONFIG_MACH_SEABOARD}             += board-seaboard-pinmux.o
 
+obj-${CONFIG_MACH_TEGRA_DT}             += board-dt.o
+obj-${CONFIG_MACH_TEGRA_DT}             += board-harmony-pinmux.o
+
 obj-${CONFIG_MACH_TRIMSLICE}            += board-trimslice.o
 obj-${CONFIG_MACH_TRIMSLICE}            += board-trimslice-pinmux.o
diff --git a/arch/arm/mach-tegra/Makefile.boot b/arch/arm/mach-tegra/Makefile.boot
index db52d61..428ad12 100644
--- a/arch/arm/mach-tegra/Makefile.boot
+++ b/arch/arm/mach-tegra/Makefile.boot
@@ -1,3 +1,6 @@
 zreladdr-$(CONFIG_ARCH_TEGRA_2x_SOC)	:= 0x00008000
 params_phys-$(CONFIG_ARCH_TEGRA_2x_SOC)	:= 0x00000100
 initrd_phys-$(CONFIG_ARCH_TEGRA_2x_SOC)	:= 0x00800000
+
+dtb-$(CONFIG_MACH_HARMONY) += tegra-harmony.dtb
+dtb-$(CONFIG_MACH_SEABOARD) += tegra-seaboard.dtb
diff --git a/arch/arm/mach-tegra/board-dt.c b/arch/arm/mach-tegra/board-dt.c
new file mode 100644
index 0000000..9f47e04
--- /dev/null
+++ b/arch/arm/mach-tegra/board-dt.c
@@ -0,0 +1,119 @@
+/*
+ * nVidia Tegra device tree board support
+ *
+ * Copyright (C) 2010 Secret Lab Technologies, Ltd.
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/serial_8250.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/pda_power.h>
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/i2c-tegra.h>
+
+#include <asm/mach-types.h>
+#include <asm/mach/arch.h>
+#include <asm/mach/time.h>
+#include <asm/setup.h>
+
+#include <mach/iomap.h>
+#include <mach/irqs.h>
+
+#include "board.h"
+#include "board-harmony.h"
+#include "clock.h"
+#include "devices.h"
+
+void harmony_pinmux_init(void);
+void seaboard_pinmux_init(void);
+
+
+struct of_dev_auxdata tegra20_auxdata_lookup[] __initdata = {
+	OF_DEV_AUXDATA("nvidia,tegra20-sdhci", TEGRA_SDMMC1_BASE, "sdhci-tegra.0", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-sdhci", TEGRA_SDMMC2_BASE, "sdhci-tegra.1", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-sdhci", TEGRA_SDMMC3_BASE, "sdhci-tegra.2", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-sdhci", TEGRA_SDMMC4_BASE, "sdhci-tegra.3", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2c", TEGRA_I2C_BASE, "tegra-i2c.0", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2c", TEGRA_I2C2_BASE, "tegra-i2c.1", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2c", TEGRA_I2C3_BASE, "tegra-i2c.2", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2c", TEGRA_DVC_BASE, "tegra-i2c.3", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2s", TEGRA_I2S1_BASE, "tegra-i2s.0", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-i2s", TEGRA_I2S1_BASE, "tegra-i2s.1", NULL),
+	OF_DEV_AUXDATA("nvidia,tegra20-das", TEGRA_APB_MISC_DAS_BASE, "tegra-das", NULL),
+	{}
+};
+
+static __initdata struct tegra_clk_init_table tegra_dt_clk_init_table[] = {
+	/* name		parent		rate		enabled */
+	{ "uartd",	"pll_p",	216000000,	true },
+	{ NULL,		NULL,		0,		0},
+};
+
+static struct of_device_id tegra_dt_match_table[] __initdata = {
+	{ .compatible = "simple-bus", },
+	{}
+};
+
+static struct of_device_id tegra_dt_gic_match[] __initdata = {
+	{ .compatible = "nvidia,tegra20-gic", },
+	{}
+};
+
+static void __init tegra_dt_init(void)
+{
+	struct device_node *node;
+
+	node = of_find_matching_node_by_address(NULL, tegra_dt_gic_match,
+						TEGRA_ARM_INT_DIST_BASE);
+	if (node)
+		irq_domain_add_simple(node, INT_GIC_BASE);
+
+	tegra_clk_init_from_table(tegra_dt_clk_init_table);
+
+	if (of_machine_is_compatible("nvidia,harmony"))
+		harmony_pinmux_init();
+	else if (of_machine_is_compatible("nvidia,seaboard"))
+		seaboard_pinmux_init();
+
+	/*
+	 * Finished with the static registrations now; fill in the missing
+	 * devices
+	 */
+	of_platform_populate(NULL, tegra_dt_match_table, tegra20_auxdata_lookup, NULL);
+}
+
+static const char * tegra_dt_board_compat[] = {
+	"nvidia,harmony",
+	"nvidia,seaboard",
+	NULL
+};
+
+DT_MACHINE_START(TEGRA_DT, "nVidia Tegra (Flattened Device Tree)")
+	.map_io		= tegra_map_common_io,
+	.init_early	= tegra_init_early,
+	.init_irq	= tegra_init_irq,
+	.timer		= &tegra_timer,
+	.init_machine	= tegra_dt_init,
+	.dt_compat	= tegra_dt_board_compat,
+MACHINE_END
diff --git a/arch/arm/mach-versatile/Kconfig b/arch/arm/mach-versatile/Kconfig
index 9cdec5a..c1f38f6 100644
--- a/arch/arm/mach-versatile/Kconfig
+++ b/arch/arm/mach-versatile/Kconfig
@@ -17,4 +17,12 @@
 	  Include support for the ARM(R) Versatile Application Baseboard
 	  for the ARM926EJ-S.
 
