arm64: dts: juno: add GPU subsystem

Since we now have bindings for Mali Midgard GPUs, let's use them to
describe Juno's GPU subsystem, if only because we can. Juno sports a
Mali-T624 integrated behind an MMU-400 (as a gesture towards
virtualisation), in their own dedicated power domain with DVFS
controlled by the SCP.

CC: Liviu Dudau <liviu.dudau@arm.com>
CC: Sudeep Holla <sudeep.holla@arm.com>
CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Documentation/devicetree/bindings/gpu/arm,mali-midgard.yaml

@@ -22,6 +22,10 @@ properties:
           - enum:
              - amlogic,meson-gxm-mali
           - const: arm,mali-t820
+      - items:
+          - enum:
+             - arm,juno-mali
+          - const: arm,mali-t624
       - items:
           - enum:
              - rockchip,rk3288-mali
@@ -39,7 +43,6 @@ properties:
              - samsung,exynos5433-mali
           - const: arm,mali-t760
 
-          # "arm,mali-t624"
           # "arm,mali-t628"
           # "arm,mali-t830"
           # "arm,mali-t880"

arch/arm64/boot/dts/arm/juno-base.dtsi

@@ -35,6 +35,18 @@ mailbox: mhu@2b1f0000 {
 		clock-names = "apb_pclk";
 	};
 
+	smmu_gpu: iommu@2b400000 {
+		compatible = "arm,mmu-400", "arm,smmu-v1";
+		reg = <0x0 0x2b400000 0x0 0x10000>;
+		interrupts = <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>;
+		#iommu-cells = <1>;
+		#global-interrupts = <1>;
+		power-domains = <&scpi_devpd 1>;
+		dma-coherent;
+		status = "disabled";
+	};
+
 	smmu_pcie: iommu@2b500000 {
 		compatible = "arm,mmu-401", "arm,smmu-v1";
 		reg = <0x0 0x2b500000 0x0 0x10000>;
@@ -487,6 +499,21 @@ cluster1_etm3_out_port: endpoint {
 		};
 	};
 
+	gpu: gpu@2d000000 {
+		compatible = "arm,juno-mali", "arm,mali-t624";
+		reg = <0 0x2d000000 0 0x10000>;
+		interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "gpu", "job", "mmu";
+		clocks = <&scpi_dvfs 2>;
+		power-domains = <&scpi_devpd 1>;
+		dma-coherent;
+		/* The SMMU is only really of interest to bare-metal hypervisors */
+		/* iommus = <&smmu_gpu 0>; */
+		status = "disabled";
+	};
+
 	sram: sram@2e000000 {
 		compatible = "arm,juno-sram-ns", "mmio-sram";
 		reg = <0x0 0x2e000000 0x0 0x8000>;