airoha: Add new target platform

Airoha is a new ARM platform based on Cortex-A53 which has recently been
merged into linux-next.

Due to BootROM limitations on this platform, the Cortex-A53 can't run in
Aarch64 mode and code must be compiled for 32-Bit ARM.

This support is based mostly on those linux-next commits backported
for kernel 5.15.

Patches:
1 - platform support = linux-next
2 - clock driver = linux-next
3 - gpio driver = linux-next
4 - linux,usable-memory-range dts support = linux-next
5 - mtd spinand driver
6 - spi driver
7 - pci driver (kconfig only, uses mediatek PCI) = linux-next

Still missing:
- Ethernet driver
- Sysupgrade support

A.t.m there exists one subtarget EN7523 with only one evaluation
board.

The initramfs can be run with the following commands from u-boot:
-
u-boot> setenv bootfile \
	openwrt-airoha-airoha_en7523-evb-initramfs-kernel.bin
u-boot> tftpboot
u-boot> bootm 0x81800000
-

Signed-off-by: Daniel Danzberger <daniel@dd-wrt.com>

1 files changed, 73 insertions, 0 deletions

diff --git a/target/linux/airoha/dts/en7523-evb.dts b/target/linux/airoha/dts/en7523-evb.dts
new file mode 100644
index 0000000000..f311c840e0
--- /dev/null
+++ b/target/linux/airoha/dts/en7523-evb.dts
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/dts-v1/;
+
+/* Bootloader installs ATF here */
+/memreserve/ 0x80000000 0x200000;
+
+#include "en7523.dtsi"
+
+/ {
+	model = "Airoha EN7523 Evaluation Board";
+	compatible = "airoha,en7523-evb", "airoha,en7523";
+
+	aliases {
+		serial0 = &uart1;
+	};
+
+	chosen {
+		bootargs = "console=ttyS0,115200 earlycon";
+		stdout-path = "serial0:115200n8";
+		linux,usable-memory-range = <0x80200000 0x1fe00000>;
+	};
+
+	memory@80000000 {
+		device_type = "memory";
+		reg = <0x80000000 0x20000000>;
+	};
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&gpio1 {
+	status = "okay";
+};
+
+&pcie0 {
+	status = "okay";
+};
+
+&pcie1 {
+	status = "okay";
+};
+
+&nand {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			label = "u-boot";
+			reg = <0x0 0x7C000>;
+			read-only;
+		};
+
+		partition@1 {
+			label = "u-boot-env";
+			reg = <0x7C000 0x4000>;
+		};
+
+		partition@2 {
+			label = "art";
+			reg = <0x80000 0x40000>;
+			read-only;
+		};
+
+		partition@3 {
+			label = "firmware";
+			reg = <0xC0000 0xDF40000>;
+		};
+	};
+};