+config MACH_VERSATILE_DT
+	bool "Support Versatile platform from device tree"
+	select USE_OF
+	select CPU_ARM926T
+	help
+	  Include support for the ARM(R) Versatile/PB platform,
+	  using the device tree for discovery
+
 endmenu
diff --git a/arch/arm/mach-versatile/Makefile b/arch/arm/mach-versatile/Makefile
index 97cf4d8..81fa3fe 100644
--- a/arch/arm/mach-versatile/Makefile
+++ b/arch/arm/mach-versatile/Makefile
@@ -5,4 +5,5 @@
 obj-y					:= core.o
 obj-$(CONFIG_ARCH_VERSATILE_PB)		+= versatile_pb.o
 obj-$(CONFIG_MACH_VERSATILE_AB)		+= versatile_ab.o
+obj-$(CONFIG_MACH_VERSATILE_DT)		+= versatile_dt.o
 obj-$(CONFIG_PCI)			+= pci.o
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 0c99cf0..e340a54 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -24,6 +24,9 @@
 #include <linux/platform_device.h>
 #include <linux/sysdev.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
 #include <linux/amba/pl061.h>
@@ -83,13 +86,26 @@
 #define PIC_MASK	0
 #endif
 
+/* Lookup table for finding a DT node that represents the vic instance */
+static const struct of_device_id vic_of_match[] __initconst = {
+	{ .compatible = "arm,versatile-vic", },
+	{}
+};
+
+static const struct of_device_id sic_of_match[] __initconst = {
+	{ .compatible = "arm,versatile-sic", },
+	{}
+};
+
 void __init versatile_init_irq(void)
 {
 	vic_init(VA_VIC_BASE, IRQ_VIC_START, ~0, 0);
+	irq_domain_generate_simple(vic_of_match, VERSATILE_VIC_BASE, IRQ_VIC_START);
 
 	writel(~0, VA_SIC_BASE + SIC_IRQ_ENABLE_CLEAR);
 
 	fpga_irq_init(IRQ_VICSOURCE31, ~PIC_MASK, &sic_irq);
+	irq_domain_generate_simple(sic_of_match, VERSATILE_SIC_BASE, IRQ_SIC_START);
 
 	/*
 	 * Interrupts on secondary controller from 0 to 8 are routed to
@@ -646,6 +662,52 @@
 	&kmi1_device,
 };
 
