arm64: dts: add SRAM, MHU mailbox and SCPI support on Juno

This patch adds support for the MHU mailbox peripheral used on Juno by
application processors to communicate with remote SCP handling most of
the CPU/system power management. It also adds the SRAM reserving the
shared memory and SCPI message protocol using that shared memory.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Jon Medhurst (Tixy) <tixy@linaro.org>

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

@@ -17,6 +17,18 @@
 		};
 	};
 
+	mailbox: mhu@2b1f0000 {
+		compatible = "arm,mhu", "arm,primecell";
+		reg = <0x0 0x2b1f0000 0x0 0x1000>;
+		interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 35 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "mhu_lpri_rx",
+				  "mhu_hpri_rx";
+		#mbox-cells = <1>;
+		clocks = <&soc_refclk100mhz>;
+		clock-names = "apb_pclk";
+	};
+
 	gic: interrupt-controller@2c010000 {
 		compatible = "arm,gic-400", "arm,cortex-a15-gic";
 		reg = <0x0 0x2c010000 0 0x1000>,
@@ -44,6 +56,48 @@
 			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(6) | IRQ_TYPE_LEVEL_LOW)>;
 	};
 
+	sram: sram@2e000000 {
+		compatible = "arm,juno-sram-ns", "mmio-sram";
+		reg = <0x0 0x2e000000 0x0 0x8000>;
+
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0 0x0 0x2e000000 0x8000>;
+
+		cpu_scp_lpri: scp-shmem@0 {
+			compatible = "arm,juno-scp-shmem";
+			reg = <0x0 0x200>;
+		};
+
+		cpu_scp_hpri: scp-shmem@200 {
+			compatible = "arm,juno-scp-shmem";
+			reg = <0x200 0x200>;
+		};
+	};
+
+	scpi {
+		compatible = "arm,scpi";
+		mboxes = <&mailbox 1>;
+		shmem = <&cpu_scp_hpri>;
+
+		clocks {
+			compatible = "arm,scpi-clocks";
+
+			scpi_dvfs: scpi_clocks@0 {
+				compatible = "arm,scpi-dvfs-clocks";
+				#clock-cells = <1>;
+				clock-indices = <0>, <1>, <2>;
+				clock-output-names = "atlclk", "aplclk","gpuclk";
+			};
+			scpi_clk: scpi_clocks@3 {
+				compatible = "arm,scpi-variable-clocks";
+				#clock-cells = <1>;
+				clock-indices = <3>, <4>;
+				clock-output-names = "pxlclk0", "pxlclk1";
+			};
+		};
+	};
+
 	/include/ "juno-clocks.dtsi"
 
 	dma@7ff00000 {