MIPS: SEAD3: Probe interrupt controllers using DT

Probe the CPU interrupt controller & optional Global Interrupt
Controller (GIC) using devicetree rather than platform code. Because the
bootloader on SEAD3 does not provide a device tree to the kernel & the
device tree is always built in, we patch out the GIC node during boot if
we detect that a GIC is not present in the system.

The appropriate IRQ domain is discovered by platform code setting up
device IRQ numbers temporarily. It will be removed by further patches
which move the devices towards being probed via device tree.

No behavioural change is intended by this patch.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14047/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/mips/boot/dts/mti/sead3.dts b/arch/mips/boot/dts/mti/sead3.dts
index e4b317d414f1..051b3a9e5a9e 100644
--- a/arch/mips/boot/dts/mti/sead3.dts
+++ b/arch/mips/boot/dts/mti/sead3.dts
@@ -4,10 +4,13 @@
 /memreserve/ 0x00001000 0x000ef000;	// ROM data
 /memreserve/ 0x000f0000 0x004cc000;	// reserved
 
+#include <dt-bindings/interrupt-controller/mips-gic.h>
+
 / {
 	#address-cells = <1>;
 	#size-cells = <1>;
 	compatible = "mti,sead-3";
+	interrupt-parent = <&gic>;
 
 	cpus {
 		cpu@0 {
@@ -19,4 +22,32 @@
 		device_type = "memory";
 		reg = <0x0 0x08000000>;
 	};
+
+	cpu_intc: interrupt-controller {
+		compatible = "mti,cpu-interrupt-controller";
+
+		interrupt-controller;
+		#interrupt-cells = <1>;
+	};
+
+	gic: interrupt-controller@1b1c0000 {
+		compatible = "mti,gic";
+		reg = <0x1b1c0000 0x20000>;
+
+		interrupt-controller;
+		#interrupt-cells = <3>;
+
+		/*
+		 * Declare the interrupt-parent even though the mti,gic
+		 * binding doesn't require it, such that the kernel can
+		 * figure out that cpu_intc is the root interrupt
+		 * controller & should be probed first.
+		 */
+		interrupt-parent = <&cpu_intc>;
+
+		timer {
+			compatible = "mti,gic-timer";
+			interrupts = <GIC_LOCAL 1 IRQ_TYPE_NONE>;
+		};
+	};
 };