+#ifdef CONFIG_OF
+/*
+ * Lookup table for attaching a specific name and platform_data pointer to
+ * devices as they get created by of_platform_populate().  Ideally this table
+ * would not exist, but the current clock implementation depends on some devices
+ * having a specific name.
+ */
+struct of_dev_auxdata versatile_auxdata_lookup[] __initdata = {
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_MMCI0_BASE, "fpga:05", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_KMI0_BASE, "fpga:06", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_KMI1_BASE, "fpga:07", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_UART3_BASE, "fpga:09", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_MMCI1_BASE, "fpga:0b", NULL),
+
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_CLCD_BASE, "dev:20", &clcd_plat_data),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_UART0_BASE, "dev:f1", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_UART1_BASE, "dev:f2", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_UART2_BASE, "dev:f3", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_SSP_BASE, "dev:f4", NULL),
+
+#if 0
+	/*
+	 * These entries are unnecessary because no clocks referencing
+	 * them.  I've left them in for now as place holders in case
+	 * any of them need to be added back, but they should be
+	 * removed before actually committing this patch.  --gcl
+	 */
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_AACI_BASE, "fpga:04", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_SCI1_BASE, "fpga:0a", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_SMC_BASE, "dev:00", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_MPMC_BASE, "dev:10", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_DMAC_BASE, "dev:30", NULL),
+
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_SCTL_BASE, "dev:e0", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_WATCHDOG_BASE, "dev:e1", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_GPIO0_BASE, "dev:e4", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_GPIO1_BASE, "dev:e5", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_GPIO2_BASE, "dev:e6", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_GPIO3_BASE, "dev:e7", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_RTC_BASE, "dev:e8", NULL),
+	OF_DEV_AUXDATA("arm,primecell", VERSATILE_SCI_BASE, "dev:f0", NULL),
+#endif
+	{}
+};
+#endif
+
 #ifdef CONFIG_LEDS
 #define VA_LEDS_BASE (__io_address(VERSATILE_SYS_BASE) + VERSATILE_SYS_LED_OFFSET)
 
diff --git a/arch/arm/mach-versatile/core.h b/arch/arm/mach-versatile/core.h
index fd6404e..e014227 100644
--- a/arch/arm/mach-versatile/core.h
+++ b/arch/arm/mach-versatile/core.h
@@ -23,6 +23,7 @@
 #define __ASM_ARCH_VERSATILE_H
 
 #include <linux/amba/bus.h>
+#include <linux/of_platform.h>
 
 extern void __init versatile_init(void);
 extern void __init versatile_init_early(void);
@@ -30,6 +31,9 @@
 extern void __init versatile_map_io(void);
 extern struct sys_timer versatile_timer;
 extern unsigned int mmc_status(struct device *dev);
+#ifdef CONFIG_OF
+extern struct of_dev_auxdata versatile_auxdata_lookup[];
+#endif
 
 #define AMBA_DEVICE(name,busid,base,plat)			\
 static struct amba_device name##_device = {			\
diff --git a/arch/arm/mach-versatile/versatile_dt.c b/arch/arm/mach-versatile/versatile_dt.c
new file mode 100644
index 0000000..54e037c
--- /dev/null
+++ b/arch/arm/mach-versatile/versatile_dt.c
@@ -0,0 +1,51 @@
+/*
+ * Versatile board support using the device tree
+ *
+ *  Copyright (C) 2010 Secret Lab Technologies Ltd.
+ *  Copyright (C) 2009 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *  Copyright (C) 2004 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/init.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <asm/mach-types.h>
+#include <asm/mach/arch.h>
+
+#include "core.h"
+
+static void __init versatile_dt_init(void)
+{
+	of_platform_populate(NULL, of_default_bus_match_table,
+			     versatile_auxdata_lookup, NULL);
+}
+
+static const char *versatile_dt_match[] __initconst = {
+	"arm,versatile-ab",
+	"arm,versatile-pb",
+	NULL,
+};
+
+DT_MACHINE_START(VERSATILE_PB, "ARM-Versatile (Device Tree Support)")
+	.map_io		= versatile_map_io,
+	.init_early	= versatile_init_early,
+	.init_irq	= versatile_init_irq,
+	.timer		= &versatile_timer,
+	.init_machine	= versatile_dt_init,
+	.dt_compat	= versatile_dt_match,
+MACHINE_END
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 5f69504..87a06f3 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -108,14 +108,18 @@
 };
 
 struct msi_desc;
+struct irq_domain;
 
 /**
  * struct irq_data - per irq and irq chip data passed down to chip functions
  * @irq:		interrupt number
+ * @hwirq:		hardware interrupt number, local to the interrupt domain
  * @node:		node index useful for balancing
  * @state_use_accessors: status information for irq chip functions.
  *			Use accessor functions to deal with it
  * @chip:		low level interrupt hardware access
+ * @domain:		Interrupt translation domain; responsible for mapping
+ *			between hwirq number and linux irq number.
  * @handler_data:	per-IRQ data for the irq_chip methods
  * @chip_data:		platform-specific per-chip private data for the chip
  *			methods, to allow shared chip implementations
@@ -128,9 +132,11 @@
  */
 struct irq_data {
 	unsigned int		irq;
+	unsigned long		hwirq;
 	unsigned int		node;
 	unsigned int		state_use_accessors;
 	struct irq_chip		*chip;
+	struct irq_domain	*domain;
 	void			*handler_data;
 	void			*chip_data;
 	struct msi_desc		*msi_desc;
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
new file mode 100644
index 0000000..e807ad6
--- /dev/null
+++ b/include/linux/irqdomain.h
@@ -0,0 +1,91 @@
+/*
+ * irq_domain - IRQ translation domains
+ *
+ * Translation infrastructure between hw and linux irq numbers.  This is
+ * helpful for interrupt controllers to implement mapping between hardware
+ * irq numbers and the Linux irq number space.
+ *
+ * irq_domains also have a hook for translating device tree interrupt
+ * representation into a hardware irq number that can be mapped back to a
+ * Linux irq number without any extra platform support code.
+ *
+ * irq_domain is expected to be embedded in an interrupt controller's private
+ * data structure.
+ */
+#ifndef _LINUX_IRQDOMAIN_H
+#define _LINUX_IRQDOMAIN_H
+
+#include <linux/irq.h>
+#include <linux/mod_devicetable.h>
+
+#ifdef CONFIG_IRQ_DOMAIN
+struct device_node;
+struct irq_domain;
+
+/**
+ * struct irq_domain_ops - Methods for irq_domain objects
+ * @to_irq: (optional) given a local hardware irq number, return the linux
+ *          irq number.  If to_irq is not implemented, then the irq_domain
+ *          will use this translation: irq = (domain->irq_base + hwirq)
+ * @dt_translate: Given a device tree node and interrupt specifier, decode
+ *                the hardware irq number and linux irq type value.
+ */
+struct irq_domain_ops {
+	unsigned int (*to_irq)(struct irq_domain *d, unsigned long hwirq);
+
+#ifdef CONFIG_OF
+	int (*dt_translate)(struct irq_domain *d, struct device_node *node,
+			    const u32 *intspec, unsigned int intsize,
+			    unsigned long *out_hwirq, unsigned int *out_type);
+#endif /* CONFIG_OF */
+};
+
+/**
+ * struct irq_domain - Hardware interrupt number translation object
+ * @list: Element in global irq_domain list.
+ * @irq_base: Start of irq_desc range assigned to the irq_domain.  The creator
+ *            of the irq_domain is responsible for allocating the array of
+ *            irq_desc structures.
+ * @nr_irq: Number of irqs managed by the irq domain
+ * @ops: pointer to irq_domain methods
+ * @priv: private data pointer for use by owner.  Not touched by irq_domain
+ *        core code.
+ * @of_node: (optional) Pointer to device tree nodes associated with the
+ *           irq_domain.  Used when decoding device tree interrupt specifiers.
+ */
+struct irq_domain {
+	struct list_head list;
+	unsigned int irq_base;
+	unsigned int nr_irq;
+	const struct irq_domain_ops *ops;
+	void *priv;
+	struct device_node *of_node;
+};
+
+/**
+ * irq_domain_to_irq() - Translate from a hardware irq to a linux irq number
+ *
+ * Returns the linux irq number associated with a hardware irq.  By default,
+ * the mapping is irq == domain->irq_base + hwirq, but this mapping can
+ * be overridden if the irq_domain implements a .to_irq() hook.
+ */
+static inline unsigned int irq_domain_to_irq(struct irq_domain *d,
+					     unsigned long hwirq)
+{
+	return d->ops->to_irq ? d->ops->to_irq(d, hwirq) : d->irq_base + hwirq;
+}
+
+extern void irq_domain_add(struct irq_domain *domain);
+extern void irq_domain_del(struct irq_domain *domain);
+#endif /* CONFIG_IRQ_DOMAIN */
+
+#if defined(CONFIG_IRQ_DOMAIN) && defined(CONFIG_OF_IRQ)
+extern void irq_domain_add_simple(struct device_node *controller, int irq_base);
+extern void irq_domain_generate_simple(const struct of_device_id *match,
+					u64 phys_base, unsigned int irq_start);
+#else /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+static inline void irq_domain_generate_simple(const struct of_device_id *match,
+					u64 phys_base, unsigned int irq_start) { }
+#endif /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+
+#endif /* _LINUX_IRQDOMAIN_H */
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index e6955f5..cd2e61c 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -63,6 +63,9 @@
 extern unsigned int irq_create_of_mapping(struct device_node *controller,
 					  const u32 *intspec,
 					  unsigned int intsize);
+#ifdef CONFIG_IRQ_DOMAIN
+extern void irq_dispose_mapping(unsigned int irq);
+#endif
 extern int of_irq_to_resource(struct device_node *dev, int index,
 			      struct resource *r);
 extern int of_irq_count(struct device_node *dev);
@@ -70,6 +73,7 @@
 		struct resource *res, int nr_irqs);
 extern struct device_node *of_irq_find_parent(struct device_node *child);
 
+
 #endif /* CONFIG_OF_IRQ */
 #endif /* CONFIG_OF */
 #endif /* __OF_IRQ_H */
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index d1d051b3..5a38bf4 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -52,6 +52,10 @@
 config GENERIC_IRQ_CHIP
        bool
 
+# Generic irq_domain hw <--> linux irq number translation
+config IRQ_DOMAIN
+	bool
+
 # Support forced irq threading
 config IRQ_FORCED_THREADING
        bool
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 7329005..fff1738 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -2,6 +2,7 @@
 obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
 obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
 obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
+obj-$(CONFIG_IRQ_DOMAIN) += irqdomain.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
 obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
new file mode 100644
index 0000000..d5828da3f
--- /dev/null
+++ b/kernel/irq/irqdomain.c
@@ -0,0 +1,180 @@
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+static LIST_HEAD(irq_domain_list);
+static DEFINE_MUTEX(irq_domain_mutex);
+
+/**
+ * irq_domain_add() - Register an irq_domain
+ * @domain: ptr to initialized irq_domain structure
+ *
+ * Registers an irq_domain structure.  The irq_domain must at a minimum be
+ * initialized with an ops structure pointer, and either a ->to_irq hook or
+ * a valid irq_base value.  Everything else is optional.
+ */
+void irq_domain_add(struct irq_domain *domain)
+{
+	struct irq_data *d;
+	int hwirq;
+
+	/*
+	 * This assumes that the irq_domain owner has already allocated
+	 * the irq_descs.  This block will be removed when support for dynamic
+	 * allocation of irq_descs is added to irq_domain.
+	 */
+	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
+		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+		if (d || d->domain) {
+			/* things are broken; just report, don't clean up */
+			WARN(1, "error: irq_desc already assigned to a domain");
+			return;
+		}
+		d->domain = domain;
+		d->hwirq = hwirq;
+	}
+
+	mutex_lock(&irq_domain_mutex);
+	list_add(&domain->list, &irq_domain_list);
+	mutex_unlock(&irq_domain_mutex);
+}
+
+/**
+ * irq_domain_del() - Unregister an irq_domain
+ * @domain: ptr to registered irq_domain.
+ */
+void irq_domain_del(struct irq_domain *domain)
+{
+	struct irq_data *d;
+	int hwirq;
+
+	mutex_lock(&irq_domain_mutex);
+	list_del(&domain->list);
+	mutex_unlock(&irq_domain_mutex);
+
+	/* Clear the irq_domain assignments */
+	for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
+		d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
+		d->domain = NULL;
+	}
+}
+
+#if defined(CONFIG_OF_IRQ)
+/**
+ * irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
+ *
+ * Used by the device tree interrupt mapping code to translate a device tree
+ * interrupt specifier to a valid linux irq number.  Returns either a valid
+ * linux IRQ number or 0.
+ *
+ * When the caller no longer need the irq number returned by this function it
+ * should arrange to call irq_dispose_mapping().
+ */
+unsigned int irq_create_of_mapping(struct device_node *controller,
+				   const u32 *intspec, unsigned int intsize)
+{
+	struct irq_domain *domain;
+	unsigned long hwirq;
+	unsigned int irq, type;
+	int rc = -EINVAL;
+
+	/* Find a domain which can translate the irq spec */
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(domain, &irq_domain_list, list) {
+		if (!domain->ops->dt_translate)
+			continue;
+		rc = domain->ops->dt_translate(domain, controller,
+					intspec, intsize, &hwirq, &type);
+		if (rc == 0)
+			break;
+	}
+	mutex_unlock(&irq_domain_mutex);
+
+	if (rc != 0)
+		return 0;
+
+	irq = irq_domain_to_irq(domain, hwirq);
+	if (type != IRQ_TYPE_NONE)
+		irq_set_irq_type(irq, type);
+	pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
+		 controller->full_name, (int)hwirq, irq, type);
+	return irq;
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+/**
+ * irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
+ * @irq: linux irq number to be discarded
+ *
+ * Calling this function indicates the caller no longer needs a reference to
+ * the linux irq number returned by a prior call to irq_create_of_mapping().
+ */
+void irq_dispose_mapping(unsigned int irq)
+{
+	/*
+	 * nothing yet; will be filled when support for dynamic allocation of
+	 * irq_descs is added to irq_domain
+	 */
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+int irq_domain_simple_dt_translate(struct irq_domain *d,
+			    struct device_node *controller,
+			    const u32 *intspec, unsigned int intsize,
+			    unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (d->of_node != controller)
+		return -EINVAL;
+	if (intsize < 1)
+		return -EINVAL;
+
+	*out_hwirq = intspec[0];
+	*out_type = IRQ_TYPE_NONE;
+	if (intsize > 1)
+		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+
+struct irq_domain_ops irq_domain_simple_ops = {
+	.dt_translate = irq_domain_simple_dt_translate,
+};
+EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+
+/**
+ * irq_domain_create_simple() - Set up a 'simple' translation range
+ */
+void irq_domain_add_simple(struct device_node *controller, int irq_base)
+{
+	struct irq_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain) {
+		WARN_ON(1);
+		return;
+	}
+
+	domain->irq_base = irq_base;
+	domain->of_node = of_node_get(controller);
+	domain->ops = &irq_domain_simple_ops;
+	irq_domain_add(domain);
+}
+EXPORT_SYMBOL_GPL(irq_domain_add_simple);
+
+void irq_domain_generate_simple(const struct of_device_id *match,
+				u64 phys_base, unsigned int irq_start)
+{
+	struct device_node *node;
+	pr_info("looking for phys_base=%llx, irq_start=%i\n",
+		(unsigned long long) phys_base, (int) irq_start);
+	node = of_find_matching_node_by_address(NULL, match, phys_base);
+	if (node)
+		irq_domain_add_simple(node, irq_start);
+	else
+		pr_info("no node found\n");
+}
+EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
+#endif /* CONFIG_OF_IRQ */